National Library of Energy BETA

Sample records for observed adverse effect

  1. Adverse testicular effects of Botox in mature rats

    SciTech Connect

    Breikaa, Randa M.; Mosli, Hisham A.; Nagy, Ayman A.; Abdel-Naim, Ashraf B.

    2014-03-01

    Botox injections are taking a consistently increasing place in urology. Intracremasteric injections, particularly, have been applied for cryptorchidism and painful testicular spasms. Studies outlining their safety for this use are, however, scanty. Thus, the present study aimed at evaluating possible testicular toxicity of Botox injections and their effect on male fertility. Mature rats were given intracremasteric Botox injections (10, 20 and 40 U/kg) three times in a two-week interval. Changes in body and testes weights were examined and gonadosomatic index compared to control group. Semen quality, sperm parameters, fructose, protein, cholesterol and triglycerides contents were assessed. Effects on normal testicular function were investigated by measuring testosterone levels and changes in enzyme activities (lactate dehydrogenase-X and acid phosphatase). To draw a complete picture, changes in oxidative and inflammatory states were examined, in addition to the extent of connective tissue deposition between seminiferous tubules. In an attempt to have more accurate information about possible spermatotoxic effects of Botox, flowcytometric analysis and histopathological examination were carried out. Botox-injected rats showed altered testicular physiology and function. Seminiferous tubules were separated by dense fibers, especially with the highest dose. Flowcytometric analysis showed a decrease in mature sperms and histopathology confirmed the findings. The oxidative state was, however, comparable to control group. This study is the first to show that intracremasteric injections of Botox induce adverse testicular effects evidenced by inhibited spermatogenesis and initiation of histopathological changes. In conclusion, decreased fertility may be a serious problem Botox injections could cause. - Highlights: Botox injections are the trend nowadays, for both medical and non-medical uses. They were recently suggested for cryptorchidism and testicular spasms

  2. Human exposure to mercury: A critical assessment of the evidence of adverse health effects

    SciTech Connect

    Ratcliffe, H.E.; Swanson, G.M.; Fischer, L.J.

    1996-10-25

    The ubiquitous nature of mercury in the environment, its global atmospheric cycling, and its toxicity to humans at levels that are uncomfortably close to exposures experienced by a proportion of the population are some of the current concerns associated with this pollutant. The purpose of this review is to critically evaluate the scientific quality of published reports involving human exposures to mercury and associated health outcomes as an aid in the risk evaluation of this chemical. A comprehensive review of the scientific literature involving human exposures to mercury was performed and each publication evaluated using a defined set of criteria that are considered standards in epidemiologic and toxicologic research. Severe, sometimes fatal, effects of mercury exposure at high levels were primarily reported as case studies. The disasters in Minamata, Japan, in the 1950s and in Iraq in 1971-1972 clearly demonstrated neurologic effects associated with ingestion of methylmercury both in adults and in infants exposed in utero. The effects were convincingly Associated with methylmercury ingestion, despite limitations of the study design. Several well-conducted studies have investigated the effects of methylmercury at levels below those in the Iraq incident but have not provided clear evidence of an effect. The lower end of the dose-response curve constructed from the Iraq data therefore still needs to be confirmed. The studies of mercury exposure in the workplace were mainly of elemental or inorganic mercury, and effects that were observed at relatively low exposure levels were primarily neurologic and renal. Several studies have investigated effects associated with dental amalgam but have been rated as inconclusive because of methodologic deficiencies. In our overall evaluation, 29 of 110 occupational studies and 20 of 54 studies where exposure occurred in the natural environment provided at least suggestive evidence of an exposure-related effect. 259 refs., 4 tabs.

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

    SciTech Connect

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

    2013-03-01

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

  4. Observable effects of anisotropic bubble nucleation

    SciTech Connect

    Blanco-Pillado, Jose J.; Salem, Michael P. E-mail: salem@cosmos.phy.tufts.edu

    2010-07-01

    Our universe may have formed via bubble nucleation in an eternally-inflating background. Furthermore, the background may have a compact dimension — the modulus of which tunnels out of a metastable minimum during bubble nucleation — which subsequently grows to become one of our three large spatial dimensions. Then the reduced symmetry of the background is equivalent to anisotropic initial conditions in our bubble universe. We compute the inflationary spectrum in such a scenario and, as a first step toward understanding the effects of anisotropy, project it onto spherical harmonics. The resulting spectrum exhibits anomalous multipole correlations, their relative amplitude set by the present curvature parameter, which appear to extend to arbitrarily large multipole moments. This raises the possibility of future detection, if slow-roll inflation does not last too long within our bubble. A full understanding of the observational signal must account for the effects of background anisotropy on photon free streaming, and is left to future work.

  5. Constraint effects observed in crack initiation stretch

    SciTech Connect

    Lambert, D.M.; Ernst, H.A.

    1995-12-31

    The current paper characterizes constraint in fracture: J-modified resistance (Jr) curves were developed for two tough structural materials, 6061-T651 (aluminum) and IN718-STA1 (nickel-base superalloy). A wide variety of configurations was tested to consider load configurations from bending to tension including three specimen types (compact tension, center-crack tension, and single-edge notched tension), and a range of ligament lengths and thicknesses, as well as side-grooved and smooth-sided ligaments. The Jr curves exhibited an inflection point after some crack extension, and the data were excluded beyond the inflection. Qualified Jr curves for the two materials showed similar behavior, but R-curves were identical for equal ligament length-to-thickness ratio (RL), for the aluminum alloy, with increasing slope for increasing RL, while for the nickel, the resistance curves aligned for equal ligament thickness, B, and the slope increased for decreasing B. Displacements at the original crack tip (CToD) were recorded throughout the test for several specimens. CToD-versus-crack extension curves were developed, and data were excluded beyond the inflection point (as with the Jr curves). The data collapsed into two distinct curves, thought to represent the surface, plane stress effect and the central, plane strain effect. This was observed for both materials. A technique called profiling is presented for the aluminum alloy only, where the crack face displacements are recorded at the final point of the test as a function of the position throughout the crack cavity, along with an effort to extract the observations in a usable form. Displacements were consistent throughout the cross-section at and behind the original crack tip. In the region where the crack grew, this displacement was developed by a combination of stretch and crack growth. The stretch required to initiate crack extension was a function of the depth beneath the surface into the cross-section.

  6. Observations of solute effects on bubble formation

    SciTech Connect

    Hofmeier, U.; Yaminsky, V.V.; Christenson, H.K.

    1995-09-01

    The authors have studied the effects of solute, in particular aqueous electrolyte, on bubble formation at capillary orifices and frits at varying gas flow rates. Using a stroboscope, video microscope, and rotating mirror, they have obtained pictures which show how bubble formation involves the interaction of bubbles at the orifice. These interactions depend on the value of the surface elasticity E due to positively (ethanol) or negatively (NaCl) adsorbed solute. At low flow rates consecutive bubbles do not interact. Each bubble detaches and leaves the orifice region before the next one starts forming. A intermediate flow rates the more closely spaced, consecutive bubbles begin to interact. In pure liquids there is no barrier to bubble coalescence and the detached bubble is fed by the subsequent bubble as this starts to grow. The process may be repeated several times before the original bubble has risen out of range. In solutions where E is large enough bubble coalescence is inhibited. Instead of feeding into the detached bubble the following bubble pushes it aside, and the bubbles appear to bounce off each other. Bouncing may give rise to a characteristic sequence of larger and smaller bubbles if the emerging bubbles break off prematurely from the orifice due to the inertia of the original bubble. The transition from feeding to bouncing depends critically on E of the solution and leads to a smaller average bubble size for large E values. At high flow rates detached bubbles are invariably fed by several subsequent ones. At very high flow rates the bubbling becomes chaotic, but the interaction of bubbles after leaving the orifice area produces smaller bubbles in solutions. Bouncing is more likely to occur with narrow and irregular capillaries. The dramatically different appearance of gas-sparged columns in salt water and freshwater has its origin in the difference between assemblies of pores showing mainly feeding (freshwater) or bouncing (salt water).

  7. First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    at Earth's Surface First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect at Earth's Surface First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect at Earth's Surface Researchers Link Rising CO₂ Levels from Fossil Fuels to Radiative Forcing February 25, 2015 Contact: Dan Krotz, dakrotz@lbl.gov, 510-486-4019 ARM Alaska Caption: The scientists used incredibly precise spectroscopic instruments at two sites operated by the Department of Energy's

  8. Observation of the chiral magnetic effect in ZrTe₅

    SciTech Connect

    Li, Qiang; Kharzeev, Dmitri E.; Zhang, Cheng; Huang, Yuan; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A.; Gu, G. D.; Valla, T.

    2015-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) – a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurement of magneto-transport in zirconium pentatelluride, ZrTe₅. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. Furthermore, the observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.

  9. Observation of the chiral magnetic effect in ZrTe₅

    DOE PAGES [OSTI]

    Li, Qiang; Kharzeev, Dmitri E.; Zhang, Cheng; Huang, Yuan; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A.; Gu, G. D.; Valla, T.

    2015-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) – a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurementmore » of magneto-transport in zirconium pentatelluride, ZrTe₅. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. Furthermore, the observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.« less

  10. Waveguides for performing spectroscopy with confined effective observation volumes

    DOEpatents

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2006-03-14

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  11. Observations of the first aerosol indirect effect in shallow cumuli

    SciTech Connect

    Berg, Larry K.; Berkowitz, Carl M.; Barnard, James C.; Senum, Gunar; Springston, Stephen R.

    2011-02-08

    Data from the Cumulus Humilis Aerosol Processing Study (CHAPS) are used to estimate the impact of both aerosol indirect effects and cloud dynamics on the microphysical and optical properties of shallow cumuli observed in the vicinity of Oklahoma City, Oklahoma. Not surprisingly, we find that the amount of light scattered by the clouds is dominated by their liquid water content (LWC), which in turn is driven by cloud dynamics. However, removing the effect of cloud dynamics by examining the scattering normalized by LWC shows a strong sensitivity of scattering to pollutant loading. These results suggest that even moderately sized cities, like Oklahoma City, can have a measureable impact on the optical properties of shallow cumuli.

  12. Regional Climate Effects of Aerosols Over China: Modeling and Observation

    SciTech Connect

    Qian, Yun; Leung, Lai R.; Ghan, Steven J.; Giorgi, Filippo

    2003-09-01

    We present regional simulations of aerosol properties, direct radiative forcing and aerosol climatic effects over China, and compare the simulations with observed aerosol characteristics and climatic data over the region. The climate simulations are performed with a regional climate model, which is shown to capture the spatial distribution and seasonal pattern of temperature and precipitation. Aerosol concentrations are obtained from a global tracer-transport model and are provided to the regional model for the calculation of radiative forcing. Different aerosols are included: sulfate, organic carbon, black carbon, mineral dust, and sea salt and MSA particles. Generally, the aerosol optical depth is well simulated in both magnitude and spatial distribution. The direct radiative forcing of the aerosol is in the range of –1 to –14 W m-2 in autumn and summer and -1 to –9 W m-2 in spring and winter, with substantial spatial variability at the regional scale. A strong maximum in aerosol optical depth and negative radiative forcing is found over the Sichuan Basin. The negative radiative forcing of aerosol induces a surface cooling in the range of –0.6 to –1.2oC in autumn and winter, –0.3 to –0.6oC in spring and 0.0 to –0.9oC in summer throughout East China. The aerosol-induced cooling is mainly due to a decrease in day-time maximum temperature. The cooling is maximum and is statistically significant over the Sichuan Basin. The effect of aerosol on precipitation is not evident in our simulations. The temporal and spatial patterns of the temperature trends observed in the second half of the twentieth century, including different trends for daily maximum and minimum temperature, are at least qualitatively consistent with the simulated aerosol-induced cooling over the Sichuan Basin and East China. This result supports the hypothesis that the observed temperature trends during the latter decades of the twentieth century, especially the cooling trends over the

  13. Observation of an ''ABC'' Effect in Proton-Proton Collisions

    SciTech Connect

    Dymov, S.; Yaschenko, S.; Hartmann, M.; Kacharava, A.; Nekipelov, M.; Ohm, H.; Rathmann, F.; Stroeher, H.; Khoukaz, A.; Mielke, M.; Komarov, V.; Kulikov, A.; Kurbatov, V.; Uzikov, Yu.; Zalikhanov, B.; Kulessa, P.; Macharashvili, G.; Merzliakov, S.; Tsirkov, D.; Mikirtychiants, S.

    2009-05-15

    The cross section for inclusive multipion production in the pp{yields}ppX reaction was measured at COSY-ANKE at four beam energies, 0.8, 1.1, 1.4, and 2.0 GeV, for low excitation energy in the final pp system, such that the diproton quasiparticle is in the {sup 1}S{sub 0} state. At the three higher energies, the missing-mass M{sub X} spectra show a strong enhancement at low M{sub X}, corresponding to an Abashian-Booth-Crowe effect that moves steadily to larger values as the energy is increased. Despite the missing-mass structure looking very different at 0.8 GeV, the variation with M{sub X} and beam energy are consistent with two-pion production being mediated through the excitation of two {delta}(1232) isobars, coupled to S and D states of the initial pp system. There is no sign of any resonancelike structure in the energy dependence of the type recently observed for the pn{yields}d{pi}{sup 0}{pi}{sup 0} total cross section.

  14. Observation of inverse spin Hall effect in ferromagnetic FePt alloys using spin Seebeck effect

    SciTech Connect

    Seki, Takeshi Takanashi, Koki; Uchida, Ken-ichi; Kikkawa, Takashi; Qiu, Zhiyong; Saitoh, Eiji

    2015-08-31

    We experimentally observed the inverse spin Hall effect (ISHE) of ferromagnetic FePt alloys. Spin Seebeck effect due to the temperature gradient generated the spin current (J{sub s}) in the FePt|Y{sub 3}Fe{sub 5}O{sub 12} (YIG) structure, and J{sub s} was injected from YIG to FePt and converted to the charge current through ISHE of FePt. The significant difference in magnetization switching fields for FePt and YIG led to the clear separation of the voltage of ISHE from that of anomalous Nernst effect in FePt. We also investigated the effect of ordering of FePt crystal structure on the magnitude of ISHE voltage in FePt.

  15. Observation of the Kondo effect in a spin-3/2 hole quantum dot (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Observation of the Kondo effect in a spin-3/2 hole quantum dot Citation Details In-Document Search Title: Observation of the Kondo effect in a spin-3/2 hole quantum dot We report the observation of the Kondo effect in a spin-3/2 hole quantum dot formed near pinch-off in a GaAs quantum wire. We clearly observe two distinctive hallmarks of quantum dot Kondo physics. First, the zero-bias peak in the differential conductance splits an in-plane magnetic field and the

  16. Adverse Diversity Analysis Guidance | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Adverse Diversity Analysis Guidance Adverse Diversity Analysis Guidance Attachment 8 - Adverse Diversity Analysis Guidance (124.04 KB) Attachment 8(a) - WFR disparate impact chart example completed (96.18 KB) Attachment 8(b) - WFR disparate impact chart clean (88.56 KB) More Documents & Publications Fact #922: April 25, 2016 Share of Older Population Holding Driver's Licenses is Up and Share of Younger Population Holding Driver's Licenses is Down - Dataset FAIR Act Inventory - FY13 FAIR Act

  17. Optimization of satellite coverage in observing cause and effect changes in the ionosphere, magnetosphere, and solar wind. Master's thesis

    SciTech Connect

    Loveless, M.J.

    1993-06-01

    Disturbances in the ionosphere sometimes cause adverse effects to communications systems, power grids, etc. on the earth. Currently, very little, if any, lead time is given to warn of an impending problem. If a forecast could be made of ionospheric occurrences, some lead time may be given to appropriate agencies and equipment may be saved. Most changes that occur in the ionosphere are a result of interaction of energy, currents, etc. between the magnetosphere and/or solar wind. Before a forecast can be made, however, improvement of ionospheric models currently in use need to be made. The models currently depict features in various regions of the ionosphere but not always where these features are actually observed. So an improvement to the model is needed to create an accurate baseline condition, or in other words an accurate depiction of the current ionosphere. Models could be improved by inputting real-time data from the ionosphere into the model. This data would come from satellites and/or ground-based stations.

  18. Observation of the Kondo effect in a spin-3/2 hole quantum dot...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Observation of the Kondo effect in a spin-32 hole quantum dot We report the ... OSTI Identifier: 22261852 Resource Type: Journal Article ...

  19. Observation of Rayleigh-Taylor-instability evolution in a plasma with magnetic and viscous effects

    DOE PAGES [OSTI]

    Adams, Colin S.; Moser, Auna L.; Hsu, Scott C.

    2015-11-06

    We present time-resolved observations of Rayleigh-Taylor-instability (RTI) evolution at the interface between an unmagnetized plasma jet colliding with a stagnated, magnetized plasma. The observed instability growth time (~10μs) is consistent with the estimated linear RTI growth rate calculated using experimentally inferred values of density (~1014cm–3) and deceleration (~109 m/s2). The observed mode wavelength (≳1 cm) nearly doubles within a linear growth time. Furthermore, theoretical estimates of magnetic and viscous stabilization and idealized magnetohydrodynamic simulations including a physical viscosity model both suggest that the observed instability evolution is subject to magnetic and/or viscous effects.

  20. An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Decade of Observations at a Mid-Continental Site An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a Decade of Observations at a Mid-Continental Site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Category: Aerosols Continuing observations of aerosol and cloud optical property have been made using MFRSR and MWR at the ARM SGP site since

  1. Carbon fiber composite characterization in adverse thermal environments.

    SciTech Connect

    Gomez-Vasquez, Sylvia; Brown, Alexander L.; Hubbard, Joshua A.; Ramirez, Ciro J.; Dodd, Amanda B.

    2011-05-01

    The behavior of carbon fiber aircraft composites was studied in adverse thermal environments. The effects of resin composition and fiber orientation were measured in two test configurations: 102 by 127 millimeter (mm) test coupons were irradiated at approximately 22.5 kW/m{sup 2} to measure thermal response, and 102 by 254 mm test coupons were irradiated at approximately 30.7 kW/m{sup 2} to characterize piloted flame spread in the vertically upward direction. Carbon-fiber composite materials with epoxy and bismaleimide resins, and uni-directional and woven fiber orientations, were tested. Bismaleimide samples produced less smoke, and were more resistant to flame spread, as expected for high temperature thermoset resins with characteristically lower heat release rates. All materials lost approximately 20-25% of their mass regardless of resin type, fiber orientation, or test configuration. Woven fiber composites displayed localized smoke jetting whereas uni-directional composites developed cracks parallel to the fibers from which smoke and flames emanated. Swelling and delamination were observed with volumetric expansion on the order of 100% to 200%. The purpose of this work was to provide validation data for SNL's foundational thermal and combustion modeling capabilities.

  2. Observation Of Electron-beam-induced Phase Evolution Mimicking The Effect

    Office of Scientific and Technical Information (OSTI)

    Of Charge-discharge Cycle In Li-rich Layered Cathode Materials Used For Li-ion Batteries (Journal Article) | SciTech Connect Observation Of Electron-beam-induced Phase Evolution Mimicking The Effect Of Charge-discharge Cycle In Li-rich Layered Cathode Materials Used For Li-ion Batteries Citation Details In-Document Search Title: Observation Of Electron-beam-induced Phase Evolution Mimicking The Effect Of Charge-discharge Cycle In Li-rich Layered Cathode Materials Used For Li-ion Batteries

  3. Observation of Rayleigh-Taylor-instability evolution in a plasma with magnetic and viscous effects

    SciTech Connect

    Adams, Colin S.; Moser, Auna L.; Hsu, Scott C.

    2015-11-06

    We present time-resolved observations of Rayleigh-Taylor-instability (RTI) evolution at the interface between an unmagnetized plasma jet colliding with a stagnated, magnetized plasma. The observed instability growth time (~10μs) is consistent with the estimated linear RTI growth rate calculated using experimentally inferred values of density (~1014cm–3) and deceleration (~109 m/s2). The observed mode wavelength (≳1 cm) nearly doubles within a linear growth time. Furthermore, theoretical estimates of magnetic and viscous stabilization and idealized magnetohydrodynamic simulations including a physical viscosity model both suggest that the observed instability evolution is subject to magnetic and/or viscous effects.

  4. Energy Department Announces Secretarial Determination of No Adverse...

    Energy Saver

    Secretarial Determination of No Adverse Material Impact for Uranium Transfers Energy Department Announces Secretarial Determination of No Adverse Material Impact for Uranium ...

  5. Secretarial Determination of No Adverse Material Impact for Uranium...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Secretarial Determination of No Adverse Material Impact for Uranium Transfers Secretarial Determination of No Adverse Material Impact for Uranium Transfers The determination covers ...

  6. Observation of the Kondo effect in a spin-3/2 hole quantum dot

    SciTech Connect

    Klochan, O.; Micolich, A. P.; Hamilton, A. R.; Trunov, K.; Reuter, D.; Wieck, A. D.

    2013-12-04

    We report the observation of the Kondo effect in a spin-3/2 hole quantum dot formed near pinch-off in a GaAs quantum wire. We clearly observe two distinctive hallmarks of quantum dot Kondo physics. First, the zero-bias peak in the differential conductance splits an in-plane magnetic field and the splitting is independent of gate voltage. Second, the splitting rate is twice as large as that for the lowest one-dimensional subband. We show that the Zeeman splitting of the zero-bias peak is highly anisotropic and attribute this to the strong spin-orbit interaction for holes in GaAs.

  7. Experimental Observation of the Inverse Spin Hall Effect at Room Temperature

    SciTech Connect

    Liu, Baoli; Shi, Junren; Wang, Wenxin; Zhao, Hongming; Li, Dafang; Zhang, Shoucheng; Xue, Qikun; Chen, Dongmin; /Beijing, Inst. Phys.

    2010-03-16

    We observe the inverse spin Hall effect in a two-dimensional electron gas confined in Al-GaAs/InGaAs quantum wells. Specifically, they find that an inhomogeneous spin density induced by the optical injection gives rise to an electric current transverse to both the spin polarization and its gradient. The spin Hall conductivity can be inferred from such a measurement through the Einstein relation and the onsager relation, and is found to have the order of magnitude of 0.5(e{sup 2}/h). The observation is made at the room temperature and in samples with macroscopic sizes, suggesting that the inverse spin Hall effects is a robust macroscopic transport phenomenon.

  8. Fiber optics in adverse environments III. SPIE volume 721

    SciTech Connect

    Greenwell, R.A.

    1987-01-01

    This book discusses the following: ENVIRONMENTAL EFFECTS ON OPTICAL FIBER COMPONENTS. Space as an adverse environment: vacuum surface and gamma ray irradiation effects on LEDs and photodiodes. Electron irradiation of InGaAsP LEDs and InGaAs photodetectors. Effects of radiation on optoelectronic devices. ENVIRONMENTAL EFFECTS ON OPTICAL FIBERS. Static fatigue of optical fibers in bending. Effect of hydrogen treatment on radiation hardness of optical fibers. AFB. Influence of preform variations and drawing conditions on transient radiation effects in pure silica fibers. Radiation resistivity of pure silica core fibers. Radiation-induced losses in pure silica core fibers. Radiation response prediction of single-mode optical fiber waveguides. Ionizing radiation effects on doped silica and pure silica core fibers. MEASUREMENTS AND CHARACTERIZATION OF OPTICAL FIBER COMPONENTS. Optical fiber radiation-damage measurements. Characterization of 820-nm single-mode fibers. Effects of test parameters on the recovery of Febetron-irradiated optical fibers. APPLICATIONS AND ENVIRONMENTS. Optical fiber waveguides for spacecraft applications. Optical fiber power delivery system. Fiber optic cables in a harsh ocean environment. Lightguide technology for adverse industrial environment. Low dispersion glass for optical fiber industrial applications. Electronic Materials Technology.

  9. GUIDANCE ON CONDUCTING ADVERSE DIVERSITY ANALYSIS

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    GUIDANCE ON CONDUCTING ADVERSE DIVERSITY ANALYSIS The Uniform Guidelines for Employee Selection Procedures adopted by the Equal Employment Opportunity Commission (EEOC), Department of Labor's Office of Federal Contract Compliance Programs (OFCCP), and U.S. Department of Justice in 1978 set out accepted statistical tests for assessing possible discriminatory impact of employment actions on protected classifications of employees. See 29 CFR Part 1607. Agencies and litigants commonly use

  10. Simultaneous effect of modified gravity and primordial non-Gaussianity in large scale structure observations

    SciTech Connect

    Mirzatuny, Nareg; Khosravi, Shahram; Baghram, Shant; Moshafi, Hossein E-mail: khosravi@mail.ipm.ir E-mail: hosseinmoshafi@iasbs.ac.ir

    2014-01-01

    In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in f(R) framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale dependent bias and growth rate functions. The deviation from ΛCDM in the case of primordial non-Gaussian models is in large scales, while the growth rate deviates from ΛCDM in small scales for modified gravity theories. We show that the redshift space distortion can be used to distinguish positive and negative f{sub NL} in standard background, while in f(R) theories they are not easily distinguishable. The galaxy power spectrum is generally enhanced in presence of non-Gaussianity and modified gravity. We also obtain the scale dependence of this enhancement. Finally we define galaxy growth rate and galaxy growth rate bias as new observational parameters to constrain cosmology.

  11. Zero-mode clad waveguides for performing spectroscopy with confined effective observation volumes

    DOEpatents

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2005-07-12

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  12. Loop for the observation of film temperature effects on decomposition (LOFTED)

    SciTech Connect

    Kruizenga, Alan Michael; Kolb, William J.; Briggs, Ronald J.; Christian, Joshua Mark; Ray, Daniel A; Gill, David.; Kelton, John W.; Chisman, Kye Martin

    2014-09-01

    Molten nitrate salt Loop for the Observation of Film Temperature Effects on Decomposition (LOFTED) was designed, fabricated, and tested. This unique experimental arrangement allowed a 60/40 molten nitrate salt to be continuously pumped through a Haynes 230 pipe, allowing simulation of a solar receiver. The wall temperature was held at 670°C during the test and the bulk temperature range from 600-610°C for approximately 1200 hours. Salt decomposition was tested using a calibrated total alkalinity methodology to assess oxide content over time. Several alloys (347SS, HR-224, In625-SQ, Haynes 230) were tested for corrosion performance over the duration of the study and compared to previous static tests. Results yielded nearly a tenfold increase in corrosion rate as compared to 600°C, owing to the need to understand the effects of flow and mass transport on corrosion in molten salt environments.

  13. Experimental observation of standing wave effect in low-pressure very-high-frequency capacitive discharges

    SciTech Connect

    Liu, Yong-Xin; Gao, Fei; Liu, Jia; Wang, You-Nian

    2014-07-28

    Radial uniformity measurements of plasma density were carried out by using a floating double probe in a cylindrical (21 cm in electrode diameter) capacitive discharge reactor driven over a wide range of frequencies (27–220 MHz). At low rf power, a multiple-node structure of standing wave effect was observed at 130 MHz. The secondary density peak caused by the standing wave effect became pronounced and shifts toward the axis as the driving frequency further to increase, indicative of a much more shortened standing-wave wavelength. With increasing rf power, the secondary density peak shift toward the radial edge, namely, the standing-wave wavelength was increased, in good qualitative agreement with the previous theory and simulation results. At higher pressures and high frequencies, the rf power was primarily deposited at the periphery of the electrode, due to the fact that the waves were strongly damped as they propagated from the discharge edge into the center.

  14. A NOVEL TECHNIQUE TO OBSERVE RAPIDLY PULSATING OBJECTS USING SPECTRAL WAVE-INTERACTION EFFECTS

    SciTech Connect

    Borra, Ermanno F.

    2010-05-20

    Conventional techniques that measure rapid time variations are inefficient or inadequate to discover and observe rapidly pulsating astronomical sources. It is therefore conceivable that there exist some classes of objects pulsating with extremely short periods that have not yet been discovered. This paper starts from the fact that rapid flux variations generate a spectral modulation that can be detected in the beat spectrum of the output current fluctuations of a quadratic detector. The telescope could observe at any frequency, although shorter frequencies would have the advantage of lower photon noise. The techniques would allow us to find and observe extremely fast time variations, opening up a new time window in astronomy. The current fluctuation technique, like intensity interferometers, uses second-order correlation effects and fits into the current renewal of interest in intensity interferometry. An interesting aspect it shares with intensity interferometry is that it can use inexpensive large telescopes that have low-quality mirrors, like Cherenkov telescopes. It has other advantages over conventional techniques that measure time variations, foremost of which is its simplicity. Consequently, it could be used for extended monitoring of astronomical sources, something that is difficult to do with conventional telescopes. Arguably, the most interesting scientific justification for the technique comes from Serendipity.

  15. Experimental observation of spin-dependent electron many-body effects in CdTe

    SciTech Connect

    Horodysk, P.; N?mec, P. Novotn, T.; Trojnek, F.; Mal, P.

    2014-08-07

    In semiconductors, the spin degree of freedom is usually disregarded in the theoretical treatment of electron many-body effects such as band-gap renormalization and screening of the Coulomb enhancement factor. Nevertheless, as was observed experimentally in GaAs, not only the single-particle phase-space filling but also many-body effects are spin sensitive. In this paper, we report on time- and polarization-resolved differential transmission pump-probe measurements in CdTe, which has the same zincblende crystal structure but different material parameters compared to that of GaAs. We show experimentally that at room temperature in CdTeunlike in GaAsthe pump-induced decrease of transmission due to the band-gap renormalization can even exceed the transmission increase due to the phase-space filling, which enables to measure directly the spin-sensitivity of the band-gap renormalization. We also observed that the influence of the band-gap renormalization is more prominent at low temperatures.

  16. Hypothesis to Explain the Size Effect Observed in APO-BMI Compression Tests

    SciTech Connect

    Schembri, Philip Edward; Siranosian, Antranik Antonio; Kingston, Lance Allen

    2015-01-07

    In 2013 compression tests were performed on cylindrical specimens of carbon-microballoon-APOBMI syntactic foam machined to different lengths (0.25, 0.5, and 2.8 inches1) (Kingston, 2013). In 2014 similar tests were performed on glass-microballoon-APO-BMI of different lengths (~0.15”, ~0.32”, and ~0.57”). In all these tests it was observed that, when strains were calculated from the platen displacement (corrected for machine compliance), the apparent Young’s modulus of the material decreased with specimen size, as shown in Table 1. The reason for this size effect was speculated to be a layer of damage on or near the top and bottom machined surfaces of the specimens (Kingston, Schembri, & Siranosian, 2014). This report examines that hypothesis in further detail.

  17. Quantifying Aerosol Direct Effects from Broadband Irradiance and Spectral Aerosol Optical Depth Observations

    SciTech Connect

    Creekmore, Torreon N.; Joseph, Everette; Long, Charles N.; Li, Siwei

    2014-05-16

    We outline a methodology using broadband and spectral irradiances to quantify aerosol direct effects on the surface diffuse shortwave (SW) irradiance. Best Estimate Flux data span a 13 year timeframe at the Department of Energy Atmospheric Radiation Measurement Program’s Southern Great Plains (SGP) site. Screened clear-sky irradiances and aerosol optical depth (AOD), for solar zenith angles ≤ 65°, are used to estimate clear-sky diffuse irradiances. We validate against detected clear-sky observations from SGP’s Basic Radiation System (BRS). BRS diffuse irradiances were in accordance with estimates, producing a root-mean-square error and mean bias errors of 4.0 W/m2 and -1.4 W/m2, respectively. Absolute differences show 99% of estimates within ±10 W/m2 (10%) of the mean BRS observations. Clear-sky diffuse estimates are used to derive quantitative estimates of aerosol radiative effects, represented as the aerosol diffuse irradiance (ADI). ADI is the contribution of diffuse SW to global SW, attributable to scattering of atmospheric transmission by natural plus anthropogenic aerosols. Estimated slope for the ADI as a function of AOD indicates an increase of ~22 W/m2 in diffuse SW for every 0.1 increase in AOD. Such significant increases in the diffuse fraction could possibly increase photosynthesis. Annual mean ADI is 28.2 W/m2, and heavy aerosol loading at SGP provides up to a maximum increase of 120 W/m2 in diffuse SW over background conditions. With regard to seasonal variation, the mean diffuse forcings are 17.2, 33.3, 39.0, and 23.6 W/m2 for winter, spring, summer, and fall, respectively.

  18. Observations and Modeling of the Green Ocean Amazon (GOAMAZON). Particulate

    Office of Scientific and Technical Information (OSTI)

    Matter and Gases Final Campaign Summary (Technical Report) | SciTech Connect Observations and Modeling of the Green Ocean Amazon (GOAMAZON). Particulate Matter and Gases Final Campaign Summary Citation Details In-Document Search Title: Observations and Modeling of the Green Ocean Amazon (GOAMAZON). Particulate Matter and Gases Final Campaign Summary Because of their proven adverse effects on human health and vegetation, and also considering their influence over the local and regional

  19. Is the effect of the Sun's gravitational potential on dark matter particles observable?

    SciTech Connect

    Bozorgnia, Nassim; Schwetz, Thomas E-mail: schwetz@fysik.su.se

    2014-08-01

    We consider the effect of the Sun's gravitational potential on the local phase space distribution of dark matter particles, focusing on its implication for the annual modulation signal in direct detection experiments. We perform a fit to the modulation signal observed in DAMA/LIBRA and show that the allowed region shrinks if Solar gravitational focusing (GF) is included compared to the one without GF. Furthermore, we consider a possible signal in a generic future direct detection experiment, irrespective of the DAMA/LIBRA signal. Even for scattering cross sections close to the current bound and a large exposure of a xenon target with 270 ton yr it will be hard to establish the presence of GF from data. In the region of dark matter masses below 40 GeV an annual modulation signal can be established for our assumed experimental setup, however GF is negligible for low masses. In the high mass region, where GF is more important, the significance of annual modulation itself is very low. We obtain similar results for lighter targets such as Ge and Ar. We comment also on inelastic scattering, noting that GF becomes somewhat more important for exothermic scattering compared to the elastic case.

  20. Secretary Chu Announces Determination of No Adverse Material...

    Energy Saver

    and market impact analysis authorizing uranium transfers to fund accelerated cleanup ... finds that the proposed transfer of uranium will not have an adverse material impact ...

  1. Nanosecond pump and probe observation of bimolecular exciton effects in rubrene single crystals

    SciTech Connect

    Ward, Kebra A.; Richman, Brittany R.; Biaggio, Ivan

    2015-06-01

    Transient grating pump and probe experiments are used to investigate excitonic processes on the nanosecond time scale in rubrene single crystals. We find that bimolecular interactions cause a photoinduced excited state density on the order of 0.5 × 10{sup 20 }cm{sup −3}—corresponding to an average distance of ∼3 nm between individual states—to decrease by a factor of 2 after 2 ns, following a typical power-law decay. We assign the observed power-law decays to high-density interactions between excited states. Because of the high efficiency singlet exciton fission observed in rubrene, these bimolecular interactions are likely those between triplet excitons or between coherent quantum superpositions of a singlet and a pair of triplet-excitons.

  2. Observations of the frequency tuning effect in the 14 GHz CAPRICE ion source

    SciTech Connect

    Celona, L.; Ciavola, G.; Consoli, F.; Gammino, S.; Maimone, F.; Mascali, D.; Spaedtke, P.; Tinschert, K.; Lang, R.; Maeder, J.; Rossbach, J.; Barbarino, S.; Catalano, R. S.

    2008-02-15

    A set of measurements with the CAPRICE ion source at the GSI test bench has been carried out to investigate its behavior in terms of intensity and shape of the extracted beam when the microwaves generating the plasma sweep in a narrow range of frequency ({+-}40 MHz) around the klystron center frequency (14.5 GHz). Remarkable variations have been observed depending on the source and the beamline operating parameters, confirming that a frequency dependent electromagnetic distribution is preserved even in the presence of plasma inside the source. Moreover, these observations confirm that the frequency tuning is a powerful method to optimize the electron cyclotron resonance ion source performances. A description of the experimental setup and of the obtained results is given in the following.

  3. Electromagnetic field interactions with the human body: observed effects and theories

    SciTech Connect

    Raines, J.K.

    1981-04-01

    The effects of nonionizing electromagnetic (EM) field interactions with the human body were reported and human related studies were collected. Nonionizing EM fields are linked to cancer in humans in three different ways: cause, means of detection, and effective treatment. Bad and benign effects are expected from nonionizing EM fields and much more knowledge is necessary to properly categorize and qualify EM field characteristics. It is concluded that knowledge of the boundary between categories, largely dependent on field intensity, is vital to proper future use of EM radiation for any purpose and the protection of the individual from hazard.

  4. Direct electrical observation of plasma wave-related effects in GaN-based two-dimensional electron gases

    SciTech Connect

    Zhao, Y.; Chen, W.; Li, W.; Zhu, M.; Yue, Y.; Song, B.; Encomendero, J.; Xing, H.; Fay, P.; Sensale-Rodriguez, B.

    2014-10-27

    In this work, signatures of plasma waves in GaN-based high electron mobility transistors were observed by direct electrical measurement at room temperature. Periodic grating-gate device structures were fabricated and characterized by on-wafer G-band (140220?GHz) s-parameter measurements as a function of gate bias voltage and device geometry. A physics-based equivalent circuit model was used to assist in interpreting the measured s-parameters. The kinetic inductance extracted from the measurement data matches well with theoretical predictions, consistent with direct observation of plasma wave-related effects in GaN-channel devices at room temperature. This observation of electrically significant room-temperature plasma-wave effects in GaN-channel devices may have implications for future millimeter-wave and THz device concepts and designs.

  5. Coherent beam-beam effects observation and mitigation at the RHIC collider

    SciTech Connect

    White S.; Fischer, W.; Luo, Y.

    2012-05-20

    In polarized proton operation in RHIC coherent beam-beam modes are routinely observed with beam transfer function measurements in the vertical plane. With the existence of coherent modes a larger space is required in the tune diagram than without them and stable conditions can be compromised for operation with high intensity beams as foreseen for future luminosity upgrades. We report on experiments and simulations carried out to understand the existence of coherent modes in the vertical plane and their absence in the horizontal plane, and investigate possible mitigation strategies.

  6. Observation of large magnetocaloric effect in HoRu{sub 2}Si{sub 2}

    SciTech Connect

    Paramanik, Tapas Das, Kalipada; Das, I.

    2014-02-28

    Detailed magnetic, magnetotransport, and magnetocaloric measurements on HoRu{sub 2}Si{sub 2} have been performed. In this Letter, we report presence of spin reorientation transition below paramagnetic to antiferromagnetic transition temperature (T{sub N} = 19 K). Large magnetic entropy change 9.1 J/kg K and large negative magnetoresistance ∼21% in a magnetic field of 5 T has been observed around T{sub N}, which is associated with field induced spin-flip metamagnetic transition.

  7. Electromagnetic field interactions with the human body: observed effects and theories

    SciTech Connect

    Raines, J.K.

    1981-04-01

    The state of published knowledge about the effects of non-ionizing EM fields on humans is summarized. In addition to over 1000 written sources in-person meetings, telephone interviews and lecture tapes were used. It is indicated that there are good, bad and benign effects to be expected from non-ionizing EM fields and much more knowledge appears necessary to properly categorize and qualify EM field characteristics. Knowledge of the boundary between categories, perhaps largely dependent on field intensity, is vital to proper future use of EM radiaton for any purpose and the protection of the individual citizen from hazard.

  8. Observation of localized states in atomically thin MoS{sub 2} field effect transistor

    SciTech Connect

    Ghatak, Subhamoy; Pal, Atindra Nath; Ghosh, Arindam

    2013-12-04

    We present electrical transport and low frequency (1/f) noise measurements on mechanically exfoliated single, bi and trilayer MoS{sub 2}-based FET devices on Si/SiO{sub 2} substrate. We find that the electronic states in MoS{sub 2} are localized at low temperatures (T) and conduction happens through variable range hopping (VRH). A steep increase of 1/f noise with decreasing T, typical for localized regime was observed in all of our devices. From gate voltage dependence of noise, we find that the noise power is inversely proportional to square of the number density (? 1/n{sup 2}) for a wide range of T, indicating number density fluctuations to be the dominant source of 1/f noise in these MoS{sub 2} FETs.

  9. Optimal preselection and postselection in weak measurements for observing photonic spin Hall effect

    SciTech Connect

    Zhou, Xinxing; Li, Xing; Luo, Hailu Wen, Shuangchun

    2014-02-03

    Photonic spin Hall effect (SHE) holds great potential applications in precision metrology. How to obtain a high measurement precision is an important issue to detect the photonic SHE. In this Letter, we propose using optimal preselection and postselection in weak measurements to enhance the measurement precision. We find that the maximum weak value and pointer shift can be obtained with an optimal overlap of preselection and postselection states. These findings offer the possibility for improving the precision of weak measurements and thereby have possible applications for accurately characterizing the parameters of nanostructures.

  10. Observation of universal strong orbital-dependent correlation effects in iron chalcogenides

    SciTech Connect

    Yi, M.; Liu, Z. -K.; Zhang, Y.; Yu, R.; Zhu, J. -X.; Lee, J. J.; Moore, R. G.; Schmitt, F. T.; Li, W.; Riggs, S. C.; Chu, J. -H.; Lv, B.; Hu, J.; Hashimoto, M.; Mo, S. -K.; Hussain, Z.; Mao, Z. Q.; Chu, C. W.; Fisher, I. R.; Si, Q.; Shen, Z. -X.; Lu, D. H.

    2015-07-23

    Establishing the appropriate theoretical framework for unconventional superconductivity in the iron-based materials requires correct understanding of both the electron correlation strength and the role of Fermi surfaces. This fundamental issue becomes especially relevant with the discovery of the iron chalcogenide superconductors. Here, we use angle-resolved photoemission spectroscopy to measure three representative iron chalcogenides, FeTe0.56Se0.44, monolayer FeSe grown on SrTiO3 and K0.76Fe1.72Se2. We show that these superconductors are all strongly correlated, with an orbital-selective strong renormalization in the dxy bands despite having drastically different Fermi surface topologies. Furthermore, raising temperature brings all three compounds from a metallic state to a phase where the dxy orbital loses all spectral weight while other orbitals remain itinerant. As a result, these observations establish that iron chalcogenides display universal orbital-selective strong correlations that are insensitive to the Fermi surface topology, and are close to an orbital-selective Mott phase, hence placing strong constraints for theoretical understanding of iron-based superconductors.

  11. Observation of universal strong orbital-dependent correlation effects in iron chalcogenides

    DOE PAGES [OSTI]

    Yi, M.; Liu, Z. -K.; Zhang, Y.; Yu, R.; Zhu, J. -X.; Lee, J. J.; Moore, R. G.; Schmitt, F. T.; Li, W.; Riggs, S. C.; et al

    2015-07-23

    Establishing the appropriate theoretical framework for unconventional superconductivity in the iron-based materials requires correct understanding of both the electron correlation strength and the role of Fermi surfaces. This fundamental issue becomes especially relevant with the discovery of the iron chalcogenide superconductors. Here, we use angle-resolved photoemission spectroscopy to measure three representative iron chalcogenides, FeTe0.56Se0.44, monolayer FeSe grown on SrTiO3 and K0.76Fe1.72Se2. We show that these superconductors are all strongly correlated, with an orbital-selective strong renormalization in the dxy bands despite having drastically different Fermi surface topologies. Furthermore, raising temperature brings all three compounds from a metallic state to a phasemore » where the dxy orbital loses all spectral weight while other orbitals remain itinerant. As a result, these observations establish that iron chalcogenides display universal orbital-selective strong correlations that are insensitive to the Fermi surface topology, and are close to an orbital-selective Mott phase, hence placing strong constraints for theoretical understanding of iron-based superconductors.« less

  12. Effects of confinement on short-period surface waves: Observations from a new dataset

    SciTech Connect

    Hooper, H.; Bonner, J.; Leidig, M.

    2006-04-15

    The Source Phenomenology Experiment (SPE) was conducted during the summer of 2003 in Arizona. Single-fired chemical shots were detonated and recorded at two locations, including a coal mine in the Black Mesa district of northern Arizona. This article reports on research into the effects of confinement on the generation of short-period, fundamental-mode Rayleigh waves (Rg), using a subset of the SPE data. Results show important differences between the Rg amplitudes of confined and unconfined explosions which must be understood to develop discriminants for mining explosions, which are an important aspect of nuclear test monitoring. Rg energy and frequency content depend on explosive weight and confinement, and unconfined explosions generate up to eight times less energy than equivalent confined explosions. For this reason, unconfined mining explosions cannot be simulated using a Mueller and Murphy (1971) source without including an empirical chemical decoupling factor. Rg chemical decoupling factors for unconfined shots vary from 0.5 to 8.2 at frequencies between 0.5 and 11 Hz. The effects of the bench free face are evident in radiation patterns. Explosions on the topographic bench show increased spectral energies for Rg (by a factor of 1.5) at azimuths behind the bench. This suggests that a discriminant based on the relative azimuthal spectral energies of Rg may be a possibility.

  13. Effects of momentum conservation and flow on angular correlations observed in experiments at the BNL Relativistic Heavy Ion Collider

    SciTech Connect

    Pratt, Scott; Schlichting, Soeren; Gavin, Sean

    2011-08-15

    Correlations of azimuthal angles observed at the Relativistic Heavy Ion Collider have gained great attention due to the prospect of identifying fluctuations of parity-odd regions in the field sector of QCD. Whereas the observable of interest related to parity fluctuations involves subtracting opposite-sign from same-sign correlations, the STAR collaboration reported the same-sign and opposite-sign correlations separately. It is shown here how momentum conservation combined with collective elliptic flow contributes significantly to this class of correlations, although not to the difference between the opposite- and same-sign observables. The effects are modeled with a crude simulation of a pion gas. Although the simulation reproduces the scale of the correlation, the centrality dependence is found to be sufficiently different in character to suggest additional considerations beyond those present in the pion gas simulation presented here.

  14. Secretarial Determination of No Adverse Material Impact for Uranium

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Transfers | Department of Energy Secretarial Determination of No Adverse Material Impact for Uranium Transfers Secretarial Determination of No Adverse Material Impact for Uranium Transfers The determination covers the Department's sales or transfers of no more than 2,705 metric tons (MTU) of natural uranium (NU) or NU equivalent in a calendar year. The proposed transfers include up to 650 MTU per year by the National Nuclear Security Administration in support of highly enriched uranium down

  15. Secretary Chu Announces Determination of No Adverse Material Impact for

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Uranium Transfer to Fund Portsmouth Cleanup | Department of Energy Determination of No Adverse Material Impact for Uranium Transfer to Fund Portsmouth Cleanup Secretary Chu Announces Determination of No Adverse Material Impact for Uranium Transfer to Fund Portsmouth Cleanup March 2, 2012 - 4:30pm Addthis WASHINGTON, D.C. - Secretary of Energy Steven Chu announced today that the Department of Energy has issued a determination and market impact analysis authorizing uranium transfers to fund

  16. Secretary Chu Announces Determination of No Adverse Material Impact for

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Uranium Transfer to Fund Portsmouth Cleanup | Department of Energy Determination of No Adverse Material Impact for Uranium Transfer to Fund Portsmouth Cleanup Secretary Chu Announces Determination of No Adverse Material Impact for Uranium Transfer to Fund Portsmouth Cleanup November 12, 2009 - 1:17pm Addthis Secretary Chu announced today that the Department of Energy has issued a final determination and market impact study for the proposed uranium transfer to fund accelerated cleanup

  17. Observational Study Designs for Comparative Effectiveness Research: An Alternative Approach to Close Evidence Gaps in Head-and-Neck Cancer

    SciTech Connect

    Goulart, Bernardo H.L.; Ramsey, Scott D.; Parvathaneni, Upendra

    2014-01-01

    Comparative effectiveness research (CER) has emerged as an approach to improve quality of care and patient outcomes while reducing healthcare costs by providing evidence to guide healthcare decisions. Randomized controlled trials (RCTs) have represented the ideal study design to support treatment decisions in head-and-neck (H and N) cancers. In RCTs, formal chance (randomization) determines treatment allocation, which prevents selection bias from distorting the measure of treatment effects. Despite this advantage, only a minority of patients qualify for inclusion in H and N RCTs, which limits the validity of their results to the broader H and N cancer patient population seen in clinical practice. Randomized controlled trials often do not address other knowledge gaps in the management of H and N cancer, including treatment comparisons for rare types of H and N cancers, monitoring of rare or late toxicity events (eg, osteoradionecrosis), or in some instances an RCT is simply not feasible. Observational studies, or studies in which treatment allocation occurs independently of investigators' choice or randomization, may address several of these gaps in knowledge, thereby complementing the role of RCTs. This critical review discusses how observational CER studies complement RCTs in generating the evidence to inform healthcare decisions and improve the quality of care and outcomes of H and N cancer patients. Review topics include a balanced discussion about the strengths and limitations of both RCT and observational CER study designs; a brief description of design and analytic techniques to handle selection bias in observational studies; examples of observational studies that inform current clinical practices and management of H and N cancers; and suggestions for relevant CER questions that could be addressed by an observational study design.

  18. Direct observation of a resolvable spin separation in the spin Hall effect of light at an air-glass interface

    SciTech Connect

    Ren, Jin-Li; Wang, Bo; Xiao, Yun-Feng; Gong, Qihuang; Li, Yan

    2015-09-14

    We theoretically and experimentally demonstrate that it is possible to directly observe the resolvable spin separation in the spin Hall effect of light at an air-glass interface by choosing optimal parameters. When a P-polarized light with a beam waist of 10 μm is incident around Brewster's angle, the two spin components of the reflected beam can be completely separated by eliminating the influence of the in-plane wavevector spread. This not only obviously reveals the strong impacts of the polarization state, the incident angle, the beam waist, and the in-plane wavevector spread, but also intuitively visualizes the observation of the spin Hall effect of light.

  19. Sunyaev-Zel'Dovich effect observations of the bullet cluster (1E 0657-56) with APEX-SZ

    SciTech Connect

    Halverson, N.W.; Lanting, T.; Ade, P.A.R.; Basu, K.; Bender, A.N.; Benson, B.A.; Bertoldi, F.; Cho, H.-M.; Chon, G.; Clarke, J.; Dobbs, M.; Ferrusca, D.; Gusten, R.; Holzapfel, W.L.; Kovacs, A.; Kennedy, J.; Kermish, Z.; Kneissl, R.; Lee, A.T.; Lueker, M.; Mehl, J.; Menten, K.M.; Muders, D.; Nord, M.; Pacaud, F.; Plagge, T.; Reichardt, C.; Richards, P.L.; Schaaf, R.; Schilke, P.; Schuller, F.; Schwan, D.; Spieler, H.; Tucker, C.; Weiss, A.; Zahn, O.

    2008-07-25

    We present observations of the Sunyaev-Zel'dovich effect (SZE) in the Bullet cluster (1E 0657-56) using the APEX-SZ instrument at 150 GHz with a resolution of 1'. The main results are maps of the SZE in this massive, merging galaxy cluster. The cluster is detected with 23 sigma significance within the central 1' radius of the source position. The SZE map has a broadly similar morphology to that in existing X-ray maps of this system, and we find no evidence for significant contamination of the SZE emission by radio or IR sources. In order to make simple quantitative comparisons with cluster gas models derived from X-ray observations, we fit our data to an isothermal elliptical beta model, despite the inadequacy of such a model for this complex merging system. With an X-ray derived prior on the power-law index, beta = 1.04+0.16-0.10, we find a core radius rc = 142" +- 18", an axial ratio of 0.889 +- 0.072, and a central temperature decrement of -771 +- 71 muKCMB, including a +-5.5percent flux calibration uncertainty. Combining the APEX-SZ map with a map of projected electron surface density from Chandra X-ray observations, we determine the mass-weighted temperature of the cluster gas to be Tmg = 10.8 +- 0.9 keV, significantly lower than some previously reported X-ray spectroscopic temperatures. Under the assumption of an isothermal cluster gas distribution in hydrostatic equilibrium, we compute the gas mass fraction for prolate and oblate spheroidal geometries and find it to be consistent with previous results from X-ray and weak-lensing observations. This work is the first result from the APEX-SZ experiment and represents the first reported scientific result from observations with a large array of multiplexed superconducting transition-edge sensor bolometers.

  20. SUNYAEV-ZEL'DOVICH EFFECT OBSERVATIONS OF THE BULLET CLUSTER (1E 0657-56) WITH APEX-SZ

    SciTech Connect

    Halverson, N. W.; Bender, A. N.; Lanting, T.; Dobbs, M.; Kennedy, J.; Ade, P. A. R.; Basu, K.; Bertoldi, F.; Benson, B. A.; Clarke, J.; Ferrusca, D.; Holzapfel, W. L.; Kermish, Z.; Lee, A. T.; Lueker, M.; Cho, H.-M.; Chon, G.; Guesten, R.; Kovacs, A.; Kneissl, R.

    2009-08-10

    We present observations of the Sunyaev-Zel'dovich effect (SZE) in the Bullet cluster (1E 0657-56) using the APEX-SZ instrument at 150 GHz with a resolution of 1'. The main results are maps of the SZE in this massive, merging galaxy cluster. The cluster is detected with 23{sigma} significance within the central 1' radius of the source position. The SZE map has a broadly similar morphology to that in existing X-ray maps of this system, and we find no evidence for significant contamination of the SZE emission by radio or IR sources. In order to make simple quantitative comparisons with cluster gas models derived from X-ray observations, we fit our data to an isothermal elliptical {beta} model, despite the inadequacy of such a model for this complex merging system. With an X-ray-derived prior on the power-law index, {beta} = 1.04{sup +0.16} {sub -0.10}, we find a core radius r {sub c} = 142'' {+-} 18'', an axial ratio of 0.889 {+-} 0.072, and a central temperature decrement of -771 {+-} 71 {mu}K{sub CMB}, including a {+-}5.5% flux calibration uncertainty. Combining the APEX-SZ map with a map of projected electron surface density from Chandra X-ray observations, we determine the mass-weighted temperature of the cluster gas to be T {sub mg} = 10.8 {+-} 0.9 keV, significantly lower than some previously reported X-ray spectroscopic temperatures. Under the assumption of an isothermal cluster gas distribution in hydrostatic equilibrium, we compute the gas mass fraction for prolate and oblate spheroidal geometries and find it to be consistent with previous results from X-ray and weak-lensing observations. This work is the first result from the APEX-SZ experiment, and represents the first reported scientific result from observations with a large array of multiplexed superconducting transition-edge sensor bolometers.

  1. Search for effects beyond the Born approximation in polarization transfer observables in $\\vec{e}p$ elastic scattering

    SciTech Connect

    Meziane, M; Brash, E J; Jones, M K; Luo, W; Pentchev, L; Perdrisat, C F; Puckett, A J.R.; Punjabi, V; Wesselmann, F R; Ahmidouch, A; Albayrak, I; Aniol, K A; Arrington, J; Asaturyan, A; Ates, O; Baghdasaryan, H; Benmokhtar, F; Bertozzi, W; Bimbot, L; Bosted, P; Boeglin, W; Butuceanu, C; Carter, P; Chernenko, S; Christy, E; Commisso, M; Cornejo, J C; Covrig, S; Danagoulian, S; Daniel, A; Davidenko, A; Day, D; Dhamija, S; Dutta, D; Ent, R; Frullani, S; Fenker, H; Frlez, E; Garibaldi, F; Gaskell, D; Gilad, S; Goncharenko, Y; Hafidi, K; Hamilton, D; Higinbothan, D W; Hinton, W; Horn, T; Hu, B; Huang, J; Huber, G M; Jensen, E; Kang, H; Keppel, C; Khandaker, M; King, P; Kirillov, D; Kohl, M; Kravtsov, V; Kumbartzki, G; Li, Y; Mamyan, V; Margaziotis, D J; Markowitz, P; Marsh, A; Matulenko, Y; Maxwell, J; Mbianda, G; Meekins, D; Melnick, Y; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Moffit, B; Moreno, O; Mulholland, J; Narayan, A; Nuruzzaman,; Nedev, S; Piasetzky, E; Pierce, W; Piskunov, N M; Prok, Y; Ransome, R D; Razin, D S; Reimer, P E; Reinhold, J; Rondon, O; Shabestari, M; Shahinyan, A; Shestermanov, K; Sirca, S; Sitnik, I; Smykov, L; Smith, G; Solovyev, L; Solvignon, P; Subedi, R; Suleiman, R; Tomasi-Gustafsson, E; Vasiliev, A; Vanderhaeghen, M; Veilleux, M; Wojtsekhowski, B B; Wood, S; Ye, Z; Zanevsky, Y; Zhang, X; Zhang, Y; Zheng, X; Zhu, L

    2011-04-01

    Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, $G_{E}/G_{M}$, obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange (TPEX) contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic $H(\\vec{e},e'\\vec{p})$ reaction for three different beam energies at a fixed squared momentum transfer $Q^2 = 2.5$ GeV$^2$, spanning a wide range of the virtual photon polarization parameter, $\\epsilon$. From these measured polarization observables, we have obtained separately the ratio $R$, which equals $\\mu_p G_{E}/G_{M}$ in the Born approximation, and the longitudinal polarization transfer component $P_\\ell$, with statistical and systematic uncertainties of $\\Delta R \\approx \\pm 0.01 \\mbox{(stat)} \\pm 0.013 \\mbox{(syst)}$ and $\\Delta P_\\ell/P^{Born}_{\\ell} \\approx \\pm 0.006 \\mbox{(stat)}\\pm 0.01 \\mbox{(syst)}$. The ratio $R$ is found to be independent of $\\epsilon$ at the 1.5% level, while the $\\epsilon$ dependence of $P_\\ell$ shows an enhancement of $(2.3 \\pm 0.6) %$ relative to the Born approximation at large $\\epsilon$.

  2. Secretary Chu Announces Determination of No Adverse Material Impact for

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Uranium Transfer to Fund Portsmouth Cleanup | Department of Energy March 2, 2011 - 12:00am Addthis WASHINGTON, D.C. - Secretary of Energy Steven Chu announced today that the Department of Energy has issued a determination and market impact analysis authorizing uranium transfers to fund accelerated cleanup activities at the Portsmouth Site in Piketon, Ohio, through the third quarter of calendar year 2013. The Determination finds that the proposed transfer of uranium will not have an adverse

  3. Minimize Adverse Motor and Adjustable Speed Drive Interactions

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Minimize Adverse Motor and Adjustable Speed Drive Interactions Electronic adjustable speed drives (ASDs) are extremely effcient and valuable assets to motor systems. They allow precise process control and provide energy savings within systems that do not need to operate continuously at full output. The most common ASD design sold today is the pulse-width-modulated (PWM) variable frequency drive (VFD) with a fast-rise-time insulated gate bipolar transistor (IGBT) to reduce switching losses and

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

    SciTech Connect

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

    2012-02-17

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

  5. Search for effects beyond the Born approximation in polarization transfer observables in e(pol)p elastic scattering.

    SciTech Connect

    Meziane, M.; Brash, E. J.; Jones, M. K.; Luo, W.; Pentchev, L.; Arrington, J.; Hafidi, K.; Reimer, P.; Solvignon, P.; Gep2 Collaboration

    2011-03-29

    Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G{sub E}/G{sub M}, obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H({rvec e}, e' {rvec p}) reaction for three different beam energies at a Q{sup 2} = 2.5 GeV{sup 2}, spanning a wide range of the kinematic parameter {epsilon}. The ratio R, which equals {mu}{sub p}G{sub E}/G{sub M} in the Born approximation, is found to be independent of {epsilon} at the 1.5% level. The {epsilon} dependence of the longitudinal polarization transfer component P{sub {ell}} shows an enhancement of (2.3 {+-} 0.6)% relative to the Born approximation at large {epsilon}.

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

    SciTech Connect

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

    2013-06-11

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

  7. Thermal effects of groundwater flow through subarctic fens: A case study based on field observations and numerical modeling

    DOE PAGES [OSTI]

    Sjöberg, Ylva; Coon, Ethan; K. Sannel, A. Britta; Pannetier, Romain; Harp, Dylan; Frampton, Andrew; Painter, Scott L.; Lyon, Steve W.

    2016-02-05

    Modeling and observation of ground temperature dynamics are the main tools for understanding current permafrost thermal regimes and projecting future thaw. Until recently, most studies on permafrost have focused on vertical ground heat fluxes. Groundwater can transport heat in both lateral and vertical directions but its influence on ground temperatures at local scales in permafrost environments is not well understood. In this paper, we combine field observations from a subarctic fen in the sporadic permafrost zone with numerical simulations of coupled water and thermal fluxes. At the Tavvavuoma study site in northern Sweden, ground temperature profiles and groundwater levels weremore » observed in boreholes. These observations were used to set up one- and two-dimensional simulations down to 2 m depth across a gradient of permafrost conditions within and surrounding the fen. Two-dimensional scenarios representing the fen under various hydraulic gradients were developed to quantify the influence of groundwater flow on ground temperature. Our observations suggest that lateral groundwater flow significantly affects ground temperatures. This is corroborated by modeling results that show seasonal ground ice melts 1 month earlier when a lateral groundwater flux is present. Further, although the thermal regime may be dominated by vertically conducted heat fluxes during most of the year, isolated high groundwater flow rate events such as the spring freshet are potentially important for ground temperatures. Finally, as sporadic permafrost environments often contain substantial portions of unfrozen ground with active groundwater flow paths, knowledge of this heat transport mechanism is important for understanding permafrost dynamics in these environments.« less

  8. Neutrino Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observations from the Sudbury Neutrino Observatory A.W.P. Poon 1 Institute for Nuclear and Particle Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA, USA Abstract. The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D 2 O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar ν e flux and the total flux of all active neutrino

  9. Simulating the Compton-Getting effect for hydrogen flux measurements: Implications for IBEX-Hi and -Lo observations

    SciTech Connect

    Zirnstein, E. J.; Heerikhuisen, J.; McComas, D. J.; Schwadron, N. A.

    2013-12-01

    The Interstellar Boundary EXplorer (IBEX), launched in 2008 October, has improved our understanding of the solar wind-local interstellar medium interaction through its detection of neutral atoms, particularly that of hydrogen (H). IBEX is able to create full maps of the sky in six-month intervals as the Earth orbits the Sun, detecting H with energies between ?0.01 and 6 keV. Due to the relative motion of IBEX to the solar inertial frame, measurements made in the spacecraft frame introduce a Compton-Getting (CG) effect, complicating measurements at the lowest energies. In this paper we provide results from a numerical simulation that calculates fluxes of H atoms at 1 AU in the inertial and spacecraft frames (both ram and anti-ram), at energies relevant to IBEX-Hi and -Lo. We show theory behind the numerical simulations, applying a simple frame transformation to derived flux equations that provides a straightforward way to simulate fluxes in the spacecraft frame. We then show results of H energetic neutral atom fluxes simulated at IBEX-Hi energy passbands 2-6 in all frames, comparing with IBEX-Hi data along selected directions, and also show results simulated at energies relevant to IBEX-Lo. Although simulations at IBEX-Hi energies agree reasonably well with the CG correction method used for IBEX-Hi data, we demonstrate the importance of properly modeling low energy H fluxes due to inherent complexities involved with measurements made in moving frames, as well as dynamic radiation pressure effects close to the Sun.

  10. A review of helium–hydrogen synergistic effects in radiation damage observed in fusion energy steels and an interaction model to guide future understanding

    DOE PAGES [OSTI]

    Marian, Jaime; Hoang, Tuan; Fluss, Michael; Hsiung, Luke L.

    2014-12-29

    Here, under fusion reactor conditions, large quantities of irradiation defects and transmutation gases are produced per unit time by neutrons, resulting in accelerated degradation of structural candidate ferritic (F) and ferritic/martensitic (F/M) steels. Due to the lack of a suitable fusion neutron testing facility, we must rely on high-dose-rate ion-beam experiments and present-day crude modeling estimates. Of particular interest is the possibility of synergistic (positive feedback) effects on materials properties due to the simultaneous action of He, H, and displacement damage (dpa) during operation. In this paper we discuss the state-of-the-art in terms of the experimental understanding of synergistic effectsmore » and carry out simulations of triple-species irradiation under ion-beam conditions using first-of-its-kind modeling techniques. Although, state-of-the-art modeling and simulation is not sufficiently well developed to shed light on the experimental uncertainties, we are able to conclude that it is not clear whether synergistic effects, the evidence of which is still not conclusive, will ultimately play a critical role in material performance under fusion energy conditions. We review here some of the evidence for the synergistic effects of hydrogen in the presence of helium and displacement damage, and also include some recent data from our research. While the experimental results to date suggest possible mechanisms for the observed synergistic effects, it is only with more advanced modeling that we can hope to understand the details underlying the experimental observations. By employing modeling and simulation we propose an interaction model that is qualitatively consistent with experimental observations of dpa/He/H irradiation behavior. Our modeling, the results of which should be helpful to researchers going forward, points to gaps and voids in the current understanding of triple ion-beam irradiation effects (displacement damage produced

  11. Analysis of Cyclic Variability of Heat Release for High-EGR GDI Engine Operation with Observations on Implications for Effective Control

    SciTech Connect

    Kaul, Brian C; Wagner, Robert M; Green Jr, Johney Boyd

    2013-01-01

    Operation of spark-ignition (SI) engines with high levels of charge dilution through exhaust gas recirculation (EGR) achieves significant engine efficiency gains while maintaining stoichiometric operation for compatibility with three-way catalysts. Dilution levels, however, are limited by cyclic variability-including significant numbers of misfires-that becomes more pronounced with increasing dilution. This variability has been shown to have both stochastic and deterministic components. Stochastic effects include turbulence, mixing variations, and the like, while the deterministic effect is primarily due to the nonlinear dependence of flame propagation rates and ignition characteristics on the charge composition, which is influenced by the composition of residual gases from prior cycles. The presence of determinism implies that an increased understanding the dynamics of such systems could lead to effective control approaches that allow operation near the edge of stability, effectively extending the dilution limit. This nonlinear dependence has been characterized previously for homogeneous charge, port fuel-injected (PFI) SI engines operating fuel-lean as well as with inert diluents such as bottled N2 gas. In this paper, cyclic dispersion in a modern boosted gasoline direct injection (GDI) engine using a cooled external EGR loop is examined, and the potential for improvement with effective control is evaluated through the use of symbol sequence statistics and other techniques from chaos theory. Observations related to the potential implications of these results for control approaches that could effectively enable engine operation at the edge of combustion stability are noted.

  12. Feasibility of observing small differences in friction mean effective pressure between different lubricating oil formations using small, single-cylinder motored engine rig

    DOE PAGES [OSTI]

    Rohr, William F.; Nguyen, Ke; Bunting, Bruce G.; Qu, Jun

    2015-09-01

    Here, the feasibility of using a motored single-cylinder 517 cc diesel engine to observe small frictional differences between oil formulations is investigated. Friction mean effective pressure (FMEP) is measured and compared for an SAE 10W-30 and an SAE 5W-20 oil in three stages of production: base oil, commercial oil without a friction and wear reducing additive, and fully formulated commercial oil. In addition, a commercial SAE 5W-30 engine oil is investigated. Friction mean effective pressure is plotted versus oil dynamic viscosity to compare the lubricant FMEP at a given viscosity. Linear regressions and average friction mean effective pressure are usedmore » as a secondary means of comparing FMEP for the various oil formulations. Differences between the oils are observed with the base oil having higher friction at a given viscosity but a lower average FMEP due to the temperature distribution of the test and lower viscosities reached by the base oil. The commercial oil is shown to have both a higher FMEP at a given viscosity and a higher average FMEP than the commercial oil without a friction and wear reducing additive. The increase in friction for the oil without a friction and wear reduction additive indicates that the operational regime of the engine may be out of the bounds of the optimal regime for the additive or that the additive is more optimized for wear reduction. Results show that it is feasible to observe small differences in FMEP between lubricating oil formulations using a small, single-cylinder motored engine.« less

  13. Feasibility of observing small differences in friction mean effective pressure between different lubricating oil formations using small, single-cylinder motored engine rig

    SciTech Connect

    Rohr, William F.; Nguyen, Ke; Bunting, Bruce G.; Qu, Jun

    2015-09-01

    Here, the feasibility of using a motored single-cylinder 517 cc diesel engine to observe small frictional differences between oil formulations is investigated. Friction mean effective pressure (FMEP) is measured and compared for an SAE 10W-30 and an SAE 5W-20 oil in three stages of production: base oil, commercial oil without a friction and wear reducing additive, and fully formulated commercial oil. In addition, a commercial SAE 5W-30 engine oil is investigated. Friction mean effective pressure is plotted versus oil dynamic viscosity to compare the lubricant FMEP at a given viscosity. Linear regressions and average friction mean effective pressure are used as a secondary means of comparing FMEP for the various oil formulations. Differences between the oils are observed with the base oil having higher friction at a given viscosity but a lower average FMEP due to the temperature distribution of the test and lower viscosities reached by the base oil. The commercial oil is shown to have both a higher FMEP at a given viscosity and a higher average FMEP than the commercial oil without a friction and wear reducing additive. The increase in friction for the oil without a friction and wear reduction additive indicates that the operational regime of the engine may be out of the bounds of the optimal regime for the additive or that the additive is more optimized for wear reduction. Results show that it is feasible to observe small differences in FMEP between lubricating oil formulations using a small, single-cylinder motored engine.

  14. Coupled-channels density-matrix approach to low-energy nuclear collision dynamics: A technique for quantifying quantum decoherence effects on reaction observables

    SciTech Connect

    Diaz-Torres, Alexis

    2010-11-15

    The coupled-channels density-matrix technique for nuclear reaction dynamics, which is based on the Liouville-von Neumann equation with Lindblad dissipative terms, is developed with the inclusion of full angular momentum couplings. It allows a quantitative study of the role and importance of quantum decoherence in nuclear scattering. Formulas of asymptotic observables that can reveal effects of quantum decoherence are given. A method for extracting energy-resolved scattering information from the time-dependent density matrix is introduced. As an example, model calculations are carried out for the low-energy collision of the {sup 16}O projectile on the {sup 154}Sm target.

  15. Observation of the inverse spin Hall effect in ZnO thin films: An all-electrical approach to spin injection and detection

    SciTech Connect

    Prestgard, Megan C.; Tiwari, Ashutosh

    2014-03-24

    The inverse spin Hall effect (ISHE) is a newly discovered, quantum mechanical phenomenon where an applied spin current results in the generation of an electrical voltage in the transverse direction. It is anticipated that the ISHE can provide a more simple way of measuring spin currents in spintronic devices. The ISHE was first observed in noble metals that exhibit strong spin-orbit coupling. However, recently, the ISHE has been detected in conventional semiconductors (such as Si and Ge), which possess weak spin-orbit coupling. This suggests that large-spin orbit coupling is not a requirement for observing the ISHE. In this paper, we are reporting the observation of the ISHE in an alternative semiconductor material, zinc oxide (ZnO) using all-electrical means. In our study, we found that when a spin-polarized current is injected into the ZnO film from a NiFe ferromagnetic injector via an MgO tunnel barrier layer, a voltage transverse to both the direction of the current as well as its spin-polarization is generated in the ZnO layer. The polarity of this voltage signal was found to flip on reversing the direction of the injected current as well as on reversing the polarization of the current, consistent with the predictions of the ISHE process. Through careful analysis of the ISHE data, we determined a spin-Hall angle of approximately 1.651 × 10{sup −2} for ZnO, which is two orders of magnitude higher than that of silicon. Observation of a detectable room-temperature ISHE signal in ZnO via electrical injection and detection is a groundbreaking step that opens a path towards achieving transparent spin detectors for next-generation spintronic device technology.

  16. This fact sheet summarizes what is known about the adverse impacts...

    Energy.gov [DOE] (indexed site)

    fact sheet summarizes what is known about the adverse impacts of land-based wind power on wildlife in North America and the status of our knowledge regarding how to avoid or ...

  17. Field observations and lessons learned

    SciTech Connect

    Nielsen, Joh B

    2010-01-01

    This presentation outlines observations and lessons learned from the Megaports program. It provides: (1) details of field and technical observations collected during LANL field activities at ports around the world and details of observations collected during radiation detections system testing at Los Alamos National Laboratory; (2) provides suggestions for improvement and efficiency; and (3) discusses possible program execution changes for more effective operations.

  18. Assessment of the Effect of Air Pollution Controls on Trends in Shortwave Radiation over the United States from 1995 through 2010 from Multiple Observation Networks

    SciTech Connect

    Gan, Chuen-Meei; Pleim, Jonathan; Mathur, Rohit; Hogrefe, Christian; Long, Charles N.; Xing, Jia; Roselle, Shawn; Wei, Chao

    2014-02-14

    Long term datasets of total (all-sky) and clear-sky downwelling shortwave (SW) radiation, cloud cover fraction (cloudiness) and aerosol optical depth (AOD) are analyzed together with aerosol concentration from several networks (e.g. SURFRAD, CASTNET, IMPROVE and ARM) in the United States (US). Seven states with varying climatology are selected to better understand the effect of aerosols and clouds on SW radiation. This analysis aims to test the hypothesis that the reductions in anthropogenic aerosol burden resulting from substantial reductions in emissions of sulfur dioxide and nitrogen oxides over the past 15 years across the US has caused an increase in surface SW radiation. We show that the total and clear-sky downwelling SW radiation from seven sites have increasing trends except Penn State which shows no tendency in clear-sky SW radiation. After investigating several confounding factors, the causes can be due to the geography of the site, aerosol distribution, heavy air traffic and increasing cloudiness. Moreover, we assess the relationship between total column AOD with surface aerosol concentration to test our hypothesis. In our findings, the trends of clear-sky SW radiation, AOD, and aerosol concentration from the sites in eastern US agree well with our hypothesis. However, the sites in western US demonstrate increasing AOD associated with mostly increasing trends in surface aerosol concentration. At these sites, the changes in aerosol burden and/or direct aerosol effects alone cannot explain the observed changes in SW radiation, but other factors need to be considered such as cloudiness, aerosol vertical profiles and elevated plumes.

  19. The role of the (111) texture on the exchange bias and interlayer coupling effects observed in sputtered NiFe/IrMn/Co trilayers

    SciTech Connect

    Castro, I. L.; Nascimento, V. P.; Passamani, E. C.; Takeuchi, A. Y.; Larica, C.; Tafur, M.; Pelegrini, F.

    2013-05-28

    Magnetic properties of sputtered NiFe/IrMn/Co trilayers grown on different seed layers (Cu or Ta) deposited on Si (100) substrates were investigated by magnetometry and ferromagnetic resonance measurements. Exchange bias effect and magnetic spring behavior have been studied by changing the IrMn thickness. As shown by X-ray diffraction, Ta and Cu seed layers provoke different degrees of (111) fcc-texture that directly affect the exchange bias and indirectly modify the exchange spring coupling behavior. Increasing the IrMn thickness, it was observed that the coupling angle between the Co and NiFe ferromagnetic layers increases for the Cu seed system, but it reduces for the Ta case. The results were explained considering (i) different anisotropies of the Co and IrMn layers induced by the different degree of the (111) texture and (ii) the distinct exchange bias set at the NiFe/IrMn and IrMn/Co interfaces in both systems. The NiFe and Co interlayer coupling angle is strongly correlated with both exchange bias and exchange magnetic spring phenomena. It was also shown that the highest exchange bias field occurs when an unstressed L1{sub 2} IrMn structure is stabilized.

  20. The potential of wetlands for mitigating adverse effects of agricultural drainage

    SciTech Connect

    Silverman, G.S.

    1995-12-01

    Agricultural runoff has been clearly identified as a major contributor to the failure of much of the surface water in the United States to meet designated use objectives. Control of agricultural drainage is very problematic. The agriculture industry strongly resists mandated controls, and warns of potential catastrophic consequences in food shortages should production methods be altered. Yet concern grows over the long and short term impact of a variety of contaminants - particularly sediments, nutrients, and pesticides - released to our waters as part of normal agricultural practices. For quite some time, wetlands have been explored for their potential in treating sewage (from both municipal and private systems) and acid mine drainage. Much less work has been done looking at the potential for wetlands to treat agricultural drainage. yet, wetlands may offer tremendous potential for mitigating problems of agricultural runoff while offering farmers desirable (or at least acceptable) uses of marginal land. This paper has two objectives. First, the opportunities for wetlands to be used as agricultural drainage treatment facilities are described. Processes are identified which trap or degrade pollutants, with particular attention given to long-term environmental fate. Second, an experimental wetlands system recently developed in Northwest Ohio is used as an example of system implementation. Emphasis will be given to how the system was developed to optimize pollutant removal within the physical constraints of the site. Preliminary performance data with respect to water quality changes will also be presented.

  1. Systematic drug safety evaluation based on public genomic expression (Connectivity Map) data: Myocardial and infectious adverse reactions as application cases

    SciTech Connect

    Wang, Kejian; Weng, Zuquan; Sun, Liya; Sun, Jiazhi; Zhou, Shu-Feng; He, Lin

    2015-02-13

    Adverse drug reaction (ADR) is of great importance to both regulatory agencies and the pharmaceutical industry. Various techniques, such as quantitative structure–activity relationship (QSAR) and animal toxicology, are widely used to identify potential risks during the preclinical stage of drug development. Despite these efforts, drugs with safety liabilities can still pass through safety checkpoints and enter the market. This situation raises the concern that conventional chemical structure analysis and phenotypic screening are not sufficient to avoid all clinical adverse events. Genomic expression data following in vitro drug treatments characterize drug actions and thus have become widely used in drug repositioning. In the present study, we explored prediction of ADRs based on the drug-induced gene-expression profiles from cultured human cells in the Connectivity Map (CMap) database. The results showed that drugs inducing comparable ADRs generally lead to similar CMap expression profiles. Based on such ADR-gene expression association, we established prediction models for various ADRs, including severe myocardial and infectious events. Drugs with FDA boxed warnings of safety liability were effectively identified. We therefore suggest that drug-induced gene expression change, in combination with effective computational methods, may provide a new dimension of information to facilitate systematic drug safety evaluation. - Highlights: • Drugs causing common toxicity lead to similar in vitro gene expression changes. • We built a model to predict drug toxicity with drug-specific expression profiles. • Drugs with FDA black box warnings were effectively identified by our model. • In vitro assay can detect severe toxicity in the early stage of drug development.

  2. Adverse reproductive outcomes in families of atomic veterans: The feasibility of epidemiologic studies

    SciTech Connect

    1995-12-31

    This is an outstanding report from a distinguished academy committee, which in 71 pages of text provides the scientific basis for the carefully crafted 8-page executive summary. The principles and issues of the required epidemiological study are presented calmly and concisely, as are the ensuing short chapters on radiation biology, genetics and risk estimation, and all other adverse reproductive outcomes. The committee was mandated by Congress to determine the feasibility, cost and duration of a study on adverse reproductive outcomes in families of atomic veteran. The committee found that a scientifically adequate and epidemiologically valid study could not be mounted and the cost would be tens of millions of dollars lasting a decade. The Committee presents a number of well-discussed approaches in support of their position.

  3. Assessing Adverse Events of Postprostatectomy Radiation Therapy for Prostate Cancer: Evaluation of Outcomes in the Regione Emilia-Romagna, Italy

    SciTech Connect

    Showalter, Timothy N.; Hegarty, Sarah E.; Rabinowitz, Carol; Maio, Vittorio; Hyslop, Terry; Dicker, Adam P.; Louis, Daniel Z.

    2015-03-15

    Purpose: Although the likelihood of radiation-related adverse events influences treatment decisions regarding radiation therapy after prostatectomy for eligible patients, the data available to inform decisions are limited. This study was designed to evaluate the genitourinary, gastrointestinal, and sexual adverse events associated with postprostatectomy radiation therapy and to assess the influence of radiation timing on the risk of adverse events. Methods: The Regione Emilia-Romagna Italian Longitudinal Health Care Utilization Database was queried to identify a cohort of men who received radical prostatectomy for prostate cancer during 2003 to 2009, including patients who received postprostatectomy radiation therapy. Patients with prior radiation therapy were excluded. Outcome measures were genitourinary, gastrointestinal, and sexual adverse events after prostatectomy. Rates of adverse events were compared between the cohorts who did and did not receive postoperative radiation therapy. Multivariable Cox proportional hazards models were developed for each class of adverse events, including models with radiation therapy as a time-varying covariate. Results: A total of 9876 men were included in the analyses: 2176 (22%) who received radiation therapy and 7700 (78%) treated with prostatectomy alone. In multivariable Cox proportional hazards models, the additional exposure to radiation therapy after prostatectomy was associated with increased rates of gastrointestinal (rate ratio [RR] 1.81; 95% confidence interval [CI] 1.44-2.27; P<.001) and urinary nonincontinence events (RR 1.83; 95% CI 1.83-2.80; P<.001) but not urinary incontinence events or erectile dysfunction. The addition of the time from prostatectomy to radiation therapy interaction term was not significant for any of the adverse event outcomes (P>.1 for all outcomes). Conclusion: Radiation therapy after prostatectomy is associated with an increase in gastrointestinal and genitourinary adverse events. However

  4. TU-A-12A-06: Intra-Observer Variability in Delineation of Target Volumes in Breast Radiotherapy and Its Effect On Accuracy of Deformation Measurements

    SciTech Connect

    Juneja, P; Harris, E; Bonora, M; Evans, P

    2014-06-15

    Purpose: In breast radiotherapy, the target volume may change during treatment and need adaptation of the treatment plan. This is possible for both tumour bed (TB) and whole breast (WB) target volumes. Delineation of the target (to detect changes) is also subject to uncertainty due to intra- and inter-observer variability. This work measured the uncertainty, due to intraobserver variability, in the quantification of tissue deformation. Methods: Datasets consisting of paired prone and supine CT scans of three patients were used. Significant deformation in target volumes is expected between prone and supine patient positions. The selected cases had 1) no seroma, 2) some seroma, and 3) large seroma. The TB and WB were outlined on each dataset three times by one clinician. Delineation variability was defined as the standard deviations of the distances between observer outlines. For each target volume and each case, tissue deformation between prone and supine delineations was quantified using the Dice similarity coefficient (DSC) and the average surface distance (ASD). The uncertainty in the tissue deformation (due to delineation variability) was quantified by measuring the ranges of DSC and ASD using all combinations of pairs of outlines (9 pairs). Results: For the TB, the range of delineation variability was 0.44-1.16 mm. The deformation, DSC and ASD, (and uncertainty in measurement) of the TB between prone and supine position of the cases were: 1) 0.21 (0.17-0.28) and 12.4 mm (11.8-13 mm); 2) 0.54 (0.51-0.57) and 3.3 mm (3.1-3.5 mm); 3) 0.62 (0.61-0.64) and 4.9 mm (4.6-5.2 mm). WB deformation measurements were subject to less uncertainty due to delineation variability than TB deformation measurements. Conclusion: For the first time, the uncertainty, due to observer variability, in the measurement of the deformation of breast target volumes was investigated. Deformations in these ranges would be difficult to detect. This work was supported in part by Cancer Research

  5. Effects of electron recirculation on a hard x-ray source observed during the interaction of a high intensity laser pulse with thin Au targets

    SciTech Connect

    Compant La Fontaine, A.; Courtois, C.; Lefebvre, E.; Bourgade, J. L.; Landoas, O.; Thorp, K.; Stoeckl, C.

    2013-12-15

    The interaction of a high intensity laser pulse on the preplasma of a high-Z solid target produced by the pulse's pedestal generates high-energy electrons. These electrons subsequently penetrate inside the solid target and produce bremsstrahlung photons, generating an x-ray source which can be used for photonuclear studies or to radiograph high area density objects. The source characteristics are compared for targets with thin (20 μm) and thick (100 μm) Au foils on the Omega EP laser at Laboratory for Laser Energetics. Simulations using the particle-in-cell code CALDER show that for a 20 μm thickness Au target, electrons perform multiple round-trips in the target under the effect of the laser ponderomotive potential and the target electrostatic potential. These relativistic electrons have random transverse displacements, with respect to the target normal, attributed to electrostatic fluctuation fields. As a result, the x-ray spot size is increased by a factor 2 for thin target compared to thick targets, in agreement with experimental results. In addition, the computed doses agree with the measured ones provided that electron recirculation in the thin target is taken into account. A dose increase by a factor 1.7 is then computed by allowing for recirculation. In the 100 μm target case, on the other hand, this effect is found to be negligible.

  6. Observation of the large magnetocaloric effect and suppression of orbital entropy change in Fe-doped MnV{sub 2}O{sub 4}

    SciTech Connect

    Huang, Z. H.; Luo, X. E-mail: ypsun@issp.ac.cn; Hu, L.; Tan, S. G.; Liu, Y.; Yuan, B.; Chen, J.; Song, W. H.; Sun, Y. P. E-mail: ypsun@issp.ac.cn

    2014-01-21

    We present the structural and magnetic properties of Mn{sub 1−x}Fe{sub x}V{sub 2}O{sub 4} (x = 0.1, 0.2, and 0.3), and investigate the magnetocaloric effect in those compounds. The ferrimagnetic spin ordering is enhanced with the Fe doping at Mn site of MnV{sub 2}O{sub 4}, while the orbital ordering is suppressed. Large magnetic entropy changes up to 3.8 J/kg K as well as the relative cooling power up to 110 J/kg at the field change of 0-2 T for Mn{sub 1−x}Fe{sub x}V{sub 2}O{sub 4} are calculated from the isothermal magnetization measurements. The large orbital entropy change of MnV{sub 2}O{sub 4} is suppressed by the Fe doping, while the spin entropy contribution arising from the strong spin-orbit coupling remains. Moreover, the doping of Fe broadens the temperature span of the large magnetic entropy change and increases the relative cooling power of MnV{sub 2}O{sub 4} by 2.4 times.

  7. Hubble space telescope/cosmic origins spectrograph observations of the quasar Q0302–003: Probing the He II reionization epoch and QSO proximity effects

    SciTech Connect

    Syphers, David; Shull, J. Michael

    2014-03-20

    Q0302–003 (z = 3.2860 ± 0.0005) was the first quasar discovered that showed a He II Gunn-Peterson trough, a sign of incomplete helium reionization at z ≳ 2.9. We present its Hubble Space Telescope/Cosmic Origins Spectrograph far-UV medium-resolution spectrum, which resolves many spectral features for the first time, allowing study of the quasar itself, the intergalactic medium, and quasar proximity effects. Q0302–003 has a harder intrinsic extreme-UV spectral index than previously claimed, as determined from both a direct fit to the spectrum (yielding α{sub ν} ≈ –0.8) and the helium-to-hydrogen ion ratio in the quasar's line-of-sight proximity zone. Intergalactic absorption along this sightline shows that the helium Gunn-Peterson trough is largely black in the range 2.87 < z < 3.20, apart from ionization due to local sources, indicating that helium reionization has not completed at these redshifts. However, we tentatively report a detection of nonzero flux in the high-redshift trough when looking at low-density regions, but zero flux in higher-density regions. This constrains the He II fraction to be about 1% in the low-density intergalactic medium (IGM) and possibly a factor of a few higher in the IGM as a whole, suggesting helium reionization has progressed substantially by z ∼ 3.1. The Gunn-Peterson trough recovers to a He II Lyα forest at z < 2.87. We confirm a transmission feature due to the ionization zone around a z = 3.05 quasar just off the sightline, and resolve the feature for the first time. We discover a similar such feature possibly caused by a luminous z = 3.23 quasar further from the sightline, which suggests that this quasar has been luminous for >34 Myr.

  8. Quantifying the Impact of Adverse Events on the Electricity Grid as a Function of Grid Topology

    SciTech Connect

    Coles, Garill A.; Sadovsky, Artyom; Du, Pengwei

    2011-11-30

    Abstract--Traditional approaches to the study of grid vulnerability have taken an asset based approach, which seeks to identify those assets most likely to result in grid-wide failures or disruptions in the event that they are compromised. We propose an alternative approach to the study of grid vulnerability, one based on the topological structure of the entire grid. We propose a method that will identify topological parameters most closely related to the ability of the grid to withstand an adverse event. We compare these topological parameters in terms of their impact on the vulnerability metric we have defined, referred to as the grid’s “survivability”. Our approach is motivated by Paul Baran’s work on communications networks, which also studied vulnerability in terms of network-wide parameters. Our approach is useful both as a planning model for evaluating proposed changes to a grid and as a risk assessment tool.

  9. Geo-neutrino Observation

    SciTech Connect

    Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.

    2009-12-17

    Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

  10. Correlation of Clinical and Dosimetric Factors With Adverse Pulmonary Outcomes in Children After Lung Irradiation

    SciTech Connect

    Venkatramani, Rajkumar; Kamath, Sunil; Wong, Kenneth; Malvar, Jemily; Sposto, Richard; Goodarzian, Fariba; Freyer, David R.; Keens, Thomas G.; and others

    2013-08-01

    Purpose: To identify the incidence and the risk factors for pulmonary toxicity in children treated for cancer with contemporary lung irradiation. Methods and Materials: We analyzed clinical features, radiographic findings, pulmonary function tests, and dosimetric parameters of children receiving irradiation to the lung fields over a 10-year period. Results: We identified 109 patients (75 male patients). The median age at irradiation was 13.8 years (range, 0.04-20.9 years). The median follow-up period was 3.4 years. The median prescribed radiation dose was 21 Gy (range, 0.4-64.8 Gy). Pulmonary toxic chemotherapy included bleomycin in 58.7% of patients and cyclophosphamide in 83.5%. The following pulmonary outcomes were identified and the 5-year cumulative incidence after irradiation was determined: pneumonitis, 6%; chronic cough, 10%; pneumonia, 35%; dyspnea, 11%; supplemental oxygen requirement, 2%; radiographic interstitial lung disease, 40%; and chest wall deformity, 12%. One patient died of progressive respiratory failure. Post-irradiation pulmonary function tests available from 44 patients showed evidence of obstructive lung disease (25%), restrictive disease (11%), hyperinflation (32%), and abnormal diffusion capacity (12%). Thoracic surgery, bleomycin, age, mean lung irradiation dose (MLD), maximum lung dose, prescribed dose, and dosimetric parameters between V{sub 22} (volume of lung exposed to a radiation dose ≥22 Gy) and V{sub 30} (volume of lung exposed to a radiation dose ≥30 Gy) were significant for the development of adverse pulmonary outcomes on univariate analysis. MLD, maximum lung dose, and V{sub dose} (percentage of volume of lung receiving the threshold dose or greater) were highly correlated. On multivariate analysis, MLD was the sole significant predictor of adverse pulmonary outcome (P=.01). Conclusions: Significant pulmonary dysfunction occurs in children receiving lung irradiation by contemporary techniques. MLD rather than prescribed

  11. Hot Pot Field Observations

    DOE Data Explorer

    Lane, Michael

    Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

  12. Hot Pot Field Observations

    DOE Data Explorer

    Lane, Michael

    2013-06-28

    Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

  13. The Great Plains low-level jet (LLJ) during the atmospheric radiation measurement (ARM) intensive observation period (IOP)-4 and simulations of land use pattern effect on the LLJ

    SciTech Connect

    Wu, Y.; Raman, S.

    1996-04-01

    The Great Plains low-level jet (LLJ) is an important element of the low-level atmospheric circulation. It transports water vapor from the Gulf of Mexico, which in turn affects the development of weather over the Great Plains of the central United States. The LLJ is generally recognized as a complex response of the atmospheric boundary layer to the diurnal cycle of thermal forcing. Early studies have attributed the Great Plains LLJ to the diurnal oscillations of frictional effect, buoyancy over sloping terrain, and the blocking effects of the Rocky Mountains. Recent investigations show that the speed of the LLJ is also affected by the soil type and soil moisture. Some studies also suggest that synoptic patterns may play an important role in the development of the LLJ. Land surface heterogeneties significantly affect mesoscale circulations by generating strong contrasts in surface thermal fluxes. Thus one would expect that the land use pattern should have effects on the LLJ`s development and structure. In this study, we try to determine the relative roles of the synoptic forcing, planetary boundary layers (PBL) processes, and the land use pattern in the formation of the LLJ using the observations from the Atmospheric Radiation Measurement (ARM) Intensive Operation Period (IOP)-4 and numerical sensitivity tests.

  14. Safety Observations Achieve Results

    Energy Science and Technology Software Center

    2000-01-16

    The SOAR web application provides a multi-checklist capability where focused observations can be created to address risk-likely work environments, tasks, etc. The SOAR web application has numerous reports to sort the data by key word, multiple factors (i.e., location, team, behavior, checklist, work environment, etc.), and the highest frequency of behaviors and error-likely predecessors, etc. Other performance indicators are also provided.

  15. Competition between pressure effects and airflow influence for the performance of plasma actuators

    SciTech Connect

    Kriegseis, J.; Barckmann, K.; Grundmann, S.; Frey, J.; Tropea, C.

    2014-05-15

    The present work addresses the combined influence of pressure variations and different airflow velocities on the discharge intensity of plasma actuators. Power consumption, plasma length, and discharge capacitance were investigated systematically for varying pressure levels (p = 0.1–1 bar) and airflow velocities (U{sub ∞}=0−100 m/s) to characterize and quantify the favorable and adverse effects on the discharge intensity. In accordance with previous reports, an increasing plasma actuator discharge intensity is observed for decreasing pressure levels. At constant pressure levels, an adverse airflow influence on the electric actuator performance is demonstrated. Despite the improved discharge intensity at lower pressure levels, the seemingly improved performance of the plasma actuators is accompanied with a more pronounced drop of the relative performance. These findings demonstrate the dependency of the (kinematic and thermodynamic) environmental conditions on the electric performance of plasma actuators, which in turn affects the control authority of plasma actuators for flow control applications.

  16. A Holistic Look at Minimizing Adverse Environmental Impact Under Section 316(b) of the Clean Water Act

    DOE PAGES [OSTI]

    Veil, John A.; Puder, Markus G.; Littleton, Debra J.; Johnson, Nancy

    2002-01-01

    Section 316(b) of the Clean Water Act (CWA) requires that “the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.” As the U.S. Environmental Protection Agency (EPA) develops new regulations to implement Section 316(b), much of the debate has centered on adverse impingement and entrainment impacts of cooling-water intake structures. Depending on the specific location and intake layout, once-through cooling systems withdrawing many millions of gallons of water per day can, to a varying degree, harm fish and other aquatic organisms in the water bodies from which the coolingmore » water is withdrawn. Therefore, opponents of once-through cooling systems have encouraged the EPA to require wet or dry cooling tower systems as the best technology available (BTA), without considering site-specific conditions. However, within the context of the broader scope of the CWA mandate, this focus seems too narrow. Therefore, this article examines the phrase “minimizing adverse environmental impact” in a holistic light. Emphasis is placed on the analysis of the terms “environmental” and “minimizing.” Congress chose “environmental” in lieu of other more narrowly focused terms like “impingement and entrainment,” “water quality,” or “aquatic life.” In this light, BTA for cooling-water intake structures must minimize the entire suite of environmental impacts, as opposed to just those associated with impingement and entrainment. Wet and dry cooling tower systems work well to minimize entrainment and impingement, but they introduce other equally important impacts because they impose an energy penalty on the power output of the generating unit. The energy penalty results from a reduction in plant operating efficiency and an increase in internal power consumption. As a consequence of the energy penalty, power companies must generate additional

  17. Observation

    Office of Scientific and Technical Information (OSTI)

    to an Orbital-Selective Mott Phase in A x Fe 2-y Se 2 (AK, Rb) Superconductors M. Yi, 1, 2 D. H. Lu, 3 R. Yu, 4 S. C. Riggs, 1, 2 J.-H. Chu, 1, 2 B. Lv, 5 Z. Liu, 1, 2 M. Lu,...

  18. Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... This interpretation explains why double structure fea- tures occur in Fig. 2 only when ... In conclusion, our data clearly show a change in magnetic topology during PPCD. The ...

  19. Observation

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Recently, energy loss in RFP experiments has been reduced tenfold through modification of ... Hence the behavior of fast electrons is a particularly sensitive indicator of magnetic ...

  20. Observation

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... How- ever, eddy currents can decelerate the mode to an extent that other sources of ... We have also ruled out other causes of braking and locking, such as the partially ...

  1. State observer for synchronous motors

    DOEpatents

    Lang, Jeffrey H.

    1994-03-22

    A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

  2. Correlation between human observer performance and model observer performance in differential phase contrast CT

    SciTech Connect

    Li, Ke; Garrett, John; Chen, Guang-Hong

    2013-11-15

    Purpose: With the recently expanding interest and developments in x-ray differential phase contrast CT (DPC-CT), the evaluation of its task-specific detection performance and comparison with the corresponding absorption CT under a given radiation dose constraint become increasingly important. Mathematical model observers are often used to quantify the performance of imaging systems, but their correlations with actual human observers need to be confirmed for each new imaging method. This work is an investigation of the effects of stochastic DPC-CT noise on the correlation of detection performance between model and human observers with signal-known-exactly (SKE) detection tasks.Methods: The detectabilities of different objects (five disks with different diameters and two breast lesion masses) embedded in an experimental DPC-CT noise background were assessed using both model and human observers. The detectability of the disk and lesion signals was then measured using five types of model observers including the prewhitening ideal observer, the nonprewhitening (NPW) observer, the nonprewhitening observer with eye filter and internal noise (NPWEi), the prewhitening observer with eye filter and internal noise (PWEi), and the channelized Hotelling observer (CHO). The same objects were also evaluated by four human observers using the two-alternative forced choice method. The results from the model observer experiment were quantitatively compared to the human observer results to assess the correlation between the two techniques.Results: The contrast-to-detail (CD) curve generated by the human observers for the disk-detection experiments shows that the required contrast to detect a disk is inversely proportional to the square root of the disk size. Based on the CD curves, the ideal and NPW observers tend to systematically overestimate the performance of the human observers. The NPWEi and PWEi observers did not predict human performance well either, as the slopes of their CD

  3. High-throughput identification of off-targets for the mechanistic study of severe adverse drug reactions induced by analgesics

    SciTech Connect

    Pan, Jian-Bo; Ji, Nan; Pan, Wen; Hong, Ru; Wang, Hao; Ji, Zhi-Liang

    2014-01-01

    Drugs may induce adverse drug reactions (ADRs) when they unexpectedly bind to proteins other than their therapeutic targets. Identification of these undesired protein binding partners, called off-targets, can facilitate toxicity assessment in the early stages of drug development. In this study, a computational framework was introduced for the exploration of idiosyncratic mechanisms underlying analgesic-induced severe adverse drug reactions (SADRs). The putative analgesic-target interactions were predicted by performing reverse docking of analgesics or their active metabolites against human/mammal protein structures in a high-throughput manner. Subsequently, bioinformatics analyses were undertaken to identify ADR-associated proteins (ADRAPs) and pathways. Using the pathways and ADRAPs that this analysis identified, the mechanisms of SADRs such as cardiac disorders were explored. For instance, 53 putative ADRAPs and 24 pathways were linked with cardiac disorders, of which 10 ADRAPs were confirmed by previous experiments. Moreover, it was inferred that pathways such as base excision repair, glycolysis/glyconeogenesis, ErbB signaling, calcium signaling, and phosphatidyl inositol signaling likely play pivotal roles in drug-induced cardiac disorders. In conclusion, our framework offers an opportunity to globally understand SADRs at the molecular level, which has been difficult to realize through experiments. It also provides some valuable clues for drug repurposing. - Highlights: A novel computational framework was developed for mechanistic study of SADRs. Off-targets of drugs were identified in large scale and in a high-throughput manner. SADRs like cardiac disorders were systematically explored in molecular networks. A number of ADR-associated proteins were identified.

  4. NS&T MANAGEMENT OBSERVATIONS

    SciTech Connect

    Gianotto, David

    2014-06-01

    The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations (observations) are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

  5. NS&T Management Observations

    SciTech Connect

    Gianotto, David

    2014-09-01

    The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations (observations) are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

  6. Singular behavior of jet substructure observables

    DOE PAGES [OSTI]

    Larkoski, Andrew J.; Moult, Ian

    2016-01-20

    Jet substructure observables play a central role at the Large Hadron Collider for identifying the boosted hadronic decay products of electroweak scale resonances. The complete description of these observables requires understanding both the limit in which hard substructure is resolved, as well as the limit of a jet with a single hard core. In this paper we study in detail the perturbative structure of two prominent jet substructure observables, N-subjettiness and the energy correlation functions, as measured on background QCD jets. In particular, we focus on the distinction between the limits in which two-prong structure is resolved or unresolved. Dependingmore » on the choice of subjet axes, we demonstrate that at fixed order, N-subjettiness can manifest myriad behaviors in the unresolved region: smooth tails, end-point singularities, or singularities in the physical region. The energy correlation functions, by contrast, only have non-singular perturbative tails extending to the end point. We discuss the effect of hadronization on the various observables with Monte Carlo simulation and demonstrate that the modeling of these effects with non-perturbative shape functions is highly dependent on the N-subjettiness axes definitions. Lastly, our study illustrates those regions of phase space that must be controlled for high-precision jet substructure calculations, and emphasizes how such calculations can be facilitated by designing substructure observables with simple singular structures.« less

  7. New particle observations in SELEX

    SciTech Connect

    Jun, Soon Yung; /Carnegie Mellon U.

    2004-12-01

    Particle observations in data from SELEX, the charm hadro-production experiment (E781) at Fermilab are reviewed. These include observations of the doubly charmed baryon {Xi}{sub cc}{sup +}(3520) and the charmed strange meson D{sub sJ}{sup +}(2632).

  8. Effects

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Effects of particles with large gyroradii on resistive magnetohydrodynamic stability V. A. Svidzinski and S. C. Prager University of Wisconsin-Madison, Madison, Wisconsin 53706 ͑Received 19 September 2003; accepted 25 November 2003͒ Fast ions in tokamaks are known to have a significant influence on global plasma instabilities. In normal mode analyses for tokamaks, the perturbed electric and magnetic fields have been evaluated at the position of the particle's guiding center. The effect of

  9. Shortwave Hyperspectral Observations during MAGIC

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... The black contours show percent cloud absorption at 1600 nm calculated with SBDART. These ... surface-based observations of marine clouds make the MAGIC data interesting as a whole. ...

  10. Observation of Electron-Beam-Induced Phase Evolution Mimicking the Effect of the Charge–Discharge Cycle in Li-Rich Layered Cathode Materials Used for Li Ion Batteries

    DOE PAGES [OSTI]

    Lu, Ping; Yan, Pengfei; Romero, Eric; Spoerke, Erik David; Zhang, Ji-Guang; Wang, Chong-Min

    2015-01-27

    Capacity loss, and voltage decrease upon electrochemical charge-discharge cycling observed in lithium-rich layered cathode oxides (Li[LixMnyTM1-x-y]O2, TM = Ni, Co or Fe) have recently been attributed to the formation of a surface reconstructed layer (SRL) that evolves from a thin (<2 nm), defect spinel layer upon the first charge, to a relatively thick (~5nm), spinel or rock-salt layer upon continuous charge-discharge cycling. Here we report observations of a SRL and structural evolution of the SRL on the Li[Li0.2Ni0.2Mn0.6]O2 (LNMO) particles, which are identical to those reported due to the charge-discharge cycle but are a result of electron-beam irradiation during scanningmore » transmission electron microscopy (STEM) imaging. Sensitivity of the lithium-rich layered oxides to high-energy electrons leads to the formation of thin, defect spinel layer on surfaces of the particles when exposed to a 200kV electron beam for as little as 30 seconds under normal high-resolution STEM imaging conditions. Further electron irradiation produces a thicker layer of the spinel phase, ultimately producing a rock-salt layer at a higher electron exposure. Atomic-scale chemical mapping by electron dispersive X-ray spectroscopy in STEM indicates the electron-beam-induced SRL formation on LNMO is accomplished by migration of the transition metal ions to the Li sites without breaking down the lattice. The observation through this study provides an insight for understanding the mechanism of forming the SRL and also possibly a mean to study structural evolution in the Li-rich layered oxides without involving the electrochemistry.« less

  11. Observation of Electron-Beam-Induced Phase Evolution Mimicking the Effect of the ChargeDischarge Cycle in Li-Rich Layered Cathode Materials Used for Li Ion Batteries

    SciTech Connect

    Lu, Ping; Yan, Pengfei; Romero, Eric; Spoerke, Erik David; Zhang, Ji-Guang; Wang, Chong-Min

    2015-01-27

    Capacity loss, and voltage decrease upon electrochemical charge-discharge cycling observed in lithium-rich layered cathode oxides (Li[LixMnyTM1-x-y]O2, TM = Ni, Co or Fe) have recently been attributed to the formation of a surface reconstructed layer (SRL) that evolves from a thin (<2 nm), defect spinel layer upon the first charge, to a relatively thick (~5nm), spinel or rock-salt layer upon continuous charge-discharge cycling. Here we report observations of a SRL and structural evolution of the SRL on the Li[Li0.2Ni0.2Mn0.6]O2 (LNMO) particles, which are identical to those reported due to the charge-discharge cycle but are a result of electron-beam irradiation during scanning transmission electron microscopy (STEM) imaging. Sensitivity of the lithium-rich layered oxides to high-energy electrons leads to the formation of thin, defect spinel layer on surfaces of the particles when exposed to a 200kV electron beam for as little as 30 seconds under normal high-resolution STEM imaging conditions. Further electron irradiation produces a thicker layer of the spinel phase, ultimately producing a rock-salt layer at a higher electron exposure. Atomic-scale chemical mapping by electron dispersive X-ray spectroscopy in STEM indicates the electron-beam-induced SRL formation on LNMO is accomplished by migration of the transition metal ions to the Li sites without breaking down the lattice. The observation through this study provides an insight for understanding the mechanism of forming the SRL and also possibly a mean to study structural evolution in the Li-rich layered oxides without involving the electrochemistry.

  12. Observational constraints on assisted k-inflation

    SciTech Connect

    Ohashi, Junko; Tsujikawa, Shinji

    2011-05-15

    We study observational constraints on the assisted k-inflation models in which multiple scalar fields join an attractor characterized by an effective single field {phi}. This effective single-field system is described by the Lagrangian P=Xg(Y), where X is the kinetic energy of {phi}, {lambda} is a constant, and g is an arbitrary function in terms of Y=Xe{sup {lambda}{phi}}. Our analysis covers a wide variety of k-inflation models such as dilatonic ghost condensate, Dirac-Born-Infeld field, and tachyon, as well as the canonical field with an exponential potential. We place observational bounds on the parameters of each model from the WMAP 7yr data combined with baryon acoustic oscillations and the Hubble constant measurement. Using the observational constraints of the equilateral non-Gaussianity parameter f{sub NL}{sup equil}, we further restrict the allowed parameter space of dilatonic ghost condensate and Dirac-Born-Infeld models. We extend the analysis to more general models with several different choices of g(Y) and show that the models such as g(Y)=c{sub 0}+c{sub p}Y{sup p} (p{>=}3) are excluded by the joint data analysis of the scalar/tensor spectra and primordial non-Gaussianities.

  13. Observation of an Antimatter Hypernucleus

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons - composed of an antiproton, antineutron, and antilambda hyperon - produced by colliding gold nuclei at high energy. Our analysis yields 70 {+-} 17 antihypertritons ({sub {bar {Lambda}}}{sup 3}{bar H}) and 157 {+-} 30 hypertritons ({sub {Lambda}}{sup 3}H). The measured yields of {sub {Lambda}}{sup 3}H ({sub {bar {Lambda}}}{sup 3}{bar H}) and {sup 3}He ({sup 3}{ovr He}) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and nuclei containing strange quarks, have implications spanning nuclear/particle physics, astrophysics, and cosmology.

  14. ARM - Surface Aerosol Observing System

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 MAOS AMF Fact Sheet Images Contacts AMF Deployments McMurdo Station, Antarctica, 2015-2016 Pearl Harbor, Hawaii, to San Francisco, California, 2015 Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs,

  15. Intensive Observation Period Projects Scheduled

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    1 Intensive Observation Period Projects Scheduled Several IOP projects have been scheduled for the SGP CART site this spring. These projects either have already begun or will begin shortly. Radiosondes The RS-90 Transition IOP is currently under way. The RS-90 model radiosonde is gradually replacing the older RS-80 model. Radiosondes are instrument packages attached to and launched by weather balloons. The instruments measure atmospheric pressure, temperature, and relative humidity as the

  16. Observation of Nonlinear Compton Scattering

    SciTech Connect

    Kotseroglou, T.

    2003-12-19

    This experiment tests Quantum Electrodynamics in the strong field regime. Nonlinear Compton scattering has been observed during the interaction of a 46.6 GeV electron beam with a 10{sup 18} W/cm{sup 2} laser beam. The strength of the field achieved was measured by the parameter {eta} = e{var_epsilon}{sub rms}/{omega}mc = 0.6. Data were collected with infrared and green laser photons and circularly polarized laser light. The timing stabilization achieved between the picosecond laser and electron pulses has {sigma}{sub rms} = 2 ps. A strong signal of electrons that absorbed up to 4 infrared photons (or up to 3 green photons) at the same point in space and time, while emitting a single gamma ray, was observed. The energy spectra of the scattered electrons and the nonlinear dependence of the electron yield on the field strength agreed with the simulation over 3 orders of magnitude. The detector could not resolve the nonlinear Compton scattering from the multiple single Compton scattering which produced rates of scattered electrons of the same order of magnitude. Nevertheless, a simulation has studied this difference and concluded that the scattered electron rates observed could not be accounted for only by multiple ordinary Compton scattering; nonlinear Compton scattering processes are dominant for n {ge} 3.

  17. Category:Observation Wells | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Observation Wells Jump to: navigation, search Geothermalpower.jpg Looking for the Observation Wells page? For detailed information on Observation Wells, click here....

  18. Observing remnants by fermions' tunneling

    SciTech Connect

    Chen, D.Y.; Wu, H.W.; Yang, H. E-mail: iverwu@uestc.edu.cn

    2014-03-01

    The standard Hawking formula predicts the complete evaporation of black holes. In this paper, we introduce effects of quantum gravity into fermions' tunneling from Reissner-Nordstrom and Kerr black holes. The quantum gravity effects slow down the increase of Hawking temperatures. This property naturally leads to a residue mass in black hole evaporation. The corrected temperatures are affected by the quantum numbers of emitted fermions. Meanwhile, the temperature of the Kerr black hole is a function of ? due to the rotation.

  19. Observational Approach to Chromium Site Remediation - 13266

    SciTech Connect

    Scott Myers, R.

    2013-07-01

    Production reactors at the U.S. Department of Energy's (DOE) Hanford Site in Richland, Washington, required massive quantities of water for reactor cooling and material processing. To reduce corrosion and the build-up of scale in pipelines and cooling systems, sodium dichromate was added to the water feedstock. Spills and other releases at the makeup facilities, as well as leaks from miles of pipelines, have led to numerous areas with chromium-contaminated soil and groundwater, threatening fish populations in the nearby Columbia River. Pump-and-treat systems have been installed to remove chromium from the groundwater, but significant contamination remain in the soil column and poses a continuing threat to groundwater and the Columbia River. Washington Closure Hanford, DOE, and regulators are working on a team approach that implements the observational approach, a strategy for effectively dealing with the uncertainties inherent in subsurface conditions. Remediation of large, complex waste sites at a federal facility is a daunting effort. It is particularly difficult to perform the work in an environment of rapid response to changing field and contamination conditions. The observational approach, developed by geotechnical engineers to accommodate the inherent uncertainties in subsurface conditions, is a powerful and appropriate method for site remediation. It offers a structured means of quickly moving into full remediation and responding to the variations and changing conditions inherent in waste site cleanups. A number of significant factors, however, complicate the application of the observational approach for chromium site remediation. Conceptual models of contamination and site conditions are difficult to establish and get consensus on. Mid-stream revisions to the design of large excavations are time-consuming and costly. And regulatory constraints and contract performance incentives can be impediments to the flexible responses required under the observational

  20. Propensity-Weighted Comparison of Long-Term Risk of Urinary Adverse Events in Elderly Women Treated For Cervical Cancer

    SciTech Connect

    Elliott, Sean P.; Fan, Yunhua; Jarosek, Stephanie; Chu, Haitao; Downs, Levi; Dusenbery, Kathryn; Geller, Melissa A.; Virnig, Beth A.

    2015-07-01

    Purpose: Cervical cancer treatment is associated with a risk of urinary adverse events (UAEs) such as ureteral stricture and vesicovaginal fistula. We sought to measure the long-term UAE risk after surgery and radiation therapy (RT), with confounding controlled through propensity-weighted models. Methods and Materials: From the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, we identified women ≥66 years old with nonmetastatic cervical cancer treated with simple surgery (SS), radical hysterectomy (RH), external beam RT plus brachytherapy (EBRT+BT), or RT+surgery. We matched them to noncancer controls 1:3. Differences in demographic and cancer characteristics were balanced by propensity weighting. Grade 3 to 4 UAEs were identified by diagnosis codes plus treatment codes. Cumulative incidence was measured using Kaplan-Meier methods. The hazard associated with different cancer treatments was compared using Cox models. Results: UAEs occurred in 272 of 1808 cases (17%) and 222 of 5424 (4%) controls; most (62%) were ureteral strictures. The raw cumulative incidence of UAEs was highest in advanced cancers. UAEs occurred in 31% of patients after EBRT+BT, 25% of patients after RT+surgery, and 15% of patients after RH; however, after propensity weighting, the incidence was similar. In adjusted Cox models (reference = controls), the UAE risk was highest after RT+surgery (hazard ratio [HR], 5.07; 95% confidence interval [CI], 2.32-11.07), followed by EBRT+BT (HR, 3.33; 95% CI, 1.45-7.65), RH (HR, 3.65; 95% CI, 1.41-9.46) and SS (HR, 0.99; 95% CI, 0.32-3.01). The higher risk after RT+surgery versus EBRT+BT was statistically significant, whereas, EBRT+BT and RH were not significantly different from each other. Conclusions: UAEs are common after cervical cancer treatment, particularly in patients with advanced cancers. UAEs are more common after RT, but these women tend to have the advanced cancers. After propensity weighting, the risk after RT was similar

  1. Observation of the Top Quark

    DOE R&D Accomplishments

    Kim, S. B.

    1995-08-01

    Top quark production is observed in{bar p}p collisions at{radical}s= 1.8 TeV at the Fermilab Tevatron. The Collider Detector at Fermilab (CDF) and D{O} observe signals consistent with t{bar t} to WWb{bar b}, but inconsistent with the background prediction by 4.8{sigma} (CDF), 4.6a (D{O}). Additional evidence for the top quark Is provided by a peak in the reconstructed mass distribution. The kinematic properties of the excess events are consistent with the top quark decay. They measure the top quark mass to be 176{plus_minus}8(stat.){plus_minus}10(sys.) GeV/c{sup 2} (CDF), 199{sub -21}{sup+19}(stat.){plus_minus}22(sys.) GeV/c{sup 2} (D{O}), and the t{bar t} production cross section to be 6.8{sub -2.4}{sup+3.6}pb (CDF), 6.4{plus_minus}2.2 pb (D{O}).

  2. Observation of the Goos-Haenchen Shift with Neutrons (Journal...

    Office of Scientific and Technical Information (OSTI)

    This phenomenon was suggested by Sir Isaac Newton, but it was not until 1947 that the effect was experimentally observed by Goos and Haenchen. We provide the first direct, ...

  3. Kalman filter data assimilation: Targeting observations and parameter estimation

    SciTech Connect

    Bellsky, Thomas Kostelich, Eric J.; Mahalov, Alex

    2014-06-15

    This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly located observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.

  4. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  5. Comet tail formation: Giotto observations

    SciTech Connect

    Wilken, B.; Jockers, K.; Johnstone, A.; Coates, A.; Heath, J.; Formisano, V.; Amata, E.; Winningham, J.D.; Thomsen, M.; Bryant, D.A.

    1986-01-01

    The process of mass loading of the solar wind by cometary ions, which forms comet tails, has been observed throughout the coma of comet Halley. Three distinct regimes were found where the nature of the energy and momentum coupling between solar wind and cometary ions is different. Outside the bow shock, where there is little angular scattering of the freshly ionized particles, the coupling is described by the simple pickup trajectory and the energy is controlled by the angle between the flow and the magnetic field. Just inside the bow shock, there is considerable scattering accompanied by another acceleration process which raises some particle energies well above the straightforward pickup value. Finally, closer to the nucleus, the amount of scattering decreases and the coupling is once more controlled by the magnetic field direction. 4 refs., 3 figs.

  6. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

    SciTech Connect

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-02

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 1–3 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ≤ 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size. From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.

  7. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

    SciTech Connect

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-02

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 13 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ? 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size. From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.

  8. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

    DOE PAGES [OSTI]

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-02

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 1–3 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ≤ 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size.more » From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.« less

  9. New photodisintegration threshold observable in

    SciTech Connect

    E.A. Wulf; R.S. Canon; Sally J. Gaff; J.H. Kelley; R.M. Prior; E.C. Schreiber; M. Spraker; D.R. Tilley; H.R. Weller; M. Viviani; A. Kievsky; S. Rosati; Rocco Schiavilla

    2000-02-01

    Measurements of the cross section, vector, and tensor analyzing powers, and linear gamma-ray polarization in the radiative capture reactions D(p,y){sup 3} He and p(d,y){sup 3}He at c.m. energies in the range 0-53 keV allow the determination of the reduced matrix elements (RMEs) relevant for these transitions. From these RMEs the value of the integral which determines the Gerasimov-Drell-Hearn sum rule for He is obtained in the threshold region, corresponding to two-body breakup, and compared with the results of an ab initio microscopic three-body model calculation.The theoretical predictions for the value of this integral based on a ''nucleons-only'' assumption are an order of magnitude smaller than experiment. The discrepancy is reduced to about a factor of 2 when two-body currents are taken into account. This factor of 2 is due to an almost exact cancellation between the dominant E1 RMEs in the theoretical calculation. The excess E1 strength observed experimentally could provide useful insights into the nuclear interaction at low energies.

  10. Observation of the Integer Quantum Hall Effect in Record High...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: DE-AC04-94AL85000 Resource Type: Journal Article Resource Relation: Journal Name: Applied Physics Letters; Related Information: Proposed for publication in ...

  11. Feasibility of observing small differences in friction mean effective...

    Office of Scientific and Technical Information (OSTI)

    Additional Journal Information: Journal Volume: 58; Journal Issue: 6; Journal ID: ISSN 1040-2004 Publisher: Taylor & Francis Research Org: Oak Ridge National Laboratory (ORNL), Oak ...

  12. Review of experimental observations about the cold fusion effect

    SciTech Connect

    Storms, E. )

    1991-12-01

    In this paper the experimental literature describing the cold fusion phenomenon is reviewed. The number and variety of careful experimental measurements of heat, tritium, neutron, and helium production strongly support the occurrence of nuclear reactions in a metal lattice near room temperature as proposed by Pons and Fleischmann and independently by Jones.

  13. GNEP Partners and Observers | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    GNEP Partners and Observers GNEP Partners and Observers A list of GNEP partners and observers. GNEP Partners and Observers (45.67 KB) More Documents & Publications Microsoft PowerPoint - GNEP PARTNERS CANDIDATE PARTNERS AND OBSERVERS.PPT Senior Delegation Officials From All GNEP Participants Meeting Materials: April 21, 2008

  14. Special Emphasis Observances | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Diversity and Inclusion » Special Emphasis Observances Special Emphasis Observances The Energy Department celebrates special emphasis observances regularly, inviting guest speakers to highlight how the agency's mission benefits from diversity and inclusion. The Energy Department celebrates special emphasis observances regularly, inviting guest speakers to highlight how the agency's mission benefits from diversity and inclusion. The Department of Energy observes special days, weeks, and months

  15. RECONCILING THE OBSERVED STAR-FORMING SEQUENCE WITH THE OBSERVED STELLAR MASS FUNCTION

    SciTech Connect

    Leja, Joel; Van Dokkum, Pieter G.; Franx, Marijn; Whitaker, Katherine E.

    2015-01-10

    We examine the connection between the observed star-forming sequence (SFR ? M {sup ?}) and the observed evolution of the stellar mass function in the range 0.2 < z < 2.5. We find that the star-forming sequence cannot have a slope ? ? 0.9 at all masses and redshifts because this would result in a much higher number density at 10 < log (M/M {sub ?}) < 11 by z = 1 than is observed. We show that a transition in the slope of the star-forming sequence, such that ? = 1 at log (M/M {sub ?}) < 10.5 and ? = 0.7-0.13z (Whitaker et al.) at log (M/M {sub ?}) > 10.5, greatly improves agreement with the evolution of the stellar mass function. We then derive a star-forming sequence that reproduces the evolution of the mass function by design. This star-forming sequence is also well described by a broken power law, with a shallow slope at high masses and a steep slope at low masses. At z = 2, it is offset by ?0.3 dex from the observed star-forming sequence, consistent with the mild disagreement between the cosmic star formation rate (SFR) and recent observations of the growth of the stellar mass density. It is unclear whether this problem stems from errors in stellar mass estimates, errors in SFRs, or other effects. We show that a mass-dependent slope is also seen in other self-consistent models of galaxy evolution, including semianalytical, hydrodynamical, and abundance-matching models. As part of the analysis, we demonstrate that neither mergers nor hidden low-mass quiescent galaxies are likely to reconcile the evolution of the mass function and the star-forming sequence. These results are supported by observations from Whitaker et al.

  16. Observations and simulations improve space weather models

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observations improve space weather models Observations and simulations improve space weather models Researchers used data from the Van Allen Probes to improve a three-dimensional...

  17. First Observation of Plasmarons in Graphene

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    First Observation of Plasmarons in Graphene First Observation of Plasmarons in Graphene Print Wednesday, 30 June 2010 00:00 An international team of scientists performing...

  18. Enterprise Assessments Operational Awareness Record of Observations...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Enterprise Assessments Operational Awareness Record of Observations of the Design and ... March 2016 Enterprise Assessments Operational Awareness Record of Observations of the ...

  19. Automated Surface Observing System: Standby Power Options

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Automated Surface Observing System Standby Options Power Automated Surface Observing System (ASOS) General System Description * Self contained group of sensors and data gathering equipment that produces an automated weather observation * Weather observations support aviation, climate data, non government weather operations, public consumption, etc. * Initial deployment began in 1991 and continued through 1997 * Located at 884 sites nationwide, normally at airports * System has two distinct

  20. Observation of the Goos-Haenchen Shift with Neutrons

    SciTech Connect

    Haan, Victor-O. de; Plomp, Jeroen; Rekveldt, Theo M.; Kraan, Wicher H.; Well, Ad A. van; Dalgliesh, Robert M.; Langridge, Sean

    2010-01-08

    The Goos-Haenchen effect is a spatial shift along an interface resulting from an interference effect that occurs for total internal reflection. This phenomenon was suggested by Sir Isaac Newton, but it was not until 1947 that the effect was experimentally observed by Goos and Haenchen. We provide the first direct, absolute, experimental determination of the Goos-Haenchen shift for a particle experiencing a potential well as required by quantum mechanics: namely, wave-particle duality. Here, the particle is a spin-polarized neutron reflecting from a film of magnetized material. We detect the effect through a subtle change in polarization of the neutron. Here, we demonstrate, through experiment and theory, that neutrons do exhibit the Goos-Haenchen effect and postulate that the associated time shift should also be observable.

  1. Cosmic microwave background observables of small field models of inflation

    SciTech Connect

    Ben-Dayan, Ido; Brustein, Ram E-mail: ramyb@bgu.ac.il

    2010-09-01

    We construct a class of single small field models of inflation that can predict, contrary to popular wisdom, an observable gravitational wave signal in the cosmic microwave background anisotropies. The spectral index, its running, the tensor to scalar ratio and the number of e-folds can cover all the parameter space currently allowed by cosmological observations. A unique feature of models in this class is their ability to predict a negative spectral index running in accordance with recent cosmic microwave background observations. We discuss the new class of models from an effective field theory perspective and show that if the dimensionless trilinear coupling is small, as required for consistency, then the observed spectral index running implies a high scale of inflation and hence an observable gravitational wave signal. All the models share a distinct prediction of higher power at smaller scales, making them easy targets for detection.

  2. A cooperative control algorithm for camera based observational systems.

    SciTech Connect

    Young, Joseph G.

    2012-01-01

    Over the last several years, there has been considerable growth in camera based observation systems for a variety of safety, scientific, and recreational applications. In order to improve the effectiveness of these systems, we frequently desire the ability to increase the number of observed objects, but solving this problem is not as simple as adding more cameras. Quite often, there are economic or physical restrictions that prevent us from adding additional cameras to the system. As a result, we require methods that coordinate the tracking of objects between multiple cameras in an optimal way. In order to accomplish this goal, we present a new cooperative control algorithm for a camera based observational system. Specifically, we present a receding horizon control where we model the underlying optimal control problem as a mixed integer linear program. The benefit of this design is that we can coordinate the actions between each camera while simultaneously respecting its kinematics. In addition, we further improve the quality of our solution by coupling our algorithm with a Kalman filter. Through this integration, we not only add a predictive component to our control, but we use the uncertainty estimates provided by the filter to encourage the system to periodically observe any outliers in the observed area. This combined approach allows us to intelligently observe the entire region of interest in an effective and thorough manner.

  3. Shortwave Hyperspectral Observations During MAGIC Final Campaign...

    Office of Scientific and Technical Information (OSTI)

    Title: Shortwave Hyperspectral Observations During MAGIC Final Campaign Summary The Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign was initiated to improve our ...

  4. Rapid Scan AERI Observations: Benefits and Analysis

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Rapid Scan AERI Observations: Benefits and Analysis W. F. Feltz, D. D. Turner, R. O. ... Madison, Wisconsin D. D. Turner Pacific Northwest National Laboratory ...

  5. Aircraft S-HIS Observations during MPACE

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Aircraft S-HIS Observations during MPACE DeSlover, Daniel University of Wisconsin Holz, Robert University of Wisconsin, CIMMS Turner, David University of Wisconsin-Madison...

  6. Spacecraft surface charging within geosynchronous orbit observed...

    Office of Scientific and Technical Information (OSTI)

    Title: Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes: SPACECRAFT CHARGING ON VAN ALLEN PROBES Authors: Sarno-Smith, Lois K. 1 ; Larsen, ...

  7. ARM - Biomass Burning Observation Project (BBOP)

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    March 2013 BNL BBOP Website Contacts Larry Kleinman, Lead Scientist Arthur Sedlacek Biomass Burning Observation Project (BBOP) Biomass Burning Plants, trees, grass, brush, and...

  8. First Observation of Plasmarons in Graphene

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    First Observation of Plasmarons in Graphene Print An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1...

  9. Radioactivity in Precipitation: Methods and Observations from...

    Office of Environmental Management (EM)

    Radioactivity in Precipitation: Methods & Observations from Savannah River Site Dennis Jackson ...operatingops- experiencetritiumplant-info.html 14 15 DOE Nuclear & NRC ...

  10. Current Observational Constraints on Cosmic Doomsday (Technical...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Current Observational Constraints on Cosmic Doomsday In a broad class of dark energy models, the universe may collapse within a finite ...

  11. EA-1964: National Ecological Observation Network (NEON)

    Energy.gov [DOE]

    The National Science Foundation (NSF) prepared an EA that evaluated potential environmental impacts of the proposed National Ecological Observation Network (NEON), a continental-scale network of...

  12. Dynamics of Molecular Clouds: Observations, Simulations, and...

    Office of Scientific and Technical Information (OSTI)

    Simulations, and NIF Experiments Citation Details In-Document Search Title: Dynamics of Molecular Clouds: Observations, Simulations, and NIF Experiments You are ...

  13. Observing and modeling Earths energy flows

    SciTech Connect

    Stevens B.; Schwartz S.

    2012-05-11

    This article reviews, from the authors perspective, progress in observing and modeling energy flows in Earth's climate system. Emphasis is placed on the state of understanding of Earth's energy flows and their susceptibility to perturbations, with particular emphasis on the roles of clouds and aerosols. More accurate measurements of the total solar irradiance and the rate of change of ocean enthalpy help constrain individual components of the energy budget at the top of the atmosphere to within {+-}2 W m{sup -2}. The measurements demonstrate that Earth reflects substantially less solar radiation and emits more terrestrial radiation than was believed even a decade ago. Active remote sensing is helping to constrain the surface energy budget, but new estimates of downwelling surface irradiance that benefit from such methods are proving difficult to reconcile with existing precipitation climatologies. Overall, the energy budget at the surface is much more uncertain than at the top of the atmosphere. A decade of high-precision measurements of the energy budget at the top of the atmosphere is providing new opportunities to track Earth's energy flows on timescales ranging from days to years, and at very high spatial resolution. The measurements show that the principal limitation in the estimate of secular trends now lies in the natural variability of the Earth system itself. The forcing-feedback-response framework, which has developed to understand how changes in Earth's energy flows affect surface temperature, is reviewed in light of recent work that shows fast responses (adjustments) of the system are central to the definition of the effective forcing that results from a change in atmospheric composition. In many cases, the adjustment, rather than the characterization of the compositional perturbation (associated, for instance, with changing greenhouse gas concentrations, or aerosol burdens), limits accurate determination of the radiative forcing. Changes in clouds

  14. ARM - PI Product - Niamey Dust Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Dust Observations ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Niamey Dust ...

  15. First Direct Observation of Spinons and Holons

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    structure has remained elusive. Working at the ALS, a team of researchers from Korea, Japan, and the U.S. has now observed electron spin-charge separation in a one-dimensional...

  16. Collaborative Research: ARM observations for the development...

    Office of Scientific and Technical Information (OSTI)

    The principal focus of the observational component of this collaborative study during this funding period was on stratocumulus clouds over the SGP site and fair-weather cumuli over ...

  17. ARM - Field Campaign - Biomass Burning Observation Project -...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    govCampaignsBiomass Burning Observation Project - BBOP Campaign Links BBOP Website ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or...

  18. First Direct Observation of Spinons and Holons

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    check on the interpretation of the data-were not available. The current observations are direct and the results are unambiguous because they were obtained from a simple material...

  19. First Direct Observation of Spinons and Holons

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Working at the ALS, a team of researchers from Korea, Japan, and the U.S. has now observed ... Research conducted by B.J. Kim and S.-J. Oh (Seoul National University, Korea), H. Koh and ...

  20. Observations and simulations improve space weather models

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observations improve space weather models Observations and simulations improve space weather models Researchers used data from the Van Allen Probes to improve a three-dimensional model created by Los Alamos scientists called DREAM3D. June 25, 2014 NASA's Van Allen Probes sample the Earth's magnetosphere. NASA's Van Allen Probes sample the Earth's magnetosphere. The work demonstrated that DREAM3D accurately simulated the behavior of a complex and dynamic event in the radiation belt that was

  1. Observation of stars produced during cold fusion

    SciTech Connect

    Matsumoto, T. . Dept. of Nuclear Engineering)

    1992-12-01

    It has been indicated tht multiple-neutron nuclei such as quad-neutrons can be emitted during cold fusion. These multiple-neutrons might bombard the nuclei of materials outside a cold fusion cell to cause nuclear reactions. In this paper, observations of nuclear emulsions that were irradiated during a cold fusion experiment with heavy water and palladium foil are described. Various traces, like stars, showing nuclear reactions caused by the multiple-neutrons have been clearly observed.

  2. Arctic Lower Troposphere Observed Structure (ALTOS)

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Lower Troposphere Observed Structure (ALTOS) will raise and lower a heavily instrumented tethered balloon system at regular intervals in the lower 2 kilometers of the atmosphere at Oliktok Point. Data obtained during the ALTOS campaign will provide a statistically significant set of observed in situ cloud properties for validating retrieval algorithms and help scientists reduce the uncertainty in the radiative forcing and heating rates on hourly time scales. The data will also help researchers

  3. Opportunities for Sustained Arctic Observations and Scientific

    Office of Scientific and Technical Information (OSTI)

    Collaborations at the US Department of Energy Atmospheric Radiation Measurement (ARM) Facilities on the North Slope of Alaska. (Conference) | SciTech Connect Conference: Opportunities for Sustained Arctic Observations and Scientific Collaborations at the US Department of Energy Atmospheric Radiation Measurement (ARM) Facilities on the North Slope of Alaska. Citation Details In-Document Search Title: Opportunities for Sustained Arctic Observations and Scientific Collaborations at the US

  4. Selecting Observation Platforms for Optimized Anomaly Detectability under Unreliable Partial Observations

    SciTech Connect

    Wen-Chiao Lin; Humberto E. Garcia; Tae-Sic Yoo

    2011-06-01

    Diagnosers for keeping track on the occurrences of special events in the framework of unreliable partially observed discrete-event dynamical systems were developed in previous work. This paper considers observation platforms consisting of sensors that provide partial and unreliable observations and of diagnosers that analyze them. Diagnosers in observation platforms typically perform better as sensors providing the observations become more costly or increase in number. This paper proposes a methodology for finding an observation platform that achieves an optimal balance between cost and performance, while satisfying given observability requirements and constraints. Since this problem is generally computational hard in the framework considered, an observation platform optimization algorithm is utilized that uses two greedy heuristics, one myopic and another based on projected performances. These heuristics are sequentially executed in order to find best observation platforms. The developed algorithm is then applied to an observation platform optimization problem for a multi-unit-operation system. Results show that improved observation platforms can be found that may significantly reduce the observation platform cost but still yield acceptable performance for correctly inferring the occurrences of special events.

  5. OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS

    SciTech Connect

    Testa, Paola; DeLuca, Ed; Golub, Leon; Korreck, Kelly; Weber, Mark; De Pontieu, Bart; Martinez-Sykora, Juan; Title, Alan; Hansteen, Viggo; Cirtain, Jonathan; Winebarger, Amy; Kobayashi, Ken; Kuzin, Sergey; Walsh, Robert; DeForest, Craig

    2013-06-10

    The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial ({approx}0.''3-0.''4) and temporal (5.5 s) resolution. The Hi-C observations show in some moss regions variability on timescales down to {approx}15 s, significantly shorter than the minute-scale variability typically found in previous observations of moss, therefore challenging the conclusion of moss being heated in a mostly steady manner. These rapid variability moss regions are located at the footpoints of bright hot coronal loops observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly in the 94 A channel, and by the Hinode/X-Ray Telescope. The configuration of these loops is highly dynamic, and suggestive of slipping reconnection. We interpret these events as signatures of heating events associated with reconnection occurring in the overlying hot coronal loops, i.e., coronal nanoflares. We estimate the order of magnitude of the energy in these events to be of at least a few 10{sup 23} erg, also supporting the nanoflare scenario. These Hi-C observations suggest that future observations at comparable high spatial and temporal resolution, with more extensive temperature coverage, are required to determine the exact characteristics of the heating mechanism(s).

  6. Testing the copernican principle via cosmological observations

    SciTech Connect

    Bolejko, Krzysztof; Wyithe, J. Stuart B. E-mail: swyithe@unimelb.edu.au

    2009-02-15

    Observations of distances to Type-Ia supernovae can be explained by cosmological models that include either a gigaparsec-scale void, or a cosmic flow, without the need for Dark Energy. Instead of invoking dark energy, these inhomogeneous models instead violate the Copernican Principle. we show that current cosmological observations (Supernovae, Baryon Acoustic Oscillations and estimates of the Hubble parameters based on the age of the oldest stars) are not able to rule out inhomogeneous anti-Copernican models. The next generation of surveys for baryonic acoustic oscillations will be sufficiently precise to either validate the Copernican Principle or determine the existence of a local Gpc scale inhomogeneity.

  7. The ESSENCE Supernova Survey: Survey Optimization, Observations...

    Office of Scientific and Technical Information (OSTI)

    Ia SNe, at redshifts from 0.10 to 0.78, identified through an impartial, effective methodology for spectroscopic classification and redshift determination. We present the...

  8. Liquid Observation Well (LOW) Functional Design

    SciTech Connect

    Paul, B.

    1995-01-04

    This document presents the Functional Design Criteria for installing Liquid Observation Wells (LOWS) into single-shell tanks containing either ferrocyanide or organic waste. The LOWs will be designed to accommodate the deployment of gamma, neutron, and electromagnetic induction probes and to interface with the existing tank structure and environment.

  9. Cold fusion observed with ordinary water

    SciTech Connect

    Matsumoto, T. )

    1990-05-01

    This paper describes a cold fusion electrolysis experiment using ordinary water. A Ge(Li) detector is used to observe signals up to {approx}130 keV; these signals show the occurrence of fusion reactions in ordinary water. The mechanism for the emission of radiation is discussed by the Nattoh model.

  10. Interference phenomena observed during cold fusion

    SciTech Connect

    Matsumoto, T. )

    1992-03-01

    In this paper the interference phenomena of waves observed during a cold fusion experiment are described. Nuclear emissions have successfully recorded two different interference phenomena of waves from an electrolyzing cell. It is inferred that the waves might be gravitational and antigravitational waves, which can be expected to be radiated from gravity decays of quad-neutrons.

  11. Observational constraints on Tachyon and DBI inflation

    SciTech Connect

    Li, Sheng; Liddle, Andrew R. E-mail: arl@roe.ac.uk

    2014-03-01

    We present a systematic method for evaluation of perturbation observables in non-canonical single-field inflation models within the slow-roll approximation, which allied with field redefinitions enables predictions to be established for a wide range of models. We use this to investigate various non-canonical inflation models, including Tachyon inflation and DBI inflation. The Lambert W function will be used extensively in our method for the evaluation of observables. In the Tachyon case, in the slow-roll approximation the model can be approximated by a canonical field with a redefined potential, which yields predictions in better agreement with observations than the canonical equivalents. For DBI inflation models we consider contributions from both the scalar potential and the warp geometry. In the case of a quartic potential, we find a formula for the observables under both non-relativistic (sound speed c{sub s}{sup 2}?1) and relativistic behaviour (c{sub s}{sup 2}||1) of the scalar DBI inflaton. For a quadratic potential we find two branches in the non-relativistic c{sub s}{sup 2}?1 case, determined by the competition of model parameters, while for the relativistic case c{sub s}{sup 2}?0, we find consistency with results already in the literature. We present a comparison to the latest Planck satellite observations. Most of the non-canonical models we investigate, including the Tachyon, are better fits to data than canonical models with the same potential, but we find that DBI models in the slow-roll regime have difficulty in matching the data.

  12. HARPS-N OBSERVES THE SUN AS A STAR

    SciTech Connect

    Dumusque, Xavier; Glenday, Alex; Phillips, David F.; Charbonneau, David; Latham, David W.; Li, Chih-Hao; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald; Buchschacher, Nicolas; Lovis, Christophe; Pepe, Francesco; Udry, Stéphane; Cameron, Andrew Collier; Cecconi, Massimo; Cosentino, Rosario; Ghedina, Adriano; Lodi, Marcello; Molinari, Emilio

    2015-12-01

    Radial velocity (RV) perturbations induced by stellar surface inhomogeneities including spots, plages and granules currently limit the detection of Earth-twins using Doppler spectroscopy. Such stellar noise is poorly understood for stars other than the Sun because their surface is unresolved. In particular, the effects of stellar surface inhomogeneities on observed stellar radial velocities are extremely difficult to characterize, and thus developing optimal correction techniques to extract true stellar radial velocities is extremely challenging. In this paper, we present preliminary results of a solar telescope built to feed full-disk sunlight into the HARPS-N spectrograph, which is in turn calibrated with an astro-comb. This setup enables long-term observation of the Sun as a star with state-of-the-art sensitivity to RV changes. Over seven days of observing in 2014, we show an average 50 cm s{sup −1} RV rms over a few hours of observation. After correcting observed radial velocities for spot and plage perturbations using full-disk photometry of the Sun, we lower by a factor of two the weekly RV rms to 60 cm s{sup −1}. The solar telescope is now entering routine operation, and will observe the Sun every clear day for several hours. We will use these radial velocities combined with data from solar satellites to improve our understanding of stellar noise and develop optimal correction methods. If successful, these new methods should enable the detection of Venus over the next two to three years, thus demonstrating the possibility of detecting Earth-twins around other solar-like stars using the RV technique.

  13. Observational constraints on gauge field production in axion inflation

    SciTech Connect

    Meerburg, P.D.; Pajer, E. E-mail: enrico.pajer@gmail.com

    2013-02-01

    Models of axion inflation are particularly interesting since they provide a natural justification for the flatness of the potential over a super-Planckian distance, namely the approximate shift-symmetry of the inflaton. In addition, most of the observational consequences are directly related to this symmetry and hence are correlated. Large tensor modes can be accompanied by the observable effects of a the shift-symmetric coupling φF F-tilde to a gauge field. During inflation this coupling leads to a copious production of gauge quanta and consequently a very distinct modification of the primordial curvature perturbations. In this work we compare these predictions with observations. We find that the leading constraint on the model comes from the CMB power spectrum when considering both WMAP 7-year and ACT data. The bispectrum generated by the non-Gaussian inverse-decay of the gauge field leads to a comparable but slightly weaker constraint. There is also a constraint from μ-distortion using TRIS plus COBE/FIRAS data, but it is much weaker. Finally we comment on a generalization of the model to massive gauge fields. When the mass is generated by some light Higgs field, observably large local non-Gaussianity can be produced.

  14. First direct observation of muon antineutrino disappearance

    DOE PAGES [OSTI]

    Adamson, P.

    2011-07-05

    This letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν¯μ production, accumulating an exposure of 1.71 x 1020 protons on target. In the Far Detector, 97 charged current ν¯μ events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm¯2| = (3.36-0.40 +0.46(stat.) ± 0.06(syst.)) x 10-3 eV2, sin2(2 θ¯) = 0.86-0.12+0.11 (stat.) ± 0.01(syst.). The MINOS νμ and ν¯μ measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

  15. Strategy application, observability, and the choice combinator.

    SciTech Connect

    Winter, Victor Lono

    2004-03-01

    In many strategic systems, the choice combinator provides a powerful mechanism for controlling the application of rules and strategies to terms. The ability of the choice combinator to exercise control over rewriting is based on the premise that the success and failure of strategy application can be observed. In this paper we present a higher-order strategic framework with the ability to dynamically construct strategies containing the choice combinator. To this framework, a combinator called hide is introduced that prevents the successful application of a strategy from being observed by the choice combinator. We then explore the impact of this new combinator on a real-world problem involving a restricted implementation of the Java Virtual Machine.

  16. Self-potential observations during hydraulic fracturing

    SciTech Connect

    Moore, Jeffrey R.; Glaser, Steven D.

    2007-09-13

    The self-potential (SP) response during hydraulic fracturing of intact Sierra granite was investigated in the laboratory. Excellent correlation of pressure drop and SP suggests that the SP response is created primarily by electrokinetic coupling. For low pressures, the variation of SP with pressure drop is linear, indicating a constant coupling coefficient (Cc) of -200 mV/MPa. However for pressure drops >2 MPa, the magnitude of the Cc increases by 80% in an exponential trend. This increasing Cc is related to increasing permeability at high pore pressures caused by dilatancy of micro-cracks, and is explained by a decrease in the hydraulic tortuosity. Resistivity measurements reveal a decrease of 2% prior to hydraulic fracturing and a decrease of {approx}35% after fracturing. An asymmetric spatial SP response created by injectate diffusion into dilatant zones is observed prior to hydraulic fracturing, and in most cases this SP variation revealed the impending crack geometry seconds before failure. At rupture, injectate rushes into the new fracture area where the zeta potential is different than in the rock porosity, and an anomalous SP spike is observed. After fracturing, the spatial SP distribution reveals the direction of fracture propagation. Finally, during tensile cracking in a point load device with no water flow, a SP spike is observed that is caused by contact electrification. However, the time constant of this event is much less than that for transients observed during hydraulic fracturing, suggesting that SP created solely from material fracture does not contribute to the SP response during hydraulic fracturing.

  17. LNG Observer: Second Qatargas train goes onstream

    SciTech Connect

    1997-01-01

    The January-February, 1997 issue of the LNG Observer is presented. The following topics are discussed: second Qatargas train goes onstream; financing for the eighth Indonesian liquefaction train; Koreans take stakes in Oman LNG; US imports and exports of LNG in 1996; A 60% increase in proved reserves on the North West Shelf; proposals for Indian LNG terminal CEDIGAZ forecasts world LNG trade by 2010; growth for North African gas production and exports; and new forecast sees strong growth for Asian gas.

  18. Posters Ground-Based Radiometric Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    7 Posters Ground-Based Radiometric Observations of Atmospheric Water for Climate Research J. B. Snider, D. A. Hazen, A. J. Francavilla, W. B. Madsen, and M. D. Jacobson National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction Surface-based microwave and infrared radiometers have been employed by the National Oceanic and Atmospheric Administration's Environmental Technology Laboratory (NOAA/ETL) in climate research since 1987. The ability

  19. Quantum mechanics problems in observer's mathematics

    SciTech Connect

    Khots, Boris; Khots, Dmitriy

    2012-11-06

    This work considers the ontology, guiding equation, Schrodinger's equation, relation to the Born Rule, the conditional wave function of a subsystem in a setting of arithmetic, algebra and topology provided by Observer's Mathematics (see www.mathrelativity.com). Observer's Mathematics creates new arithmetic, algebra, geometry, topology, analysis and logic which do not contain the concept of continuum, but locally coincide with the standard fields. Certain results and communications pertaining to solutions of these problems are provided. In particular, we prove the following theorems: Theorem I (Two-slit interference). Let {Psi}{sub 1} be a wave from slit 1, {Psi}{sub 2} - from slit 2, and {Psi} = {Psi}{sub 1}+{Psi}{sub 2}. Then the probability of {Psi} being a wave equals to 0.5. Theorem II (k-bodies solution). For W{sub n} from m-observer point of view with m>log{sub 10}((2 Multiplication-Sign 10{sup 2n}-1){sup 2k}+1), the probability of standard expression of Hamiltonian variation is less than 1 and depends on n,m,k.

  20. Apparatus for observing a hostile environment

    DOEpatents

    Nance, Thomas A.; Boylston, Micah L.; Robinson, Casandra W.; Sexton, William C.; Heckendorn, Frank M.

    2000-01-01

    An apparatus is provided for observing a hostile environment, comprising a housing and a camera capable of insertion within the housing. The housing is a double wall assembly with an inner and outer wall with an hermetically sealed chamber therebetween. A housing for an optical system used to observe a hostile environment is provided, comprising a transparent, double wall assembly. The double wall assembly has an inner wall and an outer wall with an hermetically sealed chamber therebetween. The double wall assembly has an opening and a void area in communication with the opening. The void area of the housing is adapted to accommodate the optical system within said void area. An apparatus for protecting an optical system used to observe a hostile environment is provided comprising a housing; a tube positioned within the housing; and a base for supporting the housing and the tube. The housing comprises a double wall assembly having an inner wall and an outerwall with an hermetically sealed chamber therebetween. The tube is adapted to house the optical system therein.

  1. Observation of Stueckelberg oscillations in dipole-dipole interactions

    SciTech Connect

    Ditzhuijzen, C. S. E. van; Tauschinsky, Atreju; Van Linden van den Heuvell, H. B.

    2009-12-15

    We have observed Stueckelberg oscillations in the dipole-dipole interaction between Rydberg atoms with an externally applied radio-frequency field. The oscillating rf field brings the interaction between cold Rydberg atoms in two separated volumes into resonance. We observe multiphoton transitions when varying the amplitude of the rf field and the static electric field offset. The angular momentum states we use show a quadratic Stark shift, which leads to a fundamentally different behavior than linearly shifting states. Both cases are studied theoretically using the Floquet approach and are compared. The amplitude of the sidebands, related to the interaction strength, is given by the Bessel function in the linearly shifting case and by the generalized Bessel function in the quadratically shifting case. The oscillatory behavior of both functions corresponds to Stueckelberg oscillations, an interference effect described by the semiclassical Landau-Zener-Stueckelberg model. The measurements prove coherent dipole-dipole interaction during at least 0.6 mus.

  2. ARM: Aerosol Observing System (AOS): auxiliary data (Dataset...

    Office of Scientific and Technical Information (OSTI)

    Aerosol Observing System (AOS): auxiliary data Title: ARM: Aerosol Observing System (AOS): auxiliary data Aerosol Observing System (AOS): auxiliary data Authors: Ogren, John ; ...

  3. Direct observations of field-induced assemblies in magnetite ferrofluids

    SciTech Connect

    Mousavi, N. S. Susan; Khapli, Sachin D.; Kumar, Sunil

    2015-03-14

    Evolution of microstructures in magnetite-based ferrofluids with weak dipolar moments (particle size ≤ 10 nm) is studied with an emphasis on examining the effects of particle concentration (ϕ) and magnetic field strength (H) on the structures. Nanoparticles are dispersed in water at three different concentrations, ϕ = 0.15%, 0.48%, and 0.59% (w/v) [g/ml%] and exposed to uniform magnetic fields in the range of H = 0.05–0.42 T. Cryogenic transmission electron microscopy is employed to provide in-situ observations of the field-induced assemblies in such systems. As the magnetic field increases, the Brownian colloids are observed to form randomly distributed chains aligned in the field direction, followed by head-to-tail chain aggregation and then lateral aggregation of chains termed as zippering. By increasing the field in low concentration samples, the number of chains increases, though their length does not change dramatically. Increasing concentration increases the length of the linear particle assemblies in the presence of a fixed external magnetic field. Thickening of the chains due to zippering is observed at relatively high fields. Through a systematic variation of concentration and magnetic field strength, this study shows that both magnetic field strength and change in concentration can strongly influence formation of microstructures even in weak dipolar systems. Additionally, the results of two commonly used support films on electron microscopy grids, continuous carbon and holey carbon films, are compared. Holey carbon film allows us to create local regions of high concentrations that further assist the development of field-induced assemblies. The experimental observations provide a validation of the zippering effect and can be utilized in the development of models for thermophysical properties such as thermal conductivity.

  4. Validation in the Absence of Observed Events

    SciTech Connect

    Lathrop, John; Ezell, Barry

    2015-07-22

    Here our paper addresses the problem of validating models in the absence of observed events, in the area of Weapons of Mass Destruction terrorism risk assessment. We address that problem with a broadened definition of “Validation,” based on “backing up” to the reason why modelers and decision makers seek validation, and from that basis re-define validation as testing how well the model can advise decision makers in terrorism risk management decisions. We develop that into two conditions: Validation must be based on cues available in the observable world; and it must focus on what can be done to affect that observable world, i.e. risk management. That in turn leads to two foci: 1.) the risk generating process, 2.) best use of available data. Based on our experience with nine WMD terrorism risk assessment models, we then describe three best use of available data pitfalls: SME confidence bias, lack of SME cross-referencing, and problematic initiation rates. Those two foci and three pitfalls provide a basis from which we define validation in this context in terms of four tests -- Does the model: … capture initiation? … capture the sequence of events by which attack scenarios unfold? … consider unanticipated scenarios? … consider alternative causal chains? Finally, we corroborate our approach against three key validation tests from the DOD literature: Is the model a correct representation of the simuland? To what degree are the model results comparable to the real world? Over what range of inputs are the model results useful?

  5. Validation in the Absence of Observed Events

    DOE PAGES [OSTI]

    Lathrop, John; Ezell, Barry

    2015-07-22

    Here our paper addresses the problem of validating models in the absence of observed events, in the area of Weapons of Mass Destruction terrorism risk assessment. We address that problem with a broadened definition of “Validation,” based on “backing up” to the reason why modelers and decision makers seek validation, and from that basis re-define validation as testing how well the model can advise decision makers in terrorism risk management decisions. We develop that into two conditions: Validation must be based on cues available in the observable world; and it must focus on what can be done to affect thatmore » observable world, i.e. risk management. That in turn leads to two foci: 1.) the risk generating process, 2.) best use of available data. Based on our experience with nine WMD terrorism risk assessment models, we then describe three best use of available data pitfalls: SME confidence bias, lack of SME cross-referencing, and problematic initiation rates. Those two foci and three pitfalls provide a basis from which we define validation in this context in terms of four tests -- Does the model: … capture initiation? … capture the sequence of events by which attack scenarios unfold? … consider unanticipated scenarios? … consider alternative causal chains? Finally, we corroborate our approach against three key validation tests from the DOD literature: Is the model a correct representation of the simuland? To what degree are the model results comparable to the real world? Over what range of inputs are the model results useful?« less

  6. William Herschel, the First Observational Cosmologist

    ScienceCinema

    Lemonick, Michael [Princeton University and Time Magazine, Princeton, New Jersey, United States

    2016-07-12

    In the late 1700s, a composer, orchestra director and soloist named William Herschel became fascinated with astronomy, and, having built his own reflecting telescope, went out in his garden in Bath, England, one night and discovered Uranus—the first planet in human history ever found by an individual. The feat earned him a lifetime pension from King George III. But Herschel considered the discovery to be relatively unimportant in comparison to his real work: understanding the composition, structure and evolution of the universe. In pursuing that work, he became the first observational cosmologist.

  7. Direct Observation of Paramagnons in Palladium

    SciTech Connect

    Doubble, R.; Hayden, S M.; Dai, Pengcheng; Mook Jr, Herbert A; Thompson, James R; Frost, C.

    2010-01-01

    We report an inelastic neutron scattering study of the spin fluctuations in the nearly ferromagnetic element palladium. Dispersive over-damped collective magnetic excitations or 'paramagnons' are observed up to 128 meV. We analyze our results in terms of a Moriya-Lonzarich-type spin-fluctuation model and estimate the contribution of the spin fluctuations to the low-temperature heat capacity. In spite of the paramagnon excitations being relatively strong, their relaxation rates are large. This leads to a small contribution to the low-temperature electronic specific heat.

  8. Biomass Burning Observation Project Science Plan

    SciTech Connect

    Kleinman, KI; Sedlacek, AJ

    2013-09-01

    Aerosols from biomass burning perturb Earth’s climate through the direct radiative effect (both scattering and absorption) and through influences on cloud formation and precipitation and the semi-direct effect. Despite much effort, quantities important to determining radiative forcing such as the mass absorption coefficients (MAC) of light-absorbing carbon, secondary organic aerosol (SOA) formation rates, and cloud condensation nuclei (CCN) activity remain in doubt. Field campaigns in northern temperate latitudes have been overwhelmingly devoted to other aerosol sources in spite of biomass burning producing about one-third of the fine particles (PM2.5) in the U.S.

  9. Fermi LAT Observations of LS 5039

    SciTech Connect

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; /more authors..

    2012-03-29

    The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variability that is consistent with the binary period, with the emission being modulated with a period of 3.903 {+-} 0.005 days; the first detection of this modulation at GeV energies. The light curve is characterized by a broad peak around superior conjunction in agreement with inverse Compton scattering models. The spectrum is represented by a power law with an exponential cutoff, yielding an overall flux (100 MeV-300 GeV) of 4.9 {+-} 0.5(stat) {+-} 1.8(syst) x 10{sup -7} photon cm{sup -2} s{sup -1}, with a cutoff at 2.1 {+-} 0.3(stat) {+-} 1.1(syst) GeV and photon index {Gamma} = 1.9 {+-} 0.1(stat) {+-} 0.3(syst). The spectrum is observed to vary with orbital phase, specifically between inferior and superior conjunction. We suggest that the presence of a cutoff in the spectrum may be indicative of magnetospheric emission similar to the emission seen in many pulsars by Fermi.

  10. Reported Significant Observation (RSO) studies. Revision 1

    SciTech Connect

    Eicher, R.W.

    1992-12-01

    The Reported Significant Observation (RSO) study used in the field of safety is an information-gathering technique where employee-participants describe situations they have personally witnessed involving good and bad practices and safe and unsafe conditions. This information is useful in the risk assessment process because it focuses on hazards and thereby facilitates their elimination. However, RSO cannot be the only component in a risk assessment program. Used by the Air Force in their aviation psychology program and further developed by John C. Flanagan, RSO is more commonly known as the ``Critical Incident Technique.`` However, the words ``Critical`` and ``Incident`` had other connotations in nuclear safety, prompting early users within the Aerojet Nuclear Company to coin the more fitting title of ``Reported Significant Observations.`` The technique spread slowly in the safety field primarily because the majority of users were researchers interested in after-the-fact data, with application to everyday problems and behavioral factors. RSO was formally recognized as a significant hazard reduction tool during the development of the Management Oversight and Risk Tree (MORT) program for the US Atomic Energy Commission. The Department of Energy (DOE) has, in turn, adopted MORT for its system safety program, and this has resulted in RSO being a modern and viable technique for DOE contractor safety programs.

  11. METHYL CYANIDE OBSERVATIONS TOWARD MASSIVE PROTOSTARS

    SciTech Connect

    Rosero, V.; Hofner, P.; Kurtz, S.; Bieging, J.; Araya, E. D.

    2013-07-01

    We report the results of a survey in the CH{sub 3}CN J = 12 {yields} 11 transition toward a sample of massive proto-stellar candidates. The observations were carried out with the 10 m Submillimeter Telescope on Mount Graham, AZ. We detected this molecular line in 9 out of 21 observed sources. In six cases this is the first detection of this transition. We also obtained full beam sampled cross-scans for five sources which show that the lower K-components can be extended on the arcminute angular scale. The higher K-components, however, are always found to be compact with respect to our 36'' beam. A Boltzmann population diagram analysis of the central spectra indicates CH{sub 3}CN column densities of about 10{sup 14} cm{sup -2}, and rotational temperatures above 50 K, which confirms these sources as hot molecular cores. Independent fits to line velocity and width for the individual K-components resulted in the detection of an increasing blueshift with increasing line excitation for four sources. Comparison with mid-infrared (mid-IR) images from the SPITZER GLIMPSE/IRAC archive for six sources show that the CH{sub 3}CN emission is generally coincident with a bright mid-IR source. Our data clearly show that the CH{sub 3}CN J = 12 {yields} 11 transition is a good probe of the hot molecular gas near massive protostars, and provide the basis for future interferometric studies.

  12. Boundary Layer Cloudiness Parameterizations Using ARM Observations

    SciTech Connect

    Bruce Albrecht

    2004-09-15

    This study used DOE ARM data and facilities to: (1) study macroscopic properties of continental stratus clouds at SGP and the factors controlling these properties, (2) develop a scientific basis for understanding the processes responsible for the formation of boundary layer clouds using ARM observations in conjunction with simple parametric models and LES, and (3) evaluate cumulus cloud characteristics retrieved from the MMCR operating at TWP-Nauru. In addition we have used high resolution 94 GHz observations of boundary layer clouds and precipitation to: (1) develop techniques for using high temporal resolution Doppler velocities to study large-eddy circulations and turbulence in boundary layer clouds and estimate the limitations of using current and past MMCR data for boundary layer cloud studies, (2) evaluate the capability and limitations of the current MMCR data for estimating reflectivity, vertical velocities, and spectral under low- signal-to-noise conditions associated with weak no n-precipitating clouds, (3) develop possible sampling modes for the new MMCR processors to allow for adequate sampling of boundary layer clouds, and (4) retrieve updraft and downdraft structures under precipitating conditions.

  13. Multi-robot motion control for cooperative observation

    SciTech Connect

    Parker, L.E.

    1997-06-01

    An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring (or observing) the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement--determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, the authors investigate the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. They focus primarily on developing the distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. This paper first formalizes the problem and discusses related work. The authors then present a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level reasoning control based on the ALLIANCE formalism. They analyze the effectiveness of the approach by comparing it to 3 other feasible algorithms for cooperative control, showing the superiority of the approach for a large class of problems.

  14. First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign

    DOE PAGES [OSTI]

    Furniss, Amy

    2015-10-08

    We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by amore » sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.« less

  15. First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign

    SciTech Connect

    Furniss, Amy

    2015-10-08

    We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.

  16. Observations of secondary emission chamber degradation from very high intensity proton beams at the AGS

    SciTech Connect

    Brown, K.A.; Chiang, I.H.; Pendzick, A.; Tallerico, T.

    1997-08-01

    Degradation of Secondary Emission Chamber (SEC) efficiencies has been seen in the past. As a result, instruments in use today are built to minimize any such effects. With beam intensities as high as 6 x 10{sup 13} protons per pulse incident on these devices the authors are again observing significant degradation in SEC efficiencies. In this report the authors will present observations of these effects and methods they have developed to cope with them.

  17. Head Observation Organizer (HObO)

    SciTech Connect

    Steven Predmore

    2008-03-06

    The Head Observation Organizer, HObO, is a computer program that stores and manages measured ground-water levels. HObO was developed to help ground-water modelers compile, manage, and document water-level data needed to calibrate ground-water models. Well-construction and water-level data from the U.S. Geological Survey National Water Database (NWIS) easily can be imported into HObO from the NWIS web site (NWISWeb). The water-level data can be flagged to determine which data will be included in the calibration data set. The utility program HObO_NWISWeb was developed to simplify the down loading of well and water-level data from NWISWeb. An ArcGIS NWISWeb Extension was developed to retrieve site information from NWISWeb. A tutorial is presented showing the basic elements of HObO.

  18. Observed parity-odd CMB temperature bispectrum

    SciTech Connect

    Shiraishi, Maresuke; Liguori, Michele; Fergusson, James R. E-mail: michele.liguori@pd.infn.it

    2015-01-01

    Parity-odd non-Gaussianities create a variety of temperature bispectra in the cosmic microwave background (CMB), defined in the domain: ℓ{sub 1} + ℓ{sub 2} + ℓ{sub 3} = odd. These models are yet unconstrained in the literature, that so far focused exclusively on the more common parity-even scenarios. In this work, we provide the first experimental constraints on parity-odd bispectrum signals in WMAP 9-year temperature data, using a separable modal parity-odd estimator. Comparing theoretical bispectrum templates to the observed bispectrum, we place constraints on the so-called nonlineality parameters of parity-odd tensor non-Gaussianities predicted by several Early Universe models. Our technique also generates a model-independent, smoothed reconstruction of the bispectrum of the data for parity-odd configurations.

  19. Global Volunteer Observing Ship (VOS) Program Data

    DOE Data Explorer

    CDIAC provides data management support for the Global Volunteer Observing Ship (VOS) Program. The VOS project is coordinated by the UNESCO International Ocean Carbon Coordination Project (IOCCP). The international groups from 14 countries have been outfitting research ships and commercial vessels with automated CO2 sampling equipment to analyze the carbon exchange between the ocean and atmosphere. [copied from http://cdiac.ornl.gov/oceans/genInfo.html] CDIAC provides a map interface with the shipping routes of the 14 countries involved marked in different colors. Clicking on the ship's name on that route brings up information about the vessel, the kinds of measurements collected and the timeframe, links to project pages, and, most important, the links to the data files themselves. The 14 countries are: United States, United Kingdom, Japan, France, Germany, Australia, Canada, Spain, Norway, New Zealand, China (including Taiwan), Iceland, and the Netherlands. Both archived and current, underway data can be accessed from the CDIAC VOS page.

  20. THE SIMPLE SURVEY: OBSERVATIONS, REDUCTION, AND CATALOG

    SciTech Connect

    Damen, M.; Franx, M.; Taylor, E. N.; Labbe, I.; Van Dokkum, P. G.; Muzzin, A.; Brandt, W. N.; Dickinson, M.; Gawiser, E.; Illingworth, G. D.; Marchesini, D.; Papovich, C.; Rix, H.-W.

    2011-01-20

    We present the Spitzer IRAC/MUSYC Public Legacy Survey in the Extended CDF-South (SIMPLE), which consists of deep IRAC observations covering the {approx}1600 arcmin{sup 2} area surrounding GOODS-S. The limiting magnitudes of the SIMPLE IRAC mosaics typically are 23.8, 23.6, 21.9, and 21.7, at 3.6 {mu}m, 4.5 {mu}m, 5.8 {mu}m, and 8.0 {mu}m, respectively (5{sigma} total point source magnitudes in AB). The SIMPLE IRAC images are combined with the 10' x 15' GOODS IRAC mosaics in the center. We give detailed descriptions of the observations, data reduction, and properties of the final images, as well as the detection and photometry methods used to build a catalog. Using published optical and near-infrared data from the Multiwavelength Survey by Yale-Chile (MUSYC), we construct an IRAC-selected catalog, containing photometry in UBVRIz'JHK, [3.6 {mu}m], [4.5 {mu}m], [5.8 {mu}m], and [8.0 {mu}m]. The catalog contains 43,782 sources with S/N >5 at 3.6 {mu}m, 19,993 of which have 13-band photometry. We compare this catalog to the publicly available MUSYC and FIREWORKS catalogs and discuss the differences. Using a high signal-to-noise sub-sample of 3391 sources with ([3.6] + [4.5])/2 < 21.2, we investigate the star formation rate history of massive galaxies out to z {approx} 1.8. We find that at z {approx} 1.8 at least 30% {+-} 7% of the most massive galaxies (M{sub *} >10{sup 11} M{sub sun}) are passively evolving, in agreement with earlier results from surveys covering less area.

  1. SPITZER OBSERVATIONS OF HOTSPOTS IN RADIO LOBES

    SciTech Connect

    Werner, Michael W.; Murphy, David W.; Livingston, John H.; Gorjian, Varoujan; Jones, Dayton L.; Meier, David L.; Lawrence, Charles R.

    2012-11-10

    We have carried out a systematic search with Spitzer Warm Mission and archival data for infrared emission from the hotspots in radio lobes that have been described by Hardcastle et al. These hotspots have been detected with both radio and X-ray observations, but an observation at an intermediate frequency in the infrared can be critical to distinguish between competing models for particle acceleration and radiation processes in these objects. Between the archival and warm mission data, we report detections of 18 hotspots; the archival data generally include detections at all four IRAC bands, the Warm Mission data only at 3.6 {mu}m. Using a theoretical formalism adopted from Godfrey et al., we fit both archival and warm mission spectral energy distributions (SEDs)-including radio, X-ray, and optical data from Hardcastle as well as the Spitzer data-with a synchrotron self-Compton (SSC) model, in which the X-rays are produced by Compton scattering of the radio frequency photons by the energetic electrons which radiate them. With one exception, an SSC model requires that the magnetic field be less or much less than the equipartition value which minimizes total energy and has comparable amounts of energy in the magnetic field and in the energetic particles. This conclusion agrees with those of comparable recent studies of hotspots, and with the analysis presented by Hardcastle et al. We also show that the infrared data rule out the simplest synchrotron-only models for the SEDs. We briefly discuss the implications of these results and of alternate interpretations of the data.

  2. Resolved multifrequency radio observations of GG Tau

    SciTech Connect

    Andrews, Sean M.; Birnstiel, T.; Rosenfeld, K. A.; Wilner, D. J.; Chandler, Claire J.; Pérez, L. M.; Isella, Andrea; Ricci, L.; Carpenter, J. M.; Calvet, N.; Corder, S. A.; Deller, A. T.; Dullemond, C. P.; Greaves, J. S.; Harris, R. J.; Henning, Th.; Linz, H.; Kwon, W.; Lazio, J.; Mundy, L. G.; and others

    2014-06-01

    We present subarcsecond resolution observations of continuum emission associated with the GG Tau quadruple star system at wavelengths of 1.3, 2.8, 7.3, and 50 mm. These data confirm that the GG Tau A binary is encircled by a circumbinary ring at a radius of 235 AU with a FWHM width of ∼60 AU. We find no clear evidence for a radial gradient in the spectral shape of the ring, suggesting that the particle size distribution is spatially homogeneous on angular scales ≳0.''1. A central point source, likely associated with the primary component (GG Tau Aa), exhibits a composite spectrum from dust and free-free emission. Faint emission at 7.3 mm is observed toward the low-mass star GG Tau Ba, although its origin remains uncertain. Using these measurements of the resolved, multifrequency emission structure of the GG Tau A system, models of the far-infrared to radio spectrum are developed to place constraints on the grain size distribution and dust mass in the circumbinary ring. The non-negligible curvature present in the ring spectrum implies a maximum particle size of 1-10 mm, although we are unable to place strong constraints on the distribution shape. The corresponding dust mass is 30-300 M {sub ⊕}, at a temperature of 20-30 K. We discuss how this significant concentration of relatively large particles in a narrow ring at a large radius might be produced in a local region of higher gas pressures (i.e., a particle 'trap') located near the inner edge of the circumbinary disk.

  3. How does pressure gravitate? Cosmological constant problem confronts observational cosmology

    SciTech Connect

    Narimani, Ali; Scott, Douglas; Afshordi, Niayesh E-mail: nafshordi@pitp.ca

    2014-08-01

    An important and long-standing puzzle in the history of modern physics is the gross inconsistency between theoretical expectations and cosmological observations of the vacuum energy density, by at least 60 orders of magnitude, otherwise known as the cosmological constant problem. A characteristic feature of vacuum energy is that it has a pressure with the same amplitude, but opposite sign to its energy density, while all the precision tests of General Relativity are either in vacuum, or for media with negligible pressure. Therefore, one may wonder whether an anomalous coupling to pressure might be responsible for decoupling vacuum from gravity. We test this possibility in the context of the Gravitational Aether proposal, using current cosmological observations, which probe the gravity of relativistic pressure in the radiation era. Interestingly, we find that the best fit for anomalous pressure coupling is about half-way between General Relativity (GR), and Gravitational Aether (GA), if we include Planck together with WMAP and BICEP2 polarization cosmic microwave background (CMB) observations. Taken at face value, this data combination excludes both GR and GA at around the 3 σ level. However, including higher resolution CMB observations (''highL'') or baryonic acoustic oscillations (BAO) pushes the best fit closer to GR, excluding the Gravitational Aether solution to the cosmological constant problem at the 4- 5 σ level. This constraint effectively places a limit on the anomalous coupling to pressure in the parametrized post-Newtonian (PPN) expansion, ζ{sub 4} = 0.105 ± 0.049 (+highL CMB), or ζ{sub 4} = 0.066 ± 0.039 (+BAO). These represent the most precise measurement of this parameter to date, indicating a mild tension with GR (for ΛCDM including tensors, with 0ζ{sub 4}=), and also among different data sets.

  4. Nonperturbative QCD corrections to electroweak observables

    SciTech Connect

    Dru B Renner, Xu Feng, Karl Jansen, Marcus Petschlies

    2011-12-01

    Nonperturbative QCD corrections are important to many low-energy electroweak observables, for example the muon magnetic moment. However, hadronic corrections also play a significant role at much higher energies due to their impact on the running of standard model parameters, such as the electromagnetic coupling. Currently, these hadronic contributions are accounted for by a combination of experimental measurements and phenomenological modeling but ideally should be calculated from first principles. Recent developments indicate that many of the most important hadronic corrections may be feasibly calculated using lattice QCD methods. To illustrate this, we will examine the lattice computation of the leading-order QCD corrections to the muon magnetic moment, paying particular attention to a recently developed method but also reviewing the results from other calculations. We will then continue with several examples that demonstrate the potential impact of the new approach: the leading-order corrections to the electron and tau magnetic moments, the running of the electromagnetic coupling, and a class of the next-to-leading-order corrections for the muon magnetic moment. Along the way, we will mention applications to the Adler function, the determination of the strong coupling constant and QCD corrections to muonic-hydrogen.

  5. Observation of Single Top Quark Production

    SciTech Connect

    Gerber, Cecilia E.; /Illinois U., Chicago

    2009-09-01

    The author reports on the observation of electroweak production of single top quarks in p{bar p} collisions at {radical}s = 1.96 Tev using 2.3 fb{sup -1} of data collected with the D0 detector at the fermilab Tevatron Collider. Using events containing an isolated electron or muon, missing transverse energy, two, three or four jets, with one or two of them identified as originating from the fragmentation of a b quark, the measured cross section for the process p{bar p} {yields} tb + X, tqb + X is 3.94 {+-} 0.88 pb (for a top quark mass of 170 GeV). the probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10{sup -7}, corresponding to a 5.0 standard deviation significance. Using the same dataset, the measured cross sections for the t- and the s-channel processes when determined simultaneously with no assumption on their relative production rate are 3.14{sub -0.80}{sup +0.94} pb and 1.05 {+-} 0.81 pb respectively, consistent with standard model expectations. The measured t-channel cross section has a significance of 4.8 standard deviations, representing the first evidence for the production of an individual single top process to be detected.

  6. Optical monitor for observing turbulent flow

    DOEpatents

    Albrecht, Georg F.; Moore, Thomas R.

    1992-01-01

    The present invention provides an apparatus and method for non-invasively monitoring turbulent fluid flows including anisotropic flows. The present invention uses an optical technique to filter out the rays travelling in a straight line, while transmitting rays with turbulence induced fluctuations in time. The output is two dimensional, and can provide data regarding the spectral intensity distribution, or a view of the turbulence in real time. The optical monitor of the present invention comprises a laser that produces a coherent output beam that is directed through a fluid flow, which phase-modulates the beam. The beam is applied to a temporal filter that filters out the rays in the beam that are straight, while substantially transmitting the fluctuating, turbulence-induced rays. The temporal filter includes a lens and a photorefractive crystal such as BaTiO.sub.3 that is positioned in the converging section of the beam near the focal plane. An imaging system is used to observe the filtered beam. The imaging system may take a photograph, or it may include a real time camera that is connected to a computer. The present invention may be used for many purposes including research and design in aeronautics, hydrodynamics, and combustion.

  7. Observational tests for ?(t)CDM cosmology

    SciTech Connect

    Pigozzo, C.; Carneiro, S.; Dantas, M.A.; Alcaniz, J.S. E-mail: aldinez@on.br E-mail: alcaniz@on.br

    2011-08-01

    We investigate the observational viability of a class of cosmological models in which the vacuum energy density decays linearly with the Hubble parameter, resulting in a production of cold dark matter particles at late times. Similarly to the flat ?CDM case, there is only one free parameter to be adjusted by the data in this class of ?(t)CDM scenarios, namely, the matter density parameter. To perform our analysis we use three of the most recent SNe Ia compilation sets (Union2, SDSS and Constitution) along with the current measurements of distance to the BAO peaks at z = 0.2 and z = 0.35 and the position of the first acoustic peak of the CMB power spectrum. We show that in terms of ?{sup 2} statistics both models provide good fits to the data and similar results. A quantitative analysis discussing the differences in parameter estimation due to SNe light-curve fitting methods (SALT2 and MLCS2k2) is studied using the current SDSS and Constitution SNe Ia compilations. A matter power spectrum analysis using the 2dFGRS is also performed, providing a very good concordance with the constraints from the SDSS and Constitution MLCS2k2 data.

  8. Observations on the sliding wear of ceramics

    SciTech Connect

    Yust, C.S.; Carignan, F.J.

    1984-01-01

    Modern design concepts for heat engines with increased thermal efficiency call for the utilization of ceramic components. In some applications, lubrication of these components will be difficult to maintain. Consequently, a need exists for an expanded understanding of the dry sliding wear behavior of ceramics. Sliding wear experiments were performed on several ceramic pairs (ZrO/sub 2/, Al/sub 2/O/sub 3/, Si/sub 3/N/sub 4/, SiC) from which wear rate data and information on the nature of the physical damage resulting from dry sliding were obtained. The wear evaluation was a pin-on-disc test. The test conditions included temperatures as high as 425/sup 0/C, a surface velocity of 0.3 m/s, and a normal force of 9.0 N. Most of the specimens experienced moderate to severe damage. Damage characterized as mild wear was observed in a single room temperature test. The coefficient of friction for the damaged specimens ranged from 0.7 to 1.0, while this value was consistently 0.24 for the undamaged specimen. The implications of these results for wear mechanisms are discussed.

  9. Observables can be tailored to change the entanglement of any pure state

    SciTech Connect

    Harshman, N. L.; Ranade, Kedar S.

    2011-07-15

    We show that, for a finite-dimensional Hilbert space, there exist observables that induce a tensor product structure such that the entanglement properties of any pure state can be tailored. In particular, we provide an explicit, finite method for constructing observables in an unstructured d-dimensional system so that an arbitrary known pure state has any Schmidt decomposition with respect to an induced bipartite tensor product structure. In effect, this article demonstrates that, in a finite-dimensional Hilbert space, entanglement properties can always be shifted from the state to the observables and all pure states are equivalent as entanglement resources in the ideal case of complete control of observables.

  10. ARCADE 2 OBSERVATIONS OF GALACTIC RADIO EMISSION

    SciTech Connect

    Kogut, A.; Fixsen, D. J.; Mirel, P.; Wollack, E.; Levin, S. M.; Limon, M.; Seiffert, M.; Lubin, P. M.; Singal, J.; Villela, T.; Wuensche, C. A.

    2011-06-10

    We use absolutely calibrated data from the ARCADE 2 flight in 2006 July to model Galactic emission at frequencies 3, 8, and 10 GHz. The spatial structure in the data is consistent with a superposition of free-free and synchrotron emission. Emission with spatial morphology traced by the Haslam 408 MHz survey has spectral index {beta}{sub synch} = -2.5 {+-} 0.1, with free-free emission contributing 0.10 {+-} 0.01 of the total Galactic plane emission in the lowest ARCADE 2 band at 3.15 GHz. We estimate the total Galactic emission toward the polar caps using either a simple plane-parallel model with csc |b| dependence or a model of high-latitude radio emission traced by the COBE/FIRAS map of C II emission. Both methods are consistent with a single power law over the frequency range 22 MHz to 10 GHz, with total Galactic emission toward the north polar cap T{sub Gal} = 10.12 {+-} 0.90 K and spectral index {beta} = -2.55 {+-} 0.03 at reference frequency 0.31 GHz. Emission associated with the plane-parallel structure accounts for only 30% of the observed high-latitude sky temperature, with the residual in either a Galactic halo or an isotropic extragalactic background. The well-calibrated ARCADE 2 maps provide a new test for spinning dust emission, based on the integrated intensity of emission from the Galactic plane instead of cross-correlations with the thermal dust spatial morphology. The Galactic plane intensity measured by ARCADE 2 is fainter than predicted by models without spinning dust and is consistent with spinning dust contributing 0.4 {+-} 0.1 of the Galactic plane emission at 23 GHz.

  11. Effects of phenylpropanolamine (PPA) on in vitro human erythrocyte membranes and molecular models

    SciTech Connect

    Suwalsky, Mario; Zambrano, Pablo; Mennickent, Sigrid; Villena, Fernando; Sotomayor, Carlos P.; Aguilar, Luis F.; Bolognin, Silvia

    2011-03-18

    Research highlights: {yields} PPA is a common ingredient in cough-cold medication and appetite suppressants. {yields} Reports on its effects on human erythrocytes are very scarce. {yields} We found that PPA induced in vitro morphological changes to human erythrocytes. {yields} PPA interacted with isolated unsealed human erythrocyte membranes. {yields} PPA interacted with class of lipid present in the erythrocyte membrane outer monolayer. -- Abstract: Norephedrine, also called phenylpropanolamine (PPA), is a synthetic form of the ephedrine alkaloid. After reports of the occurrence of intracranial hemorrhage and other adverse effects, including several deaths, PPA is no longer sold in USA and Canada. Despite the extensive information about PPA toxicity, reports on its effects on cell membranes are scarce. With the aim to better understand the molecular mechanisms of the interaction of PPA with cell membranes, ranges of concentrations were incubated with intact human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), and molecular models of cell membranes. The latter consisted in bilayers built-up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), phospholipid classes present in the outer and inner monolayers of most plasmatic cell membranes, respectively. The capacity of PPA to perturb the bilayer structures of DMPC and DMPE was assessed by X-ray diffraction, DMPC large unilamellar vesicles (LUV) and IUM were studied by fluorescence spectroscopy, and intact human erythrocytes were observed by scanning electron microscopy (SEM). This study presents evidence that PPA affects human red cell membranes as follows: (a) in SEM studies on human erythrocytes it was observed that 0.5 mM PPA induced shape changes; (b) in IUM PPA induced a sharp decrease in the fluorescence anisotropy in the lipid bilayer acyl chains in a concentration range lower than 100 {mu}M; (c) X-ray diffraction studies showed that PPA in the 0.1-0.5 m

  12. The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign Citation Details In-Document Search Title: The Arctic Lower Troposphere Observed Structure ...

  13. Aided by Simulations, Scientists Observe Atomic Collapse State

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Collapse State Observed Aided by Simulations, Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013...

  14. Observation of a Macroscopically Quantum-Entangled Insulator

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observation of a Macroscopically Quantum-Entangled Insulator Observation of a Macroscopically Quantum-Entangled Insulator Print Wednesday, 27 May 2009 00:00 It has recently been...

  15. SOLAR H{alpha} OSCILLATIONS FROM INTENSITY AND DOPPLER OBSERVATIONS...

    Office of Scientific and Technical Information (OSTI)

    SOLAR Halpha OSCILLATIONS FROM INTENSITY AND DOPPLER OBSERVATIONS Citation Details In-Document Search Title: SOLAR Halpha OSCILLATIONS FROM INTENSITY AND DOPPLER OBSERVATIONS ...

  16. ARM - Field Campaign - Arctic Lower Troposphere Observed Structure...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    govCampaignsArctic Lower Troposphere Observed Structure (ALTOS) Campaign Links Science Plan ALTOS Website Related Campaigns Supplement to Arctic Lower Troposphere Observed...

  17. Observational Constraints on the Nature of the Dark Energy: First...

    Office of Scientific and Technical Information (OSTI)

    Observational Constraints on the Nature of the Dark Energy: First Cosmological Results From the ESSENCE Supernova Survey Citation Details In-Document Search Title: Observational...

  18. ARM: Aerosol Observing System (AOS): cloud condensation nuclei...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Aerosol Observing System (AOS): cloud condensation nuclei data Aerosol Observing System (AOS): cloud condensation nuclei data Authors: Scott Smith ; Cynthia Salwen ; ...

  19. Measurements and Observations on Adhesion to Brittle Materials...

    Office of Scientific and Technical Information (OSTI)

    Measurements and Observations on Adhesion to Brittle Materials. Citation Details In-Document Search Title: Measurements and Observations on Adhesion to Brittle Materials. Abstract ...

  20. Biomass Burning Observation Project (BBOP) Final Campaign Report...

    Office of Scientific and Technical Information (OSTI)

    Biomass Burning Observation Project (BBOP) Final Campaign Report Citation Details In-Document Search Title: Biomass Burning Observation Project (BBOP) Final Campaign Report The Biomass ...

  1. USGS-Earth Resources Observation and Science (EROS) Center |...

    OpenEI (Open Energy Information) [EERE & EIA]

    USGS-Earth Resources Observation and Science (EROS) Center Jump to: navigation, search Tool Summary LAUNCH TOOL Name: USGS-Earth Resources Observation and Science (EROS) Center...

  2. Insights from modeling and observational evaluation of a precipitating...

    Office of Scientific and Technical Information (OSTI)

    Insights from modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign Title: Insights from modeling and ...

  3. Note: Coherent resonances observed in the dissociative electron...

    Office of Scientific and Technical Information (OSTI)

    Note: Coherent resonances observed in the dissociative electron attachment to carbon monoxide Citation Details In-Document Search Title: Note: Coherent resonances observed in the ...

  4. An observational study of entrainment rate in deep convection

    SciTech Connect

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal, gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.

  5. Confronting DGP braneworld gravity with cosmico observations after Planck data

    SciTech Connect

    Xu, Lixin

    2014-02-01

    The normal branch of Dvali-Gabadadze-Porrati braneworld gravity with brane tension is confronted by the currently available cosmic observations from the geometrical and dynamical perspectives. On the geometrical side, the type Ia supernova as standard candle, the baryon acoustic oscillation as standard ruler and the cosmic microwave background measurement from the first released 15.5 months data were used to fix the background evolutions. On the dynamical side, the redshift space distortion data will be used to determine the evolution of the matter perturbation. Through a Markov chain Monte Carlo analysis, we found the dimensionless crossover scale ?{sub r{sub c}} = 1/(4H{sup 2}{sub 0}r{sup 2}{sub c}) = 0.00183{sub ?0.00183}{sup +0.000338} in a spatially flat normal branch of Dvali-Gabadadze-Porrati braneworld. This result suggests that the crossover scale r{sub c} should be around 12H{sup ?1}{sub 0} which is consistent with the previous result r{sub c} > 3H{sup ?1}{sub 0} and greater. It also implies that the five-dimensional gravity effect is weak to be observed in H{sup ?1}{sub 0} scale.

  6. An observational study of entrainment rate in deep convection

    DOE PAGES [OSTI]

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal,more » gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.« less

  7. Rayleigh scattering: blue sky thinking for future CMB observations

    SciTech Connect

    Lewis, Antony

    2013-08-01

    Rayleigh scattering from neutral hydrogen during and shortly after recombination causes the CMB anisotropies to be significantly frequency dependent at high frequencies. This may be detectable with Planck, and would be a strong signal in any future space-based CMB missions. The later peak of the Rayleigh visibility compared to Thomson scattering gives an increased large-scale CMB polarization signal that is a greater than 4% effect for observed frequencies ν ∼> 500GHz. There is a similar magnitude suppression on small scales from additional damping. Due to strong correlation between the Rayleigh and primary signal, measurement of the Rayleigh component is limited by noise and foregrounds, not cosmic variance of the primary CMB, and should observable over a wide range of angular scales at frequencies 200GHz ∼< ν ∼< 800GHz. I give new numerical calculations of the temperature and polarization power spectra, and show that future CMB missions could measure the temperature Rayleigh cross-spectrum at high precision, detect the polarization from Rayleigh scattering, and also accurately determine the cross-spectra between the Rayleigh temperature signal and primary polarization. The Rayleigh scattering signal may provide a powerful consistency check on recombination physics. In principle it can be used to measure additional horizon-scale primordial perturbation modes at recombination, and distinguish a significant tensor mode B-polarization signal from gravitational lensing at the power spectrum level.

  8. Effect of doping of tin on optoelectronic properties of indium oxide: DFT study

    SciTech Connect

    Tripathi, Madhvendra Nath

    2015-06-24

    Indium tin oxide is widely used transparent conductor. Experimentally observed that 6% tin doping in indium oxide is suitable for optoelectronic applications and more doping beyond this limit degrades the optoelectronic property. The stoichiometry (In{sub 32-x}Sn{sub x}O{sub 48+x/2}; x=0-6) is taken to understand the change in lattice parameter, electronic structure, and optical property of ITO. It is observed that lattice parameter increases and becomes constant after 6% tin doping that is in good agreement of the experimental observation. The electronic structure calculation shows that the high tin doping in indium oxide adversely affects the dispersive nature of the bottom of conduction band of pure indium oxide and decreases the carrier mobility. Optical calculations show that transmittance goes down upto 60% for the tin concentration more than 6%. The present paper shows that how more than 6% tin doping in indium oxide adversely affects the optoelectronic property of ITO.

  9. Trading places - an innovative SO{sub 2} trading program to mitigate potential adverse impacts on class I areas: part II. Mitigation plan

    SciTech Connect

    Louis Militana; Cindy Huber; Christopher Colbert; Chris Arrington; Don Shepherd

    2005-08-01

    This is the second of two articles describing a plan that was developed to mitigate the effects of acid deposition and visibility impairment in four Class I areas from the proposed Longview Power Project. Part I (published in July 2005) discussed the air quality impacts of the proposed coal-fired power plant. Part II discusses the mitigation plan. 2 refs., 1 fig., 3 tabs.

  10. Short-Term Effects of Ankaferd Hemostat for Renal Artery Embolization: An Experimental Study

    SciTech Connect

    Ozbek, Orhan; Acar, Kadir; Koc, Osman; Saritas, Kadir; Toy, Hatice; Solak, Yalcin; Ozbek, Seda; Kucukapan, Ahmet; Guler, Ibrahim; Gaipov, Abduzhappar; Turk, Suleyman; Haznedaroglu, Ibrahim Celaleddin

    2013-04-15

    Renal artery embolization (RAE) is a minimally invasive therapeutic technique that is utilized in a number of disorders. Ankaferd is a novel hemostatic agent with a new mechanism of action independent of clotting factors. We used Ankaferd for RAE in a sheep model. Seven adult female sheep were included in the study. Selective renal arteriogram using 5-F diagnostic catheter was performed to make sure that each kidney was fed by a single renal artery and the animal had normal renal vasculature. Coaxial 2.7-F microcatheter was advanced to the distal main renal artery. Under fluoroscopic guidance, 2 mL of Ankaferd mixed with 2 mL of nonionic iodinated contrast agent was slowly injected. Fluoroscopy was used to observe the deceleration of flow and stagnation. Control renal angiograms were performed just after embolization. After the procedure, the animals were observed for 1 day and then sacrificed with intravenous sodium thiopental. The technical success was observed in seven of the seven animals.. After embolization procedure, none of the animals died or experienced a major systemic adverse event. On macroscopic examination of the embolized kidneys, thrombus at the level of main renal artery formed after Ankaferd embolization was more compact compared with the thrombi that was not Ankaferd-associated, which was observed elsewhere. Microscopically, majority of the renal tubular cells (80-90 %) were necrotic, and there was epithelial cell damage in a small portion of the cells (10-20 %). RAE was safe and effective in the short-term with Ankaferd in studied animals. Further studies should be conducted to better delineate the embolizing potential of this novel hemostatic agent.

  11. License renewal demonstration program: NRC observations and lessons learned

    SciTech Connect

    Prato, R.J.; Kuo, P.T.; Newberry, S.F.

    1996-12-01

    This report summarizes the Nuclear Regulatory Commission staff`s observations and lessons learned from the five License Renewal Demonstration Program (LRDP) site visits performed by the staff from March 25, 1996, through August 16, 1996. The LRDP was a Nuclear Energy Institute (NEI) program intended to assess the effectiveness of the guidance provided by NEI 95-10, Revision 0, {open_quotes}Industry Guideline for Implementing the Requirements of 10 CFR Part 54 - The License Renewal Rule,{close_quotes} to implement the requirements of Title 10 of the Code of Federal Regulations, Part 54 (10 CFR Part 54), {open_quotes}Requirements for Renewal of Operating Licenses for Nuclear Power Plants.{close_quotes} In general, NEI 95-10 appeared to contain the basic guidance needed for scoping, screening, identifying aging effects, developing aging management programs, and performing time-limited aging analyses. However, inconsistent implementation of this guidance in some areas was an indication that clarification of existing guidance and/or the inclusion-of some new guidance may be needed for applicants to develop a license renewal program that is consistent with the intent of the rule.

  12. On the observation of multiple volume reflection from different planes inside one bent crystal

    SciTech Connect

    Guidi, Vincenzo; Mazzolari, Andrea; Tikhomirov, Victor

    2010-06-15

    An interpretation of the first experiment on the observation of 400 GeV proton multiple volume reflection from different skew planes of one bent crystal (MVROC) is given. The possibilities of experimental observation of MVROC at lower particle energies are demonstrated. New features of the effect of particle capture into the channeling regime by bent skew planes are revealed as well as optimal choice of main crystal axis, crystal thickness, and beam orientation with respect to the crystal is discussed.

  13. Searching for Novel Gravitational Effects

    ScienceCinema

    Christopher Stubb

    2016-07-12

    Stubbs, Chair of the Physics Department at Harvard University, discusses experiments that search for novel gravitational effect and scientific observations about it.

  14. Far infrared supplement: Catalog of infrared observations, second edition

    SciTech Connect

    Gezari, D.Y.; Schmitz, M.; Mead, J.M.

    1988-08-01

    The Far Infrared Supplement: Catalog of Infrared Observations summarizes all infrared astronomical observations at far infrared wavelengths (5 to 1000 microns) published in the scientific literature from 1965 through 1986. The Supplement list contain 25 percent of the observations in the full Catalog of Infrared Observations (CIO), and essentially eliminates most visible stars from the listings. The Supplement is thus more compact than the main catalog, and is intended for easy reference during astronomical observations. The Far Infrared Supplement (2nd Edition) includes the Index of Infrared Source Positions and the Bibliography of Infrared Astronomy for the subset of far infrared observations listed.

  15. Observable spectra of induced gravitational waves from inflation

    SciTech Connect

    Alabidi, Laila; Sasaki, Misao; Kohri, Kazunori; Sendouda, Yuuiti E-mail: kohri@post.kek.jp E-mail: sendouda@cc.hirosaki-u.ac.jp

    2012-09-01

    Measuring the primordial power spectrum on small scales is a powerful tool in inflation model building, yet constraints from Cosmic Microwave Background measurements alone are insufficient to place bounds stringent enough to be appreciably effective. For the very small scale spectrum, those which subtend angles of less than 0.3 degrees on the sky, an upper bound can be extracted from the astrophysical constraints on the possible production of primordial black holes in the early universe. A recently discovered observational by-product of an enhanced power spectrum on small scales, induced gravitational waves, have been shown to be within the range of proposed space based gravitational wave detectors; such as NASA's LISA and BBO detectors, and the Japanese DECIGO detector. In this paper we explore the impact such a detection would have on models of inflation known to lead to an enhanced power spectrum on small scales, namely the Hilltop-type and running mass models. We find that the Hilltop-type model can produce observable induced gravitational waves within the range of BBO and DECIGO for integral and fractional powers of the potential within a reasonable number of e−folds. We also find that the running mass model can produce a spectrum within the range of these detectors, but require that inflation terminates after an unreasonably small number of e−folds. Finally, we argue that if the thermal history of the Universe were to accomodate such a small number of e−folds the Running Mass Model can produce Primordial Black Holes within a mass range compatible with Dark Matter, i.e. within a mass range 10{sup 20}g∼

  16. Observation of 690 MV m^-1 Electron Accelerating Gradient with...

    Office of Scientific and Technical Information (OSTI)

    Observation of 690 MV m-1 Electron Accelerating Gradient with a Laser-Driven Dielectric Microstructure Citation Details In-Document Search Title: Observation of 690 MV m-1...

  17. How Are You Observing Energy Awareness Month? | Department of...

    Energy.gov [DOE] (indexed site)

    gets you a tax credit. But there are plenty of other ways you could observe Energy Awareness Month help spread the word about saving energy. So tell us: How are you observing...

  18. Skin thickness effects on in vivo LXRF

    SciTech Connect

    Preiss, I.L.; Washington, W. II

    1995-12-31

    The analysis of lead concentration in bone utilizing LXRF can be adversely effected by overlying issue. A quantitative measure of the attenuation of the 10.5 keV Pb L a x-ray signal by skin and skin equivalent plastic has been conducted. Concentration ranges in plaster of Paris and goat bone from 7 to 90 ppm with attenuators of Lucite{reg_sign} and pig skin were examined. It is concluded that no quantitative or semi quantitative analysis can be achieved if overlying sue thickness exceeds 3 mm for Ph concentrations of less than 30 porn Ph in bone.

  19. The observational status of Galileon gravity after Planck

    SciTech Connect

    Barreira, Alexandre; Li, Baojiu; Baugh, Carlton M.; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: silvia.pascoli@durham.ac.uk

    2014-08-01

    We use the latest CMB data from Planck, together with BAO measurements, to constrain the full parameter space of Galileon gravity. We constrain separately the three main branches of the theory known as the Cubic, Quartic and Quintic models, and find that all yield a very good fit to these data. Unlike in ?CDM, the Galileon model constraints are compatible with local determinations of the Hubble parameter and predict nonzero neutrino masses at over 5? significance. We also identify that the low l part of the CMB lensing spectrum may be able to distinguish between ?CDM and Galileon models. In the Cubic model, the lensing potential deepens at late times on sub-horizon scales, which is at odds with the current observational suggestion of a positive ISW effect. Compared to ?CDM, the Quartic and Quintic models predict less ISW power in the low l region of the CMB temperature spectrum, and as such are slightly preferred by the Planck data. We illustrate that residual local modifications to gravity in the Quartic and Quintic models may render the Cubic model as the only branch of Galileon gravity that passes Solar System tests.

  20. NEOWISE-R observation of the coolest known brown dwarf

    SciTech Connect

    Wright, Edward L.; Mainzer, Amy; Bauer, James; Eisenhardt, Peter R. M.; Davy Kirkpatrick, J.; Masci, Frank; Fajardo-Acosta, Sergio; Gelino, Christopher R.; Beichman, Charles A.; Cutri, Roc; Cushing, Michael C.; Skrutskie, M. F.; Grav, T.

    2014-11-01

    The Wide-field Infrared Survey Explorer (WISE) spacecraft has been reactivated as NEOWISE-R to characterize and search for near-Earth objects. The brown dwarf WISE J085510.83–071442.5 has now been re-observed by NEOWISE-R, and we confirm the results of Luhman, who found a very low effective temperature (≈250 K), a very high proper motion (8.''1 ± 0.''1 yr{sup –1}), and a large parallax (454 ± 45 mas). The large proper motion has separated the brown dwarf from the background sources that influenced the 2010 WISE data, allowing a measurement of a very red WISE color of W1 – W2 >3.9 mag. A re-analysis of the 2010 WISE astrometry using only the W2 band, combined with the new NEOWISE-R 2014 position, gives an improved parallax of 448 ± 33 mas and a proper motion of 8.''08 ± 0.''05 yr{sup –1}. These are all consistent with values from Luhman.

  1. Observation of negative differential capacitance (NDC) in Ti Schottky diodes on SiGe islands

    SciTech Connect

    Rangel-Kuoppa, Victor-Tapio; Jantsch, Wolfgang; Tonkikh, Alexander; Zakharov, Nikolay; Werner, Peter

    2013-12-04

    The Negative Differential Capacitance (NDC) effect on Ti Schottky diodes formed on n-type Silicon samples with embedded Germanium Quantum Dots (QDs) is observed and reported. The NDC-effect is detected using capacitance-voltage (CV) method at temperatures below 200 K. It is explained by the capture of electrons in Germanium QDs. Our measurements reveal that each Ge QD captures in average eight electrons.

  2. Experimental Observation of Nuclear Reactions in Palladium and Uranium

    SciTech Connect

    J. Dufour; D. Murat; X. Dufour; J. Foos

    2001-11-12

    By submitting various metals (Pd, U) containing hydrogen (from 2000 to 700 000 atoms of hydrogen for 1 000 000 atoms of the host metal) to the combined action of electrical currents and magnetic fields, we have observed a sizeable exothermal effect (from 0.1 to 8 W for 500 mg of metal used). This effect is beyond experimental errors, the energy output being typically 130 to 250{percent} of the energy input and not of chemical origin (exothermal effect in the range of 7000 MJ/mol of metal in the case of palladium and of 60 MJ/mol in the case of uranium). New chemical species also appear in the processes metals. It has been shown by a QED calculation that resonances of long lifetime (s), nuclear dimensions (fm), and low energy of formation (eV) could exist. This concept seems to look like the 'shrunken hydrogen atoms' proposed by various authors. It is indeed very different in two ways (a) being a metastable state, it needs energy to be formed (a few eV) and reverts to normal hydrogen after a few seconds, liberating back its energy of formation (it is thus not the source of the energy observed); (b) its formation can be described as the electron spin/proton nuclear spin interaction becoming first order in the lattice environment (whereas it is third order in a normal hydrogen atom). Moreover, we consider that the hydrex cannot yield a neutron because this reaction is strongly endothermic. To explain our results, we put forward the following working hypothesis: In a metal lattice and under proper conditions, the formation of such resonances (metastable state) could be favored. We propose to call them HYDREX, and we assume that they are actually formed in cold fusion (CF) and low-energy nuclear reaction (LENR) experiments. Once formed, a number of HYDREX could gather around a nucleus of the lattice to form a cluster of nuclear size and of very long life time compared to nuclear time (10{sup -22} s). In this cluster, nuclear rearrangements could take place, yielding

  3. The Radiative Properties of Small Clouds: Multi-Scale Observations and Modeling

    SciTech Connect

    Feingold, Graham; McComiskey, Allison

    2013-09-25

    Warm, liquid clouds and their representation in climate models continue to represent one of the most significant unknowns in climate sensitivity and climate change. Our project combines ARM observations, LES modeling, and satellite imagery to characterize shallow clouds and the role of aerosol in modifying their radiative effects.

  4. Tumor histology and location predict deep nuclei toxicity: Implications for late effects from focal brain irradiation

    SciTech Connect

    Plaga, Alexis; Shields, Lisa B.E.; Sun, David A.; Vitaz, Todd W.; Spalding, Aaron C.

    2012-10-01

    Normal tissue toxicity resulting from both disease and treatment is an adverse side effect in the management of patients with central nervous system malignancies. We tested the hypothesis that despite these improvements, certain tumors place patients at risk for neurocognitive, neuroendocrine, and neurosensory late effects. Defining patient groups at risk for these effects could allow for development of preventive strategies. Fifty patients with primary brain tumors underwent radiation planning with magnetic resonance imaging scan and computed tomography datasets. Organs at risk (OAR) responsible for neurocognitive, neuroendocrine, and neurosensory function were defined. Inverse-planned intensity-modulated radiation therapy was optimized with priority given to target coverage while penalties were assigned to exceeding normal tissue tolerances. Tumor laterality, location, and histology were compared with OAR doses, and analysis of variance was performed to determine the significance of any observed correlation. The ipsilateral hippocampus exceeded dose limits in frontal (74%), temporal (94%), and parietal (100%) lobe tumor locations. The contralateral hippocampus was at risk in the following tumor locations: frontal (53%), temporal (83%), or parietal (50%) lobe. Patients with high-grade glioma were at risk for ipsilateral (88%) and contralateral (73%) hippocampal damage (P <0.05 compared with other histologies). The pituitary gland and hypothalamus exceeded dose tolerances in patients with pituitary tumors (both 100%) and high-grade gliomas (50% and 75%, P <0.05 compared with other histologies), respectively. Despite application of modern radiation therapy, certain tumor locations and histologies continue to place patients at risk for morbidity. Patients with high-grade gliomas or tumors located in the frontal, temporal, or parietal lobes are at risk for neurocognitive decline, likely because of larger target volumes and higher radiation doses. Data from this study

  5. NS&T Managment Observations - 1st Quarter

    SciTech Connect

    David Gianotto

    2014-06-01

    The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations (observations) are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

  6. ARM - Lesson Plans: Observing Wind Speed and Cloudiness

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observing Wind Speed and Cloudiness Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Lesson Plans: Observing Wind Speed and Cloudiness Objective The objective is to demonstrate students' skills in observing the atmosphere, specifically in terms of wind speed and cloudiness. Materials Each

  7. ARM: Aerosol Observing System (AOS): auxiliary data (Dataset) | Data

    Office of Scientific and Technical Information (OSTI)

    Explorer Aerosol Observing System (AOS): auxiliary data Title: ARM: Aerosol Observing System (AOS): auxiliary data Aerosol Observing System (AOS): auxiliary data Authors: Ogren, John ; Jefferson, Anne ; Sheridan, Patrick Publication Date: 1990-01-01 OSTI Identifier: 1025148 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Dataset Data Type: Numeric Data Research Org: Atmospheric Radiation Measurement (ARM) Archive, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (US) Sponsoring Org:

  8. Observations and Modeling of the Green Ocean Amazon: Sounding Enhancement

    Office of Scientific and Technical Information (OSTI)

    Field Campaign Report (Technical Report) | SciTech Connect Observations and Modeling of the Green Ocean Amazon: Sounding Enhancement Field Campaign Report Citation Details In-Document Search Title: Observations and Modeling of the Green Ocean Amazon: Sounding Enhancement Field Campaign Report The goal of this campaign was to provide higher temporal sampling of the vertical structure of the atmosphere during the two intensive observational periods (IOPs) of the GoAmazon 2014/15 campaign. The

  9. Observation of a Macroscopically Quantum-Entangled Insulator

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    method can potentially pave the way for fault-tolerant (topological) quantum computing. ... Cava and M.Z. Hasan, "Observation of Unconventional Quantum Spin Textures in Topological ...

  10. Model-Observation "Data Cubes" for the DOE Atmospheric Radiation...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Model-Observation "Data Cubes" for the DOE Atmospheric Radiation Measurement Facility's ... Program through its Atmospheric Radiation Measurement Facility. 2. Data Cube ...

  11. Observation Wells At Blue Mountain Area (Warpinski, Et Al., 2004...

    OpenEI (Open Energy Information) [EERE & EIA]

    Blue Mountain Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At Blue Mountain Area (Warpinski,...

  12. Observation Wells At Lightning Dock Geothermal Area (Reeder,...

    OpenEI (Open Energy Information) [EERE & EIA]

    Geothermal Area (Reeder, 1957) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At Lightning Dock Geothermal Area (Reeder, 1957)...

  13. Observation Wells At Lightning Dock Area (Warpinski, Et Al.,...

    OpenEI (Open Energy Information) [EERE & EIA]

    Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At Lightning Dock Area (Warpinski, Et Al., 2004)...

  14. Observation Wells At The Needles Area (DOE GTP) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    The Needles Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At The Needles Area (DOE GTP) Exploration Activity...

  15. Observation Wells At Mccoy Geothermal Area (DOE GTP) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Mccoy Geothermal Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At Mccoy Geothermal Area (DOE GTP) Exploration...

  16. Amplitude Variability in gamma Dor and delta Sct Stars Observed...

    Office of Scientific and Technical Information (OSTI)

    Title: Amplitude Variability in gamma Dor and delta Sct Stars Observed by Kepler The NASA ... Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: NASA Country of ...

  17. Observed Regimes of Mid-Latitude.and Tropical Cirrus Microphysical...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observed Regimes of Mid-Latitude and Tropical Cirrus Microphysical Behavior A. D. Del Genio and A. B. Wolf National Aeronautics Space Administration Goddard Institute for Space ...

  18. Using ARM TWP Nauru Observations to Evaluate a Simple Thermodynamic...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Using ARM TWP Nauru Observations to Evaluate a Simple Thermodynamic Model of the Subcloud Layer Under Fair-Weather Cumulus Conditions Albrecht, Bruce University of Miami Kollias, ...

  19. COLLOQUIUM: Initial Observations from the New Horizons Flyby...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Initial Observations from the New Horizons Flyby of Pluto Dr. Andy Cheng Johns Hopkins University Applied Physics Laboratory Colloquium Committee: The Princeton Plasma...

  20. Van Allen Probes observation and modeling of chorus excitation...

    Office of Scientific and Technical Information (OSTI)

    Van Allen Probes observation and modeling of chorus excitation and propagation during weak ... This content will become publicly available on August 20, 2016 Title: Van Allen Probes ...

  1. Observation of Ordered Structures in Counterion Layers near Wet...

    Office of Scientific and Technical Information (OSTI)

    Title: Observation of Ordered Structures in Counterion Layers near Wet Charged Surfaces: A Potential Mechanism for Charge Inversion Authors: Miller, Mitchell ; Chu, Miaoqi ; Lin, ...

  2. In situ observations and tuning of physical and chemical phenomena...

    Office of Scientific and Technical Information (OSTI)

    on the surfaces of strongly correlated oxides Citation Details In-Document Search Title: In situ observations and tuning of physical and chemical phenomena on the surfaces of ...

  3. Simultaneous observation of nascent plasma and bubble induced...

    Office of Scientific and Technical Information (OSTI)

    in water with various pulse durations Citation Details In-Document Search Title: Simultaneous observation of nascent plasma and bubble induced by laser ablation in water with ...

  4. Observations and Modeling of the Green Ocean Amazon: Sounding...

    Office of Scientific and Technical Information (OSTI)

    Observations and Modeling of the Green Ocean Amazon: Sounding Enhancement Field Campaign ... The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate ...

  5. Observations and Modeling of the Green Ocean Amazon (GOAMAZON...

    Office of Scientific and Technical Information (OSTI)

    Observations and Modeling of the Green Ocean Amazon (GOAMAZON). Particulate Matter and ... transmittance, elemental composition by energy dispersive x-ray fluorescence, and ionic ...

  6. Observation of Magnetoelectric Multiferroicity in a Cubic Perovskite...

    Office of Scientific and Technical Information (OSTI)

    Title: Observation of Magnetoelectric Multiferroicity in a Cubic Perovskite System: LaMn 3 ... Country of Publication: United States Language: English Word Cloud More Like This Free ...

  7. Direct Observation of the Transition from Indirect to Direct...

    Office of Scientific and Technical Information (OSTI)

    Direct Observation of the Transition from Indirect to Direct Bandgap in Atomically Thin ... Sponsoring Org: US DOE Office of Science (DOE SC) Country of Publication: United States ...

  8. Direct Observation of the Transition from Indirect to Direct...

    Office of Scientific and Technical Information (OSTI)

    Direct Observation of the Transition from Indirect to Direct Bandgap in Atomically Thin ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  9. COMPREHENSIVE OBSERVATIONS OF THE ULTRAVIOLET SPECTRUM AND IMPROVED...

    Office of Scientific and Technical Information (OSTI)

    SPECTRUM AND IMPROVED ENERGY LEVELS FOR SINGLY IONIZED CHROMIUM (Cr II) Citation Details In-Document Search Title: COMPREHENSIVE OBSERVATIONS OF THE ULTRAVIOLET SPECTRUM AND ...

  10. Observation Wells At East Brawley Area (Matlick & Jayne, 2008...

    OpenEI (Open Energy Information) [EERE & EIA]

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At East Brawley Area (Matlick & Jayne, 2008) Exploration Activity Details...

  11. Observed Relations Between Snowfall Microphysics and Triple-Frequency...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    to derive important snowfall microphysical parameters like median mass diameter, fractal dimension, or particle habit. These observations further revealed that naturally occurring...

  12. Genetically encoded sensors enable real-time observation of metabolite...

    Office of Scientific and Technical Information (OSTI)

    Title: Genetically encoded sensors enable real-time observation of metabolite production Authors: Rogers, Jameson K. ; Church, George M. Publication Date: 2016-02-08 OSTI ...

  13. Observable non-Gaussianity from gauge field production in slow...

    Office of Scientific and Technical Information (OSTI)

    Observable non-Gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis Citation Details In-Document Search Title: ...

  14. Title: Radar-observed convective characteristics during TWP-ICE

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    will describe the convective systems observed during the project by two scanning C-band Doppler radars, one of which will provide dual-polarization measurements, and ARM's...

  15. ARM - Field Campaign - The ARM Pilot Radiation Observation Experiment

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    (PROBE) govCampaignsThe ARM Pilot Radiation Observation Experiment (PROBE) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : The ARM Pilot Radiation Observation Experiment (PROBE) 1993.01.01 - 1993.02.28 Lead Scientist : C. Platt For data sets, see below. Abstract The Optical Properties of Equatorial Cirrus from Observations in the ARM Pilot Radiation Observation Experiment Campaign Data Sets IOP

  16. Biomass Burning Observation Project Science Plan (Program Document...

    Office of Scientific and Technical Information (OSTI)

    Science Plan Citation Details In-Document Search Title: Biomass Burning Observation Project Science Plan Aerosols from biomass burning perturb Earth's climate through the direct ...

  17. Observed galaxy number counts on the lightcone up to second order: I. Main result

    SciTech Connect

    Bertacca, Daniele; Maartens, Roy; Clarkson, Chris E-mail: roy.maartens@gmail.com

    2014-09-01

    We present the galaxy number overdensity up to second order in redshift space on cosmological scales for a concordance model. The result contains all general relativistic effects up to second order that arise from observing on the past light cone, including all redshift effects, lensing distortions from convergence and shear, and contributions from velocities, Sachs-Wolfe, integrated SW and time-delay terms. This result will be important for accurate calculation of the bias on estimates of non-Gaussianity and on precision parameter estimates, introduced by nonlinear projection effects.

  18. Meteorological Observations for Renewable Energy Applications at Site 300

    SciTech Connect

    Wharton, S; Alai, M; Myers, K

    2011-10-26

    In early October 2010, two Laser and Detection Ranging (LIDAR) units (LIDAR-96 and LIDAR-97), a 3 m tall flux tower, and a 3 m tall meteorological tower were installed in the northern section of Site 300 (Figure 1) as a first step in development of a renewable energy testbed facility. This section of the SMS project is aimed at supporting that effort with continuous maintenance of atmospheric monitoring instruments capable of measuring vertical profiles of wind speed and wind direction at heights encountered by future wind power turbines. In addition, fluxes of energy are monitored to estimate atmospheric mixing and its effects on wind flow properties at turbine rotor disk heights. Together, these measurements are critical for providing an accurate wind resource characterization and for validating LLNL atmospheric prediction codes for future renewable energy projects at Site 300. Accurate, high-resolution meteorological measurements of wind flow in the planetary boundary layer (PBL) and surface-atmosphere energy exchange are required for understanding the properties and quality of available wind power at Site 300. Wind speeds at heights found in a typical wind turbine rotor disk ({approx} 40-140 m) are driven by the synergistic impacts of atmospheric stability, orography, and land-surface characteristics on the mean wind flow in the PBL and related turbulence structures. This section of the report details the maintenance and labor required in FY11 to optimize the meteorological instruments and ensure high accuracy of their measurements. A detailed look at the observations from FY11 is also presented. This portion of the project met the following milestones: Milestone 1: successful maintenance and data collection of LIDAR and flux tower instruments; Milestone 2: successful installation of solar power for the LIDAR units; and Milestone 3: successful implementation of remote data transmission for the LIDAR units.

  19. Observation of dynamic water microadsorption on Au surface

    SciTech Connect

    Huang, Xiaokang, E-mail: xiaokang.huang@tqs.com; Gupta, Gaurav; Gao, Weixiang; Tran, Van; Nguyen, Bang; McCormick, Eric; Cui, Yongjie; Yang, Yinbao; Hall, Craig; Isom, Harold [TriQuint Semiconductor, Inc., 500 W Renner Road, Richardson, Texas 75080 (United States)

    2014-05-15

    Experimental and theoretical research on water wettability, adsorption, and condensation on solid surfaces has been ongoing for many decades because of the availability of new materials, new detection and measurement techniques, novel applications, and different scales of dimensions. Au is a metal of special interest because it is chemically inert, has a high surface energy, is highly conductive, and has a relatively high melting point. It has wide applications in semiconductor integrated circuitry, microelectromechanical systems, microfluidics, biochips, jewelry, coinage, and even dental restoration. Therefore, its surface condition, wettability, wear resistance, lubrication, and friction attract a lot of attention from both scientists and engineers. In this paper, the authors experimentally investigated Au{sub 2}O{sub 3} growth, wettability, roughness, and adsorption utilizing atomic force microscopy, scanning electron microscopy, reflectance spectrometry, and contact angle measurement. Samples were made using a GaAs substrate. Utilizing a super-hydrophilic Au surface and the proper surface conditions of the surrounding GaAs, dynamic microadsorption of water on the Au surface was observed in a clean room environment. The Au surface area can be as small as 12??m{sup 2}. The adsorbed water was collected by the GaAs groove structure and then redistributed around the structure. A model was developed to qualitatively describe the dynamic microadsorption process. The effective adsorption rate was estimated by modeling and experimental data. Devices for moisture collection and a liquid channel can be made by properly arranging the wettabilities or contact angles of different materials. These novel devices will be very useful in microfluid applications or biochips.

  20. The Effect of Roll Waves on the Hydrodynamics of Falling Films Observed in Vertical Column Absorbers

    SciTech Connect

    Miller, W.A.

    2001-06-28

    A thin falling film is well suited to simultaneous heat and mass transfer because of the small thermal resistance through the film and because of the large contact surface achievable at low flow rates. The film enters as a smooth laminar flow and quickly transitions into small-amplitude wavy flow. The waves grown in length and amplitude and are identified as roll waves. This flow regime is termed wavy-laminar flow, and modern heat and mass transfer equipment operate in this complicated transition regime. Research published in open literature has shown the mass flow rate in the rollwaves to be about 10 to 20 times greater than that in the laminar substrate. As the film fully develops, the waves grow in mass and the film substrate thins because fluid is swept from the substrate by the secondary flows of the roll wave. Many studies have been conducted to measure and correlate the film thickness of wavy-laminar flows. Literature data show that Nusselt's theory for smooth laminar flow can over predict the film thickness by as much as 20% for certain wavy-laminar flow conditions. The hydrodynamics of falling films were therefore studied to measure the film thickness of a free-surface falling film and to better understand the parameters that affect the variations of the film thickness. A flow loop was set up for measuring the thickness, wave amplitude,and frequency of a film during hydrodynamic flow. Decreasing the pipe diameter caused the amplitude of the wavy flow to diminish. Measurements monitored from stations along the falling film showed a thinning of film thickness. Fully developed flow required large starting lengths of about 0.5 m. The film thickness increases as the Reynolds number (Re) increases. Increasing the Kapitza number (Ka) causes a decrease in the film thickness. Regression analysis showed that the Re and Ka numbers described the data trends in wavy-laminar flow. Rather than correlating the Re number in discrete ranges of the Ka number as earlier researchers have done, this research made the Ka number an independent regression variable along with the Re number. The correlation explains 96% of the total variation in the data and predicts the experimental data within an absolute average deviation of {+-} 4.0%. The correlation supports the calculation of a fully developed film thickness for wavy-laminar falling films.

  1. GUIDANCE ON CONDUCTING ADVERSE DIVERSITY ANALYSIS

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ... Tecom, Inc., 566 F.3d 1037 (Fed. Cir. 2009), the Federal Circuit held that a government ... results of any Office of General Counsel review of the contractor's diversity analysis. ...

  2. Overcoming Adversity on New Career Paths

    Energy.gov [DOE]

    AIKEN, S.C. – Alex Somers pursued a military career with a goal of serving on a nuclear submarine until a diabetes diagnosis ended his dream.

  3. Keeping the lights on for global ocean salinity observation

    DOE PAGES [OSTI]

    Durack, Paul J.; Lee, Tong; Vinogradova, Nadya T.; Stammer, Detlef

    2016-02-24

    Here, insights about climate are being uncovered thanks to improved capacities to observe ocean salinity, an essential climate variable. However, cracks are beginning to appear in the ocean observing system that require prompt attention if we are to maintain the existing, hard-won capacity into the near future.

  4. Spin Observables in Reactions with Radioactive Ion Beams

    SciTech Connect

    Galindo-Uribarri, Alfredo {nmn}; Urrego Blanco, Juan Pablo

    2007-01-01

    Polarization observables in nuclear reactions with exotic nuclei will provide important information concerning structural properties of nuclei and reaction mechanisms. We are currently engaged in exploring the use of polarization observables with radioactive ion beams and in the development of a polarized cryogenic target.

  5. Observing the Sparks of Life | Photosynthetic Antenna Research Center

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observing the Sparks of Life December 31, 2013 Observing the Sparks of Life EFRC researchers isolate a photosynthetic complex - arguably the most important bit of organic chemistry on the planet - in its complete functioning state. http://science.energy.gov/discovery-and-innovation/stories/2013/127045/ In the News

  6. Observation of heavy elements produced during explosive cold fusion

    SciTech Connect

    Matsumoto, T.; Kurokawa, K. )

    1991-11-01

    This paper reports on many-body fusion reactions that may take place during cold fusion. Heavy elements are observed that might have been produced by such reactions during electrolysis of heavy water. Elements such as sodium, magnesium, aluminum, and zinc are observed inside grain-shaped defects in a palladium rod used in a cold fusion experiment.

  7. Aerial Observation Needs Workshop, May 13-14, 2015

    SciTech Connect

    Nasiri, Shaima; Serbin, Shawn; Lesmes, David; Petty, Rick; Schmid, Beat; Vogelmann, Andrew; de Boer, Gijs; Dafflon, Baptiste; Guenther, Alex; Moore, David

    2015-10-01

    The mission of the Climate and Environmental Sciences Division (CESD) of the Office of Biological and Environmental Research (BER) within the U.S. Department of Energy's (DOE) Office of Science is "to advance a robust, predictive understanding of Earth's climate and environmental systems and to inform the development of sustainable solutions to the nation's energy and environmental challenges." Accomplishing this mission requires aerial observations of the atmospheric and terrestrial components of the climate system. CESD is assessing its current and future aerial observation needs to develop a strategy and roadmap of capability requirements for the next decade. To facilitate this process, a workshop was convened that consisted of invited experts in the atmospheric and terrestrial sciences, airborne observations, and modeling. This workshop report summarizes the community input prior to and during the workshop on research challenges and opportunities, as well as specific science questions and observational needs that require aerial observations to address.

  8. NS&T Management Observations - 3rd Quarter

    SciTech Connect

    David Gianotto

    2014-07-01

    The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

  9. Observing terrestrial ecosystems and the carbon cycle from space

    SciTech Connect

    Schimel, David; Pavlick, Ryan; Fisher, Joshua B.; Asner, Gregory P.; Saatchi, Sassan; Townsend, Philip; Miller, Charles E.; Frankenberg, Christian; Hibbard, Kathleen A.; Cox, Peter

    2015-02-06

    Modeled terrestrial ecosystem and carbon cycle feedbacks contribute substantial uncertainty to projections of future climate. The limitations of current observing networks contribute to this uncertainty. Here we present a current climatology of global model predictions and observations for photosynthesis, biomass, plant diversity and plant functional diversity. Carbon cycle tipping points occur in terrestrial regions where fluxes or stocks are largest, and where biological variability is highest, the tropics and Arctic/Boreal zones. Global observations are predominately in the mid-latitudes and are sparse in high and low latitude ecosystems. Observing and forecasting ecosystem change requires sustained observations of sufficient density in time and space in critical regions. Using data and theory available now, we can develop a strategy to detect and forecast terrestrial carbon cycle-climate interactions, by combining in situ and remote techniques.

  10. Observation of spin-charge conversion in chemical-vapor-deposition-grown single-layer graphene

    SciTech Connect

    Ohshima, Ryo; Sakai, Atsushi; Ando, Yuichiro; Shiraishi, Masashi; Shinjo, Teruya; Kawahara, Kenji; Ago, Hiroki

    2014-10-20

    Conversion of pure spin current to charge current in single-layer graphene (SLG) is investigated by using spin pumping. Large-area SLG grown by chemical vapor deposition is used for the conversion. Efficient spin accumulation in SLG by spin pumping enables observing an electromotive force produced by the inverse spin Hall effect (ISHE) of SLG. The spin Hall angle of SLG is estimated to be 6.1 × 10{sup −7}. The observed ISHE in SLG is ascribed to its non-negligible spin-orbit interaction in SLG.

  11. Observing System Simulation Experiments (OSSEs) for the Mid-Columbia Basin

    SciTech Connect

    Zack, J; Natenberg, E J; Knowe, G V; Waight, K; Manobianco, J; Hanley, D; Kamath, C

    2011-09-13

    The overall goal of this multi-phased research project known as WindSENSE is to develop an observation system deployment strategy that would improve wind power generation forecasts. The objective of the deployment strategy is to produce the maximum benefit for 1- to 6-hour ahead forecasts of wind speed at hub-height ({approx}80 m). In this phase of the project the focus is on the Mid-Columbia Basin region, which encompasses the Bonneville Power Administration (BPA) wind generation area (Figure 1) that includes the Klondike, Stateline, and Hopkins Ridge wind plants. There are two tasks in the current project effort designed to validate the Ensemble Sensitivity Analysis (ESA) observational system deployment approach in order to move closer to the overall goal: (1) Perform an Observing System Experiment (OSE) using a data denial approach. The results of this task are presented in a separate report. (2) Conduct a set of Observing System Simulation Experiments (OSSE) for the Mid-Colombia basin region. This report presents the results of the OSSE task. The specific objective is to test strategies for future deployment of observing systems in order to suggest the best and most efficient ways to improve wind forecasting at BPA wind farm locations. OSSEs have been used for many years in meteorology to evaluate the potential impact of proposed observing systems, determine tradeoffs in instrument design, and study the most effective data assimilation methodologies to incorporate the new observations into numerical weather prediction (NWP) models (Atlas 1997; Lord 1997). For this project, a series of OSSEs will allow consideration of the impact of new observing systems of various types and in various locations.

  12. ARM - Field Campaign - Supplement to Arctic Lower Troposphere Observed

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Structure (ALTOS) govCampaignsSupplement to Arctic Lower Troposphere Observed Structure (ALTOS) Related Campaigns Arctic Lower Troposphere Observed Structure (ALTOS) 2010.10.01, Verlinde, NSA Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Supplement to Arctic Lower Troposphere Observed Structure (ALTOS) 2010.10.01 - 2010.12.31 Lead Scientist : Johannes Verlinde Abstract NOTE: An unfortunate incident in the early stages of ALTOS

  13. POSSIBLE ALTERATION OF ROCKS OBSERVED BY CHEMCAM ALONG THE TRAVERSE...

    Office of Scientific and Technical Information (OSTI)

    TO GLENELG IN GALE CRATER ON MARS. Citation Details In-Document Search Title: POSSIBLE ALTERATION OF ROCKS OBSERVED BY CHEMCAM ALONG THE TRAVERSE TO GLENELG IN GALE CRATER ON ...

  14. Analysis of In situ Observations of Cloud Microphysics from M...

    Office of Scientific and Technical Information (OSTI)

    Cloud Microphysics from M-PACE Final Report, DOE Grant Agreement No. DE-FG02-06ER64168 Citation Details In-Document Search Title: Analysis of In situ Observations of Cloud ...

  15. Field Observation GoAmazon Neutral cluster Air Ion Spectrometer...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    of the Green Ocean Amazon: Neutral Cluster Air Ion Spectrometer (NAIS) Final Campaign ... DOESC-ARM-15-060 Field Observation of the Green Ocean Amazon: Neutral Cluster Air Ion ...

  16. Press Pass - Press Release - DZero ZZ diboson observation

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    of the ZZ diboson make its discovery an essential prelude to finding or excluding the Higgs boson at the Tevatron. The observation of the ZZ, announced at a Fermilab seminar on...

  17. Observations of flow patterns in a spray dryer

    SciTech Connect

    Southwell, D.B.; Langrish, T.A.G.

    2000-03-01

    Experiments have been performed on a pilot scale, cylinder-on-cone spray dryer fitted with a vaned-wheel atomizer to observe air flow patterns, with and without water spray. A combination of tufts, smoke streams and a laser light sheet, was used to provide information about regions of recirculation, flow stability, spray trajectories and wall deposition. While atomizer-induced swirl dominated the flow patterns under typical operating conditions, some instability was observed, although different in type, for situations with and without atomizer rotation. Clockwise eddies were observed to form and collapse between the wall and the strongly anti-clockwise swirling core created by anti-clockwise atomizer rotation. Without swirl, large portions of the recirculation zones at the walls were observed to have a weak tendency to change randomly between clockwise, anti-clockwise and chaotic behavior.

  18. Fermi Large Area Telescope Observations of the Supernova Remnant...

    Office of Scientific and Technical Information (OSTI)

    Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1 Citation Details ... Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS ...

  19. Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba...

    Office of Scientific and Technical Information (OSTI)

    Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba(Fe (1-X) Co (X) ) (2) As (2) Above the Spin Density Wave Transition Citation Details In-Document Search Title: ...

  20. Observable Proxies For 26 Al Enhancement (Journal Article) |...

    Office of Scientific and Technical Information (OSTI)

    Observable Proxies For 26 Al Enhancement Citation Details ... Publication Date: 2008-01-01 OSTI Identifier: 960677 Report Number(s): LA-UR-08-05875; LA-UR-08-5875 Journal ID: ...

  1. Observation of a Macroscopically Quantum-Entangled Insulator

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Observation of a Macroscopically Quantum-Entangled Insulator Print It has recently been proposed that insulators with large band gaps and strong spin-orbit coupling can host a new...

  2. GALEX DIFFUSE OBSERVATIONS OF THE SKY: THE DATA

    SciTech Connect

    Murthy, Jayant

    2014-08-01

    I present tabulations of the diffuse observations made by the GALEX spacecraft in two UV bands (FUV: 1539 and NUV: 2316 ) from the (almost) final data release of the GALEX spacecraft (GR6/GR7). This data release includes all the FUV observations and the majority of the NUV observations. I discuss overall trends in the data but the primary purpose of this paper is to make the data available to the public. The data files described in this paper are hosted by the Mikulski Archive for Space Telescopes at the Space Telescope Science Insitute from whence they may be downloaded. For ease of use, I have also created maps of the diffuse radiation in both bands over the entire observed sky at 6' resolution.

  3. Ion-driven instabilities in the solar wind: Wind observations...

    Office of Scientific and Technical Information (OSTI)

    Ion-driven instabilities in the solar wind: Wind observations of 19 March 2005 Citation Details In-Document Search Title: Ion-driven instabilities in the solar wind: Wind ...

  4. Microsoft PowerPoint - GNEP PARTNERS CANDIDATE PARTNERS AND OBSERVERS...

    Energy Saver

    5. Ghana 6. Hungary 7. Japan 8. Jordan 9. Kazakhstan 10. Lithuania 11. Poland 12. Romania 13. Russia 14. Slovenia 15. Ukraine 16. United States GNEP Observers 1. International ...

  5. Observations and Modeling of GoAmazon Particulate Matter and...

    Office of Scientific and Technical Information (OSTI)

    ENERGY Office of Science DOESC-ARM-15-059 Observations and Modeling of the Green Ocean Amazon (GOAMAZON): Particulate Matter and Gases Final Campaign Summary RHM Godoi CGG Barbosa ...

  6. Intercomparison of model simulations of mixed-phase clouds observed...

    Office of Scientific and Technical Information (OSTI)

    Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud Citation Details In-Document ...

  7. Polarimetric radar and aircraft observations of saggy bright...

    Office of Scientific and Technical Information (OSTI)

    Polarimetric radar and aircraft observations of saggy bright bands during MC3E Citation Details In-Document Search This content will become publicly available on March 19, 2017 ...

  8. ARM - Field Campaign - Observations and Modeling of the Green...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    2 ARM Data Discovery Browse Data Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear...

  9. Experimental observation of saddle points over the quantum control...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Experimental observation of saddle points over the quantum control landscape of a two-spin system Citation Details In-Document ...

  10. Marine Boundary Layer Cloud Observations in the Azores (Journal...

    Office of Scientific and Technical Information (OSTI)

    Marine Boundary Layer Cloud Observations in the Azores Citation Details ... Publication Date: 2012-11-01 OSTI Identifier: 1059795 Report Number(s): BNL--98829-2012-JA Journal ID: ISSN ...

  11. ITEP Webinar: About the Local Environmental Observer (LEO) Network

    Energy.gov [DOE]

    Attend this Institute for Tribal Environmental Professionals (ITEP) webinar and learn how the Local Environmental Observer (LEO) Network provides a model for engaging communities; connecting with technical experts and resources; and disseminating information about specific events and the impacts, needs, and responses. This webinar will introduce LEO as a resource comprised of local experts who collect observations about unusual environmental events and serve as the eyes, ears and voice of environmental change in their communities.

  12. Net Zero Waste - Tools and Technical Support ...and other observations |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Net Zero Waste - Tools and Technical Support ...and other observations Net Zero Waste - Tools and Technical Support ...and other observations Presentation at Waste-to-Energy using Fuel Cells Webinar, July 13, 2011 wte_doe-dod_wkshp71311_usarmy.pdf (1.81 MB) More Documents & Publications DOD -DOE MOU WTE Using Fuel Cells Briefing WORKSHOP: SUSTAINABILITY IN MANUFACTURING AGENDA AND OVERVIEW CX-013695: Categorical Exclusion Determination

  13. Radiosonde observations at Pt. Reyes and cloud properties retrieved from

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    GOES-WEST Radiosonde observations at Pt. Reyes and cloud properties retrieved from GOES-WEST Inoue, Toshiro MRI/JMA Category: Field Campaigns Low-level cloud formed off the west coast of continents plays an important role in general circulation and climate. Marine Stratus Radiation Aerosol and Drizzle (MASRAD) was conducted at the ARM mobile site deployed at Pt Reyes, California during April to September. Here, we studied the relationship between meteorological parameters observed by GPS

  14. Shortwave Hyperspectral Observations During MAGIC Final Campaign Summary

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Shortwave Hyperspectral Observations During MAGIC Final Campaign Summary Citation Details In-Document Search Title: Shortwave Hyperspectral Observations During MAGIC Final Campaign Summary The Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign was initiated to improve our understanding of low-level marine clouds that have a significant influence on the Earth's climate. The campaign was conducted using an ARM mobile facility deployed on a

  15. Optimal observation time window for forecasting the next earthquake

    SciTech Connect

    Omi, Takahiro; Shinomoto, Shigeru; Kanter, Ido

    2011-02-15

    We report that the accuracy of predicting the occurrence time of the next earthquake is significantly enhanced by observing the latest rate of earthquake occurrences. The observation period that minimizes the temporal uncertainty of the next occurrence is on the order of 10 hours. This result is independent of the threshold magnitude and is consistent across different geographic areas. This time scale is much shorter than the months or years that have previously been considered characteristic of seismic activities.

  16. Magnetism and superconductivity observed to exist in harmony

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Magnetism and superconductivity exist in harmony Magnetism and superconductivity observed to exist in harmony Physicists have observed, for the first time in a single exotic phase, a situation where magnetism and superconductivity are necessary for each other's existence. August 28, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable

  17. Common Cyber Security Vulnerabilities Observed in Control System

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Assessments by the INL NSTB Program | Department of Energy Common Cyber Security Vulnerabilities Observed in Control System Assessments by the INL NSTB Program Common Cyber Security Vulnerabilities Observed in Control System Assessments by the INL NSTB Program This document presents results from 16 control system assessments performed under the NSTB program from 2003 through 2007. Information found in individual stakeholder reports is protected from disclosure. Researchers recognized that

  18. Collaboration yields 'The Right Glasses' for observing mystery behavior

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    in electrons Observing mystery behavior In electrons Collaboration yields 'The Right Glasses' for observing mystery behavior in electrons The research may lead to a better understanding of superconductors or development of better materials for powering high-speed electronics. December 13, 2007 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience,

  19. COMPARISONS OF COSMOLOGICAL MAGNETOHYDRODYNAMIC GALAXY CLUSTER SIMULATIONS TO RADIO OBSERVATIONS

    SciTech Connect

    Xu Hao; Li Hui; Collins, David C.; Govoni, Federica; Murgia, Matteo; Norman, Michael L.; Cen Renyue; Feretti, Luigina; Giovannini, Gabriele E-mail: hli@lanl.gov E-mail: mlnorman@ucsd.edu E-mail: matteo@oa-cagliari.inaf.it E-mail: lferetti@ira.inaf.it

    2012-11-01

    Radio observations of galaxy clusters show that there are {mu}G magnetic fields permeating the intracluster medium (ICM), but it is hard to accurately constrain the strength and structure of the magnetic fields without the help of advanced computer simulations. We present qualitative comparisons of synthetic Very Large Array observations of simulated galaxy clusters to radio observations of Faraday rotation measure (RM) and radio halos. The cluster formation is modeled using adaptive mesh refinement magnetohydrodynamic simulations with the assumption that the initial magnetic fields are injected into the ICM by active galactic nuclei (AGNs) at high redshift. In addition to simulated clusters in Xu et al., we present a new simulation with magnetic field injections from multiple AGNs. We find that the cluster with multiple injection sources is magnetized to a similar level as in previous simulations with a single AGN. The RM profiles from simulated clusters, both |RM| and the dispersion of RM ({sigma}{sub RM}), are consistent at a first order with the radial distribution from observations. The correlations between the {sigma}{sub RM} and X-ray surface brightness from simulations are in a broad agreement with the observations, although there is an indication that the simulated clusters could be slightly overdense and less magnetized with respect to those in the observed sample. In addition, the simulated radio halos agree with the observed correlations between the radio power versus the cluster X-ray luminosity and between the radio power versus the radio halo size. These studies show that the cluster-wide magnetic fields that originate from AGNs and are then amplified by the ICM turbulence match observations of magnetic fields in galaxy clusters.

  20. ARM - Publications: Science Team Meeting Documents: Observations of Natural

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Variability in Marine Stratocumulus Clouds Observations of Natural Variability in Marine Stratocumulus Clouds Albrecht, Bruce University of Miami Kollias, Pavlos RSMAS/University of Miami Jo, Ieng Rosentiel School of Marine & Atmospheric Science Ghate, Virendra RSMAS/Univ. Miami Serpetzoglou, Efthymious Minnis, Patrick NASA Langley Research Center Sun-Mack, Szedung SAIC Large to mesoscale features affecting the albedo of marine stratocumulus clouds are observed frequently and can have a

  1. Detection of Lensing Substructure Using Alma Observations of the Dusty Galaxy SDP.81

    DOE PAGES [OSTI]

    Hezaveh, Yashar D.; Dalal, Neal; Marrone, Daniel P.; Mao, Yao-Yuan; Morningstar, Warren; Wen, Di; Blandford, Roger D.; Carlstrom, John E.; Fassnacht, Christopher D.; Holder, Gilbert P.; et al

    2016-05-19

    We study the abundance of substructure in the matter density near galaxies using ALMA Science Verification observations of the strong lensing system SDP.81. We present a method to measure the abundance of subhalos around galaxies using interferometric observations of gravitational lenses. Using simulated ALMA observations we explore the effects of various systematics, including antenna phase errors and source priors, and show how such errors may be measured or marginalized. We apply our formalism to ALMA observations of SDP.81. We find evidence for the presence of a M = 108.96±0.12 M⊙ subhalo near one of the images, with a significance ofmore » 6.9σ in a joint fit to data from bands 6 and 7; the effect of the subhalo is also detected in both bands individually. We also derive constraints on the abundance of dark matter (DM) subhalos down to M ~ 2 × 107 M⊙, pushing down to the mass regime of the smallest detected satellites in the Local Group, where there are significant discrepancies between the observed population of luminous galaxies and predicted DM subhalos. We find hints of additional substructure, warranting further study using the full SDP.81 data set (including, for example, the spectroscopic imaging of the lensed carbon monoxide emission). We compare the results of this search to the predictions of ΛCDM halos, and find that given current uncertainties in the host halo properties of SDP.81, our measurements of substructure are consistent with theoretical expectations. Finally, observations of larger samples of gravitational lenses with ALMA should be able to improve the constraints on the abundance of galactic substructure.« less

  2. Observed galaxy number counts on the lightcone up to second order: II. Derivation

    SciTech Connect

    Bertacca, Daniele; Maartens, Roy; Clarkson, Chris E-mail: roy.maartens@gmail.com

    2014-11-01

    We present a detailed derivation of the observed galaxy number over-density on cosmological scales up to second order in perturbation theory. We include all relativistic effects that arise from observing on the past lightcone. The derivation is in a general gauge, and applies to all dark energy models (including interacting dark energy) and to metric theories of modified gravity. The result will be important for accurate cosmological parameter estimation, including non-Gaussianity, since all projection effects need to be taken into account. It also offers the potential for new probes of General Relativity, dark energy and modified gravity. This paper accompanies Paper I which presents the key results for the concordance model in Poisson gauge.

  3. Effect of transient body force on the performance of an axial grooved heat pipe. Master`s thesis

    SciTech Connect

    Wang, W.L.

    1996-06-01

    An experimental investigation was performed to determine the effect of transient body forces on the performance of an ammonia/aluminum axial groove heat pipe. The effects of increased body forces on the dryout and rewet performance were simulated by tilting the heat pipe to different inclination angles. Theoretical calculations predicted the dryout length varied with different final inclination angles. The steady state experimental work was performed by tilting the heat pipe from 0 degrees to different final inclination angles for a long period of time until totally dryout occurred. Then, from the plot of the changing temperature at each location along the heat pipe, the dryout length could be predicted. Under steady state condition, the percent error between the experimental and theoretical data differed by as low as 50%. The transient experimental work was performed by tilting the heat pipe from different initial inclination angles to different final inclination angles under three duration conditions. The time for the heat pipe to dryout, rewet, and return to the initial condition was observed as a function of the initial inclination angles, the final inclination angles, and duration of the heat pipe at the final angle. The results revealed that the larger body force (or the larger final inclination angle) increased the dryout length, and increased the time to return to its initial condition. The duration of the adverse angle had less of an effect on the time to rewet. But the initial inclination angle has a strong effect on the time to rewet. When the initial inclination angle was 0 degrees, it took around 3 to 6 seconds to rewet. When the initial inclination angle became 1 degrees, it took around 5 to 12 seconds to rewet. When the initial inclination angle was 1.25 degrees, it took around 15 to 17 seconds to rewet.

  4. An ethanolic extract of black cohosh causes hematological changes but not estrogenic effects in female rodents

    SciTech Connect

    Mercado-Feliciano, Minerva; Cora, Michelle C.; Witt, Kristine L.; Granville, Courtney A.; Hejtmancik, Milton R.; Fomby, Laurene; Knostman, Katherine A.; Ryan, Michael J.; Newbold, Retha; Smith, Cynthia; Foster, Paul M.; Vallant, Molly K.; Stout, Matthew D.

    2012-09-01

    Black cohosh rhizome (Actaea racemosa) is used as a remedy for pain and gynecological ailments; modern preparations are commonly sold as ethanolic extracts available as dietary supplements. Black cohosh was nominated to the National Toxicology Program (NTP) for toxicity testing due to its widespread use and lack of safety data. Several commercially available black cohosh extracts (BCE) were characterized by the NTP, and one with chemical composition closest to formulations available to consumers was used for all studies. Female B6C3F1/N mice and Wistar Han rats were given 0, 15 (rats only), 62.5 (mice only), 125, 250, 500, or 1000 mg/kg/day BCE by gavage for 90 days starting at weaning. BCE induced dose-dependent hematological changes consistent with a non-regenerative macrocytic anemia and increased frequencies of peripheral micronucleated red blood cells (RBC) in both species. Effects were more severe in mice, which had decreased RBC counts in all treatment groups and increased micronucleated RBC at doses above 125 mg/kg. Dose-dependent thymus and liver toxicity was observed in rats but not mice. No biologically significant effects were observed in other organs. Puberty was delayed 2.9 days at the highest treatment dose in rats; a similar magnitude delay in mice occurred in the 125 and 250 mg/kg groups but not at the higher doses. An additional uterotrophic assay conducted in mice exposed for 3 days to 0.001, 0.01, 0.1, 1, 10, 100 and 500 mg/kg found no estrogenic or anti-estrogenic activity. These are the first studies to observe adverse effects of BCE in rodents. -- Highlights: ? Mice and rats were dosed with black cohosh extract for 90 days starting at weaning. ? Hematological changes were consistent with a non-regenerative macrocytic anemia. ? Peripheral micronucleated red blood cell frequencies increased. ? Puberty was delayed 2.9 days in rats. ? No estrogenic/anti-estrogenic activity was seen in the uterotrophic assay.

  5. Observation of the tune dependence of the stability threshold current in the PSR (Proton Storage Ring)

    SciTech Connect

    Wang, Tai Sen F.; Colton, E.; Lombardi, A.; Neuffer, D.V.; Thiessen, H.A.

    1989-01-01

    In the high-intensity unbunched-beam experiments carried out in the Proton Storage Ring at Los Alamos National Laboratory, the threshold current of vertical transverse instability showed pronounced differences when the betatron tune varied across an integer. In this paper, we shall present our experimental observations and discuss the possible relations between the threshold current and the machine impedance. The possible effects related to the distorted closed orbit are also discussed. 5 refs., 3 figs., 1 tab.

  6. Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations D. D. Turner University of Wisconsin-Madison Madison, Wisconsin and Pacific Northwest National Laboratory Richland, Washington Abstract A novel new approach to retrieve cloud microphysical properties from mixed-phase clouds is presented. This algorithm retrieves cloud optical depth, ice fraction, and the effective size of the water and ice particles from ground-based, high-resolution infrared radiance

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

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

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

  8. OBSERVATION OF HEATING BY FLARE-ACCELERATED ELECTRONS IN A SOLAR CORONAL MASS EJECTION

    SciTech Connect

    Glesener, Lindsay; Bain, Hazel M.; Krucker, Sm; Lin, Robert P.

    2013-12-20

    We report a Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observation of flare-accelerated electrons in the core of a coronal mass ejection (CME) and examine their role in heating the CME. Previous CME observations have revealed remarkably high thermal energies that can far surpass the CME's kinetic energy. A joint observation by RHESSI and the Atmospheric Imaging Assembly of a partly occulted flare on 2010 November 3 allows us to test the hypothesis that this excess energy is collisionally deposited by flare-accelerated electrons. Extreme ultraviolet (EUV) images show an ejection forming the CME core and sheath, with isothermal multifilter analysis revealing temperatures of ?11MK in the core. RHESSI images reveal a large (?100 50 arcsec{sup 2}) hard X-ray (HXR) source matching the location, shape, and evolution of the EUV plasma, indicating that the emerging CME is filled with flare-accelerated electrons. The time derivative of the EUV emission matches the HXR light curve (similar to the Neupert effect observed in soft and HXR time profiles), directly linking the CME temperature increase with the nonthermal electron energy loss, while HXR spectroscopy demonstrates that the nonthermal electrons contain enough energy to heat the CME. This is the most direct observation to date of flare-accelerated electrons heating a CME, emphasizing the close relationship of the two in solar eruptive events.

  9. Mechanisms and observations of coronal dimming for the 201 August 7 event

    SciTech Connect

    Mason, James Paul; Woods, T. N.; Caspi, A.; Thompson, B. J.; Hock, R. A.

    2014-07-01

    Coronal dimming of extreme ultraviolet (EUV) emission has the potential to be a useful forecaster of coronal mass ejections (CMEs). As emitting material leaves the corona, a temporary void is left behind which can be observed in spectral images and irradiance measurements. The velocity and mass of the CMEs should impact the character of those observations. However, other physical processes can confuse the observations. We describe these processes and the expected observational signature, with special emphasis placed on the differences. We then apply this understanding to a coronal dimming event with an associated CME that occurred on 2010 August 7. Data from the Solar Dynamics Observatory's Atmospheric Imaging Assembly and EUV Variability Experiment (EVE) are used for observations of the dimming, while the Solar and Heliospheric Observatory's Large Angle and Spectrometric Coronagraph and the Solar Terrestrial Relations Observatory's COR1 and COR2 are used to obtain velocity and mass estimates for the associated CME. We develop a technique for mitigating temperature effects in coronal dimming from full-disk irradiance measurements taken by EVE. We find that for this event, nearly 100% of the dimming is due to mass loss in the corona.

  10. Filtering with Marked Point Process Observations via Poisson Chaos Expansion

    SciTech Connect

    Sun Wei; Zeng Yong; Zhang Shu

    2013-06-15

    We study a general filtering problem with marked point process observations. The motivation comes from modeling financial ultra-high frequency data. First, we rigorously derive the unnormalized filtering equation with marked point process observations under mild assumptions, especially relaxing the bounded condition of stochastic intensity. Then, we derive the Poisson chaos expansion for the unnormalized filter. Based on the chaos expansion, we establish the uniqueness of solutions of the unnormalized filtering equation. Moreover, we derive the Poisson chaos expansion for the unnormalized filter density under additional conditions. To explore the computational advantage, we further construct a new consistent recursive numerical scheme based on the truncation of the chaos density expansion for a simple case. The new algorithm divides the computations into those containing solely system coefficients and those including the observations, and assign the former off-line.

  11. Observational studies of interstellar and solar-nebula nitrogen chemistry

    SciTech Connect

    Womack, M.P.

    1991-01-01

    Despite the high cosmic abundance of nitrogen, chemical models of nitrogen-bearing species in the interstellar medium and the primordial solar nebula have not been constrained significantly by observations. Essentially nothing is known about the abundance of the simplest and most stable nitrogen compound N{sub 2} in astronomical sources. Ion-molecule chemistry models of interstellar clouds predict molecular ions to be formed primarily in cold, quiescent gas. The only well-studied molecular ion in dense clouds, HCO{sup +}, is very abundant in regions of energetic outflow from young stars, contrary to model predictions. Therefore, observations of another molecular ion are needed to better understand ion-molecule models. Here the author presents millimeter-wave observations of N{sub 2}H{sup +} toward galactic molecular clouds. These data can provide constraints on both the nitrogen and ion-molecular chemistry in the interstellar medium.

  12. SIMULATING PROTOSTELLAR JETS SIMULTANEOUSLY AT LAUNCHING AND OBSERVATIONAL SCALES

    SciTech Connect

    Ramsey, Jon P.; Clarke, David A. [Institute for Computational Astrophysics, Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3 (Canada)

    2011-02-10

    We present the first 2.5-dimensional magnetohydrodynamic (MHD) simulations of protostellar jets that include both the region in which the jet is launched magnetocentrifugally at scale lengths <0.1 AU and where the propagating jet is observed at scale lengths >10{sup 3} AU. These simulations, performed with the new adaptive mesh refinement MHD code AZEuS, reveal interesting relationships between conditions at the disk surface, such as the magnetic field strength, and direct observables such as proper motion, jet rotation, jet radius, and mass flux. By comparing these quantities with observed values, we present direct numerical evidence that the magnetocentrifugal launching mechanism is capable, by itself, of launching realistic protostellar jets.

  13. SPECTROSCOPIC OBSERVATIONS OF Fe XVIII IN SOLAR ACTIVE REGIONS

    SciTech Connect

    Teriaca, Luca; Curdt, Werner; Warren, Harry P.

    2012-08-01

    The large uncertainties associated with measuring the amount of high temperature emission in solar active regions (ARs) represents a significant impediment to making progress on the coronal heating problem. Most current observations at temperatures of 3 MK and above are taken with broadband soft X-ray instruments. Such measurements have proven difficult to interpret unambiguously. Here, we present the first spectroscopic observations of the Fe XVIII 974.86 A emission line in an on-disk AR taken with the SUMER instrument on SOHO. Fe XVIII has a peak formation temperature of 7.1 MK and provides important constraints on the amount of impulsive heating in the corona. Detailed evaluation of the spectra and comparison of the SUMER data with soft X-ray images from the X-Ray Telescope on Hinode confirm that this line is unblended. We also compare the spectroscopic data with observations from the Atmospheric Imaging Assembly (AIA) 94 A channel on the Solar Dynamics Observatory. The AIA 94 A channel also contains Fe XVIII, but is blended with emission formed at lower temperatures. We find that it is possible to remove the contaminating blends and form relatively pure Fe XVIII images that are consistent with the spectroscopic observations from SUMER. The observed spectra also contain the Ca XIV 943.63 A line that, although a factor 2-6 weaker than the Fe XVIII 974.86 A line, allows us to probe the plasma around 3.5 MK. The observed ratio between the two lines indicates (isothermal approximation) that most of the plasma in the brighter Fe XVIII AR loops is at temperatures between 3.5 and 4 MK.

  14. Basic visual observation skills training course: Appendix B. Final report

    SciTech Connect

    Toquam, J.L.; Morris, F.A.; Griggs, J.R.

    1995-06-01

    The purpose of the basic visual observation skills course is to help safeguards inspectors evaluate and improve their skills in making observations during inspections and in evaluating and interpreting this information. The first 12 hours of the course provide training in five skill areas: perception and recognition; attention to detail; memory; mental imaging, mapping, and modeling skills; and judgment and decision making. Following this training is an integrating exercise involving a simulated safeguards inspection. This report contains the in-class exercises in the five skill areas; pre- and post-course exercises in closure, hidden figures, map memory, and mental rotations; the final examination; a training evaluation form; and the integrating exercise.

  15. Automated Surface Observing System: Standby Power Options | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy Automated Surface Observing System: Standby Power Options Automated Surface Observing System: Standby Power Options This presentation by Anthony Leonardo of the National Weather Service was given at the Fuel Cell Meeting in April 2007. fuel_cell_mtng_leonardo.pdf (323.76 KB) More Documents & Publications Dominion Cove Point LNG, LP - FE Dkt. No 11-128-LNG Order 3331-A: Dominion Cove Point LNG, LP - Dk. No. 11-128-LNG Market Transformation: Fuel Cell Early Adoption (Pres

  16. Observation of excited states in /sup 128/Ba

    SciTech Connect

    Zhao Zhi-zheng; Guo Ying-xiang; Pan Zong-you; Xiao Jian-min; Lei Xiang-guo; Liu Hong-ye; Sun Xi-jun

    1987-01-01

    Excited states in /sup 128/Ba have been investigated via the /sup 120/Sn (/sup 12/C, 4n..gamma..) /sup 128/Ba reaction by means of in-beam gamma spectroscopy. A 12/sup +/ state other than the previously reported one is observed according to the properties of the 935.0 keV ..gamma..-ray. It does not belong to the ground-state band. Two new interband transitions, 224.8 keV and 632.7 keV, are observed and assigned to sidefeeding between the negative-parity band and ground-state band.

  17. Properties of solar gravity mode signals in total irradiance observations

    SciTech Connect

    Kroll, R.J.; Chen, J.; Hill, H.A.

    1988-01-01

    Further evidence has been found that a significant fraction of the gravity mode power density in the total irradiance observations appears in sidebands of classified eigenfrequencies. These sidebands whose amplitudes vary from year to year are interpreted as harmonics of the rotational frequencies of the nonuniform solar surface. These findings are for non axisymmetric modes and corroborate the findings of Kroll, Hill and Chen for axisymmetric modes. It is demonstrated the the generation of the sidebands lifts the usual restriction on the parity of the eigenfunctions for modes detectable in total irradiance observations. 14 refs.

  18. Observation of diamond turned OFHC copper using Scanning Tunneling Microscopy

    SciTech Connect

    Grigg, D.A.; Russell, P.E.; Dow, T.A.

    1988-12-01

    Diamond turned OFHC copper samples have been observed within the past few months using the Scanning Tunneling Microscope. Initial results have shown evidence of artifacts which may be used to better understand the diamond turning process. The STM`s high resolution capability and three dimensional data representation allows observation and study of surface features unobtainable with conventional profilometry systems. Also, the STM offers a better quantitative means by which to analyze surface structures than the SEM. This paper discusses findings on several diamond turned OFHC copper samples having different cutting conditions. Each sample has been cross referenced using STM and SEM.

  19. Halloween observed with costume luncheon | The Ames Laboratory

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Halloween observed with costume luncheon Halloween was observed on October 31 with a potluck luncheon and employees encouraged to come in costume. Photos from the event follow below: Melinda "Flo" Schlosser and Mark "Mayhem" Murphy. Accounting department "account-ants." Lisa Rodgers as Minnie Mouse Justin Nauman as Doc Holliday Sarah Morris-Benevides touches up her "Flo" lipstick. Stacey Trytek, as the ivy-covered wall at Wrigley Field, took Best costume

  20. ARM - Field Campaign - Routine AAF CLOWD Optical Radiative Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    (RACORO) govCampaignsRoutine AAF CLOWD Optical Radiative Observations (RACORO) Campaign Links RACORO Website ARM Data Discovery Browse Data Related Campaigns Surface Radiation Comparison Transfer Measurements for RACORO 2009.01.20, Long, SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Routine AAF CLOWD Optical Radiative Observations (RACORO) 2009.01.22 - 2009.06.30 Website : http://www.arm.gov/campaigns/racoro/ Lead Scientist :

  1. ARM - Field Campaign - Water Cycle Pilot Study Intensive Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    govCampaignsWater Cycle Pilot Study Intensive Observations ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Water Cycle Pilot Study Intensive Observations 2002.04.01 - 2002.06.30 Lead Scientist : Marvin Wesely For data sets, see below. Abstract The U.S. DOE Water Cycle Pilot Study (WCPS) is a 3-year feasibility investigation focused on accurately evaluating the water cycle components and using stable

  2. Placement of the dam for the no. 2 kambaratinskaya HPP by large-scale blasting: some observations

    SciTech Connect

    Shuifer, M. I.; Argal, E. S.

    2011-11-15

    Results of complex instrument observations of large-scale blasting during construction of the dam for the No. 2 Kambaratinskaya HPP on the Naryn River in the Republic of Kirgizia are analyzed. The purpose of these observations was: to determine the actual parameters of the seismic process, evaluate the effect of air and acoustic shock waves, and investigate the kinematics of the surface formed by the blast in its core region within the mass of fractured rocks.

  3. Observation of Ion Acceleration and Heating during Collisionless...

    Office of Scientific and Technical Information (OSTI)

    ... In collisionless plasmas, this Hall effect facilitates a faster re- connection than predicted by the classical Sweet-Parker rate 2, 3. However, the mechanisms that convert mag- ...

  4. Observation of the Second Harmonic in Thomson Scattering from...

    Office of Scientific and Technical Information (OSTI)

    A free relativistic electron in an electromagnetic field is a pure case of a light-matter ... DOPPLER EFFECT; ELECTRODYNAMICS; ELECTROMAGNETIC FIELDS; ELECTRON BEAMS; ELECTRONS; ...

  5. The Radiative Properties of Small Clouds: Multi-Scale Observations...

    Office of Scientific and Technical Information (OSTI)

    characterize shallow clouds and the role of aerosol in modifying their radiative effects. ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 54 ...

  6. First Direct Observation of Carbon Dioxide's Increasing Greenhouse...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    incoming energy from the Sun and outgoing heat from the Earth (also called the planet's energy balance) is well established. But this effect has not been experimentally confirmed...

  7. LES ARM Symbiotic Simulation and Observation (LASSO) Implementation Strategy

    SciTech Connect

    Gustafson Jr., WI; Vogelmann, AM

    2015-09-01

    This document illustrates the design of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) workflow to provide a routine, high-resolution modeling capability to augment the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s high-density observations. LASSO will create a powerful new capability for furthering ARM’s mission to advance understanding of cloud, radiation, aerosol, and land-surface processes. The combined observational and modeling elements will enable a new level of scientific inquiry by connecting processes and context to observations and providing needed statistics for details that cannot be measured. The result will be improved process understanding that facilitates concomitant improvements in climate model parameterizations. The initial LASSO implementation will be for ARM’s Southern Great Plains site in Oklahoma and will focus on shallow convection, which is poorly simulated by climate models due in part to clouds’ typically small spatial scale compared to model grid spacing, and because the convection involves complicated interactions of microphysical and boundary layer processes.

  8. Autonomous observations of the ocean biological carbon pump

    SciTech Connect

    Bishop, James K.B.

    2009-03-01

    Prediction of the substantial biologically mediated carbon flows in a rapidly changing and acidifying ocean requires model simulations informed by observations of key carbon cycle processes on the appropriate space and time scales. From 2000 to 2004, the National Oceanographic Partnership Program (NOPP) supported the development of the first low-cost fully-autonomous ocean profiling Carbon Explorers that demonstrated that year-round real-time observations of particulate organic carbon (POC) concentration and sedimentation could be achieved in the world's ocean. NOPP also initiated the development of a sensor for particulate inorganic carbon (PIC) suitable for operational deployment across all oceanographic platforms. As a result, PIC profile characterization that once required shipboard sample collection and shipboard or shore based laboratory analysis, is now possible to full ocean depth in real time using a 0.2W sensor operating at 24 Hz. NOPP developments further spawned US DOE support to develop the Carbon Flux Explorer, a free-vehicle capable of following hourly variations of particulate inorganic and organic carbon sedimentation from near surface to kilometer depths for seasons to years and capable of relaying contemporaneous observations via satellite. We have demonstrated the feasibility of real time - low cost carbon observations which are of fundamental value to carbon prediction and when further developed, will lead to a fully enhanced global carbon observatory capable of real time assessment of the ocean carbon sink, a needed constraint for assessment of carbon management policies on a global scale.

  9. Observable form of pulses emitted from relativistic collapsing objects

    SciTech Connect

    Frolov, Valeri P.; Lee, Hyun Kyu

    2005-02-15

    In this work, we discuss observable characteristics of the radiation emitted from a surface of a collapsing object. We study a simplified model in which a radiation of massless particles has a sharp in time profile, and it happens at the surface at the same moment of comoving time. Since the radiating surface has finite size the observed radiation will occur during some finite time. Its redshift and bending angle are affected by the strong gravitational field. We obtain a simple expression for the observed flux of the radiation as a function of time. To find an explicit expression for the flux we develop an analytical approximation for the bending angle and time delay for null rays emitted by a collapsing surface. In the case of the bending angle this approximation is an improved version of the earlier proposed Beloborodov-Leahy-approximation. For rays emitted at R>2R{sub g} the accuracy of the proposed improved approximations for the bending angle and time delay is of order (or less) than 2%-3%. By using this approximation we obtain an approximate analytical expression for the observed flux and study its properties.

  10. Observable Form of Pulses Emitted From Relativistic Collapsing Objects

    SciTech Connect

    Frolov, V.

    2005-01-28

    In this work, we discuss observable characteristics of the radiation emitted from a surface of a collapsing object. We study a simplified model in which a radiation of massless particles has a sharp in time profile and it happens at the surface at the same moment of comoving time. Since the radiating surface has finite size the observed radiation will occur during some finite time. Its redshift and bending angle are affected by the strong gravitational field. We obtain a simple expression for the observed flux of the radiation as a function of time. To find an explicit expression for the flux we develop an analytical approximation for the bending angle and time delay for null rays emitted by a collapsing surface. In the case of the bending angle this approximation is an improved version of the earlier proposed Beloborodov-Leahy-approximation. For rays emitted at R > 2R{sub g} the accuracy of the proposed improved approximations for the bending angle and time delay is of order (or less) than 2-3%. By using this approximation we obtain an approximate analytical expression for the observed flux and study its properties.

  11. Direct observation of photoinduced bent nitrosyl excited-state complexes

    SciTech Connect

    Sawyer, Karma R.; Steele, Ryan P.; Glascoe, Elizabeth A.; Cahoon, James F.; Schlegel, Jacob P.; Head-Gordon, Martin; Harris, Charles B.

    2008-06-28

    Ground state structures with side-on nitrosyl ({eta}{sup 2}-NO) and isonitrosyl (ON) ligands have been observed in a variety of transition-metal complexes. In contrast, excited state structures with bent-NO ligands have been proposed for years but never directly observed. Here we use picosecond time-resolved infrared spectroscopy and density functional theory (DFT) modeling to study the photochemistry of Co(CO){sub 3}(NO), a model transition-metal-NO compound. Surprisingly, we have observed no evidence for ON and {eta}{sup 2}-NO structural isomers, but have observed two bent-NO complexes. DFT modeling of the ground and excited state potentials indicates that the bent-NO complexes correspond to triplet excited states. Photolysis of Co(CO){sub 3}(NO) with a 400-nm pump pulse leads to population of a manifold of excited states which decay to form an excited state triplet bent-NO complex within 1 ps. This structure relaxes to the ground triplet state in ca. 350 ps to form a second bent-NO structure.

  12. Observation of objects under intense plasma background illumination

    SciTech Connect

    Buzhinsky, R. O.; Savransky, V. V.; Zemskov, K. I.; Isaev, A. A.; Buzhinsky, O. I.

    2010-12-15

    Experiments on the observation of a brightness-amplified image of an object through a masking arc discharge are presented. The copper-vapor laser active medium was used as an image brightness amplifier. It is shown that the image quality does not worsen under plasma background illumination.

  13. Microscopic observations of palladium used for cold fusion

    SciTech Connect

    Matsumoto, T. )

    1991-05-01

    This paper examines the microscopic structures of palladium metals used for cold fusion experiments. Tiny spot defects suggesting cold fusion have been observed in grain boundaries as the Nattoh model predicts. The relationship between these defects and a series of neutron busts and an indirect loop of hydrogen chain reactions are discussed.

  14. Expanding the Discovery Potential of VERITAS via Moonlight Observations

    SciTech Connect

    Benbow, Wystan R. [PI

    2014-10-27

    This grant partially supported the base research efforts of the Smithsonian Astrophysical Observatory (SAO), Very-High-Energy (VHE; E > 100 GeV) gamma-ray research group from 8/1/09 to 7/31/14. During the project period, the SAO gamma-ray group carried out a wide-range of research efforts, but focused on VHE observations of extragalactic sources with VERITAS. The SAO group led or co-lead nearly all VERITAS extragalactic working groups and the observations addressed themes in Particle Physics and Fundamental Laws, Cosmology, and Black Holes. The primary topics of this research were processes in exotic galaxies, especially active galactic nuclei and starburst galaxies, which have implications for cosmology and Lorentz invariance violation, as well as indirect dark matter detection via VERITAS observations of dwarf spheroidal galaxies. In addition, the SAO group let the development of unique capabilities for VERITAS to observe during all periods of moonlight. Overall, this has increased the VERITAS data yield by 60% and these data are both scientifically useful and regularly published. This grant funded research that led to contributions towards the publication of 51 refereed journal articles during the project period, including several led by, or with significant contributions from, the SAO group.

  15. Observations from The EV Project in Q4 2013

    SciTech Connect

    John Smart

    2014-02-01

    This is a summary report for The EV Project 4th quarter 2013 reports. It describes electric vehicle driver driving and charging behavior observed in Q4. It is the same report as the previously approved/published Q3 2013 report, only the numbers have been updated. It is for public release and does not have limited distribution.

  16. Tensor spin observables and spin stucture at low Q2

    SciTech Connect

    Slifer, Karl J.

    2015-04-01

    We discuss recent spin structure results from Jefferson Lab, and outline an emerging program to study tensor spin observables using solid deuteron targets. These new experiments open the potential to study hidden color, the tensor nature of short range correlations, and to probe for exotic gluonic states.

  17. Photocatalytic and magnetic behaviors observed in nanostructured BiFeO{sub 3} particles

    SciTech Connect

    Li Shun; Lin Yuanhua; Nan Cewen; Wang Yao; Zhang Boping

    2009-03-01

    Nanostructured BiFeO{sub 3} particles have been synthesized by a hydrothermal method, and the effects of particle size on photocatalytic activity and magnetic property of BiFeO{sub 3} were investigated. The optical absorption spectra indicate that the band-gap energy increases with decreasing crystalline size due to the quantum-size effect. The enhancement of room-temperature weak ferromagnetism can be observed in nanoscale BiFeO{sub 3} particles, which should be attributed to the size-confinement effect on the magnetic ordering. In addition, BiFeO{sub 3} nanoparticles with diameter about 5 nm show good photocatalytic performance by photodegradation of Congo red under visible-light ({lambda}>400 nm) irradiation.

  18. Flare heating and ionization of the low solar chromosphere. II. Observations of five solar flares

    SciTech Connect

    Metcalf, T.R.; Canfield, R.C.; Saba, J.L.R. Hawaii Univ., Honolulu Lockheed Research Laboratories, Palo Alto, CA )

    1990-12-01

    Two neutral Mg spectral lines formed in the temperature-minimum region and the low chromosphere, at 4571 and 5173 A, are used to quantify the changes in the atmospheric structure as a function of time during five solar flares. Eight proposed flare heating and ionization mechanisms and predictions of the effects of each on the temperature minimum region are discussed. Two Mg spectral observations made at the National Solar Observatory (Sacramento Peak), along with observations of hard and soft X-rays from the SMM and GOES satellites, are compared to the predictions of the eight proposed mechanisms. The initial effects in all five flares are consistent with backwarming by enhanced Balmer- and Paschen-continuum radiation originating in the upper chromosphere. Extended heating observed in two of the flares is most likely due to UV irradiation. In all cases heating by the dissipation of nonreversed electric currents, collisions with an electron or proton beam, irradiation by soft X-rays, and dissipation of Alfven waves are eliminated. 61 refs.

  19. Simulating the role of surface forcing on observed multidecadal upper-ocean salinity changes

    DOE PAGES [OSTI]

    Lago, Veronique; Wijffels, Susan E.; Durack, Paul J.; Church, John A.; Bindoff, Nathaniel L.; Marsland, Simon J.

    2016-07-18

    The ocean’s surface salinity field has changed over the observed record, driven by an intensification of the water cycle in response to global warming. However, the origin and causes of the coincident subsurface salinity changes are not fully understood. The relationship between imposed surface salinity and temperature changes and their corresponding subsurface changes is investigated using idealized ocean model experiments. The ocean’s surface has warmed by about 0.5°C (50 yr)–1 while the surface salinity pattern has amplified by about 8% per 50 years. The idealized experiments are constructed for a 50-yr period, allowing a qualitative comparison to the observed salinitymore » and temperature changes previously reported. The comparison suggests that changes in both modeled surface salinity and temperature are required to replicate the three-dimensional pattern of observed salinity change. The results also show that the effects of surface changes in temperature and salinity act linearly on the changes in subsurface salinity. In addition, surface salinity pattern amplification appears to be the leading driver of subsurface salinity change on depth surfaces; however, surface warming is also required to replicate the observed patterns of change on density surfaces. This is the result of isopycnal migration modified by the ocean surface warming, which produces significant salinity changes on density surfaces.« less

  20. X-ray observations of complex temperature structure in the cool-core cluster A85

    SciTech Connect

    Schenck, David E.; Datta, Abhirup; Burns, Jack O.; Skillman, Sam

    2014-07-01

    X-ray observations were used to examine the complex temperature structure of A85, a cool-core galaxy cluster. Temperature features can provide evidence of merging events which shock heat the intracluster gas. Temperature maps were made from both Chandra and XMM-Newton observations. The combination of a new, long-exposure XMM observation and an improved temperature map binning technique produced the highest fidelity temperature maps of A85 to date. Hot regions were detected near the subclusters to the south and southwest in both the Chandra and XMM temperature maps. The presence of these structures implies A85 is not relaxed. The hot regions may indicate the presence of shocks. The Mach numbers were estimated to be ∼1.9 at the locations of the hot spots. Observational effects will tend to systematically reduce temperature jumps, so the measured Mach numbers are likely underestimated. Neither temperature map showed evidence for a shock in the vicinity of the presumed radio relic near the southwest subcluster. However, the presence of a weak shock cannot be ruled out. There was tension between the temperatures measured by the two instruments.

  1. Observation of the Decay B??Ds(*)+K?l????l

    DOE PAGES [OSTI]

    del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; et al

    2011-07-22

    We report the observation of the decay B??Ds(*)+K?l??l based on 342fb? of data collected at the ?(4S) resonance with the BABAR detector at the PEP-II e?e? storage rings at SLAC. A simultaneous fit to three D+s decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B??Ds(*)+K?l??l with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B??Ds(*)+K?l??l)=[6.13+1.04-1.03(stat)0.43(syst)0.51(B(Ds))]10??, where the last error reflects the limited knowledge of the Ds branching fractions.

  2. Mass flows in a prominence spine as observed in EUV

    SciTech Connect

    Kucera, T. A.; Gilbert, H. R.

    2014-07-20

    We analyze a quiescent prominence observed by the Solar Dynamics Observatory's Atmospheric Imaging Assembly (AIA) with a focus on mass and energy flux in the spine, measured using Lyman continuum absorption. This is the first time this type of analysis has been applied with an emphasis on individual features and fluxes in a quiescent prominence. The prominence, observed on 2010 September 28, is detectable in most AIA wavebands in absorption and/or emission. Flows along the spine exhibit horizontal bands 5''-10'' wide and kinetic energy fluxes on the order of a few times 10{sup 5} erg s{sup 1}cm{sup 2}, consistent with quiet sun coronal heating estimates. For a discrete moving feature we estimate a mass of a few times 10{sup 11} g. We discuss the implications of our derived properties for a model of prominence dynamics, the thermal non-equilibrium model.

  3. OBSERVATIONS OF HIERARCHICAL SOLAR-TYPE MULTIPLE STAR SYSTEMS

    SciTech Connect

    Roberts, Lewis C. Jr.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Riddle, Reed L.

    2015-10-15

    Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible Robo-AO system with new near-infrared observations with PALM-3000. The physical status of most, but not all, of the new pairs is confirmed by photometry in the Ks band and new positional measurements. In addition, we resolved for the first time five close sub-systems: the known astrometric binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP 118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We place the components on a color–magnitude diagram and discuss each multiple system individually.

  4. Observational constraints on late-time {lambda}(t) cosmology

    SciTech Connect

    Carneiro, S.; Pigozzo, C.; Dantas, M. A.; Alcaniz, J. S.

    2008-04-15

    The cosmological constant {lambda}, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its observational successes, such a possibility exacerbates the well-known {lambda} problem, requiring a natural explanation for its small, but nonzero, value. In this paper we study cosmological consequences of a scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, {lambda}{proportional_to}H. We test the viability of this scenario and study a possible way to distinguish it from the current standard cosmological model by using recent observations of type Ia supernova (Supernova Legacy Survey Collaboration), measurements of the baryonic acoustic oscillation from the Sloan Digital Sky Survey, and the position of the first peak of the cosmic microwave background angular spectrum from the three-year Wilkinson Microwave Anisotropy Probe.

  5. SDO OBSERVATIONS OF MAGNETIC RECONNECTION AT CORONAL HOLE BOUNDARIES

    SciTech Connect

    Yang Shuhong; Zhang Jun; Li Ting; Liu Yang E-mail: zjun@nao.cas.cn E-mail: yliu@quake.stanford.edu

    2011-05-01

    With the observations from the Atmospheric Imaging Assembly and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we investigate the coronal hole boundaries (CHBs) of an equatorial extension of the polar coronal hole. At the CHBs, many extreme-ultraviolet jets, which appear to be the signatures of magnetic reconnection, are observed in the 193 A images, and some jets occur repetitively at the same sites. The evolution of the jets is associated with the emergence and cancellation of magnetic fields. We note that both the east and west CHBs shift westward, and the shift velocities are close to the velocities of rigid rotation compared with those of the photospheric differential rotation. This indicates that magnetic reconnection at CHBs results in the evolution of CHBs and maintains the rigid rotation of coronal holes.

  6. HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

    SciTech Connect

    Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

    2013-08-01

    Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

  7. Observation of Materials Processes in Liquids in the Electron Microscope

    SciTech Connect

    Wang, Chong M.; Liao, Honggang; Ross, Frances M.

    2015-01-01

    Materials synthesis and the functioning of devices often indispensably involve liquid media. But direct visualization of dynamic process in liquids, especially with high spatial and temporal resolution, has been challenging. For solid materials, advances in aberration corrected electron microscopy have made observation of atomic level features a routine practice. Here we discuss the extent to which one can take advantage of the resolution of modern electron microscopes to image phenomenon occuring in liquids. We will describe the fundamentals of two different experimental approaches, closed and open liquid cells. We will illustrate the capabilities of each approach by considering processes in batteries and nucleation and growth of nanoparticles from solution. We conclude that liquid cell electron microscopy appears to be duly fulfilling its role for in situ studies of nanoscale processes in liquids, revealing physical and chemical processes otherwise difficult to observe.

  8. Observational evidence of dust evolution in galactic extinction curves

    SciTech Connect

    Cecchi-Pestellini, Cesare; Casu, Silvia; Mulas, Giacomo; Zonca, Alberto E-mail: silvia@oa-cagliari.inaf.it E-mail: azonca@oa-cagliari.inaf.it

    2014-04-10

    Although structural and optical properties of hydrogenated amorphous carbons are known to respond to varying physical conditions, most conventional extinction models are basically curve fits with modest predictive power. We compare an evolutionary model of the physical properties of carbonaceous grain mantles with their determination by homogeneously fitting observationally derived Galactic extinction curves with the same physically well-defined dust model. We find that a large sample of observed Galactic extinction curves are compatible with the evolutionary scenario underlying such a model, requiring physical conditions fully consistent with standard density, temperature, radiation field intensity, and average age of diffuse interstellar clouds. Hence, through the study of interstellar extinction we may, in principle, understand the evolutionary history of the diffuse interstellar clouds.

  9. Direct Observation of SEI and Dendrite Dynamics by Operando Electrochemical

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Scanning Transmission Electron Microscopy - Joint Center for Energy Storage Research February 23, 2015, Research Highlights Direct Observation of SEI and Dendrite Dynamics by Operando Electrochemical Scanning Transmission Electron Microscopy (Top) Li deposited on the Pt anode at the beginning (left), during (middle) and end (right) of the second cycle. Residual "dead Li" can be seen around the anode. (Center) Simultaneous cyclic voltammetry of the second Li deposition/dissolution

  10. Sample Observations from the 2001.Multi-Frequency Radar IOP

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Sample Observations from the 2001 Multi-Frequency Radar IOP C. R. Williams Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder, Colorado C. R. Williams and K. S. Gage National Oceanic and Atmospheric Administration Aeronomy Laboratory Boulder, Colorado L. Leon and S. Cruz-Pol University of Puerto Rico Mayaguez Campus S. M. Sekelsky Microwave Remote Sensing Laboratory University of Massachusetts Amherst, Massachusetts Introduction The 2001 Multi-Frequency

  11. FILAMENTARY STAR FORMATION: OBSERVING THE EVOLUTION TOWARD FLATTENED ENVELOPES

    SciTech Connect

    Lee, Katherine; Looney, Leslie; Johnstone, Doug; Tobin, John E-mail: lwl@illinois.edu E-mail: jtobin@nrao.edu

    2012-12-20

    Filamentary structures are ubiquitous from large-scale molecular clouds (a few parsecs) to small-scale circumstellar envelopes around Class 0 sources ({approx}1000 AU to {approx}0.1 pc). In particular, recent observations with the Herschel Space Observatory emphasize the importance of large-scale filaments (a few parsecs) and star formation. The small-scale flattened envelopes around Class 0 sources are reminiscent of the large-scale filaments. We propose an observationally derived scenario for filamentary star formation that describes the evolution of filaments as part of the process for formation of cores and circumstellar envelopes. If such a scenario is correct, small-scale filamentary structures (0.1 pc in length) with higher densities embedded in starless cores should exist, although to date almost all the interferometers have failed to observe such structures. We perform synthetic observations of filaments at the prestellar stage by modeling the known Class 0 flattened envelope in L1157 using both the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the Atacama Large Millimeter/Submillimeter Array (ALMA). We show that with reasonable estimates for the column density through the flattened envelope, the CARMA D array at 3 mm wavelengths is not able to detect such filamentary structure, so previous studies would not have detected them. However, the substructures may be detected with the CARMA D+E array at 3 mm and the CARMA E array at 1 mm as a result of more appropriate resolution and sensitivity. ALMA is also capable of detecting the substructures and showing the structures in detail compared to the CARMA results with its unprecedented sensitivity. Such detection will confirm the new proposed paradigm of non-spherical star formation.

  12. Surface Albedo at ARM SGP from Helicopter Observations

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Albedo at the Atmospheric Radiation Measurement Southern Great Plains Site from Helicopter Observations D. A. Rutan, F. G. Rose, and J. Madigan Analytical Services and Materials Inc. Hampton, Virginia T. P. Charlock National Aeronautics and Space Administration Langley Research Center Hampton, Virginia Introduction In August 1998, scientists from the National Aeronautics and Space Administration (NASA) Langley Research Center conducted a series of helicopter flights to determine spectral

  13. Evaluating climate models: Should we use weather or climate observations?

    SciTech Connect

    Oglesby, Robert J; Erickson III, David J

    2009-12-01

    Calling the numerical models that we use for simulations of climate change 'climate models' is a bit of a misnomer. These 'general circulation models' (GCMs, AKA global climate models) and their cousins the 'regional climate models' (RCMs) are actually physically-based weather simulators. That is, these models simulate, either globally or locally, daily weather patterns in response to some change in forcing or boundary condition. These simulated weather patterns are then aggregated into climate statistics, very much as we aggregate observations into 'real climate statistics'. Traditionally, the output of GCMs has been evaluated using climate statistics, as opposed to their ability to simulate realistic daily weather observations. At the coarse global scale this may be a reasonable approach, however, as RCM's downscale to increasingly higher resolutions, the conjunction between weather and climate becomes more problematic. We present results from a series of present-day climate simulations using the WRF ARW for domains that cover North America, much of Latin America, and South Asia. The basic domains are at a 12 km resolution, but several inner domains at 4 km have also been simulated. These include regions of complex topography in Mexico, Colombia, Peru, and Sri Lanka, as well as a region of low topography and fairly homogeneous land surface type (the U.S. Great Plains). Model evaluations are performed using standard climate analyses (e.g., reanalyses; NCDC data) but also using time series of daily station observations. Preliminary results suggest little difference in the assessment of long-term mean quantities, but the variability on seasonal and interannual timescales is better described. Furthermore, the value-added by using daily weather observations as an evaluation tool increases with the model resolution.

  14. Attosecond Electron Wave-Packet Interference Observed by Transient Absorption

    SciTech Connect

    Holler, M.; Schapper, F.; Gallmann, L.; Keller, U.

    2011-03-25

    We perform attosecond time-resolved transient absorption spectroscopy around the first ionization threshold of helium and observe rapid oscillations of the absorption of the individual harmonics as a function of time delay with respect to a superimposed, moderately strong infrared laser field. The phase relation between the absorption modulation of individual harmonics gives direct evidence for the interference of transiently bound electronic wave packets as the mechanism behind the absorption modulation.

  15. ARM - LES ARM Symbiotic Simulation and Observation Workflow

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ThemesLES ARM Symbiotic Simulation and Observation Workflow LASSO Information LASSO Home LASSO Backgrounder Pilot Phase Begins for Routine Large-Eddy Simulations Pilot Project Timeline Presentations News Science LASSO Implementation Strategy LASSO Pilot Project Releases Related Information ARM Decadal Vision Archive of LASSO Information e-mail list Contacts William Gustafson, Lead Principal Investigator Andrew Vogelmann, Co-Principal Investigator Hanna Goss, Media Contact LES ARM Symbiotic

  16. Observing Oxygen Atoms Move during Information Storage in Tantalum Oxide

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Memristors | Stanford Synchrotron Radiation Lightsource Observing Oxygen Atoms Move during Information Storage in Tantalum Oxide Memristors Saturday, April 30, 2016 Memristor technology, or resistive random access memory (RRAM), is a frontrunner for next generation computer memory, owing to the promise of long endurance, low power, nanoscale device size and fast operation.1 Memristor devices are typically made of a transition metal oxide sandwiched between two metallic electrodes, and

  17. Excitons, biexcitons, and higher-order correlations: Direct observations of

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ultrafast many-body dynamics | MIT-Harvard Center for Excitonics Excitons, biexcitons, and higher-order correlations: Direct observations of ultrafast many-body dynamics April 15, 2009 at 3pm/36-428 Keith A. Nelson Department of Chemistry Massachusetts Institute of Technology nelson abstract: Much is known about the ultrafast dynamics of excitons in semiconductors and organic molecular systems. Far less is understood about higher-order correlations that may lead to bound multi-exciton

  18. Ultrafast photodetectors allow direct observation of multiple electrons

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    generated by a single photon Ultrafast photodetectors Ultrafast photodetectors allow direct observation of multiple electrons generated by a single photon The new technique involves monitoring photocurrent transients in specially engineered photodetectors that provide very high temporal resolution of only 50 picoseconds. September 11, 2015 Andrew Fidler of Los Alamos National Laboratory examines an ultrafast photodetector used to measure quantum dot carrier multiplication in real time.

  19. ARM - Publications: Science Team Meeting Documents: An Observational

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Analysis of Cumulus Congestus at Nauru An Observational Analysis of Cumulus Congestus at Nauru Jensen, Michael Brookhaven National Laboratory Del Genio, Anthony NASA/Goddard Institute for Space Studies Cumulus congestus clouds, with moderate shortwave albedos and cloud-top temperatures near freezing, occur fairly often in the tropics. These clouds may play an important role in the evolution of the Madden-Julian oscillation and the regulation of relative humidity in the mid-troposphere.

  20. Observed correlations between aerosol and cloud properties in an Indian Ocean trade cumulus regime

    DOE PAGES [OSTI]

    Pistone, Kristina; Praveen, Puppala S.; Thomas, Rick M.; Ramanathan, Veerabhadran; Wilcox, Eric M.; Bender, Frida A.-M.

    2016-04-27

    There are many contributing factors which determine the micro- and macrophysical properties of clouds, including atmospheric vertical structure, dominant meteorological conditions, and aerosol concentration, all of which may be coupled to one another. In the quest to determine aerosol effects on clouds, these potential relationships must be understood. Here we describe several observed correlations between aerosol conditions and cloud and atmospheric properties in the Indian Ocean winter monsoon season.In the CARDEX (Cloud, Aerosol, Radiative forcing, Dynamics EXperiment) field campaign conducted in February and March 2012 in the northern Indian Ocean, continuous measurements were made of atmospheric precipitable water vapor (PWV)more » and the liquid water path (LWP) of trade cumulus clouds, concurrent with measurements of water vapor flux, cloud and aerosol vertical profiles, meteorological data, and surface and total-column aerosol from instrumentation at a ground observatory and on small unmanned aircraft. We present observations which indicate a positive correlation between aerosol and cloud LWP only when considering cases with low atmospheric water vapor (PWV < 40 kg m–2), a criterion which acts to filter the data to control for the natural meteorological variability in the region.We then use the aircraft and ground-based measurements to explore possible mechanisms behind this observed aerosol–LWP correlation. The increase in cloud liquid water is found to coincide with a lowering of the cloud base, which is itself attributable to increased boundary layer humidity in polluted conditions. High pollution is found to correlate with both higher temperatures and higher humidity measured throughout the boundary layer. A large-scale analysis, using satellite observations and meteorological reanalysis, corroborates these covariations: high-pollution cases are shown to originate as a highly polluted boundary layer air mass approaching the observatory from a

  1. Observational constraints on holographic dark energy with varying gravitational constant

    SciTech Connect

    Lu, Jianbo; Xu, Lixin; Saridakis, Emmanuel N.; Setare, M.R. E-mail: msaridak@phys.uoa.gr E-mail: lxxu@dlut.edu.cn

    2010-03-01

    We use observational data from Type Ia Supernovae (SN), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and observational Hubble data (OHD), and the Markov Chain Monte Carlo (MCMC) method, to constrain the cosmological scenario of holographic dark energy with varying gravitational constant. We consider both flat and non-flat background geometry, and we present the corresponding constraints and contour-plots of the model parameters. We conclude that the scenario is compatible with observations. In 1? we find ?{sub ?0} = 0.72{sup +0.03}{sub ?0.03}, ?{sub k0} = ?0.0013{sup +0.0130}{sub ?0.0040}, c = 0.80{sup +0.19}{sub ?0.14} and ?{sub G}?G'/G = ?0.0025{sup +0.0080}{sub ?0.0050}, while for the present value of the dark energy equation-of-state parameter we obtain w{sub 0} = ?1.04{sup +0.15}{sub ?0.20}.

  2. Observation of incomplete fusion reactions at l < l {sub crit}

    SciTech Connect

    Yadav, Abhishek Sharma, Vijay R. Singh, Devendra P. Unnati,; Singh, B. P.; Prasad, R.; Singh, Pushpendra P.; Bala, Indu; Kumar, R.; Muralithar, S.; Singh, R. P.; Sharma, M. K.

    2014-08-14

    In order to understand the presence of incomplete fusion at low energies i.e. 4-7MeV/nucleon and also to study its dependence on various entrance-channel parameters, the two type of measurements (i) excitation function for {sup 12}C+{sup 159}Tb, and (ii) forward recoil ranges for {sup 12}C+{sup 159}Tb systems have been performed. The experimentally measured excitation functions have been analyzed within the framework of compound nucleus decay using statistical model code PACE4. Analysis of data suggests the production of xn/px)n-channels via complete fusion, as these are found to be well reproduced by PACE4 predictions, while, a significant enhancement in the excitation functions of ?-emitting channels has been observed over the theoretical ones, which has been attributed due to the incomplete fusion processes. Further, the incomplete fusion events observed in case of forward recoil range measurements have been explained on the basis of the breakup fusion model, where these events may be attributed to the fusion of {sup 8}Be and/or {sup 4}He from {sup 12}C projectile to the target nucleus. In the present work, the SUMRULE model calculations are found to highly underestimate the observed incomplete fusion cross-sections which indicate that the l-values lower than l {sub crit} (limit of complete fusion) significantly contribute to the incomplete fusion reactions.

  3. OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT

    SciTech Connect

    Warren, Harry P.; Doschek, George A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mariska, John T. [School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

    2013-06-20

    One of the defining characteristics of a solar flare is the impulsive formation of very high temperature plasma. The properties of the thermal emission are not well understood, however, and the analysis of solar flare observations is often predicated on the assumption that the flare plasma is isothermal. The EUV Variability Experiment (EVE) on the Solar Dynamics Observatory provides spectrally resolved observations of emission lines that span a wide range of temperatures (e.g., Fe XV-Fe XXIV) and allow for thermal flare plasma to be studied in detail. In this paper we describe a method for computing the differential emission measure distribution in a flare using EVE observations and apply it to several representative events. We find that in all phases of the flare the differential emission measure distribution is broad. Comparisons of EVE spectra with calculations based on parameters derived from the Geostationary Operational Environmental Satellites soft X-ray fluxes indicate that the isothermal approximation is generally a poor representation of the thermal structure of a flare.

  4. Solar flare impulsive phase emission observed with SDO/EVE

    SciTech Connect

    Kennedy, Michael B.; Milligan, Ryan O.; Mathioudakis, Mihalis; Keenan, Francis P., E-mail: mkennedy29@qub.ac.uk [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN (United Kingdom)

    2013-12-10

    Differential emission measures (DEMs) during the impulsive phase of solar flares were constructed using observations from the EUV Variability Experiment (EVE) and the Markov-Chain Monte Carlo method. Emission lines from ions formed over the temperature range log T{sub e} = 5.8-7.2 allow the evolution of the DEM to be studied over a wide temperature range at 10 s cadence. The technique was applied to several M- and X-class flares, where impulsive phase EUV emission is observable in the disk-integrated EVE spectra from emission lines formed up to 3-4 MK and we use spatially unresolved EVE observations to infer the thermal structure of the emitting region. For the nine events studied, the DEMs exhibited a two-component distribution during the impulsive phase, a low-temperature component with peak temperature of 1-2 MK, and a broad high-temperature component from 7 to 30 MK. A bimodal high-temperature component is also found for several events, with peaks at 8 and 25 MK during the impulsive phase. The origin of the emission was verified using Atmospheric Imaging Assembly images to be the flare ribbons and footpoints, indicating that the constructed DEMs represent the spatially average thermal structure of the chromospheric flare emission during the impulsive phase.

  5. HST/COS OBSERVATIONS OF THIRTEEN NEW He II QUASARS

    SciTech Connect

    Syphers, David; Anderson, Scott F.; Zheng Wei; Meiksin, Avery; Schneider, Donald P.; York, Donald G.

    2012-04-15

    The full reionization of intergalactic helium was a major event in the history of the intergalactic medium (IGM), and UV observations of the He II Gunn-Peterson trough allow us to characterize the end of this process at z {approx} 3. Due to intervening hydrogen absorption, quasars allowing such study are rare, with only 33 known in the literature, and most of those are very recent discoveries. We expand on our previous discovery work, and present 13 new He II quasars with redshifts 2.82 < z < 3.77, here selected with {approx}80% efficiency, and including several that are much brighter than the vast majority of those previously known. This is the largest sample of uniformly observed He II quasars covering such a broad redshift range, and they show evidence of IGM opacity increasing with redshift, as expected for the helium reionization epoch. No evidence of He II Ly{alpha} quasar emission is seen in individual or averaged spectra, posing a problem for standard models of the broad-line region. The current rapid advance in the study of He II quasars has been greatly facilitated by the Cosmic Origins Spectrograph on the Hubble Space Telescope, and we discuss the instrumental and other subtleties that must be taken into account in IGM He II observations.

  6. Observation of the $\\Xi_b^0$ Baryon

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2011-07-01

    The observation of the bottom, strange baryon {Xi}{sup 0}{sub b} through the decay chain {Xi}{sup 0}{sub b} {yields} {Xi}{sup +}{sub c} {pi}{sup -}, where {Xi}{sup +}{sub c} {yields} {Xi}{sup -} {pi}{sup +} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {yields} p {pi}{sup -}, is reported using data corresponding to an integrated luminosity of 4.2 ft{sup -1} from p{anti p} collisions at {radical}{ovr s} = 1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sup +5.6}{sub -5.4} candidates is observed whose probability of arising from a background fluctuation is 3.6 x 10{sup -12}, corresponding to 6.8 Gaussian standard deviations. The {Xi}{sup 0}{sub b} mass is measured to be 5787.8 {+-} 5.0(stat) {+-} 1.3(syst) MeV/c{sup 2}. In addition, the {Xi}{sup -}{sub b} is observed through the process {Xi}{sup -}{sub b} {yields} {Xi}{sup 0}{sub c} {pi}{sup -}, where {Xi}{sup 0}{sub c} {yields} {Xi}{sup -} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {pi}{sup -}, and {Lambda} {yields} p {pi}{sup -}.

  7. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  8. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (first echo). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  9. Off-center observers versus supernovae in inhomogeneous pressure universes

    SciTech Connect

    Balcerzak, Adam; Dabrowski, Mariusz P.; Denkiewicz, Tomasz [Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin (Poland)

    2014-09-10

    Exact luminosity distance and apparent magnitude formulae are applied to the Union2 557 supernovae sample in order to constrain the possible position of an observer outside of the center of symmetry in spherically symmetric inhomogeneous pressure Stephani universes, which are complementary to inhomogeneous density Lematre-Tolman-Bondi (LTB) void models. Two specific models are investigated. The first allows a barotropic equation of state at the center of symmetry without the need to specify a scale factor function (model IIA). The second has no barotropic equation of state at the center, but has an explicit dust-like scale factor evolution (model IIB). It is shown that even at 3? CL, an off-center observer cannot be further than about 4.4 Gpc away from the center of symmetry, which is comparable to the reported size of a void in LTB models with the most likely value of the distance from the center at about 341 Mpc for model IIA and 68 Mpc for model IIB. The off-center observer cannot be farther away from the center than about 577 Mpc for model IIB at 3? CL. It is determined that the best-fit parameters which characterize inhomogeneity are ?{sub inh} = 0.77 (dimensionless: model IIA) and ? = 7.31 10{sup 9} (s km{sup 1}){sup 2/3} Mpc{sup 4/3} (model IIB).

  10. OBSERVATION OF MAGNETIC RECONNECTION DRIVEN BY GRANULAR SCALE ADVECTION

    SciTech Connect

    Zeng Zhicheng; Cao Wenda; Ji Haisheng

    2013-06-01

    We report the first evidence of magnetic reconnection driven by advection in a rapidly developing large granule using high spatial resolution observations of a small surge event (base size {approx} 4'' Multiplication-Sign 4'') with the 1.6 m aperture New Solar Telescope at the Big Bear Solar Observatory. The observations were carried out in narrowband (0.5 A) He I 10830 A and broadband (10 A) TiO 7057 A. Since He I 10830 A triplet has a very high excitation level and is optically thin, its filtergrams enable us to investigate the surge from the photosphere through the chromosphere into the lower corona. Simultaneous space data from the Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory were used in the analysis. It is shown that the surge is spatio-temporally associated with magnetic flux emergence in the rapidly developing large granule. During the development of the granule, its advecting flow ({approx}2 km s{sup -1}) squeezed the magnetic flux into an intergranular lane area, where a magnetic flux concentration was formed and the neighboring flux with opposite magnetic polarity was canceled. During the cancellation, the surge was produced as absorption in He I 10830 A filtergrams while simultaneous EUV brightening occurred at its base. The observations clearly indicate evidence of a finest-scale reconnection process driven by the granule's motion.

  11. DRAMATIC CHANGE IN JUPITER'S GREAT RED SPOT FROM SPACECRAFT OBSERVATIONS

    SciTech Connect

    Simon, Amy A.; Wong, Michael H.; De Pater, Imke; Rogers, John H.; Orton, Glenn S.; Carlson, Robert W.; Asay-Davis, Xylar; Marcus, Philip S.

    2014-12-20

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features. Since the advent of modern telescopes, keen observers have noted its appearance and documented a change in shape from very oblong to oval, confirmed in measurements from spacecraft data. It currently spans the smallest latitude and longitude size ever recorded. Here we show that this change has been accompanied by an increase in cloud/haze reflectance as sensed in methane gas absorption bands, increased absorption at wavelengths shorter than 500nm, and increased spectral slope between 500 and 630nm. These changes occurred between 2012 and 2014, without a significant change in internal tangential wind speeds; the decreased size results in a 3.2day horizontal cloud circulation period, shorter than previously observed. As the GRS has narrowed in latitude, it interacts less with the jets flanking its north and south edges, perhaps allowing for less cloud mixing and longer UV irradiation of cloud and aerosol particles. Given its long life and observational record, we expect that future modeling of the GRS's changes, in concert with laboratory flow experiments, will drive our understanding of vortex evolution and stability in a confined flow field crucial for comparison with other planetary atmospheres.

  12. Direct observation of electric field induced pattern formation and particle aggregation in ferrofluids

    SciTech Connect

    Rajnak, Michal; Kopcansky, Peter; Timko, Milan; Petrenko, Viktor I.; Avdeev, Mikhail V.; Ivankov, Olexandr I.; Feoktystov, Artem; Dolnik, Bystrik; Kurimsky, Juraj

    2015-08-17

    Ferrofluids typically respond to magnetic fields and can be manipulated by external magnetic fields. Here, we report on formation of visually observable patterns in a diluted low-polarity ferrofluid exposed to external electric fields. This presents a specific type of ferrofluid structure driven by a combined effect of electrohydrodynamics and electrical body forces. The free charge and permittivity variation are considered to play a key role in the observed phenomenon. The corresponding changes in the ferrofluid structure have been found at nanoscale as well. By small-angle neutron scattering (SANS), we show that the magnetic nanoparticles aggregate in direct current (dc) electric field with a strong dependence on the field intensity. The anisotropic aggregates preferably orient in the direction of the applied electric field. Conducting SANS experiments with alternating current (ac) electric fields of various frequencies, we found a critical frequency triggering the aggregation process. Our experimental study could open future applications of ferrofluids based on insulating liquids.

  13. Observing Emissions of Air Pollutants from Space | Argonne National...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    to study the future turnover of vehicle fleets around the world and the likely effects on air pollution and climate. This project has used satellite data to monitor CO, CO2,...

  14. NNSA Officials Observe Russian Nuclear Emergency Response Exercise...

    National Nuclear Security Administration (NNSA)

    The exercise, which took place at a shipyard near Murmansk in late July, was intended to test the preparedness of Russian emergency response forces to mitigate the effects of a ...

  15. Observation of a Macroscopically Quantum-Entangled Insulator

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... The only previously known example was the Nobel-Prize-winning discovery of the quantum Hall effect insulator in the 1980s in a two-dimensional electron system under a large ...

  16. Observations of the impact of a major Saharan dust storm on the atmospheric radiation balance

    SciTech Connect

    Slingo, A.; Ackerman, Thomas P.; Allan, R. P.; Kassianov, Evgueni I.; McFarlane, Sally A.; Robinson, G. J.; Barnard, James C.; Miller, Mark; Harries, J. E.; Russell, J. E.; Dewitte, S.

    2006-12-01

    Saharan dust storms transport large quantities of material across the African continent and beyond, causing widespread disruption and hazards to health. The dust may be deposited into the Atlantic Ocean, where it provides an important source of nutrients1, and may be carried as far as the West Indies. Such events may also influence the growth of Atlantic tropical cyclones. Satellite observations have enabled estimates to be made of the effect of the dust on the radiation budget seen from space, but only limited in situ observations have hitherto been made at the surface. Here we present the first simultaneous and continuous observations of the effect of a major dust storm in March 2006 on the radiation budget both at the top of the atmosphere (TOA) and at the surface. We combine data from the Geostationary Earth Radiation Budget (GERB) broadband radiometer and the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on the Meteosat-8 weather satellite with remote sensing and in situ measurements from a new Mobile Facility located in Niamey, Niger (13{sup o} 29'N, 2{sup o} 10'E), operated by the US Atmospheric Radiation Measurement (ARM) program. We show that the dust produced major perturbations to the radiation budget seen from space and from the surface. By combining the two datasets, we estimate the impact on the radiation budget of the atmosphere itself. Using independent data from the Mobile Facility, we derive the optical properties of the dust and input these and other information into radiation codes to simulate the radiative fluxes. Comparisons with the observed fluxes provides a stringent test of the ability of the codes to represent the radiative properties of this important component of the global aerosol burden.

  17. Dispersion of Metals from Abandoned Mines and their Effect on Biota in the Methow River, Okanogan County, Washington: Final Report 2002-2003.

    SciTech Connect

    Peplow, Dan; Edmonds, Robert

    2003-05-15

    A study of mine-waste contamination effects on Methow River habitat on the eastern slopes of the north Cascade Mountains in Washington state, U.S.A., revealed impacts at ecosystem, community, population, individual, tissue, and cellular levels. Ore deposits in the area were mined for gold, silver, copper and zinc until the early 1950's, but the mines are now inactive. An above-and-below-mine approach was used to compare potentially impacted to control sites. The concentrations of eleven trace elements (i.e., Al, As, B, Ba, Cd, Cr, Cu, Mn, Pb, Se, and Zn) in Methow River sediments downstream from the abandoned mine sites were higher than background levels. Exposed trout and caddisfly larvae in the Methow River showed reduced growth compared to controls. Samples of liver from juvenile trout and small intestine from exposed caddisfly larvae were examined for evidence of metal accumulation, cytopathological change, and chemical toxicity. Morphological changes that are characteristic of nuclear apoptosis were observed in caddisfly small intestine columnar epithelial and trout liver nuclei where extensive chromatin condensation and margination was observed. Histopathological studies revealed glycogen bodies were present in the cytosol and nuclei, which are indicators of Type IV Glycogen Storage Disease (GSD IV). This suggests food is being converted into glycogen and stored in the liver but the glycogen is not being converted back normally into glucose for distribution to other tissues in the body resulting in poor growth. Examination of trout hepatocytes by transmission electron microscopy revealed the accumulation of electron dense granules in the mitochondrial matrix. Matrix granules contain mixtures of Cd, Cu, Au, Pb, Ni, and Ti. Contaminated sediments caused adverse biological effects at different levels of biological organization, from the cellular to ecosystem-level responses, even where dissolved metal concentrations in the corresponding surface water met water

  18. Insights from modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign

    DOE PAGES [OSTI]

    Mechem, David B.; Giangrande, Scott E.; Wittman, Carly S.; Borque, Paloma; Toto, Tami; Kollias, Pavlos

    2015-03-13

    A case of shallow cumulus and precipitating cumulus congestus sampled at the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) supersite is analyzed using a multi-sensor observational approach and numerical simulation. Observations from a new radar suite surrounding the facility are used to characterize the evolving statistical behavior of the precipitating cloud system. This is accomplished using distributions of different measures of cloud geometry and precipitation properties. Large-eddy simulation (LES) with size-resolved (bin) microphysics is employed to determine the forcings most important in producing the salient aspects of the cloud system captured in the radar observations. Our emphasis ismore » on assessing the importance of time-varying vs. steady-state large-scale forcing on the model's ability to reproduce the evolutionary behavior of the cloud system. Additional consideration is given to how the characteristic spatial scale and homogeneity of the forcing imposed on the simulation influences the evolution of cloud system properties. Results indicate that several new scanning radar estimates such as distributions of cloud top are useful to differentiate the value of time-varying (or at least temporally well-matched) forcing on LES solution fidelity.« less

  19. Insights from modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign

    SciTech Connect

    Mechem, David B.; Giangrande, Scott E.; Wittman, Carly S.; Borque, Paloma; Toto, Tami; Kollias, Pavlos

    2015-03-13

    A case of shallow cumulus and precipitating cumulus congestus sampled at the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) supersite is analyzed using a multi-sensor observational approach and numerical simulation. Observations from a new radar suite surrounding the facility are used to characterize the evolving statistical behavior of the precipitating cloud system. This is accomplished using distributions of different measures of cloud geometry and precipitation properties. Large-eddy simulation (LES) with size-resolved (bin) microphysics is employed to determine the forcings most important in producing the salient aspects of the cloud system captured in the radar observations. Our emphasis is on assessing the importance of time-varying vs. steady-state large-scale forcing on the model's ability to reproduce the evolutionary behavior of the cloud system. Additional consideration is given to how the characteristic spatial scale and homogeneity of the forcing imposed on the simulation influences the evolution of cloud system properties. Results indicate that several new scanning radar estimates such as distributions of cloud top are useful to differentiate the value of time-varying (or at least temporally well-matched) forcing on LES solution fidelity.

  20. Ulysses observations of magnetic waves due to newborn interstellar pickup ions. I. New observations and linear analysis

    SciTech Connect

    Cannon, Bradford E.; Smith, Charles W.; Isenberg, Philip A.; Vasquez, Bernard J.; Murphy, Neil; Nuno, Raquel G. E-mail: Charles.Smith@unh.edu E-mail: Bernie.Vasquez@unh.edu E-mail: raquel.nuno@asu.edu

    2014-04-01

    We have examined Ulysses magnetic field data using dynamic spectrogram techniques that compute wave amplitude, polarization, and direction of propagation over a broad range of frequencies and time. Events were identified that showed a strong polarization signature and an enhancement of power above the local proton gyrofrequency. We perform a statistical study of 502 wave events in an effort to determine when, where, and why they are observed. Most notably, we find that waves arising from newborn interstellar pickup ions are relatively rare and difficult to find. The quantities normally employed in theories of wave growth are neutral atom density and quantities related to their ionization and the subsequent dynamics such as wind speed, solar wind flux, and magnetic field orientation. We find the observations of waves to be largely uncorrelated to these quantities except for mean field direction where quasi-radial magnetic fields are favored and solar wind proton flux where wave observations appear to be favored by low flux conditions which runs contrary to theoretical expectations of wave generation. It would appear that an explanation based on source physics and instability growth rates alone is not adequate to account for the times when these waves are seen.

  1. Effective hadron theories from a quark model

    SciTech Connect

    Gardner, S.; Moniz, Ernest J.

    1987-12-01

    In the context of the quark exchange model of Lenz et al., effective hadron theories are constructed and the resulting physical observables compared to their ''experimental'' values as defined by the calculations using the exact quark model operators. This model study illustrates convergence issues for an effective hadron basis in a quark model in which all physical observables can be computed exactly.

  2. Deep z-band observations of the coolest Y dwarf

    SciTech Connect

    Kopytova, Taisiya G.; Crossfield, Ian J. M.; Deacon, Niall R.; Brandner, Wolfgang; Buenzli, Esther; Bayo, Amelia; Schlieder, Joshua E.; Manjavacas, Elena; Kopon, Derek; Biller, Beth A.

    2014-12-10

    WISE J085510.83-071442.5 (hereafter, WISE 0855-07) is the coolest Y dwarf known to date and is located at a distance of 2.31 0.08 pc, giving it the fourth largest parallax of any known star or brown dwarf system. We report deep z-band observations of WISE 0855-07 using FORS2 on UT1/Very Large Telescope. We do not detect any counterpart to WISE 0855-07 in our z-band images and estimate a brightness upper limit of AB mag > 24.8 (F {sub ?} < 0.45 ?Jy) at 910 65 nm with 3? confidence. We combine our z-band upper limit with previous near- and mid-infrared photometry to place constraints on the atmospheric properties of WISE 0855-07 via comparison to models which implement water clouds in the atmospheres of T {sub eff} < 300 K substellar objects. We find that none of the available models that implement water clouds can completely reproduce the observed spectral energy distribution of WISE 0855-07. Every model significantly disagrees with the (3.6 ?m/4.5 ?m) flux ratio and at least one other bandpass. Since methane is predicted to be the dominant absorber at 3-4 ?m, these mismatches might point to an incorrect or incomplete treatment of methane in current models. We conclude that (a) WISE0855-07 has T {sub eff} ? 200-250 K, (b) <80% of its surface is covered by clouds, and (c) deeper observations, and improved models of substellar evolution, atmospheres, clouds, and opacities will be necessary to better characterize this object.

  3. A comparison of observables for solid-solid phase transitions

    SciTech Connect

    Smilowitz, Laura B [Los Alamos National Laboratory; Henson, Bryan F [Los Alamos National Laboratory; Romero, Jerry J [Los Alamos National Laboratory

    2009-01-01

    The study of solid-solid phase transformations is hindered by the difficulty of finding a volumetric probe to use as a progress variable. Solids are typically optically opaque and heterogeneous. Over the past several years, second harmonic generation (SHG) has been used as a kinetic probe for a solid-solid phase transition in which the initial and final phases have different symmetries. Bulk generation of SHG is allowed by symmetry only in noncentrosymmetric crystallographic space groups. For the organic energetic nitramine octahydro-1,3 ,5,7 -tetranitro-1,3 ,5,7 -tatrazocine (HMX), the beta phase is centro symmetric (space group P2{sub 1}/c) and the delta phase iS noncentrosymmetric (space group P6{sub 1}22) making SHG an extremely sensitive, essentially zero background probe of the phase change progress. We have used SHG as a tool to follow the progress of the transformation from beta to delta phase during the solid-solid transformation. However, kinetic models of the transformation derived using different observables from several other groups have differed, showing later onset for the phase change and faster progression to completion. In this work, we have intercompared several techniques to understand these differences. The three techniques discussed are second harmonic generation, Raman spectroscopy, and differential scanning calorimetry (DSC). The progress of the beta to delta phase transition in HMX observed with each of these different probes will be discussed and advantages and disadvantages of each technique described. This paper compares several different observables for use in measuring the kinetics of solid-solid phase transitions. Relative advantages and disadvantages for each technique are described and a direct comparison of results is made for the beta to delta polymorphic phase transition of the energetic nitramine, octahydro-1,3,5,7-tetranitro-1,3,5,7-tatrazocine.

  4. DETAILED MOLECULAR OBSERVATIONS TOWARD THE DOUBLE HELIX NEBULA

    SciTech Connect

    Torii, K.; Enokiya, R.; Hasegawa, K.; Kudo, N.; Fukui, Y.; Morris, M. R.

    2014-07-01

    The Double Helix Nebula (DHN), located 100 pc above Sgr A* in the Galactic center (GC), is a unique structure whose morphology suggests it is a magnetic feature. Recent molecular observations toward the DHN revealed two candidate molecular counterparts of the DHN at radial velocities of 35 km s{sup 1} and 0 km s{sup 1} and discussed the model in which the DHN has its origin at the circumnuclear disk in the GC. In this paper, new CO observations toward the DHN using the Caltech Submillimeter Observatory and Mopra telescopes are presented. The higher-resolution observations of ?1 pc scale reveal the detailed distributions and kinematics of the two CO counterparts (the 0 km s{sup 1} and 35 km s{sup 1} features) and provide new information on their physical conditions. As a result, we find that the 0 km s{sup 1} feature with a mass of 3.3 10{sup 4} M {sub ?} coincides with the infrared emission of the DHN, indicating clear association with the DHN. The association of the 35 km s{sup 1} feature, with a mass of 0.8 10{sup 4} M {sub ?}, is less clear compared with the 0 km s{sup 1} feature, but the complementary distribution between the molecular gas and the DHN and velocity variation along the DHN support its association with the DHN. The two molecular features are highly excited, as shown by the relatively high CO J = 2-1/J = 1-0 intensity ratios of ?1.0, and have kinetic temperatures of ?30 K, consistent with the typical molecular clouds in the GC.

  5. Observation of Central Exclusive Diphoton Production at the Tevatron

    SciTech Connect

    Brucken, Jens Erik

    2013-01-01

    We have observed exclusive γγ production in proton-antiproton collisions at the Tevatron at √ s = 1.96 TeV. We use data corresponding to 1.11 ± 0.07 fb-1 integrated luminosity taken by the Run II Collider Detector at Fermilab, with a trigger requiring two electromagnetic showers, each with transverse energy ET > 2 GeV, and vetoing on hits in the forward beam shower counters. We select events with two electromagnetic showers, each with transverse energy ET > 2.5 GeV and pseudorapidity |η| < 1.0, with no other particles detected in -7.4 < η < +7.4. The two showers have similar ET and an azimuthal angle separation Δφ ~ π; we find 34 events with exactly two matching charged particle tracks, agreeing with expectations for the QED process p¯p → p+e+e- + ¯p by two photon exchange; and we find 43 events with no tracks. The latter are candidates for the exclusive process p¯p → p + γγ + ¯p by double pomeron exchange. We use the strip and wire chambers at the longitudinal shower maximum position within the calorimeter to measure a possible exclusive background from IP + IP → π0π0, and conclude that it is consistent with zero and is < 15 events at 95% C.L. The measured cross section is σγγ,excl(|η| < 1, ET (γ) > 2.5 GeV) = 2.48 +0.40 -0.35(stat) +0.40 -0.51(syst) pb and in agreement with the theoretical predictions. This process is closely related to exclusive Higgs boson production pp → p + H + p at the Large Hadron Collider. The observation of the exclusive production of diphotons shows that exclusive Higgs production can happen and could be observed with a proper experimental setup.

  6. First observations of tracking clouds using scanning ARM cloud radars

    DOE PAGES [OSTI]

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud fieldmore » and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.« less

  7. Properties of galactic dark matter: Constraints from astronomical observations

    SciTech Connect

    Burch, B.; Cowsik, R.

    2013-12-10

    The distributions of normal matter and of dark matter in the Galaxy are coupled to each other as they both move in the common gravitational potential. In order to fully exploit this interplay and to derive the various properties of dark matter relevant to their direct and indirect detection, we have comprehensively reviewed the astronomical observations of the spatial and velocity distributions of the components of normal matter. We then postulate that the phase-space distribution of dark matter follows a lowered-isothermal form and self-consistently solve Poisson's equation to construct several models for the spatial and velocity distributions of dark matter. In this paper, we compute the total gravitational potential of the normal and dark matter components and investigate their consistency with current observations of the rotation curve of the Galaxy and of the spatial and velocity distributions of blue horizontal-branch and blue straggler stars. Even with this demand of consistency, a large number of models with a range of parameters characterizing the dark matter distribution remain. We find that the best choice of parameters, within the range of allowed values for the surface density of the disk 55 M {sub ?} pc{sup 2}, are the following: the dark matter density at the Galactic center ?{sub DM,} {sub c} ? 100-250 GeV cm{sup 3}, the local dark matter density ?{sub DM}(R {sub 0}) ? 0.56-0.72 GeV cm{sup 3}, and the rms speed of dark matter particles ?v{sub DM}{sup 2}(R{sub 0})?{sup 1/2}?490??550 km s{sup 1}. We also discuss possible astronomical observations that may further limit the range of the allowed models. The predictions of the allowed models for direct and indirect detection will be discussed separately in a companion paper.

  8. Observation of Instabilities of Coherent Transverse Ocillations in the Fermilab Booster

    SciTech Connect

    Alexahin, Y.; Eddy, N.; Gianfelice-Wendt, E.; Lebedev, V.; Marsh, W.; Pellico, W.; Triplett, K.; /Fermilab

    2012-05-01

    The Fermilab Booster - built more than 40 years ago - operates well above the design proton beam intensity of 4 {center_dot} 10{sup 12} ppp. Still, the Fermilab neutrino experiments call for even higher intensity exceeding 5.5 {center_dot} 10{sup 12} ppp. A multitude of intensity related effects must be overcome in order to meet this goal including suppression of coherent dipole instabilities of transverse oscillations which manifest themselves as a sudden drop in the beam current. In this report we present the results of observation of these instabilities at different tune, coupling and chromaticity settings and discuss possible cures.

  9. First observation of magnetic moment precession of channeled particles in bent crystals

    SciTech Connect

    Chen, D.; Albuquerque, I.F.; Baublis, V.V.; Bondar, N.F.; Carrigan, R.A. Jr.; Cooper, P.S.; Lisheng, D.; Denisov, A.S.; Dobrovolsky, A.V.; Dubbs, T.; Endler, A.M.F.; Escobar, C.O.; Foucher, M.; Golovtsov, V.L.; Goritchev, P.A.; Gottschalk, H.; Gouffon, P.; Grachev, V.T.; Khanzadeev, A.V.; Kubantsev, M.A.; Kuropatkin, N.P.; Lach, J.; Lang Pengfei; Lebedenko, V.N.; Li Chengze; Li Yunshan; Mahon, J.R.P.; McCliment, E.; Morelos, A.; Newsom, C.; Pommot Maia, M.C.; Samsonov, V.M.; Schegelsky, V.A.; Shi Huanzhang; Smith, V.J.; Sun, C.R.; Tang Fukun; Terentyev, N.K.; Timm, S.; Tkatch, I.I.; Uvarov, L.N.; Vorobyov, A.A.; Yan Jie; Zhao Wenheng; Zheng Shuchen; Zhong Yuanyuan Institute of High Energy Physics, Beijing H. H. Wills Physics Laboratory, University of Bristol Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 Fermi National Accelerator Laboratory, Batavia, Illinois 60510

    1992-12-07

    Spin precession of channeled particles in bent crystals has been observed for the first time. Polarized [Sigma][sup +] were channeled using bent Si crystals. These crystals provided an effective magnetic field of 45 T which resulted in a measured spin precession of 60[plus minus]17[degree]. This agrees with the prediction of 62[plus minus]2[degree] using the world average of [Sigma][sup +] magnetic moment measurements. This new technique gives a [Sigma][sup +] magnetic moment of (2.40[plus minus]0.46[plus minus]0.40)[mu][sub [ital N

  10. Experimental Observation of Quantum Oscillation of Surface Chemical Reactivities

    SciTech Connect

    Ma, X.; Jiang, P.; Qi, Y.; Jia, J.; Yang, Y.; Duan, W.; Li, W. X.; Bao, X.; Zhang, S. B.

    2007-05-29

    Here we present direct observation of a quantum reactivity with respect to the amounts of O2 adsorbed and the rates of surface oxidation as a function of film thickness on ultrathin (2-6 nm) Pb mesas by scanning tunneling microscopy. Simultaneous spectroscopic measurements on the electronic structures reveal a quantum oscillation that originates from quantum well states of the mesas, as a generalization of the Fabry-P{acute e}rot modes of confined electron waves. We expect the quantum reactivity to be a general phenomenon for most ultrathin metal films with broad implications, such as nanostructure tuning of surface reactivities and rational design of heterogeneous catalysts.

  11. Researchers Directly Observe Oxygen Signature in the Oxygen-evolving

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Complex of Photosynthesis Researchers Directly Observe Oxygen Signature in the Oxygen-evolving Complex of Photosynthesis Arguably the most important chemical reaction on earth is the photosynthetic splitting of water to molecular oxygen by the Mn-containing oxygen-evolving complex (Mn-OEC) in the protein known as photosystem II (PSII). It is this reaction which has, over the course of some 3.8 billion years, gradually filled our atmosphere with O2 and consequently enabled and sustained the

  12. Report on Physics of Channelization: Theory, Experiment, and Observation

    SciTech Connect

    Kudrolli, Arshad

    2014-05-19

    The project involved a study of physical processes that create eroded channel and drainage networks. A particular focus was on how the shape of the channels and the network depended on the nature of the fluid flow. Our approach was to combine theoretical, experimental, and observational studies in close collaboration with Professor Daniel Rothman of the Massachusetts Institute of Technology. Laboratory -scaled experiments were developed and quantitative data on the shape of the pattern and erosion dynamics are obtained with a laser-aided topography technique and fluorescent optical imaging techniques.

  13. Observed hemispheric asymmetry in global sea ice changes

    SciTech Connect

    Cavalieri, D.J.; Gloersen, P.; Parkinson, C.L.; Comiso, J.C.; Zwally, H.J.

    1997-11-07

    From November 1978 through December 1996, the areal extent of sea ice decreased by 2.9 {+-} 0.4 percent decade in the Arctic and increased by 1.3 {+-} 0.2 percent per decade in the Antarctic. The observed hemispheric asymmetry in these trends is consistent with a modeled response to a carbon dioxide-induced climate warming. The interannual variations, which are 2.3 percent of the annual mean in the Arctic, with a predominant period of about 5 years, and 3.4 percent of the annual mean in the Antarctic, with a predominant period of about 3 years, are uncorrelated. 29 refs., 2 figs., 1 tab.

  14. The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign

    SciTech Connect

    Verlinde, J

    2010-10-18

    The ALTOS campaign focuses on operating a tethered observing system for routine in situ sampling of low-level (< 2 km) Arctic clouds. It has been a long-term hope to fly tethered systems at Barrow, Alaska, but it is clear that the Federal Aviation Administration (FAA) will not permit in-cloud tether systems at Barrow, even if unmanned aerial vehicle (UAV) operations are allowed in the future. We have provided the scientific rationale for long-term, routine in situ measurements of cloud and aerosol properties in the Arctic. The existing restricted air space at Oliktok offers an opportunity to do so.

  15. RADIO OBSERVATIONS OF HD 80606 NEAR PLANETARY PERIASTRON

    SciTech Connect

    Lazio, T. Joseph W.; Farrell, W. M.; Shankland, P. D.; Blank, D. L.

    2010-12-15

    This paper reports Very Large Array observations at 325 and 1425 MHz ({lambda}90 cm and {lambda}20 cm) during and near the periastron passage of HD 80606b on HJD 2454424.86 (2007 November 20). We obtain flux density limits (3{sigma}) of 1.7 mJy and 48 {mu}Jy at 325 and 1425 MHz, respectively, equivalent to planetary luminosity limits of 2.3 x 10{sup 24} erg s{sup -1} and 2.7 x 10{sup 23} erg s{sup -1}. Unfortunately, these are several orders of magnitude above the nominal Jovian value (at 40 MHz) of 2 x 10{sup 18} erg s{sup -1}. The motivation for these observations was that the planetary magnetospheric emission is driven by a stellar wind-planetary magnetosphere interaction so that the planetary luminosity would be elevated near periastron. We estimate that, near periastron, HD 80606b might be as much as 3000 times more luminous than Jupiter. Recent transit observations of HD 80606b provide reasonably stringent constraints on the planetary mass and radius, and, because of the planet's highly eccentric orbit, its rotation period is likely to be 'pseudo-synchronized' to its orbital period, allowing a robust estimate of the former. Consequently, we are able to make relatively robust estimates of the emission frequency of the planetary magnetospheric emission and find it to be around 60-90 MHz. While this is too low for our reported observations, we compare HD 80606b to other high-eccentricity systems and assess the detection possibilities for both near-term and more distant future systems. Of the known high-eccentricity planets, only HD 80606b is likely to be detectable, as the others (HD 20782B and HD 4113) are both lower mass and longer rotational periods, which imply weaker magnetic field strengths. We find that both the forthcoming 'EVLA low band' system, which will operate as low as 65 MHz, and the Low Frequency Array may be able to improve upon our planetary luminosity limits for HD 80606b, and do so at a more optimum frequency. If the low-frequency component

  16. Observation of an Electric Octupole Transition in a Single Ion

    SciTech Connect

    Roberts, M.; Taylor, P.; Barwood, G.; Gill, P.; Klein, H.; Rowley, W.; Roberts, M.; Taylor, P.

    1997-03-01

    The {sup 2} S{sub 1/2}-{sup 2}F{sub 7/2} electric octupole (E3) transition in {sup 172}Yb{sup +} has been detected by observing quantum jumps in a single laser cooled ion, stored in an electrodynamic trap. The transition frequency is 642116785.3(0.7)MHz (1{sigma}). Consideration of the transition rate and laser parameters implies a {sup 2} F{sub 7/2} level lifetime of 3700 days. This is the first time an atomic E3 transition has been driven. This transition has applications as an optical frequency reference. {copyright} {ital 1997} {ital The American Physical Society}

  17. ILLUMINATING THE DARKEST GAMMA-RAY BURSTS WITH RADIO OBSERVATIONS

    SciTech Connect

    Zauderer, B. A.; Berger, E.; Margutti, R.; Fong, W.; Laskar, T.; Chornock, R.; Soderberg, A. M. [Department of Astronomy, Harvard University, Cambridge, MA 02138 (United States); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Olivares E, F.; Greiner, J. [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Perley, D. A.; Horesh, A.; Carpenter, J. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91225 (United States); Updike, A. C. [Department of Chemistry and Physics, Roger Williams University, Bristol, RI 02809 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Menten, K. M. [Max-Planck-Institut fuer Radioastronomie, D-53121 Bonn (Germany); Nakar, E. [Department of Astrophysics, Sackler School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Chandra, P. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune University Campus, Ganeshkhind, Pune 411007 (India); Castro-Tirado, A. J. [Instituto de Astrofisica de Andalucia (IAA-CSIC), P.O. Box 03004, E-18080 Granada (Spain); Bremer, M. [Institut de Radioastronomie Millimetrique, 300 rue de la Piscine, F-38406 Saint Martin d'Heres (France); and others

    2013-04-20

    We present X-ray, optical, near-infrared (IR), and radio observations of gamma-ray bursts (GRBs) 110709B and 111215A, as well as optical and near-IR observations of their host galaxies. The combination of X-ray detections and deep optical/near-IR limits establish both bursts as ''dark''. Sub-arcsecond positions enabled by radio detections lead to robust host galaxy associations, with optical detections that indicate z {approx}< 4 (110709B) and z Almost-Equal-To 1.8-2.9 (111215A). We therefore conclude that both bursts are dark due to substantial rest-frame extinction. Using the radio and X-ray data for each burst we find that GRB 110709B requires A{sub V}{sup host}{approx}>5.3 mag and GRB 111215A requires A{sub V}{sup host}{approx}>8.5 mag (assuming z = 2). These are among the largest extinction values inferred for dark bursts to date. The two bursts also exhibit large neutral hydrogen column densities of N{sub H,{sub int}} {approx}> 10{sup 22} cm{sup -2} (z = 2) as inferred from their X-ray spectra, in agreement with the trend for dark GRBs. Moreover, the inferred values are in agreement with the Galactic A{sub V} -N{sub H} relation, unlike the bulk of the GRB population. Finally, we find that for both bursts the afterglow emission is best explained by a collimated outflow with a total beaming-corrected energy of E{sub {gamma}} + E{sub K} Almost-Equal-To (7-9) Multiplication-Sign 10{sup 51} erg (z = 2) expanding into a wind medium with a high density, M Almost-Equal-To (6-20) Multiplication-Sign 10{sup -5} M{sub Sun} yr{sup -1} (n Almost-Equal-To 100-350 cm{sup -3} at Almost-Equal-To 10{sup 17} cm). While the energy release is typical of long GRBs, the inferred density may be indicative of larger mass-loss rates for GRB progenitors in dusty (and hence metal rich) environments. This study establishes the critical role of radio observations in demonstrating the origin and properties of dark GRBs. Observations with the JVLA and ALMA will provide a sample with sub

  18. LOCALIZED PLASMA DENSITY ENHANCEMENTS OBSERVED IN STEREO COR1

    SciTech Connect

    Jones, Shaela I.; Davila, Joseph M.

    2009-08-20

    Measurements of solar wind speed in the solar corona, where it is primarily accelerated, have proven elusive. One of the more successful attempts has been the tracking of outward-moving density inhomogeneities in white-light coronagraph images. These inhomogeneities, or 'blobs', have been treated as passive tracers of the ambient solar wind. Here we report on the extension of these observations to lower altitudes using the STEREO COR1 coronagraph, and discuss the implications of these measurements for theories about the origin of these features.

  19. Computational and human observer image quality evaluation of low dose, knowledge-based CT iterative reconstruction

    SciTech Connect

    Eck, Brendan L.; Fahmi, Rachid; Miao, Jun; Brown, Kevin M.; Zabic, Stanislav; Raihani, Nilgoun; Wilson, David L.

    2015-10-15

    and model complexity according to AIC{sub c}. With parameters fixed, the model reasonably predicted detectability of human observers in blended FBP-IMR images. Semianalytic internal noise computation gave results equivalent to Monte Carlo, greatly speeding parameter estimation. Using Model-k4, the authors found an average detectability improvement of 2.7 ± 0.4 times that of FBP. IMR showed greater improvements in detectability with larger signals and relatively consistent improvements across signal contrast and x-ray dose. In the phantom tested, Model-k4 predicted an 82% dose reduction compared to FBP, verified with physical CT scans at 80% reduced dose. Conclusions: IMR improves detectability over FBP and may enable significant dose reductions. A channelized Hotelling observer with internal noise proportional to channel output standard deviation agreed well with human observers across a wide range of variables, even across reconstructions with drastically different image characteristics. Utility of the model observer was demonstrated by predicting the effect of image processing (blending), analyzing detectability improvements with IMR across dose, size, and contrast, and in guiding real CT scan dose reduction experiments. Such a model observer can be applied in optimizing parameters in advanced iterative reconstruction algorithms as well as guiding dose reduction protocols in physical CT experiments.

  20. Primordial Black Holes: Observational characteristics of the final evaporation

    DOE PAGES [OSTI]

    Ukwatta, T. N.; Stump, D. R.; Linnemann, J. T.; MacGibbon, J. H.; Marinelli, S. S.; Yapici, T.; Tollefson, K.

    2016-07-01

    For many early universe theories predict the creation of Primordial Black Holes (PBHs). PBHs could have masses ranging from the Planck mass to 105 solar masses or higher depending on the size of the universe at formation. A Black Hole (BH) has a Hawking temperature which is inversely proportional to its mass. Hence a sufficiently small BH will quasi-thermally radiate particles at an ever-increasing rate as emission lowers its mass and raises its temperature. Moreover, the final moments of this evaporation phase should be explosive and its description is dependent on the particle physics model. In this work we investigatemore » the final few seconds of BH evaporation, using the Standard Model and incorporating the most recent Large Hadron Collider (LHC) results, and provide a new parameterization for the instantaneous emission spectrum. We calculate for the first time energy-dependent PBH burst light curves in the GeV/TeV energy range. Moreover, we explore PBH burst search methods and potential observational PBH burst signatures. We have found a unique signature in the PBH burst light curves that may be detectable by GeV/TeV gamma-ray observatories such as the High Altitude Water Cerenkov (HAWC) observatory. Finally, the implications of beyond the Standard Model theories on the PBH burst observational characteristics are also discussed, including potential sensitivity of the instantaneous photon detection rate to a squark threshold in the 5–10 TeV range.« less

  1. Difference image analysis of defocused observations with CSTAR

    SciTech Connect

    Oelkers, Ryan J.; Macri, Lucas M.; Wang, Lifan; Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel; Cui, Xiangqun; Gong, Xuefei; Qiang, Liu; Yang, Huigen; Yuan, Xiangyan; Zhou, Xu; Feng, Long-Long; Zhu, Zhenxi; Pennypacker, Carl R.; York, Donald G.

    2015-02-01

    The Chinese Small Telescope ARray carried out high-cadence time-series observations of 27 square degrees centered on the South Celestial Pole during the Antarctic winter seasons of 20082010. Aperture photometry of the 2008 and 2010 i-band images resulted in the discovery of over 200 variable stars. Yearly servicing left the array defocused for the 2009 winter season, during which the system also suffered from intermittent frosting and power failures. Despite these technical issues, nearly 800,000 useful images were obtained using g, r, and clear filters. We developed a combination of difference imaging and aperture photometry to compensate for the highly crowded, blended, and defocused frames. We present details of this approach, which may be useful for the analysis of time-series data from other small-aperture telescopes regardless of their image quality. Using this approach, we were able to recover 68 previously known variables and detected variability in 37 additional objects. We also have determined the observing statistics for Dome A during the 2009 winter season; we find the extinction due to clouds to be less than 0.1 and 0.4 mag for 40% and 63% of the dark time, respectively.

  2. MOCK OBSERVATIONS OF BLUE STRAGGLERS IN GLOBULAR CLUSTER MODELS

    SciTech Connect

    Sills, Alison; Glebbeek, Evert; Chatterjee, Sourav; Rasio, Frederic A. E-mail: e.glebbeek@astro.ru.nl E-mail: rasio@northwestern.edu

    2013-11-10

    We created artificial color-magnitude diagrams of Monte Carlo dynamical models of globular clusters and then used observational methods to determine the number of blue stragglers in those clusters. We compared these blue stragglers to various cluster properties, mimicking work that has been done for blue stragglers in Milky Way globular clusters to determine the dominant formation mechanism(s) of this unusual stellar population. We find that a mass-based prescription for selecting blue stragglers will select approximately twice as many blue stragglers than a selection criterion that was developed for observations of real clusters. However, the two numbers of blue stragglers are well-correlated, so either selection criterion can be used to characterize the blue straggler population of a cluster. We confirm previous results that the simplified prescription for the evolution of a collision or merger product in the BSE code overestimates their lifetimes. We show that our model blue stragglers follow similar trends with cluster properties (core mass, binary fraction, total mass, collision rate) as the true Milky Way blue stragglers as long as we restrict ourselves to model clusters with an initial binary fraction higher than 5%. We also show that, in contrast to earlier work, the number of blue stragglers in the cluster core does have a weak dependence on the collisional parameter ? in both our models and in Milky Way globular clusters.

  3. CASSINI VIMS OBSERVATIONS SHOW ETHANE IS PRESENT IN TITAN'S RAINFALL

    SciTech Connect

    Dalba, Paul A.; Buratti, Bonnie J.; Baines, Kevin H.; Sotin, Christophe; Lawrence, Kenneth J.; Brown, Robert H.; Barnes, Jason W.; Clark, Roger N.; Nicholson, Philip D.

    2012-12-20

    Observations obtained over two years by the Cassini Imaging Science Subsystem suggest that rain showers fall on the surface. Using measurements obtained by the Visual Infrared Mapping Spectrometer, we identify the main component of the rain to be ethane, with methane as an additional component. We observe five or six probable rainfall events, at least one of which follows a brief equatorial cloud appearance, suggesting that frequent rainstorms occur on Titan. The rainfall evaporates, sublimates, or infiltrates on timescales of months, and in some cases it is associated with fluvial features but not with their creation or alteration. Thus, Titan exhibits frequent 'gentle rainfall' instead of, or in addition to, more catastrophic events that cut rivers and lay down large fluvial deposits. Freezing rain may also be present, and the standing liquid may exist as puddles interspersed with patches of frost. The extensive dune deposits found in the equatorial regions of Titan imply multi-season arid conditions there, which are consistent with small, but possibly frequent, amounts of rain, in analogy to terrestrial deserts.

  4. Estimation of solar radiation from Australian meteorological observations

    SciTech Connect

    Moriarty, W.W. )

    1991-01-01

    A carefully prepared set of Australian radiation and meteorological data was used to develop a system for estimating hourly or instantaneous broad direct, diffuse and global radiation from meteorological observations. For clear sky conditions relationships developed elsewhere were adapted to Australian data. For cloudy conditions the clouds were divided into two groups, high clouds and opaque (middle and low) clouds, and corrections were made to compensate for the bias due to reporting practices for almost clear and almost overcast skies. Careful consideration was given to the decrease of visible sky toward the horizon caused by the vertical extent of opaque clouds. Equations relating cloud and other meteorological observations to the direct and diffuse radiation contained four unknown quantities, functions of cloud amount and of solar elevation, which were estimated from the data. These were proportions of incident solar radiation passed on as direct and as diffuse radiation by high clouds, and as diffuse radiation by opaque clouds. When the resulting relationships were used to estimate global, direct and diffuse radiation on a horizontal surface, the results were good, especially for global radiation. Some discrepancies between estimates and measurements of diffuse and direct radiation were probably due to erroneously high measurements of diffuse radiation.

  5. Small solar wind transients: Stereo-A observations in 2009

    SciTech Connect

    Yu, W.; Farrugia, C. J.; Galvin, A. B.; Simunac, K. D. C.; Popecki, M. A.; Lugaz, N.; Kilpua, E. K. J.; Moestl, C.; Luhmann, J. G.; Opitz, A.; Sauvaud, J.-A.

    2013-06-13

    Year 2009 was the last year of a long and pronounced solar activity minimum. In this year the solar wind in the inner heliosphere was for 90% of the time slow (< 450 km s{sup -1}) and with a weaker magnetic field strength compared to the previous solar minimum 1995-1996. We choose this year to present the results of a systematic search for small solar wind transients (STs) observed by the STEREO-Ahead (ST-A) probe. The data are from the PLASTIC and IMPACT instrument suites. By 'small' we mean a duration from {approx}1 to 12 hours. The parameters we search for to identify STs are (i) the total field strength, (ii) the rotation of the magnetic field vector, (iii) its smoothness, (iv) proton temperature, (v) proton beta, and (vi) Alfven Mach number. We find 45 examples. The STs have an average duration of {approx}4 hours. Ensemble averages of key quantities are: (i) maximum B = 7.01 nT; (ii) proton {beta}= 0.18; (iii) proton thermal speed = 20.8 km s{sup -1}; and (iv) Alfven Mach number = 6.13. No distinctive feature is found in the pitch angle distributions of suprathermal electrons. Our statistical results are compared with those of STs observed near Earth by Wind during 2009.

  6. High resolution observations of chromospheric jets in sunspot umbra

    SciTech Connect

    Yurchyshyn, V.; Abramenko, V.; Kosovichev, A.; Goode, P.

    2014-05-20

    Recent observations of a sunspot's umbra have suggested that it may be finely structured on a subarcsecond scale representing a mix of hot and cool plasma elements. In this study, we report the first detailed observations of umbral spikes, which are cool jet-like structures seen in the chromosphere of an umbra. The spikes are cone-shaped features with a typical height of 0.5-1.0 Mm and a width of about 0.1 Mm. Their lifetime ranges from 2 to 3 minutes and they tend to re-appear at the same location. The spikes are not associated with photospheric umbral dots and they instead tend to occur above the darkest parts of the umbra where magnetic fields are strongest. The spikes exhibit up and down oscillatory motions and their spectral evolution suggests that they might be driven by upward propagating shocks generated by photospheric oscillations. It is worth noting that triggering of the running penumbral waves seems to occur during the interval when the spikes reach their maximum height.

  7. Testing coupled dark energy with large scale structure observation

    SciTech Connect

    Yang, Weiqiang; Xu, Lixin, E-mail: d11102004@mail.dlut.edu.cn, E-mail: lxxu@dlut.edu.cn [Institute of Theoretical Physics, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024 (China)

    2014-08-01

    The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with dark matter is Q-bar =3H?{sub x}?-bar {sub x}. In the frame of dark energy, we derive the evolution equations for the density and velocity perturbations. According to the Markov Chain Monte Carlo method, we constrain the model by currently available cosmic observations which include cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae, and f?{sub 8}(z) data points from redshift-space distortion. The results show the interaction rate in ? regions: ?{sub x}=0.00328{sub -0.00328-0.00328-0.00328}{sup +0.000736+0.00549+0.00816}, which means that the recently cosmic observations favor a small interaction rate which is up to the order of 10{sup -2}, meanwhile, the measurement of redshift-space distortion could rule out the large interaction rate in the ? region.

  8. Mid infrared observations of Van Maanen 2: no substellar companion.

    SciTech Connect

    Farihi, J; Becklin, E; Macintosh, B

    2004-11-03

    The results of a comprehensive infrared imaging search for the putative 0.06 M{sub {circle_dot}} astrometric companion to the 4.4 pc white dwarf van Mannen 2 are reported. Adaptive optics images acquired at 3.8 {micro}m reveal a diffraction limited core of 0.09 inch and no direct evidence of a secondary. Models predict that at 5 Gyr, a 50 M{sub J} brown dwarf would be only 1 magnitude fainter than van Maanen 2 at this wavelength and the astrometric analysis suggested a separation of 0.2 inch. In the case of a chance alignment along the line of sight, a 0.4 mag excess should be measured. An independent photometric observation at the same wavelength reveals no excess. In addition, there exist published ISO observations of van Maanen 2 at 6.8 {micro}m and 15.0 {micro}m which are consistent with photospheric flux of a 6750 K white dwarf. If recent brown dwarf models are correct, there is no substellar companion with T{sub eff} {approx}> 500 K.

  9. The effect of hydroxide ion on Cd-chalcogenide/aqueous polysulfide photoelectrochemical cells

    SciTech Connect

    Licht, S.; Manassen, J.

    1985-05-01

    Alkali hydroxide, added to the aqueous polysulfide electrolyte in n-Cd chalcogenide/S /SUB r/ photoelectrochemical solar cells (PEC's), is is shown to be detrimental to cell performance. It is demonstrated that the added hydroxide increases visible light absorption in the polysulfide solution and decreases the solution lifetime. Even after compensation for the decrease in light tranmission by the electrolyte, added hydroxide is shown to decrease the PEC photocurrent, photovoltage, and optical-to-electrical conversion efficiency. In a cell of 1 cm path length, the transmittance at 580 nm, for solutions containing 2m K/sub 2/S, 3m sulfur, and 0, 2, 6, or 12m KOH, was, respectively, 66, 55, 44, and 37.5%. Analysis of the distribution of ionic species reveals a shift from S/sub 4/ to S/sub 3/ with increasing hydroxide. Compared to S/sub 4/, the peak absorbance of S/sub 3/ is shifted 50 nm toward the vible, causing the variation in solution spectra response with hydroxide. K/sup +/ activty measrements were interpreted as indicative of increasing ion pairing with increased added hydroxide which may adversely effect charge-transfer kinetics. A measured negative shift in polysulfide redox potential with increasing hydroxide is evidently not paralleled by a comparable shift in Cd(SeTe) flatband potential resulting in the observed decrease in open-ciruit voltage. Relative conversion efficiency for an electroplated thin film CdSe /SUB 0.65/ Te /SUB 0.35/ electrode was 36% less in polysulfide with 12m KOH compared to the PEC without added KOH. The electrode immersed in 2/2/2, 2/2/3, or 0/1,3/2 (molality KOH/K/sub 2/S/S) exhibited conversion efficiencies of 4.72, 4.80, 5.24, and 5.44, respectively, at 100mW/cm/sup 2/ tungsten-halogen lamp illumination.

  10. High Burnup Effects Program

    SciTech Connect

    Barner, J.O.; Cunningham, M.E.; Freshley, M.D.; Lanning, D.D.

    1990-04-01

    This is the final report of the High Burnup Effects Program (HBEP). It has been prepared to present a summary, with conclusions, of the HBEP. The HBEP was an international, group-sponsored research program managed by Battelle, Pacific Northwest Laboratories (BNW). The principal objective of the HBEP was to obtain well-characterized data related to fission gas release (FGR) for light water reactor (LWR) fuel irradiated to high burnup levels. The HBEP was organized into three tasks as follows: Task 1 -- high burnup effects evaluations; Task 2 -- fission gas sampling; and Task 3 -- parameter effects study. During the course of the HBEP, a program that extended over 10 years, 82 fuel rods from a variety of sources were characterized, irradiated, and then examined in detail after irradiation. The study of fission gas release at high burnup levels was the principal objective of the program and it may be concluded that no significant enhancement of fission gas release at high burnup levels was observed for the examined rods. The rim effect, an as yet unquantified contributor to athermal fission gas release, was concluded to be the one truly high-burnup effect. Though burnup enhancement of fission gas release was observed to be low, a full understanding of the rim region and rim effect has not yet emerged and this may be a potential area of further research. 25 refs., 23 figs., 4 tabs.

  11. Observation and studies of double $J/\\psi$ production at the Tevatron

    SciTech Connect

    Abazov, Victor Mukhamedovich; et al.

    2014-12-08

    We present the observation of doubly-produced $J/\\psi$ mesons with the D0 detector at Fermilab in $p\\bar{p}$ collisions at $\\sqrt{s}=1.96$ TeV. The production cross section for both singly and doubly-produced $J/\\psi$ mesons is measured using a sample with an integrated luminosity of 8.1fb$^{-1}$. For the first time, the double $J/\\psi$ production cross section is separated into contributions due to single and double parton scatterings. Using these measurements, we determine the effective cross section $\\sigma_{eff}$, a parameter characterizing an effective spatial area of the parton-parton interactions and related to the parton spatial density inside the nucleon.

  12. Preliminary analysis of ground-based microwave and infrared radiance observations during the Pilot Radiation OBservation Experiment

    SciTech Connect

    Westwater, E.R.; Han, Y.; Churnside, J.H.; Snider, J.B.

    1995-04-01

    During Phase Two of the Pilot Radiation OBservation Experiment (PROBE) held in Kavieng, Papua New Guinea, the National Oceanic and Atmospheric Administration`s Environmental Technology Laboratory (ETL) operated both microwave and infrared radiometers. Phase Two lasted from January 6 to February 28, 1993. The dramatic differences in the water vapor environment between the tropics and mid-latitudes were illustrated by Westwater et al. (1994) who presented PROBE data as well as additional data that were taken during the 1991 First ISCCP Regional Experiment (FIRE) 11 experiment in Coffeyville, Kansas. We present an analysis of microwave data and a preliminary analysis of infrared data obtained during PROBE.

  13. OBSERVATIONS OF CRAB GIANT PULSES IN 20-84 MHz USING LWA1

    SciTech Connect

    Ellingson, S. W.; Wolfe, C. N.; Clarke, T. E.; Hicks, B. C.; Wilson, T. L.; Craig, J.; Taylor, G. B.; Lazio, T. J. W.

    2013-05-10

    We report the detection and observed characteristics of giant pulses from the Crab Nebula pulsar (B0531+21) in four frequency bands covering 20-84 MHz using the recently completed Long Wavelength Array Station 1 (LWA1) radio telescope. In 10 hr of observations distributed over a 72 day period in fall of 2012, 33 giant pulses having peak flux densities between 400 Jy and 2000 Jy were detected. Twenty-two of these pulses were detected simultaneously in channels of 16 MHz bandwidth centered at 44 MHz, 60 MHz, and 76 MHz, including one pulse which was also detected in a channel centered at 28 MHz. We quantify statistics of pulse amplitude and pulse shape characteristics, including pulse broadening. Amplitude statistics are consistent with expectations based on extrapolations from previous work at higher and lower frequencies. Pulse broadening is found to be relatively high, but not significantly greater than expected. We present procedures that have been found to be effective for observing giant pulses in this frequency range.

  14. Electron Energy Distributions at Relativistic Shock Sites: Observational Constraints from the Cygnus A Hotspots

    SciTech Connect

    Cheung, C.C.Teddy; Stawarz, L.; Harris, D.E.; Ostrowski, M.

    2007-10-15

    We report new detections of the hotspots in Cygnus A at 4.5 and 8.0 microns with the Spitzer Space Telescope. Together with detailed published radio observations and synchrotron self-Compton modeling of previous X-ray detections, we reconstruct the underlying electron energy spectra of the two brightest hotspots (A and D). The low-energy portion of the electron distributions have flat power-law slopes (s {approx} 1.5) up to the break energy which corresponds almost exactly to the mass ratio between protons and electrons; we argue that these features are most likely intrinsic rather than due to absorption effects. Beyond the break, the electron spectra continue to higher energies with very steep slopes s>3. Thus, there is no evidence for the 'canonical' s=2 slope expected in 1st order Fermi-type shocks within the whole observable electron energy range. We discuss the significance of these observations and the insight offered into high-energy particle acceleration processes in mildly relativistic shocks.

  15. Testing oscillating primordial spectrum and oscillating dark energy with astronomical observations

    SciTech Connect

    Liu, Jie; Li, Hong; Zhang, Xinmin; Xia, Jun-Qing E-mail: hongli@ihep.ac.cn E-mail: xmzhang@ihep.ac.cn

    2009-07-01

    In this paper we revisit the issue of determining the oscillating primordial scalar power spectrum and oscillating equation of state of dark energy from the astronomical observations. By performing a global analysis with the Markov Chain Monte Carlo method, we find that the current observations from five-year WMAP and SDSS-LRG matter power spectrum, as well as the ''union'' supernovae sample, constrain the oscillating index of primordial spectrum and oscillating equation of state of dark energy with the amplitude less than |n{sub amp}| < 0.116 and |w{sub amp}| < 0.232 at 95% confidence level, respectively. This result shows that the oscillatory structures on the primordial scalar spectrum and the equation of state of dark energy are still allowed by the current data. Furthermore, we point out that these kinds of modulation effects will be detectable (or gotten a stronger constraint) in the near future astronomical observations, such as the PLANCK satellite, LAMOST telescope and the currently ongoing supernovae projects SNLS.

  16. Observed Increase of TTL Temperature and Water Vapor in Polluted Couds over Asia

    SciTech Connect

    Su, Hui; Jiang, Jonathan; Liu, Xiaohong; Penner, J.; Read, William G.; Massie, Steven T.; Schoeberl, Mark R.; Colarco, Peter; Livesey, Nathaniel J.; Santee, Michelle L.

    2011-06-01

    Aerosols can affect cloud particle size and lifetime, which impacts precipitation, radiation and climate. Previous studies1-4 suggested that reduced ice cloud particle size and fall speed due to the influence of aerosols may increase evaporation of ice crystals and/or cloud radiative heating in the tropical tropopause layer (TTL), leading to higher water vapor abundance in air entering the stratosphere. Observational substantiation of such processes is still lacking. Here, we analyze new observations from multiple NASA satellites to show the imprint of pollution influence on stratospheric water vapor. We focus our analysis on the highly-polluted South and East Asia region during boreal summer. We find that "polluted" ice clouds have smaller ice effective radius than "clean" clouds. In the TTL, the polluted clouds are associated with warmer temperature and higher specific humidity than the clean clouds. The water vapor difference between the polluted and clean clouds cannot be explained by other meteorological factors, such as updraft and detrainment strength. Therefore, the observed higher water vapor entry value into the stratosphere in the polluted clouds than in the clean clouds is likely a manifestation of aerosol pollution influence on stratospheric water vapor. Given the radiative and chemical importance of stratospheric water vapor, the increasing emission of aerosols over Asia may have profound impacts on stratospheric chemistry and global energy balance and water cycle.

  17. He II Ly{beta} GUNN-PETERSON ABSORPTION: NEW HST OBSERVATIONS AND THEORETICAL EXPECTATIONS

    SciTech Connect

    Syphers, David; Pieri, Matthew; Shull, J. Michael; Anderson, Scott F.; Zheng, Wei; Kriss, Gerard A.; Smith, Britton; Meiksin, Avery; Schneider, Donald P.; York, Donald G.

    2011-12-01

    Observations of He II Ly{alpha} Gunn-Peterson troughs have proved to be a valuable probe of the epoch of helium reionization at z {approx} 3. Since this optical depth can become unmeasurably large even for modest He II fractions, various alternate techniques have been proposed to push to higher redshift, and among the more promising is looking at higher-order Lyman-series troughs. We here report four new observations of the He II Ly{beta} trough, including new data on the only sightline with a prior Ly{beta} observation. However, the effective optical depth ratio {tau}{sub eff,{beta}}/{tau}{sub eff,{alpha}} is not simply predicted by f{sub {beta}}{lambda}{sub {beta}}/f{sub {alpha}}{lambda}{sub {alpha}} = 0.16, and we analyze cosmological simulations to find that the correct ratio for helium at z {approx} 3 is {approx_equal}0.35. In one case we infer {tau}{sub eff,{alpha}} > 8.8, strong evidence that helium was not fully reionized at z = 3.2-3.5, in agreement with previous measurements suggesting a later completion of reionization.

  18. Observing the shadow of Einstein-Maxwell-Dilaton-Axion black hole

    SciTech Connect

    Wei, Shao-Wen; Liu, Yu-Xiao E-mail: liuyx@lzu.edu.cn

    2013-11-01

    In this paper, the shadows cast by Einstein-Maxwell-Dilaton-Axion black hole and naked singularity are studied. The shadow of a rotating black hole is found to be a dark zone covered by a deformed circle. For a fixed value of the spin a, the size of the shadow decreases with the dilaton parameter b. The distortion of the shadow monotonically increases with b and takes its maximal when the black hole approaches to the extremal case. Due to the optical properties, the area of the black hole shadow is supposed to equal to the high-energy absorption cross section. Based on this assumption, the energy emission rate is investigated. For a naked singularity, the shadow has a dark arc and a dark spot or straight, and the corresponding observables are obtained. These results show that there is a significant effect of the spin a and dilaton parameter b on these shadows. Moreover, we examine the observables of the shadow cast by the supermassive black hole at the center of the Milky Way, which is very useful for us to probe the nature of the black hole through the astronomical observations in the near future.

  19. In situ alkali-silica reaction observed by x-ray microscopy

    SciTech Connect

    Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.; Meyer-Ilse, W.

    1997-04-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques available for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.

  20. MULTIWAVELENGTH OBSERVATIONS OF THE HOT DB STAR PG 0112+104

    SciTech Connect

    Dufour, P.; Desharnais, S.; Wesemael, F.; Bergeron, P.; Fontaine, G.; Beauchamp, A.; Limoges, M.-M. E-mail: stephanie@astro.umontreal.c E-mail: bergeron@astro.umontreal.c

    2010-08-01

    We present a comprehensive multiwavelength analysis of the hot DB white dwarf PG 0112+104. Our analysis relies on newly acquired FUSE observations, on medium-resolution FOS and GHRS data, on archival high-resolution GHRS observations, on optical spectrophotometry both in the blue and around H{alpha}, as well as on time-resolved photometry. From the optical data, we derive a self-consistent effective temperature of 31,300 {+-} 500 K, a surface gravity of log g = 7.8 {+-} 0.1 (M = 0.52 M{sub sun}), and a hydrogen abundance of log N(H)/N(He)< -4.0. The FUSE spectra reveal the presence of C II and C III lines that complement the previous detection of C II transitions with the GHRS. The improved carbon abundance in this hot object is log N(C)/N(He) = -6.15 {+-} 0.23. No photospheric features associated with other heavy elements are detected. We reconsider the role of PG 0112+104 in the definition of the blue edge of the V777 Her instability strip in light of our high-speed photometry and contrast our results with those of previous observations carried out at the McDonald Observatory.

  1. Atmospheric neutrino observations in the MINOS far detector

    SciTech Connect

    Chapman, John Derek

    2007-09-01

    This thesis presents the results of atmospheric neutrino observations from a 12.23 ktyr exposure of the 5.42 kt MINOS Far Detector between 1st August 2003 until 1st March 2006. The separation of atmospheric neutrino events from the large background of cosmic muon events is discussed. A total of 277 candidate contained vertex v/$\\bar{v}$μ CC data events are observed, with an expectation of 354.4±47.4 events in the absence of neutrino oscillations. A total of 182 events have clearly identified directions, 77 data events are identified as upward going, 105 data events are identified as downward going. The ratio between the measured and expected up/down ratio is: R$data\\atop{u/d}$/R$MC\\atop{u/d}$ = 0.72$+0.13\\atop{-0.11}$(stat.)± 0.04 (sys.). This is 2.1σ away from the expectation for no oscillations. A total of 167 data events have clearly identified charge, 112 are identified as vμ events, 55 are identified as $\\bar{v}$μ events. This is the largest sample of charge-separated contained-vertex atmospheric neutrino interactions so far observed. The ratio between the measured and expected $\\bar{v}$μ/vμ ratio is: R$data\\atop{$\\bar{v}$v}$/ R$MC\\atop{$\\bar{v}$v}$ = 0.93 $+0.19\\atop{-0.15}$ (stat.) ± 0.12 (sys.). This is consistent with vμ and $\\bar{v}$μ having the same oscillation parameters. Bayesian methods were used to generate a log(L/E) value for each event. A maximum likelihood analysis is used to determine the allowed regions for the oscillation parameters Δm$2\\atop{32}$ and sin223. The likelihood function uses the uncertainty in log(L/E) to bin events in order to extract as much information from the data as possible. This fit rejects the null oscillations hypothesis at the 98% confidence level. A fit to independent vμ and $\\bar{v}$μ oscillation assuming maximal mixing for both is also performed. The projected

  2. Observations of underdense plasma lens focusing of relativistic electron beams

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Fliller, R.; Kazakevich, G.M.; Piot, P.; Santucci, J.; Li, J.; Tikhoplav, R.; /Rochester U.

    2007-06-01

    Focusing of a 15 MeV, 19 nC electron bunch by an underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated in experiments at the Fermilab NICADD Photoinjector Laboratory (FNPL). The strong 1.9 cm focal-length plasma-lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam-envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Correlations between the beam charge and the properties of the beam focus corroborate this conclusion.

  3. Observation of the sigma_b baryons at CDF

    SciTech Connect

    Pursley, Jennifer M.; /Johns Hopkins U.

    2007-03-01

    We present a measurement of four new bottom baryons in proton-antiproton collisions with a center of mass energy of 1.96 TeV. Using 1.1 fb{sup -1} of data collected by the CDF II detector, we observe four {Lambda}{sup 0}{sub b}{pi}{+-} resonances in the fully reconstructed decay mode {Lambda}{sup 0}{sub b} {yields} {Lambda}{sup +}{sub c}{pi}{sup -}, where {Lambda}{sup +}{sub c} {yields} pK{sup -}{pi}{sup +}. The probability for the background to produce a similar or larger signal is less than 8.3 x 10{sup -8}, corresponding to a significance of greater than 5.2 {sigma}. We interpret these baryons as the {Sigma}{sub b}{sup (*){+-}} baryons.

  4. TEM observations of hydrogen nanobubbles in implanted amorphous silicon

    SciTech Connect

    Jones, K.M.; Al-Jassim, M.M.; Williamson, D.L.; Acco, S.

    1996-12-31

    Over the last two decades extensive studies on the optical and electrical properties of hydrogenated amorphous Si (a-Si:H) have been reported. However, less attention was given to the structural characterization of this material partly due to the insensitivity to hydrogen of structural probes such as x-rays and electron diffraction. From a recent set of experiments, results on the solubility limit of hydrogen in a special type of a-Si:H and the characterization of hydrogen induced complexes or nanobubbles has been reported. In this study, we report TEM observations of the structural morphology of hydrogen related defects that support these recent measurements obtained by secondary ion mass spectrometry (SIMS) and small-angle x-ray scattering (SAXS).

  5. Observation of Single Colloidal Platinum Nanocrystal Growth Trajectories

    SciTech Connect

    Zheng, Haimei; Smith, Rachel; Jun, Young-wook; Kisielowski, Christian; Dahmen, Ulrich; Alivisatos, A. Paul

    2009-02-09

    It is conventionally assumed that the growth of monodisperse colloidal nanocrystals requires a temporally discrete nucleation followed by monomer attachment onto the existing nuclei. However, recent studies have reported violations of this classical growth model, and have suggested that inter-particle interactions are also involved during the growth. Mechanisms of nanocrystal growth still remain controversial. Using in situ transmission electron microscopy, we show that platinum nanocrystals can grow either by monomer attachment from solution onto the existing particles or by coalescence between the particles. Surprisingly, an initially broad size distribution of the nanocrystals can spontaneously narrow. We suggest that nanocrystals take different pathways of growth based on their size- and morphology-dependent internal energies. These observations are expected to be highly relevant for other nanocrystal systems.

  6. High-Energy Aspects of Solar Flares: Observations and Models

    SciTech Connect

    Liu, Wei; Guo, Fan

    2015-07-21

    The paper begins by describing the structure of the Sun, with emphasis on the corona. The Sun is a unique plasma laboratory, which can be probed by Sun-grazing comets, and is the driver of space weather. Energization and particle acceleration mechanisms in solar flares is presented; magnetic reconnection is key is understanding stochastic acceleration mechanisms. Then coupling between kinetic and fluid aspects is taken up; the next step is feedback of atmospheric response to the acceleration process – rapid quenching of acceleration. Future challenges include applications of stochastic acceleration to solar energetic particles (SEPs), Fermi γ-rays observations, fast-mode magnetosonic wave trains in a funnel-shaped wave guide associated with flare pulsations, and the new SMEX mission IRIS (Interface Region Imaging Spectrograph),

  7. Thermodynamic properties of mesoscale convective systems observed during BAMEX

    SciTech Connect

    Correia, James; Arritt, R.

    2008-11-01

    Dropsonde observations from the Bow-echo and Mesoscale convective vortex EXperiment (BAMEX) are used to document the spatio-temporal variability of temperature, moisture and wind within mesoscale convective systems (MCSs). Onion type sounding structures are found throughout the stratiform region of MCSs but the temperature and moisture variability is large. Composite soundings were constructed and statistics of thermodynamic variability were generated within each sub-region of the MCS. The calculated air vertical velocity helped identify subsaturated downdrafts. We found that lapse rates within the cold pool varied markedly throughout the MCS. Layered wet bulb potential temperature profiles seem to indicate that air within the lowest several km comes from a variety of source regions. We also found that lapse rate transitions across the 0 C level were more common than isothermal, melting layers. We discuss the implications these findings have and how they can be used to validate future high resolution numerical simulations of MCSs.

  8. Chandra X-ray Observations of WZ Sge in Superoutburst

    SciTech Connect

    Wheatley, P J; Mauche, C W

    2004-10-13

    We present seven separate Chandra observations of the 2001 superoutburst of WZ Sge. The high-energy outburst was dominated by intense EUV emission lines, which we interpret as boundary layer emission scattered into our line of sight in an accretion disc wind. The direct boundary layer emission was hidden from view, presumably by the accretion disc. The optical outburst orbital hump was detected in the EUV, but the common superhump was not, indicating a geometric mechanism in the former and a dissipative mechanism in the latter. X-rays detected during outburst were not consistent with boundary layer emission and we argue that there must be a second source of X-rays in dwarf novae in outburst.

  9. Parameters of cosmological models and recent astronomical observations

    SciTech Connect

    Sharov, G.S.; Vorontsova, E.G., E-mail: german.sharov@mail.ru, E-mail: elenavor@inbox.ru [Tver state university, 170002, Sadovyj per. 35, Tver (Russian Federation)

    2014-10-01

    For different gravitational models we consider limitations on their parameters coming from recent observational data for type Ia supernovae, baryon acoustic oscillations, and from 34 data points for the Hubble parameter H(z) depending on redshift. We calculate parameters of 3 models describing accelerated expansion of the universe: the ?CDM model, the model with generalized Chaplygin gas (GCG) and the multidimensional model of I. Pahwa, D. Choudhury and T.R. Seshadri. In particular, for the ?CDM model 1? estimates of parameters are: H{sub 0}=70.2620.319 km {sup -1}Mp {sup -1}, ?{sub m}=0.276{sub -0.008}{sup +0.009}, ?{sub ?}=0.7690.029, ?{sub k}=-0.0450.032. The GCG model under restriction 0?? is reduced to the ?CDM model. Predictions of the multidimensional model essentially depend on 3 data points for H(z) with z?2.3.

  10. Beam-beam observations in the Relativistic Heavy Ion Collider

    SciTech Connect

    Luo, Y.; Fischer, W.; White, S.

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  11. Biological Effects of Ionizing Radiation

    DOE R&D Accomplishments

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

    1952-04-07

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

  12. Observations of tropical cirrus properties in the pilot radiation observation experiment using lidar and the CSIRO ARM filter radiometer

    SciTech Connect

    Platt, C.M.R.; Young, S.A.; Manson, P.J.; Patterson, G.R.

    1995-04-01

    A narrow beam fast filter radiometer has been developed for the Atmospheric Radiation Measurement (ARM) Program. The radiometer is intended to operate alongside a lidar at ARM sites in a lidar/radiometer (LIRAD) configuration. The radiometer detects in three narrow bands at 8.62-, 10.86-, and 12.04-m central wavelengths in the atmospheric window. In addition, it has a variable field aperture that varies the radiance incident on the detector and also allows the field of view to be tailored to that of a lidar used in the LIRAD technique. The radiometer was deployed in the ARM Pilot Radiation Observation Experiment (PROBE) at Kavieng, Papua New Guinea in January-February 1993. The radiometer worked satisfactorily and appeared to be very stable. The radiometer was compared with a previous CSIRO radiometer and the improved performance of the ARM instrument was very evident. The ARM radiometer was also compared with a National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratories (ETL) interferometer and gave closely equivalent radiances. The LIRAD method was used at Kavieng to obtain the optical properties of cirrus clouds. Continuous observations of water vapor path obtained by the NOAA ETL microwave radiometer were employed to allow for the strong tropical water vapor absorption and emission. Cirrus cells that developed on one morning, independent of other clouds, had measured infrared emittances varying from <0.1 to 1.0.

  13. OBSERVATIONAL CONSTRAINTS ON METHANOL PRODUCTION IN INTERSTELLAR AND PREPLANETARY ICES

    SciTech Connect

    Whittet, D. C. B.; Cook, A. M.; Herbst, Eric; Chiar, J. E.; Shenoy, S. S.

    2011-11-20

    Methanol (CH{sub 3}OH) is thought to be an important link in the chain of chemical evolution that leads from simple diatomic interstellar molecules to complex organic species in protoplanetary disks that may be delivered to the surfaces of Earthlike planets. Previous research has shown that CH{sub 3}OH forms in the interstellar medium predominantly on the surfaces of dust grains. To enhance our understanding of the conditions that lead to its efficient production, we assemble a homogenized catalog of published detections and limiting values in interstellar and preplanetary ices for both CH{sub 3}OH and the other commonly observed C- and O-bearing species, H{sub 2}O, CO, and CO{sub 2}. We use this catalog to investigate the abundance of ice-phase CH{sub 3}OH in environments ranging from dense molecular clouds to circumstellar envelopes around newly born stars of low and high mass. Results show that CH{sub 3}OH production arises during the CO freezeout phase of ice-mantle growth in the clouds, after an ice layer rich in H{sub 2}O and CO{sub 2} is already in place on the dust, in agreement with current astrochemical models. The abundance of solid-phase CH{sub 3}OH in this environment is sufficient to account for observed gas-phase abundances when the ices are subsequently desorbed in the vicinity of embedded stars. CH{sub 3}OH concentrations in the ices toward embedded stars show order-of-magnitude object-to-object variations, even in a sample restricted to stars of low mass associated with ices lacking evidence of thermal processing. We hypothesize that the efficiency of CH{sub 3}OH production in dense cores and protostellar envelopes is mediated by the degree of prior CO depletion.

  14. SPITZER OBSERVATIONS OF BOW SHOCKS AND OUTFLOWS IN RCW 38

    SciTech Connect

    Winston, E.; Wolk, S. J.; Bourke, T. L.; Spitzbart, B.; Megeath, S. T.; Gutermuth, R.

    2012-01-10

    We report Spitzer observations of five newly identified bow shocks in the massive star-forming region RCW 38. Four are visible at Infrared Array Camera (IRAC) wavelengths, the fifth is only visible at 24 {mu}m. Chandra X-ray emission indicates that winds from the central O5.5 binary, IRS 2, have caused an outflow to the northeast and southwest of the central subcluster. The southern lobe of hot ionized gas is detected in X-rays; shocked gas and heated dust from the shock front are detected with Spitzer at 4.5 and 24 {mu}m. The northern outflow may have initiated the present generation of star formation, based on the filamentary distribution of the protostars in the central subcluster. Further, the bow-shock driving star, YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are identified within this pillar at near- to mid-IR wavelengths. We also report on IRAC 3.6 and 5.8 {mu}m observations of the cluster DBS2003-124, northeast of RCW 38, where 33 candidate young stellar objects (YSOs) are identified. One star associated with the cluster drives a parsec-scale jet. Two Herbig-Haro objects associated with the jet are visible at IRAC and Multiband Imaging Photometer for Spitzer (MIPS) wavelengths. The jet extends over a distance of {approx}3 pc. Assuming a velocity of 100 km s{sup -1} for the jet material gives an age of 3 Multiplication-Sign 10{sup 4} yr, indicating that the star (and cluster) are likely to be very young, with a similar or possibly younger age than RCW 38, and that star formation is ongoing in the extended RCW 38 region.

  15. Observation of Doppler broadening in β -delayed proton- γ decay

    DOE PAGES [OSTI]

    Schwartz, S. B.; Wrede, C.; Bennett, M. B.; Liddick, S. N.; Pérez-Loureiro, D.; Bowe, A.; Chen, A. A.; Chipps, K. A.; Cooper, N.; Irvine, D.; et al

    2015-09-14

    Background: The Doppler broadening of gamma-ray peaks is due to nuclear recoil from beta-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using beta-delayed proton emission or applied to a recoil heavier than A = 10. Purpose: To test and apply this Doppler broadening method using gamma-ray peaks from the P-26(beta p gamma)Al-25 decay sequence. Methods: A fast beam of P-26 was implanted into a planar Ge detector, which was used as a P-26 beta-decay trigger. The SeGA array of high-purity Ge detectors was used to detect gamma rays frommore » the P-26(beta p gamma)Al-25 decay sequence. Results: Radiative Doppler broadening in beta-delayed proton-gamma decay was observed for the first time. Moreover, the Doppler broadening analysis method was verified using the 1613-keV gamma-ray line for which the proton energies were previously known. The 1776-keV gamma ray de-exciting the 2720 keV Al-25 level was observed in P-26(beta p gamma)Al-25 decay for the first time and used to determine that the center-of-mass energy of the proton emission feeding the 2720-keV level is 5.1 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV, corresponding to a Si-26 excitation energy of 13.3 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV for the proton-emitting level. Conclusions: Finally, the Doppler broadening method has been demonstrated to provide practical measurements of the energies for beta-delayed nucleon emissions populating excited states of nuclear recoils at least as heavy as A = 25.« less

  16. A statistical study of EMIC waves observed by Cluster. 1. Wave properties. EMIC Wave Properties

    SciTech Connect

    Allen, R. C.; Zhang, J. -C.; Kistler, L. M.; Spence, H. E.; Lin, R. -L.; Klecker, B.; Dunlop, M. W.; Andr, M.; Jordanova, V. K.

    2015-07-23

    Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In our study, we present a statistical analysis of EMIC wave properties using 10 years (20012010) of data from Cluster, totaling 25,431 min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. Thus, the statistical analysis is presented in two papers. OUr paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

  17. A statistical study of EMIC waves observed by Cluster. 1. Wave properties. EMIC Wave Properties

    DOE PAGES [OSTI]

    Allen, R. C.; Zhang, J. -C.; Kistler, L. M.; Spence, H. E.; Lin, R. -L.; Klecker, B.; Dunlop, M. W.; André, M.; Jordanova, V. K.

    2015-07-23

    Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In our study, we present a statistical analysis of EMIC wave properties using 10 years (2001–2010) of datamore » from Cluster, totaling 25,431 min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. Thus, the statistical analysis is presented in two papers. OUr paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.« less

  18. A statistical study of EMIC waves observed by Cluster. 1. Wave properties. EMIC Wave Properties

    SciTech Connect

    Allen, R. C.; Zhang, J. -C.; Kistler, L. M.; Spence, H. E.; Lin, R. -L.; Klecker, B.; Dunlop, M. W.; André, M.; Jordanova, V. K.

    2015-07-23

    Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In our study, we present a statistical analysis of EMIC wave properties using 10 years (2001–2010) of data from Cluster, totaling 25,431 min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. Thus, the statistical analysis is presented in two papers. OUr paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

  19. Observation of Beam Loading in a Laser-Plasma Accelerator

    SciTech Connect

    Rechatin, C.; Ismail, A. Ben; Lim, J.; Faure, J.; Malka, V.; Davoine, X.; Lefebvre, E.; Lifschitz, A.

    2009-11-06

    Beam loading is the phenomenon which limits the charge and the beam quality in plasma based accelerators. An experimental study conducted with a laser-plasma accelerator is presented. Beam loading manifests itself through the decrease of the beam energy, the reduction of dark current, and the increase of the energy spread for large beam charge. 3D PIC simulations are compared to the experimental results and confirm the effects of beam loading. It is found that, in our experimental conditions, the trapped electron beams generate decelerating fields on the order of 1 (GV/m)/pC and that beam loading effects are optimized for trapped charges of about 20 pC.

  20. Intergalactic magnetic fields and gamma-ray observations of extreme TeV blazars

    SciTech Connect

    Arlen, Timothy C.; Vassilev, Vladimir V.; Weisgarber, Thomas; Wakely, Scott P.; Shafi, S. Yusef

    2014-11-20

    The intergalactic magnetic field (IGMF) in cosmic voids can be indirectly probed through its effect on electromagnetic cascades initiated by a source of teraelectronvolt (TeV) gamma-rays, such as active galactic nuclei (AGNs). AGNs that are sufficiently luminous at TeV energies, 'extreme TeV blazars', can produce detectable levels of secondary radiation from inverse Compton scattering of the electrons in the cascade, provided that the IGMF is not too large. We review recent work in the literature that utilizes this idea to derive constraints on the IGMF for three TeV-detected blazars, 1ES 0229+200, 1ES 1218+304, and RGB J0710+591, and we also investigate four other hard-spectrum TeV blazars in the same framework. Through a recently developed, detailed, three-dimensional particle-tracking Monte Carlo code, incorporating all major effects of QED and cosmological expansion, we research the effects of major uncertainties, such as the spectral properties of the source, uncertainty in the ultraviolet and far-infrared extragalactic background light, undersampled very high energy (energy ≥100 GeV) coverage, past history of gamma-ray emission, source versus observer geometry, and the jet AGN Doppler factor. The implications of these effects on the recently reported lower limits of the IGMF are thoroughly examined to conclude that the presently available data are compatible with a zero-IGMF hypothesis.

  1. EFFECT OF THERMAL PROCESSES ON COPPER-TIN ALLOYS FOR ZINC GETTERING

    SciTech Connect

    Korinko, P.; Golyski, M.

    2013-11-01

    A contamination mitigation plan was initiated to address the discovery of radioactive zinc‐65 in a glovebox. A near term solution was developed, installation of heated filters in the glovebox piping. This solution is effective at retaining the zinc in the currently contaminated area, but the gamma emitting contaminant is still present in a system designed for tritium beta. A project was initiated to develop a solution to contain the {sup 65}Zn in the furnace module. Copper and bronze (a Cu/Sn alloy) were found to be candidate materials to combine with zinc‐65 vapor, using thermodynamic calculations. A series of binary Cu/Sn alloys were developed (after determining that commercial alloys were unacceptable), that were found to be effective traps of zinc vapor. The task described in this report was undertaken to determine if the bronze substrates would retain their zinc gettering capability after being exposed to simulated extraction conditions with oxidizing and reducing gases. Pure copper and three bronze alloys were prepared, exposed to varying oxidation conditions from 250 to 450{degree}C, then exposed to varying reduction conditions in He-H{sub 2} from 250-450{degree}C, and finally exposed to zinc vapor at 350{degree}C for four hours. The samples were characterized using scanning electron microscopy, X-ray diffraction, differential thermal analysis, mass change, and visual observation. It was observed that the as fabricated samples and the reduced samples all retained their zinc gettering capacity while samples in the "as-oxidized" condition exhibited losses in zinc gettering capacity. Over the range of conditions tested, i.e., composition, oxidation temperature, and reduction temperature, no particular sample composition appeared better. Samples reduced at 350{degree}C exhibited the greatest zinc capacity, although there were some testing anomalies associated with these samples. This work clearly demonstrated that the zinc gettering was not adversely

  2. Designing optimal greenhouse gas observing networks that consider performance and cost

    DOE PAGES [OSTI]

    Lucas, D. D.; Yver Kwok, C.; Cameron-Smith, P.; Graven, H.; Bergmann, D.; Guilderson, T. P.; Weiss, R.; Keeling, R.

    2015-06-16

    Emission rates of greenhouse gases (GHGs) entering into the atmosphere can be inferred using mathematical inverse approaches that combine observations from a network of stations with forward atmospheric transport models. Some locations for collecting observations are better than others for constraining GHG emissions through the inversion, but the best locations for the inversion may be inaccessible or limited by economic and other non-scientific factors. We present a method to design an optimal GHG observing network in the presence of multiple objectives that may be in conflict with each other. As a demonstration, we use our method to design a prototypemore » network of six stations to monitor summertime emissions in California of the potent GHG 1,1,1,2-tetrafluoroethane (CH2FCF3, HFC-134a). We use a multiobjective genetic algorithm to evolve network configurations that seek to jointly maximize the scientific accuracy of the inferred HFC-134a emissions and minimize the associated costs of making the measurements. The genetic algorithm effectively determines a set of "optimal" observing networks for HFC-134a that satisfy both objectives (i.e., the Pareto frontier). The Pareto frontier is convex, and clearly shows the tradeoffs between performance and cost, and the diminishing returns in trading one for the other. Without difficulty, our method can be extended to design optimal networks to monitor two or more GHGs with different emissions patterns, or to incorporate other objectives and constraints that are important in the practical design of atmospheric monitoring networks.« less

  3. Designing optimal greenhouse gas observing networks that consider performance and cost

    DOE PAGES [OSTI]

    Lucas, D. D.; Yver Kwok, C.; Cameron-Smith, P.; Graven, H.; Bergmann, D.; Guilderson, T. P.; Weiss, R.; Keeling, R.

    2014-12-23

    Emission rates of greenhouse gases (GHGs) entering into the atmosphere can be inferred using mathematical inverse approaches that combine observations from a network of stations with forward atmospheric transport models. Some locations for collecting observations are better than others for constraining GHG emissions through the inversion, but the best locations for the inversion may be inaccessible or limited by economic and other non-scientific factors. We present a method to design an optimal GHG observing network in the presence of multiple objectives that may be in conflict with each other. As a demonstration, we use our method to design a prototypemore » network of six stations to monitor summertime emissions in California of the potent GHG 1,1,1,2-tetrafluoroethane (CH2FCF3, HFC-134a). We use a multiobjective genetic algorithm to evolve network configurations that seek to jointly maximize the scientific accuracy of the inferred HFC-134a emissions and minimize the associated costs of making the measurements. The genetic algorithm effectively determines a set of "optimal" observing networks for HFC-134a that satisfy both objectives (i.e., the Pareto frontier). The Pareto frontier is convex, and clearly shows the tradeoffs between performance and cost, and the diminishing returns in trading one for the other. Without difficulty, our method can be extended to design optimal networks to monitor two or more GHGs with different emissions patterns, or to incorporate other objectives and constraints that are important in the practical design of atmospheric monitoring networks.« less

  4. Observation of $t$-channel electroweak top quark production

    SciTech Connect

    Triplett, Nathan; /Iowa State U.

    2011-04-01

    The top quark is the heaviest known fundamental particle, with a mass of 172.0{sub -1.3}{sup +0.9}GeV. This is nearly twice the mass of the second heaviest known particle, the Z boson, and roughly the mass of a gold atom. Because of its unusually large mass, studying the top quark may provide insight into the Higgs mechanism and other beyond the standard model physics. Only two accelerators in the world are powerful enough to produce top quarks. The Tevatron, which first accelerated protons in 1983, has produced almost 400,000 top quarks, roughly half at each of its two detectors: DO and CDF. The LHC is a much newer accelerator which currently has accumulated about 0.5% as much data as the Tevatron. However, when running at full luminosity, the LHC is capable of producing a top quark about once every second and will quickly surpass the Tevatron as the leading producer of top quarks. This analysis uses data from the D0 detector at the Tevatron, which are described in chapter 3. Top quarks are produced most often in pairs of top and anti-top quarks through an interaction of the strong force. This production mode was first observed in 1995 at the Tevatron. However, top quarks can also be produced though an electroweak interaction, which produces just one top quark. This production mode was first observed at the Tevatron in 2008. Single top quark production can occur in different channels. In this analysis, a measurement of the cross section of the t-channel production mode is performed. This measurement uses 5.4 fb{sup -1} of data and uses the technique of boosted decision trees in order to separate signal from background events. The t-channel cross section is measured to be: {sigma}(p{bar p} {yields} tqb + X) = 3.03{sub -0.66}{sup +0.78}pb (0.0.1). Additional cross section measurements were also performed for the s-channel as well as the s + t-channel. The measurement of each one of these three cross sections was repeated three times using different techniques, and

  5. Mitigation of magnetohydrodynamic electromagnetic pulse (MHD-EMP) effects from commerical electric power systems

    SciTech Connect

    Barnes, P.R. ); Tesche, F.M. , Dallas, TX ); Vance, E.F. , Fort Worth, TX )

    1992-03-01

    A large nuclear detonation at altitudes of several hundred kilometers above the earth distorts the earth's magnetic field and produces a strong magnetohydrodynamic electromagnetic pulse (MHD-EMP). This can adversely affect electrical power systems. In this report, the effects of this nuclear environment on critical facilities connected to the commercial power system are considered. Methods of mitigating the MHD-EMP impacts are investigated, and recommended protection schemes are presented. Guidelines for testing facilities to determine the effects of MHD-EMP and to validate the mitigation methods also are discussed.

  6. Far-Infrared Spectral Observations of the Galaxy by COBE

    SciTech Connect

    Reach, W.T.; Dwek, E.; Fixsen, D.J.; Hewagama, T.; Mather, J.C.; Shafer, R.A.; Banday, A.J.; Bennett, C.L.; Cheng, E.S.; Eplee Jr., R.E.,; Leisawi tz, D.; Lubin, P.M.; Read, S.M.; Rosen, L.P.; Shuman, F.G.D.; Smoot, G.F.; Sodroski, T.J.; Wright, E.L.

    1994-10-27

    We derive Galactic continuum spectra from 5-96 cm(-1) fromCOBE/FIRAS observations. The spectra are dominated by warm dust emission,which may be fitted with a single temperature in the range 16-21 K (fornu(2) emissivity) along each line of sight. Dust heated by the attenuatedradiation field in molecular clouds gives rise tointermediate-temperature (10-14 K) emission in the inner Galaxy only. Awidespread, very cold component (4-7 K) with optical depth that isspatially correlated with the warm component is also detected. The coldcomponent is unlikely to be due to very cold dust shielded from starlightbecause it is present at high latitude. We consider hypotheses that thecold component is due to enhanced submillimeter emissivity of the dustthat gives rise to the warm component, or that it may be due to verysmall, large, or fractal particles. Lack of substantial power above theemission from warm dust places strong constraints on the amount of coldgas in the Galaxy. The microwave sky brightness due to interstellar dustis dominated by the cold component, and its angular variation could limitour ability to discern primordial fluctuations in the cosmic microwavebackground radiation.

  7. Observational constraints on electromagnetic Born-Infeld cosmology

    SciTech Connect

    Bretón, Nora; Montiel, Ariadna; Lazkoz, Ruth E-mail: amontiel@fis.cinvestav.mx

    2012-10-01

    The cosmological model consisting of an electromagnetic Born-Infeld (BI) field coupled to a Robertson-Walker geometry is tested with the standard probes of SNIa, GRBs and direct Hubble parameter. The analysis shows that the inclusion of the nonlinear electromagnetic component does not contribute in a significative way to the observed expansion. The BI electromagnetic matter is considered with an abundance of Ω{sub BI}, that our best fit leads to Ω{sub BI} = 0.037 when tested with SNIa and the Hubble parameter data (0.1 < z < 1.75); while when tested with GRBs the result is of Ω{sub BI} = 0.304, which may indicate that this electrodynamics was important at epochs close to the appearance of large structure (z ≈ 7), although this late result has not as much reliability as that corresponding to the first two probes, since we know that the dispersion in GRBs data is still considerable. In view of these results we can rule out the electromagnetic Born-Infeld matter as the origin of the present accelerated expansion, this conclusion concerns exclusively the Born-Infeld theory.

  8. APOSTLE: 11 TRANSIT OBSERVATIONS OF TrES-3b

    SciTech Connect

    Kundurthy, P.; Becker, A. C.; Agol, E.; Barnes, R.; Williams, B.

    2013-02-10

    The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed 11 transits of TrES-3b over two years in order to constrain system parameters and look for transit timing and depth variations. We describe an updated analysis protocol for APOSTLE data, including the reduction pipeline, transit model, and Markov Chain Monte Carlo analyzer. Our estimates of the system parameters for TrES-3b are consistent with previous estimates to within the 2{sigma} confidence level. We improved the errors (by 10%-30%) on system parameters such as the orbital inclination (i {sub orb}), impact parameter (b), and stellar density ({rho}{sub *}) compared to previous measurements. The near-grazing nature of the system, and incomplete sampling of some transits, limited our ability to place reliable uncertainties on individual transit depths and hence we do not report strong evidence for variability. Our analysis of the transit timing data shows no evidence for transit timing variations and our timing measurements are able to rule out super-Earth and gas giant companions in low-order mean motion resonance with TrES-3b.

  9. Collisionless shock experiments with lasers and observation of Weibel instabilities

    SciTech Connect

    Park, H.-S. Huntington, C. M.; Fiuza, F.; Levy, M. C.; Pollock, B. B.; Remington, B. A.; Ross, J. S.; Ryutov, D. D.; Turnbull, D. P.; Weber, S. V.; Drake, R. P.; Kuranz, C. C.; Froula, D. H.; Rosenberg, M.; Gregori, G.; Meinecke, J.; Koenig, M.; Kugland, N. L.; Lamb, D. Q.; Tzeferacos, P.; and others

    2015-05-15

    Astrophysical collisionless shocks are common in the universe, occurring in supernova remnants, gamma ray bursts, and protostellar jets. They appear in colliding plasma flows when the mean free path for ion-ion collisions is much larger than the system size. It is believed that such shocks could be mediated via the electromagnetic Weibel instability in astrophysical environments without pre-existing magnetic fields. Here, we present laboratory experiments using high-power lasers and investigate the dynamics of high-Mach-number collisionless shock formation in two interpenetrating plasma streams. Our recent proton-probe experiments on Omega show the characteristic filamentary structures of the Weibel instability that are electromagnetic in nature with an inferred magnetization level as high as ∼1% [C. M. Huntington et al., “Observation of magnetic field generation via the weibel instability in interpenetrating plasma flows,” Nat. Phys. 11, 173–176 (2015)]. These results imply that electromagnetic instabilities are significant in the interaction of astrophysical conditions.

  10. Observational tests of non-adiabatic Chaplygin gas

    SciTech Connect

    Carneiro, S.; Pigozzo, C. E-mail: cpigozzo@ufba.br

    2014-10-01

    In a previous paper [1] it was shown that any dark sector model can be mapped into a non-adiabatic fluid formed by two interacting components, one with zero pressure and the other with equation-of-state parameter ?=-1. It was also shown that the latter does not cluster and, hence, the former is identified as the observed clustering matter. This guarantees that the dark matter power spectrum does not suffer from oscillations or instabilities. It applies in particular to the generalised Chaplygin gas, which was shown to be equivalent to interacting models at both background and perturbation levels. In the present paper we test the non-adiabatic Chaplygin gas against the Hubble diagram of type Ia supernovae, the position of the first acoustic peak in the anisotropy spectrum of the cosmic microwave background and the linear power spectrum of large scale structures. We consider two different compilations of SNe Ia, namely the Constitution and SDSS samples, both calibrated with the MLCS2k2 fitter, and for the power spectrum we use the 2dFGRS catalogue. The model parameters to be adjusted are the present Hubble parameter, the present matter density and the Chaplygin gas parameter ?. The joint analysis best fit gives ??-0.5, which corresponds to a constant-rate energy flux from dark energy to dark matter, with the dark energy density decaying linearly with the Hubble parameter. The ?CDM model, equivalent to ?=0, stands outside the 3? confidence interval.

  11. Observations of Ag diffusion in ion implanted SiC

    DOE PAGES [OSTI]

    Gerczak, Tyler J.; Leng, Bin; Sridharan, Kumar; Jerry L. Hunter, Jr.; Giordani, Andrew J.; Allen, Todd R.

    2015-03-17

    The nature and magnitude of Ag diffusion in SiC has been a topic of interest in connection with the performance of tristructural isotropic (TRISO) coated particle fuel for high temperature gas-cooled nuclear reactors. Ion implantation diffusion couples have been revisited to continue developing a more complete understanding of Ag fission product diffusion in SiC. Ion implantation diffusion couples fabricated from single crystal 4H-SiC and polycrystalline 3C-SiC substrates and exposed to 1500–1625°C, were investigated in this study by transmission electron microscopy and secondary ion mass spectrometry (SIMS). The high dynamic range of SIMS allowed for multiple diffusion régimes to be investigated,more » including enhanced diffusion by implantation-induced defects and grain boundary (GB) diffusion in undamaged SiC. Lastly, estimated diffusion coefficients suggest GB diffusion in bulk SiC does not properly describe the release observed from TRISO fuel.« less

  12. Real-time observation of epitaxial graphene domain reorientation

    DOE PAGES [OSTI]

    Thuermer, Konrad; Foster, Michael E.; Bartelt, Norman Charles; Rogge, Paul C.; Lawrence Berkeley National Lab.; McCarty, Kevin F.; Dubon, Oscar D.; Lawrence Berkeley National Lab.; Bartelt, Norman C.

    2015-04-20

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening’; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV permore » C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This study suggests new strategies for improving the van der Waals epitaxy of 2D materials.« less

  13. Real-time observation of epitaxial graphene domain reorientation

    SciTech Connect

    Thuermer, Konrad; Foster, Michael E.; Bartelt, Norman Charles; Rogge, Paul C.; McCarty, Kevin F.; Dubon, Oscar D.; Bartelt, Norman C.

    2015-04-20

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening’; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This study suggests new strategies for improving the van der Waals epitaxy of 2D materials.

  14. Biomass Burning Observation Project (BBOP) Final Campaign Report

    SciTech Connect

    Kleinman, LI; Sedlacek, A. J.

    2016-01-01

    The Biomass Burning Observation Project (BBOP) was conducted to obtain a better understanding of how aerosols generated from biomass fires affect the atmosphere and climate. It is estimated that 40% of carbonaceous aerosol produced originates from biomass burning—enough to affect regional and global climate. Several biomass-burning studies have focused on tropical climates; however, few campaigns have been conducted within the United States, where millions of acres are burned each year, trending to higher values and greater climate impacts because of droughts in the West. Using the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the BBOP deployed the Gulfstream-1 (G-1) aircraft over smoke plumes from active wildfire and agricultural burns to help identify the impact of these events and how impacts evolve with time. BBOP was one of very few studies that targeted the near-field time evolution of aerosols and aimed to obtain a process-level understanding of the large changes that occur within a few hours of atmospheric processing.

  15. Observation manipulator bell proves worth in Transmediterranean pipeline construction

    SciTech Connect

    Lewis, R.E.

    1981-10-26

    In constructing the trans-Mediterranean undersea pipeline between Tunisia and Sicily, Perry Oceanographics used a manned, tethered vehicle called an observation manipulator bell (OMB), which has proven itself in deepwater pipelaying operations. The OMB carries a crew of two inside a pressure hull with an internal diameter of 76 in. Its overall diameter is 102 in. and it weighs 17,500 lb. The vehicle has two 5-hp port- and starboard-mounted electric thrusters. Its vertical position can be controlled by either the bell operator using a clump-weight haul-down winch or the surface operator with the umbilical winch. The OMB is fitted with video cameras and voice communication. The vehicle has reached depths of 3000 ft within 30 min with only a 10-ft overshoot. The OMB's single and/or dual manipulator-arm systems can operate its onboard impact wrenches, cut-off saws, water jets, and cable cutters. In addition, the manipulator claws can operate valve wheels and levers, attach anodes, and connect of disconnect cables and hydraulic systems. The versatility of the OMB was demonstrated recently when the vehicle rescued a PC-1602 submarine that had become entangled at 1740 ft.

  16. IMPLEMENTING THE NFPA 805 PROCESS: Observations of a Technical Reviewer

    SciTech Connect

    Short, Steven M.; Coles, Garill A.; Bohlander, Karl L.; Layton, Robert F.; Ivans, William J.; dePeralta, Fleurdeliza A.; Lowry, Peter P.

    2015-04-26

    submittals, PNNL is in a position to observe the array of implementation tactics taken in these submittals, and observe different ways licensees are making the NFPA 805 process work. For example, we see differences in how fire areas are being transitioned, the kinds of plant modifications being implemented, the changes being made to plant procedures, the number and types of recovery actions being credited, and the kinds and extent of detailed modeling being performed in support of the Fire PRAs. As a caveat, we note that it is probably too early to comment on the overall success or limitations of the NFPA 805 process or provide lessons learned for the future. Furthermore, it is not our intention to endorse any particular approach taken in a submittal over another or to critique the industry or the regulator. Rather our goal in this paper is to summarize a set of interesting and useful differences across submittals that may provide context for further future discussions about what we (i.e., reviewers, industry, and regulators) have learned in being part of the NFPA process; and how to best use that information to inform future NFPA 805 activities or other risk-informed endeavors.

  17. XMM-NEWTON OBSERVATIONS OF TWO CANDIDATE SUPERNOVA REMNANTS

    SciTech Connect

    Kargaltsev, O.; Schmitt, B. M.; Pavlov, G. G.; Misanovic, Z.

    2012-01-20

    Candidate supernova remnants (SNRs) G23.5+0.1 and G25.5+0.0 were observed by XMM-Newton in the course of a snapshot survey of plerionic and composite SNRs in the Galactic plane. In the field of G23.5+0.1, we detected an extended source, {approx}3' in diameter, which we tentatively interpret as a pulsar wind nebula (PWN) of the middle-aged radio pulsar B1830-08 (J1833-0827; P = 85.3 ms, {tau} = 147 kyr, E-dot = 5.8 Multiplication-Sign 10{sup 35} erg s{sup -1}, d = 5.7 kpc), with the PWN luminosity L{sub 0.2-10keV} Almost-Equal-To 5 Multiplication-Sign 10{sup 33} erg s{sup -1} Almost-Equal-To 8 Multiplication-Sign 10{sup -3} E-dot . The pulsar is not resolved in the EPIC images. Our analysis suggests an association between PSR B1830-08 and the surrounding diffuse radio emission. If the radio emission is due to the SNR, then the pulsar must be significantly younger than its characteristic age. Alternatively, the radio emission may come from a relic PWN. The field also contains SGR 1833-0832 and another middle-aged pulsar B1829-08 (J1832-0827; P = 647 ms, {tau} = 161 kyr, E-dot = 9.3 Multiplication-Sign 10{sup 33} erg s{sup -1}, d = 4.7 kpc), none of which are detected in our observation. In the field of G25.5+0.0, which contains the extended TeV source HESS J1837-069, we detected the recently discovered young high-energy pulsar J1838-0655 (P = 70.5 ms, {tau} = 23 kyr, E-dot = 5.5 Multiplication-Sign 10{sup 36} erg s{sup -1}) embedded in a PWN with extent of 1.'3. The unabsorbed pulsar + PWN luminosity is L{sub 2-11keV} Almost-Equal-To 2 Multiplication-Sign 10{sup 34} erg s{sup -1} Almost-Equal-To 4 Multiplication-Sign 10{sup -3} E-dot at an assumed distance of 7 kpc. We also detected another PWN candidate (AX J1837.3-0652) with an extent of 2' and unabsorbed luminosity L{sub 2-10keV} Almost-Equal-To 4 Multiplication-Sign 10{sup 33} erg s{sup -1} at d = 7 kpc. The third X-ray source, located within the extent of the HESS J1837-069, has a peculiar extended radio

  18. Electromagnetic waves near the proton cyclotron frequency: Stereo observations

    SciTech Connect

    Jian, L. K.; Wei, H. Y.; Russell, C. T.; Luhmann, J. G.; Klecker, B.; Omidi, N.; Isenberg, P. A.; Goldstein, M. L.; Figueroa-Vias, A.; Blanco-Cano, X.

    2014-05-10

    Transverse, near-circularly polarized, parallel-propagating electromagnetic waves around the proton cyclotron frequency were found sporadically in the solar wind throughout the inner heliosphere. They could play an important role in heating and accelerating the solar wind. These low-frequency waves (LFWs) are intermittent but often occur in prolonged bursts lasting over 10 minutes, named 'LFW storms'. Through a comprehensive survey of them from Solar Terrestrial Relations Observatory A using dynamic spectral wave analysis, we have identified 241 LFW storms in 2008, present 0.9% of the time. They are left-hand (LH) or right-hand (RH) polarized in the spacecraft frame with similar characteristics, probably due to Doppler shift of the same type of waves or waves of intrinsically different polarities. In rare cases, the opposite polarities are observed closely in time or even simultaneously. Having ruled out interplanetary coronal mass ejections, shocks, energetic particles, comets, planets, and interstellar ions as LFW sources, we discuss the remaining generation scenarios: LH ion cyclotron instability driven by greater perpendicular temperature than parallel temperature or by ring-beam distribution, and RH ion fire hose instability driven by inverse temperature anisotropy or by cool ion beams. The investigation of solar wind conditions is compromised by the bias of the one-dimensional Maxwellian fit used for plasma data calibration. However, the LFW storms are preferentially detected in rarefaction regions following fast winds and when the magnetic field is radial. This preference may be related to the ion cyclotron anisotropy instability in fast wind and the minimum in damping along the radial field.

  19. Spitzer observations of the thermal emission from WASP-43b

    SciTech Connect

    Blecic, Jasmina; Harrington, Joseph; Stevenson, Kevin B.; Hardy, Ryan A.; Cubillos, Patricio E.; Hardin, Matthew; Bowman, Oliver; Nymeyer, Sarah; Madhusudhan, Nikku; Anderson, David R.; Hellier, Coel; Smith, Alexis M. S.; Cameron, Andrew Collier

    2014-02-01

    WASP-43b is one of the closest-orbiting hot Jupiters, with a semimajor axis of a = 0.01526 ± 0.00018 AU and a period of only 0.81 days. However, it orbits one of the coolest stars with a hot Jupiter (T {sub *} = 4520 ± 120 K), giving the planet a modest equilibrium temperature of T {sub eq} = 1440 ± 40 K, assuming zero Bond albedo and uniform planetary energy redistribution. The eclipse depths and brightness temperatures from our jointly fit model are 0.347% ± 0.013% and 1670 ± 23 K at 3.6 μm and 0.382% ± 0.015% and 1514 ± 25 K at 4.5 μm. The eclipse timings improved the estimate of the orbital period, P, by a factor of three (P = 0.81347436 ± 1.4 × 10{sup –7} days) and put an upper limit on the eccentricity (e=0.010{sub −0.007}{sup +0.010}). We use our Spitzer eclipse depths along with four previously reported ground-based photometric observations in the near-infrared to constrain the atmospheric properties of WASP-43b. The data rule out a strong thermal inversion in the dayside atmosphere of WASP-43b. Model atmospheres with no thermal inversions and fiducial oxygen-rich compositions are able to explain all the available data. However, a wide range of metallicities and C/O ratios can explain the data. The data suggest low day-night energy redistribution in the planet, consistent with previous studies, with a nominal upper limit of about 35% for the fraction of energy incident on the dayside that is redistributed to the nightside.

  20. Mathematical analysis as required by a tachyonic observer

    SciTech Connect

    Unterberger, André

    2013-09-15

    We rely on an analysis of initial states of the wave function associated with the simplest relativistic particle—the Weyl neutrino—to construct two series of representations of SL(2,R), or of the twofold cover of this group, by operators acting on scalar functions defined on the real line. The first one, which depends on a parameter p= 0, 1, …, contains the usual one-dimensional metaplectic, or oscillator, representation. The second one, a series of representations no longer unitary but, for certain values of the parameter, pseudo-unitary with respect to some non-degenerate indefinite pseudo-scalar product, is built in a comparable way, only exchanging the time coordinate with one of the spatial ones. The first series of representations was originally introduced in connection with automorphic pseudodifferential analysis; the second one is new, except for one value of the (continuous, in this case) parameter ρ, in which case it coincides with the recently introduced anaplectic representation. For each value of the parameter λ (=p or ρ), the basic operators Q and P from the usual Heisenberg pair give way to a new pair (Q, P{sub λ}) and to another analysis of functions on the real line, with as rich a collection of (most of the time totally new) symmetries as the usual one. The unusual set of coordinates in Minkowski's space under consideration can be regarded as corresponding to a “tachyonic observer,” a notion which does not require venturing into debatable questions of Physics. On the other hand, the paper indicates in a special example the way one may recover well-posedness (in a non-classical sense) for an initial-value problem with data on a timelike surface.

  1. Uncovering the single top: observation of electroweak top quark production

    SciTech Connect

    Benitez, Jorge Armando; /Michigan State U.

    2009-08-01

    The top quark is generally produced in quark and anti-quark pairs. However, the Standard Model also predicts the production of only one top quark which is mediated by the electroweak interaction, known as 'Single Top'. Single Top quark production is important because it provides a unique and direct way to measure the CKM matrix element V{sub tb}, and can be used to explore physics possibilities beyond the Standard Model predictions. This dissertation presents the results of the observation of Single Top using 2.3 fb{sup -1} of Data collected with the D0 detector at the Fermilab Tevatron collider. The analysis includes the Single Top muon+jets and electron+jets final states and employs Boosted Decision Tress as a method to separate the signal from the background. The resulting Single Top cross section measurement is: (1) {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.74{sub -0.74}{sup +0.95} pb, where the errors include both statistical and systematic uncertainties. The probability to measure a cross section at this value or higher in the absence of signal is p = 1.9 x 10{sup -6}. This corresponds to a standard deviation Gaussian equivalence of 4.6. When combining this result with two other analysis methods, the resulting cross section measurement is: (2) {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.94 {+-} 0.88 pb, and the corresponding measurement significance is 5.0 standard deviations.

  2. Lightning and radar observations of hurricane Rita landfall

    SciTech Connect

    Henderson, Bradley G; Suszcynsky, David M; Hamlin, Timothy E; Jeffery, C A; Wiens, Kyle C; Orville, R E

    2009-01-01

    Los Alamos National Laboratory (LANL) owns and operates an array of Very-Low Frequency (VLF) sensors that measure the Radio-Frequency (RF) waveforms emitted by Cloud-to-Ground (CG) and InCloud (IC) lightning. This array, the Los Alamos Sferic Array (LASA), has approximately 15 sensors concentrated in the Great Plains and Florida, which detect electric field changes in a bandwidth from 200 Hz to 500 kHz (Smith et al., 2002). Recently, LANL has begun development of a new dual-band RF sensor array that includes the Very-High Frequency (VHF) band as well as the VLF. Whereas VLF lightning emissions can be used to deduce physical parameters such as lightning type and peak current, VHF emissions can be used to perform precise 3d mapping of individual radiation sources, which can number in the thousands for a typical CG flash. These new dual-band sensors will be used to monitor lightning activity in hurricanes in an effort to better predict intensification cycles. Although the new LANL dual-band array is not yet operational, we have begun initial work utilizing both VLF and VHF lightning data to monitor hurricane evolution. In this paper, we present the temporal evolution of Rita's landfall using VLF and VHF lightning data, and also WSR-88D radar. At landfall, Rita's northern eyewall experienced strong updrafts and significant lightning activity that appear to mark a transition between oceanic hurricane dynamics and continental thunderstorm dynamics. In section 2, we give a brief overview of Hurricane Rita, including its development as a hurricane and its lightning history. In the following section, we present WSR-88D data of Rita's landfall, including reflectivity images and temporal variation. In section 4, we present both VHF and VLF lightning data, overplotted on radar reflectivity images. Finally, we discuss our observations, including a comparison to previous studies and a brief conclusion.

  3. Arctic Mixed-Phase Cloud Properties from AERI Lidar Observations: Algorithm and Results from SHEBA

    SciTech Connect

    Turner, David D.

    2005-04-01

    A new approach to retrieve microphysical properties from mixed-phase Arctic clouds is presented. This mixed-phase cloud property retrieval algorithm (MIXCRA) retrieves cloud optical depth, ice fraction, and the effective radius of the water and ice particles from ground-based, high-resolution infrared radiance and lidar cloud boundary observations. The theoretical basis for this technique is that the absorption coefficient of ice is greater than that of liquid water from 10 to 13 ?m, whereas liquid water is more absorbing than ice from 16 to 25 ?m. MIXCRA retrievals are only valid for optically thin (?visible < 6) single-layer clouds when the precipitable water vapor is less than 1 cm. MIXCRA was applied to the Atmospheric Emitted Radiance Interferometer (AERI) data that were collected during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment from November 1997 to May 1998, where 63% of all of the cloudy scenes above the SHEBA site met this specification. The retrieval determined that approximately 48% of these clouds were mixed phase and that a significant number of clouds (during all 7 months) contained liquid water, even for cloud temperatures as low as 240 K. The retrieved distributions of effective radii for water and ice particles in single-phase clouds are shown to be different than the effective radii in mixed-phase clouds.

  4. Observing Signatures of Cosmic Rays Using High-Energy Gamma-Ray...

    Office of Scientific and Technical Information (OSTI)

    Conference: Observing Signatures of Cosmic Rays Using High-Energy Gamma-Ray Telescopes Citation Details In-Document Search Title: Observing Signatures of Cosmic Rays Using ...

  5. Observing Signatures of Cosmic Rays Using High-Energy Gamma-Ray...

    Office of Scientific and Technical Information (OSTI)

    Conference: Observing Signatures of Cosmic Rays Using High-Energy Gamma-Ray Telescopes Citation Details In-Document Search Title: Observing Signatures of Cosmic Rays Using...

  6. OPTICAL SPECTRAL OBSERVATIONS OF A FLICKERING WHITE-LIGHT KERNEL IN A C1 SOLAR FLARE

    SciTech Connect

    Kowalski, Adam F.; Cauzzi, Gianna; Fletcher, Lyndsay

    2015-01-10

    We analyze optical spectra of a two-ribbon, long-duration C1.1 flare that occurred on 2011 August 18 within AR 11271 (SOL2011-08-18T15:15). The impulsive phase of the flare was observed with a comprehensive set of space-borne and ground-based instruments, which provide a range of unique diagnostics of the lower flaring atmosphere. Here we report the detection of enhanced continuum emission, observed in low-resolution spectra from 3600 Å to 4550 Å acquired with the Horizontal Spectrograph at the Dunn Solar Telescope. A small, ≤0.''5 (10{sup 15} cm{sup 2}) penumbral/umbral kernel brightens repeatedly in the optical continuum and chromospheric emission lines, similar to the temporal characteristics of the hard X-ray variation as detected by the Gamma-ray Burst Monitor on the Fermi spacecraft. Radiative-hydrodynamic flare models that employ a nonthermal electron beam energy flux high enough to produce the optical contrast in our flare spectra would predict a large Balmer jump in emission, indicative of hydrogen recombination radiation from the upper flare chromosphere. However, we find no evidence of such a Balmer jump in the bluemost spectral region of the continuum excess. Just redward of the expected Balmer jump, we find evidence of a ''blue continuum bump'' in the excess emission which may be indicative of the merging of the higher order Balmer lines. The large number of observational constraints provides a springboard for modeling the blue/optical emission for this particular flare with radiative-hydrodynamic codes, which are necessary to understand the opacity effects for the continuum and emission line radiation at these wavelengths.

  7. Optical emission line monitor with background observation and cancellation

    DOEpatents

    Goff, D.R.; Notestein, J.E.

    1985-01-04

    A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interfering blackbody radiation by greater than 20 dB.

  8. Optical emission line monitor with background observation and cancellation

    DOEpatents

    Goff, David R.; Notestein, John E.

    1986-01-01

    A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interferring blackbody radiation by greater than 20 dB.

  9. Observations and open questions in beam-beam interactions

    SciTech Connect

    Sen, Tanaji; /Fermilab

    2010-08-01

    The first of the hadron colliders, ISR, started operation in 1970. In the following years, the hadron colliders to follow were the SPS (started 1980), the Tevatron (started 1987 first as a fixed target machine), RHIC (started 2000) and most recently the LHC, which started in 2008. HERA was a hybrid that collided electrons and protons. All of these accelerators had or have their performance limited by the effects of the beam-beam interactions. That has also been true for the electron-positron colliders such as LEP, CESR, KEKB and PEPII. In this article I will discuss how the beam-beam limitations arose in some of these machines. The discussion will be focused on common themes that span the different colliders. I will mostly discuss the hadron colliders but sometimes discuss the lepton colliders where relevant. Only a handful of common accelerator physics topics are chosen here, the list is not meant to be exhaustive. A comparative review of beam-beam performance in the ISR, SPS and Tevatron (ca 1989) can be found in reference. Table 1 shows the relevant parameters of colliders (excluding the LHC), which have accelerated protons.

  10. Observation of two different fractal structures in nanoparticle, protein and surfactant complexes

    SciTech Connect

    Mehan, Sumit Kumar, Sugam Aswal, V. K.

    2014-04-24

    Small angle neutron scattering has been carried out from a complex of nanoparticle, protein and surfactant. Although all the components are similarly (anionic) charged, we have observed strong interactions in their complex formation. It is characterized by the coexistence of two different mass fractal structures. The first fractal structure is originated from the protein and surfactant interaction and second from the depletion effect of first fractal structure leading the nanoparticle aggregation. The fractal structure of protein-surfactant complex represents to bead necklace structure of micelle-like clusters of surfactant formed along the unfolded protein chain. Its fractal dimension depends on the surfactant to protein ratio (r) and decreases with the increase in r. However, fractal dimension of nanoparticle aggregates in nanoparticle-protein complex is found to be independent of protein concentration and governed by the diffusion limited aggregation like morphology.

  11. Observation of the Λ⁷He Hypernucleus by the (e, e'K⁺) Reaction

    DOE PAGES [OSTI]

    Nakamura, S. N.; Matsumura, A.; Okayasu, Y.; Seva, T.; Rodriguez, V. M.; Baturin, P.; Yuan, L.; Acha, A.; Ahmidouch, A.; Androic, D.; et al

    2013-01-02

    An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, HeΛ⁷, was observed for the first time with the (e, e'K⁺) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The HeΛ⁷ binding energy supplies the last missing information of the A=7, T=1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.

  12. Observation of optical spin injection into Ge-based structures at room temperature

    SciTech Connect

    Yasutake, Yuhsuke; Hayashi, Shuhei; Fukatsu, Susumu; Yaguchi, Hiroyuki

    2013-06-17

    Non-zero spin polarization induced by optical orientation was clearly observed at room temperature in a Ge/Ge{sub 0.8}Si{sub 0.2} quantum well grown on Ge and a Ge layer grown on Si by molecular beam epitaxy, whereas it was absent in bulk Ge. This occurred because indirect-gap photoluminescence (PL), which can obscure the spin-polarization information carried by the direct-gap PL, was quenched by unintentional growth-related defects in the epitaxial layers. Such interpretation was confirmed by applying time gating that effectively removed the indirect-gap PL characterized by a slower rise time, which allowed us to demonstrate the existence of room-temperature spin polarization in bulk Ge.

  13. A NuSTAR observation of the center of the Coma Cluster

    DOE PAGES [OSTI]

    Gastaldello, Fabio; Wik, Daniel R.; Molendi, S.; Westergaard, N. J.; Hornstrup, A.; Madejski, G.; Ferreira, D. D. M.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; et al

    2015-02-20

    We present the results of a 55 ks NuSTAR observation of the core of the Coma Cluster. The global spectrum can be explained by thermal gas emission, with a conservative 90% upper limit to non-thermal inverse Compton (IC) emission of 5.1 × 10–12 erg cm–2 s–1 in a 12' × 12' field of view. The brightness of the thermal component in this central region does not allow more stringent upper limits on the IC component when compared with non-imaging instruments with much larger fields of view where claims of detections have been made. Future mosaic NuSTAR observations of Coma willmore » further address this issue. In addition, the temperature map shows a relatively uniform temperature distribution with a gradient from the hot northwest side to the cooler southeast, in agreement with previous measurements. The temperature determination is robust given the flat effective area and low background in the 3-20 keV band, making NuSTAR an ideal instrument to measure high temperatures in the intracluster medium.« less

  14. A NuSTAR observation of the center of the Coma Cluster

    SciTech Connect

    Gastaldello, Fabio; Wik, Daniel R.; Molendi, S.; Westergaard, N. J.; Hornstrup, A.; Madejski, G.; Ferreira, D. D. M.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Grefenstette, B. W.; Hailey, C. J.; Harrison, F. A.; Madsen, K. K.; Stern, D.; Zhang, W. W.

    2015-02-20

    We present the results of a 55 ks NuSTAR observation of the core of the Coma Cluster. The global spectrum can be explained by thermal gas emission, with a conservative 90% upper limit to non-thermal inverse Compton (IC) emission of 5.1 × 10–12 erg cm–2 s–1 in a 12' × 12' field of view. The brightness of the thermal component in this central region does not allow more stringent upper limits on the IC component when compared with non-imaging instruments with much larger fields of view where claims of detections have been made. Future mosaic NuSTAR observations of Coma will further address this issue. In addition, the temperature map shows a relatively uniform temperature distribution with a gradient from the hot northwest side to the cooler southeast, in agreement with previous measurements. The temperature determination is robust given the flat effective area and low background in the 3-20 keV band, making NuSTAR an ideal instrument to measure high temperatures in the intracluster medium.

  15. LAMOST OBSERVATIONS IN THE KEPLER FIELD. I. DATABASE OF LOW-RESOLUTION SPECTRA

    SciTech Connect

    Cat, P. De; Ren, A. B.; Yang, X. H.; Fu, J. N.; Shi, J. R.; Luo, A. L.; Yang, M.; Wang, J. L.; Zhang, H. T.; Shi, H. M.; Zhang, W.; Dong, Subo; Catanzaro, G.; Frasca, A.; Corbally, C. J.; Gray, R. O.; Żakowicz, J. Molenda-; Uytterhoeven, K.; Briquet, M.; Bruntt, H.; and others

    2015-09-15

    The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude pulsation modes that were undetectable from Earth. The long time base of Kepler light curves allows for the accurate determination of the frequencies and amplitudes of pulsation modes needed for in-depth asteroseismic modeling. However, for an asteroseismic study to be successful, the first estimates of stellar parameters need to be known and they cannot be derived from the Kepler photometry itself. The Kepler Input Catalog provides values for the effective temperature, surface gravity, and metallicity, but not always with sufficient accuracy. Moreover, information on the chemical composition and rotation rate is lacking. We are collecting low-resolution spectra for objects in the Kepler field of view with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (lamost, Xinglong observatory, China). All of the requested fields have now been observed at least once. In this paper, we describe those observations and provide a useful database for the whole astronomical community.

  16. Direct Observation of Photoinduced Charge Separation in Ruthenium Complex/Ni(OH)2 Nanoparticle Hybrid

    DOE PAGES [OSTI]

    Tang, Yu; Pattengale, Brian A.; Ludwig, John M.; Atifi, Abderrahman; Zinovev, Alexander V.; Dong, Bin; Kong, Qingyu; Zuo, Xiaobing; Zhang, Xiaoyi; Huang, Jier

    2015-12-17

    We report that Ni(OH)2 have emerged as important functional materials for solar fuel conversion because of their potential as cost-effective bifunctional catalysts for both hydrogen and oxygen evolution reactions. However, their roles as photocatalysts in the photoinduced charge separation (CS) reactions remain unexplored. In this paper, we investigate the CS dynamics of a newly designed hybrid catalyst by integrating a Ru complex with Ni(OH)2 nanoparticles (NPs). Using time resolved X-ray absorption spectroscopy (XTA), we directly observed the formation of the reduced Ni metal site (~60 ps), unambiguously demonstrating CS process in the hybrid through ultrafast electron transfer from Ru complexmore » to Ni(OH)2 NPs. Compared to the ultrafast CS process, the charge recombination in the hybrid is ultraslow (>>50 ns). These results not only suggest the possibility of developing Ni(OH)2 as solar fuel catalysts, but also represent the first time direct observation of efficient CS in a hybrid catalyst using XTA.« less

  17. Beyond Higgs couplings: Probing the Higgs with angular observables at future e$$^{+}$$e$$^{-}$$ colliders

    DOE PAGES [OSTI]

    Craig, Nathaniel; Gu, Jiayin; Liu, Zhen; Wang, Kechen

    2016-03-09

    Here, we study angular observables in themore » $$ {e}^{+}{e}^{-}\\to ZH\\to {\\ell}^{+}{\\ell}^{-}b\\overline{b} $$ channel at future circular e$$^{+}$$ e$$^{-}$$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $$ \\sqrt{s}=240 $$ GeV and 5 (30) ab$$^{-1}$$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for he Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the HZγ coupling and constraining the “blind spot” in indirect limits on supersymmetric scalar top partners.« less

  18. Stellar and gaseous nuclear disks observed in nearby (U)LIRGs

    SciTech Connect

    Medling, Anne M.; U, Vivian; Guedes, Javiera; Max, Claire E.; Holden, Bradford; Mayer, Lucio; Roškar, Rok; Armus, Lee; Sanders, David E-mail: max@ucolick.org

    2014-03-20

    We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few tens of parsecs. The resulting kinematic maps reveal gas disks in at least 16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these galaxy merger systems. In our late-stages mergers, these disks are young (stellar ages <30 Myr) and likely formed as gas disks that became unstable to star formation during the merger. On average, these disks have effective radii of a few hundred parsecs, masses between 10{sup 8} and 10{sup 10} M {sub ☉}, and v/σ between 1 and 5. These disks are similar to those created in high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and favor short coalescence times for binary black holes. The few galaxies in our sample in earlier stages of mergers have disks that are larger (r {sub eff} ∼ 200-1800 pc) and are likely remnants of the galactic disks that have not yet been completely disrupted by the merger.

  19. Alma observations of nearby luminous infrared galaxies with various agn energetic contributions using dense gas tracers

    SciTech Connect

    Imanishi, Masatoshi; Nakanishi, Kouichiro

    2014-07-01

    We present the results of our ALMA Cycle 0 observations, using HCN/HCO{sup +}/HNC J = 4-3 lines, of six nearby luminous infrared galaxies with various energetic contributions from active galactic nuclei (AGNs) estimated from previous infrared spectroscopy. These lines are very effective for probing the physical properties of high-density molecular gas around the hidden energy sources in the nuclear regions of these galaxies. We find that HCN to HCO{sup +} J = 4-3 flux ratios tend to be higher in AGN-important galaxies than in starburst-dominated regions, as was seen at the J = 1-0 transition, while there is no clear difference in the HCN-to-HNC J = 4-3 flux ratios among observed sources. A galaxy with a starburst-type infrared spectral shape and very large molecular line widths shows a high HCN-to-HCO{sup +} J = 4-3 flux ratio, which could be due to turbulence-induced heating. We propose that enhanced HCN J = 4-3 emission relative to HCO{sup +} J = 4-3 could be used to detect more energetic activity than normal starbursts, including deeply buried AGNs, in dusty galaxy populations.

  20. A SUMMARY OF TEST OBSERVATIONS WHEN IBUTTONS ARE SUBJECTED TO RF ENERGY

    SciTech Connect

    Kane, R J; Baluyot, E V

    2011-10-26

    The iButton is a 'one-wire', temperature sensor and data logger in a short metal cylinder package 17 mm in diameter and 6 mm tall. The device is designed to be attached to a surface and acquire temperature samples over time periods as short as 1 second to as long as 300 minutes. Both 8-bit and 16-bit samples are available with 8kB of memory available. Lifetime is limited to an internal battery that cannot be replaced or recharged. The RF test interest originated with the concern that the data logger could inadvertently record electrical emanations from other nearby equipment. The normal operation of the data logger does not support high speed sampling but the control interface will operate at either 15.4 kbps or 125 kbps. There were no observable effects in the operation of the module or in the data that could be attributed to the use of RF energy. They made the assumption that these devices would potentially show RF sensitivity in any of the registers and in the data memory equally, therefore gross changes in the data might show RF susceptibility. No such sensitivity was observed. Because significant power levels were used for these tests they can extrapolate downward in power to state that no RF susceptibility would occur at lower power levels given the same configurations.