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Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
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1

Escherichia coli Genes and Pathways Involved in Surviving Extreme Exposure to Ionizing Radiation  

Science Journals Connector (OSTI)

...doses of ionizing radiation does not depend on...the effects of high doses of ionizing radiation (IR). The repair...IR resistance. A range of modern screening...survive increasing doses of ionizing radiation in comparison to...

Rose T. Byrne; Stefanie H. Chen; Elizabeth A. Wood; Eric L. Cabot; Michael M. Cox

2014-07-21T23:59:59.000Z

2

Oligonucleotide microarray analysis of low-dose ionizing radiation exposure  

Science Journals Connector (OSTI)

...health risk due to low-dose ionizing radiation is still debated. Functional...pathways that are induced by ionizing irradiation (IR...transcriptionally regulated by low-dose IR in occupationally...and showed different ranges of accumulated doses...

Paola Silingardi; Elena Morandi; Cinzia Severini; Daniele Quercioli; Monica Vaccari; Wolfango Horn; Maria Concetta Nucci; Vittorio Lodi; Francesco Violante; Sandro Grilli; and Annmaria Colacci

2007-05-01T23:59:59.000Z

3

Risks from ionizing radiation  

Science Journals Connector (OSTI)

... RADON indoors now accounts for nearly half of the average UK population exposure to ionizing radiation ... exposure to ionizing radiation. We believe that the extent of the variation in exposure to radon in the United Kingdom and else-where and its magnitude in relation to exposures from ...

R. H. Clarke; T. R. E. Southwood

1989-03-16T23:59:59.000Z

4

Transcriptome Analysis Applied to Survival of Shewanella oneidensis MR-1 Exposed to Ionizing Radiation  

Science Journals Connector (OSTI)

...radiation (IR) dose that yields 20...its response to UV radiation (254 nm), which...sensitivity to IR. Ionizing radiation (IR) is potentially...damage caused by given doses of IR for different...similar, although the range of IR resistance...

Xiaoyun Qiu; Michael J. Daly; Alexander Vasilenko; Marina V. Omelchenko; Elena K. Gaidamakova; Liyou Wu; Jizhong Zhou; George W. Sundin; James M. Tiedje

2006-02-01T23:59:59.000Z

5

Ionizing radiation detector  

DOE Patents [OSTI]

An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

Thacker, Louis H. (Knoxville, TN)

1990-01-01T23:59:59.000Z

6

Proteasome Structures Affected by Ionizing Radiation  

Science Journals Connector (OSTI)

...Effect of ionizing radiation on 26S but...radiation doses, and immediately...the dose range 1 to 20 Gy...ionizing radiation induced a...38), ionizing radiation (39...over a wide range of radiation doses and further...

Milena Pervan; Keisuke S. Iwamoto; and William H. McBride

2005-07-01T23:59:59.000Z

7

Ionizing Radiation Injury (South Carolina)  

Broader source: Energy.gov [DOE]

This legislation applies to employers that have more than one employee who engages in activities which involve the presence of ionizing radiation. Employers with less than three employees can...

8

Lesson 4 - Ionizing Radiation | Department of Energy  

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

4 - Ionizing Radiation 4 - Ionizing Radiation Lesson 4 - Ionizing Radiation Lesson Three showed that unstable isotopes emit energy as they become more stable. This energy is known as radiation. This lesson explores forms of radiation, where radiation is found, how we detect and measure radiation, what sources of radiation people are exposed to, whether radiation is harmful, and how we can limit our exposure. Specific topics covered in this lesson include: Types of radiation Non-ionizing Ionizing Forms of ionizing radiation Alpha particles Beta particles Gamma rays Radiation Decay chain Half-life Dose Radiation measurements Sources of radiation Average annual exposure Lesson 4 - Ionizing Radiation.pptx More Documents & Publications DOE-HDBK-1130-2008 DOE-HDBK-1130-2008 DOE-HDBK-1130-2007

9

Human Heterochromatin Protein 1 Isoforms HP1Hs? and HP1Hs? Interfere with hTERT-Telomere Interactions and Correlate with Changes in Cell Growth and Response to Ionizing Radiation  

Science Journals Connector (OSTI)

...subsequently exposed to ionizing radiation (IR). The...a particular dose of radiation. The cells...to IR in the dose range of 0 to 8 Gy...treatment. Dose response curves...treated with ionizing radiation while growing...

Girdhar G. Sharma; Kyu-kye Hwang; Raj K. Pandita; Arun Gupta; Sonu Dhar; Julie Parenteau; Manjula Agarwal; Howard J. Worman; Raymund J. Wellinger; Tej K. Pandita

2003-11-01T23:59:59.000Z

10

Device for detecting ionizing radiation  

SciTech Connect (OSTI)

The present invention relates to ionizing radiation sensors, and , more particularly, to semiconductor spectrometers with thermoelectric cooling, and can most advantageously be used in mineral raw material exploration and evaluation under field conditions. The spectrometer comprises a vacuum chamber with an entrance window for passing the radiation therethrough. The vacuum chamber accommodates a thermoelectric cooler formed by a set of peltier elements. A heat conducting plate is mounted on the cold side of the thermoelectric cooler, and its hot side is provided with a radiator. Mounted on the heat conducting plate are sets of peltier elements, integral with the thermoelectric cooler and independent of one another. The peltier elements of these sets are stacked so as to develop the minimum temperature conditions on one set carrying a semiconductor detector and to provide the maximum refrigeration capacity conditions on the other set provided with the field-effect transistor mounted thereon.

Anatychuk, L.I.; Kharitonov, J.P.; Kusniruk, V.F.; Meir, V.A.; Melnik, A.P.; Ponomarev, V.S.; Skakodub, V.A.; Sokolov, A.D.; Subbotin, V.G.; Zhukovsky, A.N.

1980-10-28T23:59:59.000Z

11

p53-Mediated Regulation of Proliferating Cell Nuclear Antigen Expression in Cells Exposed to Ionizing Radiation  

Science Journals Connector (OSTI)

...exposed to increasing doses of IR at 24 h posttransfection...cellular response to ionizing radiation in which p53-mediated...IR at 12 Gy, a dose that induced maximal...the 1- to 4-Gy range does not effectively...because a high radiation dose is used and the...

Jin Xu; Gilbert F. Morris

1999-01-01T23:59:59.000Z

12

Low dose ionizing radiation induces tumor growth promoting factors in  

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

ionizing radiation induces tumor growth promoting factors in ionizing radiation induces tumor growth promoting factors in stress-induced premature senescent fibroblasts David Boothman University of Texas Southwestern Medical Center at Dallas Abstract Recent evidence suggest that the causes of cancer development are not limited to mutations within cancer cells, but also involve in alterations of cancer microenvironment. Senescent cells are irreversibly growth arrested, but remain metabolically active. Senescent cells, especially senescent fibroblasts in the stroma may provide a beneficial environment for tumor growth through secretion of certain factors. Accumulation of senescent cells in the stroma of patients repeatedly exposed to low doses of IR or low dose rates of IR, could be an important factor, causing alteration of the microenvironment that ultimately benefits tumor

13

6 - Industrial Applications of Ionizing Radiation  

Science Journals Connector (OSTI)

The chapter summarizes the industrial applications of ionizing radiation. Ionizing radiation finds use in a variety of industrial applications such as wire and cable insulation, tire manufacturing, production of polymeric foams, heat-shrinkable films and tubings, curing of coatings, adhesives and composites, printing, and other technological development. It provides extensive information on EB process in wire and cable and tire technology. The chapter also provides discussion on EB process in the manufacture of polyolefin foams and heat-shrinkable materials. Detailed discussion on cross-linked PE pipes (PEX) including methods for production, irradiation, and its advantages, is presented. Other applications for ionizing radiation include sterilization of medical devices, hydrogels, radiation curing of polymeric composites, production of fluoroadditives, radiation-cured flexography, coatings, adhesives, paints, and printing inks. Keywords Ionizing radiation; tire manufacturing; wire and cable insulations; printing inks; polyolefin foams; heat-shrinkable materials; cross-linked PE pipes (PEX); hydrogels; flexography

Jiri George Drobny

2013-01-01T23:59:59.000Z

14

Detoxification of Salmonella typhimurium Lipopolysaccharide by Ionizing Radiation  

Science Journals Connector (OSTI)

...efficiency of ionizing radiation in detoxifying...decreased with doses above 1 Mrad...efficiency of ionizing radiation in detoxifying...decreased with doses above 1 Mrad...the visible range. After radiation, the general...radiation doses through 20...

Joseph J. Previte; Y. Chang; H. M. El-Bisi

1967-05-01T23:59:59.000Z

15

Ionizing Radiation Activates the Nrf2 Antioxidant Response  

Science Journals Connector (OSTI)

...Scientific). Results Ionizing radiation does not activate ARE-reporter...determine if exposure to varying doses of ionizing radiation would activate the Nrf2-ARE pathway. The radiation dose range was extended below that used...

J. Tyson McDonald; Kwanghee Kim; Andrew J. Norris; Erina Vlashi; Tiffany M. Phillips; Chann Lagadec; Lorenza Della Donna; Josephine Ratikan; Heather Szelag; Lynn Hlatky; and William H. McBride

2010-11-01T23:59:59.000Z

16

Low Dose Radiation Research Program: Comparisons of IR and ROS for  

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

Comparisons of IR and ROS for Induction of Damage to Cells Comparisons of IR and ROS for Induction of Damage to Cells Kathryn D. Held1, Yvonne L. McCarey1, Laurence Tartier1, Elena V. Rusyn1, Giuseppe Schettino2, Melvyn Folkard2, Kevin M. Prise2, and Barry D. Michael2 1Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114; 2Gray Laboratory Cancer Research Trust, Mount Vernon Hospital, Northwood, HA6 2JR, UK Accurate evaluation of the risks associated with exposure to low doses of ionizing radiation (IR) is a major challenge for environmental sciences. Studies on the mechanisms of the actions of low doses of IR are needed to help understand possible risks. IR exerts its effects on cells through production of reactive oxidizing species (ROS) such as ·OH, H2O2 and

17

Epidemiological Studies of Leukemia in Persons Exposed to Ionizing Radiation  

Science Journals Connector (OSTI)

...exposed to ionizing radiation, the author...the higher dose range regardless...low dose range, it is emphasized...possibility of radiation hazards existing at low doses should not...exposed to ionizing radiation...exposed to ionizing radiation, the author...the higher dose range regardless...

L. H. Hempelmann

1960-01-01T23:59:59.000Z

18

Composite scintillators for detection of ionizing radiation  

DOE Patents [OSTI]

Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

Dai, Sheng (Knoxville, TN) [Knoxville, TN; Stephan, Andrew Curtis (Knoxville, TN) [Knoxville, TN; Brown, Suree S. (Knoxville, TN) [Knoxville, TN; Wallace, Steven A. (Knoxville, TN) [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

2010-12-28T23:59:59.000Z

19

The Degradation of Solid Polymethylmethacrylate by Ionizing Radiation  

Science Journals Connector (OSTI)

...Polymethylmethacrylate by Ionizing Radiation P. Alexander A. Charlesby...inversely proportional to the radiation dose (plus a small quantity of...of measuring high-energy radiation doses in the range of about 1 million rontgens...

1954-01-01T23:59:59.000Z

20

Ionizing Radiation Induces Delayed Hyperrecombination in Mammalian Cells  

Science Journals Connector (OSTI)

...instability is critical to radiation risk assessment and for determining...the many delayed effects of radiation, chromosomal instability is...detrimental effects over a range of doses of ionizing radiation. Furthermore, a rapid and...

Lei Huang; Suzanne Grim; Leslie E. Smith; Perry M. Kim; Jac A. Nickoloff; Olga G. Goloubeva; William F. Morgan

2004-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

22.01 Introduction to Ionizing Radiation, Fall 2003  

E-Print Network [OSTI]

Introduction to basic properties of ionizing radiations and their uses in medicine, industry, science, and environmental studies. Discusses natural and man-made radiation sources, energy deposition and dose calculations, ...

Coderre, Jeffrey A.

22

1. Introduction Alanine-based ionizing radiation dosimetry is firmly  

E-Print Network [OSTI]

1. Introduction Alanine-based ionizing radiation dosimetry is firmly woven into the fabric of high-dose System and Its Implications in High-Dose Ionizing Radiation Metrology Volume 113 Number 2 March.g., radiochromic dosimetry). From the NMI's perspective, the broad absorbed- dose range of the alanine system

23

Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation  

SciTech Connect (OSTI)

Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression.

Nicolay, Nils H., E-mail: n.nicolay@dkfz.de [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sommer, Eva; Lopez, Ramon; Wirkner, Ute [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Trinh, Thuy [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sisombath, Sonevisay [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Debus, Jrgen [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Ho, Anthony D.; Saffrich, Rainer [Department of Hematology and Oncology, Heidelberg University Hospital, Heidelberg (Germany); Huber, Peter E. [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany)

2013-12-01T23:59:59.000Z

24

Ionizing Radiation Activates AMP-Activated Kinase (AMPK): A Target for Radiosensitization of Human Cancer Cells  

SciTech Connect (OSTI)

Purpose: Adenosine monophosphate (AMP)-activated kinase (AMPK) is a molecular energy sensor regulated by the tumor suppressor LKB1. Starvation and growth factors activate AMPK through the DNA damage sensor ataxia-telangiectasia mutated (ATM). We explored the regulation of AMPK by ionizing radiation (IR) and its role as a target for radiosensitization of human cancer cells. Methods and Materials: Lung, prostate, and breast cancer cells were treated with IR (2-8 Gy) after incubation with either ATM or AMPK inhibitors or the AMPK activator metformin. Then, cells were subjected to either lysis and immunoblotting, immunofluorescence microscopy, clonogenic survival assays, or cell cycle analysis. Results: IR induced a robust phosphorylation and activation of AMPK in all tumor cells, independent of LKB1. IR activated AMPK first in the nucleus, and this extended later into cytoplasm. The ATM inhibitor KU-55933 blocked IR activation of AMPK. AMPK inhibition with Compound C or anti-AMPK {alpha} subunit small interfering RNA (siRNA) blocked IR induction of the cell cycle regulators p53 and p21{sup waf/cip} as well as the IR-induced G2/M arrest. Compound C caused resistance to IR, increasing the surviving fraction after 2 Gy, but the anti-diabetic drug metformin enhanced IR activation of AMPK and lowered the surviving fraction after 2 Gy further. Conclusions: We provide evidence that IR activates AMPK in human cancer cells in an LKB1-independent manner, leading to induction of p21{sup waf/cip} and regulation of the cell cycle and survival. AMPK appears to (1) participate in an ATM-AMPK-p21{sup waf/cip} pathway, (2) be involved in regulation of the IR-induced G2/M checkpoint, and (3) may be targeted by metformin to enhance IR responses.

Sanli, Toran; Rashid, Ayesha; Liu Caiqiong [Department of Oncology, Juravinski Cancer Center and McMaster University, Hamilton, Ontario (Canada)

2010-09-01T23:59:59.000Z

25

Extreme resistance of bdelloid rotifers to ionizing radiation  

Science Journals Connector (OSTI)

...of IR or high-energy electrons required...that the measured efficiency of IR...where the decreased efficiency of repair is more...dilatata are free-swimming and may easily be...geothermalis: The pool of extreme radiation...International Atomic Energy Agency Final Research...

Eugene Gladyshev; Matthew Meselson

2008-01-01T23:59:59.000Z

26

9.01 - Interaction of Ionizing Radiation with Matter  

Science Journals Connector (OSTI)

Abstract The aim of this chapter is to give an overview and try to show how the different interaction probabilities will influence the transport of ionizing radiation through matter. This knowledge is important in different aspects of medical applications of radiation. It has an impact in designing an optimal treatment gantry, in the choice of radiation quality, and of course when determining the absorbed dose distribution in the body. It is also important in diagnostic radiology when optimizing the image quality. Knowledge of the interaction of radiation with matter is also fundamental for understanding the biological effect of radiation and its variation with ionization density. The focus will not be on the basic physics and deriving the different cross sections but on the impact of these cross sections on imaging and therapy in medical physics applications. Ionizing radiation is normally divided into charged particles (previously called directly ionizing radiation) such as leptons, ?-particles, protons and other light ions, and uncharged particles (previously called indirectly ionizing radiation) such as photons (x-rays or ?-rays) and neutrons. This chapter will concentrate on radiation qualities used in radiotherapy, and the main part will be dedicated to electrons and photons with energies up to around 50MeV and light ions with energies up to 900MeV per nucleon. The presentation is divided into two main sections, charged particles and photons.

B. Nilsson; A. Brahme

2014-01-01T23:59:59.000Z

27

Rules and Regulations for Control of Ionizing Radiation (Arkansas) |  

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

Rules and Regulations for Control of Ionizing Radiation (Arkansas) Rules and Regulations for Control of Ionizing Radiation (Arkansas) Rules and Regulations for Control of Ionizing Radiation (Arkansas) < Back Eligibility Utility Program Info State Arkansas Program Type Environmental Regulations Siting and Permitting Provider Department of Health The Rules and Regulations for Control of Ionizing Radiation are the Arkansas state laws made in accordance the federal Nuclear Regulatory Commission Rules. Any contractor with the US DOE or US Nuclear Regulatory Commission is exempt from the state laws. This set of rules and regulations basically restates the federal policy to ensure that Arkansas is in compliance with the federal standards governing nuclear energy. Specifically the State rules are equivalent to Nuclear Regulatory

28

The similar effects of low-dose ionizing radiation and non-ionizing radiation from background environmental levels of exposure  

Science Journals Connector (OSTI)

The meltdown and release of radioactivity (ionizing radiation) from four damaged nuclear reactors at the Fukushima Nuclear Facility in Japan in March 2011 continues to contaminate air and ocean water even 1year ...

Cindy Sage

2012-06-01T23:59:59.000Z

29

Oxidative Stress and Skeletal Health with Low Dose, Ionizing Radiation  

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

Oxidative Stress and Skeletal Health with Low Dose, Ionizing Radiation Oxidative Stress and Skeletal Health with Low Dose, Ionizing Radiation Globus Ruth NASA Ames Research Center Abstract Osteoporosis profoundly affects the aging U.S. population and exposure to high doses of radiation causes bone loss similar to age-related osteoporosis, although the influence of low dose radiation exposures is not known. The central hypothesis of our DOE project (NASA supplement) is that low doses of radiation modulate subsequent skeletal degeneration via oxidative pathways. Our working hypothesis is that a prior exposure to low dose radiation regulates oxidative metabolism within bone and contributes to bone loss caused either by subsequent high, challenge doses of radiation or by aging. HZE source: Because astronauts are exposed to radiation from GCR and solar

30

Cell cycle responses to low-dose ionizing radiation.  

Science Journals Connector (OSTI)

...47, 2006] 5178 Low-dose hyper-radiosensitivity...radiosensitivity of cells to doses of ionizing radiation less than 0.5 Gy...connection between low-dose HRS survival, Ataxia...the low dose radiation range (0-1 Gy). MR4 cells...

Sarah A. Krueger; George D. Wilson; Michael C. Joiner; and Brian Marples

2006-04-15T23:59:59.000Z

31

Toxicity of Pasteurella tularensis Killed by Ionizing Radiation  

Science Journals Connector (OSTI)

...to 106 r of y-radiation. When injected...suspension. Lethal doses of newly prepared...by exposure to ionizing radia- tion induced...to 106 r of y-radiation from a 60Co source at a dose rate of approximately...only in a limited range of dilutions...

Marshall E. Landay; George G. Wright; James D. Pulliam; Milton J. Finegold

1968-09-01T23:59:59.000Z

32

Discovering Clinical Biomarkers of Ionizing Radiation Exposure with Serum Proteomic Analysis  

Science Journals Connector (OSTI)

...with a wide range of diagnoses and radiation treatment...and during ionizing radiation...from low dose-volume...of a wide range of diagnoses...volume, and dose of radiotherapy...exposed to ionizing radiation between the...with a wide range of diagnoses and radiation treatment...and during ionizing radiation...from low dose-volume...

Cynthia Mnard; Donald Johann; Mark Lowenthal; Thierry Muanza; Mary Sproull; Sally Ross; James Gulley; Emanuel Petricoin; C. Norman Coleman; Gordon Whiteley; Lance Liotta; and Kevin Camphausen

2006-02-01T23:59:59.000Z

33

Enhanced Sensitivity of the RET Proto-Oncogene to Ionizing Radiation In vitro  

Science Journals Connector (OSTI)

...the RET sensitivity to ionizing radiation exposure, and to elucidate...were first exposed to ionizing radiation, electrophoresed in...Table 1 Table 1. Range of tail moment in non...for comet Radiation dose Cell line Range of tail...

Claudia Bu Volpato; Minerva Martnez-Alfaro; Raffaella Corvi; Coralie Gabus; Sylvie Sauvaigo; Pietro Ferrari; Elena Bonora; Alessandro De Grandi; and Giovanni Romeo

2008-11-01T23:59:59.000Z

34

Extremely Low Dose Ionizing Radiation Up-regulates CXC Chemokines in Normal Human Fibroblasts  

Science Journals Connector (OSTI)

...with radiation exposure (1). Ionizing radiation at moderate and higher doses (0.1-10 Gy) can produce DNA strand...death. Studies of mutants sensitive to ionizing radiation at this range of doses have revealed that the responsible genes...

Akira Fujimori; Ryuichi Okayasu; Hiroshi Ishihara; Satoshi Yoshida; Kiyomi Eguchi-Kasai; Kumie Nojima; Satoru Ebisawa; and Sentaro Takahashi

2005-11-15T23:59:59.000Z

35

INDUSTRIAL EFFLUENT TREATMENT USING IONIZING RADIATION COMBINED TO TITANIUM DIOXIDE  

SciTech Connect (OSTI)

The Advanced Oxidation Process (AOP) with OH radicals are the most efficient to mineralize organic compounds, and there are various methods to generate OH radicals as the use of ozone, hydrogen peroxide and ultra-violet radiation and ionizing radiation. The irradiation of aqueous solutions with high-energy electrons results in the excitation and ionizing of the molecules and rapid (10{sup -14} - 10{sup -9} s) formation of reactive intermediates. These reactive species will react with organic compounds present in industrial effluent inducing their decomposition. Titanium dioxide (TiO{sub 2}) catalyzed photoreaction is used to remove a wide range of pollutants in air and water media, combined to UV/VIS light, FeO{sub 2}, and H{sub 2}O{sub 2}, but as far as known there is no report on the combination with ionizing radiation. In some recent studies, the removal of organic pollutants in industrial effluent, such as Benzene, Toluene, and Xylene from petroleum production using ionizing radiation was investigated. It has been ob served that none of the methods can be used individually in wastewater treatment applications with good economics and high degree of energy efficiency. In the present work, the efficiency of ionizing radiation in presence of TiO{sub 2} to treat industrial effluent was evaluated. The main aim to combine these technologies is to improve the efficiency for very hard effluents and to reduce the processing cost for future implementation to large-scale design.

Duarte, C.L.; Oikawa, H.; Mori, M.N.; Sampa, M.H.O.

2004-10-04T23:59:59.000Z

36

Physical and biological properties of U.S. standard endotoxin EC after exposure to ionizing radiation.  

Science Journals Connector (OSTI)

...in the UV range, radiation treatment...pattern. Dose-related...effects of the ionizing radiation...milligram-per-milliliter range) (13...in the UV range, we found...ioniz- ing radiation. Regarding...effective, dose- dependent...EXPOSED TO IONIZING RADIATION...

G Csako; R J Elin; H D Hochstein; C M Tsai

1983-07-01T23:59:59.000Z

37

Ionic Liquids and Ionizing Radiation: Reactivity of Highly Energetic  

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

Ionizing Radiation: Reactivity of Highly Energetic Ionizing Radiation: Reactivity of Highly Energetic Species James F. Wishart J. Phys. Chem. Lett. 1, 3225-3231 (2010). [Find paper at ACS Publications] or use ACS Articles on Request View the video on this Perspective article at The Journal of Physical Chemistry Letters (5:03) Selected for the ACS Special Virtual Issue on Ionic Liquids (March 2011). Abstract: Due to their unique properties, ionic liquids present many opportunities for basic research on the interactions of radiation with materials under conditions not previously available. At the same time, there are practical applied reasons for characterizing, understanding, and being able to predict how ionic-liquid-based devices and industrial-scale systems will perform under conditions of extreme reactivity, including radiation. This

38

The Inactivation of $\\alpha$-Chymotrypsin by Ionizing Radiations  

Science Journals Connector (OSTI)

...Chymotrypsin by Ionizing Radiations J. A. V. Butler...studied over a range of concentrations...where D is the dose required to cause...air over a wide range of concentrations...by varying the dose rate of the electron...over a very wide range. An enhanced...

1960-01-01T23:59:59.000Z

39

Sensitivity of aflatoxin b1 to ionizing radiation.  

Science Journals Connector (OSTI)

...activity with respective doses of 2.5, 5, 10...irradiation aflatoxin B1 dose of: in upper layediteionre...in foodstuffs may range from levels of 0...with an irradiation dose of10 kGy (the maximum...its sensitivity to ionizing radiation. When aflatoxin...

P J Van Dyck; P Tobback; M Feyes; H van de Voorde

1982-06-01T23:59:59.000Z

40

production under ionizing radiation in aluminoborosilicate glasses by EPR spectroscopy.  

E-Print Network [OSTI]

1 Ti3+ production under ionizing radiation in aluminoborosilicate glasses by EPR spectroscopy. P irradiation of Ti4+ ions in aluminoborosilicate glasses have been studied by EPR spectroscopy at 20 K of the Ti3+ ion EPR spectra has shown three different Ti3+ environment attributed to one [VI] Ti3+ and two

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Preservation of food by ionizing radiation  

SciTech Connect (OSTI)

This study is presented in three volumes. Vol. I: Presents a concise description of the philosophy of radiation, protection for people working with irradiation processes, including problems associated with the design and operation of a large facility and solutions to problems encountered. Radiation dosimetry and radiolytic effects in foods are also presented. Vol. II: Effects of radiation on bacteria and viruses are discussed as well as the lethal effect on microorganisms and insects. Also presented are the effects of irradiated food on packaging materials. Vol. III: The effects of radurization on meats, poultry, fish, shellfish, fruits, vegetables, and spices. Also included are the effects of irradiation for the use of shelf-life extension.

Josephson, E.S.; Peterson, M.S.

1983-01-01T23:59:59.000Z

42

Characterization of Cell Cycle Checkpoint Responses after Ionizing Radiation in Nijmegen Breakage Syndrome Cells  

Science Journals Connector (OSTI)

...events leading to G, and G2 arrests following ionizing radiation is abnormal in cells from AT patients. p53 protein up- regulation following low doses of ionizing radiation ranges from delayed and reduced to completely absent...

Vikky Yamazaki; Rolf-Dieter Wegner; and Cordula U. Kirchgessner

1998-06-01T23:59:59.000Z

43

Low Dose Radiation Research Program: Research Highlights - Ionizing  

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

Affects Cancer Frequency and Characteristics by Acting Affects Cancer Frequency and Characteristics by Acting on the Microenvironment Background: For more than a quarter century the scientific rationale for extrapolating radiation health effects has been underpinned by biophysical target theory. Fundamental to target theory is that the effect (e.g., DNA damage, mutation, cancer) is proportional to dose based on interaction of energy with biological targets, specifically DNA. However, the biology following ionizing radiation is more than just DNA damage, repair, or misrepair. Cellular responses to ionizing radiation can affect phenotype, cell interactions, lineage commitment, differentiation and genomic stability, all of which have been widely documented in cultured cells and many observed in vivo. This class of non-targeted effects induced

44

Ionizing radiation effects on silicon test structures  

SciTech Connect (OSTI)

The effects of {sup 60}Co gamma irradiation on MOSCAPS and special junction diode detectors have been studied. The capacitors were used to ellicit the charge accumulation and anneal in two types of thermally grown oxides representative of those used in routine detector processing. Ion implanted, oxide passivated junction detectors having 0.25 and 1 cm{sup 2} areas and perimeter to area ratios of 1 (a square), 2 and 5 were designed and constructed to amplify the ionizing effects expected to largely affect junction edges through changes in fixed oxide charges. Detectors were exposed to over 4 Mrad and showed clear increases in leakage current in proportion to the junction edge length. Annealing schedules were determined to provide a continuous response to incremental irradiations and subsequent room temperature anneals of leakage current. Besides an increase in gate threshold, little effect on the C(V) response was found. PISCES simulation of the edge fields using different fixed oxide charge revealed regions of very high lateral fields near the junction edges for fixed charges in the 2 {times} 10{sup 12}/cm{sup 2} range expected from the capacitor studies which could be responsible for the observed leakage currents.

Kraner, H.W.; Beuttenmuller, R.; Chen, W.; Kierstead, J.A.; Li, Z.; Zhang, Y. [Brookhaven National Lab., Upton, NY (United States); Dou, L. [Wayne State Univ., Detroit, MI (United States); Fretwurst, E.; Lindstroem, G. [Univ. of Hamburg (Germany)

1993-12-01T23:59:59.000Z

45

Physiological Responses of the Hyperthermophilic Archaeon Pyrococcus abyssi to DNA Damage Caused by Ionizing Radiation  

Science Journals Connector (OSTI)

...Damage Caused by Ionizing Radiation Edmond Jolivet 1 Corresponding...Fukuoka 812-8581, Japan The mechanisms by which...temperature and/or ionizing radiation. The hyperthermophilic...Matsunaga thanks the Japan Society for the Promotion...resistant to ionizing radiation? Trends Microbiol...

Edmond Jolivet; Fujihiko Matsunaga; Yoshizumi Ishino; Patrick Forterre; Daniel Prieur; Hannu Myllykallio

2003-07-01T23:59:59.000Z

46

Ionizing Radiation-induced, Mitochondria-dependent Generation of Reactive Oxygen/Nitrogen  

Science Journals Connector (OSTI)

...exposing cells to ionizing radiation. In the 1-10 Gy dose range, the amount...demonstrated that ionizing radiation in the therapeutic dose range stimulates a...exposing cells to ionizing radiation. In the 1-10 Gy dose range, the amount...

J. Kevin Leach; Glenn Van Tuyle; Peck-Sun Lin; Rupert Schmidt-Ullrich; and Ross B. Mikkelsen

2001-05-15T23:59:59.000Z

47

MACHINE LEARNING FOR IDENTIFICATION OF SOURCES OF IONIZING RADIATION DURING SPACE MISSIONS  

E-Print Network [OSTI]

MACHINE LEARNING FOR IDENTIFICATION OF SOURCES OF IONIZING RADIATION DURING SPACE MISSIONS Ricardo for the automated identification and classification of tracks of ionizing radiation during space missions. The tracks of ionizing radiation are mea- sured by the hybrid semiconductor Medipix2 pixel de- tector system

Vilalta, Ricardo

48

Ionizing Radiation Effects on CMOS Imagers Manufactured in Deep Submicron Process  

E-Print Network [OSTI]

, ionizing radiation, total dose, dark current, STI, hardening by design, RHDB 1. INTRODUCTION IonizingIonizing Radiation Effects on CMOS Imagers Manufactured in Deep Submicron Process Vincent Goiffona a large dynamic range. This can significantly impact the radiation hardness of "in-pixel" devices which

Mailhes, Corinne

49

Interactive visual intervention planning in particle accelerator environments with ionizing radiation  

E-Print Network [OSTI]

Radiation is omnipresent. It has many interesting applications: in medicine, where it allows curing and diagnosing patients; in communication, where modern communication systems make use of electromagnetic radiation; and in science, where it is used to discover the structure of materials; to name a few. Physically, radiation is a process in which particles or waves travel through any kind of material, usually air. Radiation can be very energetic, in which case it can break the atoms of ordinary matter (ionization). If this is the case, radiation is called ionizing. It is known that ionizing radiation can be far more harmful to living beings than non-ionizing radiation. In this dissertation, we are concerned with ionizing radiation. Naturally occurring ionizing radiation in the form of radioactivity is a most natural phenomenon. Almost everything is radioactive: there is radiation emerging from the soil, it is in the air, and the whole planet is constantly undergoing streams of energetic cosmic radiation. Sinc...

Fabry, Thomas

50

Effects of ionizing radiation on modern ion exchange materials  

SciTech Connect (OSTI)

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.

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

1993-10-01T23:59:59.000Z

51

To: John R. Novak Radiation Safety - IRS From: G. T. Lonergan Radiation Safety - II§  

Office of Legacy Management (LM)

7, 19% 7, 19% To: John R. Novak Radiation Safety - IRS From: G. T. Lonergan Radiation Safety - II§ Subject: Extrusion of Billets, Titus Metals, Inc., Waterloo, Iowa A grpup of ANL aqloyees consisting of LE. Walker and S. Matsas (MET), E. Leverens (SSE), I(. C.~Buffy'(SPM), and G. T. Lonergan (IRS), traveled to Waterloo, Iowa, on June 29 where they accomplished the extrusion of U308 billets into fuel plates for Argonaut. Prior to beginning the extrusion operation, the floor area around the press, run-out table, stretch straightener, and all accessible portions of the press were surveyed. No activity was detected. The floor area from the furnace (uhere the billets were heated) to the press was coveredwith a layer of vinyl approximately 48fl wide and topped

52

PP2A regulates ionizing radiationinduced apoptosis through Ser46 phosphorylation of p53  

Science Journals Connector (OSTI)

...Articles PP2A regulates ionizing radiation-induced apoptosis through Ser46...virginia.edu 1 Department of Radiation Oncology and 2 Center for Cell...and Dental University, Tokyo, Japan). Radiation Treatment Cell cultures were irradiated...

Jun Mi; Elzbieta Bolesta; David L. Brautigan; and James M. Larner

2009-01-01T23:59:59.000Z

53

Calicivirus Inactivation by Nonionizing (253.7-Nanometer-Wavelength [UV]) and Ionizing (Gamma) Radiation  

Science Journals Connector (OSTI)

...7-nm-wavelength [UV]) radiation, inactivation by ionizing (gamma) radiation was studied as a process...constituents on inactivation by radiation. MATERIALS AND METHODS Viruses...Shoji Corporation, Tokyo, Japan) was propagated in MDCK...

Ana Maria de Roda Husman; Paul Bijkerk; Willemijn Lodder; Harold van den Berg; Walter Pribil; Alexander Cabaj; Peter Gehringer; Regina Sommer; Erwin Duizer

2004-09-01T23:59:59.000Z

54

Low Dose Radiation Research Program: Low Dose Ionizing Radiation-Induced  

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

Low Dose Ionizing Radiation-Induced Effects in Irradiated and Low Dose Ionizing Radiation-Induced Effects in Irradiated and Unirradiated cells: Pathways Analysis in Support of Risk Assessment. Authors: B.E. Lehnert, R. Cary, D. Gadbois, and G. Gupta. Institutions: Bioscience Division, Los Alamos National Laboratory. The scientific literature presents a confusing picture concerning health risks due to low dose ionizing radiation (LDIR), e.g., <1-10 cGy. Some effects of LDIR such as enhanced rates of cell proliferation and the induction of radioadaptation may be benign under some circumstances. Other evidence suggests LDIR can be hazardous and that a threshold for potentially detrimental responses, e.g., increases in intracellular reactive oxygen species (ROS), increases in sister chromatid exchanges (SCE), alterations in gene or protein expression profiles, and increased

55

FT-IR microscopical analysis with synchrotron radiation: The microscope optics and system performance  

SciTech Connect (OSTI)

When a Fourier transform infrared (FT-IR) microspectrometer was first interfaced with the National Synchrotron Light Source (NSLS) in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40-100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high-quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad-ranging applications of this technology and its potential for materials characterization.

Reffner, J.A.; Martoglio, P.A. [Spectra-Tech, Inc., Shelton, CT (United States); Williams, G.P. [Brookhaven National Lab., Upton, NY (United States)

1995-01-01T23:59:59.000Z

56

Optical remote diagnostics of atmospheric propagating beams of ionizing radiation  

DOE Patents [OSTI]

Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

Karl, Jr., Robert R. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

57

Densely Ionizing Radiation Acts via the Microenvironment to Promote Aggressive Trp53-Null Mammary Carcinomas  

Science Journals Connector (OSTI)

...Radiation Acts via the Microenvironment to Promote Aggressive Trp53-Null Mammary...changes from radiation contribute strongly to carcinogenic potential. Densely ionizing...radiation chimera in which mice were exposed to densely ionizing 350 MeV/amu Si-particles...

Irineu Illa-Bochaca; Haoxu Ouyang; Jonathan Tang; Christopher Sebastiano; Jian-Hua Mao; Sylvain V. Costes; Sandra Demaria; Mary Helen Barcellos-Hoff

2014-12-01T23:59:59.000Z

58

ATM Requirement in Gene Expression Responses to Ionizing Radiation in Human Lymphoblasts and Fibroblasts  

Science Journals Connector (OSTI)

...St. Charles, MO) software program. A two-dimensional...analysis was done using software and methods as described...ATM kinase by ionizing radiation and phosphorylation...toxicology, and drug safety evaluation. Cancer...exposure to ionizing radiation. Radiat Res 2000...

Cynthia L. Innes; Alexandra N. Heinloth; Kristina G. Flores; Stella O. Sieber; Paula B. Deming; Pierre R. Bushel; William K. Kaufmann; and Richard S. Paules

2006-03-01T23:59:59.000Z

59

Physiological Responses of the Hyperthermophilic Archaeon Pyrococcus abyssi to DNA Damage Caused by Ionizing Radiation  

Science Journals Connector (OSTI)

...before and after radiation and was in good...performed at a sublethal dose of 2,000 Gy to...our preliminary estimation reveals that 0...been observed for radiation-resistant Chroococcidiopsis...caused by ionizing radiation. | The mechanisms...furiosus, survive high doses of ionizing gamma...

Edmond Jolivet; Fujihiko Matsunaga; Yoshizumi Ishino; Patrick Forterre; Daniel Prieur; Hannu Myllykallio

2003-07-01T23:59:59.000Z

60

Ionizing radiation and atherosclerosis: Current knowledge and future challenges  

Science Journals Connector (OSTI)

Abstract The evaluation of the health effects of low-dose ionizing radiation has always been a focus of debate and investigation within the scientific community. During the last decade, epidemiological studies provided evidence that an excess risk of cardiovascular diseases (CVDs) can be associated with moderate and low dose radiation. The precise quantification of CVD risk in the low-dose radiation range (dose below which there is no risk. A limited number of studies with imaging surrogate endpoints and cardiovascular biomarkers in asymptomatic patients revealed early signs of cardiovascular alterations, even at a low dose. Invitro studies have shown that several mechanisms, including endothelial dysfunction, inflammation, oxidative stress, alterations of coagulation and platelet activity may have a relevant role in radiation-induced cardiovascular effects. Exposure to high-dose data in experimental models accelerates the development of atherosclerosis, predisposing to the formation of an inflammatory, thrombotic plaque phenotype, especially in animals that are genetically predisposed to this disease. On the contrary, low dose exposure produced both protective and detrimental effects, suggesting that multiple mechanisms may influence radiation-induced atherosclerosis. However, only very limited and specific information can be obtained from cell cultures and animal models. Planned studies of radiation-exposed cohorts need to be conducted to explore biological mechanisms of low-dose radiation-associated cardiovascular disease. Further investigations with functional imaging to assess vascular function and cardiovascular biomarkers have great potential for providing new insights into low-dose radiation cardiovascular risk, especially in occupational exposure and modern medicine.

Andrea Borghini; Emilio Antonio Luca Gianicolo; Eugenio Picano; Maria Grazia Andreassi

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Low Dose Ionizing Radiation Modulates Immune Function New Project Overview  

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

Modulates Immune Function New Project Overview Modulates Immune Function New Project Overview Gregory Nelson Loma Linda University Abstract The immune system provides the first line of defense for exposures to environmental hazards. Protective immunity mechanisms using innate or adaptive responses are employed to mitigate acute challenges or amplify the readiness of the system to respond to future challenges. Some stimuli lead to amplified inflammatory reactions such as delayed hypersensitivity which is required for immunity to parasites and can also lead to adverse consequences such as contact dermatitis. Radiation exposure has the potential to aggravate hypersensitivity reactions as well as to suppress protective immunity. Ionizing radiation at high doses has long been recognized as highly effective in destroying cells of the immune system,

62

extremely low-dose ionizing radiation upregulates CXC chemokines in normal human fibroblasts  

Science Journals Connector (OSTI)

...2006 Abstract Tumor Biology 32: Radiation Biology 2 Proc Amer Assoc Cancer...Volume 47, 2006 extremely low-dose ionizing radiation upregulates CXC chemokines in...biological effects of this low dose range have not been established. We...

Akira Fujimori; Katsutoshi Suetomi; Keiji Kinoshita; Ayako Kojima; Yaqun Fang; Ayako Egusa; and Ryuichi Okayasu

2006-04-15T23:59:59.000Z

63

Polymorphisms in DNA Repair Genes, Medical Exposure to Ionizing Radiation, and Breast Cancer Risk  

Science Journals Connector (OSTI)

...the role of DSB repair in response to low-dose radiation, particularly the range experienced by women from mammograms and other...breast cancer associated with exposure to low doses of ionizing radiation. Although we specifically designed our questionnaire...

Robert C. Millikan; Jon S. Player; Allan Rene deCotret; Chiu-Kit Tse; and Temitope Keku

2005-10-01T23:59:59.000Z

64

E-Print Network 3.0 - astrophysical ionizing radiation Sample...  

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

Perturbations and level splittings 8-3 Ionization and the Saha equation 2. Textbook Radiative processes... the following chapters: Chapter 1 Basic concepts 1-1 Radiative flux and...

65

Retinal Degeneration and Ionizing Radiation Hypersensitivity in a Mouse Model for Cockayne Syndrome  

Science Journals Connector (OSTI)

...sensitive to a single dose of ionizing radiation at doses up to 10 Gy. In marked...least within the age range investigated, the...photoreceptor cells for ionizing radiation. This finding underscores...experiment (cumulative dose, 35 kJ/m2). The...

Theo G. M. F. Gorgels; Ingrid van der Pluijm; Renata M. C. Brandt; George A. Garinis; Harry van Steeg; Gerard van den Aardweg; Gerard H. Jansen; Jan M. Ruijter; Arthur A. B. Bergen; Dirk van Norren; Jan H. J. Hoeijmakers; Gijsbertus T. J. van der Horst

2006-12-04T23:59:59.000Z

66

Chromosome translocations and cosmic sources of ionizing radiation: The NIOSH-NCI airline pilot biomarker study  

Science Journals Connector (OSTI)

...and cosmic sources of ionizing radiation: The NIOSH-NCI airline...are exposed to cosmic ionizing radiation, an efficient inducer...bone marrow absorbed dose in cGy from personal...SD; 46.7 5.3, range 37-55 vs. 45.8...

Lee Yong; Alice Sigurdson; Elizabeth Ward; Martha Waters; Elizabeth Whelan; Martin Petersen; Elaine Ron; Marilyn Ramsey; Parveen Bhatti; and James Tucker

2007-05-01T23:59:59.000Z

67

Use of the Tetrazolium Assay in Measuring the Response of Human Tumor Cells to Ionizing Radiation  

Science Journals Connector (OSTI)

...irradiation dose rate was...demonstrated a range of absorbance...RESPONSE TO IONIZING RADIATION with 1 mg...with graded doses of irradiation...each with a range of seeded...MGHU1 0 5 10 DOSE (Gy) RT112...RESPONSE TO IONIZING RADIATION 150000 FF...

Patricia Price and Trevor J. McMillan

1990-03-01T23:59:59.000Z

68

Quantitative estimation of UV light dose concomitant to irradiation with ionizing radiation  

Science Journals Connector (OSTI)

A simple mathematical model for biological estimation of UV light dose concomitant to ionizing radiation was suggested. This approach was applied to determine the dependency of equivalent UV light dose accompanied by 100Gy of ionizing radiation on energy of sparsely ionizing radiation and on volume of the exposed cell suspension. It was revealed that the relative excitation contribution to the total lethal effect and the value of UV dose was greatly increased with an increase in energy of ionizing radiation and volume of irradiated suspensions. It is concluded that these observations are in agreement with the supposition that ?erenkov emission is responsible for the production of UV light damage and the phenomenon of photoreactivation observed after ionizing exposure of bacterial and yeast cells hypersensitive to UV light. A possible synergistic interaction of the damages produced by ionizations and excitations as well as a probable participation of UV component of ionizing radiation in the mechanism of hormesis and adaptive response observed after ionizing radiation exposure is discussed.

Vladislav G. Petin; Ivan I. Morozov; Jin Kyu Kim; Maria A. Semkina

2011-01-01T23:59:59.000Z

69

Interaction of Ionizing Radiation with Paclitaxel (Taxol) and Docetaxel (Taxotere) in HeLa and SQ20B Cells  

Science Journals Connector (OSTI)

...drawn from survival to radiation alone. Therefore...large decrease of the radiation susceptibility among...fraction over the whole range of radiation doses investigated. Interestingly...1844 TAXOIDS AND IONIZING RADIATION 70 TAX or...

Christophe Hennequin; Nicole Giocanti; and Vincent Favaudon

1996-04-15T23:59:59.000Z

70

Detecting excess ionizing radiation by electromagnetic breakdown of air  

Science Journals Connector (OSTI)

A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanchebreakdown time (10200 ns) and could profitably be as long as the statistical lag time in ambient air (typically microseconds). Candidate pulsed electromagnetic sources over a wavelength range 3 ? mm > ? > 10.6 ? ? m are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW 10 ? ? s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO 2 laser with 30 MW 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO 2 laser could have a longer range > 100 ? m .

Victor L. Granatstein; Gregory S. Nusinovich

2010-01-01T23:59:59.000Z

71

Detecting excess ionizing radiation by electromagnetic breakdown of air  

SciTech Connect (OSTI)

A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanche breakdown time (10-200 ns) and could profitably be as long as the statistical lag time in ambient air (typically, microseconds). Candidate pulsed electromagnetic sources over a wavelength range, 3 mm>{lambda}>10.6 {mu}m, are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW, 10 {mu}s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO{sub 2} laser with 30 MW, 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO{sub 2} laser could have a longer range >100 m.

Granatstein, Victor L.; Nusinovich, Gregory S. [Center for Applied Electromagnetics, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

2010-09-15T23:59:59.000Z

72

Extremely Low Dose Ionizing Radiation Up-regulates CXC Chemokines in Normal Human Fibroblasts  

Science Journals Connector (OSTI)

...Research Center for Radiation Safety, National...263-8555 Chiba, Japan. Phone: 81-43-206-3159...doses of ionizing radiation (5). A recent...study showed that Japan has the worlds highest...Research Center for Radiation Safety, National...Inage, Chiba, Japan. fujimora@nirs...

Akira Fujimori; Ryuichi Okayasu; Hiroshi Ishihara; Satoshi Yoshida; Kiyomi Eguchi-Kasai; Kumie Nojima; Satoru Ebisawa; and Sentaro Takahashi

2005-11-15T23:59:59.000Z

73

IR Spectroscopy Spectroscopy: Branch of science in which light or other electromagnetic radiation  

E-Print Network [OSTI]

is resolved into its component wavelengths to produce spectra, which are graphs of intensity vs. wavelength or frequency of radiation. Current usage broadens this definition to include some methods that don't involve the energy difference of 2 quantum levels of the sample of matter. hE = IR Spectroscopy Tool for examining

Sherrill, David

74

Mechanisms Underlying Cellular Responses to Low Doses/Low LET Ionizing Radiation in Primary Haemopoietic Cells.  

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

Mechanisms Underlying Cellular Responses to Low Doses/Low LET Ionizing Radiation Mechanisms Underlying Cellular Responses to Low Doses/Low LET Ionizing Radiation in Primary Haemopoietic Cells. Munira Kadhim 1 , Stefania Militi 1 , Debbie Bowler 1 , Denise Macdonald 1 and Kevin Prise 2 1 Radiation and Genome Stability Unit, MRC, Harwell, Didcot, Oxon, OX11 0RD, UK 2 Gray Cancer Institute ,PO Box 100, Mount Vernon Hospital, Northwood, HA6 2JR, UK Because the human population is genetically heterogeneous, it is important to understand the role that heterogeneity may play in radiation response. Exposure to ionizing radiation can lead to a suite of changes, including increased mutation rate, delayed reproductive cell death, and delayed chromosomal aberrations, all of which are manifestations of the complex genomic instability (GI) phenotype. Following exposure to either high LET

75

IONIZING RADIATION RISKS TO SATELLITE POWER SYSTEMS (SPS) WORKERS  

E-Print Network [OSTI]

Dose-Response Relationships for Radiation-Induced Cancer EstimationDose-Response Relationships for Radiation-Induced Cancer A general hypothesis for estimationof the total dose. Estimation of Space Radiation Induced

Lyman, J.T.

2010-01-01T23:59:59.000Z

76

Telomerase-Dependent Oncolytic Adenovirus Sensitizes Human Cancer Cells to Ionizing Radiation via Inhibition of DNA Repair Machinery  

Science Journals Connector (OSTI)

...surgical resection, radiation, and cytotoxic...the threshold for radiation-induced tumor cell death; the safety and efficacy of...1-3). Ionizing radiation primarily targets...with the CalcuSyn software (BioSoft), and...

Shinji Kuroda; Toshiya Fujiwara; Yasuhiro Shirakawa; Yasumoto Yamasaki; Shuya Yano; Futoshi Uno; Hiroshi Tazawa; Yuuri Hashimoto; Yuichi Watanabe; Kazuhiro Noma; Yasuo Urata; Shunsuke Kagawa; and Toshiyoshi Fujiwara

2010-11-15T23:59:59.000Z

77

Targeted and Nontargeted Effects of Low-Dose Ionizing Radiation on Delayed Genomic Instability in Human Cells  

Science Journals Connector (OSTI)

...humans receive some radiation exposure, mostly...risks associated with radiation exposure come from populations exposed to ionizing radiation, primarily from epidemiologic...However, those doses, in the range of 0.2 to 2.5...

Lei Huang; Perry M. Kim; Jac A. Nickoloff; and William F. Morgan

2007-02-01T23:59:59.000Z

78

Functional proteomic pattern identification under low dose ionizing radiation  

Science Journals Connector (OSTI)

Objective: High dose radiation has been well known for increasing the risk of carcinogenesis. However, the understanding of biological effects of low dose radiation is limited. Low dose radiation is reported to affect several signaling pathways including ... Keywords: Feature selection, Jumping emerging identification, Low dose radiation, Proteomic signaling patterns

Young Bun Kim; Chin-Rang Yang; Jean Gao

2010-07-01T23:59:59.000Z

79

The Relative Effects of Direct and Indirect Actions of Ionizing Radiations on Deoxyribonucleic Acid  

Science Journals Connector (OSTI)

...determined over a range of concentrations...means that over this range of concentration...independent of the dose rate and of the hardness of the radiations within the ranges used and identical...indirect actions of ionizing radiations on deoxyribonucleic...

1958-01-01T23:59:59.000Z

80

The Effects of High Dose Rates of Ionizing Radiations on Solutions of Iron and Cerium Salts  

Science Journals Connector (OSTI)

...research-article The Effects of High Dose Rates of Ionizing Radiations on Solutions of Iron and Cerium...of 1.3 duration and over a range of dose rates from 0.5 to 20 000 rads/pulse. Radiation yields at constant dose rate...

1960-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Inactivation of 14-3-3? Influences Telomere Behavior and Ionizing Radiation-Induced Chromosomal Instability  

Science Journals Connector (OSTI)

...per dish was chosen to ensure that about 50 colonies would survive a particular radiation dose treatment. Cells were exposed to ionizing radiation in the dose range of 0 to 8 Gy at room temperature using a 137Cs ray at a dose rate of 1.1 Gy...

Sonu Dhar; Jeremy A. Squire; M. Prakash Hande; Raymund J. Wellinger; Tej K. Pandita

2000-10-01T23:59:59.000Z

82

Identification of novel ionizing radiation signaling targets in reconstituted human skin  

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

of novel ionizing radiation signaling targets in reconstituted human skin of novel ionizing radiation signaling targets in reconstituted human skin Feng Yang, Katrina M. Waters, Bobbie-Jo Webb-Robertson, Lye-Meng Markillie, Rachel M. Wirgau, Shawna M. Hengel, Ljiljana Pasa-Tolic, and David L. Stenoien. Pacific Northwest National Laboratory Our focus has been on identifying the early events that occur after low dose ionizing radiation exposure that precede and often regulate downstream events such as altered transcription, protein secretion and epigenetic regulation. Phosphorylation is one of the earliest detectible events that occurs following radiation exposure and plays important roles in multiple biological pathways including DNA damage repair, transcription, apoptosis, and cell cycle progression. Very robust

83

Human In vivo Dose-Response to Controlled, Low-Dose Low Linear Energy Transfer Ionizing Radiation Exposure  

Science Journals Connector (OSTI)

...effects of low-dose low-linear energy transfer ionizing radiation (LDIR) in humans...direct evidence that doses in the range of 1 to 10 cGy...the intentional radiation of healthy tissue...the response to ionizing radiation. Attempts...

Zelanna Goldberg; David M. Rocke; Chad Schwietert; Susanne R. Berglund; Alison Santana; Angela Jones; Jrg Lehmann; Robin Stern; Ruixiao Lu; and Christine Hartmann Siantar

2006-06-15T23:59:59.000Z

84

Effect of Sunitinib Combined with Ionizing Radiation on Endothelial Cells  

Science Journals Connector (OSTI)

......Statistical analysis Statistical significance was determined using two-tailed Students's t-test (Fig. 13) or the Kruskal-Wallis test (Fig. 6B). P-value < 0.05 was considered statistically significant. RESULTS Sunitinib increased IR-induced......

Hai-Ping Zhang; Koichi Takayama; Bo Su; Xiao-dong Jiao; Rui Li; Jie-Jun Wang

2011-01-01T23:59:59.000Z

85

MMTF DISCOVERY OF GIANT IONIZATION CONES IN MR 2251-178: IMPLICATIONS FOR QUASAR RADIATIVE FEEDBACK  

SciTech Connect (OSTI)

We report the discovery of giant ionization cones in the 140 kpc nebula around quasar MR 2251-178 based on deep [O III] {lambda}5007/H{beta} and [N II] {lambda}6583/H{alpha} flux ratio maps obtained with the Maryland-Magellan Tunable Filter on the Baade-Magellan 6.5 m Telescope. These cones are aligned with the weak double-lobed radio source observed on smaller scale (<30 kpc). They have an opening angle {approx}120 Degree-Sign {+-} 10 Degree-Sign and subtend {approx}65%-90% of 4{pi} sr, where the uncertainty takes into account possible projection effects. The material in the outer ionization cones is matter-bounded, indicating that all ionizing photons emitted through the cones escape from the system. The quasar ionizing flux is {approx}2-3 times fainter outside of these cones, despite the largely symmetric geometry of the nebula in [O III]. Overall, adding up the contributions from both inside and outside the cones, we find that {approx}65%-95% of the quasar ionizing radiation makes its way out of the system. These results emphasize the need for line ratio maps to quantify the escape fraction of ionizing radiation from quasars and the importance of quasar radiative feedback on the intergalactic medium.

Kreimeyer, Kory; Veilleux, Sylvain, E-mail: kory@astro.umd.edu, E-mail: veilleux@astro.umd.edu [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

2013-07-20T23:59:59.000Z

86

The Influence of Resonance Helical Field on the Z eff and Impurity Radiation in IR-T1 Tokamak  

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The influence of resonant helical field, RHF, on effective ion charge, Z eff, and impurity radiations on IR-T1 tokamak discharges was studied. The theoretical calculation of...Z ef...

M. Mahmoodi Darian; A. Hojabri; M. K. Salem; M. Ghoranneviss

2006-12-01T23:59:59.000Z

87

Investigation of non-targeted effects of low dose ionizing radiation on the mammary gland  

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

non-targeted effects of low dose ionizing radiation on the mammary gland non-targeted effects of low dose ionizing radiation on the mammary gland utilizing three-dimensional culture models of mammary cells derived from mouse strains that differ in susceptibility to tumorigenesis Joni D. Mott, Antoine M. Snijders, Alvin Lo, Dinah Levy-Groesser, Bahram Parvin, Andrew J. Wyrobek, Jian-Hua Mao, and Mina J. Bissell Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720 Goal: Within the Lawrence Berkeley National Laboratory's SFA, Project 2, our studies focus on utilizing three dimensional (3D) cell culture models as surrogates for in vivo studies to determine how low doses of ionizing radiation influence mammary gland tissue architecture and how this may relate both to tumor progression and/or adaptive response.

88

Low-Dose Ionizing Radiation Alters the Epigenome of the Avy Mouse  

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

Ionizing Radiation Alters the Epigenome of the A Ionizing Radiation Alters the Epigenome of the A vy Mouse Autumn Bernal 1,2,3 , Dale Huang 1 , Yue Li 4 , Dana Dolinoy 5 , and Randy Jirtle 1 Department of Radiation Oncology 1 , University Program in Genetics and Genomic 2 , Integrated Toxicology & Environmental Health Program 3 , Department of Community and Family Medicine 4 , Duke University Medical Center, Durham, NC, USA, Department of Environmental and Health Sciences, University of Michigan, Ann Arbor, MI, USA 4 Background: Humans have evolved and thrived amidst constant low-dose (0-10 cGy) background radiation exposure from natural sources. Currently, however, the frequency of exposures to low doses of radiation is increasing due to man-made sources such as diagnostic imaging and nuclear power. This increased exposure has led to concerns amongst the general public and the government about the

89

Solar irradiance changes and photobiological effects at Earth's surface following astrophysical ionizing radiation events  

E-Print Network [OSTI]

Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In this work, we employed the TUV radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light) for clear-sky conditions and fixed aerosol parameter values. We also considered a wide range of biological effects on organisms ranging from humans to phytoplankton. We found that past work overestimated UVB irradiance, but that relative estimates for increase in exposure to DNA damaging radi...

Thomas, Brian C; Snyder, Brock R

2015-01-01T23:59:59.000Z

90

Directed Evolution of Ionizing Radiation Resistance in Escherichia coli  

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...repeated. The dose of radiation administered was adjusted...day at 37C, with the dose increasing as radioresistance...source until the desired dose was achieved. Irradiated...Genomic DNA from the radiation-sensitive E. coli...reads, respectively. Estimation of the level of sequencing...

Dennis R. Harris; Steve V. Pollock; Elizabeth A. Wood; Reece J. Goiffon; Audrey J. Klingele; Eric L. Cabot; Wendy Schackwitz; Joel Martin; Julie Eggington; Timothy J. Durfee; Christina M. Middle; Jason E. Norton; Michael C. Popelars; Hao Li; Sarit A. Klugman; Lindsay L. Hamilton; Lukas B. Bane; Len A. Pennacchio; Thomas J. Albert; Nicole T. Perna; Michael M. Cox; John R. Battista

2009-06-05T23:59:59.000Z

91

Altered Telomere Nuclear Matrix Interactions and Nucleosomal Periodicity in Ataxia Telangiectasia Cells before and after Ionizing Radiation Treatment  

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...mean P/mean S Mean () Range () Mean () Range () RKO 71 67-75 29 25-33...significant. Influence of ionizing radiation on telomere-nuclear matrix...cells were treated with a dose of 5 Gy of ionizing radiation, and proportions of S...

Lubomir B. Smilenov; Sonu Dhar; Tej K. Pandita

1999-10-01T23:59:59.000Z

92

Human In vivo Dose-Response to Controlled, Low-Dose Low Linear Energy Transfer Ionizing Radiation Exposure  

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...biotinylated nucleotide analogue/ribonucleotide mix. The biotinylated cRNA targets were then...dose-response to controlled, low-dose low linear energy transfer ionizing radiation exposure. | The effect of low doses of low-linear energy transfer (photon) ionizing radiation...

Zelanna Goldberg; David M. Rocke; Chad Schwietert; Susanne R. Berglund; Alison Santana; Angela Jones; Jrg Lehmann; Robin Stern; Ruixiao Lu; and Christine Hartmann Siantar

2006-06-15T23:59:59.000Z

93

Measurement of absorbed dose-to-water for an HDR {sup 192}Ir source with ionization chambers in a sandwich setup  

SciTech Connect (OSTI)

Purpose: In this study, a dedicated device for ion chamber measurements of absorbed dose-to-water for a Nucletron microSelectron-v2 HDR {sup 192}Ir brachytherapy source is presented. The device uses two ionization chambers in a so-called sandwich assembly. Using this setup and by taking the average reading of the two chambers, any dose error due to difficulties in absolute positioning (centering) of the source in between the chambers is cancelled to first order. The method's accuracy was examined by comparing measurements with absorbed dose-to-water determination based on the AAPM TG-43 protocol.Methods: The optimal source-to-chamber distance (SCD) for {sup 192}Ir dosimetry was determined from ion chamber measurements in a water phantom. The {sup 192}Ir source was sandwiched between two Exradin A1SL chambers (0.057 cm{sup 3}) at the optimal SCD separation. The measured ionization was converted to the absorbed dose-to-water using a {sup 60}Co calibration factor and a Monte Carlo-calculated beam quality conversion factor, k{sub Q}, for {sup 60}Co to {sup 192}Ir. An uncertainty estimate of the proposed method was determined based on reproducibility of measurements at different institutions for the same type of source.Results: The optimal distance for the A1SL chamber measurements was determined to be 5 cm from the {sup 192}Ir source center, considering the depth dependency of k{sub Q} for {sup 60}Co to {sup 192}Ir and the chamber positioning. The absorbed dose to water measured at (5 cm, 90) on the transverse axis was 1.3% lower than TG-43 values and its reproducibility and overall uncertainty were 0.8% and 1.7%, respectively. The measurement doses at anisotropic points agreed within 1.5% with TG-43 values.Conclusions: The ion chamber measurement of absorbed dose-to-water with a sandwich method for the {sup 192}Ir source provides a more accurate, direct, and reference dose compared to the dose-to-water determination based on air-kerma strength in the TG-43 protocol. Due to the simple but accurate assembly, the sandwich measurement method is useful for daily dose management of {sup 192}Ir sources.

Araki, Fujio; Kouno, Tomohiro; Ohno, Takeshi [Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto 862-0976 (Japan)] [Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto 862-0976 (Japan); Kakei, Kiyotaka; Yoshiyama, Fumiaki [Department of Radiotherapy, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto 860-8556 (Japan)] [Department of Radiotherapy, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto 860-8556 (Japan); Kawamura, Shinji [Department of Radiotherapy, Miyazaki University Hospital, 5200 Kihara Ohaza Kiyotake-Machi, Miyazaki 889-1692 (Japan)] [Department of Radiotherapy, Miyazaki University Hospital, 5200 Kihara Ohaza Kiyotake-Machi, Miyazaki 889-1692 (Japan)

2013-09-15T23:59:59.000Z

94

Densely Ionizing Radiation Acts via the Microenvironment to Promote Aggressive Trp53-Null Mammary Carcinomas  

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...charged particle species from protons through uranium at varying energies of up to tens of GeV/amu (7). Estimating the cancer risk...cancer than sparsely ionizing radiation. The unique pattern of energy deposition incurred by particle traversal is considered to...

Irineu Illa-Bochaca; Haoxu Ouyang; Jonathan Tang; Christopher Sebastiano; Jian-Hua Mao; Sylvain V. Costes; Sandra Demaria; Mary Helen Barcellos-Hoff

2014-12-01T23:59:59.000Z

95

Densely Ionizing Radiation Acts via the Microenvironment to Promote Aggressive Trp53-Null Mammary Carcinomas  

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...ionizing radiation. The unique pattern of energy deposition incurred by particle traversal...epithelial cells were positive for K18 (green).Nuclei were counterstained with DAPI...positive either for K18 or K14 (n = 20, green; D), K14+18 type with K14 and K18...

Irineu Illa-Bochaca; Haoxu Ouyang; Jonathan Tang; Christopher Sebastiano; Jian-Hua Mao; Sylvain V. Costes; Sandra Demaria; and Mary Helen Barcellos-Hoff

2014-12-01T23:59:59.000Z

96

The effects of diet and ionizing radiation on azoxymethane induced colon carcinogenesis  

E-Print Network [OSTI]

cancer, by suppressing apoptosis and upregulating proliferation in colonocytes. Diets contained a combination of fish oil or corn oil and either pectin or cellulose. We exposed 40 male Sprague-Dawley rats to 1 Gy ionizing radiation (1 GeV Fe) 10 d prior...

Mann, John Clifford

2006-10-30T23:59:59.000Z

97

Ionizing Radiation as an Initiator: Effects of Proliferation and Promotion Time on Tumor Incidence in Mice  

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...portion of the dose-response curve these two doses reside, we cannot accu rately say that the...cell carcinomas did not appear to depend on dose. A wider range of doses of ionizing radiation needs to be studied. A representative basal...

Deborah Jaffe and G. Tim Bowden

1987-12-15T23:59:59.000Z

98

Mammalian Tissue Response to Low Dose Ionizing Radiation: The Role of Oxidative Metabolism and Intercellular Communication  

SciTech Connect (OSTI)

The objective of the project was to elucidate the mechanisms underlying the biological effects of low dose/low dose rate ionizing radiation in organs/tissues of irradiated mice that differ in their susceptibility to ionizing radiation, and in human cells grown under conditions that mimic the natural in vivo environment. The focus was on the effects of sparsely ionizing cesium-137 gamma rays and the role of oxidative metabolism and intercellular communication in these effects. Four Specific Aims were proposed. The integrated outcome of the experiments performed to investigate these aims has been significant towards developing a scientific basis to more accurately estimate human health risks from exposures to low doses ionizing radiation. By understanding the biochemical and molecular changes induced by low dose radiation, several novel markers associated with mitochondrial functions were identified, which has opened new avenues to investigate metabolic processes that may be affected by such exposure. In particular, a sensitive biomarker that is differentially modulated by low and high dose gamma rays was discovered.

Azzam, Edouard I

2013-01-16T23:59:59.000Z

99

The Escape of Ionizing Photons from OB Associations in Disk Galaxies Radiation Transfer Through Superbubbles  

E-Print Network [OSTI]

By solving the time-dependent radiation transfer problem of stellar radiation through evolving superbubbles within a smoothly varying H I distribution, we have estimated the fraction of ionizing photons emitted by OB associations that escapes the H I disk of our Galaxy. We considered a coeval star-formation history and a Gaussian star-formation history with a time spread sigma_t = 2 Myr. We find that the shells of the expanding superbubbles quickly trap or attenuate the ionizing flux, such that most of the escaping radiation escapes shortly after the formation of the superbubble. Superbubbles of large associations can blowout of the H I disk and form dynamic chimneys, which allow the ionizing radiation directly to escape the H I disk. However, blowout occurs when the ionizing photon luminosity has dropped well below the association's maximum luminosity. For the coeval star-formation history, the fraction of photons that escape each side of the disk in the solar vicinity is f_esc approx 6% (the total fraction ...

Dove, J B; Ferrara, A; Dove, James B.; Ferrara, Andrea

1999-01-01T23:59:59.000Z

100

Escherichia coli Genes and Pathways Involved in Surviving Extreme Exposure to Ionizing Radiation  

Science Journals Connector (OSTI)

...doses of ionizing radiation does not depend on a single mechanism...metabolism (2). This listing does not include a few gene products...from Deinococcus radiodurans R1 does not restore radioresistance...genetics: a laboratory manual and handbook for Escherichia coli and related...

Rose T. Byrne; Stefanie H. Chen; Elizabeth A. Wood; Eric L. Cabot; Michael M. Cox

2014-07-21T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Extremely Low-Dose Ionizing Radiation Causes Activation of Mitogen-activated Protein Kinase Pathway and Enhances Proliferation of Normal Human Diploid Cells  

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...stimulative effect of low-dose irradiation. These results indicate that a limited range of low-dose ionizing radiation differentially activates...indicate that a limited range of low-dose ionizing radiation differentially activates...

Keiji Suzuki; Seiji Kodama; and Masami Watanabe

2001-07-15T23:59:59.000Z

102

Roles of the Major, Small, Acid-Soluble Spore Proteins and Spore-Specific and Universal DNA Repair Mechanisms in Resistance of Bacillus subtilis Spores to Ionizing Radiation from X Rays and High-Energy Charged-Particle Bombardment  

Science Journals Connector (OSTI)

...mutagenic effects induced by ionizing radiation are thought to be the result...of DNA damage caused by given doses of ionizing radiation for different bacteria are very similar, although the range of ionizing-radiation resistance...

Ralf Moeller; Peter Setlow; Gerda Horneck; Thomas Berger; Gnther Reitz; Petra Rettberg; Aidan J. Doherty; Ryuichi Okayasu; Wayne L. Nicholson

2007-11-30T23:59:59.000Z

103

Proteomic and Biochemical Studies of Human Mesenchymal Stem Cells in Response to Low Dose Ionizing Radiation  

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

Proteomic and Biochemical Studies of Human Mesenchymal Stem Cells Proteomic and Biochemical Studies of Human Mesenchymal Stem Cells in Response to Low Dose Ionizing Radiation Deok-Jin Jang 1 , Mingquan Guo 1 , Julia S.F.Chu 2 , Kyle T. Kurpinski 2 , Bjorn Rydberg 1 , Song Li 2 , and Daojing Wang 1 1. Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720 2. Department of Bioengineering, University of California, Berkeley, CA 94720 We will present data obtained during the first year of our DOE/NASA Low Dose Radiation Research program. We utilized a comprehensive approach including transcriptomics, proteomics, phosphoproteomics, and biochemistry to characterize human mesenchymal stem cells (MSCs) in response to low dose ionizing radiation. We first determined the cell survival, proliferation, and osteogenic differentiation of

104

Exposure to Low-Dose Ionizing Radiation from Medical Imaging Procedures  

Science Journals Connector (OSTI)

...did not use measures of radiation dose that are specific to the subjects we studied but instead relied on estimates of effective doses, which are neither precisely measured nor subject-specific. The effective dose is a calculated estimate designed to provide a sex-averaged dose for a reference subject... Experimental and epidemiologic evidence has linked exposure to low-dose, ionizing radiation with the development of solid cancers and leukemia.1 As a result, persons at risk for repeated radiation exposure, such as workers in health care and the nuclear ...

Fazel R.; Krumholz H.M.; Wang Y.

2009-08-27T23:59:59.000Z

105

UNSCEAR Report 2000: Sources and Effects of Ionizing Radiation  

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Since its inception in 1955 the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has periodically undertaken a broad review of the sources and the effects of ionising radiation. This latest report is in two concurrently published separate volumes. Volumes I and II provide updated reviews of sources and effects of ionising radiation respectively. A considerable amount of new material supports the review of sources. The review of biological effects takes on board various contemporary issues raised by the `linear-no-threshold' controversy. Particular emphasis has been given to the evaluation of exposures and health consequences of the Chernobyl accident. As usual the report has an extended summary (17 pages) backed up by a number of technical annexes (A-J). The annexes have a wealth of basic data, extensive tables and voluminous reference lists. The two volumes are available separately from the United Nations and cost 60 per volume. They are also available from the Stationery Office, but only as a two volume set. If you are interested only in `sources' then you should be aware that the source-related aspects of the Chernobyl accident are largely covered in volume II on effects. Annex A of volume I provides a description of the methodologies used for the assessment of doses from natural, man-made environmental, medical and occupational radiation exposures, which are presented in subsequent annexes B, C, D and E respectively. The components of natural radiation (cosmic rays, terrestrial gamma rays, inhalation and ingestion) have been evaluated and added to provide an estimate of the global average exposure. Since there are wide distributions of exposures from each source, the consequent effective doses combine in various ways at each location, depending on the specific concentration of radionuclides in the environment and in the body, the latitude and altitude of the location, and many other factors. The total annual global per caput effective dose due to natural radiation sources is 2.4 mSv. A typical range of individual doses is considered to be 1-10 mSv. In any large population about 65% would be expected to have annual effective doses between 1 and 3 mSv, about 25% of the population would have annual effective doses less than 1 mSv and 10% would have annual effective doses greater than 3 mSv. The main man-made contribution to the environmental exposure of the world's population has come from the testing of nuclear weapons in the atmosphere that occurred mainly between 1945-1980. Since the previous UNSCEAR review of this topic in 1982 new information, previously classified, has become available on the numbers and yields of nuclear tests. An updated listing of atmospheric nuclear tests conducted at each of the test sites is included in this report. Although the total explosive yields of each test have been divulged, the fission and fusion yields are still mostly suppressed. Some general assumptions have been made to allow the evaluation of fission and fusion yields of each test in order to estimate the amounts of radionuclides produced in the explosions. The estimated total of fission yields of individual tests is in agreement with the global deposition of the main fission radionuclides 90Sr and 137Cs, as determined by worldwide monitoring networks. It has been calculated that the world average annual effective dose reached a peak of 150 ?Sv in 1963 and has since decreased to about 5 ?Sv in 2000, from residual radionuclides in the environment, mainly of 14C, 90Sr and 137Cs. The contribution to man-made exposures from the generation of electrical energy by nuclear power reactors has been estimated using a collective (100 year truncated) dose of 6 man-Sv per GW year. Assuming the present annual generation of 250 GW years continues, the truncated collective dose per year of practice is 1500 man-Sv to the world population, giving an estimated maximum per caput dose of less than 0.2 ?Sv per year. UNSCEAR has assessed the exposures from medical radiation procedures based on information obtaine

Monty Charles

2001-01-01T23:59:59.000Z

106

Bikini Atoll ionizing radiation survey, May 1985-May 1986  

SciTech Connect (OSTI)

Between 1946 and 1958, the United States conducted 23 nuclear tests at the Bikini Atoll in the Marshall Islands, which resulted in extensive radioactive contamination of a number of islands in the atoll and prevented the timely resettlement of the native population. Although the external dose rates from beta and gamma radiation have been previously determined by aerial survey and a variety of ground measurement techniques, technical constraints limited the assessment of external beta dose rates that result from the /sup 137/Cs and /sup 90/Sr//sup 90/Y contamination on the islands. Now, because of the recent development of very thin thermoluminescent dosimeters (TLDs), the external beta dose rates can be measured. 18 refs., 7 figs., 5 tabs.

Shingleton, K.L.; Cate, J.L.; Trent, M.G.; Robison, W.L.

1987-10-01T23:59:59.000Z

107

Genetic susceptibility to low-dose ionizing radiation in the mouse mammary  

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

Genetic susceptibility to low-dose ionizing radiation in the mouse mammary Genetic susceptibility to low-dose ionizing radiation in the mouse mammary gland as a means of understanding human risk for breast cancer Antoine M. Snijders Lawrence Berkeley National Laboratory Abstract Goal: Our goal is to develop an in vivo mechanistic model of genetic variation in the low-dose damage responses of mammary glands using inbred mice known to vary in their sensitivity to low-dose induced mammary gland cancer, and to develop molecular predictors for susceptibility or resistance to low-dose induced breast cancer. Background and Significance: It is increasingly believed that individuals differ in their genetic susceptibilities to environmental insults for diseases such as cancer. This concern is especially important for the large numbers of individuals receiving low-dose exposures in the nuclear energy

108

Effects of ionizing radiation on the response of certain photosensitive seeds to red light  

E-Print Network [OSTI]

and molecular oxygen. Studies of phosphate metabolism (Surrey and Gordon, 1962) and phosphorylation (Gordon and Surrey, 1961) indicate that energy transfer through phosphate esterification plays an important role and may be the key enzymatic reaction in red... spectrum promoting the germination of light-sensitive lettuce seed. Smithsonian Inst. Pubis. Misc. Collections 96: 1-8 ~ 11. Gordon, S. A. , and K. Surrey. 1961. Phosphorylation and red-spectrum photomorphogenesis. ~n Effects of ionizing radiations...

Richardson, Billy

2012-06-07T23:59:59.000Z

109

Low dose ionizing radiation produces too few reactive oxygen species to directly affect antioxidant concentrations in cells  

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...Radiolysis products and internal dose distribution - Calculation of...products and internal distribution of doses Low dose ionizing radiation produces too few reactive oxygen...stress is the mechanism for a wide range of negative impacts on biota living...

2012-01-01T23:59:59.000Z

110

Hypothesis regarding a membrane-associated mechanism of biological action due to low-dose ionizing radiation  

Science Journals Connector (OSTI)

A novel theory is proposed regarding the action of ionizing radiation in the range of very low doses. The basic premise of the theory presented is that the low-dose effect cannot be explained by direct damage ......

Lazar Kh. Eidus

2000-09-01T23:59:59.000Z

111

Multi-Dimensional Broadband IR Radiative Forcing of Marine Stratocumulus in a Large Eddy Simulation Model  

SciTech Connect (OSTI)

In order to address the interactive and evolutionary nature of the cloud-radiation interaction, we have coupled to a Large Eddy Simulation (LES) model the sophisticated multi-dimensional radiative transfer (MDRT) scheme of Evans (Spherical Harmonics Discrete Ordinate Method; 1998). Because of computational expense, we are at this time only able to run 2D experiments. Preliminary runs consider only the broadband longwave component, in large part because IR cloud top cooling is the significant forcing mechanism for marine stratocumulus. Little difference is noted in the evolution of unbroken stratocumulus between three-hour runs using MDRT and independent pixel approximation (IPA) for 2D domains of 50 km in the horizontal and 1.5 km in the vertical. Local heating rates differ slightly near undulating regions of cloud top, and a slight bias in mean heating rate from 1 to 3 h is present, yet the differences are never strong enough to result in a pronounced evolutionary bias in typical boundary layer metrics (e.g. inversion height, vertical velocity variance, TKE). Longer integration times may eventually produce a physical response to the bias in radiative cooling rates. A low-CCN case, designed to produce significant drizzle and induce cloud breakup does show subtle differences between MDRT and IPA. Over the course of the 6 hour simulations, entrainment is slightly less in the MDRT case, and the transition to the surface-based trade cumulus regime is delayed. Mean cooling rates appear systematically weaker in the MDRT case, indicative of a less energetic PBL and reflected in profiles of vertical velocity variance and TKE.

Mechem, David B.; Ovtchinnikov, Mikhail; Kogan, Y. L.; Davis, Anthony B; Cahalan, Robert F.; Takara, Ezra E.; Ellingson, Robert G.

2002-06-03T23:59:59.000Z

112

Radiochromic film dosimetry of HDR {sup 192}Ir source radiation fields  

SciTech Connect (OSTI)

Purpose: A radiochromic film based dosimetry system for high dose rate (HDR) Iridium-192 brachytherapy source was described. A comparison between calibration curves established in water and Solid Water was provided. Methods: Pieces of EBT-2 model GAFCHROMIC film were irradiated in both water and Solid Water with HDR {sup 192}Ir brachytherapy source in a dose range from 0 to 50 Gy. Responses of EBT-2 GAFCHROMIC film were compared for irradiations in water and Solid Water by scaling the dose between media through Monte Carlo calculated conversion factor for both setups. To decrease uncertainty in dose delivery due to positioning of the film piece with respect to the radiation source, traceable calibration irradiations were performed in a parallel-opposed beam setup. Results: The EBT-2 GAFCHROMIC film based dosimetry system described in this work can provide an overall one-sigma dose uncertainty of 4.12% for doses above 1 Gy. The ratio of dose delivered to the sensitive layer of the film in water to the dose delivered to the sensitive layer of the film in Solid Water was calculated using Monte Carlo simulations to be 0.9941 {+-} 0.0007. Conclusions: A radiochromic film based dosimetry system using only the green color channel of a flatbed document scanner showed superior precision if used alone in a dose range that extends up to 50 Gy, which greatly decreases the complexity of work. In addition, Solid Water material was shown to be a viable alternative to water in performing radiochromic film based dosimetry with HDR {sup 192}Ir brachytherapy sources.

Aldelaijan, Saad; Mohammed, Huriyyah; Tomic, Nada; Liang Liheng; DeBlois, Francois; Sarfehnia, Arman; Abdel-Rahman, Wamied; Seuntjens, Jan; Devic, Slobodan [Medical Physics Unit, McGill University, Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2 (Canada); Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4 (Canada); Medical Physics Unit, McGill University, Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2 (Canada)

2011-11-15T23:59:59.000Z

113

Cumulative exposure to medical sources of ionizing radiation in the first year after pediatric heart transplantation  

Science Journals Connector (OSTI)

Background Pediatric heart transplant recipients undergo a variety of radiologic tests with the attendant risk of exposure to ionizing radiation. We sought to quantify and describe the cumulative exposure to all forms of medical radiation during the first year after pediatric heart transplantation and identify factors associated with higher exposure. Methods Pediatric patients who received a heart transplant between January 2009 and May 2012 with follow-up at our institution were retrospectively reviewed. Patients were included if they survived through 1 year and the first coronary angiography. All medical testing using ionizing radiation performed during follow-up was compiled, and exposures were converted to effective dose (mSv). Results Included were 31 patients who underwent heart transplantation at a median age of 13.6 years (range, 0.318.3 years). The median number of radiologic tests performed was 38 (range, 18154), including 8 catheterizations (range, 212), and 28 X-ray images (range, 11135). Median cumulative effective dose was 53.5 mSv (range, 10.6153.5 mSv), of which 91% (range, 34%98%) derived from catheterizations, 31% (range, 8%89%) of the exposure occurred during the transplant admission, 59% (range, 11%88%) during planned follow-up, and 3% (0%56%) during unplanned follow-up. Older age at transplant was a risk factor for increased exposure (p = 0.006). When adjusted for age, a trend toward increased exposure was shown for congenital heart disease as the indication for transplant (p = 0.08), pre-sensitization (p = 0.12), and positive crossmatch (p = 0.09). Conclusions Pediatric heart transplant patients are exposed to significant amounts of ionizing radiation during the first post-transplant year, most during scheduled catheterization. As survival improves, considering the long-term risks associated with these levels of exposure is important.

Alicia McDonnell; Tacy E. Downing; Xiaowei Zhu; Rachel Ryan; Joseph W. Rossano; Andrew C. Glatz

2014-01-01T23:59:59.000Z

114

Polymorphisms in Apoptosis- and Proliferation-Related Genes, Ionizing Radiation Exposure, and Risk of Breast Cancer among U.S. Radiologic Technologists  

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...radiation and breast cancer dose-response relationship...controls and quantified radiation breast doses in the low-to-moderate range. (Cancer Epidemiol Biomarkers...Breast Cancer|SNPs|Ionizing radiation|Interaction|Radiobiological...

Alice J. Sigurdson; Parveen Bhatti; Michele M. Doody; Michael Hauptmann; Laura Bowen; Steven L. Simon; Robert M. Weinstock; Martha S. Linet; Marvin Rosenstein; Marilyn Stovall; Bruce H. Alexander; Dale L. Preston; Jeffrey P. Struewing; and Preetha Rajaraman

2007-10-01T23:59:59.000Z

115

Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation  

Science Journals Connector (OSTI)

While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7mGy/h) and low (3.95mGy/h) dose rate for the total dose of 0.2 and 2Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4+ T, CD8+ T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1?, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-?. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of nave T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose ?-radiation, which may be associated with the functional benefits observed in various experimental models.

Suk Chul Shin; Kyung-Mi Lee; Yu Mi Kang; Kwanghee Kim; Cha Soon Kim; Kwang Hee Yang; Young-Woo Jin; Chong Soon Kim; Hee Sun Kim

2010-01-01T23:59:59.000Z

116

Whole Genome Analysis of Functional Protein Binding Sites and DNA Methylation: Application to p53 and Low Dose Ionizing Radiation.  

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

Whole Genome Analysis of Functional Protein Binding Sites and DNA Methylation: Whole Genome Analysis of Functional Protein Binding Sites and DNA Methylation: Application to p53 and Low Dose Ionizing Radiation. Krassimira Botcheva, John J. Dunn and Carl W. Anderson Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA The effects of exposure to low doses of ionizing radiation on humans results largely from changes in gene expression mediated by the activation of sequence-specific DNA binding proteins (transcription factors) as well as changes to other chromosomal proteins and perhaps to DNA. To develop a molecular understanding of the consequences of exposures to low doses of ionizing radiation, it will be necessary to understanding where radiation-activated transcription factors bind in whole genomes and how

117

Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on Spore Core Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification  

Science Journals Connector (OSTI)

...Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on...Institute of Aerospace Medicine, Radiation Biology Department, Cologne...Radiological Sciences, Chiba-shi, Japan c University of Florida, Proton...different types of ionizing radiation including X rays, protons...

Ralf Moeller; Marina Raguse; Gnther Reitz; Ryuichi Okayasu; Zuofeng Li; Stuart Klein; Peter Setlow; Wayne L. Nicholson

2013-10-11T23:59:59.000Z

118

Ionizing Radiation Causes a Dose-Dependent Release of Transforming Growth Factor ? In vitro from Irradiated Xenografts and during Palliative Treatment of Hormone-Refractory Prostate Carcinoma  

Science Journals Connector (OSTI)

...Preclinical Pharmacology Ionizing Radiation Causes a Dose-Dependent Release of...linear function of the radiation dose over the range 0-10 Gy with r2 0...20: 91-5, 2000. Ionizing radiation causes a dose-dependent release of...

Michael Hagan; Adly Yacoub; and Paul Dent

2004-09-01T23:59:59.000Z

119

Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on Spore Core Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification  

Science Journals Connector (OSTI)

...samples for radiation exposure has...different types of ionizing radiation: X rays...mum, and a range of 301 mm in...mum, and a range of 99 mm in...dosimetry, and dose calculations...the dose of ionizing radiation killing 90...

Ralf Moeller; Marina Raguse; Gnther Reitz; Ryuichi Okayasu; Zuofeng Li; Stuart Klein; Peter Setlow; Wayne L. Nicholson

2013-10-11T23:59:59.000Z

120

Abstract #2302: NVP-BEZ235 a dual inhibitor of phosphatidylinositol 3-Kinase (PI3 Kinase) and mammalian target of rapamycin (mTOR) potently enhances the effects of ionizing radiation.  

Science Journals Connector (OSTI)

...ionizing radiation. Benjamin...effects of ionizing radiation in vitro...BEZ235 at doses of 50 nM...radiation dose range from 0-8...NVP-BEZ235 doses of 1microM...damage after radiation.-H2AX...effect of ionizing radiation in a range of epithelial...

Benjamin Solomon; Anthony Natoli; Jim Hagekyriakou; Carleen Cullinane; and Grant McArthur

2009-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Theory of Multiphoton Multielectron Ionization of Xenon under Strong 93-eV Radiation  

Science Journals Connector (OSTI)

We present a theoretical interpretation of recent experimental results on multiphoton multiple ionization of xenon by soft-x-ray radiation of photon energy ?93??eV and intensity up to 1016??W/cm2 [A.?A Sorokin et al., Phys. Rev. Lett. 99, 213002 (2007)]. The data are interpreted within multiphoton perturbation theory, taking into account the spatiotemporal distribution of the radiation. Multiphoton cross sections have been obtained through a technique of scaling, with occasional adjustment to the data, provided the two prove to be compatible. Whatever discrepancies between theory and experiment persist can be reasonably attributed to some uncertainty in the experimental conditions and possibly to the value of some cross sections, without, however, any evidence for nonperturbative behavior.

M. G. Makris; P. Lambropoulos; A. Miheli?

2009-01-21T23:59:59.000Z

122

Electron density and temperature measurement by continuum radiation emitted from weakly ionized atmospheric pressure plasmas  

SciTech Connect (OSTI)

The electron-atom neutral bremsstrahlung continuum radiation emitted from weakly ionized plasmas is investigated for electron density and temperature diagnostics. The continuum spectrum in 4501000?nm emitted from the argon atmospheric pressure plasma is found to be in excellent agreement with the neutral bremsstrahlung formula with the electron-atom momentum transfer cross-section given by Popovi?. In 280450?nm, however, a large discrepancy between the measured and the neutral bremsstrahlung emissivities is observed. We find that without accounting for the radiative H{sub 2} dissociation continuum, the temperature, and density measurements would be largely wrong, so that it should be taken into account for accurate measurement.

Park, Sanghoo; Choe, Wonho, E-mail: wchoe@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Youn Moon, Se [High-enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 561-756 (Korea, Republic of); Park, Jaeyoung [5771 La Jolla Corona Drive, La Jolla, CA 92037 (United States)

2014-02-24T23:59:59.000Z

123

Activation of mitogen-activated protein kinase pathway by extremely low-dose ionizing radiation  

Science Journals Connector (OSTI)

X-ray irradiation at very low doses, between 2 and 5 cGy, stimulated activity of a member of the mitogen-activated protein (MAP) kinase, the extracellular signal-regulated kinase (ERK) 1/2 in normal human diploid cells. Higher doses of irradiation at more than 1 Gy induced phosphorylation of ERK1/2 and accumulated p53 protein. Phosphorylation of ERK1/2 decreased with doses down to 50 cGy, however, doses of between 2 and 5 cGy phosphorylated ERK1/2 as efficiently as higher doses of X-rays, while the p53 protein level was no longer changed by doses below 50 cGy. Ataxia telangiectasia-mutated (ATM)-dependent phosphorylation of p53 protein at Ser15 and histone H2AX at Ser139 was only observed at higher doses of more than 10 cGy of X-rays. We found that the MEK1 inhibitor, PD98059, and the specific epidermal growth factor receptor tyrosine kinase inhibitor, AG1478, decreased phosphorylation of the ERK1/2 proteins induced by 2 cGy or 6 Gy of X-rays. These results indicate that a limited range of low-dose ionizing radiation differentially activates ERK1/2 kinases via activation of the epidermal growth factor receptor and MAP kinaseERK kinase, which mediates various effects of cells receiving very low doses of ionizing radiation.

Keiji Suzuki; Seiji Kodama; Masami Watanabe

2003-01-01T23:59:59.000Z

124

Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe  

DOE Patents [OSTI]

An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

1996-10-22T23:59:59.000Z

125

Ionizing Radiation Damage to the Folded Chromosome of Escherichia coli K-12: Repair of Double-Strand Breaks in Deoxyribonucleic Acid  

Science Journals Connector (OSTI)

...cell survival Dose (krad) % Recovery...it is in the range of sedimentation...that direct, radiation-induced cross-linking...during repair of ionizing radiation damage (3...is within the range ofsedimentation...biologically significant dose range. Unfortu...

Kevin M. Ulmer; Reinaldo F. Gomez; Anthony J. Sinskey

1979-05-01T23:59:59.000Z

126

Ionizing radiation damage to the folded chromosome of Escherichia coli K-12: sedimentation properties of irradiated nucleoids and chromosomal deoxyribonucleic acid.  

Science Journals Connector (OSTI)

...double-strand breaks by ionizing radiation listed in Table 2 were calculated...4, 5). For this reason, doses of ionizing radiation in excess of 10 krads were used...the biologically significant dose range of less than 10 krads suggested...

K M Ulmer; R F Gomez; A J Sinskey

1979-05-01T23:59:59.000Z

127

Enhancement of Antitumor Activity of Ionizing Radiation by Combined Treatment with the Selective Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor ZD1839 (Iressa)  

Science Journals Connector (OSTI)

...Table 1 Effect of ionizing radiation or of ZD1839 treatment on the...were calculated by performing dose-response experiments. Cancer cells were exposed to different doses of ionizing radiation (range, 10-250 cGy) or to different...

Cataldo Bianco; Giampaolo Tortora; Roberto Bianco; Roberta Caputo; Bianca Maria Veneziani; Rosa Caputo; Vincenzo Damiano; Teresa Troiani; Gabriella Fontanini; David Raben; Stefano Pepe; A. Raffaele Bianco; and Fortunato Ciardiello

2002-10-01T23:59:59.000Z

128

TWO-DIMENSIONAL RADIATIVE MAGNETOHYDRODYNAMIC SIMULATIONS OF THE IMPORTANCE OF PARTIAL IONIZATION IN THE CHROMOSPHERE  

SciTech Connect (OSTI)

The bulk of the solar chromosphere is weakly ionized and interactions between ionized particles and neutral particles likely have significant consequences for the thermodynamics of the chromospheric plasma. We investigate the importance of introducing neutral particles into the MHD equations using numerical 2.5D radiative MHD simulations obtained with the Bifrost code. The models span the solar atmosphere from the upper layers of the convection zone to the low corona, and solve the full MHD equations with non-gray and non-LTE radiative transfer, and thermal conduction along the magnetic field. The effects of partial ionization are implemented using the generalized Ohm's law, i.e., we consider the effects of the Hall term and ambipolar diffusion in the induction equation. The approximations required in going from three fluids to the generalized Ohm's law are tested in our simulations. The Ohmic diffusion, Hall term, and ambipolar diffusion show strong variations in the chromosphere. These strong variations of the various magnetic diffusivities are absent or significantly underestimated when, as has been common for these types of studies, using the semi-empirical VAL-C model as a basis for estimates. In addition, we find that differences in estimating the magnitude of ambipolar diffusion arise depending on which method is used to calculate the ion-neutral collision frequency. These differences cause uncertainties in the different magnetic diffusivity terms. In the chromosphere, we find that the ambipolar diffusion is of the same order of magnitude or even larger than the numerical diffusion used to stabilize our code. As a consequence, ambipolar diffusion produces a strong impact on the modeled atmosphere. Perhaps more importantly, it suggests that at least in the chromospheric domain, self-consistent simulations of the solar atmosphere driven by magnetoconvection can accurately describe the impact of the dominant form of resistivity, i.e., ambipolar diffusion. This suggests that such simulations may be more realistic in their approach to the lower solar atmosphere (which directly drives the coronal volume) than previously assumed.

Martinez-Sykora, Juan; De Pontieu, Bart; Hansteen, Viggo, E-mail: j.m.sykora@astro.uio.no [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States)

2012-07-10T23:59:59.000Z

129

Nitric Acid Deposition following an Astrophysical Ionizing Radiation Event is below Critical Loads for Terrestrial and Freshwater Ecosystems  

E-Print Network [OSTI]

Nitric acid rainout is one of the effects of an astrophysical ionizing radiation event. The predicted values of nitrate rainout from previous work for a typical gamma ray burst (GRB) within our galaxy serve as an extreme example and are shown to be below critical loads of eutrophication and acidification for ecoregions in Europe and the US.

Melott, Ben Neuenswander Adrian

2014-01-01T23:59:59.000Z

130

Excitational energy transfer enhancing ionization and spatial-temporal evolution of air breakdown with UV laser radiation  

E-Print Network [OSTI]

with UV laser radiation Jason S. Hummelta and John E. Scharer Department of Electrical and Computer of oxygen has on the ionization of nitrogen in laser air breakdown. Plasma is created by focusing a 193 nm ArF excimer laser using an 18 cm focal length lens, producing a cylindrical 540 m wide spot

Scharer, John E.

131

New Limits to the IR Background: Bounds on Radiative Neutrino Decay and on VMO Contributions to the Dark Matter Problem  

E-Print Network [OSTI]

From considering the effect of gamma-gamma interactions on recently observed TeV gamma-ray spectra, improved limits are set to the density of extragalactic infrared (IR) photons which are robust and essentially model-independent. The resulting limits are up to two orders of magnitude more restrictive than direct observations in the 0.025-0.3eV regime. These limits are used to improve constraints on radiative neutrino decay in the mass range above 0.05eV and on Very Massive Objects (VMOs) as providing the dark matter needed to explain galaxy rotation curves.

S. D. Biller; J. Buckley; A. Burdett; J. Bussons Gordo; D. A. Carter-Lewis; D. J. Fegan; J. Findley; J. A. Gaidos; A. M. Hillas; F. Krennrich; R. C. Lamb; R. Lessard; J. E. McEnery; G. Mohanty; J. Quinn; A. J. Rodgers; H. J. Rose; F. Samuelson; G. Sembroski; P. Skelton; T. C. Weekes; J; Zweerink

1998-02-18T23:59:59.000Z

132

PARP-1, PARP-2, and the cellular response to low doses of ionizing radiation  

Science Journals Connector (OSTI)

Purpose Poly(ADP-ribose) polymerase-1 (PARP-1) is rapidly and directly activated by single-strand breaks and is required for efficient base excision repair. These properties indicate that inhibition of PARP-1 might enhance the cellular response to low doses of radiation. We tested the effect of chemical inhibition of PARP-1 on low-dose clonogenic survival in a number of cell lines and the low-dose radiation response of a PARP-1 knockout murine cell line. Methods and materials Clonogenic cell survival of V79-379A and CHO-K1 hamster fibroblasts, T98G and U373-MG human glioma cells, and 3T3 mouse embryo fibroblast PARP-1 knockout cells was measured using a precise flow cytometry-based plating assay. Chemical inhibitors of PARP enzymes were tested for their effect on clonogenic survival after a range of ionizing radiation doses. Results Chemical inhibition of PARP activity induced marked radiosensitization of V79, CHO, and exponentially growing T98G cells in the 0.050.3-Gy range. This effect was not seen in U373 cells or in confluent T98G populations. Low-dose radiosensitization was not apparent in PARP-1 knockout cells. Conclusion Low-dose radiosensitization of actively dividing tumor cells by PARP-1 inhibitors suggests that they may have a role in enhancing the efficacy of ultrafractionated or low-dose-rate radiotherapy regimens. We hypothesize that PARP-2 compensates for the absence of PARP-1 in the knockout cell line.

Anthony Chalmers; Peter Johnston; Mick Woodcock; Michael Joiner; Brian Marples

2004-01-01T23:59:59.000Z

133

Extensive Diversity of Ionizing-Radiation-Resistant Bacteria Recovered from Sonoran Desert Soil and Description of Nine New Species of the Genus Deinococcus Obtained from a Single Soil Sample  

Science Journals Connector (OSTI)

...ionizing radiation on Earth...the acute doses to which...damage of ionizing radiation but rather...from a wide range of environments...showing the range of morphological...to various doses of gamma ionizing radiation Dose (kGy...

Fred A. Rainey; Keren Ray; Margarida Ferreira; Bridget Z. Gatz; M. Fernanda Nobre; Danielle Bagaley; Brian A. Rash; Mie-Jung Park; Ashlee M. Earl; Nicole C. Shank; Alanna M. Small; Margaret C. Henk; John R. Battista; Peter Kmpfer; Milton S. da Costa

2005-09-01T23:59:59.000Z

134

Polyamide woven fabrics with 2,3,5-triphenyltetrazolium chloride or nitro blue tetrazolium chloride as 2D ionizing radiation dosimeters  

Science Journals Connector (OSTI)

The development of flat woven fabric-based ionizing radiation 2D dosimeters is reported in this work. Polyamide fabric was surface modified with radiation-sensitive 2,3,5-triphenyltetrazolium chloride (TTC) or nitro blue tetrazolium chloride (NBT). These samples responded to gamma radiation of 60Co through a colour change: red and blue for TTC and NBT, respectively. The tinge intensity was observed to depend on the absorbed dose, which allowed for the reflectance of light (R) measurements and calculation of the calibration parameters: dose range, quasi-linear range, threshold dose and sensitivity. Oxygen was shown to be an important factor determining the dose response of the samples. For this reason, a range of additional modifications to the TTC- and NBT-polyamide fabric was proposed which lead to a decrease in the threshold dose and increase in the sensitivity to irradiation of the samples. For instance, a dosimeter made of polyamide fabric modified with 10g/dm3 TTC, 0.5mol/dm3 tert-butyl alcohol, 7.5% gelatine hydrogel at pH 10 (vacuum packed) showed the lowest dose threshold (50Gy), dose range up to 2.8kGy and the highest sensitivity to irradiation (?0.0396%/Gy) among the compositions studied. In consequence, this dosimeter was examined in terms of response to inhomogeneous irradiation from a 192Ir brachytherapy radiation source. The relative dose distribution profiles across the source's longitudinal axis were calculated. This showed potential of the textile dosimeters for 2D dose distribution measurements; however, further modifications towards improvement of the dosimeter's low dose response can be considered.

M. Kozicki; E. S?siadek

2012-01-01T23:59:59.000Z

135

Properties of transition metal-doped zinc chalcogenide crystals for tunable IR laser radiation  

SciTech Connect (OSTI)

The spectroscopic properties of Cr{sup 2+}, Co{sup 2+}, and Ni{sup 2+}-doped single crystals of ZnS, ZnSe, and ZnTe have been investigated to understand their potential application as mid-IR tunable solid-state laser media. The spectroscopy indicated divalent Cr was the most favorable candidate for efficient room temperature lasing, and accordingly, a laser-pumped laser demonstration of Cr:ZnS and Cr:ZnSe has been performed. The lasers` output were peaked at {approximately} 2.35 {mu}m and the highest measured slope efficiencies were {approximately} 20% in both cases.

DeLoach, L.D.; Page, R.H.; Wilke, G.D. [and others

1995-03-17T23:59:59.000Z

136

European Integrated Project RISC-RAD Radiosensitivity of Individuals and Susceptibility to Cancer induced by Ionizing Radiations  

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

Integrated Project RISC-RAD Integrated Project RISC-RAD Radiosensitivity of Individuals and Susceptibility to Cancer induced by Ionizing Radiations Laure Sabatier 1 , L.H.F Mullenders 2 , Mike Atkinson 3 , Simon Bouffler 4 , Herwig Paretzke 5 1 Laboratory of Radiobiology and Oncology, CEA, 18 route du panorama BP6 92265 Fontenay-aux- Roses, France 2 LUMC, Department of Toxicogenetics, Postal Zone S-4-P, P.O. Box 9600, 2300 RC Leiden, The Netherlands 3 GSF- Institute of Pathology, Ingolstädter Landstrasse 1, 85764 Neuherberg Germany 4 HPA Radiation Protection Division, Centre for Radiation Chemical and Environmental Hazards, Chilton, UK 5 GSF- Institute of Radiation Protection, Ingolstädter Landstrasse 1, Neuherberg, D-85764 Germany In radiological protection, the risks of inducing stochastic health effects (largely cancer) by a

137

Measurements of forbidden line radiation of Ar II (6. 99. mu. m) in W3 IRS 1  

SciTech Connect (OSTI)

Observations of the (Ar II) (6.99 ..mu..m) line flux in W3 IRS 1 are combined with previously obtained measurements of the (Ar III) (8.99 ..mu..m) line flux. The observed ratio of (Ar II)/(Ar III) is inconsistent with the calculated ratio for an H II region with the densities required by radio observations and with a central 40,000--45,000 K star with atmosphere as described by a Mihalas model. A solar effective UV radiation field is required; a dusty model we had previously invoked fits the observations. In addition we determine that the argon abundance is n(Ar)/n(H)roughly-equal8 x 10/sup -6/, a value about twice that usually adopted for normal solar abundance; however, there are uncertainties in the extinction and the model which do not allow us to preclude solar abundance.

Herter, T.; Pipher, J.L.; Helfer, H.L.; Willner, S.P.; Puetter, R.C.; Rudy, R.J.; Soifer, B.T.

1981-03-01T23:59:59.000Z

138

Molecular stress response in the CNS of mice after systemic exposureto interferon-alpha, ionizing radiation and ketamine  

SciTech Connect (OSTI)

We previously showed that the expression of troponin T1 (Tnnt 1) was induced in the central nervous system (CNS) of adultmice 30 min after treatment with ketamine, a glutamate N-methyl-D-aspartic acid (NMDA) receptor antagonist. We hypothesized that Tnnt 1 expression may be an early molecular biomarker of stress response in the CNS of mice. To further evaluate this hypothesis, we investigated the regional expression of Tnnt 1 in the mouse brain using RNA in situ hybridization 4 h after systemic exposure to interferon-a (IFN-a) and gamma ionizing radiation, both of which have be associated with wide ranges of neuropsychiatric complications. Adult B6C3F1 male mice were treated with either human IFN-a (a single i.p. injection at 1 x 105 IU/kg) or whole body gamma-radiation (10 cGy or 2 Gy). Patterns of Tnnt 1 transcript expression were compared in various CNS regions after IFN-a, radiation and ketamine treatments (previous study). Tnnt 1 expression was consistently induced in pyramidal neurons of cerebral cortex and hippocampus after all treatment regimens including 10 cGy of ionizing radiation. Regional expression of Tnnt 1 was induced in Purkinje cells of cerebellum after ionizing radiation and ketamine treatment; but not after IFN-a treatment. None of the three treatments induced Tnnt 1 expression in glial cells. The patterns of Tnnt 1 expression in pyramidal neurons of cerebral cortex andhippocampus, which are both known to play important roles in cognitive function, memory and emotion, suggest that the expression of Tnnt 1 may be an early molecular biomarker of induced CNS stress.

Lowe, Xiu R.; Marchetti, Francesco; Lu, Xiaochen; Wyrobek, Andrew J.

2009-03-03T23:59:59.000Z

139

High-pressure phase transition and behavior of protons in brucite Mg(OH)2: a high-pressuretemperature study using IR synchrotron radiation  

Science Journals Connector (OSTI)

?Infrared absorption spectra of brucite Mg (OH)2...were measured under high pressure and high temperature from 0.1?MPa 25?C to 16?GPa 360?C using infrared synchrotron radiation at BL43IR of Spring-8 and a high-...

K. Shinoda; M. Yamakata; T. Nanba; H. Kimura

2002-07-01T23:59:59.000Z

140

Ionizing-Radiation Resistance in the Desiccation-Tolerant CyanobacteriumChroococcidiopsis  

Science Journals Connector (OSTI)

...differences between radiation-resistant and radiation-susceptible microorganisms...after exposure to high doses of X rays ranging...cultures used for radiation experiments were 3-month-old...Goleta, Calif.). Estimation of survival. To determine...

Daniela Billi; E. Imre Friedmann; Kurt G. Hofer; Maria Grilli Caiola; Roseli Ocampo-Friedmann

2000-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Low Dose IR Creates an Oncogenic Microenvironment by Inducing Premature  

SciTech Connect (OSTI)

Introduction Much of the work addressing ionizing radiation-induced cellular response has been carried out mainly with the traditional cell culture technique involving only one cell type, how cellular response to IR is influenced by the tissue microenvironment remains elusive. By use of a three-dimensional (3D) co-culture system to model critical interactions of different cell types with their neighbors and with their environment, we recently showed that low-dose IR-induced extracellular signaling via the tissue environment affects profoundly cellular responses. This proposal aims at determining the response of mammary epithelial cells in a tissue-like setting.

Yuan, Zhi-Min [Harvard School of Public Health

2013-04-28T23:59:59.000Z

142

Effects of Mn and Fe Levels on Bacillus subtilis Spore Resistance and Effects of Mn2+, Other Divalent Cations, Orthophosphate, and Dipicolinic Acid on Protein Resistance to Ionizing Radiation  

Science Journals Connector (OSTI)

...exposed to ionizing radiation in vitro display...response to dose, with increasing...doses of gamma radiation increase...within a narrow range of Mn concentrations...from gamma ray doses (15 kGy...resistance to ionizing radiation, desiccation...

Amanda C. Granger; Elena K. Gaidamakova; Vera Y. Matrosova; Michael J. Daly; Peter Setlow

2010-11-05T23:59:59.000Z

143

Polymorphisms in DNA Repair Genes, Medical Exposure to Ionizing Radiation, and Breast Cancer Risk  

Science Journals Connector (OSTI)

...Session Abstracts Treatment Radiation Therapy CTRC-AACR San...breast-conserving therapy in Japan: comparison of the treatment...Mitsumori 1 1 Department of Radiation Oncology and Image-Applied...Kyoto University, Kyoto, Japan 2 Department of Radiology...

Robert C. Millikan; Jon S. Player; Allan Rene deCotret; Chiu-Kit Tse; and Temitope Keku

2005-10-01T23:59:59.000Z

144

End group characterization in DNA of thymocytes after low doses of ionizing radiation  

Science Journals Connector (OSTI)

Investigations into the configuration of the radiation induced strand breaks in the low dose range are presented. DNA sections containing the radiation induced strand breaks were separated from the undamaged s...

Th. Coquerelle; C. Sexauer

1977-01-01T23:59:59.000Z

145

Zebrafish as a Biosensor? Effects of Ionizing Radiation and Amifostine on Embryonic Viability and Development  

Science Journals Connector (OSTI)

...Environmental Health and Radiation Safety at the University...LabSpectrum v2.0.1 software (Scanalytics...and exposed to radiation at 4 hpf. Immediately...minutes before radiation exposure. For...Molecular Imaging Software, version 4.0...

Geoffrey A. Geiger; Sharon E. Parker; Andrew P. Beothy; Jennifer A. Tucker; Mary C. Mullins; and Gary D. Kao

2006-08-15T23:59:59.000Z

146

Discovering Clinical Biomarkers of Ionizing Radiation Exposure with Serum Proteomic Analysis  

Science Journals Connector (OSTI)

...radiation treatment plans provided serum...long-established gold standard biomarker of radiation...Institutional Review Board-approved...using visual data mining techniques showed...exposure, gold standard lymphocyte assays...through visual data mining activities that...radiation treatment plans provided serum...

Cynthia Mnard; Donald Johann; Mark Lowenthal; Thierry Muanza; Mary Sproull; Sally Ross; James Gulley; Emanuel Petricoin; C. Norman Coleman; Gordon Whiteley; Lance Liotta; and Kevin Camphausen

2006-02-01T23:59:59.000Z

147

Cancer risk at low doses of ionizing radiation: artificial neural networks inference from atomic bomb survivors  

Science Journals Connector (OSTI)

......with low linear energy transfer (LET...Obviously, the challenge of understanding...but the stable integration of viral DNA...activation should be sustainable for a long period...SA. Directed integration of viral DNA...adeno-associated virus DNA integration. Proc Natl...high linear energy transfer ionizing......

Masao S. Sasaki; Akira Tachibana; Shunichi Takeda

2014-05-01T23:59:59.000Z

148

Phase II study of radiation therapy combined with weekly nedaplatin in locally advanced uterine cervical carcinoma: Kitasato Gynecologic Radiation Oncology Group (KGROG 0501) - an initial analysis  

Science Journals Connector (OSTI)

...of Medicine, Chiba, Japan, The University of...induced by ionizing radiation (IR) and can be repaired...of the character and radiation survival ratio of cancer...Hemagglutinating Virus of Japan envelope vector (HVJ-E...clonogenic assay to evaluate radiation sensitivity. Furthermore...

Yuzuru Niibe; Shimpei Tsunoda; Toshiko Jobo; Yukihiro Hamada; and Kazushige Hayakawa

2007-05-01T23:59:59.000Z

149

Specific gene expression by extremely low-dose ionizing radiation which related to enhance proliferation of normal human diploid cells  

Science Journals Connector (OSTI)

We demonstrated that X-ray irradiation at low doses of between 2 and 5 cGy stimulated proliferation of a normal human diploid. At low doses of between 2 and 5 cGy, ERK1/2 was phosphorylated as efficiently as at higher doses between 50 and 100 cGy of X-rays, while the p53 protein level was not increased by doses below 50 cGy. On the other hand, the p53 protein was efficiently accumulated at higher doses of X-ray more than 100 cGy. ERK1/2 was phosphorylated by doses over 50 cGy with increasing doses. We found that activated ERK1/2 augmented phosphorylation of the Elk-1 protein. Furthermore, over expression of ERK2 in NCI-H1299, and human lung carcinoma cells, potentiated enhanced proliferation, while down-regulation of ERK2 using the anti-sense ERK2 gene abrogated the stimulative effect of low-dose irradiation. These results indicate that a limited range of low-dose ionizing radiation differentially activate ERK1/2 kinases, which causes enhanced proliferation of cells receiving very low doses of ionizing radiation.

Masami Watanabe; Keiji Suzuki; Seiji Kodama

2002-01-01T23:59:59.000Z

150

E-Print Network 3.0 - attenuates ionizing radiation-induced Sample...  

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

silica optical Summary: measurements and the so-called radiation-induced attenuation (RIA) measured in dBm. TSL measurements have been... measurements. Connections between...

151

The effect of thymosin on the survival of CBA/J mice exposed to lethal and acute doses of ionizing radiation  

E-Print Network [OSTI]

THE EFFECT OF THYMOSIN ON THE SURVIVAL OF CBA/J MICE EXPOSED TO LETHAL AND ACUTE DOSES OF IONIZING RADIATION A Thesis ROGER LYNN HUCHTON Submitted to the Graduate College of Texas A&M Unrversrty in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1978 Major Subject: Biophysrcs THE EFFECT OF THYMQSIN ON THE SURVIVAL OF CBA/J MICE EXPOSED TO LETHAL AND ACUTE DOSES OF IONIZING RADIATION A Thesis by ROGER LYNN HUCHTQN Approved as to style and content by...

Huchton, Roger Lynn

1978-01-01T23:59:59.000Z

152

ON THE DETECTION OF IONIZING RADIATION ARISING FROM STAR-FORMING GALAXIES AT REDSHIFT z {approx} 3-4: LOOKING FOR ANALOGS OF 'STELLAR RE-IONIZERS'  

SciTech Connect (OSTI)

We use the spatially resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z {approx} 3.7 identified using ultradeep imaging below the Lyman limit (1{sigma} limit of Almost-Equal-To 30 AB in a 2'' diameter aperture). In 19 candidates out of a sample of 20 with flux detected at >3{sigma} level, the light centroid of the candidate LyC emission is offset from that of the Lyman break galaxy (LBG) by up to 1.''5. We fit the spectral energy distribution of the LyC candidates to spectral population synthesis models to measure photometric redshifts and the stellar population parameters. We also discuss the differences in the UV colors between the LBG and the LyC candidates, and how to estimate the escape fraction of ionizing radiation (f{sub esc}) in cases, like in most of our galaxies, where the LyC emission is spatially offset from the host galaxy. In all but one case we conclude that the candidate LyC emission is most likely due to lower redshift interlopers. Based on these findings, we argue that the majority of similar measurements reported in the literature need further investigation before it can be firmly concluded that LyC emission is detected. Our only surviving LyC candidate is an LBG at z = 3.795, which shows the bluest (B - V) color among LBGs at similar redshift, a stellar mass of M {approx} 2 Multiplication-Sign 10{sup 9} M{sub Sun }, weak interstellar absorption lines, and a flat UV spectral slope with no Ly{alpha} in emission. We estimate its f{sub esc} to be in the range 25%-100%, depending on the dust and intergalactic attenuation.

Vanzella, Eros; Cristiani, Stefano; Nonino, Mario [INAF Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, 34131 Trieste (Italy); Guo Yicheng; Giavalisco, Mauro [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Grazian, Andrea; Castellano, Marco; Fontana, Adriano; Giallongo, Emanuele; Pentericci, Laura; Galametz, Audrey [INAF Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio (RM) (Italy); Dickinson, Mark [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States); Faber, S. M. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Ferguson, Henry C.; Grogin, Norman A.; Koekemoer, Anton M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Newman, Jeffrey [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Siana, Brian D., E-mail: vanzella@oats.inaf.it [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)

2012-05-20T23:59:59.000Z

153

HIV-1 Tat depresses DNA-PK{sub CS} expression and DNA repair, and sensitizes cells to ionizing radiation  

SciTech Connect (OSTI)

Purpose There is accumulating evidence that cancer patients with human immmunodeficiency virus-1/acquired immunodeficency syndrome (HIV-1/AIDS) have more severe tissue reactions and often develop cutaneous toxic effects when subjected to radiotherapy. Here we explored the effects of the HIV-1 Tat protein on cellular responses to ionizing radiation. Methods and Materials Two Tat-expressing cell lines, TT2 and TE671-Tat, were derived from human rhabdomyosarcoma cells by transfecting with the HIV-1 tat gene. Radiosensitivity was determined using colony-forming ability. Gene expression was assessed by cDNA microarray and immunohybridization. The Comet assay and {gamma}-H2AX foci were use to detect DNA double-strand breaks (DSBs) and repair. Radiation-induced cell cycle changes were detected by flow cytometry. Results The radiosensitivity of TT2 and TE671-Tat cells was significantly increased as compared with parental TE671 cells or the control TE671-pCI cells. Tat also increased proliferation activity. The comet assay and {gamma}H2AX foci detection revealed a decreased capacity to repair radiation-induced DNA DSBs in Tat-expressing cells. Microarray assay demonstrated that the DNA repair gene DNA-PKcs, and cell cycle-related genes Cdc20, Cdc25C, KIF2C and CTS1 were downregulated in Tat-expressing cells. Depression of DNA-PKcs in Tat-expressing cells was further confirmed by RT-PCR and immuno-hybridization analysis. Tat-expressing cells exhibited a prolonged S phase arrest after 4 Gy {gamma}-irradiation, and a noticeable delay in the initiation and elimination of radiation-induced G{sub 2}/M arrest as compared with parental cells. In addition, the G{sub 2}/M arrest was incomplete in TT2 cells. Moreover, HIV-1 Tat resulted in a constitutive overexpression of cyclin B1 protein. Conclusion HIV-1 Tat protein sensitizes cells to ionizing radiation via depressing DNA repair and dysregulating cell cycle checkpoints. These observations provide new insight into the increased tissue reactions of AIDS cancer patients to radiotherapy.

Sun Yi [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China); Huang Yuechen [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China); Xu Qinzhi [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China); Wang Huiping [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China); Bai Bei [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China); Sui Jianli [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China); Zhou Pingkun [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Beijing (China)]. E-mail: zhoupk@nic.bmi.ac.cn

2006-07-01T23:59:59.000Z

154

The effects of emitter-tied field plates on lateral PNP ionizing radiation response  

SciTech Connect (OSTI)

Radiation response comparisons of lateral PNP bipolar technologies reveal that device hardening may be achieved by extending the emitter contact over the active base. The emitter-tied field plate suppresses recombination of carriers with interface traps.

Barnaby, H.J.; Schrimpf, R.D.; Cirba, C.R. [Vanderbilt Univ., Nashville, TN (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L. [VTC Inc., Bloomington, MN (United States)

1998-03-01T23:59:59.000Z

155

A DSM-based 2.0 System for Human Intervention Planning and Scheduling in Facilities Emitting Ionizing Radiations  

E-Print Network [OSTI]

To efficiently and safely plan, schedule and control its interventions in underground facilities, which are subject to ionizing radiations, CERN is currently developing a collaborative Web-based system. A similar project for maintenance management is also under way. On top of presenting their key requirements, this paper shows how the implementation of DSM can enhance a so-called Web 2.0 or collaborative dimension by bringing an intuitive and fair way of taking the dependencies between several activities into account. It is also discussed that the incoherencies brought in DSM by collaborative use (for instance regarding the time intervals) can be addressed by enlarging the binary DSM span of dependencies to ones of the Allens interval algebra or at least a subset of its dependencies.

Baudin, M; De Jonghe, J

2012-01-01T23:59:59.000Z

156

Ionization chamber  

DOE Patents [OSTI]

An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

Walenta, Albert H. (Port Jefferson Station, NY)

1981-01-01T23:59:59.000Z

157

Nuclear and Non-Ionizing Energy-Loss for Coulomb Scattered Particles from Low Energy up to Relativistic Regime in Space Radiation Environment  

E-Print Network [OSTI]

In the space environment, instruments onboard of spacecrafts can be affected by displacement damage due to radiation. The differential scattering cross section for screened nucleus--nucleus interactions - i.e., including the effects due to screened Coulomb nuclear fields -, nuclear stopping powers and non-ionization energy losses are treated from about 50\\,keV/nucleon up to relativistic energies.

Boschini, M J; Gervasi, M; Giani, S; Grandi, D; Ivantchenko, V; Pensotti, S; Rancoita, P G; Tacconi, M

2011-01-01T23:59:59.000Z

158

Low Dose Ionizing Radiation and HZE Particle Effects on Adult Hippocampal  

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

and HZE Particle Effects on Adult Hippocampal and HZE Particle Effects on Adult Hippocampal Neurogenesis and mRNA Expression Kerry O'Banion University of Rochester School of Medicine & Dentistry Abstract Most of our knowledge about low dose radiation effects relates to DNA damage and chromosomal aberrations that result in cell death or alterations in genetic programs leading to malignancy. In addition To direct DNA damage, there is accumulating evidence that radiation induced alterations in the microenvironment can have significant effects on programs of cell replication and differentiation such as neurogenesis in adult mammalian brain. Adult neurogenesis in the hippocampus is postulated to play an important role in learning and memory and manipulations that alter neurogenesis, including inhibition following radiation exposure, have been

159

EGFR Nuclear Translocation Modulates DNA Repair following Cisplatin and Ionizing Radiation Treatment  

Science Journals Connector (OSTI)

...results suggest that nuclear expression of EGFR plays...the mechanisms by which nuclear expression modulates...C2259/A9994). The costs of publication of this...DNA-PK kinase assay. The graph shows the percentage...radiation-induced EGFR nuclear import by C225 (cetuximab...

Gianmaria Liccardi; John A. Hartley; and Daniel Hochhauser

2011-02-01T23:59:59.000Z

160

A molecular dynamics simulation of DNA damage induction by ionizing radiation  

E-Print Network [OSTI]

We present a multi-scale simulation of early stage of DNA damages by the indirect action of hydroxyl ($^\\bullet$OH) free radicals generated by electrons and protons. The computational method comprises of interfacing the Geant4-DNA Monte Carlo with the ReaxFF molecular dynamics software. A clustering method was employed to map the coordinates of $^\\bullet$OH-radicals extracted from the ionization track-structures onto nano-meter simulation voxels filled with DNA and water molecules. The molecular dynamics simulation provides the time evolution and chemical reactions in individual simulation voxels as well as the energy-landscape accounted for the DNA-$^\\bullet$OH chemical reaction that is essential for the first principle enumeration of hydrogen abstractions, chemical bond breaks, and DNA-lesions induced by collection of ions in clusters less than the critical dimension which is approximately 2-3 \\AA. We show that the formation of broken bonds leads to DNA base and backbone damages that collectively propagate ...

Abolfath, Ramin M; Chen, Zhe J; Nath, Ravinder

2013-01-01T23:59:59.000Z

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161

Adaptive Response Against Spontaneous Neoplastic Transformation In Vitro Induced by Ionizing Radiation  

SciTech Connect (OSTI)

The goal of this project was to establish a dose response curve for radiation-induced neoplastic transformation of HeLa x skin fibroblast human hybrid cells in vitro under experimental conditions were an adaptive response, if it were induced, would have an opportunity to be expressed. During the first two years of the grant an exhaustive series of experiments were performed and the resulting data were reported at the 2000 Annual Meeting of the Radiation Research Society and then Subsequently published. The data showed that an adaptive response against spontaneous neoplastic transformation was seen up to doses of 10cGy of Cs-137 gamma rays. At dose of 30, 50 and 100 cGy the transformation frequencies were above background. This indicated that for this system, under the specific experimental conditions used, there was a threshold of somewhere between 10 and 30 cGy. The results also indicated some unexpected, though very interesting, correlations with relative risk estimates made from human epidemiologic studies.

J. Leslie Redpath, Ph.D.

2003-11-10T23:59:59.000Z

162

Mitigation Effect of an FGF-2 Peptide on Acute Gastrointestinal Syndrome After High-Dose Ionizing Radiation  

SciTech Connect (OSTI)

Purpose: Acute gastrointestinal syndrome (AGS) resulting from ionizing radiation causes death within 7 days. Currently, no satisfactory agent exists for mitigation of AGS. A peptide derived from the receptor binding domain of fibroblast growth factor 2 (FGF-P) was synthesized and its mitigation effect on AGS was examined. Methods and Materials: A subtotal body irradiation (sub-TBI) model was created to induce gastrointestinal (GI) death while avoiding bone marrow death. After 10.5 to 16 Gy sub-TBI, mice received an intramuscular injection of FGF-P (10 mg/kg/day) or saline (0.2 ml/day) for 5 days; survival (frequency and duration) was measured. Crypt cells and their proliferation were assessed by hematoxylin, eosin, and BrdU staining. In addition, GI hemoccult score, stool formation, and plasma levels of endotoxin, insulin, amylase, interleukin (IL)-6, keratinocyte-derived chemokine (KC) monocyte chemoattractant protein 1 (MCP-1) and tumor necrosis factor (TNF)-alpha were evaluated. Results: Treatment with FGF-P rescued a significant fraction of four strains of mice (33-50%) exposed to a lethal dose of sub-TBI. Use of FGF-P improved crypt survival and repopulation and partially preserved or restored GI function. Furthermore, whereas sub-TBI increased plasma endotoxin levels and several pro-inflammation cytokines (IL-6, KC, MCP-1, and TNF-alpha), FGF-P reduced these adverse responses. Conclusions: The study data support pursuing FGF-P as a mitigator for AGS.

Zhang Lurong [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States); Sun Weimin; Wang Jianjun [Second Military Medical College, Shanghai (China); Zhang Mei; Yang Shanmin [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States); Tian Yeping [Second Military Medical College, Shanghai (China); Vidyasagar, Sadasivan [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States); Pena, Louis A. [Brookhaven National Laboratory, Medical Department, Upton, NY (United States); Zhang Kunzhong [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States); Cao Yongbing [Second Military Medical College, Shanghai (China); Yin Liangjie [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States); Wang Wei [Department of Surgery, Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian (China); Zhang Lei [Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan (China); Schaefer, Katherine L.; Saubermann, Lawrence J. [Department of Medicine, University of Rochester Medical Center, Rochester, NY (United States); Swarts, Steven G.; Fenton, Bruce M.; Keng, Peter C. [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States); Okunieff, Paul, E-mail: Paul_Okunieff@URMC.Rochester.ed [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY (United States)

2010-05-01T23:59:59.000Z

163

Reduction of Eu{sup 3+} to Eu{sup 2+} in aluminoborosilicate glasses under ionizing radiation  

SciTech Connect (OSTI)

Eu{sub 2}O{sub 3}-doped aluminoborosilicate glasses were prepared by melting in air at high temperature ({approx}1500 {sup o}C). It was shown by luminescence and Electron Paramagnetic Resonance (EPR) measurements that both Eu{sup 3+} and Eu{sup 2+} ions can exist simultaneously in the glass matrix studied after glass synthesis as well as after exposure to ionizing radiation. Increase of total Eu{sub 2}O{sub 3} concentration leads to the increase of Eu{sup 3+} luminescence intensity while the luminescence intensity of Eu{sup 2+} ions tends to decrease. In contrast the EPR indicates that the amount of Eu{sup 2+} ions in the glass increases with total Eu{sub 2}O{sub 3} concentration. The difference in the results of the two spectroscopies is explained in terms of energy transfer from Eu{sup 2+} to Eu{sup 3+} leading to an Eu{sup 2+} luminescence quenching. Irradiation results in the increase of reduced Eu{sup 2+} quantity detected by EPR measurements. It was shown that Eu{sup 2+} ions are located in both high (g {approx} 4.6) and low symmetry ('U' spectrum) sites in the structure of aluminoborosilicate glasses. The increase of Eu{sup 2+} content by the increase of the irradiation dose manifests the strong reduction process Eu{sup 3+} {yields} Eu{sup 2+}.

Malchukova, E., E-mail: genia@poly.polytechnique.fr [Laboratoire des Solides Irradies, UMR 7642 CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau Cedex (France); Boizot, B. [Laboratoire des Solides Irradies, UMR 7642 CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau Cedex (France)] [Laboratoire des Solides Irradies, UMR 7642 CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau Cedex (France)

2010-09-15T23:59:59.000Z

164

Genetic susceptibility to low-dose ionizing radiation in the mouse mammary glandas a means of understanding human risk for breast cancer  

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

susceptibility to low-dose ionizing radiation in the mouse mammary gland susceptibility to low-dose ionizing radiation in the mouse mammary gland as a means of understanding human risk for breast cancer Antoine M. Snijders 1 , Francesco Marchetti 1 , Ju Han 1 , Sandhya Bhatnagar 1 , Nadire Duru 1 , Zhi Hu 1 , Jian-Hua Mao 1 , Mina Bissell 1 , Joe Gray 1,2 , Gary H. Karpen 1 , Priscilla K. Cooper 1 and Andrew J. Wyrobek 1 1 Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 2 Current affiliation: Biomedical Engineering, Oregon Health Science Univ, Portland, OR Goal: Our goal is to develop an in vivo mechanistic model of genetic variation in the low-dose damage responses of mammary glands using inbred mice known to vary in their sensitivity to low-dose induced mammary gland cancer, and to develop molecular predictors for susceptibility or resistance to low-dose induced breast cancer.

165

Ionizing Radiation-Induced DNA Damage and Its Repair in Human Cells  

SciTech Connect (OSTI)

DNA damage in mammalian chromatin in vitro and in cultured mammalian cells including human cells was studied. In the first phase of these studies, a cell culture laboratory was established. Necessary equipment including an incubator, a sterile laminar flow hood and several centrifuges was purchased. We have successfully grown several cell lines such as murine hybridoma cells, V79 cells and human K562 leukemia cells. This was followed by the establishment of a methodology for the isolation of chromatin from cells. This was a very important step, because a routine and successful isolation of chromatin was a prerequisite for the success of the further studies in this project, the aim of which was the measurement of DNA darnage in mammalian chromatin in vitro and in cultured cells. Chromatin isolation was accomplished using a slightly modified procedure of the one described by Mee & Adelstein (1981). For identification and quantitation of DNA damage in cells, analysis of chromatin was preferred over the analysis of "naked DNA" for the following reasons: i. DNA may not be extracted efficiently from nucleoprotein in exposed cells, due to formation of DNA-protein cross-links, ii. the extractability of DNA is well known to decrease with increasing doses of radiation, iii. portions of DNA may not be extracted due to fragmentation, iv. unextracted DNA may contain a significant portion of damaged DNA bases and DNA-protein cross-links. The technique of gas chromatography/mass spectrometry (GC/MS), which was used in the present project, permits the identification and quantitation of modified DNA bases in chromatin in the presence of proteins without the necessity of first isolating DNA from chromatin. This has been demonstrated previously by the results from our laboratory and by the results obtained during the course of the present project. The quality of isolated chromatin was tested by measurement of its content of DNA, proteins, and RNA, by analysis of its protein components using gel electrophoresis, and by absorption spectral analysis. GeneraUy, the RNA content was <5% of the amount of DNA, and the ratio of the amount of protein to that of DNA was =1. 8-2 (w/w). Having developed a suitable methodology for routine isolation of chromatin from mammalian cells, studies of DNA damage in chromatin in vitro and in cultured human cells were pursued.

Dizdaroglu, Miral

1999-05-12T23:59:59.000Z

166

Induction by ionizing radiation of the gadd45 gene in cultured human cells: lack of mediation by protein kinase C.  

Science Journals Connector (OSTI)

...coordinately induced by UV radiation and alkylating agents...rapidly after X rays at doses as low as 2 Gy. After...isolation & purification radiation effects DNA Damage Dose-Response Relationship, Radiation Genes radiation effects...

M A Papathanasiou; N C Kerr; J H Robbins; O W McBride; I Alamo Jr; S F Barrett; I D Hickson; A J Fornace Jr

1991-02-01T23:59:59.000Z

167

Exposure to Ionizing Radiation and Estimate of Secondary Cancers in the Era of High-Speed CT Scanning: Projections From the Medicare Population  

Science Journals Connector (OSTI)

Purpose The aims of this study were to analyze the distribution and amount of ionizing radiation delivered by CT scans in the modern era of high-speed CT and to estimate cancer risk in the elderly, the patient group most frequently imaged using CT scanning. Methods A retrospective cohort study was conducted using Medicare claims spanning 8 years (1998-2005) to assess CT use. The data were analyzed in two 4-year cohorts, 1998 to 2001 (n = 5,267,230) and 2002 to 2005 (n = 5,555,345). The number and types of CT scans each patient received over the 4-year periods were analyzed to determine the percentage of patients exposed to threshold radiation of 50 to 100 mSv (defined as low) and >100 mSv (defined as high). The National Research Council's Biological Effects of Ionizing Radiation VII models were used to estimate the number of radiation-induced cancers. Results CT scans of the head were the most common examinations in both Medicare cohorts, but abdominal imaging delivered the greatest proportion (43% in the first cohort and 40% in the second cohort) of radiation. In the 1998 to 2001 cohort, 42% of Medicare patients underwent CT scans, with 2.2% and 0.5% receiving radiation doses in the low and high ranges, respectively. In the 2002 to 2005 cohort, 50% of Medicare patients received CT scans, with 4.2% and 1.2% receiving doses in the low and high ranges. In the two populations, 1,659 (0.03%) and 2,185 (0.04%) cancers related to ionizing radiation were estimated, respectively. Conclusions Although radiation doses have been increasing along with the increasing reliance on CT scans for diagnosis and therapy, using conservative estimates with worst-case scenario methodology, the authors found that the risk for secondary cancers is low in older adults, the group subjected to the most frequent CT scanning. Trends showing increasing use, however, underscore the importance of monitoring CT utilization and its consequences.

Aabed B. Meer; Pat A. Basu; Laurence C. Baker; Scott W. Atlas

2012-01-01T23:59:59.000Z

168

Low Dose Radiation Research Program: Computational Modeling of Biochemical  

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

Computational Modeling of Biochemical Pathways Linking Ionizing Computational Modeling of Biochemical Pathways Linking Ionizing Radiation to Cell Cycle Arrest, Apoptosis, and Tumor Incidence Authors: Yuchao Maggie Zhao and Rory Conolly Institutions: Center for Computational Systems Biology CIIT Centers for Health Research Long-Range Goal: To develop an integrated, computational framework for the prediction of low-dose-response to ionizing radiation (IR) in people. Methodology: To provide a flexible framework to evaluate mechanisms of cellular adaptive responses after exposure to IR, three progressively more complicated descriptions of biochemical pathways linking DNA damage with cell-cycle checkpoint control and apoptosis were developed. These descriptions focus on p53-dependent checkpoint arrest and apoptosis, p73-dependent apoptosis, and Chk2-dependent checkpoint arrest,

169

IR-2003-  

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

Relations Office Washington, D.C. Media Contact: 202.622.4000 Relations Office Washington, D.C. Media Contact: 202.622.4000 www.IRS.gov/newsroom Public Contact: 800.829.1040 $1 BILLION IN TAX CREDITS ALLOCATED TO CLEAN COAL PROJECTS IR-2006-184, Nov. 30, 2006 WASHINGTON - The Internal Revenue Service announced that it has allocated nearly $1 billion of tax credits to nine planned clean coal projects. The Energy Policy Act of 2005 authorized $1.65 billion in tax credits for clean coal projects. The Act allocated $800 million of credits to integrated gasification combined cycle (IGCC) projects, $500 million to non-IGCC advanced coal electricity generation projects and $350 million to gasification projects. The $800 million allocated to IGCC projects is required to be allocated in relatively equal amounts among bituminous coal,

170

Retinoblastoma 94 Enhances Radiation Treatment of Esophageal Squamous Cell Carcinoma in Vitro and in Vivo  

Science Journals Connector (OSTI)

......ionizing radiation (IR) was car- ried out both in vitro and...head and neck squamous cell car- cinoma and bladder cancer...we constructed replication-defective adenoviral vector containing...with tumor invasion in gastric car- cinoma. World J Gastroenterol......

Heng Zhang; Jin Li; Yue-ying Wang; Ai-min Meng; Qiang Liu; Lei Wang; Feng-hua Chen; Xiao-chun Wang; Zhi-bin Zhai; Yue Fu; Qin Wang

2012-01-01T23:59:59.000Z

171

Translocation analysis by the FISH-painting method for retrospective dose reconstruction in individuals exposed to ionizing radiation 10 years after exposure  

Science Journals Connector (OSTI)

Fluorescence in situ hybridization (FISH) is a powerful method largely used for detecting chromosomal rearrangements, translocations in particular, which are important biomarkers for dose assessment in case of human exposure to ionizing radiation. To test the possibility of using the translocation analysis by FISH-painting method in retrospective dose assessment, we carried out in vitro experiments in irradiated human lymphocytes, in parallel with the analysis of translocations in lymphocytes from 10 individuals, who were exposed to 137cesium in the Goinia (Brazil) accident (samples collected 10 years after exposure). The in vitro doseresponse curve for the genomic translocation frequencies (FGs) fits a linear quadratic model, according to the equation: Y=0.0243X2+0.0556X. The FG values were also calculated for the individuals exposed to 137cesium, ranging from 0.58 to 5.91 per 100 cells, and the doses were estimated and compared with the results obtained by dicentric analysis soon after the accident, taking the opportunity to test the validity of translocation analysis in retrospective biodosimetry. A tentative of retrospective dosimetry was performed, indicating that the method is feasible only for low level exposure (below 0.5Gy), while for higher doses there is a need to apply appropriate correction factors, which take into consideration mainly the persistence of chromosomal translocations along with time, and the influence of endogenous and exogenous factors determining the inter-individual variability in the cellular responses to radiation.

Marjori L. Camparoto; Adriana T. Ramalho; Adayapalam T. Natarajan; Maria P. Curado; Elza T. Sakamoto-Hojo

2003-01-01T23:59:59.000Z

172

[Ionizing radiation-induced DNA damage and its repair in human cells]. Progress report, [April 1, 1993--February 28, 1994  

SciTech Connect (OSTI)

The excision of radiation-induced lesions in DNA by a DNA repair enzyme complex, namely the UvrABC nuclease complex, has been investigated. Irradiated DNA was treated with the enzyme complex. DNA fractions were analyzed by gas chromatography/isotope-dilution mass spectrometry. The results showed that a number pyrimidine- and purine-derived lesions in DNA were excised by the UvrABC nuclease complex and that the enzyme complex does not act on radiation-induced DNA lesions as a glycosylase. This means that it does not excise individual base products, but it excises oligomers containing these lesions. A number of pyrimidine-derived lesions that were no substrates for other DNA repair enzymes investigated in our laboratory were substrates for the UvrABC nuclease complex.

Not Available

1994-07-01T23:59:59.000Z

173

PM2 DNA, Forms I and I: a quantitative comparison of strand breakage induced by ionizing radiation  

E-Print Network [OSTI]

of Advisory Committee: Dr R. D. Neff A quantitative comparison of strand breakage production rates, induced by 250 kvP X-rays, was examined for PM2 DNA, Form I and Form I . Assay of the irrad. iated DNA samples was 0 accomplished by tube gel... AND METHODS DNA Preparation Radiation Protocol Azarose 1 Buffer ~garose Gels Tube Gel Electrophoresis Spectrofluorometry with Electronic Quantif'ication RESULTS DISCUSSION AND CONCLUSION REFERENCES APPENDIX 1 APPENDIX 2 VITA ~Pa e ~ 22 22 24...

Myers, Peter Hall

1981-01-01T23:59:59.000Z

174

Assessment of retrospective dose estimation, with fluorescence in situ hybridization (FISH), of six victims previously exposed to accidental ionizing radiation  

Science Journals Connector (OSTI)

Abstract The present study aims to evaluate the use of the fluorescence in situ hybridization (FISH) translocation assay for retrospective dose estimation of acute accidental exposure to radiation in the past. Reciprocal translocation analysis by FISH with three whole-chromosome probes was performed on normal peripheral blood samples. Samples were irradiated with 05Gy 60Co ?-rays in vitro, and doseeffect curves were established. FISH-based translocation analyses for six accident victims were then performed, and biological doses were estimated retrospectively by comparison with the doseeffect curves. Reconstructed doses by FISH were compared with estimated doses obtained by analysis of di-centrics performed soon after exposure, or with dose estimates from tooth-enamel electron paramagnetic resonance (EPR) data obtained at the same time as the FISH analysis. Follow-up FISH analyses for an adolescent victim were performed. Results showed that doseeffect curves established in the present study follow a linear-quadratic model, regardless of the background translocation frequency. Estimated doses according to two doseeffect curves for all six victims were similar. FISH dose estimations of three adult victims exposed to accidental radiation less than a decade prior to analysis (3, 6, or 7 years ago) were consistent with those estimated with tooth-enamel EPR measurements or analyses of di-centrics. Estimated doses of two other adult victims exposed to radiation over a decade prior to analysis (16 or 33 years ago) were underestimated and two to three times lower than the values obtained from analysis of di-centrics or tooth-enamel EPR. Follow-up analyses of the adolescent victim showed that doses estimated by FISH analysis decrease rapidly over time. Therefore, the accuracy of dose estimates by FISH is acceptable only when analysis is performed less than 7 years after exposure. Measurements carried out more than a decade after exposure through FISH analysis resulted in underestimation of the biological doses compared with values obtained through analysis of di-centrics and tooth-enamel EPR.

Qing-Jie Liu; Xue Lu; Xiao-Tao Zhao; Jiang-Bin Feng; Yu-Min L; En-Hai Jiang; Shu-Lan Zhang; De-Qing Chen; Ting-Zhen Jia; Li Liang

2014-01-01T23:59:59.000Z

175

E-Print Network 3.0 - assisted laser ionization Sample Search...  

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

Summary: of a high power pulsed far-infrared laser. Furthermore, impurity ionization with terahertz radiation can... of ionization capture processes due to the Poole-Frenkel...

176

E-Print Network 3.0 - activities involving ionizing Sample Search...  

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

Collection: Physics 62 Magnetic field effect on tunnel ionization of deep impurities by terahertz radiation S.D. Ganichev1 Summary: Magnetic field effect on tunnel ionization of...

177

Effect of neutral collision and radiative heat-loss function on self-gravitational instability of viscous thermally conducting partially-ionized plasma  

SciTech Connect (OSTI)

The problem of thermal instability and gravitational instability is investigated for a partially ionized self-gravitating plasma which has connection in astrophysical condensations. We use normal mode analysis method in this problem. The general dispersion relation is derived using linearized perturbation equations of the problem. Effects of collisions with neutrals, radiative heat-loss function, viscosity, thermal conductivity and magnetic field strength, on the instability of the system are discussed. The conditions of instability are derived for a temperature-dependent and density-dependent heat-loss function with thermal conductivity. Numerical calculations have been performed to discuss the effect of various physical parameters on the growth rate of the gravitational instability. The temperature-dependent heat-loss function, thermal conductivity, viscosity, magnetic field and neutral collision have stabilizing effect, while density-dependent heat-loss function has a destabilizing effect on the growth rate of the gravitational instability. With the help of Routh-Hurwitz's criterion, the stability of the system is discussed.

Kaothekar, Sachin [School of Studies in Physics, Vikram University, Ujjain-456010, Madhya Pradesh (India); Department of Physics, Mahakal Institute of Technology, Ujjain-456664, Madhya Pradesh (India); Soni, Ghanshyam D. [Government Girls Degree College, Dewas, Madhya Pradesh (India); Chhajlani, Rajendra K. [School of Studies in Physics, Vikram University, Ujjain-456010, Madhya Pradesh (India)

2012-12-15T23:59:59.000Z

178

Colour and lipid oxidation changes in dry-cured loins from free-range reared and intensively reared pigs as affected by ionizing radiation dose level  

Science Journals Connector (OSTI)

The effect of irradiation (0, 5 and 10 kGy) of vacuum-packaged Iberian dry-cured loin slices from pigs fed on concentrate (CON) or free-range reared (FRG) was studied in relation to colour changes, TBA-RS and hexanal content. Both, ionizing radiation and type of loin had a significant effect on the instrumental colour parameters of the samples. Irradiation resulted in significantly higher a*-values in both sets of loins, indicating a redder colour. Numerically calculated total colour difference (?E) changes were significantly less intense in CON vacuum-packaged dry-cured loin slices than in FRG samples and changed significantly at 10 kGy dose levels in both types of samples. TBA-RS numbers were significantly affected by irradiation dose and type of loin and increased linearly with dose in both types of slices. Increments in TBA-RS numbers in FRG loin slices was dose-dependent and was closely related to the type of dry-cured loin. Irradiation of dry-cured loin slices significantly increased hexanal contents in both groups of loins and the increases were dose-dependent and greater in FRG samples than in CON samples. Differences in the characteristics of the raw material and initial lipid oxidation level could play an important role in the irradiation-induced changes in vacuum-packaged dry-cured loin slices.

A. Carrasco; R. Trrega; M.R. Ramrez; F.J. Mingoarranz; R. Cava

2005-01-01T23:59:59.000Z

179

On The Detection Of Ionizing Radiation Arising From Star-Forming Galaxies At Redshift z ~ 3-4 : Looking For Analogs Of "Stellar Reionizers"  

E-Print Network [OSTI]

We use the spatially-resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z~3.7 identified using ultra-deep imaging below the Lyman limit (1-sigma limit of ~30 AB in a 2" diameter aperture). In 18 candidates, out of a sample of 19 with flux detected at >3-sigma level, the light centroid of the candidate LyC emission is offset from that of the LBG by up to 1.5". We fit the SED of the LyC candidates to spectral population synthesis models to measure photometric redshifts and the stellar population parameters. We also discuss the differences in the UV colors between the LBG and the LyC candidates, and how to estimate the escape fraction of ionizing radiation (f_esc) in cases, like in most of our galaxies, where the LyC emission is spatially offset from the host galaxy. In all but one case we conclude that the candidate LyC emission is most likely due to lower redshift interlopers. Based on these fi...

Vanzella, Eros; Giavalisco, Mauro; Grazian, Andrea; Castellano, Marco; Cristiani, Stefano; Dickinson, Mark; Fontana, Adriano; Nonino, Mario; Giallongo, Emanuele; Pentericci, Laura; Galametz, Audrey; Faber, S M; Ferguson, Henry C; Grogin, Norman A; Koekemoer, Anton M; Newman, Jeffrey; Siana, Brian D

2012-01-01T23:59:59.000Z

180

PAH chemistry and IR emission from circumstellar disks  

E-Print Network [OSTI]

Aims. The chemistry of, and infrared (IR) emission from, polycyclic aromatic hydrocarbons (PAHs) in disks around Herbig Ae/Be and T Tauri stars are investigated. The equilibrium distribution of the PAHs over all accessible charge/hydrogenation states depends on the size and shape of the PAHs and on the physical properties of the star and surrounding disk. Methods. A chemistry model is created to calculate this equilibrium distribution. Destruction of PAHs by ultraviolet (UV) photons, possibly in multi-photon absorption events, is taken into account. The chemistry model is coupled to a radiative transfer code to provide the physical parameters and to combine the PAH emission with the spectral energy distribution (SED) from the star+disk system. Results. Normally hydrogenated PAHs in Herbig Ae/Be disks account for most of the observed PAH emission, with neutral and positively ionized species contributing in roughly equal amounts. Close to the midplane, the PAHs are more strongly hydrogenated and negatively ionized, but these species do not contribute to the overall emission because of the low UV/optical flux deep inside the disk. PAHs of 50 carbon atoms are destroyed out to 100 AU in the disk's surface layer, and the resulting spatial extent of the emission does not agree well with observations. Rather, PAHs of about 100 carbon atoms or more are predicted to cause most of the observed emission. The emission is extended on a scale similar to that of the size of the disk. Furthermore, the emission from T Tauri disks is much weaker and concentrated more towards the central star than that from Herbig Ae/Be disks. Positively ionized PAHs are predicted to be largely absent in T Tauri disks because of the weaker radiation field.

R. Visser; V. C. Geers; C. P. Dullemond; J. -C. Augereau; K. M. Pontoppidan; E. F. van Dishoeck

2007-01-22T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

IR Spectra of Dense Xenon and Argon Plasmas  

Science Journals Connector (OSTI)

The results are presented of experimental studies of IR radiation spectra of dense Xe and Ar shock compressed plasmas. The radiation cutoff is found at the wavelength ??1?mThe experimental data are interpreted...

V. E. Fortov; M. U. Kulish; V. B. Mintsev; J. Ortner

1992-01-01T23:59:59.000Z

182

Persistent DNA damage foci, cellular senescence and low dose radiation  

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

Persistent DNA damage foci, cellular senescence and low dose radiation Persistent DNA damage foci, cellular senescence and low dose radiation Denise Munoz 1 , Albert Davalos 1 , Francis Rodier 1 , Misako Kawahara 1 , Judith Campisi 1,2 and Steven Yannone 1,3 1 Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Mailstop 84-171, Berkeley CA 94720; 2 Buck Institute for Age Research, 8001 Redwood Boulevard, Novato CA 94945; 3 Corresponding author Ionizing radiation (IR) induced DNA double-strand breaks (DSBs) are cytologically detectable as large nuclear foci that contain phosphorylated histone H2AX (γH2AX), the adaptor protein 53BP1, and several other proteins that participate in the sensing and processing of DNA damage (DNA damage foci). In normal human cells, moderately high IR (0.5-1 Gy) doses cause the rapid appearance of these foci (acute DNA damage foci), which gradually disappear

183

Cell Cycle Disturbances and Mitotic Catastrophes in HeLa Hep2 Cells following 2.5 to 10 Gy of Ionizing Radiation  

Science Journals Connector (OSTI)

...death (2-5). Radiation is known to exert...molecules involved in this radiation-induced cellular safety machinery is p53...different doses of radiation at the molecular and...using the CellQuest software program, setting...

David Eriksson; Per-Olov Lfroth; Lennart Johansson; Katrine hlstrm Riklund; and Torgny Stigbrand

2007-09-15T23:59:59.000Z

184

Hydrogen peroxide significantly contributes to radiation-induced genomic instability  

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

peroxide significantly contributes to radiation- peroxide significantly contributes to radiation- induced genomic instability Disha Dayal 1 , Sean M. Martin 1 , Sujatha Venkataraman 1 , Charles L. Limoli 2 , Douglas R Spitz 1 . 1 Free Radical and Radiation Biology Program, The University of Iowa, Iowa City, IA- 52246, 2 Department of Radiation Oncology, The University of California, Irvine, CA-92697 Chronic metabolic oxidative stress is associated with genomic instability following exposure to ionizing radiation (IR). Mitochondria have long been known to be a major source of reactive oxygen species (ROS) capable of causing oxidative stress. We hypothesized that radiation damages mitochondria, leading to oxidative stress and eventually genomic instability. This hypothesis is based on preliminary studies in parental

185

Measurements of photon ionizing radiation fields in the reactor room of the 4th power-generating unit of the chernobyl nuclear power plant  

Science Journals Connector (OSTI)

A radiation examination of the reactor room of the damaged fourth unit of the Chernobyl nuclear power plant was performed. The most strongly radiating surfaces...

A. G. Volkovich; V. N. Potapov; S. V. Smirnov; L. I. Urutskoev

2000-03-01T23:59:59.000Z

186

Radiation Protection and Safety Training | Environmental Radiation...  

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

The objective of this course is to provide students with an introduction to the fundamentals of ionizing radiation protection and safety. The course curriculum combines...

187

Theoretical study of ionization profiles of molecular clouds near supernova remnants: Tracing the hadronic origin of GeV gamma radiation  

E-Print Network [OSTI]

Context: Since a few years, signatures of supernova remnants associated with molecular clouds have been detected in gamma rays. Whether these gamma rays are generated by cosmic ray electrons or by cosmic ray protons is usually not known. The detection of hadronic ionization signatures in spatial coincidence with gamma ray signatures can help to unambiguously identify supernova remnants as sources of cosmic ray protons. Methods: In order to calculate hadronic signatures from cosmic ray-induced ionization for an examination of the origin of the observed gamma rays, the transport equation for cosmic ray protons propagating in a molecular cloud, including the relevant momentum loss processes, is solved analytically and the proton flux at any position in the cloud is determined. Results: Since the solution of the transport equation is obtained for arbitrary source functions, it can be used for a variety of supernova remnants. The corresponding theoretical ionization rate, as a function of the penetration depth, is...

Schuppan, Florian; Tjus, Julia Becker

2014-01-01T23:59:59.000Z

188

Low Dose Radiation Research Program: Assessing Biological Function of DNA  

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

Assessing Biological Function of DNA Damage Response Genes Assessing Biological Function of DNA Damage Response Genes Larry H. Thompson Lawrence Livermore National Laboratory Why This Project To understand the relative importance of individual DNA repair and DNA-damage response pathways to the recovery of mammalian cells after exposure to low doses of ionizing radiation (IR). This understanding may lead to better ways of setting limits on human exposure to IR. In spite of the discovery of many mammalian DNA repair genes, our current knowledge of how many of these genes contribute to cellular recovery from IR exposure is quite limited. Project Goals Measure cellular responses at doses in the 5-100 cGy range, which generally cause changes too small to detect in normal, repair-proficient cells Focus on DNA double-strand breaks (DSBs) and DNA oxidative base

189

Inference of Causal Networks from Time-course Transcription Data in Response to a2 Gy Challenge Dose of Ionizing Radiation with or without a 10 cGy Priming Dose  

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

Causal Networks from Time-course Transcription Data in Response to a Causal Networks from Time-course Transcription Data in Response to a 2 Gy Challenge Dose of Ionizing Radiation with or without a 10 cGy Priming Dose Kai Zhang, Ju Han, Torsten Groesser, Priscilla Cooper, and Bahram Parvin Lawrence Berkeley National Laboratory Goal: To elucidate temporal-dependent gene templates, causal networks, and underlying biological processes that can be inferred in response to a 10 cGy priming dose with or without a later higher challenged dose. Background and significance: Mechanistic inference of regulatory network can provide new insights into radiation systems biology. The main challenge continues to be high dimensionality of data, complex network architecture and limited knowledge of biological processes.

190

IR-2003- | Department of Energy  

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

IR-2003- IR-2003- IR-2003- More Documents & Publications Fact Sheet: Clean Coal Technology Ushers In New Era in Energy Fact Sheet: Clean Coal Technology Ushers In New Era in Energy...

191

Total ionizing dose effect of ?-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory  

SciTech Connect (OSTI)

The total ionizing dose (TID) effect of gamma-ray (?-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ?5.2 Mrad (HfO{sub 2}) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy ?-ray exposure.

Fang, Runchen; Yu, Shimeng, E-mail: shimengy@asu.edu [School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona 85281 (United States); School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Gonzalez Velo, Yago; Chen, Wenhao; Holbert, Keith E.; Kozicki, Michael N.; Barnaby, Hugh [School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)

2014-05-05T23:59:59.000Z

192

Standard Test Method for Application of Ionization Chambers to Assess the Low Energy Gamma Component of Cobalt-60 Irradiators Used in Radiation-Hardness Testing of Silicon Electronic Devices  

E-Print Network [OSTI]

1.1 Low energy components in the photon energy spectrum of Co-60 irradiators lead to absorbed dose enhancement effects in the radiation-hardness testing of silicon electronic devices. These low energy components may lead to errors in determining the absorbed dose in a specific device under test. This method covers procedures for the use of a specialized ionization chamber to determine a figure of merit for the relative importance of such effects. It also gives the design and instructions for assembling this chamber. 1.2 This method is applicable to measurements in Co-60 radiation fields where the range of exposure rates is 7 10 ?6 to 3 10?2 C kg ?1 s?1 (approximately 100 R/h to 100 R/s). For guidance in applying this method to radiation fields where the exposure rate is >100 R/s, see Appendix X1. Note 1See Terminology E170 for definition of exposure and its units. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information onl...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

193

10 CFR 835- Occupational Radiation Protection  

Broader source: Energy.gov [DOE]

The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

194

Code of Federal Regulations OCCUPATIONAL RADIATION PROTECTION  

Broader source: Energy.gov [DOE]

The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

195

Photo-Electric Ionization of Caesium Vapor  

Science Journals Connector (OSTI)

Measurement of photo-electric ionization in gases.The current from a filament, normally limited by space change, is increased by the presence of positive ions. As shown by Kingdon this effect may be greatly magnified if a small cathode is practically enclosed by the anode so that the ions are imprisoned. This method was used for the detection of photo-electric ionization. Besides possessing extreme sensitivity it is unaffected by photo-electric emission from the electrodes.Photo-electric effect in caesium vapor.The change in thermionic current with the unresolved radiation from a mercury arc was measured as functions of the applied voltage, filament temperature, and vapor pressure. Then the photo-electric effect as a function of wave-length was studied using a monochromatic illuminator to disperse light from the arc or a Mazda lamp. The ionization per unit flux was found to increase with increasing wave-length to a sharp maximum at the limit 1s=3184A of the principal series, as is required by the Bohr theory. For longer wave-lengths the ionization decreased to about 10 percent at 3400A. Photo-excitation. The simple theory does not admit of ionization by wave-lengths greater than 3184A but the data are in qualitative agreement with the hypothesis that such radiation produces excited atoms which upon collision with other atoms acquire sufficient additional energy to become ionized. Hence, unlike an x-ray limit, the photo-ionization effect for a valence electron is not sharply discontinuous at the true threshold for direct ionization.Photo-ionization photometer and intensitometer. A tube of the type described, with suitable gases for the range of wave-length involved, may be used as a photometer or may be calibrated to measure intensity of radiation directly.

Paul D. Foote and F. L. Mohler

1925-08-01T23:59:59.000Z

196

Alanine-EPR dosimetry for measurements of ionizing radiation absorbed doses in the range 0.5-10 kGy  

E-Print Network [OSTI]

The usefulness of two, easy accessible alanine dosimeters (ALANPOL from IChTJ and foil dosimeter from Gamma Service, Radeberg, Germany) to radiation dose measurement in the range of 0.5-10 kGy, were investigated. In both cases, the result of the test was positive. The foil dosemeter from Gamma Service is recommended for dose distribution measurements in fantoms or products, ALANPOL - for routine measurements. The EPR-alanine method based on the described dosimeters can be successfully used, among others, in the technology of radiation protection of food.

Peimel-Stuglik, Z

2001-01-01T23:59:59.000Z

197

Release of Inorganic Phosphate from Irradiated Yeast: Radiation Biodosimetry and Evaluation of Radioprotective Compounds  

Science Journals Connector (OSTI)

...irradiated with ionizing radiation, inorganic...radiation dose and on the...somewhat limited range of the yeast...irradiated with ionizing radiation, inorganic...radiation dose and on the...somewhat limited range of the yeast...represent range ofvaluesfrom...but with dose plotted on...effect of ionizing radiation (27...

Hillel S. Levinson; Esther B. Garber

1967-03-01T23:59:59.000Z

198

Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation  

SciTech Connect (OSTI)

Highlights: Parg{sup ?/?} ES cells were more sensitive to ?-irradiation than Parp-1{sup ?/?} ES cells. Parg{sup ?/?} cells were more sensitive to carbon-ion irradiation than Parp-1{sup ?/?} cells. Parg{sup ?/?} cells showed defects in DSB repair after carbon-ion irradiation. PAR accumulation was enhanced after carbon-ion irradiation compared to ?-irradiation. -- Abstract: Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme involved in poly(ADP-ribose) degradation. Here, the effects of Parg deficiency on sensitivity to low and high linear-energy-transfer (LET) radiation were investigated in mouse embryonic stem (ES) cells. Mouse Parg{sup ?/?} and poly(ADP-ribose) polymerase-1 deficient (Parp-1{sup ?/?}) ES cells were used and responses to low and high LET radiation were assessed by clonogenic survival and biochemical and biological analysis methods. Parg{sup ?/?} cells were more sensitive to ?-irradiation than Parp-1{sup ?/?} cells. Transient accumulation of poly(ADP-ribose) was enhanced in Parg{sup ?/?} cells. Augmented levels of phosphorylated H2AX (?-H2AX) from early phase were observed in Parg{sup ?/?} ES cells. The induction level of p53 phophorylation at ser18 was similar in wild-type and Parp-1{sup ?/?} cells and apoptotic cell death process was mainly observed in the both genotypes. These results suggested that the enhanced sensitivity of Parg{sup ?/?} ES cells to ?-irradiation involved defective repair of DNA double strand breaks. The effects of Parg and Parp-1 deficiency on the ES cell response to carbon-ion irradiation (LET13 and 70 keV/?m) and Fe-ion irradiation (200 keV/?m) were also examined. Parg{sup ?/?} cells were more sensitive to LET 70 keV/?m carbon-ion irradiation than Parp-1{sup ?/?} cells. Enhanced apoptotic cell death also accompanied augmented levels of ?-H2AX in a biphasic manner peaked at 1 and 24 h. The induction level of p53 phophorylation at ser18 was not different between wild-type and Parg{sup ?/?} cells. The augmented level of poly(ADP-ribose) accumulation was noted after carbon-ion irradiation compared to ?-irradiation even in the wild-type cells. An enhanced poly(ADP-ribose) accumulation was further observed in Parg{sup ?/?} cells. Both Parg{sup ?/?} cells and Parp-1{sup ?/?} cells did not show sensitization to Fe-ion irradiation. Parg deficiency sensitizes mouse ES cells to a wide therapeutic range of LET radiation through the effects on DNA double strand break repair responses and enhanced cell death.

Shirai, Hidenori; Fujimori, Hiroaki [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)] [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Gunji, Akemi [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)] [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Maeda, Daisuke [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan) [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Hirai, Takahisa [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan) [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Department of Radiation Oncology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Poetsch, Anna R. [ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)] [ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Harada, Hiromi [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)] [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Yoshida, Tomoko [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan) [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Kyoritsu College of Pharmacy, 1-5-30 Shibakoen, Minatoku, Tokyo 105-8512 (Japan); Sasai, Keisuke [Department of Radiation Oncology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan)] [Department of Radiation Oncology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Okayasu, Ryuichi [International Open Laboratory, National Institute of Radiological Science, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)] [International Open Laboratory, National Institute of Radiological Science, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Masutani, Mitsuko, E-mail: mmasutan@ncc.go.jp [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan) [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

2013-05-24T23:59:59.000Z

199

Poly [1,1'-bis(ethynyl)-4,4'-biphenyl(bis-tributylphosphine)Pt(II)] solutions used as low dose ionizing radiation dosimeter  

SciTech Connect (OSTI)

In this work, the effect of gamma radiation on the optical properties of polymetallayne poly[1,1'-bis(ethynyl)-4,4'-biphenyl(bis-tributylphosphine)Pt(II)] (Pt-DEBP) in chloroform solution is studied. The samples were irradiated at room temperature with doses from 0.01 Gy to 1 Gy using a {sup 60}Co gamma ray source. A new band at 420 nm is observed in the emission spectra, in superposition to the emission maximum at 398 nm, linearly dependent on dose. We propose to use the ratio of the emission amplitude bands as the dosimetric parameter. This method proved to be robust, accurate, and can be used as a dosimeter in medical applications.

Bronze-Uhle, E. S.; Graeff, C. F. O. [Department of Physics, FC-UNESP, Av. Eng. Luiz Edmundo Carrijo Coube 14-01, 17033-360 Bauru (Brazil)] [Department of Physics, FC-UNESP, Av. Eng. Luiz Edmundo Carrijo Coube 14-01, 17033-360 Bauru (Brazil); Batagin-Neto, A.; Fernandes, D. M. [UNESP-Univ Estadual Paulista, POSMAT-Programa de Pos-Graduacao em Ciencia e Tecnologia de Materiais, Bauru, Sao Paulo (Brazil)] [UNESP-Univ Estadual Paulista, POSMAT-Programa de Pos-Graduacao em Ciencia e Tecnologia de Materiais, Bauru, Sao Paulo (Brazil); Fratoddi, I.; Russo, M. V. [Department of Chemistry, University of Rome 'Sapienza,' P.le A. Moro 5, 00185 Rome (Italy)] [Department of Chemistry, University of Rome 'Sapienza,' P.le A. Moro 5, 00185 Rome (Italy)

2013-06-17T23:59:59.000Z

200

Strong-field high-frequency approximation to the multiphoton ionization of hydrogen  

Science Journals Connector (OSTI)

The strong-field multiphoton ionization of atoms is considered and a theoretical approach dealing nonperturbatively with the radiation field formulated. The general computational...

Trombetta, F; Basile, S; Ferrante, G

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

COLUMBIA UNIVERSITY Radiation Safety Program  

E-Print Network [OSTI]

DDE ESTIMATED DOSE FROM CONCEPTION TO DECLARATION: DDE Radiation Safety Officer Signature for increased protection from ionizing radiation for declared pregnant radiation workers. The radiation dose of the occupational dose limit of 50 mSv (5.0 rem). The CPMC Radiation Safety Office will provide education

Jia, Songtao

202

IONIZATION IN ATMOSPHERES OF BROWN DWARFS AND EXTRASOLAR PLANETS. V. ALFVN IONIZATION  

SciTech Connect (OSTI)

Observations of continuous radio and sporadic X-ray emission from low-mass objects suggest they harbor localized plasmas in their atmospheric environments. For low-mass objects, the degree of thermal ionization is insufficient to qualify the ionized component as a plasma, posing the question: what ionization processes can efficiently produce the required plasma that is the source of the radiation? We propose Alfvn ionization as a mechanism for producing localized pockets of ionized gas in the atmosphere, having sufficient degrees of ionization (?10{sup 7}) that they constitute plasmas. We outline the criteria required for Alfvn ionization and demonstrate its applicability in the atmospheres of low-mass objects such as giant gas planets, brown dwarfs, and M dwarfs with both solar and sub-solar metallicities. We find that Alfvn ionization is most efficient at mid to low atmospheric pressures where a seed plasma is easier to magnetize and the pressure gradients needed to drive the required neutral flows are the smallest. For the model atmospheres considered, our results show that degrees of ionization of 10{sup 6}-1 can be obtained as a result of Alfvn ionization. Observable consequences include continuum bremsstrahlung emission, superimposed with spectral lines from the plasma ion species (e.g., He, Mg, H{sub 2}, or CO lines). Forbidden lines are also expected from the metastable population. The presence of an atmospheric plasma opens the door to a multitude of plasma and chemical processes not yet considered in current atmospheric models. The occurrence of Alfvn ionization may also be applicable to other astrophysical environments such as protoplanetary disks.

Stark, C. R.; Helling, Ch.; Rimmer, P. B. [SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS (United Kingdom); Diver, D. A., E-mail: craig.stark@st-andrews.ac.uk [SUPA, School of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

2013-10-10T23:59:59.000Z

203

Low Dose Radiation Research Program: Mary Helen Barcellos-Hoff - 2003  

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

DOE Low Dose Radiation Program Workshop IV DOE Low Dose Radiation Program Workshop IV Abstract Title: TGF-β Protects Human Mammary Epithelial Cells from Radiation-Induced Centrosome Amplification Authors: Mary Helen Barcellos-Hoff, Bahram Parvin, Anna C. Erickson and Rishi Gupta Institutions: Department of Cell and Molecular Biology, Life Sciences Division, Ernest Orlando Lawrence, Berkeley National Laboratory, Berkeley, California In recent studies we have shown that ionizing radiation (IR), a known carcinogen of human and murine mammary gland, compromises human mammary epithelial cell (HMEC) polarity and multicellular organization in a manner characteristic of neoplastic progression through a heritable, non-mutational mechanism (1). Thus, when all cells are irradiated with a significant dose (2 Gy), the daughters of irradiated cells lose their

204

Molecular Pathways: Targeted ?-Particle Radiation Therapy  

Science Journals Connector (OSTI)

...and profibrotic cytokines. Radiation-induced malignancy can...1-5 Gy). Kyoji Furukawa (Radiation Effect Research Foundation, Hiroshima, Japan) reviewed the Japanese atomic...late effects of ionizing radiation exposure at low/moderate...

Kwamena E. Baidoo; Kwon Yong; and Martin W. Brechbiel

2013-02-01T23:59:59.000Z

205

Ionizing radiation dosimetry in the absorbed dose range 0.0150 \\{MGy\\} based on resistance and ESR linewidth measurements of organic conducting crystals  

Science Journals Connector (OSTI)

The materials studied in the present work as high-dose dosimeters are members of a large class of molecular crystals which are organic conductors of electricity. Very different from each other in the details of their molecular and crystal structures, they all behave in the same way when subjected to increasing high doses of radiation, at least from the point of view of their electronic transport properties, because of the quasi-one-dimensional character of the conduction process. Their resistivities increase exponentially with the absorbed dose while their electron spin resonance (ESR) linewidths decrease exponentially. Very small single crystals less than 10 ?m thick can be used as dosimeters in the dose range 0.0150 \\{MGy\\} for ? rays as well as for electron irradiations, by applying four probe resistance measurements. Only a few compounds over a large number of candidates have been irradiated in the present work with ?-rays, low energy x-rays and electrons. In some favourable cases the energy and temperature dependences of the dosimeters have been checked experimentally. Their mass energy absorption coefficients and electron stopping powers have been also calculated. It is hoped to extend this kind of dosimetry to lower and higher doses by trying new compounds from the large family of organic conductors or by improving the resistivity and ESR measurement techniques.

L. Zuppiroli; S. Bouffard; J.J. Jacob

1985-01-01T23:59:59.000Z

206

Ir I L  

Office of Legacy Management (LM)

LIST OF FIGURES LIST OF FIGURES 1 2 General location of the Granite City Steel Facility' Granite City, Illinois . . . View of the betatron building, looking south . ' ' 3 View o[ the betatron building, looking west . ' ' ' ' ' 11 4 Diagram of the ground floor of the betatron building ' 5 Photo showing the larger of the two betatrons (no. 1, Fig. ) 6 View of transformer storage area inside the betatron building 7 Directly measured radiation levels inside the betatron building, first level 8 Results of directly measured radiation levels taken in the betatron building, second level . Industrial vacuum cleaner having elevated radiation levels and radionuclide concentrations . I-ocations of smears, and indoor dust and debris samples Results of direct radiation measurements and locations

207

I\r'  

Office of Legacy Management (LM)

r' r' ( g-.] ic' fz .; w .fl ! : L ' ..j : i ?- z -2"" . 2,-3X-~ Aw23-t 11, 1949 J c. s. ?.%omic ?zaru ccm3ission 7-t i-~n,~-;ra-& 3&-p.Cz' ;"ica P. ' 3. 30x 3 Eacsrs 17, lIaw York :. , ::; /. 1 httetii OP J xl-. P, 3. 2gp C+~t~Sil;lsXl t ?~~$Tly~lf .t: GA.3 L?wjpnaJiQn Of p-3&7:2-Liop 9.0";:7~+50 s' , -ir ,.,,3 iashlla+im it i3 our da3irs 20 be rslia-T.73 of _"\L:t&?T --:wzk&ili* of the SC1298 ' _ _ Zj31Wf end i~i3sio~~31.3 rsskeri31ii izxLi.c~~t& S' ;az&;-d -D~YX-C.I o-Ada - 451 g3ac SyT,kd jl-J$; 3.xi.da - 2% p3 I :&at a 1 a azqi?L;3 3 - ' T-44 pi3. 3 ,LS oxid-\ 3aqr1.93 aar9 ~z;cc?33a~jr la 5.x0 st?%zl*hl~iao- ::>a of In'se-3' -J*-y chs=iical r9tag;P,sta d.ili::d fn cm2 sxlgtit3sl -.- -n4A..*

208

Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION  

Broader source: Energy.gov [DOE]

General. The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

209

Gamma radiation field intensity meter  

DOE Patents [OSTI]

A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

Thacker, L.H.

1995-10-17T23:59:59.000Z

210

Gamma radiation field intensity meter  

DOE Patents [OSTI]

A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

Thacker, L.H.

1994-08-16T23:59:59.000Z

211

Gamma radiation field intensity meter  

DOE Patents [OSTI]

A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

Thacker, Louis H. (Knoxville, TN)

1995-01-01T23:59:59.000Z

212

Gamma radiation field intensity meter  

DOE Patents [OSTI]

A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

Thacker, Louis H. (Knoxville, TN)

1994-01-01T23:59:59.000Z

213

NETL: IRS Tax Credit Program  

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

Solicitations & Business Opportunities IRS Tax Credit Program The Department of Energy's National Energy Technology Laboratory (NETL) is collaborating with the Internal Revenue Service (IRS) to evaluate applications for Tax Credits under Section 1307 of the Energy Policy Act of 2005, and the Emergency Economic Stabilization Act of 2008, per instruction in the Treasury and IRS Announcement 2010-56, which can be found at: http://www.irs.gov/irb/2010-39_IRB/ar09.html or http://www.irs.gov/pub/irs-drop/a-10-56.pdf Specifically, NETL will be evaluating and providing certifications of feasibility for advanced coal and gasification projects consistent with energy policy goals (“DOE certification”). To facilitate the review process, NETL has established this website to receive and respond to questions from prospective applicants regarding the Notices. NETL will post responses to questions or groups of similar questions.

214

Low Dose Radiation Research Program: Cooperation Between Homologous  

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

Cooperation Between Homologous Recombination and the Fanconi Anemia Cooperation Between Homologous Recombination and the Fanconi Anemia Cancer Suppressor Proteins in Minimizing Spontaneous and Radiation-Induced Chromosomal Instability Authors: Larry H. Thompson, John M. Hinz, Robert S. Tebbs, and N. Alice Yamada Institutions: Biosciences Directorate, Lawrence Livermore National Laboratory, Livermore, California Purpose and experimental approach. This study addresses the genetic basis of spontaneous mutagenesis as a means of understanding the DNA damage-response pathways that maintain chromosome stability. It is our view that knowledge of these processes is fundamental to understanding how low dose ionizing radiation (IR) produces chromosomal rearrangements that lead to carcinogenesis. Endogenous oxidative DNA damage is presumed to be a

215

Weak interaction studies using resonance ionization spectroscopy  

SciTech Connect (OSTI)

Important developments in laser sources for the vacuum ultraviolet (VUV) region of the spectrum are making it possible to carry out resonance ionization of some of the noble gases. It has already been shown that xenon can be ionized in a two-photon allowed excitation from the ground state. Recently a new method of generating radiation by four-wave mixing in mercury vapor enables excitation of xenon in a one-photon resonance process. With these new laser sources we expect to have effective ionization volumes of 10/sup -3/ to 10/sup -2/ cm/sup 3/ for the cases of argon, krypton, and xenon. This has important consequences in weak interaction physics and environmental research.

Payne, M.G.; Hurst, G.S.

1982-01-01T23:59:59.000Z

216

Plasmadynamics and ionization kinetics of thermionic energy conversion  

SciTech Connect (OSTI)

To reduce the plasma arc-drop, thermionic energy conversion is studied with both analytical and numerical tools. Simplifications are made in both the plasmadynamic and ionization-recombination theories. These are applied to a scheme proposed presently using laser irradiation to enhance the ionization kinetics of the thermionic plasma and thereby reduce the arc-drop. It is also predicted that it is possible to generate the required laser light from a thermionic-type cesium plasma. The analysis takes advantage of theoretical simplifications derived for the ionization-recombination kinetics. It is shown that large laser ionization enhancements can occur and that collisional cesium recombination lasing is expected. To complement the kinetic theory, a numerical method is developed to solve the thermionic plasma dynamics. To combine the analysis of ionization-recombination kinetics with the plasma dynamics of thermionic conversion, a finite difference computer program is constructed. It is capable of solving for both unsteady and steady thermionic converter behavior including possible laser ionization enhancement or atomic recombination lasing. A proposal to improve thermionic converter performance using laser radiation is considered. In this proposed scheme, laser radiation impinging on a thermionic plasma enhances the ionization process thereby raising the plasma density and reducing the plasma arc-drop. A source for such radiation may possibly be a cesium recombination laser operating in a different thermionic converter. The possibility of this being an energy efficient process is discussed. (WHK)

Lawless, J.L. Jr.; Lam, S.H.

1982-02-01T23:59:59.000Z

217

Radiation Sources and Radioactive Materials (Connecticut)  

Broader source: Energy.gov [DOE]

These regulations apply to persons who receive, transfer, possess, manufacture, use, store, handle, transport or dispose of radioactive materials and/or sources of ionizing radiation. Some...

218

EPA's Radiation Protection Standards Protecting the Environment from  

E-Print Network [OSTI]

cancer. EPA does not regulate naturally occurring radiation or the non-ionizing radiation that is emittedEPA's Radiation Protection Standards Protecting the Environment from Radioactive Materials EPA materials. These radioactive materials emit ionizing radiation, which can damage living tissue and cause

219

College of Health Sciences RAS Radiation Sciences  

E-Print Network [OSTI]

; excitation and ionization processes; selected nuclear reactions; basic radiation detection and dosimetry, and nuclear medical physics. Prereq or concur: RM/PHY 472G or consent of instructor. (Same as PHY/RM 546.) RAS 601 ADVANCED RADIATION DOSIMETRY. (2

MacAdam, Keith

220

(Resonance ionization spectroscopy)  

SciTech Connect (OSTI)

J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

Young, J.P.

1990-10-11T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION Subpart A- General Provisions  

Broader source: Energy.gov [DOE]

The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

222

Radiation effects on humans  

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

Radiation effects on humans Radiation effects on humans Name: Joe Kemna Location: N/A Country: N/A Date: N/A Question: I am trying to find information on radiation. I need the effects on humans, the damage it causes to the environment, and any extra information you might have on the subject. Thank you for your time. Replies: Your library should be a good place to start, but first you need to narrow your question a bit. "Radiation" means radio waves, heat, light (including the ultraviolet light that causes suntan and sunburn), and what's called "ionizing radiation." By far the major source of the first three is the Sun, while the last I believe comes principally from cosmic rays and various naturally radioactive elements like uranium and radon. The most significant manmade sources of exposure would --- I think --- be household wiring and appliances (radio), engines and heating devices (heat), lamps (light), and X-ray machines, flying at high altitude in airplanes, and living in well-insulated homes built over radon sources (ionizing radiation). Heat, light and ionizing radiation play vital roles in the ecology of the Earth. Radio, light (in particular "tanning" ultraviolet), and ionizing radiation have all been widely assumed at different times to be particularly good or particularly bad for human health. Some recent issues of public concern have been the effect of radio waves from electric transmission lines, the effect on skin cancer incidence from tanning and sunburns, the depletion of the ultraviolet-light-produced ozone in the upper atmosphere by chlorofluorocarbons (CFCs), "global warming" from the increased absorption of heat radiation from the surface by atmospheric carbon dioxide and methane, and the effect of a long exposure to low levels of ionizing radiation as for example the people of Eastern Europe are experiencing from the Chernobyl nuclear power plant accident.

223

Curcumin Regulates Low-Linear Energy Transfer {gamma}-Radiation-Induced NF{kappa}B-Dependent Telomerase Activity in Human Neuroblastoma Cells  

SciTech Connect (OSTI)

Purpose: We recently reported that curcumin attenuates ionizing radiation (IR)-induced survival signaling and proliferation in human neuroblastoma cells. Also, in the endothelial system, we have demonstrated that NF{kappa}B regulates IR-induced telomerase activity (TA). Accordingly, we investigated the effect of curcumin in inhibiting IR-induced NF{kappa}B-dependent hTERT transcription, TA, and cell survival in neuroblastoma cells. Methods and Materials: SK-N-MC or SH-SY5Y cells exposed to IR and treated with curcumin (10-100 nM) with or without IR were harvested after 1 h through 24 h. NF{kappa}B-dependent regulation was investigated either by luciferase reporter assays using pNF{kappa}B-, pGL3-354-, pGL3-347-, or pUSE-I{kappa}B{alpha}-Luc, p50/p65, or RelA siRNA-transfected cells. NF{kappa}B activity was analyzed using an electrophoretic mobility shift assay and hTERT expression using the quantitative polymerase chain reaction. TA was determined using the telomerase repeat amplification protocol assay and cell survival using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide and clonogenic assay. Results: Curcumin profoundly inhibited IR-induced NF{kappa}B. Consequently, curcumin significantly inhibited IR-induced TA and hTERT mRNA at all points investigated. Furthermore, IR-induced TA is regulated at the transcriptional level by triggering telomerase reverse transcriptase (TERT) promoter activation. Moreover, NF{kappa}B becomes functionally activated after IR and mediates TA upregulation by binding to the {kappa}B-binding region in the promoter region of the TERT gene. Consistently, elimination of the NF{kappa}B-recognition site on the telomerase promoter or inhibition of NF{kappa}B by the I{kappa}B{alpha} mutant compromises IR-induced telomerase promoter activation. Significantly, curcumin inhibited IR-induced TERT transcription. Consequently, curcumin inhibited hTERT mRNA and TA in NF{kappa}B overexpressed cells. Furthermore, curcumin enhanced the IR-induced inhibition of cell survival. Conclusions: These results strongly suggest that curcumin inhibits IR-induced TA in an NF{kappa}B dependent manner in human neuroblastoma cells.

Aravindan, Natarajan, E-mail: naravind@ouhsc.ed [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Veeraraghavan, Jamunarani; Madhusoodhanan, Rakhesh; Herman, Terence S. [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Natarajan, Mohan [Department of Otolaryngology, Head and Neck Surgery, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States)

2011-03-15T23:59:59.000Z

224

Roles of the Major, Small, Acid-Soluble Spore Proteins and Spore-Specific and Universal DNA Repair Mechanisms in Resistance of Bacillus subtilis Spores to Ionizing Radiation from X Rays and High-Energy Charged-Particle Bombardment  

Science Journals Connector (OSTI)

...Aerospace Medicine, Radiation Biology Division, Cologne...International Space Radiation Laboratory, National...Sciences, Chiba-shi, Japan 5 University of Florida...Sciences in Chiba, Japan, under the aegis of...components of space radiation and span a range of...

Ralf Moeller; Peter Setlow; Gerda Horneck; Thomas Berger; Gnther Reitz; Petra Rettberg; Aidan J. Doherty; Ryuichi Okayasu; Wayne L. Nicholson

2007-11-30T23:59:59.000Z

225

Low Dose Radiation Induced DNA Damage Signaling and Repair Responses in  

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

Induced DNA Damage Signaling and Repair Responses in Induced DNA Damage Signaling and Repair Responses in Human 3-Dimensional Skin Model System Yanrong Su, Jarah Meador and Adayabalam S. Balajee Center for Radiological Research, College of Physicians and Surgeons, Columbia University, 630 West, 168th Street, New York, NY 10032. Exposure to ionizing radiation (IR) inflicts a wide variety of lesions in the genomic DNA. Among them, DNA double strand break (DSB) is considered to be the critical lesion for most of the deleterious radiation effects including carcinogenesis. Much of our knowledge on induction and repair kinetics of DSB has come from studies in two dimensional cell culture systems. However, the damage signaling and repair responses to DSB in tissue microenvironment are largely unknown. Knowledge of tissue responses to

226

Semiconductor radiation detector  

DOE Patents [OSTI]

A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

2010-03-30T23:59:59.000Z

227

Hysteresis of ionization waves  

SciTech Connect (OSTI)

A quasi-logistic, nonlinear model for ionization wave modes is introduced. Modes are due to finite size of the discharge and current feedback. The model consists of competing coupled modes and it incorporates spatial wave amplitude saturation. The hysteresis of wave mode transitions under current variation is reproduced. Sidebands are predicted by the model and found in experimental data. The ad hoc model is equivalent to a general--so-called universal--approach from bifurcation theory.

Dinklage, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); Bruhn, B.; Testrich, H. [Institut fuer Physik, E.-M.-Arndt Universitaet Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald (Germany); Wilke, C. [Leibniz-Institut fuer Plasmaforschung und Technologie, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

2008-06-15T23:59:59.000Z

228

Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Electrospray Ionization (ESI) is a process whereby gas phase ions are created from molecules in solution. As a solution exits a narrow tube in the presence of a strong electric field, an aerosol of charged droplets are is formed that produces gas phase ions as they it desolvates. ESI-MS comprises the creation of ions by ESI and the determination of their mass to charge ratio (m/z) by MS.

Kelly, Ryan T.; Marginean, Ioan; Tang, Keqi

2014-06-13T23:59:59.000Z

229

The effect of photo-ionization on the cooling rates of enriched, astrophysical plasmas  

E-Print Network [OSTI]

Radiative cooling is central to a wide range of astrophysical problems. Despite its importance, cooling rates are generally computed using very restrictive assumptions, such as collisional ionization equilibrium and solar relative abundances. We simultaneously relax both assumptions and investigate the effects of photo-ionization of heavy elements by the meta-galactic UV/X-ray background and of variations in relative abundances on the cooling rates of optically thin gas in ionization equilibrium. We find that photo-ionization by the meta-galactic background radiation reduces the net cooling rates by up to an order of magnitude for gas densities and temperatures typical of the shock-heated intergalactic medium and proto-galaxies. In addition, photo-ionization changes the relative contributions of different elements to the cooling rates. We conclude that photo-ionization by the ionizing background and heavy elements both need to be taken into account in order for the cooling rates to be correct to order of magnitude. Moreover, if the rates need to be known to better than a factor of a few, then departures of the relative abundances from solar need to be taken into account. We propose a method to compute cooling rates on an element-by-element basis by interpolating pre-computed tables that take photo-ionization into account. We provide such tables for a popular model of the evolving UV/X-ray background radiation, computed using the photo-ionization package CLOUDY.

Robert P. C. Wiersma; Joop Schaye; Britton D. Smith

2008-07-23T23:59:59.000Z

230

Risk Estimation; Background Radiation (Natural and Artificial )  

E-Print Network [OSTI]

-threshold mode estimate the response at lower doses. · The Committee on Biological Effects of Ionizing RadiationModule 9 Risk Estimation; Background Radiation (Natural and Artificial ) · sources of background radiation · various risk models. · estimating risk and on the sources of background radiation, both

Massey, Thomas N.

231

FEATURE ARTICLE Photoexcitation, Ionization, and Dissociation of Molecules Using Intense Near-Infrared  

E-Print Network [OSTI]

FEATURE ARTICLE Photoexcitation, Ionization, and Dissociation of Molecules Using Intense Near-Infrared The coupling mechanism between an intense (1013 W cm-2, 780 nm) near-infrared radiation field of duration 50 above threshold dissociation,3 multiple electron emission,4 and mo- lecular ionization using near-infrared

Levis, Robert J.

232

Plasmadynamics and ionization kinetics of thermionic energy conversion  

SciTech Connect (OSTI)

To reduce the plasma arc-drop, thermionic energy conversion is studied with both analytical and numerical tools. Simplifications are made in both the plasmadynamic and ionization-recombination theories. These are applied to a scheme proposed presently using laser irradiation to enhance the ionization kinetics of the thermionic plasma and thereby reduce the arc-drop. It is also predicted that it is possible to generate the required laser light from a thermionic-type Cesium plasma. The analysis takes advantage of theoretical simplifications derived for the ionization-recombination kinetics. It is shown that large laser ionization enhancements can occur and that collisional Cesium recombination lasing is expected. To complement the kinetic theory, a numerical method is developed to solve the thermionic plasma dynamics. The effects of the complete system of electron-atom inelastic collisions on the ionization-recombination problem are shown to reduce to a system nearly as simple as the well-known one-quantum approximation. To combine the above analysis of ionization-recombination kinetics with the plasma dynamics of thermionic conversion, a finite difference computer program is constructed. Using the above developments, a proposal to improve thermionic converter performance using laser radiation is considered. In this proposed scheme, laser radiation impinging on a thermionic plasma enhances the ionization process thereby raising the plasma density and reducing the plasma arc-drop. A source for such radiation may possibly be a Cesium recombination laser operating in a different thermionic converter. The possibility of this being an energy efficient process is discussed.

Lawless, J.L. Jr.

1981-01-01T23:59:59.000Z

233

Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks  

SciTech Connect (OSTI)

The whole-genome sequence of Deinococcus geothermalis is the second for an extremely ionizing radiation (IR) resistant bacterium. The first was for Deinococcus radiodurans, which for 50 years has been the subject of extensive investigations aimed at solving the mystery of how this microbe can survive immense doses of ?-rays. So far, comparative analyses between the genome of D. radiodurans and genomes of other bacteria have failed to produce a coherent picture of the underlying resistance systems. Most surprisingly, many critical DNA repair genes identified in D. radiodurans are present in sensitive bacteria, whereas the involvement of many uncharacterized genes implicated in resistance by transcriptome analyses has not been borne out by mutant studies. Genomic subtraction of D. geothermalis from D. radiodurans was used to define a minimal gene set for extreme resistance, whereby unique genes were ruled out, and shared genes were pooled as candidates for resistance. We revise down substantially the number of potential genetic determinants of extreme radiation resistance, identify a putative regulator and a palindromic binding site for genes which comprise a distinct Deinococcus radiation response regulon, and consider the impact of those findings on the prevailing models of extreme radiation resistance.

Makarova, Kira S.; Omelchenko, M. V.; Gaidamakova, E.; Matrosova, V.; Vasilenko, A.; Zhai, M.; Lapidus, Alla; Copeland, A.; Kim, E.; Land, M.; Mavromatis, Konstantinos; Pitluck, S.; Richardson, P. M.; Detter, J. C.; Brettin, T.; Saunders, Elizabeth; Lai, Barry; Ravel, B.; Kemmer, K. M.; Wolf, Y. I.; Sorokin, Alexander; Gerasimova, A. V.; Gelfand, Mikhail S.; Fredrickson, Jim K.; Koonin, Eugene V.; Daly, M. J.

2007-09-26T23:59:59.000Z

234

Low Dose Radiation Program: Radiation Biology and the Radiation Research  

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

Biology and the Radiation Research Program Biology and the Radiation Research Program The Department of Energy (DOE) and its predecessor organizations, Energy Research and Development Agency (ERDA) and Atomic Energy Commission (AEC), always have been concerned about the health effects of ionizing radiation. Extensive research has been conducted under their sponsorship at all levels of biological organization from molecules to man. Over the past 60 years, studies using every type of radiation source have included exposure to both external radiation sources and to internally deposited radioactive materials. These exposures used different dose patterns and distributions delivered over a wide range of experimental times. This extensive research provided the basis for the new Low Dose Radiation Research Program, linking

235

IR  

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

on several major projects, including current inspection of welds for an oil and gas pipeline company from Italy, welding and inspection system for the National Spent Nuclear...

236

High resolution resonance ionization imaging detector and method  

DOE Patents [OSTI]

A resonance ionization imaging device (RIID) and method for imaging objects using the RIID are provided, the RIID system including a RIID cell containing an ionizable vapor including monoisotopic atoms or molecules, the cell being positioned to intercept scattered radiation of a resonance wavelength .lambda..sub.1 from the object which is to be detected or imaged, a laser source disposed to illuminate the RIID cell with laser radiation having a wavelength .lambda..sub.2 or wavelengths .lambda..sub.2, .lambda..sub.3 selected to ionize atoms in the cell that are in an excited state by virtue of having absorbed the scattered resonance laser radiation, and a luminescent screen at the back surface of the RIID cell which presents an image of the number and position of charged particles present in the RIID cell as a result of the ionization of the excited state atoms. The method of the invention further includes the step of initially illuminating the object to be detected or imaged with a laser having a wavelength selected such that the object will scatter laser radiation having the resonance wavelength .lambda..sub.1.

Winefordner, James D. (Gainesville, FL); Matveev, Oleg I. (Gainesville, FL); Smith, Benjamin W. (Gainesville, FL)

1999-01-01T23:59:59.000Z

237

Modulated voltage metastable ionization detector  

SciTech Connect (OSTI)

Metastable ionization detectors used for chromatographic analysis usually employa fixed high voltage for the ionization potential. For this reason, the operating range is limited to about three orders of magnitude. By use of the technique disclosed in the instant invention, operating ranges of about nine orders of magnitude are obtained. The output current from a metastable ionization detector (MID) is applied to a modulation voltage circuit. An adjustment is made to balance out the background current, and an output current, above background, is applied to an input of a strip chart recorder. For low level concentrations, i.e., low detected output current, the ionization potential will be at a maximum and the metastable ionization detector will operate at its most sensitive level. When the detected current from the metastable ionization detector increases above a predetermined threshold level, a voltage control circuit is activated which turns on a high voltage transistor which acts to reduce the ionization potential. The ionization potential applied to the metastable ionization detector is then varied so as to maintain the detected signal level constant. The variation in ionization potential is now related to the concentration fo the constituent and a representative amplitude is applied to another input of said strip chart recorder.

Carle, G. C.; Humphry, D. E.; Kojiro, D. R.

1985-08-27T23:59:59.000Z

238

Compact IR Quadrupoles for Linear Colliders Based on Rutherford-type Cable  

SciTech Connect (OSTI)

The upcoming and disrupted beams in the interaction region (IR) of a linear collider are focused by doublets consisting of two small-aperture superconducting quadrupoles. These magnets need an effective compact magnetic shielding to minimize magnetic coupling between the two channels and sufficient temperature margin to withstand radiation-induced heat depositions in the coil. This paper presents conceptual designs of IR quadrupoles for linear colliders based on NbTi and Nb{sub 3}Sn Rutherford-type cables.

Lopes, M.L.; Kashikhin, V.S.; Kashikhin, V.V.; Zlobin, A.V.; /Fermilab

2008-08-01T23:59:59.000Z

239

A Low-Cost Reflectance FT-IR Microscope  

Science Journals Connector (OSTI)

A Fourier transform infrared spectroscopy (FT-IR) microscope combines microscopy with infrared (IR) spectroscopic molecular characterization. IR microspectroscopy presents a...

Jansen, J A J; Van Der Maas, J H; Posthuma De Boer, A

1991-01-01T23:59:59.000Z

240

A surface ionization source  

E-Print Network [OSTI]

The Einzel Lens. 2 The Quadrupole Triplet . . 3. The Beam Scanner. . . 4 The Four-plate Detectors and Faraday Cups. III TESTING AND OPTIMIZING THE BEAM LINE 10 12 13 A. Initial Results. IV THE THEORY OF SURFACE IONIZATION . . . . . V ION SOURCES. 21... aperture and through a beam scanner. The scanner translates the beam's cross-section to an image visible on the oscilloscope A movable Faraday cup connected to a sensitive electrometer is used to maximize the beam transmission at the opening into the 2...

Buzatu, Daniel J.

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Plasma Production via Field Ionization  

SciTech Connect (OSTI)

Plasma production via field ionization occurs when an incoming particle beam is sufficiently dense that the electric field associated with the beam ionizes a neutral vapor or gas. Experiments conducted at the Stanford Linear Accelerator Center explore the threshold conditions necessary to induce field ionization by an electron beam in a neutral lithium vapor. By independently varying the transverse beam size, number of electrons per bunch or bunch length, the radial component of the electric field is controlled to be above or below the threshold for field ionization. Additional experiments ionized neutral xenon and neutral nitric oxide by varying the incoming beam's bunch length. A self-ionized plasma is an essential step for the viability of plasma-based accelerators for future high-energy experiments.

O'Connell, C.L.; Barnes, C.D.; Decker, F.; Hogan, M.J.; Iverson, R.; Krejcik, P.; Siemann, R.; Walz, D.R.; /SLAC; Clayton, C.E.; Huang, C.; Johnson, D.K.; Joshi, C.; Lu,; Marsh, K.A.; Mori, W.; Zhou, M.; /UCLA; Deng, S.; Katsouleas, T.; Muggli, P.; Oz, E.; /Southern California U.

2007-01-02T23:59:59.000Z

242

Ionization photophysics and spectroscopy of dicyanoacetylene  

SciTech Connect (OSTI)

Photoionization of dicyanoacetylene was studied using synchrotron radiation over the excitation range 825 eV, with photoelectron-photoion coincidence techniques. The absolute ionization cross-section and detailed spectroscopic aspects of the parent ion were recorded. The adiabatic ionization energy of dicyanoacetylene was measured as 11.80 0.01 eV. A detailed analysis of the cation spectroscopy involves new aspects and new assignments of the vibrational components to excitation of the quasi-degenerate A{sup 2}?{sub g}, B{sup 2}?{sub g}{sup +} states as well as the C{sup 2}?{sub u}{sup +} and D{sup 2}?{sub u} states of the cation. Some of the structured autoionization features observed in the 12.415 eV region of the total ion yield spectrum were assigned to vibrational components of valence shell transitions and to two previously unknown Rydberg series converging to the D{sup 2}?{sub u} state of C{sub 4}N{sub 2}{sup +}. The appearance energies of the fragment ions C{sub 4}N{sup +}, C{sub 3}N{sup +}, C{sub 4}{sup +}, C{sub 2}N{sup +}, and C{sub 2}{sup +} were measured and their heats of formation were determined and compared with existing literature values. Thermochemical calculations of the appearance potentials of these and other weaker ions were used to infer aspects of dissociative ionization pathways.

Leach, Sydney, E-mail: Sydney.Leach@obspm.fr, E-mail: Martin.Schwell@lisa.u-pec.fr; Champion, Norbert [LERMA UMR CNRS 8112, Observatoire de Paris-Meudon, 5 place Jules-Jansen, 92195 Meudon (France)] [LERMA UMR CNRS 8112, Observatoire de Paris-Meudon, 5 place Jules-Jansen, 92195 Meudon (France); Schwell, Martin, E-mail: Sydney.Leach@obspm.fr, E-mail: Martin.Schwell@lisa.u-pec.fr; Bnilan, Yves; Fray, Nicolas; Gazeau, Marie-Claire [LISA UMR CNRS 7583, Universit Paris-Est Crteil and Universit Paris Diderot, Institut Pierre Simon Laplace, 61 Avenue du Gnral de Gaulle, 94010 Crteil (France)] [LISA UMR CNRS 7583, Universit Paris-Est Crteil and Universit Paris Diderot, Institut Pierre Simon Laplace, 61 Avenue du Gnral de Gaulle, 94010 Crteil (France); Garcia, Gustavo A.; Gaie-Levrel, Franois [Synchrotron SOLEIL, LOrme des Merisiers, St. Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex (France)] [Synchrotron SOLEIL, LOrme des Merisiers, St. Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex (France); Guillemin, Jean-Claude [Institut des Sciences Chimiques de Rennes, Ecole Nationale Suprieure de Chimie de Rennes, CNRS UMR 6226, 11 Alle de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)] [Institut des Sciences Chimiques de Rennes, Ecole Nationale Suprieure de Chimie de Rennes, CNRS UMR 6226, 11 Alle de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)

2013-11-14T23:59:59.000Z

243

Radiation physics, biophysics, and radiation biology  

SciTech Connect (OSTI)

The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

Hall, E.J.

1992-05-01T23:59:59.000Z

244

Carbon nanotube IR detectors (SV)  

SciTech Connect (OSTI)

Sandia National Laboratories (Sandia) and Lockheed Martin Corporation (LMC) collaborated to (1) evaluate the potential of carbon nanotubes as channels in infrared (IR) photodetectors; (2) assemble and characterize carbon nanotube electronic devices and measure the photocurrent generated when exposed to infrared light;(3) compare the performance of the carbon nanotube devices with that of traditional devices; and (4) develop and numerically implement models of electronic transport and opto-electronic behavior of carbon nanotube infrared detectors. This work established a new paradigm for photodetectors.

Leonard, F. L.

2012-03-01T23:59:59.000Z

245

Heating and Ionization of the Primordial Intergalactic Medium by High Mass X-ray Binaries  

E-Print Network [OSTI]

We investigate the influence of High Mass X-ray Binaries on their high redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 10^8 solar mass NFW halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy SEDs and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower IGM temp...

Knevitt, Gillian; Power, Chris; Bolton, James

2014-01-01T23:59:59.000Z

246

Ionization and maximum energy of nuclei in shock acceleration theory  

E-Print Network [OSTI]

We study the acceleration of heavy nuclei at SNR shocks when the process of ionization is taken into account. Heavy atoms ($Z_N >$ few) in the interstellar medium which start the diffusive shock acceleration (DSA) are never fully ionized at the moment of injection. The ionization occurs during the acceleration process, when atoms already move relativistically. For typical environment around SNRs the photo-ionization due to the background galactic radiation dominates over Coulomb collisions. The main consequence of ionization is the reduction of the maximum energy which ions can achieve with respect to the standard result of the DSA. In fact the photo-ionization has a timescale comparable to the beginning of the Sedov-Taylor phase, hence the maximum energy is no more proportional to the nuclear charge, as predicted by standard DSA, but rather to the effective ions' charge during the acceleration process, which is smaller than the total nuclear charge $Z_N$. This result can have a direct consequence in the pred...

Morlino, Giovanni

2011-01-01T23:59:59.000Z

247

Low Dose Radiation Program: Links - Organizations Conducting Radiation  

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

Conducting Low Dose Radiation Research Conducting Low Dose Radiation Research DOE Low Dose Radiation Research Program DoReMi Integrating Low Dose Research High Level Expert Group (HLEG) on European Low Dose Risk Research Multidisciplinary European Low Dose Initiative (MELODI) RISC-RAD Radiosensitivity of Individuals and Susceptibility to Cancer induced by Ionizing Radiation United States Transuranium & Uranium Registries Organizations Conducting other Radiation Research Argonne National Laboratory (ANL) Armed Forces Radiology Research Institute (AFRRI) Atmospheric Radiation Measurement (ARM) Program Brookhaven National Laboratory (BNL) Center for Devices and Radiological Health (CDRH) Central Research Institute of Electric Power Industry (CRIEPI) Colorado State University Columbia University

248

Ir L (I.~ DEPARTMENT OF ENERGY ALBUQUERQUE OPERATIONS OFFICE  

Office of Legacy Management (LM)

Ir Ir L (I.~ DEPARTMENT OF ENERGY ALBUQUERQUE OPERATIONS OFFICE I.: ~ CONTRACT NO. DE-AC04-83AL18796 1. Vicinity Property i: Completion Report i , . Remedial Actions , cContractor 4,. -~'~ ~for the Uranium Mill Tailings ~~~z ~ Remedial Actions Project - MK-FEROUSON COMPANY *C~Ad PEE *CMIWN>tfIOW VICINITY PROPERTY COMPLETION REPORT AT CA-401 MAYERS STREET BRIDGEVILLE, PA 15017 JUNE 30, 1987 FOR URANIUM MILL TAILINGS REMEDIAL ACTION PROJECT OFFICE ALBUQUERQUE OPERATIONS OFFICE U.S. DEPARTMENT OF ENERGY ALBUQUERQUE, NM BY MK-FERGUSON CC IPANY AND CHEM-NUCLEAR SYSTEMS, INC. MK-Ferguson Company has been granted authorization to perform remedial action under the Uranium Mill Tailings Radiation Control Act of 1978, Public Law 95-604. Remedial action was done in accordance to the EPA Standards for

249

Ionized Iron Lines in X-ray Reflection Spectra  

E-Print Network [OSTI]

We present results from new calculations of the X-ray reflection spectrum from ionized accretion discs. These computations improve on our previous models by including the condition of hydrostatic balance in the vertical direction, following the work of Nayakshin, Kazanas & Kallman. We find that an ionized Fe K$\\alpha$ line is prominent in the reflection spectra for a wide variety of physical conditions. The results hold for both gas and radiation pressure dominated discs and when the metal abundances have been varied.

D. R. Ballantyne; R. R. Ross; A. C. Fabian

2001-02-15T23:59:59.000Z

250

Quality management system in the CIEMAT Radiation Dosimetry Service  

Science Journals Connector (OSTI)

......for technical services in radiation safety. (2008) IAEA. Safety Guide, No. GS-G-3...protection against ionizing radiation. (2001) 27284-27393...Publication 103. ICRP. 9 Certool Software. AENOR. http://www......

R. Martn; T. Navarro; A. M. Romero; M. A. Lpez

2011-03-01T23:59:59.000Z

251

The Polyamine Catabolic Enzyme SAT1 Modulates Tumorigenesis and Radiation Response in GBM  

Science Journals Connector (OSTI)

...Introduction Exposure to ionizing radiation is a well-established...moderate to high-dose radiation exposure. Examples include...atomic bomb survivors in Japan, women treated with repeated exposure to radiation from fluoroscopic chest...

Adina Brett-Morris; Bradley M. Wright; Yuji Seo; Vinay Pasupuleti; Junran Zhang; Jun Lu; Raffaella Spina; Eli E. Bar; Maneesh Gujrati; Rebecca Schur; Zheng-Rong Lu; and Scott M. Welford

2014-12-01T23:59:59.000Z

252

A COMPARATIVE ASTROCHEMICAL STUDY OF THE HIGH-MASS PROTOSTELLAR OBJECTS NGC 7538 IRS 9 AND IRS 1  

SciTech Connect (OSTI)

We report the results of a spectroscopic study of the high-mass protostellar object NGC 7538 IRS 9 and compare our observations to published data on the nearby object NGC 7538 IRS 1. Both objects originated in the same molecular cloud and appear to be at different points in their evolutionary histories, offering an unusual opportunity to study the temporal evolution of envelope chemistry in objects sharing a presumably identical starting composition. Observations were made with the Texas Echelon Cross Echelle Spectrograph, a sensitive, high spectral resolution (R {lambda}/{Delta}{lambda} {approx_equal} 100,000) mid-infrared grating spectrometer. Forty-six individual lines in vibrational modes of the molecules C{sub 2}H{sub 2}, CH{sub 4}, HCN, NH{sub 3}, and CO were detected, including two isotopologues ({sup 13}CO, {sup 12}C{sup 18}O) and one combination mode ({nu}{sub 4} + {nu}{sub 5} C{sub 2}H{sub 2}). Fitting synthetic spectra to the data yielded the Doppler shift, excitation temperature, Doppler b parameter, column density, and covering factor for each molecule observed; we also computed column density upper limits for lines and species not detected, such as HNCO and OCS. We find differences among spectra of the two objects likely attributable to their differing radiation and thermal environments. Temperatures and column densities for the two objects are generally consistent, while the larger line widths toward IRS 9 result in less saturated lines than those toward IRS 1. Finally, we compute an upper limit on the size of the continuum-emitting region ({approx}2000 AU) and use this constraint and our spectroscopy results to construct a schematic model of IRS 9.

Barentine, John C.; Lacy, John H. [Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712-0259 (United States)

2012-10-01T23:59:59.000Z

253

Effects of Substerilization Doses of Co60 Gamma Radiation on the Cold-Storage Life Extension of Shucked Soft-Shelled Clams and Haddock Fillets  

Science Journals Connector (OSTI)

...000 rad of ionizing radiation. In the dose range from 200,000...000 rad of ionizing radiation. In the dose range from 200,000...000 rad of ionizing radiation. Nevertheless...indicate that in the dose range from 400,000...

E. B. Masurovsky; S. A. Goldblith; J. T. R. Nickerson

1963-05-01T23:59:59.000Z

254

Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks  

SciTech Connect (OSTI)

Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at itsoptimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to resistance; and strengthen the case for a role in survival of systems involved in manganese and iron homeostasis.

Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min; Lapidus, Alla; Copeland, Alex; Kim, Edwin; Land, Miriam; Mavrommatis, Konstantinos; Pitluck, Samuel; Richardson, Paul M.; Detter, Chris; Brettin, Thomas; Saunders, Elizabeth; Lai, Barry; Ravel, Bruce; Kemner, Kenneth M.; Wolf, Yuri I.; Sorokin, Alexander; Gerasimova, Anna V.; Gelfand, Mikhail S.; Fredrickson, James K.; Koonin, Eugene V.; Daly, Michael J.

2007-07-24T23:59:59.000Z

255

Concepts of radiation safety and protection: Beyond BEIR V  

SciTech Connect (OSTI)

The publication of an updated report on the biological effects of ionizing radiation (BEIR V) has focused new attention on the potential hazards associated with the use of low doses of ionizing radiation for diagnostic purposes. This article reviews the BEIR V report findings and suggests methods for reducing the risks to dental patients and the operators of dental x-ray equipment.

Farman, A.G. (University of Louisville School of Dentistry, KY (USA))

1991-01-01T23:59:59.000Z

256

Optical ionization detector  

DOE Patents [OSTI]

An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium. 3 figures.

Wuest, C.R.; Lowry, M.E.

1994-03-29T23:59:59.000Z

257

Optical ionization detector  

DOE Patents [OSTI]

An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium.

Wuest, Craig R. (Danville, CA); Lowry, Mark E. (Castro Valley, CA)

1994-01-01T23:59:59.000Z

258

Improved ARM-SGP TOA OLR Fluxes from GOES-8 IR Radiances Based on CERES Data  

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

ARM-SGP TOA OLR Fluxes from GOES-8 IR ARM-SGP TOA OLR Fluxes from GOES-8 IR Radiances Based on CERES Data D. R. Doelling and M. M. Khaiyer Analytical Services and Materials, Inc. Hampton, Virginia P. Minnis National Aeronautics and Space Administration Langley Research Center Hampton, Virginia Introduction The radiation budget at the top of the atmosphere (TOA) is a quantity of fundamental importance to the Atmospheric Radiation Measurement (ARM) Program. Thus, it is necessary to measure the radiation budget components, broadband shortwave albedo and outgoing longwave radiation (OLR), as accurately as possible. Measurement of OLR over the ARM surface sites has only been possible since the advent of Clouds and the Earth's Radiant Energy System (CERES; Wielicki et al. 1998) in 1998. Prior to

259

An Improved Daylight Correction for IR Loss in ARM Diffuse SW Measurements  

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

An Improved Daylight Correction for IR Loss An Improved Daylight Correction for IR Loss in ARM Diffuse SW Measurements C. N. Long, K. Younkin, and K. L. Gaustad Pacific Northwest National Laboratory Richland, Washington J. A. Augustine National Oceanic and Atmospheric Administration Air Resources Laboratory Surface Radiation Research Branch Boulder, Colorado Introduction A paper by Cess et al. (2000) notes that some clear-sky diffuse shortwave (SW) measurements they were using from the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site exhibited less than Rayleigh magnitude. Remarking that this is a physical impossibility, the obvious conclusion forwarded by the authors was that there was some problem with the ARM SGP diffuse SW data. Shortly thereafter, the problem of infrared (IR) loss from thermopile-based single black detector

260

General situation of radiation accidents in China  

Science Journals Connector (OSTI)

......never received any formal safety culture education, so...professionals, and during safety culture education, for...dose results, relevant software has been developed for...International basic safety standards for protection against ionizing radiation and for the safety of......

Zhou Li; Zhang Wenyi; Zhang Liang'an

2007-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

INSTITUTE OF NUCLEAR TECHNOLOGY RADIATION PROTECTION  

E-Print Network [OSTI]

of the impact of ionizing radiation on several types of ecosystems, atmospheric aerosol, and heavy metal. Stubos Computer Simulation of Atmospheric Pollution S. Andronopoulos Analyses & Assessment of Environmental Pollutants S. Andronopoulos ENVIRONMENTAL RESEARCH LABORATORY A. Stubos Diagnostics of Boundary

262

United States Environmental Protection Agency Radiation Office...  

Office of Legacy Management (LM)

and non-ionizing radiation, and to promote the controls necessary to protect the public health and safety. The purpose of this report is to present the results of a survey of...

263

Resonance Ionization Laser Ion Sources  

E-Print Network [OSTI]

The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

Marsh, B

2013-01-01T23:59:59.000Z

264

Field ionization from carbon nanofibers  

E-Print Network [OSTI]

The Micro Gas Analyzer project aims to develop power-efficient, high resolution, high sensitivity, portable and real-time gas sensors. We developed a field ionizer array based on gated CNTs. Arrays of CNTs are used because ...

Adeoti, Bosun J

2008-01-01T23:59:59.000Z

265

Measurement of the radiation field surrounding the Collider Detector at Fermilab  

SciTech Connect (OSTI)

We present here the first direct and detailed measurements of the spatial distribution of the ionizing radiation surrounding a hadron collider experiment. Using data from two different exposures we measure the effect of additional shielding on the radiation field around the Collider Detector at Fermilab (CDF). Employing a simple model we parameterize the ionizing radiation field surrounding the detector.

K. Kordas et al.

2004-01-28T23:59:59.000Z

266

IONIZATION OF EXTRASOLAR GIANT PLANET ATMOSPHERES  

SciTech Connect (OSTI)

Many extrasolar planets orbit close in and are subject to intense ionizing radiation from their host stars. Therefore, we expect them to have strong, and extended, ionospheres. Ionospheres are important because they modulate escape in the upper atmosphere and can modify circulation, as well as leave their signatures, in the lower atmosphere. In this paper, we evaluate the vertical location Z{sub I} and extent D{sub I} of the EUV ionization peak layer. We find that Z{sub I{approx}}1-10 nbar-for a wide range of orbital distances (a = 0.047-1 AU) from the host star-and D{sub I}/H{sub p{approx}}>15, where H{sub p} is the pressure scale height. At Z{sub I}, the plasma frequency is {approx}80-450 MHz, depending on a. We also study global ion transport, and its dependence on a, using a three-dimensional thermosphere-ionosphere model. On tidally synchronized planets with weak intrinsic magnetic fields, our model shows only a small, but discernible, difference in electron density from the dayside to the nightside ({approx}9 x 10{sup 13} m{sup -3} to {approx}2 x 10{sup 12} m{sup -3}, respectively) at Z{sub I}. On asynchronous planets, the distribution is essentially uniform. These results have consequences for hydrodynamic modeling of the atmospheres of close-in extrasolar giant planets.

Koskinen, Tommi T. [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ (United States); Cho, James Y-K. [Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Achilleos, Nicholas; Aylward, Alan D., E-mail: tommi@lpl.arizona.ed [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2010-10-10T23:59:59.000Z

267

Observation of ionization fronts in low density foam targets  

SciTech Connect (OSTI)

Ionization fronts have been observed in low density chlorinated foam targets and low density foams confined in gold tubes using time resolved {ital K}-shell absorption spectroscopy. The front was driven by an intense pulse of soft x-rays produced by high power laser irradiation. The density and temperature profiles inferred from the radiographs provided detailed measurement of the conditions. The experimental data were compared to radiation hydrodynamics simulations and reasonable agreement was obtained. {copyright} {ital 1999 American Institute of Physics.}

Hoarty, D. [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [Imperial College of Science, Technology and Medicine, London (United Kingdom); [Radiation Physics Department, AWE Aldermaston, Reading, Berkshire (United Kingdom); Willi, O.; Barringer, L.; Vickers, C. [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [Imperial College of Science, Technology and Medicine, London (United Kingdom); Watt, R. [P24, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [P24, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Nazarov, W. [Chemistry Department, University of Dundee (United Kingdom)] [Chemistry Department, University of Dundee (United Kingdom)

1999-05-01T23:59:59.000Z

268

Neutron And Gamma Detector Using An Ionization Chamber With An Integrated  

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

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. Available for thumbnail of Feynman Center (505) 665-9090 Email Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an

269

MID-INFRARED ATOMIC FINE-STRUCTURE EMISSION-LINE SPECTRA OF LUMINOUS INFRARED GALAXIES: SPITZER/IRS SPECTRA OF THE GOALS SAMPLE  

SciTech Connect (OSTI)

We present the data and our analysis of mid-infrared atomic fine-structure emission lines detected in Spitzer/Infrared Spectrograph high-resolution spectra of 202 local Luminous Infrared Galaxies (LIRGs) observed as part of the Great Observatories All-sky LIRG Survey (GOALS). We readily detect emission lines of [S IV], [Ne II], [Ne V], [Ne III], [S III]{sub 18.7{sub ?m}}, [O IV], [Fe II], [S III]{sub 33.5{sub ?m}}, and [Si II]. More than 75% of these galaxies are classified as starburst-dominated sources in the mid-infrared, based on the [Ne V]/[Ne II] line flux ratios and equivalent width of the 6.2 ?m polycyclic aromatic hydrocarbon feature. We compare ratios of the emission-line fluxes to those predicted from stellar photo-ionization and shock-ionization models to constrain the physical and chemical properties of the gas in the starburst LIRG nuclei. Comparing the [S IV]/[Ne II] and [Ne III]/[Ne II] line ratios to the Starburst99-Mappings III models with an instantaneous burst history, the emission-line ratios suggest that the nuclear starbursts in our LIRGs have ages of 1-4.5 Myr, metallicities of 1-2 Z{sub ?}, and ionization parameters of 2-8 10{sup 7} cm s{sup 1}. Based on the [S III]{sub 33.5{sub ?m}}/[S III]{sub 18.7{sub ?m}} ratios, the electron density in LIRG nuclei is typically one to a few hundred cm{sup 3}, with a median electron density of ?300 cm{sup 3}, for those sources above the low density limit for these lines. We also find that strong shocks are likely present in 10 starburst-dominated sources of our sample. A significant fraction of the GOALS sources (80) have resolved neon emission-line profiles (FWHM ?600 km s{sup 1}) and five show clear differences in the velocities of the [Ne III] or [Ne V] emission lines, relative to [Ne II], of more than 200 km s{sup 1}. Furthermore, six starburst and five active galactic nucleus dominated LIRGs show a clear trend of increasing line width with ionization potential, suggesting the possibility of a compact energy source and stratified interstellar medium in their nuclei. We confirm a strong correlation between the sum of the [Ne II]{sub 12.8{sub ?m}} and [Ne III]{sub 15.5{sub ?m}} emission, as well as [S III]{sub 33.5{sub ?m}}, with both the infrared luminosity and the 24 ?m warm dust emission measured from the spectra, consistent with all three lines tracing ongoing star formation. Finally, we find no correlation between the hardness of the radiation field or the emission-line width and the ratio of the total infrared to 8 ?m emission (IR8), a measure of the strength of the starburst and the distance of the LIRGs from the star-forming main sequence. This may be a function of the fact that the infrared luminosity and the mid-infrared fine-structure lines are sensitive to different timescales over the starburst, or that IR8 is more sensitive to the geometry of the region emitting the warm dust than the radiation field producing the H II region emission.

Inami, H. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Armus, L.; Stierwalt, S.; Daz-Santos, T.; Surace, J.; Howell, J.; Marshall, J. [Spitzer Science Center, California Institute of Technology, CA 91125 (United States); Charmandaris, V. [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Groves, B. [Max Planck Institute for Astronomy, Knigstuhl 17, D-69117 Heidelberg (Germany); Kewley, L. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Petric, A. [Department of Astronomy, California Institute of Technology, MS 320-47, Pasadena, CA 91125 (United States); Rich, J. [The Observatories, Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Haan, S. [CSIRO Astronomy and Space Science, Marsfield, NSW 2122 (Australia); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Mazzarella, J.; Lord, S. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Appleton, P. [NASA Herschel Science Center, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Spoon, H. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Frayer, D. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Matsuhara, H., E-mail: inami@noao.edu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (Japan); and others

2013-11-10T23:59:59.000Z

270

Low Dose Radiation Research Program: Image Gallery  

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

Image Gallery Image Gallery These are images, photographs, and charts presented or developed for Low Dose Radiation Research Investigators’ Meetings. They may be used for presentations or reports. To save, right click on the picture, then choose "Save picture as." U.S. annual per-capita effective radiation dose from various sources for 1980. various sources 1980 Enlarge Image. U.S. annual per-capita effective radiation dose from various sources for 2006. various sources 2006 Enlarge Image. U.S. annual per-capita effective radiation dose from man-made sources in the United States for 2006. man-made 2006 Enlarge Image. Ionizing Radiation Dose Ranges showing the wide range of radiation doses that humans experience (Rem) Enlarge Image. Ionizing Radiation Dose Ranges showing the wide range of radiation doses that humans experience

271

Intensity-resolved Above Threshold Ionization Yields of Atoms with Ultrashort Laser Pulses  

E-Print Network [OSTI]

. Electron ionization yields of xenon were measured for a set of laser pulse intensities using a time of flight (TOF) setup. Horizontally polarized, unchirped, pulses were used in the ionization process. All laser parameters other than the radiation... Tiezer, I am grateful for all their time and help. I would like to thank Dr. James Strohaber for detailed discussions and assistance related to this experiment. I acknowledge the Department of Physics at Texas A&M and the US Air Force...

Hart, Nathan Andrew

2012-10-19T23:59:59.000Z

272

Low Dose Radiation Research Program: Bruce E. Lehnert  

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

E. Lehnert E. Lehnert Los Alamos National Laboratory Past Project Low Dose Ionizing Radiation-Induced Effects in Irradiated and Unirradiated Cells: Pathways Analysis in Support of Risk Assessment. Technical Abstracts 2002 Workshop: Low Dose Ionizing Radiation-Induced Effects in Irradiated and Unirradiated cells: Pathways Analysis in Support of Risk Assessment. Lehnert, B.E., Cary, R., Gadbois, D. and Gupta G. 2001 Workshop: Low Dose, Low Dose Rate Effects of Ionizing Radiation in Irradiated and Unirradiated Cells. Lehnert, B.E. 1999 Workshop: Low Dose, Low Dose Rate Effects of Ionizing Radiation in Irradiated and Unirradiated Cells. Lehnert, B.E. Publications Lehnert, B.E., Radiation bystander effects. U.S.Department of Energy Research News (March 6 issue) Goldberg, Z. and Lehnert, B.E. (2002). Radiation-induced effects in

273

E-Print Network 3.0 - absorbed radiation dose Sample Search Results  

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

know Summary: . Absorbed dose is the physical quantity describing energy deposited per unit mass. For radiation protection... Cancer risks attributable to low doses of ionizing...

274

E-Print Network 3.0 - accumulated radiation dose Sample Search...  

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

. At the end, this seminar concentrates on the dose contributions of naturally occurring ionizing radiation... particles. - The equivalent dose, HT, which takes into account...

275

Broadly tunable picosecond IR source  

DOE Patents [OSTI]

A picosecond traveling-wave parametric device capable of controlled spectral bandwidth and wavelength in the infrared is reported. Intense 1.064 .mu.m picosecond pulses (1) pass through a 4.5 cm long LiNbO.sub.3 optical parametric oscillator crystal (2) set at its degeneracy angle. A broad band emerges, and a simple grating (3) and mirror (4) arrangement is used to inject a selected narrow-band into a 2 cm long LiNbO.sub.3 optical parametric amplifier crystal (5) along a second pump line. Typical input energies at 1.064 .mu.m along both pump lines are 6-8 mJ for the oscillator and 10 mJ for the amplifier. This yields 1 mJ of tunable output in the range 1.98 to 2.38 .mu.m which when down-converted in a 1 cm long CdSe crystal mixer (6) gives 2 .mu.J of tunable radiation over the 14.8 to 18.5 .mu.m region. The bandwidth and wavelength of both the 2 and 16 .mu.m radiation output are controlled solely by the diffraction grating.

Campillo, Anthony J. (Nesconset, NY); Hyer, Ronald C. (Los Alamos, NM); Shapiro, Stanley J. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

276

IRS Announces New Tribal Economic Development Bond Allocation...  

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

IRS Announces New Tribal Economic Development Bond Allocation Guidance IRS Announces New Tribal Economic Development Bond Allocation Guidance July 18, 2012 - 3:46pm Addthis To...

277

Project Lyman: Quantifying 11 Gyrs of Metagalactic Ionizing Background Evolution  

E-Print Network [OSTI]

The timing and duration of the reionization epoch is crucial to the emergence and evolution of structure in the universe. The relative roles that star-forming galaxies, active galactic nuclei and quasars play in contributing to the metagalactic ionizing background across cosmic time remains uncertain. Deep quasar counts provide insights into their role, but the potentially crucial contribution from star-formation is highly uncertain due to our poor understanding of the processes that allow ionizing radiation to escape into the intergalactic medium (IGM). The fraction of ionizing photons that escape from star-forming galaxies is a fundamental free parameter used in models to "fine-tune" the timing and duration of the reionization epoch that occurred somewhere between 13.4 and 12.7 Gyrs ago (redshifts between 12 > z > 6). However, direct observation of Lyman continuum (LyC) photons emitted below the rest frame \\ion{H}{1} ionization edge at 912 \\AA\\ is increasingly improbable at redshifts z > 3, due to the stead...

McCandliss, Stephan R; Bergvall, Nils; Bianchi, Luciana; Bridge, Carrie; Bogosavljevic, Milan; Cohen, Seth H; Deharveng, Jean-Michel; Dixon, W Van Dyke; Ferguson, Harry; Friedman, Peter; Hayes, Matthew; Howk, J Christopher; Inoue, Akio; Iwata, Ikuru; Kaiser, Mary Elizabeth; Kriss, Gerard; Kruk, Jeffrey; Kutyrev, Alexander S; Leitherer, Claus; Meurer, Gerhardt R; Prochaska, Jason X; Sonneborn, George; Stiavelli, Massimo; Teplitz, Harry I; Windhorst, Rogier A

2012-01-01T23:59:59.000Z

278

Low Dose Radiation Program: Links - Online Literature  

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

Online Literature Online Literature Journals, Books and other Publications Armed Forces Radiobiology Research Institute Chornobyl Center for Nuclear Safety Radioactive Waste and Radioecology "Insight" Magazine Central Research Institute of the Electric Power Industry (CRIEPI) News: Aiming at an information center on low dose radiation research Health Physics International Journal of Radiation Biology Iranian Journal of Radiation Research Journal of Radiological Protection National Council on Radiation Protection and Measurements Radiation Research U.S. Department of Energy (DOE) Information Bridge Reports Animal Cancer Tests and Human Cancer Risk Assessment: A Broad Perspective Effects of Ionizing Radiation: Atomic Bomb Survivors and Their Children (1945-1995) Health Effects of Exposure to Low Levels of Ionizing Radiation: BEIR

279

Telomere Targeting with a New G4 Ligand Enhances Radiation-Induced Killing of Human Glioblastoma Cells  

Science Journals Connector (OSTI)

...sensitivity to ionizing radiation of 2 human telomerase-positive...Coulter) using CellQuest software. Apoptosis assessment...of TAC combined with radiation on GBM cells in vitro...trials with acceptable safety (49). In conclusion...sensitivity to ionizing radiation of 2 human hTERT-positive...

Patrick Merle; Bertrand Evrard; Anne Petitjean; Jean-Marie Lehn; Marie-Paule Teulade-Fichou; Emmanuel Chautard; Anne De Cian; Lionel Guittat; Phong Lan Thao Tran; Jean-Louis Mergny; Pierre Verrelle; and Andre Tchirkov

2011-10-01T23:59:59.000Z

280

Method to Improve Total Dose Radiation Hardness in a CMOS dc-dc Boost  

E-Print Network [OSTI]

in a wide range of radiation environment, with increasing total dose radiation, The efticieney also greatlyMethod to Improve Total Dose Radiation Hardness in a CMOS dc-dc Boost Converter Huadian Pan to natural radiation in space. Among the effects of ionizing radiation are shiftsin threshold voltageand

Wilamowski, Bogdan Maciej

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281

IR LASER BASED CHEMICAL SENSOR FOR THE COOPERATIVE MONITORING PROGRAM  

SciTech Connect (OSTI)

The purpose of this project was to investigate the device properties of the quantum cascade laser (QCL), a type of laser invented at Bell Laboratories, Lucent Technologies in the device physics research lab of Dr. Federico Capasso and more specifically to determine the remote sensing capability of this device. The PI and Stevens Institute of Technology collaborated with Dr. Capasso and Bell Laboratories to carry out this research project. The QCL is a unique laser source capable of generating laser radiation in the middle-infrared spectral region that overlaps the most important molecular absorption bands. With appropriate modulation techniques it is possible to use the laser to measure the concentration of many molecules of interest to the remote sensing community. In addition, the mid-IR emission wavelength is well suited to atmospheric transmission as mid-IR experiences much less scattering due to dust and fog. At the onset of this project little was known about several key device performance parameters of this family of lasers and the NNSA supported research enabled them to determine values of several of these characteristics.

Edward A Whitaker

2005-08-08T23:59:59.000Z

282

Electron impact ionization of neutral and ionized fullerenes: ionization crosssections and kinetic energy release  

Science Journals Connector (OSTI)

...and 1000 eV, with an energy spread of approximately...exit electrode by an electric field penetrating from...measurements of appearance energies and ionization cross-sections...measurements have been car- ried out (in both...cross-sections versus electron energy from threshold up to...

1999-01-01T23:59:59.000Z

283

High Power Operation of the JLab IR FEL Driver Accelerator  

SciTech Connect (OSTI)

Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

Kevin Beard; Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Christopher Gould; Albert Grippo; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; J. Hovater; Kevin Jordan; John Klopf; Rui Li; Steven Moore; George Neil; Benard Poelker; Thomas Powers; Joseph Preble; Robert Rimmer; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Gwyn Williams; Shukui Zhang

2007-08-01T23:59:59.000Z

284

Fiber Delivery of mid-IR lasers  

SciTech Connect (OSTI)

Fiber optics for the visible to near infrared (NIR) wavelength regimes (i.e. = 0.42 {mu}m) have proven to be extremely useful for a myriad of applications such as telecommunications, illumination, and sensors because they enable convenient, compact, and remote delivery of laser beams. Similarly, there is a need for fiber optics operating at longer wavelengths. For example, systems operating in the mid-IR regime (i.e., = 314 {mu}m) are being developed to detect trace molecular species with far-reaching applications, such as detecting explosives on surfaces, pollutants in the environment, and biomarkers in the breath of a patient. Furthermore, with the increasing availability of quantum cascade lasers (QCLs) which are semiconductor lasers that operate in the mid-IR regime additional uses are rapidly being developed. Here, we describe the development of hollow-core fibers for delivery of high-quality mid-IR laser beams across a broad spectral range.

Kriesel, J.M.; Gat, N.; Bernacki, Bruce E.; Myers, Tanya L.; Bledt, Carlos M.; Harrington, James P.

2011-08-24T23:59:59.000Z

285

About EffectiveŽ Height of the Aerosol Atmosphere in Visible and IR Wavelength Range  

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

"Effective" Height of the Aerosol Atmosphere in "Effective" Height of the Aerosol Atmosphere in Visible and IR Wavelength Range V. N. Uzhegov, D. M. Kabanov, M. V. Panchenko, Yu. A. Pkhalagov, and S. M. Sakerin Institute of Atmospheric Optics Tomsk, Russia Introduction Aerosol component of the atmosphere is one of the important factors affecting the radiation budget of the space - atmosphere - underlying surface system in visible and infrared (IR) wavelength ranges. It is extremely important to take into account the contribution of this component into the extinction of solar radiation under cloudless sky conditions. Sometimes it is important to know not only the total value of the aerosol component of extinction, but also to have the possibility to estimate the "effective" height of

286

Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body  

Science Journals Connector (OSTI)

...photoelectrons. For most ionizing radiations, a large proportion...the absorbed dose is deposited...having a shorter range and being more strongly ionizing close to the...in high local doses, causing damage...enhancement of the radiation dose in volumes...

2010-01-01T23:59:59.000Z

287

Applied Radiation and Isotopes 57 (2002) 875882 Energy response of an imaging plate exposed to  

E-Print Network [OSTI]

, TN 37232-5671, USA b Ionizing Radiation Division, National Institute of Standard and Technology, 100 when exposed to ionizing radiation, store a latent image that can be read out with a red laser beta emitters such as P-32 and Sr- 90 due to the advantages of short range dose delivery and suitable

Tolk, Norman H.

288

Assessment of the Technologies for Molecular Biodosimetry for Human Low-Dose Radiation Exposure Symposium  

SciTech Connect (OSTI)

Exposure to ionizing radiation produces few immediate outwardly-visible clinical signs, yet, depending on dose, can severely damage vital physiological functions within days to weeks and produce long-lasting health consequences among survivors. In the event of a radiological accident, the rapid evaluation of the individual absorbed dose is paramount to discriminate the worried but unharmed from those individuals who must receive medical attention. Physical, clinical and biological dosimetry are usually combined for the best dose assessment. However, because of the practical limits of physical and clinical dosimetry, many attempts have been made to develop a dosimetry system based on changes in biological parameters, including techniques for hematology, biochemistry, immunology, cytogenetics, etc. Lymphocyte counts and chromosome aberrations analyses are among the methods that have been routinely used for estimating radiation dose. However, these assays require several days to a week to be completed and therefore cannot be used to obtain a fast estimate of the dose during the first few days after exposure when the information would be most critical for identifying victims of radiation accidents who could benefit the most by medical intervention. The steadily increasing sophistication in our understanding of the early biochemical responses of irradiated cells and tissues provides the opportunity for developing mechanism-based biosignatures of exposure. Compelling breakthroughs have been made in the technologies for genome-scale analysis of cellular transcriptional and proteomic profiles. There have also been major strides in the mechanistic understanding of the early events in DNA damage and radiation damage products, as well as in the cellular pathways that lead to radiation injury. New research with genomic- and proteomic-wide tools is showing that within minutes to hours after exposure to ionizing radiation protein machines are modified and activated, and large-scale changes occur in the gene expression profile involving a broad variety of cell-process pathways after a wide range of both low (<10 cGy) and high dose (>10 cGy) exposures. Evaluation of these potential gene and protein biomarkers for early and late diagnostic information will be critical for determining the efficacy of the signatures to both low and high dose IR exposures. Also needed are approaches that enable rapid handling and processing for mass-casualty and population triage scenarios. Development of in vivo model system will be crucial for validating both the biological and the instrumentation for biodosimetry. Such studies will also help further understanding of the molecular mechanisms of the biological effects of radiation and the differences of responses due to individual genetic variation.

Matthew A. Coleman Ph.D.; Narayani Ramakrishnan, Ph.D.; Sally A. Amundson; James D. Tucker, Ph.D.; Stephen D. Dertinger, Ph.D.; Natalia I. Ossetrova, Ph.D.; Tao Chen

2009-11-16T23:59:59.000Z

289

IR-4 Ornamental Horticulture Program Trial Report  

E-Print Network [OSTI]

IR-4 Ornamental Horticulture Program Trial Report Researcher(s): Heiner Lieth, UC Davis PRNumber. The phytotoxicity index values generally averaged less than 2, suggesting very light damage which is probably-4 Ornamental Horticulture Program Trial Report Researcher(s): Heiner Lieth, UC Davis PRNumber

Lieth, J. Heinrich

290

Cosmic IR Backgrounds Ned Wright (UCLA)  

E-Print Network [OSTI]

Cosmic IR Backgrounds by Ned Wright (UCLA) http://www.astro.ucla.edu/~wright/intro.html See: · http://www.astro.ucla.edu/~wright/cosmolog.htm · http://www.astro.ucla.edu/~wright/DIRBE · http://www.astro.ucla.edu/~wright/CIBR · http

Wright, Edward L. "Ned"

291

Molecular mechanisms and cellular consequences of low-dose exposure to ionizing  

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

mechanisms and cellular consequences of low-dose exposure to ionizing mechanisms and cellular consequences of low-dose exposure to ionizing radiation Andrew J. Wyrobek 1 , Francesco Marchetti 1 , Xiu Lowe 1 , Xiaochen Lu 2 , Terumi Kohwi- Shigematsu 1 , Brian Davy 1 , Thomas E. Schmid 1 , Sylvia Ahn 1 , Tarlochan Nijjar 1 Matthew A. Coleman 2 , Contact information: ajwyrobek@gmail.com 1 Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 2 BioSciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA. The objectives of this research are to characterize the genome-wide molecular responses to low-dose ionizing radiation (<10cGy), to identify tissue and cell-type specific differences in pathways responses, and to identify the pivotal molecular pathway responses that control risks to genome integrity and health. This project utilizes mouse in

292

A study of the response of a gas ionization chamber to different sources of ionizing radiation  

E-Print Network [OSTI]

ranged from a few keV to 20 MeV and peaked at 5 MeV. The neutrons were produced by the (n, n) reaction o(5. 16MeV)+ Be ~ C+n( 5MeV). A 2-in thick lead brick was placed in front of the chamber to absorb the soft 7-rays emitted from the source along... with the neutrons. The source was kept 9in away from the chamber during all runs. Data were taken for both gas mixtures with the cathode pad facing the source and also with the chamber turned around. In addition to these measurements, four more runs were made...

Zamble?-Die?guez, Filiberto Edmundo

2012-06-07T23:59:59.000Z

293

Safety Around Sources of Radiation  

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

Keeping Exposure Low 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 BEIR V (Biological Effects of Ionizing Radiation) Committee of the National Research Council estimates that among 100,000 people exposed to a one-time dose of 10 rem (10,000 mrem) and followed over their life span, about 790 more would die of cancer than the estimated 20,000 cancer deaths that would be expected among a non-exposed group of the same size. NOTE: 10 rem = 100 millisieverts (100 mSv).

294

Graphene Field Effect Transistors for Detection of Ionizing Radiation  

E-Print Network [OSTI]

University, West Lafayette, IN, 47907 and with Birck Nanotechnology Center, Purdue Univer- sity, West Lafayette, IN, 47907, and with Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907 variety of applications like nuclear security, medicine, and basic research. Fig. 1a. A prototype graphene

Chen, Yong P.

295

Exposure assessment: implications for epidemiological studies of ionizing radiation  

Science Journals Connector (OSTI)

......et al. (4) used average doses to birth cohorts...were made in the homes of 58% of the interviewed...histories (e.g. consumption of milk) in order...exposure to radon in homes and lung cancer have...controls on radon in homes are often based on...exposure to high linear energy transfer (LET......

Colin R. Muirhead

2008-12-01T23:59:59.000Z

296

Ionizing Radiation Microbeam Facilities for Radiobiological Studies in Europe  

Science Journals Connector (OSTI)

......and is currently under development and test at INFN-LNL...the one developed at SNAKE facility. It makes...than 95%) is under development at LIPSION. Cell detection...glued using low fusion temperature wax.26) A similar...irradiation cycles.26) At SNAKE facility an appropriate......

Silvia Gerardi

2009-03-01T23:59:59.000Z

297

Radiative Heating in Underexplored Bands Campaign (RHUBC)  

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

Bands Campaign (RHUBC) D. Turner and E. Mlawer RHUBC Breakout Session 2008 ARM Science Team Meeting 13 March, 2008 Norfolk, Virginia Motivation * Radiative heating/cooling in the mid-troposphere modulate the vertical motions of the atmosphere - This heating/cooling occurs primarily in water vapor absorption bands that are opaque at the surface * Approximately 40% of the OLR comes from the far-IR * Until recently, the observational tools were not available to evaluate the accuracy of the far-IR radiative transfer models - Spectrally resolved far-IR radiances, accurate PWV * Need to validate both clear sky (WV) absorption and cirrus scattering properties in these normally opaque bands Scientific Objectives * Conduct clear sky radiative closure studies in order to reduce uncertainties

298

Audible radiation monitor  

SciTech Connect (OSTI)

This invention consists of 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.

Odell, D.M.C.

1992-12-31T23:59:59.000Z

299

Sample Desorption/Ionization From Mesoporous Silica  

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

Sample Desorption/Ionization From Mesoporous Silica Sample Desorption/Ionization From Mesoporous Silica Sample Desorption/Ionization From Mesoporous Silica Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Available for thumbnail of Feynman Center (505) 665-9090 Email Sample Desorption/Ionization From Mesoporous Silica Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Supported mesoporous silica was prepared by coating an ethanolic silicate solution having a removable surfactant onto a substrate to produce a self-assembled, ordered, nanocomposite silica thin film. The surfactant was chosen to provide a desired pore size between about 1 nanometer diameter and 50 nanometers diameter. Removal of the surfactant resulted in a mesoporous silica thin

300

Ionized gas at the edge of the Central Molecular Zone  

E-Print Network [OSTI]

To determine the properties of the ionized gas at the edge of the CMZ near Sgr E we observed a small portion of the edge of the CMZ near Sgr E with spectrally resolved [C II] 158 micron and [N II] 205 micron fine structure lines at six positions with the GREAT instrument on SOFIA and in [C II] using Herschel HIFI on-the-fly strip maps. We use the [N II] spectra along with a radiative transfer model to calculate the electron density of the gas and the [C II] maps to illuminate the morphology of the ionized gas and model the column density of CO-dark H2. We detect two [C II] and [N II] velocity components, one along the line of sight to a CO molecular cloud at -207 km/s associated with Sgr E and the other at -174 km/s outside the edge of another CO cloud. From the [N II] emission we find that the average electron density is in the range of about 5 to 25 cm{-3} for these features. This electron density is much higher than that of the warm ionized medium in the disk. The column density of the CO-dark H$_2$ layer ...

Langer, W D; Pineda, J L; Velusamy, T; Requena-Torres, M A; Wiesemeyer, H

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Low-Dose/Dose-Rate Low-LET Radiation Protects Us from Cancer  

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

Dose/Dose-Rate Low-LET Radiation Protects Us from Cancer Dose/Dose-Rate Low-LET Radiation Protects Us from Cancer Bobby R. Scott, Ph.D. and Jennifer D. Di Palma Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive SE Albuquerque, NM 87108 USA Life on earth evolved in a low-level ionizing radiation environment comprised of terrestrial radiation and cosmic rays. Today we all reside in an ionizing radiation environment comprised of both natural background radiation and radiation from human activities (e.g., Chernobyl accident). An evolutionary benefit of the interaction of low-level, low linear-energy-transfer (LET) ionizing radiation with mammalian life forms on earth is adapted protection. Adapted protection involves low-dose/dose-rate, low-LET radiation induced high-fidelity DNA repair in cooperation with normal apoptosis (presumed p53

302

Ionization probes of molecular structure and chemistry  

SciTech Connect (OSTI)

Various photoionization processes provide very sensitive probes for the detection and understanding of the spectra of molecules relevant to combustion processes. The detection of ionization can be selective by using resonant multiphoton ionization or by exploiting the fact that different molecules have different sets of ionization potentials. Therefore, the structure and dynamics of individual molecules can be studied even in a mixed sample. The authors are continuing to develop methods for the selective spectroscopic detection of molecules by ionization, and to use these methods for the study of some molecules of combustion interest.

Johnson, P.M. [State Univ. of New York, Stony Brook (United States)

1993-12-01T23:59:59.000Z

303

Low Dose Radiation Research Program: Earlier Events  

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

Earlier Events Earlier Events 2000 | 2001 | 2002 | 2003 | 2004 April 2000 Ionizing Radiation Science and Protection in the 21st Century, NCRP, April 5-6, Arlington, VA. RADIATION RESEARCH 2000, Association for Radiation Research, April 10-12, Bristol, UK. Florida Chapter of the Health Physics Society Spring 2000 Meeting, Gainesville, FL, April 13-14. 47th Annual Meeting of the Radiation Research Society, April 29-May 3, Albuquerque, NM. May 2000 IRPA-10 International Congress 2000, May 14-19, Hiroshima, Japan. IRPA-10 Secretariat, c/o Japan Convention Services, Inc., Nippon Press Center Building, 2-2-1, Uchisaiwai-cho, Chiyoda-ku, Tokyo 100, Japan. Phone: 81-3-3508-1214. Fax: 81-3-3508-0820. irpa10@convention.jp. 4th International Non-Ionizing Radiation Workshop, May 22-25, Kyoto,

304

Radiation physics, biophysics, and radiation biology  

SciTech Connect (OSTI)

Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

Hall, E.J.; Zaider, M.

1993-05-01T23:59:59.000Z

305

Auger spectrum of a water molecule after single and double core ionization  

SciTech Connect (OSTI)

The high intensity of free electron lasers opens up the possibility to perform single-shot molecule scattering experiments. However, even for small molecules, radiation damage induced by absorption of high intense x-ray radiation is not yet fully understood. One of the striking effects which occurs under intense x-ray illumination is the creation of double core ionized molecules in considerable quantity. To provide insight into this process, we have studied the dynamics of water molecules in single and double core ionized states by means of electronic transition rate calculations and ab initio molecular dynamics (MD) simulations. From the MD trajectories, photoionization and Auger transition rates were computed based on electronic continuum wavefunctions obtained by explicit integration of the coupled radial Schroedinger equations. These rates served to solve the master equations for the populations of the relevant electronic states. To account for the nuclear dynamics during the core hole lifetime, the calculated electron emission spectra for different molecular geometries were incoherently accumulated according to the obtained time-dependent populations, thus neglecting possible interference effects between different decay pathways. We find that, in contrast to the single core ionized water molecule, the nuclear dynamics for the double core ionized water molecule during the core hole lifetime leaves a clear fingerprint in the resulting electron emission spectra. The lifetime of the double core ionized water was found to be significantly shorter than half of the single core hole lifetime.

Inhester, L.; Burmeister, C. F.; Groenhof, G.; Grubmueller, H. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany)

2012-04-14T23:59:59.000Z

306

Parallelization of Radiation Therapy Treatment Planning(RTTP) : A Case Study \\Lambda  

E-Print Network [OSTI]

Abstract Radiation therapy uses ionizing radiation to treat cancer­ ous tumors. This paper reports our, thereby concentrating radiation dose in the tumor. The maximum dose that can be delivered to the tumorParallelization of Radiation Therapy Treatment Planning(RTTP) : A Case Study \\Lambda V. Chaudhary

Xu, Cheng-Zhong

307

Parallelization of Radiation Therapy Treatment Planning(RTTP) : A Case Study  

E-Print Network [OSTI]

Radiation therapy uses ionizing radiation to treat cancer- ous tumors. This paper reports our experiences with the parallelization of a real-world 3-D radiation therapy treat- ment planning (RTTP) system on a wide range of plat at the tumor in a patient from different directions, thereby concentrating radiation dose in the tumor

Chaudhary, Vipin

308

Galaxies that Shine: radiation-hydrodynamical simulations of disk galaxies  

E-Print Network [OSTI]

Radiation feedback is typically implemented using subgrid recipes in hydrodynamical simulations of galaxies. Very little work has so far been performed using radiation-hydrodynamics (RHD), and there is no consensus on the importance of radiation feedback in galaxy evolution. We present RHD simulations of isolated galaxy disks of different masses with a resolution of 18 pc. Besides accounting for supernova feedback, our simulations are the first galaxy-scale simulations to include RHD treatments of photo-ionisation heating and radiation pressure, from both direct optical/UV radiation and multi-scattered, re-processed infrared (IR) radiation. Photo-heating smooths and thickens the disks and suppresses star formation about as much as the inclusion of ("thermal dump") supernova feedback does. These effects decrease with galaxy mass and are mainly due to the prevention of the formation of dense clouds, as opposed to their destruction. Radiation pressure, whether from direct or IR radiation, has little effect, but ...

Rosdahl, Joakim; Teyssier, Romain; Agertz, Oscar

2015-01-01T23:59:59.000Z

309

Mobile Robotics I: Lab 3 Obstacle Avoidance with IR Sensors  

E-Print Network [OSTI]

Sensors Background IR SENSORS INTERFACE The CEENBoT comes equipped with a Left and Right non-contact bumpMobile Robotics I: Lab 3 Obstacle Avoidance with IR Sensors CEENBoTTM Mobile Robotics Platform 1.01 #12;. ( Blank ) #12;Mobile Robotics I ­ Obstacle Avoidance with IR Sensors Purpose

Farritor, Shane

310

Extreme Galactic-Winds and Starburst in IR Mergers and IR QSOs  

E-Print Network [OSTI]

We report -as a part of a long-term study of mergers and IR QSOs- detailed spectroscopic evidences for outflow (OF) and/or Wolf Rayet features in: (i) low velocity OF in the ongoing mergers NGC 4038/39 and IRAS 23128-5919; (ii) extreme velocity OF (EVOF) in the QSOs IRAS 01003-2238 and IRAS 13218+0552; (iii) OF and EVOF in a complete sample of ultra-luminous IR galaxies/QSOs ("The IRAS 1 Jy MKO-KPNO Survey", of 118 objects). We found EVOF in IRAS 11119+3257, 14394+5332, 15130+1958 and 15462-0450. The OF components detected in these objects were mainly associated to starburst processes: i.e., to galactic-winds generated in multiple type II SN explosions and massive stars. The EVOF were detected in objects with strong starburst plus obscured IR QSOs; which suggest that interaction of both processes could generate EVOF. In addition, we analyze the presence of Wolf Rayet features in the large sample of Bright PG-QSOs (Boroson and Green 1992), and nearby mergers and galactic-wind galaxies. We found clear WR features in the Fe II QSOs (type I): PG 1244+026, 1444+407, 1448+273, 1535+547; and in the IR merger Arp 220. HST archive images of IR+BAL QSOs show in practically all of these objects "arc or shell" features probably associated to galactic-winds (i.e., to multiple type II SN explosions) and/or merger processes. Finally, we discuss the presence of extreme starburst and galactic wind as a possible evolutive link between IR merger and IR QSOs; where the relation between mergers and extreme starburst (with powerful galactic-winds) plays in important role, in the evolution of galaxies.

S. Lipari; D. Sanders; R. Terlevich; S. Veilleux; R. Diaz; Y. Taniguchi; W. Zheng; D. Kim; Z. Tsvetanov; G. Carranza; H. Dottori

2000-07-20T23:59:59.000Z

311

7 - Estimation of Radiation Doses  

Science Journals Connector (OSTI)

Abstract Radiation doses to the Japanese population from inhalation of contaminated air, external irradiation, terrestrial and marine food contamination are estimated and compared with other sources of anthropogenic (global fallout, Chernobyl accident), natural (radionuclides in food, cosmic radiation) and medical applications (X-ray tests, CT-tests, etc.) of ionizing radiation. The estimated doses from inhalation, ingestion of terrestrial and marine food, and radiation exposure from radioactive clouds and deposited radionuclides were generally below the levels which could cause health damage of the Japanese population, as well as of the world population. The estimated total radiation doses to fish and shellfish in coastal waters during the largest radionuclide releases were by a factor of 10 lower than the baseline safe level postulated for the marine organisms, therefore no harmful effects are expected for the marine ecosystem as well.

Pavel P. Povinec; Katsumi Hirose; Michio Aoyama

2013-01-01T23:59:59.000Z

312

Low radiative efficiency accretion at work in active galactic nuclei: the nuclear spectral energy distribution of NGC4565  

E-Print Network [OSTI]

We derive the spectral energy distribution (SED) of the nucleus of the Seyfert galaxy NGC4565. Despite its classification as a Seyfert2, the nuclear source is substantially unabsorbed. The absorption we find from Chandra data (N_H=2.5 X 10^21 cm^-2) is consistent with that produced by material in the galactic disk of the host galaxy. HST images show a nuclear unresolved source in all of the available observations, from the near-IR H band to the optical U band. The SED is completely different from that of Seyfert galaxies and QSO, as it appears basically ``flat'' in the IR-optical region, with a small drop-off in the U-band. The location of the object in diagnostic planes for low luminosity AGNs excludes a jet origin for the optical nucleus, and its extremely low Eddington ratio L_o/L_Edd indicates that the radiation we observe is most likely produced in a radiatively inefficient accretion flow (RIAF). This would make NGC4565 the first AGN in which an ADAF-like process is identified in the optical. We find that the relatively high [OIII] flux observed from the ground cannot be all produced in the nucleus. Therefore, an extended NLR must exist in this object. This may be interpreted in the framework of two different scenarios: i) the radiation from ADAFs is sufficient to give rise to high ionization emission-line regions through photoionization, or ii) the nuclear source has recently ``turned-off'', switching from a high-efficiency accretion regime to the present low-efficiency state.

M. Chiaberge; R. Gilli; F. D. Macchetto; W. B. Sparks

2006-07-26T23:59:59.000Z

313

Photo-Ionization of a Gas by a Discharge in the Same Gas  

Science Journals Connector (OSTI)

Method. Measurements were made in a tube containing two thermionic units electrically shielded from each other. The first served to give a discharge, the second detected ions produced by the radiation from the first by means of their effect on the space charge.Results. Relatively little photo-ionization is produced by arc radiation, while spark excitation and soft x-radiation give a strong effect. Curves of photo-effect versus discharge voltage show critical potentials which have been interpreted as follows: Ionization of n2 rare gas shellCs, 13.0; K, 19.0: Spark excitationCs, 18.5; K, 21.6; A, 32.2; Ne, 48.0: Double ionizationCs, 21.5; K, 31.8; A, 34.8; Ne, 54.9: Ionization of n1 rare gas shellCs, 39.0; K, 48.0; A, 39.6. The neon II spectrum is excited at 55 volts.It was shown that photo-electric emission from the electrodes was at least ten times as great as the photo-electric emission from the gas, while the current change produced by the space charge effect was more than 2400 times the ion current in argon and caesium, the upper limit being quite indefinite.

F. L. Mohler

1926-07-01T23:59:59.000Z

314

WARM IONIZED GAS REVEALED IN THE MAGELLANIC BRIDGE TIDAL REMNANT: CONSTRAINING THE BARYON CONTENT AND THE ESCAPING IONIZING PHOTONS AROUND DWARF GALAXIES  

SciTech Connect (OSTI)

The Magellanic System includes some of the nearest examples of galaxies disturbed by galaxy interactions. These interactions have redistributed much of their gas into the halos of the Milky Way (MW) and the Magellanic Clouds. We present Wisconsin H{alpha} Mapper kinematically resolved observations of the warm ionized gas in the Magellanic Bridge over the velocity range of +100 to +300 km s{sup -1} in the local standard of rest reference frame. These observations include the first full H{alpha} intensity map and the corresponding intensity-weighted mean velocity map of the Magellanic Bridge across (l, b) = (281 Degree-Sign .5, -30 Degree-Sign .0) to (302. Degree-Sign 5, -46. Degree-Sign 7). Using the H{alpha} emission from the Small Magellanic Cloud (SMC)-Tail and the Bridge, we estimate that the mass of the ionized material is between (0.7-1.7) Multiplication-Sign 10{sup 8} M{sub Sun }, compared to 3.3 Multiplication-Sign 10{sup 8} M{sub Sun} for the neutral mass over the same region. The diffuse Bridge is significantly more ionized than the SMC-Tail, with an ionization fraction of 36%-52% compared to 5%-24% for the Tail. The H{alpha} emission has a complex multiple-component structure with a velocity distribution that could trace the sources of ionization or distinct ionized structures. We find that incident radiation from the extragalactic background and the MW alone are insufficient to produced the observed ionization in the Magellanic Bridge and present a model for the escape fraction of the ionizing photons from both the SMC and Large Magellanic Cloud (LMC). With this model, we place an upper limit of 4.0% for the average escape fraction of ionizing photons from the LMC and an upper limit of 5.5% for the SMC. These results, combined with the findings of a half a dozen other studies for dwarf galaxies in different environments, provide compelling evidence that only a small percentage of the ionizing photons escape from dwarf galaxies in the present epoch to influence their surroundings.

Barger, K. A.; Haffner, L. M. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Bland-Hawthorn, J., E-mail: kbargers@nd.edu, E-mail: haffner@astro.wisc.edu, E-mail: jbh@physics.usyd.edu.au [Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006 (Australia)

2013-07-10T23:59:59.000Z

315

Low Dose Radiation Research Program: Genetic Factors Affecting  

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

Genetic Factors Affecting Susceptibility to Low-Doses of Ionizing Genetic Factors Affecting Susceptibility to Low-Doses of Ionizing Radiation. Authors: William F. Morgan, Pat Concannon & John H.J. Petrini The goal of this program is to test the hypothesis that mice heterozygous for the NBS1 gene are genetically susceptible to low doses of ionizing radiation. Patients with Nijmegen Breakage Syndrome (NBS) are radiation sensitive, because of defects in cellular responses to radiation induced genetic damage. It is unclear whether humans heterozygous for the mutations associated with NBS are radiation sensitive and results from cell culture experiments give conflicting results. In collaboration with John Petrini at the Memorial Sloan Kettering Cancer Center in New York City we developed a mouse model of this disorder and are directly testing the hypothesis

316

Ionization tube simmer current circuit  

DOE Patents [OSTI]

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Steinkraus, Jr., Robert F. (Livermore, CA)

1994-01-01T23:59:59.000Z

317

Ionization tube simmer current circuit  

DOE Patents [OSTI]

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

Steinkraus, R.F. Jr.

1994-12-13T23:59:59.000Z

318

Anomalous laser-induced ionization rates of molecules and rare-gas atoms  

SciTech Connect (OSTI)

Electron tunnel ionization is considered as the mechanism for producing free electrons in gases under laser radiation. The Keldysh result and the Ammosov-Delone-Krainov (ADK) formulation are amended by considering the excess forces due to the interaction of the electric field of the laser with the electron cloud in a simple mass-on-a-spring approximation. The result of this excess force is a kinetic energy that is directed along the polarization vector of the laser field and an induced potential energy that are proposed as a determining factor in electron tunnel ionization. Relative ionization rates for various pairs of gases are calculated and compared with reported figures. Comparisons were made between several combinations of O{sub 2}, Xe, Ar, N{sub 2}, Cl{sub 2}, H{sub 2}, CO, Kr, NO, F{sub 2}, and D{sub 2}. Predicted ratios of ionization rates between pairs of gases are compared to ADK predictions. Apparently anomalous ionization rates of O{sub 2}, D{sub 2}, and H{sub 2} are explained. A simple expression is developed that reveals why the ionization rate of Xe is about an order of magnitude larger than that of O{sub 2} even though their ionization potentials are nearly identical; why CO is only about half that of Kr even though their ionization potentials are nearly the same; why the ratio of O{sub 2} to O is about ten times larger than predicted by ADK; and why the ratio of NO to Xe is about an order of magnitude less than predicted by ADK.

Bettis, Jerry Ray [5701 Woodlake Drive, Stillwater, Oklahoma 74074 (United States)

2009-12-15T23:59:59.000Z

319

Standoff imaging of chemicals using IR spectroscopy  

SciTech Connect (OSTI)

Here we report on a standoff spectroscopic technique for identifying chemical residues on surfaces. A hand-held infrared camera was used in conjunction with a wavelength tunable mid-IR quantum cascade laser (QCL) to create hyperspectral image arrays of a target with an explosive residue on its surface. Spectral signatures of the explosive residue (RDX) were extracted from the hyperspectral image arrays and compared with a reference spectrum. Identification of RDX was achieved for residue concentrations of 20 g per cm2 at a distance of 1.5 m, and for 5 g per cm2 at a distance of 15 cm.

Senesac, Larry R [ORNL] [ORNL; Thundat, Thomas George [ORNL] [ORNL; Morales Rodriguez, Marissa E [ORNL] [ORNL

2011-01-01T23:59:59.000Z

320

Nevada Test Site Radiation Protection Program  

SciTech Connect (OSTI)

Title 10 Code of Federal Regulations (CFR) 835, 'Occupational Radiation Protection', establishes radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of U.S. Department of Energy (DOE) activities. 10 CFR 835.101(a) mandates that DOE activities be conducted in compliance with a documented Radiation Protection Program (RPP) as approved by DOE. This document promulgates the RPP for the Nevada Test Site (NTS), related (onsite or offsite) DOE National Nuclear Security Administration Nevada Site Office (NNSA/NSO) operations, and environmental restoration offsite projects.

Radiological Control Managers' Council, Nevada Test Site

2007-08-09T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Alpha Radiation  

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

Basics of Radiation 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 have been designed to measure alpha radiation. Special training in use of these instruments is essential for making accurate measurements. 4. A civil defense instrument (CD V-700) cannot detect the presence of radioactive materials that produce alpha radiation unless the radioactive materials also produce beta and/or gamma radiation.

322

Neutron And Gamma Detector Using An Ionization Chamber With An...  

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

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting...

323

Photo double ionization of ethylene and acetylene near threshold  

E-Print Network [OSTI]

Photo double ionization of ethylene and acetylene nearcomplete measurements of the photo double ionization ofkinetic energy of the photo electrons and the nuclear

Gaire, B.

2014-01-01T23:59:59.000Z

324

Direct Experimental Observation of the Low Ionization Potentials...  

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

Observation of the Low Ionization Potentials of Guanine in Free Oligonucleotides by Using Photoelectron Direct Experimental Observation of the Low Ionization Potentials of Guanine...

325

Photo double ionization of ethylene and acetylene near threshold  

E-Print Network [OSTI]

double ionization of ethylene and acetylene near thresholdphoto double ionization of ethylene (dou- ble CC bond) andsimilar yields of metastable ethylene dications produced by

Gaire, B.

2014-01-01T23:59:59.000Z

326

Applications of High-Resolution Electrospray Ionization Mass...  

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

High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Applications of High-Resolution Electrospray Ionization Mass...

327

Ambient Ionization Mass Spectrometry Analysis Pertaining To Biofuel Process Development.  

E-Print Network [OSTI]

??Mass spectrometry (MS) has undergone a revolution with the introduction of a new group of desorption/ionization (DI) techniques known collectively as Ambient Ionization mass spectrometry. (more)

Dendukuri, Sushma

2012-01-01T23:59:59.000Z

328

Radiation: Radiation Control (Indiana)  

Broader source: Energy.gov [DOE]

It is the policy of the state to encourage the constructive uses of radiation and to control its harmful effects. This section contains regulations pertaining to the manufacture, use,...

329

Pigments which reflect infrared radiation from fire  

DOE Patents [OSTI]

Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer (.mu.m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 .mu.m or, for cool smoky fires, about 2 .mu.m to about 16 .mu.m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 .mu.m to about 2 .mu.m and thin leafing aluminum flake pigments.

Berdahl, Paul H. (Oakland, CA)

1998-01-01T23:59:59.000Z

330

Pigments which reflect infrared radiation from fire  

DOE Patents [OSTI]

Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer ({micro}m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 {micro}m or, for cool smoky fires, about 2 {micro}m to about 16 {micro}m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 {micro}m to about 2 {micro}m and thin leafing aluminum flake pigments. 4 figs.

Berdahl, P.H.

1998-09-22T23:59:59.000Z

331

IY:ILrnr IR-rl?l'  

Office of Legacy Management (LM)

IY:ILrnr IR-rl?l' IY:ILrnr IR-rl?l' w&m PadmmmTuJ tmml' aIs~#l!REm m-t, - 188kwxm BYI alahard 0. cr*rrror cy- r' , ' .~ -' - -' ^ , /' cs< 4. .c :' ; *. .h,- ' (z&&y .' ,/ ;f. .* &J >l a. L \' P" ,,,' ,.' I * :{' \ !' l t ..b c&~ tf ~ , r ,, r. ,* .;;;., k J ;, b $y$' Lrmprrw)rlt&tmxJ- a@. Frqrr at t&i8 raoLli:.y SC\ daummiI~Luualndr8rr~lfCUIf@@?~~oy-~ d )I t rq ,i .* 1 Virium~~bUrlJlOgarspvlr at ma rdutw. (500 p-4 3) i" 1 ) ,ip" 2. rt A8 - u %I* mm 4almpa~&rnbM Itrr+@# vbrp a** -y ;I11 ~*~~*- miw&mmwlrrwrbsr* ~rSthLtL,ort' tar,da*pcr¶.florllj pi &8~wl~cm@n-~ t#barwatla~r~tOf~. hwrl'r#tarr,urueunUr .--,U-L BirLl#a ofmml -vom. pe a ,Tjm-&,, i L) cc (. a 41 IA.9 #y7 /.& r*-rc * &ah&L- '2 , p-

332

Low Dose Radiation Program: Workshop VI Abstracts  

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

Workshop VI Principal Investigator and Abstracts Workshop VI Principal Investigator and Abstracts Anderson, Carl Whole Genome Analysis of Functional Protein Binding Sites and DNA Methylation: Application to p53 and Low Dose Ionizing Radiation. Averbeck, Dietrich Cellular Responses at Low Doses of Ionizing Radiation. Azzam, Edouard Adaptive Responses to Low Dose/Low Dose-Rate ?-Rays in Normal Human Fibroblasts: The Role of Oxidative Metabolism. Bailey, Susan The Role of Telomere Dysfunction in Driving Genomic Instability. Balajee, Adayabalam Low Dose Radiation Induced DNA Damage Signaling and Repair Responses in Human 3-Dimensional Skin Model System. Barcellos-Hoff, Mary Helen Imaging Bioinformatics for Mapping Multidimensional Responses. Barcellos-Hoff, Mary Helen Biological Response to Radiation Mediated through the Microenvironment and

333

Rocket Determination of the Ionization Spectrum of Charged Cosmic Rays at ?=41N  

Science Journals Connector (OSTI)

In a V-2 rocket measurement at ?=41N an analysis has been made of the various components of the charged particle radiation on the basis of ionization and absorption in lead. The ionization was determined by two proportional counters, the particle paths through which were defined by Geiger counters. With increasing zenith angle toward the north, the intensity is found to be substantially constant until the earth ceases to cover the under side of the telescope. The intensity of all particles with range ?7 g/cm2 is 0.0790.005 (cm2secsteradian)-1. Of this an intensity 0.0120.002 is absorbed in the next 14 g/cm2. The ionization measurement is consistent with 34 of these soft particles being electrons of 2.

G. J. Perlow; L. R. Davis; C. W. Kissinger; J. D. Shipman; Jr.

1952-10-15T23:59:59.000Z

334

Ionization threshold of crystalline LiF  

Science Journals Connector (OSTI)

The ionization threshold for crystalline LiF is calculated using a cluster embedded model. The experimental ionization threshold is 9.8 eV; however, previous band and cluster model calculations gave 1415 eV. These earlier calculations used a crystal having a perfect lattice. In the present work, a crystal with lattice defects is introduced. The calculated surface and bulk ionization thresholds are 8.1 and 8.7 eV, respectively, showing good correspondence with experiment. The electron affinity and other band parameters are also studied.

Hiroshi Tatewaki

1999-08-01T23:59:59.000Z

335

Radiation, Matter and Energy What is light?  

E-Print Network [OSTI]

Radiation, Matter and Energy #12;What is light? #12;Light is an electromagnetic wave #12;Light the visible spectrum, blue light has higher energy than red light Within the electromagnetic spectrum, X-rays have the highest energy, followed by UV, visible light, IR, and radio Remember: Light is just one form

Shirley, Yancy

336

Radiation effects on polypropylene/polybutylene blends  

SciTech Connect (OSTI)

Polymer blends of polypropylene and polybutylene have been found to exhibit substantial maintenance of structural integrity after exposure to ionizing radiation. This radiation resistance has been found to be related to processing conditions and the resulting morphology of the blend. This article discusses (a) the processing conditions and the resulting mechanical properties after irradiation and (b) the role of morphology in this unexpected blend property.

Rolando, R.J. (3M Engineering Systems and Technology, St. Paul, MN (United States))

1993-06-01T23:59:59.000Z

337

Medical applications of synchrotron radiation  

SciTech Connect (OSTI)

Ever since the first diagnostic x-ray was done in the United States on February 3, 1896, the application of ionizing radiation to the field of medicine has become increasingly important. Both in clinical medicine and basic research the use of x-rays for diagnostic imaging and radiotherapy is now widespread. Radiography, angiography, CAT and PETT scanning, mammography, and nuclear medicine are all examples of technologies developed to image the human anatomy. In therapeutic applications, both external and internal sources of radiation are applied to the battle against cancer. The development of dedicated synchrotron radiation sources has allowed exciting advances to take place in many of these applications. The new sources provide tunable, high-intensity monochromatic beams over a wide range of energies which can be tailored to specific programmatic needs. This paper surveys those areas of medical research in which synchrotron radiation facilities are actively involved.

Thomlinson, W.

1991-10-01T23:59:59.000Z

338

Medical Applications of Synchrotron Radiation  

DOE R&D Accomplishments [OSTI]

Ever since the first diagnostic x-ray was done in the United States on February 3, 1896, the application of ionizing radiation to the field of medicine has become increasingly important. Both in clinical medicine and basic research the use of x-rays for diagnostic imaging and radiotherapy is now widespread. Radiography, angiography, CAT and PETT scanning, mammography, and nuclear medicine are all examples of technologies developed to image the human anatomy. In therapeutic applications, both external and internal sources of radiation are applied to the battle against cancer. The development of dedicated synchrotron radiation sources has allowed exciting advances to take place in many of these applications. The new sources provide tunable, high-intensity monochromatic beams over a wide range of energies which can be tailored to specific programmatic needs. This paper surveys those areas of medical research in which synchrotron radiation facilities are actively involved.

Thomlinson, W.

1991-10-00T23:59:59.000Z

339

Molecular signatures of low dose radiation exposure in human subjects  

Science Journals Connector (OSTI)

...Molecular signatures of low dose radiation exposure in human subjects...Volume 46, 2005] 3096 Low dose ionizing radiation (LDIR) in the 1-10 cGy range has largely unknown biological...the effect and risk at low dose by extrapolation from measured...

Zelanna Goldberg; Chad W. Schwietert; Maggie Isbell; Joerg Lehmann; Robin Stern; Christine Hartmann Siantar; and David M. Rocke

2005-05-01T23:59:59.000Z

340

Effects of low levels of radiation on humans  

SciTech Connect (OSTI)

The state of knowledge on effects of low-level ionizing radiations on humans is reviewed. Several problems relating to dose thresholds or lack of thresholds for several types of cancer and high LET radiations and the effects of fractionation and dose protection are discussed. (ACR)

Auxier, J.A.

1981-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

"Dust, Ice, and Gas In Time" (DIGIT) Herschel Observations of GSS30-IRS1 in Ophiuchus  

E-Print Network [OSTI]

As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d = 120 pc), with Herschel/Photodetector Array Camera and Spectrometer (PACS). More than 70 lines were detected within a wavelength range from 50 micron to 200 micron, including CO, H2O, OH, and two atomic [O I] lines at 63 and 145 micron. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field, is also detected at 158 micron. All lines, except [O I] and [C II], are detected only at the central spaxel of 9.4" X 9.4". The [O I] emissions are extended along a NE-SW orientation, and the [C II] line is detected over all spaxels, indicative of external PDR. The total [C II] intensity around GSS30 reveals that the far-ultraviolet radiation field is in the range of 3 to 20 G0, where G0 is in units of the Habing Field, 1.6 X 10^{-3} erg cm^{-2} s^{-1}. This enhanced external radiation field heats the envelope of GSS30-IRS1, causing the...

Je, Hyerin; Lee, Seokho; Green, Joel D; Evans, Neal J

2015-01-01T23:59:59.000Z

342

Nonlinearities in Flame Ionization Detector Response  

Science Journals Connector (OSTI)

......ionization detector (FIO) to various hydrocarbons hat been found to be proportional to powers of the concentration which ex- ceed unity In certain ranges. The sample elution rates at which this effect is observed and operating condi- tions employed correspond......

J.H. Bromly; P. Roga

1980-11-01T23:59:59.000Z

343

Electrical conductivity of nondegenerate, fully ionized plasmas  

Science Journals Connector (OSTI)

Within a virial expansion of the electrical conductivity of a fully ionized plasma, which takes into account many-particle effects, different limiting cases are considered. An appropriate interpolation formula is compared with experimental values.

G. Rpke and R. Redmer

1989-01-15T23:59:59.000Z

344

NON-EQUILIBRIUM IONIZATION MODELING OF THE CURRENT SHEET IN A SIMULATED SOLAR ERUPTION  

SciTech Connect (OSTI)

The current sheet that extends from the top of flare loops and connects to an associated flux rope is a common structure in models of coronal mass ejections (CMEs). To understand the observational properties of CME current sheets, we generated predictions from a flare/CME model to be compared with observations. We use a simulation of a large-scale CME current sheet previously reported by Reeves et al. This simulation includes ohmic and coronal heating, thermal conduction, and radiative cooling in the energy equation. Using the results of this simulation, we perform time-dependent ionization calculations of the flow in a CME current sheet and construct two-dimensional spatial distributions of ionic charge states for multiple chemical elements. We use the filter responses from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory and the predicted intensities of emission lines to compute the count rates for each of the AIA bands. The results show differences in the emission line intensities between equilibrium and non-equilibrium ionization. The current sheet plasma is underionized at low heights and overionized at large heights. At low heights in the current sheet, the intensities of the AIA 94 A and 131 A channels are lower for non-equilibrium ionization than for equilibrium ionization. At large heights, these intensities are higher for non-equilibrium ionization than for equilibrium ionization inside the current sheet. The assumption of ionization equilibrium would lead to a significant underestimate of the temperature low in the current sheet and overestimate at larger heights. We also calculate the intensities of ultraviolet lines and predict emission features to be compared with events from the Ultraviolet Coronagraph Spectrometer on the Solar and Heliospheric Observatory, including a low-intensity region around the current sheet corresponding to this model.

Shen Chengcai; Reeves, Katharine K.; Raymond, John C.; Murphy, Nicholas A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ko, Yuan-Kuen [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lin Jun [Yunnan Astronomical Observatory, Chinese Academy of Sciences, P. O. Box 110, Kunming, Yunnan 650011 (China); Mikic, Zoran; Linker, Jon A. [Predictive Science, Inc. (PSI), San Diego, CA 92121-2910 (United States)

2013-08-20T23:59:59.000Z

345

New Cryogenic Apparatus for FT-IR Spectroscopic Studies  

Science Journals Connector (OSTI)

Cryogenic Fourier transform infrared (FT-IR) spectroscopy, being an effective technique in improving the spectral resolution and signal-to-noise ratio, is utilized in our group....

Kang, Ning; Xu, Yizhuang; Ferraro, J R; Li, Weihong; Weng, Shifu; Xu, Duanfu; Wu, Jinguang; Soloway, R D; Xu, Guangxian

2001-01-01T23:59:59.000Z

346

High-Field Magnetoresistance of IrO2  

Science Journals Connector (OSTI)

The monotonic and oscillatory magnetoresistance of IrO2 is reported and found to be consistent with the Fermi-surface model proposed by Graebner.

W. D. Ryden; W. A. Reed; E. S. Greiner

1972-09-15T23:59:59.000Z

347

Radiative Importance of ThinŽ Liquid Water Clouds  

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

Program Program Accomplishments of the Instantaneous Radiative Flux (IRF) Working Group August 2006 AERI Observations at Southern Great Plains Improve Infrared Radiative Transfer Models Turner et al., JAS, 2004 * AERI observations used to evaluate clear sky IR radiative transfer models * Long-term comparisons have improved - Spectral line database parameters - Water vapor continuum absorption models * Reduced errors in computation of downwelling radiative IR flux by approx 4; current uncertainty is on the order of 1.5 W/m 2 AERI - (Pre-ARM Model) AERI - (Model in 2003) 1 RU = 1 mW / (m 2 sr cm -1 ) Excellent Agreement in Clear Sky Shortwave Radiative Transfer Between Obs and Calcs Shortwave Flux Bias (Solid) Shortwave Flux RMS (Hatched) W m -2 * Comparison of shortwave radiative flux at the surface

348

Cancer Mortality in a Radiation-exposed Cohort of Massachusetts Tuberculosis Patients  

Science Journals Connector (OSTI)

...Osaka 565-0871 Japan Ionized radiation leads to G1 arrest...Osaka 565-0871, Japan. Phone: 81-6-6879-3251...resistant to radiation; SR, sensitive...G2-M checkpoint in radiation therapy. | Department...University, Suita, Japan. | Journal Article...

Faith G. Davis; John D. Boice, Jr.; Zdenek Hrubec; and Richard R. Monson

1989-11-01T23:59:59.000Z

349

EXTRAPOLATING RADIATION-INDUCED CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES  

E-Print Network [OSTI]

. Brenner* Abstract--There is strong evidence that ionizing radiation increases cancer risks at high doses. There exists a range of high radiation doses which demonstra- bly increase cancer risks, and a lower dose rangePaper EXTRAPOLATING RADIATION-INDUCED CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES David J

Brenner, David Jonathan

350

Electrical properties of MOS radiation dosimeters G. Sarrabayrouse, A. Bellaouar and P. Rossel  

E-Print Network [OSTI]

. Abstract. 2014 MOS transistors are used for radiation dosimetry. The sensitivity obtained is ranging. IntroductiorL The use of MOS transistors for the detection and dosimetry of ionizing radiation has been in the insulating layer of a MOS transistor and at the insulator semiconductor interface. For a given radiation dose

Paris-Sud XI, Université de

351

MEASUREMENT OF THE HIGH GAMMA RADIATION DOSE USING THE MEMS BASED DOSIMETER AND RADIOLISYS EFFECT  

E-Print Network [OSTI]

radiation dose. If we consider, that the average time of exploitation is estimated to be 40 years and veryMEASUREMENT OF THE HIGH GAMMA RADIATION DOSE USING THE MEMS BASED DOSIMETER AND RADIOLISYS EFFECT M of high and very high doses of ionizing radiation is crucial for the monitoring of the existing Nuclear

Boyer, Edmond

352

Biological effects in unirradiated human tissue induced by radiation damage up to 1 mm away  

E-Print Network [OSTI]

in extrapolating radiation risk estimates from epidemi- ologically accessible doses down to very low doses where) and for assessing the risk from a low-dose exposure to a carcinogen such as ionizing radiation, where only a smallBiological effects in unirradiated human tissue induced by radiation damage up to 1 mm away Oleg V

353

Large-Area Plasma-Panel Radiation Detectors for Nuclear Medicine Imaging to Homeland Security and the Super Large Hadron Collider  

E-Print Network [OSTI]

A new radiation sensor derived from plasma panel display technology is introduced. It has the capability to detect ionizing and non-ionizing radiation over a wide energy range and the potential for use in many applications. The principle of operation is described and some early results presented.

Friedman, Peter S; Chapman, J Wehrley; Levin, Daniel S; Weaverdyck, Curtis; Zhou, Bing; Benhammou, Yan; Etzion, Erez; Moshe, M Ben; Silver, Yiftah; Beene, James R; Varner, Robert L

2010-01-01T23:59:59.000Z

354

Growth of graphene on Ir(111) Johann Coraux1  

E-Print Network [OSTI]

Growth of graphene on Ir(111) Johann Coraux1 ,, Alpha T. N'Diaye1 §, Martin Engler1 , Carsten Busse a renewed interest as a route towards high quality graphene prepared in a reproducible manner. Here we employ two growth methods for graphene on Ir(111), namely room temperature adsorption and thermal

Paris-Sud XI, Université de

355

Which Oxidation State Leads to O-O Bond Formation in Cp*Ir(bpy)Cl-Catalyzed Water Oxidation, Ir(V), Ir(VI), or Ir(VII)?  

E-Print Network [OSTI]

Which Oxidation State Leads to O-O Bond Formation in Cp*Ir(bpy)Cl-Catalyzed Water Oxidation, Ir: Density functional calculations are used to revisit the reaction mechanism of water oxidation catalyzed oxidation at higher oxidation state even though it can also promote O-O bond formation. Therefore, [(bpy

Liao, Rongzhen

356

IR Vibration-Rotation Spectra of the Ammonia Molecule  

Science Journals Connector (OSTI)

The IR spectrum of the ammonia inversion vibration-rotation normal mode is obtained using Fourier Transform IR Spectroscopy and analyzed using Maple, to easily obatin the relation between the N-H bond length and the H-N-H bond angle. As expected, the ...

Carl W. David

1996-01-01T23:59:59.000Z

357

Selective Dissociation of Sulfur Hexafluoride by Intense CO2 Laser Radiation in Pulsed Gas Dynamic Flow  

Science Journals Connector (OSTI)

Isotopically selective IR multiphoton dissociation (MPD) of SF6 in a pulsed gas dynamic flow was studied. The dependence of the yield of the product SF4 on the frequency of CO2 laser radiation exciting SF6 molecu...

G. N. Makarov; A. N. Petin

2000-11-01T23:59:59.000Z

358

Tunable and collimated terahertz radiation generation by femtosecond laser pulses  

SciTech Connect (OSTI)

A mechanism is proposed for the generation of tunable terahertz (THz) radiation under the application of two femtosecond laser pulses and an external magnetic field, where quick tunnel ionization is achieved that leads to higher plasma density evolution and large residual current for the efficient THz radiation generation. With the optimization of magnetic field, phase difference, and amplitudes of lasers' fields, a THz source can be obtained with tunable frequency and power along with a control on the direction of radiation emission.

Malik, Hitendra K.; Malik, Anil K.

2011-12-19T23:59:59.000Z

359

Infrared Radiation Filament And Metnod Of Manufacture  

DOE Patents [OSTI]

An improved IR radiation source is provided by the invention. A radiation filament has a textured surface produced by seeded ion bombardment of a metal foil which is cut to a serpentine shape and mounted in a windowed housing. Specific ion bombardment texturing techniques tune the surface to maximize emissions in the desired wavelength range and to limit emissions outside that narrow range, particularly at longer wavelengths. A combination of filament surface texture, thickness, material, shape and power circuit feedback control produce wavelength controlled and efficient radiation at much lower power requirements than devices of the prior art.

Johnson, Edward A. (Bedford, MA)

1998-11-17T23:59:59.000Z

360

Multiphoton ionization of large water clusters  

SciTech Connect (OSTI)

Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

Apicella, B., E-mail: apicella@irc.cnr.it [Combustion Research Institute, IRCC.N.R., P.le Tecchio 80, 80125 Napoli (Italy); Li, X. [Key Laboratory of Power Machinery and Engineering, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Passaro, M. [CNISM and Chemical Engineering, Materials and Industrial Production Department, University of Naples Federico II, P.le Tecchio 80, 80125 Napoli (Italy); Spinelli, N. [CNISM and Physics Department, University of Naples Federico II, Via Cintia, 80124 Napoli (Italy); Wang, X. [SPINC.N.R., Via Cintia, 80124 Napoli (Italy)

2014-05-28T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Identification of radiation-induced microRNA transcriptome by next-generation massively parallel sequencing  

Science Journals Connector (OSTI)

......induction of DNA damage and repair, cell cycle perturbation...performed using Illumina processing pipeline software (version 1.5...homologous recombination-mediated repair, and renders cells hypersensitive...Chaudhry MA . Base excision repair of ionizing radiation-induced......

M. Ahmad Chaudhry; Romaica A. Omaruddin; Christopher D. Brumbaugh; Muhammad A. Tariq; Nader Pourmand

2013-09-01T23:59:59.000Z

362

MUCOOL: Ionization Cooling R&D  

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

Laboratory Laboratory MUCOOL Muon Ionization Cooling R&D Welcome to the muon ionization cooling experimental R&D page. The MuCool collaboration has been formed to pursue the development of a muon ionization cooling channel for a high luminosity muon collider. For more information please contact Alan Bross (Spokesperson: bross@fnal.gov), Rick Fernow (BNL Contact person: fernow1@bnl.gov), or Mike Zisman (LBNL Contact person: mszisman@lbl.gov). General MUCOOL Telephone Book MUCOOL Notes MUCOOL Collaborating Institutes and Interests Useful Links Link to IIT MUCOOL page Meetings Muon Collaboration Friday Meetings Fermilab Muon Group Monday Meetings MTA RF Workshop (August 22, 2007 - Fermilab) Low Emittance Muon Collider Workshop (February 12-16, 2007, Fermilab) Low Emittance Muon Collider Workshop (February 6-10, 2006, Fermilab)

363

Method and apparatus for generating radiation utilizing DC to AC conversion with a conductive front  

DOE Patents [OSTI]

Method and apparatus for generating radiation of high power, variable duration and broad tunability over several orders of magnitude from a laser-ionized gas-filled capacitor array. The method and apparatus convert a DC electric field pattern into a coherent electromagnetic wave train when a relativistic ionization front passes between the capacitor plates. The frequency and duration of the radiation is controlled by the gas pressure and capacitor spacing.

Dawson, John M. (Pacific Palisades, CA); Mori, Warren B. (Hermosa Beach, CA); Lai, Chih-Hsiang (So. Pasadena, CA); Katsouleas, Thomas C. (Malibu, CA)

1998-01-01T23:59:59.000Z

364

Method and apparatus for generating radiation utilizing DC to AC conversion with a conductive front  

DOE Patents [OSTI]

Method and apparatus ar disclosed for generating radiation of high power, variable duration and broad tunability over several orders of magnitude from a laser-ionized gas-filled capacitor array. The method and apparatus convert a DC electric field pattern into a coherent electromagnetic wave train when a relativistic ionization front passes between the capacitor plates. The frequency and duration of the radiation is controlled by the gas pressure and capacitor spacing. 4 figs.

Dawson, J.M.; Mori, W.B.; Lai, C.H.; Katsouleas, T.C.

1998-07-14T23:59:59.000Z

365

About Radiation  

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

Radiation Radiation What is radiation? Radiation is a form of energy that is a part of our everyday lives. All of us receive a "dose" of radiation each day. Most of the dose comes from naturally occurring radioactive materials such as uranium, thorium, radon, and certain forms of potassium and carbon. The air we breathe contains radon, the food we eat contains uranium and thorium from the soil, and our bodies contain radioactive forms of potassium and carbon. Cosmic radiation from the sun also contributes to our natural radiation dose. We also receive radiation doses from man-made sources such as X-rays, nuclear medical procedures, power plants, smoke detectors and older television sets. Some people, such as nuclear plant operators, flight crews, and nuclear medicine staff may also receive an occupational radiation dose.

366

Low Dose Radiation Research Program: Genetic Factors Affecting  

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

Affecting Susceptibility to Low-Dose Radiation Affecting Susceptibility to Low-Dose Radiation William F. Morgan Pacific Northwest National Laboratory Why This Project The short-term effects of high doses of ionizing radiation on cellular responses are relatively well understood. Less clear are the long-term consequences of exposure to low dose/low dose-rate radiation and the effects of radiation exposure on the progeny of surviving cells. If a cell survives radiation, it is generally thought to have repaired all the radiation-induced insults and be capable of a "normal healthy life". At a certain frequency, however, we have found that some cells surviving radiation grow normally, but will rearrange their genetic material during time in culture. We call this radiation-induced genomic instability. Many

367

Progress on a Cavity with Beryllium Walls for Muon Ionization Cooling Channel R&D.  

E-Print Network [OSTI]

WITH BERYLLIUM WALLS FOR MUON IONIZATION COOLING CHANNELNY 11973, USA Abstract The Muon Accelerator Program (MAP)an ionization cooling channel for muon beams. An ionization

Bowring, D.L.

2014-01-01T23:59:59.000Z

368

A Brief Discussion of Radiation Hardening of CMOS Microelectronics  

SciTech Connect (OSTI)

Commercial microchips work well in their intended environments. However, generic microchips will not fimction correctly if exposed to sufficient amounts of ionizing radiation, the kind that satellites encounter in outer space. Modern CMOS circuits must overcome three specific concerns from ionizing radiation: total-dose, single-event, and dose-rate effects. Minority-carrier devices such as bipolar transistors, optical receivers, and solar cells must also deal with recombination-generation centers caused by displacement damage, which are not major concerns for majority-carrier CMOS devices. There are ways to make the chips themselves more resistant to radiation. This extra protection, called radiation hardening, has been called both a science and an art. Radiation hardening requires both changing the designs of the chips and altering the ways that the chips are manufactured.

Myers, D.R.

1998-12-18T23:59:59.000Z

369

Danger radiations  

ScienceCinema (OSTI)

Le confrencier Mons.Hofert parle des dangers et risques des radiations, le contrle des zones et les prcautions prendre ( p.ex. film badge), comment mesurer les radiations etc.

None

2011-04-25T23:59:59.000Z

370

Salt Tolerance of Desorption Electrospray Ionization (DESI)  

SciTech Connect (OSTI)

Suppression of ion intensity in the presence of high salt matrices is common in most mass spectrometry ionization techniques. Desorption electrospray ionization (DESI) is an ionization method that exhibits salt tolerance, and this is investigated. DESI analysis was performed on three different drug mixtures in the presence of 0, 0.2, 2, 5, 10, and 20% NaCl:KCl weight by volume from seven different surfaces. At physiological concentrations individual drugs in each mixture were observed with each surface. Collision-induced dissociation (CID) was used to provide additional confirmation for select compounds. Multiple stage experiments, to MS5, were performed for select compounds. Even in the absence of added salt, the benzodiazepine containing mixture yielded sodium and potassium adducts of carbamazepine which masked the ions of interest. These adducts were eliminated by adding 0.1% 7M ammonium acetate to the standard methanol:water (1:1) spray solvent. Comparison of the salt tolerance of DESI with that of electrospray ionization (ESI) demonstrated much better signal/noise characteristics for DESI in this study. The salt tolerance of DESI was also studied by performing limit of detection and dynamic range experiments. Even at a salt concentration significantly above physiological concentrations, select surfaces were effective in providing spectra that allowed the ready identification of the compounds of interest. The already high salt tolerance of DESI can be optimized further by appropriate choices of surface and spray solution.

Jackson, Ayanna U. [Purdue University; Talaty, Nari [Purdue University; Cooks, R G [Purdue University; Van Berkel, Gary J [ORNL

2007-01-01T23:59:59.000Z

371

Muon Cooling via Ionization Andrea Kay Forget  

E-Print Network [OSTI]

1 Muon Cooling via Ionization Andrea Kay Forget Department of Physics, Wayne State University, Detroit, Michigan 48202 Dated: August 7, 2006 Muons only live a few microseconds before they ultimately, and laser cooling) cannot be used to properly cool muons that are being used in proposed accelerators

Cinabro, David

372

Studies of Anomalous Ionization Edgar Y. Choueiri  

E-Print Network [OSTI]

Laboratory (EPPDyL) Princeton University, Princeton NJ 08544. Hideo Okuda Princeton Plasma Physics LabStudies of Anomalous Ionization Edgar Y. Choueiri Electric Propulsion and Plasma Dynamics., Princeton University Princeton, NJ. 08544 AIAA Paper: AIAA-94-2465 Abstract In order to improve the accuracy

Choueiri, Edgar

373

Radiation-tolerant imaging device  

DOE Patents [OSTI]

A barrier at a uniform depth for an entire wafer is used to produce imaging devices less susceptible to noise pulses produced by the passage of ionizing radiation. The barrier prevents charge created in the bulk silicon of a CCD detector or a semiconductor logic or memory device from entering the collection volume of each pixel in the imaging device. The charge barrier is a physical barrier, a potential barrier, or a combination of both. The physical barrier is formed by an SiO{sub 2} insulator. The potential barrier is formed by increasing the concentration of majority carriers (holes) to combine with the electron`s generated by the ionizing radiation. A manufacturer of CCD imaging devices can produce radiation-tolerant devices by merely changing the wafer type fed into his process stream from a standard wafer to one possessing a barrier beneath its surface, thus introducing a very small added cost to his production cost. An effective barrier type is an SiO{sub 2} layer. 7 figs.

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

1996-11-19T23:59:59.000Z

374

The Application of IR Spectroscopy to the Investigation of Minerals  

Science Journals Connector (OSTI)

Traditionally, the application of IR spectroscopy in mineralogy is reduced to the determination of wavelengths or frequencies of discrete absorption maxima. These values are brought in correspondence with normal ...

Nikita V. Chukanov

2014-01-01T23:59:59.000Z

375

DWEA Webinar: IRS Guidance for Small Wind Turbines  

Broader source: Energy.gov [DOE]

The U.S. Internal Revenue Service (IRS) has issued Notice 2015-4 providing new performance and quality standards of small wind turbines defined as having a nameplate capacity of up to 100 kW in...

376

Gas Analysis with IR-Diode Laser Spectrometers  

Science Journals Connector (OSTI)

An IR laser diode spectrometer of modular design with micro-processor control is presented. ... It consists of laser source (vibration decoupled refrigerator with temperature control unit and laser power...

Gerhard Schmidtke; Wolfgang Julius Riedel

1984-01-01T23:59:59.000Z

377

Gas analysis with IR-diode laser spectrometers  

Science Journals Connector (OSTI)

An IR laser diode spectrometer of modular design with micro-processor control is presented. ... It consists of laser source (vibration decoupled refrigerator with temperature control unit and laser power...

Gerhard Schmidtke; Wolfgang Julius Riedel

1984-01-01T23:59:59.000Z

378

US-LHC IR magnet error analysis and compensation  

SciTech Connect (OSTI)

This paper studies the impact of the insertion-region (IR) magnet field errors on LHC collision performance. Compensation schemes including magnet orientation optimization, body-end compensation, tuning shims, and local nonlinear correction are shown to be highly effective.

Wei, J.; Ptitsin, V.; Pilat, F.; Tepikian, S. [Brookhaven National Lab., Upton, NY (United States); Gelfand, N.; Wan, W.; Holt, J. [Fermi National Accelerator Lab., Batavia, IL (United States)

1998-08-01T23:59:59.000Z

379

US-LHC IR MAGNET ERROR ANALYSIS AND COMPENSATION.  

SciTech Connect (OSTI)

This paper studies the impact of the insertion-region (IR) magnet field errors on LHC collision performance. Compensation schemes including magnet orientation optimization, body-end compensation, tuning shims, and local nonlinear correction are shown to be highly effective.

WEI, J.

1998-06-26T23:59:59.000Z

380

IRS Announces New Tribal Economic Development Bond Allocation Guidance |  

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

IRS Announces New Tribal Economic Development Bond Allocation IRS Announces New Tribal Economic Development Bond Allocation Guidance IRS Announces New Tribal Economic Development Bond Allocation Guidance July 18, 2012 - 3:46pm Addthis To promote economic growth in tribal communities, Treasury and the Internal Revenue Service (IRS) published new guidance on July 18, 2012, allocating Tribal Economic Development Bonds (TEDBs). The TEDB program was established under the American Reinvestment and Recovery Act, and provides Tribes with the authority to issue tax-exempt debt for a wider range of activities to spur job creation and promote economic growth in Indian country. Providing Tribes with the ability to issue tax-exempt debt for a broader scope of activities similar to that available to states and local governments lowers

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Performance parameters of a liquid filled ionization chamber array  

SciTech Connect (OSTI)

Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within 0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of 2.6% from the reference condition for the setup used. The ?-values of the Gaussian dose response function for a single detector of the array were found to be (0.72 0.25) mm at 6 MV and (0.74 0.25) mm at 15 MV and the corresponding low pass cutoff frequencies are 0.22 and 0.21 mm{sup ?1}, respectively. For the inner 5 5 cm{sup 2} region and the outer 11 11 cm{sup 2} region of the array the Nyquist theorem is fulfilled for maximum sampling frequencies of 0.2 and 0.1 mm{sup ?1}, respectively. An IMRT field verification with a Gamma-Index analysis yielded a passing rate of 95.2% for a 3 mm/3% criterion with a TPS calculation as reference.Conclusions: This study shows the applicability of the Octavius 1000SRS in modern dosimetry. Output factor and dose profile measurements illustrated the applicability of the array in small field and stereotactic dosimetry. The high spatial resolution ensures adequate measurements of dose profiles in regular and intensity modulated photon-beam fields.

Poppe, B.; Stelljes, T. S.; Looe, H. K.; Chofor, N. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Gttingen 37073 (Germany)] [Prof. em., Medical Physics and Biophysics, Georg August University, Gttingen 37073 (Germany); Willborn, K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)

2013-08-15T23:59:59.000Z

382

Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1991--November 30, 1992  

SciTech Connect (OSTI)

The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

Hall, E.J.

1992-05-01T23:59:59.000Z

383

Photo-Ionization and the Electrical Breakdown of Gases  

Science Journals Connector (OSTI)

25 June 1953 research-article Photo-Ionization and the Electrical Breakdown...theoretical investigation is made of the role of photo-ionization of the gas in the development...obtained experimentally. It is shown that photo-ionization can lead to electrical breakdown...

1953-01-01T23:59:59.000Z

384

Critical Behavior of Electron Impact Ionization of Atoms  

E-Print Network [OSTI]

Critical Behavior of Electron Impact Ionization of Atoms IMAD LADADWA,1,2 SABRE KAIS1 1 Department of the electron impact ionization for different atoms are calculated numerically in the Born approximation as a function of both the incident electron energy and the nuclear charge Z of the ionized atom. We show

Kais, Sabre

385

148 IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 18, NO. 1, JANUARY 1, 2006 Radiation Resistance of Single-Frequency 1310-nm  

E-Print Network [OSTI]

experiments, and for space and medical applications. Typical radiation doses in medical applications range to ionizing radiation using 200-MeV/c proton beams are reported. Twelve powered lasers survived a total radiation dose of up to 22.3 Mrad. One of the two not-powered lasers survived a total dose of 1.5 Mrad

Ye, Jingbo

386

Nuclear Instruments and Methods in Physics Research A 476 (2002) 758764 Observation of radiation induced latchup in the readout  

E-Print Network [OSTI]

to high levels of radiation resulting in an ionizing radiation dose of more than 200 krad and displacement with a radia- tion hard technology that can resist up to radiation dose levels greater than 1 Mrad. Both chips were fabricated according to almost identical designs. 2. Estimation of dose and fluence NA50

Ramello, Luciano

387

Radiation sensitive devices and systems for detection of radioactive materials and related methods  

DOE Patents [OSTI]

Radiation sensitive devices include a substrate comprising a radiation sensitive material and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to resonate responsive to non-ionizing incident radiation. Systems for detecting radiation from a special nuclear material include a radiation sensitive device and a sensor located remotely from the radiation sensitive device and configured to measure an output signal from the radiation sensitive device. In such systems, the radiation sensitive device includes a radiation sensitive material and a plurality of resonance elements positioned on the radiation sensitive material. Methods for detecting a presence of a special nuclear material include positioning a radiation sensitive device in a location where special nuclear materials are to be detected and remotely interrogating the radiation sensitive device with a sensor.

Kotter, Dale K

2014-12-02T23:59:59.000Z

388

Co-Regulation among genes and pathways that are responsive to low-dose ionizing  

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

Regulation among genes and pathways that are responsive to low-dose ionizing Regulation among genes and pathways that are responsive to low-dose ionizing radiation. Matthew A. Coleman 1 , Anya Krefft 1 , Francesca Pearson 1 , Leif E. Peterson 2 , Jian Jian Li 3 , Xiaowen Xin 1 , Terrence Critchlow 1 , Ilkay Altintas 4 , Bertram Ludaescher 5 and Andrew J. Wyrobek 6 . 1 Biosciences, LLNL, Livermore, CA, 94550, 2 Departments of Molecular and Human Genetics and Medicine, Baylor College of Medicine, Houston, TX, 77030, 3 School of Health Sciences, Purdue University, West Lafayette, IN, 47907. 4 San Diego Supercomputer Center, University of California, San Diego La Jolla, CA 92093. 5 Department of Computer Science, University of California, Davis, CA 95616. 6 Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA. 94706. Contact information: coleman16@llnl.gov

389

Multiple ionization of Ar, Kr, and Xe in a superstrong laser field  

Science Journals Connector (OSTI)

We report the numerical calculation of Ar9+? Ar13+, Kr13+? Kr17+, and Xe19+? Xe23+ ion yield in the laser field with intensity exceeding 1019 W/cm2. The results of the calculations agree with the experimental data [K. Yamakava et al., Phys. Rev. A 68, 065403 (2003)] quantitatively (for the Ar ions) or qualitatively (for the Kr ions). The theoretical results disagree with the experimental data for the Xe ions. We discuss the possible influence of the relativistic effects on this disagreement between theory and experiment. We obtained the approximation formula for the position of the maximum ionic population with the given ionization multiplicity Z depending on the radiation intensity. This position is described by the power function of Z; the exponent is determined by the dependence of sequential ionization potentials on Z value. We discuss the dependence of the approximation formula parameters on the value of the FWHM of the laser pulse.

Aleksei S. Kornev; Elena B. Tulenko; Boris A. Zon

2011-11-21T23:59:59.000Z

390

A numerical scheme for ionizing shock waves  

SciTech Connect (OSTI)

A two-dimensional (2D) visual computer code to solve the steady state (SS) or transient shock problems including partially ionizing plasma is presented. Since the flows considered are hypersonic and the resulting temperatures are high, the plasma is partially ionized. Hence the plasma constituents are electrons, ions and neutral atoms. It is assumed that all the above species are in thermal equilibrium, namely, that they all have the same temperature. The ionization degree is calculated from Saha equation as a function of electron density and pressure by means of a nonlinear Newton type root finding algorithms. The code utilizes a wave model and numerical fluctuation distribution (FD) scheme that runs on structured or unstructured triangular meshes. This scheme is based on evaluating the mesh averaged fluctuations arising from a number of waves and distributing them to the nodes of these meshes in an upwind manner. The physical properties (directions, strengths, etc.) of these wave patterns are obtained by a new wave model: ION-A developed from the eigen-system of the flux Jacobian matrices. Since the equation of state (EOS) which is used to close up the conservation laws includes electronic effects, it is a nonlinear function and it must be inverted by iterations to determine the ionization degree as a function of density and temperature. For the time advancement, the scheme utilizes a multi-stage Runge-Kutta (RK) algorithm with time steps carefully evaluated from the maximum possible propagation speed in the solution domain. The code runs interactively with the user and allows to create different meshes to use different initial and boundary conditions and to see changes of desired physical quantities in the form of color and vector graphics. The details of the visual properties of the code has been published before (see [N. Aslan, A visual fluctuation splitting scheme for magneto-hydrodynamics with a new sonic fix and Euler limit, J. Comput. Phys. 197 (2004) 1-27]). The two-dimensional nature of ION-A was presented by a planar shock wave propagating over a circular obstacle. It was demonstrated that including the effects of ionization in calculating complex flows is important, even when they appear initially negligible. This code can be used to accurately simulate the nonlinear time dependent evolution of neutral or ionized plasma flows from supersonic to hypersonic regimes.

Aslan, Necdet [Yeditepe University, Physics Department, Kayisda g-circumflex i, 34755 Istanbul (Turkey)]. E-mail: naslan@yeditepe.edu.tr; Mond, Michael [Ben Gurion University, Mechanical Engineering Department, Beer Sheva (Israel)

2005-12-10T23:59:59.000Z

391

Evaluation and Control of Radiation Dose to the Embryo/Fetus Guide for Use with Title 10, Code of Federal Regulations, Part 835, Occupational Radiation Protection  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

This Guide provides an acceptable methodology for establishing and operating a program to control fetal exposure to ionizing radiation and evaluate the resultant dose that will comply with U.S. Department of Energy (DOE) requirements specified in Title 10 of the Code of Federal Regulations (CFR), Part 835, Occupational Radiation Protection (DOE 1998), hereinafter referred to as 10 CFR 835.

1999-04-29T23:59:59.000Z

392

KUB5/HERA: a dual acting protein that suppresses genomic instability and promotes DNA repair after low dose IR exposure  

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

KUB5/HERA: a dual acting protein that suppresses genomic instability and KUB5/HERA: a dual acting protein that suppresses genomic instability and promotes DNA repair after low dose IR exposure Julio C. Morales 1 , Amy Rommel 1 , Konstantin Leskov 2 , Walter M. Hittelman 3 , David A. Boothman 1# 1 Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. 2 Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH 44106, USA. 3 Department of Experimental Therapeutics, M.D. Anderson Cancer Center, Houston, TX 77030, USA. # To whom correspondence should be addressed. E-mail: David.Boothman@utsouthwestern.edu Eukaryotic cells can respond to DNA double strand breaks created by low doses of IR by activating homologous recombination (HR) or non-homologous end- joining (NHEJ) pathways to repair DNA. A yeast two-hybrid screen using Ku70 as

393

E-Print Network 3.0 - assisted resonance ionization Sample Search...  

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

ionization PADIACplasma43 Dielectricbarrierdischarge... Matrix-assisted ionization ... Source: Oak Ridge National Laboratory Fossil Energy Program Collection: Fossil Fuels 28...

394

Photo-Ionization of Molecules near Threshold  

Science Journals Connector (OSTI)

An orthogonalized Coulomb-wave method for the construction of continuum wave functions of molecules is described. Hydrogenic functions of definite angular momentum, which transform according to the irreducible representations of the point group of the molecule, are phenomenologically used as trial functions. Corrections to the trial functions are made by orthogonalizing them to charge rearrangement states of the molecule. The photo-ionization cross section is obtained by summing over the asymptotic angular-momentum quantum number. The method is exemplified by calculation of the photo-ionization cross sections of the ground and first excited states of the anthracene molecule in the range of 1.5 eV above threshold.

John P. Hernandez

1968-03-05T23:59:59.000Z

395

Photo-Auger ionization of lithiumlike ions  

Science Journals Connector (OSTI)

The photo-Auger ionization process is a higher-order contribution to the direct photoelectric effect in which photoexcitation of an inner-shell electron is followed by the emission of an Auger electron. The frequency-integrated photo-Auger ionization cross section for ions of the lithium isoelectronic sequence is calculated in the isolated resonance approximation. The effects of transitions into all accessible intermediate states are explicitly included. Results are compared with the frequency-integrated direct photoionization cross section. The relative contribution of the photo-Auger effect for three-electron ions is a maximum in the Ne(7 +) region, where it is of order 70% of the direct process.

K. J. LaGattuta and Yukap Hahn

1982-01-01T23:59:59.000Z

396

External ionization mechanisms for advanced thermionic converters  

SciTech Connect (OSTI)

This work investigates ion generation and recombination mechanisms in the cesium plasma as they pertain to the advanced mode thermionic energy converter. The changes in plasma density and temperature within the converter have been studied under the influence of several promising auxiliary ionization candidate sources. Three novel approaches of external cesium ion generation have been investigated in some detail, namely vibrationally excited N/sub 2/ as are energy source of ionization of Cs ions in a dc discharge, microwave power as a means of resonant sustenance of the cesium plasma, and ion generation in a pulse N/sub 2/-Cs mixture. The experimental data obtained and discussed in this work show that all three techniques - i.e. the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave power - have considerable promise as schemes in auxiliary ion generation applicable to the advanced thermionic energy converter.

Hatziprokopiou, M.E.

1981-01-01T23:59:59.000Z

397

Protective effect of hydroferrate fluid, MRN-100, against lethality and hematopoietic tissue damage in -radiated Nile tilapia, Oreochromis niloticus  

Science Journals Connector (OSTI)

......other damage. Environ Health Perspect (1997) 105...ionizing-radiation lethality. Health Phys (2003) 84:565-75...Oxidative Stress and Health. In: Oxidative Stress...cytotoxicity induced by depleted uranium in isolated rat hepatocytes......

Mamdooh Ghoneum; Heba Allah M. Elbaghdady; Abdallah A. El-Shebly; Deyu Pan; Edward Assanah; Greg Lawson

2013-09-01T23:59:59.000Z

398

Photo-Ionization of Crystalline Anthracene  

Science Journals Connector (OSTI)

The photo-ionization spectra of the ground, first singlet, and first triplet states of crystalline anthracene are calculated assuming transitions to a simple continuum. The calculations neglect vibrational-overlap factors which will reduce the cross sections perhaps by as much as a factor of 10. Recombination is also neglected, and is blamed for discrepancies between the calculation and experiments which measure photo-currents. Kepler has reported a cross section of 210-19 cm2 from the first singlet, Courtens et al., one of 0.610-19; the calculation gives 610-18. Holzman et al. report 10-20 cm2 from the first triplet; the calculation gives 610-18. If one accounted for vibrational overlap and recombination (which will be larger in the second experiment, because of the smaller kinetic energy), the agreement would be good. The agreement is not so good with the magnitude of transitions from the ground state, though the energy dependence gives a good fit. The discrepancy may be due to the (neglected) influence of auto-ionizing states on the final-state wave functions. Based on a theory by Choi, the singlet exciton-exciton ionization rate constant is calculated to be 210-9 cm3 sec-1 (vibrations and recombination neglected) compared with Silver's experimental value of 0.810-10; again the agreement is good. Finally, the time needed for a photo-ionized electron to lose kinetic energy by exciting a triplet is calculated to be 10-9 sec or longer, so this mechanism is ruled out as an energy-loss process in comparison with the emission of optical vibrations, which has been estimated to take about 10-13 sec.

John P. Hernandez

1968-05-15T23:59:59.000Z

399

The multiphoton ionization of uranium hexafluoride  

SciTech Connect (OSTI)

Multiphoton ionization (MPI) time-of-flight mass spectroscopy and photoelectron spectroscopy studies of UF{sub 6} have been conducted using focused light from the Nd:YAG laser fundamental ({lambda}=1064 nm) and its harmonics ({lambda}=532, 355, or 266 nm), as well as other wavelengths provided by a tunable dye laser. The MPI mass spectra are dominated by the singly and multiply charged uranium ions rather than by the UF{sub x}{sup +} fragment ions even at the lowest laser power densities at which signal could be detected. The laser power dependence of U{sup n+} ions signals indicates that saturation can occur for many of the steps required for their ionization. In general, the doubly-charged uranium ion (U{sup 2+}) intensity is much greater than that of the singly-charged uranium ion (U{sup +}). For the case of the tunable dye laser experiments, the U{sup n+} (n = 1- 4) wavelength dependence is relatively unstructured and does not show observable resonance enhancement at known atomic uranium excitation wavelengths. The dominance of the U{sup 2+} ion and the absence or very small intensities of UF{sub x}{sup +} fragments, along with the unsaturated wavelength dependence, indicate that mechanisms may exist other than ionization of bare U atoms after the stepwise photodissociation of F atoms from the parent molecule.

Armstrong, D.P. (Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.) [Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.

1992-05-01T23:59:59.000Z

400

Low Dose Radiation Research Program: Current Funded Project Descriptions  

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

Funded Project Descriptions Funded Project Descriptions Effects Of Low Doses of Radiation on DNA Repair Jointly funded by NASA and DOE Eric J Ackerman Pacific Northwest National Laboratory Richland, WA 99352 Dr. Ackerman will study the effect of low doses of ionizing radiation on the repair of different types of damage to DNA, including damage from ionizing radiation and that produced by the normal internal operation of the cell. Using a very sensitive technique called host cell reactivation assay (HCR), he will quantitatively measure the repair of each type of DNA damage and thereby measure if the cellular repair system itself has been damaged. He will also determine if unique forms of DNA repair system damage are induced by low doses of cosmic radiation exposure present during space

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Low Dose Radiation Research Program: Project Descriptions-Archive  

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

Project Descriptions-Archive Project Descriptions-Archive Effects Of Low Doses of Radiation on DNA Repair Eric J Ackerman (former PNNL) (Jointly funded by NASA and DOE) Pacific Northwest National Laboratory Richland, WA Dr. Ackerman will study the effect of low doses of ionizing radiation on the repair of different types of damage to DNA, including damage from ionizing radiation and that produced by the normal internal operation of the cell. Using a very sensitive technique called host cell reactivation assay (HCR), he will quantitatively measure the repair of each type of DNA damage and thereby measure if the cellular repair system itself has been damaged. He will also determine if unique forms of DNA repair system damage are induced by low doses of cosmic radiation exposure present during space

402

BNL NASA Space Radiation Laboratory  

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

Purpose: To use beams of heavy ions provided by the Booster accelerator at Brookhaven to study the effects of simulated space radiation on biological and physical systems, with the goal of developing methods and materials to reduce the risk to human beings on prolonged space missions of the effects of ionizing radiation Sponsor: National Aeronautics and Space Administration (NASA) Project cost $34 million over 4 years Operating costs Nearly $8 million per year in 2007 Features * beams of heavy ions extracted from the Booster accelerator with masses and energies similar to the cosmic rays encountered in space: * 1-billion electron volt (GeV)/nucleon iron-56 * 0.3-GeV/nucleon gold-97 * 0.6-GeV/nucleon silicon-28 * 1-GeV/nucleon protons * 1-GeV/nucleon titanium

403

OH/IR stars and their superwinds as observed by the Herschel Space Observatory  

E-Print Network [OSTI]

Aim : In order to study the history of mass loss in extreme OH/IR stars, we observed a number of these objects using CO as a tracer of the density and temperature structure of their circumstellar envelopes. Method : Combining CO observations from the Herschel Space Observatory with those from the ground, we trace mass loss rates as a function of radius in five extreme OH/IR stars. Using radiative transfer modelling, we modelled the dusty envelope as well as the CO emission. The high-rotational transitions of CO indicate that they originate in a dense superwind region close to the star while the lower transitions tend to come from a more tenuous outer wind which is a result of the mass loss since the early AGB phase. Result : The models of the circumstellar envelopes around these stars suggest that they have entered a superwind phase in the past 200 - 500 years. The low 18O/17O (~ 0.1 compared to the solar abundance ratio of ~ 5) and 12C/13C (3-30 cf. the solar value of 89) ratios derived from our study suppor...

Justtanont, K; Barlow, M J; Matsuura, M; Swinyard, B; Waters, L B F M; Yates, J

2013-01-01T23:59:59.000Z

404

X radiation and the human fetus - a bibliography. Final report  

SciTech Connect (OSTI)

The bibliography is the end result of many years' survey of the literature pertaining to the effects of ionizing radiation, particularly x radiation, on the human embryo and fetus. It is intended to provide the technical and scientific community with a ready identification of material available to them in this discipline. It is divided into three sections: an index (KWIC) by keywords, an author list, and the bibliography.

Rugh, R.

1980-03-01T23:59:59.000Z

405

ARM - Field Campaign - IR Cloud Camera Feasibility Study  

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

govCampaignsIR Cloud Camera Feasibility Study govCampaignsIR Cloud Camera Feasibility Study Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : IR Cloud Camera Feasibility Study 2010.12.06 - 2010.12.13 Lead Scientist : Kyle Leesman For data sets, see below. Description During December 2010, a prototype LWIR cloud camera system was deployed at the Southern Great Plains Guest Instrument Facility (SGP-GIF). The system consisted of a microbolometer camera (~7-15 ìm) to capture sky imagery, a blackbody calibration source, and a GPS receiver used to estimate atmospheric column water vapor and constrain atmospheric compensation. The camera system collected calibrated sky radiance images co-incident with the SGP Central Facility with the goal of quantitatively assessing its ability

406

Device for calibrating a radiation detector system  

DOE Patents [OSTI]

A device is disclosed for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a ''shield plate'' or shell, and an opposing ''source plate'' containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects. 3 figures.

McFee, M.C.; Kirkham, T.J.; Johnson, T.H.

1994-12-27T23:59:59.000Z

407

Device for calibrating a radiation detector system  

DOE Patents [OSTI]

A device for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a "shield plate" or shell, and an opposing "source plate" containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, heart, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects.

Mc Fee, Matthew C. (New Ellenton, SC); Kirkham, Tim J. (Beech Island, SC); Johnson, Tippi H. (Aiken, SC)

1994-01-01T23:59:59.000Z

408

Low Dose Radiation Research Program: Radiation-Induced Nuclear Factor kB  

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

Radiation-Induced Nuclear Factor kB mediates survival advantage by Radiation-Induced Nuclear Factor kB mediates survival advantage by Telomerase Activation. Authors: Natarajan M.,1 Mohan S.,2 Pandeswara, S.L.,1 and Herman T.S.1 Institutions: Departments of 1Radiation Oncology and 2Pathology, The University of Texas Health Science Center, San Antonio, Texas Activation of NF-kB in response to low doses of ionizing radiation was first shown in our laboratory. Although studies have shown that NF-kB plays an important role in anti-apoptotic function, little has been done to understand the molecular link between the activation of NF-kB and cellular outcome such as enhanced cell survival after low dose low-linear transfer (LET) radiation. Because upregulation of telomerase activity is associated with longevity and allows cells to escape from senescence, we hypothesize

409

Plasma Radiation  

Science Journals Connector (OSTI)

... JUST over ten years ago the first book on plasma physics as a subject in its own right appeared; in a gradually swelling stream ... been surprisingly few monographs. One topic which has had scant coverage in any form is plasma radiation (except for spectral-line radiation which has been dealt with very fully in ...

T. J. M. BOYD

1967-07-01T23:59:59.000Z

410

Radiation Physics and Chemistry 71 (2004) 363368 A study of the alanine dosimeter irradiation temperature  

E-Print Network [OSTI]

. Puhla , Anna L. McBainb , Glenn W. Calvertb a Ionizing Radiation Division, Physics Laboratory, National. Since the temperature coefficient is known to be dose dependent [Radiat. Phys. Chem. 57 (2000) 1], a series of dose response studies were conducted over a dose range of 0.5­100 kGy. The study revealed

411

A RADIATION TOLERANT COUNTING A/D CONVERTER VICKRAM SELVAKUMAR, BEng Hons  

E-Print Network [OSTI]

. Finally I would like to thanks GOD for giving me the ability and the opportunity to undertake to the effects of ionizing radiation. A single charged particle of radiation can knock thousands of electrons particle traverses an electronic circuit, causing errors to appear. Single Event Effects were first

Furth, Paul

412

Mutation Research 504 (2002) 91100 Bystander effects in radiation-induced genomic instability  

E-Print Network [OSTI]

Mutation Research 504 (2002) 91­100 Bystander effects in radiation-induced genomic instability recombination and other phenotypes associated with genomic instability. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Bystander effects; Genomic instability; Ionizing radiation 1. Introduction Exposure

413

X-ray radiation effects in multilayer epitaxial graphene Jeremy Hicks1  

E-Print Network [OSTI]

1 X-ray radiation effects in multilayer epitaxial graphene Jeremy Hicks1 , Rajan Arora2 , Eleazar and after exposure to a total ionizing dose (TID) of 12 Mrad(SiO2) using a 10 keV X-ray source. While we are mostly unaffected by radiation exposure. Combined with X-ray photoelectron spectroscopy (XPS) data

414

Conceptual design for a fast neutron ionization chamber for fusion reactor plasma diagnostics  

SciTech Connect (OSTI)

A conceptual design for a radiation-hard ``pointing`` fast neutron ionization chamber that is capable of delivering a 1 MHz countrate of T(D,n) events at ITER is given. The detector will use a {approximately}1 cm{sup 3} volume of CO{sub 2} fill gas at 0.1 bar pressure in a 500 V/cm electric field. The pulse widths will be {approximately}10 ns, enabling it to operate in a flux of {approximately} 6 {times} 10{sup 13} DT n/cm{sup 2}/sec. A special collimator design is used, giving an estimated angular resolution of 4.5 degrees HWHM.

Sailor, W.C.; Barnes, C.W.

1994-06-01T23:59:59.000Z

415

Toward Single-Cell Analysis by Plume Collimation in Laser Ablation Electrospray Ionization Mass Spectrometry  

Science Journals Connector (OSTI)

In the plume collimation experiments, laser radiation was delivered through a germanium oxide (GeO2) optical fiber (450 ?m core diameter, HP Fiber, Infrared Fiber Systems, Inc., Silver Spring, MD) with a tip etched in a 2% nitric acid solution as described earlier. ... Upon ablation in the capillary, a collimated plume emerges (shown in blue) and is ionized by an electrospray. ... Individual sea urchin eggs were selected by using the micromanipulator system and deposited into a capillary for LAESI mass spectrometry with plume collimation. ...

Jessica A. Stolee; Akos Vertes

2013-02-28T23:59:59.000Z

416

Origin of the ionized wind in MWC 349A  

E-Print Network [OSTI]

The UC-HII region of MWC 349A is the prototype of an ionized wind driven by a massive star surrounded by a disk. Recent high angular resolution observations of the millimeter recombination lines have shown that the disk rotates with a Keplerian law in its outer parts. However, the kinematics of innermost regions in the UC-HII region of MWC 349A is still unknown, in particular the radius where the wind is launched from the disk. We performed hydrogen recombination line observations with the Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory to study the kinematics of its innermost regions by studying their spectral features. In addition to the two laser peaks, we report the first detection of two new components that are blueshifted with respect to the laser peaks for all the recombination lines with principal quantum number nwind is ejected from the disk. We used our 3D non-LTE radiative transfer model...

Bez-Rubio, Alejandro; Thum, Clemens; Planesas, Pere; Torres-Redondo, Josefina

2014-01-01T23:59:59.000Z

417

Generating coherent broadband continuum soft-x-ray radiation by  

E-Print Network [OSTI]

Generating coherent broadband continuum soft-x-ray radiation by attosecond ionization gating Thomas as the driver for high-harmonic generation that has a cosine-like electric field stabilized with respect the generation of broadband and tunable attosecond pulses. Instead of fixing the carrier-envelope phase

Neumark, Daniel M.

418

INSTITUTE OF NUCLEAR ENERGY RADIATION ANNUAL REPORT 2003  

E-Print Network [OSTI]

Dynamic reliability of Complex System & decision Analysis I. Papazoglou Occupational Risk Assessment I PHYSICS OF THE REACTOR I. Stamatelatos Exposure of the Population to Ionizing Radiations of the Enironment LABORATORY G. Pantelias Operation & Maintenance of Research Reactor M. Stakakis Nuclear Analytical Techniques

419

Research priorities for occupational radiation protection  

SciTech Connect (OSTI)

The Subpanel on Occupational Radiation Protection Research concludes that the most urgently needed research is that leading to the resolution of the potential effects of low-level ionizing radiation. This is the primary driving force in setting appropriate radiation protection standards and in directing the emphasis of radiation protection efforts. Much has already been done in collecting data that represents a compendium of knowledge that should be fully reviewed and understood. It is imperative that health physics researchers more effectively use that data and apply the findings to enhance understanding of the potential health effects of low-level ionizing radiation and improve the risk estimates upon which current occupational radiation protection procedures and requirements depend. Research must be focused to best serve needs in the immediate years ahead. Only then will we get the most out of what is accomplished. Beyond the above fundamental need, a number of applied research areas also have been identified as national priority issues. If effective governmental focus is achieved on several of the most important national priority issues, important occupational radiation protection research will be enhanced, more effectively coordinated, and more quickly applied to the work environment. Response in the near term will be enhanced and costs will be reduced by: developing microprocessor-aided {open_quotes}smart{close_quotes} instruments to simplify the use and processing of radiation data; developing more sensitive, energy-independent, and tissue-equivalent dosimeters to more accurately quantify personnel dose; and developing an improved risk assessment technology base. This can lead to savings of millions of dollars in current efforts needed to ensure personnel safety and to meet new, more stringent occupational guidelines.

Not Available

1994-02-01T23:59:59.000Z

420

Ionization Chambers in the FLASH Dump Line  

E-Print Network [OSTI]

. 7, 2010FLASH Seminar, Dec. 7, 2010 BPM 13DUMP Dump Line Upgrade 2009Dump Line Upgrade 2009 BPM 9DUMP BPM 5DUMP Toroid 9DUMP OTR screen 9DUMP BLM 14DUMP BLM 13.1DUMP 13.2DUMP BLM 9DUMP BLM 6DUMP BLM 1.1DUMP 1.2DUMP BPM 10DUMP BPM 16DUMP 8 x BHM 16DUMP BLM 14R.DUMP 14L.DUMP 14U.DUMP 14D.DUMP Ionization

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Resonance ionization detection of combustion radicals  

SciTech Connect (OSTI)

Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated aromatic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and disposal of hazardous chemical wastes. Selective laser ionization techniques are used in this laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames.

Cool, T.A. [Cornell Univ., Ithaca, NY (United States)

1993-12-01T23:59:59.000Z

422

(Resonance ionization spectroscopy and its applications)  

SciTech Connect (OSTI)

The field of Resonance Ionization Spectroscopy grew out of work done in the Photophysics Group at Oak Ridge National Laboratory. As one of the original developers of this field the traveler has continued to attend this meeting on a regular basis. The traveler was originally asked to present an invited talk and to present part of a short course offered to graduate students attending the conference. Subsequently, the traveler was also asked to chair a session and to be a judge of the students papers entered in a contest for a $1000 first prize.

Payne, M.G.

1990-10-05T23:59:59.000Z

423

Impurity radiation from a tokamak plasma  

SciTech Connect (OSTI)

In tokamak operating modes, energy balance is often governed by impurity radiation. This is the case near the divertor plates, during impurity pellet injection, during controlled discharge disruptions, etc. The calculation of impurity radiation is a fairly involved task (it is sometimes the most difficult part of the general problem) because the radiation power is determined by the distribution of ions over the excited states and by the rate constants of elementary processes of radiation and absorption. The objective of this paper is to summarize in one place all the approximate formulas that would help investigators to describe radiation from the most often encountered impurities in a fairly simple way in their calculations accounting for plasma radiation, without reference to special literature. Simple approximating formulas describing ionization, recombination, and charge-exchange processes, as well as radiative losses from ions with a given charge, are presented for five impurity species: beryllium, carbon, oxygen, neon, and argon. Estimating formulas that allow one to take into account plasma opacity for resonant photons in line impurity radiation are also presented.

Morozov, D. Kh.; Baronova, E. O. [Russian Research Centre Kurchatov Institute, Nuclear Fusion Institute (Russian Federation); Senichenkov, I. Yu. [St. Petersburg State Polytechnical University (Russian Federation)

2007-11-15T23:59:59.000Z

424

Radiation dosimeter  

DOE Patents [OSTI]

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.

Fox, Richard J. (Oak Ridge, TN)

1983-01-01T23:59:59.000Z

425

Radiation dosimeter  

DOE Patents [OSTI]

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.

Fox, R.J.

1981-09-01T23:59:59.000Z

426

Mid-IR FORCAST/SOFIA Observations of M82  

E-Print Network [OSTI]

We present 75"x75" size maps of M82 at 6.4 micron, 6.6 micron, 7.7 micron, 31.5 micron, and 37.1 micron with a resolution of ~4" that we have obtained with the mid-IR camera FORCAST on SOFIA. We find strong emission from the inner 60" (~1kpc) along the major axis, with the main peak 5" west-southwest of the nucleus and a secondary peak 4" east-northeast of the nucleus. The detailed morphology of the emission differs among the bands, which is likely due to different dust components dominating the continuum emission at short mid-IR wavelengths and long mid-IR wavelengths. We include Spitzer-IRS and Herschel/PACS 70 micron data to fit spectral energy distribution templates at both emission peaks. The best fitting templates have extinctions of A_V = 18 and A_V = 9 toward the main and secondary emission peak and we estimated a color temperature of 68 K at both peaks from the 31 micron and 37 micron measurement. At the emission peaks the estimated dust masses are on the order of 10^{4} M_sun.

Nikola, T; Vacca, W D; Adams, J D; De Buizer, J M; Gull, G E; Henderson, C P; Keller, L D; Morris, M R; Schoenwald, J; Stacey, G; Tielens, A

2012-01-01T23:59:59.000Z

427

Interference effects in IR photon echo spectroscopy of liquid water  

SciTech Connect (OSTI)

Heterodyne-detected transient grating experiments on the OH-stretch mode of HDO dissolved in D{sub 2}O resolve two distinctly different contributions originating from the initially excited OH stretch and the OD stretch which is thermally activated during the OH population relaxation. It is demonstrated that interference of both contributions greatly affects the outcome of IR photon echo experiments.

Yeremenko, Sergey; Pshenichnikov, Maxim S.; Wiersma, Douwe A. [Ultrafast Laser and Spectroscopy Laboratory, Materials Science Centre, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

2006-02-15T23:59:59.000Z

428

Ecological and agricultural applications of synchrotron IR microscopy  

E-Print Network [OSTI]

Ecological and agricultural applications of synchrotron IR microscopy T.K. Raab a,*, J.P. Vogel b factors to the fungus Erysiphe cichoracearum, a causative agent of powdery mildew disease. Three genes to pro- liferate when environmental conditions and re- sources are optimum. Cellulose, an abundant

429

WEB QUERY STRUCTURE: IMPLICATIONS FOR IR SYSTEM DESIGN  

E-Print Network [OSTI]

WEB QUERY STRUCTURE: IMPLICATIONS FOR IR SYSTEM DESIGN Bernard J. Jansen Computer Science Program Military Academy West Point, New York 10996 Please Cite: Jansen, B. J., Spink, A., & Pfaff, A. 2000. Web in the context of the Web (Jansen, Spink, & Saracevic, 2000; Jansen and Pooch (under review), Lawrence & Giles

Jansen, James

430

Dielectric liquid ionization chambers for detecting fast neutrons  

E-Print Network [OSTI]

Three ionization chambers with different geometries have been constructed and filled with dielectric liquids for detection of fast neutrons. The three dielectric liquids studied were Tetramethylsilane (TMS), Tetramethylpentane ...

Boyd, Erin M

2008-01-01T23:59:59.000Z

431

Implied Dynamic Feedback of 3D IR Radiative Transfer on Simulated...  

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

and macroscale cloud field structure relative to independent pixel approximation (IPA) RT. Methodology The Cooperative Institute for Mesoscale Meteorological Studies (CIMMS)...

432

Low Dose Radiation Research Program: Impact of Genetic Factors on the  

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

Genetic Factors on the Heritable Effects of Paternal Exposure to Genetic Factors on the Heritable Effects of Paternal Exposure to Low-Dose Radiation Janet E. Baulch University of California, Davis Why This Project? There is concern about the possible genetic effects of low dose radiation exposure. As a result, much effort has gone towards understanding mutation of cells due to radiation exposure. While recognition of the potential for mutation from exposure to ionizing radiation has led to extensive research, less effort has been given to the possible delayed risk of radiation exposure transmitted to the offspring of the exposed parent. Data from animal models show that parental exposures to DNA-damaging agents, such as ionizing radiation, predispose the offspring to serious health effects, including cancer offspring. Additionally, data from both humans and animal

433

Appendix G. Radiation Appendix G. Radiation  

E-Print Network [OSTI]

-made sources. People are exposed to naturally occurring radiation constantly. For example, cosmic radiation of radiation and its effects on the environment and biological systems. Radiation comes from natural and humanAppendix G. Radiation #12;#12;Appendix G. Radiation This appendix presents basic facts about

Pennycook, Steve

434

Nevada Test Site Radiation Protection Program - Revision 1  

SciTech Connect (OSTI)

Title 10 Code of Federal Regulations (CFR) Part 835, 'Occupational Radiation Protection,' establishes radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of U.S. Department of Energy (DOE) activities. 10 CFR 835.101(a) mandates that DOE activities be conducted in compliance with a documented Radiation Protection Program (RPP) as approved by DOE. This document promulgates the RPP for the Nevada Test Site (NTS), related (on-site or off-site) U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) operations, and environmental restoration off-site projects. This NTS RPP promulgates the radiation protection standards, limits, and program requirements for occupational exposure to ionizing radiation resulting from NNSA/NSO activities at the NTS and other operational areas as stated in 10 CFR 835.1(a). NNSA/NSO activities (including design, construction, operation, and decommissioning) within the scope of this RPP may result in occupational exposures to radiation or radioactive material. Therefore, a system of control is implemented through specific references to the site-specific NV/YMP RCM. This system of control is intended to ensure that the following criteria are met: (1) occupational exposures are maintained as low as reasonably achievable (ALARA), (2) DOE's limiting values are not exceeded, (3) employees are aware of and are prepared to cope with emergency conditions, and (4) employees are not inadvertently exposed to radiation or radioactive material.

Radiological Control Managers' Council

2008-06-01T23:59:59.000Z

435

Low Dose Radiation Research Program: 2003 Molecular Characterization of the  

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

Characterization of the Roles of SOD Genes in Mammalian Characterization of the Roles of SOD Genes in Mammalian Cellular Response to Low Dose Radiation Authors: Chuan-Yuan Li,1 Eric Chuang2 Institutions: 1Dept of Radiation Oncology, Duke University Medical Center, Durham, NC, 2Advanced Technology Center, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland The potential risks of exposure to low dose radiation are of major concerns to the DOE/OBER Low Dose Radiation Research Program. It has been long recognized that much of the radiation-induced genetic damage to cells are caused by secondary oxidative species. Therefore, internal cellular defense systems against oxidative stress play significant roles in countering genetic damage induced by ionizing radiation. The role of the detoxifying

436

Low Dose Radiation Research Program: Molecular Characterization of the  

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

Molecular Characterization of the Roles of SOD Genes in Mammalian Molecular Characterization of the Roles of SOD Genes in Mammalian Cellular Response to Low Dose Radiation Authors: Chuan-Yuan Li, Zhanjun Guo, Zhonghui Yang, and Eric Chuang Institutions: Dept of Radiation Oncology, Duke University Medical Center, Durham, NC Advanced Technology Center, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland Background The potential risks of exposure to low dose radiation are of major concerns to the DOE/OBER Low Dose Radiation Research Program. It has been long recognized that much of the radiation-induced genetic damage to cells are caused by secondary oxidative species. Therefore internal cellular defense systems against oxidative stress play significant roles in countering genetic damage induced by ionizing radiation. The role of the detoxifying

437

Low Dose Radiation Research Program: DOE / NASA Joint Funded Projects  

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

DOE/NASA Joint Funded Projects DOE/NASA Joint Funded Projects NASA Source Photo Space explorers are subject to exposure to low dose ionizing radiation. Research that helps determine health risks from this exposure is funded by NASA and DOE. Source: NASA DOE's Low Dose Program and the National Aeronautics and Space Administration (NASA) jointly fund new research to develop a better scientific basis for understanding risks to humans from exposures to low doses or low fluences of ionizing radiation. Research must focus on elucidating molecular mechanisms and pathways involved in normal radiobiological responses to low dose exposure, and must have the potential to ultimately increase understanding of health outcomes from radiation exposures that are at or near current workplace exposure

438

Estimation of radiation dose and risk to children undergoing cardiac catheterization for the treatment of a congenital heart disease using Monte Carlo simulations  

Science Journals Connector (OSTI)

Many mathematical models have been developed for estimating the cancer risk resulting from exposure to ionizing radiation. One such set of models has been...10...]. The BEIR VII committee has derived risk models ...

Emmanuel Yakoumakis; Helen Kostopoulou; Triantafilia Makri

2013-03-01T23:59:59.000Z

439

Electron Capture in a Fully Ionized Plasma  

E-Print Network [OSTI]

Properties of fully ionized water plasmas are discussed including plasma charge density oscillations and the screening of the Coulomb law especially in the dilute classical Debye regime. A kinetic model with two charged particle scattering events determines the transition rate per unit time for electron capture by a nucleus with the resulting nuclear transmutations. Two corrections to the recent Maiani et al. calculations are made: (i) The Debye screening length is only employed within its proper domain of validity. (ii) The WKB approximation employed by Maiani in the long De Broglie wave length limit is evidently invalid. We replace this incorrect approximation with mathematically rigorous Calogero inequalities in order to discuss the scattering wave functions. Having made these corrections, we find a verification for our previous results based on condensed matter electro-weak quantum field theory for nuclear transmutations in chemical batteries.

A. Widom; J. Swain; Y. N. Srivastava

2014-09-17T23:59:59.000Z

440

Photo-Ionization of the Hydrogen Molecule  

Science Journals Connector (OSTI)

One-center wave functions are employed to investigate the photo-ionization of the hydrogen molecule from its ground state X(1s??g1+), from 700 to 300 . It is assumed that the residual ion is left in its ground state, and the free electron is in a p?orp? orbital. Using the one-center wave functions for H2+ for the internuclear distance equal to 1. 4a0, the free-electron wave functions are obtained by solving the integrodifferential equations in exchange and polarized-orbital approximations. The oscillator strengths obtained in the polarized-orbital approximation are found to be in satisfactory agreement with the experimental data.

S. P. Khare

1968-09-05T23:59:59.000Z

Note: This page contains sample records for the topic "ionizing radiation ir" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Calculation ofZ eff from plasma resistivity in IR-T1 tokamak  

Science Journals Connector (OSTI)

We estimatedZ eff in the IR-T1 tokamak through anomaly factor. The IR-T1 tokamak is a small air-core transformer tokamak with circular cross section and with out... ...

M. Mahmoodi Darian; M. Ghoranneviss; M. K. Salem

2004-03-01T23:59:59.000Z

442

The starburst phenomenon from the optical/near-IR perspective  

E-Print Network [OSTI]

The optical/near-IR stellar continuum carries unique information about the stellar population in a galaxy, its mass function and star-formation history. Star-forming regions display rich emission-line spectra from which we can derive the dust and gas distribution, map velocity fields, metallicities and young massive stars and locate shocks and stellar winds. All this information is very useful in the dissection of the starburst phenomenon. We discuss a few of the advantages and limitations of observations in the optical/near-IR region and focus on some results. Special attention is given to the role of interactions and mergers and observations of the relatively dust-free starburst dwarfs. In the future we expect new and refined diagnostic tools to provide us with more detailed information about the IMF, strength and duration of the burst and its triggering mechanisms.

Nils Bergvall; Thomas Marquart; Gran stlin; Erik Zackrisson

2004-12-06T23:59:59.000Z

443

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation  

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

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Understanding charge-transfer processes at the atomic level of nanoscale systems is of the utmost importance for designing nanodevices based on quantum-dot structures, nanotubes, or two-dimensional graphene sheets. Researchers from Western Michigan University, Berkeley Lab, and other international research facilities investigated charge-transfer processes and subsequent ion fragmentation dynamics in nanoclusters composed of argon (Ar) shells and xenon (Xe) cores. The clusters were site-selectively ionized (i.e, ionization took place either in the xenon core or in the argon shell). Using a high-resolution photoelectron-ion coincidence technique at ALS Beamlines 10.0.1 and 11.0.2, the researchers concluded that charge-transfer processes and fragmentation dynamics are strongly influenced by the environment of the initially ionized atoms.

444

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation  

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

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Understanding charge-transfer processes at the atomic level of nanoscale systems is of the utmost importance for designing nanodevices based on quantum-dot structures, nanotubes, or two-dimensional graphene sheets. Researchers from Western Michigan University, Berkeley Lab, and other international research facilities investigated charge-transfer processes and subsequent ion fragmentation dynamics in nanoclusters composed of argon (Ar) shells and xenon (Xe) cores. The clusters were site-selectively ionized (i.e, ionization took place either in the xenon core or in the argon shell). Using a high-resolution photoelectron-ion coincidence technique at ALS Beamlines 10.0.1 and 11.0.2, the researchers concluded that charge-transfer processes and fragmentation dynamics are strongly influenced by the environment of the initially ionized atoms.

445

Laser plasma formation assisted by ultraviolet pre-ionization  

SciTech Connect (OSTI)

We present experimental and modeling studies of air pre-ionization using ultraviolet (UV) laser pulses and its effect on laser breakdown of an overlapped near-infrared (NIR) pulse. Experimental studies are conducted with a 266?nm beam (fourth harmonic of Nd:YAG) for UV pre-ionization and an overlapped 1064?nm NIR beam (fundamental of Nd:YAG), both having pulse duration of ?10?ns. Results show that the UV beam produces a pre-ionized volume which assists in breakdown of the NIR beam, leading to reduction in NIR breakdown threshold by factor of >2. Numerical modeling is performed to examine the ionization and breakdown of both beams. The modeled breakdown threshold of the NIR, including assist by pre-ionization, is in reasonable agreement with the experimental results.

Yalin, Azer P., E-mail: ayalin@engr.colostate.edu; Dumitrache, Ciprian [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Wilvert, Nick [Sandia Laboratory, Albuquerque, New Mexico 87123 (United States); Joshi, Sachin [Cummins Inc., Columbus, Indiana 47201 (United States); Shneider, Mikhail N. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2014-10-15T23:59:59.000Z

446

A comprehensive range of X-ray ionized reflection models  

E-Print Network [OSTI]

X-ray ionized reflection occurs when a surface is irradiated with X-rays so intense that its ionization state is determined by the ionization parameter xi propto F/n, where F is the incident flux and n the gas density. It occurs in accretion, onto compact objects including black holes in both active galaxies and stellar-mass binaries, and possibly in gamma-ray bursts. Computation of model reflection spectra is often time-consuming. Here we present the results from a comprehensive grid of models computed with our code, which has now been extended to include what we consider to be all energetically-important ionization states and transitions. This grid is being made available as an ionized-reflection model, REFLION, for XSPEC.

R. R. Ross; A. C. Fabian

2005-01-07T23:59:59.000Z

447

Near-threshold positron impact ionization of hydrogen  

SciTech Connect (OSTI)

The hyperspherical hidden crossing method (HHCM) is used to investigate positron impact ionization of hydrogen near threshold. An important feature of this method is that it can provide valuable insight into scattering processes. In the calculation of positron-hydrogen ionization, the adiabatic Hamiltonian is expanded about the Wannier saddle point; anharmonic corrections are treated perturbatively. The S-wave results are consistent with the Wannier threshold law and with the extended threshold law that was previously derived using the HHCM. We have extended the previous HHCM calculation to higher angular momenta L and have calculated the absolute ionization cross-section for L = 0, 1 and 2. The HHCM calculation confirms that the S-wave ionization cross-section is small and provides the reason why it is small. The HHCM ionization cross-section (summed over the lowest partial waves) is compared with a convergent close-coupling calculation, a 33-state close-coupling calculation and experimental data.

Macek, Joseph H [ORNL; Ward, S.J. [University of North Texas; Jansen, Krista [University of North Texas; Shertzer, J. [College Holy Cross, Worcester, MA

2008-01-01T23:59:59.000Z

448

Radiation receiver  

DOE Patents [OSTI]

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.

Hunt, A.J.

1983-09-13T23:59:59.000Z

449

Epitaxial HTS bolometers on silicon for IR detection  

SciTech Connect (OSTI)

Silicon wafers have shown promise for the fabrication of photothermal IR detectors (i.e., bolometers) from epitaxial HTS thin films of YBa{sub 2}Cu{sub 3}O{sub (7{minus}{delta})} (YBCO). Conventional IC-grade wafers, ultrathin wafers, and micromachined-silicon membrane windows in conventional wafers, are all suitable, but the latter provides considerable advantage for bolometer performance. The high thermal conductivity and strength of silicon make it ideal for submicron-thick window designs. Epitaxy in the HTS film is advantageous, since it reduces granular disorder, the primary cause of dark noise (resistance-fluctuations) in the detector. Mid-to-far-IR transparency of Si at 90 K is unique among those substrates that support high-quality epitaxial YBCO films. This Si transparency to IR can be used for various improvements in the optical design of these devices. The authors review the thermal and optical advantages of silicon substrates, device fabrication issues, and bolometer modeling. Thermal modeling of membrane bolometers indicates that the steady-state temperature-rise profile is nonuniform, but that this does not degrade the response linearity of the bolometer. Certain size limits and trade-offs in the design, will be important in the final device performance. They also discuss applications to FTIR instruments, and extensions of this technology to arrays including a novel on-chip transform spectrometer design.

Fenner, D.B.; Li, Q.; Hamblen, W.D.; Luo, J.; Hamblen, D.G. [AFR, Inc., East Hartford, CT (United States). Superconductivity Group; Budnick, J.I. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Physics

1994-12-31T23:59:59.000Z

450

Backward Raman amplification in a partially ionized gas A. A. Balakin,1  

E-Print Network [OSTI]

was accessed 10,11 . The experimental success was achieved using a gas jet of propane, subse- quently ionized of propane opens up the question of coupling in a partially ionized gas. Any additional ionization during

451

Studies on Induced Variation in the Rhizobia: II. Radiation Sensitivity and Induction of Antibiotic-resistance Markers  

Science Journals Connector (OSTI)

...0.I 0 1 2 DOSE (ergs/mm2...quantitative estimations, as in the...DISCUSSION Radiation dose-survival...an ionizing radiation, i.e...more accurate estimation of mutation...ergs/mm2XIO3 DOSE FIG. 3. Effect...

E. A. Schwinghamer; R. L. Dalmas

1961-09-01T23:59:59.000Z

452

Mekanisk integration av en IR-detektor i en Stirlingkylare; Mechanical Integration of an IR-detector in a Micro Cooler.  

E-Print Network [OSTI]

?? The master thesis Mechanical Integration of an IR-detector in a Micro Cooler has been performed at FLIR Systems AB in Danderyd. FLIR Systems is (more)

Gibson, Camilla

2008-01-01T23:59:59.000Z

453

Radiation Protection Act (Pennsylvania)  

Broader source: Energy.gov [DOE]

This Act combines the radiation safety provisions of The Atomic Energy Development and Radiation Control Act and the Environmental Radiation Protection Act, and empowers the Department of...

454

BNL NASA Space Radiation Laboratory  

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

Dosimetry Calibration: Primary Ion Chamber Dosimetry Calibration: Primary Ion Chamber Dosimetry Calibration: Secondary Ion Chamber Dosimetry Calibration: Secondary Ion Chamber with Gain Dosimetry Calibration: Scintillator Based Dosimetry Dosimetry Calibration: Primary Ion Chamber The primary method of calibrating the dose delivered at NSRL is via a small ion chamber called a "Calibration Ion Chamber" (aka EGG counter) produced by Far West Technology. This is an air-filled bulb with electrodes for collecting ionization inside a tissue-equivalent plastic cap. The Calibration Ion Chamber is sent back to the manufacturer yearly to be calibrated using a standard gamma ray source (Cs-137). The calibration is based on a standard defied by the International Commission on Radiation Units and Measurements (ICRU) and reported in their ICRU Report 59, 15 December 1998.

455

Kinetics of oxygen reduction at IrO{sub 2}-coated titanium electrode in alkaline solution  

SciTech Connect (OSTI)

Oxygen reduction is an industrially important electrochemical reaction, for fuel cells, electrochemical caustic concentrators, air depolarized cathodes, metal-air batteries, and oxidant production. Oxygen reduction at IrO{sub 2}-coated titanium electrodes fabricated by thermal decomposition was investigated by employing cyclic voltammetry and rotating-disk electrode techniques. Cyclic voltammetric results indicated that oxygen reduction begins during the Ir(III)/Ir(IV) transition on an IrO{sub 2} electrode. On the basis of measurements using a rotating disk electrode together with polarization curves, Tafel slopes, and stoichiometric number determinations, a mechanism for oxygen reduction on an IrO{sub 2}-coated titanium electrode is proposed.

Chang, C.C.; Wen, T.C. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering

1996-05-01T23:59:59.000Z

456

Radiation protection: Natural radiation risks  

Science Journals Connector (OSTI)

... radiation to which humans are exposed consists of four components - cosmic, gamma, internal, radon. The relative contribution that each makes to the sum is shown in the chart. ... but exposure of the whole body to terrestrial gamma rays and of the lungs to radon daughters are influenced by the nature and location of housing. Gamma rays are emitted ...

M. C. O'Riordan

1983-11-17T23:59:59.000Z

457

Lattice Boltzmann method for weakly ionized isothermal plasmas  

Science Journals Connector (OSTI)

In this paper, a lattice Boltzmann method (LBM) for weakly ionized isothermal plasmas is presented by introducing a rescaling scheme for the Boltzmann transport equation. Without using this rescaling, we found that the nondimensional relaxation time used in the LBM is too large and the LBM does not produce physically realistic results. The developed model was applied to the electrostatic wave problem and the diffusion process of singly ionized helium plasmas with a 13% degree of ionization under an electric field. The obtained results agree well with theoretical values.

Huayu Li and Hyungson Ki

2007-12-21T23:59:59.000Z

458

Lattice Boltzmann method for weakly ionized isothermal plasmas  

SciTech Connect (OSTI)

In this paper, a lattice Boltzmann method (LBM) for weakly ionized isothermal plasmas is presented by introducing a rescaling scheme for the Boltzmann transport equation. Without using this rescaling, we found that the nondimensional relaxation time used in the LBM is too large and the LBM does not produce physically realistic results. The developed model was applied to the electrostatic wave problem and the diffusion process of singly ionized helium plasmas with a 1-3% degree of ionization under an electric field. The obtained results agree well with theoretical values.

Li Huayu; Ki, Hyungson [Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48824-1226 (United States)

2007-12-15T23:59:59.000Z

459

Photo-double-ionization of the nitrogen molecule  

Science Journals Connector (OSTI)

The triple differential cross sections of the photo-double-ionization of the nitrogen molecule to the X 1?+g and a3?u N22+ states have been measured at about 20 eV above their respective ionization thresholds in the equal energy sharing kinematics and calculated using a model which makes use of correlated two-center double continuum wave functions. The comparison of the results with those obtained by the Gaussian parametrization method applied in the past with success to heliumlike targets shows the influence of the molecular nature of the N2 target in the photo-double-ionization.

P. Bolognesi; B. Joulakian; A. A. Bulychev; O. Chuluunbaatar; L. Avaldi

2014-05-07T23:59:59.000Z

460

The Density Effect for the Ionization Loss in Various Materials  

Science Journals Connector (OSTI)

The density effect for the ionization loss of charged particles has been calculated for a number of metals, scintillating materials, gases at various pressures, and photographic emulsion, using a dispersion model involving an appropriate number of dispersion oscillators for each substance. The results are presented in the form of graphs which can be used to correct the ionization loss for the density effect. The theoretical curves for silver chloride and anthracene are in reasonable agreement with experiments on the ionization loss of ?-mesons. A general derivation of the equations for the density effect is given.

R. M. Sternheimer

1952-11-15T23:59:59.000Z

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461

Ionization and scintillation of nuclear recoils in gaseous xenon  

E-Print Network [OSTI]

Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope $\\alpha$-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.

J. Renner; V. M. Gehman; A. Goldschmidt; H. S. Matis; T. Miller; Y. Nakajima; D. Nygren; C. A. B. Oliveira; D. Shuman; V. lvarez; F. I. G. Borges; S. Crcel; J. Castel; S. Cebrin; A. Cervera; C. A. N. Conde; T. Dafni; T. H. V. T. Dias; J. Daz; R. Esteve; P. Evtoukhovitch; L. M. P. Fernandes; P. Ferrario; A. L. Ferreira; E. D. C. Freitas; A. Gil; H. Gmez; J. J. Gmez-Cadenas; D. Gonzlez-Daz; R. M. Gutirrez; J. Hauptman; J. A. Hernando Morata; D. C. Herrera; F. J. Iguaz; I. G. Irastorza; M. A. Jinete; L. Labarga; A. Laing; I. Liubarsky; J. A. M. Lopes; D. Lorca; M. Losada; G. Luzn; A. Mar; J. Martn-Albo; A. Martnez; A. Moiseenko; F. Monrabal; M. Monserrate; C. M. B. Monteiro; F. J. Mora; L. M. Moutinho; J. Muoz Vidal; H. Natal da Luz; G. Navarro; M. Nebot-Guinot; R. Palma; J. Prez; J. L. Prez Aparicio; L. Ripoll; A. Rodrguez; J. Rodrguez; F. P. Santos; J. M. F. dos Santos; L. Segu; L. Serra; A. Simn; C. Sofka; M. Sorel; J. F. Toledo; A. Toms; J. Torrent; Z. Tsamalaidze; J. F. C. A. Veloso; J. A. Villar; R. C. Webb; J. White; N. Yahlali

2014-09-09T23:59:59.000Z

462

Low dose radiation combines with the Src oncoprotein to transform  

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

radiation combines with the Src oncoprotein to transform radiation combines with the Src oncoprotein to transform pre-malignant human breast cells Paul Yaswen Lawrence Berkeley National Laboratory Abstract Goal: Determine whether low dose radiation exerts persistent epigenetic effects that promote malignancy. Background and Significance: Some persistent carcinogenic effects of radiation may not be traceable to specific DNA sequence alterations and may not be linearly related to dose. Through the biochemical initiation of positive feedback loops, ionization-induced events may have heritable non-linear effects on cellular behavior. Inflammatory responses involving the transcription factor NFκB may be subject to such effects. Increased NFκB activity has been strongly linked to carcinogenesis in a number of published in vitro and in vivo studies (reviewed in [1]). Since radiation

463

ORISE: Advanced Radiation Medicine | REAC/TS Continuing Medical Education  

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

Advanced Radiation Medicine Advanced Radiation Medicine Dates Scheduled Register Online March 24-28, 2014 August 18-22, 2014 Fee: $250 Maximum enrollment: 28 30 hours AMA PRA Category 1 Credits(tm) This 4½-day course includes more advanced information for medical practitioners. This program is academically more rigorous than the Radiation Emergency Medicine course and is primarily for Physicians, Clinical Nurse Practitioners and Physician Assistants desiring an advanced level of information on the diagnosis and management of ionizing radiation injuries and illnesses. Advanced topics in the diagnosis and management of radiation-induced injuries and illnesses includes the use of cytokines, stem cell transplants, antimicrobials, wound care and other advanced techniques. Group problem-solving is used to thoroughly orient attendees to the

464

Radiative Plasmas At The Edge And Their Basic Properties  

SciTech Connect (OSTI)

Plasma radiation plays the determining role in temperature balance, equilibrium and stability of plasmas at the edge of fusion devices. The differences in properties of radiative plasmas and pure hydrogen ones are significant. The sound branch is split into two branches, i.e. fast and slow sounds. They may be destabilize by radiation and stabilized by internal relative motion of species. The basic properties of radiative plasmas are discussed in the current presentation. Radiation of multi-electron impurity ions is significant, even if the impurity concentration is small. It depends strongly on the Impurity Distribution Over Ionization States (IDOIS). One can find many interesting effects taking into account the finite relaxation time of IDOIS and thermal forces. In particular, the anomalous sound damping due to the internal friction, decompression shocks, slow thermal waves, and self-sustained thermal oscillation are discussed in the current presentation. Opacity effects also are discussed in the current presentation.

Morozov, D. Kh. [Institute of Nuclear Fusion, RRC 'Kurchatov Institute' Kurchatov square, 1, MOSCOW, 123182 (Russian Federation)

2006-11-30T23:59:59.000Z

465

Line-driven winds, ionizing fluxes and UV-spectra of hot stars at extremely low metallicity. I. Very massive O-stars  

E-Print Network [OSTI]

Wind models of very massive stars with metallicities in a range from 1E-4 to 1.0 solar are calculated using a new treatment of radiation driven winds with depth dependent radiative force multipliers and a comprehensive list of more than two million spectral lines in NLTE. The models are tested by a comparison with observed stellar wind properties of O stars in the Galaxy and the SMC. Satisfying agreement is found. The calculations yield mass-loss rates, wind velocities, wind momenta and wind energies as a function of metallicity and can be used to discuss the influence of stellar winds on the evolution of very massive stars in the early universe and on the interstellar medium in the early phases of galaxy formation. The normal scaling laws, which predict stellar mass-loss rates and wind momenta to decrease as a power law with metal abundance break down at a certain threshold. Analytical fit formulae for mass-loss rates are provided as a function of stellar parameters and metallicity. The new wind models are applied to calculate ionizing fluxes and observable spectra of very massive stars as a function of metallicity using the new hydrodynamic, non-LTE line-blanketed flux constant model atmosphere code developed by Pauldrach et al. Numbers of ionizing photons for the crucial ionization stages are given. For a fixed effective temperature the He II ionizing emergent flux depends very strongly on metallicity but also on stellar luminosity. A strong dependence on metallicity is also found for the C III, Ne II and O II ionizing photons, whereas the H I and He I ionizing flux is almost independent of metallicity. We also calculate UV spectra for all the models and discuss the behaviour of significant line features as a function of metallicity.

Rolf P. Kudritzki

2002-05-14T23:59:59.000Z

466

Properties of Natural Radiation and Radioactivity  

SciTech Connect (OSTI)

Ubiquitous natural sources of radiation and radioactive material (naturally occurring radioactive material, NORM) have exposed humans throughout history. To these natural sources have been added technologically-enhanced naturally occurring radioactive material (TENORM) sources and human-made (anthropogenic) sources. This chapter describes the ubiquitous radiation sources that we call background, including primordial radionuclides such as 40K, 87Rb, the 232Th series, the 238U series, and the 235U series; cosmogenic radionuclides such as 3H and 14C; anthropogenic radionuclides such as 3H, 14C, 137Cs, 90Sr, and 129I; radiation from space; and radiation from technologically-enhanced concentrations of natural radionuclides, particularly the short-lived decay products of 222Rn ("radon") and 220Rn ("thoron") in indoor air. These sources produce radiation doses to people principally via external irradiation or internal irradiation following intakes by inhalation or ingestion. The effective doses from each are given, with a total of 3.11 mSv y-1 (311 mrem y-1) to the average US resident. Over 2.5 million US residents receive over 20 mSv y-1 (2 rem y-1), primarily due to indoor radon. Exposure to radiation from NORM and TENORM produces the largest fraction of ubiquitous background exposure to US residents, on the order of 2.78 mSv (278 mrem) or about 89%. This is roughly 45% of the average annual effective dose to a US resident of 6.2 mSv y-1 (620 mrem y-1) that includes medical (48%), consumer products and air travel (2%), and occupational and industrial (0.1%). Much of this chapter is based on National Council on Radiation Protection and Measurements (NCRP) Report No. 160, "Ionizing Radiation Exposure of the Population of the United States," for which the author chaired the subcommittee that wrote Chapter 3 on "Ubiquitous Background Radiation."

Strom, Daniel J.

2009-07-13T23:59:59.000Z

467

Systems and methods for cylindrical hall thrusters with independently controllable ionization and acceleration stages  

DOE Patents [OSTI]

Systems and methods may be provided for cylindrical Hall thrusters with independently controllable ionization and acceleration stages. The systems and methods may include a cylindrical channel having a center axial direction, a gas inlet for directing ionizable gas to an ionization section of the cylindrical channel, an ionization device that ionizes at least a portion of the ionizable gas within the ionization section to generate ionized gas, and an acceleration device distinct from the ionization device. The acceleration device may provide an axial electric field for an acceleration section of the cylindrical channel to accelerate the ionized gas through the acceleration section, where the axial electric field has an axial direction in relation to the center axial direction. The ionization section and the acceleration section of the cylindrical channel may be substantially non-overlapping.

Diamant, Kevin David; Raitses, Yevgeny; Fisch, Nathaniel Joseph

2014-05-13T23:59:59.000Z

468

Ionization and transmission efficiency in an electrospray ionization-mass spectrometry interface  

SciTech Connect (OSTI)

The efficiency of sample ionization by electrospray ionization (ESI) and the transmission of the charged droplets and gas-phase ions through an ESI interface were investigated in order to advance the understanding of how these factors affect mass spectrometry (MS) sensitivity. In addition, the effects of the ES emitter distance to the inlet, solution flow rate, and inlet temperature to the ionization and transmission efficiency were characterized. Quantitative measurements of ES current loss throughout the ESI interface were accomplished by electrically isolating the front surface of the interface from the inner wall of the heated inlet capillary, enabling losses on the two surfaces to be distinguished. The ES current lost to the front surface of the ESI interface was also spatially profiled with a linear array of 340-m-dia. electrodes placed adjacent to the inlet capillary entrance. Current transmitted as gas-phase ions was differentiated from charged droplets and solvent clusters by directly measuring sensitivity with a single quadrupole mass spectrometer. The study has revealed a large sampling efficiency into the inlet capillary (>90% at an emitter distance of 1 mm), a global rather than a local gas dynamic effect on the shape of the ES plume due to the gas flow conductance limit of the inlet capillary, a large (>80%) loss of analyte after transmission through the inlet due to incomplete desolvation at a solution flow rate of 1.0 L/min, and a decrease in analyte peak intensity at lower temperatures, despite a large increase in ES current transmission efficiency. These studies provide a clearer understanding of the parameters affecting ion transmission into the mass spectrometer, and will serve to guide the design of more efficient instrument interfaces.

Page, Jason S.; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

2007-09-01T23:59:59.000Z

469

Characterization of nonpolar lipids and steroids by using laser-induced acoustic desorption/chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

Laser-induced acoustic desorption (LIAD) combined with ClMn(H{sub 2}O){sup +} chemical ionization (CI) was tested for the analysis of nonpolar lipids and selected steroids in a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR). The nonpolar lipids studied, cholesterol, 5?-cholestane, cholesta-3,5-diene, squalene, and ?-carotene, were found to solely form the desired water replacement product (adduct-H{sub 2}O) upon reaction with the ClMn(H{sub 2}O){sup +} ions. The steroids, androsterone, dehydroepiandrosterone (DHEA), estrone, estradiol, and estriol, also form abundant adduct-H{sub 2}O ions, but less abundant adduct-2H{sub 2}O ions were also observed. Neither (+)APCI nor (+)ESI can ionize the saturated hydrocarbon lipid, cholestane. APCI successfully ionizes the unsaturated hydrocarbon lipids to form exclusively the intact protonated analytes. However, it causes extensive fragmentation for cholesterol and the steroids. The worst case is cholesterol that does not produce any stable protonated molecules. On the other hand, ESI cannot ionize any of the hydrocarbon analytes, saturated or unsaturated. However, ESI can be used to protonate the oxygen-containing analytes with substantially less fragmentation than for APCI in all cases except for cholesterol and estrone. In conclusion, LIAD/ClMn(H{sub 2}O){sup +} chemical ionization is superior over APCI and ESI for the mass spectrometric characterization of underivatized nonpolar lipids and steroids.

Jin, Z.; Daiya, S.; Kenttmaa, Hilkka I.

2011-01-01T23:59:59.000Z

470

IR Spectrometer Using 90-degree Off-axis Parabolic Mirrors  

SciTech Connect (OSTI)

A gated spectrometer has been designed for real-time, pulsed infrared (IR) studies at the National Synchrotron Light ource at the Brookhaven National Laboratory. A pair of 90-degree, off-axis parabolic mirrors are used to relay the light from an entrance slit to an output IR recording camera. With an initial wavelength range of 15004500 nm required, gratings could not be used in the spectrometer because grating orders would overlap. A magnesium oxide prism, placed between these parabolic mirrors, serves as the dispersion element. The spectrometer is doubly telecentric. With proper choice of the air spacing between the prism and the second parabolic mirror, any spectral region of interest within the InSb camera arrays sensitivity region can be recorded. The wavelengths leaving the second parabolic mirror are collimated, thereby relaxing the camera positioning tolerance. To set up the instrument, two different wavelength (visible) lasers are introduced at the entrance slit and made collinear with the optical axis via flip mirrors. After dispersion by the prism, these two laser beams are directed to tick marks located on the outside housing of the gated IR camera. This provides first-order wavelength calibration for the instrument. Light that is reflected off the front prism face is coupled into a high-speed detector to verify steady radiance during the gated spectral imaging. Alignment features include tick marks on the prism and parabolic mirrors. This instrument was designed to complement singlepoint pyrometry, which provides continuous time histories of a small collection of spots from shock-heated targets.

Robert M. Malone,