National Library of Energy BETA

Sample records for radiative effects study

  1. Carbonaceous Aerosols and Radiative Effects Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carbonaceous Aerosols and Radiative Effects Study Science Objective This field campaign is designed to increase scientific knowledge about the evolution of black carbon, primary organic aerosols (POA), and secondary organic aerosols (SOA) from both man-made and biogenic sources. Black carbon and primary organic aerosols are emitted directly into the atmosphere through diesel and gasoline vehicle exhaust, as well as during meat cooking and biomass burning; secondary organic aerosols are formed

  2. ARM - Carbonaceous Aerosols and Radiative Effects Study (CARES...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    News & Press Backgrounder (PDF, 1.45MB) G-1 Aircraft Fact Sheet (PDF, 1.3MB) Contacts Rahul Zaveri, Lead Scientist Carbonaceous Aerosols and Radiative Effects Study (CARES)...

  3. ARM - Field Campaign - Carbonaceous Aerosol and Radiation Effects Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (CARES) - Surface Meteorological Sounding - Surface Meteorological Sounding Campaign Links ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiative Effects Study (CARES) 2010.06.02, Zaveri, AAF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Carbonaceous Aerosol and Radiation Effects Study (CARES) - Surface Meteorological Sounding 2010.05.26 - 2010.07.07 Lead Scientist : Rahul Zaveri For data sets, see

  4. ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (CARES) Ground Based Instruments Ground Based Instruments ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiative Effects Study (CARES) 2010.06.02, Zaveri, AAF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Carbonaceous Aerosol and Radiative Effects Study (CARES) Ground Based Instruments 2010.04.01 - 2010.07.15 Lead Scientist : Daniel Cziczo For data sets, see below. Abstract New ARRA funded ARM

  5. CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-05-27

    Carbonaceous aerosol components, which include black carbon (BC), urban primary organic aerosols (POA), biomass burning aerosols, and secondary organic aerosols (SOA) from both urban and biogenic precursors, have been previously shown to play a major role in the direct and indirect radiative forcing of climate. The primary objective of the CARES 2010 intensive field study is to investigate the evolution of carbonaceous aerosols of different types and their effects on optical and cloud formation properties.

  6. Effect of microwave radiation on Jayadhar cotton fibers: WAXS studies

    SciTech Connect (OSTI)

    Niranjana, A. R. Mahesh, S. S. Divakara, S. Somashekar, R.

    2014-04-24

    Thermal effect in the form of micro wave energy on Jayadhar cotton fiber has been investigated. Microstructural parameters have been estimated using wide angle x-ray scattering (WAXS) data and line profile analysis program developed by us. Physical properties like tensile strength are correlated with X-ray results. We observe that the microwave radiation do affect significantly many parameters and we have suggested a multivariate analysis of these parameters to arrive at a significant result.

  7. Radiation Effects Sciences

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Facilities Atmospheric Radiation Measurement Climate Reasearch Facility Geomechanics and ... Twitter Google + Vimeo Newsletter Signup SlideShare Radiation Effects Sciences Home...

  8. CARES: Carbonaceous Aerosol and Radiative Effects Study Operations Plan

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-07-12

    The CARES field campaign is motivated by the scientific issues described in the CARES Science Plan. The primary objectives of this field campaign are to investigate the evolution and aging of carbonaceous aerosols and their climate-affecting properties in the urban plume of Sacramento, California, a mid-size, mid-latitude city that is located upwind of a biogenic volatile organic compound (VOC) emission region. Our basic observational strategy is to make comprehensive gas, aerosol, and meteorological measurements upwind, within, and downwind of the urban area with the DOE G-1 aircraft and at strategically located ground sites so as to study the evolution of urban aerosols as they age and mix with biogenic SOA precursors. The NASA B-200 aircraft, equipped with the High Spectral Resolution Lidar (HSRL), digital camera, and the Research Scanning Polarimeter (RSP), will be flown in coordination with the G-1 to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties, and to provide the vertical context for the G-1 and ground in situ measurements.

  9. Carbonaceous Aerosols and Radiative Effects Study (CARES), g1-aircraft, sedlacek sp2

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sedlacek, Art

    The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume.

  10. Carbonaceous Aerosols and Radiative Effects Study (CARES), g1-aircraft, sedlacek sp2

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sedlacek, Art

    2011-08-30

    The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume.

  11. Study of the effect of properties of material on vacuum breakdown initiated by laser radiation

    SciTech Connect (OSTI)

    Seleznev, V. P.; Revazov, V. O.

    2015-12-15

    In this work, the effect of various properties of materials on vacuum breakdown initiated by laser radiation is considered. Estimating calculations are performed which show that the material of the target electrode distinctly affects the minimum energy of laser radiation needed for igniting a vacuum spark. The experimental studies carried out confirm the estimating calculations, and a number of materials are revealed which can be arranged in order of increase in the energy needed for the formation of breakdown in vacuum by the impact of a laser pulse.

  12. Radiosensitivity study and radiation effects on morphology characterization of grey oyster mushroom Pleurotus sajor-caju

    SciTech Connect (OSTI)

    Rashid, Rosnani Abdul; Awang, Mat Rasol; Mohamad, Azhar; Mutaat, Hassan Hamdani; Maskom, Mohd Meswan; Daud, Fauzi; Senafi, Sahidan

    2014-09-03

    Radiosensitive dosage and morphology characterization of irradiated grey oyster mushroom Pleurotus sajor-caju by gamma rays was investigated due to effects of irradiation. In order to establish the effect, mycelium of P. sajor-caju was irradiated by gamma rays at dose 0.1 to 8.0 kGy with dose rate 0.227 Gy sec{sup ?1}. The irradiation of mycelia was carried out at the radiation facility in Malaysian Nuclear Agency. The radiosensitivity study was performed by evaluating the percentage of survival irradiated mycelia. The lethal dose of the mycelium P. sajor-caju was determined at 4.0 kGy and LD{sub 50} to be equal at 2.2 kGy. The radiation effects on morphology were evaluated based on growth rate of irradiated mycelia, mycelia types, colonization period on substrate, morphology of fruit bodies and yields. The results shown growth rate of irradiated mycelium was slightly lower than the control and decreased as the dose increased. Irradiation was found can induced the primordia formation on PDA and the BE of irradiated seed is higher than to control. The irradiation is proven to be useful for generating new varieties of mushroom with commercial value to the industry.

  13. Radiation Effects In Space

    SciTech Connect (OSTI)

    Tripathi, Ram K.

    2011-06-01

    Protecting space missions from severe exposures from radiation, in general, and long duration/deep space human missions, in particular, is a critical design driver, and could be a limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues and microelectronic devices. One is required to know how every element (and all isotopes of each element) in the periodic table interacts and fragments on every other element in the same table as a function of kinetic energy ranging over many decades. In addition, the accuracy of the input information and database, in general and nuclear data in particular, impacts radiation exposure health assessments and payload penalty. After a brief review of effects of space radiation on materials and electronics, human space missions to Mars is discussed.

  14. Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

    SciTech Connect (OSTI)

    Zaveri, R. A.; Shaw, W. J.; Cziczo, D. J.; Schmid, B.; Ferrare, R. A.; Alexander, M. L.; Alexandrov, M.; Alvarez, R. J.; Arnott, W. P.; Atkinson, D. B.; Baidar, S.; Banta, R. M.; Barnard, J. C.; Beranek, J.; Berg, L. K.; Brechtel, F.; Brewer, W. A.; Cahill, J. F.; Cairns, B.; Cappa, C. D.; Chand, D.; China, S.; Comstock, J. M.; Dubey, M. K.; Easter, R. C.; Erickson, M. H.; Fast, J. D.; Floerchinger, C.; Flowers, B. A.; Fortner, E.; Gaffney, J. S.; Gilles, M. K.; Gorkowski, K.; Gustafson, W. I.; Gyawali, M.; Hair, J.; Hardesty, R. M.; Harworth, J. W.; Herndon, S.; Hiranuma, N.; Hostetler, C.; Hubbe, J. M.; Jayne, J. T.; Jeong, H.; Jobson, B. T.; Kassianov, E. I.; Kleinman, L. I.; Kluzek, C.; Knighton, B.; Kolesar, K. R.; Kuang, C.; Kubátová, A.; Langford, A. O.; Laskin, A.; Laulainen, N.; Marchbanks, R. D.; Mazzoleni, C.; Mei, F.; Moffet, R. C.; Nelson, D.; Obland, M. D.; Oetjen, H.; Onasch, T. B.; Ortega, I.; Ottaviani, M.; Pekour, M.; Prather, K. A.; Radney, J. G.; Rogers, R. R.; Sandberg, S. P.; Sedlacek, A.; Senff, C. J.; Senum, G.; Setyan, A.; Shilling, J. E.; Shrivastava, M.; Song, C.; Springston, S. R.; Subramanian, R.; Suski, K.; Tomlinson, J.; Volkamer, R.; Wallace, H. W.; Wang, J.; Weickmann, A. M.; Worsnop, D. R.; Yu, X. -Y.; Zelenyuk, A.; Zhang, Q.

    2012-01-01

    Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program’s Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites – one within the Sacramento urban area and another about 40 km to the northeast in the foothills area – were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and “aged” urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: a) the scientific background and motivation for the study, b) the operational and logistical information pertinent to the execution of the study, c) an overview of key observations and initial findings from the aircraft and ground-based sampling platforms, and d) a roadmap of

  15. Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

    SciTech Connect (OSTI)

    Zaveri, Rahul A.; Shaw, William J.; Cziczo, D. J.; Schmid, Beat; Ferrare, R.; Alexander, M. L.; Alexandrov, Mikhail; Alvarez, R. J.; Arnott, W. P.; Atkinson, D.; Baidar, Sunil; Banta, Robert M.; Barnard, James C.; Beranek, Josef; Berg, Larry K.; Brechtel, Fred J.; Brewer, W. A.; Cahill, John F.; Cairns, Brian; Cappa, Christopher D.; Chand, Duli; China, Swarup; Comstock, Jennifer M.; Dubey, Manvendra K.; Easter, Richard C.; Erickson, Matthew H.; Fast, Jerome D.; Floerchinger, Cody; Flowers, B. A.; Fortner, Edward; Gaffney, Jeffrey S.; Gilles, Mary K.; Gorkowski, K.; Gustafson, William I.; Gyawali, Madhu S.; Hair, John; Hardesty, Michael; Harworth, J. W.; Herndon, Scott C.; Hiranuma, Naruki; Hostetler, Chris A.; Hubbe, John M.; Jayne, J. T.; Jeong, H.; Jobson, Bertram T.; Kassianov, Evgueni I.; Kleinman, L. I.; Kluzek, Celine D.; Knighton, B.; Kolesar, K. R.; Kuang, Chongai; Kubatova, A.; Langford, A. O.; Laskin, Alexander; Laulainen, Nels S.; Marchbanks, R. D.; Mazzoleni, Claudio; Mei, F.; Moffet, Ryan C.; Nelson, Danny A.; Obland, Michael; Oetjen, Hilke; Onasch, Timothy B.; Ortega, Ivan; Ottaviani, M.; Pekour, Mikhail S.; Prather, Kimberly A.; Radney, J. G.; Rogers, Ray; Sandberg, S. P.; Sedlacek, Art; Senff, Christoph; Senum, Gunar; Setyan, Ari; Shilling, John E.; Shrivastava, ManishKumar B.; Song, Chen; Springston, S. R.; Subramanian, R.; Suski, Kaitlyn; Tomlinson, Jason M.; Volkamer, Rainer M.; Wallace, Hoyt A.; Wang, J.; Weickmann, A. M.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zelenyuk, Alla; Zhang, Qi

    2012-08-22

    Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites - one within the Sacramento urban area and another about 40 km to the northeast in the foothills area - were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and 'aged' urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: a) the scientific background and motivation for the study, b) the operational and logistical information pertinent to the execution of the study, c) an overview of key observations and initial results from the aircraft and ground-based sampling platforms, and d) a roadmap of planned data

  16. Biological Effects of Ionizing Radiation

    DOE R&D Accomplishments [OSTI]

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  17. JCCRER Project 2.3 -- Deterministic effects of occupational exposure to radiation. Phase 1: Feasibility study; Final report

    SciTech Connect (OSTI)

    Okladnikova, N.; Pesternikova, V.; Sumina, M.

    1998-12-01

    Phase 1 of Project 2.3, a short-term collaborative Feasibility Study, was funded for 12 months starting on 1 February 1996. The overall aim of the study was to determine the practical feasibility of using the dosimetric and clinical data on the MAYAK worker population to study the deterministic effects of exposure to external gamma radiation and to internal alpha radiation from inhaled plutonium. Phase 1 efforts were limited to the period of greatest worker exposure (1948--1954) and focused on collaboratively: assessing the comprehensiveness, availability, quality, and suitability of the Russian clinical and dosimetric data for the study of deterministic effects; creating an electronic data base containing complete clinical and dosimetric data on a small, representative sample of MAYAK workers; developing computer software for the testing of a currently used health risk model of hematopoietic effects; and familiarizing the US team with the Russian diagnostic criteria and techniques used in the identification of Chronic Radiation Sickness.

  18. Combined Treatment Effects of Radiation and Immunotherapy: Studies in an Autochthonous Prostate Cancer Model

    SciTech Connect (OSTI)

    Wada, Satoshi; Harris, Timothy J.; Tryggestad, Erik; Yoshimura, Kiyoshi; Zeng, Jing; Yen, Hung-Rong; Getnet, Derese; Grosso, Joseph F.; Bruno, Tullia C.; De Marzo, Angelo M.; and others

    2013-11-15

    Purpose: To optimize the combination of ionizing radiation and cellular immunotherapy using a preclinical autochthonous model of prostate cancer. Methods and Materials: Transgenic mice expressing a model antigen under a prostate-specific promoter were treated using a platform that integrates cone-beam CT imaging with 3-dimensional conformal therapy. Using this technology we investigated the immunologic and therapeutic effects of combining ionizing radiation with granulocyte/macrophage colony-stimulating factor-secreting cellular immunotherapy for prostate cancer in mice bearing autochthonous prostate tumors. Results: The combination of ionizing radiation and immunotherapy resulted in a significant decrease in pathologic tumor grade and gross tumor bulk that was not evident with either single-modality therapy. Furthermore, combinatorial therapy resulted in improved overall survival in a preventive metastasis model and in the setting of established micrometastases. Mechanistically, combined therapy resulted in an increase of the ratio of effector-to-regulatory T cells for both CD4 and CD8 tumor-infiltrating lymphocytes. Conclusions: Our preclinical model establishes a potential role for the use of combined radiation-immunotherapy in locally advanced prostate cancer, which warrants further exploration in a clinical setting.

  19. Radiation Effects Facility - Facilities - Cyclotron Institute

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation Effects Facility Typical DUT(device under test) set-up at the end of the Radiation Effects beamline. The Radiation Effects Facility is available for commercial, ...

  20. Numerical study of radiation effect on the municipal solid waste combustion characteristics inside an incinerator

    SciTech Connect (OSTI)

    Wang, Jingfu Xue, Yanqing; Zhang, Xinxin; Shu, Xinran

    2015-10-15

    Highlights: • A 3-D model for the MSW incinerator with preheated air was developed. • Gas radiative properties were obtained from a statistical narrow-band model. • Non-gray body radiation model can provide more accurate simulation results. - Abstract: Due to its advantages of high degree volume reduction, relatively stable residue, and energy reclamation, incineration becomes one of the best choices for Municipal Solid Waste (MSW) disposal. However, detailed measurements of temperature and gas species inside a furnace are difficulty by conventional experimental techniques. Therefore, numerical simulation of MSW incineration in the packed bed and gas flow field was applied. In this work, a three dimensional (3-D) model of incinerator system, including flow, heat transfer, detailed chemical mechanisms, and non-gray gas models, was developed. Radiation from the furnace wall and the flame formed above the bed is of importance for drying and igniting the waste. The preheated air with high temperature is used for the MSW combustion. Under the conditions of high temperature and high pressure, MSW combustion produces a variety of radiating gases. The wavelength-depend radiative properties of flame adopted in non-gray radiation model were obtained from a statistical narrow-band model. The influence of radiative heat transfer on temperature, flow field is researched by adiabatic model (without considering radiation), gray radiation model, and non-gray radiation model. The simulation results show that taking into account the non-gray radiation is essential.

  1. ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiation ... Carbonaceous Aerosol and Radiation Effects Study (CARES) Photo-Acoustic Aerosol Light ...

  2. Study of Interfacial Interactions Using Thing Film Surface Modification: Radiation and Oxidation Effects in Materials

    SciTech Connect (OSTI)

    Sridharan, Kumar; Zhang, Jinsuo

    2014-01-09

    Interfaces play a key role in dictating the long-term stability of materials under the influence of radiation and high temperatures. For example, grain boundaries affect corrosion by way of providing kinetically favorable paths for elemental diffusion, but they can also act as sinks for defects and helium generated during irradiation. Likewise, the retention of high-temperature strength in nanostructured, oxide-dispersion strengthened steels depends strongly on the stoichiometric and physical stability of the (Y, Ti)-oxide particles/matrix interface under radiation and high temperatures. An understanding of these interfacial effects at a fundamental level is important for the development of materials for extreme environments of nuclear reactors. The goal of this project is to develop an understanding stability of interfaces by depositing thin films of materials on substrates followed by ion irradiation of the film-substrate system at elevated temperatures followed by post-irradiation oxidation treatments. Specifically, the research will be performed by depositing thin films of yttrium and titanium (~500 nm) on Fe-12%Cr binary alloy substrate. Y and Ti have been selected as thin-film materials because they form highly stable protective oxides layers. The Fe-12%Cr binary alloy has been selected because it is representative of ferritic steels that are widely used in nuclear systems. The absence of other alloying elements in this binary alloy would allow for a clearer examination of structures and compositions that evolve during high-temperature irradiations and oxidation treatments. The research is divided into four specific tasks: (1) sputter deposition of 500 nm thick films of Y and Ti on Fe-12%Cr alloy substrates, (2) ion irradiation of the film-substrate system with 2MeV protons to a dose of 2 dpa at temperatures of 300°C, 500°C, and 700°C, (3) oxidation of as-deposited and ion-irradiated samples in a controlled oxygen environment at 500°C and 700°C, (4

  3. Experimental study of variations in background radiation and the effect on Nuclear Car Wash sensitivity

    SciTech Connect (OSTI)

    Church, J; Slaughter, D; Norman, E; Asztalos, S; Biltoft, P

    2007-02-07

    Error rates in a cargo screening system such as the Nuclear Car Wash [1-7] depend on the standard deviation of the background radiation count rate. Because the Nuclear Car Wash is an active interrogation technique, the radiation signal for fissile material must be detected above a background count rate consisting of cosmic, ambient, and neutron-activated radiations. It was suggested previously [1,6] that the Corresponding negative repercussions for the sensitivity of the system were shown. Therefore, to assure the most accurate estimation of the variation, experiments have been performed to quantify components of the actual variance in the background count rate, including variations in generator power, irradiation time, and container contents. The background variance is determined by these experiments to be a factor of 2 smaller than values assumed in previous analyses, resulting in substantially improved projections of system performance for the Nuclear Car Wash.

  4. Effect of coolant chemistry on PWR radiation transport processes. Progress report on reactor loop studies

    SciTech Connect (OSTI)

    Brown, D.J.; Flynn, G.; Haynes, J.W.; Kitt, G.P.; Large, N.R.; Lawson, D.; Mead, A.P.; Nichols, J.L.; Woodwark, D.R.

    1986-05-01

    The effect of various PWR-type coolant chemistry regimes on the behavior of corrosion products has been studied in the DIDO Water Loop at Harwell. There are strong indications that the in-core deposition behavior of corrosion product species is not fully accounted for by the solubility model based on nickel ferrite; boric acid plays a role apart from its influence on pH, and corrosion products are adsorbed to some extent in the zirconium oxide film on the fuel cladding. In DWL, soluble species appear to be dominant in deposition processes. A most important factor governing deposition behavior is surface condition; the influence of weld regions and the effect of varying pretreatment conditions have both been demonstrated. 13 figs.

  5. Effects of Voice Rehabilitation After Radiation Therapy for Laryngeal Cancer: A Randomized Controlled Study

    SciTech Connect (OSTI)

    Tuomi, Lisa; Andrll, Paulin

    2014-08-01

    Background: Patients treated with radiation therapy for laryngeal cancer often experience voice problems. The aim of this randomized controlled trial was to assess the efficacy of voice rehabilitation for laryngeal cancer patients after having undergone radiation therapy and to investigate whether differences between different tumor localizations with regard to rehabilitation outcomes exist. Methods and Materials: Sixty-nine male patients irradiated for laryngeal cancer participated. Voice recordings and self-assessments of communicative dysfunction were performed 1 and 6 months after radiation therapy. Thirty-three patients were randomized to structured voice rehabilitation with a speech-language pathologist and 36 to a control group. Furthermore, comparisons with 23 healthy control individuals were made. Acoustic analyses were performed for all patients, including the healthy control individuals. The Swedish version of the Self Evaluation of Communication Experiences after Laryngeal Cancer and self-ratings of voice function were used to assess vocal and communicative function. Results: The patients who received vocal rehabilitation experienced improved self-rated vocal function after rehabilitation. Patients with supraglottic tumors who received voice rehabilitation had statistically significant improvements in voice quality and self-rated vocal function, whereas the control group did not. Conclusion: Voice rehabilitation for male patients with laryngeal cancer is efficacious regarding patient-reported outcome measurements. The patients experienced better voice function after rehabilitation. Patients with supraglottic tumors also showed an improvement in terms of acoustic voice outcomes. Rehabilitation with a speech-language pathologist is recommended for laryngeal cancer patients after radiation therapy, particularly for patients with supraglottic tumors.

  6. Electronic system for data acquisition to study radiation effects on operating MOSFET transistors

    SciTech Connect (OSTI)

    Alves de Oliveira, Juliano; Assis de Melo, Marco Antnio; Guazzelli da Silveira, Marcilei A.; Medina, Nilberto H.

    2014-11-11

    In this work we present the development of an acquisition system for characterizing transistors under X-ray radiation. The system is able to carry out the acquisition and to storage characteristic transistor curves. To test the acquisition system we have submitted polarized P channel MOS transistors under continuous 10-keV X-ray doses up to 1500 krad. The characterization system can operate in the saturation region or in the linear region in order to observe the behavior of the currents or voltages involved during the irradiation process. Initial tests consisted of placing the device under test (DUT) in front of the X-ray beam direction, while its drain current was constantly monitored through the prototype generated in this work, the data are stored continuously and system behavior was monitored during the test. In order to observe the behavior of the DUT during the radiation tests, we used an acquisition system that consists of an ultra-low consumption16-bit Texas Instruments MSP430 microprocessor. Preliminary results indicate linear behavior of the voltage as a function of the exposure time and fast recovery. These features may be favorable to use this device as a radiation dosimeter to monitor low rate X-ray.

  7. Support - Facilities - Radiation Effects Facility / Cyclotron...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    During experiments at the Radiation Effects Facility users are assisted by the experienced ... shops are available to the users of the Radiation Effects Facility for design, ...

  8. Russian Health Studies Program - Joint Coordinating Committee for Radiation

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Effects Research (JCCRER) | Department of Energy Joint Coordinating Committee for Radiation Effects Research (JCCRER) Russian Health Studies Program - Joint Coordinating Committee for Radiation Effects Research (JCCRER) Joint Coordinating Committee for Radiation Effects Research (JCCRER) All About the Joint Coordinating Committee for Radiation Effects Research What is the JCCRER? Why is it important? DOE's Russian Health Studies Program Principal Areas of Cooperation Under the JCCRER

  9. Russian Health Studies Program - Relationship to Other Radiation Research

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Programs | Department of Energy Relationship to Other Radiation Research Programs Russian Health Studies Program - Relationship to Other Radiation Research Programs Relationship to Other Radiation Research Programs Russian Health Studies Program What is the relationship of the Russian Health Studies Program to other radiation health effects programs? Current radiation protection standards are derived primarily from studies of the Japanese atomic bomb survivors and patients who received

  10. Study on effect of geometrical configuration of radioactive source material to the radiation intensity of betavoltaic nuclear battery

    SciTech Connect (OSTI)

    Badrianto, Muldani Dwi; Riupassa, Robi D.; Basar, Khairul

    2015-09-30

    Nuclear batteries have strategic applications and very high economic potential. One Important problem in application of nuclear betavoltaic battery is its low efficiency. Current efficiency of betavoltaic nuclear battery reaches only arround 2%. One aspect that can influence the efficiency of betavoltaic nuclear battery is the geometrical configuration of radioactive source. In this study we discuss the effect of geometrical configuration of radioactive source material to the radiation intensity in betavoltaic nuclear battery system. received by the detector. By obtaining the optimum configurations, the optimum usage of radioactive materials can be determined. Various geometrical configurations of radioactive source material are simulated. It is obtained that usage of radioactive source will be optimum for circular configuration.

  11. ARM - Field Campaign - Carbonaceous Aerosol and Radiation Effects...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Photo-Acoustic Aerosol Light Absorption and Scattering Campaign Links ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiative Effects Study (CARES) ...

  12. Radiation effects in the environment

    SciTech Connect (OSTI)

    Begay, F.; Rosen, L.; Petersen, D.F.; Mason, C.; Travis, B.; Yazzie, A.; Isaac, M.C.P.; Seaborg, G.T.; Leavitt, C.P.

    1999-04-01

    Although the Navajo possess substantial resource wealth-coal, gas, uranium, water-this potential wealth has been translated into limited permanent economic or political power. In fact, wealth or potential for wealth has often made the Navajo the victims of more powerful interests greedy for the assets under limited Navajo control. The primary focus for this education workshop on the radiation effects in the environment is to provide a forum where scientists from the nuclear science and technology community can share their knowledge toward the advancement and diffusion of nuclear science and technology issues for the Navajo public. The scientists will make an attempt to consider the following basic questions; what is science; what is mathematics; what is nuclear radiation? Seven papers are included in this report: Navajo view of radiation; Nuclear energy, national security and international stability; ABC`s of nuclear science; Nuclear medicine: 100 years in the making; Radon in the environment; Bicarbonate leaching of uranium; and Computational methods for subsurface flow and transport. The proceedings of this workshop will be used as a valuable reference materials in future workshops and K-14 classrooms in Navajo communities that need to improve basic understanding of nuclear science and technology issues. Results of the Begay-Stevens research has revealed the existence of strange and mysterious concepts in the Navajo Language of nature. With these research results Begay and Stevens prepared a lecture entitled The Physics of Laser Fusion in the Navajo language. This lecture has been delivered in numerous Navajo schools, and in universities and colleges in the US, Canada, and Alaska.

  13. Japan Program: Radiation Effects Research Foundation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Japan Program: Radiation Effects Research Foundation Japan Program: Radiation Effects Research Foundation Background: The Department of Energy, Office of Environment, Health, Safety and Security, Office of Health and Safety funds studies of the Japanese atomic bomb survivors at the Radiation Effects Research Foundation (RERF) in Hiroshima and Nagasaki, Japan. The RERF program is believed to have the longest history of any ongoing international research program. DOE and its predecessor agencies

  14. Spallation radiation effects in materials

    SciTech Connect (OSTI)

    Mansur, L.K.; Farrell, K.; Wechsler, M.S.

    1996-06-01

    Spallation refers to the process whereby particles (chiefly neutrons) are ejected from nuclei upon bombardment by high-energy protons. Spallation neutron sources (SNS`s) use these neutrons for neutron scattering and diffraction research, and SNS`s are proposed as the basis for systems for tritium production and transmutation of nuclear waste. Materials in SNS`s are exposed to the incident proton beam (energies typically about 1000 MeV) and to the spallation neutrons (spectrum of energies extending up to about 1000 MeV). By contrast the fission neutrons in nuclear reactors have an average energy of only about 2 MeV, and the neutrons in fusion reactors would have energies below about 14 MeV. Furthermore, the protons and neutrons in SNS`s for scattering and diffraction research are pulsed at frequencies of about 10 to 60 Hz, from which significant changes in the kinetics of point and extended defects may be expected. In addition, much higher transmutation rates occur in SNS-irradiated materials, On the whole, then, significant differences in microstructural development and macroscopic properties may result upon exposure in SNS systems, as compared with fission and fusion irradiations. In a more general sense, subjecting materials to new radiation environments has almost routinely led to new discoveries. To the extent that data are avaiable, however, the spallation environment appears to increase the degree of damage without introducing totally new effects. The first part of this presentation is an overview of radiation effects in materials, outlining essential concepts and property changes and their physical bases. This background is followed by a description of SNS irradiation environments and the effects on materials of exposure to these environments. A special discussion is given of the selection of target (e.g., liquid mercury), container (e.g., austenitic stainless steel or ferritic/martensitic steel), and structural materials in SNS systems.

  15. Radiation damage and associated phase change effect on photodesorption rates from icesLy? studies of the surface behavior of CO{sub 2}(ice)

    SciTech Connect (OSTI)

    Yuan, Chunqing; Yates, John T. Jr.

    2014-01-01

    Photodesorption from a crystalline film of CO{sub 2}(ice) at 75 K has been studied using Ly? (10.2 eV) radiation. We combine quantitative mass spectrometric studies of gases evolved and transmission IR studies of species trapped in the ice. Direct CO desorption is observed from the primary CO{sub 2} photodissociation process, which occurs promptly for CO{sub 2} molecules located on the outermost surface of the ice (Process I). As the fluence of Ly? radiation increases to ?5.5 10{sup 17} photons cm{sup 2}, extensive damage to the crystalline ice occurs and photo-produced CO molecules from deeper regions (Process II) are found to desorb at a rapidly increasing rate, which becomes two orders of magnitude greater than Process I. It is postulated that deep radiation damage to produce an extensive amorphous phase of CO{sub 2} occurs in the 50 nm ice film and that CO (and CO{sub 2}) diffusive transport is strongly enhanced in the amorphous phase. Photodesorption in Process II is a combination of electronic and thermally activated processes. Radiation damage in crystalline CO{sub 2} ice has been monitored by its effects on the vibrational line shapes of CO{sub 2}(ice). Here the crystalline-to-amorphous phase transition has been correlated with the occurrence of efficient molecular transport over long distances through the amorphous phase of CO{sub 2}(ice). Future studies of the composition of the interstellar region, generated by photodesorption from ice layers on grains, will have to consider the significant effects of radiation damage on photodesorption rates.

  16. Using nitrogen-14 nuclear quadrupole resonance and electric field gradient information for the study of radiation effects

    SciTech Connect (OSTI)

    Iselin, L.H.

    1995-12-01

    Nitrogen-14 nuclear quadrupole resonance (NQR) was used in an attempt to detect the effects of ionizing radiation on organic material. Previously reported resonances for urea were detected at 2,913.32 {+-} 0.01 kHz and 2,347.88 {+-} 0.08 kHz with associated T{sub 2}* values 780 {+-} 20 {micro}s and 523 {+-} 24 {micro}s, respectively. The previously unreported {nu}{sub {minus}} line for urea-d{sup 4} was detected at 2,381 {+-} 0.04 Khz and used to determine accurately for the first time the values for the nuclear quadrupole coupling constant {chi} (3,548.74 {+-} 0.03 kHz) and the asymmetry parameter {eta} (0.31571 {+-} 0.00007) for urea-d{sup 4}. The inverse linewidth parameter T{sub 2}* for {nu}{sub +} was measured at 928 {+-} 23 {micro}s and for {nu}{sub {minus}} at 721 {+-} 12 {micro}s. Townes and Dailey analysis was performed and urea-d{sup 4} exhibits a 0.004 increase in lone pair electronic density and a slight decrease in N-H bond electronic density, as compared to urea, probably due to the mass difference. A relationship is proposed, referred to as NQR linewidth analysis, between the dynamic spin relaxation times T{sub 2} and T{sub 2}* and the widths of the distributions of the NQR parameters. Linewidth analysis is presented as a tool for possible use in future NQR work in all area, not just radiation effects. This relationship is tested using sodium nitrite T{sub 2} and T{sub 2}* values for {nu}{sub {minus}} and {nu}{sub {minus}} as a function of temperature.

  17. Biologically based multistage modeling of radiation effects

    SciTech Connect (OSTI)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of epidemiologic studies using multistage

  18. Treatment of cloud radiative effects in general circulation models

    SciTech Connect (OSTI)

    Wang, W.C.; Dudek, M.P.; Liang, X.Z.; Ding, M.

    1996-04-01

    We participate in the Atmospheric Radiation Measurement (ARM) program with two objectives: (1) to improve the general circulation model (GCM) cloud/radiation treatment with a focus on cloud verticle overlapping and layer cloud optical properties, and (2) to study the effects of cloud/radiation-climate interaction on GCM climate simulations. This report summarizes the project progress since the Fourth ARM Science Team meeting February 28-March 4, 1994, in Charleston, South Carolina.

  19. Real-time Molecular Study of Bystander Effects of Low dose Low LET radiation Using Living Cell Imaging and Nanoparticale Optics

    SciTech Connect (OSTI)

    Natarajan, Mohan; Xu, Nancy R; Mohan, Sumathy

    2013-06-03

    In this study two novel approaches are proposed to investigate precisely the low dose low LET radiation damage and its effect on bystander cells in real time. First, a flow shear model system, which would provide us a near in vivo situation where endothelial cells in the presence of extra cellular matrix experiencing continuous flow shear stress, will be used. Endothelial cells on matri-gel (simulated extra cellular matrix) will be subjected to physiological flow shear (that occurs in normal blood vessels). Second, a unique tool (Single nano particle/single live cell/single molecule microscopy and spectroscopy; Figure A) will be used to track the molecular trafficking by single live cell imaging. Single molecule chemical microscopy allows one to single out and study rare events that otherwise might be lost in assembled average measurement, and monitor many target single molecules simultaneously in real-time. Multi color single novel metal nanoparticle probes allow one to prepare multicolor probes (Figure B) to monitor many single components (events) simultaneously and perform multi-complex analysis in real-time. These nano-particles resist to photo bleaching and hence serve as probes for unlimited timeframe of analysis. Single live cell microscopy allows one to image many single cells simultaneously in real-time. With the combination of these unique tools, we will be able to study under near-physiological conditions the cellular and sub-cellular responses (even subtle changes at one molecule level) to low and very low doses of low LET radiation in real time (milli-second or nano-second) at sub-10 nanometer spatial resolution. This would allow us to precisely identify, at least in part, the molecular mediators that are responsible of radiation damage in the irradiated cells and the mediators that are responsible for initiating the signaling in the neighboring cells. Endothelial cells subjected to flow shear (2 dynes/cm2 or 16 dynes/cm2) and exposed to 0.1, 1 and 10

  20. Human radiation studies: Remembering the early years. Oral history...

    Office of Scientific and Technical Information (OSTI)

    the acute and long term effects of radiation, his inhalation studies, and his activities at the 1961 INL reactor accident (SL-1 Reactor). After a brief biographical sketch, Dr. ...

  1. Contact Us - Radiation Effects Facility / Cyclotron Institute...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Texas A&M University MS 3366 College Station, TX 77843-3366 Phone: 979-845-1411 Fax: 979-845-1899 Quick Links Radiation Effects Facility Cyclotron Institute Texas A&M ...

  2. Radiation Effects on Spacecraft Structural Materials

    SciTech Connect (OSTI)

    Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

    2002-07-01

    Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

  3. A Study of Past, Present, and Future Radiation Dose Pathways...

    Office of Scientific and Technical Information (OSTI)

    Study of Past, Present, and Future Radiation Dose Pathways from Hanford Site Effluents Citation Details In-Document Search Title: A Study of Past, Present, and Future Radiation ...

  4. Radiation effects on corrosion of zirconium alloys

    SciTech Connect (OSTI)

    Johnson, A.B. Jr.

    1989-06-01

    From the wide use of zirconium alloys as components in nuclear reactors, has come clear evidence that reactor radiation is a major corrosion parameter. The evidence emerges from comparisons of zirconium alloy corrosion behavior in different reactor types, for example, BWRs versus PWRs and in corresponding reactor loop chemistries; also, oxidation rates differ with location along components such as fuel rods and reactor pressure tubes. In most respects, oxidation effects on power reactor components are paralleled by oxidation behavior on specimens exposed to radiation in reactor loops.

  5. Atmospheric Radiation Measurement (ARM) Data from Shouxian, China for the Study of Aerosol Indirect Effects in China

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    In a complex ARM Mobile Facility (AMF) deployment, monitoring data was collected at four locations in China during 2008. The various sites are located in regions with different climate regimes and with high aerosol loadings of different optical, physical, and chemical properties. Measurements obtained at all the AMF sites during the 8-month deployment in China will help scientists to validate satellite-based findings, understand the mechanisms of the aerosol indirect effects in the region, and examine the roles of aerosols in affecting regional climate and atmospheric circulation, with a special focus on the impact of the East Asian monsoon system. As with other collections from the ARM Mobile Facility, the datasets are available from the ARM Archive. The ARM Archive physically resides at the Oak Ridge National Laboratory.

  6. Environmental effects on composite airframes: A study conducted for the ARM UAV Program (Atmospheric Radiation Measurement Unmanned Aerospace Vehicle)

    SciTech Connect (OSTI)

    Noguchi, R.A.

    1994-06-01

    Composite materials are affected by environments differently than conventional airframe structural materials are. This study identifies the environmental conditions which the composite-airframe ARM UAV may encounter, and discusses the potential degradation processes composite materials may undergo when subjected to those environments. This information is intended to be useful in a follow-on program to develop equipment and procedures to prevent, detect, or otherwise mitigate significant degradation with the ultimate goal of preventing catastrophic aircraft failure.

  7. Radiation Effects in Nuclear Waste Materials

    SciTech Connect (OSTI)

    Weber, William J.

    2005-09-30

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  8. Radiation Effects in Nuclear Waste Materials

    SciTech Connect (OSTI)

    Weber, William J.

    2005-06-01

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  9. Radiation Effects Research Foundation Links Past and Future | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Effects Research Foundation Links Past and Future Radiation Effects Research Foundation Links Past and Future August 2009 This document provides historical information about the Radiation Effects Research Foundation and its core research activities. Radiation Effects Research Foundation Links Past and Future (195.71 KB) More Documents & Publications Report of the Blue Ribbon Panel on the Review of the Radiation Effects Research Foundation Commemoration of the 60th Annniversary of

  10. Effects of ionizing radiation on modern ion exchange materials

    SciTech Connect (OSTI)

    Marsh, S.F.; Pillay, K.K.S.

    1993-10-01

    We review published studies of the effects of ionizing radiation on ion exchange materials, emphasizing those published in recent years. A brief overview is followed by a more detailed examination of recent developments. Our review includes styrene/divinylbenzene copolymers with cation-exchange or anion-exchange functional groups, polyvinylpyridine anion exchangers, chelating resins, multifunctional resins, and inorganic exchangers. In general, strong-acid cation exchange resins are more resistant to radiation than are strong-base anion exchange resins, and polyvinylpyridine resins are more resistant than polystyrene resins. Cross-linkage, salt form, moisture content, and the surrounding medium all affect the radiation stability of a specific exchanger. Inorganic exchangers usually, but not always, exhibit high radiation resistance. Liquid ion exchangers, which have been used so extensively in nuclear processing applications, also are included.

  11. Radiation and transmutation effects relevant to solid nuclear waste forms

    SciTech Connect (OSTI)

    Vance, E.R.; Roy, R.; Pillay, K.K.S.

    1981-03-15

    Radiation effects in insulating solids are discussed in a general way as an introduction to the quite sparse published work on radiation effects in candidate nuclear waste forms other than glasses. Likely effects of transmutation in crystals and the chemical mitigation strategy are discussed. It seems probable that radiation effects in solidified HLW will not be serious if the actinides can be wholly incorporated in such radiation-resistant phases as monazite or uraninite.

  12. Third Radiation Effects Research Foundation Board of Councilors...

    Broader source: Energy.gov (indexed) [DOE]

    Radiation Effects Research Foundation Board of Councilors Meeting Held in Hiroshima The third Board of Councilors (BOC) meeting was held on June 18-19 at the Hiroshima Radiation ...

  13. Analytical study of the effects of the Low-Level Jet on moisture convergence and vertical motion fields at the Southern Great Plains Cloud and Radiation Testbed site

    SciTech Connect (OSTI)

    Bian, X.; Zhong, S.; Whiteman, C.D.; Stage, S.A.

    1996-04-01

    The Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) is located in a region that is strongly affected by a prominent meteorological phenomenon--the Great Plains Low-Level Jet (LLJ). Observations have shown that the LLJ plays a vital role in spring and summertime cloud formation and precipitation over the Great Plains. An improved understanding of the LLJ characteristics and its impact on the environment is necessary for addressing the fundamental issue of development and testing of radiational transfer and cloud parameterization schemes for the general circulation models (GCMs) using data from the SGP CART site. A climatological analysis of the summertime LLJ over the SGP has been carried out using hourly observations from the National Oceanic and Atmospheric Administration (NOAA) Wind Profiler Demonstration Network and from the ARM June 1993 Intensive Observation Period (IOP). The hourly data provide an enhanced temporal and spatial resolution relative to earlier studies which used 6- and 12-hourly rawinsonde observations at fewer stations.

  14. Radiation damage studies for the D0 silicon detector

    SciTech Connect (OSTI)

    Lehner, F.; /Zurich U.

    2004-01-01

    We report on irradiation studies performed on spare production silicon detector modules for the current D0 silicon detector. The lifetime expectations due to radiation damage effects of the existing silicon detector are reviewed. A new upgrade project was started with the goal of a complete replacement of the existing silicon detector. In that context, several investigations on the radiation hardness of new prototype silicon microstrip detectors were carried out. The irradiation on different detector types was performed with 10 MeV protons up to fluences of 10{sup 14} p/cm{sup 2} at the J.R. Mcdonald Laboratory at Kansas State University. The flux calibration was carefully checked using different normalization techniques. As a result, we observe roughly 40-50% less radiation damage in silicon for 10 MeV p exposure than it is expected by the predicted NIEL scaling.

  15. STRUCTURAL AND MECHANICAL EFFECTS OF RADIATION EXPOSURE ON FILLED...

    Office of Scientific and Technical Information (OSTI)

    MODELING Citation Details In-Document Search Title: STRUCTURAL AND MECHANICAL EFFECTS OF RADIATION EXPOSURE ON FILLED ELASTOMERS - RECENT INSIGHTS FROM EXPERIMENTS AND MODELING ...

  16. Characterization of ion-induced radiation effects in nuclear...

    Office of Scientific and Technical Information (OSTI)

    in nuclear materials using synchrotron x-ray techniques Citation Details In-Document Search Title: Characterization of ion-induced radiation effects in nuclear materials using ...

  17. Modeling of ionizing radiation effects in short-channel MOSFETs

    SciTech Connect (OSTI)

    Wilson, C.L.; Blue, J.L.

    1982-12-01

    The effect of ionizing radiation on short-channel MOSFETs is modeled using a charge-sheet approach. The primary effect of ionizing radiation is the introduction of oxide trapped charge (OTC) and interface trapped charge (ITC). Using a two-dimensional charge-sheet model, transistors with channel lengths between 4.65 ..mu..m and 0.27 ..mu..m were studied. A range of net OTC and ITC values of + 4.0 X 10/sup 11/ cm/sup -2/ corresponding to a dose of approximately 10/sup 6/ rad (SiO/sub 2/) was used to study total dose effects. ITC and OTC cause significant effects in each region of operation. In the subthreshold region, the sensitivity of drain current to these charges is exponential. A more realistic model must include the energy distribution of the ITC charge as well as two-dimensional charge sharing effects. In the triode region, the effects of ITC and OTC are indistinguishable from two-dimensional charge sharing effects.

  18. Posters The Effects of Radiative Transfer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... with difluence and sinking motion during cyclogenesis over ... How is the greater baroclinicity generated? Radiative ... The similar time structure of the water averages between the ...

  19. Radiation chemical effects in experiments to study the reaction of glass in an environment of gamma-irradiated air, groundwater, and tuff

    SciTech Connect (OSTI)

    Van Konynenburg, R.A.

    1986-05-02

    The results of experiments performed by John K. Bates et al. on the reaction of nuclear waste glass with a gamma-irradiated 90{sup 0}C aqueous solution were analyzed using theory developed from past research in radiation chemistry. The aqueous solution they used is similar to what would be expected in a water-saturated environment in a nuclear waste repository in tuff. The purpose of our study was to develop an understanding of the radiation-chemical processes that occurred in the Bates et al. experiments so the results could be applied to the design and performance analysis of a proposed repository in unsaturated tuff in Nevada. For the Bates et al. experiments at the highest dose (269 Mrad), which originally contained about 16 ml of "equilibrated" water taken from Nevada Test Site Well J-13 and 5.4 ml of air, we predicted that water decomposition to H{sub 2} and O{sub 2} would produce a pressure increase of at least 1.0 MPa at 20{sup 0}C. We also predicted that nitrogen fixation from the air would occur, producing an increase of 1.6 x 10{sup -4} M in total fixed nitrogen concentration in solution. In addition, an equimolar production of H{sup +} would occur, which would be buffered by the HCO{sub 3}{sup -} in the water. The fixed nitrogen in solution was predicted to be present as NO{sub 2}{sup -} and NO{sub 3}{sup -} with the ratio influenced by the presence of materials catalytic to the decomposition of H{sub 2}O{sub 2}. We found reasonable agreement between our predictions and the observations of Bates et al., where comparisons were possible. We apply the results to the proposed Nevada repository to the degree possible, given the different expected conditions.

  20. Study of material properties using channeling radiation

    SciTech Connect (OSTI)

    Pantell, R.H.; Kephart, J.O.; Klein, R.K.; Park, H.; Berman, B.L.; Datz, S.

    1986-01-01

    A possible application for channeling radiation is for investigating the properties of crystals in which the channeling occurs. In this paper we present some general considerations concerning channeling radiation as a measurement technique, and then we proceed to describe several specific examples.

  1. Synchrotron radiation infrared microscopic study of non-bridging...

    Office of Scientific and Technical Information (OSTI)

    Title: Synchrotron radiation infrared microscopic study of non-bridging oxygen modes associated with laser-induced breakdown of fused silica Authors: Matthews, M J ; Carr, C W ; ...

  2. Molecular photoemission studies using synchrotron radiation

    SciTech Connect (OSTI)

    Truesdale, C.M.

    1983-04-01

    The angular distributions of photoelectrons and Auger electrons were measured by electron spectroscopy using synchrotron radiation. The experimental results are compared with theoretical calculations to interpret the electronic behavior of photoionization for molecular systems.

  3. Advances in Radiation Mutagenesis through Studies on Drosophila

    DOE R&D Accomplishments [OSTI]

    Muller, H. J.

    1958-06-01

    The approximately linear relation between radiation dose and induced lethals known for Drosophila spermatozoa, is now extended to spermatids. Data are included regarding oogonia. The linearity principle has been confined for minute structural changes in sperm as multi-hit events, on about the 1.5 power of the dose, long known for spermatozoa, is now extended to spermatids and late oocytes, for relatively short exposures. are found to allow union of broken chromosomes. Therefore, the frequencies are lower for more dispersed exposures of varies with lethals induced in late oocytes follow the same frequency pattern and there fore are multi-hit events. Yet han spermatozoan irradiation that two broken ends derived from nonreciprocal. The following is the order of decreasing radiation mutability of different stages found by ourselves and others: spermatids, spermatozoa in females, spermatozoa 0 to 1 day before ejaculation, earlier spermatozoa, late oocytes, gonia of either sex. Lethal frequencies for these stages range over approximately an order of magnitude, gross structural changes far more widely. Of potential usefulness is our extension of genesis by anoxia, known for spermatozoa in adult males, to those in pupal males and in females, to sperion is especially marked but the increase caused by substituting oxygen for air is less marked, perhaps because of enzymatic differences. In contrast, the induction of gross structural changes in oocytes, but not in spermatids, is markedly reduced by oxygen post-treatment; it is increased by dehydration. The efficacy of induction of structural changes by treatment of spermatozoa, whether with radiation or chemical mutagen, is correlated with the conditions of sperm utilization and egg production. Improving our perspective on radiation effects, some 800,000 offspring have been scored for spontaneous visible mutations of 13 specific loci. The average point-mutation rate was 0.5 to 1.0 per locus among 10/sup 5/ germ cells. Most

  4. Coherent Radiation Effects in the LCLS Undulator

    SciTech Connect (OSTI)

    Reiche, S.; /UCLA; Huang, Z.; /SLAC

    2010-12-14

    For X-ray Free-Electron Lasers such as LCLS and TESLA FEL, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is the emission of incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for frequencies comparable to or longer than the bunch dimension. If the emitted coherent energy becomes comparable to that of the incoherent emission, it has to be included in the taper as well. However, the coherent loss depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the practical operation of Free-Electron Lasers, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator radiation and transition undulator radiation for LCLS, and estimate whether the resulting energy losses are significant for the operation of LCLS.

  5. Errors and Uncertainties in Dose Reconstruction for Radiation Effects Research

    SciTech Connect (OSTI)

    Strom, Daniel J.

    2008-04-14

    Dose reconstruction for studies of the health effects of ionizing radiation have been carried out for many decades. Major studies have included Japanese bomb survivors, atomic veterans, downwinders of the Nevada Test Site and Hanford, underground uranium miners, and populations of nuclear workers. For such studies to be credible, significant effort must be put into applying the best science to reconstructing unbiased absorbed doses to tissues and organs as a function of time. In many cases, more and more sophisticated dose reconstruction methods have been developed as studies progressed. For the example of the Japanese bomb survivors, the dose surrogate “distance from the hypocenter” was replaced by slant range, and then by TD65 doses, DS86 doses, and more recently DS02 doses. Over the years, it has become increasingly clear that an equal level of effort must be expended on the quantitative assessment of uncertainty in such doses, and to reducing and managing uncertainty. In this context, this paper reviews difficulties in terminology, explores the nature of Berkson and classical uncertainties in dose reconstruction through examples, and proposes a path forward for Joint Coordinating Committee for Radiation Effects Research (JCCRER) Project 2.4 that requires a reasonably small level of effort for DOSES-2008.

  6. Use of In Situ Observations to Characterize Cloud Microphysical and Radiative Properties: Application to Climate Studies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Use of In Situ Observations to Characterize Cloud Microphysical and Radiative Properties: Application to Climate Studies G. M. McFarquhar and T. Nousiainen Department of Atmospheric Sciences University of Illinois Urbana, Illinois M. S. Timlin, S. F. Iacobellis, and R. C. J. Somerville Scripps Institution of Oceanography La Jolla, California Introduction Cloud radiative feedback is the most important effect determining climate response to human activity. Ice clouds reflect solar radiation and

  7. Influence of size effects on the radiation stability of nanocrystalline materials

    SciTech Connect (OSTI)

    Gerasimenko, N. N.; Smirnov, D. I.; Medetov, N. A.; Zaporozhan, O. A.

    2014-12-15

    The data reported in publications are analyzed, and on this basis, problems arising in studies of the radiation stability of nanostructures and nanomaterials are formulated. A phenomenological model of the radiation stability of such objects is considered. The model is based on the concept of the behavior of close Frenkel pairs. To test the model proposed in the study, the effect of the size factor on the degree of structural degradation in nanoporous silicon samples when irradiated with phosphorus ions is studied. The effect of elastic strains on the radiation stability of the structures is established.

  8. A study of Monte Carlo radiative transfer through fractal clouds

    SciTech Connect (OSTI)

    Gautier, C.; Lavallec, D.; O`Hirok, W.; Ricchiazzi, P.

    1996-04-01

    An understanding of radiation transport (RT) through clouds is fundamental to studies of the earth`s radiation budget and climate dynamics. The transmission through horizontally homogeneous clouds has been studied thoroughly using accurate, discreet ordinates radiative transfer models. However, the applicability of these results to general problems of global radiation budget is limited by the plane parallel assumption and the fact that real clouds fields show variability, both vertically and horizontally, on all size scales. To understand how radiation interacts with realistic clouds, we have used a Monte Carlo radiative transfer model to compute the details of the photon-cloud interaction on synthetic cloud fields. Synthetic cloud fields, generated by a cascade model, reproduce the scaling behavior, as well as the cloud variability observed and estimated from cloud satellite data.

  9. Posters Treatment of Cloud Radiative Effects in General Circulation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5 Posters Treatment of Cloud Radiative Effects in General Circulation Models W.-C. Wang, M. P. Dudek, X.-Z. Liang, M. Ding, L. Zhu, E. Joseph, and S. Cox Atmospheric Sciences...

  10. Useful Graphs and Charts - Ion Beams - Radiation Effects Facility...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Times 15 MeVu LET vs Range Graph 25 MeVu LET vs Range Graph 40 Mevu LET vs Range Graph Radiation Effects Facility Cyclotron Institute Texas A&M University MS 3366 ...

  11. National group honors Sandia radiation effects expert | National Nuclear

    National Nuclear Security Administration (NNSA)

    Security Administration | (NNSA) National group honors Sandia radiation effects expert Monday, July 21, 2014 - 1:26pm NNSA Blog Sandia radiation effects researcher Jim Schwank has won the 2014 IEEE Nuclear and Plasma Sciences Society Merit Award, which recognizes outstanding technical contributions to the fields of nuclear and plasma sciences. The award is based on the importance of individual technical contributions, importance of technical contributions made by teams the individual led,

  12. Consideration of Dynamical Effects on Parameterization of Clooud radiative Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Consideration of Dynamical Effects on Parameterization of Cloud Radiative Properties P. H. Daum and Y. Liu Environmental Sciences Department Brookhaven National Laboratory Upton, New York Introduction Effective radius (r e ) (defined as the ratio of the third to the second moment of a droplet size distribution) is one of the key variables that are used for calculation of the radiative properties of liquid water clouds (Hansen and Travis 1974). The inclusion and parameterization of r e in climate

  13. Report of the Blue Ribbon Panel on the Review of the Radiation Effects

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Research Foundation | Department of Energy Blue Ribbon Panel on the Review of the Radiation Effects Research Foundation Report of the Blue Ribbon Panel on the Review of the Radiation Effects Research Foundation October 11, 1995 This report summarizes the findings of the Blue Ribbon Panel's review of the RERF scientific projects and future research plans The report recommended that the core studies be continued for the next 20 years. Report of the Blue Ribbon Panel on the Review of the

  14. RADIATION EFFECTS ON EPOXY CARBON FIBER COMPOSITE

    SciTech Connect (OSTI)

    Hoffman, E

    2008-05-30

    Carbon fiber-reinforced bisphenol-A epoxy matrix composite was evaluated for gamma radiation resistance. The composite was exposed to total gamma doses of 50, 100, and 200 Mrad. Irradiated and baseline samples were tested for tensile strength, hardness and evaluated using FTIR (Fourier transform infrared) spectroscopy and DSC (differential scanning calorimetry) for structural changes. Scanning electron microscopy was used to evaluate microstructural behavior. Mechanical testing of the composite bars revealed no apparent change in modulus, strain to failure, or fracture strength after exposures. However, testing of only the epoxy matrix revealed changes in hardness, thermal properties, and FTIR results with increasing gamma irradiation. The results suggest the epoxy within the composite can be affected by exposure to gamma irradiation.

  15. Biomarkers and Surrogate Endpoints for Normal-Tissue Effects of Radiation Therapy: The Importance of Dose-Volume Effects

    SciTech Connect (OSTI)

    Bentzen, Soren M.; Parliament, Matthew; Deasy, Joseph O.; Dicker, Adam; Curran, Walter J.; Williams, Jacqueline P.; Rosenstein, Barry S.

    2010-03-01

    Biomarkers are of interest for predicting or monitoring normal tissue toxicity of radiation therapy. Advances in molecular radiobiology provide novel leads in the search for normal tissue biomarkers with sufficient sensitivity and specificity to become clinically useful. This article reviews examples of studies of biomarkers as predictive markers, as response markers, or as surrogate endpoints for radiation side effects. Single nucleotide polymorphisms are briefly discussed in the context of candidate gene and genomewide association studies. The importance of adjusting for radiation dose distribution in normal tissue biomarker studies is underlined. Finally, research priorities in this field are identified and discussed.

  16. RADIATION EFFECTS ON EPOXY/CARBON FIBER COMPOSITE

    SciTech Connect (OSTI)

    Hoffman, E; Eric Skidmore, E

    2008-12-12

    The Department of Energy Savannah River Site vitrifies nuclear waste incident to defense programs through its Defense Waste Processing Facility (DWPF). The piping in the DWPF seal pot jumper configuration must withstand the stresses during an unlikely but potential deflagration event, and maintain its safety function for a 20-year service life. Carbon fiber-reinforced epoxy composites (CFR) were proposed for protection and reinforcement of piping during such an event. The proposed CFR materials have been ASME-approved (Section XI, Code Case N-589-1) for post-construction maintenance and is DOT-compliant per 49CFR 192 and 195. The proposed carbon fiber/epoxy composite reinforcement system was originally developed for pipeline rehabilitation and post-construction maintenance in petrochemical, refineries, DOT applications and other industries. The effects of ionizing radiation on polymers and organic materials have been studied for many years. The majority of available data are based on traditional exposures to gamma irradiation at high dose rates ({approx}10,000 Gy/hr) allowing high total dose within reasonable test periods and general comparison of different materials exposed at such conditions. However, studies in recent years have shown that degradation of many polymers are sensitive to dose rate, with more severe degradation often observed at similar or even lower total doses when exposed to lower dose rates. This behavior has been primarily attributed to diffusion-limited oxidation which is minimized during very high dose rate exposures. Most test standards for accelerated aging and nuclear qualification of components acknowledge these limitations. The results of testing to determine the radiation resistance and microstructural effects of gamma irradiation exposure on a bisphenol-A based epoxy matrix composite reinforced with carbon fibers are presented. This work provides a foundation for a more extensive evaluation of dose rate effects on advanced epoxy

  17. Radiation effects in concrete for nuclear power plants Part I: Quantification of radiation exposure and radiation effects

    SciTech Connect (OSTI)

    Field, Kevin G; Pape, Yann Le; Remec, Igor

    2015-01-01

    A large fraction of light water reactor (LWR) construction utilizes concrete, including safety-related structures such as the biological shielding and containment building. Concrete is an inherently complex material, with the properties of concrete structures changing over their lifetime due to the intrinsic nature of concrete and influences from local environment. As concrete structures within LWRs age, the total neutron fluence exposure of the components, in particular the biological shield, can increase to levels where deleterious effects are introduced as a result of neutron irradiation. This work summarizes the current state of the art on irradiated concrete, including a review of the current literature and estimates the total neutron fluence expected in biological shields in typical LWR configurations. It was found a first-order mechanism for loss of mechanical properties of irradiated concrete is due to radiation-induced swelling of aggregates, which leads to volumetric expansion of the concrete. This phenomena is estimated to occur near the end of life of biological shield components in LWRs based on calculations of estimated peak neutron fluence in the shield after 80 years of operation.

  18. Effective-medium model of wire metamaterials in the problems of radiative heat transfer

    SciTech Connect (OSTI)

    Mirmoosa, M. S. Nefedov, I. S. Simovski, C. R.; Rüting, F.

    2014-06-21

    In the present work, we check the applicability of the effective medium model (EMM) to the problems of radiative heat transfer (RHT) through so-called wire metamaterials (WMMs)—composites comprising parallel arrays of metal nanowires. It is explained why this problem is so important for the development of prospective thermophotovoltaic (TPV) systems. Previous studies of the applicability of EMM for WMMs were targeted by the imaging applications of WMMs. The analogous study referring to the transfer of radiative heat is a separate problem that deserves extended investigations. We show that WMMs with practically realizable design parameters transmit the radiative heat as effectively homogeneous media. Existing EMM is an adequate tool for qualitative prediction of the magnitude of transferred radiative heat and of its effective frequency band.

  19. Heat pipe radiation cooling evaluation: Task 2 concept studies report

    SciTech Connect (OSTI)

    Silverstein, C.C.

    1991-10-01

    This report presents the result of Task 2, Concept Studies for Heat Pipe Radiation Cooling (HPRC), which was performed for Los Alamos National Laboratory under Contract 9-XT1-U9567. Studies under a prior contract defined a reference HPRC conceptual design for hypersonic aircraft engines operating at Mach 5 and an altitude of 80,000 ft. Task 2 involves the further investigation of heat pipe radiation cooling (HPRC) systems for additional design and operating conditions.

  20. Non-Targeted Effects Induced by Ionizing Radiation: Mechanisms and Potential Impact on Radiation Induced Health Effects

    SciTech Connect (OSTI)

    Morgan, William F.; Sowa, Marianne B.

    2015-01-01

    Not-targeted effects represent a paradigm shift from the "DNA centric" view that ionizing radiation only elicits biological effects and subsequent health consequences as a result of an energy deposition event in the cell nucleus. While this is likely true at higher radiation doses (> 1Gy), at low doses (< 100mGy) non-targeted effects associated with radiation exposure might play a significant role. Here definitions of non-targeted effects are presented, the potential mechanisms for the communication of signals and signaling networks from irradiated cells/tissues are proposed, and the various effects of this intra- and intercellular signaling are described. We conclude with speculation on how these observations might lead to and impact long-term human health outcomes.

  1. Beam Echo Effect for Generation of Short-Wavelength Radiation

    SciTech Connect (OSTI)

    Stupakov, G.; /SLAC

    2009-12-09

    The Echo-Enabled Harmonic Generation (EEHG) FEL uses two modulators in combination with two dispersion sections to generate a high-harmonic density modulation starting with a relatively small initial energy modulation of the beam. After presenting the concept of the EEHG, we address several practically important issues, such as the effect of coherent and incoherent synchrotron radiation in the dispersion sections. Using a representative realistic set of beam parameters, we show how the EEHG scheme enhances the FEL performance and allows one to generate a fully (both longitudinally and transversely) coherent radiation. We then discuss application of the echo modulation for generation of attosecond pulses of radiation, and also using echo for generation of terahertz radiation. We present main parameters of a proof-of-principle experiment currently being planned at SLAC for demonstration of the echo modulation mechanism.

  2. Effects of radiation on direct-drive laser fusion targets

    SciTech Connect (OSTI)

    Colombant, D. G.; Bodner, S. E.; Schmitt, A. J.; Klapisch, M.; Gardner, J. H.; Aglitskiy, Y.; Deniz, A. V.; Obenschain, S. P.; Pawley, C. J.; Serlin, V.

    2000-05-01

    The role played by radiation in the radiation-preheated direct-drive laser fusion target design is discussed. The soft x-rays emitted during the foot of the laser pulse--at a few 10{sup 12} W/cm{sup 2}--preheat the low-opacity foam ablator which helps to control the Rayleigh-Taylor instability. The foam opacity is, however, thick enough to stop that radiation, keeping the fuel on a low adiabat. Radiation effects are also important in the blow-off corona of the target because they establish a long scale-length plasma. This may help to shield the ablation region from the nonuniformities in the laser absorption. (c) 2000 American Institute of Physics.

  3. Second Solid Cancers After Radiation Therapy: A Systematic Review of the Epidemiologic Studies of the Radiation Dose-Response Relationship

    SciTech Connect (OSTI)

    Berrington de Gonzalez, Amy; Gilbert, Ethel; Curtis, Rochelle; Inskip, Peter; Kleinerman, Ruth; Morton, Lindsay; Rajaraman, Preetha; Little, Mark P.

    2013-06-01

    Rapid innovations in radiation therapy techniques have resulted in an urgent need for risk projection models for second cancer risks from high-dose radiation exposure, because direct observation of the late effects of newer treatments will require patient follow-up for a decade or more. However, the patterns of cancer risk after fractionated high-dose radiation are much less well understood than those after lower-dose exposures (0.1-5 Gy). In particular, there is uncertainty about the shape of the dose-response curve at high doses and about the magnitude of the second cancer risk per unit dose. We reviewed the available evidence from epidemiologic studies of second solid cancers in organs that received high-dose exposure (>5 Gy) from radiation therapy where dose-response curves were estimated from individual organ-specific doses. We included 28 eligible studies with 3434 second cancer patients across 11 second solid cancers. Overall, there was little evidence that the dose-response curve was nonlinear in the direction of a downturn in risk, even at organ doses of ≥60 Gy. Thyroid cancer was the only exception, with evidence of a downturn after 20 Gy. Generally the excess relative risk per Gray, taking account of age and sex, was 5 to 10 times lower than the risk from acute exposures of <2 Gy among the Japanese atomic bomb survivors. However, the magnitude of the reduction in risk varied according to the second cancer. The results of our review provide insights into radiation carcinogenesis from fractionated high-dose exposures and are generally consistent with current theoretical models. The results can be used to refine the development of second solid cancer risk projection models for novel radiation therapy techniques.

  4. Electronic effects in high-energy radiation damage in tungsten

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zarkadoula, Eva; Duffy, Dorothy M.; Nordlund, Kai; Seaton, M. A.; Todorov, I. T.; Weber, William J.; Trachenko, Kostya

    2015-01-01

    Even though the effects of the electronic excitations during high-energy radiation damage processes are not currently understood, it is shown that their role in the interaction of radiation with matter is important. We perform molecular dynamics simulations of high-energy collision cascades in bcc-tungsten using the coupled two-temperature molecular dynamics (2T-MD) model that incorporates both the effects of electronic stopping and electron–phonon interaction. We compare the combination of these effects on the induced damage with only the effect of electronic stopping, and conclude in several novel insights. In the 2T-MD model, the electron–phonon coupling results in less damage production in themore » molten region and in faster relaxation of the damage at short times. We show these two effects lead to a significantly smaller amount of the final damage at longer times.« less

  5. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect (OSTI)

    Lambert, D.; Pickenheim, B.; Hay, M.

    2011-06-20

    The Defense Waste Processing Facility (DWPF) is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and

  6. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect (OSTI)

    Pickenheim, B.; Bibler, N.

    2010-06-08

    The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be

  7. The mechanism of the effect of a plasma layer with negative permittivity on the antenna radiation field

    SciTech Connect (OSTI)

    Wang, Chunsheng Liu, Hui; Jiang, Binhao; Li, Xueai

    2015-06-15

    A model of a plasma–antenna system is developed to study the mechanism of the effect of the plasma layer on antenna radiation. Results show a plasma layer with negative permittivity is inductive, and thus affects the phase difference between electric and magnetic fields. In the near field of antenna radiation, a plasma layer with proper parameters can compensate the capacitivity of the vacuum and enhance the radiation power. In the far field of antenna radiation, the plasma layer with negative permittivity increases the inductivity of the vacuum and reduces the radiation power.

  8. Diffraction effects in the coherent transition radiation bunch length diagnostics

    SciTech Connect (OSTI)

    Kazakevich, G.; Lebedev, V.; Nagaitsev, S.; /Fermilab

    2007-08-01

    Diffraction effects in the Coherent Transition Radiation (CTR) bunch length diagnostics are considered for the A0 Photoinjector and the New Muon Laboratory (NML) injection module. The effects can cause a noticeable distortion of the measured CTR spectra depending on the experimental setup and the bunch parameters and resulting in errors of the bunch length measurements. Presented calculations show possible systematic errors in the bunch length in measurements based on the CTR spectra at A0 Photo injector and the NML injection module.

  9. Total aerosol effect: forcing or radiative flux perturbation?

    SciTech Connect (OSTI)

    Lohmann, Ulrike; Storelvmo, Trude; Jones, Andy; Rotstayn, Leon; Menon, Surabi; Quaas, Johannes; Ekman, Annica; Koch, Dorothy; Ruedy, Reto

    2009-09-25

    Uncertainties in aerosol forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of rain formation. Traditionally these feedbacks were not included in estimates of total aerosol forcing. Here we argue that they should be included because these feedbacks act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases) the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP), that takes these fast feedbacks and interactions into account. Thus we propose replacing the direct and indirect aerosol forcing in the IPCC forcing chart with RFP estimates. This implies that it is better to evaluate the total anthropogenic aerosol effect as a whole.

  10. Non-Targeted Effects of Ionizing Radiation: Implications for Risk Assessment and the Radiation Dose Response Profile

    SciTech Connect (OSTI)

    Morgan, William F.; Sowa, Marianne B.

    2009-11-01

    Radiation risks at low doses remain a hotly debated topic. Recent experimental advances in our understanding of effects occurring in the progeny of irradiated cells, and/or the non-irradiated neighbors of irradiated cells, i.e., non-targeted effects associated with exposure to ionizing radiation, have influenced this debate. The goal of this document is to summarize the current status of this debate and speculate on the potential impact of non-targeted effects on radiation risk assessment and the radiation dose response profile.

  11. Ceiling art in a radiation therapy department: its effect on patient treatment experience

    SciTech Connect (OSTI)

    Bonett, Jotham

    2015-09-15

    A new initiative has been implemented at the Sunshine Hospital Radiation Therapy Centre, to provide a calming and comforting environment for patients attending radiation therapy treatment. As part of this initiative, the department's computed tomography (CT) room and radiation therapy bunkers were designed to incorporate ceiling art that replicates a number of different visual scenes. The study was undertaken to determine if ceiling art in the radiation therapy treatment CT and treatment bunkers had an effect on a patient's experience during treatment at the department. Additionally, the study aimed to identify which of the visuals in the ceiling art were most preferred by patients. Patients were requested to complete a 12-question survey. The survey solicited a patient's opinion/perception on the unit's unique ceiling display with emphasis on aesthetic appeal, patient treatment experience and the patient's engagement due to the ceiling display. The responses were dichotomised to ‘positive’ or ‘negative’. Every sixth patient who completed the survey was invited to have a general face-to-face discussion to provide further information about their thoughts on the displays. The results demonstrate that the ceiling artwork solicited a positive reaction in 89.8% of patients surveyed. This score indicates that ceiling artwork contributed positively to patients’ experiences during radiation therapy treatment. The study suggests that ceiling artwork in the department has a positive effect on patient experience during their radiation therapy treatment at the department.

  12. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    SciTech Connect (OSTI)

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-11-06

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.

  13. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-11-06

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZEmore » particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.« less

  14. Coastal-inland solar radiation difference study. Final report

    SciTech Connect (OSTI)

    Bach, W.D. Jr.; Vukovich, F.M.

    1980-04-01

    The purpose of this study was to quantify the characteristics of solar insolation in the coastal zone and to determine the effect of the sea breeze circulation on the global insolation. In order to satisfy these objectives, a six station sampling network was established in the coastal plain of southeastern North Carolina, where previous evidence has indicated that the sea breeze circulation is almost a daily occurrence from late May through October. Three sites (Sloop Point, Onslow Beach, and Cape Fear Technical Institute (CFTI)) were located near the coast (coastal sites) to assess the insolation at the coast. A site (Clinton) was located in an area seldom affected by the sea breeze (about 100 km from the coast). Two additional sites, Wallace and Ellis Airport, located between the coastal sites and the control site, were to be used to assess the transient impact of the sea breeze upon the insolation. Pyranometers were located at each site to measure the global insolation. Direct normal insolation measured by a pyrheliometer and ultraviolet radiation measured by uv radiometers were observed at the Sloop Point and Clinton sites only. Data were collected during the calendar year 1978. The results of the study indicated that the global insolation had greater variability over the network during the summer season (June, July, and August). During the summer, there was a systematicdiurnal variation of the difference in global insolation between the inland and the coastal sites.

  15. Radiative Closure Studies at the NSA ACRF Site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiative Closure Studies at the NSA ACRF Site Delamere, Jennifer Atmospheric and Environmental Research, Inc. Mlawer, Eli Atmospheric & Environmental Research, Inc. Turner, David University of Wisconsin-Madison Clough, Shepard Atmospheric and Environmental Research Jensen, Michael Brookhaven National Laboratory Miller, Mark Brookhaven National Laboratory Johnson, Karen Brookhaven National Laboratory Troyan, David Brookhaven National Laboratory Shippert, Timothy Pacific Northwest National

  16. The study of pinch regimes based on radiation-enhanced compression and anomalous resistivity phenomena and their effects on hard x-ray emission in a Mather type dense plasma focus device (SABALAN2)

    SciTech Connect (OSTI)

    Piriaei, D.; Javadi, S.; Ghoranneviss, M.; Mahabadi, T. D.; Saw, S. H.; Lee, S.

    2015-12-15

    In this study, by using argon and nitrogen as the filling gases in a Mather type dense plasma focus device at different values of pressure and charging voltage, two different kinds of pinch regimes were observed for each of the gases. The physics of the pinch regimes could be explained by using the two versions of the Lee's computational model which predicted each of the scenarios and clarified their differences between the two gases according to the radiation-enhanced compression and, additionally, predicted the pinch regimes through the anomalous resistivity effect during the pinch time. This was accomplished through the fitting process (simulation) on the current signal. Moreover, the characteristic amplitude and time scales of the anomalous resistances were obtained. The correlations between the features of the plasma current dip and the emitted hard x-ray pulses were observed. The starting time, intensity, duration, and the multiple or single feature of the emitted hard x-ray strongly correlated to the same respective features of the current dip.

  17. Epidemiologic Study of One Million American Workers and Military Veterans Exposed to Ionizing Radiation

    SciTech Connect (OSTI)

    Boice, John D.

    2015-02-27

    A pilot study was completed demonstrating the feasibility of conducting an epidemiologic study assessing cancer and other disease mortality among nearly one million US veterans and workers exposed to ionizing radiation, a population 10 times larger than atomic bomb survivor study with high statistical power to evaluate low dose rate effects. Among the groups enumerated and/or studied were: (1) 194,000 Department of Energy Uranium Workers; (2) 6,700 Rocketdyne Radiation Workers; (3) 7,000 Mound Radiation Workers; (4) 156,000 DOE Plutonium Workers; (5) 212,000 Nuclear Power Plant Workers; (6) 130,000 Industrial Radiography Workers; (7) 1.7 million Medical Workers and (8) 135,000 Atomic Veterans.

  18. Fermionic Tunneling Effect and Hawking Radiation in a Non Commutative FRW Universe

    SciTech Connect (OSTI)

    Bouhalouf, H.; Aissaoui, H.; Mebarki, N.

    2010-10-31

    The formalism of a non commutative gauge gravity is applied to an FRW universe and the corresponding modified metric, veirbein and spin connection components are obtained. Moreover, using the Hamilton-Jacobi method and as a pure space-time deformation effect, the NCG Hawking radiation via a fermionic tunneling transition through the dynamical NCG horizon is also studied.

  19. Dusty Plasma Modeling of the Fusion Reactor Sheath Including Collisional-Radiative Effects

    SciTech Connect (OSTI)

    Dezairi, Aouatif; Samir, Mhamed; Eddahby, Mohamed; Saifaoui, Dennoun; Katsonis, Konstantinos; Berenguer, Chloe

    2008-09-07

    The structure and the behavior of the sheath in Tokamak collisional plasmas has been studied. The sheath is modeled taking into account the presence of the dust{sup 2} and the effects of the charged particle collisions and radiative processes. The latter may allow for optical diagnostics of the plasma.

  20. Quantitative Proteomic Profiling of Low Dose Ionizing Radiation Effects in a Human Skin Model

    SciTech Connect (OSTI)

    Hengel, Shawna; Aldrich, Joshua T.; Waters, Katrina M.; Pasa-Tolic, Ljiljana; Stenoien, David L.

    2014-07-29

    To assess molecular responses to low doses of radiation that may be encountered during medical diagnostic procedures, nuclear accidents, or terrorist acts, a quantitative global proteomic approach was used to identify protein alterations in a reconstituted human skin tissue treated with 10 cGy of ionizing radiation. Subcellular fractionation was employed to remove highly abundant structural proteins and provide insight on radiation induced alterations in protein abundance and localization. In addition, peptides were post-fractionated using high resolution 2-dimensional liquid chromatography to increase the dynamic range of detection of protein abundance and translocation changes. Quantitative data was obtained by labeling peptides with 8-plex isobaric iTRAQ tags. A total of 207 proteins were detected with statistically significant alterations in abundance and/or subcellular localization compared to sham irradiated tissues. Bioinformatics analysis of the data indicated that the top canonical pathways affected by low dose radiation are related to cellular metabolism. Among the proteins showing alterations in abundance, localization and proteolytic processing was the skin barrier protein filaggrin which is consistent with our previous observation that ionizing radiation alters profilaggrin processing with potential effects on skin barrier functions. In addition, a large number of proteases and protease regulators were affected by low dose radiation exposure indicating that altered proteolytic activity may be a hallmark of low dose radiation exposure. While several studies have demonstrated altered transcriptional regulation occurs following low dose radiation exposures, the data presented here indicates post-transcriptional regulation of protein abundance, localization, and proteolytic processing play an important role in regulating radiation responses in complex human tissues.

  1. Clear Skies A Study of Longwave Radiation Codes for Climate Studies: Validation with Observations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A Study of Longwave Radiation Codes for Climate Studies: Validation with Observations and Tests in General Circulation Models-an Update R. G. Ellingson and F. Baer Department of Meteorology University of Maryland College Park, MD 20742 Introduction to compare calculations from a set of models with operationally observed data. The differences we find will lead to the development of new models to be tested with new data. Similarly. our GCM studies will use existing GCMs to study the radiation

  2. A new radiometer for earth radiation budget studies

    SciTech Connect (OSTI)

    Weber, P.G.

    1992-05-01

    A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for radiation balance studies. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on (small) satellites, aircraft, or Unmanned Aerospace Vehicles (UAVs). Some considerations for the implementation of this radiometer on a small satellite are given. 17 refs.

  3. A new radiometer for earth radiation budget studies

    SciTech Connect (OSTI)

    Weber, P.G.

    1992-01-01

    A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for radiation balance studies. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on (small) satellites, aircraft, or Unmanned Aerospace Vehicles (UAVs). Some considerations for the implementation of this radiometer on a small satellite are given. 17 refs.

  4. EFFECTS OF GAMMA RADIATION ON ELECTROCHEMICAL PROPERTIES OF IONIC LIQUIDS

    SciTech Connect (OSTI)

    Visser, A; Nicholas Bridges, N; Thad Adams, T; John Mickalonis, J; Mark02 Williamson, M

    2009-04-21

    The electrochemical properties of ionic liquids (ILs) make them attractive for possible replacement of inorganic salts in high temperature molten salt electrochemical processing of nuclear fuel. To be a feasible replacement solvent, ILs need to be stable in moderate and high doses of radiation without adverse chemical and physical effects. Here, we exposed seven different ILs to a 1.2 MGy dose of gamma radiation to investigate their physical and chemical properties as they related to radiological stability. The azolium-based ILs experienced the greatest change in appearance, but these ILs were chemically more stable to gamma radiation than some of the other classes of ILs tested, due to the presence of aromatic electrons in the azolium ring. All the ILs exhibited a decrease in their conductivity and electrochemical window (at least 1.1 V), both of which could affect the utility of ILs in electrochemical processing. The concentration of the irradiation decomposition products was less than 3 mole %, with no impurities detectable using NMR techniques.

  5. Determination of the effective sample thickness via radiative capture

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hurst, A. M.; Summers, N. C.; Szentmiklosi, L.; Firestone, R. B.; Basunia, M. S.; Escher, J. E.; Sleaford, B. W.

    2015-09-14

    Our procedure for determining the effective thickness of non-uniform irregular-shaped samples via radiative capture is described. In this technique, partial γ-ray production cross sections of a compound nucleus produced in a neutron-capture reaction are measured using Prompt Gamma Activation Analysis and compared to their corresponding standardized absolute values. For the low-energy transitions, the measured cross sections are lower than their standard values due to significant photoelectric absorption of the γ rays within the bulk-sample volume itself. Using standard theoretical techniques, the amount of γ-ray self absorption and neutron self shielding can then be calculated by iteratively varying the sample thicknessmore » until the observed cross sections converge with the known standards. The overall attenuation provides a measure of the effective sample thickness illuminated by the neutron beam. This procedure is illustrated through radiative neutron capture using powdered oxide samples comprising enriched 186W and 182W from which their tungsten-equivalent effective thicknesses are deduced to be 0.077(3) mm and 0.042(8) mm, respectively.« less

  6. Determination of the effective sample thickness via radiative capture

    SciTech Connect (OSTI)

    Hurst, A. M.; Summers, N. C.; Szentmiklosi, L.; Firestone, R. B.; Basunia, M. S.; Escher, J. E.; Sleaford, B. W.

    2015-09-14

    Our procedure for determining the effective thickness of non-uniform irregular-shaped samples via radiative capture is described. In this technique, partial ?-ray production cross sections of a compound nucleus produced in a neutron-capture reaction are measured using Prompt Gamma Activation Analysis and compared to their corresponding standardized absolute values. For the low-energy transitions, the measured cross sections are lower than their standard values due to significant photoelectric absorption of the ? rays within the bulk-sample volume itself. Using standard theoretical techniques, the amount of ?-ray self absorption and neutron self shielding can then be calculated by iteratively varying the sample thickness until the observed cross sections converge with the known standards. The overall attenuation provides a measure of the effective sample thickness illuminated by the neutron beam. This procedure is illustrated through radiative neutron capture using powdered oxide samples comprising enriched 186W and 182W from which their tungsten-equivalent effective thicknesses are deduced to be 0.077(3) mm and 0.042(8) mm, respectively.

  7. United States-Russian workshop on the stochastic health effects of radiation

    SciTech Connect (OSTI)

    1992-12-31

    In August 1988, two years after the Chernobyle accident, the United States and the Soviet Union signed an agreement to sponsor a Joint coordinating Committee on Civilian Nuclear Reactor Safety, (JCCCNRS). The Soviet Union agreed to provide some information on late effects of radiation exposures and to attempt to add some new insights into low dose and low dose rate radiation consequences. At that time, it had just been revealed that significant radiation exposures had occurred in the South Ural Mountains, associated with the early years of operation of the MAYAK nuclear complex. The need to be able to better predict the long term consequences of overexposures, such as occurred with the Chernobyl accident, was a major factor in organizing this workshop. We decided to invite a small number of experts from the Soviet Union, who had direct knowledge of the situation. A small group of American experts was invited to help in a discussion of the state of knowledge of continual low level exposure. The experts and expertise included: Aspects of bask theoretical radiobiological models, studies on experimental animals exposed to chronic or fractionated external or internal radiation, studies on populations exposed to chronic intake and continual exposures, workers exposed to low or high continual levels of radiation. The intent was to begin a dialog on the issue of a better understanding of the dose rate effect in humans. No detailed conclusions could be reached at this first interaction between out two countries, but a model was prepared which seems to support a range of what are known as low dose and dose rate effectiveness factors. A beginning of an evaluation of the role of radiation dose rate on leukemia risk was also accomplished.

  8. Nauru Island Effect Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Although these shallow cumulus clouds have little impact on the total radiation budget of ... 1999 through June 2000 by Nordeen et al. (2001), cloud plumes were seen in 50% of the ...

  9. Effect of MPG on radiation-induced odontogenic tissue metaplasia

    SciTech Connect (OSTI)

    Geist, J.R.; Kafrawy, A.H.; Shupe, R.E.

    1988-01-01

    This investigation monitored the effect of 2-mercaptopropionylglycine (MPG) in reducing radiation damage to the tooth-forming tissues. Fifty rats were exposed to x-ray doses of between 3 and 19 Gy directed toward the maxillary incisor germinal centers. Half of the animals were given an injection of MPG before irradiation, while the other rats were injected with saline solution. Administration of MPG did not significantly reduce the frequency of dentinal niche formation relative to the control teeth. The average lengths and percentage depths of the apicoincisal niches were statistically smaller in the groups treated with MPG. Although statistically significant, the mild protective effect of MPG was not clinically important because damage to the irradiated teeth was still extensive.

  10. Implications of Intercellular Signaling for Radiation Therapy: A Theoretical Dose-Planning Study

    SciTech Connect (OSTI)

    McMahon, Stephen J.; McGarry, Conor K.; Butterworth, Karl T.; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2013-12-01

    Purpose: Recent in vitro results have shown significant contributions to cell killing from signaling effects at doses that are typically used in radiation therapy. This study investigates whether these in vitro observations can be reconciled with in vivo knowledge and how signaling may have an impact on future developments in radiation therapy. Methods and Materials: Prostate cancer treatment plans were generated for a series of 10 patients using 3-dimensional conformal therapy, intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy techniques. These plans were evaluated using mathematical models of survival following modulated radiation exposures that were developed from in vitro observations and incorporate the effects of intercellular signaling. The impact on dosevolume histograms and mean doses were evaluated by converting these survival levels into signaling-adjusted doses for comparison. Results: Inclusion of intercellular communication leads to significant differences between the signalling-adjusted and physical doses across a large volume. Organs in low-dose regions near target volumes see the largest increases, with mean signaling-adjusted bladder doses increasing from 23 to 33 Gy in IMRT plans. By contrast, in high-dose regions, there is a small decrease in signaling-adjusted dose due to reduced contributions from neighboring cells, with planning target volume mean doses falling from 74 to 71 Gy in IMRT. Overall, however, the dose distributions remain broadly similar, and comparisons between the treatment modalities are largely unchanged whether physical or signaling-adjusted dose is compared. Conclusions: Although incorporating cellular signaling significantly affects cell killing in low-dose regions and suggests a different interpretation for many phenomena, their effect in high-dose regions for typical planning techniques is comparatively small. This indicates that the significant signaling effects observed in vitro are

  11. Final Report of project entitled "A metabolomics and mouse models approach to study inflammatory and immune responses to radiation"

    SciTech Connect (OSTI)

    Fornace, Albert J.; Li, Henghong

    2013-12-02

    The three-year project entitled ?A Metabolomics and Mouse Models Approach to Study Inflammatory and Immune Responses to Radiation? was initiated in September 2009. The overall objectives of this project were to investigate the acute and persistent effects of low dose radiation on T cell lymphocyte function and physiology, as well the contributions of these cells to radiation-induced inflammatory responses. Inflammation after ionizing radiation (IR), even at low doses, may impact a variety of disease processes, including infectious disease, cardiovascular disease, cancer, and other potentially inflammatory disorders. There were three overall specific aims: 1. To investigate acute and persistent effects of low dose radiation on T cell subsets and function; 2. A genetic approach with mouse models to investigate p38 MAPK pathways that are involved in radiation-induced inflammatory signaling; 3. To investigate the effect of radiation quality on the inflammatory response. We have completed the work proposed in these aims. Below are our major accomplishments: ? Our data show that T cells from low dose irradiated animals have lower proliferation potency and cytokine production upon T cell receptor (TCR) stimulation. This effect was observed as early as 4 hours after radiation, and lasted up to two weeks. ? Using our ultraperformance liquid chromatography coupled with highly sensitive time-of-flight mass spectrometry (UPLC-QTOF) metabolomics method, we demonstrated the global changes of metabolites in T cells upon TCR stimulation in a time-dependent pattern. ? We found that the TCR activation induced metabolome changes are remarkably altered in a dose-dependent manner after radiation. At a dose of 0.5 Gy and above, IR mitigated TCR activation induced metabolome changes while at the dose of as low as 0.1Gy IR had a mild stimulatory effect on some of the metabolome changes. ? We revealed the mechanism for how radiation affects T cell activation by showing that the energy

  12. Silicon field-effect transistors as radiation detectors for the Sub-THz range

    SciTech Connect (OSTI)

    But, D. B. Golenkov, O. G.; Sakhno, N. V.; Sizov, F. F.; Korinets, S. V.; Gumenjuk-Sichevska, J. V.; Reva, V. P.; Bunchuk, S. G.

    2012-05-15

    The nonresonance response of silicon metal-oxide-semiconductor field-effect transistors (Si-MOSFETs) with a long channel (1-20 {mu}m) to radiation in the frequency range 43-135 GHz is studied. The transistors are fabricated by the standard CMOS technology with 1-{mu}m design rules. The volt-watt sensitivity and the noise equivalent power (NEP) for such detectors are estimated with the calculated effective area of the detecting element taken into account. It is shown that such transistors can operate at room temperature as broadband direct detectors of sub-THz radiation. In the 4-5 mm range of wavelengths, the volt-watt sensitivity can be as high as tens of kV/W and the NEP can amount to 10{sup -11} - 10{sup -12}W/{radical}Hz . The parameters of detectors under study can be improved by the optimization of planar antennas.

  13. Human radiation studies: Remembering the early years. Oral history...

    Office of Scientific and Technical Information (OSTI)

    California, Berkeley and his biomedical work at Lawrence Livermore Radiation Laboratory. ... LIPOPROTEINS; RADIOTHERAPY; LAWRENCE LIVERMORE NATIONAL LABORATORY; LOW DOSE ...

  14. Measurements of radiation effects on a 4 Mb PSRAM memory

    SciTech Connect (OSTI)

    Gonalez, Odair Lelis; Pereira Junior, Evaldo Carlos Fonseca; Vaz, Rafael Galhardo; Pereira, Marlon Antonio; Wirth, Gilson Incio; Both, Thiago Hanna

    2014-11-11

    The results of a static test of total ionizing dose (TID) effects on an ISSI 4Mb PSRAM memory are reported in this work. The irradiation was performed at the IEAvs Laboratory of Ionizing Radiation with 1.17 and 1.32 MeV gamma-rays from a {sup 60}Co source at a dose rate of 2.5 krad/h up to an accumulated dose of 215.7 krad. The TID threshold for bit flip found in this experiment was 52.5 krad. From a sampling of 4096 memory addresses it was estimated a bit flip rate of approximately 50% at an accumulated dose of 215.7 krad.

  15. Safety - Radiation Effects Facility / Cyclotron Institute / Texas A&M

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    University Safety Numerous safety mechanisms in the form of administrative and engineered controls are incorporated into the design of the Radiation Effects Facility. Radiation levels in the surrounding areas were measured while each available beam was brought into the heavily shielded target area at full intensity. It was found that the measured radiation levels would be safe for the beam intensities several orders of magnitude larger than those needed for typical radiation testing

  16. Effect of radiation on properties of ENR/PVC/SiO{sub 2} membrane

    SciTech Connect (OSTI)

    Ismail, Nur Farahein Hadina; Abdullah, Ibrahim; Daik, Rusli; Ahmad, Ishak; Jamil, Suzereen; Lazim, Mohammad Azwan Mat; Othaman, Rizafizah

    2015-09-25

    In this study epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) matrix was prepared by melt blending. The matrix was swelled in THF and silica as a filler was introduced to the solution to generate pore formation. The ENR/PVC/10 % SiO{sub 2} membrane was prepared using a casting knife technique. The membrane was irradiated using 2 MeV electron beam accelerator at a dose range of 10-100 kGy. The effect of electron beam irradiation of the membrane was studied by undergo characterization of Scanning electron microscope (SEM) and Fourier transform infra red (FTIR). Morphological studies showed that pores generated in ENR/PVC/10 % SiO{sub 2} membrane increased with the dosage of radiation. While FTIR analysis showed the presence of peak of Si-O-Si asymmetric stretching at 834 cm{sup −1}. There are no significant changes in the functional group before and after radiation.

  17. Report of the Senior Review Panel on the Review of the Radiation Effects

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Research Foundation | Department of Energy Senior Review Panel on the Review of the Radiation Effects Research Foundation Report of the Senior Review Panel on the Review of the Radiation Effects Research Foundation June 2008 This report summarizes the findings of the Senior Review Panel's review of the Radiation Effects Research Foundation (RERF) scientific projects and future research plans. It also includes a necessity of discussions between the Japanese and U.S. governments and RERF

  18. Final Report - Epigenetics of low dose radiation effects in an animal model

    SciTech Connect (OSTI)

    Kovalchuk, Olga

    2014-10-22

    dose radiation effects and adaptive response • To correlate the levels of epigenetic changes with genetic rearrangement levels and gene expression patterns. In sum, we determined the precise global and locus-specific DNA methylation patterns in the LDR-exposed cells and tissues of mice, and to correlated DNA methylation changes with the gene expression patterns and manifestations of genome instability. We also determined the alterations of global histone modification pattern in the LDR exposed tissues. Additionally, we established the nature of microRNAome changes in the LDR exposed tissue. In this study we for the first time found that LDR exposure caused profound tissue-specific epigenetic changes in the exposed tissues. We established that LDR exposure affect methylation of repetitive elements in the murine genome, causes changes in histone methylation, acetylation and phosphorylation. Importantly, we found that LDR causes profound and persistent effects on small RNA profiles and gene expression, and that miRNAs are excellent biomarkers of LDR exposure. Furthermore, we extended our analysis and studied LDR effects in rat tissues and human tissues and cell lines. There we also analyzed LDR-induced gene expression, DNA methylation and miRNA changes. Our datasets laid foundation for several new research projects aimed to understand molecular underpinnings of low dose radiation responses, and biological repercussions of low dose radiation effects and radiation carcinogenesis.

  19. Placement and efficiency effects on radiative forcing of solar installations

    SciTech Connect (OSTI)

    Burg, Brian R.; Ruch, Patrick; Paredes, Stephan; Michel, Bruno

    2015-09-28

    The promise for harnessing solar energy being hampered by cost, triggered efforts to reduce them. As a consequence low-efficiency, low-cost photovoltaics (PV) panels prevail. Conversely, in the traditional energy sector efficiency is extremely important due to the direct costs associated to fuels. This also affects solar energy due to the radiative forcing caused by the dark solar panels. In this paper we extend the concept of energy payback time by including the effect of albedo change, which gives a better assessment of the system sustainability. We present an analysis on the short and medium term climate forcing effects of different solar collectors in Riyadh, Saudi Arabia and demonstrate that efficiency is important to reduce the collector area and cost. This also influences the embodied energy and the global warming potential. We show that a placement of a high concentration photovoltaic thermal solar power station outside of the city using a district cooling system has a double beneficial effect since it improves the solar conversion efficiency and reduces the energy demand for cooling in the city. We also explain the mechanisms of the current economic development of solar technologies and anticipate changes.

  20. Outstanding Conference Paper Award: 2015 IEEE Nuclear and Space Radiation Effects Conference

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dodds, Nathaniel Anson; Martinez, Marino; Dodd, Paul E.; Shaneyfelt, Marty R.; Sexton, Frederick W.; Black, Jeffrey D.; Lee, David S.; Swanson, Scot E.; Bhuva, Bharat L.; Warren, Kevin M.; et al

    2015-12-01

    This conference presents the recipients of the Outstanding Conference Paper Award from the 2015 IEEE Nuclear and Space Radiation Effects Conference.

  1. Radiation defect dynamics in Si at room temperature studied by pulsed ion beams

    SciTech Connect (OSTI)

    Wallace, J. B.; Myers, M. T.; Charnvanichborikarn, S.; Bayu Aji, L. B.; Kucheyev, S. O.; Shao, L.

    2015-10-07

    The evolution of radiation defects after the thermalization of collision cascades often plays the dominant role in the formation of stable radiation disorder in crystalline solids of interest to electronics and nuclear materials applications. Here, we explore a pulsed-ion-beam method to study defect interaction dynamics in Si crystals bombarded at room temperature with 500 keV Ne, Ar, Kr, and Xe ions. The effective time constant of defect interaction is measured directly by studying the dependence of lattice disorder, monitored by ion channeling, on the passive part of the beam duty cycle. The effective defect diffusion length is revealed by the dependence of damage on the active part of the beam duty cycle. Results show that the defect relaxation behavior obeys a second order kinetic process for all the cases studied, with a time constant in the range of ∼4–13 ms and a diffusion length of ∼15–50 nm. Both radiation dynamics parameters (the time constant and diffusion length) are essentially independent of the maximum instantaneous dose rate, total ion dose, and dopant concentration within the ranges studied. However, both the time constant and diffusion length increase with increasing ion mass. This demonstrates that the density of collision cascades influences not only defect production and annealing efficiencies but also the defect interaction dynamics.

  2. Multi-Dimensional Effects in Longwave Radiative Forcing of PBL...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ellingson Florida State University Tallahassee, Florida 1. Introduction Numerical cloud models nearly universally employ one-dimensional (1D) treatments of radiative transfer (RT). ...

  3. Incorporating Radiation Effects into Edge Plasma Transport Models...

    Office of Scientific and Technical Information (OSTI)

    radiation can significantly affect the ionization and energy balance in these plasmas. ... Subject: 70 PLASMA PHYSICS AND FUSION; DIMENSIONS; ENERGY BALANCE; HYDROGEN; IONIZATION; ...

  4. ORISE: Worker Health Studies - Radiation Exposure Data Collection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    How ORISE is Making a Difference Overview Argonne Electronic Medical Records System Beryllium Testing and Surveillance Radiation Exposure Information and Reporting System (REIRS) U.S. Department of Energy Radiation Exposure Monitoring System (REMS) DOE IISP 10-Year Summary Report Resources Overview Reports Peer-Reviewed Journal Articles Human Subjects Resource Book How to Work With Us Contact Us Oak Ridge Institute for Science Education Radiation Exposure Data Collection ORISE manages large,

  5. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    SciTech Connect (OSTI)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  6. ORISE: Worker Health Studies - Radiation Exposure Data Collection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    How ORISE is Making a Difference Overview Argonne Electronic Medical Records System Beryllium Testing and Surveillance Radiation Exposure Information and Reporting System (REIRS) ...

  7. A review of ground-based heavy-ion radiobiology relevant to space radiation risk assessment: Part II. Cardiovascular and immunological effects

    SciTech Connect (OSTI)

    Blakely, Eleanor A.; Chang, Polly Y.

    2007-02-26

    The future of manned space flight depends on an analysis of the numerous potential risks of travel into deep space. Currently no radiation dose limits have been established for these exploratory missions. To set these standards more information is needed about potential acute and late effects on human physiology from appropriate radiation exposure scenarios, including pertinent radiation types and dose rates. Cancer risks have long been considered the most serious late effect from chronic daily relatively low-dose exposures to the complex space radiation environment. However, other late effects from space radiation exposure scenarios are under study in ground-based accelerator facilities and have revealed some unique particle radiation effects not observed with conventional radiations. A comprehensive review of pertinent literature that considers tissue effects of radiation leading to functional detriments in specific organ systems has recently been published (NCRP National Council on Radiation Protection and Measurements, Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit, Report 153, Bethesda, MD, 2006). This paper highlights the review of two non-cancer concerns from this report: cardiovascular and immunological effects.

  8. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³⁷Cs at 0.13, 2.4, 21, and 222 mGy d⁻¹, resulting in total doses up to 15.8 Gy. Radiation treatments did notmore » affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d⁻¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.« less

  9. A Population-Based Study of the Fractionation of Postlumpectomy Breast Radiation Therapy

    SciTech Connect (OSTI)

    Ashworth, Allison; Cancer Center of Southeastern Ontario, Kingston, Ontario ; Kong, Weidong; Whelan, Timothy; Mackillop, William J.

    2013-05-01

    Purpose: The optimal fractionation schedule of post lumpectomy radiation therapy remains controversial. The objective of this study was to describe the fractionation of post-lumpectomy radiation therapy (RT) in Ontario, before and after the seminal Ontario Clinical Oncology Group (OCOG) trial, which showed the equivalence of 16- and 25-fraction schedules. Methods and Materials: This was a retrospective cohort study conducted by linking electronic treatment records to a population-based cancer registry. The study population included all patients who underwent lumpectomy for invasive breast cancer in Ontario, Canada, between 1984 and 2008. Results: Over the study period, 41,747 breast cancer patients received post lumpectomy radiation therapy to the breast only. Both 16- and 25-fraction schedules were commonly used throughout the study period. In the early 1980s, shorter fractionation schedules were used in >80% of cases. Between 1985 and 1995, the proportion of patients treated with shorter fractionation decreased to 48%. After completion of the OCOG trial, shorter fractionation schemes were once again widely adopted across Ontario, and are currently used in about 71% of cases; however, large intercenter variations in fractionation persisted. Conclusions: The use of shorter schedules of post lumpectomy RT in Ontario increased after completion of the OCOG trial, but the trial had a less normative effect on practice than expected.

  10. Intensity-modulated radiation therapy to bilateral lower limb extremities concurrently: a planning case study

    SciTech Connect (OSTI)

    Fitzgerald, Emma Miles, Wesley; Fenton, Paul; Frantzis, Jim

    2014-09-15

    Non-melanomatous skin cancers represent 80% of all newly diagnosed cancers in Australia with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being the most common. A previously healthy 71-year-old woman presented with widespread and tender superficial skin cancers on the lower bilateral limbs. External beam radiation therapy through the use of intensity-modulated radiation therapy (IMRT) was employed as the treatment modality of choice as this technique provides conformal dose distribution to a three-dimensional treatment volume while reducing toxicity to surrounding tissues. The patient was prescribed a dose of 60 Gy to the planning target volume (PTV) with 1.0 cm bolus over the ventral surface of each limb. The beam arrangement consisted of six treatment fields that avoided entry and exit through the contralateral limb. The treatment plans met the International Commission on Radiation Units and Measurements (ICRU) guidelines and produced highly conformal dosimetric results. Skin toxicity was measured against the National Cancer Institute: Common Terminology Criteria for Adverse Events (NCI: CTCAE) version 3. A well-tolerated treatment was delivered with excellent results given the initial extent of the disease. This case study has demonstrated the feasibility and effectiveness of IMRT for skin cancers as an alternative to surgery and traditional superficial radiation therapy, utilising a complex PTV of the extremities for patients with similar presentations.

  11. Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: An FTIR microspectroscopic imaging study

    SciTech Connect (OSTI)

    Cakmak G.; Miller L.; Zorlu, F.; Severcan, F.

    2012-03-03

    Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH{sub 2} groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH{sub 3} groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.

  12. Study of Scalar Mesons and Related Radiative Decays

    SciTech Connect (OSTI)

    Deirdre Black; Masayasu Harada; Joseph Schechter

    2002-06-01

    After a brief review of the puzzling light scalar meson sector of QCD, a brief summary will be given of a paper concerning radiative decays involving the light scalars. There, a simple vector meson dominance model is constructed in an initial attempt to relate a large number of the radiative decays involving a putative scalar nonet to each other. As an application it is illustrated why a{sub 0}(980)-f{sub 0}(980) mixing is not expected to greatly alter the f{sub 0}/a{sub 0} production ratio for radiative {phi} decays.

  13. Finite-size effects on the radiative energy loss of a fast parton...

    Office of Scientific and Technical Information (OSTI)

    This is done by introducing the concept of a radiation rate in the presence of finite-size effects. This effectively extends the finite-temperature approach of Arnold, Moore, and ...

  14. Aerosol Radiative Effects in the Tropical Western Pacific

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2001) found that during August to October 1997, such aerosols had a large impact on the surface radiative energy budget ... U.S. Department of Energy (DOE), Office of Science, Office ...

  15. A boundary-layer cloud study using Southern Great Plains Cloud and radiation testbed (CART) data

    SciTech Connect (OSTI)

    Albrecht, B.; Mace, G.; Dong, X.; Syrett, W.

    1996-04-01

    Boundary layer clouds-stratus and fairweather cumulus - are closely coupled involves the radiative impact of the clouds on the surface energy budget and the strong dependence of cloud formation and maintenance on the turbulent fluxes of heat and moisture in the boundary layer. The continuous data collection at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site provides a unique opportunity to study components of the coupling processes associated with boundary layer clouds and to provide descriptions of cloud and boundary layer structure that can be used to test parameterizations used in climate models. But before the CART data can be used for process studies and parameterization testing, it is necessary to evaluate and validate data and to develop techniques for effectively combining the data to provide meaningful descriptions of cloud and boundary layer characteristics. In this study we use measurements made during an intensive observing period we consider a case where low-level stratus were observed at the site for about 18 hours. This case is being used to examine the temporal evolution of cloud base, cloud top, cloud liquid water content, surface radiative fluxes, and boundary layer structure. A method for inferring cloud microphysics from these parameters is currently being evaluated.

  16. Determining the Radiation Damage Effect on Glovebox Glove Material.

    SciTech Connect (OSTI)

    Cournoyer, M. E.; Balkey, J. J.; Andrade, R.M.

    2005-01-01

    The Nuclear Material Technology (NMT) Division has the largest inventory of glove box gloves at Los Alamos National Laboratory. The minimization of unplanned breaches in the glovebox, e.g., glove failures, is a primary concern in the daily operations in NMT Division facilities, including the Plutonium Facility (PF-4) at TA-55 and Chemical and Metallurgy Research (CMR) Facility. Glovebox gloves in these facilities are exposed to elevated temperatures and exceptionally aggressive radiation environments (particulate {sup 239}Pu and {sup 238}Pu). Predictive models are needed to estimate glovebox glove service lifetimes, i.e. change-out intervals. Towards this aim aging studies have been initiated that correlate changes in mechanical (physical) properties with degradation chemistry. This present work derives glovebox glove change intervals based on previously reported mechanical data of thermally aged hypalon glove samples. Specifications for 30 mil tri-layered hypalon/lead glovebox gloves (TLH) and 15 mil hypalon gloves (HYP) have already been established. The relevant mechanical properties are shown on Table 1. Tensile strength is defined as the maximum load applied in breaking a tensile test piece divided by the original cross-sectional area of the test piece (Also termed maximum stress and ultimate tensile stress). Ultimate elongation is the elongation at time of rupture (Also termed maximum strain). The specification for the tensile test and ultimate elongation are the minimum acceptable values. In addition, the ultimate elongation must not vary 20% from the original value. In order to establish a service lifetimes for glovebox gloves in a thermal environment, the mechanical properties of glovebox glove materials were studied.

  17. Health effects of low-level radiation in shipyard workers. Final report: [Draft

    SciTech Connect (OSTI)

    Matanoski, G.M.

    1991-06-01

    The Nuclear Shipyard Workers Study (NSWS) was designed to determine whether there is an excess risk of leukemia or other cancers associated with exposure to low levels of gamma radiation. The study compares the mortality experience of shipyard workers who qualified to work in radiation areas to the mortality of similar workers who hold the same types of jobs but who are not authorized to work in radiation areas. The population consists of workers from six government and two private shipyards.

  18. The effect of low dose ionizing radiation on homeostasis and functional integrity in an organotypic human skin model

    SciTech Connect (OSTI)

    von Neubeck, Claere; Geniza, Matthew; Kauer, Paula M.; Robinson, Joseph E.; Chrisler, William B.; Sowa, Marianne B.

    2015-05-01

    Outside the protection of earth’s atmosphere, astronauts are exposed to low doses of high linear energy transfer (LET) radiation. Future NASA plans for deep space missions or a permanent settlement on the moon are limited by the health risks associated with space radiation exposures. There is a paucity of direct epidemiological data for low dose exposures to space radiation-relevant high LET ions. Health risk models are used to estimate the risk for such exposures, though these models are based on high dose experiments. There is increasing evidence, however, that low and high dose exposures result in different signaling events at the molecular level, and may involve different response mechanisms. Further, despite their low abundance, high LET particles have been identified as the major contributor to health risk during manned space flight. The human skin is exposed in every external radiation scenario, making it an ideal epithelial tissue model in which to study radiation induced effects. Here, we exposed an in vitro three dimensional (3-D) human organotypic skin tissue model to low doses of high LET oxygen (O), silicon (Si) and iron (Fe) ions. We measured proliferation and differentiation profiles in the skin tissue and examined the integrity of the skin’s barrier function. We discuss the role of secondary particles in changing the proportion of cells receiving a radiation dose, emphasizing the possible impact on radiation-induced health issues in astronauts.

  19. Preliminary Analysis of the Nauru Island Effect Study Data

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to the surrounding ocean) induces convection and cloud formation (Nordeen et al. 2001). ... relatively small effect on the radiation budget in the region, it may cause the radiation ...

  20. Mechanical Behavior and Radiation Effects | U.S. DOE Office of Science (SC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mechanical Behavior and Radiation Effects Materials Sciences and Engineering (MSE) Division MSE Home About Research Areas Energy Frontier Research Centers (EFRCs) DOE Energy Innovation Hubs BES Funding Opportunities Reports and Activities Science Highlights Principal Investigators' Meetings BES Home Research Areas Mechanical Behavior and Radiation Effects Print Text Size: A A A FeedbackShare Page This research area supports basic research to understand defects in materials and their effects on

  1. Workshop Report on Atomic Bomb Dosimetry--Residual Radiation Exposure: Recent Research and Suggestions for Future Studies

    SciTech Connect (OSTI)

    2013-06-06

    There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewed at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report.

  2. Study of global daily solar radiation and its relation to sunshine duration in Bahrain

    SciTech Connect (OSTI)

    Al-Sadah, F.H.; Ragab, F.M. )

    1991-01-01

    The regression coefficients a and b of Angstrom type correlation for the monthly daily average global solar radiation have been determined. The two constants a and b have been derived for different months during the period 1983-1987. The clearness index (H/H{sub 0}) based on predicted and measured values of global daily solar radiation is presented for different seasons of the year. The study depicts the various astronomical and meteorological parameters affecting the global radiation in Bahrain.

  3. Effects of radiation and compression on propagating spherical flames of methane/air mixtures near the lean flammability limit

    SciTech Connect (OSTI)

    Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Aerospace Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2010-12-15

    Large discrepancies between the laminar flame speeds and Markstein lengths measured in experiments and those predicted by simulations for ultra-lean methane/air mixtures bring a great concern for kinetic mechanism validation. In order to quantitatively explain these discrepancies, a computational study is performed for propagating spherical flames of lean methane/air mixtures in different spherical chambers using different radiation models. The emphasis is focused on the effects of radiation and compression. It is found that the spherical flame propagation speed is greatly reduced by the coupling between thermal effect (change of flame temperature or unburned gas temperature) and flow effect (inward flow of burned gas) induced by radiation and/or compression. As a result, for methane/air mixtures near the lean flammability limit, the radiation and compression cause large amounts of under-prediction of the laminar flame speeds and Markstein lengths extracted from propagating spherical flames. Since radiation and compression both exist in the experiments on ultra-lean methane/air mixtures reported in the literature, the measured laminar flame speeds and Markstein lengths are much lower than results from simulation and thus cannot be used for kinetic mechanism validation. (author)

  4. Third Radiation Effects Research Foundation Board of Councilors Meeting Held in Hiroshima

    Office of Energy Efficiency and Renewable Energy (EERE)

    The third Board of Councilors (BOC) meeting was held on June 18-19 at the Hiroshima Radiation Effects Research Foundation (RERF), a bi-national U.S.-Japan research organization.

  5. Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

    SciTech Connect (OSTI)

    Juneja, Prabhjot; Harris, Emma J.; Kirby, Anna M.; Evans, Philip M.

    2012-11-01

    Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue segmentation

  6. EFFECTS OF RADIATION ON ESTABLISHED FORENSIC EVIDENCE CONTAINMENT METHODS

    SciTech Connect (OSTI)

    Ferguson, C.; Duff, M.; Clark, E.; Chapman, G.

    2010-11-29

    The Federal Bureau of Investigation (FBI) Laboratory is currently exploring needs and protocols for the storage of evidentiary items contaminated with radioactive material. While a large body of knowledge on the behavior of storage polymers in radiation fields exists, this knowledge has not been applied to the field of forensics and maintaining evidentiary integrity. The focus of this research was to evaluate the behavior of several traditional evidentiary containment polymers when exposed to significant alpha, beta, gamma, neutron and mixed radiation sources. Doses were designed to simulate exposures possible during storage of materials. Several products were found to be poorly suited for use in this specific application based on standardized mechanical testing results. Remaining products were determined to warrant further investigation for the storage of radiologically contaminated evidence.

  7. Combination Effect of Regulatory T-Cell Depletion and Ionizing Radiation in Mouse Models of Lung and Colon Cancer

    SciTech Connect (OSTI)

    Son, Cheol-Hun; Bae, Jae-Ho; Shin, Dong-Yeok; Lee, Hong-Rae; Jo, Wol-Soon; Yang, Kwangmo; Park, You-Soo

    2015-06-01

    Purpose: To investigate the potential of low-dose cyclophosphamide (LD-CTX) and anti-CD25 antibody to prevent activation of regulatory T cells (Tregs) during radiation therapy. Methods and Materials: We used LD-CTX and anti-CD25 monoclonal antibody as a means to inhibit Tregs and improve the therapeutic effect of radiation in a mouse model of lung and colon cancer. Mice were irradiated on the tumor mass of the right leg and treated with LD-CTX and anti-CD25 antibody once per week for 3 weeks. Results: Combined treatment of LD-CTX or anti-CD25 antibody with radiation significantly decreased Tregs in the spleen and tumor compared with control and irradiation only in both lung and colon cancer. Combinatorial treatments resulted in a significant increase in the effector T cells, longer survival rate, and suppressed irradiated and distal nonirradiated tumor growth. Specifically, the combinatorial treatment of LD-CTX with radiation resulted in outstanding regression of local and distant tumors in colon cancer, and almost all mice in this group survived until the end of the study. Conclusions: Our results suggest that Treg depletion strategies may enhance radiation-mediated antitumor immunity and further improve outcomes after radiation therapy.

  8. Radiation Protection Studies for LCLS Tune Up Dump

    SciTech Connect (OSTI)

    Santana-Leitner, M.; Fass, A.; Mao, S.; Nuhn, H.D.; Roesler, S.; Rokni, S.; Vollaire, J.; /SLAC

    2010-04-29

    The Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center is a pioneer fourth generation hard x-ray free electron laser that shall start to deliver laser pulses in 2009. Among other components of LCLS that present radiation protection concerns, the tune up dump (tdund) is of special interest because it also constitutes an issue for machine protection, as it is placed close to radiation sensitive components, like electronic devices and permanent magnets in the undulators. This paper first introduces the stopper of tdund looking at the heat load, and then it describes the shielding around the dump necessary to maintain the prompt and residual dose within design values. Next, preliminary comparisons of the magnetization loss in a dedicated on-site magnet irradiation experiment with FLUKA simulations serve to characterize the magnetic response to radiation of magnets like those of LCLS. The previous knowledge, together with the limit for the allowed demagnetization, are used to estimate the lifetime of the undulator. Further simulations provide guidelines on which lifetime can be expected for an electronic device placed at a given distance of tdund.

  9. Radiation effects in the stainless steel primary coolant supply adapter

    SciTech Connect (OSTI)

    Farrell, K.

    1995-09-01

    The primary coolant supply adapter (PCSA) is a flanged, cylindrical collar of 316NG stainless steel that is part of the primary pressure boundary of the Advanced Neutron Source. The radiation fluxes on the PCSA are dominated by thermal neutrons. During its intended 40-year service life, the PCSA will receive a thermal neutron fluence of 1.8 {times} 10{sup 26} m{sup {minus}2} in its upper sections at a temperature of <1OO{degree}C. The PCSA will suffer radiation damage, caused primarily by the interaction of thermal neutrons with the 14% nickel in the steel, which will generate helium by the sequential reactions {sup 58}Ni (n,y){sup 59}Ni (n,{alpha}){sup 56}Fe and will concurrently produce significant atomic displacements per atom (dpa) from the {sup 59}Ni (n,{alpha}){sup 56}Fe recoils. It is estimated that the helium concentration and total atomic displacements in the upper parts of the PCSA will be about 430 atomic parts per million and 1 dpa, respectively. From newly compiled trend curves of tensile properties and fracture toughness data versus atomic displacements for 316 steel, it is deduced that the irradiated PCSA will retain at least 20% uniform tensile elongation and a fracture toughness of more than 200 Mpa{radical}m, which are judged adequate to resist brittle failure. Tberefore, employment of a neutron shield around the PCSA is unnecessary.

  10. Radiation Damage Studies of Materials and Electronic Devices Using Hadrons

    SciTech Connect (OSTI)

    Pellett, David; Baldwin, Andrew; Gallagher, Garratt; Olson, David; Styczinski, Marshall

    2014-05-14

    We have irradiated NdFeB permanent magnet samples from different manufacturers and with differing values of coercivity and remanence using stepped doses of 1 MeV equivalent neutrons up to a fluence of 0:64 #2; 1015n=cm2 to evaluate effects on magnetization and B field distributions. The samples with high coercivity, irradiated in open circuit configurations, showed no or minimal effects when compared with unirradiated samples, whereas the lower coercivity magnets suffered significant losses of magnetization and changes in the shapes of their field patterns. One such magnet underwent a fractional magnetization loss of 13.1% after a fluence of 0:59 #2; 1015 n=cm2. This demagnetization was not uniform. With increasing fluence, B field scans along the centerlines of the pole faces revealed that the normal component of B decreased more near the midpoint of the scan than near the ends. In addition, a fit to the curve of overall magnetization loss with fluence showed a significant deviation from linearity. The results are discussed in light of other measurements and theory. The high coercivity materials appear suitable for use in accelerator applications subject to irradiation by fast neutrons such as dipoles where the internal demagnetizing field is comparable to or less than that of the open circuit samples tested in this study.

  11. Prospective Study of Local Control and Late Radiation Toxicity After Intraoperative Radiation Therapy Boost for Early Breast Cancer

    SciTech Connect (OSTI)

    Chang, David W.; Marvelde, Luc te; Chua, Boon H.

    2014-01-01

    Purpose: To report the local recurrence rate and late toxicity of intraoperative radiation therapy (IORT) boost to the tumor bed using the Intrabeam System followed by external-beam whole-breast irradiation (WBI) in women with early-stage breast cancer in a prospective single-institution study. Methods and Materials: Women with breast cancer ?3 cm were recruited between February 2003 and May 2005. After breast-conserving surgery, a single dose of 5 Gy IORT boost was delivered using 50-kV x-rays to a depth of 10 mm from the applicator surface. This was followed by WBI to a total dose of 50 Gy in 25 fractions. Patients were reviewed at regular, predefined intervals. Late toxicities were recorded using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring systems. Results: Fifty-five patients completed both IORT boost and external-beam WBI. Median follow-up was 3.3 years (range, 1.4-4.1 years). There was no reported locoregional recurrence or death. One patient developed distant metastases. Grade 2 and 3 subcutaneous fibrosis was detected in 29 (53%) and 8 patients (15%), respectively. Conclusions: The use of IORT as a tumor bed boost using kV x-rays in breast-conserving therapy was associated with good local control but a clinically significant rate of grade 2 and 3 subcutaneous fibrosis.

  12. Near-field thermal radiative transfer and thermoacoustic effects from vapor plumes produced by pulsed CO{sub 2} laser ablation of bulk water

    SciTech Connect (OSTI)

    Kudryashov, S. I.; Lyon, Kevin; Allen, S. D.

    2006-12-15

    Submillimeter deep heating of bulk water by thermal radiation from ablative water plumes produced by a 10.6 {mu}m transversely excited atmospheric CO{sub 2} laser and the related acoustic generation has been studied using a contact time-resolved photoacoustic technique. Effective penetration depths of thermal radiation in water were measured as a function of incident laser fluence and the corresponding plume temperatures were estimated. The near-field thermal and thermoacoustic effects of thermal radiation in laser-ablated bulk water and their potential near-field implications are discussed.

  13. Review of the Current State of Knowledge on the Effects of Radiation on Concrete

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rosseel, Thomas M.; Maruyama, Ippei; Le Pape, Yann; Kontani, Osamu; Giorla, Alain B.; Remec, Igor; Wall, James J.; Sircar, Madhumita; Andrade, Carmen; Ordonez, Manuel

    2016-07-01

    A review of the current state of knowledge on the effects of radiation on concrete in nuclear applications is presented. Emphasis is placed on the effects of radiation damage as reflected by changes in engineering properties of concrete in the evaluation of the long-term operation (LTO) and for Plant Life or Aging Management of nuclear power plants (NPPs) in Japan, Spain, and the United States. National issues and concerns are described for Japan and the US followed by a discussion of the fundamental understanding of the effects radiation on concrete. Specifically, the effects of temperature, moisture content, and irradiation onmore » ordinary Portland cement paste and the role of temperature and neutron energy spectra on radiation induced volumetric expansion (RIVE) of aggregate-forming minerals are described. This is followed by a discussion of the bounding conditions for extended operation, the significance of accelerated irradiation conditions, the role of temperature, creep, and how these issues are being incorporated into numerical and meso-scale models. From these insights on radiation damage, analyses of these effects on concrete structures are reviewed and the current status of work in Japan and the US are described. Also discussed is the recent formation of a new international scientific and technical organization, the International Committee on Irradiated Concrete (ICIC), to provide a forum for timely information exchanges among organizations pursuing the identification, quantification, and modeling of the effects of radiation on concrete in commercial nuclear applications. Lastly, the paper concludes with a discussion of research gaps including: 1) interpreting test-reactor data, 2) evaluating service-irradiated concrete for aging management and to inform radiation damage models with the Zorita NPP (Spain) serving as the first comprehensive test case, 3) irradiated-assisted alkali-silica reactions, and 4) RIVE under constrained conditions.« less

  14. On the effect of a radiation field in modifying the intermolecular interaction between two chiral molecules

    SciTech Connect (OSTI)

    Salam, A.

    2006-01-07

    The change in the mutual energy of interaction between a pair of chiral molecules coupled via the exchange of a single virtual photon and in the presence of an electromagnetic field is calculated using nonrelativistic quantum electrodynamics. The particular viewpoint adopted is one that has an intuitive physical appeal and resembles a classical treatment. It involves the coupling of electric and magnetic dipole moments induced at each center by the incident radiation field to the resonant dipole-dipole interaction tensor. The energy shift is evaluated for fixed as well as random orientations of the molecular pair with respect to the direction of propagation of the field. A complete polarization analysis is carried out for the former situation by examining the effect of incident radiation that is linearly or circularly polarized and traveling in a direction that is parallel or perpendicular to the intermolecular distance vector. After tumble averaging, all polarization dependence of the energy shift vanishes. In both cases the interaction energy is directly proportional to the irradiance of the applied field, and is discriminatory, changing sign when one optically active species is replaced by its enantiomer. The asymptotic behavior of the energy shift at the limits of large and small separations is also studied.

  15. A Study of Longwave Radiation Codes for Climate Studies: Validation with ARM Observations and Tests in General Circulation Models

    SciTech Connect (OSTI)

    Robert G. Ellingson

    2004-09-28

    One specific goal of the Atmospheric Radiation Measurements (ARM) program is to improve the treatment of radiative transfer in General Circulation Models (GCMs) under clear-sky, general overcast and broken cloud conditions. Our project was geared to contribute to this goal by attacking major problems associated with one of the dominant radiation components of the problem --longwave radiation. The primary long-term project objectives were to: (1) develop an optimum longwave radiation model for use in GCMs that has been calibrated with state-of-the-art observations for clear and cloudy conditions, and (2) determine how the longwave radiative forcing with an improved algorithm contributes relatively in a GCM when compared to shortwave radiative forcing, sensible heating, thermal advection and convection. The approach has been to build upon existing models in an iterative, predictive fashion. We focused on comparing calculations from a set of models with operationally observed data for clear, overcast and broken cloud conditions. The differences found through the comparisons and physical insights have been used to develop new models, most of which have been tested with new data. Our initial GCM studies used existing GCMs to study the climate model-radiation sensitivity problem. Although this portion of our initial plans was curtailed midway through the project, we anticipate that the eventual outcome of this approach will provide both a better longwave radiative forcing algorithm and from our better understanding of how longwave radiative forcing influences the model equilibrium climate, how improvements in climate prediction using this algorithm can be achieved.

  16. Radiation-Induced Liver Damage: Correlation of Histopathology with Hepatobiliary Magnetic Resonance Imaging, a Feasibility Study

    SciTech Connect (OSTI)

    Seidensticker, Max; Burak, Miroslaw; Kalinski, Thomas; Garlipp, Benjamin; Koelble, Konrad; Wust, Peter; Antweiler, Kai; Seidensticker, Ricarda; Mohnike, Konrad; Pech, Maciej; Ricke, Jens

    2015-02-15

    PurposeRadiotherapy of liver malignancies shows promising results (radioembolization, stereotactic irradiation, interstitial brachytherapy). Regardless of the route of application, a certain amount of nontumorous liver parenchyma will be collaterally damaged by radiation. The functional reserve may be significantly reduced with an impact on further treatment planning. Monitoring of radiation-induced liver damage by imaging is neither established nor validated. We performed an analysis to correlate the histopathological presence of radiation-induced liver damage with functional magnetic resonance imaging (MRI) utilizing hepatobiliary contrast media (Gd-BOPTA).MethodsPatients undergoing local high-dose-rate brachytherapy for whom a follow-up hepatobiliary MRI within 120 days after radiotherapy as well as an evaluable liver biopsy from radiation-exposed liver tissue within 7 days before MRI were retrospectively identified. Planning computed tomography (CT)/dosimetry was merged to the CT-documentation of the liver biopsy and to the MRI. Presence/absence of radiation-induced liver damage (histopathology) and Gd-BOPTA uptake (MRI) as well as the dose applied during brachytherapy at the site of tissue sampling was determined.ResultsFourteen biopsies from eight patients were evaluated. In all cases with histopathological evidence of radiation-induced liver damage (n = 11), no uptake of Gd-BOPTA was seen. In the remaining three, cases no radiation-induced liver damage but Gd-BOPTA uptake was seen. Presence of radiation-induced liver damage and absence of Gd-BOPTA uptake was correlated with a former high-dose exposition.ConclusionsAbsence of hepatobiliary MRI contrast media uptake in radiation-exposed liver parenchyma may indicate radiation-induced liver damage. Confirmatory studies are warranted.

  17. A morphological study of radiation nephropathy in the pig

    SciTech Connect (OSTI)

    Robbins, M.E.; Wooldridge, M.J.; Jaenke, R.S.; Whitehouse, E.; Golding, S.J.; Rezvani, M.; Hopewell, J.W. )

    1991-06-01

    Both kidneys of mature pigs received a single dose of 9.8 Gy {sup 60}Co gamma rays. Pigs were killed between 2 and 24 weeks after irradiation and the kidneys examined histologically. Glomerular and tubular changes were observed within 2 weeks of irradiation. Neutrophils and other leukocytes were seen within glomerular capillary loops; mesangial matrix and cell number increased. A progressive increase in thickening of the basement membrane and a decrease in capillary lumina were then noted. Basement membrane duplication occurred within 12 weeks. By 24 weeks these lesions had increased in severity, sclerotic endstage glomeruli, predominantly subcapsular or juxtamedullary, being evident. Tubular lesions initially consisted of focal areas of tubular atrophy in the juxtamedullary region. By 6 weeks subcapsular foci of tubular degeneration, regeneration, and necrosis were found; these appeared to resolve 12 weeks after irradiation. At later times the severity of the tubular lesions varied between pigs, with some exhibiting interstitial fibrosis involving a complete band of subcapsular tissue, while others showed relatively mild changes. There was no apparent change in the vasculature. These findings indicate that (a) there is no one target or dose-limiting cell, and (b) the vasculature does not play a primary role in the development of radiation nephropathy.

  18. Cost-Effectiveness Analysis of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Anal Cancer

    SciTech Connect (OSTI)

    Hodges, Joseph C.; Beg, Muhammad S.; Das, Prajnan; Meyer, Jeffrey

    2014-07-15

    Purpose: To compare the cost-effectiveness of intensity modulated radiation therapy (IMRT) and 3-dimensional conformal radiation therapy (3D-CRT) for anal cancer and determine disease, patient, and treatment parameters that influence the result. Methods and Materials: A Markov decision model was designed with the various disease states for the base case of a 65-year-old patient with anal cancer treated with either IMRT or 3D-CRT and concurrent chemotherapy. Health states accounting for rates of local failure, colostomy failure, treatment breaks, patient prognosis, acute and late toxicities, and the utility of toxicities were informed by existing literature and analyzed with deterministic and probabilistic sensitivity analysis. Results: In the base case, mean costs and quality-adjusted life expectancy in years (QALY) for IMRT and 3D-CRT were $32,291 (4.81) and $28,444 (4.78), respectively, resulting in an incremental cost-effectiveness ratio of $128,233/QALY for IMRT compared with 3D-CRT. Probabilistic sensitivity analysis found that IMRT was cost-effective in 22%, 47%, and 65% of iterations at willingness-to-pay thresholds of $50,000, $100,000, and $150,000 per QALY, respectively. Conclusions: In our base model, IMRT was a cost-ineffective strategy despite the reduced acute treatment toxicities and their associated costs of management. The model outcome was sensitive to variations in local and colostomy failure rates, as well as patient-reported utilities relating to acute toxicities.

  19. Types of Radiation Exposure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    External Irradiation Contamination Incorporation Biological Effects of Acute, Total Body Irradiation Managing Radiation Emergencies Procedure Demonstration Types of radiation ...

  20. The role of pyrimidine and water as underlying molecular constituents for describing radiation damage in living tissue: A comparative study

    SciTech Connect (OSTI)

    Fuss, M. C.; Ellis-Gibbings, L.; Jones, D. B.; Brunger, M. J.; Blanco, F.; Muoz, A.; Limo-Vieira, P.; Garca, G.

    2015-06-07

    Water is often used as the medium for characterizing the effects of radiation on living tissue. However, in this study, charged-particle track simulations are employed to quantify the induced physicochemical and potential biological implications when a primary ionising particle with energy 10?keV strikes a medium made up entirely of water or pyrimidine. Note that pyrimidine was chosen as the DNA/RNA bases cytosine, thymine, and uracil can be considered pyrimidine derivatives. This study aims to assess the influence of the choice of medium on the charged-particle transport, and identify how appropriate it is to use water as the default medium to describe the effects of ionising radiation on living tissue. Based on the respective electron interaction cross sections, we provide a model, which allows the study of radiation effects not only in terms of energy deposition (absorbed dose and stopping power) but also in terms of the number of induced molecular processes. Results of these parameters for water and pyrimidine are presented and compared.

  1. Experimental and theoretical study of organometallic radiation-protective materials adapted to radiation sources with a complex isotopic composition

    SciTech Connect (OSTI)

    Russkikh, I. M.; Seleznev, E. N.; Tashlykov, O. L. Shcheklein, S. E.

    2015-12-15

    The significance of optimizing the content of components of a radiation-protective material, which is determined by the isotopic composition of radioactive contamination, depending on the reactor type, operating time, and other factors is demonstrated. The results of computational and experimental investigation of the gamma-radiation attenuation capacity of homogenous radiation-protective materials with different fillers are reported.

  2. The whitehouse effect: shortwave radiative forcing of climate by anthropogenic aerosols

    SciTech Connect (OSTI)

    Schwartz, S.E.

    1994-12-31

    Increases in atmospheric concentrations of carbon dioxide and other infrared active gases over the industrial period are thought to have increased the average flux of longwave (thermal infrared) radiation between the surface of the earth and the lower atmosphere, leading to an increase in global mean temperature. Over the same period it is though that concentrations of aerosol particles in the troposphere have similarly increased as a consequence of industrial emissions and that these increased concentrations of particles have increased the earth`s reflectivity of shortwave (solar) radiation incident on the planet both directly, by scattering radiation, and indirectly, by increasing the reflectivity of clouds. The term ``whitehouse effect`` is introduced to refer to this increased scattering of shortwave radiation by analogy to the term ``greenhouse effect,`` which refers to the enhanced trapping of longwave radiation resulting from increased concentrations of infrared active gases. Each of these phenomena is referred to as a ``forcing`` of the earth`s climate, that is a secular change imposed on the system; such a forcing is to be distinguished from a ``response`` of the system, such as a change in global mean temperature or other index of global climate. The forcing due to the direct and indirect effects induced by anthropogenic aerosols has been estimated to be comparable in global- average magnitude to that due to increased concentrations of greenhouse gases, but it is of opposite direction, that is exerting a cooling influence. The shortwave radiative influence of anthropogenic aerosols may thus be considered to be offsetting some, perhaps a great fraction, of the longwave radiative influence of anthropogenic greenhouse gases.

  3. Bystander effects of ionizing radiation can be modulated by signaling amines

    SciTech Connect (OSTI)

    Poon, R.C.C.; Agnihotri, N.; Seymour, C.; Mothersill, C.

    2007-10-15

    Actual risk and risk management of exposure to ionizing radiation are among the most controversial areas in environmental health protection. Recent developments in radiobiology especially characterization of bystander effects have called into question established dogmas and are thought to cast doubt on the scientific basis of the risk assessment framework, leading to uncertainty for regulators and concern among affected populations. In this paper we test the hypothesis that small signaling molecules widely used throughout the animal kingdom for signaling stress or environmental change, such as 5-Hydroxytryptamine (5-HT, serotonin), L-DOPA, glycine or nicotine are involved in bystander signaling processes following ionizing radiation exposure. We report data which suggest that nano to micromolar concentrations of these agents can modulate bystander-induced cell death. Depletion of 5-HT present in tissue culture medium, occurred following irradiation of cells. This suggested that 5-HT might be bound by membrane receptors after irradiation. Expression of 5-HT type 3 receptors which are Ca{sup 2+} ion channels was confirmed in the cells using immunocytochemistry and receptor expression could be increased using radiation or 5-HT exposure. Zofran and Kitryl, inhibitors of 5-HT type 3 receptors, and reserpine a generic serotonin antagonist block the bystander effect induced by radiation or by serotonin. The results may be important for the mechanistic understanding of how low doses of radiation interact with cells to produce biological effects.

  4. Mechanistic and quantitative studies of bystander response in 3D tissues for low-dose radiation risk estimations

    SciTech Connect (OSTI)

    Amundson, Sally A.

    2013-06-12

    We have used the MatTek 3-dimensional human skin model to study the gene expression response of a 3D model to low and high dose low LET radiation, and to study the radiation bystander effect as a function of distance from the site of irradiation with either alpha particles or low LET protons. We have found response pathways that appear to be specific for low dose exposures, that could not have been predicted from high dose studies. We also report the time and distance dependent expression of a large number of genes in bystander tissue. the bystander response in 3D tissues showed many similarities to that described previously in 2D cultured cells, but also showed some differences.

  5. Inverse Compton Emission from Galactic Supernova Remnants: Effect of the Interstellar Radiation Field

    SciTech Connect (OSTI)

    Porter, Troy A.; Moskalenko, Igor V.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

    2006-08-01

    The evidence for particle acceleration in supernova shells comes from electrons whose synchrotron emission is observed in radio and X-rays. Recent observations by the HESS instrument reveal that supernova remnants also emit TeV {gamma}-rays; long awaited experimental evidence that supernova remnants can accelerate cosmic rays up to the ''knee'' energies. Still, uncertainty exists whether these {gamma}-rays are produced by electrons via inverse Compton scattering or by protons via {pi}{sup 0}-decay. The multi-wavelength spectra of supernova remnants can be fitted with both mechanisms, although a preference is often given to {pi}{sup 0}-decay due to the spectral shape at very high energies. A recent study of the interstellar radiation field indicates that its energy density, especially in the inner Galaxy, is higher than previously thought. In this paper we evaluate the effect of the interstellar radiation field on the inverse Compton emission of electrons accelerated in a supernova remnant located at different distances from the Galactic Centre. We show that contribution of optical and infra-red photons to the inverse Compton emission may exceed the contribution of cosmic microwave background and in some cases broaden the resulted {gamma}-ray spectrum. Additionally, we show that if a supernova remnant is located close to the Galactic Centre its {gamma}-ray spectrum will exhibit a ''universal'' cutoff at very high energies due to the Klein-Nishina effect and not due to the cut-off of the electron spectrum. As an example, we apply our calculations to the supernova remnants RX J1713.7-3946 and G0.9+0.1 recently observed by HESS.

  6. The effects of pulse duration on ablation pressure driven by laser radiation

    SciTech Connect (OSTI)

    Zhou, Lei; Li, Xiao-Ya Zhu, Wen-Jun; Wang, Jia-Xiang; Tang, Chang-Jian

    2015-03-28

    The effects of laser pulse duration on the ablation pressure induced by laser radiation are investigated using Al target. Numerical simulation results using one dimensional radiation hydro code for laser intensities from 5×10{sup 12}W/cm{sup 2} to 5×10{sup 13}W/cm{sup 2} and pulse durations from 0.5 ns to 20 ns are presented. These results suggest that the laser intensity scaling law of ablation pressure differs for different pulse durations. And the theoretical analysis shows that the effects of laser pulse duration on ablation pressure are mainly caused by two regimes: the unsteady-state flow and the radiative energy loss to vacuum.

  7. CONVERGENCE STUDIES OF MASS TRANSPORT IN DISKS WITH GRAVITATIONAL INSTABILITIES. II. THE RADIATIVE COOLING CASE

    SciTech Connect (OSTI)

    Steiman-Cameron, Thomas Y.; Durisen, Richard H.; Michael, Scott; McConnell, Caitlin R.; Boley, Aaron C. E-mail: durisen@astro.indiana.edu E-mail: carmccon@indiana.edu

    2013-05-10

    We conduct a convergence study of a protoplanetary disk subject to gravitational instabilities (GIs) at a time of approximate balance between heating produced by the GIs and radiative cooling governed by realistic dust opacities. We examine cooling times, characterize GI-driven spiral waves and their resultant gravitational torques, and evaluate how accurately mass transport can be represented by an {alpha}-disk formulation. Four simulations, identical except for azimuthal resolution, are conducted with a grid-based three-dimensional hydrodynamics code. There are two regions in which behaviors differ as resolution increases. The inner region, which contains 75% of the disk mass and is optically thick, has long cooling times and is well converged in terms of various measures of structure and mass transport for the three highest resolutions. The longest cooling times coincide with radii where the Toomre Q has its minimum value. Torques are dominated in this region by two- and three-armed spirals. The effective {alpha} arising from gravitational stresses is typically a few Multiplication-Sign 10{sup -3} and is only roughly consistent with local balance of heating and cooling when time-averaged over many dynamic times and a wide range of radii. On the other hand, the outer disk region, which is mostly optically thin, has relatively short cooling times and does not show convergence as resolution increases. Treatment of unstable disks with optical depths near unity with realistic radiative transport is a difficult numerical problem requiring further study. We discuss possible implications of our results for numerical convergence of fragmentation criteria in disk simulations.

  8. Modeling of transient ionizing radiation effects in bipolar devices at high dose-rates

    SciTech Connect (OSTI)

    FJELDLY,T.A.; DENG,Y.; SHUR,M.S.; HJALMARSON,HAROLD P.; MUYSHONDT,ARNOLDO

    2000-04-25

    To optimally design circuits for operation at high intensities of ionizing radiation, and to accurately predict their a behavior under radiation, precise device models are needed that include both stationary and dynamic effects of such radiation. Depending on the type and intensity of the ionizing radiation, different degradation mechanisms, such as photoelectric effect, total dose effect, or single even upset might be dominant. In this paper, the authors consider the photoelectric effect associated with the generation of electron-hole pairs in the semiconductor. The effects of low radiation intensity on p-II diodes and bipolar junction transistors (BJTs) were described by low-injection theory in the classical paper by Wirth and Rogers. However, in BJTs compatible with modem integrated circuit technology, high-resistivity regions are often used to enhance device performance, either as a substrate or as an epitaxial layer such as the low-doped n-type collector region of the device. Using low-injection theory, the transient response of epitaxial BJTs was discussed by Florian et al., who mainly concentrated on the effects of the Hi-Lo (high doping - low doping) epilayer/substrate junction of the collector, and on geometrical effects of realistic devices. For devices with highly resistive regions, the assumption of low-level injection is often inappropriate, even at moderate radiation intensities, and a more complete theory for high-injection levels was needed. In the dynamic photocurrent model by Enlow and Alexander. p-n junctions exposed to high-intensity radiation were considered. In their work, the variation of the minority carrier lifetime with excess carrier density, and the effects of the ohmic electric field in the quasi-neutral (q-n) regions were included in a simplified manner. Later, Wunsch and Axness presented a more comprehensive model for the transient radiation response of p-n and p-i-n diode geometries. A stationary model for high-level injection in p

  9. Studies Of Coherent Synchrotron Radiation And Longitudinal Space Charge In The Jefferson Lab FEL Driver

    SciTech Connect (OSTI)

    Tennant, Christopher D.; Douglas, David R.; Li, Rui; Tsai, C.-Y.

    2014-12-01

    The Jefferson Laboratory IR FEL Driver provides an ideal test bed for studying a variety of beam dynamical effects. Recent studies focused on characterizing the impact of coherent synchrotron radiation (CSR) with the goal of benchmarking measurements with simulation. Following measurements to characterize the beam, we quantitatively characterized energy extraction via CSR by measuring beam position at a dispersed location as a function of bunch compression. In addition to operating with the beam on the rising part of the linac RF waveform, measurements were also made while accelerating on the falling part. For each, the full compression point was moved along the backleg of the machine and the response of the beam (distribution, extracted energy) measured. Initial results of start-to-end simulations using a 1D CSR algorithm show remarkably good agreement with measurements. A subsequent experiment established lasing with the beam accelerated on the falling side of the RF waveform in conjunction with positive momentum compaction (R56) to compress the bunch. The success of this experiment motivated the design of a modified CEBAF-style arc with control of CSR and microbunching effects.

  10. Human radiation studies: Remembering the early years. Oral history of biophysicist Cornelius A. Tobias, Ph.D., January 16, 1995

    SciTech Connect (OSTI)

    1995-07-01

    Dr. Cornelius A. Tobias was interviewed by representatives of US DOE Office of Human Radiation Experiments (OHRE). He was chosen for this interview because of his extensive biophysics and medical physics research activities while he was employed by the University of California, Berkeley and San Francisco and at the Donner Laboratory. He discusses his involvement in wartime studies of effects of high altitude on aviators, carbon monoxide with radioactive tracers, blood studies with radioactive iron, human use committees, heavy-ion research with the Bevatron, boron isotope research, classified research involving human subjects, heavy-particle radiography, heavy- particle beams and medical research, and pituitary irradiation studies,.

  11. Out of band radiation effects on resist patterning

    SciTech Connect (OSTI)

    George, Simi A .; Naulleau, Patrick P.

    2011-03-11

    Our previous work estimated the expected out-of-band (OOB) flare contribution at the wafer level assuming that there is a given amount of OOB at the collector focus. We found that the OOB effects are wavelength, resist, and pattern dependent. In this paper, results from rigorous patterning evaluation of multiple OOB-exposed resists using the SEMATECH Berkeley 0.3-NA MET are presented. A controlled amount of OOB is applied to the resist films before patterning is completed with the MET. LER and process performance above the resolution limit and at the resolution limits are evaluated and presented. The results typically show a negative impact on LER and process performance after the OOB exposures except in the case of single resist formulation, where resolution and performance improvement was observed.

  12. Radiation Damage/Materials Modification

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    radiation damage materials modification Radiation Damage/Materials Modification High-energy ion irradiation is an important tool for studying radiation damage effects Materials in a nuclear reactor are exposed to extreme temperature and radiation conditions that degrade their physical properties to the point of failure. For example, alpha-decay in nuclear fuels results in dislocation damage to and accumulation of helium and fission gasses in the material. Similarly, neutrons interacting with

  13. Quantifying the Combined Effect of Radiation Therapy and Hyperthermia in Terms of Equivalent Dose Distributions

    SciTech Connect (OSTI)

    Kok, H. Petra; Crezee, Johannes; Franken, Nicolaas A.P.; Barendsen, Gerrit W.

    2014-03-01

    Purpose: To develop a method to quantify the therapeutic effect of radiosensitization by hyperthermia; to this end, a numerical method was proposed to convert radiation therapy dose distributions with hyperthermia to equivalent dose distributions without hyperthermia. Methods and Materials: Clinical intensity modulated radiation therapy plans were created for 15 prostate cancer cases. To simulate a clinically relevant heterogeneous temperature distribution, hyperthermia treatment planning was performed for heating with the AMC-8 system. The temperature-dependent parameters α (Gy{sup −1}) and β (Gy{sup −2}) of the linear–quadratic model for prostate cancer were estimated from the literature. No thermal enhancement was assumed for normal tissue. The intensity modulated radiation therapy plans and temperature distributions were exported to our in-house-developed radiation therapy treatment planning system, APlan, and equivalent dose distributions without hyperthermia were calculated voxel by voxel using the linear–quadratic model. Results: The planned average tumor temperatures T90, T50, and T10 in the planning target volume were 40.5°C, 41.6°C, and 42.4°C, respectively. The planned minimum, mean, and maximum radiation therapy doses were 62.9 Gy, 76.0 Gy, and 81.0 Gy, respectively. Adding hyperthermia yielded an equivalent dose distribution with an extended 95% isodose level. The equivalent minimum, mean, and maximum doses reflecting the radiosensitization by hyperthermia were 70.3 Gy, 86.3 Gy, and 93.6 Gy, respectively, for a linear increase of α with temperature. This can be considered similar to a dose escalation with a substantial increase in tumor control probability for high-risk prostate carcinoma. Conclusion: A model to quantify the effect of combined radiation therapy and hyperthermia in terms of equivalent dose distributions was presented. This model is particularly instructive to estimate the potential effects of interaction from different

  14. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    SciTech Connect (OSTI)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³⁷Cs at 0.13, 2.4, 21, and 222 mGy d⁻¹, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d⁻¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  15. Medical Malpractice Claims in Radiation Oncology: A Population-Based Study 1985-2012

    SciTech Connect (OSTI)

    Marshall, Deborah C.; Punglia, Rinaa S.; Fox, Dov; Recht, Abram; Hattangadi-Gluth, Jona A.

    2015-10-01

    Purpose: The purpose of this study was to determine trends in radiation oncology malpractice claims and expenses during the last 28 years and to compare radiation oncology malpractice claims to those of other specialties. Methods and Materials: We performed a retrospective analysis of closed malpractice claims filed from 1985 to 2012, collected by a nationwide medical liability insurance trade association. We analyzed characteristics and trends among closed claims, indemnity payments (payments to plaintiff), and litigation expenses. We also compared radiation oncology malpractice claims to those of 21 other medical specialties. Time series dollar amounts were adjusted for inflation (2012 was the index year). Results: There were 1517 closed claims involving radiation oncology, of which 342 (22.5%) were paid. Average and median indemnity payments were $276,792 and $122,500, respectively, ranking fifth and eighth, respectively, among the 22 specialty groups. Linear regression modeling of time trends showed decreasing total numbers of claims (β = −1.96 annually, P=.003), increasing average litigation expenses paid (β = +$1472 annually, P≤.001), and no significant changes in average indemnity payments (β = −$681, P=.89). Conclusions: Medical professional liability claims filed against radiation oncologists are not common and have declined in recent years. However, indemnity payments in radiation oncology are large relative to those of many other specialties. In recent years, the average indemnity payment has been stable, whereas litigation expenses have increased.

  16. Radiation Damage Study in Natural Zircon Using Neutrons Irradiation

    SciTech Connect (OSTI)

    Lwin, Maung Tin Moe; Amin, Yusoff Mohd.; Kassim, Hasan Abu; Mohamed, Abdul Aziz; Karim, Julia Abdul

    2011-03-30

    Changes of atomic displacements in crystalline structure of natural zircon (ZrSiO{sub 4}) can be studied by using neutron irradiation on the surface of zircon and compared the data from XRD measurements before and after irradiation. The results of neutron irradiation on natural zircon using Pneumatic Transfer System (PTS) at PUSPATI TRIGA Research Reactor in the Malaysian Nuclear Agency are discussed in this work. The reactor produces maximum thermal power output of 1 MWatt and the neutron flux of up to 1x10{sup 13} ncm{sup -2}s{sup -1}. From serial decay processes of uranium and thorium radionuclides in zircon crystalline structure, the emission of alpha particles can produce damage in terms of atomic displacements in zircon. Hence, zircon has been extensively studied as a possible candidate for immobilization of fission products and actinides.

  17. Effect of electromagnetic pulse transverse inhomogeneity on ion acceleration by radiation pressure

    SciTech Connect (OSTI)

    Lezhnin, K. V.; Kamenets, F. F.; Beskin, V. S.; Kando, M.; Esirkepov, T. Zh.; Bulanov, S. V.

    2015-03-15

    During ion acceleration by radiation pressure, a transverse inhomogeneity of an electromagnetic pulse leads to an off-axis displacement of the irradiated target, limiting the achievable ion energy. This effect is analytically described within the framework of a thin foil target model and with particle-in-cell simulations showing that the maximum energy of the accelerated ions decreases as the displacement from the axis of the target's initial position increases. The results obtained can be applied to the optimization of ion acceleration by the laser radiation pressure with mass-limited targets.

  18. Effect of prophylactic hyperbaric oxygen treatment for radiation-induced brain injury after stereotactic radiosurgery of brain metastases

    SciTech Connect (OSTI)

    Ohguri, Takayuki . E-mail: ogurieye@med.uoeh-u.ac.jp; Imada, Hajime; Kohshi, Kiyotaka; Kakeda, Shingo; Ohnari, Norihiro; Morioka, Tomoaki; Nakano, Keita; Konda, Nobuhide; Korogi, Yukunori

    2007-01-01

    Purpose: The purpose of the present study was to evaluate the prophylactic effect of hyperbaric oxygen (HBO) therapy for radiation-induced brain injury in patients with brain metastasis treated with stereotactic radiosurgery (SRS). Methods and Materials: The data of 78 patients presenting with 101 brain metastases treated with SRS between October 1994 and September 2003 were retrospectively analyzed. A total of 32 patients with 47 brain metastases were treated with prophylactic HBO (HBO group), which included all 21 patients who underwent subsequent or prior radiotherapy and 11 patients with common predictors of longer survival, such as inactive extracranial tumors and younger age. The other 46 patients with 54 brain metastases did not undergo HBO (non-HBO group). Radiation-induced brain injuries were divided into two categories, white matter injury (WMI) and radiation necrosis (RN), on the basis of imaging findings. Results: Radiation-induced brain injury occurred in 5 lesions (11%) in the HBO group (2 WMIs and 3 RNs) and in 11 (20%) in the non-HBO group (9 WMIs and 2 RNs). The WMI was less frequent for the HBO group than for the non-HBO group (p = 0.05), although multivariate analysis by logistic regression showed that WMI was not significantly correlated with HBO (p = 0.07). The 1-year actuarial probability of WMI was significantly better for the HBO group (2%) than for the non-HBO group (36%) (p < 0.05). Conclusions: The present study showed a potential value of prophylactic HBO for Radiation-induced WMIs, which justifies further evaluation to confirm its definite benefit.

  19. JLab, College of W&M researchers study radiation blockers while conducting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nuclear imaging of Iodine uptake in mouse tissues | Jefferson Lab JLab, College of W&amp;M researchers study radiation blockers while conducting nuclear imaging of Iodine uptake in mouse tissues JLab, College of W&M researchers study radiation blockers while conducting nuclear imaging of Iodine uptake in mouse tissues April 20, 2005 Scientists have found that a dose five times higher than the FDA-recommended dosage of potassium iodide in the event of a nuclear accident is needed to

  20. Non-radiative carrier recombination enhanced by two-level process: A first-principles study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Ji -Hui; Shi, Lin; Wang, Lin -Wang; Wei, Su -Huai

    2016-02-16

    In this study, non-radiative recombination plays an important role in the performance of optoelectronic semiconductor devices such as solar cells and light-emitting diodes. Most textbook examples assume that the recombination process occurs through a single defect level, where one electron and one hole are captured and recombined. Based on this simple picture, conventional wisdom is that only defect levels near the center of the bandgap can be effective recombination centers. Here, we present a new two-level recombination mechanism: first, one type of carrier is captured through a defect level forming a metastable state; then the local defect configuration rapidly changesmore » to a stable state, where the other type of carrier is captured and recombined through another defect level. This novel mechanism is applied to the recombination center Te2+cd in CdTe. We show that this two-level process can significantly increase the recombination rate (by three orders of magnitude) in agreement with experiments. We expect that this two-level recombination process can exist in a wide range of semiconductors, so its effect should be carefully examined in characterizing optoelectronic materials.« less

  1. A Study of Electromagnetic Radiation of Corona Discharge Near 500-Kv Electric Installations

    SciTech Connect (OSTI)

    Korzhov, A. V.; Okrainskaya, I. S.; Sidorov, A. I.; Kufel'd, V. D.

    2004-01-15

    Data on the spectral composition and intensity of electromagnetic radiation of corona discharge are obtained in an experimental study performed on the outdoor switchgear of the Shagol 500-kV substation of the Chelyabinsk Enterprise of Trunk Transmission Grids and under a 500-kV Shagol - Kozyrevo overhead transmission line. The electromagnetic environment on the territory of the 500-kV outdoor switchgear is shown to be determined by narrow-band radiations (harmonics of the frequency of electric supply) and wide-band radiations due to corona discharges of high-voltage sources. This means that the personnel experience the action of a commercial-frequency electric field and electromagnetic radiation of a quite wide range, which is not allowed for by the existing guidelines. It is recommended to continue the study in cooperation with medical institutions in order to create guidelines that would allow for the joint action of commercial-frequency electric field and electromagnetic radiation and for the voltage in the line, the current load, the meteorological situation, and other factors.

  2. Radiation effects on the electrical properties of hafnium oxide based MOS capacitors.

    SciTech Connect (OSTI)

    Petrosky, J. C.; McClory, J. W.; Bielejec, Edward Salvador; Foster, J. C.

    2010-10-01

    Hafnium oxide-based MOS capacitors were investigated to determine electrical property response to radiation environments. In situ capacitance versus voltage measurements were analyzed to identify voltage shifting as a result of changes to trapped charge with increasing dose of gamma, neutron, and ion radiation. In situ measurements required investigation and optimization of capacitor fabrication to include dicing, cleaning, metalization, packaging, and wire bonding. A top metal contact of 200 angstroms of titanium followed by 2800 angstroms of gold allowed for repeatable wire bonding and proper electrical response. Gamma and ion irradiations of atomic layer deposited hafnium oxide on silicon devices both resulted in a midgap voltage shift of no more than 0.2 V toward less positive voltages. This shift indicates recombination of radiation induced positive charge with negative trapped charge in the bulk oxide. Silicon ion irradiation caused interface effects in addition to oxide trap effects that resulted in a flatband voltage shift of approximately 0.6 V also toward less positive voltages. Additionally, no bias dependent voltage shifts with gamma irradiation and strong oxide capacitance room temperature annealing after ion irradiation was observed. These characteristics, in addition to the small voltage shifts observed, demonstrate the radiation hardness of hafnium oxide and its applicability for use in space systems.

  3. Study of Synchrotron Radiation for the Electron Beam Polarimeter for the MEIC

    SciTech Connect (OSTI)

    Sullivan, M.

    2015-08-06

    This is a look at the synchrotron radiation coming from the chicane in the electron beam line for the MEIC design. The power density on the beam pipe as well as transmission through the beam pipe is studied. The optics design is version 12.

  4. System level latchup mitigation for single event and transient radiation effects on electronics

    DOE Patents [OSTI]

    Kimbrough, J.R.; Colella, N.J.

    1997-09-30

    A ``blink`` technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements. 18 figs.

  5. System level latchup mitigation for single event and transient radiation effects on electronics

    DOE Patents [OSTI]

    Kimbrough, Joseph Robert; Colella, Nicholas John

    1997-01-01

    A "blink" technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements.

  6. Comparative study of microwave radiation-induced magnetoresistive oscillations induced by circularly- and linearly- polarized photo-excitation

    SciTech Connect (OSTI)

    Ye, Tianyu; Liu, Han -Chun; Wang, Zhuo; Wegscheider, W.; Mani, Ramesh G.

    2015-10-09

    A comparative study of the radiation-induced magnetoresistance oscillations in the high mobility GaAs/AlGaAs heterostructure two dimensional electron system (2DES) under linearly- and circularly- polarized microwave excitation indicates a profound difference in the response observed upon rotating the microwave launcher for the two cases, although circularly polarized microwave radiation induced magnetoresistance oscillations observed at low magnetic fields are similar to the oscillations observed with linearly polarized radiation. For the linearly polarized radiation, the magnetoresistive response is a strong sinusoidal function of the launcher rotation (or linear polarization) angle, θ. As a result, for circularly polarized radiation, the oscillatory magnetoresistive response is hardly sensitive to θ.

  7. Identification and Characterization of Soluble Factors Involved in Delayed Effects of Low Dose Radiation. Final report

    SciTech Connect (OSTI)

    Baulch, Janet

    2013-09-11

    This is a 'glue grant' that was part of a DOE Low Dose project entitled 'Identification and Characterization of Soluble Factors Involved in Delayed Effects of Low Dose Radiation'. This collaborative program has involved Drs. David L. Springer from Pacific Northwest National Laboratory (PNNL), John H. Miller from Washington State University, Tri-cities (WSU) and William F. Morgan then from the University of Maryland, Baltimore (UMB). In July 2008, Dr. Morgan moved to PNNL and Dr. Janet E. Baulch became PI for this project at University of Maryland. In November of 2008, a one year extension with no new funds was requested to complete the proteomic analyses. The project stemmed from studies in the Morgan laboratory demonstrating that genomically unstable cells secret a soluble factor or factors into the culture medium, that cause cytogenetic aberrations and apoptosis in normal parental GM10115 cells. The purpose of this project was to identify the death inducing effect (DIE) factor or factors, estimate their relative abundance, identify the cell signaling pathways involved and finally recapitulate DIE in normal cells by exogenous manipulation of putative DIE factors in culture medium. As reported in detail in the previous progress report, analysis of culture medium from the parental cell line, and stable and unstable clones demonstrated inconsistent proteomic profiles as relate to candidate DIE factors. While the proposed proteomic analyses did not provide information that would allow DIE factors to be identified, the analyses provided another important set of observations. Proteomic analysis suggested that proteins associated with the cellular response to oxidative stress and mitochondrial function were elevated in the medium from unstable clones in a manner consistent with mitochondrial dysfunction. These findings correlate with previous studies of these clones that demonstrated functional differences between the mitochondria of stable and unstable clones. These

  8. Dose reconstruction for the Urals population. Joint Coordinating Committee on Radiation Effects Research, Project 1.1 -- Final report

    SciTech Connect (OSTI)

    Degteva, M.O.; Drozhko, E.; Anspaugh, L.R.; Napier, B.A.; Bouville, A.C.; Miller, C.W.

    1996-02-01

    This work is being carried out as a feasibility study to determine if a long-term course of work can be implemented to assess the long-term risks of radiation exposure delivered at low to moderate dose rates to the populations living in the vicinity of the Mayak Industrial Association (MIA). This work was authorized and conducted under the auspices of the US-Russian Joint Coordinating Committee on Radiation Effects Research (JCCRER) and its Executive Committee (EC). The MIA was the first Russian site for the production and separation of plutonium. This plant began operation in 1948, and during its early days there were technological failures that resulted in the release of large amounts of waste into the rather small Techa River. There were also gaseous releases of radioiodines and other radionuclides during the early days of operation. In addition, there was an accidental explosion in a waste storage tank in 1957 that resulted in a significant release. The Techa River Cohort has been studied for several years by scientists from the Urals Research Centre for Radiation Medicine and an increase in both leukemia and solid tumors has been noted.

  9. Edge effects in propagation of terahertz radiation in subwavelength periodic structures

    SciTech Connect (OSTI)

    Gelmont, B. Parthasarathy, R.; Globus, T.

    2008-08-15

    Improving detection sensitivity of biological molecules with low absorption characteristics in the terahertz gap still remains an important issue in terahertz vibrational resonance spectroscopy. One possible way to increase coupling of incident terahertz radiation to molecules is to exploit local enhancement of electromagnetic field in periodic slot arrays. In this work, we show that periodic arrays of rectangular slots with subwavelength widths provide for local electromagnetic field enhancements due to edge effects in our low frequency range of interest, 10-25 cm{sup -1}. Periodic structures of Au doped Si and InSb were studied. The half power enhancement width is {approx}500 nm or less around the slot, edges in all cases, thereby possibly bringing terahertz sensing to the nanoscale. InSb is confirmed to offer the highest results with local power enhancements on the order of 1100 at frequency 14 cm{sup -1}. InSb and Si have large skin depths in our frequency range of interest and so the analysis of their structures was done through the Fourier expansion method of field diffracted from gratings. Surface impedance boundary conditions were employed to model the Au structure. The applications possibly include development of novel biosensors, and monitoring biophysical processes such as DNA denaturation.

  10. Radiation Effects Facility / Cyclotron Institute / Texas A&M University

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Important note about entry to the Cyclotron Building. Welcome to the Radiation Effects Facility at The Cyclotron Institute located on the campus of Texas A&M University in College Station, Texas. Available for commercial, governmental and educational use, the testing facility is installed on a dedicated beam line with complete diagnostic equipment and controls. With the modern K500 superconducting cyclotron and the advanced ECR ion source, a diverse range of particle beams and energies are

  11. Estimating Three-Dimensional Cloudy Radiative Transfer Effects from Time-Height Cross Sections

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Estimating Three-Dimensional Cloudy Radiative Transfer Effects from Time-Height Cross Sections C. Hannay and R. Pincus National Oceanic and Atmospheric Administration Climate Diagnostics Center Boulder, Colorado K. F. Evans Program in Atmospheric and Oceanic Sciences University of Colorado Boulder, Colorado Introduction Clouds in the atmosphere are finite in extent and variable in every direction and in time. Long data sets from ground-based profilers, such as lidars or cloud radars, could

  12. Effect of focal geometry on radiation from atomic ionization in an ultrastrong and ultrafast laser field

    SciTech Connect (OSTI)

    Ghebregziabher, Isaac; Walker, Barry C.

    2007-08-15

    We use a tunneling-Monte Carlo model to calculate the dynamics and emitted Larmor radiation from electrons ionized in an ultrashort and ultrastrong pulsed laser focus over the intensity range from 10{sup 17} to 10{sup 20} W/cm{sup 2}. We find the spatial variation of a laser field affects the radiation and can no longer be neglected at laser intensities leading to relativistic effects. We identify three regimes for the interaction as a function of the ratio of the single cycle quiver amplitude of the photoelectron to the laser focus waist. Adopting a one-dimensional or plane wave approximation when the laser driven excursion of the photoelectron exceeds the focus waist overestimates the total radiated energy by as much as an order of magnitude. Despite this, the spectral amplitude of the highest-energy photons from ionization in a laser focus is comparable to the plane wave case for excursions up to the beam waist since the laser focus imparts an extra boost of speed for electrons exiting the focus. Full spatial and temporal integration that includes the ionization of charge states before the peak of the pulse do not differ significantly from results that include only the radiation from ionization of the charge state at the peak of the laser field.

  13. Effects of radiative heat transfer on the turbulence structure in inert and reacting mixing layers

    SciTech Connect (OSTI)

    Ghosh, Somnath; Friedrich, Rainer

    2015-05-15

    We use large-eddy simulation to study the interaction between turbulence and radiative heat transfer in low-speed inert and reacting plane temporal mixing layers. An explicit filtering scheme based on approximate deconvolution is applied to treat the closure problem arising from quadratic nonlinearities of the filtered transport equations. In the reacting case, the working fluid is a mixture of ideal gases where the low-speed stream consists of hydrogen and nitrogen and the high-speed stream consists of oxygen and nitrogen. Both streams are premixed in a way that the free-stream densities are the same and the stoichiometric mixture fraction is 0.3. The filtered heat release term is modelled using equilibrium chemistry. In the inert case, the low-speed stream consists of nitrogen at a temperature of 1000 K and the highspeed stream is pure water vapour of 2000 K, when radiation is turned off. Simulations assuming the gas mixtures as gray gases with artificially increased Planck mean absorption coefficients are performed in which the large-eddy simulation code and the radiation code PRISSMA are fully coupled. In both cases, radiative heat transfer is found to clearly affect fluctuations of thermodynamic variables, Reynolds stresses, and Reynolds stress budget terms like pressure-strain correlations. Source terms in the transport equation for the variance of temperature are used to explain the decrease of this variance in the reacting case and its increase in the inert case.

  14. Public meetings on radiation and its health effects caused by the Fukushima nuclear accident

    SciTech Connect (OSTI)

    Sugiyama, K.; Ayame, J.; Takashita, H.; Yamamoto, R.

    2013-07-01

    The Japan Atomic Energy Agency (JAEA) has held public meetings on radiation and its health effects mainly for parents of students in kindergartens, elementary schools, and junior high schools in Fukushima and Ibaraki prefectures after the Fukushima nuclear accident. These meetings are held based on our experience of practicing risk communication activities for a decade in JAEA with local residents. By analyzing questionnaires collected after the meetings, we confirmed that interactive communication is effective in increasing participants' understanding and in decreasing their anxiety. Most of the participants answered that they understood the contents and that it eased their mind. (authors)

  15. Differences in Brainstem Fiber Tract Response to Radiation: A Longitudinal Diffusion Tensor Imaging Study

    SciTech Connect (OSTI)

    Uh, Jinsoo; Merchant, Thomas E.; Li, Yimei; Feng, Tianshu; Gajjar, Amar; Ogg, Robert J.; Hua, Chiaho

    2013-06-01

    Purpose: To determine whether radiation-induced changes in white matter tracts are uniform across the brainstem. Methods and Materials: We analyzed serial diffusion tensor imaging data, acquired before radiation therapy and over 48 to 72 months of follow-up, from 42 pediatric patients (age 6-20 years) with medulloblastoma. FSL software (FMRIB, Oxford, UK) was used to calculate fractional anisotropy (FA) and axial, radial, and mean diffusivities. For a consistent identification of volumes of interest (VOIs), the parametric maps of each patient were transformed to a standard brain space (MNI152), on which we identified VOIs including corticospinal tract (CST), medial lemniscus (ML), transverse pontine fiber (TPF), and middle cerebellar peduncle (MCP) at the level of pons. Temporal changes of DTI parameters in VOIs were compared using a linear mixed effect model. Results: Radiation-induced white matter injury was marked by a decline in FA after treatment. The decline was often accompanied by decreased axial diffusivity, increased radial diffusivity, or both. This implied axonal damage and demyelination. We observed that the magnitude of the changes was not always uniform across substructures of the brainstem. Specifically, the changes in DTI parameters for TPF were more pronounced than in other regions (P<.001 for FA) despite similarities in the distribution of dose. We did not find a significant difference among CST, ML, and MCP in these patients (P>.093 for all parameters). Conclusions: Changes in the structural integrity of white matter tracts, assessed by DTI, were not uniform across the brainstem after radiation therapy. These results support a role for tract-based assessment in radiation treatment planning and determination of brainstem tolerance.

  16. Search for: "atmospheric radiation measurement" | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    ... Atmospheric Radiation Measurement (ARM) Data from Shouxian, China for the Study of Aerosol Indirect Effects in China In a complex ARM Mobile Facility (AMF) deployment, monitoring ...

  17. Study of runaway electrons using dosimetry of hard x-ray radiations in Damavand tokamak

    SciTech Connect (OSTI)

    Rasouli, C.; Pourshahab, B.; Rasouli, H.; Hosseini Pooya, S. M.; Orouji, T.

    2014-05-15

    In this work several studies have been conducted on hard x-ray emissions of Damavand tokamak based on radiation dosimetry using the Thermoluminescence method. The goal was to understand interactions of runaway electrons with plasma particles, vessel wall, and plasma facing components. Total of 354 GR-200 (LiF:Mg,Cu,P) thermoluminescence dosimeter (TLD) crystals have been placed on 118 points – three TLDs per point – to map hard x-ray radiation doses on the exterior of the vacuum vessel. Results show two distinctive levels of x-ray radiations doses on the exterior of the vessel. The low-dose area on which measured dose is about 0.5 mSv/shot. In the low-dose area there is no particular component inside the vessel. On the contrary, on high-dose area of the vessel, x-ray radiations dose exceeds 30 mSv/shot. The high-dose area coincides with the position of limiters, magnetic probe ducts, and vacuum vessel intersections. Among the high-dose areas, the highest level of dose is measured in the position of the limiter, which could be due to its direct contact with the plasma column and with runaway electrons. Direct collisions of runaway electrons with the vessel wall and plasma facing components make a major contribution for production of hard x-ray photons in Damavand tokamak.

  18. Review of Department of Energy research on human health effects of low doses of ionizing radiation

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    The Department of Energy research program on the human health effects of low-dose ionizing radiation consists of 16 projects conducted under the sponsorship of the Human Health and Assessments Division of the Office of Health and Environmental Research. Each of these projects was reviewed by the Committee with the project's principal investigators and associated scientific personnel and with the DOE staff and the associate directors of the national laboratories where appropriate. The principal objectives of this research program include the determination of the risks from exposure to external radiation and from internally deposited radionuclides and the use of this information in the development of standards to protect the health of nuclear workers at DOE and related facilities and of the population at large. 5 figs., 5 tabs.

  19. Effects of Pharmacological Inhibition and Genetic Deficiency of Plasminogen Activator Inhibitor-1 in Radiation-Induced Intestinal Injury

    SciTech Connect (OSTI)

    Abderrahmani, Rym; Francois, Agnes; Buard, Valerie; Benderitter, Marc; Sabourin, Jean-Christophe; Crandall, David L.; Milliat, Fabien

    2009-07-01

    Purpose: To investigate effects of plasminogen activator inhibitor 1 (PAI-1) genetic deficiency and pharmacological PAI-1 inhibition with PAI-039 in a mouse model of radiation-induced enteropathy. Methods and Materials: Wild-type (Wt) and PAI-1{sup -/-} knockout mice received a single dose of 19 Gy to an exteriorized localized intestinal segment. Sham and irradiated Wt mice were treated orally with 1 mg/g of PAI-039. Histological modifications were quantified using a radiation injury score. Moreover, intestinal gene expression was monitored by real-time PCR. Results: At 3 days after irradiation, PAI-039 abolished the radiation-induced increase in the plasma active form of PAI-1 and limited the radiation-induced gene expression of transforming growth factor {beta}1 (TGF-{beta}1), CTGF, PAI-1, and COL1A2. Moreover, PAI-039 conferred temporary protection against early lethality. PAI-039 treatment limited the radiation-induced increase of CTGF and PAI-1 at 2 weeks after irradiation but had no effect at 6 weeks. Radiation injuries were less severe in PAI-1{sup -/-} mice than in Wt mice, and despite the beneficial effect, 3 days after irradiation, PAI-039 had no effects on microscopic radiation injuries compared to untreated Wt mice. Conclusions: A genetic deficiency of PAI-1 is associated with amelioration of late radiation enteropathy. Pharmacological inhibition of PAI-1 by PAI-039 positively impacts the early, acute phase increase in plasma PAI-1 and the associated radiation-induced gene expression of inflammatory/extracellular matrix proteins. Since PAI-039 has been shown to inhibit the active form of PAI-1, as opposed to the complete loss of PAI-1 in the knockout animals, these data suggest that a PAI-1 inhibitor could be beneficial in treating radiation-induced tissue injury in acute settings where PAI-1 is elevated.

  20. The Effect of Gas Absorption on the Scattered Radiation in the...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Gas Absorption on the Scattered Radiation in the Solar Almucantar: Results of Numerical ... albedo) from diffuse and direct radiation measured in the solar almucantar has ...

  1. Effects of chronic gamma radiation on seed production in an oak...

    Office of Scientific and Technical Information (OSTI)

    of radiation, but were sporadic in appearance. It more is suggested that many of the radiation damaged acorns abscised from the tree and thus escaped detection. (auth) less...

  2. Radiation-induced DNA damage and the relative biological effectiveness of 18F-FDG in wild-type mice

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Taylor, Kristina; Lemon, Jennifer A.; Boreham, Douglas R.

    2014-05-28

    Clinically, the most commonly used positron emission tomography (PET) radiotracer is the glucose analog 2-[18F] fluoro-2-deoxy-d-glucose (18F-FDG), however little research has been conducted on the biological effects of 18F-FDG injections. The induction and repair of DNA damage and the relative biological effectiveness (RBE) of radiation from 18F-FDG relative to 662 keV γ-rays were investigated. The study also assessed whether low-dose radiation exposure from 18F-FDG was capable of inducing an adaptive response. DNA damage to the bone marrow erythroblast population was measured using micronucleus formation and lymphocyte γH2A.X levels. To test the RBE of 18F-FDG, mice were injected with a rangemore » of activities of 18F-FDG (0–14.80 MBq) or irradiated with Cs-137 γ-rays (0–100 mGy). The adaptive response was investigated 24 h after the 18F-FDG injection by 1 Gy in vivo challenge doses for micronucleated reticulocyte (MN-RET) formation or 1, 2 and 4 Gy in vitro challenges doses for γH2A.X formation. A significant increase in MN-RET formation above controls occurred following injection activities of 3.70, 7.40 or 14.80 MBq (P < 0.001) which correspond to bone marrow doses of ~35, 75 and 150 mGy, respectively. Per unit dose, the Cs-137 radiation exposure induced significantly more damage than the 18F-FDG injections (RBE = 0.79 ± 0.04). A 20% reduction in γH2A.X fluorescence was observed in mice injected with a prior adapting low dose of 14.80 MBq 18F-FDG relative to controls (P < 0.019). A 0.74 MBq 18F-FDG injection, which gives mice a dose approximately equal to a typical human PET scan, did not cause a significant increase in DNA damage nor did it generate an adaptive response. Typical 18F-FDG injection activities used in small animal imaging (14.80 MBq) resulted in a decrease in DNA damage, as measured by γH2A.X formation, below spontaneous levels observed in control mice. Lastly, the 18F-FDG RBE was <1.0, indicating that the mixed radiation quality

  3. Radiation Effects of n-type, Low Resistivity, Spiral Silicon Drift Detector Hybrid Systems

    SciTech Connect (OSTI)

    Chen W.; De Geronimo G.; Carini, G.A.; Gaskin, J.A.; Keister, J.W.; Li, S.; Li, Z.; Ramsey, B.D.; Siddons, D.P.; Smith, G.C.; Verbitskaya, E.

    2011-11-15

    We have developed a new thin-window, n-type, low-resistivity, spiral silicon drift detector (SDD) array - to be used as an extraterrestrial X-ray spectrometer (in varying environments) for NASA. To achieve low-energy response, a thin SDD entrance window was produced using a previously developed method. These thin-window devices were also produced on lower resistivity, thinner, n-type, silicon material, effectively ensuring their radiation hardness in anticipation of operation in potentially harsh radiation environments (such as found around the Jupiter system). Using the Indiana University Cyclotron Facility beam line RERS1, we irradiated a set of suitable diodes up to 5 Mrad and the latest iteration of our ASICs up to 12 Mrad. Then we irradiated two hybrid detectors consisting of newly, such-produced in-house (BNL) SDD chips bonded with ASICs with doses of 0.25 Mrad and 1 Mrad. Also we irradiated another hybrid detector consisting of previously produced (by KETEK) on n-type, high-resistivity SDD chip bonded with BNL's ASICs with a dose of 1 Mrad. The measurement results of radiated diodes (up to 5 Mrad), ASICs (up to 12 Mrad) and hybrid detectors (up to 1 Mrad) are presented here.

  4. Anisotropic mechanical properties of zircon and the effect of radiation damage

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Beirau, Tobias; Nix, William D.; Bismayer, Ulrich; Boatner, Lynn A.; Isaacson, Scott G.; Ewing, Rodney C.

    2016-06-02

    Our study provides new insights into the relationship between radiation-dose-dependent structural damage, due to natural U and Th impurities, and the anisotropic mechanical properties (Poisson s ratio, elastic modulus and hardness) of zircon. Natural zircon samples from Sri Lanka (see Muarakami et al. 1991) and synthetic samples, covering a dose range of zero up to 6.8 x 1018 -decays/g, have been studied by nanoindentation. Measurements along the [100] crystallographic direction and calculations, based on elastic stiffness constants determined by zkan (1976), revealed a general radiation-induced decrease in stiffness (~ 54 %) and hardness (~ 48 %) and an increase ofmore » the Poisson s ratio (~ 54 %) with increasing dose. Additional indentations on selected samples along the [001] allowed one to follow the amorphization process to the point that the mechanical properties are isotropic. This work shows that the radiation-dose-dependent changes of the mechanical properties of zircon can be directly correlated with the amorphous fraction as determined by previous investigations with local and global probes (Rios et al. 2000a; Farnan and Salje 2001; Zhang and Salje 2001). This agreement, revealed by the different methods, indicates a huge influence of structural and even local phenomena on the macroscopic mechanical properties.« less

  5. Minibeam radiation therapy for the management of osteosarcomas: A Monte Carlo study

    SciTech Connect (OSTI)

    Martnez-Rovira, I.; Prezado, Y.

    2014-06-15

    Purpose: Minibeam radiation therapy (MBRT) exploits the well-established tissue-sparing effect provided by the combination of submillimetric field sizes and a spatial fractionation of the dose. The aim of this work is to evaluate the feasibility and potential therapeutic gain of MBRT, in comparison with conventional radiotherapy, for osteosarcoma treatments. Methods: Monte Carlo simulations (PENELOPE/PENEASY code) were used as a method to study the dose distributions resulting from MBRT irradiations of a rat femur and a realistic human femur phantoms. As a figure of merit, peak and valley doses and peak-to-valley dose ratios (PVDR) were assessed. Conversion of absorbed dose to normalized total dose (NTD) was performed in the human case. Several field sizes and irradiation geometries were evaluated. Results: It is feasible to deliver a uniform dose distribution in the target while the healthy tissue benefits from a spatial fractionation of the dose. Very high PVDR values (?20) were achieved in the entrance beam path in the rat case. PVDR values ranged from 2 to 9 in the human phantom. NTD{sub 2.0} of 87 Gy might be reached in the tumor in the human femur while the healthy tissues might receive valley NTD{sub 2.0} lower than 20 Gy. The doses in the tumor and healthy tissues might be significantly higher and lower than the ones commonly delivered used in conventional radiotherapy. Conclusions: The obtained dose distributions indicate that a gain in normal tissue sparing might be expected. This would allow the use of higher (and potentially curative) doses in the tumor. Biological experiments are warranted.

  6. Effects of breathing variation on gating window internal target volume in respiratory gated radiation therapy

    SciTech Connect (OSTI)

    Cai Jing; McLawhorn, Robert; Read, Paul W.; Larner, James M.; Yin, Fang-fang; Benedict, Stanley H.; Sheng, Ke

    2010-08-15

    Purpose: To investigate the effects of breathing variation on gating window internal target volume (ITV{sub GW}) in respiratory gated radiation therapy. Method and Materials: Two-dimensional dynamic MRI (dMRI) of lung motion was acquired in ten volunteers and eight lung cancer patients. Resorted dMRI using 4DCT acquisition method (RedCAM) was generated for selected subjects by simulating the image rebinning process. A dynamic software generated phantom (dSGP) was created by moving a solid circle (to mimic the ''tumor'') with dMRI-determined motion trajectories. The gating window internal target area (ITA{sub GW}, 2D counterpart of ITV{sub GW}) was determined from both RedCAM and dSGP/dMRI. Its area (A), major axis (L1), minor axis (L2), and similarity (S) were calculated and compared. Results: In the phantom study of 3 cm tumor, measurements of the ITA{sub GW} from dSGP (A=10.0{+-}1.3 cm{sup 2}, L1=3.8{+-}0.4 cm, and L2=3.3{+-}0.1 cm) are significantly (p<0.001) greater than those from RedCAM (A=8.5{+-}0.7 cm{sup 2}, L1=3.5{+-}0.2 cm, and L2=3.1{+-}0.1 cm). Similarly, the differences are significantly greater (p<0.001) for the 1 cm tumor (A=1.9{+-}0.5 cm{sup 2}, L1=1.9{+-}0.4 cm, and L2=1.3{+-}0.1 cm in dSGP; A=1.3{+-}0.1 cm{sup 2}, L1=1.5{+-}0.2 cm, and L2=1.1{+-}0.1 cm in RedCAM). In patient studies, measurements of the ITA{sub GW} from dMRI (A=15.5{+-}8.2 cm{sup 2}, L1=5.0{+-}1.1 cm, and L2=3.8{+-}1.2 cm) are also significantly greater (p<0.05) than those from RedCAM (A=13.2{+-}8.5 cm{sup 2}, L1=4.3{+-}1.4 cm, and L2=3.7{+-}1.2 cm). Similarities were 0.9{+-}0.1, 0.8{+-}0.1, and 0.8{+-}0.1 in the 3 cm tumor phantom, 1 cm tumor phantom, and patient studies, respectively. Conclusion: ITV{sub GW} can be underestimated by 4DCT due to breathing variations. An additional margin may be needed to account for this potential error in generating a PTV{sub GW}. Cautions need to be taken when generating ITV{sub GW} from 4DCT in respiratory gated radiation therapy, especially

  7. Imprinted genes and transpositions: epigenomic targets for low dose radiation effects. Final report

    SciTech Connect (OSTI)

    Jirtle, Randy L.

    2012-10-11

    The overall hypothesis of this grant application is that low dose ionizing radiation (LDIR) elicits adaptive responses in part by causing heritable DNA methylation changes in the epigenome. This novel postulate was tested by determining if the level of DNA methylation at the Agouti viable yellow (A{sup vy}) metastable locus is altered, in a dose-dependent manner, by low dose radiation exposure (<10 cGy) during early gestation. This information is particularly important to ascertain given the increased use of CT scans in disease diagnosis, increased number of people predicted to live and work in space, and the present concern about radiological terrorism. We showed for the first time that LDIR significantly increased DNA methylation at the A{sup vy} locus in a sex-specific manner (p=0.004). Average DNA methylation was significantly increased in male offspring exposed to doses between 0.7 cGy and 7.6 cGy with maximum effects at 1.4 cGy and 3.0 cGy (p<0.01). Offspring coat color was concomitantly shifted towards pseudoagouti (p<0.01). Maternal dietary antioxidant supplementation mitigated both the DNA methylation changes and coat color shift in the irradiated offspring (p<0.05). Thus, LDIR exposure during gestation elicits epigenetic alterations that lead to positive adaptive phenotypic changes that are negated with antioxidants, indicating they are mediated in part by oxidative stress. These findings provide evidence that in the isogenic Avy mouse model epigenetic alterations resulting from LDIR play a role in radiation hormesis, bringing into question the assumption that every dose of radiation is harmful. Our findings not only have significant implications concerning the mechanism of hormesis, but they also emphasize the potential importance of this phenomenon in determining human risk at low radiation doses. Since the epigenetic regulation of genes varies markedly between species, the effect of LDIR on other epigenetically labile genes (e.g. imprinted genes) in

  8. Gray and multigroup radiation transport models for two-dimensional binary stochastic media using effective opacities

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olson, Gordon L.

    2015-09-24

    One-dimensional models for the transport of radiation through binary stochastic media do not work in multi-dimensions. In addition, authors have attempted to modify or extend the 1D models to work in multidimensions without success. Analytic one-dimensional models are successful in 1D only when assuming greatly simplified physics. State of the art theories for stochastic media radiation transport do not address multi-dimensions and temperature-dependent physics coefficients. Here, the concept of effective opacities and effective heat capacities is found to well represent the ensemble averaged transport solutions in cases with gray or multigroup temperature-dependent opacities and constant or temperature-dependent heat capacities. Inmore » every case analyzed here, effective physics coefficients fit the transport solutions over a useful range of parameter space. The transport equation is solved with the spherical harmonics method with angle orders of n=1 and 5. Although the details depend on what order of solution is used, the general results are similar, independent of angular order.« less

  9. Gray and multigroup radiation transport models for two-dimensional binary stochastic media using effective opacities

    SciTech Connect (OSTI)

    Olson, Gordon L.

    2015-09-24

    One-dimensional models for the transport of radiation through binary stochastic media do not work in multi-dimensions. In addition, authors have attempted to modify or extend the 1D models to work in multidimensions without success. Analytic one-dimensional models are successful in 1D only when assuming greatly simplified physics. State of the art theories for stochastic media radiation transport do not address multi-dimensions and temperature-dependent physics coefficients. Here, the concept of effective opacities and effective heat capacities is found to well represent the ensemble averaged transport solutions in cases with gray or multigroup temperature-dependent opacities and constant or temperature-dependent heat capacities. In every case analyzed here, effective physics coefficients fit the transport solutions over a useful range of parameter space. The transport equation is solved with the spherical harmonics method with angle orders of n=1 and 5. Although the details depend on what order of solution is used, the general results are similar, independent of angular order.

  10. Surface radiation survey and soil sampling of the 300-FF-1 operable unit, Hanford Site, southeastern Washington: A case study

    SciTech Connect (OSTI)

    Teel, S.S.; Olsen, K.B.

    1990-10-01

    The methods used for conducting a radiological characterization of the soil surface for the Phase I Remedial Investigation of a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) site is presented via a case study. The study site is an operable unit (300-FF-1) located in and adjacent to the 300 Area of the US Department of Energy's Hanford Site in southeastern Washington State. The operable unit contains liquid and solid waste disposal facilities associated with nuclear fuels fabrication. Continuous surface radiation surveying and soil sampling of selected locations were conducted. Contamination was found in several locations within the operable unit including areas near the liquid and solid waste disposal facilities. Instruments used during surveying included portable beta/gamma (P-11) detectors, and the Ultrasonic Ranging and Data System using an NaI (Tl) detector. Laboratory analyses results indicate that above-background radiation levels were primarily due to the presence of uranium. Both types of field instruments used in the study were effective in detecting surface contamination from radionuclides; however, each had specific advantages. Guidelines are presented for the optimum use of these instruments when performing a radiological characterization of the soil surface. 4 refs., 3 figs., 3 tabs.

  11. Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems

    SciTech Connect (OSTI)

    Martin, R.A.; Merrigan, M.A.; Elder, M.G.; Sena, J.T.; Keddy, E.S. ); Silverstein, C.C. )

    1992-01-01

    Preliminary, research-oriented, analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, we found that heat loads produced by considering both convection and radiation heat transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the heat load by about one-half and to reduce peak HPRC system temperatures to below 2700{degrees}F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90, 000 ft lowers peak hot section temperatures to around 2800{degrees}F. An HPRC heat pipe was successfully fabricated and tested at Mach 5 conditions of heat flux, heat load, and temperature. 24 refs.

  12. Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems

    SciTech Connect (OSTI)

    Martin, R.A.; Merrigan, M.A.; Elder, M.G.; Sena, J.T.; Keddy, E.S.; Silverstein, C.C.

    1992-06-01

    Preliminary, research-oriented, analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, we found that heat loads produced by considering both convection and radiation heat transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the heat load by about one-half and to reduce peak HPRC system temperatures to below 2700{degrees}F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90, 000 ft lowers peak hot section temperatures to around 2800{degrees}F. An HPRC heat pipe was successfully fabricated and tested at Mach 5 conditions of heat flux, heat load, and temperature. 24 refs.

  13. Low Dose Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ancient Salt Beds Repository Science Renewable Energy The WIPP Underground may be ideal to study effects of Very Low Dose Rates on Biological Systems Low Background Radiation Experiment We're all bathing in it. It's in the food we eat, the water we drink, the soil we tread and even the air we breathe. It's background radiation, it's everywhere and we can't get away from it. But what would happen if you somehow "pulled the plug" on natural background radiation? Would organisms suffer or

  14. Determining an Imaging Literacy Curriculum for Radiation Oncologists: An International Delphi Study

    SciTech Connect (OSTI)

    Giuliani, Meredith E.; Gillan, Caitlin; Milne, Robin A.; Uchino, Minako; Millar, Barbara-Ann; Catton, Pamela

    2014-03-15

    Purpose: Rapid evolution of imaging technologies and their integration into radiation therapy practice demands that radiation oncology (RO) training curricula be updated. The purpose of this study was to develop an entry-to-practice image literacy competency profile. Methods and Materials: A list of 263 potential imaging competency items were assembled from international objectives of training. Expert panel eliminated redundant or irrelevant items to create a list of 97 unique potential competency items. An international 2-round Delphi process was conducted with experts in RO. In round 1, all experts scored, on a 9-point Likert scale, the degree to which they agreed an item should be included in the competency profile. Items with a mean score ≥7 were included, those 4 to 6 were reviewed in round 2, and items scored <4 were excluded. In round 2, items were discussed and subsequently ranked for inclusion or exclusion in the competency profile. Items with >75% voting for inclusion were included in the final competency profile. Results: Forty-nine radiation oncologists were invited to participate in round 1, and 32 (65%) did so. Participants represented 24 centers in 6 countries. Of the 97 items ranked in round 1, 80 had a mean score ≥7, 1 item had a score <4, and 16 items with a mean score of 4 to 6 were reviewed and rescored in round 2. In round 2, 4 items had >75% of participants voting for inclusion and were included; the remaining 12 were excluded. The final list of 84 items formed the final competency profile. The 84 enabling competency items were aggregated into the following 4 thematic groups of key competencies: (1) imaging fundamentals (42 items); (2) clinical application (27 items); (3) clinical management (5 items); and (4) professional practice (10 items). Conclusions: We present an imaging literacy competency profile which could constitute the minimum training standards in radiation oncology residency programs.

  15. Radiation environment simulations at the Tevatron, studies of the beam profile and measurement of the Bc meson mass

    SciTech Connect (OSTI)

    Nicolas, Ludovic Y.

    2005-09-01

    The description of a computer simulation of the CDF detector at Fermilab and the adjacent accelerator parts is detailed, with MARS calculations of the radiation background in various elements of the model due to the collision of beams and machine-related losses. Three components of beam halo formation are simulated for the determination of the principal source of radiation background in CDF due to beam losses. The effect of a collimator as a protection for the detector is studied. The simulation results are compared with data taken by a CDF group. Studies of a 150 GeV Tevatron proton beam are performed to investigate the transverse diffusion growth and distribution. A technique of collimator scan is used to scrape the beam under various experimental conditions, and computer programs are written for the beam reconstruction. An average beam halo growth speed is given and the potential of beam tail reconstruction using the collimator scan is evaluated. A particle physics analysis is conducted in order to detect the B{sub c} {yields} J/{psi}{pi} decay signal with the CDF Run II detector in 360 pb{sup -1} of data. The cut variables and an optimization method to determine their values are presented along with a criterion for the detection threshold of the signal. The mass of the B{sub c} meson is measured with an evaluation of the significance of the signal.

  16. The Radiation Reaction Effect on Electrons at Super-High Laser Intensities with Application to Ion Acceleration

    SciTech Connect (OSTI)

    Naumova, N. M.; Sokolov, I. V.; Tikhonchuk, V. T.; Schlegel, T.; Nees, J. A.; Yanovsky, V. P.; Labaune, C.; Mourou, G. A.

    2009-07-25

    At super-high laser intensities the radiation back reaction on electrons becomes so significant that its influence on laser-plasma interaction cannot be neglected while simulating these processes with particle-in-cell (PIC) codes. We discuss a way of taking the radiation effect on electrons into account and extracting spatial and frequency distributions of the generated high-frequency radiation. We also examine ponderomotive acceleration of ions in the double layer created by strong laser pulses and we compare an analytical description with PIC simulations as well. We discuss: (1) non-stationary features found in simulations, (2) electron cooling effect due to radiation losses, and (3) the limits of the analytical model.

  17. Weakly dissipative dust-ion-acoustic solitons in complex plasmas and the effect of electromagnetic radiation

    SciTech Connect (OSTI)

    Losseva, T. V.; Popel, S. I.; Golub', A. P.; Izvekova, Yu. N.; Shukla, P. K.

    2012-01-15

    Possibility for dust ion-acoustic solitons to exist in complex (dusty) plasmas in the presence of electromagnetic radiation, which results in positive dust particle charges, is investigated. Dissipative processes occurring during the propagation of dust ion-acoustic perturbations, among which are the charging of dust grains, the absorption of ions by grains, the transfer of the ion momentum to the grains, and ion-neutral collisions, are taken into account. Temporal evolution of the soliton-like perturbation and interaction of two soliton-like perturbations are studied. Compressive soliton-like perturbations are shown to possess the main properties of the soltons, in particular, the interacting perturbations conserve their form.

  18. A Prospective, Multicenter Study of Complementary/Alternative Medicine (CAM) Utilization During Definitive Radiation for Breast Cancer

    SciTech Connect (OSTI)

    Moran, Meena S.; Ma Shuangge; Jagsi, Reshma; Yang, Tzu-I Jonathan; Higgins, Susan A.; Department of Radiation Therapy, Shoreline Medical Center, Guilford, Connecticut ; Weidhaas, Joanne B.; Wilson, Lynn D.; Department of Radiation Therapy, Lawrence and Memorial Hospital, New London, Connecticut ; Lloyd, Shane; Peschel, Richard; Department of Radiation Therapy, Lawrence and Memorial Hospital, New London, Connecticut ; Gaudreau, Bryant; Rockwell, Sara

    2013-01-01

    Purpose: Although complementary and alternative medicine (CAM) utilization in breast cancer patients is reported to be high, there are few data on CAM practices in breast patients specifically during radiation. This prospective, multi-institutional study was conducted to define CAM utilization in breast cancer during definitive radiation. Materials/Methods: A validated CAM instrument with a self-skin assessment was administered to 360 Stage 0-III breast cancer patients from 5 centers during the last week of radiation. All data were analyzed to detect significant differences between users/nonusers. Results: CAM usage was reported in 54% of the study cohort (n=194/360). Of CAM users, 71% reported activity-based CAM (eg, Reiki, meditation), 26% topical CAM, and 45% oral CAM. Only 16% received advice/counseling from naturopathic/homeopathic/medical professionals before initiating CAM. CAM use significantly correlated with higher education level (P<.001), inversely correlated with concomitant hormone/radiation therapy use (P=.010), with a trend toward greater use in younger patients (P=.066). On multivariate analysis, level of education (OR: 6.821, 95% CI: 2.307-20.168, P<.001) and hormones/radiation therapy (OR: 0.573, 95% CI: 0.347-0.949, P=.031) independently predicted for CAM use. Significantly lower skin toxicity scores were reported in CAM users vs nonusers, respectively (mild: 34% vs 25%, severe: 17% vs 29%, P=.017). Conclusion: This is the first prospective study to assess CAM practices in breast patients during radiation, with definition of these practices as the first step for future investigation of CAM/radiation interactions. These results should alert radiation oncologists that a large percentage of breast cancer patients use CAM during radiation without disclosure or consideration for potential interactions, and should encourage increased awareness, communication, and documentation of CAM practices in patients undergoing radiation treatment for breast

  19. Study of the processes of degradation of the optical properties of mesoporous and macroporous silicon upon exposure to simulated solar radiation

    SciTech Connect (OSTI)

    Levitskii, V. S.; Lenshin, A. S. Seredin, P. V.; Terukov, E. I.

    2015-11-15

    The effect of solar radiation on the surface composition of mesoporous and macroporous silicon is studied by infrared spectroscopy, Raman spectroscopy, and photoluminescence measurements in order to analyze the possibility of using these materials as a material for solar-power engineering. The studies are conducted in the laboratory environment, with the use of a solar-radiation simulator operating under conditions close to the working conditions of standard silicon solar cells. The studies show that, in general, the materials meet the requirements of solar-power engineering, if it is possible to preclude harmful effects associated with the presence of heat-sensitive and photosensitive bonds at the nanomaterial surface by standard processing methods.

  20. Dose-Effect Relationships for Adverse Events After Cranial Radiation Therapy in Long-term Childhood Cancer Survivors

    SciTech Connect (OSTI)

    Dijk, Irma W.E.M. van; Cardous-Ubbink, Mathilde C.; Pal, Helena J.H. van der; Oldenburger, Foppe; Os, Rob M. van; Ronckers, Cécile M.; Schouten–van Meeteren, Antoinette Y.N.; Department of Pediatric Oncology, Emma Children's Hospital Koning, Caro C.E.; Kremer, Leontien C.M.; Department of Pediatric Oncology, Emma Children's Hospital/Academic Medical Center, Amsterdam

    2013-03-01

    Purpose: To evaluate the prevalence and severity of clinical adverse events (AEs) and treatment-related risk factors in childhood cancer survivors treated with cranial radiation therapy (CRT), with the aim of assessing dose-effect relationships. Methods and Materials: The retrospective study cohort consisted of 1362 Dutch childhood cancer survivors, of whom 285 were treated with CRT delivered as brain irradiation (BI), as part of craniospinal irradiation (CSI), and as total body irradiation (TBI). Individual CRT doses were converted into the equivalent dose in 2-Gy fractions (EQD{sub 2}). Survivors had received their diagnoses between 1966 and 1996 and survived at least 5 years after diagnosis. A complete inventory of Common Terminology Criteria for Adverse Events grade 3.0 AEs was available from our hospital-based late-effect follow-up program. We used multivariable logistic and Cox regression analyses to examine the EQD{sub 2} in relation to the prevalence and severity of AEs, correcting for sex, age at diagnosis, follow-up time, and the treatment-related risk factors surgery and chemotherapy. Results: There was a high prevalence of AEs in the CRT group; over 80% of survivors had more than 1 AE, and almost half had at least 5 AEs, both representing significant increases in number of AEs compared with survivors not treated with CRT. Additionally, the proportion of severe, life-threatening, or disabling AEs was significantly higher in the CRT group. The most frequent AEs were alopecia and cognitive, endocrine, metabolic, and neurologic events. Using the EQD{sub 2}, we found significant dose-effect relationships for these and other AEs. Conclusion: Our results confirm that CRT increases the prevalence and severity of AEs in childhood cancer survivors. Furthermore, analyzing dose-effect relationships with the cumulative EQD{sub 2} instead of total physical dose connects the knowledge from radiation therapy and radiobiology with the clinical experience.

  1. Improvement in Clouds and the Earth's Radiant Energy System/Surface and Atmosphere Radiation Budget Dust Aerosol Properties, Effects on Surface Validation of Clouds and Radiative Swath

    SciTech Connect (OSTI)

    Rutan, D.; Rose, F.; Charlock, T.P.

    2005-03-18

    Within the Clouds and the Earth's Radiant Energy System (CERES) science team (Wielicki et al. 1996), the Surface and Atmospheric Radiation Budget (SARB) group is tasked with calculating vertical profiles of heating rates, globally, and continuously, beneath CERES footprint observations of Top of Atmosphere (TOA) fluxes. This is accomplished using a fast radiative transfer code originally developed by Qiang Fu and Kuo-Nan Liou (Fu and Liou 1993) and subsequently highly modified by the SARB team. Details on the code and its inputs can be found in Kato et al. (2005) and Rose and Charlock (2002). Among the many required inputs is characterization of the vertical column profile of aerosols beneath each footprint. To do this SARB combines aerosol optical depth information from the moderate-resolution imaging spectroradiometer (MODIS) instrument along with aerosol constituents specified by the Model for Atmosphere and Chemical Transport (MATCH) of Collins et al. (2001), and aerosol properties (e.g. single scatter albedo and asymmetry parameter) from Tegen and Lacis (1996) and OPAC (Hess et al. 1998). The publicly available files that include these flux profiles, called the Clouds and Radiative Swath (CRS) data product, available from the Langley Atmospheric Sciences Data Center (http://eosweb.larc.nasa.gov/). As various versions of the code are completed, publishable results are named ''Editions.'' After CRS Edition 2A was finalized it was found that dust aerosols were too absorptive. Dust aerosols have subsequently been modified using a new set of properties developed by Andy Lacis and results have been released in CRS Edition 2B. This paper discusses the effects of changing desert dust aerosol properties, which can be significant for the radiation budget in mid ocean, a few thousand kilometers from the source regions. Resulting changes are validated via comparison of surface observed fluxes from the Saudi Solar Village surface site (Myers et al. 1999), and the E13 site

  2. Rectal wall sparing by dosimetric effect of rectal balloon used during Intensity-Modulated Radiation Therapy (IMRT) for prostate cancer

    SciTech Connect (OSTI)

    Teh, Bin S.

    2005-03-31

    The use of an air-filled rectal balloon has been shown to decrease prostate motion during prostate radiotherapy. However, the perturbation of radiation dose near the air-tissue interfaces has raised clinical concerns of underdosing the prostate gland. The aim of this study was to investigate the dosimetric effects of an air-filled rectal balloon on the rectal wall/mucosa and prostate gland. Clinical rectal toxicity and dose-volume histogram (DVH) were also assessed to evaluate for any correlation. A film phantom was constructed to simulate the 4-cm diameter air cavity created by a rectal balloon. Kodak XV2 films were utilized to measure and compare dose distribution with and without air cavity. To study the effect in a typical clinical situation, the phantom was computed tomography (CT) scanned on a Siemens DR CT scanner for intensity-modulated radiation therapy (IMRT) treatment planning. A target object was drawn on the phantom CT images to simulate the treatment of prostate cancer. Because patients were treated in prone position, the air cavity was situated superiorly to the target. The treatment used a serial tomotherapy technique with the Multivane Intensity Modulating Collimator (MIMiC) in arc treatment mode. Rectal toxicity was assessed in 116 patients treated with IMRT to a mean dose of 76 Gy over 35 fractions (2.17-Gy fraction size). They were treated in the prone position, immobilized using a Vac-LokTM bag and carrier-box system. Rectal balloon inflated with 100 cc of air was used for prostate gland immobilization during daily treatment. Rectal toxicity was assessed using modifications of the Radiation Therapy Oncology Group (RTOG) and late effects Normal Tissue Task Force (LENT) scales systems. DVH of the rectum was also evaluated. From film dosimetry, there was a dose reduction at the distal air-tissue interface as much as 60% compared with the same geometry without the air cavity for 15-MV photon beam and 2 x 2-cm field size. The dose beyond the

  3. Comparative study of microwave radiation-induced magnetoresistive oscillations induced by circularly- and linearly- polarized photo-excitation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ye, Tianyu; Liu, Han -Chun; Wang, Zhuo; Wegscheider, W.; Mani, Ramesh G.

    2015-10-09

    A comparative study of the radiation-induced magnetoresistance oscillations in the high mobility GaAs/AlGaAs heterostructure two dimensional electron system (2DES) under linearly- and circularly- polarized microwave excitation indicates a profound difference in the response observed upon rotating the microwave launcher for the two cases, although circularly polarized microwave radiation induced magnetoresistance oscillations observed at low magnetic fields are similar to the oscillations observed with linearly polarized radiation. For the linearly polarized radiation, the magnetoresistive response is a strong sinusoidal function of the launcher rotation (or linear polarization) angle, θ. As a result, for circularly polarized radiation, the oscillatory magnetoresistive response ismore » hardly sensitive to θ.« less

  4. Radiation Dose to the Esophagus From Breast Cancer Radiation Therapy, 1943-1996: An International Population-Based Study of 414 Patients

    SciTech Connect (OSTI)

    Lamart, Stephanie; Stovall, Marilyn; Simon, Steven L.; Smith, Susan A.; Weathers, Rita E.; Howell, Rebecca M.; Curtis, Rochelle E.; Aleman, Berthe M.P.; Travis, Lois; Kwon, Deukwoo; Morton, Lindsay M.

    2013-07-15

    Purpose: To provide dosimetric data for an epidemiologic study on the risk of second primary esophageal cancer among breast cancer survivors, by reconstructing the radiation dose incidentally delivered to the esophagus of 414 women treated with radiation therapy for breast cancer during 1943-1996 in North America and Europe. Methods and Materials: We abstracted the radiation therapy treatment parameters from each patients radiation therapy record. Treatment fields included direct chest wall (37% of patients), medial and lateral tangentials (45%), supraclavicular (SCV, 64%), internal mammary (IM, 44%), SCV and IM together (16%), axillary (52%), and breast/chest wall boosts (7%). The beam types used were {sup 60}Co (45% of fields), orthovoltage (33%), megavoltage photons (11%), and electrons (10%). The population median prescribed dose to the target volume ranged from 21 Gy to 40 Gy. We reconstructed the doses over the length of the esophagus using abstracted patient data, water phantom measurements, and a computational model of the human body. Results: Fields that treated the SCV and/or IM lymph nodes were used for 85% of the patients and delivered the highest doses within 3 regions of the esophagus: cervical (population median 38 Gy), upper thoracic (32 Gy), and middle thoracic (25 Gy). Other fields (direct chest wall, tangential, and axillary) contributed substantially lower doses (approximately 2 Gy). The cervical to middle thoracic esophagus received the highest dose because of its close proximity to the SCV and IM fields and less overlying tissue in that part of the chest. The location of the SCV field border relative to the midline was one of the most important determinants of the dose to the esophagus. Conclusions: Breast cancer patients in this study received relatively high incidental radiation therapy doses to the esophagus when the SCV and/or IM lymph nodes were treated, whereas direct chest wall, tangentials, and axillary fields contributed lower doses.

  5. MO-G-BRE-09: Validating FMEA Against Incident Learning Data: A Study in Stereotactic Body Radiation Therapy

    SciTech Connect (OSTI)

    Yang, F; Cao, N; Young, L; Howard, J; Sponseller, P; Logan, W; Arbuckle, T; Korssjoen, T; Meyer, J; Ford, E

    2014-06-15

    Purpose: Though FMEA (Failure Mode and Effects Analysis) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge it has never been validated against actual incident learning data. The objective of this study was to perform an FMEA analysis of an SBRT (Stereotactic Body Radiation Therapy) treatment planning process and validate this against data recorded within an incident learning system. Methods: FMEA on the SBRT treatment planning process was carried out by a multidisciplinary group including radiation oncologists, medical physicists, and dosimetrists. Potential failure modes were identified through a systematic review of the workflow process. Failure modes were rated for severity, occurrence, and detectability on a scale of 1 to 10 and RPN (Risk Priority Number) was computed. Failure modes were then compared with historical reports identified as relevant to SBRT planning within a departmental incident learning system that had been active for two years. Differences were identified. Results: FMEA identified 63 failure modes. RPN values for the top 25% of failure modes ranged from 60 to 336. Analysis of the incident learning database identified 33 reported near-miss events related to SBRT planning. FMEA failed to anticipate 13 of these events, among which 3 were registered with severity ratings of severe or critical in the incident learning system. Combining both methods yielded a total of 76 failure modes, and when scored for RPN the 13 events missed by FMEA ranked within the middle half of all failure modes. Conclusion: FMEA, though valuable, is subject to certain limitations, among them the limited ability to anticipate all potential errors for a given process. This FMEA exercise failed to identify a significant number of possible errors (17%). Integration of FMEA with retrospective incident data may be able to render an improved overview of risks within a process.

  6. Radiation-Induced Changes in Normal-Appearing White Matter in Patients With Cerebral Tumors: A Diffusion Tensor Imaging Study

    SciTech Connect (OSTI)

    Nagesh, Vijaya Tsien, Christina I.; Chenevert, Thomas L.; Ross, Brian D.; Lawrence, Theodore S.; Junick, Larry; Cao Yue

    2008-03-15

    Purpose: To quantify the radiation-induced changes in normal-appearing white matter before, during, and after radiotherapy (RT) in cerebral tumor patients. Methods and Materials: Twenty-five patients with low-grade glioma, high-grade glioma, or benign tumor treated with RT were studied using diffusion tensor magnetic resonance imaging. The biologically corrected doses ranged from 50 to 81 Gy. The temporal changes were assessed before, during, and to 45 weeks after the start of RT. The mean diffusivity of water (), fractional anisotropy of diffusion, diffusivity perpendicular ({lambda}{sub perpendicular}) and parallel ({lambda}{sub parallel}) to white matter fibers were calculated in normal-appearing genu and splenium of the corpus callosum. Results: In the genu and splenium, fractional anisotropy decreased and , {lambda}{sub parallel}, {lambda}{sub -perpendicular} increased linearly and significantly with time (p < 0.01). At 45 weeks after the start of RT, {lambda}{sub -perpendicular} had increased {approx}30% in the genu and splenium, and {lambda}{sub parallel} had increased 5% in the genu and 9% in the splenium, suggesting that demyelination is predominant. The increases in {lambda}{sub perpendicular} and {lambda}{sub parallel} were dose dependent, starting at 3 weeks and continuing to 32 weeks from the start of RT. The dose-dependent increase in {lambda}{sub perpendicular} and {lambda}{sub parallel} was not sustained after 32 weeks, indicating the transition from focal to diffuse effects. Conclusion: The acute and subacute changes in normal-appearing white matter fibers indicate radiation-induced demyelination and mild structural degradation of axonal fibers. The structural changes after RT are progressive, with early dose-dependent demyelination and subsequent diffuse dose-independent demyelination and mild axonal degradation. Diffusion tensor magnetic resonance imaging is potentially a biomarker for the assessment of radiation-induced white matter injury.

  7. Radiation effects in a muon collider ring and dipole magnet protection

    SciTech Connect (OSTI)

    Mokhov, N.V.; Kashikhin, V.V.; Novitski, I.; Zlobin, A.V.; /Fermilab

    2011-03-01

    The requirements and operating conditions for a Muon Collider Storage Ring (MCSR) pose significant challenges to superconducting magnets. The dipole magnets should provide a high magnetic field to reduce the ring circumference and thus maximize the number of muon collisions during their lifetime. One third of the beam energy is continuously deposited along the lattice by the decay electrons at the rate of 0.5 kW/m for a 1.5-TeV c.o.m. and a luminosity of 10{sup 34} cm{sup -2}s{sup -1}. Unlike dipoles in proton machines, the MCSR dipoles should allow this dynamic heat load to escape the magnet helium volume in the horizontal plane, predominantly towards the ring center. This paper presents the analysis and comparison of radiation effects in MCSR based on two dipole magnets designs. Tungsten masks in the interconnect regions are used in both cases to mitigate the unprecedented dynamic heat deposition and radiation in the magnet coils.

  8. Effect of Fractionation in Stereotactic Body Radiation Therapy Using the Linear Quadratic Model

    SciTech Connect (OSTI)

    Yang, Jun; Philadelphia Cyberknife, Havertown, Pennsylvania ; Lamond, John; Philadelphia Cyberknife, Havertown, Pennsylvania ; Fowler, Jack; Lanciano, Rachelle; Philadelphia Cyberknife, Havertown, Pennsylvania ; Feng, Jing; Brady, Luther; Philadelphia Cyberknife, Havertown, Pennsylvania

    2013-05-01

    Purpose: To examine the fractionation effect of stereotactic body radiation therapy with a heterogeneous dose distribution. Methods: Derived from the linear quadratic formula with measurements from a hypothetical 2-cm radiosurgical tumor, the threshold percentage was defined as (?/?{sub tissue}/?/?{sub tumor}), the balance ?/? ratio was defined as (prescription dose/tissue tolerance*?/?{sub tumor}), and the balance dose was defined as (tissue tolerance/threshold percentage). Results: With increasing fractions and equivalent peripheral dose to the target, the biological equivalent dose of hot spots in a target decreases. The relative biological equivalent doses of serial organs decrease only when the relative percentage of its dose to the prescription dose is above the threshold percentage. The volume of parallel organs at risk decreases only when the tumor's ?/? ratio is above the balance ?/? ratio and the prescription dose is lower than balance dose. Conclusions: The potential benefits of fractionation in stereotactic body radiation therapy depend on the complex interplay between the total dose, ?/? ratios, and dose differences between the target and the surrounding normal tissues.

  9. Simulating 3-D Radiative Transfer Effects over the Sierra Nevada Mountains using WRF

    SciTech Connect (OSTI)

    Gu, Yu; Liou, K. N.; Lee, W- L.; Leung, Lai-Yung R.

    2012-10-30

    A surface solar radiation parameterization based on deviations between 3-D and conventional plane-parallel radiative transfer models has been incorporated into the Weather Research and Forecasting (WRF) model to understand the solar insolation over mountain/snow areas and to investigate the impact of the spatial and temporal distribution and variation of surface solar fluxes on land-surface processes. Using the Sierra-Nevada in the western United States as a testbed, we show that mountain effect could produce up to ?50 to + 50Wm?2 deviations in the surface solar fluxes over the mountain areas, resulting in a temperature increase of up to 1 C on the sunny side. Upward surface sensible and latent heat fluxes are modulated accordingly to compensate for the change in surface solar fluxes. Snow water equivalent and surface albedo both show decreases on the sunny side of the mountains, indicating more snowmelt and hence reduced snow albedo associated with more solar insolation due to mountain effect. Soil moisture increases on the sunny side of the mountains due to enhanced snowmelt, while decreases on the shaded side. Substantial differences are found in the morning hours from 8-10 a.m. and in the afternoon around 3-5 p.m., while differences around noon and in the early morning and late afternoon are comparatively smaller. Variation in the surface energy balance can also affect atmospheric processes, such as cloud fields, through the modulation of vertical thermal structure. Negative changes of up to ?40 gm?2 are found in the cloud water path, associated with reductions in the surface insolation over the cloud region. The day-averaged deviations in the surface solar flux are positive over the mountain areas and negative in the valleys, with a range between ?12~12Wm?2. Changes in sensible and latent heat fluxes and surface skin temperature follow the solar insolation pattern. Differences in the domain-averaged diurnal variation over the Sierras show that the mountain

  10. SU-E-I-49: Simulation Study for Removing Scatter Radiation in Cesium-Iodine Based Flat Panel Detector System

    SciTech Connect (OSTI)

    Yoon, Y; Park, M; Kim, H; Kim, K; Kim, J; Morishita, J

    2015-06-15

    Purpose: This study aims to identify the feasibility of a novel cesium-iodine (CsI)-based flat-panel detector (FPD) for removing scatter radiation in diagnostic radiology. Methods: The indirect FPD comprises three layers: a substrate, scintillation, and thin-film-transistor (TFT) layer. The TFT layer has a matrix structure with pixels. There are ineffective dimensions on the TFT layer, such as the voltage and data lines; therefore, we devised a new FPD system having net-like lead in the substrate layer, matching the ineffective area, to block the scatter radiation so that only primary X-rays could reach the effective dimension.To evaluate the performance of this new FPD system, we conducted a Monte Carlo simulation using MCNPX 2.6.0 software. Scatter fractions (SFs) were acquired using no grid, a parallel grid (8:1 grid ratio), and the new system, and the performances were compared.Two systems having different thicknesses of lead in the substrate layer—10 and 20μm—were simulated. Additionally, we examined the effects of different pixel sizes (153×153 and 163×163μm) on the image quality, while keeping the effective area of pixels constant (143×143μm). Results: In case of 10μm lead, the SFs of the new system (∼11%) were lower than those of the other system (∼27% with no grid, ∼16% with parallel grid) at 40kV. However, as the tube voltage increased, the SF of new system (∼19%) was higher than that of parallel grid (∼18%) at 120kV. In the case of 20μm lead, the SFs of the new system were lower than those of the other systems at all ranges of the tube voltage (40–120kV). Conclusion: The novel CsI-based FPD system for removing scatter radiation is feasible for improving the image contrast but must be optimized with respect to the lead thickness, considering the system’s purposes and the ranges of the tube voltage in diagnostic radiology. This study was supported by a grant(K1422651) from Institute of Health Science, Korea University.

  11. Parametric study of broadband terahertz radiation generation based on interaction of two-color ultra-short laser pulses

    SciTech Connect (OSTI)

    Moradi, S.; Ganjovi, A.; Shojaei, F.; Saeed, M.

    2015-04-15

    In this work, using a two-dimensional kinetic model based on particle in cell-Monte Carlo collision simulation method, the influence of different parameters on the broadband intense Terahertz (THz) radiation generation via application of two-color laser fields, i.e., the fundamental and second harmonic modes, is studied. These two modes are focused into the molecular oxygen (O{sub 2}) with uniform density background gaseous media and the plasma channels are created. Thus, a broadband THz pulse that is around the plasma frequency is emitted from the formed plasma channel and co-propagates with the laser pulse. For different laser pulse shapes, the THz electric field and its spectrum are both calculated. The effects of laser pulse and medium parameters, i.e., positive and negative chirp pulse, number of laser cycles in the pulse, laser pulse shape, background gas pressure, and exerted DC electric field on THz spectrum are verified. Application of a negatively chirped femtosecond (40 fs) laser pulse results in four times enhancement of the THz pulse energy (2 times in THz electric field). The emission of THz radiation is mostly observed in the forward direction.

  12. The radiation response of the cervical spinal cord of the pig: Effects of changing the irradiated volume

    SciTech Connect (OSTI)

    Van den Aardweg, G.J.M.J.; Hopewell, J.W.; Whitehouse, E.M.

    1995-01-01

    An investigation of the field size effect for the cervical spinal cord of the pig after single doses of {gamma}-rays. In this study, clinically relevant volumes of the spinal cord were irradiated. The effects of the local irradiation of different lengths of the spinal cord (2.5 cm, 5.0 cm, and 10.0 cm) have been evaluated in mature pigs (37-43 weeks). Single doses of 25-31 Gy were given using a {sup 60}Co {gamma}-source, at a dose rate of 0.21-0.30 Gy/min. The incidence of radiation-induced paralysis was used as the endpoint. The data were analyzed using probit analysis and a normal tissue complication probability (NTCP)-model. Twenty-five animals out of a total of 53 developed paralysis, with histological evidence of parenchymal and vascular changes in their white matter. The slope of the dose-response curves decreased with the decrease in field size; however, there was no significant difference at the radiation dose associated with a 50% incidence of paralysis (ED{sub 50}) irrespective of the method of analysis. The ED{sub 50} values {+-} standard errors ({+-} SE) were 27.02 {+-} 0.36 Gy, 27.68 {+-} 0.57 Gy, and 28.28 {+-} 0.78 Gy for field lengths of 10, 5, and 2.5 cm, respectively. Analysis of the data with a normal tissue complication probability (NCTP) model gave similar results. The latent period of paralysis was 7.5-16.5 weeks with no significant differences between dose and field size. No significant field size-related differences in response were detectable in the cervical spinal cord of mature pigs after single dose irradiations, specifically at a clinically relevant level of effect (< ED{sub 10}). 21 refs., 1 fig., 1 tab.

  13. SU-E-J-72: Dosimetric Study of Cone-Beam CT-Based Radiation Treatment...

    Office of Scientific and Technical Information (OSTI)

    ... Subject: 60 APPLIED LIFE SCIENCES; ACCURACY; CARTILAGE; COMPUTERIZED TOMOGRAPHY; DOSIMETRY; HEAD; LUNGS; NECK; PANCREAS; PATIENTS; PELVIS; PLANNING; RADIATION DOSE DISTRIBUTIONS; ...

  14. Spreader-Bar Radiation Detection System Enhancements: A Modeling and Simulation Study

    SciTech Connect (OSTI)

    Ely, James H.; Ashbaker, Eric D.; Batdorf, Michael T.; Baciak, James E.; Hensley, Walter K.; Jarman, Kenneth D.; Robinson, Sean M.; Sandness, Gerald A.; Schweppe, John E.

    2012-11-13

    This report provides the modeling and simulation results of the investigation of enhanced spreader bar radiation detection systems.

  15. On the effect of bias on the behavior of MOS structures subjected to ionizing radiation

    SciTech Connect (OSTI)

    Aleksandrov, O. V.

    2015-06-15

    Using a quantitative model [6], the analysis of published data on the effect of the gate bias on the behavior of MOS structure subjected to ionizing radiation is performed. It is shown that, along with hydrogen-containing traps, there are hydrogen-free hole traps in samples with a low content of hydrogen; traps of both types are distributed inhomogeneously over the thickness of the gate insulator. In addition to ionized hydrogen, neutral hydrogen is involved in the formation of surface states and provides the main contribution to this process at negative gate bias. A decrease in the shift of the threshold voltage in the case of high fields is caused by an increase in the drift component of the hole drain to the electrodes.

  16. Acoustic effects at interaction of laser radiation with a liquid accompanied by optical breakdown

    SciTech Connect (OSTI)

    Bulanov, A. V.; Nagorny, I. G.

    2012-09-04

    The experimental researches of acoustic emission from optical breakdown in liquids are presented. Spectral characteristics and power of the acoustic waves generated in a liquid by optical breakdown at interaction of laser radiation with the wavelength of 532 nanometers were studied. It is shown, that two spectral maxima characterizing acoustic emission are observed. The shift of low-frequency maximum depending on the laser energy pulse is observed. As a whole, the linear dependence of acoustic pressure on the energy of laser pulse is observed. It is shown, that using acoustic data it is possible to reproduce function R(t) which will be in accord with characteristic dependences R(t), obtained from optical data. The last is especially important for breakdown studying in opaque environments.

  17. Cellular and molecular research to reduce uncertainties in estimates of health effects from low-level radiation

    SciTech Connect (OSTI)

    Elkind, M.M.; Bedford, J.; Benjamin, S.A.; Waldren, C.A. ); Gotchy, R.L. )

    1990-10-01

    A study was undertaken by five radiation scientists to examine the feasibility of reducing the uncertainties in the estimation of risk due to protracted low doses of ionizing radiation. In addressing the question of feasibility, a review was made by the study group: of the cellular, molecular, and mammalian radiation data that are available; of the way in which altered oncogene properties could be involved in the loss of growth control that culminates in tumorigenesis; and of the progress that had been made in the genetic characterizations of several human and animal neoplasms. On the basis of this analysis, the study group concluded that, at the present time, it is feasible to mount a program of radiation research directed at the mechanism(s) of radiation-induced cancer with special reference to risk of neoplasia due to protracted, low doses of sparsely ionizing radiation. To implement a program of research, a review was made of the methods, techniques, and instruments that would be needed. This review was followed by a survey of the laboratories and institutions where scientific personnel and facilities are known to be available. A research agenda of the principal and broad objectives of the program is also discussed. 489 refs., 21 figs., 14 tabs.

  18. A study on leakage radiation dose at ELV-4 electron accelerator bunker

    SciTech Connect (OSTI)

    Chulan, Mohd Rizal Md E-mail: redzuwan@ukm.my; Yahaya, Redzuwan E-mail: redzuwan@ukm.my; Ghazali, Abu BakarMhd

    2014-09-03

    Shielding is an important aspect in the safety of an accelerator and the most important aspects of a bunker shielding is the door. The bunkers door should be designed properly to minimize the leakage radiation and shall not exceed the permitted limit of 2.5?Sv/hr. In determining the leakage radiation dose that passed through the door and gaps between the door and the wall, 2-dimensional manual calculations are often used. This method is hard to perform because visual 2-dimensional is limited and is also very difficult in the real situation. Therefore estimation values are normally performed. In doing so, the construction cost would be higher because of overestimate or underestimate which require costly modification to the bunker. Therefore in this study, two methods are introduced to overcome the problem such as simulation using MCNPX Version 2.6.0 software and manual calculation using 3-dimensional model from Autodesk Inventor 2010 software. The values from the two methods were eventually compared to the real values from direct measurements using Ludlum Model 3 with Model 44-9 probe survey meter.

  19. Radiation detector

    DOE Patents [OSTI]

    Fultz, B.T.

    1980-12-05

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  20. Radiation detector

    DOE Patents [OSTI]

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  1. Proteomic-based mechanistic investigation of low-dose radiation-induced cellular responses/effects

    SciTech Connect (OSTI)

    Chen, Xian

    2013-10-23

    The goal of our project is to apply our unique systems investigation strategy to reveal the molecular mechanisms underlying the radiation induction and transmission of oxidative damage, adaptive response, and bystander effect at low-doses. Beginning with simple in vitro systems such as fibroblast or epithelial pure culture, our amino acid-coded mass tagging (AACT) comparative proteomic platform will be used to measure quantitatively proteomic changes at high- or low-dose level with respect to their endogenous damage levels respectively, in which a broad range of unique regulated proteins sensitive to low-dose IR will be distinguished. To zoom in how these regulated proteins interact with other in the form of networks in induction/transmission pathways, these regulated proteins will be selected as baits for making a series of fibroblast cell lines that stably express each of them. Using our newly developed method of ?dual-tagging? quantitative proteomics that integrate the capabilities of natural complex expression/formation, simple epitope affinity isolation (not through tandem affinity purification or TAP), and ?in-spectra? AACT quantitative measurements using mass spectrometry (MS), we will be able to distinguish systematically interacting proteins with each bait in real time. Further, in addition to both proteome-wide (global differentially expressed proteins) and pathway-scale (bait-specific) profiling information, we will perform a computational network analysis to elucidate a global pathway/mechanisms underlying cellular responses to real-time low-dose IR. Similarly, we will extend our scheme to investigate systematically those induction/transmission pathways occurring in a fibroblast-epithelial interacting model in which the bystander cell (fibroblast) monitor the IR damage to the target cell (epithelial cell). The results will provide the proteome base (molecular mechanisms/pathways for signaling) for the low dose radiation-induced essential tissue

  2. Study of CSR Effects in the Jefferson Laboratory FEL Driver

    SciTech Connect (OSTI)

    Hall, C. C.; Biedron, S.; Burleson, Theodore A.; Milton, Stephen V.; Morin, Auralee L.; Benson, Stephen V.; Douglas, David R.; Evtushenko, Pavel E.; Hannon, Fay E.; Li, Rui; Tennant, Christopher D.; Zhang, Shukui; Carlsten, Bruce E.; Lewellen, John W.

    2013-08-01

    In a recent experiment conducted on the Jefferson Laboratory IR FEL driver the effects of Coherent Synchrotron Radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR chicane. This experiment also provides a valuable opportunity to benchmark existing CSR models in a system that may not be fully represented by a 1-D CSR model. Here we present results from this experiment and compare to initial simulations of CSR in the magnetic compression chicane of the machine. Finally, we touch upon the possibility for CSR induced microbunching gain in the magnetic compression chicane, and show that parameters in the machine are such that it should be thoroughly damped.

  3. Time-dependent study of radiation trapping by time-delayed two-photon absorption

    SciTech Connect (OSTI)

    Molander, W.; Belsley, M.; Streater, A.; Burnett, K.

    1983-10-01

    The transport of resonance radiation through an optically thick vapor of Sr atoms is studied. A pulsed dye laser tuned to the 461 nm resonance line excites a narrow (approx. 60 ..mu..m diam) column of Sr atoms along the axis of a cylindrical oven containing Sr vapor and Ar buffer gas. After a delay of less than or equal to 80 ns, a second dye laser excites the atom from the first excited state (5s5p) to a higher excited state (5s7s). The fluorescence from this latter transition is monitored as the second laser is translated parallel to the first. Since the excited state-excited state fluorescence is not trapped the result is a plot of density of atoms in the 5s5p state as a function of position from the originally excited volume. The results are discussed qualitatively.

  4. Radiation Effects on the Sorption and Mobilization of Radionuclide during Transport through the Geosphere

    SciTech Connect (OSTI)

    L.M. Wang; R.C. Eqing; K.F. Hayes

    2004-03-14

    Site restoration activities at DOE facilities and the permanent disposal of nuclear waste inevitably involve understanding the behavior of materials in a radiation field. Radionuclide decay and the associated radiation fields lead to physical and chemical changes that can degrade or enhance important material properties. Alpha-decay of the actinide elements and beta-decay of the fission products lead to atomic-scale changes in materials (radiation damage and transmutation).

  5. A Sensitivity Study on Modeling Black Carbon in Snow and its Radiative Forcing over the Arctic and Northern China

    SciTech Connect (OSTI)

    Qian, Yun; Wang, Hailong; Zhang, Rudong; Flanner, M. G.; Rasch, Philip J.

    2014-06-02

    Black carbon in snow (BCS) simulated in the Community Atmosphere Model (CAM5) is evaluated against measurements over Northern China and the Arctic, and its sensitivity to atmospheric deposition and two parameters that affect post-depositional enrichment is explored. The BCS concentration is overestimated (underestimated) by a factor of two in Northern China (Arctic) in the default model, but agreement with observations is good over both regions in the simulation with improvements in BC transport and deposition. Sensitivity studies indicate that uncertainty in the melt-water scavenging efficiency (MSE) parameter substantially affects BCS and its radiative forcing (by a factor of 2-7) in the Arctic through post-depositional enrichment. The MSE parameter has a relatively small effect on the magnitude of BCS seasonal cycle but can alter its phase in Northern China. The impact of the snow aging scaling factor (SAF) on BCS, partly through the post-depositional enrichment effect, shows more complex latitudinal and seasonal dependence. Similar to MSE, SAF affects more significantly the magnitude (phase) of BCS season cycle over the Arctic (Northern China). While uncertainty associated with the representation of BC transport and deposition processes in CAM5 is more important than that associated with the two snow model parameters in Northern China, the two uncertainties have comparable effect in the Arctic.

  6. Individualized Positron Emission Tomography–Based Isotoxic Accelerated Radiation Therapy Is Cost-Effective Compared With Conventional Radiation Therapy: A Model-Based Evaluation

    SciTech Connect (OSTI)

    Bongers, Mathilda L.; Coupé, Veerle M.H.; De Ruysscher, Dirk; Oberije, Cary; Lambin, Philippe; Uyl-de Groot, Cornelia A.

    2015-03-15

    Purpose: To evaluate long-term health effects, costs, and cost-effectiveness of positron emission tomography (PET)-based isotoxic accelerated radiation therapy treatment (PET-ART) compared with conventional fixed-dose CT-based radiation therapy treatment (CRT) in non-small cell lung cancer (NSCLC). Methods and Materials: Our analysis uses a validated decision model, based on data of 200 NSCLC patients with inoperable stage I-IIIB. Clinical outcomes, resource use, costs, and utilities were obtained from the Maastro Clinic and the literature. Primary model outcomes were the difference in life-years (LYs), quality-adjusted life-years (QALYs), costs, and the incremental cost-effectiveness and cost/utility ratio (ICER and ICUR) of PET-ART versus CRT. Model outcomes were obtained from averaging the predictions for 50,000 simulated patients. A probabilistic sensitivity analysis and scenario analyses were carried out. Results: The average incremental costs per patient of PET-ART were €569 (95% confidence interval [CI] €−5327-€6936) for 0.42 incremental LYs (95% CI 0.19-0.61) and 0.33 QALYs gained (95% CI 0.13-0.49). The base-case scenario resulted in an ICER of €1360 per LY gained and an ICUR of €1744 per QALY gained. The probabilistic analysis gave a 36% probability that PET-ART improves health outcomes at reduced costs and a 64% probability that PET-ART is more effective at slightly higher costs. Conclusion: On the basis of the available data, individualized PET-ART for NSCLC seems to be cost-effective compared with CRT.

  7. Coordination of Breast Cancer Care Between Radiation Oncologists and Surgeons: A Survey Study

    SciTech Connect (OSTI)

    Jagsi, Reshma; Abrahamse, Paul; Morrow, Monica; Hamilton, Ann S.; Katz, Steven J.

    2012-04-01

    Purpose: To assess whether radiation oncologists and surgeons differ in their attitudes regarding the local management of breast cancer, and to examine coordination of care between these specialists. Methods and Materials: We surveyed attending surgeons and radiation oncologists who treated a population-based sample of patients diagnosed with breast cancer in metropolitan Detroit and Los Angeles. We identified 419 surgeons, of whom 318 (76%) responded, and 160 radiation oncologists, of whom 117 (73%) responded. We assessed demographic, professional, and practice characteristics; challenges to coordinated care; and attitudes toward management in three scenarios. Results: 92.1% of surgeons and 94.8% of radiation oncologists indicated access to a multidisciplinary tumor board. Nevertheless, the most commonly identified challenge to radiation oncologists, cited by 27.9%, was failure of other providers to include them in the treatment decision process early enough. Nearly half the surgeons (49.7%) stated that few or almost none of the breast cancer patients they saw in the past 12 months had consulted with a radiation oncologist before undergoing definitive surgery. Surgeons and radiation oncologists differed in their recommendations in management scenarios. Radiation oncologists were more likely to favor radiation than were surgeons for a patient with 3/20 lymph nodes undergoing mastectomy (p = 0.03); surgeons were more likely to favor more widely clear margins after breast conservation than were radiation oncologists (p = 0.001). Conclusions: Despite the widespread availability of tumor boards, a substantial minority of radiation oncologists indicated other providers failed to include them in the breast cancer treatment decision-making process early enough. Earlier inclusion of radiation oncologists may influence patient decisions, and interventions to facilitate this should be considered.

  8. A Phase I Study of Short-Course Accelerated Whole Brain Radiation...

    Office of Scientific and Technical Information (OSTI)

    Cattolica del S. Cuore, Campobasso (Italy) Department of Radiation Oncology, The Lacks Cancer Center Saint Mary's Health Care, Grand Rapids, Michigan (United States) Department of...

  9. ASA conference on radiation and health: Health effects of electric and magnetic fields: Statistical support for research strategies. Final report

    SciTech Connect (OSTI)

    Not Available

    1990-05-01

    This report is a collection of papers documenting presentations made at the VIII ASA (American Statistical Association) Conference on Radiation and Health entitled Health Effects of Electric and Magnetic Fields: Statistical Support for Research Strategies. Individual papers are abstracted and indexed for the database.

  10. Structural changes caused by radiation-induced reduction and radiolysis: the effect of X-ray absorbed dose in a fungal multicopper oxidase

    SciTech Connect (OSTI)

    De la Mora, Eugenio; Lovett, Janet E.; Blanford, Christopher F.; Garman, Elspeth F.; Valderrama, Brenda; Rudino-Pinera, Enrique

    2012-05-01

    Radiation-induced reduction, radiolysis of copper sites and the effect of pH value together with the concomitant geometrical distortions of the active centres were analysed in several fungal (C. gallica) laccase structures collected at cryotemperature. This study emphasizes the importance of careful interpretation when the crystallographic structure of a metalloprotein is described. X-ray radiation induces two main effects at metal centres contained in protein crystals: radiation-induced reduction and radiolysis and a resulting decrease in metal occupancy. In blue multicopper oxidases (BMCOs), the geometry of the active centres and the metal-to-ligand distances change depending on the oxidation states of the Cu atoms, suggesting that these alterations are catalytically relevant to the binding, activation and reduction of O{sub 2}. In this work, the X-ray-determined three-dimensional structure of laccase from the basidiomycete Coriolopsis gallica (Cg L), a high catalytic potential BMCO, is described. By combining spectroscopic techniques (UVVis, EPR and XAS) and X-ray crystallography, structural changes at and around the active copper centres were related to pH and absorbed X-ray dose (energy deposited per unit mass). Depletion of two of the four active Cu atoms as well as low occupancies of the remaining Cu atoms, together with different conformations of the metal centres, were observed at both acidic pH and high absorbed dose, correlating with more reduced states of the active coppers. These observations provide additional evidence to support the role of flexibility of copper sites during O{sub 2} reduction. This study supports previous observations indicating that interpretations regarding redox state and metal coordination need to take radiation effects explicitly into account.

  11. Impact of Concomitant Chemotherapy on Outcomes of Radiation Therapy for Head-and-Neck Cancer: A Population-Based Study

    SciTech Connect (OSTI)

    Gupta, Shlok; Kong, Weidong; Booth, Christopher M.; Mackillop, William J.

    2014-01-01

    Purpose: Clinical trials have shown that the addition of chemotherapy to radiation therapy (RT) improves survival in advanced head-and-neck cancer. The objective of this study was to describe the effectiveness of concomitant chemoradiation therapy (C-CRT) in routine practice. Methods and Materials: This was a population-based cohort study. Electronic records of treatment from all provincial cancer centers were linked to a population--based cancer registry to describe the adoption of C-CRT for head-and-neck cancer patients in Ontario, Canada. The study population was then divided into pre- and postadoption cohorts, and their outcomes were compared. Results: Between 1992 and 2008, 18,867 patients had diagnoses of head-and-neck cancer in Ontario, of whom 7866 (41.7%) were treated with primary RT. The proportion of primary RT cases that received C-CRT increased from 2.2% in the preadoption cohort (1992-1998) to 39.3% in the postadoption cohort (2003-2008). Five-year survival among all primary RT cases increased from 43.6% in the preadoption cohort to 51.8% in the postadoption cohort (P<.001). Over the same period, treatment-related hospital admissions increased significantly, but there was no significant increase in treatment-related deaths. Conclusions: C-CRT was widely adopted in Ontario after 2003, and its adoption was temporally associated with an improvement in survival.

  12. Effects of stratospheric ozone depletion, solar UV radiation, and climate change on biogeochemical cycling: interactions and feedbacks

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Erickson III, David J.; Sulzberger, Barbara; Zepp, Richard G.; Austin, Amy T.

    2014-11-07

    Climate change modulates the effects of solar UV radiation on biogeochemical cycles in terrestrial and aquatic ecosystems, particularly for carbon cycling, resulting in UV-mediated positive or negative feedbacks on climate. Possible positive feedbacks discussed in this assessment include: (i) enhanced UV-induced mineralisation of above ground litter due to aridification; (ii) enhanced UV-induced mineralisation of photoreactive dissolved organic matter (DOM) in aquatic ecosystems due to changes in continental runoff and ice melting; (iii) reduced efficiency of the biological pump due to UV-induced bleaching of coloured dissolved organic matter (CDOM) in stratified aquatic ecosystems, where CDOM protects phytoplankton from the damaging solarmore » UV-B radiation. Mineralisation of organic matter results in the production and release of CO2, whereas the biological pump is the main biological process for CO2 removal by aquatic ecosystems. This research also assesses the interactive effects of solar UV radiation and climate change on the biogeochemical cycling of aerosols and trace gases other than CO2, as well as of chemical and biological contaminants. Lastly,, interacting effects of solar UV radiation and climate change on biogeochemical cycles are particularly pronounced at terrestrial-aquatic interfaces.« less

  13. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    SciTech Connect (OSTI)

    Keene, William C.; Long, Michael S.

    2013-05-20

    This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry's MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of

  14. Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations

    SciTech Connect (OSTI)

    Qian, Yun; Long, Charles N.; Wang, Hailong; Comstock, Jennifer M.; McFarlane, Sally A.; Xie, Shaocheng

    2012-02-17

    Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for the total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction

  15. HRTEM Study of Oxide Nanoparticles in K3-ODS Ferritic Steel Developed for Radiation Tolerance

    SciTech Connect (OSTI)

    Hsiung, L; Fluss, M; Tumey, S; Kuntz, J; El-Dasher, B; Wall, M; Choi, W; Kimura, A; Willaime, F; Serruys, Y

    2009-11-02

    Crystal and interfacial structures of oxide nanoparticles and radiation damage in 16Cr-4.5Al-0.3Ti-2W-0.37 Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous shell were frequently observed. The crystal structure of complex-oxide core is identified to be mainly monoclinic Y{sub 4}Al{sub 2}O{sub 9} (YAM) oxide compound. Orientation relationships between the oxide and the matrix are found to be dependent on the particle size. Large particles (> 20 nm) tend to be incoherent and have a spherical shape, whereas small particles (< 10 nm) tend to be coherent or semi-coherent and have a faceted interface. The observations of partially amorphous nanoparticles and multiple crystalline domains formed within a nanoparticle lead us to propose a three-stage mechanism to rationalize the formation of oxide nanoparticles containing core/shell structures in as-fabricated ODS steels. Effects of nanoparticle size and density on cavity formation induced by (Fe{sup 8+} + He{sup +}) dual-beam irradiation are briefly addressed.

  16. NONTHERMAL RADIATION FROM SUPERNOVA REMNANTS: EFFECTS OF MAGNETIC FIELD AMPLIFICATION AND PARTICLE ESCAPE

    SciTech Connect (OSTI)

    Kang, Hyesung; Jones, T. W.; Edmon, Paul P. E-mail: twj@msi.umn.edu

    2013-11-01

    We explore nonlinear effects of wave-particle interactions on the diffusive shock acceleration (DSA) process in Type Ia-like supernova remnant (SNR) blast waves by implementing phenomenological models for magnetic field amplification (MFA), Alfvnic drift, and particle escape in time-dependent numerical simulations of nonlinear DSA. For typical SNR parameters, the cosmic-ray (CR) protons can be accelerated to PeV energies only if the region of amplified field ahead of the shock is extensive enough to contain the diffusion lengths of the particles of interest. Even with the help of Alfvnic drift, it remains somewhat challenging to construct a nonlinear DSA model for SNRs in which of the order of 10% of the supernova explosion energy is converted into CR energy and the magnetic field is amplified by a factor of 10 or so in the shock precursor, while, at the same time, the energy spectrum of PeV protons is steeper than E {sup 2}. To explore the influence of these physical effects on observed SNR emission, we also compute the resulting radio-to-gamma-ray spectra. Nonthermal emission spectra, especially in X-ray and gamma-ray bands, depend on the time-dependent evolution of the CR injection process, MFA, and particle escape, as well as the shock dynamic evolution. This result comes from the fact that the high-energy end of the CR spectrum is composed of particles that are injected in the very early stages of the blast wave evolution. Thus, it is crucial to better understand the plasma wave-particle interactions associated with collisionless shocks in detailed modeling of nonthermal radiation from SNRs.

  17. Apparatus for generating partially coherent radiation

    DOE Patents [OSTI]

    Naulleau, Patrick P.

    2005-02-22

    Techniques for generating partially coherent radiation and particularly for converting effectively coherent radiation from a synchrotron to partially coherent EUV radiation suitable for projection lithography.

  18. Cloud Effects on Radiative Heating Rate Profiles over Darwin using ARM and A-train Radar/Lidar Observations

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.

    2013-06-11

    Observations of clouds from the ground-based U.S. Department of Energy Atmospheric Radiation Measurement program (ARM) and satellite-based A-train are used to compute cloud radiative forcing profiles over the ARM Darwin, Australia site. Cloud properties are obtained from both radar (the ARM Millimeter Cloud Radar (MMCR) and the CloudSat satellite in the A-train) and lidar (the ARM Micropulse lidar (MPL) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite in the A-train) observations. Cloud microphysical properties are taken from combined radar and lidar retrievals for ice clouds and radar only or lidar only retrievals for liquid clouds. Large, statistically significant differences of up to 1.43 K/day exist between the mean ARM and A-train net cloud radiative forcing profiles. The majority of the difference in cloud radiative forcing profiles is shown to be due to a large difference in the cloud fraction above 12 km. Above this altitude the A-train cloud fraction is significantly larger because more clouds are detected by CALIPSO than by the ground-based MPL. It is shown that the MPL is unable to observe as many high clouds as CALIPSO due to being more frequently attenuated and a poorer sensitivity even in otherwise clear-sky conditions. After accounting for cloud fraction differences and instrument sampling differences due to viewing platform we determined that differences in cloud radiative forcing due to the retrieved ice cloud properties is relatively small. This study demonstrates that A-train observations are better suited for the calculation cloud radiative forcing profiles. In addition, we find that it is necessary to supplement CloudSat with CALIPSO observations to obtain accurate cloud radiative forcing profiles since a large portion of clouds at Darwin are detected by CALIPSO only.

  19. A Variable-Energy Soft X-Ray Microprobe to Investigate Mechanisms of the Radiation-Induced Bystander Effect.

    SciTech Connect (OSTI)

    Folkard, Melvyn; Vojnovic, Borivoj; Schettino, Giuseppe; Atkinson, Kirk; Prise, Kevin, M.; Michael, Barry, D.

    2007-01-23

    The Gray Cancer Institute has pioneered the use of X ray focussing techniques to develop systems for micro irradiating individual cells and sub cellular targets in vitro. Cellular micro irradiation is now recognised as a highly versatile technique for understanding how ionising radiation interacts with living cells and tissues. The strength of the technique lies in its ability to deliver precise doses of radiation to selected individual cells (or sub cellular targets). The application of this technique in the field of radiation biology continues to be of great interest for investigating a number of phenomena currently of concern to the radiobiological community. One important phenomenon is the so called ‘bystander effect’ where it is observed that unirradiated cells can also respond to signals transmitted by irradiated neighbours. Clearly, the ability of a microbeam to irradiate just a single cell or selected cells within a population is well suited to studying this effect. Our prototype ‘tabletop’ X-ray microprobe was optimised for focusing 278 eV C-K X rays and has been used successfully for a number of years. However, we have sought to develop a new variable energy soft X-ray microprobe capable of delivering focused CK (0.28 keV), Al-K (1.48 keV) and notably, Ti-K (4.5 keV) X rays. Ti-K X rays are capable of penetrating several cell layers and are therefore much better suited to studies involving tissues and multi cellular layers. In our new design, X-rays are generated by the focussed electron bombardment of a material whose characteristic-K radiation is required. The source is mounted on a 1.5 x 1.0 metre optical table. Electrons are generated by a custom built gun, designed to operate up to 15 kV. The electrons are focused using a permanent neodymium iron boron magnet assembly. Focusing is achieved by adjusting the accelerating voltage and by fine tuning the target position via a vacuum position feedthrough. To analyze the electron beam properties, a

  20. Assessment of multi-decadal WRF-CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gan, C.-M.; Pleim, J.; Mathur, R.; Hogrefe, C.; Long, C. N.; Xing, J.; Wong, D.; Gilliam, R.; Wei, C.

    2015-07-01

    Multi-decadal simulations with the coupled WRF-CMAQ model have been conducted to systematically investigate the changes in anthropogenic emissions of SO2 and NOx over the past 21 years (1990–2010) across the United States (US), their impacts on anthropogenic aerosol loading over North America, and subsequent impacts on regional radiation budgets. In particular, this study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act (CAA) especially on trends in solar radiation. Extensive analyses conducted by Gan et al. (2014) utilizingmore » observations (e.g. SURFRAD, CASTNET, IMPROVE and ARM) over the past 16 years (1995–2010) indicate a shortwave (SW) radiation (both all-sky and clear-sky) "brightening" in the US. The relationship of the radiation brightening trend with decreases in the aerosol burden is less apparent in the western US. One of the main reasons for this is that the emission controls under the CAA were aimed primarily at reducing pollutants in areas violating national air quality standards, most of which were located in the eastern US while the relatively less populated areas in the western US were less polluted at the beginning of this study period. Comparisons of model results with observations of aerosol optical depth (AOD), aerosol concentration, and radiation demonstrate that the coupled WRF-CMAQ model is capable of replicating the trends well even through it tends to underestimate the AOD. In particular, the sulfate concentration predictions were well matched with the observations. The discrenpancies found in the clear-sky diffuse SW radiation are likely due to several factors such as potential increase of ice particles associated with increasing air traffic, the definition of "clear-sky" in the radiation retrieval methodology and aerosol semi-direct and/or indirect effects which cannot be

  1. Assessment of long-term WRF–CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gan, C.-M.; Pleim, J.; Mathur, R.; Hogrefe, C.; Long, C. N.; Xing, J.; Wong, D.; Gilliam, R.; Wei, C.

    2015-11-03

    Long-term simulations with the coupled WRF–CMAQ (Weather Research and Forecasting–Community Multi-scale Air Quality) model have been conducted to systematically investigate the changes in anthropogenic emissions of SO2 and NOx over the past 16 years (1995–2010) across the United States (US), their impacts on anthropogenic aerosol loading over North America, and subsequent impacts on regional radiation budgets. In particular, this study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act (CAA) especially on trends in solar radiation. Extensive analysesmore » conducted by Gan et al. (2014a) utilizing observations (e.g., SURFRAD, CASTNET, IMPROVE, and ARM) over the past 16 years (1995–2010) indicate a shortwave (SW) radiation (both all-sky and clear-sky) "brightening" in the US. The relationship of the radiation brightening trend with decreases in the aerosol burden is less apparent in the western US. One of the main reasons for this is that the emission controls under the CAA were aimed primarily at reducing pollutants in areas violating national air quality standards, most of which were located in the eastern US, while the relatively less populated areas in the western US were less polluted at the beginning of this study period. Comparisons of model results with observations of aerosol optical depth (AOD), aerosol concentration, and radiation demonstrate that the coupled WRF–CMAQ model is capable of replicating the trends well even though it tends to underestimate the AOD. In particular, the sulfate concentration predictions were well matched with the observations. The discrepancies found in the clear-sky diffuse SW radiation are likely due to several factors such as the potential increase of ice particles associated with increasing air traffic, the definition of "clear-sky" in the radiation retrieval

  2. Atmospheric Radiation Measurement (ARM) Data from Black Forest Germany for the Convective and Orographically Induced Precipitation Study (COPS)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The primary goal of the ARM Program is to improve the treatment of cloud and radiation physics in global climate models in order to improve the climate simulation capabilities of these models. ARM maintains four major, permanent sites for data collection and deploys the ARM Mobile Facility (AMF) to other sites as determined. In 2007 the AMF operated in the Black Forest region of Germany as part of the Convective and Orographically Induced Precipitation Study (COPS). Scientists studied rainfall resulting from atmospheric uplift (convection) in mountainous terrain, otherwise known as orographic precipitation. This was part of a six -year duration of the German Quantitative Precipitation Forecasting (QPF) Program. COPS was endorsed as a Research and Development Project by the World Weather Research Program. This program was established by the World Meteorological Organization to develop improved and cost-effective forecasting techniques, with an emphasis on high-impact weather. A large collection of data plots based on data streams from specific instruments used at Black Forest are available via a link from ARM's Black Forest site information page. Users will be requested to create a password, but the plots and the data files in the ARM Archive are free for viewing and downloading.

  3. The Impact of Radiation Therapy on the Risk of Lymphedema After Treatment for Breast Cancer: A Prospective Cohort Study

    SciTech Connect (OSTI)

    Warren, Laura E.G.; Miller, Cynthia L.; Horick, Nora; Skolny, Melissa N.; Jammallo, Lauren S.; Sadek, Betro T.; Shenouda, Mina N.; O'Toole, Jean A.; MacDonald, Shannon M.; Specht, Michelle C.; Taghian, Alphonse G.

    2014-03-01

    Purpose/Objective: Lymphedema after breast cancer treatment can be an irreversible condition with a negative impact on quality of life. The goal of this study was to identify radiation therapy-related risk factors for lymphedema. Methods and Materials: From 2005 to 2012, we prospectively performed arm volume measurements on 1476 breast cancer patients at our institution using a Perometer. Treating each breast individually, 1099 of 1501 patients (73%) received radiation therapy. Arm measurements were performed preoperatively and postoperatively. Lymphedema was defined as ≥10% arm volume increase occurring >3 months postoperatively. Univariate and multivariate Cox proportional hazard models were used to evaluate risk factors for lymphedema. Results: At a median follow-up time of 25.4 months (range, 3.4-82.6 months), the 2-year cumulative incidence of lymphedema was 6.8%. Cumulative incidence by radiation therapy type was as follows: 3.0% no radiation therapy, 3.1% breast or chest wall alone, 21.9% supraclavicular (SC), and 21.1% SC and posterior axillary boost (PAB). On multivariate analysis, the hazard ratio for regional lymph node radiation (RLNR) (SC ± PAB) was 1.7 (P=.025) compared with breast/chest wall radiation alone. There was no difference in lymphedema risk between SC and SC + PAB (P=.96). Other independent risk factors included early postoperative swelling (P<.0001), higher body mass index (P<.0001), greater number of lymph nodes dissected (P=.018), and axillary lymph node dissection (P=.0001). Conclusions: In a large cohort of breast cancer patients prospectively screened for lymphedema, RLNR significantly increased the risk of lymphedema compared with breast/chest wall radiation alone. When considering use of RLNR, clinicians should weigh the potential benefit of RLNR for control of disease against the increased risk of lymphedema.

  4. Reproductive Status at First Diagnosis Influences Risk of Radiation-Induced Second Primary Contralateral Breast Cancer in the WECARE Study

    SciTech Connect (OSTI)

    Brooks, Jennifer D.; Boice, John D.; Stovall, Marilyn; Reiner, Anne S.; Bernstein, Leslie; John, Esther M.; Lynch, Charles F.; Mellemkjaer, Lene; Knight, Julia A.; Thomas, Duncan C.; Haile, Robert W.; Smith, Susan A.; Capanu, Marinela; Bernstein, Jonine L.; Shore, Roy E.; Radiation Effects Research Foundation, Hiroshima

    2012-11-15

    Purpose: Our study examined whether reproductive and hormonal factors before, at the time of, or after radiation treatment for a first primary breast cancer modify the risk of radiation-induced second primary breast cancer. Methods and Materials: The Women's Environmental, Cancer and Radiation Epidemiology (WECARE) Study is a multicenter, population-based study of 708 women (cases) with asynchronous contralateral breast cancer (CBC) and 1399 women (controls) with unilateral breast cancer. Radiotherapy (RT) records, coupled with anthropomorphic phantom simulations, were used to estimate quadrant-specific radiation dose to the contralateral breast for each patient. Rate ratios (RR) and 95% confidence intervals (CI) were computed to assess the relationship between reproductive factors and risk of CBC. Results: Women who were nulliparous at diagnosis and exposed to {>=}1 Gy to the contralateral breast had a greater risk for CBC than did matched unexposed nulliparous women (RR = 2.2; 95% CI, 1.2-4.0). No increased risk was seen in RT-exposed parous women (RR = 1.1; 95% CI, 0.8-1.4). Women treated with RT who later became pregnant (8 cases and 9 controls) had a greater risk for CBC (RR = 6.0; 95% CI, 1.3-28.4) than unexposed women (4 cases and 7 controls) who also became pregnant. The association of radiation with risk of CBC did not vary by number of pregnancies, history of breastfeeding, or menopausal status at the time of first breast cancer diagnosis. Conclusion: Nulliparous women treated with RT were at an increased risk for CBC. Although based on small numbers, women who become pregnant after first diagnosis also seem to be at an increased risk for radiation-induced CBC.

  5. Study of the Exclusive Initial State RadiationProduction of the D \\bar D System

    SciTech Connect (OSTI)

    Aubert, B.

    2006-09-07

    A study of exclusive production of the D{bar D} system through initial-state radiation is performed in a search for charmonium states, where D = D{sup 0} or D{sup +}. The D{sup 0} mesons are reconstructed in the D{sup 0} {yields} K{sup -}{pi}{sup +}, D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup 0}, and D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} decay modes. The D{sup +} is reconstructed through the D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} decay mode. The analysis makes use of an integrated luminosity of 288.5 fb{sup -1} collected by the BABAR experiment. The D{bar D} mass spectrum shows a clear {psi}(3770) signal. Further structures appear in the 3.9 and 4.1 GeV/c{sup 2} regions. No evidence is found for Y(4260) decays to D{bar D}, implying an upper limit {Beta}(Y(4260) {yields} D{bar D})/{Beta}(Y(4260) {yields} J/{psi}{pi}{sup +}{pi}{sup -}) < 7.6 (95% confidence level).

  6. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; et al

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reachmore »the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.« less

  7. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; et al

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reachmore » the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.« less

  8. Radiation effects on interface reactions of U/Fe, U/(Fe+Cr), and U/(Fe+Cr+Ni)

    SciTech Connect (OSTI)

    Shao, Lin; Chen, Di; Wei, Chaochen; Martin, Michael S.; Wang, Xuemei; Park, Youngjoo; Dein, Ed; Coffey, Kevin R.; Sohn, Yongho; Sencer, Bulent H.; Rory Kennedy, J.

    2014-10-01

    We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/Fe, U/(Fe + Cr), and U/(Fe + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of Fe, Fe + Cr, or Fe + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV Fe++ ion irradiation. The Fe++ ion penetration depth is sufficient to reach the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, Fe++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/Fe couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.

  9. Preliminary Studies on the Variational Assimilation of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Studies on the Variational Assimilation of Cloud-Radiation Observations Using ARM ... A linearized cloud scheme and a radiation scheme including cloud effects have been ...

  10. 1989 neutron and gamma personnel dosimetry intercomparison study using RADCAL (Radiation Calibration Laboratory) sources

    SciTech Connect (OSTI)

    Sims, C.S.; Casson, W.H.; Patterson, G.R. ); Murakami, H. . Dept. of Health Physics); Liu, J.C. )

    1990-10-01

    The fourteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 14) was conducted during May 1-5, 1989. A total of 48 organizations (33 from the US and 15 from abroad) participated in PDIS 14. Participants submitted by mail a total of 1,302 neutron and gamma dosimeters for this mixed field study. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (40%), direct interaction TLD (22%), track (20%), film (7%), combination (7%), and bubble detectors (4%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: TLD (84%) and film (16%). Radiation sources used in the six PDIS 14 exposures included {sup 252}Cf moderated by 15-cm D{sub 2}O, {sup 252}Cf moderated by 15-cm polyethylene (gamma-enhanced with {sup 137}Cs), and {sup 238}PuBe. Neutron dose equivalents ranged from 0.44--2.63 mSv and gamma doses ranged from 0. 01-1.85 mSv. One {sup 252}Cf(D{sub 2}O) exposure was performed at a 60{degree} angle of incidence (most performance tests are at perpendicular incidence). The average neutron dosimeter response for this exposure was 70% of that at normal incidence. The average gamma dosimeter response was 96% of that at normal incidence. A total of 70% of individual reported neutron dosimeter measurements were within {plus minus}50% of reference values. If the 0.01 mSv data are omitted, approximately 90% of the individual reported gamma measurements were within {plus minus}50% of reference values. 33 refs., 9 figs., 27 tabs.

  11. The Effects of Radiation Chemistry on Solvent Extraction 4. Separation of the Trivalent Actinides and Considerations for Radiation-Resistant Solvent Systems

    SciTech Connect (OSTI)

    Bruce J. Mincher; Giuseppe Modolo; Stephen P. Mezyk

    2010-07-01

    The separation of the minor actinides from dissolved nuclear fuel is one of the more formidable challenges associated with the design of the advanced fuel cycle. The partitioning of americium and its transmutation in fast reactor fuel would reduce high-level-waste long-term storage requirements by as much as two orders of magnitude. However, the lanthanides have very similar chemistry. They also have large neutron capture cross sections and poor metal alloy properties and thus they can not be incorporated into fast reactor fuel. A separation amenable to currently existing aqueous solvent extraction processes is therefore desired, and research is underway in Europe, Asia and the USA toward this end. Current concepts for this final separation rely on the use of soft-donor nitrogen or sulfur-containing ligands that favor complexation with the 5f orbitals of the actinides. In the USA, the most developed process is the TALSPEAK (Trivalent Actinide Lanthanide Separation by Phosphorous reagent Extraction from Aqueous Komplexes) process, based upon the competition between bis(2-ethylhexyl)phosphoric acid (HDEHP) in the organic phase and lactate-buffered diethylenetriamine pentaacetic acid (DTPA) in the aqueous phase. In Europe and Japan, current investigation is focused on the BTP diamide mixtures or dithiophosphinic acids. Any process eventually adopted must be robust under conditions of high-radiation dose-rates and acid hydrolysis. The effects of irradiation on solvent extraction formulations may result in: 1) decreased ligand concentrations resulting in lower metal distribution ratios, 2) decreased selectivity due to the generation of ligand radiolysis products that are complexing agents, 3) decreased selectivity due to the generation of diluent radiolysis products that are complexing agents, and 4) altered solvent performance due to films, precipitates, and increased viscocity. Many of the ligands associated with minor actinide/lanthanide separations are relatively

  12. Alpha Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Basics of Radiation Gamma Radiation and X-Rays Beta Radiation Alpha Radiation Irradiation Radioactive Contamination Definitions Detection Measurement Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Basics of Radiation Characteristics of Alpha Radiation 1. Alpha radiation is not able to penetrate skin. 2. Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds. 3. A variety of instruments

  13. Stereotactic Ablative Radiation Therapy as First Local Therapy for Lung Oligometastases From Colorectal Cancer: A Single-Institution Cohort Study

    SciTech Connect (OSTI)

    Filippi, Andrea Riccardo; Badellino, Serena; Ceccarelli, Manuela; Guarneri, Alessia; Franco, Pierfrancesco; Monagheddu, Chiara; Spadi, Rosella; Ragona, Riccardo; Racca, Patrizia; Ricardi, Umberto

    2015-03-01

    Purpose: To estimate stereotactic ablative radiation therapy (SABR) efficacy and its potential role as an alternative to surgery for the treatment of lung metastases from colorectal cancer. Methods and Materials: Forty consecutive patients who received SABR as first local therapy at the time of lung progression were included, from 2004 to 2014. The primary study endpoint was overall survival. Secondary endpoints were progression-free survival and safety. Results: A single nodule was treated in 26 patients (65%), 2 nodules in 10 patients (25%), 3 in 3 patients (7.5%), and 4 in 1 patient (2.5%), for a total of 59 lesions. The median delivered biological effective dose was 96 Gy, in 1 to 8 daily fractions. Median follow-up time was 20 months (range, 3-72 months). Overall survival rates at 1, 2, and 5 years were, respectively, 84%, 73%, and 39%, with 14 patients (35%) dead. Median overall survival was 46 months. Progression occurred in 25 patients (62.5%), at a median interval of 8 months; failure at SABR site was observed in 3 patients (7.5%). Progression-free survival rates were 49% and 27% at 1 and 2 years, respectively. Discussion: The results of this retrospective exploratory analysis suggest safety and efficacy of SABR in patients affected with colorectal cancer lung oligometastases and urge inclusion of SABR in prospective clinical trials.

  14. A Phase I Study of the Combination of Sorafenib With Temozolomide and Radiation Therapy for the Treatment of Primary and Recurrent High-Grade Gliomas

    SciTech Connect (OSTI)

    Den, Robert B.; Kamrava, Mitchell; Sheng, Zhi; Werner-Wasik, Maria; Dougherty, Erin; Marinucchi, Michelle; Lawrence, Yaacov R.; Center for Translational Research in Radiation Oncology, Sheba Medical Center ; Hegarty, Sarah; Hyslop, Terry; Andrews, David W.; Glass, Jon; Friedman, David P.; Green, Michael R.; Camphausen, Kevin; Dicker, Adam P.

    2013-02-01

    Purpose: Despite recent advances in the management of high-grade and recurrent gliomas, survival remains poor. Antiangiogenic therapy has been shown to be efficacious in the treatment of high-grade gliomas both in preclinical models and in clinical trials. We sought to determine the safety and maximum tolerated dose of sorafenib when combined with both radiation and temozolomide in the primary setting or radiation alone in the recurrent setting. Methods and Materials: This was a preclinical study and an open-label phase I dose escalation trial. Multiple glioma cell lines were analyzed for viability after treatment with radiation, temozolomide, or sorafenib or combinations of them. For patients with primary disease, sorafenib was given concurrently with temozolomide (75 mg/m{sup 2}) and 60 Gy radiation, for 30 days after completion of radiation. For patients with recurrent disease, sorafenib was combined with a hypofractionated course of radiation (35 Gy in 10 fractions). Results: Cell viability was significantly reduced with the combination of radiation, temozolomide, and sorafenib or radiation and sorafenib. Eighteen patients (11 in the primary cohort, 7 in the recurrent cohort) were enrolled onto this trial approved by the institutional review board. All patients completed the planned course of radiation therapy. The most common toxicities were hematologic, fatigue, and rash. There were 18 grade 3 or higher toxicities. The median overall survival was 18 months for the entire population. Conclusions: Sorafenib can be safely combined with radiation and temozolomide in patients with high-grade glioma and with radiation alone in patients with recurrent glioma. The recommended phase II dose of sorafenib is 200 mg twice daily when combined with temozolomide and radiation and 400 mg with radiation alone. To our knowledge, this is the first publication of concurrent sorafenib with radiation monotherapy or combined with radiation and temozolomide.

  15. Imaging Biomarker Dynamics in an Intracranial Murine Glioma Study of Radiation and Antiangiogenic Therapy

    SciTech Connect (OSTI)

    Chung, Caroline; Jalali, Shahrzad; Foltz, Warren; Burrell, Kelly; Wildgoose, Petra; Lindsay, Patricia; Graves, Christian; Camphausen, Kevin; Milosevic, Michael; Jaffray, David; Zadeh, Gelareh; Mnard, Cynthia

    2013-03-01

    Purpose: There is a growing need for noninvasive biomarkers to guide individualized spatiotemporal delivery of radiation therapy (RT) and antiangiogenic (AA) therapy for brain tumors. This study explored early biomarkers of response to RT and the AA agent sunitinib (SU), in a murine intracranial glioma model, using serial magnetic resonance imaging (MRI). Methods and Materials: Mice with MRI-visible tumors were stratified by tumor size into 4 therapy arms: control, RT, SU, and SU plus RT (SURT). Single-fraction conformal RT was delivered using MRI and on-line cone beam computed tomography (CT) guidance. Serial MR images (T2-weighted, diffusion, dynamic contrast-enhanced and gadolinium-enhanced T1-weighted scans) were acquired biweekly to evaluate tumor volume, apparent diffusion coefficient (ADC), and tumor perfusion and permeability responses (K{sub trans}, K{sub ep}). Results: Mice in all treatment arms survived longer than those in control, with a median survival of 35 days for SURT (P<.0001) and 30 days for RT (P=.009) and SU (P=.01) mice vs 26 days for control mice. At Day 3, ADC rise was greater with RT than without (P=.002). Sunitinib treatment reduced tumor perfusion/permeability values with mean K{sub trans} reduction of 27.6% for SU (P=.04) and 26.3% for SURT (P=.04) mice and mean K{sub ep} reduction of 38.1% for SU (P=.01) and 27.3% for SURT (P=.02) mice. The magnitude of individual mouse ADC responses at Days 3 and 7 correlated with subsequent tumor growth rate R values of ?0.878 (P=.002) and ?0.80 (P=.01), respectively. Conclusions: Early quantitative changes in diffusion and perfusion MRI measures reflect treatment responses soon after starting therapy and thereby raise the potential for these imaging biomarkers to guide adaptive and potentially individualized therapy approaches in the future.

  16. Stereotactic Body Radiation Therapy for Oligometastases to the Lung: A Phase 2 Study

    SciTech Connect (OSTI)

    Nuyttens, Joost J.; Voort van Zyp, Noëlle C.M.G. van der; Verhoef, Cornelis; Maat, A.; Klaveren, Robertus J. van; Holt, Bronno van der; Aerts, Joachim; Hoogeman, Mischa

    2015-02-01

    Purpose: To assess, in a phase 2 study, the efficacy and toxicity of stereotactic body radiation therapy for oligometastases to the lung in inoperable patients. Methods and Materials: Patients with lung metastases were included in this study if (1) the primary tumor was controlled; (2) patients were ineligible for or refused surgery and chemotherapy; and (3) patients had 5 or fewer metastatic lesions in no more than 2 organs. Large peripheral tumors were treated with a dose of 60 Gy (3 fractions), small peripheral tumors with 30 Gy (1 fraction), central tumors received 60 Gy (5 fractions), and mediastinal tumors or tumors close to the esophagus received 56 Gy (7 fractions). Results: Thirty patients with 57 metastatic lung tumors from various primary cancers were analyzed. The median follow-up was 36 months (range, 4-60 months). At 2 years, local control for the 11 central tumors was 100%, for the 23 peripheral tumors treated to 60 Gy it was 91%, and for the 23 tumors treated in a single 30-Gy fraction it was 74% (P=.13). This resulted in an overall local control rate at 1 year of 79%, with a 2-sided 80% confidence interval of 67% to 87%. Because the hypothesized value of 70% lies within the confidence interval, we cannot reject the hypothesis that the true local control rate at 1 year is ≤70%, and therefore we did not achieve the goal of the study: an actuarial local control of the treated lung lesions at 1 year of 90%. The 4-year overall survival rate was 38%. Grade 3 acute toxicity occurred in 5 patients. Three patients complained of chronic grade 3 toxicity, including pain, fatigue, and pneumonitis, and 3 patients had rib fractures. Conclusions: The local control was promising, and the 4-year overall survival rate was 38%. The treatment was well tolerated, even for central lesions.

  17. Los Alamos provides HOPE for radiation belt storm probes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    HOPE for radiation belt storm probes Los Alamos provides HOPE for radiation belt storm probes The HOPE analyzer is one of a suite of instruments that was successfully launched as part of the Radiation Belt Storm Probe mission. August 30, 2012 Artist's rendering showing two spacecraft representing the not-yet-designed Radiation Belt Storm Probes that will study the sun and its effects on Earth. PHOTO CREDIT: Johns Hopkins University Applied Physics Laboratory Artist's rendering showing two

  18. SU-E-T-320: The Effect of Survivin Perturbation On the Radiation Response of Breast Cancer Cell Lines

    SciTech Connect (OSTI)

    Smith, D; Debeb, B; Woodward, W

    2014-06-01

    Purpose: Survivin is the smallest member of the inhibitor of apoptosis protein family and is well-known for its universal over-expression in human cancers. Due to its role in apoptosis and cellular proliferation, survivin is implicated in the radiation response in several cancer types, and antisurvivin treatments have had success as a radiation sensitizer in many preclinical cancer models. As no studies to date have reported survivin as a factor affecting radiation resistance in breast cancer models, we sought to evaluate the synergistic relationship between survivin function and irradiation in breast cancer cell lines. Methods: Information regarding survivin protein expression in breast cancer was retrieved from three public databases: Oncomine, Kaplan-Meier Plotter, and GOBO. For the in vitro studies, survivin function was compromised by transducing a non-functional mutant form (survivin-DN) into two breast cancer cell lines, the estrogen receptor-positive MCF7 and the triple-negative, inflammatory SUM149. Cell growth was compared in the survivin-DN and control populations with colony-formation assays. To assess how survivin affects radiation response, clonogenic assays were performed by irradiating the cell lines up to 6 Gy. Results: From the public databases, survivin is more highly expressed in triple-negative breast cancer compared to all other subtypes, and is prognostic of poor survival in all breast cancer patients. In MCF7, the survivin-DN population had decreased colony-formation potential; the opposite was true in SUM149. In the clonogenic assays, abrogation of survivin function radio-protected MCF7 cells in monolayer and 3D growth conditions, while SUM149 survivin-DN cells were radiosensitized in monolayer conditions. Conclusion: We observed synergy between survivin function and radiation, although the results between the two cell lines were disparate. Further investigation is required to identify the mechanism of this discrepancy, including evaluation

  19. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    SciTech Connect (OSTI)

    Gomez-Cardona, Daniel; Nagle, Scott K.; Li, Ke; Chen, Guang-Hong; Robinson, Terry E.

    2015-10-15

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

  20. The effects of ionizing radiation on Reillex trademark HPQ, a new macroporous polyvinylpyridine resin, and on four conventional polystyrene anion exchange resins

    SciTech Connect (OSTI)

    Marsh, S.F.

    1990-11-01

    This study compares the effects of ionizing radiation on Reillex{trademark} HPQ, a recently available macroporous copolymer of 1-methyl-4-vinylpyridine/divinylbenzene, and on four conventional strong-base polystyrene anion exchange resins. The polystyrene resins investigated included one gel type, Dowex{trademark} 1 {times} 4, and three macroporous resins: Dow{trademark} MSA-1, Amberlite{trademark} IRA-900, and Lewatit{trademark} MP-500-FK. Each resin, in 7 M nitric acid, was subjected to seven different levels of {sup 60}Co gamma radiation ranging from 100 to 1000 megarads. Irradiated resins were measured for changes in dry weight, wet volume, chloride and Pu(IV) exchange capacities, and thermal stability. In separate experiments, each resin was subjected to approximately 340 megarads of in situ alpha particles from sorbed plutonium. Resin damage from alpha particles was less than half that caused by gamma rays, which may be a consequence of different production rates of radiolytic nitrite and nitro radicals in the two systems. Reillex{trademark} HPQ resin provided the greatest radiation stability, whereas Lewatit{trademark} MP-500-FK was the least stable of the resins tested. Thermogravimetric analyses of dry, nitrate-form resin revealed that dry Reillex{trademark} HPQ resin offered the best thermal stability for absorbed gamma doses to 370 megarads, but the worst thermal stability after exposures of 550 megarads or more. 25 refs., 11 figs., 13 tabs.

  1. Effects of estrogen and gender on cataractogenesis induced by high-LET radiation

    SciTech Connect (OSTI)

    Henderson, M.A.; Rusek, A.; Valluri, S.; Garrett, J.; Lopez, J.; Caperell-Grant, A.; Mendonca, M.; Bigsby, R.; Dynlacht, J.

    2010-02-01

    Planning for long-duration manned lunar and interplanetary missions requires an understanding of radiation-induced cataractogenesis. Previously, it was demonstrated that low-linear energy transfer (LET) irradiation with 10 Gy of {sup 60}Co {gamma} rays resulted in an increased incidence of cataracts in male rats compared to female rats. This gender difference was not due to differences in estrogen, since male rats treated with the major secreted estrogen 17-{beta}-estradiol (E2) showed an identical increase compared to untreated males. We now compare the incidence and rate of progression of cataracts induced by high-LET radiation in male and female Sprague-Dawley rats. Rats received a single dose of 1 Gy of 600 MeV {sup 56}Fe ions. Lens opacification was measured at 2-4 week intervals with a slit lamp. The incidence and rate of progression of radiation-induced cataracts was significantly increased in the animals in which estrogen was available from endogenous or exogenous sources. Male rats with E2 capsules implanted had significantly higher rates of progression compared to male rats with empty capsules implanted (P = 0.025) but not compared to the intact female rats. These results contrast with data obtained after low-LET irradiation and suggest the possibility that the different types of damage caused by high- and low-LET radiation may be influenced differentially by steroid sex hormones.

  2. RTOG 0211: A Phase 1/2 Study of Radiation Therapy With Concurrent Gefitinib for Newly Diagnosed Glioblastoma Patients

    SciTech Connect (OSTI)

    Chakravarti, Arnab; Wang, Meihua; Robins, H. Ian; Lautenschlaeger, Tim; Curran, Walter J.; Brachman, David G.; Schultz, Christopher J.; Choucair, Ali; Dolled-Filhart, Marisa; Christiansen, Jason; Gustavson, Mark; Molinaro, Annette; Ludwig Institute for Cancer Research, University of CaliforniaSan Diego, La Jolla, California ; Mischel, Paul; Dicker, Adam P.; and others

    2013-04-01

    Purpose: To determine the safety and efficacy of gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in combination with radiation for newly diagnosed glioblastoma (GBM) patients. Methods and Materials: Between March 21, 2002, and May 3, 2004, Radiation Therapy Oncology Group (RTOG) 0211 enrolled 31 and 147 GBM patients in the phase 1 and 2 arms, respectively. Treatment consisted of daily oral gefinitnib started at the time of conventional cranial radiation therapy (RT) and continued post RT for 18 months or until progression. Tissue microarrays from 68 cases were analyzed for EGFR expression. Results: The maximum tolerated dose (MTD) of gefitinib was determined to be 500 mg in patients on non-enzyme-inducing anticonvulsant drugs (non-EIAEDs). All patients in the phase 2 component were treated at a gefitinib dose of 500 mg; patients receiving EIADSs could be escalated to 750 mg. The most common side effects of gefitinib in combination with radiation were dermatologic and gastrointestinal. Median survival was 11.5 months for patients treated per protocol. There was no overall survival benefit for patients treated with gefitinib + RT when compared with a historical cohort of patients treated with RT alone, matched by RTOG recursive partitioning analysis (RPA) class distribution. Younger age was significantly associated with better outcome. Per protocol stratification, EGFR expression was not found to be of prognostic value for gefitinib + RT-treated patients. Conclusions: The addition of gefitinib to RT is well tolerated. Median survival of RTOG 0211 patients treated with RT with concurrent and adjuvant gefitinib was similar to that in a historical control cohort treated with radiation alone.

  3. Continuous Positive Airway Pressure for Motion Management in Stereotactic Body Radiation Therapy to the Lung: A Controlled Pilot Study

    SciTech Connect (OSTI)

    Goldstein, Jeffrey D.; Lawrence, Yaacov R.; Appel, Sarit; Landau, Efrat; Ben-David, Merav A.; Rabin, Tatiana; Benayun, Maoz; Dubinski, Sergey; Weizman, Noam; Alezra, Dror; Gnessin, Hila; Goldstein, Adam M.; Baidun, Khader; Segel, Michael J.; Peled, Nir; Symon, Zvi

    2015-10-01

    Objective: To determine the effect of continuous positive airway pressure (CPAP) on tumor motion, lung volume, and dose to critical organs in patients receiving stereotactic body radiation therapy (SBRT) for lung tumors. Methods and Materials: After institutional review board approval in December 2013, patients with primary or secondary lung tumors referred for SBRT underwent 4-dimensional computed tomographic simulation twice: with free breathing and with CPAP. Tumor excursion was calculated by subtracting the vector of the greatest dimension of the gross tumor volume (GTV) from the internal target volume (ITV). Volumetric and dosimetric determinations were compared with the Wilcoxon signed-rank test. CPAP was used during treatment if judged beneficial. Results: CPAP was tolerated well in 10 of the 11 patients enrolled. Ten patients with 18 lesions were evaluated. The use of CPAP decreased tumor excursion by 0.5 ± 0.8 cm, 0.4 ± 0.7 cm, and 0.6 ± 0.8 cm in the superior–inferior, right–left, and anterior–posterior planes, respectively (P≤.02). Relative to free breathing, the mean ITV reduction was 27% (95% confidence interval [CI] 16%-39%, P<.001). CPAP significantly augmented lung volume, with a mean absolute increase of 915 ± 432 cm{sup 3} and a relative increase of 32% (95% CI 21%-42%, P=.003), contributing to a 22% relative reduction (95% CI 13%-32%, P=.001) in mean lung dose. The use of CPAP was also associated with a relative reduction in mean heart dose by 29% (95% CI 23%-36%, P=.001). Conclusion: In this pilot study, CPAP significantly reduced lung tumor motion compared with free breathing. The smaller ITV, the planning target volume (PTV), and the increase in total lung volume associated with CPAP contributed to a reduction in lung and heart dose. CPAP was well tolerated, reproducible, and simple to implement in the treatment room and should be evaluated further as a novel strategy for motion management in radiation therapy.

  4. Origin of radiative recombination and manifestations of localization effects in GaAs/GaNAs core/shell nanowires

    SciTech Connect (OSTI)

    Chen, S. L.; Filippov, S.; Chen, W. M.; Buyanova, I. A.; Ishikawa, Fumitaro

    2014-12-22

    Radiative carrier recombination processes in GaAs/GaNAs core/shell nanowires grown by molecular beam epitaxy on a Si substrate are systematically investigated by employing micro-photoluminescence (?-PL) and ?-PL excitation (?-PLE) measurements complemented by time-resolved PL spectroscopy. At low temperatures, alloy disorder is found to cause localization of photo-excited carriers leading to predominance of optical transitions from localized excitons (LE). Some of the local fluctuations in N composition are suggested to lead to strongly localized three-dimensional confining potential equivalent to that for quantum dots, based on the observation of sharp and discrete PL lines within the LE contour. The localization effects are found to have minor influence on PL spectra at room temperature due to thermal activation of the localized excitons to extended states. Under these conditions, photo-excited carrier lifetime is found to be governed by non-radiative recombination via surface states which is somewhat suppressed upon N incorporation.

  5. Evaluation of radiation dose and image quality of CT scan for whole-body pediatric PET/CT: A phantom study

    SciTech Connect (OSTI)

    Yang, Ching-Ching; Liu, Shu-Hsin; Mok, Greta S. P.; Wu, Tung-Hsin

    2014-09-15

    Purpose: This study aimed to tailor the CT imaging protocols for pediatric patients undergoing whole-body PET/CT examinations with appropriate attention to radiation exposure while maintaining adequate image quality for anatomic delineation of PET findings and attenuation correction of PET emission data. Methods: The measurements were made by using three anthropomorphic phantoms representative of 1-, 5-, and 10-year-old children with tube voltages of 80, 100, and 120 kVp, tube currents of 10, 40, 80, and 120 mA, and exposure time of 0.5 s at 1.75:1 pitch. Radiation dose estimates were derived from the dose-length product and were used to calculate risk estimates for radiation-induced cancer. The influence of image noise on image contrast and attenuation map for CT scans were evaluated based on Pearson's correlation coefficient and covariance, respectively. Multiple linear regression methods were used to investigate the effects of patient age, tube voltage, and tube current on radiation-induced cancer risk and image noise for CT scans. Results: The effective dose obtained using three anthropomorphic phantoms and 12 combinations of kVp and mA ranged from 0.09 to 4.08 mSv. Based on our results, CT scans acquired with 80 kVp/60 mA, 80 kVp/80 mA, and 100 kVp/60 mA could be performed on 1-, 5-, and 10-year-old children, respectively, to minimize cancer risk due to CT scans while maintaining the accuracy of attenuation map and CT image contrast. The effective doses of the proposed protocols for 1-, 5- and 10-year-old children were 0.65, 0.86, and 1.065 mSv, respectively. Conclusions: Low-dose pediatric CT protocols were proposed to balance the tradeoff between radiation-induced cancer risk and image quality for patients ranging in age from 1 to 10 years old undergoing whole-body PET/CT examinations.

  6. Evaluation on the Effect of Composition on Radiation Hardening and Embrittlement in Model FeCrAl Alloys

    SciTech Connect (OSTI)

    Field, Kevin G.; Briggs, Samuel A.; Edmondson, Philip; Hu, Xunxiang; Littrell, Kenneth C.; Howard, Richard; Parish, Chad M.; Yamamoto, Yukinori

    2015-09-18

    networks acting as defect sinks, resulting in variations in the observed microstructures after irradiation. Dose trends were also observed, with increasing radiation dose promoting changes in the size and number density of the Cr-rich α' precipitates. Based on the microstructural analysis, performed tensile testing, and prior knowledge from FeCr literature it was hypothesized that the formation of the Cr-rich α' precipitates could lead to significant radiation-induced embrittlement in the alloys, and this could be composition dependent, a result which would mirror the trends observed for radiation-induced hardening. Due to the limited database on embrittlement in the FeCrAl alloy class after irradiation, a series of radiation experiments have been implemented. The overarching point of view within this report is the radiation tolerance of FeCrAl is complex, with many mechanisms and factors to be considered at once. Further development of the FeCrAl alloy class for enhanced accident tolerant applications requires detailed, single (or at least limited) variable experiments to fully comprehend and predict the performance of this alloy in LWRs. This report has been submitted as fulfillment of milestone M2FT-15OR0202321 titled, Summary report on the effect of composition on the irradiation embrittlement of Gen 1 ATF FeCrAl for the Department of Energy Office of Nuclear Energy, Advanced Fuel Campaign of the Fuel Cycle R&D program.

  7. Effects of sulfate aerosol on the central Pennsylvania surface shortwave radiation budget. Master's thesis

    SciTech Connect (OSTI)

    Guimond, P.W.

    1994-12-01

    Surface radiation measurements are taken simultaneously with measurements of meteorological variables including temperature, pressure, relative humidity, and visibility to evaluate the impact of sulfate haze on the surface radiation budget. A relationship is sought between flux losses due only to aerosol and relative humidity, visibility or both, with the goal of facilitating parameterization of sulfate hazes by climate modelers. At the same time, a rotating shadowband radiometer (RSR) is compared with a more costly sun photometer to determine the feasibility of substituting the former for the latter in future research. It is found that depletion of surface radiation due to aerosol is typically ten to twenty percent of initial insolation, and that the losses can be correlated with zenith angle, relative humidity and optical depth. In the case of flux loss as a function of optical depth, the two are related in a nearly linear fashion. It is also discovered that the RSR has a predictable error owing to a wider field of view than the sun photometer, and can be used as a replacement for the former by correcting for the error.

  8. MD simulations of phase stability of PuGa alloys: Effects of primary radiation defects and helium bubbles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dremov, V. V.; Sapozhnikov, F. A.; Ionov, G. V.; Karavaev, A. V.; Vorobyova, M. A.; Chung, B. W.

    2013-05-14

    We present classical molecular dynamics (MD) with Modified Embedded Atom Model (MEAM) simulations to investigate the role of primary radiation defects and radiogenic helium as factors affecting the phase stability of PuGa alloys in cooling–heating cycles at ambient pressure. The models of PuGa alloys equilibrated at ambient conditions were subjected to cooling–heating cycles in which they were initially cooled down to 100 K and then heated up to 500 K at ambient pressure. The rate of temperature change in the cycles was 10 K/ns. The simulations showed that the initial FCC phase of PuGa alloys undergo polymorphous transition in coolingmore » to a lower symmetry α'-phase. All the alloys undergo direct and reverse polymorphous transitions in the cooling–heating cycles. The alloys containing vacancies shift in both transitions to lower temperatures relative to the defect-free alloys. The radiogenic helium has much less effect on the phase stability compared to that of primary radiation defects (in spite of the fact that helium concentration is twice of that for the primary radiation defects). Lastly, this computational result agrees with experimental data on unconventional stabilization mechanism of PuGa alloys.« less

  9. Use of ARM Mobile Facility (AMF) Data to Study Aerosol Indirect Effects in China

    SciTech Connect (OSTI)

    Li, Zhanqing

    2012-12-19

    General goals: 1) Facilitating the deployment of the ARM Mobile Facility (AMF) and Ancillary Facility (AAF) in China in 2008, 2) Processing, retrieving, improving and analyzing observation data from ground-based, air-borne and space-borne instruments; 3) Conducting a series of studies to gain insights into the direct and indirect effects of these aerosols on radiation, clouds, and precipitation using both

  10. Poster — Thur Eve — 18: Cherenkov Emission By High-Energy Radiation Therapy Beams: A Characterization Study

    SciTech Connect (OSTI)

    Zlateva, Y.; El Naqa, I.; Quitoriano, N.

    2014-08-15

    We investigate Cherenkov emission (CE) by radiotherapy beams via radiation dose-versus-CE correlation analyses, CE detection optimization by means of a spectral shift towards the near-infrared (NIR) window of biological tissue, and comparison of CE to on-board MV imaging. Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissue-simulating phantom composed of water, Intralipid®, and beef blood; plastic phantom with solid water insert. The detector system comprises an optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated CCD. The NIR shift was carried out with CdSe/ZnS quantum dots (QDs), emitting at (650±10) nm. CE and MV images were acquired with a CMOS camera and electronic portal imaging device. MC and experimental studies indicate a strong linear dose-CE correlation (Pearson coefficient > 0.99). CE by an 18-MeV beam was effectively NIR-shifted in water and a tissue-simulating phantom, exhibiting a significant increase at 650 nm for QD depths up to 10 mm. CE images exhibited relative contrast superior to MV images by a factor of 30. Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing and QDs can be used to improve CE detectability, potentially yielding image quality superior to MV imaging for the case of low-density-variability, low-optical-attenuation materials (ex: breast/oropharynx). Ongoing work involves microenvironment functionalization of QDs and application of multi-channel spectrometry for simultaneous acquisition of dosimetric and tumor oxygenation signals.

  11. Study of the spatial coherence of high order harmonic radiation generated from pre-formed plasma plumes

    SciTech Connect (OSTI)

    Kumar, M.; Singhal, H.; Chakera, J. A.; Naik, P. A.; Khan, R. A.; Gupta, P. D.

    2013-07-21

    A study of the spatial coherence of the high order harmonic radiation generated by the interaction of 45 fs Ti:sapphire laser beam with carbon (graphite) plasma plume has been carried out using Young's double slit interferometry. It is observed that the spatial coherence varies with harmonic order, laser focal spot size in plasma plume, and peaks at an optimal spot size. It is also observed that the spatial coherence is higher when the laser pulse is focused before the plasma plume than when focused after the plume, and it decreases with increase in the harmonic order. The optimum laser parameters and the focusing conditions to achieve good spatial coherence with high harmonic conversion have been identified, which is desirable for practical applications of the harmonic radiation.

  12. Study of Engine Operating Parameter Effects on GDI Engine Particle...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Study of Engine Operating Parameter Effects on GDI Engine Particle-Number Emissions Study of Engine Operating Parameter Effects on GDI Engine Particle-Number Emissions Results show ...

  13. Radiation Exposure During Uterine Artery Embolization: Effective Measures to Minimize Dose to the Patient

    SciTech Connect (OSTI)

    Scheurig-Muenkler, Christian; Powerski, Maciej J.; Mueller, Johann-Christoph; Kroencke, Thomas J.

    2015-06-15

    PurposeEvaluation of patient radiation exposure during uterine artery embolization (UAE) and literature review to identify techniques minimizing required dose.MethodsA total of 224 of all included 286 (78 %) women underwent UAE according to a standard UAE-protocol (bilateral UAE from unilateral approach using a Rösch inferior mesenteric and a microcatheter, no aortography, no ovarian artery catheterization or embolization) and were analyzed for radiation exposure. Treatment was performed on three different generations of angiography systems: (I) new generation flat-panel detector (N = 108/151); (II) classical image amplifier and pulsed fluoroscopy (N = 79/98); (III) classical image amplifier and continuous fluoroscopy (N = 37/37). Fluoroscopy time (FT) and dose-area product (DAP) were documented. Whenever possible, the following dose-saving measures were applied: optimized source-object, source-image, and object-image distances, pulsed fluoroscopy, angiographic runs in posterior-anterior direction with 0.5 frames per second, no magnification, tight collimation, no additional aortography.ResultsIn a standard bilateral UAE, the use of the new generation flat-panel detector in group I led to a significantly lower DAP of 3,156 cGy × cm{sup 2} (544–45,980) compared with 4,000 cGy × cm{sup 2} (1,400–13,000) in group II (P = 0.033). Both doses were significantly lower than those of group III with 8,547 cGy × cm{sup 2} (3,324–35,729; P < 0.001). Other reasons for dose escalation were longer FT due to difficult anatomy or a large leiomyoma load, additional angiographic runs, supplementary ovarian artery embolization, and obesity.ConclusionsThe use of modern angiographic units with flat panel detectors and strict application of methods of radiation reduction lead to a significantly lower radiation exposure. Target DAP for UAE should be kept below 5,000 cGy × cm{sup 2}.

  14. Impacts, Effectiveness and Regional Inequalities of the GeoMIP G1 to G4 Solar Radiation Management Scenarios

    SciTech Connect (OSTI)

    Yu, Xiaoyong; Moore, John; Cui, Xuefeng; Rinke, Annette; Ji, Duoying; Kravitz, Benjamin S.; Yoon, Jin-Ho

    2015-06-01

    We evaluate the regional effectiveness of solar radiation management (SRM) to compensate for simultaneous changes in temperature and precipitation induced by increased greenhouse gas concentrations. We analyze results from multiple earth system models under four Geoengineering Model Intercomparison Project(GeoMIP) experiments with a modified form of the Residual Climate Response approach. Under the solar dimming geoengineering experiments G1(4xCO2) and G2(increasing CO2 by 1% per year), global average temperature is successfully restored to pre-industrial level over 50 years simulations. However, these two SRM experiments also produce a robust global precipitation decrease. The stratospheric aerosol GeoMIP geoengineering experiment, G4 has significantly greater regional inequality and lower effectiveness for compensating temperature change than G1 and G2. G4 also has significantly larger regional inequality for compensating precipitation change than G1and G2. However, there is no significant difference between precipitation change compensation effectiveness of G4 and G2, though there is much larger across model variability in G4 results. G3 has significant greater regional inequality for compensating temperature change than G1 and G2, and has significant lower effectiveness than G1. The effectiveness of four SRMs to compensate for temperature change is much higher than for precipitation. The large cross-model variation in adjustment percentage of compensated SAT and precipitation change by SRM to achieve optimal compensation effectiveness shed a light on the uncertainty accumulation effect in optimizing compensation effectiveness of SRM.

  15. Radiation doses in volume-of-interest breast computed tomography—A Monte Carlo simulation study

    SciTech Connect (OSTI)

    Lai, Chao-Jen Zhong, Yuncheng; Yi, Ying; Wang, Tianpeng; Shaw, Chris C.

    2015-06-15

    Purpose: Cone beam breast computed tomography (breast CT) with true three-dimensional, nearly isotropic spatial resolution has been developed and investigated over the past decade to overcome the problem of lesions overlapping with breast anatomical structures on two-dimensional mammographic images. However, the ability of breast CT to detect small objects, such as tissue structure edges and small calcifications, is limited. To resolve this problem, the authors proposed and developed a volume-of-interest (VOI) breast CT technique to image a small VOI using a higher radiation dose to improve that region’s visibility. In this study, the authors performed Monte Carlo simulations to estimate average breast dose and average glandular dose (AGD) for the VOI breast CT technique. Methods: Electron–Gamma-Shower system code-based Monte Carlo codes were used to simulate breast CT. The Monte Carlo codes estimated were validated using physical measurements of air kerma ratios and point doses in phantoms with an ion chamber and optically stimulated luminescence dosimeters. The validated full cone x-ray source was then collimated to simulate half cone beam x-rays to image digital pendant-geometry, hemi-ellipsoidal, homogeneous breast phantoms and to estimate breast doses with full field scans. 13-cm in diameter, 10-cm long hemi-ellipsoidal homogeneous phantoms were used to simulate median breasts. Breast compositions of 25% and 50% volumetric glandular fractions (VGFs) were used to investigate the influence on breast dose. The simulated half cone beam x-rays were then collimated to a narrow x-ray beam with an area of 2.5 × 2.5 cm{sup 2} field of view at the isocenter plane and to perform VOI field scans. The Monte Carlo results for the full field scans and the VOI field scans were then used to estimate the AGD for the VOI breast CT technique. Results: The ratios of air kerma ratios and dose measurement results from the Monte Carlo simulation to those from the physical

  16. Outstanding conference paper award 2014 IEEE nuclear and space radiation effects conference

    SciTech Connect (OSTI)

    Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; Dodd, Paul E.; Doyle, Barney Lee; Trinczek, Michael; Blackmore, Ewart W.; Rodbell, Kenneth P.; Reed, Robert A.; Pellish, Jonathan A.; LaBel, Kenneth A.; Marshall, Paul W.; Swanson, Scot E.; Vizkelethy, Gyorgy; Van Deusen, Stuart B.; Sexton, Frederick W.; Martinez, Marino John

    2014-12-01

    The recipients of the 2014 NSREC Outstanding Conference Paper Award are Nathaniel A. Dodds, James R. Schwank, Marty R. Shaneyfelt, Paul E. Dodd, Barney L. Doyle, Michael Trinczek, Ewart W. Blackmore, Kenneth P. Rodbell, Michael S. Gordon, Robert A. Reed, Jonathan A. Pellish, Kenneth A. LaBel, Paul W. Marshall, Scot E. Swanson, Gyorgy Vizkelethy, Stuart Van Deusen, Frederick W. Sexton, and M. John Martinez, for their paper entitled "Hardness Assurance for Proton Direct Ionization-Induced SEEs Using a High-Energy Proton Beam." For older CMOS technologies, protons could only cause single-event effects (SEEs) through nuclear interactions. Numerous recent studies on 90 nm and newer CMOS technologies have shown that protons can also cause SEEs through direct ionization. Furthermore, this paper develops and demonstrates an accurate and practical method for predicting the error rate caused by proton direct ionization (PDI).

  17. Outstanding conference paper award 2014 IEEE nuclear and space radiation effects conference

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; Dodd, Paul E.; Doyle, Barney Lee; Trinczek, Michael; Blackmore, Ewart W.; Rodbell, Kenneth P.; Reed, Robert A.; Pellish, Jonathan A.; et al

    2014-12-01

    The recipients of the 2014 NSREC Outstanding Conference Paper Award are Nathaniel A. Dodds, James R. Schwank, Marty R. Shaneyfelt, Paul E. Dodd, Barney L. Doyle, Michael Trinczek, Ewart W. Blackmore, Kenneth P. Rodbell, Michael S. Gordon, Robert A. Reed, Jonathan A. Pellish, Kenneth A. LaBel, Paul W. Marshall, Scot E. Swanson, Gyorgy Vizkelethy, Stuart Van Deusen, Frederick W. Sexton, and M. John Martinez, for their paper entitled "Hardness Assurance for Proton Direct Ionization-Induced SEEs Using a High-Energy Proton Beam." For older CMOS technologies, protons could only cause single-event effects (SEEs) through nuclear interactions. Numerous recent studies on 90 nmmore » and newer CMOS technologies have shown that protons can also cause SEEs through direct ionization. Furthermore, this paper develops and demonstrates an accurate and practical method for predicting the error rate caused by proton direct ionization (PDI).« less

  18. WE-D-BRE-01: A Sr-90 Irradiation Device for the Study of Cutaneous Radiation Injury

    SciTech Connect (OSTI)

    Dorand, JE; Bourland, JD; Burnett, LR; Tytell, M

    2014-06-15

    Purpose: To determine dosimetric character for a custom-built Sr-90 beta irradiator designed for the study of Cutaneous Radiation Injury (CRI) in a porcine animal model. In the event of a radiological accident or terrorist event, Sr-90, a fission by-product, will likely be produced. CRI is a main concern due to the low energy and superficial penetration in tissue of beta particles from Sr-90. Seven 100 mCi plaque Sr-90 radiation sources within a custom-built irradiation device create a 40 mm diameter region of radiation-induced skin injury as part of a larger project to study the efficacy of a topical keratin-based product in CRI healing. Methods: A custom-built mobile irradiation device was designed and implemented for in vivo irradiations. Gafchromic™ EBT3 radiochromic film and a PTW Markus chamber type 23343 were utilized for dosimetric characterization of the beta fluence at the surface produced by this device. Films were used to assess 2-dimensional dose distribution and percent depth dose characteristics of the radiation field. Ion chamber measurements provided dose rate data within the field. Results: The radiation field produced by the irradiation device is homogeneous with high uniformity (∼5%) and symmetry (∼3%) with a steep dose fall-off with depth from the surface. Dose rates were determined to be 3.8 Gy/min and 3.3 Gy/min for film and ion chamber measurements, respectively. A dose rate of 3.4 Gy/min was used to calculate irradiation times for in vivo irradiations. Conclusion: The custom-built irradiation device enables the use of seven Sr-90 beta sources in an array to deliver a 40 mm diameter area of homogeneous skin dose with a dose rate that is useful for research purposes and clinically relevant for the induction of CRI. Doses of 36 and 42 Gy successfully produce Grade III CRI and are used in the study of the efficacy of KeraStat™. This project has been funded in whole or in part with Federal funds from the Biomedical Advanced Research and

  19. Extraterrestrial Materials: The Role of Synchrotron Radiation Analyses in the Study of Our Solar System

    ScienceCinema (OSTI)

    Sutton, Stephen R. [University of Chicago, Chicago, Illinois, United States

    2010-01-08

    Sample-return missions and natural collection processes have provided us with a surprisingly extensive collection of matter from Solar System bodies other than the Earth. These collections include samples from the Moon, Mars, asteroids, interplanetary dust, and, recently, from the Sun (solar wind) and a comet. This presentation will describe some of these materials, how they were collected, and what we have learned from them. Synchrotron radiation analyses of these materials are playing an increasingly valuable role in unraveling the histories and properities of the parent Solar System bodies.

  20. Targeting the Renin–Angiotensin System Combined With an Antioxidant Is Highly Effective in Mitigating Radiation-Induced Lung Damage

    SciTech Connect (OSTI)

    Mahmood, Javed; Jelveh, Salomeh; Zaidi, Asif; Doctrow, Susan R.; Medhora, Meetha; Hill, Richard P.

    2014-07-15

    Purpose: To investigate the outcome of suppression of the renin angiotensin system using captopril combined with an antioxidant (Eukarion [EUK]-207) for mitigation of radiation-induced lung damage in rats. Methods and Materials: The thoracic cavity of female Sprague-Dawley rats was irradiated with a single dose of 11 Gy. Treatment with captopril at a dose of 40 mg/kg/d in drinking water and EUK-207 given by subcutaneous injection (8 mg/kg daily) was started 1 week after irradiation (PI) and continuing until 14 weeks PI. Breathing rate was monitored until the rats were killed at 32 weeks PI, when lung fibrosis was assessed by lung hydroxyproline content. Lung levels of the cytokine transforming growth factor-β1 and macrophage activation were analyzed by immunohistochemistry. Oxidative DNA damage was assessed by 8-hydroxy-2-deoxyguanosine levels, and lipid peroxidation was measured by a T-BARS assay. Results: The increase in breathing rate in the irradiated rats was significantly reduced by the drug treatments. The drug treatment also significantly decreased the hydroxyproline content, 8-hydroxy-2-deoxyguanosine and malondialdehyde levels, and levels of activated macrophages and the cytokine transforming growth factor-β1 at 32 weeks. Almost complete mitigation of these radiation effects was observed by combining captopril and EUK-207. Conclusion: Captopril and EUK-207 can provide mitigation of radiation-induced lung damage out to at least 32 weeks PI after treatment given 1-14 weeks PI. Overall the combination of captopril and EUK-207 was more effective than the individual drugs used alone.

  1. Ultra-spatial synchrotron radiation for imaging molecular chemical structure: Applications in plant and animal studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yu, Peiqiang

    2007-01-01

    Synchrotron-based Fourier transform infrared microspectroscopy (S-FTIR) has been developed as a rapid, direct, non-destructive, bioanalytical technique. This technique takes advantage of synchrotron light brightness and small effective source size and is capable of exploring the molecular chemical features and make-up within microstructures of a biological tissue without destruction of inherent structures at ultra-spatial resolutions within cellular dimension. To date there has been very little application of this advanced synchrotron technique to the study of plant and animal tissues' inherent structure at a cellular or subcellular level. In this article, a novel approach was introduced to show the potential of themore » newly developed, advanced synchrotron-based analytical technology, which can be used to reveal molecular structural-chemical features of various plant and animal tissues.« less

  2. L-Boronophenylalanine-Mediated Boron Neutron Capture Therapy for Malignant Glioma Progressing After External Beam Radiation Therapy: A Phase I Study

    SciTech Connect (OSTI)

    Kankaanranta, Leena; Seppaelae, Tiina; Koivunoro, Hanna; Vaelimaeki, Petteri; Beule, Annette; Collan, Juhani; Kortesniemi, Mika; Uusi-Simola, Jouni; Kotiluoto, Petri; Auterinen, Iiro; Seren, Tom; Paetau, Anders; Saarilahti, Kauko; Savolainen, Sauli; Joensuu, Heikki

    2011-06-01

    Purpose: To investigate the safety of boronophenylalanine-mediated boron neutron capture therapy (BNCT) in the treatment of malignant gliomas that progress after surgery and conventional external beam radiation therapy. Methods and Materials: Adult patients who had histologically confirmed malignant glioma that had progressed after surgery and external beam radiotherapy were eligible for this Phase I study, provided that >6 months had elapsed from the last date of radiation therapy. The first 10 patients received a fixed dose, 290 mg/kg, of L-boronophenylalanine-fructose (L-BPA-F) as a 2-hour infusion before neutron irradiation, and the remaining patients were treated with escalating doses of L-BPA-F, either 350 mg/kg, 400 mg/kg, or 450 mg/kg, using 3 patients on each dose level. Adverse effects were assessed using National Cancer Institute Common Toxicity Criteria version 2.0. Results: Twenty-two patients entered the study. Twenty subjects had glioblastoma, and 2 patients had anaplastic astrocytoma, and the median cumulative dose of prior external beam radiotherapy was 59.4 Gy. The maximally tolerated L-BPA-F dose was reached at the 450 mg/kg level, where 4 of 6 patients treated had a grade 3 adverse event. Patients who were given >290 mg/kg of L-BPA-F received a higher estimated average planning target volume dose than those who received 290 mg/kg (median, 36 vs. 31 Gy [W, i.e., a weighted dose]; p = 0.018). The median survival time following BNCT was 7 months. Conclusions: BNCT administered with an L-BPA-F dose of up to 400 mg/kg as a 2-hour infusion is feasible in the treatment of malignant gliomas that recur after conventional radiation therapy.

  3. Simultaneous Integrated Boost–Intensity Modulated Radiation Therapy With Concomitant Capecitabine and Mitomycin C for Locally Advanced Anal Carcinoma: A Phase 1 Study

    SciTech Connect (OSTI)

    Deenen, Maarten J.; Dewit, Luc; Boot, Henk; Beijnen, Jos H.; Faculty of Science, Department of Pharmaceutical Sciences, Division of Pharmaco-epidemiology and Clinical Pharmacology, Utrecht University, Utrecht ; Schellens, Jan H.M.; Faculty of Science, Department of Pharmaceutical Sciences, Division of Pharmaco-epidemiology and Clinical Pharmacology, Utrecht University, Utrecht ; Cats, Annemieke

    2013-04-01

    Purpose: Newer radiation techniques, and the application of continuous 5-FU exposure during radiation therapy using oral capecitabine may improve the treatment of anal cancer. This phase 1, dose-finding study assessed the feasibility and efficacy of simultaneous integrated boost–intensity modulated radiation therapy (SIB-IMRT) with concomitant capecitabine and mitomycin C in locally advanced anal cancer, including pharmacokinetic and pharmacogenetic analyses. Methods and Materials: Patients with locally advanced anal carcinoma were treated with SIB-IMRT in 33 daily fractions of 1.8 Gy to the primary tumor and macroscopically involved lymph nodes and 33 fractions of 1.5 Gy electively to the bilateral iliac and inguinal lymph node areas. Patients received a sequential radiation boost dose of 3 × 1.8 Gy on macroscopic residual tumor if this was still present in week 5 of treatment. Mitomycin C 10 mg/m{sup 2} (maximum 15 mg) was administered intravenously on day 1, and capecitabine was given orally in a dose-escalated fashion (500-825 mg/m{sup 2} b.i.d.) on irradiation days, until dose-limiting toxicity emerged in ≥2 of maximally 6 patients. An additional 8 patients were treated at the maximum tolerated dose (MTD). Results: A total of 18 patients were included. The MTD of capecitabine was determined to be 825 mg/m{sup 2} b.i.d. The predominant acute grade ≥3 toxicities included radiation dermatitis (50%), fatigue (22%), and pain (6%). Fifteen patients (83% [95%-CI: 66%-101%]) achieved a complete response, and 3 (17%) patients a partial response. With a median follow-up of 28 months, none of the complete responders, and 2 partial responders had relapsed. Conclusions: SIB-IMRT with concomitant single dose mitomycin C and capecitabine 825 mg/m{sup 2} b.i.d. on irradiation days resulted in an acceptable safety profile, and proved to be a tolerable and effective treatment regimen for locally advanced anal cancer.

  4. SU-E-T-549: Modeling Relative Biological Effectiveness of Protons for Radiation Induced Brain Necrosis

    SciTech Connect (OSTI)

    Mirkovic, D; Peeler, C; Grosshans, D; Titt, U; Taleei, R; Mohan, R

    2015-06-15

    Purpose: To develop a model of the relative biological effectiveness (RBE) of protons as a function of dose and linear energy transfer (LET) for induction of brain necrosis using clinical data. Methods: In this study, treatment planning information was exported from a clinical treatment planning system (TPS) and used to construct a detailed Monte Carlo model of the patient and the beam delivery system. The physical proton dose and LET were computed in each voxel of the patient volume using Monte Carlo particle transport. A follow-up magnetic resonance imaging (MRI) study registered to the treatment planning CT was used to determine the region of the necrosis in the brain volume. Both, the whole brain and the necrosis volumes were segmented from the computed tomography (CT) dataset using the contours drawn by a physician and the corresponding voxels were binned with respect to dose and LET. The brain necrosis probability was computed as a function of dose and LET by dividing the total volume of all necrosis voxels with a given dose and LET with the corresponding total brain volume resulting in a set of NTCP-like curves (probability as a function of dose parameterized by LET). Results: The resulting model shows dependence on both dose and LET indicating the weakness of the constant RBE model for describing the brain toxicity. To the best of our knowledge the constant RBE model is currently used in all clinical applications which may Result in increased rate of brain toxicities in patients treated with protons. Conclusion: Further studies are needed to develop more accurate brain toxicity models for patients treated with protons and other heavy ions.

  5. Safety Around Sources of Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Keeping Exposure Low Working Safely Around Radioactive Contamination Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Is it safe to be around sources? Too much radiation exposure is harmful. The degree of radiation injury depends on the amount of radiation received and the time involved. In general, the higher the amount, the greater the severity of early effects (occurring within a few weeks) and the greater the possibility of late effects such as cancer. The

  6. An evaluation of the effect of volcanic eruption on the solar radiation at Australian and Canadian stations

    SciTech Connect (OSTI)

    Yatko, B.R.; Garrison, J.D.

    1996-11-01

    Peak (most probable) and average values of {angstrom}`s turbidity coefficient {beta} and peak (most probable) and average values of the diffuse index k{sub d} are obtained from the solar radiation data from 21 stations in Australia and 5 stations in Canada. These data exhibit clear increases in their values when the volcanic aerosols in the stratosphere increase following volcanic eruptions of sufficient magnitude. The effect of the eruptions of Fuego (1974), El Chichon (1982) and Pinatubo (1991) are seen most clearly in the data. The effect of lesser eruptions is also seen. The store of volcanic aerosols in the stratosphere shifts with the season so that scattering by volcanic aerosols in the spring half of the year is stronger than in the fall.

  7. Application of STEM characterization for investigating radiation effects in BCC Fe-based alloys

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Parish, Chad M.; Field, Kevin G.; Certain, Alicia G.; Wharry, Janelle P.

    2015-04-20

    This paper provides a general overview of advanced scanning transmission electron microscopy (STEM) techniques used for characterization of irradiated BCC Fe-based alloys. Advanced STEM methods provide the high-resolution imaging and chemical analysis necessary to understand the irradiation response of BCC Fe-based alloys. The use of STEM with energy dispersive x-ray spectroscopy (EDX) for measurement of radiation-induced segregation (RIS) is described, with an illustrated example of RIS in proton- and self-ion irradiated T91. Aberration-corrected STEM-EDX for nanocluster/nanoparticle imaging and chemical analysis is also discussed, and examples are provided from ion-irradiated oxide dispersion strengthened (ODS) alloys. In conclusion, STEM techniques for void,more » cavity, and dislocation loop imaging are described, with examples from various BCC Fe-based alloys.« less

  8. The effect of back scatter radiation on surface dose as measured by TLDs

    SciTech Connect (OSTI)

    Boguslavsky, R.; Gmuer, N.; Thomlinson, W.

    1991-12-01

    A group of scientists at HASYLAB in Germany are doing an Angiography project in parallel with a group of scientists at the Brookhaven National, National Synchrotron Light Source. In order to determine the X-ray dose to a patient, the German group places lithium fluoride thermoluminescent dosimeters (TLD) on the front (upstream) surface of their patient. The found that the TLD dose was higher than the dose calculated from an ionization chamber. An ionization chamber is a device that counts the number of photons when a beam of synchrotron radiation passes through Dr. Wolf-Rainer Dix of HASYLAB found that there is a difference of about 15% between dose data from TLDs put on a water tub and TLDs in the air. The goal of the experiment we did was to understand and maybe match the dose numbers Dix obtained.

  9. Effect of synchrotron radiation in the proposed 4 GeV Argonne microtron

    SciTech Connect (OSTI)

    Crosbie, E.A.

    1983-01-01

    Synchrotron radiation in the sector magnets of the 4-GeV microtron designed at the Argonne National Laboratory produces a small but noticeable distortion of the closed orbits of the system and a very-significant growth of the horizontal and longitudinal phase-space emittances. Because of the small apertures in the three 25-meter linacs, it is important that the expected growth of the beam be calculated as accurately as possible. For this reason, a computer program has been written which follows the motions of individual electrons in the four dimensional horizontal and longitudinal phase space as they are accelerated in the system. As the electrons go through the sector magnets, they emit quanta at random with randomly chosen energies. The final results show 63% emittance (area ..pi..) values of 0.15 mm mrad and 630 keV degrees for the horizontal and longitudinal phase spaces, respectively. The 99% values are about 4.6 times larger.

  10. Mirror effect induced by the dilaton field on the Hawking radiation

    SciTech Connect (OSTI)

    Maeda, Kengo; Okamura, Takashi

    2006-11-03

    A ''stringy particle'' action is naturally derived from Kaluza-Klein compactification of a test string action coupled to the dilaton field in a conformally invariant manner. According to the standard procedure, we perform the second quantization of the stringy particle. As an interesting application, we consider evaporation of a near-extremal dilatonic black hole by Hawking radiation via the stringy particles. We show that a mirror surface which reflects them is induced by the dilaton field outside the the horizon when the size of the black hole is comparable to the Planck scale. As a result, the energy flux does not propagate across the surface, and hence the evaporation of the dilatonic black hole stops just before the naked singularity at the extremal state appears even though the surface gravity is non-zero in the extremal limit.

  11. Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: Detectability and effectiveness of a flexible monitoring system

    SciTech Connect (OSTI)

    Tachibana, Hidenobu; Kitamura, Nozomi; Ito, Yasushi; Kawai, Daisuke; Nakajima, Masaru; Tsuda, Akihisa; Shiizuka, Hisao

    2011-07-15

    Purpose: In respiratory-gated radiation therapy, a baseline shift decreases the accuracy of target coverage and organs at risk (OAR) sparing. The effectiveness of audio-feedback and audio-visual feedback in correcting the baseline shift in the breathing pattern of the patient has been demonstrated previously. However, the baseline shift derived from the intrafraction motion of the patient's body cannot be corrected by these methods. In the present study, the authors designed and developed a simple and flexible system. Methods: The system consisted of a web camera and a computer running our in-house software. The in-house software was adapted to template matching and also to no preimage processing. The system was capable of monitoring the baseline shift in the intrafraction motion of the patient's body. Another marker box was used to monitor the baseline shift due to the flexible setups required of a marker box for gated signals. The system accuracy was evaluated by employing a respiratory motion phantom and was found to be within AAPM Task Group 142 tolerance (positional accuracy <2 mm and temporal accuracy <100 ms) for respiratory-gated radiation therapy. Additionally, the effectiveness of this flexible and independent system in gated treatment was investigated in healthy volunteers, in terms of the results from the differences in the baseline shift detectable between the marker positions, which the authors evaluated statistically. Results: The movement of the marker on the sternum [1.599 {+-} 0.622 mm (1 SD)] was substantially decreased as compared with the abdomen [6.547 {+-} 0.962 mm (1 SD)]. Additionally, in all of the volunteers, the baseline shifts for the sternum [-0.136 {+-} 0.868 (2 SD)] were in better agreement with the nominal baseline shifts than was the case for the abdomen [-0.722 {+-} 1.56 mm (2 SD)]. The baseline shifts could be accurately measured and detected using the monitoring system, which could acquire the movement of the marker on the

  12. Parametric study of radiation dose rates from rail and truck spent fuel transport casks

    SciTech Connect (OSTI)

    Parks, C.V.; Hermann, O.W.; Knight, J.R.

    1985-08-01

    Neutron and gamma dose rates from typical rail and truck spent fuel transport casks are reported for a variety of spent PWR fuel sources and cask conditions. The IF 300 rail cask and NLI 1/2 truck cask were selected for use as appropriate cask models. All calculations (cross section preparation, generation of spent fuel source terms, radiation transport calculations, and dose evaluation) were performed using various modules of the SCALE computational system. Conditions or parameters for which there were variations between cases include: detector distance from cask, spent fuel cooling time, the setting of fuel or neutron shielding cavities to either wet or dry, the cobalt content of assembly materials, normal fuel assemblies and consolidated cannisters, the geometry mesh interval size, and the order of the angular quadrature set. 13 refs., 6 figs., 9 tabs.

  13. Human radiation studies: Remembering the early years. Oral history of Julie Langham Grilly, February 3, 1995

    SciTech Connect (OSTI)

    1995-09-01

    Julie Langham Grilly was interviewed by representatives of the US DOE Office of Human Radiation Experiments (OHRE) being the widow of Dr. Wright Langham, an investigator of principal interest of the committee. Her extensive experience with research at LANL was also of interest to the committee. Following a brief biographical sketch, Ms. Grilly relates her early postwar experience and her knowledge of Wright Langham`s involvement in animal research at Los Alamos, radiolanthanum tests on monkeys, Eniwetok tissue examinations, research on tritium uptake in humans, plutonium injections, tritium injections, EDTA, and etc. In addition to illuminating her former husband as a researcher and as an individual, she also relates her remembrances of Louis Hempelman, Enrico Fermi, Oppenheimer, Edward Teller, and many others.

  14. A Study of SSI Effects Incorporating Seismic Wave Incoherence...

    Office of Environmental Management (EM)

    A Study of SSI Effects Incorporating Seismic Wave Incoherence within the DOE Complex A Study of SSI Effects Incorporating Seismic Wave Incoherence within the DOE Complex A Study of...

  15. A Phase 1 Study of Everolimus + Weekly Cisplatin + Intensity Modulated Radiation Therapy in Head-and-Neck Cancer

    SciTech Connect (OSTI)

    Fury, Matthew G.; Lee, Nancy Y.; Sherman, Eric; Ho, Alan L.; Rao, Shyam; Heguy, Adriana; Shen, Ronglai; Korte, Susan; Lisa, Donna; Ganly, Ian; Patel, Snehal; Wong, Richard J.; Shaha, Ashok; Shah, Jatin; Haque, Sofia; Katabi, Nora; Pfister, David G.

    2013-11-01

    Purpose: Elevated expression of eukaryotic protein synthesis initiation factor 4E (eIF4E) in histologically cancer-free margins of resected head and neck squamous cell carcinomas (HNSCCs) is mediated by mammalian target of rapamycin complex 1 (mTORC1) and has been associated with increased risk of disease recurrence. Preclinically, inhibition of mTORC1 with everolimus sensitizes cancer cells to cisplatin and radiation. Methods and Materials: This was single-institution phase 1 study to establish the maximum tolerated dose of daily everolimus given with fixed dose cisplatin (30 mg/m{sup 2} weekly 6) and concurrent intensity modulated radiation therapy for patients with locally and/or regionally advanced head-and-neck cancer. The study had a standard 3 + 3 dose-escalation design. Results: Tumor primary sites were oral cavity (4), salivary gland (4), oropharynx (2), nasopharynx (1), scalp (1), and neck node with occult primary (1). In 4 of 4 cases in which resected HNSCC surgical pathology specimens were available for immunohistochemistry, elevated expression of eIF4E was observed in the cancer-free margins. The most common grade ?3 treatment-related adverse event was lymphopenia (92%), and dose-limiting toxicities (DLTs) were mucositis (n=2) and failure to thrive (n=1). With a median follow up of 19.4 months, 2 patients have experienced recurrent disease. The maximum tolerated dose was everolimus 5 mg/day. Conclusions: Head-and-neck cancer patients tolerated everolimus at therapeutic doses (5 mg/day) given with weekly cisplatin and intensity modulated radiation therapy. The regimen merits further evaluation, especially among patients who are status post resection of HNSCCs that harbor mTORC1-mediated activation of eIF4E in histologically negative surgical margins.

  16. Beta Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Beta Radiation 1. Beta radiation may travel meters in air and is moderately penetrating. 2. Beta radiation can penetrate human skin to the "germinal layer," where new skin cells ...

  17. Preliminary experimental investigation of a Ku-band radial line oscillator based on transition radiation effect

    SciTech Connect (OSTI)

    Dang, Fangchao Zhang, Xiaoping; Zhong, Huihuang; Li, Yangmei

    2015-09-15

    A Ku-band radial line oscillator (RLO) with low guiding magnetic field was proposed in our previous work. In order to weaken the impedance mismatch between the oscillator and an intense electron accelerator with higher impedance, a transverse electromagnetic reflector is added to improve the RLO, which is favorable to increase the Q-factor and accelerate the device saturation. A preliminary experiment is carried out to investigate the performance of the improved RLO. The radial-radiated electron beam is restrained well under the designed guiding magnetic field of 0.52 T. The preliminary experimental results indicates that high power microwaves with a power of 120 MW and a frequency of 14.12 GHz are generated when the diode voltage is 420 kV and the beam current 14.2 kA. The experimental results suggest the feasibility of the presented RLO generating high power microwaves at a high frequency band. Additionally, more work is needed regarding promotion of the electron beam quality and the impedance match between the electron beam accelerator and the oscillator.

  18. A novel approach in electron beam radiation therapy of lips carcinoma: A Monte Carlo study

    SciTech Connect (OSTI)

    Shokrani, Parvaneh; Baradaran-Ghahfarokhi, Milad; Zadeh, Maryam Khorami

    2013-04-15

    Purpose: Squamous cell carcinoma (SCC) is commonly treated by electron beam radiotherapy (EBRT) followed by a boost via brachytherapy. Considering the limitations associated with brachytherapy, in this study, a novel boosting technique in EBRT of lip carcinoma using an internal shield as an internal dose enhancer tool (IDET) was evaluated. An IDET is referred to a partially covered internal shield located behind the lip. It was intended to show that while the backscattered electrons are absorbed in the portion covered with a low atomic number material, they will enhance the target dose in the uncovered area. Methods: Monte-Carlo models of 6 and 8 MeV electron beams were developed using BEAMnrc code and were validated against experimental measurements. Using the developed models, dose distributions in a lip phantom were calculated and the effect of an IDET on target dose enhancement was evaluated. Typical lip thicknesses of 1.5 and 2.0 cm were considered. A 5 Multiplication-Sign 5 cm{sup 2} of lead covered by 0.5 cm of polystyrene was used as an internal shield, while a 4 Multiplication-Sign 4 cm{sup 2} uncovered area of the shield was used as the dose enhancer. Results: Using the IDET, the maximum dose enhancement as a percentage of dose at d{sub max} of the unshielded field was 157.6% and 136.1% for 6 and 8 MeV beams, respectively. The best outcome was achieved for lip thickness of 1.5 cm and target thickness of less than 0.8 cm. For lateral dose coverage of planning target volume, the 80% isodose curve at the lip-IDET interface showed a 1.2 cm expansion, compared to the unshielded field. Conclusions: This study showed that a boost concomitant EBRT of lip is possible by modifying an internal shield into an IDET. This boosting method is especially applicable to cases in which brachytherapy faces limitations, such as small thicknesses of lips and targets located at the buccal surface of the lip.

  19. Human radiation studies: Remembering the early years: Oral history of physician James S. Robertson, M.D., Ph.D., conducted January 20, 1995

    SciTech Connect (OSTI)

    1995-09-01

    This report is a transcript of in interview of Dr. James S. Robertson by representatives of the DOE Office of Human Radiation Experiments. Dr. Robertson was chosen for this interview because of his research at Brookhaven National Laboratory, especially on Boron Neutron Capture Therapy (BNCT); his work at the United States Naval Defense Laboratory; and his work at the Atomic Energy Commission. After a brief biographical sketch Dr. Robertson discusses research on human subjects at Berkeley, his contributions to the beginnings of Neutron Capture Therapy at Brookhaven, his participation with the Brookhaven Human Use Committee, his involvement in the study of the effects of Castle Bravo event on the Marshallese, and his work with the Naval Radiological Defense Laboratory.

  20. SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling

    SciTech Connect (OSTI)

    Edvardsen, Hege; K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo ; Landmark-Hyvik, Hege; K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo ; Reinertsen, Kristin V.; Zhao, Xi; K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo ; Grenaker-Alns, Grethe Irene; Nebdal, Daniel; Syvnen, Ann-Christine; Rdningen, Olaug; Alsner, Jan; Overgaard, Jens; Borresen-Dale, Anne-Lise; K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo ; Foss, Sophie D.; National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo ; Kristensen, Vessela N.; K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo; Department of Clinical Molecular Biology , Division of Medicine, Ahus University Hospital

    2013-07-15

    Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P?.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance.

  1. Dealing with the size-of-source effect in the calibration of direct-reading radiation thermometer

    SciTech Connect (OSTI)

    Saunders, P.

    2013-09-11

    The majority of general-purpose low-temperature handheld radiation thermometers are severely affected by the size-of-source effect (SSE). Calibration of these instruments is pointless unless the SSE is accounted for in the calibration process. Traditional SSE measurement techniques, however, are costly and time consuming, and because the instruments are direct-reading in temperature, traditional SSE results are not easily interpretable, particularly by the general user. This paper describes a simplified method for measuring the SSE, suitable for second-tier calibration laboratories and requiring no additional equipment, and proposes a means of reporting SSE results on a calibration certificate that should be easily understood by the non-specialist user.

  2. ARM - Lesson Plans: Effects of Solar Radiation on Land and Sea

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    However, on some of the larger islands of Melanesia (Fiji, Vanuatu, Solomons, and Papua New Guinea), the effect of land and sea on temperature is noticeable, particularly on fine ...

  3. Computer simulation of protein solvation, hydrophobic mapping, and the oxygen effect in radiation biology

    SciTech Connect (OSTI)

    Pratt, L.R.; Garcia, A.E.; Hummer, G.

    1997-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development project at the Los Alamos National Laboratory. Hydrophobic effects are central to the structural stability of biomolecules, particularly proteins, in solution but are not understood at a molecular level. This project developed a new theoretical approach to calculation of hydrophobic effects. This information theory approach can be implemented with experimental, including computer simulation-experimental, information. The new theory is consistent with, builds upon, and subsumes previous integral equation and scaled particle statistical thermodynamic modes of hydrophobic effects. the new theory is sufficiently simple to permit application directly to complex biomolecules in solution and to permit further expansion to incorporate more subtle effects.

  4. Using Beam Echo Effect for Generation of Short-Wavelength Radiation

    SciTech Connect (OSTI)

    Stupakov, G; /SLAC

    2008-10-31

    We propose to use an echo effect previously observed in hadron accelerators for up-frequency conversion of density modulation in an electron beam. We show that, for generation of high harmonics, this method is much more efficient in comparison with the currently used approach. A one dimensional model of the effect is developed which allows to optimize the amplitude of the modulation for a given harmonic number.

  5. Impact of Radiation Biology on Fundamental Insights in Biology

    DOE R&D Accomplishments [OSTI]

    Setlow, Richard B.

    1982-07-27

    Research supported by OHER [Office of Health and Environmental Research] and its predecessors has as one of its major goals an understanding of the effects of radiation at low doses and dose rates on biological systems, so as to predict their effects on humans. It is not possible to measure such effects directly. They must be predicted from basic knowledge on how radiation affects cellular components such as DNA and membranes and how cells react to such changes. What is the probability of radiation producing human mutations and what are the probabilities of radiation producing cancer? The end results of such studies are radiation exposure standards for workers and for the general population. An extension of these goals is setting standards for exposure to chemicals involved in various energy technologies. This latter problem is much more difficult because chemical dosimetry is a primitive state compared to radiation dosimetry.

  6. Impact of Radiation Biology on Fundamental in Biology

    SciTech Connect (OSTI)

    Setlow, Richard B.

    1983-01-20

    Research supported by OHER and its predecessors has as one of its major goals an understanding of the effects of radiation at low doses and dose rates on biological systems, so as to predict their effects on humans. It is not possible to measure such effects directly. They must be predicted from basic knowledge on how radiation affects cellular components such as DNA and membranes and how cells react to such changes. What is the probability of radiation producing human mutations and what are the probabilities of radiation producing cancer? The end results of such studies are radiation exposure standards for workers and for the general population. An extension of these goals is setting standards for exposure to chemicals involved in various energy technologies. This latter problem is much more difficult because chemical dosimetry is is a primitive state compared to radiation dosimetry.

  7. Recent experimental results on ICF target implosions by Z-pinch radiation sources and their relevance to ICF ignition studies.

    SciTech Connect (OSTI)

    Bailey, James E.; Chandler, Gordon Andrew; Vesey, Roger Alan; Hanson, David Lester; Olson, Craig Lee; Nash, Thomas J.; Matzen, Maurice Keith; Ruiz, Carlos L.; Porter, John Larry, Jr.; Cuneo, Michael Edward; Varnum, William S.; Bennett, Guy R.; Cooper, Gary Wayne; Schroen, Diana Grace; Slutz, Stephen A.; MacFarlane, Joseph John; Leeper, Ramon Joe; Golovkin, I. E.; Mehlhorn, Thomas Alan; Mancini, Roberto Claudio

    2003-07-01

    Inertial confinement fusion capsule implosions absorbing up to 35 kJ of x-rays from a {approx}220 eV dynamic hohlraum on the Z accelerator at Sandia National Laboratories have produced thermonuclear D-D neutron yields of (2.6 {+-} 1.3) x 10{sup 10}. Argon spectra confirm a hot fuel with Te {approx} 1 keV and n{sub e} {approx} (1-2) x 10{sup 23} cm{sup -3}. Higher performance implosions will require radiation symmetry control improvements. Capsule implosions in a {approx}70 eV double-Z-pinch-driven secondary hohlraum have been radiographed by 6.7 keV x-rays produced by the Z-beamlet laser (ZBL), demonstrating a drive symmetry of about 3% and control of P{sub 2} radiation asymmetries to {+-}2%. Hemispherical capsule implosions have also been radiographed in Z in preparation for future experiments in fast ignition physics. Z-pinch-driven inertial fusion energy concepts are being developed. The refurbished Z machine (ZR) will begin providing scaling information on capsule and Z-pinch in 2006. The addition of a short pulse capability to ZBL will enable research into fast ignition physics in the combination of ZR and ZBL-petawatt. ZR could provide a test bed to study NIF-relevant double-shell ignition concepts using dynamic hohlraums and advanced symmetry control techniques in the double-pinch hohlraum backlit by ZBL.

  8. Twenty-channel bolometer array for studying impurity radiation and transport in the TCS field-reversed configuration

    SciTech Connect (OSTI)

    Kostora, M. R.; Hsu, S. C.; Wurden, G. A.

    2006-10-15

    A bolometer array diagnostic has been developed for the University of Washington Translation, Confinement, and Sustainment (TCS) field-reversed configuration (FRC) experiment in order to measure radially resolved total radiated power per unit length of the FRC. This will provide radiation energy loss information, useful in power balance and impurity studies. The 20-element photodiode bolometer will be mounted at the midplane of the TCS cylindrical vacuum chamber to view the rotating magnetic field (RMF) generated FRC plasma. Key features of this new bolometer array are (1) extensive electrical shielding against the RMF, (2) robust electrical isolation, (3) trans-impedance amplifiers using a microcoax interface at the array and a fiber optic interface to the screen room, and (4) a custom glass-on-metal socket for the 20-element photodiode chip to ensure high vacuum compatibility. The bolometer array can be retracted behind a gate valve using a stepper motor to protect it during vacuum chamber bakeout. The slit assembly housing is interchangeable to provide flexibility for the viewing sightlines.

  9. Microscopic Study Of Alpha + N Bremsstrahlung From Effective...

    Office of Scientific and Technical Information (OSTI)

    Microscopic Study Of Alpha + N Bremsstrahlung From Effective And Realistic Inter-Nucleon Interactions Citation Details In-Document Search Title: Microscopic Study Of Alpha + N ...

  10. Study of Aerosol Indirect Effects in China

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Indirect Effects in China In 2008, the U.S. Department of Energy (DOE)'s ... of regional aerosol impacts in China as part of a joint program with the ...

  11. Health effects models for nuclear power plant accident consequence analysis: Low LET radiation: Part 2, Scientific bases for health effects models

    SciTech Connect (OSTI)

    Abrahamson, S.; Bender, M.; Book, S.; Buncher, C.; Denniston, C.; Gilbert, E.; Hahn, F.; Hertzberg, V.; Maxon, H.; Scott, B.

    1989-05-01

    This report provides dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Two-parameter Weibull hazard functions are recommended for estimating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary and gastrointestinal syndromes -- are considered. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid and ''other''. The category, ''other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also provided. For most cancers, both incidence and mortality are addressed. Linear and linear-quadratic models are also recommended for assessing genetic risks. Five classes of genetic disease -- dominant, x-linked, aneuploidy, unbalanced translocation and multifactorial diseases --are considered. In addition, the impact of radiation-induced genetic damage on the incidence of peri-implantation embryo losses is discussed. The uncertainty in modeling radiological health risks is addressed by providing central, upper, and lower estimates of all model parameters. Data are provided which should enable analysts to consider the timing and severity of each type of health risk. 22 refs., 14 figs., 51 tabs.

  12. Plasma induced DNA damage: Comparison with the effects of ionizing radiation

    SciTech Connect (OSTI)

    Lazovi?, S.; Maleti?, D.; Pua?, N.; Malovi?, G.; Petrovi?, Z. Lj.; Leskovac, A.; Filipovi?, J.; Joksi?, G.

    2014-09-22

    We use human primary fibroblasts for comparing plasma and gamma rays induced DNA damage. In both cases, DNA strand breaks occur, but of fundamentally different nature. Unlike gamma exposure, contact with plasma predominantly leads to single strand breaks and base-damages, while double strand breaks are mainly consequence of the cell repair mechanisms. Different cell signaling mechanisms are detected confirming this (ataxia telangiectasia mutated - ATM and ataxia telangiectasia and Rad3 related - ATR, respectively). The effective plasma doses can be tuned to match the typical therapeutic doses of 2?Gy. Tailoring the effective dose through plasma power and duration of the treatment enables safety precautions mainly by inducing apoptosis and consequently reduced frequency of micronuclei.

  13. Method and apparatus for control of coherent synchrotron radiation effects during recirculation with bunch compression

    SciTech Connect (OSTI)

    Douglas, David R; Tennant, Christopher

    2015-11-10

    A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.

  14. Radiation-induced DNA damage and the relative biological effectiveness of 18F-FDG in wild-type mice

    SciTech Connect (OSTI)

    Taylor, Kristina; Lemon, Jennifer A.; Boreham, Douglas R.

    2014-05-28

    Clinically, the most commonly used positron emission tomography (PET) radiotracer is the glucose analog 2-[18F] fluoro-2-deoxy-d-glucose (18F-FDG), however little research has been conducted on the biological effects of 18F-FDG injections. The induction and repair of DNA damage and the relative biological effectiveness (RBE) of radiation from 18F-FDG relative to 662 keV γ-rays were investigated. The study also assessed whether low-dose radiation exposure from 18F-FDG was capable of inducing an adaptive response. DNA damage to the bone marrow erythroblast population was measured using micronucleus formation and lymphocyte γH2A.X levels. To test the RBE of 18F-FDG, mice were injected with a range of activities of 18F-FDG (0–14.80 MBq) or irradiated with Cs-137 γ-rays (0–100 mGy). The adaptive response was investigated 24 h after the 18F-FDG injection by 1 Gy in vivo challenge doses for micronucleated reticulocyte (MN-RET) formation or 1, 2 and 4 Gy in vitro challenges doses for γH2A.X formation. A significant increase in MN-RET formation above controls occurred following injection activities of 3.70, 7.40 or 14.80 MBq (P < 0.001) which correspond to bone marrow doses of ~35, 75 and 150 mGy, respectively. Per unit dose, the Cs-137 radiation exposure induced significantly more damage than the 18F-FDG injections (RBE = 0.79 ± 0.04). A 20% reduction in γH2A.X fluorescence was observed in mice injected with a prior adapting low dose of 14.80 MBq 18F-FDG relative to controls (P < 0.019). A 0.74 MBq 18F-FDG injection, which gives mice a dose approximately equal to a typical human PET scan, did not cause a significant increase in DNA damage nor did it generate an adaptive response. Typical 18F-FDG injection activities used in small animal imaging (14.80 MBq) resulted in a decrease in DNA damage, as measured by γH2A.X formation

  15. Including shielding effects in application of the TPCA method for detection of embedded radiation sources.

    SciTech Connect (OSTI)

    Johnson, William C.; Shokair, Isaac R.

    2011-12-01

    Conventional full spectrum gamma spectroscopic analysis has the objective of quantitative identification of all the radionuclides present in a measurement. For low-energy resolution detectors such as NaI, when photopeaks alone are not sufficient for complete isotopic identification, such analysis requires template spectra for all the radionuclides present in the measurement. When many radionuclides are present it is difficult to make the correct identification and this process often requires many attempts to obtain a statistically valid solution by highly skilled spectroscopists. A previous report investigated using the targeted principal component analysis method (TPCA) for detection of embedded sources for RPM applications. This method uses spatial/temporal information from multiple spectral measurements to test the hypothesis of the presence of a target spectrum of interest in these measurements without the need to identify all the other radionuclides present. The previous analysis showed that the TPCA method has significant potential for automated detection of target radionuclides of interest, but did not include the effects of shielding. This report complements the previous analysis by including the effects of spectral distortion due to shielding effects for the same problem of detection of embedded sources. Two examples, one with one target radionuclide and the other with two, show that the TPCA method can successfully detect shielded targets in the presence of many other radionuclides. The shielding parameters are determined as part of the optimization process using interpolation of library spectra that are defined on a 2D grid of atomic numbers and areal densities.

  16. Radiation Shielding Properties of Some Marbles in Turkey

    SciTech Connect (OSTI)

    Guenoglu, K.; Akkurt, I.

    2011-12-26

    Especially after development of technology, radiation started to be used in a large fields such as medicine, industry and energy. Using radiation in those fields bring hazardous effect of radiation into humancell. Thus radiation protection becomes important in physics. Although there are three ways for radiation protection, shielding of the radiation is the most commonly used method. Natural Stones such as marble is used as construction material especially in critical building and thus its radiation shielding capability should be determined.In this study, gamma ray shielding properties of some different types of marble mined in Turkey, have been measured using a NaI(Tl) scintillator detector. The measured results were also compared with the theoretical calculations XCOM.

  17. Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes

    SciTech Connect (OSTI)

    Basyigit, Celalettin; Uysal, Volkan; Kilincarslan, Semsettin; Akkas, Ayse; Mavi, Betuel; Guenoglu, Kadir; Akkurt, Iskender

    2011-12-26

    The radiation although has hazardous effects for human health, developing technologies bring lots of usage fields to radiation like in medicine and nuclear power station buildings. In this case protecting from undesirable radiation is a necessity for human health. Heavyweight concrete is one of the most important materials used in where radiation should be shielded, like those areas. In this study, used heavyweight aggregates of different mineral origin (Limonite, Siderite), in order to prepare different series in concrete mixtures and investigated radiation shielding properties. The experimental results on measuring the radiation shielding, the heavyweight concrete prepared with heavyweight aggregates of different mineral origin show that, are useful radiation absorbents when they used in concrete mixtures.

  18. Assessment of the Effect of Air Pollution Controls on Trends in Shortwave Radiation over the United States from 1995 through 2010 from Multiple Observation Networks

    SciTech Connect (OSTI)

    Gan, Chuen-Meei; Pleim, Jonathan; Mathur, Rohit; Hogrefe, Christian; Long, Charles N.; Xing, Jia; Roselle, Shawn; Wei, Chao

    2014-02-14

    Long term datasets of total (all-sky) and clear-sky downwelling shortwave (SW) radiation, cloud cover fraction (cloudiness) and aerosol optical depth (AOD) are analyzed together with aerosol concentration from several networks (e.g. SURFRAD, CASTNET, IMPROVE and ARM) in the United States (US). Seven states with varying climatology are selected to better understand the effect of aerosols and clouds on SW radiation. This analysis aims to test the hypothesis that the reductions in anthropogenic aerosol burden resulting from substantial reductions in emissions of sulfur dioxide and nitrogen oxides over the past 15 years across the US has caused an increase in surface SW radiation. We show that the total and clear-sky downwelling SW radiation from seven sites have increasing trends except Penn State which shows no tendency in clear-sky SW radiation. After investigating several confounding factors, the causes can be due to the geography of the site, aerosol distribution, heavy air traffic and increasing cloudiness. Moreover, we assess the relationship between total column AOD with surface aerosol concentration to test our hypothesis. In our findings, the trends of clear-sky SW radiation, AOD, and aerosol concentration from the sites in eastern US agree well with our hypothesis. However, the sites in western US demonstrate increasing AOD associated with mostly increasing trends in surface aerosol concentration. At these sites, the changes in aerosol burden and/or direct aerosol effects alone cannot explain the observed changes in SW radiation, but other factors need to be considered such as cloudiness, aerosol vertical profiles and elevated plumes.

  19. Effect of Field Size and Length of Plantar Spur on Treatment Outcome in Radiation Therapy of Plantar Fasciitis: The Bigger the Better?

    SciTech Connect (OSTI)

    Hermann, Robert Michael; Meyer, Andreas; Reible, Michael; Carl, Ulrich Martin; Nitsche, Mirko

    2013-12-01

    Purpose: Radiation therapy is well established in the treatment of painful plantar fasciitis or heel spur. A retrospective analysis was conducted to investigate the effect of field definition on treatment outcome and to determine the impact of factors potentially involved. Methods and Materials: A review of treatment data of 250 patients (285 heels) with a mean follow-up time of 11 months showed that complete symptom remission occurred in 38%, partial remission in 32%, and no change in 19% (11% were lost to follow-up). Variables such as radiologic evidence of plantar spurs, their length, radiation dose, field size, age, sex, and onset of pain before administration of radiation therapy were investigated in univariate and multivariate regression analyses. Results: Treatment response depended upon age >53 years, length of heel spur ≤6.5 mm (or no radiologic evidence of a heel spur), and onset of pain <12 months before radiation therapy. Patients with these clinical prerequisites stood a 93% chance of clinical response. Without these prerequisites, only 49% showed any impact. No influence of field size on treatment outcome became evident. Conclusion: Patients with short plantar heel spurs benefit from radiation therapy equally well as patients without any radiologic evidence. Moreover, smaller field sizes have the same positive effect as commonly used large field definitions covering the entire calcaneal bone. This leads to a recommendation of a considerable reduction of field size in future clinical practice.

  20. The Chernobyl papers. Volume 1. Doses to the Soviet population and early health effects studies

    SciTech Connect (OSTI)

    Merwin, S.E.; Balonov, M.I.

    1993-01-01

    The papers in this Volume 1 of a series, discuss studies initiated following the nuclear reactor accident at the Chernobyl Nuclear Power Plant Unit 4. All authored by scientists of the former Soviet Union. Included in Volume 1 are considerations of the internal and external radiation doses received by the inhabitants of the regions recording the highest levels of radioactive contamination (the republics of Russia, Belarus, and Ukraine). Also included are three papers presenting data and analysis pretaining to actual and potential health effects from the accident.

  1. Magnetic Resonance Imaging–Guided versus Surrogate-Based Motion Tracking in Liver Radiation Therapy: A Prospective Comparative Study

    SciTech Connect (OSTI)

    Paganelli, Chiara; Seregni, Matteo; Fattori, Giovanni; Summers, Paul; Bellomi, Massimo; Baroni, Guido; Riboldi, Marco

    2015-03-15

    Purpose: This study applied automatic feature detection on cine–magnetic resonance imaging (MRI) liver images in order to provide a prospective comparison between MRI-guided and surrogate-based tracking methods for motion-compensated liver radiation therapy. Methods and Materials: In a population of 30 subjects (5 volunteers plus 25 patients), 2 oblique sagittal slices were acquired across the liver at high temporal resolution. An algorithm based on scale invariant feature transform (SIFT) was used to extract and track multiple features throughout the image sequence. The position of abdominal markers was also measured directly from the image series, and the internal motion of each feature was quantified through multiparametric analysis. Surrogate-based tumor tracking with a state-of-the-art external/internal correlation model was simulated. The geometrical tracking error was measured, and its correlation with external motion parameters was also investigated. Finally, the potential gain in tracking accuracy relying on MRI guidance was quantified as a function of the maximum allowed tracking error. Results: An average of 45 features was extracted for each subject across the whole liver. The multi-parametric motion analysis reported relevant inter- and intrasubject variability, highlighting the value of patient-specific and spatially-distributed measurements. Surrogate-based tracking errors (relative to the motion amplitude) were were in the range 7% to 23% (1.02-3.57mm) and were significantly influenced by external motion parameters. The gain of MRI guidance compared to surrogate-based motion tracking was larger than 30% in 50% of the subjects when considering a 1.5-mm tracking error tolerance. Conclusions: Automatic feature detection applied to cine-MRI allows detailed liver motion description to be obtained. Such information was used to quantify the performance of surrogate-based tracking methods and to provide a prospective comparison with respect to MRI

  2. The impact of fuel cladding failure events on occupational radiation exposures at nuclear power plants: Case study, PWR (pressurized-water reactor) during an outage

    SciTech Connect (OSTI)

    Moeller, M.P.; Martin, G.F.; Kenoyer, J.L.

    1987-08-01

    This report is the second in a series of case studies designed to evaluate the magnitude of increase in occupational radiation exposures at commercial US nuclear power plants resulting from small incidents or abnormal events. The event evaluated is fuel cladding failure, which can result in elevated primary coolant activity and increased radiation exposure rates within a plant. For this case study, radiation measurements were made at a pressurized-water reactor (PWR) during a maintenance and refueling outage. The PWR had been operating for 22 months with fuel cladding failure characterized as 105 pin-hole leakers, the equivalent of 0.21% failed fuel. Gamma spectroscopy measurements, radiation exposure rate determinations, thermoluminescent dosimeter (TLD) assessments, and air sample analyses were made in the plant's radwaste, pipe penetration, and containment buildings. Based on the data collected, evaluations indicate that the relative contributions of activation products and fission products to the total exposure rates were constant over the duration of the outage. This constancy is due to the significant contribution from the longer-lived isotopes of cesium (a fission product) and cobalt (an activation product). For this reason, fuel cladding failure events remain as significant to occupational radiation exposure during an outage as during routine operations. As documented in the previous case study (NUREG/CR-4485 Vol. 1), fuel cladding failure events increased radiation exposure rates an estimated 540% at some locations of the plant during routine operations. Consequently, such events can result in significantly greater radiation exposure rates in many areas of the plant during the maintenance and refueling outages than would have been present under normal fuel conditions.

  3. Influence of compensator thickness, field size, and off-axis distance on the effective attenuation coefficient of a cerrobend compensator for intensity-modulated radiation therapy

    SciTech Connect (OSTI)

    Haghparast, Abbas; Hashemi, Bijan; Eivazi, Mohammad Taghi

    2013-04-01

    Intensity-modulated radiation therapy (IMRT) can be performed by using compensators. To make a compensator for an IMRT practice, it is required to calculate the effective attenuation coefficient (?{sub eff}) of its material, which is affected by various factors. We studied the effect of the variation of the most important factors on the calculation of the ?{sub eff} of the cerrobend compensator for 6-MV photon beams, including the field size, compensator thickness, and off-axis distance. Experimental measurements were carried out at 100 cm source-to-surface distance and 10 cm depth for the 6-MV photon beams of an Elekta linac using various field size, compensator thickness, and off-axis settings. The field sizes investigated ranged from 4 4 to 25 25 cm{sup 2} and the cerrobend compensator thicknesses from 0.56 cm. For a fixed compensator thickness, variation of the ?{sub eff} with the field size ranged from 3.76.8%, with the highest value attributed to the largest compensator thickness. At the reference field size of 10 10 cm{sup 2}, the ?{sub eff} varied by 16.5% when the compensator thickness was increased from 0.56 cm. However, the variation of the ?{sub eff} with the off-axis distance was only 0.99% at this field size, whereas for the largest field size, it was more significant. Our results indicated that the compensator thickness and field size have the most significant effect on the calculation of the compensator ?{sub eff} for the 6-MV photon beam. Therefore, it is recommended to consider these parameters when calculating the compensator thickness for an IMRT practice designed for these beams. The off-axis distance had a significant effect on the calculation of the ?{sub eff} only for the largest field size. Hence, it is recommended to consider the effect of this parameter only for field sizes larger than 25 25 cm{sup 2}.

  4. Radiation effects in nuclear materials: Role of nuclear and electronic energy losses and their synergy

    SciTech Connect (OSTI)

    Thomé, Lionel; Debelle, Aurelien; Garrido, Frederico; Mylonas, Stamatis; Décamps, B.; Bachelet, C.; Sattonnay, G.; Pellegrino, S.; Miro, S.; Trocellier, P.; Serruys, Y.; Velisa, G.; Grygiel, C.; Monnet, I.; Toulemonde, Marcel; Simon, P.; Jagielski, Jacek; Jozwik-Biala, Iwona; Nowicki, Lech; Behar, M.; Weber, William J; Zhang, Yanwen; Backman, Marie; Nordlund, Kai; Djurabekova, Flyura

    2013-01-01

    Ceramic oxides and carbides are promising matrices for the immobilization and/or transmutation of nuclear wastes, cladding materials for gas-cooled fission reactors and structural components for fusion reactors. For these applications there is a need of fundamental data concerning the behavior of nuclear ceramics upon irradiation. This article is focused on the presentation of a few remarkable examples regarding ion-beam modifications of nuclear ceramics with an emphasis on the mechanisms leading to damage creation and phase transformations. Results obtained by combining advanced techniques (Rutherford backscattering spectrometry and channeling, X-ray diffraction, transmission electron microscopy, Raman spectroscopy) concern irradiations in a broad energy range (from keV to GeV) with the aim of exploring both nuclear collision (Sn) and electronic excitation (Se) regimes. Finally, the daunting challenge of the demonstration of the existence of synergistic effects between Sn and Se is tackled by discussing the healing due to intense electronic energy deposition (SHIBIEC) and by reporting results recently obtained in dual-beam irradiation (DBI) experiments.

  5. Proton radiation effect on performance of InAs/GaSb complementary barrier infrared detector

    SciTech Connect (OSTI)

    Soibel, Alexander; Rafol, Sir B.; Khoshakhlagh, Arezou; Nguyen, Jean; Hoglund, Linda; Fisher, Anita M.; Keo, Sam. A.; Ting, David Z.-Y.; Gunapala, Sarath D.

    2015-12-28

    In this work, we investigated the effect of proton irradiation on the performance of long wavelength infrared InAs/GaSb photodiodes (λ{sub c} = 10.2 μm), based on the complementary barrier infrared detector design. We found that irradiation with 68 MeV protons causes a significant increase of the dark current from j{sub d} = 5 × 10{sup −5} A/cm{sup 2} to j{sub d} = 6 × 10{sup −3} A/cm{sup 2}, at V{sub b} = 0.1 V, T = 80 K and fluence 19.2 × 10{sup 11 }H{sup +}/cm{sup 2}. Analysis of the dark current as a function of temperature and bias showed that the dominant contributor to the dark current in these devices changes from diffusion current to tunneling current after proton irradiation. This change in the dark current mechanism can be attributed to the onset of surface leakage current, generated by trap-assisted tunneling processes in proton displacement damage areas located near the device sidewalls.

  6. Radiation doses in cone-beam breast computed tomography: A Monte Carlo simulation study

    SciTech Connect (OSTI)

    Yi Ying; Lai, Chao-Jen; Han Tao; Zhong Yuncheng; Shen Youtao; Liu Xinming; Ge Shuaiping; You Zhicheng; Wang Tianpeng; Shaw, Chris C.

    2011-02-15

    Purpose: In this article, we describe a method to estimate the spatial dose variation, average dose and mean glandular dose (MGD) for a real breast using Monte Carlo simulation based on cone beam breast computed tomography (CBBCT) images. We present and discuss the dose estimation results for 19 mastectomy breast specimens, 4 homogeneous breast models, 6 ellipsoidal phantoms, and 6 cylindrical phantoms. Methods: To validate the Monte Carlo method for dose estimation in CBBCT, we compared the Monte Carlo dose estimates with the thermoluminescent dosimeter measurements at various radial positions in two polycarbonate cylinders (11- and 15-cm in diameter). Cone-beam computed tomography (CBCT) images of 19 mastectomy breast specimens, obtained with a bench-top experimental scanner, were segmented and used to construct 19 structured breast models. Monte Carlo simulation of CBBCT with these models was performed and used to estimate the point doses, average doses, and mean glandular doses for unit open air exposure at the iso-center. Mass based glandularity values were computed and used to investigate their effects on the average doses as well as the mean glandular doses. Average doses for 4 homogeneous breast models were estimated and compared to those of the corresponding structured breast models to investigate the effect of tissue structures. Average doses for ellipsoidal and cylindrical digital phantoms of identical diameter and height were also estimated for various glandularity values and compared with those for the structured breast models. Results: The absorbed dose maps for structured breast models show that doses in the glandular tissue were higher than those in the nearby adipose tissue. Estimated average doses for the homogeneous breast models were almost identical to those for the structured breast models (p=1). Normalized average doses estimated for the ellipsoidal phantoms were similar to those for the structured breast models (root mean square (rms

  7. Cost-Effectiveness Analysis of Single Fraction of Stereotactic Body Radiation Therapy Compared With Single Fraction of External Beam Radiation Therapy for Palliation of Vertebral Bone Metastases

    SciTech Connect (OSTI)

    Kim, Hayeon; Rajagopalan, Malolan S.; Beriwal, Sushil; Huq, M. Saiful; Smith, Kenneth J.

    2015-03-01

    Purpose: Stereotactic body radiation therapy (SBRT) has been proposed for the palliation of painful vertebral bone metastases because higher radiation doses may result in superior and more durable pain control. A phase III clinical trial (Radiation Therapy Oncology Group 0631) comparing single fraction SBRT with single fraction external beam radiation therapy (EBRT) in palliative treatment of painful vertebral bone metastases is now ongoing. We performed a cost-effectiveness analysis to compare these strategies. Methods and Materials: A Markov model, using a 1-month cycle over a lifetime horizon, was developed to compare the cost-effectiveness of SBRT (16 or 18 Gy in 1 fraction) with that of 8 Gy in 1 fraction of EBRT. Transition probabilities, quality of life utilities, and costs associated with SBRT and EBRT were captured in the model. Costs were based on Medicare reimbursement in 2014. Strategies were compared using the incremental cost-effectiveness ratio (ICER), and effectiveness was measured in quality-adjusted life years (QALYs). To account for uncertainty, 1-way, 2-way and probabilistic sensitivity analyses were performed. Strategies were evaluated with a willingness-to-pay (WTP) threshold of $100,000 per QALY gained. Results: Base case pain relief after the treatment was assumed as 20% higher in SBRT. Base case treatment costs for SBRT and EBRT were $9000 and $1087, respectively. In the base case analysis, SBRT resulted in an ICER of $124,552 per QALY gained. In 1-way sensitivity analyses, results were most sensitive to variation of the utility of unrelieved pain; the utility of relieved pain after initial treatment and median survival were also sensitive to variation. If median survival is ≥11 months, SBRT cost <$100,000 per QALY gained. Conclusion: SBRT for palliation of vertebral bone metastases is not cost-effective compared with EBRT at a $100,000 per QALY gained WTP threshold. However, if median survival is ≥11 months, SBRT costs ≤$100

  8. Danger radiations

    ScienceCinema (OSTI)

    None

    2011-04-25

    Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.

  9. Investigation of radial wire arrays for inertial confinement fusion and radiation effects science.

    SciTech Connect (OSTI)

    Serrano, Jason Dimitri; Bland, Simon Nicholas; McBride, Ryan D.; Chittenden, Jeremy Paul; Suzuki-Vidal, Francisco Andres; Jennings, Christopher A.; Hall, Gareth Neville; Ampleford, David J.; Peyton, Bradley Philip; Lebedev, Sergey V.; Cleveland, Monica; Rogers, Thomas John; Cuneo, Michael Edward; Coverdale, Christine Anne; Jones, Brent Manley; Jones, Michael C.

    2010-02-01

    Radial wire arrays provide an alternative x-ray source for Z-pinch driven Inertial Confinement Fusion. These arrays, where wires are positioned radially outwards from a central cathode to a concentric anode, have the potential to drive a more compact ICF hohlraum. A number of experiments were performed on the 7MA Saturn Generator. These experiments studied a number of potential risks in scaling radial wire arrays up from the 1MA level, where they have been shown to provide similar x-ray outputs to larger diameter cylindrical arrays, to the higher current levels required for ICF. Data indicates that at 7MA radial arrays can obtain higher power densities than cylindrical wire arrays, so may be of use for x-ray driven ICF on future facilities. Even at the 7MA level, data using Saturn's short pulse mode indicates that a radial array should be able to drive a compact hohlraum to temperatures {approx}92eV, which may be of interest for opacity experiments. These arrays are also shown to have applications to jet production for laboratory astrophysics. MHD simulations require additional physics to match the observed behavior.

  10. Double-Blind, Placebo-Controlled Pilot Study of Processed Ultra Emu Oil Versus Placebo in the Prevention of Radiation Dermatitis

    SciTech Connect (OSTI)

    Rollmann, Denise C.; Novotny, Paul J.; Petersen, Ivy A.; Garces, Yolanda I.; Bauer, Heather J.; Yan, Elizabeth S.; Wahner-Roedler, Dietlind; Vincent, Ann; Sloan, Jeff A.; Issa Laack, Nadia N.

    2015-07-01

    Purpose: The purpose of this single-institution pilot study was to evaluate the feasibility and safety of an oil-based skin agent, Ultra Emu Oil, on skin-related toxicity in patients undergoing radiation therapy to the breast or chest wall. Methods and Materials: Patients were randomized 2:1 in a double-blind fashion and were instructed to apply processed Ultra Emu Oil or placebo (cottonseed oil) twice daily during the course of radiation therapy. The oils were applied before the third fraction and continued for 6 weeks after completion of treatment. The primary endpoint was the area under the curve (AUC) of Skindex-16 scale scores over time. Secondary outcomes included maximum grade of radiation dermatitis using the Common Terminology Criteria (CTC) for Adverse Events (CTCAE 3.0), the Skin Toxicity Assessment Tool, quality of life (QOL) measured by Linear Analogue Self-Assessment, and a symptom experience diary (SED). Results: In all, 42 of 45 patients completed the study and were evaluable. The median times to peak rash, skin redness, peeling, and skin swelling were weeks 6, 6, 7, and 7, respectively as measured by the SED. The Skindex AUC scores tended to be lower in emu oil patients than in placebo patients (mean total AUC 7.2 vs 10.4, respectively). This trend was also seen in all the Skindex subdomains. The overall QOL was slightly better in the emu oil group but remained stable throughout the study for both arms. Peak CTC toxicity occurred at week 6. Patients using emu oil appeared slightly worse on maximum CTC grade, but the difference was not significant. Conclusions: This pilot study confirmed the safety of oil-based skin treatments during radiation therapy and suggests a trend for reduced skin toxicity for patients receiving emu oil. A larger study is needed to evaluate the efficacy of emu oil in reducing radiation dermatitis in patients receiving breast radiation.

  11. Acupuncture-Like Transcutaneous Electrical Nerve Stimulation Versus Pilocarpine in Treating Radiation-Induced Xerostomia: Results of RTOG 0537 Phase 3 Study

    SciTech Connect (OSTI)

    Wong, Raimond K.W.; Deshmukh, Snehal; Wyatt, Gwen; Sagar, Stephen; Singh, Anurag K.; Sultanem, Khalil; Nguyen-Tân, Phuc F.; Yom, Sue S.; Cardinale, Joseph; Yao, Min; Hodson, Ian; Matthiesen, Chance L.; Suh, John; Thakrar, Harish; Pugh, Stephanie L.; Berk, Lawrence

    2015-06-01

    Purpose and Objectives: This report presents the analysis of the RTOG 0537 multicenter randomized study that compared acupuncture-like transcutaneous stimulation (ALTENS) with pilocarpine (PC) for relieving radiation-induced xerostomia. Methods and Materials: Eligible patients were randomized to twice-weekly 20-minute ALTENS sessions for 24 sessions during 12 weeks or PC (5 mg 3 times daily for 12 weeks). The primary endpoint was the change in the University of Michigan Xerostomia-Related Quality of Life Scale (XeQOLS) scores from baseline to 9 months from randomization (MFR). Secondary endpoints included basal and citric acid primed whole salivary production (WSP), ratios of positive responders (defined as patients with ≥20% reduction in overall radiation-induced xerostomia symptom burden), and the presence of adverse events based on the Common Terminology Criteria for Adverse Events version 3. An intention-to-treat analysis was conducted. Results: One hundred forty-eight patients were randomized. Only 96 patients completed the required XeQOLS and were evaluable at 9 MFR (representing merely 68.6% statistical power). Seventy-six patients were evaluable at 15 MFR. The median change in the overall XeQOLS in ALTENS and PC groups at 9 and 15 MFR were −0.53 and −0.27 (P=.45) and −0.6 and −0.47 (P=.21). The corresponding percentages of positive responders were 81% and 72% (P=.34) and 83% and 63% (P=.04). Changes in WSP were not significantly different between the groups. Grade 3 or less adverse events, mostly consisting of grade 1, developed in 20.8% of patients in the ALTENS group and in 61.6% of the PC group. Conclusions: The observed effect size was smaller than hypothesized, and statistical power was limited because only 96 of the recruited 148 patients were evaluable. The primary endpoint—the change in radiation-induced xerostomia symptom burden at 9 MFR—was not significantly different between the ALTENS and PC groups. There was significantly less

  12. RADIATIVE OPACITY OF IRON STUDIED USING A DETAILED LEVEL ACCOUNTING MODEL

    SciTech Connect (OSTI)

    Jin Fengtao; Zeng Jiaolong; Yuan Jianmin; Huang Tianxuan; Ding Yongkun; Zheng Zhijian

    2009-03-01

    The opacity of iron plasma in local thermodynamic equilibrium is studied using an independently developed detailed level accounting model. Atomic data are generated by solving the full relativistic Dirac-Fock equations. State mixing within one electronic configuration is considered to include part of the correlations between electrons without configuration interaction matrices that are too large being involved. Simulations are carried out and compared with several recent experimental transmission spectra in the M- and L-shell absorption regions to reveal the high accuracy of the model. The present model is also compared with the OPAL, LEDCOP and OP models for two isothermal series at T = 20 eV and T = 19.3 eV. It is found that our model is in good agreement with OPAL and LEDCOP while it has discrepancies with OP at high densities. Systematic Rosseland and Planck mean opacities in the range 10-1000 eV for temperature and 10{sup -5}-10{sup -1} g cm{sup -3} for density are also presented and compared with LEDCOP results, finding good agreement at lower temperatures but apparent differences at high temperatures where the L- and K-shell absorptions are dominant.

  13. Simulations of Clouds and Sensitivity Study by Weather Research and Forecast Model for Atmospheric Radiation Measurement Case 4

    SciTech Connect (OSTI)

    Wu, J.; Zhang, M.

    2005-03-18

    One of the large errors in general circulation models (GCMs) cloud simulations is from the mid-latitude, synoptic-scale frontal cloud systems. Now, with the availability of the cloud observations from Atmospheric Radiation Measurement (ARM) 2000 cloud Intensive Operational Period (IOP) and other observational datasets, the community is able to document the model biases in comparison with the observations and make progress in development of better cloud schemes in models. Xie et al. (2004) documented the errors in midlatitude frontal cloud simulations for ARM Case 4 by single-column models (SCMs) and cloud resolving models (CRMs). According to them, the errors in the model simulated cloud field might be caused by following reasons: (1) lacking of sub-grid scale variability; (2) lacking of organized mesoscale cyclonic advection of hydrometeors behind a moving cyclone which may play important role to generate the clouds there. Mesoscale model, however, can be used to better under stand these controls on the subgrid variability of clouds. Few studies have focused on applying mesoscale models to the forecasting of cloud properties. Weaver et al. (2004) used a mesoscale model RAMS to study the frontal clouds for ARM Case 4 and documented the dynamical controls on the sub-GCM-grid-scale cloud variability.

  14. Microscopic Study Of Alpha + N Bremsstrahlung From Effective...

    Office of Scientific and Technical Information (OSTI)

    Of Alpha + N Bremsstrahlung From Effective And Realistic Inter-Nucleon Interactions Citation Details In-Document Search Title: Microscopic Study Of Alpha + N Bremsstrahlung ...

  15. Pilot study for compact microbeam radiation therapy using a carbon nanotube field emission micro-CT scanner

    SciTech Connect (OSTI)

    Hadsell, Mike Cao, Guohua; Zhang, Jian; Burk, Laurel; Schreiber, Torsten; Lu, Jianping; Zhou, Otto; Schreiber, Eric; Chang, Sha

    2014-06-15

    Purpose: Microbeam radiation therapy (MRT) is defined as the use of parallel, microplanar x-ray beams with an energy spectrum between 50 and 300 keV for cancer treatment and brain radiosurgery. Up until now, the possibilities of MRT have mainly been studied using synchrotron sources due to their high flux (100s Gy/s) and approximately parallel x-ray paths. The authors have proposed a compact x-ray based MRT system capable of delivering MRT dose distributions at a high dose rate. This system would employ carbon nanotube (CNT) field emission technology to create an x-ray source array that surrounds the target of irradiation. Using such a geometry, multiple collimators would shape the irradiation from this array into multiple microbeams that would then overlap or interlace in the target region. This pilot study demonstrates the feasibility of attaining a high dose rate and parallel microbeam beams using such a system. Methods: The microbeam dose distribution was generated by our CNT micro-CT scanner (100?m focal spot) and a custom-made microbeam collimator. An alignment assembly was fabricated and attached to the scanner in order to collimate and superimpose beams coming from different gantry positions. The MRT dose distribution was measured using two orthogonal radiochromic films embedded inside a cylindrical phantom. This target was irradiated with microbeams incident from 44 different gantry angles to simulate an array of x-ray sources as in the proposed compact CNT-based MRT system. Finally, phantom translation in a direction perpendicular to the microplanar beams was used to simulate the use of multiple parallel microbeams. Results: Microbeams delivered from 44 gantry angles were superimposed to form a single microbeam dose distribution in the phantom with a FWHM of 300?m (calculated value was 290 ?m). Also, during the multiple beam simulation, a peak to valley dose ratio of ?10 was found when the phantom translation distance was roughly 4x the beam width. The

  16. Study of strong enhancement of synchrotron radiation via surface plasma waves excitation by particle-in-cell simulations

    SciTech Connect (OSTI)

    Pan, K. Q.; Zheng, C. Y. Cao, L. H.; He, X. T.; Wu, Dong; Liu, Z. J.

    2015-11-02

    Synchrotron radiation is strongly enhanced by the resonant excitation of surface plasma waves (SPWs). Two-dimensional particle-in-cell simulations show that energy conversion efficiency from laser to radiation in the case of SPWs excitation is about 18.7%, which is improved by more than 2 orders of magnitude compared with that of no SPWs excitation. Besides the high energy conversion efficiency, the frequency spectrum and the angular distribution of the radiation are also improved in the case of SPWs excitation because of the quasi-static magnet field induced by surface plasma waves excitation.

  17. Study of x-ray radiant characteristics and thermal radiation redistribution in CH foam filling cylindrical cavities

    SciTech Connect (OSTI)

    Shang Wanli; Zhu Tuo; Song Tianming; Zhang Wenhai; Zhao Yang; Xiong Gang; Zhang Jiyan; Yang Jiamin

    2011-04-15

    Experiments are presented, which demonstrate the properties of x-ray radiation and redistribution of radiant thermal energy in high Z cylindrical cavities filled with low Z CH foam. Time integrated spectra records were obtained by a calibrated space-resolved transmission grating spectrometer. The x-ray radiation became weaker in intensity and was changed to a softer near-Planckian radiation light after a 1500 {mu}m long transport in the foam filling cavity. The experimental redistribution of the radiant thermal energy was plotted and compared to the numerical results of a simplified model. Good agreements have been achieved.

  18. Space Radiation and Cataracts (LBNL Summer Lecture Series)

    ScienceCinema (OSTI)

    Blakely, Eleanor

    2011-04-28

    Summer Lecture Series 2009: Eleanor Blakely, radiation biologist of the Life Sciences Division at Lawrence Berkeley National Laboratory, has been a scientist at Berkeley Lab since 1975. She is studying the effect of radiation on cataracts which concerns not only cancer patients, but also astronauts. As astronauts spend increasingly longer time in space, the effects of cosmic radiation exposure will become an increasingly important health issue- yet there is little human data on these effects. Blakely reviews this emerging field and the contributions made at Berkeley Lab

  19. STANFORD SYNCHROTRON RADIATION LIGHTSOURCE The Stanford Synchrotron...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    STANFORD SYNCHROTRON RADIATION LIGHTSOURCE The Stanford Synchrotron Radiation Lightsource at SLAC National Accelerator Laboratory produces extremely bright X-rays used to study our ...

  20. Comparative study of radiation emission without and with target in a 2.2 kJ plasma focus device

    SciTech Connect (OSTI)

    Khan, Muhammad Zubair; Ling, Yap Seong; San, Wong Chiow

    2014-03-24

    The radiation emission in a 2.2 kJ Mather-type dense plasma focus device is investigated using a five channel BPX65 PIN diode spectrometer. Estimated X-ray associated with the hollow anode without and with target in Argon gas medium is compared. At optimum conditions, the radiation emission from the system is found to be strongly influenced with target in hollow anode and the filling gas pressure. The maximum X-ray yield in 4? sr was obtained in case of hollow anode in argon gas medium with target 'Lead' due to interaction of electron beam. Results indicated that an appropriate design of hollow anode with target could enhance the radiation emission by more intense interaction of expected electron beam with target. The outcomes are helpful in designing a plasma focus with enhanced X-ray radiation with improved shot to shot reproducibility in plasma focus device.

  1. Impact of fuel cladding failure events on occupational radiation exposures at nuclear power plants. Case study: PWR during routine operations

    SciTech Connect (OSTI)

    Moeller, M.P.; Martin, G.F.; Haggard, D.L.

    1986-01-01

    The purpose of this report is to present data in support of evaluating the impact of fuel cladding failure events on occupational radiation exposure. To determine quantitatively whether fuel cladding failure contributes significantly to occupational radiation exposure, radiation exposure measurements were taken at comparable locations in two mirror-image pressurized-water reactors (PWRs) and their common auxiliary building. One reactor, Unit B, was experiencing degraded fuel characterized as 0.125% fuel pin-hole leakers and was operating at approximately 55% of the reactor's licensed maximum core power, while the other reactor, Unit A, was operating under normal conditions with less than 0.01% fuel pin-hole leakers at 100% of the reactor's licensed maximum core power. Measurements consisted of gamma spectral analyses, radiation exposure rates and airborne radionuclide concentrations. In addition, data from primary coolant sample results for the previous 20 months on both reactor coolant systems were analyzed. The results of the measurements and coolant sample analyses suggest that a 3560-megawatt-thermal (1100 MWe) PWR operating at full power with 0.125% failed fuel can experience an increase of 540% in radiation exposure rates as compared to a PWR operating with normal fuel. In specific plant areas, the degraded fuel may elevate radiation exposure rates even more.

  2. Effects of Adenovirus-Mediated Delivery of the Human Hepatocyte Growth Factor Gene in Experimental Radiation-Induced Heart Disease

    SciTech Connect (OSTI)

    Hu Shunying; Chen Yundai; Li Libing; Chen Jinlong; Wu Bin; Zhou, Xiao; Zhi Guang; Li Qingfang; Wang Rongliang; Duan Haifeng; Guo Zikuan; Yang Yuefeng; Xiao Fengjun; Wang Hua; Wang Lisheng

    2009-12-01

    Purpose: Irradiation to the heart may lead to late cardiovascular complications. The purpose of this study was to investigate whether adenovirus-mediated delivery of the human hepatocyte growth factor gene could reduce post-irradiation damage of the rat heart and improve heart function. Methods and Materials: Twenty rats received single-dose irradiation of 20 Gy gamma ray locally to the heart and were randomized into two groups. Two weeks after irradiation, these two groups of rats received Ad-HGF or mock adenovirus vector intramyocardial injection, respectively. Another 10 rats served as sham-irradiated controls. At post-irradiation Day 120, myocardial perfusion was tested by myocardial contrast echocardiography with contrast agent injected intravenously. At post-irradiation Day 180, cardiac function was assessed using the Langendorff technique with an isolated working heart model, after which heart samples were collected for histological evaluation. Results: Myocardial blood flow was significantly improved in HGF-treated animals as measured by myocardial contrast echocardiography at post-irradiation Day 120 . At post-irradiation Day 180, cardiac function was significantly improved in the HGF group compared with mock vector group, as measured by left ventricular peak systolic pressure (58.80 +- 9.01 vs. 41.94 +- 6.65 mm Hg, p < 0.05), the maximum dP/dt (5634 +- 1303 vs. 1667 +- 304 mm Hg/s, p < 0.01), and the minimum dP/dt (3477 +- 1084 vs. 1566 +- 499 mm Hg/s, p < 0.05). Picrosirius red staining analysis also revealed a significant reduction of fibrosis in the HGF group. Conclusion: Based on the study findings, hepatocyte growth factor gene transfer can attenuate radiation-induced cardiac injury and can preserve cardiac function.

  3. Serum Proteome Signature of Radiation Response: Upregulation of Inflammation-Related Factors and Downregulation of Apolipoproteins and Coagulation Factors in Cancer Patients Treated With Radiation Therapy—A Pilot Study

    SciTech Connect (OSTI)

    Widlak, Piotr; Jelonek, Karol; Wojakowska, Anna; Pietrowska, Monika; Polanska, Joanna; Marczak, Łukasz; Miszczyk, Leszek; Składowski, Krzysztof

    2015-08-01

    Purpose: Ionizing radiation affects the proteome of irradiated cells and tissue, yet data concerning changes induced during radiation therapy (RT) in human blood are fragmentary and inconclusive. We aimed to identify features of serum proteome and associated processes involved in response to partial body irradiation during cancer treatment. Methods and Materials: Twenty patients with head and neck squamous cell cancer (HNSCC) and 20 patients with prostate cancer received definitive intensity modulated RT. Blood samples were collected before RT, just after RT, and 1 month after the end of RT. Complete serum proteome was analyzed in individual samples, using a shotgun liquid chromatography-tandem mass spectrometry approach which allowed identification of approximately 450 proteins. Approximately 100 unique proteins were quantified in all samples after exclusion of immunoglobulins, and statistical significance of differences among consecutive samples was assessed. Processes associated with quantified proteins and their functional interactions were predicted using gene ontology tools. Results: RT-induced changes were marked in the HNSCC patient group: 22 upregulated and 33 downregulated proteins were detected in post-RT sera. Most of the changes reversed during follow-up, yet levels of some proteins remained affected 1 month after the end of RT. RT-upregulated proteins were associated with acute phase, inflammatory response, and complement activation. RT-downregulated proteins were associated with transport and metabolism of lipids (plasma apolipoproteins) and blood coagulation. RT-induced changes were much weaker in prostate cancer patients, which corresponded to differences in acute radiation toxicity observed in both groups. Nevertheless, general patterns of RT-induced sera proteome changes were similar in both of the groups of cancer patients. Conclusions: In this pilot study, we proposed to identify a molecular signature of radiation response, based on specific

  4. Measuring Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurement Activity SI Units and Prefixes Conversions Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Measurement Activity: How Much Is Present? The size or weight of a container or shipment does not indicate how much radioactivity is in it. The amount of radioactivity in a quantity of material can be determined by noting how many curies of the material are present. This information should be found on labels and/or shipping

  5. Radiation Safety

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Safety Home MSDS Search MSDS Help Safety Training and Tests Contact Links LSU Campus Safety Glossary Radiation Safety Manual Radiation Safety Test NOTE: All Training and Testing Material is for LSU CAMD Users ONLY! **Please allow two weeks for your badge to be processed.** Regulations and Hierarchy The CAMD Safety Officer reports to two separate individuals regarding safety. These are the Radiation Safety Officer for the University, and the Campus Safety Officer in all other matters. Thus safety

  6. Unilateral radiation pneumonitis in sheep: Physiological changes and bronchoalveolar lavage

    SciTech Connect (OSTI)

    Tillman, B.F.; Loyd, J.E.; Malcolm, A.W.; Holm, B.A.; Brigham, K.L. )

    1989-03-01

    Radiation pneumonitis is a life-threatening result of therapeutic thoracic irradiation, yet its mechanisms are poorly understood. We studied the effects of unilateral lung irradiation (3,000 rad) in sheep from the immediate response to the later development of radiation pneumonitis. We defined radiation pneumonitis by its diagnostic clinical feature, radiographic infiltration of the irradiated zone with a straight margin corresponding to the radiation port. The immediate response in the few hours after irradiation was characterized by cough, labored respiration, hypoxemia (arterial PO{sub 2} decreased 19 Torr), mild pulmonary hypertension (pulmonary arterial pressure increased 20%), and lymphopenia. Hemodynamics and gas exchange returned to normal by day 2 but became abnormal again before or during radiation pneumonitis at 32 +/- 2 days. Respiratory distress, hypoxemia, and pulmonary hypertension recurred during radiation pneumonitis. Bronchoalveolar lavage during radiation pneumonitis contained increased neutrophils (19 +/- 4%, control = 7%), increased protein (0.27 +/- 0.1 g/dl, control = 0.12 +/- 0.03), and severely impaired ability to lower surface tension. Alveolar macrophages from both lungs during unilateral radiation pneumonitis exhibited impaired generation of superoxide after phorbol myristate (only a 30% increase). Normal control alveolar macrophages increased superoxide production after stimulation greater than 400%. We conclude that unilateral lung irradiation in sheep causes a mild immediate response followed by radiation pneumonitis at 1 mo. Unilateral radiation pneumonitis in this model is associated with ipsilateral neutrophilic alveolitis, increased bronchoalveolar lavage protein, and impaired surfactant function, as well as bilateral functional abnormalities of alveolar macrophages.

  7. Energy balance studies over varying ground cover of the Colorado River riparian zone below Glen Canyon Dam, Part II. Modeling of solar and net radiation

    SciTech Connect (OSTI)

    Brazel, A.J.; Brazel, S.W.; Marcus, M.G.

    1995-06-01

    A numerical radiation model was utilized to investigate the diurnal and seasonal variability of solar input at four sites along the Colorado River below Glen Canyon Dam: river miles -14.5, 43, 55, and 194. These simulations were compared to observations made during the spring growing season (April, 1994), the pre-monsoon dry season (June-July, 1994), the monsoon season (August, 1994), and winter (January 1995). At each river mile above, a main station was established for a 24-36 hour period observing radiation components. This station serves as a reference point to compare with simulations. The model requires specifications of sky horizon effects, albedo, atmospheric attentuation, and nearby terrain emissivity and reflectivity. A combination of field data, surveying information, and radiation theory provides an adequate methodology to yield close agreement between observations and simulations in the canyon environment. Solar shading by canyon topography can be responsible for as much 40% loss of potential photosynthetic radiation in summer months, even more at the equinoxes, and a near total reduction at some sites in winter.

  8. Motexafin-Gadolinium and Involved Field Radiation Therapy for Intrinsic Pontine Glioma of Childhood: A Children's Oncology Group Phase 2 Study

    SciTech Connect (OSTI)

    Bradley, Kristin A.; Zhou Tianni; McNall-Knapp, Rene Y.; Jakacki, Regina I.; Pollack, Ian F.

    2013-01-01

    Purpose: To evaluate the effects on 1-year event-free survival (EFS) and overall survival (OS) of combining motexafin and gadolinium (MGd), a potent radiosensitizer, with daily fractionated radiation therapy in children with newly diagnosed intrinsic pontine gliomas. Methods and Materials: Patients with newly diagnosed intrinsic pontine glioma were treated with MGd daily for 5 consecutive days each week, for a total of 30 doses. Patients received a 5- to 10-min intravenous bolus of MGd, 4.4 mg/kg/day, given 2 to 5 h prior to standard dose irradiation. Radiation therapy was administered at a daily dose of 1.8 Gy for 30 treatments over 6 weeks. The total dose was 54 Gy. Results: Sixty eligible children received MGd daily, concurrent with 6 weeks of radiation therapy. The estimated 1-year EFS was 18% {+-} 5%, and the estimated 1-year OS was 53% {+-} 6.5%. The most common grade 3 to 4 toxicities were lymphopenia, transient elevation of liver transaminases, and hypertension. Conclusions: Compared to historical controls, the addition of MGd to a standard 6-week course of radiation did not improve the survival of pediatric patients with newly diagnosed intrinsic pontine gliomas.

  9. Can We Predict Plan Quality for External Beam Partial Breast Irradiation: Results of a Multicenter Feasibility Study (Trans Tasman Radiation Oncology Group Study 06.02)

    SciTech Connect (OSTI)

    Kron, Tomas; Willis, David; Link, Emma; Lehman, Margot; Campbell, Gillian; O'Brien, Peter; Chua, Boon

    2013-11-15

    Purpose: Partial breast irradiation (PBI) after lumpectomy may be an option for selected patients with early breast cancer. A feasibility study of accelerated PBI delivered using external beam 3-dimensional conformal radiation therapy (RT) was undertaken at 8 Australasian centers. The present study evaluated the impact of patient, tumor, and RT technique-related factors on the quality of RT plans as determined by the dosevolume parameters of organs at risk. Methods and Materials: Forty-eight patients were enrolled in the study. All RT plans were centrally reviewed using predefined dosimetric criteria before commencement and after completion of protocol therapy. The RT plans of 47 patients met the dosevolume constraints, and all 47 patients received PBI to a prescribed dose of 38.5 Gy in 10 fractions. The RT plan quality was determined by volumes of the ipsilateral whole breast, lung, and heart that received 50% and 95%; 30%; and 5% of the prescribed dose, respectively. Patient, tumor, and RT technique-related factors were investigated for association with the parameters of RT plan quality. Results: The ratio of the planning target volume to the ipsilateral whole-breast volume was significantly associated with the ipsilateral breast doses on multiple variable analyses. The distance of the postlumpectomy surgical cavity from the heart and lung were predictive for heart and lung doses, respectively. A distance between surgical cavity and heart of >4 cm typically resulted in <1% of the heart volume receiving 5 Gy or less. It was more difficult to meet the heart dose constraint for left-sided and medially located tumors. Conclusions: Partial breast irradiation using 3-dimensional conformal RT was feasible within the study constraints. The ratio of planning target volume to ipsilateral whole-breast volume and the distance of surgical cavity from the heart were significant predictors of the quality of treatment plan for external beam PBI.

  10. Gamma Radiation Aging Study of a Dow Corning SE 1700 Porous Structure Made by Direct Ink Writing

    SciTech Connect (OSTI)

    Small, Ward; Alviso, Cindy T.; Metz, Tom R.

    2015-11-13

    Dow Corning SE 1700 (reinforced polydimethylsiloxane) porous structures were made by direct ink writing (DIW). The specimens (~50% porosity) were subjected to a compressive strain of ~25% while exposed to a gamma radiation dose of 1, 5, or 10 Mrad under vacuum. Compression set and load retention of the aged specimens were measured after a ~24 h relaxation period. Compression set (relative to deflection) increased with radiation dose: 11, 35, and 51% after 1, 5, and 10 Mrad, respectively. Load retention was 96-97% for the doses tested. The SE 1700 compared favorably to M9763 cellular silicone tested under the same conditions.

  11. Radiation damage in a micron-sized protein crystal studied via reciprocal space mapping and Bragg coherent diffractive imaging

    SciTech Connect (OSTI)

    Coughlan, H. D.; Darmanin, C.; Phillips, N. W.; Hofmann, F.; Clark, J. N.; Harder, R. J.; Vine, D. J.; Abbey, B.

    2015-04-29

    For laboratory and synchrotron based X-ray sources, radiation damage has posed a significant barrier to obtaining high-resolution structural data from biological macromolecules. The problem is particularly acute for micron-sized crystals where the weaker signal often necessitates the use of higher intensity beams to obtain the relevant data. Here, we employ a combination of techniques, including Bragg coherent diffractive imaging to characterise the radiation induced damage in a micron-sized protein crystal over time. The approach we adopt here could help screen for potential protein crystal candidates for measurement at X-ray free election laser sources.

  12. MO-G-BRF-09: Investigating Magnetic Field Dose Effects in Mice: A Monte Carlo Study

    SciTech Connect (OSTI)

    Rubinstein, A; Guindani, M; Followill, D; Melancon, A; Hazle, J; Court, L

    2014-06-15

    Purpose: In MRI-linac treatments, radiation dose distributions are affected by magnetic fields, especially at high-density/low-density interfaces. Radiobiological consequences of magnetic field dose effects are presently unknown; therefore, preclinical studies are needed to ensure the safe clinical use of MRI-linacs. This study investigates the optimal combination of beam energy and magnetic field strength needed for preclinical murine studies. Methods: The Monte Carlo code MCNP6 was used to simulate the effects of a magnetic field when irradiating a mouse-sized lung phantom with a 1.0cmx1.0cm photon beam. Magnetic field effects were examined using various beam energies (225kVp, 662keV[Cs-137], and 1.25MeV[Co-60]) and magnetic field strengths (0.75T, 1.5T, and 3T). The resulting dose distributions were compared to Monte Carlo results for humans with various field sizes and patient geometries using a 6MV/1.5T MRI-linac. Results: In human simulations, the addition of a 1.5T magnetic field caused an average dose increase of 49% (range:36%60%) to lung at the soft tissue-to-lung interface and an average dose decrease of 30% (range:25%36%) at the lung-to-soft tissue interface. In mouse simulations, the magnetic fields had no effect on the 225kVp dose distribution. The dose increases for the Cs-137 beam were 12%, 33%, and 49% for 0.75T, 1.5T, and 3.0T magnetic fields, respectively while the dose decreases were 7%, 23%, and 33%. For the Co-60 beam, the dose increases were 14%, 45%, and 41%, and the dose decreases were 18%, 35%, and 35%. Conclusion: The magnetic field dose effects observed in mouse phantoms using a Co-60 beam with 1.5T or 3T fields and a Cs-137 beam with a 3T field compare well with those seen in simulated human treatments with an MRI-linac. These irradiator/magnet combinations are suitable for preclinical studies investigating potential biological effects of delivering radiation therapy in the presence of a magnetic field. Partially funded by Elekta.

  13. Effect of radiation and magnetohydrodynamic free convection boundary layer flow on a solid sphere with Newtonian heating in a micropolar fluid

    SciTech Connect (OSTI)

    Alkasasbeh, Hamzeh Taha Sarif, Norhafizah Md Salleh, Mohd Zuki; Tahar, Razman Mat; Nazar, Roslinda; Pop, Ioan

    2015-02-03

    In this paper, the effect of radiation on magnetohydrodynamic free convection boundary layer flow on a solid sphere with Newtonian heating in a micropolar fluid, in which the heat transfer from the surface is proportional to the local surface temperature, is considered. The transformed boundary layer equations in the form of nonlinear partial differential equations are solved numerically using an implicit finite difference scheme known as the Keller-box method. Numerical solutions are obtained for the local wall temperature and the local skin friction coefficient, as well as the velocity, angular velocity and temperature profiles. The features of the flow and heat transfer characteristics for various values of the Prandtl number Pr, micropolar parameter K, magnetic parameter M, radiation parameter N{sub R}, the conjugate parameter γ and the coordinate running along the surface of the sphere, x are analyzed and discussed.

  14. The inhibitory effect of ionizing radiation on Fc and C3 receptors on mouse and human leukocytes, and the protective potential of human albumin

    SciTech Connect (OSTI)

    Herrera, M.A.; Diaz-Perches, R.; Gutierrez, M.; Gamminio, E.; Liera, C.; Nieto, P.; Weiss-Steider, B. )

    1990-08-01

    The effect that ionizing radiation has in vitro on Fc and C3 receptors was evaluated at various doses and measured by means of erythrocytes coated with antibody (EA) and erythrocytes coated with antibody and complement (EAC) rosettes on human peripheral blood leukocytes (PBL) and on mouse bone marrow cells (BMC) and PBL. We found that the number of cells with either EA and EAC rosettes decreased as the radiation doses increased, and that they were almost absent when the highest doses were employed. We obtained evidence that albumin is a natural source of radio-protection for Fc and C3 receptors, and we showed that by increasing the amount of this molecule we could completely protect receptors for EA and EAC in vitro. Finally, the possible therapeutic value of the administration of human albumin to patients undergoing radiotherapy is discussed.

  15. Definition of Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Gamma Radiation and X-Rays Beta Radiation Alpha Radiation Irradiation Radioactive Contamination Definitions Detection Measurement Safety Around Radiation Sources Types of ...

  16. Radiation damage in silicon trackers at the Tevatron experiments

    SciTech Connect (OSTI)

    Gonzalez, Oscar; /Madrid, CIEMAT

    2009-01-01

    An overview of the studies performed on the radiation damage affecting the silicon detectors at the CDF and D0 experiments is presented. These detectors have been exposed to a much larger radiation dose (and operating for a longer time) than originally planned and therefore these studies are fundamental to assess the status and future of the sensors. Results are summarized with special emphasis on the techniques used and their complementarity to achieve a complete picture of the effect of the radiation on the sensors and their performance for physics analysis.

  17. Radiation dosimeter

    DOE Patents [OSTI]

    Fox, R.J.

    1981-09-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  18. Radiation dosimeter

    DOE Patents [OSTI]

    Fox, Richard J.

    1983-01-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  19. Studies of acute and chronic radiation injury at the Biological and Medical Research Division, Argonne National Laboratory, 1953-1970: Description of individual studies, data files, codes, and summaries of significant findings

    SciTech Connect (OSTI)

    Grahn, D.; Fox, C.; Wright, B.J.; Carnes, B.A.

    1994-05-01

    Between 1953 and 1970, studies on the long-term effects of external x-ray and {gamma} irradiation on inbred and hybrid mouse stocks were carried out at the Biological and Medical Research Division, Argonne National Laboratory. The results of these studies, plus the mating, litter, and pre-experimental stock records, were routinely coded on IBM cards for statistical analysis and record maintenance. Also retained were the survival data from studies performed in the period 1943-1953 at the National Cancer Institute, National Institutes of Health, Bethesda, Maryland. The card-image data files have been corrected where necessary and refiled on hard disks for long-term storage and ease of accessibility. In this report, the individual studies and data files are described, and pertinent factors regarding caging, husbandry, radiation procedures, choice of animals, and other logistical details are summarized. Some of the findings are also presented. Descriptions of the different mouse stocks and hybrids are included in an appendix; more than three dozen stocks were involved in these studies. Two other appendices detail the data files in their original card-image format and the numerical codes used to describe the animal`s exit from an experiment and, for some studies, any associated pathologic findings. Tabular summaries of sample sizes, dose levels, and other variables are also given to assist investigators in their selection of data for analysis. The archive is open to any investigator with legitimate interests and a willingness to collaborate and acknowledge the source of the data and to recognize appropriate conditions or caveats.

  20. A Sensitivity Study of Radiative Fluxes at the Top of Atmosphere to Cloud-Microphysics and Aerosol Parameters in the Community Atmosphere Model CAM5

    SciTech Connect (OSTI)

    Zhao, Chun; Liu, Xiaohong; Qian, Yun; Yoon, Jin-Ho; Hou, Zhangshuan; Lin, Guang; McFarlane, Sally A.; Wang, Hailong; Yang, Ben; Ma, Po-Lun; Yan, Huiping; Bao, Jie

    2013-11-08

    In this study, we investigated the sensitivity of net radiative fluxes (FNET) at the top of atmosphere (TOA) to 16 selected uncertain parameters mainly related to the cloud microphysics and aerosol schemes in the Community Atmosphere Model version 5 (CAM5). We adopted a quasi-Monte Carlo (QMC) sampling approach to effectively explore the high dimensional parameter space. The output response variables (e.g., FNET) were simulated using CAM5 for each parameter set, and then evaluated using generalized linear model analysis. In response to the perturbations of these 16 parameters, the CAM5-simulated global annual mean FNET ranges from -9.8 to 3.5 W m-2 compared to the CAM5-simulated FNET of 1.9 W m-2 with the default parameter values. Variance-based sensitivity analysis was conducted to show the relative contributions of individual parameter perturbation to the global FNET variance. The results indicate that the changes in the global mean FNET are dominated by those of cloud forcing (CF) within the parameter ranges being investigated. The size threshold parameter related to auto-conversion of cloud ice to snow is confirmed as one of the most influential parameters for FNET in the CAM5 simulation. The strong heterogeneous geographic distribution of FNET variation shows parameters have a clear localized effect over regions where they are acting. However, some parameters also have non-local impacts on FNET variance. Although external factors, such as perturbations of anthropogenic and natural emissions, largely affect FNET variations at the regional scale, their impact is weaker than that of model internal parameters in terms of simulating global mean FNET in this study. The interactions among the 16 selected parameters contribute a relatively small portion of the total FNET variations over most regions of the globe. This study helps us better understand the CAM5 model behavior associated with parameter uncertainties, which will aid the next step of reducing model

  1. Phase I Three-Dimensional Conformal Radiation Dose Escalation Study in Newly Diagnosed Glioblastoma: Radiation Therapy Oncology Group Trial 98-03

    SciTech Connect (OSTI)

    Tsien, Christina Moughan, Jennifer; Michalski, Jeff M.; Gilbert, Mark R.; Purdy, James; Simpson, Joseph; Kresel, John J.; Curran, Walter J.; Diaz, Aidnag; Mehta, Minesh P.

    2009-03-01

    Purpose: To evaluate in a Phase I trial the feasibility and toxicity of dose-escalated three-dimensional conformal radiotherapy (3D-CRT) concurrent with chemotherapy in patients with primary supratentorial glioblastoma (GBM). Methods and Materials: A total of 209 patients were enrolled. All received 46 Gy in 2-Gy fractions to the first planning target volume (PTV{sub 1}), defined as the gross tumor volume (GTV) plus 1.8 cm. A subsequent boost was given to PTV{sub 2}, defined as GTV plus 0.3 cm. Patients were stratified into two groups (Group 1: PTV{sub 2} <75 cm{sup 3}; Group 2: PTV{sub 2} {>=}75 cm{sup 3}). Four RT dose levels were evaluated: 66, 72, 78, and 84 Gy. Carmustine 80 mg/m{sup 2} was given during RT, then every 8 weeks for 6 cycles. Pretreatment characteristics were well balanced. Results: Acute and late Grade 3/4 RT-related toxicities were no more frequent at higher RT dose or with larger tumors. There were no dose-limiting toxicities (acute Grade {>=}3 irreversible central nervous system toxicities) observed on any dose level in either group. On the basis of the absence of dose-limiting toxicities, dose was escalated to 84 Gy in both groups. Late RT necrosis was noted at 66 Gy (1 patient), 72 Gy (2 patients), 78 Gy (2 patients), and 84 Gy (3 patients) in Group 1. In Group 2, late RT necrosis was noted at 78 Gy (1 patient) and 84 Gy (2 patients). Median time to RT necrosis was 8.8 months (range, 5.1-12.5 months). Median survival in Group 1 was 11.6-19.3 months. Median survival in Group 2 was 8.2-13.9 months. Conclusions: Our study shows the feasibility of delivering higher than standard (60 Gy) RT dose with concurrent chemotherapy for primary GBM, with an acceptable risk of late central nervous system toxicity.

  2. Numerical Study of Three Dimensional Effects in Longitudinal Space-Charge Impedance

    SciTech Connect (OSTI)

    Halavanau, A.; Piot, P.

    2015-06-01

    Longitudinal space-charge (LSC) effects are generally considered as detrimental in free-electron lasers as they can seed instabilities. Such “microbunching instabilities” were recently shown to be potentially useful to support the generation of broadband coherent radiation pulses [1, 2]. Therefore there has been an increasing interest in devising accelerator beamlines capable of sustaining this LSC instability as a mechanism to produce a coherent light source. To date most of these studies have been carried out with a one-dimensional impedance model for the LSC. In this paper we use a N-body “Barnes-Hut” algorithm [3] to simulate the 3D space charge force in the beam combined with elegant [4] and explore the limitation of the 1D model often used

  3. Method for microbeam radiation therapy

    DOE Patents [OSTI]

    Slatkin, Daniel N.; Dilmanian, F. Avraham; Spanne, Per O.

    1994-01-01

    A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue.

  4. Method for microbeam radiation therapy

    DOE Patents [OSTI]

    Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

    1994-08-16

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

  5. DOE 2011 occupational radiation exposure

    SciTech Connect (OSTI)

    none,

    2012-12-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2011 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past five years.

  6. DOE 2012 occupational radiation exposure

    SciTech Connect (OSTI)

    none,

    2013-10-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site.

  7. RADIATION DETECTOR

    DOE Patents [OSTI]

    Wilson, H.N.; Glass, F.M.

    1960-05-10

    A radiation detector of the type is described wherein a condenser is directly connected to the electrodes for the purpose of performing the dual function of a guard ring and to provide capacitance coupling for resetting the detector system.

  8. Radiation Transport

    SciTech Connect (OSTI)

    Urbatsch, Todd James

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  9. Human radiation studies: Remembering the early years: Oral history of radiologist Hymer L. Friedell, M.D., Ph.D., conducted January 28, 1995

    SciTech Connect (OSTI)

    Fisher, D.; Melamed, E.

    1995-07-01

    NThis report is a transcript of an interview with Hymer L. Friedell by representatives of the US DOE Office of Human Radiation Experiments. Dr. Friedell was selected for this interview because of his participation in the early stages of the medical use of radioisotopes, his important role in the Manhattan Engineer District Medical Division, and his distinguished medical career and his involvement in the distribution of isotopes and the approval for their use in humans. After a brief biographical sketch Dr. Friedell discusses his remembrances on a wide range of subjects. Topics discussed include pre-war radiation therapy, information provided to patients, the Army Medical Corps and the Manhattan Project, his work at the Chicago Metallurgical Laboratory, inspection visits of Manhattan Project facilities and proposed sites, Plutonium injection studies, and actions of the AEC Isotope Distribution Committee.

  10. Simulating Black Carbon and Dust and their Radiative Forcing in Seasonal Snow: A Case Study over North China with Field Campaign Measurements

    SciTech Connect (OSTI)

    Zhao, Chun; Hu, Zhiyuan; Qian, Yun; Leung, Lai-Yung R.; Huang, J.; Huang, Maoyi; Jin, Jiming; Flanner, M. G.; Zhang, Rudong; Wang, Hailong; Yan, Huiping; Lu, Zifeng; Streets, D. G.

    2014-10-30

    A state-of-the-art regional model, WRF-Chem, is coupled with the SNICAR model that includes the sophisticated representation of snow metamorphism processes available for climate study. The coupled model is used to simulate the black carbon (BC) and dust concentrations and their radiative forcing in seasonal snow over North China in January-February of 2010, with extensive field measurements used to evaluate the model performance. In general, the model simulated spatial variability of BC and dust mass concentrations in the top snow layer (hereafter BCS and DSTS, respectively) are quantitatively or qualitatively consistent with observations. The model generally moderately underestimates BCS in the clean regions but significantly overestimates BCS in some polluted regions. Most model results fall into the uncertainty ranges of observations. The simulated BCS and DSTS are highest with >5000 ng g-1 and up to 5 mg g-1, respectively, over the source regions and reduce to <50 ng g-1 and <1 ?g g-1, respectively, in the remote regions. BCS and DSTS introduce similar magnitude of radiative warming (~10 W m-2) in snowpack, which is comparable to the magnitude of surface radiative cooling due to BC and dust in the atmosphere. This study represents the first effort in using a regional modeling framework to simulate BC and dust and their direct radiative forcing in snow. Although a variety of observational datasets have been used to attribute model biases, some uncertainties in the results remain, which highlights the need for more observations, particularly concurrent measurements of atmospheric and snow aerosols and the deposition fluxes of aerosols, in future campaigns.

  11. A 2-Stage Genome-Wide Association Study to Identify Single Nucleotide Polymorphisms Associated With Development of Erectile Dysfunction Following Radiation Therapy for Prostate Cancer

    SciTech Connect (OSTI)

    Kerns, Sarah L.; Departments of Pathology and Genetics, Albert Einstein College of Medicine, Bronx, New York ; Stock, Richard; Stone, Nelson; Department of Urology, Mount Sinai School of Medicine, New York, New York ; Buckstein, Michael; Shao, Yongzhao; Campbell, Christopher; Rath, Lynda; De Ruysscher, Dirk; Lammering, Guido; Hixson, Rosetta; Cesaretti, Jamie; Terk, Mitchell; Ostrer, Harry; Rosenstein, Barry S.

    2013-01-01

    Purpose: To identify single nucleotide polymorphisms (SNPs) associated with development of erectile dysfunction (ED) among prostate cancer patients treated with radiation therapy. Methods and Materials: A 2-stage genome-wide association study was performed. Patients were split randomly into a stage I discovery cohort (132 cases, 103 controls) and a stage II replication cohort (128 cases, 102 controls). The discovery cohort was genotyped using Affymetrix 6.0 genome-wide arrays. The 940 top ranking SNPs selected from the discovery cohort were genotyped in the replication cohort using Illumina iSelect custom SNP arrays. Results: Twelve SNPs identified in the discovery cohort and validated in the replication cohort were associated with development of ED following radiation therapy (Fisher combined P values 2.1 Multiplication-Sign 10{sup -5} to 6.2 Multiplication-Sign 10{sup -4}). Notably, these 12 SNPs lie in or near genes involved in erectile function or other normal cellular functions (adhesion and signaling) rather than DNA damage repair. In a multivariable model including nongenetic risk factors, the odds ratios for these SNPs ranged from 1.6 to 5.6 in the pooled cohort. There was a striking relationship between the cumulative number of SNP risk alleles an individual possessed and ED status (Sommers' D P value = 1.7 Multiplication-Sign 10{sup -29}). A 1-allele increase in cumulative SNP score increased the odds for developing ED by a factor of 2.2 (P value = 2.1 Multiplication-Sign 10{sup -19}). The cumulative SNP score model had a sensitivity of 84% and specificity of 75% for prediction of developing ED at the radiation therapy planning stage. Conclusions: This genome-wide association study identified a set of SNPs that are associated with development of ED following radiation therapy. These candidate genetic predictors warrant more definitive validation in an independent cohort.

  12. Absorption of solar radiation in broken clouds

    SciTech Connect (OSTI)

    Zuev, V.E.; Titov, G.A.; Zhuravleva, T.B.

    1996-04-01

    It is recognized now that the plane-parallel model unsatisfactorily describes the transfer of radiation through broken clouds and that, consequently, the radiation codes of general circulation models (GCMs) must be refined. However, before any refinement in a GCM code is made, it is necessary to investigate the dependence of radiative characteristics on the effects caused by the random geometry of cloud fields. Such studies for mean fluxes of downwelling and upwelling solar radiation in the visible and near-infrared (IR) spectral range were performed by Zuev et al. In this work, we investigate the mean spectral and integrated absorption of solar radiation by broken clouds (in what follows, the term {open_quotes}mean{close_quotes} will be implied but not used, for convenience). To evaluate the potential effect of stochastic geometry, we will compare the absorption by cumulus (0.5 {le} {gamma} {le} 2) to that by equivalent stratus ({gamma} <<1) clouds; here {gamma} = H/D, H is the cloud layer thickness and D the characteristic horizontal cloud size. The equivalent stratus clouds differ from cumulus only in the aspect ratio {gamma}, all the other parameters coinciding.

  13. Radiation tolerance of the FOXFET biasing scheme for AC-coupled Si microstrip detectors

    SciTech Connect (OSTI)

    Bacchetta, N.; Gotra, Yu. ); Bisello, D.; Da Ros, R.; Giraldo, A. Univ. di Padova . Dipt. di Fisica); Canali, C. Univ. di Modena . Facolta di Ingegneria); Fuochi, P.G. ); Fusaro, G. . Dept. di Elettronica e Informatica); Paccagnella, A. Univ. di Cagliari . Instituto di Elettrotecnica); Verzellesi, G. Univ. di Padova . Dept. di Elettronica e Informatica)

    1993-12-01

    The radiation response of FOXFETs has been studied for proton, gamma and neutron exposures. The punch-through behavior, which represents the normal FET operating conditions in Si microstrip detectors, has been found to be much less sensitive to radiation damage than threshold voltage. The device performance has been elucidated by means of two-dimensional simulations. The main radiation effects have been also taken into account in the numerical analysis and separately examined.

  14. WE-E-BRE-06: High-Dose Microbeam Radiation Induces Different Responses in Tumor Microenvironment Compared to Conventional Seamless Radiation in Window Chamber Tumor Models

    SciTech Connect (OSTI)

    Chang, S; Zhang, J; Hadsell, M; Fontanella, A; Schroeder, T; Palmer, G; Dewhirst, M; Boss, M; Berman, K

    2014-06-15

    Purpose: Microbeam radiation therapy and GRID therapy are different forms of Spatially-Fractioned Radiation Therapy (SFRT) that is fundamentally different from the conventional seamless and temporally fractionated radiation therapy. SFRT is characterized by a ultra-high dose (10s –100s Gy) dose single treatment with drastic inhomogeneity pattern of given spatial frequencies. Preclinical and limited clinical studies have shown that the SFRT treatments may offer significant improvements in reducing treatment toxicity, especially for those patients who have not benefited from the state-of-the-art radiation therapy approaches. This preliminary study aims to elucidate the underlying working mechanisms of SFRT, which currently remains poorly understood. Methods: A genetically engineered 4T1 murine mammary carcinoma cell line and nude mice skin fold window chamber were used. A nanotechnology-based 160kV x-ray irradiator delivered 50Gy (entrance dose) single treatments of microbeam or seamless radiation. Animals were in 3 groups: mock, seamless radiation, and 300μm microbeam radiation. The windows were imaged using a hyperspectral system to capture total hemoglobin/saturation, GFP fluorescence emission, RFP fluorescence emission, and vessel density at 9 time points up to 7 days post radiation. Results: We found unique physiologic changes in different tumor/normal tissue regions and differential effects between seamless and microbeam treatments. They include 1) compared to microbeam and mock radiation seamless radiation damaged more microvasculature in tumor-surrounding normal tissue, 2) a pronounced angiogenic effect was observed with vascular proliferation in the microbeam irradiated portion of the tumor days post treatment (no such effect observed in seamless and mock groups), and 3) a notable change in tumor vascular orientation was observed where vessels initially oriented parallel to the beam length were replaced by vessels running perpendicular to the irradiation

  15. Monte Carlo Studies of the Radiation Fields in the Linac Coherent Light Source Undulators and of the Corresponding Signals in the Cerenkov Beam Loss Monitors

    SciTech Connect (OSTI)

    Santana Leitner, Mario; Fasso, Alberto; Fisher, Alan S.; Nuhn, Heinz D.; Dooling, Jeffrey C.; Berg, William; Yang, Bin X.; /Argonne

    2010-09-14

    In 2009 the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Center started free electron laser (FEL) operation. In order to continue to produce the bright and short-pulsed x-ray laser demanded by FEL scientists, this pioneer hard x-ray FEL requires a perfectly tailored magnetic field at the undulators, so that the photons generated at the electron wiggling path interact at the right phase with the electron beam. In such a precise system, small (>0.01%) radiation-induced alterations of the magnetic field in the permanent magnets could affect FEL performance. This paper describes the simulation studies of radiation fields in permanent magnets and the expected signal in the detectors. The transport of particles from the radiation sources (i.e. diagnostic insert) to the undulator magnets and to the beam loss monitors (BLM) was simulated with the intra nuclear cascade codes FLUKA and MARS15. In order to accurately reproduce the optics of LCLS, lattice capabilities and magnetic fields were enabled in FLUKA and betatron oscillations were validated against reference data. All electron events entering the BLMs were printed in data files. The paper also introduces the Radioactive Ion Beam Optimizer (RIBO) Monte Carlo 3-D code, which was used to read from the event files, to compute Cerenkov production and then to simulate the optical coupling of the BLM detectors, accounting for the transmission of light through the quartz.

  16. PROTOSTELLAR OUTFLOWS AND RADIATIVE FEEDBACK FROM MASSIVE STARS

    SciTech Connect (OSTI)

    Kuiper, Rolf; Yorke, Harold W.; Turner, Neal J. E-mail: Harold.W.Yorke@jpl.nasa.gov

    2015-02-20

    We carry out radiation hydrodynamical simulations of the formation of massive stars in the super-Eddington regime including both their radiative feedback and protostellar outflows. The calculations start from a prestellar core of dusty gas and continue until the star stops growing. The accretion ends when the remnants of the core are ejected, mostly by the force of the direct stellar radiation in the polar direction and elsewhere by the reradiated thermal infrared radiation. How long the accretion persists depends on whether the protostellar outflows are present. We set the mass outflow rate to 1% of the stellar sink particle's accretion rate. The outflows open a bipolar cavity extending to the core's outer edge, through which the thermal radiation readily escapes. The radiative flux is funneled into the polar directions while the core's collapse proceeds near the equator. The outflow thus extends the ''flashlight effect'', or anisotropic radiation field, found in previous studies from the few hundred AU scale of the circumstellar disk up to the 0.1 parsec scale of the core. The core's flashlight effect allows core gas to accrete on the disk for longer, in the same way that the disk's flashlight effect allows disk gas to accrete on the star for longer. Thus although the protostellar outflows remove material near the core's poles, causing slower stellar growth over the first few free-fall times, they also enable accretion to go on longer in our calculations. The outflows ultimately lead to stars of somewhat higher mass.

  17. Mobile Technology and Social Media in the Clinical Practice of Young Radiation Oncologists: Results of a Comprehensive Nationwide Cross-sectional Study

    SciTech Connect (OSTI)

    Bibault, Jean-Emmanuel; Leroy, Thomas; Blanchard, Pierre; Biau, Julian; Cervellera, Mathilde; Diaz, Olivia; Faivre, Jean Christophe; and others

    2014-09-01

    Purpose: Social media and mobile technology are transforming the way in which young physicians are learning and practicing medicine. The true impact of such technologies has yet to be evaluated. Methods and Materials: We performed a nationwide cross-sectional survey to better assess how young radiation oncologists used these technologies. An online survey was sent out between April 24, 2013, and June 1, 2013. All residents attending the 2013 radiation oncology French summer course were invited to complete the survey. Logistic regressions were performed to assess predictors of use of these tools in the hospital on various clinical endpoints. Results: In all, 131 of 140 (93.6%) French young radiation oncologists answered the survey. Of these individuals, 93% owned a smartphone and 32.8% owned a tablet. The majority (78.6%) of the residents owning a smartphone used it to work in their department. A total of 33.5% had more than 5 medical applications installed. Only 60.3% of the residents verified the validity of the apps that they used. In all, 82.9% of the residents had a social network account. Conclusions: Most of the residents in radiation oncology use their smartphone to work in their department for a wide variety of tasks. However, the residents do not consistently check the validity of the apps that they use. Residents also use social networks, with only a limited impact on their relationship with their patients. Overall, this study highlights the irruption and the risks of new technologies in the clinical practice and raises the question of a possible regulation of their use in the hospital.

  18. Stereotactic Body Radiation Therapy Can Be Used Safely to Boost Residual Disease in Locally Advanced Non-Small Cell Lung Cancer: A Prospective Study

    SciTech Connect (OSTI)

    Feddock, Jonathan; Arnold, Susanne M.; Department of Medical Oncology, University of Kentucky, Lexington, Kentucky ; Shelton, Brent J.; Sinha, Partha; Conrad, Gary; Chen, Li; Rinehart, John; McGarry, Ronald C.

    2013-04-01

    Purpose: To report the results of a prospective, single-institution study evaluating the feasibility of conventional chemoradiation (CRT) followed by stereotactic body radiation therapy (SBRT) as a means of dose escalation for patients with stage II-III non-small cell lung cancer (NSCLC) with residual disease. Methods and Materials: Patients without metastatic disease and with radiologic evidence of limited residual disease (?5 cm) within the site of the primary tumor and good or complete nodal responses after standard CRT to a target dose of 60 Gy were considered eligible. The SBRT boost was done to achieve a total combined dose biological equivalent dose >100 Gy to the residual primary tumor, consisting of 10 Gy 2 fractions (20 Gy total) for peripheral tumors, and 6.5 Gy 3 fractions (19.5 Gy total) for medial tumors using the Radiation Therapy Oncology Group protocol 0813 definitions. The primary endpoint was the development of grade ?3 radiation pneumonitis (RP). Results: After a median follow-up of 13 months, 4 patients developed acute grade 3 RP, and 1 (2.9%) developed late and persistent grade 3 RP. No patients developed grade 4 or 5 RP. Mean lung dose, V2.5, V5, V10, and V20 values were calculated for the SBRT boost, and none were found to significantly predict for RP. Only advancing age (P=.0147), previous smoking status (P=.0505), and high CRT mean lung dose (P=.0295) were significantly associated with RP development. At the time of analysis, the actuarial local control rate at the primary tumor site was 82.9%, with only 6 patients demonstrating recurrence. Conclusions: Linear accelerator-based SBRT for dose escalation of limited residual NSCLC after definitive CRT was feasible and did not increase the risk for toxicity above that for standard radiation therapy.

  19. RADIATION INTEGRATOR

    DOE Patents [OSTI]

    Glass, F.M.; Wilson, H.N.

    1959-02-17

    Radiation detecting and measuring systems, particularly a compact, integrating, background monitor, are discussed. One of the principal features of the system is the use of an electrometer tube where the input of the tube is directly connected to an electrode of the radiation detector and a capacitor is coupled to the tube input. When a predetermined quantity of radiation has been integrated, a trigger signal is fed to a recorder and a charge is delivered to the capacitor to render the tube inoperative. The capacitor is then recharged for the next period of operation. With this arrangement there is a substantial reduction in lead lengths and the principal components may be enclosed and hermetically sealed to insure low leakage.

  20. Influence of Extraterrestrial Radiation on Radiation Portal Monitors

    SciTech Connect (OSTI)

    Keller, Paul E.; Kouzes, Richard T.

    2009-06-01

    Cosmic radiation and solar flares can be a major source of background radiation at the Earths surface. This paper examines the relationship between extraterrestrial radiation and the detectable background in radiation portal monitors used for homeland security applications. Background radiation data from 13 radiation portal monitor facilities are examined and compared against external sources of data related to extraterrestrial radiation, including measurements at neutron monitors located at 53 cosmic-ray observatories around the Earth, four polar orbiting satellites, three geostationary satellites, ground-based geomagnetic field data from observatories around the Earth, a solar magnetic index, solar radio flux data, and sunspot activity data. Four-years (January 2003 through December 2006) of data are used in this study, which include the latter part of Solar Cycle 23 as solar activity was on the decline. The analysis shows a significant relationship between some extraterrestrial radiation and the background detected in the radiation portal monitors. A demonstrable decline is shown in the average gamma ray and neutron background at the radiation portal monitors as solar activity declined over the period of the study.

  1. Radiation receiver

    DOE Patents [OSTI]

    Hunt, Arlon J.

    1983-01-01

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

  2. Radiation receiver

    DOE Patents [OSTI]

    Hunt, A.J.

    1983-09-13

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.

  3. Daily Sodium Butyrate Enema for the Prevention of Radiation Proctitis in Prostate Cancer Patients Undergoing Radical Radiation Therapy: Results of a Multicenter Randomized Placebo-Controlled Dose-Finding Phase 2 Study

    SciTech Connect (OSTI)

    Maggio, Angelo; Magli, Alessandro; Rancati, Tiziana; Fiorino, Claudio; Valvo, Francesca; Fellin, Giovanni; Ricardi, Umberto; Munoz, Fernando; Cosentino, Dorian; Cazzaniga, Luigi Franco; Valdagni, Riccardo; Vavassori, Vittorio

    2014-07-01

    Purpose: To evaluate the efficacy of sodium butyrate enemas (NABUREN) in prostate cancer radiation therapy (RT) in reducing the incidence, severity, and duration of acute RT-induced proctitis. Methods and Materials: 166 patients, randomly allocated to 1 of 4 groups (rectal sodium butyrate 1 g, 2 g, or 4 g daily or placebo), were treated with NABUREN during and 2 weeks after RT. The grade of proctitis was registered in a daily diary. The correlation between NABUREN and proctitis was investigated through χ{sup 2} statistics. The toxicity endpoints considered were as follows: total number of days with grade ≥1 proctitis (≥G1); total number of days with grade ≥2 proctitis (≥G2); ≥G1 and ≥G2 proctitis lasting at least 3 and 5 consecutive days starting from week 4 (≥G1+3d, ≥G2+3d); damaging effects of RT on rectal mucosa as measured by endoscopy. The relationship between endpoints and pretreatment morbidities, hormonal therapy, presence of diabetes or hypertension, abdominal surgery, or hemorrhoids was investigated by univariate analysis. Results: The patients were randomly allocated to the 4 arms. No difference in the distribution of comorbidities among the arms was observed (P>.09). The mean ≥G1 and ≥G2 proctitis were 7.8 and 4.9 for placebo and 8.9 and 4.7 for the NABUREN group, respectively. No favorable trend in reduction of incidence, severity, and duration of ≥G1 and ≥G2 proctitis was observed with NABUREN use. In univariate analysis, ≥G1+3d toxicity was found to be related to hemorrhoids (P=.008), and a slight correlation was found between ≥G2 proctitis and hormonal therapy (P=.06). The RT effects on rectal mucosa as based on endoscopic assessment were mainly related to diabetes (P<.01). Endoscopy data at 6 week showed no significant difference between the placebo and butyrate arms. The other investigated endpoints were not correlated with any of the clinical risk factors analyzed. Conclusion: There was no evidence of efficacy

  4. Radiation Leukemogenesis: Applying Basic Science of Epidemiological Estimates of Low Dose Risks and Dose-Rate Effects

    SciTech Connect (OSTI)

    Hoel, D. G.

    1998-11-01

    The next stage of work has been to examine more closely the A-bomb leukemia data which provides the underpinnings of the risk estimation of CML in the above mentioned manuscript. The paper by Hoel and Li (Health Physics 75:241-50) shows how the linear-quadratic model has basic non-linearities at the low dose region for the leukemias including CML. Pierce et. al., (Radiation Research 123:275-84) have developed distributions for the uncertainty in the estimated exposures of the A-bomb cohort. Kellerer, et. al., (Radiation and Environmental Biophysics 36:73-83) has further considered possible errors in the estimated neutron values and with changing RBE values with dose and has hypothesized that the tumor response due to gamma may not be linear. We have incorporated his neutron model and have constricted new A-bomb doses based on his model adjustments. The Hoel and Li dose response analysis has also been applied using the Kellerer neutron dose adjustments for the leukemias. Finally, both Pierce's dose uncertainties and Kellerer neutron adjustments are combined as well as the varying RBE with dose as suggested by Rossi and Zaider and used for leukemia dose-response analysis. First the results of Hoel and Li showing a significantly improved fit of the linear-quadratic dose response by the inclusion of a threshold (i.e. low-dose nonlinearity) persisted. This work has been complete for both solid tumor as well as leukemia for both mortality as well as incidence data. The results are given in the manuscript described below which has been submitted to Health Physics.

  5. DOE 2008 occupational radiation exposure

    SciTech Connect (OSTI)

    none,

    2009-10-01

    The U.S. Department of Energy (DOE) Office of Corporate Safety Analysis (HS-30) within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE. The DOE 2008 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. This report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  6. DOE 2010 occupational radiation exposure

    SciTech Connect (OSTI)

    none,

    2011-11-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The DOE 2010 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  7. Linear Energy Transfer Painting With Proton Therapy: A Means of Reducing Radiation Doses With Equivalent Clinical Effectiveness

    SciTech Connect (OSTI)

    Fager, Marcus; Toma-Dasu, Iuliana; Kirk, Maura; Dolney, Derek; Diffenderfer, Eric S.; Vapiwala, Neha; Carabe, Alejandro

    2015-04-01

    Purpose: The purpose of this study was to propose a proton treatment planning method that trades physical dose (D) for dose-averaged linear energy transfer (LET{sub d}) while keeping the radiobiologically weighted dose (D{sub RBE}) to the target the same. Methods and Materials: The target is painted with LET{sub d} by using 2, 4, and 7 fields aimed at the proximal segment of the target (split target planning [STP]). As the LET{sub d} within the target increases with increasing number of fields, D decreases to maintain the D{sub RBE} the same as the conventional treatment planning method by using beams treating the full target (full target planning [FTP]). Results: The LET{sub d} increased 61% for 2-field STP (2STP) compared to FTP, 72% for 4STP, and 82% for 7STP inside the target. This increase in LET{sub d} led to a decrease of D with 5.3 ± 0.6 Gy for 2STP, 4.4 ± 0.7 Gy for 4STP, and 5.3 ± 1.1 Gy for 7STP, keeping the DRBE at 90% of the volume (DRBE, 90) constant to FTP. Conclusions: LET{sub d} painting offers a method to reduce prescribed dose at no cost to the biological effectiveness of the treatment.

  8. 11th International Conference of Radiation Research

    SciTech Connect (OSTI)

    1999-07-18

    Topics discussed in the conference included the following: Radiation Physics, Radiation Chemistry and modelling--Radiation physics and dosimetry; Electron transfer in biological media; Radiation chemistry; Biophysical and biochemical modelling; Mechanisms of DNA damage; Assays of DNA damage; Energy deposition in micro volumes; Photo-effects; Special techniques and technologies; Oxidative damage. Molecular and cellular effects-- Photobiology; Cell cycle effects; DNA damage: Strand breaks; DNA damage: Bases; DNA damage Non-targeted; DNA damage: other; Chromosome aberrations: clonal; Chromosomal aberrations: non-clonal; Interactions: Heat/Radiation/Drugs; Biochemical effects; Protein expression; Gene induction; Co-operative effects; ``Bystander'' effects; Oxidative stress effects; Recovery from radiation damage. DNA damage and repair -- DNA repair genes; DNA repair deficient diseases; DNA repair enzymology; Epigenetic effects on repair; and Ataxia and ATM.

  9. How to Detect Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    How to Detect Radiation How to Survey Measurement Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Detection How to Detect Radiation Radiation cannot be detected by human senses. A variety of instruments are available for detecting and measuring radiation. Examples of radiation survey meters: photos of survey meters alphacounter1.JPG (28857 bytes) This probe is used for the detection of alpha radiation. The most common type of

  10. The Great Plains low-level jet (LLJ) during the atmospheric radiation measurement (ARM) intensive observation period (IOP)-4 and simulations of land use pattern effect on the LLJ

    SciTech Connect (OSTI)

    Wu, Y.; Raman, S.

    1996-04-01

    The Great Plains low-level jet (LLJ) is an important element of the low-level atmospheric circulation. It transports water vapor from the Gulf of Mexico, which in turn affects the development of weather over the Great Plains of the central United States. The LLJ is generally recognized as a complex response of the atmospheric boundary layer to the diurnal cycle of thermal forcing. Early studies have attributed the Great Plains LLJ to the diurnal oscillations of frictional effect, buoyancy over sloping terrain, and the blocking effects of the Rocky Mountains. Recent investigations show that the speed of the LLJ is also affected by the soil type and soil moisture. Some studies also suggest that synoptic patterns may play an important role in the development of the LLJ. Land surface heterogeneties significantly affect mesoscale circulations by generating strong contrasts in surface thermal fluxes. Thus one would expect that the land use pattern should have effects on the LLJ`s development and structure. In this study, we try to determine the relative roles of the synoptic forcing, planetary boundary layers (PBL) processes, and the land use pattern in the formation of the LLJ using the observations from the Atmospheric Radiation Measurement (ARM) Intensive Operation Period (IOP)-4 and numerical sensitivity tests.

  11. Five-year Local Control in a Phase II Study of Hypofractionated Intensity Modulated Radiation Therapy With an Incorporated Boost for Early Stage Breast Cancer

    SciTech Connect (OSTI)

    Freedman, Gary M.; Anderson, Penny R.; Bleicher, Richard J.; Litwin, Samuel; Li Tianyu; Swaby, Ramona F.; Ma, Chang-Ming Charlie; Li Jinsheng; Sigurdson, Elin R.; Watkins-Bruner, Deborah; Morrow, Monica; Goldstein, Lori J.

    2012-11-15

    Purpose: Conventional radiation fractionation of 1.8-2 Gy per day for early stage breast cancer requires daily treatment for 6-7 weeks. We report the 5-year results of a phase II study of intensity modulated radiation therapy (IMRT), hypofractionation, and incorporated boost that shortened treatment time to 4 weeks. Methods and Materials: The study design was phase II with a planned accrual of 75 patients. Eligibility included patients aged {>=}18 years, Tis-T2, stage 0-II, and breast conservation. Photon IMRT and an incorporated boost was used, and the whole breast received 2.25 Gy per fraction for a total of 45 Gy, and the tumor bed received 2.8 Gy per fraction for a total of 56 Gy in 20 treatments over 4 weeks. Patients were followed every 6 months for 5 years. Results: Seventy-five patients were treated from December 2003 to November 2005. The median follow-up was 69 months. Median age was 52 years (range, 31-81). Median tumor size was 1.4 cm (range, 0.1-3.5). Eighty percent of tumors were node negative; 93% of patients had negative margins, and 7% of patients had close (>0 and <2 mm) margins; 76% of cancers were invasive ductal type: 15% were ductal carcinoma in situ, 5% were lobular, and 4% were other histology types. Twenty-nine percent of patients 29% had grade 3 carcinoma, and 20% of patients had extensive in situ carcinoma; 11% of patients received chemotherapy, 36% received endocrine therapy, 33% received both, and 20% received neither. There were 3 instances of local recurrence for a 5-year actuarial rate of 2.7%. Conclusions: This 4-week course of hypofractionated radiation with incorporated boost was associated with excellent local control, comparable to historical results of 6-7 weeks of conventional whole-breast fractionation with sequential boost.

  12. Audible radiation monitor

    DOE Patents [OSTI]

    Odell, Daniel M. C.

    1993-01-01

    A method and apparatus for monitoring ionizing radiation comprising radiation detectors in electrical connection with an isotopic analyzer and a device for producing chords to which each isotope is mapped so that the device produces a unique chord for each isotope. Preferably the chords are pleasing to the ear, except for chords representing unexpected isotopes, and are louder or softer depending on the level of radioactivity produced by each isotope, and musical instrument voices may be simulated in producing the chords as an aid to distinguishing similar-sounding chords. Because of the representation by chords, information regarding the level and composition of the radiation in an area can be conveyed to workers in that area more effectively and yet without distracting them.

  13. radiation.p65

    Office of Legacy Management (LM)

    Potential Health Hazards of Radiation Man-made sources of radiation, most notably from medical uses and consumer products, contribute to the remaining radiation dose that ...

  14. Sandia National Laboratories: Research: Research Foundations: Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Effects and High Energy Density Science Radiation Effects and High Energy Density Science Rings of Saturn, Sandia's workhorse pulsed-power machine. The Radiation Effects and High Energy Density Science Research Foundation seeks to advance science and engineering in the areas of radiation effects sciences, high energy density science, and pulsed-power science and technology to address critical national security issues. Why our work matters We address several issues key to nuclear security and

  15. Global Distribution and Climate Forcing of Marine Organic Aerosol - Part 2: Effects on Cloud Properties and Radiative Forcing

    SciTech Connect (OSTI)

    Gantt, Brett; Xu, Jun; Meskhidze, N.; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

    2012-07-25

    A series of simulations with the Community Atmosphere Model version 5 (CAM5) with a 7-mode Modal Aerosol Model were conducted to assess the changes in cloud microphysical properties and radiative forcing resulting from marine organic aerosols. Model simulations show that the anthropogenic aerosol indirect forcing (AIF) predicted by CAM5 is decreased in absolute magnitude by up to 0.09 Wm{sup -2} (7 %) when marine organic aerosols are included. Changes in the AIF from marine organic aerosols are associated with small global increases in low-level incloud droplet number concentration and liquid water path of 1.3 cm{sup -3} (1.5 %) and 0.22 gm{sup -2} (0.5 %), respectively. Areas especially sensitive to changes in cloud properties due to marine organic aerosol include the Southern Ocean, North Pacific Ocean, and North Atlantic Ocean, all of which are characterized by high marine organic emission rates. As climate models are particularly sensitive to the background aerosol concentration, this small but non-negligible change in the AIF due to marine organic aerosols provides a notable link for ocean-ecosystem marine low-level cloud interactions and may be a candidate for consideration in future earth system models.

  16. Keys to success: Ten case studies of effective weatherization programs

    SciTech Connect (OSTI)

    Brown, M.A.; Berry, L.G.; Kolb, J.O.; White, D.L.; Kinney, L.F.; Wilson, T.

    1993-11-01

    In 1990, DOE initiated a nationwide evaluation of its Weatherization Program, with assistance from Oak Ridge National Laboratory and an advisory group of 40 weatherization professionals, program managers, and researchers. The evaluation is comprised of three impact studies covering the Program`s major market segments: Single-family homes, mobile homes, and dwellings in small (2 to 4-unit) multifamily buildings (the Single-Family Study), Single-family homes heated primarily with fuel oil (the Fuel-Oil Study), and Dwellings in buildings with five or more units (the Multifamily Study). The Single-Family Study, the subject of this report, is a critical part of this coordinated evaluation effort. Its focus on single-family dwellings, mobile homes, and dwellings in small multifamily buildings covers 83% of the income-eligible population and 96% of the dwellings weatherized during Program Year 1989. The first phase of the Single-Family Study involved the analysis of a massive data base of information collected from 368 local weatherization agencies and 543 electric and gas utilities. This analysis resulted in energy-saving and cost-effectiveness estimates for the Weatherization Program and the identification of a set of ten high-performing agencies located throughout the country. The second phase, which is the subject of this report, involves a ``process`` evaluation of these ten high performers, aimed at identifying those weatherization practices that explain their documented success.

  17. Radiation Protection and Safety Training | Environmental Radiation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation Protection and Safety Training (3 hrs) Instructors: John Seaman and Neil Miller ... with an introduction to the fundamentals of ionizing radiation protection and safety. ...

  18. Parylene-based active micro space radiator with thermal contact switch

    SciTech Connect (OSTI)

    Ueno, Ai; Suzuki, Yuji

    2014-03-03

    Thermal management is crucial for highly functional spacecrafts exposed to large fluctuations of internal heat dissipation and/or thermal boundary conditions. Since thermal radiation is the only means for heat removal, effective control of radiation is required for advanced space missions. In the present study, a MEMS (Micro Electro Mechanical Systems) active radiator using the contact resistance change has been proposed. Unlike previous bulky thermal louvers/shutters, higher fill factor can be accomplished with an array of electrostatically driven micro diaphragms suspended with polymer tethers. With an early prototype developed with parylene MEMS technologies, radiation heat flux enhancement up to 42% has been achieved.

  19. Electroresistance and field effect studies on manganite based heterostructure

    SciTech Connect (OSTI)

    Solanki, P. S.; Khachar, Uma; Vagadia, Megha; Ravalia, Ashish; Katba, Savan; Kuberkar, D. G.

    2015-04-14

    Electronic properties of manganites are significantly important for various spintronic applications such as microelectronics, magnetic data storage, communication technologies, and memory devices. Influence of applied electric field on the room temperature charge transport in ZnO/La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrNb{sub 0.002}Ti{sub 0.998}O{sub 3} (SNTO) heterostructure has been investigated using field effect studies. Large negative and positive electroresistance has been observed in heterostructure under various possible circuit geometries. Field effect studies have been carried out using three different circuit geometries, namely: (i) ZnO as a control electrode (E{sub LZ}), (ii) SNTO as a control electrode (E{sub LS}), and (iii) shorted ZnO and SNTO as control electrodes (E{sub LZS}). For this, channel electric field (E{sub CH}) dependent variation in channel resistance (R{sub C}) (of manganite channel) and I-V (across manganite channel) under various control fields (E{sub C}) have been studied. Variation in barrier height (Φ{sub B}) with control field (E{sub C}) for different geometries has been discussed.

  20. Stanford Synchrotron Radiation Lightsource

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Contacts Hirohito Ogasawara, Stanford Synchrotron Radiation Lightsource Dennis Nordlund, Stanford Synchrotron Radiation Lightsource Anders Nilsson, Stanford Synchrotron ...

  1. Effect of number of stack on the thermal escape and non-radiative and radiative recombinations of photoexcited carriers in strain-balanced InGaAs/GaAsP multiple quantum-well-inserted solar cells

    SciTech Connect (OSTI)

    Aihara, Taketo; Fukuyama, Atsuhiko; Ikari, Tetsuo; Suzuki, Hidetoshi; Fujii, Hiromasa; Nakano, Yoshiaki; Sugiyama, Masakazu

    2015-02-28

    Three non-destructive methodologies, namely, surface photovoltage (SPV), photoluminescence, and piezoelectric photothermal (PPT) spectroscopies, were adopted to detect the thermal carrier escape from quantum well (QW) and radiative and non-radiative carrier recombinations, respectively, in strain-balanced InGaAs/GaAsP multiple-quantum-well (MQW)-inserted GaAs p-i-n solar cell structure samples. Although the optical absorbance signal intensity was proportional to the number of QW stack, the signal intensities of the SPV and PPT methods decreased at high number of stack. To explain the temperature dependency of these signal intensities, we proposed a model that considers the three carrier dynamics: the thermal escape from the QW, and the non-radiative and radiative carrier recombinations within the QW. From the fitting procedures, it was estimated that the activation energies of the thermal escape ΔE{sub barr} and non-radiative recombination ΔE{sub NR} were 68 and 29 meV, respectively, for a 30-stacked MQW sample. The estimated ΔE{sub barr} value agreed well with the difference between the first electron subband and the top of the potential barrier in the conduction band. We found that ΔE{sub barr} remained constant at approximately 70 meV even with increasing QW stack number. However, the ΔE{sub NR} value monotonically increased with the increase in the number of stack. Since this implies that non-radiative recombination becomes improbable as the number of stack increases, we found that the radiative recombination probability for electrons photoexcited within the QW increased at a large number of QW stack. Additional processes of escaping and recapturing of carriers at neighboring QW were discussed. As a result, the combination of the three non-destructive methodologies provided us new insights for optimizing the MQW components to further improve the cell performance.

  2. Stereotactic Body Radiation Therapy for Locally Advanced and Borderline Resectable Pancreatic Cancer Is Effective and Well Tolerated

    SciTech Connect (OSTI)

    Chuong, Michael D.; Springett, Gregory M.; Freilich, Jessica M.; Park, Catherine K.; Weber, Jill M.; Mellon, Eric A.; Hodul, Pamela J.; Malafa, Mokenge P.; Meredith, Kenneth L.; Hoffe, Sarah E.; Shridhar, Ravi

    2013-07-01

    Purpose: Stereotactic body radiation therapy (SBRT) provides high rates of local control (LC) and margin-negative (R0) resections for locally advanced pancreatic cancer (LAPC) and borderline resectable pancreatic cancer (BRPC), respectively, with minimal toxicity. Methods and Materials: A single-institution retrospective review was performed for patients with nonmetastatic pancreatic cancer treated with induction chemotherapy followed by SBRT. SBRT was delivered over 5 consecutive fractions using a dose painting technique including 7-10 Gy/fraction to the region of vessel abutment or encasement and 5-6 Gy/fraction to the remainder of the tumor. Restaging scans were performed at 4 weeks, and resectable patients were considered for resection. The primary endpoints were overall survival (OS) and progression-free survival (PFS). Results: Seventy-three patients were evaluated, with a median follow-up time of 10.5 months. Median doses of 35 Gy and 25 Gy were delivered to the region of vessel involvement and the remainder of the tumor, respectively. Thirty-two BRPC patients (56.1%) underwent surgery, with 31 undergoing an R0 resection (96.9%). The median OS, 1-year OS, median PFS, and 1-year PFS for BRPC versus LAPC patients was 16.4 months versus 15 months, 72.2% versus 68.1%, 9.7 versus 9.8 months, and 42.8% versus 41%, respectively (all P>.10). BRPC patients who underwent R0 resection had improved median OS (19.3 vs 12.3 months; P=.03), 1-year OS (84.2% vs 58.3%; P=.03), and 1-year PFS (56.5% vs 25.0%; P<.0001), respectively, compared with all nonsurgical patients. The 1-year LC in nonsurgical patients was 81%. We did not observe acute grade ?3 toxicity, and late grade ?3 toxicity was minimal (5.3%). Conclusions: SBRT safely facilitates margin-negative resection in patients with BRPC pancreatic cancer while maintaining a high rate of LC in unresectable patients. These data support the expanded implementation of SBRT for pancreatic cancer.

  3. 2011 DOE Occupational Radiation Exposure Summary poster

    SciTech Connect (OSTI)

    ORAU

    2012-12-12

    This poster graphically presents data pertaining to occupational radiation exposure in terms of total effective dose (TED), primarily, but also collective dose and average measureable dose.

  4. DOE 2012 occupational radiation exposure (Technical Report) ...

    Office of Scientific and Technical Information (OSTI)

    In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The...

  5. DOE 2011 occupational radiation exposure (Technical Report) ...

    Office of Scientific and Technical Information (OSTI)

    In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The...

  6. DOE 2013 occupational radiation exposure (Technical Report) ...

    Office of Scientific and Technical Information (OSTI)

    In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The...

  7. Human radiation studies: Remembering the early years: Oral history of cell biologist Don Francis Petersen, Ph.D., conducted November 29, 1994

    SciTech Connect (OSTI)

    1995-08-01

    This report is a transcript of an interview of Dr. Don Francis Petersen by representatives of the US DOE Office of Human Radiation Experiments. Dr. Petersen was selected for this interview because of his long research career at Los Alamos and his knowledge of the Atomic Energy Commission`s biomedical program. Dr. Petersen did not personally conduct research on human subjects. After a brief biographical sketch Dr. Petersen discusses his remembrances of the early use of radionuclides as biological tracers, aspects of nuclear weapons testing in the 1940`s and 1950`s including fallout studies, the means by which research projects were approved, use of humans in the whole-body counter, and the Health Division Biomedical responsibilities.

  8. Modeling the Transport and Radiative Forcing of Taklimakan Dust over the Tibetan Plateau: A case study in the summer of 2006

    SciTech Connect (OSTI)

    Chen, Siyu; Huang, J.; Zhao, Chun; Qian, Yun; Leung, Lai-Yung R.; Yang, Ben

    2013-01-30

    The Weather Research and Forecasting model with chemistry (WRF-Chem) is used to investigate an intense dust storm event during 26 to 30 July 2006 that originated over the Taklimakan Desert (TD) and transported to the northern slope of Tibetan Plateau (TP). The dust storm is initiated by the approach of a strong cold frontal system over the TD. In summer, the meridional transport of TD dust to the TP is favored by the thermal effect of the TP and the weakening of the East Asian westerly winds. During this dust storm, the transport of TD dust over the TP is further enhanced by the passage of the cold front. As a result, TD dust breaks through the planetary boundary layer and extends to the upper troposphere over the northern TP. TD dust flux arrived at the TP with a value of 6.6 Gg/day in this 5 day event but decays quickly during the southward migration over the TP due to dry deposition. The simulations show that TD dust cools the atmosphere near the surface and heats the atmosphere above with a maximum heating rate of 0.11 K day-1 at ~7 km over the TP. The event-averaged net radiative forcings of TD dust over the TP are -3.97, 1.61, and -5.58 Wm-2 at the top of the atmosphere (TOA), in the atmosphere, and at the surface, respectively. The promising performance of WRF-Chem in simulating dust and its radiative forcing provides confidence for use in further investigation of climatic impact of TD dust over the TP.

  9. Applications of x-ray synchrotron radiation techniques to the study of dispersed electrocatalysts in high area materials

    SciTech Connect (OSTI)

    McBreen, J.

    1991-12-31

    This report discusses work demonstrating that X-Ray Absorption Spectroscopy is a very powerful technique for the study of electrocatalysts. Results for a prototech catalyst, and platinum are presented. (JL)

  10. Applications of x-ray synchrotron radiation techniques to the study of dispersed electrocatalysts in high area materials

    SciTech Connect (OSTI)

    McBreen, J.

    1991-01-01

    This report discusses work demonstrating that X-Ray Absorption Spectroscopy is a very powerful technique for the study of electrocatalysts. Results for a prototech catalyst, and platinum are presented. (JL)

  11. Comparison study of the partial-breast irradiation techniques: Dosimetric analysis of three-dimensional conformal radiation therapy, electron beam therapy, and helical tomotherapy depending on various tumor locations

    SciTech Connect (OSTI)

    Kim, Min-Joo; Park, So-Hyun; Son, Seok-Hyun; Cheon, Keum-Seong; Choi, Byung-Ock; Suh, Tae-Suk

    2013-10-01

    The partial-breast irradiation (PBI) technique, an alternative to whole-breast irradiation, is a beam delivery method that uses a limited range of treatment volume. The present study was designed to determine the optimal PBI treatment modalities for 8 different tumor locations. Treatment planning was performed on computed tomography (CT) data sets of 6 patients who had received lumpectomy treatments. Tumor locations were classified into 8 subsections according to breast quadrant and depth. Three-dimensional conformal radiation therapy (3D-CRT), electron beam therapy (ET), and helical tomotherapy (H-TOMO) were utilized to evaluate the dosimetric effect for each tumor location. Conformation number (CN), radical dose homogeneity index (rDHI), and dose delivered to healthy tissue were estimated. The Kruskal-Wallis, Mann-Whitney U, and Bonferroni tests were used for statistical analysis. The ET approach showed good sparing effects and acceptable target coverage for the lower inner quadrant—superficial (LIQ-S) and lower inner quadrant—deep (LIQ-D) locations. The H-TOMO method was the least effective technique as no evaluation index achieved superiority for all tumor locations except CN. The ET method is advisable for treating LIQ-S and LIQ-D tumors, as opposed to 3D-CRT or H-TOMO, because of acceptable target coverage and much lower dose applied to surrounding tissue.

  12. Study of the effects of guide field on Hall reconnection

    SciTech Connect (OSTI)

    Tharp, T. D.; Yamada, M.; Ji, H.; Lawrence, E.; Dorfman, S.; Myers, C.; Yoo, J.; Huang, Y.-M.; Bhattacharjee, A.

    2013-05-15

    The results from guide field studies on the Magnetic Reconnection Experiment (MRX) are compared with results from Hall magnetohydrodynamic (HMHD) reconnection simulation with guide field. The quadrupole field, a signature of two-fluid reconnection at zero guide field, is modified by the presence of a finite guide field in a manner consistent with HMHD simulation. The modified Hall current profile contains reduced electron flows in the reconnection plane, which quantitatively explains the observed reduction of the reconnection rate. The present results are consistent with the hypothesis that the local reconnection dynamics is dominated by Hall effects in the collisionless regime of the MRX plasmas. While very good agreement is seen between experiment and simulations, we note that an important global feature of the experiments, a compression of the guide field by the reconnecting plasma, is not represented in the simulations.

  13. Effects of solar radiation on organic matter cycling: Formation of carbon monoxide and carbonyl sulfide (Chapter 11). Book chapter

    SciTech Connect (OSTI)

    Zepp, R.G.

    1994-01-01

    The effects of photoinduced processes on carbon cycling and the biospheric emission of two important trace carbon gases--carbon monoxide and carbonyl sulfide--are examined. Both of these gases are likely to play an important role in the biospheric feedbacks that may reinforce or attenuate future changes in climate. Evidence is presented to support the hypothesis that a significant fraction of the global sources of both of these gases derives from the photochemical fragmentation of decayed plant materials and other biogenic organic matter in terrestrial and marine environments.

  14. SU-E-T-145: Effects of Temporary Tachytherapy Inhibition Magnet On MOSFET Dose Measurements of Cardiovascular Implantable Electronic Devices (CIED) in Radiation Therapy Patients

    SciTech Connect (OSTI)

    P, Joshi; Salomons, G; Kerr, A; Peters, C; Lalonde, M

    2014-06-01

    Purpose: To determine the effects of temporary tachytherapy inhibition magnet on MOSFET dose measurements of cardiovascular implantable electronic devices (CIED) in radiation therapy patients. Methods: Infield and peripheral MOSFET dose measurements with 6MV photon beams were performed to evaluate dose to a CIED in the presence of a doughnut shaped temporary tachytherapy inhibition magnet. Infield measurements were done to quantify the effects of the magnetic field alone and shielding by the magnet. MOSFETs were placed inside a 2020cm{sup 2} field at a depth of 3cm in the isocentre plane in the presence and absence of the magnet. Peripheral dose measurements were done to determine the impact of the magnet on dose to the CIED in a clinical setting. These measurements were performed at the centre, under the rim and half way between a 1010cm{sup 2} field edge and the magnet with MOSFETS placed at the surface, 0.5cm and 1cm depths in the presence and absence of the magnet. Results: Infield measurements showed that effects of magnetic field on the MOSFET readings were within the 2% MOSFET dose measurement uncertainty; a 20% attenuation of dose under the magnet rim was observed. Peripheral dose measurements at the centre of the magnet show an 8% increase in surface dose and a 6% decrease in dose at 1cm depth. Dose under the magnet rim was reduced by approximately 68%, 45% and 25% for MOSFET placed at 0.0, 0.5 and 1.0cm bolus depths, respectively. Conclusions: The magnetic field has an insignificant effect on MOSFET dose measurements. Dose to the central region of CIED represented by centre of the magnet doughnut increases at the surface, and decreases at depths due to low energy scattering contributions from the magnet. Dose under the magnet rim, representing CIED edges, decreased significantly due to shielding.

  15. Characterization of commercial proton exchange membrane materials after exposure to beta and gamma radiation

    SciTech Connect (OSTI)

    Thomson, S.N.; Carson, R.; Muirhead, C.; Li, H.; Castillo, I.; Boniface, H.; Suppiah, S.; Ratnayake, A.; Robinson, J.

    2015-03-15

    Proton Exchange Membrane (PEM) type electrolysis cells have a potential use for tritium removal and heavy water upgrading. AECL is currently exposing various commercial PEM materials to both gamma (Cobalt-60 source) and beta (tritiated water) radiation to study the effects of radiation on these materials. This paper summarizes the testing methods and results that have been collected to date. The PEM materials that are or have been exposed to radiation are: Nafion 112, 212, 117 and 1110. Membrane characterization pre- and post- exposure consists of non-destructive inspection (FTIR, SEM/XPS), mechanical (tensile strength, percentage elongation, and modulus), electrical (resistance), or chemical (ion-exchange capacity - IEC). It has appeared that the best characterization techniques to compare exposed versus unexposed membranes were IEC, ultimate tensile strength and percent elongation. These testing techniques are easy and cheap to perform. The non-destructive tests, such as SEM and FTIR did not provide particularly useful information on radiation-induced degradation. Where changes in material properties were measured after radiation exposure, they would be expected to result in poorer cell performance. However, for modest ?-radiation exposure, all membranes showed a slight decrease in cell voltage (better performance). In contrast, the one ?-radiation exposed membrane did show the expected increase in cell voltage. The counterintuitive trend for ?-radiation exposed membranes is not yet understood. Based on these preliminary results, it appears that ?- and ?-radiation exposures have different effects.

  16. RADIATION COUNTER

    DOE Patents [OSTI]

    Goldsworthy, W.W.

    1958-02-01

    This patent relates to a radiation counter, and more particularly, to a scintillation counter having high uniform sensitivity over a wide area and capable of measuring alpha, beta, and gamma contamination over wide energy ranges, for use in quickly checking the contami-nation of personnel. Several photomultiplier tubes are disposed in parallel relationship with a light tight housing behind a wall of scintillation material. Mounted within the housing with the photomultipliers are circuit means for producing an audible sound for each pulse detected, and a range selector developing a voltage proportional to the repetition rate of the detected pulses and automatically altering its time constant when the voltage reaches a predetermined value, so that manual range adjustment of associated metering means is not required.

  17. Radiation dosimeters

    DOE Patents [OSTI]

    Hoelsher, James W.; Hegland, Joel E.; Braunlich, Peter F.; Tetzlaff, Wolfgang

    1992-01-01

    Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

  18. NRG Oncology Radiation Therapy Oncology Group 0822: A Phase 2 Study of Preoperative Chemoradiation Therapy Using Intensity Modulated Radiation Therapy in Combination With Capecitabine and Oxaliplatin for Patients With Locally Advanced Rectal Cancer

    SciTech Connect (OSTI)

    Hong, Theodore S.; Moughan, Jennifer; Garofalo, Michael C.; Bendell, Johanna; Berger, Adam C.; Oldenburg, Nicklas B.E.; Anne, Pramila Rani; Perera, Francisco; Jabbour, Salma K.; Nowlan, Adam; DeNittis, Albert; Crane, Christopher

    2015-09-01

    Purpose: To evaluate the rate of gastrointestinal (GI) toxicity of neoadjuvant chemoradiation with capecitabine, oxaliplatin, and intensity modulated radiation therapy (IMRT) in cT3-4 rectal cancer. Methods and Materials: Patients with localized, nonmetastatic T3 or T4 rectal cancer <12 cm from the anal verge were enrolled in a prospective, multi-institutional, single-arm study of preoperative chemoradiation. Patients received 45 Gy with IMRT in 25 fractions, followed by a 3-dimensional conformal boost of 5.4 Gy in 3 fractions with concurrent capecitabine/oxaliplatin (CAPOX). Surgery was performed 4 to 8 weeks after the completion of therapy. Patients were recommended to receive FOLFOX chemotherapy after surgery. The primary endpoint of the study was acute grade 2 to 5 GI toxicity. Seventy-one patients provided 80% probability to detect at least a 12% reduction in the specified GI toxicity with the treatment of CAPOX and IMRT, at a significance level of .10 (1-sided). Results: Seventy-nine patients were accrued, of whom 68 were evaluable. Sixty-one patients (89.7%) had cT3 disease, and 37 (54.4%) had cN (+) disease. Postoperative chemotherapy was given to 42 of 68 patients. Fifty-eight patients had target contours drawn per protocol, 5 patients with acceptable variation, and 5 patients with unacceptable variations. Thirty-five patients (51.5%) experienced grade ≥2 GI toxicity, 12 patients (17.6%) experienced grade 3 or 4 diarrhea, and pCR was achieved in 10 patients (14.7%). With a median follow-up time of 3.98 years, the 4-year rate of locoregional failure was 7.4% (95% confidence interval [CI]: 1.0%-13.7%). The 4-year rates of OS and DFS were 82.9% (95% CI: 70.1%-90.6%) and 60.6% (95% CI: 47.5%-71.4%), respectively. Conclusion: The use of IMRT in neoadjuvant chemoradiation for rectal cancer did not reduce the rate of GI toxicity.

  19. Predictors of Grade 3 or Higher Late Bowel Toxicity in Patients Undergoing Pelvic Radiation for Cervical Cancer: Results From a Prospective Study

    SciTech Connect (OSTI)

    Chopra, Supriya; Dora, Tapas; Chinnachamy, Anand N.; Thomas, Biji; Kannan, Sadhna; Engineer, Reena; Mahantshetty, Umesh; Phurailatpam, Reena; Paul, Siji N.; Shrivastava, Shyam Kishore

    2014-03-01

    Purpose: The present study investigates relationship between dosevolume parameters and severe bowel toxicity after postoperative radiation treatment (PORT) for cervical cancer. Methods and Materials: From June 2010 to December 2012, a total of 71 patients undergoing PORT were included. Small bowel (SB) and large bowel (LB) loops were contoured 2cm above the target volume. The volume of SB and LB that received 15Gy, 30Gy, and 40Gy was calculated (V15 SB, V15 LB, V30 SB, V30 LB, V40 SB, V 40 LB). On follow-up, bowel toxicity was scored using Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. A reciever operating characteristic (ROC) curve identified volume thresholds that predicted for grade 3 or higher toxicity with highest specificity. All data was dichotomized across these identified cut-off values. Univariate and multivariate analysis was performed using SPSS, version15. Results: The median patient age was 47years (range, 35-65years). Of the 71 patients, 46 received image-guided intensity modulated radiation therapy, and 25 received conformal radiation (50Gy in 25 fractions for 5weeks). Overall, 63 of 71 patients received concurrent chemotherapy. On a median follow-up of 18months (range, 8-29months), grade 2 or higher bowel toxicity was seen in 22 of 71 patients (30.9%) and grade 3 or higher bowel toxicity was seen in 9 patients (12.6%). On univariate analysis, V15 SB <275 cc (P=.01), V30 SB <190 cc (P=.02), V40 SB <150 cc (P=.01), and V15 LB <250 cc (P=.03), and V40 LB <90 cc (P=.04) predicted for absence of grade 3 or higher toxicity. No other patient- or treatment-related factors were statistically significant. On multivariate analysis, only V15 SB (P=.002) and V15 LB (P=.03) were statistically significant. Conclusions: V 15Gy SB and LB are independent predictors of late grade 3 or higher toxicity. Restricting V15 SB and V15 LB to <275 cc and <250 cc can reduce grade 3 or higher toxicity to less than 5%.

  20. CIRRPC: Committee on Interagency Radiation Research and Policy Coordination. Eighth annual report

    SciTech Connect (OSTI)

    Young, A.L.

    1992-12-01

    CIRRPC`s eighth year was marked by the completion of several CIRRPC projects, including: An independent study on the possible health effects of extremely low-frequency electric and magnetic fields; a report evaluating the uncertainties identified in a National Academy of Sciences (NAS) report on the biological effects of ionizing radiation and their impact on the report`s application to Federal risk assessment; an analysis of the use of two reports on radiation risk assessment from NAS and the United Nations; and an update of Part 11 of ORAU`s radiation protection fact sheets, a compilation of major US radiation protection standards and guides. CIRRPC also sponsored a workshop on internal dosimetry and provided financial support to the 1991 Health Physics Society Summer School on the biological basis of radiation protection practice. The program highlights are briefly described in this report.

  1. Adaptors for radiation detectors

    DOE Patents [OSTI]

    Livesay, Ronald Jason

    2014-04-22

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  2. Adaptors for radiation detectors

    SciTech Connect (OSTI)

    Livesay, Ronald Jason

    2015-07-28

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  3. Does Local Recurrence of Prostate Cancer After Radiation Therapy Occur at the Site of Primary Tumor? Results of a Longitudinal MRI and MRSI Study

    SciTech Connect (OSTI)

    Arrayeh, Elnasif; Westphalen, Antonio C.; Kurhanewicz, John; Roach, Mack; Jung, Adam J.; Carroll, Peter R.; Coakley, Fergus V.

    2012-04-01

    Purpose: To determine if local recurrence of prostate cancer after radiation therapy occurs at the same site as the primary tumor before treatment, using longitudinal magnetic resonance (MR) imaging and MR spectroscopic imaging to assess dominant tumor location. Methods and Materials: This retrospective study was HIPAA compliant and approved by our Committee on Human Research. We identified all patients in our institutional prostate cancer database (1996 onward) who underwent endorectal MR imaging and MR spectroscopic imaging before radiotherapy for biopsy-proven prostate cancer and again at least 2 years after radiotherapy (n = 124). Two radiologists recorded the presence, location, and size of unequivocal dominant tumor on pre- and postradiotherapy scans. Recurrent tumor was considered to be at the same location as the baseline tumor if at least 50% of the tumor location overlapped. Clinical and biopsy data were collected from all patients. Results: Nine patients had unequivocal dominant tumor on both pre- and postradiotherapy imaging, with mean pre- and postradiotherapy dominant tumor diameters of 1.8 cm (range, 1-2.2) and 1.9 cm (range, 1.4-2.6), respectively. The median follow-up interval was 7.3 years (range, 2.7-10.8). Dominant recurrent tumor was at the same location as dominant baseline tumor in 8 of 9 patients (89%). Conclusions: Local recurrence of prostate cancer after radiation usually occurs at the same site as the dominant primary tumor at baseline, suggesting supplementary focal therapy aimed at enhancing local tumor control would be a rational addition to management.

  4. Terahertz radiation mixer

    DOE Patents [OSTI]

    Wanke, Michael C.; Allen, S. James; Lee, Mark

    2008-05-20

    A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

  5. Parameterization and analysis of 3-D radiative transfer in clouds

    SciTech Connect (OSTI)

    Varnai, Tamas

    2012-03-16

    found that local effects were often much larger than the overall values mentioned above, and were especially large for high sun and near convective clouds such as cumulus. The study also found that statistical methods such as neural networks appear promising for enabling cloud models to consider radiative interactions between nearby atmospheric columns. Finally, through collaboration with German scientists, the project found that new methods (especially one called stepwise kriging) show great promise in filling gaps between cloud radar scans. If applied to data from the new DOE scanning cloud radars, these methods can yield large, continuous three-dimensional cloud structures for future radiative simulations.

  6. Study of volume and surface effects in pure hydrogen discharges

    SciTech Connect (OSTI)

    Taccogna, F.; Schneider, R.; Fantz, U.; Longo, S.; Capitelli, M.

    2007-08-10

    The work concerns the simulation of negative ion formation and acceleration in a radio-frequency discharge for neutral beam injection system for ITER, with particular emphasis on the IPP negative ion source. To generate intense beams of negative ions and to optimize the negative ion source, understanding of transport properties of negative ions H- is indispensable. To study this effect, we have developed a 1D(z)-3V Particle-in-Cell electrostatic model of the production and extraction regions. The motion of charged particles (e, H+, H{sub 2}{sup +} and H-) in their self-consistent electric field and of neutral particles (H(n=1,2,3) and H2(X{sup 1}{sigma}{sub g}{sup +}, {nu}=0,...,14)) is simulated. Surface and volumetric processes involving plasma and neutral systems have been included by using different Monte Carlo Collision methods. Comparisons between numerical and experimental results have been done in order to validate the code.

  7. Radiation-induced lung injury

    SciTech Connect (OSTI)

    Rosiello, R.A.; Merrill, W.W. )

    1990-03-01

    The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

  8. DOE 2013 occupational radiation exposure

    SciTech Connect (OSTI)

    none,

    2014-11-01

    The Office of Analysis within the U.S. Department of Energy (DOE) Office of Environment, Health, Safety and Security (EHSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2013 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past five-year period, the occupational radiation exposure information has been analyzed in terms of aggregate data, dose to individuals, and dose by site.

  9. Radiation feedback in ULIRGs: are photons movers and shakers?

    SciTech Connect (OSTI)

    Davis, Shane W.; Murray, Norman; Jiang, Yan-Fei; Stone, James M.

    2014-12-01

    We perform multidimensional radiation hydrodynamics simulations to study the impact of radiation forces on atmospheres composed of dust and gas. Our setup closely follows that of Krumholz and Thompson, assuming that dust and gas are well-coupled and that the radiation field is characterized by blackbodies with temperatures ≳ 80 K, as might be found in ultraluminous infrared galaxies (ULIRGs). In agreement with previous work, we find that Rayleigh-Taylor instabilities develop in radiation supported atmospheres, leading to inhomogeneities that limit momentum exchange between radiation and dusty gas, and eventually providing a near balance of the radiation and gravitational forces. However, the evolution of the velocity and spatial distributions of the gas differs significantly from previous work, which utilized a less accurate flux-limited diffusion (FLD) method. Our variable Eddington tensor simulations show continuous net acceleration of the gas and never reach a steady state. In contrast, our FLD results show little net acceleration of the gas and settle into a quasi-steady, turbulent state with low velocity dispersion. The discrepancies result primarily from the inability of FLD to properly model the variation of the radiation field around structures that are less than a few optical depths across. We consider the effect of varying the optical depth and study the differences between two-dimensional and three-dimensional runs. We conclude that radiation feedback remains a plausible mechanism for driving high-Mach number turbulence in ULIRGs with sufficiently high optical depths. We discuss implications for observed systems and galactic-scale numerical simulations of feedback.

  10. Study of electron acceleration and x-ray radiation as a function of plasma density in capillary-guided laser wakefield accelerators

    SciTech Connect (OSTI)

    Ju, J.; Döpp, A.; Cros, B.; Svensson, K.; Genoud, G.; Wojda, F.; Burza, M.; Persson, A.; Lundh, O.; Wahlström, C.-G.; Ferrari, H.

    2013-08-15

    Laser wakefield electron acceleration in the blow-out regime and the associated betatron X-ray radiation were investigated experimentally as a function of the plasma density in a configuration where the laser is guided. Dielectric capillary tubes were employed to assist the laser keeping self-focused over a long distance by collecting the laser energy around its central focal spot. With a 40 fs, 16 TW pulsed laser, electron bunches with tens of pC charge were measured to be accelerated to an energy up to 300 MeV, accompanied by X-ray emission with a peak brightness of the order of 10{sup 21} ph/s/mm{sup 2}/mrad{sup 2}/0.1%BW. Electron trapping and acceleration were studied using the emitted X-ray beam distribution to map the acceleration process; the number of betatron oscillations performed by the electrons was inferred from the correlation between measured X-ray fluence and beam charge. A study of the stability of electron and X-ray generation suggests that the fluctuation of X-ray emission can be reduced by stabilizing the beam charge. The experimental results are in good agreement with 3D particle-in-cell (PIC) simulation.

  11. Inhibition of Vascular Endothelial Growth Factor A and Hypoxia-Inducible Factor 1α Maximizes the Effects of Radiation in Sarcoma Mouse Models Through Destruction of Tumor Vasculature

    SciTech Connect (OSTI)

    Lee, Hae-June; Yoon, Changhwan; Park, Do Joong; Kim, Yeo-Jung; Schmidt, Benjamin; Lee, Yoon-Jin; Tap, William D.; Eisinger-Mathason, T.S. Karin; Choy, Edwin; Kirsch, David G.; Simon, M. Celeste; and others

    2015-03-01

    Purpose: To examine the addition of genetic or pharmacologic inhibition of hypoxia-inducible factor 1α (HIF-1α) to radiation therapy (RT) and vascular endothelial growth factor A (VEGF-A) inhibition (ie trimodality therapy) for soft-tissue sarcoma. Methods and Materials: Hypoxia-inducible factor 1α was inhibited using short hairpin RNA or low metronomic doses of doxorubicin, which blocks HIF-1α binding to DNA. Trimodality therapy was examined in a mouse xenograft model and a genetically engineered mouse model of sarcoma, as well as in vitro in tumor endothelial cells (ECs) and 4 sarcoma cell lines. Results: In both mouse models, any monotherapy or bimodality therapy resulted in tumor growth beyond 250 mm{sup 3} within the 12-day treatment period, but trimodality therapy with RT, VEGF-A inhibition, and HIF-1α inhibition kept tumors at <250 mm{sup 3} for up to 30 days. Trimodality therapy on tumors reduced HIF-1α activity as measured by expression of nuclear HIF-1α by 87% to 95% compared with RT alone, and cytoplasmic carbonic anhydrase 9 by 79% to 82%. Trimodality therapy also increased EC-specific apoptosis 2- to 4-fold more than RT alone and reduced microvessel density by 75% to 82%. When tumor ECs were treated in vitro with trimodality therapy under hypoxia, there were significant decreases in proliferation and colony formation and increases in DNA damage (as measured by Comet assay and γH2AX expression) and apoptosis (as measured by cleaved caspase 3 expression). Trimodality therapy had much less pronounced effects when 4 sarcoma cell lines were examined in these same assays. Conclusions: Inhibition of HIF-1α is highly effective when combined with RT and VEGF-A inhibition in blocking sarcoma growth by maximizing DNA damage and apoptosis in tumor ECs, leading to loss of tumor vasculature.

  12. Stanford Synchrotron Radiation Lightsource

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Sheep Cortical Bone Using Synchrotron Radiation Transmission X-ray Microscopy", PLoS ONE ... Garry R. Brock, Cornell University Joy C. Andrews, Stanford Synchrotron Radiation ...

  13. Life-span effects of ionizing radiation in the beagle dog: A summary account of four decades of research funded by the US Department of Energy and its predecessor agencies

    SciTech Connect (OSTI)

    Thompson, R.C.

    1989-01-01

    Nearly 40 years ago, the US Atomic Energy Commission made a far- reaching commitment to the support of life-span radiation-effects studies in a relatively long-lived animal, the beagle dog. Something in the range of 200 million dollars has already been spent on a group of closely related experiments, many of which are only now coming to fruition. Responsible fiscal management of these studies, directed toward securing an optimum return from past investments, and toward creative planning of future directions, requires a comprehensive view of this total effort. This report is designed to provide that comprehensive view. This is primarily intended as a research management document. Evaluation and interpretation are tasks for those directly involved in conducting these experiments. The limited objective of the present document is to describe what has been done, to give some of the background for why it was done, to describe results already realized and applications that have been made of these results -- all in a manner designed to display the total effort rather than piecemeal details. While proposing no specific answers to the questions ''Where do we go from here.''it is hoped that the document will provide a basis for approaching that question in an informed manner. The maintenance of a continuity of scientific understanding and direction in these experiments, which often continue beyond the initiating investigators' working life, is no small part of the problem involved in conducting these experiments.

  14. Study of Mechanisms of Aerosol Indirect Effects on Glaciated...

    Office of Scientific and Technical Information (OSTI)

    ... clouds, was seen to be of higher importance in regulating aerosol indirect effects ... DOE Contract Number: SC0007396 Resource Type: Technical Report Research Org: Leeds ...

  15. Radiation Leukemogenesis at Low Dose Rates

    SciTech Connect (OSTI)

    Weil, Michael; Ullrich, Robert

    2013-09-25

    The major goals of this program were to study the efficacy of low dose rate radiation exposures for the induction of acute myeloid leukemia (AML) and to characterize the leukemias that are caused by radiation exposures at low dose rate. An irradiator facility was designed and constructed that allows large numbers of mice to be irradiated at low dose rates for protracted periods (up to their life span). To the best of our knowledge this facility is unique in the US and it was subsequently used to study radioprotectors being developed for radiological defense (PLoS One. 7(3), e33044, 2012) and is currently being used to study the role of genetic background in susceptibility to radiation-induced lung cancer. One result of the irradiation was expected; low dose rate exposures are ineffective in inducing AML. However, another result was completely unexpected; the irradiated mice had a very high incidence of hepatocellular carcinoma (HCC), approximately 50%. It was unexpected because acute exposures are ineffective in increasing HCC incidence above background. This is a potential important finding for setting exposure limits because it supports the concept of an 'inverse dose rate effect' for some tumor types. That is, for the development of some tumor types low dose rate exposures carry greater risks than acute exposures.

  16. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    SciTech Connect (OSTI)

    Kleiman, Norman Jay

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  17. Defining a Possible Low LET Bystander Effect

    SciTech Connect (OSTI)

    Charles R. Geard

    2009-05-04

    Current radiation protection guidelines assume a linear response to ionizing radiations down through doses where epidemiological studies provide very limited to no information as to the propriety of such assumptions. The bystander response is a non-targeted effect which might impact such guidelines. These studies while clearly affirming a bystander response for high LET radiations, do not provide such affirmation for environmentally relevant low dose, low LET radiations. Caution and further study are necessary before making judgements that could impact on current standards.

  18. Final Report for Project DE-SC0006958: "An Investigation of the Effects of magnetic Fields and Collisionality on Shock Formation in Radiatively Cooled Plasma Flows"

    SciTech Connect (OSTI)

    Bott-Suzuki, Simon

    2014-11-05

    We have developed a new experimental platform to study bow-shock formation in plasma flows generated using an inverse wire array z-pinch. We have made significant progress on the analysis of both hydrodynamic and magnetized shocks using this system. The hydrodynamic experiments show formation of a well-defined Mach cone, and highly localized shock strong associated with radiative losses and rapidly cooling over the shock. Magnetized shocks show that the balance of magnetic and ram pressures dominate the evolution of the shock region, generating a low plasma beta void around the target. Manuscripts are in preparation for publication on both these topics. We have also published the development of a novel diagnostic method which allow recovery of interferometry and self-emission data along the same line of sight. Finally, we have carried out work to integrate a kinetic routine with the 3D MHD code Gorgon, however it remains to complete this process. Both undergraduate and graduate students have been involved in both the experimental work and publications.

  19. High-Pressure Synchtron Radiation X-Ray Diffraction Studies of Pentaerythritol Tetranitrate C(CH[subscript 2]ONO[subscript 2 ])[subscript 4

    SciTech Connect (OSTI)

    Lipinska-Kalita, K.E.; Pravica, M.; Nicol, M.

    2006-02-02

    A high-pressure x-ray diffraction study of nanocrystalline pentaerythritol tetranitrate, C(CH{sub 2}ONO{sub 2}){sub 4}, (PETN), has been performed in a diamond-anvil cell at ambient temperature using synchrotron radiation. Pressure-induced alterations in the profiles of the diffraction lines, including their positions, widths and intensities were followed up to 30 GPa in a compressino cycle. The spectral changes in the diffraction patterns at low pressures indicated continuous densification of the tetragonal structure (space group P{bar 4}2{sub 1}c). The diffraction patterns confirmed that PETN compressed from ambient pressure to 7.4 GPa by 17%. At 8.2 GPa and above, several new diffraction lines appeared in the patterns. These lines suggest that the lattice undergoes an incomplete stress-induced structural transformation from the tetragonal to an orthorhombic structure (most probably space group P2{sub 1}22{sub 1}). The mixture of both structures appeared to persist to 30 GPa. The progressive broadening of the diffraction lines as the pressure increased beyond 10 GPa is attributed to the combined diffraction lines of a mixture of two coexisting PETN phases and inhomogeneous pressure distribution within the sample.

  20. SU-E-P-58: Dosimetric Study of Conventional Intensity-Modulated Radiotherapy and Knowledge-Based Radiation Therapy for Postoperation of Cervix Cancer

    SciTech Connect (OSTI)

    Ma, C; Yin, Y

    2015-06-15

    Purpose: To compare the dosimetric difference of the target volume and organs at risk(OARs) between conventional intensity-modulated radiotherapy(C-IMRT) and knowledge-based radiation therapy (KBRT) plans for cervix cancer. Methods: 39 patients with cervical cancer after surgery were randomly selected, 20 patient plans were used to create the model, the other 19 cases used for comparative evaluation. All plans were designed in Eclipse system. The prescription dose was 30.6Gy, 17 fractions, OARs dose satisfied to the clinical requirement. A paired t test was used to evaluate the differences of dose-volume histograms (DVH). Results: Comparaed to C-IMRT plan, the KBRT plan target can achieve the similar target dose coverage, D98,D95,D2,HI and CI had no difference (P≥0.05). The dose of rectum, bladder and femoral heads had no significant differences(P≥0.05). The time was used to design treatment plan was significant reduced. Conclusion: This study shows that postoperative radiotherapy of cervical KBRT plans can achieve the similar target and OARs dose, but the shorter designing time.

  1. STUDY OF THE EFFECT OF PRIVATE WIRE LAWS ON DEVELOPMENT OF COMBINED...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    STUDY OF THE EFFECT OF PRIVATE WIRE LAWS ON DEVELOPMENT OF COMBINED HEAT AND POWER FACILITIE STUDY OF THE EFFECT OF PRIVATE WIRE LAWS ON DEVELOPMENT OF COMBINED HEAT AND POWER ...

  2. STUDY OF THE EFFECT OF PRIVATE WIRE LAWS ON DEVELOPMENT OF COMBINED...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    STUDY OF THE EFFECT OF PRIVATE WIRE LAWS ON DEVELOPMENT OF COMBINED HEAT AND POWER FACILITIE STUDY OF THE EFFECT OF PRIVATE WIRE LAWS ON DEVELOPMENT OF COMBINED HEAT AND POWER...

  3. Theoretical study of quantum molecular reaction dynamics and of the effects of intense laser radiation on a diatomic molecule

    SciTech Connect (OSTI)

    Dardi, P.S.

    1984-11-01

    Within the very broad field of molecular dynamics, we have concentrated on two simple yet important systems. The systems are simple enough so that they are adequately described with a single Born-Oppenheimer potential energy surface and that the dynamics can be calculated accurately. They are important because they give insight into solving more complicated systems. First we discuss H + H/sub 2/ reactive scattering. We present an exact formalism for atom-diatom reactive scattering which avoids the problem of finding a coordinate system appropriate for both reactants and products. We present computational results for collinear H + H/sub 2/ reactive scattering which agree very well with previous calculations. We also present a coupled channel distorted wave Born approximation for atom-diatom reactive scattering which we show is a first order approximation to our exact formalism. We present coupled channel DWBA results for three dimensional H + H/sub 2/ reactive scattering. The second system is an isolated HF molecule in an intense laser field. Using classical trajectories and quantum dynamics, we look at energy absorbed and transition probabilities as a function of the laser pulse time and also averaged over the pulse time. Calculations are performed for both rotating and nonrotating HF. We examine one and two photon absorption about the fundamental frequency, multiphoton absorption, and overtone absorption. 127 references, 31 figures, 12 tables.

  4. Electroreflectance study of the effect of {gamma} radiation on the optical properties of epitaxial GaN films

    SciTech Connect (OSTI)

    Belyaev, A. E.; Klyui, N. I. Konakova, R. V.; Lukyanov, A. N.; Danilchenko, B. A.; Sveshnikov, J. N.; Klyui, A. N.

    2012-03-15

    Experimental data on the electroreflectance spectra of {gamma}-irradiated epitaxial GaN films on sapphire are reported. The irradiation doses are 10{sup 5}-2 Multiplication-Sign 10{sup 6} rad. The theoretical electroreflectance spectra calculated on the basis of a model of three types of transitions are in agreement with experimental data with reasonable accuracy. The energies and broadenings of the transitions derived in the context of the model give grounds to infer that, in the GaN films, there are internal stresses dependent on the {gamma}-irradiation dose.

  5. Human radiation studies: Remembering the early years. Oral history of radiologist Earl R. Miller, M.D., August 9 and 17, 1994

    SciTech Connect (OSTI)

    1995-06-01

    Dr. Earl R. Miller was interviewed by representatives of US DOE Office of Human Radiation Research (OHRE). The interview covers Dr. Miller`s involvement with the Manhattan Engineer District, with total body irradiation, and heavy-ion therapy. Dr. Miller`s remembrances include wartime work on radiation exposure, Joe Hamilton, Neutron Therapy research, means of obtaining isotopes, consent forms, infinite laminograms, invention of a baby holder to alleviate exposure of radiological technicians in diagnostic procedures involving infants, and several personages.

  6. Future directions in therapy of whole body radiation injury

    SciTech Connect (OSTI)

    Cronkite, E.P.

    1989-01-01

    Clinicians have long known that marked granulocytopenia predisposed patients to bacterial infections either from pathogens or commensal organisms with which an individual usually lives in harmony. Evidence that infection was of major importance derives from several observations: (a) clinical observations of bacterial infection in human beings exposed to atomic bomb radiation in Hiroshima and Nagasaki, in reactor accidents, and in large animals dying from radiation exposure, (b) correlative studies on mortality rate, time of death, and incidence of positive culture in animals, (c) challenge of irradiated animals with normally non-virulent organisms, (d) studies of germ free mice and rats, and (e) studies of the effectiveness of antibiotics in reducing mortality rate. General knowledge and sound experimental data on animals and man clearly demonstrated that the sequelae of pancytopenia (bacterial infection, thrombopenic hemorrhage, and anemia) are the lethal factors. A lot of research was required to demonstrate that there were no mysterious radiations toxins, that hyperheparinemia was not a cause of radiation hemorrhage and that radiation hemorrhage could be prevented by fresh platelet transfusions.

  7. Evaluation of GCM Column Radiation Models Under Cloudy Conditions with The Arm BBHRP Value Added Product

    SciTech Connect (OSTI)

    Oreopoulos, Lazaros; Norris, Peter M.

    2010-03-14

    The overarching goal of the project was to improve the transfer of solar and thermal radiation in the most sophisticated computer tools that are currently available for climate studies, namely Global Climate Models (GCMs). This transfer can be conceptually separated into propagation of radiation under cloudy and under cloudless conditions. For cloudless conditions, the factors that affect radiation propagation are gaseous absorption and scattering, aerosol particle absorption and scattering and surface albedo and emissivity. For cloudy atmospheres the factors are the various cloud properties such as cloud fraction, amount of cloud condensate, the size of the cloud particles, and morphological cloud features such as cloud vertical location, cloud horizontal and vertical inhomogeneity and cloud shape and size. The project addressed various aspects of the influence of the above contributors to atmospheric radiative transfer variability. In particular, it examined: (a) the quality of radiative transfer for cloudless and non-complex cloudy conditions for a substantial number of radiation algorithms used in current GCMs; (b) the errors in radiative fluxes from neglecting the horizontal variabiity of cloud extinction; (c) the statistical properties of cloud horizontal and vertical cloud inhomogeneity that can be incorporated into radiative transfer codes; (d) the potential albedo effects of changes in the particle size of liquid clouds; (e) the gaseous radiative forcing in the presence of clouds; and (f) the relative contribution of clouds of different sizes to the reflectance of a cloud field. To conduct the research in the various facets of the project, data from both the DOE ARM project and other sources were used. The outcomes of the project will have tangible effects on how the calculation of radiative energy will be approached in future editions of GCMs. With better calculations of radiative energy in GCMs more reliable predictions of future climate states will be

  8. Refinement, Validation and Application of Cloud-Radiation Parameterization in a GCM

    SciTech Connect (OSTI)

    Dr. Graeme L. Stephens

    2009-04-30

    The research performed under this award was conducted along 3 related fronts: (1) Refinement and assessment of parameterizations of sub-grid scale radiative transport in GCMs. (2) Diagnostic studies that use ARM observations of clouds and convection in an effort to understand the effects of moist convection on its environment, including how convection influences clouds and radiation. This aspect focuses on developing and testing methodologies designed to use ARM data more effectively for use in atmospheric models, both at the cloud resolving model scale and the global climate model scale. (3) Use (1) and (2) in combination with both models and observations of varying complexity to study key radiation feedback Our work toward these objectives thus involved three corresponding efforts. First, novel diagnostic techniques were developed and applied to ARM observations to understand and characterize the effects of moist convection on the dynamical and thermodynamical environment in which it occurs. Second, an in house GCM radiative transfer algorithm (BUGSrad) was employed along with an optimal estimation cloud retrieval algorithm to evaluate the ability to reproduce cloudy-sky radiative flux observations. Assessments using a range of GCMs with various moist convective parameterizations to evaluate the fidelity with which the parameterizations reproduce key observable features of the environment were also started in the final year of this award. The third study area involved the study of cloud radiation feedbacks and we examined these in both cloud resolving and global climate models.

  9. A Prospective Pathologic Study to Define the Clinical Target Volume for Partial Breast Radiation Therapy in Women With Early Breast Cancer

    SciTech Connect (OSTI)

    Nguyen, Brandon T.; Deb, Siddhartha; Victorian Cancer Biobank, Cancer Council of Victoria, Carlton, Victoria ; Fox, Stephen; Hill, Prudence; Collins, Marnie; Chua, Boon H.; University of Melbourne, Parkville, Victoria

    2012-12-01

    Purpose: To determine an appropriate clinical target volume for partial breast radiation therapy (PBRT) based on the spatial distribution of residual invasive and in situ carcinoma after wide local excision (WLE) for early breast cancer or ductal carcinoma in situ (DCIS). Methods and Materials: We performed a prospective pathologic study of women potentially eligible for PBRT who had re-excision and/or completion mastectomy after WLE for early breast cancer or DCIS. A pathologic assessment protocol was used to determine the maximum radial extension (MRE) of residual carcinoma from the margin of the initial surgical cavity. Women were stratified by the closest initial radial margin width: negative (>1 mm), close (>0 mm and {<=}1 mm), or involved. Results: The study population was composed of 133 women with a median age of 59 years (range, 27-82 years) and the following stage groups: 0 (13.5%), I (40.6%), II (38.3%), and III (7.5%). The histologic subtypes of the primary tumor were invasive ductal carcinoma (74.4%), invasive lobular carcinoma (12.0%), and DCIS alone (13.5%). Residual carcinoma was present in the re-excision and completion mastectomy specimens in 55.4%, 14.3%, and 7.2% of women with an involved, close, and negative margin, respectively. In the 77 women with a noninvolved radial margin, the MRE of residual disease, if present, was {<=}10 mm in 97.4% (95% confidence interval 91.6-99.5) of cases. Larger MRE measurements were significantly associated with an involved margin (P<.001), tumor size >30 mm (P=.03), premenopausal status (P=.03), and negative progesterone receptor status (P=.05). Conclusions: A clinical target volume margin of 10 mm would encompass microscopic residual disease in >90% of women potentially eligible for PBRT after WLE with noninvolved resection margins.

  10. Fully Automated Simultaneous Integrated Boosted-Intensity Modulated Radiation Therapy Treatment Planning Is Feasible for Head-and-Neck Cancer: A Prospective Clinical Study

    SciTech Connect (OSTI)

    Wu Binbin; McNutt, Todd; Zahurak, Marianna; Simari, Patricio; Pang, Dalong; Taylor, Russell; Sanguineti, Giuseppe

    2012-12-01

    Purpose: To prospectively determine whether overlap volume histogram (OVH)-driven, automated simultaneous integrated boosted (SIB)-intensity-modulated radiation therapy (IMRT) treatment planning for head-and-neck cancer can be implemented in clinics. Methods and Materials: A prospective study was designed to compare fully automated plans (APs) created by an OVH-driven, automated planning application with clinical plans (CPs) created by dosimetrists in a 3-dose-level (70 Gy, 63 Gy, and 58.1 Gy), head-and-neck SIB-IMRT planning. Because primary organ sparing (cord, brain, brainstem, mandible, and optic nerve/chiasm) always received the highest priority in clinical planning, the study aimed to show the noninferiority of APs with respect to PTV coverage and secondary organ sparing (parotid, brachial plexus, esophagus, larynx, inner ear, and oral mucosa). The sample size was determined a priori by a superiority hypothesis test that had 85% power to detect a 4% dose decrease in secondary organ sparing with a 2-sided alpha level of 0.05. A generalized estimating equation (GEE) regression model was used for statistical comparison. Results: Forty consecutive patients were accrued from July to December 2010. GEE analysis indicated that in APs, overall average dose to the secondary organs was reduced by 1.16 (95% CI = 0.09-2.33) with P=.04, overall average PTV coverage was increased by 0.26% (95% CI = 0.06-0.47) with P=.02 and overall average dose to the primary organs was reduced by 1.14 Gy (95% CI = 0.45-1.8) with P=.004. A physician determined that all APs could be delivered to patients, and APs were clinically superior in 27 of 40 cases. Conclusions: The application can be implemented in clinics as a fast, reliable, and consistent way of generating plans that need only minor adjustments to meet specific clinical needs.

  11. Studies of the effects of curvature on dilution jet mixing

    SciTech Connect (OSTI)

    Holdeman, J.D.; Srinivasan, Ram: Reynolds, R.S.; White, C.D. Allied-Signal Aerospace Co., Phoenix, AZ )

    1992-02-01

    An analytical program was conducted using both three-dimensional numerical and empirical models to investigate the effects of transition liner curvature on the mixing of jets injected into a confined crossflow. The numerical code is of the TEACH type with hybrid numerics; it uses the power-law and SIMPLER algorithms, an orthogonal curvilinear coordinate system, and an algebraic Reynolds stress turbulence model. From the results of the numerical calculations, an existing empirical model for the temperature field downstream of single and multiple rows of jets injected into a straight rectangular duct was extended to model the effects of curvature. Temperature distributions, calculated with both the numerical and empirical models, are presented to show the effects of radius of curvature and inner and outer wall injection for single and opposed rows of cool dilution jets injected into a hot mainstream flow. 27 refs.

  12. Wireless radiation sensor

    DOE Patents [OSTI]

    Lamberti, Vincent E.; Howell, Jr, Layton N.; Mee, David K.; Kress, Reid L.

    2016-08-09

    Disclosed is a sensor for detecting radiation. The sensor includes a ferromagnetic metal and a radiation sensitive material coupled to the ferromagnetic metal. The radiation sensitive material is operable to change a tensile stress of the ferromagnetic metal upon exposure to radiation. The radiation is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

  13. Spontaneous radiation of a finite-size dipole emitter in hyperbolic media

    SciTech Connect (OSTI)

    Poddubny, Alexander N.; Belov, Pavel A.; Kivshar, Yuri S.

    2011-08-15

    We study the radiative decay and Purcell effect for a finite-size dipole emitter placed in a homogeneous uniaxial medium. We demonstrate that the radiative rate is strongly enhanced when the signs of the medium longitudinal and transverse dielectric constants are opposite, and that the isofrequency contour corresponds to a hyperbolic medium. We reveal that the Purcell enhancement factor remains finite even in the absence of losses and that it depends on the emitter size.

  14. DISPERSION ANALYSIS OF RADIATION/THERMAL FRONTS WITH FULL RESOLVED SPECTRAL OPACITY VARIATION.

    SciTech Connect (OSTI)

    L. AUER; R. LOWRIE

    2000-12-01

    The radiation transport and linearized thermal energy equations have been analyzed to find the temporal dependence of the component modes in a radiation/thermal front. The fully resolved spectral variation of the opacity as a function of energy, as well as the exact time and angular dependence, is treated in this work. As we are able to study arbitrarily complicated opacity spectra, we stress the importance of the new results as a check on the effect of using opacity averages.

  15. Aluminoborosilicate glasses codoped with rare-earth elements as radiation-protective covers for solar cells

    SciTech Connect (OSTI)

    Malchukova, E. V. Abramov, A. S.; Nepomnyashchikh, A. I.; Terukov, E. I.

    2015-06-15

    The radiation hardness of aluminoborosilicate glasses codoped with rare-earth ions of Sm, Gd or Sm, Eu in various ratios is studied. The effect of codoping and β irradiation at a dose of 10{sup 9} Gr on the optical transmission and electron paramagnetic resonance spectra is examined. It is found that the introduction of Sm and Gd codopants in a 1 : 1 ratio reduces the number of radiation defects and raises the transmission of irradiated glasses in the visible spectral range.

  16. Vitamin D Deficiency Is Associated With the Severity of Radiation-Induced Proctitis in Cancer Patients

    SciTech Connect (OSTI)

    Ghorbanzadeh-Moghaddam, Amir; Gholamrezaei, Ali; Hemati, Simin

    2015-07-01

    Purpose: Radiation-induced injury to normal tissues is a common complication of radiation therapy in cancer patients. Considering the role of vitamin D in mucosal barrier hemostasis and inflammatory responses, we investigated whether vitamin D deficiency is associated with the severity of radiation-induced acute proctitis in cancer patients. Methods and Materials: This prospective observational study was conducted in cancer patients referred for pelvic radiation therapy. Serum concentration of 25-hydroxyvitamin D was measured before radiation therapy. Vitamin D deficiency was defined as 25-hydroxyvitamin D concentrations of <35 nmol/L and <40 nmol/L in male and female patients, respectively, based on available normative data. Acute proctitis was assessed after 5 weeks of radiation therapy (total received radiation dose of 50 Gy) and graded from 0 to 4 using Radiation Therapy Oncology Group (RTOG) criteria. Results: Ninety-eight patients (57.1% male) with a mean age of 62.8 ± 9.1 years were studied. Vitamin D deficiency was found in 57 patients (58.1%). Symptoms of acute proctitis occurred in 72 patients (73.4%) after radiation therapy. RTOG grade was significantly higher in patients with vitamin D deficiency than in normal cases (median [interquartile range] of 2 [0.5-3] vs 1 [0-2], P=.037). Vitamin D deficiency was associated with RTOG grade of ≥2, independent of possible confounding factors; odds ratio (95% confidence interval) = 3.07 (1.27-7.50), P=.013. Conclusions: Vitamin D deficiency is associated with increased severity of radiation-induced acute proctitis. Investigating the underlying mechanisms of this association and evaluating the effectiveness of vitamin D therapy in preventing radiation-induced acute proctitis is warranted.

  17. Radiation-Induced Upregulation of Gene Expression From Adenoviral Vectors Mediated by DNA Damage Repair and Regulation

    SciTech Connect (OSTI)

    Nokisalmi, Petri; Rajecki, Maria; Pesonen, Sari; Escutenaire, Sophie; Soliymani, Rabah; Tenhunen, Mikko; Ahtiainen, Laura; Hemminki, Akseli

    2012-05-01

    Purpose: In the present study, we evaluated the combination of replication-deficient adenoviruses and radiotherapy in vitro. The purpose of the present study was to analyze the mechanism of radiation-mediated upregulation of adenoviral transgene expression. Methods and Materials: Adenoviral transgene expression (luciferase or green fluorescent protein) was studied with and without radiation in three cell lines: breast cancer M4A4-LM3, prostate cancer PC-3MM2, and lung cancer LNM35/enhanced green fluorescent protein. The effect of the radiation dose, modification of the viral capsid, and five different transgene promoters were studied. The cellular responses were studied using mass spectrometry and immunofluorescence analysis. Double strand break repair was modulated by inhibitors of heat shock protein 90, topoisomerase-I, and DNA protein kinase, and transgene expression was measured. Results: We found that a wide range of radiation doses increased adenoviral transgene expression regardless of the cell line, transgene, promoter, or viral capsid modification. Treatment with adenovirus, radiation, and double strand break repair inhibitors resulted in persistence of double strand breaks and subsequent increases in adenovirus transgene expression. Conclusions: Radiation-induced enhancement of adenoviral transgene expression is linked to DNA damage recognition and repair. Radiation induces a global cellular response that results in increased production of RNA and proteins, including adenoviral transgene products. This study provides a mechanistic rationale for combining radiation with adenoviral gene delivery.

  18. The Radiative Transfer Of CH{sub 4}-N{sub 2} Plasma Arc

    SciTech Connect (OSTI)

    Benallal, R.; Liani, B.

    2008-09-23

    Any physical modelling of a circuit-breaker arc therefore requires an understanding of the radiated energy which is taken into account in the form of a net coefficient. The evaluation of the net emission coefficient is performed by the knowledge of the chemical plasma composition and the resolution of the radiative transfer equation. In this paper, the total radiation which escapes from a CH{sub 4}-N{sub 2} plasma is calculated in the temperature range between 5000 and 30000K on the assumption of a local thermodynamic equilibrium and we have studied the nitrogen effect in the hydrocarbon plasmas.

  19. Small Angle Neutron Scattering Studies of the Counterion Effects...

    Office of Scientific and Technical Information (OSTI)

    The structural properties of generation 4 (G4) poly(amidoamine) starburst dendrimers (PAMAM) with an ethylenediamine ne (EDA) central core in D O 2 solutions have been studied by ...

  20. Genotoxicology of Rads | Environmental Radiation Protection Curriculum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Genotoxicology: Genetic Effects of Radiation and Other Environmental Mutagens (3 hrs) Instructor: Stacey Lance Course Description: The goal of this course is provide students with an in-depth knowledge concerning the genetic effects of radiation and other environmental mutagens. Topics to be covered include: the molecular mechanisms of mutation and mutation repair, biomarkers and biomonitoring, genomic instability, transgenerational effects, and individual susceptibility. In addition to gaining

  1. An apparatus for the study of high temperature water radiolysis in a nuclear reactor: Calibration of dose in a mixed neutron/gamma radiation field

    SciTech Connect (OSTI)

    Edwards, Eric J.; Wilson, Paul P. H.; Anderson, Mark H.; Mezyk, Stephen P.; Pimblott, Simon M.; Bartels, David M.

    2007-12-15

    The cooling water of nuclear reactors undergoes radiolytic decomposition induced by gamma, fast electron, and neutron radiation in the core. To model the process, recombination reaction rates and radiolytic yields for the water radical fragments need to be measured at high temperature and pressure. Yields for the action of neutron radiation are particularly hard to determine independently because of the beta/gamma field also present in any reactor. In this paper we report the design of an apparatus intended to measure neutron radiolysis yields as a function of temperature and pressure. A new methodology for separation of neutron and beta/gamma radiolysis yields in a mixed radiation field is proposed and demonstrated.

  2. Anisotropy of radiation emitted from planar wire arrays

    SciTech Connect (OSTI)

    Kantsyrev, V. L.; Esaulov, A. A.; Safronova, A. S.; Williamson, K. M.; Osborne, G. C.; Shrestha, I. K.; Weller, M. E.; Shlyaptseva, V. V.; Chuvatin, A. S.; Rudakov, L. I.; Velikovich, A.

    2013-07-15

    The planar wire array (PWA) is a promising load for new multi-source inertial confinement fusion (ICF) hohlraums [B. Jones et al., Phys. Rev. Lett. 104, 125001 (2010)]. The hohlraum radiation symmetry is an important issue for ICF. It was found that extreme ultraviolet and sub-keV photon emission from PWAs may have considerable anisotropy in the load azimuthal plane. This experimental result is obtained on the UNR 1–1.7 MA Zebra generator. The time-dependent anisotropy effect is detected. This feature is studied in 2D numerical simulations and can be explained by initial anisotropy of implosion of those non-cylindrical loads radiating essentially as surface sources in sub-keV quanta and also by radiation absorption in cold magnetized plasma tails forming in the direction of magnetic compression.

  3. Radiation Safety Poster | Y-12 National Security Complex

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation Safety Poster Radiation Safety Poster Radiation Safety Poster

  4. DOE occupational radiation exposure 2007 report

    SciTech Connect (OSTI)

    none,

    2007-12-31

    The U.S. Department of Energy (DOE) Office of Corporate Safety Analysis (HS-30) within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The annual DOEOccupational Radiation Exposure 2007 Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and ALARA process requirements. In addition the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. This report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past five years.

  5. Plutonium radiation surrogate

    DOE Patents [OSTI]

    Frank, Michael I.

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  6. NREL: Solar Radiation Research - Solar Radiation Research Laboratory...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solar Radiation Research Laboratory Photographs The Solar Radiation Research Laboratory (SRRL) houses more than 70 instruments to analyze and record solar radiation and surface ...

  7. Collisional-Radiative Modeling for Radiation Hydrodynamics (Book...

    Office of Scientific and Technical Information (OSTI)

    Publisher: Modern Methods in Collisional-Radiative Modelling of Plasmas, Collisional-Radiative Modeling for Radiation Hydrodynamics, Springer International Publishing, unknown, ...

  8. Theoretical study of plasma effect on a conical shock wave

    SciTech Connect (OSTI)

    Kuo, S.P.; Kuo, Steven S.

    2006-03-15

    Experiments conducted previously in a Mach 2.5 wind tunnel showed that localized plasma generated by an on-board 60 Hz electric discharge in front of a 60 deg. cone-shaped model considerably increases the shock angle of the attached shock generated by the cone model. Based on the measured power and cycle energy of the electric discharge, the estimated peak and average temperature enhancements were too low to justify the heating effect as a possible cause of the observed shock wave modification. In this work, a theory also using a cone model as the shock wave generator is presented to explain the observed plasma effect on the shock wave. Through electron-neutral elastic collisions and ion-neutral charge transfer collisions, plasma generated in front of the baseline shock front can deflect the incoming flow before it reaches the cone model; such a flow deflection modifies the structure of the shock wave generated by the cone model from a conic shape to a slightly curved one. The shock remains to be attached to the tip of the cone; however, the shock front moves upstream to increase the shock angle, consistent with the experimental results.

  9. Dummy Run of Quality Assurance Program in a Phase 3 Randomized Trial Investigating the Role of Internal Mammary Lymph Node Irradiation in Breast Cancer Patients: Korean Radiation Oncology Group 08-06 Study

    SciTech Connect (OSTI)

    Chung, Yoonsun; Kim, Jun Won; Shin, Kyung Hwan; Kim, Su Ssan; Ahn, Sung-Ja; Park, Won; Lee, Hyung-Sik; Kim, Dong Won; Lee, Kyu Chan; Suh, Hyun Suk; Kim, Jin Hee; Shin, Hyun Soo; Kim, Yong Bae; Suh, Chang-Ok

    2015-02-01

    Purpose: The Korean Radiation Oncology Group (KROG) 08-06 study protocol allowed radiation therapy (RT) technique to include or exclude breast cancer patients from receiving radiation therapy to the internal mammary lymph node (IMN). The purpose of this study was to assess dosimetric differences between the 2 groups and potential influence on clinical outcome by a dummy run procedure. Methods and Materials: All participating institutions were asked to produce RT plans without irradiation (Arm 1) and with irradiation to the IMN (Arm 2) for 1 breast-conservation treatment case (breast-conserving surgery [BCS]) and 1 mastectomy case (modified radical mastectomy [MRM]) whose computed tomography images were provided. We assessed interinstitutional variations in IMN delineation and evaluated the dose-volume histograms of the IMN and normal organs. A reference IMN was delineated by an expert panel group based on the study guidelines. Also, we analyzed the potential influence of actual dose variation observed in this study on patient survival. Results: Although physicians intended to exclude the IMN within the RT field, the data showed almost 59.0% of the prescribed dose was delivered to the IMN in Arm 1. However, the mean doses covering the IMN in Arm 1 and Arm 2 were significantly different for both cases (P<.001). Due to the probability of overdose in Arm 1, the estimated gain in 7-year disease-free survival rate would be reduced from 10% to 7.9% for BCS cases and 7.1% for MRM cases. The radiation doses to the ipsilateral lung, heart, and coronary artery were lower in Arm 1 than in Arm 2. Conclusions: Although this dummy run study indicated that a substantial dose was delivered to the IMN, even in the nonirradiation group, the dose differences between the 2 groups were statistically significant. However, this dosimetric profile should be studied further with actual patient samples and be taken into consideration when analyzing clinical outcomes according to IMN

  10. Mega borg oil spill: Fate and effect studies

    SciTech Connect (OSTI)

    Not Available

    1992-09-28

    The Mega Borg, a Norwegian tanker, released an estimated 5.1 million gallons (gal) of Palanca Angola crude oil into the Gulf of Mexico during a lightering accident and subsequent fire. The collection of reports was designed to provide a comprehensive overview of the spill chronology, the fate of the oil released, and subsequent studies that were conducted to assess the impacts of the oil spill on the environment and its biota.

  11. Experimental studies of the early effects of inhaled beta-emitting radionuclides for nuclear accident risk assessment: Phase 2 report

    SciTech Connect (OSTI)

    Scott, B.R.; Hahn, F.F.; Newton, G.J.; Snipes, M.B.; Damon, E.G.; Mauderly, J.L.; Boecker, B.B.; Gray, D.H.

    1987-11-01

    This report summarizes a series of experiments concerning the effect of linear energy transfer and temporal radiation dose pattern to the lung from inhaled beta-emitting radionuclides. The results were used to test the validity of a hazard-function mathematical model for predicting death from radiation pneumonitis. Both morbidity and mortality within 18 months after exposure were examined in rats exposed to beta-emitting radionuclides, giving brief or protracted irradiation of the lung or having weak or strong beta emissions. Protraction of the radiation dose to the lung from a half-time in the lung of less than three days to a half-time with a long-term component of about 150 days has a sparing effect. The median lethal dose for the protracted irradiation is about 1.7 times the median lethal dose for the brief irradiation. Low energy beta emissions from /sup 147/Pm have a similar effectiveness in producing lethal injury as high energy beta emissions from /sup 90/Sr. Changes in three parameters of morbidity were measured: body weight, hematology and pulmonary function; only changes in pulmonary function correlated well with pulmonary radiation injury. The doses of radiation required to produce impaired function, however, were not significantly different from those that produced death. The hazard-function model for predicting death from radiation pneumonitis, which was developed from previously obtained data for inhalation exposures of dogs to beta-emitting radionuclides, adequately predicted the median lethal doses for rats receiving one of several different beta dose rate patterns to the lung, thus strengthening the validity of the mathematical model. 23 refs., 41 figs., 12 tabs.

  12. NMR studies of aging effects in palladium tritide

    SciTech Connect (OSTI)

    Abell, G.C.; Attalla, A.

    1988-09-01

    This paper presents Nuclear Magnetic Resonance (NMR) studies of aging phenomena in palladium tritide. /sup 3/He NMR relaxation parameters have been measured as a function of temperature for 6-, 13-, and 22-month-old beta phase palladium tritide. The most significant result of this study is the observation of a solid/fluid phase transition near 250 K of /sup 3/He that has accumulated in the PdT/sub x/ substrate via triton decay. Although the existence of solid helium at relatively high temperatures had been predicted for helium in metals, it had not previously been confirmed in any metal/helium system. The observed melting temperatures, together with the known equation of state for /sup 4/He, allow a determination of the helium density as a function of age. The atomic density obtained in this way is approximately 2.0 times that of palladium metal, agreeing with densities inferred from dilatometric measurements of other metal tritides and also with predictions based on the concept of dislocation loop punching by highly overpressurized He bubbles. The /sup 3/He signal in the 22-month-old sample was sufficiently strong to allow a detailed study of melting as a function of temperature, and provides information on the distribution of densities over the ensemble of bubbles.

  13. Indentation Rate Effect on Pop-out in Silicon Studied by Cross...

    Office of Scientific and Technical Information (OSTI)

    Conference: Indentation Rate Effect on Pop-out in Silicon Studied by Cross-sectional TEM Citation Details In-Document Search Title: Indentation Rate Effect on Pop-out in Silicon ...

  14. Population-Based Study of Cardiovascular Mortality Among Patients With Prostate Cancer Treated With Radical External Beam Radiation Therapy With and Without Adjuvant Androgen Deprivation Therapy at the British Columbia Cancer Agency

    SciTech Connect (OSTI)

    Kim, Julian; Vaid, Moninder; Tyldesley, Scott; Woods, Ryan; Pickles, Tom

    2011-07-01

    Purpose: There are conflicting studies of the impact of androgen deprivation therapy (ADT) on cardiovascular (CV) mortality among prostate cancer patients receiving curative intent external beam radiation therapy (EBRT). We assessed the impact of ADT on CV mortality in patients treated in British Columbia. Methods and Materials: Provincial pharmacy and radiotherapy databases were linked to the provincial cancer registry, and defined a cohort of patients treated with curative intent EBRT between 1998 and 2005. We determined the duration of ADT and the cumulative incidence of CV death. We compared death from CV disease with and without ADT, and by duration of ADT using competing risk analysis and Fine and Gray multivariant analysis. A total of 600 randomly selected patients were reviewed to determine baseline CV disease, CV risk factors, and Charlson Index. Results: Of 5,948 prostate cancer patients treated with radical intent EBRT, of whom 1,933 were treated without ADT, 674 received ADT for {<=}6 months and 3,341 received > 6 months of ADT. The cumulative CV mortality at 7 years was 2.6% (95% confidence interval [CI] 1.9-3.5%), 2.1% (95% CI = 1.2-3.5%), and 1.4 (95% CI = 1.0-2.0%) for patients with no ADT, {<=}6 months of ADT, and >6 months of ADT, respectively (Gray's p = 0.002). Baseline CV disease and risk factors were more prevalent in the no-ADT group compared with the >6-month ADT group. Conclusions: This study demonstrated a lower CV mortality rate among patients treated with longer durations of ADT than those treated without ADT. These differences likely relate to selection of patients for ADT rather than effect of ADT itself.

  15. Radiative properties of ice clouds

    SciTech Connect (OSTI)

    Mitchell, D.L.; Koracin, D.; Carter, E.

    1996-04-01

    A new treatment of cirrus cloud radiative properties has been developed, based on anomalous diffraction theory (ADT), which does not parameterize size distributions in terms of an effective radius. Rather, is uses the size distribution parameters directly, and explicitly considers the ice particle shapes. There are three fundamental features which characterize this treatment: (1) the ice path radiation experiences as it travels through an ice crystal is parameterized, (2) only determines the amount of radiation scattered and absorbed, and (3) as in other treatments, the projected area of the size distribution is conserved. The first two features are unique to this treatment, since it does not convert the ice particles into equivalent volume or area spheres in order to apply Mie theory.

  16. Radiation.cdr

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation is a natural part of our everyday environment. Cosmic rays showering the Earth ... and radon gas seeping up from the soil are only two examples of natural radiation. ...

  17. Proportional counter radiation camera

    DOE Patents [OSTI]

    Borkowski, C.J.; Kopp, M.K.

    1974-01-15

    A gas-filled proportional counter camera that images photon emitting sources is described. A two-dimensional, positionsensitive proportional multiwire counter is provided as the detector. The counter consists of a high- voltage anode screen sandwiched between orthogonally disposed planar arrays of multiple parallel strung, resistively coupled cathode wires. Two terminals from each of the cathode arrays are connected to separate timing circuitry to obtain separate X and Y coordinate signal values from pulse shape measurements to define the position of an event within the counter arrays which may be recorded by various means for data display. The counter is further provided with a linear drift field which effectively enlarges the active gas volume of the counter and constrains the recoil electrons produced from ionizing radiation entering the counter to drift perpendicularly toward the planar detection arrays. A collimator is interposed between a subject to be imaged and the counter to transmit only the radiation from the subject which has a perpendicular trajectory with respect to the planar cathode arrays of the detector. (Official Gazette)

  18. Radiation Embrittlement Archive Project

    SciTech Connect (OSTI)

    Klasky, Hilda B; Bass, Bennett Richard; Williams, Paul T; Phillips, Rick; Erickson, Marjorie A; Kirk, Mark T; Stevens, Gary L

    2013-01-01

    The Radiation Embrittlement Archive Project (REAP), which is being conducted by the Probabilistic Integrity Safety Assessment (PISA) Program at Oak Ridge National Laboratory under funding from the U.S. Nuclear Regulatory Commission s (NRC) Office of Nuclear Regulatory Research, aims to provide an archival source of information about the effect of neutron radiation on the properties of reactor pressure vessel (RPV) steels. Specifically, this project is an effort to create an Internet-accessible RPV steel embrittlement database. The project s website, https://reap.ornl.gov, provides information in two forms: (1) a document archive with surveillance capsule(s) reports and related technical reports, in PDF format, for the 104 commercial nuclear power plants (NPPs) in the United States, with similar reports from other countries; and (2) a relational database archive with detailed information extracted from the reports. The REAP project focuses on data collected from surveillance capsule programs for light-water moderated, nuclear power reactor vessels operated in the United States, including data on Charpy V-notch energy testing results, tensile properties, composition, exposure temperatures, neutron flux (rate of irradiation damage), and fluence, (Fast Neutron Fluence a cumulative measure of irradiation for E>1 MeV). Additionally, REAP contains data from surveillance programs conducted in other countries. REAP is presently being extended to focus on embrittlement data analysis, as well. This paper summarizes the current status of the REAP database and highlights opportunities to access the data and to participate in the project.

  19. Development of accelerator radiation protection at the SSC

    SciTech Connect (OSTI)

    Toohig, T.

    1993-11-01

    The design of the Superconducting Super Collider evolved over a series of studies from 1984 to 1989. Considerations of concentration of radiation sources and provisions for operational control and monitoring of radiation were determining elements in the design concepts for the facility. The development of the designs involved an extension of the range of applicability of energy deposition and radiation shielding codes beyond the 3 TeV level of the proposed UNK collider to 20 TeV for single beam effects and to 40 TeV in the collision regions. This extrapolation was complicated by the newly discovered, very energetic muons from short-lived states associated with heavy quark states. The design guideline for radiation protection was specified to be 10 mRem/yr, 10% of the Federal limit. In order to limit the amount of land required for the facility, which would extend over some 250 mi. sq., the configuration of the land to be acquired was tailored to the requirements for radiation containment below the levels of the guideline.

  20. Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report

    SciTech Connect (OSTI)

    2013-10-18

    This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing sedimentation. In addition