National Library of Energy BETA

Sample records for negligible negligible negligible

  1. Negligible sample heating from synchrotron infrared beam

    SciTech Connect (OSTI)

    Martin, Michael C.; Tsvetkova, Nelly M.; Crowe, John H.; McKinney, Wayne R.

    2000-08-30

    The use of synchrotron sources for infrared (IR) spectromicroscopy provides greatly increased brightness enabling high-quality IR measurements at diffraction-limited spatial resolutions. This permits synchrotron-based IR spectromicroscopy to be applied to biological applications at spatial resolutions of the order of the size of a single mammalian cell. The question then arises, ''Does the intense synchrotron beam harm biological samples?'' Mid-IR photons are too low in energy to break bonds directly, however they could cause damage to biological molecules due to heating. In this work, we present measurements showing negligible sample heating effects from a diffraction-limited synchrotron IR source. The sample used is fully hydrated lipid bilayers composed of dipalmitoylphosphatidylcholine(DPPC), which undergoes a phase transition from a gel into a liquid-crystalline state at about 315 K during heating. Several IR-active vibrational modes clearly shift in frequency when the sample passes through the phase transition. We calibrate and then use these shifting vibrational modes as an in situ temperature sensor.

  2. Application of Negligible Creep Criteria to Candidate Materials for HTGR Pressure Vessels

    SciTech Connect (OSTI)

    Jetter, Robert I; Sham, Sam; Swindeman, Robert W

    2011-01-01

    Two of the proposed High Temperature Gas Reactors (HTGRs) under consideration for a demonstration plant have the design object of avoiding creep effects in the reactor pressure vessel (RPV) during normal operation. This work addresses the criteria for negligible creep in Subsection NH, Division 1 of the ASME B&PV (Boiler and Pressure Vessel) Code, Section III, other international design codes and some currently suggested criteria modifications and their impact on permissible operating temperatures for various reactor pressure vessel materials. The goal of negligible creep could have different interpretations depending upon what failure modes are considered and associated criteria for avoiding the effects of creep. It is shown that for the materials of this study, consideration of localized damage due to cycling of peak stresses results in a lower temperature for negligible creep than consideration of the temperature at which the allowable stress is governed by creep properties. In assessing the effect of localized cyclic stresses it is also shown that consideration of cyclic softening is an important effect that results in a higher estimated temperature for the onset of significant creep effects than would be the case if the material were cyclically hardening. There are other considerations for the selection of vessel material besides avoiding creep effects. Of interest for this review are (1) the material s allowable stress level and impact on wall thickness (the goal being to minimize required wall thickness) and (2) ASME Code approval (inclusion as a permitted material in the relevant Section and Subsection of interest) to expedite regulatory review and approval. The application of negligible creep criteria to two of the candidate materials, SA533 and Mod 9Cr-1Mo (also referred to as Grade 91), and to a potential alternate, normalized and tempered 2 Cr-1Mo, is illustrated and the relative advantages and disadvantages of the materials are discussed.

  3. Negligible substrate clamping effect on piezoelectric response in (111)-epitaxial tetragonal Pb(Zr, Ti)O{sub 3} films

    SciTech Connect (OSTI)

    Yamada, Tomoaki; Yasumoto, Jun; Ito, Daisuke; Yoshino, Masahito; Nagasaki, Takanori; Sakata, Osami; Imai, Yasuhiko; Kiguchi, Takanori; Shiraishi, Takahisa; Shimizu, Takao; Funakubo, Hiroshi

    2015-08-21

    The converse piezoelectric responses of (111)- and (001)-epitaxial tetragonal Pb(Zr{sub 0.35}Ti{sub 0.65})O{sub 3} [PZT] films were compared to investigate the orientation dependence of the substrate clamping effect. Synchrotron X-ray diffraction (XRD) and piezoelectric force microscopy revealed that the as-grown (111)-PZT film has a polydomain structure with normal twin boundaries that are changed by the poling process to inclined boundaries, as predicted by Romanov et al. [Phys. Status Solidi A 172, 225 (1999)]. Time-resolved synchrotron XRD under bias voltage showed the negligible impact of substrate clamping on the piezoelectric response in the (111)-PZT film, unlike the case for (001)-PZT film. The origin of the negligible clamping effect in the (111)-PZT film is discussed from the viewpoint of the elastic properties and the compensation of lattice distortion between neighboring domains.

  4. Assessment of Negligible Creep, Off-Normal Welding and Heat Treatment of Gr91 Steel for Nuclear Reactor Pressure Vessel Application

    SciTech Connect (OSTI)

    Ren, Weiju; Terry, Totemeier

    2006-10-01

    Two different topics of Grade 91 steel are investigated for Gen IV nuclear reactor pressure vessel application. On the first topic, negligible creep of Grade 91 is investigated with the motivation to design the reactor pressure vessel in negligible creep regime and eliminate costly surveillance programs during the reactor operation. Available negligible creep criteria and creep strain laws are reviewed, and new data needs are evaluated. It is concluded that modifications of the existing criteria and laws, together with their associated parameters, are needed before they can be reliably applied to Grade 91 for negligible creep prediction and reactor pressure vessel design. On the second topic, effects of off-normal welding and heat treatment on creep behavior of Grade 91 are studied with the motivation to better define the control over the parameters in welding and heat treatment procedures. The study is focused on off-normal austenitizing temperatures and improper cooling after welding but prior to post-weld heat treatment.

  5. Negligible Magnetism in Excellent Structural Quality Cr[subscript x]Ti[subscript 1-x]O[subscript 2] Anatase: Contrast with High-T[subscript C] Ferromagnetism in Structurally Defective Cr[subscript x]Ti[subscript 1-x]O[subscript 2

    SciTech Connect (OSTI)

    Kaspar, T.C.; Heald, S.M.; Wang, C.M.; Bryan, J.D.; Droubay, T.; Shutthanandan, V.; Thevuthasan, S.; McCready, D.E.; Kellock, A.J.; Gamelin, D.R.; Chambers, S.A.

    2010-07-19

    We reexamine the mechanism of ferromagnetism in doped TiO{sub 2} anatase, using epitaxial Cr:TiO{sub 2} with excellent structural quality as a model system. In contrast to highly oriented but defective Cr:TiO{sub 2} ({approx}0.5{micro}{sub B}/Cr), these structurally superior single crystal films exhibit negligible ferromagnetism. Similar results were obtained for Co:TiO{sub 2}. We show for the first time that charge-compensating oxygen vacancies alone, as predicted by F-center mediated exchange, are not sufficient to activate ferromagnetism. Instead, the onset of ferromagnetism correlates with the presence of structural defects.

  6. Down-regulation of gibberellic acid in poplar has negligible effects on host-plant suitability and insect pest response

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

    Buhl, Christine; Strauss, Steven H.; Lindroth, Richard L.

    2015-01-06

    Abstract Endogenous levels and signaling of gibberellin plant hormones such as gibberellic acid (GA) have been genetically down-regulated to create semi-dwarf varieties of poplar. The potential benefits of semi-dwarf stature include reduced risk of wind damage, improved stress tolerance, and improved wood quality. Despite these benefits, modification of growth traits may have consequences for non-target traits that confer defense against insect herbivores. According to the growth-differentiation balance hypothesis, reductions in growth may shift allocation of carbon from growth to chemical resistance traits, thereby altering plant defense. To date, host-plant suitability and pest response have not been comprehensively evaluated in GAmore » down-regulated plants. We quantified chemical resistance and nitrogen (an index of protein) in GA down-regulated and wild-type poplar (Populus alba × P. tremula) genotypes. We also evaluated performance of both generalist (Lymantria dispar) and specialist (Chrysomela scripta) insect pests reared on these genotypes. Our evaluation of resistance traits in four GA down-regulated genotypes revealed increased phenolic glycosides in one modified genotype and reduced lignin in two modified genotypes relative to the non-transgenic wild type. Nitrogen levels did not vary significantly among the experimental genotypes. Generalists reared on the four GA down-regulated genotypes exhibited reduced performance on only one modified genotype relative to the wild type. Specialists, however, performed similarly across all genotypes. Results from this study indicate that although some non-target traits varied among GA down-regulated genotypes, the differences in poplar pest susceptibility were modest and highly genotype-specific.« less

  7. Down-regulation of gibberellic acid in poplar has negligible effects on host-plant suitability and insect pest response

    SciTech Connect (OSTI)

    Buhl, Christine; Strauss, Steven H.; Lindroth, Richard L.

    2015-01-06

    Abstract Endogenous levels and signaling of gibberellin plant hormones such as gibberellic acid (GA) have been genetically down-regulated to create semi-dwarf varieties of poplar. The potential benefits of semi-dwarf stature include reduced risk of wind damage, improved stress tolerance, and improved wood quality. Despite these benefits, modification of growth traits may have consequences for non-target traits that confer defense against insect herbivores. According to the growth-differentiation balance hypothesis, reductions in growth may shift allocation of carbon from growth to chemical resistance traits, thereby altering plant defense. To date, host-plant suitability and pest response have not been comprehensively evaluated in GA down-regulated plants. We quantified chemical resistance and nitrogen (an index of protein) in GA down-regulated and wild-type poplar (Populus alba × P. tremula) genotypes. We also evaluated performance of both generalist (Lymantria dispar) and specialist (Chrysomela scripta) insect pests reared on these genotypes. Our evaluation of resistance traits in four GA down-regulated genotypes revealed increased phenolic glycosides in one modified genotype and reduced lignin in two modified genotypes relative to the non-transgenic wild type. Nitrogen levels did not vary significantly among the experimental genotypes. Generalists reared on the four GA down-regulated genotypes exhibited reduced performance on only one modified genotype relative to the wild type. Specialists, however, performed similarly across all genotypes. Results from this study indicate that although some non-target traits varied among GA down-regulated genotypes, the differences in poplar pest susceptibility were modest and highly genotype-specific.

  8. Slide 1

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

    Research Details - Cellulose particles (1 cm 3 ) spontaneously move at pyrolysisgasification temperatures and accelerate with negligible resistance - Locomotive force is ...

  9. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... of linear simulation results using the ... which ion kinetic dynamics are negligible. Electron wave-particle interactions (Landau ... invalidate the fluid theory in the ...

  10. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    reactor systems is negligible because the neutron capture cross-section is low for fast fission neutrons. At the INL, scientists have previously transported fission products...

  11. DOE/EIA-0358

    U.S. Energy Information Administration (EIA) Indexed Site

    of nonpurchased byproduct or waste stream fuels and a negligible amount of nontraditional energy sources such as solar, hydropower, etc. When this figure is adjusted to account for...

  12. Defect tolerant transmission lithography mask (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Structural imperfections and defects in the coating have negligible effect on the aerial ... the phase defect problem, and is independent of the thermal load during exposure. ...

  13. U.S. DEPARTMENT OF ENERGY * SAVANNAH RIVER ...

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

    E-mail: dale.haas@srnl.doe.gov Uses naturally occurring microorganisms Negligible toxicity Promotes rapid hydrocarbon breakdown Provides for oil recovery from existing waste...

  14. Microsoft Word - Final-report-05-07.doc

    Office of Scientific and Technical Information (OSTI)

    and improvement of nanoparticle-based solar cells, including dye-sensitized solar cells. ... and were shown to be negligible under low dye coverage and excitation power density. ...

  15. Stochastic

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

    ... inertial and collision terms are negligible compared to ... charge transport does not enter Eqs. 9 explicitly since ... the charge flux 20 and search for a localized density ...

  16. Research Highlights Sorted by Submission Data

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

    ... Frost Flowers Have Negligible Influence on Cloud Longwave Warming ARM ASR Xu, L., Russell, L. M. Are Increases in Thunderstorm Activity in Southeast China Related to Air Pollution? ...

  17. UNITED STATES GOVERNMENT

    Office of Legacy Management (LM)

    ... This data *- ' <. .presents strong evidence of negligible pollution of river waters due i ... Although no air sample data is available, reasonable inferences may be drawn as to the ...

  18. Research Highlights Sorted by Title

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

    ... Frost Flowers Have Negligible Influence on Cloud Longwave Warming ARM ASR Xu, L., Russell, L. M. Are Increases in Thunderstorm Activity in Southeast China Related to Air Pollution? ...

  19. MiniBooNE E. D. Zimmerman

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

    SciBooNE Detector TargetHorn SciBooNE constraint reduces error at MiniBooNE * Flux errors become 1-2% level: negligible for this analysis * Cross-section errors reduced, but...

  20. Microsoft Word - Chapter 6_021411

    National Nuclear Security Administration (NNSA)

    ... Estimates are not possible until more precise plans are finalized by the CD-1 process. 6.3.6 Air Quality ORR's contribution to air pollution in the ROI is negligible compared to ...

  1. Final Environmental Impact Statement for Construction and Operation...

    Office of Environmental Management (EM)

    ... risks of less than 10 -6 are considered negligible. d For the uranium air concentration, the reported concentration for uranium-238 and thorium-234 combined was used (DOE 2001b). ...

  2. Directory

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

    order Object Created Object Last Modified Assessment of Negligible Creep Off-Normal Welding and Heat Treatment of GR91 Steel for Nuclear Reactor Pressure Vessel Application.pdf...

  3. A High-Wavenumber Viscosity for High-Resolution Numerical Methods

    SciTech Connect (OSTI)

    Cook, A; Cabot, W H

    2003-02-19

    Numerical simulations of compressible flows are commonly based on the Euler equations when effects of viscosity are thought to be negligible. These equations admit singular solutions, even in cases where the initial and boundary conditions are smooth. So-called ''Euler solvers'' rely on numerical dissipation, explicitly or implicitly present in the scheme, to regularize the problem, such that physical solutions are selected.

  4. Cycling firing method for bypass operation of bridge converters

    DOE Patents [OSTI]

    Zabar, Zivan

    1982-01-01

    The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

  5. Ultrashort pulse laser machining of metals and alloys

    DOE Patents [OSTI]

    Perry, Michael D.; Stuart, Brent C.

    2003-09-16

    The invention consists of a method for high precision machining (cutting, drilling, sculpting) of metals and alloys. By using pulses of a duration in the range of 10 femtoseconds to 100 picoseconds, extremely precise machining can be achieved with essentially no heat or shock affected zone. Because the pulses are so short, there is negligible thermal conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond approximately 0.1-1 micron (dependent upon the particular material) from the laser machined surface. Due to the short duration, the high intensity (>10.sup.12 W/cm.sup.2) associated with the interaction converts the material directly from the solid-state into an ionized plasma. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces with negligible redeposition either within the kerf or on the surface. Since there is negligible heating beyond the depth of material removed, the composition of the remaining material is unaffected by the laser machining process. This enables high precision machining of alloys and even pure metals with no change in grain structure.

  6. Entropy and hadrochemical composition in heavy ion collision

    SciTech Connect (OSTI)

    Biro, T.; Barz, H.W.; Lukacs, B.; Zimanyi, J.

    1983-06-01

    The composite particle production in a heavy ion collision is calculated in the framework of a hadrochemical model. A critical comparison is performed between the produced entropy and the observables. The entropy production during the hadrochemical processes is found to be negligible.

  7. TMX-upgrade. X-ray diagnostic: low-energy temperature determination

    SciTech Connect (OSTI)

    Jacoby, B.A.

    1981-05-01

    In order to properly design the x-ray filter set, a reasonable computational model of the plasma emission had to be developed. The radiation continuum computed consisted of two components: bremsstrahlung and recombination radiation. The contribution of line radiation from low Z impurities was estimated to be negligible for x-ray energies above 1 keV.

  8. Recovery of EUVL substrates

    SciTech Connect (OSTI)

    Vernon, S.P.; Baker, S.L.

    1995-01-19

    Mo/Si multilayers, were removed from superpolished zerodur and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

  9. Electrocatalytic Reduction of Carbon Dioxide with a Well-Defined PN 3 -Ru Pincer Complex

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

    Min, Shixiong; Rasul, Shahid; Li, Huaifeng; Grills, David C.; Takanabe, Kazuhiro; Li, Lain-Jong; Huang, Kuo-Wei

    2015-11-13

    We established a well-defined PN3-Ru pincer complex (5) bearing a redox-active bipyridine ligand with an aminophosphine arm as an effective and stable molecular electrocatalyst for CO2 reduction to CO and HCOOH with negligible formation of H2 in a H2O/MeCN mixture.

  10. Rotary pneumatic valve

    DOE Patents [OSTI]

    Hardee, Harry C.

    1991-01-01

    A rotary pneumatic valve which is thrust balanced and the pneumatic pressure developed produces only radial loads on the valve cylinder producing negligible resistance and thus minimal torque on the bearings of the valve. The valve is multiplexed such that at least two complete switching cycles occur for each revolution of the cylinder spindle.

  11. SU-E-T-277: Raystation Electron Monte Carlo Commissioning and Clinical Implementation

    SciTech Connect (OSTI)

    Allen, C; Sansourekidou, P; Pavord, D

    2014-06-01

    Purpose: To evaluate the Raystation v4.0 Electron Monte Carlo algorithm for an Elekta Infinity linear accelerator and commission for clinical use. Methods: A total of 199 tests were performed (75 Export and Documentation, 20 PDD, 30 Profiles, 4 Obliquity, 10 Inhomogeneity, 55 MU Accuracy, and 5 Grid and Particle History). Export and documentation tests were performed with respect to MOSAIQ (Elekta AB) and RadCalc (Lifeline Software Inc). Mechanical jaw parameters and cutout magnifications were verified. PDD and profiles for open cones and cutouts were extracted and compared with water tank measurements. Obliquity and inhomogeneity for bone and air calculations were compared to film dosimetry. MU calculations for open cones and cutouts were performed and compared to both RadCalc and simple hand calculations. Grid size and particle histories were evaluated per energy for statistical uncertainty performance. Acceptability was categorized as follows: performs as expected, negligible impact on workflow, marginal impact, critical impact or safety concern, and catastrophic impact of safety concern. Results: Overall results are: 88.8% perform as expected, 10.2% negligible, 2.0% marginal, 0% critical and 0% catastrophic. Results per test category are as follows: Export and Documentation: 100% perform as expected, PDD: 100% perform as expected, Profiles: 66.7% perform as expected, 33.3% negligible, Obliquity: 100% marginal, Inhomogeneity 50% perform as expected, 50% negligible, MU Accuracy: 100% perform as expected, Grid and particle histories: 100% negligible. To achieve distributions with satisfactory smoothness level, 5,000,000 particle histories were used. Calculation time was approximately 1 hour. Conclusion: Raystation electron Monte Carlo is acceptable for clinical use. All of the issues encountered have acceptable workarounds. Known issues were reported to Raysearch and will be resolved in upcoming releases.

  12. Are the argon metastables important in high power impulse magnetron sputtering discharges?

    SciTech Connect (OSTI)

    Gudmundsson, J. T.; Lundin, D.; Minea, T. M.; Stancu, G. D.; Brenning, N.

    2015-11-15

    We use an ionization region model to explore the ionization processes in the high power impulse magnetron sputtering (HiPIMS) discharge in argon with a titanium target. In conventional dc magnetron sputtering (dcMS), stepwise ionization can be an important route for ionization of the argon gas. However, in the HiPIMS discharge stepwise ionization is found to be negligible during the breakdown phase of the HiPIMS pulse and becomes significant (but never dominating) only later in the pulse. For the sputtered species, Penning ionization can be a significant ionization mechanism in the dcMS discharges, while in the HiPIMS discharge Penning ionization is always negligible as compared to electron impact ionization. The main reasons for these differences are a higher plasma density in the HiPIMS discharge, and a higher electron temperature. Furthermore, we explore the ionization fraction and the ionized flux fraction of the sputtered vapor and compare with recent experimental work.

  13. Production of higher silanes in radio frequency SiH{sub 4} and H{sub 2}-SiH{sub 4} plasmas

    SciTech Connect (OSTI)

    Horvath, P.; Rozsa, K.; Gallagher, A.

    2004-12-15

    Stable gases produced in SiH{sub 4} and H{sub 2}-SiH{sub 4}, capacitively coupled rf discharges operated at typical device-production conditions, were investigated by quadrupole mass spectrometry. The production of disilane and trisilane and the depletion of silane and pressure change were measured during consecutive short discharges. Dissociation rate constants and branching ratios for higher-silane production are obtained from the time-dependent densities. The influence of suspended Si particles on stable-gas production is found to be negligible, by changing the duration of individual discharges and thereby the particle densities and sizes. We have also observed pyrolitic decay of disilane and trisilane at 200 deg. C, although this is negligible under normal reactor conditions.

  14. Retrofit device to improve vapor compression cooling system performance by dynamic blower speed modulation

    DOE Patents [OSTI]

    Roth, Robert Paul; Hahn, David C.; Scaringe, Robert P.

    2015-12-08

    A device and method are provided to improve performance of a vapor compression system using a retrofittable control board to start up the vapor compression system with the evaporator blower initially set to a high speed. A baseline evaporator operating temperature with the evaporator blower operating at the high speed is recorded, and then the device detects if a predetermined acceptable change in evaporator temperature has occurred. The evaporator blower speed is reduced from the initially set high speed as long as there is only a negligible change in the measured evaporator temperature and therefore a negligible difference in the compressor's power consumption so as to obtain a net increase in the Coefficient of Performance.

  15. Bias in Dynamic Monte Carlo Alpha Calculations

    SciTech Connect (OSTI)

    Sweezy, Jeremy Ed; Nolen, Steven Douglas; Adams, Terry R.; Trahan, Travis John

    2015-02-06

    A 1/N bias in the estimate of the neutron time-constant (commonly denoted as α) has been seen in dynamic neutronic calculations performed with MCATK. In this paper we show that the bias is most likely caused by taking the logarithm of a stochastic quantity. We also investigate the known bias due to the particle population control method used in MCATK. We conclude that this bias due to the particle population control method is negligible compared to other sources of bias.

  16. Nonproliferation, Nuclear Security, and the Insider Threat

    SciTech Connect (OSTI)

    Balatsky, Galya I.; Duggan, Ruth

    2012-07-12

    Insider threat concept is evolving and getting more attention: (1) Domestically, internationally and in foreign countries, (2) At the government, academia, and industry levels, and (3) Public awareness and concerns are also growing. Negligence can be an insider's action. Technology advancements provide more opportunities, new tools for the insider. Our understanding of the insider is shaped by our cultural, social and ethnic perceptions and traditions. They also can limit our recognition of the issues and response actions.

  17. Relaying an optical wavefront

    DOE Patents [OSTI]

    Sweatt, William C.; Vawter, G. Allen

    2007-03-06

    A wavefront rely devices samples an incoming optical wavefront at different locations, optically relays the samples while maintaining the relative position of the samples and the relative phase between the samples. The wavefront is reconstructed due to interference of the samples. Devices can be designed for many different wavelengths, including for example the ultraviolet, visible, infrared and even longer wavelengths such as millimeter waves. In one application, the device function as a telescope but with negligible length.

  18. The fluctuation induced Hall effect

    SciTech Connect (OSTI)

    Shen, W.; Prager, S.C.

    1993-02-01

    The fluctuation induced Hall term, [le][approximately][ovr J] [times] [approximately][ovr B][ge], has been measured in the MST reversed field pinch. The term is of interest as a possible source of current self-generation (dynamo). It is found to be non-negligible, but small in that it can account for less than 25% of the dynamo driven current.

  19. The fluctuation induced Hall effect

    SciTech Connect (OSTI)

    Shen, W.; Prager, S.C.

    1993-02-01

    The fluctuation induced Hall term, {le}{approximately}{ovr J} {times} {approximately}{ovr B}{ge}, has been measured in the MST reversed field pinch. The term is of interest as a possible source of current self-generation (dynamo). It is found to be non-negligible, but small in that it can account for less than 25% of the dynamo driven current.

  20. Self-pumping impurity control

    DOE Patents [OSTI]

    Brooks, Jeffrey N.; Mattas, Richard F.

    1991-01-01

    Apparatus for removing the helium ash from a fusion reactor having a D-T plasma comprises a helium trapping site within the reactor plasma confinement device, said trapping site being formed of a trapping material having negligible helium solubility and relatively high hydrogen solubility; and means for depositing said trapping material on said site at a rate sufficient to prevent saturation of helium trapping.

  1. Deformed special relativity as an effective theory of measurements on quantum gravitational backgrounds

    SciTech Connect (OSTI)

    Aloisio, R.; Grillo, A.; Galante, A.; Liberati, S.; Luzio, E.; Mendez, F.

    2006-02-15

    In this article we elaborate on a recently proposed interpretation of deformed special relativity (DSR) as an effective measurement theory in the presence of non-negligible (albeit small) quantum gravitational fluctuations. We provide several heuristic arguments to explain how such a new theory can emerge and discuss the possible observational consequences of this framework. Given that our discussion considers leading order corrections to the standard dispersion relations, our results apply to a very wide class of possible modifications of special relativity.

  2. Nitric acid recovery from waste solutions

    DOE Patents [OSTI]

    Wilson, A. S.

    1959-04-14

    The recovery of nitric acid from aqueous nitrate solutions containing fission products as impurities is described. It is desirable to subject such solutions to concentration by evaporation since nitric acid is regenerated thereby. A difficulty, however, is that the highly radioactive fission product ruthenium is volatilized together with the nitric acid. It has been found that by adding nitrous acid, ruthenium volatilization is suppressed and reduced to a negligible degree so that the distillate obtained is practically free of ruthenium.

  3. NITRIC ACID RECPVERY FROM WASTE COLUTIONS

    DOE Patents [OSTI]

    Wilson, A.S.

    1959-04-14

    The recovery of nitric acid from aqueous nitrate solutions containing fission products as impurities is described. It is desirable to subject such solutions to concentration by evaporation since nitric acid is regenerated thereby. A difficulty, however, is that the highly radioactive fission product ruthenium is volatilized together with the nitric acid. It has been found that by adding nitrous acids ruthenium volatilization is suppressed and reduced to a negligible degree so that the distillate obtained is practically free of rutheniuim.

  4. Controlled Rapid Pressurization Using Liquid Propellants for EGS Well

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

    Stimulation | Department of Energy Controlled Rapid Pressurization Using Liquid Propellants for EGS Well Stimulation Controlled Rapid Pressurization Using Liquid Propellants for EGS Well Stimulation Project objective: Investigate the use of non-toxicŽ or negligible environmental impact liquid propellants for the stimulation of geothermal fields. chemistry_grubelich_rapid_pressurization.pdf (299.78 KB) More Documents & Publications Energetic Materials for EGS Well Stimulation (solids,

  5. Study Shows Active Power Controls from Wind May Increase Revenues and Improve System Reliability

    Office of Energy Efficiency and Renewable Energy (EERE)

    The DOE Wind Program and the National Renewable Energy Laboratory recently published a study conducted in collaboration with the Electric Power Research Institute and the University of Colorado. Researchers examined how the contribution of wind power providing active power controls could benefit the total power system economics, increase revenue streams, and improve the reliability and security of the nation’s power system, all while having negligible impacts on the turbine and its components.

  6. Research Highlight

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

    Arctic Winter Frost Flowers Have Negligible Influence on Cloud Longwave Warming Download a printable PDF Submitter: Xu, L., University of California, San Diego Russell, L. M., Scripps Institution of Oceanography Area of Research: Aerosol Processes Working Group(s): Aerosol Life Cycle, Cloud-Aerosol-Precipitation Interactions Journal Reference: Xu L, LM Russell, RC Somerville, and PK Quinn. 2013. "Frost flower aerosol effects on Arctic wintertime longwave cloud radiative forcing."

  7. Alignment of Iron Nanoparticles in a Magnetic Field Due to Shape Anisotropy

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

    Radhakrishnan, Balasubramaniam; Nicholson, Don M; Eisenbach, Markus; Ludtka, Gerard Michael; Rios, Orlando; Parish, Chad M

    2015-07-09

    During high magnetic field processing there is evidence for alignment of non-spherical metallic particles above the Curie temperature in alloys with negligible magneto-crystalline anisotropy. The main driving force for alignment is the magnetic shape anisotropy. Current understanding of the phenomenon is not adequate to quantify the effect of particle size, aspect ratio, temperature and the magnetic field on particle alignment. We demonstrate a Monte Carlo approach coupled with size scaling to show the conditions under which alignment is possible.

  8. Phase-Controlled Electrochemical Activity of Epitaxial Spinel Thin films as

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

    Mg-Cathodes - Joint Center for Energy Storage Research 7, 2015, Research Highlights Phase-Controlled Electrochemical Activity of Epitaxial Spinel Thin films as Mg-Cathodes Using epitaxial thin film methods, two polymorphs of MgMn2O4 (MMO) are stabilized in tetragonal (MMOT) and cubic (MMOC) phases. The MMOT thin film shows negligible activity with no structural changes, while MMOC (normally found at high temperature or high pressure) exhibits reversible Mg2+ activity with associated changes

  9. FRAP-T5 predictions during reactor shutdown events. [PWR; BWR

    SciTech Connect (OSTI)

    Peeler, G.B.; Laats, E.T.

    1980-01-01

    The Transient Fuel Rod Analysis Program, FRAP-T5, was recently assessed by EG and G Idaho, Inc. As part of this assessment, the measured and FRAP-T5 predicted fuel centerline temperature response during reactor shutdown events were compared. For these events either forced convection or nucleate boiling boundary conditions existed, resulting in a negligible effect on fuel behavior from cladding temperature and deformation uncertainties. This allowed the assessment of internal heat transfer to be emphasized.

  10. siemens-postcap | netl.doe.gov

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

    Slipstream Development and Testing of Siemens POSTCAP Capture and Separation Technology Project No.: DE-FE0003714 Siemens Energy, Inc. will design, install, and operate a pilot plant for treating a 2.5 MW equivalent slipstream at the TECO Energy Big Bend Station to demonstrate POSTCAP technology for post-combustion CO2 gas capture. POSTCAP based technology utilizes an amino acid salt (AAS) that can operate in a conventional scrubber system similar to that for MEA, but with negligible solvent

  11. Electroactive-Zone Extension in Flow-Battery Stacks - Joint Center for

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

    Energy Storage Research 30, 2014, Research Highlights Electroactive-Zone Extension in Flow-Battery Stacks Predicted contours of energy efficiency accounting for EAZ-extension losses. At C/10 rate only short current collectors are affected substantially by EAZ extension. Longer collectors (> 20 mm) can achieve very high efficiency (> 99%), showing that EAZ extension has a negligible effect for scaled flow-cell stacks. Scientific Achievement Flowable suspensions that conduct both

  12. 1

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

    Inversion of Multi-Angle Radiation Measurement B. Cairns and M. Alexandrov Columbia University New York, New York A. Lacis and B. Carlson National Aeronautics and Space Administration - Goddard Institute for Space Studies New York, New York Motivation Observations of the polarization and reflectance in bands at 865 nm (negligible liquid water absorption) and 2250 nm (strong liquid water absorption) cannot be fitted by a simple atmospheric model consisting of a homogeneous cloud with a single

  13. 1

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

    Sensitivity of Cloud Field Structure to Three Dimensional Radiative Effects W. O'Hirok and P. Ricchiazzi Institute for Computational Earth System Science University of California Santa Barbara, California C. Gautier Department of Geography and Institute for Computational Earth System Science University of California Santa Barbara, California Introduction During the past decade, research has shown that while 3 dimensional (D) radiative effects are negligible at the horizontal resolution of GCMs,

  14. Shell structure in the density profiles for noninteracting fermions in anisotropic harmonic confinement

    SciTech Connect (OSTI)

    Vignolo, Patrizia; Minguzzi, Anna

    2003-05-01

    We develop a Green's function method to evaluate the exact equilibrium particle-density profiles of noninteracting Fermi gases in external harmonic confinement in any spatial dimension and for arbitrary trap anisotropy. While in a spherically symmetric configuration the shell effects are negligible in the case of a large number of particles, we find that for very anisotropic traps the quantum effects due to single-level occupancy and the deviations from the Thomas-Fermi approximation are also visible for mesoscopic clouds.

  15. Emerging trends in environmental consultant liability

    SciTech Connect (OSTI)

    Witkin, J.B.

    1995-12-01

    Two federal district judges have recently opened the door for negligence suits aimed specifically an environmental consultants. In William Levy and Harper Realty, Inc. v. Versar, Inc., the respective courts allowed negligence-based claims to survive motions to dismiss, suggesting environmental consultants who fail to discover and/or disclose contamination on the properties they are investigating may be liable for considerable damages, including remediation costs and the economic losses suffered as a result of a claimant`s reliance on the environmental consultant`s work product. These cases poses great concern for environmental consultants. This paper will review these cases in detail, and other legal issues of concern to environmental consultants. It will also review the steps consultants can take to limit their liability, including obtaining errors and omissions insurance, using properly drafted environmental services agreements, properly training their employees, effectively communicating about risks with their clients, and other risk management techniques. In light of the exorbitant costs of environmental clean up, and the expansive breadth of liability imposed by federal environmental laws, consultants need to understand the potential causes of action that can be brought against them. Two federal district judges from Illinois have recently opened the door for negligence suits aimed specifically at environmental consultants, in William Levy and Harper Realty, Inc. v. Versar Inc. This paper will analyze the versar and Mobil Oil cases in detail. It will also explore other issues on professional liability generally of concern to environmental consultants. Finally, suggestion are briefly offered to guide environmental consultants as they embark on clean up activities, to reduce their potential liability to third parties.

  16. Hermetic G-16 percussion primer

    SciTech Connect (OSTI)

    Durand, N.A.; Weinmaster, R.R.; Massis, T.M.

    1988-01-01

    Studies were conducted to optimize a Hermetic percussion primer capable of surviving temperatures of 200/degree/C for up to 48 hours. These studies included work with typical brass percussion primers and the pyrotechnic composition designed G-16. The G-16 mixture is composed of antimony sulfide, calcium silicide, and potassium. The hermetically sealed assembly consists of a brass cup and anvil loaded with G-16 pyrotechnic mixture and assembly includes a steel disc which is laser welded over the sealing mechanisms cause negligible changes. This assembly can be used with other primers and is capable of enhanced output for specialized applications. 4 refs., 8 figs., 4 tabs.

  17. Spin-current diode with a ferromagnetic semiconductor

    SciTech Connect (OSTI)

    Sun, Qing-Feng Xie, X. C.

    2015-05-04

    Diode is a key device in electronics: the charge current can flow through the device under a forward bias, while almost no current flows under a reverse bias. Here, we propose a corresponding device in spintronics: the spin-current diode, in which the forward spin current is large but the reversed one is negligible. We show that the lead/ferromagnetic quantum dot/lead system and the lead/ferromagnetic semiconductor/lead junction can work as spin-current diodes. The spin-current diode, a low dissipation device, may have important applications in spintronics, as the conventional charge-current diode does in electronics.

  18. Improved self-absorption correction for extended x-ray absorption fine-structure measurements

    SciTech Connect (OSTI)

    Booth, C.H.; Bridges, F.

    2003-06-04

    Extended x-ray absorption fine-structure (EXAFS) data collected in the fluorescence mode are susceptible to an apparent amplitude reduction due to the self-absorption of the fluorescing photon by the sample before it reaches a detector. Previous treatments have made the simplifying assumption that the effect of the EXAFS on the correction term is negligible, and that the samples are in the thick limit. We present a nearly exact treatment that can be applied for any sample thickness or concentration, and retains the EXAFS oscillations in the correction term.

  19. Robust broadcast-communication control of electric vehicle charging

    SciTech Connect (OSTI)

    Chertkov, Michael; Turitsyn, Konstantin; Sulc, Petr; Backhaus, Scott

    2010-01-01

    The anticipated increase in the number of plug-in electric vehicles (EV) will put additional strain on electrical distribution circuits. Many control schemes have been proposed to control EV charging. Here, we develop control algorithms based on randomized EV charging start times and simple one-way broadcast communication allowing for a time delay between communication events. Using arguments from queuing theory and statistical analysis, we seek to maximize the utilization of excess distribution circuit capacity while keeping the probability of a circuit overload negligible.

  20. Electron impact ionization of N/sup 4 +/ and N/sup 5 +/

    SciTech Connect (OSTI)

    Defrance, P.; Chantrenne, S.; Brouillard, F.; Rachafi, S.; Belic, D.; Jureta, J.; Gregory, D.

    1984-01-01

    A new crossed beams apparatus for measuring absolute electron impact ionization cross-sections of multiply charged ions is described. First measurements are also reported which deal with N/sup 4 +/ and N/sup 5 +/. The results are in good agreements with those previously obtained by the Oak Ridge group. For N/sup 5 +/ a non negligible signal is observed below the ground state ionization threshold. It is attributed to the presence of ions in metastable states. From the semi-empirical Lotz formula, the population of ions in those states is estimated to some 3%. 8 refs., 3 figs.

  1. Glucose Biosensor Based on Immobilization of Glucose Oxidase in Platinum Nanoparticles/Graphene/Chitosan Nanocomposite Film

    SciTech Connect (OSTI)

    Wu, Hong; Wang, Jun; Kang, Xinhuang; Wang, Chong M.; Wang, Donghai; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2009-09-01

    The bionanocomposite film consisting of glucose oxidase/Pt/functional graphene sheets/chitosan (GOD/Pt/FGS/chitosan) for glucose sensing was described. With the electrocatalytic synergy of FGS and Pt nanoparticles to hydrogen peroxide, a sensitive biosensor with detection limit of 0.6 µM glucose was achieved. The biosensor also had good reproducibility, long term stability and negligible interfering signals from ascorbic acid and uric acid comparing to the response to glucose. The large surface area and good conductivity of graphene suggests that graphene is a potential candidate for sensor material. The hybrid nanocomposite glucose sensor provides new opportunity for clinical diagnosis and point-of-care applications.

  2. Method for producing uranium atomic beam source

    DOE Patents [OSTI]

    Krikorian, Oscar H.

    1976-06-15

    A method for producing a beam of neutral uranium atoms is obtained by vaporizing uranium from a compound UM.sub.x heated to produce U vapor from an M boat or from some other suitable refractory container such as a tungsten boat, where M is a metal whose vapor pressure is negligible compared to that of uranium at the vaporization temperature. The compound, for example, may be the uranium-rhenium compound, URe.sub.2. An evaporation rate in excess of about 10 times that of conventional uranium beam sources is produced.

  3. An ultra-thin diamond membrane as a transmission particle detector and vacuum window for external microbeams

    SciTech Connect (OSTI)

    Grilj, V.; Skukan, N.; Jakšić, M.; Pomorski, M.; Kada, W.; Iwamoto, N.; Kamiya, T.; Ohshima, T.

    2013-12-09

    Several applications of external microbeam techniques demand a very accurate and controlled dose delivery. To satisfy these requirements when post-sample ion detection is not feasible, we constructed a transmission single-ion detector based on an ultra-thin diamond membrane. The negligible intrinsic noise provides an excellent signal-to-noise ratio and enables a hit-detection efficiency of close to 100%, even for energetic protons, while the small thickness of the membrane limits beam spreading. Moreover, because of the superb mechanical stiffness of diamond, this membrane can simultaneously serve as a vacuum window and allow the extraction of an ion microbeam into the atmosphere.

  4. Ideal solar cell equation in the presence of photon recycling

    SciTech Connect (OSTI)

    Lan, Dongchen Green, Martin A.

    2014-11-07

    Previous derivations of the ideal solar cell equation based on Shockley's p-n junction diode theory implicitly assume negligible effects of photon recycling. This paper derives the equation in the presence of photon recycling that modifies the values of dark saturation and light-generated currents, using an approach applicable to arbitrary three-dimensional geometries with arbitrary doping profile and variable band gap. The work also corrects an error in previous work and proves the validity of the reciprocity theorem for charge collection in such a more general case with the previously neglected junction depletion region included.

  5. Gravitomagnetic gyroscope precession in Palatini f(R) gravity

    SciTech Connect (OSTI)

    Ruggiero, Matteo Luca

    2009-04-15

    We study gravitomagnetic effects in the Palatini formalism of f(R) gravity. On using the Kerr-de Sitter metric, which is a solution of f(R) field equations, we calculate the impact of f(R) gravity on the gravitomagnetic precession of an orbiting gyroscope. We show that, even though an f(R) contribution is present in principle, its magnitude is negligibly small and far to be detectable in the present (like GP-B) and foreseeable space missions or observational tests around the Earth.

  6. Relativistic Point Coupling Model for Vibrational Excitations in the Continuum

    SciTech Connect (OSTI)

    Ring, P.; Daoutidis, J.; Litvinova, E.; Niksic, T.; Paar, N.; Vretenar, D.

    2009-08-26

    An implementation of the relativistic random phase approximation with the proper treatment of the continuum has been developed for the relativistic point coupling model and applied to investigate collective excitations in spherical nuclei. The results are compared with the spectral implementation of the same model. In heavy nuclei, where the escape width is negligible, we find an excellent agreement between both methods in the region of giant resonance and some discrepancies in the region of low-lying pygmy resonance. The differences are more pronounced in light nuclei due to the larger values of the escape widths.

  7. Entire plasmas can be restructured when electrons are emitted from the boundaries

    SciTech Connect (OSTI)

    Campanell, M. D.

    2015-04-14

    It is well known that electron emission can restructure the thin sheaths at plasma-facing surfaces. But conventional models assume that the plasma's structure negligibly changes (the “presheath” is still thought to be governed by ion acceleration to the Bohm speed). Here, it is shown by theory and simulation that the presheath can take a fundamentally different structure where the emitted electrons entering the quasineutral region cause numerous changes. As a result, gradients of total plasma density, ion and electron pressures, and electric potential throughout the “inverted” presheath can carry different magnitudes, and opposite signs, from Bohm presheaths.

  8. Current Renewable Energy Technologies and Future Projections

    SciTech Connect (OSTI)

    Allison, Stephen W; Lapsa, Melissa Voss; Ward, Christina D; Smith, Barton; Grubb, Kimberly R; Lee, Russell

    2007-05-01

    The generally acknowledged sources of renewable energy are wind, geothermal, biomass, solar, hydropower, and hydrogen. Renewable energy technologies are crucial to the production and utilization of energy from these regenerative and virtually inexhaustible sources. Furthermore, renewable energy technologies provide benefits beyond the establishment of sustainable energy resources. For example, these technologies produce negligible amounts of greenhouse gases and other pollutants in providing energy, and they exploit domestically available energy sources, thereby reducing our dependence on both the importation of fossil fuels and the use of nuclear fuels. The market price of renewable energy technologies does not reflect the economic value of these added benefits.

  9. Early considerations: NAFTA: Possible indications for Mexico's oil and gas industry

    SciTech Connect (OSTI)

    Not Available

    1993-12-20

    After rancorous debate in the US over the North American Free Trade Agreement (NAFTA), the treaty is scheduled to become effective January 1, 1994. The topic of energy was scarcely mentioned during all of the discussions because NAFTA is expected to have only a negligible effect on the US energy industry. But NAFTA is a trade agreement among three oil producers, and that is worth remembering. According to the U.S. Congressional Budget Office, the U.S. energy industry can expect marginal gains and a framework for future opportunities in Mexico's energy sector as NAFTA takes effect. In terms of energy, Mexico gains the most from NAFTA.

  10. Development of a gas backup heater for solar domestic hot-water systems. Final report, April 1978-April 1980

    SciTech Connect (OSTI)

    Morrison, D.J.; Grunes, H.E.; de Winter, F.; Armstrong, P.R.

    1980-06-01

    A comprehensive program was undertaken to develop a unique gas fired backup for solar domestic hot water systems. Detailed computer design tools were written. A series of heat transfer experiments were performed to characterize the performance of individual components. A full scale engineering prototype, including the solar preheat tank and solar heat exchanger, was designed, fabricated and subjected to limited testing. Firing efficiency for the backup system was found to be 81.4% at a firing rate of 50,000 Btu/h. Long term standby losses should be negligible.

  11. Fact #914: February 29, 2016 Plug-in Vehicle Sales Climb as Battery Costs

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

    Decline | Department of Energy 4: February 29, 2016 Plug-in Vehicle Sales Climb as Battery Costs Decline Fact #914: February 29, 2016 Plug-in Vehicle Sales Climb as Battery Costs Decline SUBSCRIBE to the Fact of the Week In 2009, the cost for lithium-ion plug-in vehicle batteries was about $1,000 per kilowatt-hour (kW-hr) and plug-in vehicle sales were negligible. The first mass-marketed plug-in vehicles were introduced just prior to 2011, when the cost of batteries was nearing $600 per

  12. Inelastic transport through Aharonov-Bohm interferometer in Kondo regime

    SciTech Connect (OSTI)

    Yoshii, Ryosuke; Eto, Mikio; Sakano, Rui; Affleck, Ian

    2013-12-04

    We formulate elastic and inelastic parts of linear conductance through an Aharonov-Bohm (AB) ring with an embedded quantum dot in the Kondo regime. The inelastic part G{sub inel} is proportional to T{sup 2} when the temperature T is much smaller than the Kondo temperature T{sub K}, whereas it is negligibly small compared with elastic part G{sub el} when T ? T{sub K}. G{sub inel} weakly depends on the magnetic flux penetrating the AB ring, which disturbs the precise detection of G{sub el}/(G{sub el}+G{sub inel}) by the visibility of AB oscillation.

  13. Integrated Modeling of Building Energy Requirements IncorporatingSolar Assisted Cooling

    SciTech Connect (OSTI)

    Firestone, Ryan; Marnay, Chris; Wang, Juan

    2005-08-10

    This paper expands on prior Berkeley Lab work on integrated simulation of building energy systems by the addition of active solar thermal collecting devices, technology options not previously considered (Siddiqui et al 2005). Collectors can be used as an alternative or additional source of hot water to heat recovery from reciprocating engines or microturbines. An example study is presented that evaluates the operation of solar assisted cooling at a large mail sorting facility in southern California with negligible heat loads and year-round cooling loads. Under current conditions solar thermal energy collection proves an unattractive option, but is a viable carbon emission control strategy.

  14. Numerical calculation of the ion polarization in MEIC

    SciTech Connect (OSTI)

    Derbenev, Yaroslav; Lin, Fanglei; Morozov, Vasiliy; Zhang, Yuhong; Kondratenko, Anatoliy; Kondratenko, M A; Filatov, Yury

    2015-09-01

    Ion polarization in the Medium-energy Electron-Ion Collider (MEIC) is controlled by means of universal 3D spin rotators designed on the basis of "weak" solenoids. We use numerical calculations to demonstrate that the 3D rotators have negligible effect on the orbital properties of the ring. We present calculations of the polarization dynamics along the collider's orbit for both longitudinal and transverse polarization directions at a beam interaction point. We calculate the degree of depolarization due to the longitudinal and transverse beam emittances in case when the zero-integer spin resonance is compensated.

  15. Current Status of the R-Matrix Code SAMMY, with Emphasis on the Relationship to ENDF Formats

    SciTech Connect (OSTI)

    Larson, Nancy M; Leal, Luiz C; Sayer, Royce O; Derrien, Herve; Wiarda, Dorothea; Arbanas, Goran

    2008-01-01

    During the last decade, advances in evaluations of neutron-induced cross sections in the resolved resonance region have surpassed the ability of the Evaluated Nuclear Data Files (ENDF) to make use of those evaluations. At the higher energies used in new evaluations, effects that in the past were deemed to be negligible are now important. There is also a great demand for including uncertainty information in ENDF files. In this paper, we describe recently approved ENDF formats to accommodate new evaluations and their implementation in SAMMY. Other new features of the SAMMY code, available in the 2006 Revision 7 release, are also described.

  16. A Monolithic Interconnected module with a tunnel Junction for Enhanced Electrical and Optical Performance

    SciTech Connect (OSTI)

    Murray, Christopher Sean; Wilt, David Morgan

    1999-06-30

    An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMs), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

  17. Comments on ''The optimization of electronic precision in ultrasonic velocity measurements: A comparison of the time interval averaging and sing around methods'' (J. Acoust. Soc. Am. 73, 1833--1837 (1983))

    SciTech Connect (OSTI)

    Karplus, H.B.

    1984-06-01

    J. D. Aindow and R. C. Chivers (J. Acoust. Soc. Am. 73, 1833 (1983)) compared the precision of the direct ''time-of-flight'' technique with the ''sing-around'' method for sound velocity measurement. Their conclusion is changed by the newer, faster, commercial clocks (2 ns HP5345<0.1 ns HP5370), giving the advantage to the time of flight method. The analysis is herewith augmented by calculating the time jitter in terms of signal to noise ratio, which was correctly shown to be negligible with 100-ns clocks, but becomes increasingly more significant with faster clocks.

  18. Testing results of tubeless flat-plate phase-change solar collectors

    SciTech Connect (OSTI)

    Tamimi, A. ); Rawajfeh, K. )

    1991-01-01

    This paper reports on a tubeless solar collector charged with Refrigerant-113 (R-113) that was installed and tested. Steady-state performance of this system showed high efficiency values; this was due to phase-change heat transfer characteristics of a boiling process that is accompanied by low plate temperature as well as low thermal resistance to heat flow from the absorber plate to the working fluid. The only resistance to heat flow toward the working fluid is the conduction resistance through the upper plate, which is negligible.

  19. Calculation of anharmonic couplings and THz linewidths in crystalline PETN

    SciTech Connect (OSTI)

    Pereverzev, Andrey Sewell, Thomas D. Thompson, Donald L.

    2014-03-14

    We have developed a method for calculating the cubic anharmonic couplings in molecular crystals for normal modes with the zero wave vector in the framework of classical mechanics, and have applied it, combined with perturbation theory, to obtain the linewidths of all infrared absorption lines of crystalline pentaerythritol tetranitrate in the terahertz region (<100 cm{sup ?1}). Contributions of the up- and down-conversion processes to the total linewidth were calculated. The computed linewidths are in qualitative agreement with experimental data and the results of molecular dynamics simulations. Quantum corrections to the linewidths in the terahertz region are shown to be negligible.

  20. Negative to positive magnetoresistance and magnetocaloric effect in Pr0.6Er0.4Al2

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

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Pecharsky, V. K.

    2014-10-13

    We report on the magnetic, magnetocaloric and magnetotransport properties of Pr0.6Er0.4Al2. The title compound exhibits a large positive magnetoresistance (MR) for H ≥ 40 kOe and a small but non negligible negative MR for H ≤ 30 kOe. The maximum positive MR reaches 13% at H = 80 kOe. The magnetic entropy and adiabatic temperature changes as functions of temperature each show two anomalies: a broad dome-like maximum below 20 K and a relatively sharp peak at higher temperature. As a result, observed behaviors are unique among other binary and mixed lanthanide compounds.

  1. Tracking single-particle rotation during macrophage uptake

    SciTech Connect (OSTI)

    Sanchez, Lucero; Patton, Paul; Anthony, Stephen Michael; Yi, Yi; Yu, Yan

    2015-06-10

    We investigated the rotational dynamics of single microparticles during their internalization by macrophage cells. The microparticles used were triblock patchy particles that display two fluorescent patches on their two poles. The optical anisotropy made it possible to directly visualize and quantify the orientation and rotation of the particles. We show that particles exhibit a mixture of fast and slow rotation as they are uptaken by macrophages and transiently undergo directional rotation during their entry into the cell. As a result, the size of the particles and the surface presentation of ligands exerted a negligible influence on this heterogeneity of particle rotation.

  2. Tracking single-particle rotation during macrophage uptake

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

    Sanchez, Lucero; Patton, Paul; Anthony, Stephen Michael; Yi, Yi; Yu, Yan

    2015-06-10

    We investigated the rotational dynamics of single microparticles during their internalization by macrophage cells. The microparticles used were triblock patchy particles that display two fluorescent patches on their two poles. The optical anisotropy made it possible to directly visualize and quantify the orientation and rotation of the particles. We show that particles exhibit a mixture of fast and slow rotation as they are uptaken by macrophages and transiently undergo directional rotation during their entry into the cell. As a result, the size of the particles and the surface presentation of ligands exerted a negligible influence on this heterogeneity of particlemore » rotation.« less

  3. Electronic band structure imaging of three layer twisted graphene on single crystal Cu(111)

    SciTech Connect (OSTI)

    Marquez Velasco, J.; Department of Physics, National Technical University of Athens, Athens ; Kelaidis, N.; Xenogiannopoulou, E.; Tsoutsou, D.; Tsipas, P.; Speliotis, Th.; Pilatos, G.; Likodimos, V.; Falaras, P.; Dimoulas, A.; Raptis, Y. S.

    2013-11-18

    Few layer graphene (FLG) is grown on single crystal Cu(111) by Chemical Vapor Deposition, and the electronic valence band structure is imaged by Angle-Resolved Photo-Emission Spectroscopy. It is found that graphene essentially grows polycrystalline. Three nearly ideal Dirac cones are observed along the Cu ?{sup }K{sup } direction in k-space, attributed to the presence of ?4 twisted three layer graphene with negligible interlayer coupling. The number of layers and the stacking order are compatible with Raman data analysis demonstrating the complementarity of the two techniques for a more accurate characterization of FLG.

  4. Reducing gain shifts in photomultiplier tubes

    DOE Patents [OSTI]

    Cohn, Charles E.

    1976-01-01

    A means is provided for reducing gain shifts in multiplier tubes due to varying event count rates. It includes means for limiting the number of cascaded, active dynodes of the multiplier tube to a predetermined number with the last of predetermined number of dynodes being the output terminal of the tube. This output is applied to an amplifier to make up for the gain sacrificed by not totally utilizing all available active stages of the tube. Further reduction is obtained by illuminating the predetermined number of dynodes with a light source of such intensity that noise appearing at the output dynode associated with the illumination is negligible.

  5. Process for forming silicon carbide films and microcomponents

    DOE Patents [OSTI]

    Hamza, A.V.; Balooch, M.; Moalem, M.

    1999-01-19

    Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C{sub 60} precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C{sub 60} with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C{sub 60} on silicon dioxide at surface temperatures less than 1250 K. 5 figs.

  6. Process for forming silicon carbide films and microcomponents

    DOE Patents [OSTI]

    Hamza, Alex V.; Balooch, Mehdi; Moalem, Mehran

    1999-01-01

    Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C.sub.60 precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C.sub.60 with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C.sub.60 on silicon dioxide at surface temperatures less than 1250 K.

  7. Vacuum leak detector and method

    DOE Patents [OSTI]

    Edwards, Jr., David (7 Brown's La., Bellport, NY 11713)

    1983-01-01

    Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

  8. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, S.L.; Vernon, S.P.; Stearns, D.G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO{sub 2} overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates. 5 figs.

  9. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, Sherry L.; Vernon, Stephen P.; Stearns, Daniel G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO.sub.2 overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

  10. A Materials-Based Mitigation Strategy for SU/SD in PEM Fuel Cells: Properties and Performance-Specific Testing of IrRu OER Catalysts.

    SciTech Connect (OSTI)

    Atanasoski, Radoslav; Cullen, David A; Vernstrom, George; Haugen, Gregory; Atanasoska, Liliana

    2013-01-01

    Catalysts that enable proton exchange membrane fuel cells to weather the damaging conditions experienced during transient periods of fuel starvation have been developed. The addition of minute amounts of iridium and ruthenium to the cathode enhances the oxygen evolution reaction (OER) during start-up/shutdown events, thus lowering the peak cell voltage closer to the onset of water oxidation. The catalyst loadings ranged from 1 to 10 g/cm2, but showed surprisingly high activity and durability. At such low loadings, it is possible to fully integrate the OER catalysts with negligible interference on fuel cell performance and a marginal increase in catalyst cost.

  11. Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance

    DOE Patents [OSTI]

    Murray, Christopher S.; Wilt, David M.

    2000-01-01

    An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMS), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

  12. Suppressed grain-boundary scattering in atomic layer deposited Nb:TiO{sub 2} thin films

    SciTech Connect (OSTI)

    Niemelä, Janne-Petteri; Karppinen, Maarit; Hirose, Yasushi; Hasegawa, Tetsuya; Shigematsu, Kei; Sano, Masahito

    2015-11-09

    We have fabricated high-quality thin films of the transparent conducting anatase Nb:TiO{sub 2} on glass substrates through atomic layer deposition, and a subsequent reductive heat treatment of the as-deposited amorphous films. Hall-effect measurements and Drude-fitting of the Vis-NIR spectra indicate that for lightly doped films deposited at temperatures around 170 °C, grain boundary scattering becomes negligible and the mobility is predominately limited by phonon-electron scattering inherent to the anatase lattice and by impurities. Simultaneously, such lighter doping leads to reduced plasma absorption, thereby improving material's performance as a transparent conductor.

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

    SciTech Connect (OSTI)

    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.

  14. Enhanced retained dose uniformity in NiTi spinal correction rod treated by three-dimensional mesh-assisted nitrogen plasma immersion ion implantation

    SciTech Connect (OSTI)

    Lu, Q. Y.; Hu, T.; Kwok, Dixon T. K.; Chu, Paul K.

    2010-05-15

    Owing to the nonconformal plasma sheath in plasma immersion ion implantation of a rod sample, the retained dose can vary significantly. The authors propose to improve the implant uniformity by introducing a metal mesh. The depth profiles obtained with and without the mesh are compared and the implantation temperature at various locations is evaluated indirectly by differential scanning calorimeter. Our results reveal that by using the metal mesh, the retained dose uniformity along the length is greatly improved and the effects of the implantation temperature on the localized mechanical properties of the implanted NiTi shape memory alloy rod are nearly negligible.

  15. Evaluation of lithium-ion synergetic battery pack as battery charger

    SciTech Connect (OSTI)

    Davis, A.; Salameh, Z.M.; Eaves, S.S.

    1999-09-01

    A new battery configuration technique and accompanying control circuitry, termed a Synergetic Battery Pack (SBP), is designed to work with Lithium batteries, and can be used as both an inverter for an electric vehicle AC induction motor drive and a battery charger. In this paper, the authors compare the performance of the Synergetic Battery Pack as a battery charger with several simple conventional battery charging circuits via computer simulation. The factors of comparison were power factor, harmonic distortion, and circuit efficiency. The simulations showed that the SBP is superior to the conventional charging circuits since the power factor is unity and harmonic distortion is negligible.

  16. Plasma column displacement measurements by modified Rogowski sine-coil and Biot-Savart/magnetic flux equation solution on IR-T1 tokamak

    SciTech Connect (OSTI)

    Razavi, M.; Mollai, M.; Khorshid, P.; Nedzelskiy, I.; Ghoranneviss, M.

    2010-05-15

    The modified Rogowski sine-coil (MRSC) has been designed and implemented for the plasma column horizontal displacement measurements on small IR-T1 tokamak. MRSC operation has been examined on test assembly and tokamak. Obtained results show high sensitivity to the plasma column horizontal displacement and negligible sensitivity to the vertical displacement; linearity in wide, {+-}0.1 m, range of the displacements; and excellent, 1.5%, agreement with the results of numerical solution of Biot-Savart and magnetic flux equations.

  17. Monitoring the fate of radionuclides released to the environment: May 1991 report

    SciTech Connect (OSTI)

    Bauer, L.R.

    1992-08-13

    A review of the radiological effluent and environmental monitoring practices in use at Mound has been conducted. The radionuclides under consideration were HT, Pu-239, U-233,234, U-238, Th-230, Th-232, Co-60, Cs-137, and Ac-227. It is concluded from this analysis that additional continuous monitoring programs are not warranted. Dose contributions from these radionuclides are negligible. Further, in many cases environmental surveillance would not be practical due to the extremely low concentrations encountered in the offsite environment. For these reasons, it is believed that no additional action is required in response to DOE Tiger Team Finding R/CF-1.

  18. Bolivia: rural electrification. Project impact evaluation report No. 16

    SciTech Connect (OSTI)

    Butler, E.; Poe, K.M.; Tendler, J.

    1980-12-01

    Two rural electrification systems initiated in Bolivia in 1973 and 1974 are the subject of this report. By 1979, all distribution networks were completed, except in the La Paz region. Power was supplied to 42,000 consumers and was used primarily for residential lighting. Although demand outpaced supply, consumption per household was lower than projected, and irrigation and industrial use was negligible. The preponderant positive impact of the projects was social. Household lighting improved the physical quality of life for 7% of Bolivia's rural population.

  19. Direct Measurements of an increased threshold for stimulated Brillouin scattering with polarization smoothing in ignition hohlraum plasmas

    SciTech Connect (OSTI)

    Froula, D; Divol, L; Berger, R L; London, R; Meezan, N; Neumayer, P; Ross, J S; Stagnito, S; Suter, L; Glenzer, S H; Strozzi, D

    2007-11-08

    We demonstrate a significant reduction of stimulated Brillouin scattering by polarization smoothing. The intensity threshold is measured to increase by a factor of 1.7 {+-} 0.2 when polarization smoothing is applied. The results were obtained in a high-temperature (T{sub 3} {approx_equal} 3 keV) hohlraum plasma where filamentation is negligible in determining the backscatter threshold. These results are explained by an analytical model relevant to ICF plasma conditions that modifies the linear gain exponent to account for polarization smoothing.

  20. Doping suppression and mobility enhancement of graphene transistors fabricated using an adhesion promoting dry transfer process

    SciTech Connect (OSTI)

    Cheol Shin, Woo; Hun Mun, Jeong; Yong Kim, Taek; Choi, Sung-Yool; Jin Cho, Byung E-mail: tskim1@kaist.ac.kr; Yoon, Taeshik; Kim, Taek-Soo E-mail: tskim1@kaist.ac.kr

    2013-12-09

    We present the facile dry transfer of graphene synthesized via chemical vapor deposition on copper film to a functional device substrate. High quality uniform dry transfer of graphene to oxidized silicon substrate was achieved by exploiting the beneficial features of a poly(4-vinylphenol) adhesive layer involving a strong adhesion energy to graphene and negligible influence on the electronic and structural properties of graphene. The graphene field effect transistors (FETs) fabricated using the dry transfer process exhibit excellent electrical performance in terms of high FET mobility and low intrinsic doping level, which proves the feasibility of our approach in graphene-based nanoelectronics.

  1. The effects of heat conduction on the vaporization of liquid invading superheated permeable rock

    SciTech Connect (OSTI)

    Woods, Andrew, W.; Fitzgerald, Shaun D.

    1996-01-24

    We examine the role of conductive and convective heat transfer in the vaporization of liquid as it slowly invades a superheated permeable rock. For very slow migration, virtually all of the liquid vaporizes. As the liquid supply rate increases beyond the rate of heat transfer by thermal conduction, a decreasing fraction of the liquid can vaporize. Indeed, for sufficiently high flow rates, the fraction vaporizing depends solely on the superheat of the rock, and any heat transfer from the superheated region is negligible. These results complement earlier studies of vaporization under very high injection rates, in which case the dynamic vapour pressure reduces the mass fraction vaporizing to very small values.

  2. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #s 46000606120, 46000722120, AND 46000808120

    SciTech Connect (OSTI)

    Taylor-Pashow, K.

    2012-10-08

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #s 46000706120, 46000722120, and 460008081120 qualification and verification samples met each of the selected specification requirements that were tested with the exception of a few pails being marginally below the lower weight percent solids limit. These deviations from the specifications are viewed as negligible since the corresponding density of the slurries indicates no appreciable shortage of MST solids. Therefore, SRNL recommends acceptance and use of these pails.

  3. Results of First Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)

    SciTech Connect (OSTI)

    Reda, I.; Grobner, J.; Wacker, S.; Stoffel, T.

    2013-03-01

    The ACP and IRIS are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are unwindowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The first outdoor comparison between the two designs was held from January 28 to February 8, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of IRIS was within 1 W/m2. A difference of 5 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG).

  4. A=4HE (1992TI02)

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

    He (1992TI02) (See Energy Level Diagrams for 4He) GENERAL: Ground state:Due to non-central forces, the wave function for the Jπ = 0+ ground state of 4He can be a positive-parity mixture of three 1S0, six 3P0, and five 5D0 orthogonal states (1967BE74). Of course, the symmetric S-wave component is the dominant part of the wavefunction, with significant D-wave and almost negligible P-wave contributions. Since the D-state admixture can be inferred from measurements such as the tensor analyzing

  5. Influence of pulse duration, energy, and focusing on laser-assisted water condensation

    SciTech Connect (OSTI)

    Petit, Y.; Henin, S.; Kasparian, J.; Wolf, J. P.; Rohwetter, P.; Stelmaszczyk, K.; Hao, Z. Q.; Nakaema, W. M.; Woeste, L.; Vogel, A.; Pohl, T.; Weber, K.

    2011-01-24

    We investigate the influence of laser parameters on laser-assisted water condensation in the atmosphere. Pulse energy is the most critical parameter. Nanoparticle generation depends linearly on energy beyond the filamentation threshold. Shorter pulses are more efficient than longer ones with saturation at {approx}1.5 ps. Multifilamenting beams appear more efficient than strongly focused ones in triggering the condensation and growth of submicronic particles, while polarization has a negligible influence on the process. The data suggest that the initiation of laser-assisted condensation relies on the photodissociation of the air molecules rather than on their photoionization.

  6. High strength graphite and method for preparing same

    DOE Patents [OSTI]

    Overholser, Lyle G.; Masters, David R.; Napier, John M.

    1976-01-01

    High strength graphite is manufactured from a mixture of a particulate filler prepared by treating a particulate carbon precursor at a temperature in the range of about 400.degree. to 1000.degree. C., an organic carbonizable binder, and green carbonizable fibers in a concentration of not more than 2 weight per cent of the filler. The use of the relatively small quantity of green fibers provides a substantial increase in the flexural strength of the graphite with only a relatively negligible increase in the modulus of elasticity.

  7. Adsorption of silver dimer on graphene - A DFT study

    SciTech Connect (OSTI)

    Kaur, Gagandeep, E-mail: gaganj1981@yahoo.com [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014, India and Chandigarh Engineering College, Landran, Mohali-140307, Punjab (India); Gupta, Shuchi [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014, India and University Institute of Engineering and Technology, Panjab University, Chandigarh -160014 (India); Rani, Pooja; Dharamvir, Keya [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014 (India)

    2014-04-24

    We performed a systematic density functional theory (DFT) study of the adsorption of silver dimer (Ag{sub 2}) on graphene using SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) package, in the generalized gradient approximation (GGA). The adsorption energy, geometry, and charge transfer of Ag2-graphene system are calculated. The minimum energy configuration for a silver dimer is parallel to the graphene sheet with its two atoms directly above the centre of carbon-carbon bond. The negligible charge transfer between the dimer and the surface is also indicative of a weak bond. The methodology demonstrated in this paper may be applied to larger silver clusters on graphene sheet.

  8. Impact of graphene polycrystallinity on the performance of graphene field-effect transistors

    SciTech Connect (OSTI)

    Jimnez, David; Chaves, Ferney [Departament d'Enginyeria Electrnica, Escola d'Enginyeria, Universitat Autnoma de Barcelona, 08193-Bellaterra (Spain); Cummings, Aron W.; Van Tuan, Dinh [ICN2, Institut Catal de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona) (Spain); Kotakoski, Jani [Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien (Austria); Department of Physics, University of Helsinki, P.O. Box 43, 00014 University of Helsinki (Finland); Roche, Stephan [ICN2, Institut Catal de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona) (Spain); ICREA, Instituci Catalana de Recerca i Estudis Avanats, 08070 Barcelona (Spain)

    2014-01-27

    We have used a multi-scale physics-based model to predict how the grain size and different grain boundary morphologies of polycrystalline graphene will impact the performance metrics of graphene field-effect transistors. We show that polycrystallinity has a negative impact on the transconductance, which translates to a severe degradation of the maximum and cutoff frequencies. On the other hand, polycrystallinity has a positive impact on current saturation, and a negligible effect on the intrinsic gain. These results reveal the complex role played by graphene grain boundaries and can be used to guide the further development and optimization of graphene-based electronic devices.

  9. Operation Sandstone. Scientific Director's report of atomic-weapon tests at Eniwetok, 1948. Annex 8. Gamma-ray measurements. Parts 1, 2, 3, 4, and 5. Sandstone report No. 29

    SciTech Connect (OSTI)

    Shonka, F.R.; Pawlicki, G.S.

    1985-09-01

    Curves of absorption of gamma rays in boron carbide and a few points on the absorption curve in lead were obtained during the three atomic explosions of Operation Sandstone. Radiation was detected by integrating ionization chambers and by photographic emulsions. A few recording-type ionization chambers were used to give intensities as a function of time. Radiation detectors were located inside of shelters which protected them from blast and shielded them from scattered radiation. Because of geometry, scattered radiation was negligible and the analysis of absorption curves yields the true total absorption coefficient for the radiation.

  10. Quantum effects in the dynamics of deeply supercooled water

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

    Agapov, Alexander L.; Kolesnikov, Alexander I.; Novikov, Vladimir N.; Richert, Ranko; Sokolov, Alexei P

    2015-02-26

    In spite of its simple chemical structure, water remains one of the most puzzling liquids with many anomalies at low temperatures. Combining neutron scattering and dielectric relaxation spectroscopy, we show that quantum fluctuations are not negligible in deeply supercooled water. Our dielectric measurements reveal the anomalously weak temperature dependence of structural relaxation in vapor-deposited water close to the glass transition temperature Tg~136K. We demonstrate that this anomalous behavior can be explained well by quantum effects. In conclusion, these results have significant implications for our understanding of water dynamics.

  11. Active Climate Stabilization: Practical Physics-Based Approaches to Prevention of Climate Change

    DOE R&D Accomplishments [OSTI]

    Teller, E.; Hyde, T.; Wood, L.

    2002-04-18

    We offer a case for active technical management of the radiative forcing of the temperatures of the Earth's fluid envelopes, rather than administrative management of atmospheric greenhouse gas inputs, in order to stabilize both the global- and time-averaged climate and its mesoscale features. We suggest that active management of radiative forcing entails negligible--indeed, likely strongly negative--economic costs and environmental impacts, and thus best complies with the pertinent mandate of the UN Framework Convention on Climate Change. We propose that such approaches be swiftly evaluated in sub-scale in the course of an intensive international program.

  12. Oxidation of methanol on single crystal platinum electrodes in alkaline solution

    SciTech Connect (OSTI)

    Tripkovic, A.V.; Marinkovic, N.; Adzic, R.R.

    1995-10-01

    Methanol oxidation has been studied on three low-index single crystal Pt electrodes and four stepped surfaces, vicinal to the (111) and (100) orientations in alkaline solutions. Considering the onset of the reaction, it appears that the activity decreases in the sequence Pt(100), Pt(110) and Pt(111). This can also be inferred from the quasi-steady-state measurements. The current peaks, observed at different potentials, show the highest activity of Pt(111). The steps cause increase of the surface activity, but are prone to a fast poisoning. The reaction involves a formation of a small amount of CO on Pt(100) but a negligible amount on Pt(111). This was inferred from the in situ FTIR measurements. Two different reaction mechanisms were identified for the Pt(111) and Pt(100). The data clearly show that a large difference of the activity of Pt for methanol oxidation in acid and alkaline solutions originates in a smaller or negligible poisoning effects in alkaline solutions.

  13. Effect of MLC leaf position, collimator rotation angle, and gantry rotation angle errors on intensity-modulated radiotherapy plans for nasopharyngeal carcinoma

    SciTech Connect (OSTI)

    Bai, Sen; Li, Guangjun; Wang, Maojie; Jiang, Qinfeng; Zhang, Yingjie; Wei, Yuquan

    2013-07-01

    The purpose of this study was to investigate the effect of multileaf collimator (MLC) leaf position, collimator rotation angle, and accelerator gantry rotation angle errors on intensity-modulated radiotherapy plans for nasopharyngeal carcinoma. To compare dosimetric differences between the simulating plans and the clinical plans with evaluation parameters, 6 patients with nasopharyngeal carcinoma were selected for simulation of systematic and random MLC leaf position errors, collimator rotation angle errors, and accelerator gantry rotation angle errors. There was a high sensitivity to dose distribution for systematic MLC leaf position errors in response to field size. When the systematic MLC position errors were 0.5, 1, and 2 mm, respectively, the maximum values of the mean dose deviation, observed in parotid glands, were 4.63%, 8.69%, and 18.32%, respectively. The dosimetric effect was comparatively small for systematic MLC shift errors. For random MLC errors up to 2 mm and collimator and gantry rotation angle errors up to 0.5°, the dosimetric effect was negligible. We suggest that quality control be regularly conducted for MLC leaves, so as to ensure that systematic MLC leaf position errors are within 0.5 mm. Because the dosimetric effect of 0.5° collimator and gantry rotation angle errors is negligible, it can be concluded that setting a proper threshold for allowed errors of collimator and gantry rotation angle may increase treatment efficacy and reduce treatment time.

  14. Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference

    DOE Patents [OSTI]

    Simpson, James E.

    1999-01-01

    An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp.

  15. Laser machining of explosives

    DOE Patents [OSTI]

    Perry, Michael D.; Stuart, Brent C.; Banks, Paul S.; Myers, Booth R.; Sefcik, Joseph A.

    2000-01-01

    The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

  16. First principles studies of proton conduction in KTaO{sub 3}

    SciTech Connect (OSTI)

    Kang, Sung Gu; Sholl, David S.

    2014-07-14

    KTaO{sub 3} (KTO) is a useful prototypical perovskite for examining the mechanisms of proton transport in perovskites. Previously, Gomez et al. [J. Chem. Phys. 126, 194701 (2007)] reported density functional theory (DFT) calculations describing proton hopping in defect-free KTO. We use DFT calculations to extend that work in two directions, namely, understanding isotope effects in low and high temperature proton transport and the role of native point defects in KTO. At cryogenic temperatures, quantum tunneling plays a vital role in the net hopping of protons in KTO. At the elevated temperature characteristic of applications involving proton-conducting perovskites, tunneling is negligible but zero point energy effects still lead to non-negligible isotope effects for H{sup +}, D{sup +}, and T{sup +}. We also use DFT to characterize the populations of relevant point defects in KTO as a function of experimental conditions, and to examine the migration of protons that are close in proximity to these defects. This information gives useful insight into the overall transport rates of protons through KTO under a variety of external environments. We also assess the overall diffusivity of protons in KTO at various ranges of oxygen vacancy concentrations by performing kinetic Monte Carlo simulations.

  17. Exact analytical solution of the linear structure growth rate in {Lambda}CDM cosmology and its cosmological applications

    SciTech Connect (OSTI)

    Zhang Pengjie [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Science, 80 Nandan Road, Shanghai, China, 200030 (China)

    2011-03-15

    We derive the exact analytical solution of the linear structure growth rate in {Lambda}CDM cosmology with flat or curved geometry, under the Newtonian gauge. Unlike the well known solution under the Newtonian limit [D. J. Heath, Mon. Not. R. Astron. Soc. 179, 351 (1977)], our solution takes all general relativistic corrections into account and is hence valid at both the sub- and superhorizon scales. With this exact solution, we evaluate cosmological impacts induced by these relativistic corrections. (1) General relativistic corrections alter the density growth from z=100 to z=0 by 10% at k=0.01 h/Mpc and the impact becomes stronger toward larger scales. We caution the readers that the overdensity is not gauge invariant and the above statement is restrained to the Newtonian gauge. (2) Relativistic corrections introduce a k{sup -2} scale dependence in the density fluctuation. It mimics a primordial non-Gaussianity of the local type with f{sub NL}{sup local{approx}}1. This systematical error may become non-negligible for future all sky deep galaxy surveys. (3) Cosmological simulations with box size greater than 1 Gpc are also affected by these relativistic corrections. We provide a postprocessing recipe to correct for these effects. (4) These relativistic corrections affect the redshift distortion. However, at redshifts and scales relevant to redshift distortion measurements, such effect is negligible.

  18. Dependence of enhanced asymmetry-induced transport on collision frequency

    SciTech Connect (OSTI)

    Eggleston, D. L.

    2014-07-15

    A single-particle code with collisional effects is used to study how asymmetry-induced radial transport in a non-neutral plasma depends on collision frequency. For asymmetries of the form ?{sub 1}(r)?cos(kz)?cos(?t?l?), two sources for the transport have been identified: resonant particles and axially trapped particles. The simulation shows that this latter type, which occurs near the radius where ? matches the azimuthal rotation frequency ?{sub R}, is usually dominant at low collision frequency ? but becomes negligible at higher ?. This behavior can be understood by noting that axially trapped particles have a lower trapping frequency than resonant particles. In the low ? (banana) regime, the radial oscillations have amplitude ?r???v{sub r}/?{sub T}, so axially trapped particles dominate, and the transport may even exceed the resonant particle plateau regime level. As ? increases, collisions start to interrupt the slower axially trapped particle oscillations, while the resonant particles are still in the banana regime, so the axially trapped particle contribution to the transport decreases. At the largest ? values, axially trapped particle transport is negligible and the observed diffusion coefficient matches that given by plateau regime resonant particle theory. Heuristic models based on these considerations give reasonable agreement with the observed scaling laws for the value of the collision frequency where axially trapped particle transport starts to decrease and for the enhancement of the diffusion coefficient produced by axially trapped particles.

  19. Relativistic ponderomotive Hamiltonian of a Dirac particle in a vacuum laser field

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

    Ruiz, D. E.; Ellison, C. L.; Dodin, I. Y.

    2015-12-16

    Here, we report a point-particle ponderomotive model of a Dirac electron oscillating in a high-frequency field. Starting from the Dirac Lagrangian density, we derive a reduced phase-space Lagrangian that describes the relativistic time-averaged dynamics of such a particle in a geometrical-optics laser pulse propagating in vacuum. The pulse is allowed to have an arbitrarily large amplitude provided that radiation damping and pair production are negligible. The model captures the Bargmann-Michel-Telegdi (BMT) spin dynamics, the Stern-Gerlach spin-orbital coupling, the conventional ponderomotive forces, and the interaction with large-scale background fields (if any). Agreement with the BMT spin precession equation is shown numerically.more » The commonly known theory in which ponderomotive effects are incorporated in the particle effective mass is reproduced as a special case when the spin-orbital coupling is negligible. This model could be useful for studying laser-plasma interactions in relativistic spin-1/2 plasmas.« less

  20. Relativistic ponderomotive Hamiltonian of a Dirac particle in a vacuum laser field

    SciTech Connect (OSTI)

    Ruiz, D. E.; Ellison, C. L.; Dodin, I. Y.

    2015-12-16

    Here, we report a point-particle ponderomotive model of a Dirac electron oscillating in a high-frequency field. Starting from the Dirac Lagrangian density, we derive a reduced phase-space Lagrangian that describes the relativistic time-averaged dynamics of such a particle in a geometrical-optics laser pulse propagating in vacuum. The pulse is allowed to have an arbitrarily large amplitude provided that radiation damping and pair production are negligible. The model captures the Bargmann-Michel-Telegdi (BMT) spin dynamics, the Stern-Gerlach spin-orbital coupling, the conventional ponderomotive forces, and the interaction with large-scale background fields (if any). Agreement with the BMT spin precession equation is shown numerically. The commonly known theory in which ponderomotive effects are incorporated in the particle effective mass is reproduced as a special case when the spin-orbital coupling is negligible. This model could be useful for studying laser-plasma interactions in relativistic spin-1/2 plasmas.

  1. Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference

    DOE Patents [OSTI]

    Simpson, J.E.

    1999-06-08

    An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp. 18 figs.

  2. Introduction of a methoxymethyl side chain into p-phenylenediamine attenuates its sensitizing potency and reduces the risk of allergy induction

    SciTech Connect (OSTI)

    Goebel, Carsten; Troutman, John; Hennen, Jenny; Rothe, Helga; Schlatter, Harald; Gerberick, G. Frank; Blmeke, Brunhilde

    2014-02-01

    The strong sensitizing potencies of the most important primary intermediates of oxidative hair dyes, p-phenylenediamine (PPD) and p-toluylenediamine (PTD, i.e. 2-methyl-PPD) are well established. They are considered as the key sensitizers in hair dye allergic contact dermatitis. While modification of their molecular structure is expected to alter their sensitizing properties, it may also impair their color performance. With introduction of a methoxymethyl side chain we found the primary intermediate 2-methoxymethyl-p-phenylenediamine (ME-PPD) with excellent hair coloring performance but significantly reduced sensitizing properties compared to PPD and PTD: In vitro, ME-PPD showed an attenuated innate immune response when analyzed for its protein reactivity and dendritic cell activation potential. In vivo, the effective concentration of ME-PPD necessary to induce an immune response 3-fold above vehicle control (EC3 value) in the local lymph node assay (LLNA) was 4.3%, indicating a moderate skin sensitizing potency compared to values of 0.1 and 0.17% for PPD and PTD, respectively. Finally, assessing the skin sensitizing potency of ME-PPD under consumer hair dye usage conditions through a quantitative risk assessment (QRA) indicated an allergy induction risk negligible compared to PPD or PTD. - Highlights: Methoxymethyl side chain in p-phenylenediamine reduces its strong skin sensitizing properties. Reduced protein reactivity and dendritic cell activation. Reduced skin sensitizing potency in local lymph node assay (LLNA). Negligible allergy induction risk under hair dye usage conditions.

  3. Fast dose kernel interpolation using Fourier transform with application to permanent prostate brachytherapy dosimetry

    SciTech Connect (OSTI)

    Liu, Derek Sloboda, Ron S.

    2014-05-15

    Purpose: Boyer and Mok proposed a fast calculation method employing the Fourier transform (FT), for which calculation time is independent of the number of seeds but seed placement is restricted to calculation grid points. Here an interpolation method is described enabling unrestricted seed placement while preserving the computational efficiency of the original method. Methods: The Iodine-125 seed dose kernel was sampled and selected values were modified to optimize interpolation accuracy for clinically relevant doses. For each seed, the kernel was shifted to the nearest grid point via convolution with a unit impulse, implemented in the Fourier domain. The remaining fractional shift was performed using a piecewise third-order Lagrange filter. Results: Implementation of the interpolation method greatly improved FT-based dose calculation accuracy. The dose distribution was accurate to within 2% beyond 3 mm from each seed. Isodose contours were indistinguishable from explicit TG-43 calculation. Dose-volume metric errors were negligible. Computation time for the FT interpolation method was essentially the same as Boyer's method. Conclusions: A FT interpolation method for permanent prostate brachytherapy TG-43 dose calculation was developed which expands upon Boyer's original method and enables unrestricted seed placement. The proposed method substantially improves the clinically relevant dose accuracy with negligible additional computation cost, preserving the efficiency of the original method.

  4. Analysis of core damage frequency due to external events at the DOE (Department of Energy) N-Reactor

    SciTech Connect (OSTI)

    Lambright, J.A.; Bohn, M.P.; Daniel, S.L. ); Baxter, J.T. ); Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P. ); Brosseau, D.A. )

    1990-11-01

    A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

  5. Magnetic anisotropies in epitaxial Fe{sub 3}O{sub 4}/GaAs(100) patterned structures

    SciTech Connect (OSTI)

    Zhang, W. Zhang, D.; Yuan, S. J.; Huang, Z. C.; Zhai, Y.; Wong, P. K. J.; Wu, J.; Xu, Y. B.

    2014-10-15

    Previous studies on epitaxial Fe{sub 3}O{sub 4} rings in the context of spin-transfer torque effect have revealed complicated and undesirable domain structures, attributed to the intrinsic fourfold magnetocrystalline anisotropy in the ferrite. In this Letter, we report a viable solution to this problem, utilizing a 6-nm-thick epitaxial Fe{sub 3}O{sub 4} thin film on GaAs(100), where the fourfold magnetocrystalline anisotropy is negligible. We demonstrate that in the Fe{sub 3}O{sub 4} planar wires patterned from our thin film, such a unique magnetic anisotropy system has been preserved, and relatively simple magnetic domain configurations compared to those previous reports can be obtained.

  6. Spin Hall magnetoresistance in CoFe2O4/Pt films

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

    Wu, Hao; Qintong, Zhang; Caihua, Wan; Ali, Syed Shahbaz; Yuan, Zhonghui; You, Lu; Wang, Junling; Choi, Yongseong; Han, Xiufeng

    2015-05-13

    Pulse laser deposition and magnetron sputtering techniques have been employed to prepare MgO(001)//CoFe2O4/Pt samples. Cross section transmission electron microscope results prove that the CoFe2O4 film epitaxially grew along (001) direction. X-ray magnetic circular dichroism results show that magnetic proximity effect in this sample is negligible. Magnetoresistance (MR) properties confirm that spin Hall MR (SMR) dominates in this system. Spin Hall effect-induced anomalous Hall voltage was also observed in this sample. Lastly, these results not only demonstrate the universality of SMR effect but also demonstrate the utility in spintronics of CoFe2O4 as a new type of magnetic insulator.

  7. On the variations of optical property and electronic structure in heavily Al-doped ZnO films during double-step growth process

    SciTech Connect (OSTI)

    Hu, Q. C.; Ding, K. Zhang, J. Y.; Yan, F. P.; Pan, D. M.; Huang, F.; Chiou, J. W.

    2014-01-13

    We have investigated the variations of optical property and electronic structure in heavily Al-doped ZnO (AZO) films during the growth process, which were formed by first creating Zn vacancies in O{sub 2}-rich atmosphere and second filling the vacancies with Zn atoms in Zn-vapor atmosphere. After the first step, the high-resistance AZO films have the same optical bandgap with nominally undoped ZnO, indicating that negligible variations in the fundamental bandgap happened to the AZO films although Al atom was incorporated into the ZnO lattice. After the second step, once free electrons were brought into the lattice by Zn-filling, the optical transition energy blueshifts due to the band-filling effect. X-ray absorption fine structure measurements suggest that Zn-filling process decreased the unoccupied states of the conduction band, but not raised the conduction band minimum.

  8. PEAK READING VOLTMETER

    DOE Patents [OSTI]

    Dyer, A.L.

    1958-07-29

    An improvement in peak reading voltmeters is described, which provides for storing an electrical charge representative of the magnitude of a transient voltage pulse and thereafter measuring the stored charge, drawing oniy negligible energy from the storage element. The incoming voltage is rectified and stored in a condenser. The voltage of the capacitor is applied across a piezoelectric crystal between two parallel plates. Amy change in the voltage of the capacitor is reflected in a change in the dielectric constant of the crystal and the capacitance between a second pair of plates affixed to the crystal is altered. The latter capacitor forms part of the frequency determlning circuit of an oscillator and means is provided for indicating the frequency deviation which is a measure of the peak voltage applied to the voltmeter.

  9. Apparatus and method for polarizing polarizable nuclear species

    DOE Patents [OSTI]

    Hersman, F. William; Leuschner, Mark; Carberry, Jeannette

    2005-09-27

    The present invention is a polarizing process involving a number of steps. The first step requires moving a flowing mixture of gas, the gas at least containing a polarizable nuclear species and vapor of at least one alkali metal, with a transport velocity that is not negligible when compared with the natural velocity of diffusive transport. The second step is propagating laser light in a direction, preferably at least partially through a polarizing cell. The next step is directing the flowing gas along a direction generally opposite to the direction of laser light propagating. The next step is containing the flowing gas mixture in the polarizing cell. The final step is immersing the polarizing cell in a magnetic field. These steps can be initiated in any order, although the flowing gas, the propagating laser and the magnetic field immersion must be concurrently active for polarization to occur.

  10. Magnetization plateaus of dipolar spin ice on kagome lattice

    SciTech Connect (OSTI)

    Xie, Y. L.; Wang, Y. L.; Yan, Z. B.; Liu, J.-M.

    2014-05-07

    Unlike spin ice on pyrochlore lattice, the spin ice structure on kagome lattice retains net magnetic charge, indicating non-negligible dipolar interaction in modulating the spin ice states. While it is predicted that the dipolar spin ice on kagome lattice exhibits a ground state with magnetic charge order and ?3???3 spin order, our work focuses on the magnetization plateau of this system. By employing the Wang-Landau algorithm, it is revealed that the lattice exhibits the fantastic three-step magnetization in response to magnetic field h along the [10] and [01] directions, respectively. For the h//[1 0] case, an additional ?3/6M{sub s} step, where M{sub s} is the saturated magnetization, is observed in a specific temperature range, corresponding to a new state with charge order and short-range spin order.

  11. Gradient corrections to the exchange-correlation free energy

    SciTech Connect (OSTI)

    Sjostrom, Travis; Daligault, Jerome

    2014-10-07

    We develop the first-order gradient correction to the exchange-correlation free energy of the homogeneous electron gas for use in finite-temperature density functional calculations. Based on this, we propose and implement a simple temperature-dependent extension for functionals beyond the local density approximation. These finite-temperature functionals show improvement over zero-temperature functionals, as compared to path-integral Monte Carlo calculations for deuterium equations of state, and perform without computational cost increase compared to zero-temperature functionals and so should be used for finite-temperature calculations. Furthermore, while the present functionals are valid at all temperatures including zero, non-negligible difference with zero-temperature functionals begins at temperatures above 10 000 K.

  12. Criticality calculations and criticality monitoring studies of the slagging pyrolysis incinerator facility

    SciTech Connect (OSTI)

    Close, D.A.; Booth, T.E.; Caldwell, J.T.

    1981-01-01

    It was determined that the criticality hazard associated with the Slagging Pyrolysis Incinerator (SPI) Facility would be minimal if a three-level criticality-hazard prevention program were implemented. The first strategy consists of screening all incoming wastes for fissile content. The second prevention level is provided by introducing a small concentration of a neutron-absorbing compound, such as B/sub 2/O/sub 3/, into the input waste stream. The third prevention level is provided by direct criticality-hazard monitoring using sensitive neutron detectors in all regions of the facility where a significant hazard has been identified - principally the drying, pyrolysis, and slag regions. The facility could be shut down rapidly for cleanout if the measurements indicate an unsafe condition is developing. The criticality safety provided by the product of these three independent measures should reduce the hazard to a negligible level.

  13. Bacillus anthracis spores germinate extracellularly at air-liquid interface in an in vitro lung model under serum-free conditions

    SciTech Connect (OSTI)

    Powell, Joshua D.; Hutchison, Janine R.; Hess, Becky M.; Straub, Tim M.

    2015-07-30

    Aims: To better understand the parameters that govern spore dissemination after lung exposure using in vitro cell systems. Methods and Results: We evaluated the kinetics of uptake, germination and proliferation of B. anthracis Sterne spores in association with human primary lung epithelial cells, Calu-3, and A549 cell lines. We also analyzed the influence of various cell culture media formulations related to spore germination. Conclusions: We found negligible spore uptake by epithelial cells, but germination and proliferation of spores in the extracellular environment was evident, and was appreciably higher in A549 and Calu-3 cultures than in primary epithelial cells. Additionally, our results revealed spores in association with primary cells submerged in cell culture media germinated 1 h

  14. Bacillus anthracis spores germinate extracellularly at air-liquid interface in an in vitro lung model under serum-free conditions

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

    Powell, Joshua D.; Hutchison, Janine R.; Hess, Becky M.; Straub, Tim M.

    2015-07-30

    Aims: To better understand the parameters that govern spore dissemination after lung exposure using in vitro cell systems. Methods and Results: We evaluated the kinetics of uptake, germination and proliferation of B. anthracis Sterne spores in association with human primary lung epithelial cells, Calu-3, and A549 cell lines. We also analyzed the influence of various cell culture media formulations related to spore germination. Conclusions: We found negligible spore uptake by epithelial cells, but germination and proliferation of spores in the extracellular environment was evident, and was appreciably higher in A549 and Calu-3 cultures than in primary epithelial cells. Additionally, ourmore » results revealed spores in association with primary cells submerged in cell culture media germinated 1 h« less

  15. Simulation of Electric Field in Semi Insulating Au/CdTe/Au Detector under Flux

    SciTech Connect (OSTI)

    Franc, J.; James, R.; Grill, R.; Kubat, J.; Belas, E.; Hoschl, P.; Moravec, P.; Praus, P.

    2009-08-02

    We report our simulations on the profile of the electric field in semi insulating CdTe and CdZnTe with Au contacts under radiation flux. The type of the space charge and electric field distribution in the Au/CdTe/Au structure is at high fluxes result of a combined influence of charge formed due to band bending at the electrodes and from photo generated carriers, which are trapped at deep levels. Simultaneous solution of drift-diffusion and Poisson equations is used for the calculation. We show, that the space charge originating from trapped photo-carriers starts to dominate at fluxes 10{sup 15}-10{sup 16}cm{sup -2}s{sup -1}, when the influence of contacts starts to be negligible.

  16. Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing

    DOE Patents [OSTI]

    Thomas, Stanley W.

    1995-01-01

    The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible.

  17. Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing

    DOE Patents [OSTI]

    Thomas, S.W.

    1995-04-18

    The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible. 4 figs.

  18. Giant magnetoelastic distortions of the crystal structure of the weakly anisotropic compound UFe/sub 2/

    SciTech Connect (OSTI)

    Popov, Y.F.; Levitin, R.Z.; Zeleny, M.; Deryagin, A.V.; Andreev, A.V.

    1980-06-01

    We investigate the temperature dependences of the crystal-lattice parameters, of the anisotropy, and of the Young's modulus of the intermetallide compound UFe/sub 2/. The contribution of the uranium ions to the magnetic moment of this compound is negligible (..mu../sub U/=0.06..mu../sub B/), owing to the almoft complete delocalization of the uranium 5f electrons. The measured magnetic anisotropy is relatively small (K/sub 1/approx. =-10/sup 6/ erg/cm/sup 3/ at 0 K). However, the transition to the magnetically ordered state (T/sub c/=170 K) is accompanied by large rhombohedral distortions of the UFe/sub 2/ crystal structure and by a considerable anomaly of the Young's modulus, thus attesting to a large value of the magnetoelastic interaction in this compound (..delta..K/sub 1/ /sup m/eapprox. =-8 x 10/sup 6/ erg/cm/sup 3/).

  19. Movable multi-probes for plasma boundary measurement in sino-united spherical tokamak

    SciTech Connect (OSTI)

    Chai, Song Wang, Wenhao; Tan, Yi; Gao, Zhe

    2014-11-15

    A novel movable multi-probes is developed to get local magnetic and electrostatic profiles on Sino-UNIted Spherical Tokamak (SUNIST). This multi-probes combines a four-tips Langmuir probe, a magnetic coil, and a retarding field energy analyzer (RFEA). It can be used to simultaneously measure the poloidal magnetic field B{sub p}, electric field E{sub r}, electron temperature T{sub e}, electron density n{sub e}, and ion temperature T{sub i}. Its small overall size (20 × 20 × 38 mm{sup 3}) enables the movable multi-probes to measure the magnetic and electrostatic profiles in high spatial resolution, with negligible impact to plasma in SUNIST. This paper presents the design of the movable multi-probes, in particular, details of RFEA for reliable ion energy measurements. Preliminary experimental results of the movable multi-probes are given as well.

  20. Interferometric tests of Planckian quantum geometry models

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

    Kwon, Ohkyung; Hogan, Craig J.

    2016-04-19

    The effect of Planck scale quantum geometrical effects on measurements with interferometers is estimated with standard physics, and with a variety of proposed extensions. It is shown that effects are negligible in standard field theory with canonically quantized gravity. Statistical noise levels are estimated in a variety of proposals for nonstandard metric fluctuations, and these alternatives are constrained using upper bounds on stochastic metric fluctuations from LIGO. Idealized models of several interferometer system architectures are used to predict signal noise spectra in a quantum geometry that cannot be described by a fluctuating metric, in which position noise arises from holographicmore » bounds on directional information. Lastly, predictions in this case are shown to be close to current and projected experimental bounds.« less

  1. Investigation of Wave Energy Converter Effects on the Nearshore Environment: A Month-Long Study in Monterey Bay CA.

    SciTech Connect (OSTI)

    Roberts, Jesse D.; Chang, Grace; Magalen, Jason; Jones, Craig

    2014-09-01

    A modified version of an indust ry standard wave modeling tool, SNL - SWAN, was used to perform model simulations for hourly initial wave conditio ns measured during the month of October 2009. The model was run with an array of 50 wave energy converters (WECs) and compared with model runs without WECs. Maximum changes in H s were found in the lee of the WEC array along the angles of incident wave dire ction and minimal changes were found along the western side of the model domain due to wave shadowing by land. The largest wave height reductions occurred during observed typhoon conditions and resulted in 14% decreases in H s along the Santa Cruz shoreline . Shoreline reductions in H s were 5% during s outh swell wave conditions and negligible during average monthly wave conditions.

  2. Investigation of Wave Energy Converter Effects on Wave Fields: A Modeling Sensitivity Study in Monterey Bay CA.

    SciTech Connect (OSTI)

    Roberts, Jesse D.; Grace Chang; Jason Magalen; Craig Jones

    2014-08-01

    A n indust ry standard wave modeling tool was utilized to investigate model sensitivity to input parameters and wave energy converter ( WEC ) array deploym ent scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that b oth wave height and near - bottom orbital velocity we re subject to the largest pote ntial variations, each decreas ed in sensitivity as transmission coefficient increase d , as number and spacing of WEC devices decrease d , and as the deployment location move d offshore. Wave direction wa s affected consistently for all parameters and wave perio d was not affected (or negligibly affected) by varying model parameters or WEC configuration .

  3. Performance of An Adjustable Strength Permanent Magnet Quadrupole

    SciTech Connect (OSTI)

    Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; Spencer, C.M.; Volk, J.T.; /Fermilab

    2006-03-01

    An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

  4. Detection and imaging of the oxygen deficiency in single crystalline YBa{sub 2}Cu{sub 3}O{sub 7??} thin films using a scanning positron beam

    SciTech Connect (OSTI)

    Reiner, M.; Gigl, T.; Hugenschmidt, C.; Jany, R.; Hammerl, G.

    2015-03-16

    Single crystalline YBa{sub 2}Cu{sub 3}O{sub 7??} (YBCO) thin films were grown by pulsed laser deposition in order to probe the oxygen deficiency ? using a mono-energetic positron beam. The sample set covered a large range of ? (0.191?negligible influence of potentially present Ba or Cu vacancies to the found correlation. Moreover, scanning with the positron beam allowed us to analyze the spatial variation of ?, which was found to fluctuate with a standard deviation of up to 0.079(5) within a single YBCO film.

  5. FULLY CONVECTIVE MAGNETOROTATIONAL TURBULENCE IN STRATIFIED SHEARING BOXES

    SciTech Connect (OSTI)

    Bodo, G.; Rossi, P.; Cattaneo, F.; Mignone, A.

    2013-07-10

    We present a numerical study of turbulence and dynamo action in stratified shearing boxes with zero magnetic flux. We assume that the fluid obeys the perfect gas law and has finite (constant) thermal diffusivity. We choose radiative boundary conditions at the vertical boundaries in which the heat flux is proportional to the fourth power of the temperature. We compare the results with the corresponding cases in which fixed temperature boundary conditions are applied. The most notable result is that the formation of a fully convective state in which the density is nearly constant as a function of height and the heat is transported to the upper and lower boundaries by overturning motions is robust and persists even in cases with radiative boundary conditions. Interestingly, in the convective regime, although the diffusive transport is negligible, the mean stratification does not relax to an adiabatic state.

  6. Nonlocal microscopic theory of quantum friction between parallel metallic slabs

    SciTech Connect (OSTI)

    Despoja, Vito

    2011-05-15

    We present a new derivation of the friction force between two metallic slabs moving with constant relative parallel velocity, based on T=0 quantum-field theory formalism. By including a fully nonlocal description of dynamically screened electron fluctuations in the slab, and avoiding the usual matching-condition procedure, we generalize previous expressions for the friction force, to which our results reduce in the local limit. Analyzing the friction force calculated in the two local models and in the nonlocal theory, we show that for physically relevant velocities local theories using the plasmon and Drude models of dielectric response are inappropriate to describe friction, which is due to excitation of low-energy electron-hole pairs, which are properly included in nonlocal theory. We also show that inclusion of dissipation in the nonlocal electronic response has negligible influence on friction.

  7. Beam plasma electromagnetic instabilities in a smooth density gradient: Application to the fast ignition scenario

    SciTech Connect (OSTI)

    Bret, A.; Deutsch, C.

    2005-10-01

    The integrated growth rate of various relativistic beam/plasma instabilities in a weakly varying plasma density gradient is calculated using a WKB-like approximation. It is proven that such an assumption can be made in fast ignition scenario conditions. The formalism is applied to the two-stream, the filamentation, and the two-stream/filamentation instabilities, the latter instability being a mixture of the former two, and is the fastest growing one. The results are restricted to collisionless plasmas and nonrelativistic beam and plasma temperatures. Filamentation instability is reduced by the density gradient and eventually does not develop in the core, whereas two-stream and two-stream/filamentation instabilities should saturate even before they feel the gradient. Various effects connected to the density gradient are discussed. It is found they should be negligible as long as these later instabilities remain in their respective linear regime.

  8. Reference electrode for strong oxidizing acid solutions

    DOE Patents [OSTI]

    Rigdon, Lester P.; Harrar, Jackson E.; Bullock, Sr., Jack C.; McGuire, Raymond R.

    1990-01-01

    A reference electrode for the measurement of the oxidation-reduction potentials of solutions is especially suitable for oxidizing solutions such as highly concentrated and fuming nitric acids, the solutions of nitrogen oxides, N.sub.2 O.sub.4 and N.sub.2 O.sub.5, in nitric acids. The reference electrode is fabricated of entirely inert materials, has a half cell of Pt/Ce(IV)/Ce(III)/70 wt. % HNO.sub.3, and includes a double-junction design with an intermediate solution of 70 wt. % HNO.sub.3. The liquid junctions are made from Corning No. 7930 glass for low resistance and negligible solution leakage.

  9. Collisionless damping of circularly polarized nonlinear Alfvn waves in solar wind plasmas with and without beam protons

    SciTech Connect (OSTI)

    Nariyuki, Y.; Hada, T.; Tsubouchi, K.

    2014-10-01

    The damping process of field-aligned, low-frequency right-handed polarized nonlinear Alfvn waves (NAWs) in solar wind plasmas with and without proton beams is studied by using a two-dimensional ion hybrid code. The numerical results show that the obliquely propagating kinetic Alfvn waves (KAWs) excited by beam protons affect the damping of the low-frequency NAW in low beta plasmas, while the nonlinear wave-wave interaction between parallel propagating waves and nonlinear Landau damping due to the envelope modulation are the dominant damping process in high beta plasmas. The nonlinear interaction between the NAWs and KAWs does not cause effective energy transfer to the perpendicular direction. Numerical results suggest that while the collisionless damping due to the compressibility of the envelope-modulated NAW plays an important role in the damping of the field-aligned NAW, the effect of the beam instabilities may not be negligible in low beta solar wind plasmas.

  10. Energetics of runaway electrons during tokamak disruptions

    SciTech Connect (OSTI)

    Riemann, J.; Helander, P.; Smith, H. M.

    2012-01-15

    In a tokamak disruption, a substantial fraction of the plasma current can be converted into runaway electrons. Although these are usually highly relativistic, their total energy is initially much smaller than that of the pre-disruption plasma. However, following a suggestion by Putvinski et al.[Plasma Phys. Controlled Fusion 39, B157 (1997)], it is shown that as the post-disruption plasma drifts toward the first wall, a non-negligible part of the energy contained in the poloidal magnetic field can be converted into kinetic energy of the runaway electrons. This process is simulated numerically, and it is found that in an ITER-like tokamak runaway electrons can gain kinetic energies up to about 70 MJ by this mechanism.

  11. On the minimum dark matter mass testable by neutrinos from the Sun

    SciTech Connect (OSTI)

    Busoni, Giorgio; Simone, Andrea De; Huang, Wei-Chih E-mail: andrea.desimone@sissa.it

    2013-07-01

    We discuss a limitation on extracting bounds on the scattering cross section of dark matter with nucleons, using neutrinos from the Sun. If the dark matter particle is sufficiently light (less than about 4 GeV), the effect of evaporation is not negligible and the capture process goes in equilibrium with the evaporation. In this regime, the flux of solar neutrinos of dark matter origin becomes independent of the scattering cross section and therefore no constraint can be placed on it. We find the minimum values of dark matter masses for which the scattering cross section on nucleons can be probed using neutrinos from the Sun. We also provide simple and accurate fitting functions for all the relevant processes of GeV-scale dark matter in the Sun.

  12. Search for supersymmetry in pp collisions at 7 TeV in events with jets and missing transverse energy

    SciTech Connect (OSTI)

    Khachatryan, Vardan; et al.

    2011-04-01

    A search for supersymmetry with R-parity conservation in proton-proton collisions at a centre-of-mass energy of 7 TeV is presented. The data correspond to an integrated luminosity of 35 inverse picobarns collected by the CMS experiment at the LHC. The search is performed in events with jets and significant missing transverse energy, characteristic of the decays of heavy, pair-produced squarks and gluinos. The primary background, from standard model multijet production, is reduced by several orders of magnitude to a negligible level by the application of a set of robust kinematic requirements. With this selection, the data are consistent with the standard model backgrounds, namely t t-bar, W + jet and Z + jet production, which are estimated from data control samples. Limits are set on the parameters of the constrained minimal supersymmetric extension of the standard model. These limits extend those set previously by experiments at the Tevatron and LEP colliders.

  13. Regimes of enhanced electromagnetic emission in beam-plasma interactions

    SciTech Connect (OSTI)

    Timofeev, I. V.; Annenkov, V. V.; Arzhannikov, A. V.

    2015-11-15

    The ways to improve the efficiency of electromagnetic waves generation in laboratory experiments with high-current relativistic electron beams injected into a magnetized plasma are discussed. It is known that such a beam can lose, in a plasma, a significant part of its energy by exciting a high level of turbulence and heating plasma electrons. Beam-excited plasma oscillations may simultaneously participate in nonlinear processes resulting in a fundamental and second harmonic emissions. It is obvious, however, that in the developed plasma turbulence the role of these emissions in the total energy balance is always negligible. In this paper, we investigate whether electromagnetic radiation generated in the beam-plasma system can be sufficiently enhanced by the direct linear conversion of resonant beam-driven modes into electromagnetic ones on preformed regular inhomogeneities of plasma density. Due to the high power of relativistic electron beams, the mechanism discussed may become the basis for the generator of powerful sub-terahertz radiation.

  14. Gradient corrections to the exchange-correlation free energy

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

    Sjostrom, Travis; Daligault, Jerome

    2014-10-07

    We develop the first-order gradient correction to the exchange-correlation free energy of the homogeneous electron gas for use in finite-temperature density functional calculations. Based on this, we propose and implement a simple temperature-dependent extension for functionals beyond the local density approximation. These finite-temperature functionals show improvement over zero-temperature functionals, as compared to path-integral Monte Carlo calculations for deuterium equations of state, and perform without computational cost increase compared to zero-temperature functionals and so should be used for finite-temperature calculations. Furthermore, while the present functionals are valid at all temperatures including zero, non-negligible difference with zero-temperature functionals begins at temperatures abovemore » 10 000 K.« less

  15. Line-focus solar central power system, phase I. Subsystem experiment: receiver heat transfer

    SciTech Connect (OSTI)

    Slemmons, A J

    1980-04-01

    Wind-tunnel tests confirmed that heat losses due to natural convection are negligible in the line-focus, solar-powered receiver. Anomalies in the forced-convection tests prevented definitive conclusions regarding the more important forced convection. Flow-visualization tests using a water table show much lower velocities inside the receiver cavity than outside, supporting the supposition that the forced-heat transfer should be less than that from a standard exposed cylinder. Furthermore, the water-table tests showed ways to decrease the low velocities in the cavity should this be desired. Further wind-tunnel testing should be done to confirm estimates and to support advanced design. This testing can be done in standard wind tunnels since only the forced convection is of concern.

  16. Measurement of cross-field power loss due to rovibrationally excited H{sub 2} in a detached hydrogen divertor plasma simulator

    SciTech Connect (OSTI)

    Hollmann, E.M.; Pigarov, A.Yu.; Yan, Z.

    2006-05-15

    The cross-field power loss due to radiation, plasma, and neutrals are measured for hydrogen discharges in a linear divertor simulator experiment. Radiation appears to be the dominant power loss channel; however, power loss due to heating of H{sub 2} neutrals is found to be quite significant, being only 2x weaker than radiation in the higher neutral pressure experiments. The H{sub 2} vibrational temperature T{sub vib} is found to be the most important channel for carrying neutral energy out of the plasma--more important than either kinetic temperature T{sub kin} or rotational temperature T{sub rot}. Power carried radially to the wall by plasma cross-field transport is found to be negligible when compared to neutral and radiation losses. These results demonstrate the importance of including of H{sub 2} neutrals in understanding power balance in detached tokamak divertors.

  17. Cryogenic Test of a Coaxial Coupling Scheme for Fundamental and Higher Order Modes in Superconducting Cavities

    SciTech Connect (OSTI)

    J.K. Sekutowicz, P. Kneisel

    2009-05-01

    A coaxial coupling device located in the beam pipe of the TESLA type superconducting cavities provides for better propagation of Higher Order Modes (HOMs) and their strong damping in appropriate HOM couplers. Additionally, it also provides efficient coupling for fundamental mode RF power into the superconducting cavity. The whole coupling device can be designed as a detachable system. If appropriately dimensioned, the magnetic field can be minimized to a negligible level at the flange position. This scheme, presented previously*, provides for several advantages: strong HOM damping, flangeable solution, exchangeability of the HOM damping device on a cavity, less complexity of the superconducting cavity, possible cost advantages. This contribution will describe the results of the first cryogenic test.

  18. Half-metallic ferromagnetism in Cr-doped semiconducting Ge-chalcogenide: Density functional approach

    SciTech Connect (OSTI)

    Saini, Hardev S.; Singh, Mukhtiyar; Thakur, Jyoti; Kashyap, Manish K.

    2014-04-24

    A supercell approach has been used to calculate the electronic and magnetic properties of Cr-doped Ge chalcogenide, Ge{sub 1−x}Cr{sub x}Te (x = 0.25 and 0.125). The calculations have been performed using full potential Linear Augmented Plane Wave (FPLAPW) method within generalized gradient approximation (GGA) as exchange-correlation (XC) potential. The calculated results show that the doping of Cr induces the 100% spin polarization at Fermi level (EF) and showed the robust half metallic ferromagnetism in this compound. Thus, the compound at both dopant concentrations behave as dilute magnetic semiconductor (DMS) showing metallic property in majority and semiconducting for minority spin channels which is best suited for spintronic applications. The total magnetic moments of this compound are mainly due to Cr-d states present at E{sup F} with negligible contribution from electronic states of other atoms.

  19. Robustness of n-GaAs carrier spin properties to 5 MeV proton irradiation

    SciTech Connect (OSTI)

    Pursley, Brennan C.; Song, X.; Torres-Isea, R. O.; Bokari, E. A.; Kayani, A.; Sih, V.

    2015-02-16

    Modern electronic devices utilize charge to transmit and store information. This leaves the information susceptible to external influences, such as radiation, that can introduce short timescale charge fluctuations and, long term, degrade electronic properties. Encoding information as spin polarizations offers an attractive alternative to electronic logic that should be robust to randomly polarized transient radiation effects. As a preliminary step towards radiation-resistant spintronic devices, we measure the spin properties of n-GaAs as a function of radiation fluence using time-resolved Kerr rotation and photoluminescence spectroscopy. Our results show a modest to negligible change in the long-term electron spin properties up to a fluence of 1 × 10{sup 14} (5 MeV protons)/cm{sup 2}, even as the luminescence decreases by two orders of magnitude.

  20. Method for reducing nitrogen oxides in combustion effluents

    DOE Patents [OSTI]

    Zauderer, Bert

    2000-01-01

    Method for reducing nitrogen oxides (NO.sub.x) in the gas stream from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone, NO.sub.x is converted to nitrogen by reaction with urea or ammonia with negligible remaining ammonia and other reaction pollutants. Specially designed injectors are used to introduce air atomized water droplets containing dissolved urea or ammonia into the gaseous combustion products in a manner that widely disperses the droplets exclusively in the optimum reaction temperature zone. The injector operates in a manner that forms droplet of a size that results in their vaporization exclusively in this optimum NO.sub.x -urea/ammonia reaction temperature zone. Also disclosed is a design of a system to effectively accomplish this injection.

  1. Lepton-mediated electroweak baryogenesis

    SciTech Connect (OSTI)

    Chung, Daniel J. H.; Garbrecht, Bjorn [University of Wisconsin, Madison, Wisconsin, 53706-1390 (United States); Ramsey-Musolf, Michael J. [University of Wisconsin, Madison, Wisconsin, 53706-1390 (United States); California Institute of Technology, Pasadena, California 91125 (United States); Tulin, Sean [California Institute of Technology, Pasadena, California 91125 (United States)

    2010-03-15

    We investigate the impact of the tau and bottom Yukawa couplings on the transport dynamics for electroweak baryogenesis in supersymmetric extensions of the standard model. Although it has generally been assumed in the literature that all Yukawa interactions except those involving the top quark are negligible, we find that the tau and bottom Yukawa interaction rates are too fast to be neglected. We identify an illustrative 'lepton-mediated electroweak baryogenesis' scenario in which the baryon asymmetry is induced mainly through the presence of a left-handed leptonic charge. We derive analytic formulas for the computation of the baryon asymmetry that, in light of these effects, are qualitatively different from those in the established literature. In this scenario, for fixed CP-violating phases, the baryon asymmetry has opposite sign compared to that calculated using established formulas.

  2. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

    SciTech Connect (OSTI)

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; deQuilettes, Dane W.; Sadhanala, Aditya; Li, Wenzhe; Wang, Liduo; Ginger, David S.; Friend, Richard H.; Snaith, Henry J.

    2015-11-30

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I-, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.

  3. ESR of Gd{sup 3+} in the Kondo-lattice compound YbAgCu{sub 4} and its reference compounds RAgCu{sub 4} (R=Y,Lu)

    SciTech Connect (OSTI)

    Pagliuso, P.G.; Rettori, C.; Oseroff, S.B.; Sarrao, J.; Fisk, Z.; Cornelius, A.; Hundley, M.F.

    1997-10-01

    Low-temperature (T{lt}30thinspK) electron-spin-resonance (ESR) experiments of Gd{sup 3+} diluted in the Kondo-lattice compound YbAgCu{sub 4} and its reference compounds YAgCu{sub 4} and LuAgCu{sub 4} are interpreted in terms of an enhanced density of states at the Fermi level for the Yb-based compound. The results of susceptibility and ESR (Korringa rate and g-shift) measurements show negligible electron-electron exchange enhancement for all the studied compounds. The exchange interaction between the Gd{sup 3+} local moment and the conduction electrons (c-e) is c-e wave vector dependent in all three compounds. {copyright} {ital 1997} {ital The American Physical Society}

  4. High-resolution single-shot spectral monitoring of hard x-ray free-electron laser radiation

    SciTech Connect (OSTI)

    Makita, M.; Karvinen, P.; Zhu, D.; Juranic, P. N.; Grünert, J.; Cartier, S.; Jungmann-Smith, J. H.; Lemke, H. T.; Mozzanica, A.; Nelson, S.; Patthey, L.; Sikorski, M.; Song, S.; Feng, Y.; David, C.

    2015-10-16

    We have developed an on-line spectrometer for hard x-ray free-electron laser (XFEL) radiation based on a nanostructured diamond diffraction grating and a bent crystal analyzer. Our method provides high spectral resolution, interferes negligibly with the XFEL beam, and can withstand the intense hard x-ray pulses at high repetition rates of >100 Hz. The spectrometer is capable of providing shot-to-shot spectral information for the normalization of data obtained in scientific experiments and optimization of the accelerator operation parameters. We have demonstrated these capabilities of the setup at the Linac Coherent Light Source, in self-amplified spontaneous emission mode at full energy of >1 mJ with a 120 Hz repetition rate, obtaining a resolving power of Ε/δΕ > 3 × 104. In conclusion, the device was also used to monitor the effects of pulse duration down to 8 fs by analysis of the spectral spike width.

  5. The green entrepreneur: Business opportunities that can save the Earth make you money

    SciTech Connect (OSTI)

    Berle, G.

    1993-01-01

    The Green Entrepreneur looks at business opportunities for the many small operators working their way through the landslide. Gustav Berle's book is an alarming cornucopia of good ideas, helpful references, and summaries of today's preoccupying business concerns to reduce waste, save materials, and conserve energy. This quick-read is also interspersed with a lower-octane blend of popularist solutions to such global problems as world hunger, world peace, and the world's needs for resource reallocation. The ideas spread throughout this text may trigger some start-up thoughts, and the many helpful references may assist those eager to learn how to use the backhoe and pick axe. Unfortunately, the small players are probably a small part of the needed answer. The momentous claim of the book - the need to combine environmentally sound concepts with sharp business plans and competent management' - isn't bad nor negligent advice for the giants, either, that still roam the globe.

  6. Neutron Resonance Spectroscopy for the Analysis of Materials and Objects

    SciTech Connect (OSTI)

    Borella, A.; Lampoudis, C.; Schillebeeckx, P.; Kopecky, S.; Postma, H.; Moxon, M.

    2009-12-02

    The presence of resonances in neutron induced reaction cross sections is the basis of the Neutron Resonance Capture (NRCA) and Transmission (NRTA) Analysis techniques. Since resonances can be observed at neutron energies which are specific for each nuclide, they can be used as fingerprints to identify and quantify elements in materials and objects. Both NRCA and NRTA are fully non-destructive methods which determine the bulk elemental composition, do not require any sample preparation and result in a negligible residual activation. In this text we review the technique and present an analysis procedures including one based on a more methodological approach which relies on a full Resonance Shape Analysis (RSA) and accounts directly for the neutron self-shielding, multiple scattering, Doppler broadening and instrumental resolution.

  7. Collisional effects on Rayleigh-Taylor-induced magnetic fields

    SciTech Connect (OSTI)

    Manuel, M. J.-E.; Flaig, M.; Plewa, T.; Li, C. K.; Séguin, F. H.; Frenje, J. A.; Casey, D. T.; Petrasso, R. D.; Hu, S. X.; Betti, R.; Hager, J.; Meyerhofer, D. D.; Smalyuk, V.

    2015-05-15

    Magnetic-field generation from the Rayleigh-Taylor (RT) instability was predicted more than 30 years ago, though experimental measurements of this phenomenon have only occurred in the past few years. These pioneering observations demonstrated that collisional effects are important to B-field evolution. To produce fields of a measurable strength, high-intensity lasers irradiate solid targets to generate the nonaligned temperature and density gradients required for B-field generation. The ablation process naturally generates an unstable system where RT-induced magnetic fields form. Field strengths inferred from monoenergetic-proton radiographs indicate that in the ablation region diffusive effects caused by finite plasma resistivity are not negligible. Results from the first proof-of-existence experiments are reviewed and the role of collisional effects on B-field evolution is discussed in detail.

  8. Scale dependence of f{sub NL} in N-flation

    SciTech Connect (OSTI)

    Huang, Qing-Guo

    2010-12-01

    Adopting the horizon-crossing approximation, we derive the spectral index of f{sub NL} in general N-flation model. Axion N-flation model is taken as a typical model for generating a large f{sub NL} which characterizes the size of local form bispectrum. We find that its tilt n{sub f{sub N{sub L}}} is negligibly small when all inflatons have the same potential, but a negative detectable n{sub f{sub N{sub L}}} can be achieved in the axion N-flation with different decay constants for different inflatons. The measurement of n{sub f{sub N{sub L}}} can be used to support or falsify the axion N-flation in the near future.

  9. Particle-in-cell/accelerator code for space-charge dominated beam simulation

    SciTech Connect (OSTI)

    2012-05-08

    Warp is a multidimensional discrete-particle beam simulation program designed to be applicable where the beam space-charge is non-negligible or dominant. It is being developed in a collaboration among LLNL, LBNL and the University of Maryland. It was originally designed and optimized for heave ion fusion accelerator physics studies, but has received use in a broader range of applications, including for example laser wakefield accelerators, e-cloud studies in high enery accelerators, particle traps and other areas. At present it incorporates 3-D, axisymmetric (r,z) planar (x-z) and transverse slice (x,y) descriptions, with both electrostatic and electro-magnetic fields, and a beam envelope model. The code is guilt atop the Python interpreter language.

  10. Modified special relativity on a fluctuating spacetime

    SciTech Connect (OSTI)

    Aloisio, R.; Galante, A.; Grillo, A. F.; Liberati, S.; Luzio, E.; Mendez, F.

    2006-10-15

    It was recently proposed that deformations of the relativistic symmetry, as those considered in deformed special relativity (DSR), can be seen as the outcome of a measurement theory in the presence of non-negligible (albeit small) quantum gravitational fluctuations [S. Liberati, S. Sonego, and M. Visser, Phys. Rev. D 71, 045001 (2005).][R. Aloisio, A. Galante, A. Grillo, S. Liberati, E. Luzio, and F. Mendez, Phys. Rev. D 73, 045020 (2006).]. In this paper we explicitly consider the case of a spacetime described by a flat metric endowed with stochastic fluctuations and, for a free particle, we show that DSR-like nonlinear relations between the spaces of the measured and classical momenta, can result from the average of the stochastic fluctuations over a scale set to be the de Broglie wavelength of the particle. As illustrative examples we consider explicitly the averaging procedure for some simple stochastic processes and discuss the physical implications of our results.

  11. The effects of neutral gas heating on H mode transition and maintenance currents in a 13.56 MHz planar coil inductively coupled plasma reactor

    SciTech Connect (OSTI)

    Jayapalan, Kanesh K.; Chin, Oi-Hoong

    2012-09-15

    The H mode transition and maintenance currents in a 13.56 MHz laboratory 6 turn planar coil inductively coupled plasma (ICP) reactor are simulated for low pressure argon discharge range of 0.02-0.3 mbar with neutral gas heating and at ambient temperature. An experimentally fitted 3D power evolution plot for 0.02 mbar argon pressure is also shown to visualize the effects of hysteresis in the system. Comparisons between simulation and experimental measurements show good agreement in the pressure range of 0.02-0.3 mbar for transition currents and 0.02-0.1 mbar for maintenance currents only when neutral gas heating is considered. This suggests that neutral gas heating plays a non-negligible role in determining the mode transition points of a rf ICP system.

  12. Ghost dark matter

    SciTech Connect (OSTI)

    Furukawa, Tomonori; Yokoyama, Shuichiro; Ichiki, Kiyotomo; Sugiyama, Naoshi; Mukohyama, Shinji E-mail: shu@a.phys.nagoya-u.ac.jp E-mail: naoshi@a.phys.nagoya-u.ac.jp

    2010-05-01

    We revisit ghost dark matter, the possibility that ghost condensation may serve as an alternative to dark matter. In particular, we investigate the Friedmann-Robertson-Walker (FRW) background evolution and the large-scale structure (LSS) in the ΛGDM universe, i.e. a late-time universe dominated by a cosmological constant and ghost dark matter. The FRW background of the ΛGDM universe is indistinguishable from that of the standard ΛCDM universe if M∼>1eV, where M is the scale of spontaneous Lorentz breaking. From the LSS we find a stronger bound: M∼>10eV. For smaller M, ghost dark matter would have non-negligible sound speed after the matter-radiation equality, and thus the matter power spectrum would significantly differ from observation. These bounds are compatible with the phenomenological upper bound M∼<100GeV known in the literature.

  13. Analytical and computational study of the ideal full two-fluid plasma model and asymptotic approximations for Hall-magnetohydrodynamics

    SciTech Connect (OSTI)

    Srinivasan, B.; Shumlak, U.

    2011-09-15

    The 5-moment two-fluid plasma model uses Euler equations to describe the ion and electron fluids and Maxwell's equations to describe the electric and magnetic fields. Two-fluid physics becomes significant when the characteristic spatial scales are on the order of the ion skin depth and characteristic time scales are on the order of the ion cyclotron period. The full two-fluid plasma model has disparate characteristic speeds ranging from the ion and electron speeds of sound to the speed of light. Two asymptotic approximations are applied to the full two-fluid plasma to arrive at the Hall-MHD model, namely negligible electron inertia and infinite speed of light. The full two-fluid plasma model and the Hall-MHD model are studied for applications to an electromagnetic plasma shock, geospace environmental modeling (GEM challenge) magnetic reconnection, an axisymmetric Z-pinch, and an axisymmetric field reversed configuration (FRC).

  14. Temporal characterization of a time-compensated monochromator for high-efficiency selection of extreme-ultraviolet pulses generated by high-order harmonics

    SciTech Connect (OSTI)

    Poletto, L.; Villoresi, P.; Benedetti, E.; Ferrari, F.; Stagira, S.; Sansone, G.; Nisoli, M.

    2008-07-15

    Ultrafast extreme-ultraviolet pulses are spectrally selected by a time-delay-compensated grating monochromator. The intrinsic very short duration of the pulses is obtained by exploiting the high-order harmonic generation process. The temporal characterization of the harmonic pulses is obtained using a cross-correlation method: pulses as short as 8 fs are measured at the output of the monochromator in the case of the 23rd harmonic. This value is in agreement with the expected duration of such pulses, indicating that the influence of the monochromator is negligible. The photon flux has been measured with a calibrated photodiode, pointing out the good efficiency of the monochromator, derived by the exploitation for the two gratings of the conical diffraction mounting.

  15. Assessment of acreage and vegetation change in Florida`s Big Bend tidal wetlands using satellite imagery

    SciTech Connect (OSTI)

    Raabe, E.A.; Stumpf, R.P.

    1997-06-01

    Fluctuations in sea level and impending development on the west coast of Florida have aroused concern for the relatively pristine tidal marshes of the Big Bend. Landsat Thematic Mapper (TM) images for 1986 and 1995 are processed and evaluated for signs of change. The images cover 250 km of Florida`s Big Bend Gulf Coast, encompassing 160,000 acres of tidal marshes. Change is detected using the normalized difference vegetation index (NDVI) and land cover classification. The imagery shows negligible net loss or gain in the marsh over the 9-year period. However, regional changes in biomass are apparent and are due to natural disturbances such as low winter temperatures, fire, storm surge, and the conversion of forest to marsh. Within the marsh, the most prominent changes in NDVI and in land cover result from the recovery of mangroves from freezes, a decline of transitional upland vegetation, and susceptibility of the marsh edge and interior to variations in tidal flooding.

  16. Chemical stability and Ce doping of LiMgAlF6 neutron scintillator

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

    Du, M. H.

    2014-11-13

    We perform density functional calculations to investigate LiMgAlF6 as a potential neutron scintillator material. The calculations of enthalpy of formation and phase diagram show that single-phase LiMgAlF6 can be grown but it should be more difficult than growing LiCaAlF6 and LiSrAlF6. Moreover, the formation energy calculations for substitutional Ce show that the concentration of Ce on the Al site is negligible but a high concentration (>1 at.%) of Ce on the Mg site is attainable provided that the Fermi level is more than 5 eV lower than the conduction band minimum. Acceptor doping should promote Ce incorporation in LiMgAlF6.

  17. Fluid dynamics, particulate segregation, chemical processes, and natural ore analog discussions that relate to the potential for criticality in Hanford tanks

    SciTech Connect (OSTI)

    Barney, G.S.

    1996-09-27

    This report presents an in-depth review of the potential for nuclear criticality to occur in Hanford defense waste tanks during past, current and future safe storage and maintenance operations. The report also briefly discusses the potential impacts of proposed retrieval activities, although retrieval was not a main focus of scope. After thorough review of fluid dynamic aspects that focus on particle segregation, chemical aspects that focus on solubility and adsorption processes that might concentrate plutonium and/or separate plutonium from the neutron absorbers in the tank waste, and ore-body formation and mining operations, the interdisciplinary team has come to the conclusion that there is negligible risk of nuclear critically under existing storage conditions in Hanford site underground waste storage tanks. Further, for the accident scenarios considered an accidental criticality is incredible.

  18. Quantum gates controlled by spin chain soliton excitations

    SciTech Connect (OSTI)

    Cuccoli, Alessandro; Nuzzi, Davide; Vaia, Ruggero; Verrucchi, Paola

    2014-05-07

    Propagation of soliton-like excitations along spin chains has been proposed as a possible way for transmitting both classical and quantum information between two distant parties with negligible dispersion and dissipation. In this work, a somewhat different use of solitons is considered. Solitons propagating along a spin chain realize an effective magnetic field, well localized in space and time, which can be exploited as a means to manipulate the state of an external spin (i.e., a qubit) that is weakly coupled to the chain. We have investigated different couplings between the qubit and the chain, as well as different soliton shapes, according to a Heisenberg chain model. It is found that symmetry properties strongly affect the effectiveness of the proposed scheme, and the most suitable setups for implementing single qubit quantum gates are singled out.

  19. A novel design for monolithic interconnected modules (MIMs) for thermophotovoltaic (TPV) power conversion

    SciTech Connect (OSTI)

    Ward, J.S.; Duda, A.; Wanlass, M.W.

    1997-06-01

    The design for the fabrication of Monolithic Interconnected Modules (MIMs) for thermophotovoltaic (TPV) power conversion described in this paper utilizes a novel, interdigitated contacting scheme that increases the flexibility in the size of the component cells and hence the output current and voltage of the module. This flexibility is gained at the expense of only minimally increased grid obscuration. Because the design uses the grid fingers of the component cells as the interconnect structure, the area of the device used for this purpose becomes negligible. In this paper the authors report on the specifics of the design as well as issues related to the fabrication of the modules. Preliminary performance data for representative modules also are offered.

  20. Magnetic resonance imaging without field cycling at less than earth's magnetic field

    SciTech Connect (OSTI)

    Lee, Seong-Joo Shim, Jeong Hyun; Kim, Kiwoong; Yu, Kwon Kyu; Hwang, Seong-min

    2015-03-09

    A strong pre-polarization field, usually tenths of a milli-tesla in magnitude, is used to increase the signal-to-noise ratio in ordinary superconducting quantum interference device-based nuclear magnetic resonance/magnetic resonance imaging experiments. Here, we introduce an experimental approach using two techniques to remove the need for the pre-polarization field. A dynamic nuclear polarization (DNP) technique enables us to measure an enhanced resonance signal. In combination with a π/2 pulse to avoid the Bloch-Siegert effect in a micro-tesla field, we obtained an enhanced magnetic resonance image by using DNP technique with a 34.5 μT static external magnetic field without field cycling. In this approach, the problems of eddy current and flux trapping in the superconducting pickup coil, both due to the strong pre-polarization field, become negligible.

  1. Environmental Impacts, Health and Safety Impacts, and Financial Costs of the Front End of the Nuclear Fuel Cycle

    SciTech Connect (OSTI)

    Brett W Carlsen; Urairisa Phathanapirom; Eric Schneider; John S. Collins; Roderick G. Eggert; Brett Jordan; Bethany L. Smith; Timothy M. Ault; Alan G. Croff; Steven L. Krahn; William G. Halsey; Mark Sutton; Clay E. Easterly; Ryan P. Manger; C. Wilson McGinn; Stephen E. Fisher; Brent W. Dixon; Latif Yacout

    2013-07-01

    FEFC processes, unlike many of the proposed fuel cycles and technologies under consideration, involve mature operational processes presently in use at a number of facilities worldwide. This report identifies significant impacts resulting from these current FEFC processes and activities. Impacts considered to be significant are those that may be helpful in differentiating between fuel cycle performance and for which the FEFC impact is not negligible relative to those from the remainder of the full fuel cycle. This report: • Defines ‘representative’ processes that typify impacts associated with each step of the FEFC, • Establishes a framework and architecture for rolling up impacts into normalized measures that can be scaled to quantify their contribution to the total impacts associated with various fuel cycles, and • Develops and documents the bases for estimates of the impacts and costs associated with each of the representative FEFC processes.

  2. Regular perturbation solution of the Elenbaas-Heller equation

    SciTech Connect (OSTI)

    Shaw, B.D.

    2006-02-01

    The Elenbaas-Heller equation is nondimensionalized and solved using regular perturbation theory to provide closed-form analytical solutions to describe structures of cylindrically symmetrical steady electric arc discharges with negligible radiant heat transfer. Based on available data, it is assumed that the electrical conductivity varies with the heat-flux potential in an Arrhenius fashion. The leading-order solution is equivalent to an asymptotic solution proposed by Kuiken [J. Appl. Phys. 58, 1833 (1991)]. Higher-order terms are also derived in the present paper, and it is shown that quantitatively accurate analytical solutions can be developed when higher-order terms are included. Analysis shows that appreciable Joule heating is restricted to an inner zone when a dimensionless parameter is large relative to unity, leading to arc-channel models suggested by previous investigators.

  3. Self-field effects on instability of wave modes in a two-stream free-electron laser with an axial magnetic field

    SciTech Connect (OSTI)

    Mohsenpour, Taghi Rezaee Rami, Omme Kolsoum

    2014-07-15

    Free electron lasers (FEL) play major roles in the Raman Regime, due to the charge and current densities of the beam self-field. The method of perturbation has been applied to study the influence of self-electric and self-magnetic fields. A dispersion relation for two-stream free electron lasers with a helical wiggler and an axial magnetic field has been found. This dispersion relation is solved numerically to investigate the influence of self-fields on the FEL coupling and the two-stream instability. It was found that self-fields can produce very large effects on the FEL coupling, but they have almost negligible effects on two-stream instability.

  4. Electron heating due to microwave photoexcitation in the high mobility GaAs/AlGaAs two dimensional electron system

    SciTech Connect (OSTI)

    Ramanayaka, A. N.; Mani, R. G.; Wegscheider, W.

    2013-12-04

    We extract the electron temperature in the microwave photo-excited high mobility GaAs/AlGaAs two dimensional electron system (2DES) by studying the influence of microwave radiation on the amplitude of Shubnikov-de Haas oscillations (SdHOs) in a regime where the cyclotron frequency, ?{sub c}, and the microwave angular frequency, ?, satisfy 2? ? ?{sub c} ? 3.5? The results indicate that increasing the incident microwave power has a weak effect on the amplitude of the SdHOs and therefore the electron temperature, in comparison to the influence of modest temperature changes on the dark-specimen SdH effect. The results indicate negligible electron heating under modest microwave photo-excitation, in good agreement with theoretical predictions.

  5. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method

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

    Qiu, Jiaqi; Zhu, Yimei; Ha, Gwanghui; Jing, Chunguang; Baryshev, Sergey V.; Reed, Bryan W.; Lau, June W.

    2015-11-10

    In this study, a device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1 GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incomingmore » dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges.« less

  6. Effects of solar ultraviolet photons on mammalian cell DNA. [UVA (320-400 nm):a2

    SciTech Connect (OSTI)

    Peak, M.J.; Peak, J.G.

    1991-01-01

    This document presents information on the possible mechanisms of carcinogenesis caused by UVA (ultraviolet radiation in the 320--400 nm region). Most studies showing the carcinogenic effects of ultraviolet light have concentrated on UVB (280--320 nm). UVA had been considered harmless even though it penetrates biological tissues better than UVB. Recently, it has become apparent that UVA is also capable of causing damage to cellular DNA. This was unexpected because the DNA UV absorption spectrum indicates a negligible probability that photons of wavelengths longer than 320 nm will be directly absorbed. The most common defects induced in DNA by UVB are pyrimidine photoproducts, such as thymidine dimers. UVA photons produce defects resembling those caused by ionizing radiations: single- and double-strand breaks, and DNA-protein crosslinks. This paper also discusses the role of DNA repair mechanisms in UVA-induced defects and the molecular mechanisms of UVA damage induction. 38 refs. (MHB)

  7. Indirect excitation of ultrafast demagnetization

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

    Vodungbo, Boris; Tudu, Bahrati; Perron, Jonathan; Delaunay, Renaud; Müller, Leonard; Berntsen, Magnus H.; Grübel, Gerhard; Malinowski, Grégory; Weier, Christian; Gautier, Julien; et al

    2016-01-06

    Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset andmore » at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. As a result, our data thus confirm recent theoretical predictions.« less

  8. Status report on a solar photovoltaic concentrating energy system for a hospital in Hawaii

    SciTech Connect (OSTI)

    Seki, A.; Curtis, G.; Yuen, P.

    1983-06-01

    The largest parabolic concentrating photovoltaic/solar thermal system in the U.S. began producing electricity and hot water for a hospital on the island of Kauai, Hawaii in November 1981. Each of the 80 parabolic collectors is 6 feet by 10 feet and concentrates incident sunlight on photovoltaic cells mounted on two faces of the receiver at the focus. Although the 35 kilowatt system has been designed to produce 22,000 net kilowatt-hours per year of electricity and 620,000 gallons of 180 F water, electrical output (12 to 15 kilowatt-hours per day) is only 20 percent of that expected, primarily because insolation at the site has been only 40 percent of predicted values. A second problem with fungal attack on the receivers has been solved by better sealing. The system has also withstood a hurricane with negligible damage.

  9. An inflationary model with small scalar and large tensor nongaussianities

    SciTech Connect (OSTI)

    Cook, Jessica L.; Sorbo, Lorenzo E-mail: sorbo@physics.umass.edu

    2013-11-01

    We study a model of inflation where the scalar perturbations are almost gaussian while there is sizable (equilateral) nongaussianity in the tensor sector. In this model, a rolling pseudoscalar gravitationally coupled to the inflaton amplifies the vacuum fluctuations of a vector field. The vector sources both scalar and tensor metric perturbations. Both kinds of perturbations are nongaussian, but, due to helicity conservation, the tensors have a larger amplitude, so that nongaussianity in the scalar perturbations is negligible. Moreover, the tensors produced this way are chiral. We study, in the flat sky approximation, how constraints on tensor nongaussianities affect the detectability of parity violation in the Cosmic Microwave Background. We expect the model to feature interesting patterns on nongaussianities in the polarization spectra of the CMB.

  10. Induced fission of Pu240 within a real-time microscopic framework

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

    Bulgac, Aurel; Magierski, Piotr; Roche, Kenneth J.; Stetcu, Ionel

    2016-03-25

    Here, we describe the fissioning dynamics of 240Pu from a configuration in the proximity of the outer fission barrier to full scission and the formation of the fragments within an implementation of density functional theory extended to superfluid systems and real-time dynamics. The fission fragments emerge with properties similar to those determined experimentally, while the fission dynamics appears to be quite complex, with many excited shape and pairing modes. The evolution is found to be much slower than previously expected, and the ultimate role of the collective inertia is found to be negligible in this fully nonadiabatic treatment of nuclearmore » dynamics, where all collective degrees of freedom (CDOF) are included (unlike adiabatic treatments with a small number of CDOF).« less

  11. Effect of {alpha} variation on a prospective experiment to detect variation of m{sub e}/m{sub p} in diatomic molecules

    SciTech Connect (OSTI)

    Beloy, K.; Borschevsky, A.; Schwerdtfeger, P.; Flambaum, V. V.

    2011-10-15

    We consider the influence of variation in the fine structure constant {alpha} on a promising experiment proposed by DeMille et al. to search for variation in the electron-to-proton mass ratio {mu} using diatomic molecules [DeMille et al., Phys. Rev. Lett. 100, 043202 (2008)]. The proposed experiment involves spectroscopically probing the splitting between two nearly degenerate vibrational levels supported by different electronic potentials. Here we demonstrate that this splitting may be equally or more sensitive to variation in {alpha} as to variation in {mu}. For the anticipated experimental precision, this implies that the {alpha} variation may not be negligible, as previously assumed, and further suggests that the method could serve as a competitive means to search for {alpha} variation as well.

  12. The Dependence of the Oxidation Enhancement of InP(100) Surface on the Coverage of the Adsorbed Cs

    SciTech Connect (OSTI)

    Sun, Yun

    2010-06-07

    We report the oxidation of the InP(100) surface promoted by adsorbed Cs by synchrotron radiation photoemission. Oxygen exposure causes reduction of the charge transferred to the InP substrate from Cs and the growth of indium oxide and phosphorous oxide. The oxide growth displays a clear dependence on the Cs coverage. The oxidation of phosphorous is negligible up to 1000 L of O{sub 2} exposure when the Cs coverage is less than half a monolayer (ML), but the formation of the second half monolayer of Cs greatly accelerates the oxidation. This different enhancement of the InP oxidation by the first and the second half monolayer of Cs is due to the double layer structure of the adsorbed Cs atoms, and consequently the higher 6s electron density in the Cs atoms when Cs coverage is larger than 0.5 ML.

  13. The beaming pattern of external Compton emission from relativistic outflows: The case of anisotropic distribution of electrons

    SciTech Connect (OSTI)

    Kelner, S. R.; Lefa, E.; Rieger, F. M.; Aharonian, F. A.

    2014-04-20

    The beaming pattern of radiation emitted by a relativistically moving source, such as jets in microquasars, active galactic nuclei, and gamma-ray bursts, is a key issue for understanding acceleration and radiation processes in these objects. In this paper, we introduce a formalism based on a solution of the photon transfer equation to study the beaming patterns for emission produced by electrons accelerated in the jet and the upscattering photons of low-energy radiation fields of external origin (the so-called external Compton scenario). The formalism allows us to treat non-stationary, non-homogeneous, and anisotropic distributions of electrons, but assuming homogeneous/isotropic and non-variable target photon fields. We demonstrate the non-negligible impact of the anisotropy in the electron distribution on angular and spectral characteristics of the EC radiation.

  14. Defect tolerant transmission lithography mask

    DOE Patents [OSTI]

    Vernon, Stephen P.

    2000-01-01

    A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

  15. Absence of exchange interaction between localized magnetic moments and conduction-electrons in diluted Er{sup 3+} gold-nanoparticles

    SciTech Connect (OSTI)

    Lesseux, G. G. Urbano, R. R.; Iwamoto, W.; Garca-Flores, A. F.; Rettori, C.

    2014-05-07

    The Electron Spin Resonance (ESR) of diluted Er{sup 3+} magnetic ions in Au nanoparticles (NPs) is reported. The NPs were synthesized by reducing chloro triphenyl-phosphine gold(I) and erbium(III) trifluoroacetate. The Er{sup 3+} g-value along with the observed hyperfine splitting indicate that the Er{sup 3+} impurities are in a local cubic symmetry. Furthermore, the Er{sup 3+} ESR spectra show that the exchange interaction between the 4f and the conduction electrons (ce) is absent or negligible in Au{sub 1x}Er{sub x} NPs, in contrast to the ESR results in bulk Au{sub 1x}Er{sub x}. Therefore, the nature of this interaction needs to be reexamined at the nano scale range.

  16. Two-neutron stripping in ({sup 18}O, {sup 16}O) and (t,p) reactions

    SciTech Connect (OSTI)

    Cavallaro, M.; Agodi, A.; Carbone, D.; Cunsolo, A.; Bond, M.; Cappuzzello, F.; Nicolosi, D.; Tropea, S.; Borello-Lewin, T.; Rodrigues, M. R. D.; De Napoli, M.; Garcia, V. N.

    2014-11-11

    The {sup 12}C({sup 18}O,{sup 16}O){sup 14}C reactions has been investigated at 84 MeV incident energy. The charged ejectiles produced in the reaction have been momentum analyzed and identified by the MAGNEX magnetic spectrometer. Q-value spectra have been extracted with an energy resolution of 160 keV (Full Width at Half Maximum) and several known bound and resonant states of {sup 14}C have been identified up to 15 MeV. In particular, excited states with dominant 2p - 4h configuration are the most populated. The absolute values of the cross sections have been extracted showing a striking similarity with those measured for the same transitions by (t,p) reactions. This indicates that the effect of the {sup 16}O core is negligible in the reaction mechanism.

  17. Electron acceleration by a tightly focused Hermite-Gaussian beam: higher-order corrections

    SciTech Connect (OSTI)

    Zhao Zhiguo; Yang Dangxiao; Lue Baida

    2008-03-15

    Taking the TEM{sub 1,0}-mode Hermite-Gaussian (H-G) beam as a numerical calculation example, and based on the method of the perturbation series expansion, the higher-order field corrections of H-G beams are derived and used to study the electron acceleration by a tightly focused H-G beam in vacuum. For the case of the off-axis injection the field corrections to the terms of order f{sup 3} (f=1/kw{sub 0}, k and w{sub 0} being the wavenumber and waist width, respectively) are considered, and for the case of the on-axis injection the contributions of the terms of higher orders are negligible. By a suitable optimization of injection parameters the energy gain in the giga-electron-volt regime can be achieved.

  18. van der Waals forces in density functional theory: a review of the vdW-DF method

    SciTech Connect (OSTI)

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T.; Hyldgaard, Per; Lundqvist, Bengt I.

    2015-05-15

    We review a density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology. The insights that led to the construction of the Rutgers–Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only for dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.

  19. Radiation pressure efficiency measurements of nanoparticle coated microspheres

    SciTech Connect (OSTI)

    Kim, Soo Y.; Taylor, Joseph D.; Ladouceur, Harold D.; Hart, Sean J.; Terray, Alex

    2013-12-02

    Experimental measurements of the radiation pressure efficiency (Q{sub pr}) for several microparticles have been compared to theoretical calculations extrapolated from the Bohren-Huffman code for Mie scattering of coated particles. An increased shift of the Q{sub pr} parameter was observed for 2??m SiO{sub 2} core particles coated with nanoparticles of higher refractive indices. Coatings of 14?nm melamine particles were found to increase the Q{sub pr} parameter 135 times over similar coatings using SiO{sub 2} particles of the same size. While a coating of 100?nm polystyrene particles also showed a significant increase, they did not agree well with theoretical values. It is hypothesized that other factors such as increased scatter, drag, and finite coating coverage are no longer negligible for coatings using nanoparticles in this size regime.

  20. X-ray photoelectron spectroscopy studies on Pd doped SnO{sub 2} liquid petroleum gas sensor

    SciTech Connect (OSTI)

    Phani, A.R.

    1997-10-01

    The present investigation deals with the electrical response of palladium doped tin oxide, as a means of improving the selectivity for liquid petroleum gas (LPG) in the presence of CO, CH{sub 4}. The sensor element with the composition of Pd(1.5 wt{percent}) in the base material SnO{sub 2} sintered at 800{degree}C, has shown a high sensitivity towards LPG with a negligible cross interference of CO and CH{sub 4} at an operating temperature of 350{degree}C. This greatly suggests the possibility of utilizing the sensor for the detection of LPG. X-ray photoelectron spectroscopy studies have been carried out to determine the possible chemical species involved in the gas-solid interaction and the enhancing mechanism of the Pd doped SnO{sub 2} sensor element, towards LPG sensitivity. {copyright} {ital 1997 American Institute of Physics.}

  1. Effect of chlorine on furnace wall corrosion in utility boilers

    SciTech Connect (OSTI)

    Kung, S.C.; Daniel, P.L.; Seeley, R.R.

    1996-08-01

    The corrosion resistance of several commercial alloys was investigated in laboratory retort tests under a reducing/sulfidizing mixed gas at 700 and 900 F (371 and 482 C) for 1,000 hours. The test conditions were designed to simulate the corrosion of furnace walls in the combustion zone of utility boilers burning sulfur/chlorine-bearing coal substoichiometrically. Corrosion rates of these alloys were determined and compared to those obtained from a previous study in which the same alloys were evaluated under chlorine-free substoichiometric combustion environments. Results of the two studies reveal that the presence of chlorine in the reducing/sulfidizing mixed gas has a negligible effect on the corrosion behavior of these alloys in this gas at 700 F (371 C), whereas a beneficial effect was observed at 900 F (482 C). The beneficial effect implies that the presence of HCl may impede the sulfidation attack by H{sub 2}S under certain substoichiometric combustion environments.

  2. Analytical gradients of the state-average complete active space self-consistent field method with density fitting

    SciTech Connect (OSTI)

    Delcey, Mickaël G.; Pedersen, Thomas Bondo; Aquilante, Francesco; Lindh, Roland

    2015-07-28

    An efficient implementation of the state-averaged complete active space self-consistent field (SA-CASSCF) gradients employing density fitting (DF) is presented. The DF allows a reduction both in scaling and prefactors of the different steps involved. The performance of the algorithm is demonstrated on a set of molecules ranging up to an iron-Heme b complex which with its 79 atoms and 811 basis functions is to our knowledge the largest SA-CASSCF gradient computed. For smaller systems where the conventional code could still be used as a reference, both the linear response calculation and the gradient formation showed a clear timing reduction and the overall cost of a geometry optimization is typically reduced by more than one order of magnitude while the accuracy loss is negligible.

  3. Particle Image Velocimetry Measurements and Analysis of Bypass Data for a Scaled 6mm Gap

    SciTech Connect (OSTI)

    J.R. Wolf; T.E. Conder; R.R. Schultz

    2012-09-01

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments will use optical techniques, primarily particle image velocimetry (PIV) in the INL Matched Index of Refraction (MIR) flow system.

  4. Highly Excited Baryons in Large-Nc QCD

    SciTech Connect (OSTI)

    Matagne, N.; Stancu, Fl.

    2005-06-14

    We use the 1/Nc expansion of QCD to analyse the spectrum of positive parity resonances with strangeness S = 0, -1, -2 and -3 in the 2-3 GeV mass region, supposed to belong to the [56,4+] multiplet. The mass operator is similar to that of [56,2+], previously studied in the literature. The analysis of the latter is revisited. In the [56,4+] multiplet we find that the spin-spin term brings the dominant contribution and that the spin-orbit term is entirely negligible in the hyperfine interaction, in agreement with the constituent quark model practice, where this interaction is usually neglected. More data are strongly desirable, especially in the strange sector in order to fully exploit the power of this approach. We discuss possibilities of extending the calculations to other excited baryons belonging to the N = 2 or the N = 4 band.

  5. Structural modifications due to interface chemistry at metal-nitride interfaces

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

    Yadav, S. K.; Shao, S.; Wang, J.; Liu, X. -Y.

    2015-11-27

    Based on accurate first principles density functional theory (DFT) calculations, an unusual phenomenon of interfacial structural modifications, due to the interface chemistry influence is identified at two metal-nitride interfaces with strong metal-nitrogen affinity, Al/TiN {111} and Al/VN {111} interfaces. It is shown that at such interfaces, a faulted stacking structure is energetically preferred on the Al side of the interface. And both intrinsic and extrinsic stacking fault energies in the vicinity Al layers are negligibly small. However, such phenomenon does not occur in Pt/TiN and Pt/VN interfaces because of the weak Pt-N affinity. As a result, corresponding to structural energiesmore » of metal-nitride interfaces, the linear elasticity analysis predicts characteristics of interfacial misfit dislocations at metal-nitride interfaces.« less

  6. Capacitance of a passive iron electrode in acidic solutions

    SciTech Connect (OSTI)

    Grilikhes, M.S.; Berezin, M.Yu.; Gorlin, A.V.; Sapelova, E.V.; Sokolov, M.A.; Sukhotin, A.M.

    1985-12-01

    In the present work the authors measured the capacitance of the electrical double layer on passive Armco iron in acidic solutions with the simultaneous recording of the potentiodynamic curves. The measurements were carried out on an apparatus which is based on the double-pulse variant of the galvanostatic method with a pulse lifetime of 2 microseconds, in which the influence of the faradic processes on the capacitance curves is negligibly small in the case of electrochemical systems with small exchange currents. The experiments were carried out at room temperature in 0.5 M sulfuric acid (pH 0.25) and 0.5 M tartaric acid H/sub 2/C/sub 4/H/sub 4/O/sub 6/ (pH 1.6).

  7. Probabilistic ecological risk assessment of selected PAH`s in sediments near a petroleum refinery

    SciTech Connect (OSTI)

    Arnold, W.R.; Biddinger, G.R.

    1995-12-31

    Sediment samples were collected and analyzed for a number of polynuclear aromatic hydrocarbons (PAHs) along a gradient from a petroleum refinery`s wastewater diffuser. These data were used to calculate the potential risk to aquatic organisms using probabilistic modeling and Monte Carlo sampling procedures. Sediment chemistry data were used in conjunction with estimates of Biota-Sediment Accumulation Factors and Non-Polar Narcosis Theory to predict potential risk to bivalves. Bivalves were the receptors of choice because of their lack of a well-developed enzymatic system for metabolizing PAHs. Thus, they represent a species of higher inherent risk of adverse impact. PAHs considered in this paper span a broad range of octanol-water partition coefficients. Results indicate negligible risk of narcotic effects from PAHs existing near the refinery wastewater discharge.

  8. Toward crystal design in organic conductors and superconductors.

    SciTech Connect (OSTI)

    Geiser, U.

    1999-04-23

    We have seen that many different types of intermolecular interactions in organic conducting cation radical salts. Hydrogen bonding between the donor molecules and the anions is weak but not negligible. The ionic Madelung energy is insufficient to completely intersperse anions and cations, thus the layers favored by the van der Waals interactions remain intact. The search for new conducting and superconducting salts has been mainly by trial-and-error methods, even though simple substitutions have been employed in order to obtain isostructural analogs of successful (e.g., superconducting) salts. However, even seemingly minor substitutions sometimes destroy the packing type, and different crystal structures result. Simulations with the aim at predicting crystal structures have not succeeded, mainly because the different interaction types are of comparable energy, and the delocalized and partial charges render the calculations of the ionic terms extremely unreliable. Clearly, the development of suitable crystal modeling techniques with predictive capabilities is one of the great needs of the field.

  9. Metallic heat exchangers for coal gasification

    SciTech Connect (OSTI)

    Natesan, K.

    1984-07-01

    A high-temperature corrosion program is being conducted to evaluate the corrosion behavior of selected metallic alloys and coatings in mixed-gas atmospheres for application in heat recovery systems of coal gasification schemes. The experiments conducted with internally air-cooled specimens have established three key variables, namely the gas temperature, metal temperature, and gas chemistry. In addition, the alloy chemistry and exposure time have a strong influence on the corrosion scale morphologies and metal recession rates. The results showed that the scale growth in carbon steel and low- to medium-chromium steels is predominantly linear with time. Selection of these materials will be primarily based upon acceptable corrosion wastage rate. On the other hand, high-chromium alloys can develop thin oxide scales resulting in negligible wastage via corrosion, but are susceptible to accelerated corrosion in mixed-gas atmospheres. 6 references, 12 figures, 4 tables.

  10. Metallic heat exchangers for coal gasification. Final report

    SciTech Connect (OSTI)

    Natesan, K.

    1984-05-01

    A high-temperature corrosion program is being conducted to evaluate the corrosion behavior of selected metallic alloys and coatings in mixed-gas atmospheres for application in heat recovery systems of coal gasification schemes. The experiments conducted with internally air-cooled specimens have established three key variables, namely the gas temperature, metal temperature, and gas chemistry. In addition, the alloy chemistry and exposure time have a strong influence on the corrosion scale morphologies and metal recession rates. The results showed that the scale growth in carbon steel and low- to medium-chromium steels is predominantly linear with time. Selection of these materials will be primarily based upon acceptable corrosion wastage rate. On the other hand, high-chromium alloys can develop thin oxide scales resulting in negligible wastage via corrosion, but are susceptible to accelerated corrosion in mixed-gas atmospheres.

  11. Particle-in-cell/accelerator code for space-charge dominated beam simulation

    Energy Science and Technology Software Center (OSTI)

    2012-05-08

    Warp is a multidimensional discrete-particle beam simulation program designed to be applicable where the beam space-charge is non-negligible or dominant. It is being developed in a collaboration among LLNL, LBNL and the University of Maryland. It was originally designed and optimized for heave ion fusion accelerator physics studies, but has received use in a broader range of applications, including for example laser wakefield accelerators, e-cloud studies in high enery accelerators, particle traps and other areas.more » At present it incorporates 3-D, axisymmetric (r,z) planar (x-z) and transverse slice (x,y) descriptions, with both electrostatic and electro-magnetic fields, and a beam envelope model. The code is guilt atop the Python interpreter language.« less

  12. A comment on the thermal conductivity of (U,Pu)O2 and (U,Th)O2 by molecular dynamics with adjustment for phonon-spin scattering

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

    Cooper, Michael William D.; Liu, Xiang -Yang; Stanek, Christopher Richard; Andersson, David Anders

    2016-07-15

    In this study, a new approach for adjusting molecular dynamics results on UO2 thermal conductivity to include phonon-spin scattering has been used to improve calculations on Ux Pu1–x O2 and UxTh1xO2. We demonstrate that by including spin scattering a strong asymmetry as a function of uranium actinide fraction, x, is obtained. Greater degradation is shown for UxTh1–xO2 than UxPu1-xO2. Minimum thermal conductivities are predicted at U0.97Pu0.03O2 and U0.58Th0.42O2, although the degradation in UxPu1–xO2 is negligible relative to pure UO2.

  13. Compressed air energy storage system reservoir size for a wind energy baseload power plant

    SciTech Connect (OSTI)

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload resource using an oversized wind farm in conjunction with a compressed air energy storage (CAES) system. The size of the storage reservoir for the CAES system (solution mined salt cavern or porous media) as a function of the wind speed autocorrelation time (C) has been examined using a Monte Carlo simulation for a wind class 4 (wind power density 450 W m{sup -2} at 50 m hub height) wind regime with a Weibull k factor of 2.5. For values of C typically found for winds over the US Great Plains, the storage reservoir must have a 60 to 80 hour capacity. Since underground reservoirs account for only a small fraction of total system cost, this larger storage reservoir has a negligible effect on the cost of energy from the wind energy baseload system. 7 refs., 2 figs., 1 tab.

  14. The effect of charged quantum dots on the mobility of a two-dimensional electron gas: How important is the Coulomb scattering?

    SciTech Connect (OSTI)

    Kurzmann, A. Beckel, A.; Lorke, A.; Geller, M.; Ludwig, A.; Wieck, A. D.

    2015-02-07

    We have investigated the influence of a layer of charged self-assembled quantum dots (QDs) on the mobility of a nearby two-dimensional electron gas (2DEG). Time-resolved transconductance spectroscopy was used to separate the two contributions of the change in mobility, which are: (i) The electrons in the QDs act as Coulomb scatterers for the electrons in the 2DEG. (ii) The screening ability and, hence, the mobility of the 2DEG decreases when the charge carrier density is reduced by the charged QDs, i.e., the mobility itself depends on the charge carrier concentration. Surprisingly, we find a negligible influence of the Coulomb scattering on the mobility for a 2DEG, separated by a 30 nm tunneling barrier to the layer of QDs. This means that the mobility change is completely caused by depletion, i.e., reduction of the charge carrier density in the 2DEG, which indirectly influences the mobility.

  15. van der Waals forces in density functional theory: a review of the vdW-DF method

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

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T.; Hyldgaard, Per; Lundqvist, Bengt I.

    2015-05-15

    We review a density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology. The insights that led to the construction of the Rutgers–Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only formore » dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.« less

  16. Study on LiCl waste salt treatment process by layer melt crystallization

    SciTech Connect (OSTI)

    Cho, Yung-Zun; Lee, Tae-Kyo; Choi, Jung-Hoon; Eun, Hee-Chul; Park, Hwan-Seo; Kim, In-Tae; Park, Geun-Il

    2013-07-01

    Layer melt crystallization operated in a static mode has been applied to separate Group I and II chlorides from surrogate LiCl waste salt. The effects of operating conditions such as crystal growing rate(or flux) and initial impurity concentration on separation (or concentration) of cesium, strontium and barium involved in a LiCl melts were analyzed. In a layer crystallization process, separation was impaired by occlusion of impurities and by residual melt adhering to LiCl crystal after at the end of the process. The crystal growth rate strongly affects the crystal structure, therefore the separation efficiency, while the effect of the initial Cs and Sr concentration in LiCl molten salt was nearly negligible. (authors)

  17. Method of making dense, conformal, ultra-thin cap layers for nanoporous low-k ILD by plasma assisted atomic layer deposition

    DOE Patents [OSTI]

    Jiang, Ying-Bing; Cecchi, Joseph L.; Brinker, C. Jeffrey

    2011-05-24

    Barrier layers and methods for forming barrier layers on a porous layer are provided. The methods can include chemically adsorbing a plurality of first molecules on a surface of the porous layer in a chamber and forming a first layer of the first molecules on the surface of the porous layer. A plasma can then be used to react a plurality of second molecules with the first layer of first molecules to form a first layer of a barrier layer. The barrier layers can seal the pores of the porous material, function as a diffusion barrier, be conformal, and/or have a negligible impact on the overall ILD k value of the porous material.

  18. Wind load design methods for ground-based heliostats and parabolic dish collectors

    SciTech Connect (OSTI)

    Peterka, J A; Derickson, R G

    1992-09-01

    The purpose of this design method is to define wind loads on flat heliostat and parabolic dish collectors in a simplified form. Wind loads are defined for both mean and peak loads accounting for the protective influence of upwind collectors, wind protective fences, or other wind-blockage elements. The method used to define wind loads was to generalize wind load data obtained during tests on model collectors, heliostats or parabolic dishes, placed in a modeled atmospheric wind in a boundary-layer wind-tunnel at Colorado State University. For both heliostats and parabolic dishes, loads are reported for solitary collectors and for collectors as elements of a field. All collectors were solid with negligible porosity; thus the effects of porosity in the collectors is not addressed.

  19. Structural modifications due to interface chemistry at metal-nitride interfaces

    SciTech Connect (OSTI)

    Yadav, S. K.; Shao, S.; Wang, J.; Liu, X. -Y.

    2015-11-27

    Based on accurate first principles density functional theory (DFT) calculations, an unusual phenomenon of interfacial structural modifications, due to the interface chemistry influence is identified at two metal-nitride interfaces with strong metal-nitrogen affinity, Al/TiN {111} and Al/VN {111} interfaces. It is shown that at such interfaces, a faulted stacking structure is energetically preferred on the Al side of the interface. And both intrinsic and extrinsic stacking fault energies in the vicinity Al layers are negligibly small. However, such phenomenon does not occur in Pt/TiN and Pt/VN interfaces because of the weak Pt-N affinity. As a result, corresponding to structural energies of metal-nitride interfaces, the linear elasticity analysis predicts characteristics of interfacial misfit dislocations at metal-nitride interfaces.

  20. Evaluation of two-stage system for neutron measurement aiming at increase in count rate at Japan Atomic Energy Agency-Fusion Neutronics Source

    SciTech Connect (OSTI)

    Shinohara, K. Ochiai, K.; Sukegawa, A.; Ishii, K.; Kitajima, S.; Baba, M.; Sasao, M.

    2014-11-15

    In order to increase the count rate capability of a neutron detection system as a whole, we propose a multi-stage neutron detection system. Experiments to test the effectiveness of this concept were carried out on Fusion Neutronics Source. Comparing four configurations of alignment, it was found that the influence of an anterior stage on a posterior stage was negligible for the pulse height distribution. The two-stage system using 25 mm thickness scintillator was about 1.65 times the count rate capability of a single detector system for d-D neutrons and was about 1.8 times the count rate capability for d-T neutrons. The results suggested that the concept of a multi-stage detection system will work in practice.

  1. Negative to positive magnetoresistance and magnetocaloric effect in Pr0.6Er0.4Al2

    SciTech Connect (OSTI)

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Pecharsky, V. K.

    2014-10-13

    We report on the magnetic, magnetocaloric and magnetotransport properties of Pr0.6Er0.4Al2. The title compound exhibits a large positive magnetoresistance (MR) for H ≥ 40 kOe and a small but non negligible negative MR for H ≤ 30 kOe. The maximum positive MR reaches 13% at H = 80 kOe. The magnetic entropy and adiabatic temperature changes as functions of temperature each show two anomalies: a broad dome-like maximum below 20 K and a relatively sharp peak at higher temperature. As a result, observed behaviors are unique among other binary and mixed lanthanide compounds.

  2. Measurement of tool forces in diamond turning

    SciTech Connect (OSTI)

    Drescher, J.; Dow, T.A.

    1988-12-01

    A dynamometer has been designed and built to measure forces in diamond turning. The design includes a 3-component, piezoelectric transducer. Initial experiments with this dynamometer system included verification of its predicted dynamic characteristics as well as a detailed study of cutting parameters. Many cutting experiments have been conducted on OFHC Copper and 6061-T6 Aluminum. Tests have involved investigation of velocity effects, and the effects of depth and feedrate on tool forces. Velocity has been determined to have negligible effects between 4 and 21 m/s. Forces generally increase with increasing depth of cut. Increasing feedrate does not necessarily lead to higher forces. Results suggest that a simple model may not be sufficient to describe the forces produced in the diamond turning process.

  3. Infrared Absorption Spectroscopy and Chemical Kinetics of Free Radicals, Final Technical Report

    DOE R&D Accomplishments [OSTI]

    Curl, Robert F.; Glass, Graham P.

    2004-11-01

    This research was directed at the detection, monitoring, and study of the chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. Work on the reaction of OH with acetaldehyde has been completed and published and work on the reaction of O({sup 1}D) with CH{sub 4} has been completed and submitted for publication. In the course of our investigation of branching ratios of the reactions of O({sup 1}D) with acetaldehyde and methane, we discovered that hot atom chemistry effects are not negligible at the gas pressures (13 Torr) initially used. Branching ratios of the reaction of O({sup 1}D) with CH{sub 4} have been measured at a tenfold higher He flow and fivefold higher pressure.

  4. Precision Model Independent Determination of vertical bar V{sub ub} vertical bar from B{yields}{pi}l{nu}

    SciTech Connect (OSTI)

    Arnesen, Christian M.; Stewart, Iain W.; Grinstein, Benjamin; Rothstein, Ira Z.

    2005-08-12

    A precision method for determining vertical bar V{sub ub} vertical bar using the full range in q{sup 2} of B{yields}{pi}l{nu} data is presented. At large q{sup 2} the form factor is taken from unquenched lattice QCD, at q{sup 2}=0 we impose a model independent constraint obtained from B{yields}{pi}{pi} using the soft-collinear effective theory, and the shape is constrained using QCD dispersion relations. We find vertical bar V{sub ub} vertical bar=(3.54{+-}0.17{+-}0.44)x10{sup -3}. With 5% experimental error and 12% theory error, this is competitive with inclusive methods. Theory error is dominated by the input points, with negligible uncertainty from the dispersion relations.

  5. Impact of the control rod consumption on the reactivity control of a SFR break-even core

    SciTech Connect (OSTI)

    Blanchet, D.; Fontaine, B.

    2012-07-01

    Current design studies on Sodium Fast Reactor (SFR) differ from those performed in the past by the fact that design criteria are now those of the Generation IV reactors. In order to improve their safety, reactors with break-even cores are preferred because they minimize the needs in terms of reactivity control and limit the consequences of control rod withdrawal. Furthermore, as the reactivity control needs are low, break-even core enables the use of absorbing materials with reduced efficiency (natural boron, hafnium...). Nevertheless, the use of control rods with few absorbing materials may present the disadvantage of a non-negligible ({approx}10%) loss of efficiency due to their consumption under irradiation. This paper presents a methodology to calculate accurately and analyze this consumption. (authors)

  6. A full dimensional investigation of infrared spectroscopy of the RbCs dimer using the multi-configuration time-dependent Hartree method

    SciTech Connect (OSTI)

    Wang, Huihui; Yang, Yonggang Xiao, Liantuan; Jia, Suotang

    2013-12-28

    The geometry and infrared absorption spectrum of (RbCs){sub 2} have been studied by full dimensional quantum dynamics simulations. For this purpose, the potential energy and dipole moment surfaces are generated by means of a cluster expansion with all two and three mode correlations, and fitted to analytical expressions with negligible deviations. Accordingly, the ground state (RbCs){sub 2} has a diamond geometry with D{sub 2h} symmetry. The infrared spectrum with frequencies up to 120 cm{sup −1}, exhibits rich details of the fundamentals, overtones, and combination bands; the highest fundamental frequency of (RbCs){sub 2} is only 40.26 cm{sup −1}. The present study unravels important details of the interactions between the widely investigated ultracold RbCs molecules.

  7. Molten uranium dioxide structure and dynamics

    SciTech Connect (OSTI)

    Skinner, L. B.; Parise, J. B.; Benmore, C. J.; Weber, J. K.R.; Williamson, M. A.; Tamalonis, A.; Hebden, A.; Wiencek, T.; Alderman, O. L.G.; Guthrie, M.; Leibowitz, L.

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.

  8. Spin Hall magnetoresistance in CoFe2O4/Pt films

    SciTech Connect (OSTI)

    Wu, Hao; Qintong, Zhang; Caihua, Wan; Ali, Syed Shahbaz; Yuan, Zhonghui; You, Lu; Wang, Junling; Choi, Yongseong; Han, Xiufeng

    2015-05-13

    Pulse laser deposition and magnetron sputtering techniques have been employed to prepare MgO(001)//CoFe2O4/Pt samples. Cross section transmission electron microscope results prove that the CoFe2O4 film epitaxially grew along (001) direction. X-ray magnetic circular dichroism results show that magnetic proximity effect in this sample is negligible. Magnetoresistance (MR) properties confirm that spin Hall MR (SMR) dominates in this system. Spin Hall effect-induced anomalous Hall voltage was also observed in this sample. Lastly, these results not only demonstrate the universality of SMR effect but also demonstrate the utility in spintronics of CoFe2O4 as a new type of magnetic insulator.

  9. Fatigue flaw growth assessment and inclusion of stratification to the LBB assessment

    SciTech Connect (OSTI)

    Samohyl, P.

    1997-04-01

    The application of the LBB requires also fatigue flaw growth assessment. This analysis was performed for PWR nuclear power plants types VVER 440/230, VVER 440/213c, VVER 1000/320. Respecting that these NPP`s were designed according to Russian codes that differ from US codes it was needed to compare these approaches. Comparison with our experimental data was accomplished, too. Margins of applicability of the US methods and their modifications for the materials used for construction of Czech and Slovak NPP`s are shown. Computer code accomplishing the analysis according to described method is presented. Some measurement and calculations show that thermal stratifications in horizontal pipelines can lead to additive loads that are not negligible and can be dangerous. An attempt to include these loads induced by steady-state stratification was made.

  10. Fracture properties evaluation of stainless steel piping for LBB applications

    SciTech Connect (OSTI)

    Kim, Y.J.; Seok, C.S.; Chang, Y.S.

    1997-04-01

    The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for shutdown cooling line and safety injection line of nuclear generating stations. A total of 82 tensile tests and 58 fracture toughness tests on specimens taken from actual pipes were performed and the effect of various parameters such as the pipe size, the specimen orientation, the test temperature and the welding procedure on the material properties are discussed. Test results show that the effect of the test temperature on the fracture toughness was significant while the effects of the pipe size and the specimen orientation on the fracture toughness were negligible. The material properties of the GTAW weld metal was in general higher than those of the base metal.

  11. Anomalous Hall effect in epitaxial ferrimagnetic anti-perovskite Mn{sub 4−x}Dy{sub x}N films

    SciTech Connect (OSTI)

    Meng, M.; Wu, S. X. Zhou, W. Q.; Ren, L. Z.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2015-08-07

    Anomalous Hall effect (AHE) has been studied for ferrimagnetic antiperovskite Mn{sub 4−x}Dy{sub x}N films grown by molecular-beam epitaxy. The introduction of Dy changes the AHE dramatically, even changes its sign, while the variations in magnetization are negligible. Two sign reversals of the AHE (negative-positive-negative) are ascribed to the variation of charge carriers as a result of Fermi surface reconstruction. We further demonstrate that the AHE current J{sub AH} is dissipationless (independent of the scattering rate), by confirming that anomalous Hall conductivity, σ{sub AH}, is proportional to the carrier density n at 5 K. Our study may provide a route to further utilize antiperovskite manganese nitrides in spintronics.

  12. Renormalization group flow and fixed point of the lattice topological charge in the 2D O(3) {sigma} model

    SciTech Connect (OSTI)

    DElia, M.; Farchioni, F.; Papa, A.

    1997-02-01

    We study the renormalization group evolution up to the fixed point of the lattice topological susceptibility in the 2D O(3) nonlinear {sigma} model. We start with a discretization of the continuum topological charge by a local charge density polynomial in the lattice fields. Among the different choices we propose also a Symanzik-improved lattice topological charge. We check step by step in the renormalization group iteration the progressive dumping of quantum fluctuations, which are responsible for the additive and multiplicative renormalizations of the lattice topological susceptibility with respect to the continuum definition. We find that already after three iterations these renormalizations are negligible and an excellent approximation of the fixed point is achieved. We also check by an explicit calculation that the assumption of slowly varying fields in iterating the renormalization group does not lead to a good approximation of the fixed point charge operator. {copyright} {ital 1997} {ital The American Physical Society}

  13. Sagittal focusing of synchrotron x radiation with curved crystals

    SciTech Connect (OSTI)

    Sparks, C.J. Jr.; Ice, G.E.; Wong, J.; Batterman, B.W.

    1981-01-01

    We describe the sagittal focusing of x rays with singly bent crystals that accept the meridian plane divergence from a similar but flat crystal to form a pair in a nondispersive two-crystal Bragg monochromator. Curved crystals can intercept from 5 to 20 times the sagittal divergence of curved mirrors at x-ray energies above 10 keV. Anticlastic (transverse) bending of the crystal is made negligible in the meridian plane with reinforcing ribs cut parallel to the plane of scattering. Results show that at energies of 10, 20, and 30 keV the bent crystal performs efficiently and images the source size at the Cornell High Energy Synchrotron Source.

  14. Influence of Li ions on the oxygen reduction reaction of platinum electrocatalyst

    SciTech Connect (OSTI)

    Liu, H; Xing, YC

    2011-06-01

    A Li-air battery can provide a much higher theoretical energy density than a Li-ion battery. The use of aqueous acidic electrolytes may prevent lithium oxide deposition from aprotic electrolytes and lithium carbonate precipitation from alkaline electrolytes. The present communication reports a study on the effect of Li ions on the oxygen reduction reaction (ORR) in sulfuric acid electrolytes. It was found that the Li ions have negligible interactions with the active surface of Pt catalysts. However, significantly lower ORR activities were found when Li ions are present in the sulfuric acid. The intrinsic kinetic activities were found to decrease with the increase of Li ion concentrations, but level off when the Li ion concentrations are larger than 1.0 M. The low activities of Pt catalysts in Li ion containing electrolytes were attributed to a constraining effect of Li ions on the diffusion of oxygen in the electrolyte solution. (C) 2011 Elsevier B.V. All rights reserved.

  15. Non-adiabatic perturbations in decaying vacuum cosmology

    SciTech Connect (OSTI)

    Zimdahl, W.; Fabris, J.C.; Borges, H.A.; Carneiro, S.; Hiplito-Ricaldi, W.S. E-mail: humberto@ufba.br E-mail: fabris@pq.cnpq.br

    2011-04-01

    We investigate a spatially flat Friedmann-Lematre-Robertson-Walker cosmology in which a decaying vacuum term causes matter production at late times. Assuming a decay proportional to the Hubble rate, the ratio of the background energy densities of dark matter and dark energy changes with the cosmic scale factor as a{sup ?3/2}. The intrinsically non-adiabatic two-component perturbation dynamics of this model is reduced to a single second-order equation. Perturbations of the vacuum term are shown to be negligible on scales that are relevant for structure formation. On larger scales, dark-energy perturbations give a somewhat higher contribution but remain always smaller than the dark-matter perturbations.

  16. Synergy between pair coupled cluster doubles and pair density functional theory

    SciTech Connect (OSTI)

    Garza, Alejandro J.; Bulik, Ireneusz W.; Henderson, Thomas M.; Scuseria, Gustavo E.

    2015-01-28

    Pair coupled cluster doubles (pCCD) has been recently studied as a method capable of accounting for static correlation with low polynomial cost. We present three combinations of pCCD with KohnSham functionals of the density and on-top pair density (the probability of finding two electrons on top of each other) to add dynamic correlation to pCCD without double counting. With a negligible increase in computational cost, these pCCD+DFT blends greatly improve upon pCCD in the description of typical problems where static and dynamic correlations are both important. We argue thatas a black-box method with low scaling, size-extensivity, size-consistency, and a simple quasidiagonal two-particle density matrixpCCD is an excellent match for pair density functionals in this type of fusion of multireference wavefunctions with DFT.

  17. Accelerated high-temperature tests with spent PWR and BWR fuel rods under dry storage conditions

    SciTech Connect (OSTI)

    Porsch, G.; Fleisch, J.; Heits, B.

    1986-09-01

    Accelerated high-temperature tests on 25 intact pressurized water and boiling water reactor rods were conducted for more than 16 months at 400, 430, and 450/sup 0/C in a helium gas atmosphere. The pretest characterized rods were examined by nondestructive methods after each of the three test cycles. No cladding breaches occurred and the creep deformation remained below 1%, which was in good agreement with model calculations. The test atmospheres were analyzed for /sup 85/Kr and tritium. The /sup 85/Kr concentrations were negligible and the tritium release agreed with the theoretical predictions. It can be concluded that for Zircaloy-clad fuel, cladding temperatures up to 450/sup 0/C are acceptable for dry storage in inert cover gases.

  18. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method

    SciTech Connect (OSTI)

    Qiu, Jiaqi; Zhu, Yimei; Ha, Gwanghui; Jing, Chunguang; Baryshev, Sergey V.; Reed, Bryan W.; Lau, June W.

    2015-11-10

    In this study, a device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1 GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incoming dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges.

  19. High-Definition Differential Ion Mobility Spectrometry with Resolving Power up to 500

    SciTech Connect (OSTI)

    Shvartsburg, Alexandre A.; Seim, Thomas A.; Danielson, William F.; Norheim, Randolph V.; Moore, Ronald J.; Anderson, Gordon A.; Smith, Richard D.

    2013-01-20

    As the resolution of analytical methods improve, further progress tends to be increasingly limited by instrumental parameter instabilities that could be ignored before. This is now the case with differential ion mobility spectrometry (FAIMS), where fluctuations of the voltages and gas pressure have become critical. A new high-definition generator for FAIMS compensation voltage reported here provides a stable and accurate output than can be scanned with negligible steps. This reduces the spectral drift and peak width, thus improving the resolving power (R) and resolution. The gain for multiply-charged peptides that have narrowest peaks is up to ~40%, and R ~ 400 - 500 is achievable using He/N2 or H2/N2 gas mixtures.

  20. Commissioning a passive-scattering proton therapy nozzle for accurate SOBP delivery

    SciTech Connect (OSTI)

    Engelsman, M.; Lu, H.-M.; Herrup, D.; Bussiere, M.; Kooy, H. M.

    2009-06-15

    Proton radiotherapy centers that currently use passively scattered proton beams do field specific calibrations for a non-negligible fraction of treatment fields, which is time and resource consuming. Our improved understanding of the passive scattering mode of the IBA universal nozzle, especially of the current modulation function, allowed us to re-commission our treatment control system for accurate delivery of SOBPs of any range and modulation, and to predict the output for each of these fields. We moved away from individual field calibrations to a state where continued quality assurance of SOBP field delivery is ensured by limited system-wide measurements that only require one hour per week. This manuscript reports on a protocol for generation of desired SOBPs and prediction of dose output.

  1. Nonlinear propagation of ultraintense and ultrashort laser pulses in a plasma channel limited by metallic walls

    SciTech Connect (OSTI)

    Sid, A.; Debbache, D.; Bendib, A.

    2006-08-15

    The nonlinear propagation of an ultraintense and ultrashort (UIUS) laser pulse in a metallic capillary is investigated using a classical model which takes into account the inverse bremsstrahlung absorption (IBA) in the formed plasma. The attenuation of the laser pulse due to the IBA in the plasma and to the laser energy dissipation in the metallic walls is shown. The guiding length and the twist of the laser pulse temporal envelope are presented for several values of the parameters of the plasma, the laser pulse and the metal. The numerical treatment shows that the guiding length increases when the pulse duration becomes shorter. This calculus shows also that in the case of moderate electronic densities, n{sub e}<10{sup 17} m{sup -3}, the formed plasma has a negligible effect compared to that of the metallic walls.

  2. Enhanced photoluminescence of Si nanocrystals-doped cellulose nanofibers by plasmonic light scattering

    SciTech Connect (OSTI)

    Sugimoto, Hiroshi; Zhang, Ran; Reinhard, Björn M.; Fujii, Minoru; Perotto, Giovanni; Marelli, Benedetto; Omenetto, Fiorenzo G.; Dal Negro, Luca

    2015-07-27

    We report the development of bio-compatible cellulose nanofibers doped with light emitting silicon nanocrystals and Au nanoparticles via facile electrospinning. By performing photoluminescence (PL) spectroscopy as a function of excitation wavelength, we demonstrate plasmon-enhanced PL by a factor of 2.2 with negligible non-radiative quenching due to plasmon-enhanced scattering of excitation light from Au nanoparticles to silicon nanocrystals inside the nanofibers. These findings provide an alternative approach for the development of plasmon-enhanced active systems integrated within the compact nanofiber geometry. Furthermore, bio-compatible light-emitting nanofibers prepared by a cost-effective solution-based processing are very promising platforms for biophotonic applications such as fluorescence sensing and imaging.

  3. Mode specific dynamics of the H{sub 2} + CH{sub 3} → H + CH{sub 4} reaction studied using quasi-classical trajectory and eight-dimensional quantum dynamics methods

    SciTech Connect (OSTI)

    Wang, Yan; Li, Jun; Guo, Hua E-mail: hguo@unm.edu; Chen, Liuyang; Yang, Minghui E-mail: hguo@unm.edu; Lu, Yunpeng

    2015-10-21

    An eight-dimensional quantum dynamical model is proposed and applied to the title reaction. The reaction probabilities and integral cross sections have been determined for both the ground and excited vibrational states of the two reactants. The results indicate that the H{sub 2} stretching and CH{sub 3} umbrella modes, along with the translational energy, strongly promote the reactivity, while the CH{sub 3} symmetric stretching mode has a negligible effect. The observed mode specificity is confirmed by full-dimensional quasi-classical trajectory calculations. The mode specificity can be interpreted by the recently proposed sudden vector projection model, which attributes the enhancement effects of the reactant modes to their strong couplings with the reaction coordinate at the transition state.

  4. Reduction of Carbon Monoxide. Past Research Summary

    DOE R&D Accomplishments [OSTI]

    Schrock, R. R.

    1982-01-01

    Research programs for the year on the preparation, characterization, and reactions of binuclear tantalum complexes are described. All evidence to date suggest the following of these dimeric molecules: (1) the dimer does not break into monomers under mild conditions; (2) intermolecular hydride exchange is not negligible, but it is slow; (3) intermolecular non-ionic halide exchange is fast; (4) the ends of the dimers can rotate partially with respect to one another. The binuclear tantalum hydride complexes were found to react with carbon monoxide to give a molecule which is the only example of reduction of CO by a transition metal hydride to give a complex containing a CHO ligand. Isonitrides also reacted in a similar manner with dimeric tantalum hydride. (ATT)

  5. Intumescent flame retardants for polymers. I. The poly(acrylonitrile)-ammonium polyphosphate-hexabromocyclododecane system

    SciTech Connect (OSTI)

    Ballistreri, A.; Montaudo, G.; Puglisi, C.; Scamporrino, E.; Vitalini, D.

    1983-05-01

    The influence of ammonium polyphosphate (APP) and hexabromocyclododecane (HBCD) as flame retardant (FR) on poly(acrylonitrile) (PAN) has been examined. The APP-HBCD system behaves as an intumescent flame retardant (IFR) formulation, APP being the char-forming agent and HBCD the blowing agent. A negligible gas-phase mode of action was ascertained for HBCD with this substrate. A synergism between the two FR agents was observed, corresponding to about 50% increased efficacy with respect to the separate effects of the two components. Thermogravimetry (TG), oxygen index (OI), nitrous oxide index (NOI) experiments and phosphorous residue measurements were performed to substantiate the conclusion that a condensed phase mechanism of action accounts for all the facts observed.

  6. Study of surface morphology and alignment of MWCNTs grown by chemical vapor deposition

    SciTech Connect (OSTI)

    Shukrullah, S. E-mail: noranimuti-mohamed@petronas.com.my Mohamed, N. M. E-mail: noranimuti-mohamed@petronas.com.my Shaharun, M. S. E-mail: noranimuti-mohamed@petronas.com.my; Yasar, M.

    2014-10-24

    In this research work, Multiwalled Carbon Nanotubes (MWCNTs) have been synthesized successfully by using floating catalytic chemical vapor deposition (FCCVD) method. Different ferrocene amounts (0.1, 0.125 and 0.15 g) were used as catalyst and ethylene was used as a carbon precursor at reaction temperature of 800°C. Characterization of the grown MWCNTs was carried out by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained data showed that the catalyst weight affects the nanotubes diameter, alignment, crystallinity and growth significantly, whereas negligible influence was noticed on CNTs forest length. The dense, uniform and meadow like patterns of grown CNTs were observed for 0.15 g ferrocene. The average diameter of the grown CNTs was found in the range of 32 to 75 nm. Close inspection of the TEM images also confirmed the defects in some of the grown CNTs, where few black spots were evident in CNTs structure.

  7. Graphene-enhanced intermolecular interaction at interface between copper- and cobalt-phthalocyanines

    SciTech Connect (OSTI)

    Dou, Wei-Dong; Huang, Shu-Ping; Lee, Chun-Sing

    2015-10-07

    Interfacial electronic structures of copper-phthalocyanine (CuPc), cobalt-phthalocyanine (CoPc), and graphene were investigated experimentally by using photoelectron spectroscopy. While the CuPc/graphene interface shows flat band structure and negligible interfacial dipole indicating quite weak molecule-substrate interaction, the CuPc/CoPc/graphene interface shows a large interfacial dipole and obvious energy level bending. Controlled experiments ruled out possible influences from the change in film structure of CuPc and pure π–π interaction between CoPc and CuPc. Analysis based on X-ray photoelectron spectroscopy and density functional theory reveals that the decrease in the work function for the CuPc/CoPc/graphene system is induced by the intermolecular interaction between CuPc and CoPc which is enhanced owning to the peculiar electronic properties at the CoPc-graphene interface.

  8. Cr/sup 3 +/-doped colquiriite solid state laser material

    DOE Patents [OSTI]

    Payne, S.A.; Chase, L.L.; Newkirk, H.W.; Krupke, W.F.

    1988-03-31

    Chromium doped colquiriite, LiCaAlF/sub 6/:Cr/sup 3 +/, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr/sup 3 +/ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slope efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd/sup 3 +/ or Tm/sup 3 +/ for use in a multimegajoule single shot fusion research facility. 4 figs.

  9. Cr.sup.3+ -doped colquiriite solid state laser material

    DOE Patents [OSTI]

    Payne, Stephen A.; Chase, Lloyd L.; Newkirk, Herbert W.; Krupke, William F.

    1989-01-01

    Chromium doped colquiriite, LiCaAlF.sub.6 :Cr.sup.3+, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr.sup.3+ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slop efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd.sup.3+ or Tm.sup.3+ for use in a multimegajoule single shot fusion research facility.

  10. Dominance of interface chemistry over the bulk properties in determining the electronic structure of epitaxial metal/perovskite oxide heterojunctions

    SciTech Connect (OSTI)

    Chambers, Scott A.; Du, Yingge; Gu, Meng; Droubay, Timothy C.; Hepplestone, Steven; Sushko, Petr

    2015-06-09

    We show that despite very similar crystallographic properties and work function values in the bulk, epitaxial Fe and Cr metallizations on Nb:SrTiO3(001) generate completely different heterojunction electronic properties. Cr is Ohmic whereas Fe forms a Schottky barrier with a barrier height of 0.50 eV. This contrast arises because of differences in interface chemistry. In contrast to Cr [Chambers, S. A. et al., Adv. Mater. 2013, 25, 4001.], Fe exhibits a +2 oxidation state and occupies Ti sites in the perovskite lattice, resulting in negligible charge transfer to Ti, upward band bending, and Schottky barrier formation. The differences between Cr and Fe are understood by performing first-principles calculations of the energetics of defect formation which corroborate the observed interface chemistry and structure.