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Sample records for minimum gap runner

  1. Development of a more fish tolerant turbine runner advanced hydropower turbine project. Final report

    SciTech Connect (OSTI)

    Cook, T.C.; Hecker, G.E.; Faulkner, H.B.; Jansen, W.

    1997-01-01

    The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. Flow characteristics of the new runner were analyzed using two- dimensional and three-dimensional Computational Fluid Dynamic (CFD) models. The basic runner geometry was initially selected using the two-dimensional model. The three-dimensional model was used to investigate the flow characteristics in detail through the entire runner and to refine the design by eliminating potential problem areas at the leading and trailing edges. Results of the analyses indicated that the runner has characteristics which should provide safe fish passage with an overall power efficiency of approximately 90%. The size of the new runner, which is larger than conventional turbine runners with the same design flow and head, will provide engineering, fabrication, and installation.challenges related to the turbine components and the civil works. A small reduction in the overall efficiency would reduce the size of the runner considerably, would simplify the turbine manufacturing operations, and would allow installation of the new turbine at more hydroelectric sites.

  2. Final Reports on the Top Runner Target Product Standards (Japan...

    Open Energy Info (EERE)

    Reports on the Top Runner Target Product Standards (Japan) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Final Reports on the Top Runner Target Product Standards...

  3. GAP | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    GAP

  4. New runners to boost peak output at Niagara Falls

    SciTech Connect (OSTI)

    Reason, J.

    1990-01-01

    Retrofitted Francis turbines will improve the value of power generated from Niagara Falls by increasing the peak output of the hydroturbine units at the Robert Moses hydroelectric plant. The computer-designed runners are expected to add 330 MW to the peak capacity of the 28-yr-old plant and significantly increase the efficiency at high flow rates. Next year, the first new runner will be retrofit to the highly instrumented Unit 4. If the retrofit unit meets it increased-performance expectations, the other 12 units will be upgraded between 1993 and 1998. The work is part of an overall expansion of the Niagara Power Project designed to made better use of the power value of Niagara river water, within the constraints of a treaty with Canada and the scenic value of the falls. These constraints, together with varying flows and heads, introduced enormous complexities into the selection and design of the new runners. The alterations being made to Unit 4, in addition to replacing the turbine runner, include modifying the draft tube-liners, increasing the wicket-gate stroke, replacing the turbine discharge ring (to accommodate longer blades), making various electrical modifications to the generator, and replacing the transformer. But the key to the retrofit is the computer-designed runner. Charles Grose, senior project manager, New York Power Authority, White Plains, NY, emphasizes that such computer design techniques were not available a few years ago; neither were the computer-controlled machining techniques necessary to manufacture the new runners. Other aspects of the upgrading that were analyzed include runner stability, resonance, shaft torsional stress, and runaway speed.

  5. Concentration of Ca in blood of amateur runners using NAA

    SciTech Connect (OSTI)

    Kovacs, L.; Zamboni, C. B.; Metairon, S.; Nunes, L. A. S.; Lourenco, T. F.; Macedo, D. V.

    2013-05-06

    In this study the Ca levels were determined in amateur runners blood at LABEX (Laboratorio de Bioquimica do Exercicio - UNICAMP, Brazil), using Neutron Activation Analyses (NAA) technique. The range established at rest (162 - 410 mgL{sup -1}) when compared with control group (51 - 439 mgL{sup -1}) suggests that there is a dependency of these limits in the function of the adopted physical training.

  6. Webinar: America's Next Top Energy Innovator Runner-Up Presents Hydrogen

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

    Detection Technologies | Department of Energy America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies Webinar: America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies Below is the text version of the webinar titled "America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technology," originally presented on April 3, 2012. In addition to this text version of the audio, you can access the presentation

  7. Gap Resolution

    Energy Science and Technology Software Center (OSTI)

    2009-06-16

    With the continued improvements of next generation DNA sequencing technologies and their advantages over traditional Sanger sequencing, the Joint Genome Institute (JGI) has modified its sequencing pipeline to take advantage of the benefits of such technologies. Currently, standard 454 Titanium, paired end 454 Titanium, and Illumina GAll data are generated for all microbial projects and then assembled using draft assemblies at a much greater throughput than before. However, it also presents us with new challenges.more » In addition to the increased throughput, we also have to deal with a larger number of gaps in the Newbler genome assemblies. Gaps in these assemblies are usually caused by repeats (Newbler collapses repeat copies into individual contigs, thus creating gaps), strong secondary structures, and artifacts of the PCR process (specific to 454 paired end libraries). Some gaps in draft assemblies can be resolved merely by adding back the collapsed data from repeats. To expedite gap closure and assembly improvement on large numbers of these assemblies, we developed software to address this issue.« less

  8. Cross-sectional relationships of exercise and age to adiposity in60,617 male runners

    SciTech Connect (OSTI)

    Williams, Paul T.; Pate, Russell R.

    2004-06-01

    The objective of this report is to assess in men whether exercise affects the estimated age-related increase in adiposity, and contrariwise, whether age affects the estimated exercise-related decrease in adiposity. Cross-sectional analyses of 64,911 male runners who provided data on their body mass index (97.6 percent), waist (91.1 percent), hip (47.1 percent), and chest circumferences (77.9 percent). Between 18 to 55 years old, the decline in BMI with weekly distance run (slope+-SE) was significantly greater in men 25-55 years old (slope+-:-0.036+-0.001 kg/m2 per km/wk) than in younger men (-0.020+-0.002 kg/m 2 per km/wk). Declines in waist circumference with running distance were also significantly greater in older than younger men (P<10-9 for trend),i.e., the slopes decreased progressively from -0.035+-0.004 cm per km/wk in 18-25 year old men to -0.097+-0.003 cm per km/wk in 50-55 year old men. Increases in BMI with age were greater for men who ran under 16km/wk than for longer distance runners. Waist circumference increased with age at all running levels, but the increase appeared to diminish by running further (0.259+-0.015 cm per year if running<8 km/wk and 0.154+-0.003 cm per year for>16 km/wk). In men over 50 years old, BMI declined -0.038+-0.001 kg/m2 per km/wk run when adjusted for age and declined -0.054+-0.003 kg/m2 (increased 0.021+-0.007 cm) per year of age when adjusted for running distance. Their waist circumference declined-0.096+-0.002 cm per km/wk run when adjusted for age and increased 0.021+-0.007 cm per year of age when adjusted for running distance. These cross-sectional data suggest that age and vigorous exercise interact with each other in affecting mens adiposity, and support the proposition that vigorous physical activity must increase with age to prevent middle-age weight gain. We estimate that a man who ran 16 km/wk at age 25 would need to increase their weekly running distance by 65.7 km/wk by age 50 in order to maintain his same waist circumference.

  9. SPARK GAP SWITCH

    DOE Patents [OSTI]

    Neal, R.B.

    1957-12-17

    An improved triggered spark gap switch is described, capable of precisely controllable firing time while switching very large amounts of power. The invention in general comprises three electrodes adjustably spaced and adapted to have a large potential impressed between the outer electrodes. The central electrode includes two separate elements electrically connected togetaer and spaced apart to define a pair of spark gaps between the end electrodes. Means are provided to cause the gas flow in the switch to pass towards the central electrode, through a passage in each separate element, and out an exit disposed between the two separate central electrode elements in order to withdraw ions from the spark gap.

  10. Japan's Residential Energy Demand Outlook to 2030 Considering Energy Efficiency Standards"Top-Runner Approach"

    SciTech Connect (OSTI)

    Lacommare, Kristina S H; Komiyama, Ryoichi; Marnay, Chris

    2008-05-15

    As one of the measures to achieve the reduction in greenhouse gas emissions agreed to in the"Kyoto Protocol," an institutional scheme for determining energy efficiency standards for energy-consuming appliances, called the"Top-Runner Approach," was developed by the Japanese government. Its goal is to strengthen the legal underpinnings of various energy conservation measures. Particularly in Japan's residential sector, where energy demand has grown vigorously so far, this efficiency standard is expected to play a key role in mitigating both energy demand growth and the associated CO2 emissions. This paper presents an outlook of Japan's residential energy demand, developed by a stochastic econometric model for the purpose of analyzing the impacts of the Japan's energy efficiency standards, as well as the future stochastic behavior of income growth, demography, energy prices, and climate on the future energy demand growth to 2030. In this analysis, we attempt to explicitly take into consideration more than 30 kinds of electricity uses, heating, cooling and hot water appliances in order to comprehensively capture the progress of energy efficiency in residential energy end-use equipment. Since electricity demand, is projected to exhibit astonishing growth in Japan's residential sector due to universal increasing ownership of electric and other appliances, it is important to implement an elaborate efficiency standards policy for these appliances.

  11. Fiber optic gap gauge

    DOE Patents [OSTI]

    Wood, Billy E.; Groves, Scott E.; Larsen, Greg J.; Sanchez, Roberto J.

    2006-11-14

    A lightweight, small size, high sensitivity gauge for indirectly measuring displacement or absolute gap width by measuring axial strain in an orthogonal direction to the displacement/gap width. The gap gauge includes a preferably titanium base having a central tension bar with springs connecting opposite ends of the tension bar to a pair of end connector bars, and an elongated bow spring connected to the end connector bars with a middle section bowed away from the base to define a gap. The bow spring is capable of producing an axial strain in the base proportional to a displacement of the middle section in a direction orthogonal to the base. And a strain sensor, such as a Fabry-Perot interferometer strain sensor, is connected to measure the axial strain in the base, so that the displacement of the middle section may be indirectly determined from the measurement of the axial strain in the base.

  12. GMTI radar minimum detectable velocity.

    SciTech Connect (OSTI)

    Richards, John Alfred

    2011-04-01

    Minimum detectable velocity (MDV) is a fundamental consideration for the design, implementation, and exploitation of ground moving-target indication (GMTI) radar imaging modes. All single-phase-center air-to-ground radars are characterized by an MDV, or a minimum radial velocity below which motion of a discrete nonstationary target is indistinguishable from the relative motion between the platform and the ground. Targets with radial velocities less than MDV are typically overwhelmed by endoclutter ground returns, and are thus not generally detectable. Targets with radial velocities greater than MDV typically produce distinct returns falling outside of the endoclutter ground returns, and are thus generally discernible using straightforward detection algorithms. This document provides a straightforward derivation of MDV for an air-to-ground single-phase-center GMTI radar operating in an arbitrary geometry.

  13. Precision gap particle separator

    DOE Patents [OSTI]

    Benett, William J.; Miles, Robin; Jones, II., Leslie M.; Stockton, Cheryl

    2004-06-08

    A system for separating particles entrained in a fluid includes a base with a first channel and a second channel. A precision gap connects the first channel and the second channel. The precision gap is of a size that allows small particles to pass from the first channel into the second channel and prevents large particles from the first channel into the second channel. A cover is positioned over the base unit, the first channel, the precision gap, and the second channel. An port directs the fluid containing the entrained particles into the first channel. An output port directs the large particles out of the first channel. A port connected to the second channel directs the small particles out of the second channel.

  14. MULTIPLE SPARK GAP SWITCH

    DOE Patents [OSTI]

    Schofield, A.E.

    1958-07-22

    A multiple spark gap switch of unique construction is described which will permit controlled, simultaneous discharge of several capacitors into a load. The switch construction includes a disc electrode with a plurality of protuberances of generally convex shape on one surface. A firing electrode is insulatingly supponted In each of the electrode protuberances and extends substantially to the apex thereof. Individual electrodes are disposed on an insulating plate parallel with the disc electrode to form a number of spark gaps with the protuberances. These electrodes are each connected to a separate charged capacitor and when a voltage ls applied simultaneously between the trigger electrodes and the dlsc electrode, each spark gap fires to connect its capacitor to the disc electrode and a subsequent load.

  15. Multiple gap photovoltaic device

    DOE Patents [OSTI]

    Dalal, Vikram L.

    1981-01-01

    A multiple gap photovoltaic device having a transparent electrical contact adjacent a first cell which in turn is adjacent a second cell on an opaque electrical contact, includes utilizing an amorphous semiconductor as the first cell and a crystalline semiconductor as the second cell.

  16. HEAT Loan Minimum Standards and Requirements

    Broader source: Energy.gov [DOE]

    Presents additional resources on loan standards and requirements from Elise Avers' presentation on HEAT Loan Minimum Standards and Requirements.

  17. Minimum Day Time Load Calculation and Screening

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

    ... DPU 36 Supplemental Review Screens * Penetration screen (Minimum load screen) * Power quality and voltage screen * Safety and reliability screen 37 Federal Energy Regulatory ...

  18. An estimate for the sum of a Dirichlet series in terms of the minimum of its modulus on a vertical line segment

    SciTech Connect (OSTI)

    Gaisin, Ahtyar M; Rakhmatullina, Zhanna G

    2011-12-31

    The behaviour of the sum of an entire Dirichlet series is analyzed in terms of the minimum of its modulus on a system of vertical line segments. Also a more general problem, connected with the Polya conjecture is posed and solved. It concerns the minimum modulus of an entire function with Fabri gaps and its growth along curves going to infinity. Bibliography: 33 titles.

  19. Gap and stripline combined monitor

    DOE Patents [OSTI]

    Yin, Y.

    1986-08-19

    A combined gap and stripline monitor device for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchrotron radiation facility is disclosed. The monitor has first and second beam pipe portions with an axial gap therebetween. An outer pipe cooperates with the first beam pipe portion to form a gap enclosure, while inner strips cooperate with the first beam pipe portion to form a stripline monitor, with the stripline length being the same as the gap enclosure length. 4 figs.

  20. Axial gap rotating electrical machine

    DOE Patents [OSTI]

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  1. Gap and stripline combined monitor

    DOE Patents [OSTI]

    Yin, Y.

    1984-02-16

    A combined gap and stripline monitor device for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchrotron radiation facility. The monitor has first and second beam pipe portions with an axial gap therebetween. An outer pipe cooperates with the first beam pipe portion to form a gap enclosure, while inner strips cooperate with the first beam pipe portion to form a stripline monitor, with the stripline length being the same as the gap enclosure length.

  2. Gap and stripline combined monitor

    DOE Patents [OSTI]

    Yin, Yan

    1986-01-01

    A combined gap and stripline monitor device (10) for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchotron radiation facility. The monitor has first and second beam pipe portions (11a, 11b) with an axial gap (12) therebetween. An outer pipe (14) cooperates with the first beam pipe portion (11a) to form a gap enclosure, while inner strips (23a-d) cooperate with the first beam pipe portion (11a) to form a stripline monitor, with the stripline length being the same as the gap enclosure length.

  3. FAQS Gap Analysis Qualification Card - Chemical Processing |...

    Office of Environmental Management (EM)

    Chemical Processing FAQS Gap Analysis Qualification Card - Chemical Processing Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences ...

  4. HEAT Loan Minimum Standards and Requirements

    Energy Savers [EERE]

    you must meet the following minimum standards listed below. * New natural gas or propane boilers must be at least 90% AFUE to be eligible. * New oil boilers must be at least...

  5. Pneumatic gap sensor and method

    DOE Patents [OSTI]

    Bagdal, Karl T.; King, Edward L.; Follstaedt, Donald W.

    1992-01-01

    An apparatus and method for monitoring and maintaining a predetermined width in the gap between a casting nozzle and a casting wheel, wherein the gap is monitored by means of at least one pneumatic gap sensor. The pneumatic gap sensor is mounted on the casting nozzle in proximity to the casting surface and is connected by means of a tube to a regulator and a transducer. The regulator provides a flow of gas through a restictor to the pneumatic gap sensor, and the transducer translates the changes in the gas pressure caused by the proximity of the casting wheel to the pneumatic gap sensor outlet into a signal intelligible to a control device. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. The apparatus and method enables accurate monitoring of the actual casting gap in a simple and reliable manner resistant to the extreme temperatures and otherwise hostile casting environment.

  6. Pneumatic gap sensor and method

    DOE Patents [OSTI]

    Bagdal, K.T.; King, E.L.; Follstaedt, D.W.

    1992-03-03

    An apparatus and method for monitoring and maintaining a predetermined width in the gap between a casting nozzle and a casting wheel, wherein the gap is monitored by means of at least one pneumatic gap sensor. The pneumatic gap sensor is mounted on the casting nozzle in proximity to the casting surface and is connected by means of a tube to a regulator and a transducer. The regulator provides a flow of gas through a restictor to the pneumatic gap sensor, and the transducer translates the changes in the gas pressure caused by the proximity of the casting wheel to the pneumatic gap sensor outlet into a signal intelligible to a control device. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. The apparatus and method enables accurate monitoring of the actual casting gap in a simple and reliable manner resistant to the extreme temperatures and otherwise hostile casting environment. 6 figs.

  7. Outrunning major weight gain: a prospective study of 8,340consistent runners during 7 years of follow-up

    SciTech Connect (OSTI)

    Williams, Paul T.

    2006-01-06

    Background: Body weight increases with aging. Short-term,longitudinal exercise training studies suggest that increasing exerciseproduces acute weight loss, but it is not clear if the maintenance oflong-term, vigorous exercise attenuates age-related weight gain inproportion to the exercise dose. Methods: Prospective study of 6,119 maleand 2,221 female runners whose running distance changed less than 5 km/wkbetween their baseline and follow-up survey 7 years later. Results: Onaverage, men who ran modest (0-24 km/wk), intermediate (24-48 km/wk) orprolonged distances (>_48 km/wk) all gained weight throughage 64,however, those who ran ?48 km/wk had one-half the average annual weightgain of those who ran<24 km/wk. Age-related weight gain, and itsreduction by running, were both greater in younger than older men. Incontrast, men s gain in waist circumference with age, and its reductionby running, were the same in older and younger men. Women increased theirbody weight and waist and hip circumferences over time, regardless ofage, which was also reduced in proportion to running distance. In bothsexes, running did not attenuate weight gain uniformly, but ratherdisproportionately prevented more extreme increases. Conclusion: Men andwomen who remain vigorously active gain less weight as they age and thereduction is in proportion to the exercise dose.

  8. Bridging Gaps | Department of Energy

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

    Bridging Gaps Bridging Gaps Analysis to identify issues, best practices, and recommendations Implementation of modernization, infrastructure planning, and sustainability efforts Evaluation of planning practices to develop an adaptable method that considers revitalization and reuse Analysis of issues with transfers at less than fair market value and recommendations for improvement Evaluation of the Ten-Year (25-year) Site Plans for revitalization and strategic planning interests Tools to be

  9. Eight electrode optical readout gap

    DOE Patents [OSTI]

    Boettcher, G.E.; Crain, R.W.

    1984-01-01

    A protective device for a plurality of electrical circuits includes a plurality of isolated electrodes forming a gap with a common electrode. An output signal, electrically isolated from the circuits being monitored, is obtained by a photosensor viewing the discharge gap through an optical window. Radioactive stabilization of discharge characteristics is provided for slowly changing voltages and carbon tipped dynamic starters provide desirable discharge characteristics for rapidly varying voltages. A hydrogen permeation barrier is provided on external surfaces of the device.

  10. Eight electrode optical readout gap

    DOE Patents [OSTI]

    Boettcher, Gordon E.; Crain, Robert W.

    1985-01-01

    A protective device for a plurality of electrical circuits includes a pluity of isolated electrodes forming a gap with a common electrode. An output signal, electrically isolated from the circuits being monitored, is obtained by a photosensor viewing the discharge gap through an optical window. Radioactive stabilization of discharge characteristics is provided for slowly changing voltages and carbon tipped dynamic starters provide desirable discharge characteristics for rapidly varying voltages. A hydrogen permeation barrier is provided on external surfaces of the device.

  11. DOE CYBER SECURITY EBK: MINIMUM CORE COMPETENCY TRAINING REQUIREMENTS...

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

    CYBER SECURITY EBK: MINIMUM CORE COMPETENCY TRAINING REQUIREMENTS DOE CYBER SECURITY EBK: MINIMUM CORE COMPETENCY TRAINING REQUIREMENTS puzzle-693870960720.jpg PDF icon DOE CYBER ...

  12. ITP Steel: Theoretical Minimum Energies to Produce Steel for...

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

    Theoretical Minimum Energies to Produce Steel for Selected Conditions, March 2000 ITP Steel: Theoretical Minimum Energies to Produce Steel for Selected Conditions, March 2000 PDF ...

  13. HEAT Loan Minimum Standards and Requirements | Department of...

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

    Presents additional resources on loan standards and requirements from Elise Avers' presentation on HEAT Loan Minimum Standards and Requirements. PDF icon Minimum Standards and ...

  14. Virtual gap dielectric wall accelerator

    DOE Patents [OSTI]

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  15. Minimum Day Time Load Calculation and Screening

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

    Minimum Day Time Load Calculation and Screening" Dora Nakafuji and Anthony Hong, Hawaiian Electric Co. Babak Enayati, DG Techincal Standards Review Group April 30, 2014 2 Speakers Babak Enayati Chair of Massachusetts DG Technical Standards Review Group Dora Nakafuji Director of Renewable Energy Planning Hawaiian Electric Company (HECO) Kristen Ardani Solar Analyst, (today's moderator) NREL Anthony Hong Director of Distribution Planning Hawaiian Electric Company (HECO) Standardization of

  16. Multiple input electrode gap controller

    DOE Patents [OSTI]

    Hysinger, Christopher L.; Beaman, Joseph J.; Melgaard, David K.; Williamson, Rodney L.

    1999-01-01

    A method and apparatus for controlling vacuum arc remelting (VAR) furnaces by estimation of electrode gap based on a plurality of secondary estimates derived from furnace outputs. The estimation is preferably performed by Kalman filter. Adaptive gain techniques may be employed, as well as detection of process anomalies such as glows.

  17. Multiple input electrode gap controller

    DOE Patents [OSTI]

    Hysinger, C.L.; Beaman, J.J.; Melgaard, D.K.; Williamson, R.L.

    1999-07-27

    A method and apparatus for controlling vacuum arc remelting (VAR) furnaces by estimation of electrode gap based on a plurality of secondary estimates derived from furnace outputs. The estimation is preferably performed by Kalman filter. Adaptive gain techniques may be employed, as well as detection of process anomalies such as glows. 17 figs.

  18. Air Gap Effects in LX-17

    SciTech Connect (OSTI)

    Souers, P C; Ault, S; Avara, R; Bahl, K L; Boat, R; Cunningham, B; Gidding, D; Janzen, J; Kuklo, D; Lee, R; Lauderbach, L; Weingart, W C; Wu, B; Winer, K

    2005-09-26

    Three experiments done over twenty years on gaps in LX-17 are reported. For the detonation front moving parallel to the gaps, jets of gas products were seen coming from the gaps at velocities greater than the detonation velocity. A case can be made that the jet velocity increased with gap thickness but the data is scattered. For the detonation front moving transverse to the gap, time delays were seen. The delays roughly increase with gap width, going from 0-70 ns at 'zero gap' to around 300 ns at 0.5-1 mm gap. Larger gaps of up to 6 mm width almost certainly stopped the detonation, but this was not proved. Real-time resolution of the parallel jets and determination of the actual re-detonation or failure in the transverse case needs to be done in future experiments.

  19. Electronic gap sensor and method

    DOE Patents [OSTI]

    Williams, Robert S.; King, Edward L.; Campbell, Steven L.

    1991-01-01

    An apparatus and method for regulating the gap between a casting nozzle and a casting wheel in which the gap between the casting nozzle and the casting wheel is monitored by means of at least one sensing element protruding from the face of the casting nozzle. The sensing element is preferably connected to a voltage source and the casting wheel grounded. When the sensing element contacts the casting wheel, an electric circuit is completed. The completion of the circuit can be registered by an indicator, and the presence or absence of a completed circuit indicates the relative position of the casting nozzle to the casting wheel. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces.

  20. Electronic gap sensor and method

    DOE Patents [OSTI]

    Williams, R.S.; King, E.L.; Campbell, S.L.

    1991-08-06

    Disclosed are an apparatus and method for regulating the gap between a casting nozzle and a casting wheel in which the gap between the casting nozzle and the casting wheel is monitored by means of at least one sensing element protruding from the face of the casting nozzle. The sensing element is preferably connected to a voltage source and the casting wheel grounded. When the sensing element contacts the casting wheel, an electric circuit is completed. The completion of the circuit can be registered by an indicator, and the presence or absence of a completed circuit indicates the relative position of the casting nozzle to the casting wheel. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. 5 figures.

  1. Closed Gap Enzen | Open Energy Information

    Open Energy Info (EERE)

    search Name: Closed Gap-Enzen Place: Bangalore, India Zip: 560 052 Product: Formed as a joint venture, Closed Gap-Enzen provides a new integrated meter enabling seamless customer...

  2. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, Gerald J.; Roose, Lars D.

    1996-01-01

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.

  3. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, G.J.; Roose, L.D.

    1996-04-23

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed. 13 figs.

  4. Minimum wear tube support hole design

    DOE Patents [OSTI]

    Glatthorn, Raymond H. (St. Petersburg, FL)

    1986-01-01

    A minimum-wear through-bore (16) is defined within a heat exchanger tube support plate (14) so as to have an hourglass configuration as determined by means of a constant radiused surface curvature (18) as defined by means of an external radius (R3), wherein the surface (18) extends between the upper surface (20) and lower surface (22) of the tube support plate (14). When a heat exchange tube (12) is disposed within the tube support plate (14) so as to pass through the through-bore (16), the heat exchange tube (12) is always in contact with a smoothly curved or radiused portion of the through-bore surface (16) whereby unacceptably excessive wear upon the heat exchange tube (12), as normally developed by means of sharp edges, lands, ridges, or the like conventionally part of the tube support plates, is eliminated or substantially reduced.

  5. Calibration curves for some standard Gap Tests

    SciTech Connect (OSTI)

    Bowman, A.L.; Sommer, S.C.

    1989-01-01

    The relative shock sensitivities of explosive compositions are commonly assessed using a family of experiments that can be described by the generic term ''Gap Test.'' Gap tests include a donor charge, a test sample, and a spacer, or gap, between two explosives charges. The donor charge, gap material, and test dimensions are held constant within each different version of the gap test. The thickness of the gap is then varied to find the value at which 50% of the test samples will detonate. The gap tests measure the ease with a high-order detonation can be established in the test explosive, or the ''detonability,'' of the explosive. Test results are best reported in terms of the gap thickness at the 50% point. It is also useful to define the shock pressure transmitted into the test sample at the detonation threshold. This requires calibrating the gap test in terms of shock pressure in the gap as a function of the gap thickness. It also requires a knowledge of the shock Hugoniot of the sample explosive. We used the 2DE reactive hydrodynamic code with Forest Fire burn rates for the donor explosives to calculate calibration curves for several gap tests. The model calculations give pressure and particle velocity on the centerline of the experimental set-up and provide information about the curvature and pulse width of the shock wave. 10 refs., 1 fig.

  6. Photonic band gap structure simulator

    DOE Patents [OSTI]

    Chen, Chiping; Shapiro, Michael A.; Smirnova, Evgenya I.; Temkin, Richard J.; Sirigiri, Jagadishwar R.

    2006-10-03

    A system and method for designing photonic band gap structures. The system and method provide a user with the capability to produce a model of a two-dimensional array of conductors corresponding to a unit cell. The model involves a linear equation. Boundary conditions representative of conditions at the boundary of the unit cell are applied to a solution of the Helmholtz equation defined for the unit cell. The linear equation can be approximated by a Hermitian matrix. An eigenvalue of the Helmholtz equation is calculated. One computation approach involves calculating finite differences. The model can include a symmetry element, such as a center of inversion, a rotation axis, and a mirror plane. A graphical user interface is provided for the user's convenience. A display is provided to display to a user the calculated eigenvalue, corresponding to a photonic energy level in the Brilloin zone of the unit cell.

  7. Gap Assessment (FY 13 Update)

    SciTech Connect (OSTI)

    Getman, Dan

    2013-09-30

    To help guide its future data collection efforts, The DOE GTO funded a data gap analysis in FY2012 to identify high potential hydrothermal areas where critical data are needed. This analysis was updated in FY2013 and the resulting datasets are represented by this metadata. The original process was published in FY 2012 and is available here: https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2013/Esposito.pdf Though there are many types of data that can be used for hydrothermal exploration, five types of exploration data were targeted for this analysis. These data types were selected for their regional reconnaissance potential, and include many of the primary exploration techniques currently used by the geothermal industry. The data types include: 1. well data 2. geologic maps 3. fault maps 4. geochemistry data 5. geophysical data To determine data coverage, metadata for exploration data (including data type, data status, and coverage information) were collected and catalogued from nodes on the National Geothermal Data System (NGDS). It is the intention of this analysis that the data be updated from this source in a semi-automated fashion as new datasets are added to the NGDS nodes. In addition to this upload, an online tool was developed to allow all geothermal data providers to access this assessment and to directly add metadata themselves and view the results of the analysis via maps of data coverage in Geothermal Prospector (http://maps.nrel.gov/gt_prospector). A grid of the contiguous U.S. was created with 88,000 10-km by 10-km grid cells, and each cell was populated with the status of data availability corresponding to the five data types. Using these five data coverage maps and the USGS Resource Potential Map, sites were identified for future data collection efforts. These sites signify both that the USGS has indicated high favorability of occurrence of geothermal resources and that data gaps exist. The uploaded data are contained in two data files for each data category. The first file contains the grid and is in the SHP file format (shape file.) Each populated grid cell represents a 10k area within which data is known to exist. The second file is a CSV (comma separated value) file that contains all of the individual layers that intersected with the grid. This CSV can be joined with the map to retrieve a list of datasets that are available at any given site. The attributes in the CSV include: 1. grid_id : The id of the grid cell that the data intersects with 2. title: This represents the name of the WFS service that intersected with this grid cell 3. abstract: This represents the description of the WFS service that intersected with this grid cell 4. gap_type: This represents the category of data availability that these data fall within. As the current processing is pulling data from NGDS, this category universally represents data that are available in the NGDS and are ready for acquisition for analytic purposes. 5. proprietary_type: Whether the data are considered proprietary 6. service_type: The type of service 7. base_url: The service URL

  8. Gap between active and passive solar heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  9. ITP Steel: Theoretical Minimum Energies to Produce Steel for Selected

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

    Conditions, March 2000 | Department of Energy Theoretical Minimum Energies to Produce Steel for Selected Conditions, March 2000 ITP Steel: Theoretical Minimum Energies to Produce Steel for Selected Conditions, March 2000 PDF icon theoretical_minimum_energies.pdf More Documents & Publications Ironmaking Process Alternatives Screening Study ITP Steel: Steel Industry Marginal Opportunity Study September 2005 ITP Steel: Steel Industry Energy Bandwidth Study October 2004

  10. FAQS Gap Analysis Qualification Card Emergency Management

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  11. FAQS Gap Analysis Qualification Card- Quality Assurance

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  12. Hydrothermal Exploration Data Gap Analysis Update

    Broader source: Energy.gov [DOE]

    Hydrothermal Exploration Data Gap Analysis presentation by Kate Young, Dan Getman, and Ariel Esposito at the 2012 Peer Review Meeting on May 10, 2012

  13. Minimum Efficiency Requirements Tables for Heating and Cooling...

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

    Minimum Efficiency Requirements Tables for Heating and Cooling Product Categories The Federal Energy Management Program (FEMP) created tables that mirror American Society of ...

  14. Optimizing minimum free-energy crossing points in solution: Linear...

    Office of Scientific and Technical Information (OSTI)

    Optimizing minimum free-energy crossing points in solution: Linear-response free energyspin-flip density functional theory approach Citation Details In-Document Search Title:...

  15. FAQS Gap Analysis Qualification Card - Occupational Safety | Department

    Energy Savers [EERE]

    of Energy Occupational Safety FAQS Gap Analysis Qualification Card - Occupational Safety Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard. File Occupational Safety Gap Analysis Qualification Card More Documents & Publications FAQS Gap Analysis Qualification Card - Environmental Restoration FAQS Gap Analysis Qualification Card - Waste Management FAQS Gap Analysis Qualification Card -

  16. Drop short control of electrode gap

    DOE Patents [OSTI]

    Fisher, Robert W.; Maroone, James P.; Tipping, Donald W.; Zanner, Frank J.

    1986-01-01

    During vacuum consumable arc remelting the electrode gap between a consumable electrode and a pool of molten metal is difficult to control. The present invention monitors drop shorts by detecting a decrease in the voltage between the consumable electrode and molten pool. The drop shorts and their associated voltage reductions occur as repetitive pulses which are closely correlated to the electrode gap. Thus, the method and apparatus of the present invention controls electrode gap based upon drop shorts detected from the monitored anode-cathode voltage. The number of drop shorts are accumulated, and each time the number of drop shorts reach a predetermined number, the average period between drop shorts is calculated from this predetermined number and the time in which this number is accumulated. This average drop short period is used in a drop short period electrode gap model which determines the actual electrode gap from the drop short. The actual electrode gap is then compared with a desired electrode gap which is selected to produce optimum operating conditions and the velocity of the consumable error is varied based upon the gap error. The consumable electrode is driven according to any prior art system at this velocity. In the preferred embodiment, a microprocessor system is utilized to perform the necessary calculations and further to monitor the duration of each drop short. If any drop short exceeds a preset duration period, the consumable electrode is rapidly retracted a predetermined distance to prevent bonding of the consumable electrode to the molten remelt.

  17. Gas mixtures for spark gap closing switches

    DOE Patents [OSTI]

    Christophorou, Loucas G.; McCorkle, Dennis L.; Hunter, Scott R.

    1988-01-01

    Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches.

  18. Gas mixtures for spark gap closing switches

    DOE Patents [OSTI]

    Christophorou, L.G.; McCorkle, D.L.; Hunter, S.R.

    1987-02-20

    Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches. 6 figs.

  19. Electron Elevator: Excitations across the Band Gap via a Dynamical Gap

    Office of Scientific and Technical Information (OSTI)

    State (Journal Article) | SciTech Connect Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State Citation Details In-Document Search This content will become publicly available on January 26, 2017 Title: Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State Authors: Lim, A. ; Foulkes, W. M. C. ; Horsfield, A. P. ; Mason, D. R. ; Schleife, A. ; Draeger, E. W. ; Correa, A. A. Publication Date: 2016-01-27 OSTI Identifier: 1236285 Grant/Contract

  20. Narrow band gap amorphous silicon semiconductors

    DOE Patents [OSTI]

    Madan, A.; Mahan, A.H.

    1985-01-10

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  1. Theoretical minimum energies to produce steel for selected conditions

    SciTech Connect (OSTI)

    Fruehan, R. J.; Fortini, O.; Paxton, H. W.; Brindle, R.

    2000-03-01

    An ITP study has determined the theoretical minimum energy requirements for producing steel from ore, scrap, and direct reduced iron. Dr. Richard Fruehan's report, Theoretical Minimum Energies to Produce Steel for Selected Conditions, provides insight into the potential energy savings (and associated reductions in carbon dioxide emissions) for ironmaking, steelmaking, and rolling processes (PDF459 KB).

  2. Engine piston having an insulating air gap

    DOE Patents [OSTI]

    Jarrett, Mark Wayne; Hunold,Brent Michael

    2010-02-02

    A piston for an internal combustion engine has an upper crown with a top and a bottom surface, and a lower crown with a top and a bottom surface. The upper crown and the lower crown are fixedly attached to each other using welds, with the bottom surface of the upper crown and the top surface of the lower crown forming a mating surface. The piston also has at least one centrally located air gap formed on the mating surface. The air gap is sealed to prevent substantial airflow into or out of the air gap.

  3. Columbia River Component Data Gap Analysis

    SciTech Connect (OSTI)

    L. C. Hulstrom

    2007-10-23

    This Data Gap Analysis report documents the results of a study conducted by Washington Closure Hanford (WCH) to compile and reivew the currently available surface water and sediment data for the Columbia River near and downstream of the Hanford Site. This Data Gap Analysis study was conducted to review the adequacy of the existing surface water and sediment data set from the Columbia River, with specific reference to the use of the data in future site characterization and screening level risk assessments.

  4. Gap between jets at the LHC

    SciTech Connect (OSTI)

    Royon, Christophe

    2013-04-15

    We describe a NLL BFKL calculation implemented in the HERWIG MC of the gap between jets cross section, that represent a test of BFKL dynamics. We compare the predictions with recent measurements at the Tevatron and present predictions for the LHC. We also discuss the interesting process of looking for gap between jets in diffractive events when protons are detected in the ATLAS Forward Physics (AFP) detectors.

  5. Modeling an Application's Theoretical Minimum and Average Transactional Response Times

    SciTech Connect (OSTI)

    Paiz, Mary Rose

    2015-04-01

    The theoretical minimum transactional response time of an application serves as a ba- sis for the expected response time. The lower threshold for the minimum response time represents the minimum amount of time that the application should take to complete a transaction. Knowing the lower threshold is beneficial in detecting anomalies that are re- sults of unsuccessful transactions. On the converse, when an application's response time falls above an upper threshold, there is likely an anomaly in the application that is causing unusual performance issues in the transaction. This report explains how the non-stationary Generalized Extreme Value distribution is used to estimate the lower threshold of an ap- plication's daily minimum transactional response time. It also explains how the seasonal Autoregressive Integrated Moving Average time series model is used to estimate the upper threshold for an application's average transactional response time.

  6. Minimum Velocity Required to Transport Solid Particles from the...

    Office of Scientific and Technical Information (OSTI)

    Required to Transport Solid Particles from the 2H-Evaporator to the Tank Farm Citation Details In-Document Search Title: Minimum Velocity Required to Transport Solid Particles ...

  7. Incorporate Minimum Efficiency Requirements for Heating and Cooling

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

    Products into Federal Acquisition Documents | Department of Energy Incorporate Minimum Efficiency Requirements for Heating and Cooling Products into Federal Acquisition Documents Incorporate Minimum Efficiency Requirements for Heating and Cooling Products into Federal Acquisition Documents The Federal Energy Management Program (FEMP) organized information about FEMP-designated and ENERGY STAR-qualified heating, ventilating, and air conditioning (HVAC) and water heating products into tables

  8. Gas mixtures for spark gap closing switches (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Gas mixtures for spark gap closing switches Title: Gas mixtures for spark gap closing switches Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low ...

  9. Tuning the energy gap of conjugated polymer zwitterions for efficient...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Tuning the energy gap of conjugated polymer zwitterions for efficient interlayers and solar cells Citation Details In-Document Search Title: Tuning the energy gap...

  10. Bridging the Gap between Fundamental Physics and Chemistry and...

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

    Bridging the Gap between Fundamental Physics and Chemistry and Applied Models for HCCI Engines Bridging the Gap between Fundamental Physics and Chemistry and Applied Models for HCCI ...

  11. Olene Gap Space Heating Low Temperature Geothermal Facility ...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Olene Gap Space Heating Low Temperature Geothermal Facility Facility Olene Gap Sector Geothermal...

  12. Miscibility gap closure, interface morphology, and phase microstructur...

    Office of Scientific and Technical Information (OSTI)

    Miscibility gap closure, interface morphology, and phase microstructure of 3D LixFePO4 ... Title: Miscibility gap closure, interface morphology, and phase microstructure of 3D ...

  13. Development of Low Energy Gap and Fully Regioregular Polythienylenevin...

    Office of Scientific and Technical Information (OSTI)

    Gap and Fully Regioregular Polythienylenevinylene Derivative Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. ...

  14. Rapidity gap survival in central exclusive diffraction: Dynamical...

    Office of Scientific and Technical Information (OSTI)

    Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties Citation Details In-Document Search Title: Rapidity gap survival in central exclusive ...

  15. CHP: Connecting the Gap between Markets and Utility Interconnection...

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

    Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, 2006 CHP: Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, ...

  16. Natural Gas Engine Development Gaps (Presentation)

    SciTech Connect (OSTI)

    Zigler, B.T.

    2014-03-01

    A review of current natural gas vehicle offerings is presented for both light-duty and medium- and heavy-duty applications. Recent gaps in the marketplace are discussed, along with how they have been or may be addressed. The stakeholder input process for guiding research and development needs via the Natural Gas Vehicle Technology Forum (NGVTF) to the U.S. Department of Energy and the California Energy Commission is reviewed. Current high-level natural gas engine development gap areas are highlighted, including efficiency, emissions, and the certification process.

  17. Homolumo gap from dynamical energy levels

    SciTech Connect (OSTI)

    Andric, I.; Jonke, L.; Jurman, D.; Nielsen, H. B.

    2009-11-15

    We introduce a dynamical matrix model where the matrix is interpreted as a Hamiltonian representing interaction of a bosonic system with a single fermion. We show how a system of second-quantized fermions influences the ground state of the whole system by producing a gap between the highest eigenvalue of the occupied single-fermion states and the lowest eigenvalue of the unoccupied single-fermion states. We describe the development of the gap in both the strong and weak coupling regimes, while for the intermediate coupling strength we expect formation of homolumo kinks.

  18. Theoretical solution of the minimum charge problem for gaseous detonations

    SciTech Connect (OSTI)

    Ostensen, R.W.

    1990-12-01

    A theoretical model was developed for the minimum charge to trigger a gaseous detonation in spherical geometry as a generalization of the Zeldovich model. Careful comparisons were made between the theoretical predictions and experimental data on the minimum charge to trigger detonations in propane-air mixtures. The predictions are an order of magnitude too high, and there is no apparent resolution to the discrepancy. A dynamic model, which takes into account the experimentally observed oscillations in the detonation zone, may be necessary for reliable predictions. 27 refs., 9 figs.

  19. Five Facts About the Gender Pay Gap

    Broader source: Energy.gov [DOE]

    Over the past century, American women have made tremendous strides in increasing their labor market experience and their skills. On Equal Pay Day, however, we focus on a stubborn and troubling fact: Despite women’s gains, a large gender pay gap still exists.

  20. Spark gap device for precise switching

    DOE Patents [OSTI]

    Boettcher, Gordon E.

    1984-01-01

    A spark gap device for precise switching of an energy storage capacitor into an exploding bridge wire load is disclosed. Niobium electrodes having a melting point of 2,415 degrees centrigrade are spaced apart by an insulating cylinder to define a spark gap. The electrodes are supported by conductive end caps which, together with the insulating cylinder, form a hermetically sealed chamber filled with an inert, ionizable gas, such as pure xenon. A quantity of solid radioactive carbon-14 within the chamber adjacent the spark gap serves as a radiation stabilizer. The sides of the electrodes and the inner wall of the insulating cylinder are spaced apart a sufficient distance to prevent unwanted breakdown initiation. A conductive sleeve may envelop the outside of the insulating member from the midpoint of the spark gap to the cap adjacent the cathode. The outer metallic surfaces of the device may be coated with a hydrogen-impermeable coating to lengthen the shelf life and operating life of the device. The device breaks down at about 1,700 volts for input voltage rates up to 570 volts/millisecond and allows peak discharge currents of up to 3,000 amperes from a 0.3 microfarad energy storage capacitor for more than 1,000 operations.

  1. Spark gap device for precise switching

    DOE Patents [OSTI]

    Boettcher, G.E.

    1984-10-02

    A spark gap device for precise switching of an energy storage capacitor into an exploding bridge wire load is disclosed. Niobium electrodes having a melting point of 2,415 degrees centigrade are spaced apart by an insulating cylinder to define a spark gap. The electrodes are supported by conductive end caps which, together with the insulating cylinder, form a hermetically sealed chamber filled with an inert, ionizable gas, such as pure xenon. A quantity of solid radioactive carbon-14 within the chamber adjacent the spark gap serves as a radiation stabilizer. The sides of the electrodes and the inner wall of the insulating cylinder are spaced apart a sufficient distance to prevent unwanted breakdown initiation. A conductive sleeve may envelop the outside of the insulating member from the midpoint of the spark gap to the cap adjacent the cathode. The outer metallic surfaces of the device may be coated with a hydrogen-impermeable coating to lengthen the shelf life and operating life of the device. The device breaks down at about 1,700 volts for input voltage rates up to 570 volts/millisecond and allows peak discharge currents of up to 3,000 amperes from a 0.3 microfarad energy storage capacitor for more than 1,000 operations. 3 figs.

  2. The"minimum information about an environmental sequence" (MIENS) specification

    SciTech Connect (OSTI)

    Yilmaz, P.; Kottmann, R.; Field, D.; Knight, R.; Cole, J.R.; Amaral-Zettler, L.; Gilbert, J.A.; Karsch-Mizrachi, I.; Johnston, A.; Cochrane, G.; Vaughan, R.; Hunter, C.; Park, J.; Morrison, N.; Rocca-Serra, P.; Sterk, P.; Arumugam, M.; Baumgartner, L.; Birren, B.W.; Blaser, M.J.; Bonazzi, V.; Bork, P.; Buttigieg, P. L.; Chain, P.; Costello, E.K.; Huot-Creasy, H.; Dawyndt, P.; DeSantis, T.; Fierer, N.; Fuhrman, J.; Gallery, R.E.; Gibbs, R.A.; Giglio, M.G.; Gil, I. San; Gonzalez, A.; Gordon, J.I.; Guralnick, R.; Hankeln, W.; Highlander, S.; Hugenholtz, P.; Jansson, J.; Kennedy, J.; Knights, D.; Koren, O.; Kuczynski, J.; Kyrpides, N.; Larsen, R.; Lauber, C.L.; Legg, T.; Ley, R.E.; Lozupone, C.A.; Ludwig, W.; Lyons, D.; Maguire, E.; Methe, B.A.; Meyer, F.; Nakieny, S.; Nelson, K.E.; Nemergut, D.; Neufeld, J.D.; Pace, N.R.; Palanisamy, G.; Peplies, J.; Peterson, J.; Petrosino, J.; Proctor, L.; Raes, J.; Ratnasingham, S.; Ravel, J.; Relman, D.A.; Assunta-Sansone, S.; Schriml, L.; Sodergren, E.; Spor, A.; Stombaugh, J.; Tiedje, J.M.; Ward, D.V.; Weinstock, G.M.; Wendel, D.; White, O.; Wikle, A.; Wortman, J.R.; Glockner, F.O.; Bushman, F.D.; Charlson, E.; Gevers, D.; Kelley, S.T.; Neubold, L.K.; Oliver, A.E.; Pruesse, E.; Quast, C.; Schloss, P.D.; Sinha, R.; Whitely, A.

    2010-10-15

    We present the Genomic Standards Consortium's (GSC) 'Minimum Information about an ENvironmental Sequence' (MIENS) standard for describing marker genes. Adoption of MIENS will enhance our ability to analyze natural genetic diversity across the Tree of Life as it is currently being documented by massive DNA sequencing efforts from myriad ecosystems in our ever-changing biosphere.

  3. Minimum Efficiency Requirements Tables for Heating and Cooling Product Categories

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) created tables that mirror American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1-2013 tables, which include minimum efficiency requirements for FEMP-designated and ENERGY STAR-qualified heating and cooling product categories. Download the tables below to incorporate FEMP and ENERGY STAR purchasing requirements into federal product acquisition documents.

  4. Band-gap and band-edge engineering of multicomponent garnet scintillators from first principles

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

    Yadav, Satyesh K.; Uberuaga, Blas P.; Nikl, Martin; Jiang, Chao; Stanek, Christopher R.

    2015-11-24

    Complex doping schemes in R3Al5O12 (where R is the rare-earth element) garnet compounds have recently led to pronounced improvements in scintillator performance. Specifically, by admixing lutetium and yttrium aluminate garnets with gallium and gadolinium, the band gap is altered in a manner that facilitates the removal of deleterious electron trapping associated with cation antisite defects. Here, we expand upon this initial work to systematically investigate the effect of substitutional admixing on the energy levels of band edges. Density-functional theory and hybrid density-functional theory (HDFT) are used to survey potential admixing candidates that modify either the conduction-band minimum (CBM) or valence-bandmore » maximum (VBM). We consider two sets of compositions based on Lu3B5O12 where B is Al, Ga, In, As, and Sb, and R3Al5O12, where R is Lu, Gd, Dy, and Er. We find that admixing with various R cations does not appreciably affect the band gap or band edges. In contrast, substituting Al with cations of dissimilar ionic radii has a profound impact on the band structure. We further show that certain dopants can be used to selectively modify only the CBM or the VBM. Specifically, Ga and In decrease the band gap by lowering the CBM, while As and Sb decrease the band gap by raising the VBM, the relative change in band gap is quantitatively validated by HDFT. These results demonstrate a powerful approach to quickly screen the impact of dopants on the electronic structure of scintillator compounds, identifying those dopants which alter the band edges in very specific ways to eliminate both electron and hole traps responsible for performance limitations. Furthermore, this approach should be broadly applicable for the optimization of electronic and optical performance for a wide range of compounds by tuning the VBM and CBM.« less

  5. Gap Assessment in the Emergency Response Community

    SciTech Connect (OSTI)

    Barr, Jonathan L.; Burtner, Edwin R.; Pike, William A.; Peddicord, Annie M Boe; Minsk, Brian S.

    2010-09-27

    This report describes a gap analysis of the emergency response and management (EM) community, performed during the fall of 2009. Pacific Northwest National Laboratory (PNNL) undertook this effort to identify potential improvements to the functional domains in EM that could be provided by the application of current or future technology. To perform this domain-based gap analysis, PNNL personnel interviewed subject matter experts (SMEs) across the EM domain; to make certain that the analyses reflected a representative view of the community, the SMEs were from a variety of geographic areas and from various sized communities (urban, suburban, and rural). PNNL personnel also examined recent and relevant after-action reports and U.S. Government Accountability Office reports.

  6. Dynamically Generated Mott Gap from Holography

    SciTech Connect (OSTI)

    Edalati, Mohammad; Leigh, Robert G.; Phillips, Philip W.

    2011-03-04

    In the fermionic sector of top-down approaches to holographic systems, one generically finds that the fermions are coupled to gravity and gauge fields in a variety of ways, beyond minimal coupling. In this Letter, we take one such interaction--a Pauli, or dipole, interaction--and study its effects on fermion correlators. We find that this interaction modifies the fermion spectral density in a remarkable way. As we change the strength of the interaction, we find that spectral weight is transferred between bands, and beyond a critical value, a gap emerges in the fermion density of states. A possible interpretation of this bulk interaction then is that it drives the dynamical formation of a (Mott) gap, in the absence of continuous symmetry breaking.

  7. Codoped direct-gap semiconductor scintillators

    DOE Patents [OSTI]

    Derenzo, Stephen Edward; Bourret-Courchesne, Edith; Weber, Marvin J.; Klintenberg, Mattias K.

    2008-07-29

    Fast, bright inorganic scintillators at room temperature are based on radiative electron-hole recombination in direct-gap semiconductors, e.g. CdS and ZnO. The direct-gap semiconductor is codoped with two different impurity atoms to convert the semiconductor to a fast, high luminosity scintillator. The codopant scheme is based on dopant band to dopant trap recombination. One dopant provides a significant concentration of carriers of one type (electrons or holes) and the other dopant traps carriers of the other type. Examples include CdS:In,Te; CdS:In,Ag; CdS:In,Na; ZnO:Ga,P; ZnO:Ga,N; ZnO:Ga,S; and GaN:Ge,Mg.

  8. Codoped direct-gap semiconductor scintillators

    DOE Patents [OSTI]

    Derenzo, Stephen E.; Bourret-Courchesne, Edith; Weber, Marvin J.; Klintenberg, Mattias K.

    2006-05-23

    Fast, bright inorganic scintillators at room temperature are based on radiative electron-hole recombination in direct-gap semiconductors, e.g. CdS and ZnO. The direct-gap semiconductor is codoped with two different impurity atoms to convert the semiconductor to a fast, high luminosity scintillator. The codopant scheme is based on dopant band to dopant trap recombination. One dopant provides a significant concentration of carriers of one type (electrons or holes) and the other dopant traps carriers of the other type. Examples include CdS:In,Te; CdS:In,Ag; CdS:In,Na; ZnO:Ga,P; ZnO:Ga,N; ZnO:Ga,S; and GaN:Ge,Mg.

  9. Bridging the Gaps on Prepaid Utility Service

    Broader source: Energy.gov [DOE]

    Prepaid utility service — which is an alternative payment option in which consumers buy a dollar amount of electricity, and utilities deduct energy usage from that balance as it is used — is one area where these changes converge. The Office of Electricity Delivery and Energy Reliability’s report entitled “Bridging the Gaps on Prepaid Utility Service” examines utilities’ and consumers’ experiences with prepay.

  10. Fabrication of photonic band gap materials

    DOE Patents [OSTI]

    Constant, Kristen; Subramania, Ganapathi S.; Biswas, Rana; Ho, Kai-Ming

    2002-01-15

    A method for forming a periodic dielectric structure exhibiting photonic band gap effects includes forming a slurry of a nano-crystalline ceramic dielectric or semiconductor material and monodisperse polymer microspheres, depositing a film of the slurry on a substrate, drying the film, and calcining the film to remove the polymer microspheres therefrom. The film may be cold-pressed after drying and prior to calcining. The ceramic dielectric or semiconductor material may be titania, and the polymer microspheres may be polystyrene microspheres.

  11. Spark gap switch with spiral gas flow

    DOE Patents [OSTI]

    Brucker, John P.

    1989-01-01

    A spark gap switch having a contaminate removal system using an injected gas. An annular plate concentric with an electrode of the switch defines flow paths for the injected gas which form a strong spiral flow of the gas in the housing which is effective to remove contaminates from the switch surfaces. The gas along with the contaminates is exhausted from the housing through one of the ends of the switch.

  12. HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH

    DOE Patents [OSTI]

    Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

    1962-04-17

    A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

  13. Improved initial guess for minimum energy path calculations

    SciTech Connect (OSTI)

    Smidstrup, Sren; Pedersen, Andreas; Stokbro, Kurt

    2014-06-07

    A method is presented for generating a good initial guess of a transition path between given initial and final states of a system without evaluation of the energy. An objective function surface is constructed using an interpolation of pairwise distances at each discretization point along the path and the nudged elastic band method then used to find an optimal path on this image dependent pair potential (IDPP) surface. This provides an initial path for the more computationally intensive calculations of a minimum energy path on an energy surface obtained, for example, by ab initio or density functional theory. The optimal path on the IDPP surface is significantly closer to a minimum energy path than a linear interpolation of the Cartesian coordinates and, therefore, reduces the number of iterations needed to reach convergence and averts divergence in the electronic structure calculations when atoms are brought too close to each other in the initial path. The method is illustrated with three examples: (1) rotation of a methyl group in an ethane molecule, (2) an exchange of atoms in an island on a crystal surface, and (3) an exchange of two Si-atoms in amorphous silicon. In all three cases, the computational effort in finding the minimum energy path with DFT was reduced by a factor ranging from 50% to an order of magnitude by using an IDPP path as the initial path. The time required for parallel computations was reduced even more because of load imbalance when linear interpolation of Cartesian coordinates was used.

  14. Buffalo Gap 3 Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    3 Wind Farm Jump to: navigation, search Name Buffalo Gap 3 Wind Farm Facility Buffalo Gap 3 Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner...

  15. Vehicle Codes and Standards: Overview and Gap Analysis

    SciTech Connect (OSTI)

    Blake, C.; Buttner, W.; Rivkin, C.

    2010-02-01

    This report identifies gaps in vehicle codes and standards and recommends ways to fill the gaps, focusing on six alternative fuels: biodiesel, natural gas, electricity, ethanol, hydrogen, and propane.

  16. ROSS Skills, Knowledge, and Abilities Training Evaluation. Gaps and Recommendations

    SciTech Connect (OSTI)

    Ala, Maureen; Gruidl, Jeremiah; Buddemeier, Brooke

    2015-09-30

    This document describes the development of the ROSS SKAs, the cross-mapping of the SKAs to the available training, identifies gaps in the SKA and training, and provides recommendations to address those gaps.

  17. Coexistence of a pseudogap and a superconducting gap for the...

    Office of Scientific and Technical Information (OSTI)

    Coexistence of a pseudogap and a superconducting gap for the high - T c superconductor La ... Title: Coexistence of a pseudogap and a superconducting gap for the high - T c ...

  18. Minimum information about a marker gene sequence (MIMARKS) and minimum information about any (x) sequence (MIxS) specifications.

    SciTech Connect (OSTI)

    Yilmaz, P.; Kottmann, R.; Field, D.; Knight, R.; Cole, J. R.; Amaral-Zettler, L.; Gilbert, J. A.

    2011-05-01

    Here we present a standard developed by the Genomic Standards Consortium (GSC) for reporting marker gene sequences - the minimum information about a marker gene sequence (MIMARKS). We also introduce a system for describing the environment from which a biological sample originates. The 'environmental packages' apply to any genome sequence of known origin and can be used in combination with MIMARKS and other GSC checklists. Finally, to establish a unified standard for describing sequence data and to provide a single point of entry for the scientific community to access and learn about GSC checklists, we present the minimum information about any (x) sequence (MIxS). Adoption of MIxS will enhance our ability to analyze natural genetic diversity documented by massive DNA sequencing efforts from myriad ecosystems in our ever-changing biosphere.

  19. Functional Area Qualification Standard Gap Analysis Qualification Cards

    Broader source: Energy.gov [DOE]

    FAQS Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  20. Minority Serving Institutions (MSIs): Bridging the Gap between Federal

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

    Agencies and MSIs | Department of Energy Minority Serving Institutions (MSIs): Bridging the Gap between Federal Agencies and MSIs Minority Serving Institutions (MSIs): Bridging the Gap between Federal Agencies and MSIs Different Minority Serving institutions PDF icon Minority Serving Institutions (MSIs): Bridging the Gap between Federal Agencies and MSIs More Documents & Publications Bridging the Gap Between Federal Agencies and MSIs Research and Services at the Alabama A&M

  1. FAQS Gap Analysis Qualification Card - Waste Management | Department of

    Office of Environmental Management (EM)

    Energy Technical Training FAQS Gap Analysis Qualification Card - Technical Training Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard. File Technical Training Gap Analysis Qualification Card More Documents & Publications DOE-STD-1179-2004 DOE-HDBK-1078-94 FAQS Reference Guide - Technical Training Energy

    Waste Management FAQS Gap Analysis Qualification Card - Waste Management

  2. Technical Standards, MELCOR - Gap Analysis - May 3, 2004 | Department of

    Office of Environmental Management (EM)

    Energy MELCOR - Gap Analysis - May 3, 2004 Technical Standards, MELCOR - Gap Analysis - May 3, 2004 May 3, 2004 Software Quality Assurance Improvement Plan: MELCOR Gap Analysis This report documents the outcome of an evaluation of the Software Quality Assurance (SQA) attributes of the MELCOR computer code for leak path factor applications, relative to established software requirements. This evaluation, a "gap analysis," is performed to meet Commitment 4.2.1.3 of the Department of

  3. Quantum chaos and thermalization in gapped systems

    SciTech Connect (OSTI)

    Rigol, Marcos [Department of Physics, Georgetown University, Washington, DC 20057 (United States); Santos, Lea F. [Department of Physics, Yeshiva University, New York, New York 10016 (United States)

    2010-07-15

    We investigate the onset of thermalization and quantum chaos in finite one-dimensional gapped systems of hard-core bosons. Integrability in these systems is broken by next-nearest-neighbor repulsive interactions, which also generate a superfluid to insulator transition. By employing full exact diagonalization, we study chaos indicators and few-body observables. We show that with increasing system size, chaotic behavior is seen over a broader range of parameters and, in particular, deeper into the insulating phase. Concomitantly, we observe that, as the system size increases, the eigenstate thermalization hypothesis extends its range of validity inside the insulating phase and is accompanied by the thermalization of the system.

  4. Turbine blade tip gap reduction system

    DOE Patents [OSTI]

    Diakunchak, Ihor S.

    2012-09-11

    A turbine blade sealing system for reducing a gap between a tip of a turbine blade and a stationary shroud of a turbine engine. The sealing system includes a plurality of flexible seal strips extending from a pressure side of a turbine blade generally orthogonal to the turbine blade. During operation of the turbine engine, the flexible seal strips flex radially outward extending towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the turbine blades and increasing the efficiency of the turbine engine.

  5. Next Generation Nuclear Plant GAP Analysis Report

    SciTech Connect (OSTI)

    Ball, Sydney J; Burchell, Timothy D; Corwin, William R; Fisher, Stephen Eugene; Forsberg, Charles W.; Morris, Robert Noel; Moses, David Lewis

    2008-12-01

    As a follow-up to the phenomena identification and ranking table (PIRT) studies conducted recently by NRC on next generation nuclear plant (NGNP) safety, a study was conducted to identify the significant 'gaps' between what is needed and what is already available to adequately assess NGNP safety characteristics. The PIRT studies focused on identifying important phenomena affecting NGNP plant behavior, while the gap study gives more attention to off-normal behavior, uncertainties, and event probabilities under both normal operation and postulated accident conditions. Hence, this process also involved incorporating more detailed evaluations of accident sequences and risk assessments. This study considers thermal-fluid and neutronic behavior under both normal and postulated accident conditions, fission product transport (FPT), high-temperature metals, and graphite behavior and their effects on safety. In addition, safety issues related to coupling process heat (hydrogen production) systems to the reactor are addressed, given the limited design information currently available. Recommendations for further study, including analytical methods development and experimental needs, are presented as appropriate in each of these areas.

  6. Minimum length, extra dimensions, modified gravity and black hole remnants

    SciTech Connect (OSTI)

    Maziashvili, Michael

    2013-03-01

    We construct a Hilbert space representation of minimum-length deformed uncertainty relation in presence of extra dimensions. Following this construction, we study corrections to the gravitational potential (back reaction on gravity) with the use of correspondingly modified propagator in presence of two (spatial) extra dimensions. Interestingly enough, for r?0 the gravitational force approaches zero and the horizon for modified Schwarzschild-Tangherlini space-time disappears when the mass approaches quantum-gravity energy scale. This result points out to the existence of zero-temperature black hole remnants in ADD brane-world model.

  7. Method for selecting minimum width of leaf in multileaf adjustable collimator while inhibiting passage of particle beams of radiation through sawtooth joints between collimator leaves

    DOE Patents [OSTI]

    Ludewigt, Bernhard; Bercovitz, John; Nyman, Mark; Chu, William

    1995-01-01

    A method is disclosed for selecting the minimum width of individual leaves of a multileaf adjustable collimator having sawtooth top and bottom surfaces between adjacent leaves of a first stack of leaves and sawtooth end edges which are capable of intermeshing with the corresponding sawtooth end edges of leaves in a second stack of leaves of the collimator. The minimum width of individual leaves in the collimator, each having a sawtooth configuration in the surface facing another leaf in the same stack and a sawtooth end edge, is selected to comprise the sum of the penetration depth or range of the particular type of radiation comprising the beam in the particular material used for forming the leaf; plus the total path length across all the air gaps in the area of the joint at the edges between two leaves defined between lines drawn across the peaks of adjacent sawtooth edges; plus at least one half of the length or period of a single sawtooth. To accomplish this, in accordance with the method of the invention, the penetration depth of the particular type of radiation in the particular material to be used for the collimator leaf is first measured. Then the distance or gap between adjoining or abutting leaves is selected, and the ratio of this distance to the height of the sawteeth is selected. Finally the number of air gaps through which the radiation will pass between sawteeth is determined by selecting the number of sawteeth to be formed in the joint. The measurement and/or selection of these parameters will permit one to determine the minimum width of the leaf which is required to prevent passage of the beam through the sawtooth joint.

  8. Theoretical Minimum Energies to Produce Steel for Selected Conditions

    SciTech Connect (OSTI)

    Fruehan, R.J.; Fortini, O.; Paxton, H.W.; Brindle, R.

    2000-05-01

    The energy used to produce liquid steel in today's integrated and electric arc furnace (EAF) facilities is significantly higher than the theoretical minimum energy requirements. This study presents the absolute minimum energy required to produce steel from ore and mixtures of scrap and scrap alternatives. Additional cases in which the assumptions are changed to more closely approximate actual operating conditions are also analyzed. The results, summarized in Table E-1, should give insight into the theoretical and practical potentials for reducing steelmaking energy requirements. The energy values have also been converted to carbon dioxide (CO{sub 2}) emissions in order to indicate the potential for reduction in emissions of this greenhouse gas (Table E-2). The study showed that increasing scrap melting has the largest impact on energy consumption. However, scrap should be viewed as having ''invested'' energy since at one time it was produced by reducing ore. Increasing scrap melting in the BOF mayor may not decrease energy if the ''invested'' energy in scrap is considered.

  9. Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting

    DOE Patents [OSTI]

    Williamson, Rodney L.; Zanner, Frank J.; Grose, Stephen M.

    1998-01-01

    The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap.

  10. Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting

    DOE Patents [OSTI]

    Williamson, R.L.; Zanner, F.J.; Grose, S.M.

    1998-01-13

    The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap. 4 figs.

  11. Rapidity gap survival in central exclusive diffraction: Dynamical

    Office of Scientific and Technical Information (OSTI)

    mechanisms and uncertainties (Conference) | SciTech Connect Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties Citation Details In-Document Search Title: Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties We summarize our understanding of the dynamical mechanisms governing rapidity gap survival in central exclusive diffraction, pp -> p + H + p (H = high-mass system), and discuss the uncertainties in

  12. Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene

    Office of Scientific and Technical Information (OSTI)

    Derivative (Journal Article) | SciTech Connect Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative Citation Details In-Document Search Title: Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a

  13. FAQS Gap Analysis Qualification Card - Civil Structural Engineering |

    Energy Savers [EERE]

    Department of Energy Civil Structural Engineering FAQS Gap Analysis Qualification Card - Civil Structural Engineering Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard. File Civil Structural Engineering Gap Analysis Qualification Card More Documents & Publications DOE-STD-1182-2014 FAQS Qualification Card - Civil Structural Engineering FAQS Job Task Analyses - Civil/Structural

  14. Closing Gaps in Modeling Multifamily Retrofits | Department of Energy

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

    Closing Gaps in Modeling Multifamily Retrofits Closing Gaps in Modeling Multifamily Retrofits This presentation was delivered at the U.S. Department of Energy Building America Technical Update meeting on April 29-30, 2013, in Denver, Colorado. PDF icon cq6_closing_gaps_multifamily_dentz.pdf More Documents & Publications Critical Question #6: What are the Challenges and Solutions for Modeling Multifamily Buildings? Building America Webinar: Central Multifamily Water Heating Systems -

  15. Sensitivity Analysis of the Gap Heat Transfer Model in BISON.

    SciTech Connect (OSTI)

    Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard; Perez, Danielle

    2014-10-01

    This report summarizes the result of a NEAMS project focused on sensitivity analysis of the heat transfer model in the gap between the fuel rod and the cladding used in the BISON fuel performance code of Idaho National Laboratory. Using the gap heat transfer models in BISON, the sensitivity of the modeling parameters and the associated responses is investigated. The study results in a quantitative assessment of the role of various parameters in the analysis of gap heat transfer in nuclear fuel.

  16. FAQS Gap Analysis Qualification Card – Nuclear Explosive Safety Study

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  17. FAQS Gap Analysis Qualification Card – Construction Management

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  18. FAQS Gap Analysis Qualification Card – Nuclear Safety Specialist

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  19. FAQS Gap Analysis Qualification Card – Fire Protection Engineering

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  20. Catalysis by Design: Bridging the Gap between Theory and Experiments...

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

    Catalysis by Design: Bridging the Gap between Theory and Experiments Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 ...

  1. Info-Gap Analysis of Truncation Errors in Numerical Simulations...

    Office of Scientific and Technical Information (OSTI)

    Title: Info-Gap Analysis of Truncation Errors in Numerical Simulations. Authors: Kamm, James R. ; Witkowski, Walter R. ; Rider, William J. ; Trucano, Timothy Guy ; Ben-Haim, Yakov. ...

  2. Info-Gap Analysis of Numerical Truncation Errors. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Info-Gap Analysis of Numerical Truncation Errors. Authors: Kamm, James R. ; Witkowski, Walter R. ; Rider, William J. ; Trucano, Timothy Guy ; Ben-Haim, Yakov. Publication ...

  3. FAQS Gap Analysis Qualification Card – Radiation Protection

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  4. FAQS Gap Analysis Qualification Card – General Technical Base

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  5. FAQS Gap Analysis Qualification Card – Senior Technical Safety Manager

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  6. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

  7. FAQS Gap Analysis Qualification Card – Technical Training

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  8. GAPS Power Infrastructure Pvt Ltd | Open Energy Information

    Open Energy Info (EERE)

    Pvt Ltd Jump to: navigation, search Name: GAPS Power & Infrastructure Pvt Ltd. Place: Mumbai, Maharashtra, India Zip: 400098 Sector: Biomass Product: Mumbai-based biomass project...

  9. FAQS Gap Analysis Qualification Card – Criticality Safety

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  10. Interface orbital engineering of large-gap topological states...

    Office of Scientific and Technical Information (OSTI)

    Interface orbital engineering of large-gap topological states: Decorating gold on a ... This content will become publicly available on March 9, 2017 Title: Interface orbital ...

  11. FAQS Gap Analysis Qualification Card – Mechanical Systems

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  12. Summary of Gaps and Barriers for Implementing Residential Building...

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

    of Energy's Building America 2010 Residential Energy Efficiency Meeting held in Denver, Colorado, on July 20-22, 2010. PDF icon Summary of Gaps and Barriers for Implementing ...

  13. FAQS Gap Analysis Qualification Card – Industrial Hygiene

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  14. FAQS Gap Analysis Qualification Card – Facility Representative

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  15. Minority Serving Institutions (MSIs): Bridging the Gap between...

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

    More Documents & Publications Bridging the Gap Between Federal Agencies and MSIs Research and Services at the Alabama A&M University Research Institute Office of Energy Efficiency ...

  16. Shape-memory transformations of NiTi: Minimum-energy pathways...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states Title: Shape-memory ...

  17. IDAPA 37.03.03 - Rules and Minimum Standards for the Construction...

    Open Energy Info (EERE)

    3 - Rules and Minimum Standards for the Construction and Use of Injection Wells Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document-...

  18. Radial-Gap Permanent Magnet Motor and Drive Research FY 2004

    SciTech Connect (OSTI)

    McKeever, J.W.

    2005-02-11

    The objective of this task was to study permanent magnet (PM) radial-gap traction drive systems that could meet the U.S. Department of Energy FreedomCAR Program's 2010 goals to expose weaknesses or identify strengths. Initially, the approach was to compare attributes such as physical deformations during operation, performance (torque, power, efficiency versus speed), material requirements (strength), material costs, manufacturability, weight, power density, specific power, reliability, and drivability for specific motors. Three motors selected were the commercially available 60-kW radial-gap surface-mounted PM motor manufactured by UQM Technologies, Inc.; a hypothetical PM motor with rotor-supported magnets similar to the Honda MCF-21; and Delphi's automotive electric machine drive motor, whose rotor is a ferromagnetic cylinder, held at one end by a shaft that supports the magnets on its inner surface. Potential problems have appeared related to PM motors, such as (1) high no-load spin losses and high operational power losses, probably from eddy current losses in the rotor; (2) the undemonstrated dual mode inverter control (DMIC) for driving a brushless dc motor (BDCM) (UQM and Delphi motors); (3) uncertainty about the potential for reducing current with DMIC; and (4) uncertainty about the relation between material requirements and maximum rotor speed. Therefore, the approach was changed to study in detail three of the comparison attributes: drivability, performance, and material requirements. Drivability and related problems were examined by demonstrating that DMIC may be used to drive an 18-pole 30-kW PM motor to 6000 rpm, where the maximum electrical frequency is 900 Hz. An available axial-gap test motor with 18 poles was used because its control is identical to that of a radial gap PM motor. Performance was analytically examined, which led to a derivation showing that DMIC controls a PM motor so that the motor uses minimum current to produce any power regardless of speed for relative speeds, n = {omega}/{omega}{sub base} {ge} 2. Performance was also examined with efficiency measurements during the 30-kW PM motor test. Material requirements were examined with finite-element analyses (FEA) to determine the speed and location where yield starts and the corresponding deformations and stresses.

  19. To Bridge LEDs' Green Gap, Scientists Think Small

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

    To Bridge LEDs' Green Gap, Scientists Think Small To Bridge LEDs' Green Gap, Scientists Think Small Nanostructures Half a DNA Strand-Wide Show Promise for Efficient LEDs April 4, 2014 Contact: Margie Wylie, mwylie@lbl.gov, +1 510 486 7421 Nanostructures half the breadth of a DNA strand could improve the efficiency of light emitting diodes (LEDs), especially in the "green gap," a portion of the spectrum where LED efficiency plunges, simulations at the U.S. Department of Energy's

  20. Fact #687: August 8, 2011 The Transportation Petroleum Gap

    Broader source: Energy.gov [DOE]

    In 1989 the transportation sector petroleum consumption surpassed U.S. petroleum production for the first time, creating a gap that must be met with imports of petroleum. By the year 2035,...

  1. Fact #609: February 8, 2010 The Transportation Petroleum Gap

    Broader source: Energy.gov [DOE]

    In 1989 the transportation sector petroleum consumption surpassed U.S. petroleum production for the first time, creating a gap that must be met with imports of petroleum. By the year 2035,...

  2. Fact #560: March 2, 2009 The Transportation Petroleum Gap

    Broader source: Energy.gov [DOE]

    In 1989 the transportation sector petroleum consumption surpassed U.S. petroleum production for the first time, creating a gap that must be met with imports of petroleum. By the year 2030,...

  3. Catalysis by Design: Bridging the Gap Between Theory and Experiments...

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

    by Design: Bridging the Gap Between Theory and Experiments at Nanoscale Level Studies on a simple platinum-alumina system constitute a first step toward a "catalyst by design" ...

  4. Proper Sustainability: GAP Grant Proposal Work Plan Strategy Webinar

    Broader source: Energy.gov [DOE]

    In this webinar I will discuss the new GAP grant requirements for tribal environmental programs and strategies for crafting a work plan that focuses on capacity building activities.  My goal is to...

  5. Enhanced Superconducting Gaps in Trilayer High-Temperature Bi...

    Office of Scientific and Technical Information (OSTI)

    ...-Temperature Bi (2) Sr (2) Ca (2) Cu (3) O (10+delta) Cuprate Superconductor Citation Details In-Document Search Title: Enhanced Superconducting Gaps in Trilayer High-Temperature ...

  6. Interface Ferroelectric Transition near the Gap-Opening Temperature...

    Office of Scientific and Technical Information (OSTI)

    Interface Ferroelectric Transition near the Gap-Opening Temperature in a Single-Unit-Cell FeSe Film Grown on Nb-DopedSrTiO3Substrate Citation Details In-Document Search This...

  7. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2013-03-05

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  8. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2012-02-07

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  9. CHP: Connecting the Gap between Markets and Utility Interconnection and

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

    Tariff Practices, 2006 | Department of Energy Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, 2006 CHP: Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, 2006 The adoption of combined heat and power (CHP) systems by American industries has made substantial strides in the last few years. The purpose of this report is threefold: one, to expose still existent barriers to entry for proposed CHP facilities; secondarily, to

  10. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest

  11. Miscibility gap closure, interface morphology, and phase microstructure of

    Office of Scientific and Technical Information (OSTI)

    3D LixFePO4 nanoparticles from surface wetting and coherency strain (Journal Article) | SciTech Connect Miscibility gap closure, interface morphology, and phase microstructure of 3D LixFePO4 nanoparticles from surface wetting and coherency strain Citation Details In-Document Search Title: Miscibility gap closure, interface morphology, and phase microstructure of 3D LixFePO4 nanoparticles from surface wetting and coherency strain Authors: Welland, Michael J. ; Heinonen, Olle ; Karpeyev,

  12. Computation of radiative heat transport across a nanoscale vacuum gap

    SciTech Connect (OSTI)

    Budaev, Bair V. Bogy, David B.

    2014-02-10

    Radiation heat transport across a vacuum gap between two half-spaces is studied. By consistently applying only the fundamental laws of physics, we obtain an algebraic equation that connects the temperatures of the half-spaces and the heat flux between them. The heat transport coefficient generated by this equation for such structures matches available experimental data for nanoscale and larger gaps without appealing to any additional specific mechanisms of energy transfer.

  13. Hydrogeologic Model for the Gable Gap Area, Hanford Site

    SciTech Connect (OSTI)

    Bjornstad, Bruce N.; Thorne, Paul D.; Williams, Bruce A.; Last, George V.; Thomas, Gregory S.; Thompson, Michael D.; Ludwig, Jami L.; Lanigan, David C.

    2010-09-30

    Gable Gap is a structural and topographic depression between Gable Mountain and Gable Butte within the central Hanford Site. It has a long and complex geologic history, which includes tectonic uplift synchronous with erosional downcutting associated with the ancestral Columbia River during both Ringold and Cold Creek periods, and by the later Ice Age (mostly glacial Lake Missoula) floods. The gap was subsequently buried and partially backfilled by mostly coarse-grained, Ice Age flood deposits (Hanford formation). Erosional remnants of both the Ringold Formation and Cold Creek unit locally underlie the high-energy flood deposits. A large window exists in the gap where confined basalt aquifers are in contact with the unconfined suprabasalt aquifer. Several paleochannels, of both Hanford and Ringold Formation age, were eroded into the basalt bedrock across Gable Gap. Groundwater from the Central Plateau presently moves through Gable Gap via one or more of these shallow paleochannels. As groundwater levels continue to decline in the region, groundwater flow may eventually be cut off through Gable Gap.

  14. Momentum dependence of the superconducting gap and in-gap states in MgB2 multiband superconductor

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

    Mou, Daixiang; Jiang, Rui; Taufour, Valentin; Bud'ko, S. L.; Canfield, P. C.; Kaminski, Adam

    2015-06-29

    We use tunable laser-based angle-resolved photoemission spectroscopy to study the electronic structure of the multiband superconductor MgB2. These results form the baseline for detailed studies of superconductivity in multiband systems. We find that the magnitude of the superconducting gap on both σ bands follows a BCS-like variation with temperature with Δ0 ~ 7meV. Furthermore, the value of the gap is isotropic within experimental uncertainty and in agreement with a pure s-wave pairing symmetry. We observe in-gap states confined to kF of the σ band that occur at some locations of the sample surface. As a result, the energy of thismore » excitation, ~ 3 meV, was found to be somewhat larger than the previously reported gap on π Fermi sheet and therefore we cannot exclude the possibility of interband scattering as its origin.« less

  15. Integration of MEA Components-Status and Technology Gaps: A Stakeholde...

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

    Integration of MEA Components-Status and Technology Gaps: A Stakeholder's Perspective Integration of MEA Components-Status and Technology Gaps: A Stakeholder's Perspective ...

  16. Amorphous copper tungsten oxide with tunable band gaps

    SciTech Connect (OSTI)

    Chen Le; Shet, Sudhakar; Tang Houwen; Wang Heli; Yan Yanfa; Turner, John; Al-Jassim, Mowafak; Ahn, Kwang-soon

    2010-08-15

    We report on the synthesis of amorphous copper tungsten oxide thin films with tunable band gaps. The thin films are synthesized by the magnetron cosputtering method. We find that due to the amorphous nature, the Cu-to-W ratio in the films can be varied without the limit of the solubility (or phase separation) under appropriate conditions. As a result, the band gap and conductivity type of the films can be tuned by controlling the film composition. Unfortunately, the amorphous copper tungsten oxides are not stable in aqueous solution and are not suitable for the application of photoelectrochemical splitting of water. Nonetheless, it provides an alternative approach to search for transition metal oxides with tunable band gaps.

  17. A Fixed Gap APPLE II Undulator for SLS

    SciTech Connect (OSTI)

    Schmidt, T.; Imhof, A.; Ingold, G.; Jakob, B.; Vollenweider, C.

    2007-01-19

    To vary the polarization vector of an APPLE II undulator continuously from 0 - 180 deg., all four magnet arrays need to be movable. Following the adjustable-phase undulator approach by R. Carr, a 3.4 m long fixed gap undulator for SLS with a gap of 11.6 mm has been constructed. It will be installed in fall 2006. The gap drive is replaced by a pair-wise shift of the magnet arrays to change the energy, while the polarization is changed by shifts of diagonal arrays. The high injection efficiency and standard operation top-up mode at the SLS allows this simplified undulator design. The design as well as the operational aspects will be discussed.

  18. Band gap engineering strategy via polarization rotation in perovskite ferroelectrics

    SciTech Connect (OSTI)

    Wang, Fenggong Grinberg, Ilya; Rappe, Andrew M.

    2014-04-14

    We propose a strategy to engineer the band gaps of perovskite oxide ferroelectrics, supported by first principles calculations. We find that the band gaps of perovskites can be substantially reduced by as much as 1.2 eV through local rhombohedral-to-tetragonal structural transition. Furthermore, the strong polarization of the rhombohedral perovskite is largely preserved by its tetragonal counterpart. The B-cation off-center displacements and the resulting enhancement of the antibonding character in the conduction band give rise to the wider band gaps of the rhombohedral perovskites. The correlation between the structure, polarization orientation, and electronic structure lays a good foundation for understanding the physics of more complex perovskite solid solutions and provides a route for the design of photovoltaic perovskite ferroelectrics.

  19. NGNP Project Regulatory Gap Analysis for Modular HTGRs

    SciTech Connect (OSTI)

    Wayne Moe

    2011-09-01

    The Next Generation Nuclear Plant (NGNP) Project Regulatory Gap Analysis (RGA) for High Temperature Gas-Cooled Reactors (HTGR) was conducted to evaluate existing regulatory requirements and guidance against the design characteristics specific to a generic modular HTGR. This final report presents results and identifies regulatory gaps concerning current Nuclear Regulatory Commission (NRC) licensing requirements that apply to the modular HTGR design concept. This report contains appendices that highlight important HTGR licensing issues that were found during the RGA study. The information contained in this report will be used to further efforts in reconciling HTGR-related gaps in the NRC licensing structure, which has to date largely focused on light water reactor technology.

  20. GAP Flow Measurements During the Mesoscale Alpine Programme

    SciTech Connect (OSTI)

    Mayr, G.; Armi, L.; Arnold, S.; Banta, Robert M.; Darby, Lisa S.; Durran, D. D.; Flamant, C.; Gabersek, S.; Gohm, A.; Mayr, R.; Mobbs, S.; Nance, L. B.; Vergeiner, I.; Vergeiner, J.; Whiteman, Charles D.

    2004-04-30

    This article provides an overview of the Gap Flow sub-program of the Mesoscale Alpine Programme, a major international meteorological field experiment conducted in the European Alps. The article describes the initial results of an investigation of the wind flow through the Brenner Pass gap in the east-west oriented central section of the European Alps under conditions of south foehn. The overview describes the objectives of the experiments, the instrumentation used for the field investigation, and the mesoscale model simulations. Initial findings of the scientific program are provided.

  1. Multi-gap high impedance plasma opening switch

    DOE Patents [OSTI]

    Mason, R.J.

    1996-10-22

    A high impedance plasma opening switch having an anode and a cathode and at least one additional electrode placed between the anode and cathode is disclosed. The presence of the additional electrodes leads to the creation of additional plasma gaps which are in series, increasing the net impedance of the switch. An equivalent effect can be obtained by using two or more conventional plasma switches with their plasma gaps wired in series. Higher impedance switches can provide high current and voltage to higher impedance loads such as plasma radiation sources. 12 figs.

  2. Multi-gap high impedance plasma opening switch

    DOE Patents [OSTI]

    Mason, Rodney J.

    1996-01-01

    A high impedance plasma opening switch having an anode and a cathode and at least one additional electrode placed between the anode and cathode. The presence of the additional electrodes leads to the creation of additional plasma gaps which are in series, increasing the net impedance of the switch. An equivalent effect can be obtained by using two or more conventional plasma switches with their plasma gaps wired in series. Higher impedance switches can provide high current and voltage to higher impedance loads such as plasma radiation sources.

  3. Closing the Gender Gap in Energy Policy | Department of Energy

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

    Closing the Gender Gap in Energy Policy Closing the Gender Gap in Energy Policy April 7, 2011 - 3:07pm Addthis Melanie A. Kenderdine Melanie A. Kenderdine Director of the Office of Energy Policy and Systems Analysis What are the key facts? There's not just a shortage of women in technical energy-related fields, there's also a shortage of women in energy policy. Women hold only 27 percent of the science and engineering jobs in the United States. Editor's Note: Join the conversation surrounding

  4. Special purpose modes in photonic band gap fibers

    DOE Patents [OSTI]

    Spencer, James; Noble, Robert; Campbell, Sara

    2013-04-02

    Photonic band gap fibers are described having one or more defects suitable for the acceleration of electrons or other charged particles. Methods and devices are described for exciting special purpose modes in the defects including laser coupling schemes as well as various fiber designs and components for facilitating excitation of desired modes. Results are also presented showing effects on modes due to modes in other defects within the fiber and due to the proximity of defects to the fiber edge. Techniques and devices are described for controlling electrons within the defect(s). Various applications for electrons or other energetic charged particles produced by such photonic band gap fibers are also described.

  5. From Fjords to Open Seas: Ecological Genomics of Expanding Oxygen Minimum Zones (2010 JGI User Meeting)

    ScienceCinema (OSTI)

    Hallam, Steven

    2011-04-26

    Steven Hallam of the University of British Columbia talks "From Fjords to Open Seas: Ecological Genomics of Expanding Oxygen Minimum Zones" on March 24, 2010 at the 5th Annual DOE JGI User Meeting

  6. Title 43 CFR 3206.12 What are the Minimum and Maximum Lease Sizes...

    Open Energy Info (EERE)

    .12 What are the Minimum and Maximum Lease Sizes? Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- Federal RegulationFederal Regulation: Title 43...

  7. Shape-memory transformations of NiTi: Minimum-energy pathways between

    Office of Scientific and Technical Information (OSTI)

    austenite, martensites, and kinetically limited intermediate states (Journal Article) | DOE PAGES Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states Title: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding the associated

  8. Energy and IAQ Implications of Alternative Minimum Ventilation Rates in California Retail and School Buildings

    SciTech Connect (OSTI)

    Dutton, Spencer M.; Fisk, William J.

    2015-01-01

    For a stand-alone retail building, a primary school, and a secondary school in each of the 16 California climate zones, the EnergyPlus building energy simulation model was used to estimate how minimum mechanical ventilation rates (VRs) affect energy use and indoor air concentrations of an indoor-generated contaminant. The modeling indicates large changes in heating energy use, but only moderate changes in total building energy use, as minimum VRs in the retail building are changed. For example, predicted state-wide heating energy consumption in the retail building decreases by more than 50% and total building energy consumption decreases by approximately 10% as the minimum VR decreases from the Title 24 requirement to no mechanical ventilation. The primary and secondary schools have notably higher internal heat gains than in the retail building models, resulting in significantly reduced demand for heating. The school heating energy use was correspondingly less sensitive to changes in the minimum VR. The modeling indicates that minimum VRs influence HVAC energy and total energy use in schools by only a few percent. For both the retail building and the school buildings, minimum VRs substantially affected the predicted annual-average indoor concentrations of an indoor generated contaminant, with larger effects in schools. The shape of the curves relating contaminant concentrations with VRs illustrate the importance of avoiding particularly low VRs.

  9. The effects of turbine passage on C-start behavior of salmon...

    Office of Scientific and Technical Information (OSTI)

    gap runner (MGR) turbine is predicted to have lower values for several potential fish injury mechanisms, and therefore was expected to improve turbine-passage fish survival. ...

  10. 2009 Voluntary Protection Programs Participants' Association (VPPPA) Presentation: Gaps in your Safety Program?

    Broader source: Energy.gov [DOE]

    2009 Voluntary Protection Programs Participants' Association (VPPPA) Presentation: Gaps in your Safety Program?

  11. Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative

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

    David, Tanya M. S.; Zhang, Cheng; Sun, Sam-Shajing

    2014-01-01

    Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene) or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO) level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO) level of −3.33 eV based on optical energy gap. The polymer wasmore » synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.« less

  12. Gaps and pseudogaps in perovskite rare earth nickelates

    SciTech Connect (OSTI)

    Allen, S. James; Ouellette, Daniel G.; Kally, James; Kozhanov, Alex; Hauser, Adam J.; Mikheev, Evgeny; Zhang, Jack Y.; Moreno, Nelson E.; Son, Junwoo; Stemmer, Susanne; Balents, Leon

    2015-06-01

    We report on tunneling measurements that reveal the evolution of the quasiparticle state density in two rare earth perovskite nickelates, NdNiO{sub 3} and LaNiO{sub 3}, that are close to a bandwidth controlled metal to insulator transition. We measure the opening of a sharp gap of ∼30 meV in NdNiO{sub 3} in its insulating ground state. LaNiO{sub 3}, which remains a correlated metal at all practical temperatures, exhibits a pseudogap of the same order. The results point to both types of gaps arising from a common origin, namely, a quantum critical point associated with the T = 0 K metal-insulator transition. The results support theoretical models of the quantum phase transition in terms of spin and charge instabilities of an itinerant Fermi surface.

  13. Profile of single-pulsed ion beams in acceleration gap

    SciTech Connect (OSTI)

    Xiang, W.; Tang, P.Y.

    2006-03-15

    In an attempt to understand the characteristics of single-pulsed ion beams extracted from a miniature occluded-gas sources with electrodes of metallic hydride, a two-dimensional (2D) projected image of ion beams extracted from the single-pulsed occluded-gas source was captured using a digital charge-coupled device camera on a test bench. Based on image processing and the inverse Abel transform, the 2D integrally projected image with cylindrical symmetry was used to determine the profile of ion beams in the acceleration gap. The result shows that the radial beam profile in acceleration gap has a Gaussian-like shape, and the maximum beam intensity behind the plasma electrode is about 40% higher than that in front of the extraction electrode.

  14. Continuously controlled optical band gap in oxide semiconductor thin films

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

    Herklotz, Andreas; Rus, Stefania Florina; Ward, Thomas Zac

    2016-02-02

    The optical band gap of the prototypical semiconducting oxide SnO2 is shown to be continuously controlled through single axis lattice expansion of nanometric films induced by low-energy helium implantation. While traditional epitaxy-induced strain results in Poisson driven multidirectional lattice changes shown to only allow discrete increases in bandgap, we find that a downward shift in the band gap can be linearly dictated as a function of out-of-plane lattice expansion. Our experimental observations closely match density functional theory that demonstrates that uniaxial strain provides a fundamentally different effect on the band structure than traditional epitaxy-induced multiaxes strain effects. In conclusion, chargemore » density calculations further support these findings and provide evidence that uniaxial strain can be used to drive orbital hybridization inaccessible with traditional strain engineering techniques.« less

  15. First Operation of the Abort Gap Monitor for LHC

    SciTech Connect (OSTI)

    Lefevre, Thibaut; Bart Pedersen, Stephane; Boccardi, Andrea; Bravin, Enrico; Goldblatt, A.; Jeff, Adam; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-06

    The Large Hadron Collider (LHC) beam-dump system relies on extraction kickers that need 3 microseconds to rise to their nominal field. Since particles transiting the kickers during the rise will not be dumped properly, the proton population in this interval must always remain below quench and damage limits. A specific monitor to measure the particle population of this gap has been designed based on the detection of synchrotron radiation using a gated photomultiplier. Since the quench and damage limits change with the beam energy, the acceptable population in the abort gap and the settings of the monitor must adapt accordingly. This paper presents the design of the monitor, the calibration procedure and the detector performance with beam.

  16. Systematic study of photoluminescence upon band gap excitation in

    Office of Scientific and Technical Information (OSTI)

    perovskite-type titanates R {sub 1/2}Na{sub 1/2}TiO{sub 3}:Pr (R=La, Gd, Lu, and Y) (Journal Article) | SciTech Connect Systematic study of photoluminescence upon band gap excitation in perovskite-type titanates R {sub 1/2}Na{sub 1/2}TiO{sub 3}:Pr (R=La, Gd, Lu, and Y) Citation Details In-Document Search Title: Systematic study of photoluminescence upon band gap excitation in perovskite-type titanates R {sub 1/2}Na{sub 1/2}TiO{sub 3}:Pr (R=La, Gd, Lu, and Y) Pr{sup 3+}-doped perovskites R

  17. Spark gap switch system with condensable dielectric gas

    DOE Patents [OSTI]

    Thayer, III, William J.

    1991-01-01

    A spark gap switch system is disclosed which is capable of operating at a high pulse rate comprising an insulated switch housing having a purging gas entrance port and a gas exit port, a pair of spaced apart electrodes each having one end thereof within the housing and defining a spark gap therebetween, an easily condensable and preferably low molecular weight insulating gas flowing through the switch housing from the housing, a heat exchanger/condenser for condensing the insulating gas after it exits from the housing, a pump for recirculating the condensed insulating gas as a liquid back to the housing, and a heater exchanger/evaporator to vaporize at least a portion of the condensed insulating gas back into a vapor prior to flowing the insulating gas back into the housing.

  18. Bridging the Gaps of High-Tc Superconductor

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

    Bridging the Gaps of High-Tc Superconductor Since the discovery of high-temperature superconductor by Bednorz and Müller in 1986, this field has become one of the most important research topics in solid state physics. In the past 20 years many unconventional properties have been discovered in this new class of materials. These have challenged our conventional wisdom and driven the development of many novel theories. Among these discoveries, the most mysterious is probably the pseudogap

  19. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  20. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  1. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  2. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  3. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  4. Point sensitive NMR imaging system using a magnetic field configuration with a spatial minimum

    DOE Patents [OSTI]

    Eberhard, Philippe H. (El Cerrito, CA)

    1985-01-01

    A point-sensitive NMR imaging system (10) in which a main solenoid coil (11) produces a relatively strong and substantially uniform magnetic field and a pair of perturbing coils (PZ1 and PZ2) powered by current in the same direction superimposes a pair of relatively weak perturbing fields on the main field to produce a resultant point of minimum field strength at a desired location in a direction along the Z-axis. Two other pairs of perturbing coils (PX1, PX2; PY1, PY2) superimpose relatively weak field gradients on the main field in directions along the X- and Y-axes to locate the minimum field point at a desired location in a plane normal to the Z-axes. An RF generator (22) irradiates a tissue specimen in the field with radio frequency energy so that desired nuclei in a small volume at the point of minimum field strength will resonate.

  5. Gas flow stabilized megavolt spark gap for repetitive pulses

    DOE Patents [OSTI]

    Lawson, Robert N.; O'Malley, Martin W.; Rohwein, Gerald J.

    1986-01-01

    A high voltage spark gap switch including a housing having first and second end walls being spaced apart by a predetermined distance. A first electrode is positioned on the first end wall and a second electrode is positioned on the second end wall. The first and second electrodes are operatively disposed relative to each other and are spaced apart by a predetermined gap. An inlet conduit is provided for supplying gas to the first electrode. The conduit includes a nozzle for dispersing the gas in the shape of an annular jet. The gas is supplied into the housing at a predetermined velocity. A venturi housing is disposed within the second electrode. An exhaust conduit is provided for discharging gas and residue from the housing. The gas supplied at the predetermined velocity to the housing through the inlet conduit and the nozzle in an annular shape traverses the gap between the first and second electrodes and entrains low velocity gas within the housing decreasing the velocity of the gas supplied to the housing and increasing the diameter of the annular shape. The venturi disposed within the second electrode recirculates a large volume of gas to clean and cool the surface of the electrodes.

  6. Gas flow stabilized megavolt spark gap for repetitive pulses

    DOE Patents [OSTI]

    Lawson, R.N.; O'Malley, M.W.; Rohwein, G.J.

    A high voltage spark gap switch is disclosed including a housing having first and second end walls being spaced apart by a predetermined distance. A first electrode is positioned on the first end wall and a second electrode is positioned on the second end wall. The first and second electrodes are operatively disposed relative to each other and are spaced apart by a predetermined gap. An inlet conduit is provided for supplying gas to the first electrode. The conduit includes a nozzle for dispersing the gas in the shape of an annular jet. The gas is supplied into the housing at a predetermined velocity. A venturi housing is disposed within the second electrode. An exhaust conduit is provided for discharging gas and residue from the housing. The gas supplied at the predetermined velocity to the housing through the inlet conduit and the nozzle in an annular shape traverses the gap between the first and second electrodes and entrains low velocity gas within the housing decreasing the velocity of the gas supplied to the housing and increasing the diameter of the annular shape. The venturi disposed within the second electrode recirculates a large volume of gas to clean and cool the surface of the electrodes.

  7. Contrasting Behavior of GaP(001) and InP(001) at the Interface...

    Office of Scientific and Technical Information (OSTI)

    Contrasting Behavior of GaP(001) and InP(001) at the Interface with Water Citation Details In-Document Search Title: Contrasting Behavior of GaP(001) and InP(001) at the Interface ...

  8. Pressure Dependence of the Charge-Density-Wave Gap in Rare-Earth...

    Office of Scientific and Technical Information (OSTI)

    Pressure Dependence of the Charge-Density-Wave Gap in Rare-Earth Tri-Tellurides Citation Details In-Document Search Title: Pressure Dependence of the Charge-Density-Wave Gap in...

  9. Microsoft Word - EM_CM_3_Risk_Management_Best Practices and Gaps...

    Energy Savers [EERE]

    EMCM3RiskManagementBest Practices and Gaps.doc Microsoft Word - EMCM3RiskManagementBest Practices and Gaps.doc Microsoft Word - EMCM3RiskManagementBest Practices and...

  10. In-gap collective mode spectrum of the topological Kondo insulator...

    Office of Scientific and Technical Information (OSTI)

    In-gap collective mode spectrum of the topological Kondo insulator SmB 6 Title: In-gap collective mode spectrum of the topological Kondo insulator SmB 6 Authors: Fuhrman, W. T. ; ...

  11. Controlling electrode gap during vacuum arc remelting at low melting current

    DOE Patents [OSTI]

    Williamson, R.L.; Zanner, F.J.; Grose, S.M.

    1997-04-15

    An apparatus and method are disclosed for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived. 5 figs.

  12. Universal versus Materials-Dependent Two-Gap Behaviour of the...

    Office of Scientific and Technical Information (OSTI)

    Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc Cuprate ... Title: Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc Cuprate ...

  13. Ultrashort pulse laser-triggering of long gap high voltage switches...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Ultrashort pulse laser-triggering of long gap high voltage switches. Citation Details In-Document Search Title: Ultrashort pulse laser-triggering of long gap high ...

  14. Controlling electrode gap during vacuum arc remelting at low melting current

    DOE Patents [OSTI]

    Williamson, Rodney L.; Zanner, Frank J.; Grose, Stephen M.

    1997-01-01

    An apparatus and method for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived.

  15. Apparatus and method for tuned unsteady flow purging of high pulse rate spark gaps

    DOE Patents [OSTI]

    Thayer, III, William J.

    1990-01-01

    A spark gap switch apparatus is disclosed which is capable of operating at a high pulse rate which comprises an insulated housing; a pair of spaced apart electrodes each having one end thereof within a first bore formed in the housing and defining a spark gap therebetween; a pressure wave reflector in the first bore in the housing and spaced from the spark gap and capable of admitting purge flow; and a second enlarged bore contiguous with the first bore and spaced from the opposite side of the spark gap; whereby pressure waves generated during discharge of a spark across the spark gap will reflect off the wave reflector and back from the enlarged bore to the spark gap to clear from the spark gap hot gases residues generated during the discharge and simultaneously restore the gas density and pressure in the spark gap to its initial value.

  16. ASHRAE Minimum Efficiency Requirements Tables for Heating and Cooling Product Categories

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) created tables that mirror American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1-2013 tables, which include minimum efficiency requirements for FEMP-designated and ENERGY STAR-qualified heating and cooling product categories. Download the tables below to incorporate FEMP and ENERGY STAR purchasing requirements into federal product acquisition documents.

  17. Band gap narrowing in zinc oxide-based semiconductor thin films...

    Office of Scientific and Technical Information (OSTI)

    ABSORPTION; ALUMINIUM COMPOUNDS; BORON COMPOUNDS; CHARGE CARRIERS; CONCENTRATION RATIO; DENSITY; DOPED MATERIALS; ELECTRONIC STRUCTURE; ENERGY GAP; GALLIUM COMPOUNDS; INDIUM...

  18. Digital Architecture – Results From a Gap Analysis

    SciTech Connect (OSTI)

    Oxstrand, Johanna Helene; Thomas, Kenneth David; Fitzgerald, Kirk

    2015-09-01

    The digital architecture is defined as a collection of IT capabilities needed to support and integrate a wide-spectrum of real-time digital capabilities for nuclear power plant performance improvements. The digital architecture can be thought of as an integration of the separate I&C and information systems already in place in NPPs, brought together for the purpose of creating new levels of automation in NPP work activities. In some cases, it might be an extension of the current communication systems, to provide digital communications where they are currently analog only. This collection of IT capabilities must in turn be based on a set of user requirements that must be supported for the interconnected technologies to operate in an integrated manner. These requirements, simply put, are a statement of what sorts of digital work functions will be exercised in a fully-implemented seamless digital environment and how much they will be used. The goal of the digital architecture research is to develop a methodology for mapping nuclear power plant operational and support activities into the digital architecture, which includes the development of a consensus model for advanced information and control architecture. The consensus model should be developed at a level of detail that is useful to the industry. In other words, not so detailed that it specifies specific protocols and not so vague that it is only provides a high level description of technology. The next step towards the model development is to determine the current state of digital architecture at typical NPPs. To investigate the current state, the researchers conducted a gap analysis to determine to what extent the NPPs can support the future digital technology environment with their existing I&C and IT structure, and where gaps exist with respect to the full deployment of technology over time. The methodology, result, and conclusions from the gap analysis are described in this report.

  19. Direct control of air gap flux in permanent magnet machines

    DOE Patents [OSTI]

    Hsu, John S.

    2000-01-01

    A method and apparatus for field weakening in PM machines uses field weakening coils (35, 44, 45, 71, 72) to produce flux in one or more stators (34, 49, 63, 64), including a flux which counters flux normally produced in air gaps between the stator(s) (34, 49, 63, 64) and the rotor (20, 21, 41, 61) which carries the PM poles. Several modes of operation are introduced depending on the magnitude and polarity of current in the field weakening coils (35, 44, 45, 71, 72). The invention is particularly useful for, but not limited to, the electric vehicle drives and PM generators.

  20. Active Power Controls from Wind Power: Bridging the Gaps

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

    Active Power Controls from Wind Power: Bridging the Gaps E. Ela, V. Gevorgian, P. Fleming, Y.C. Zhang, M. Singh, E. Muljadi, and A. Scholbrook National Renewable Energy Laboratory J. Aho, A. Buckspan, and L. Pao University of Colorado V. Singhvi, A. Tuohy, P. Pourbeik, D. Brooks, and N. Bhatt Electric Power Research Institute Technical Report NREL/TP-5D00-60574 January 2014 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated

  1. Gap-dependent transitions of atmospheric microplasma in open air

    SciTech Connect (OSTI)

    Chu, Hong-Yu; Huang, Bo-Shiun

    2011-04-15

    We report on the gap dependence of the planar atmospheric microplasma in air. We investigate the transitions of the dielectric barrier discharge in open air, including the random walk filaments (plasma columns), localized filaments, stochastic filaments, and diffuse discharge. A star-shaped filamentary discharge pattern is observed after the formation of the localized filaments. The liquid drops found on the dielectric surface further become a confining pattern for star-shaped discharge. We also demonstrate the applications of the insulating pattern for the use of the plasma display in open air by the handwritten characters with UV adhesive.

  2. Energy Gaps and Interaction Blockade in Confined Quantum Systems

    SciTech Connect (OSTI)

    Capelle, K.; Borgh, M.; Kaerkkaeinen, K.; Reimann, S. M.

    2007-07-06

    We investigate universal properties of strongly confined particles that turn out to be dramatically different from what is observed for electrons in atoms and molecules. For a large class of harmonically confined systems, such as small quantum dots and optically trapped atoms, many-body particle addition and removal energies, and energy gaps, are accurately obtained from single-particle eigenvalues. Transport blockade phenomena are related to the derivative discontinuity of the exchange-correlation functional. This implies that they occur very generally, with Coulomb blockade being a particular realization of a more general phenomenon. In particular, we predict a van der Waals blockade in cold atom gases in traps.

  3. Low-pressure spark gap triggered by an ion diode

    DOE Patents [OSTI]

    Prono, D.S.

    1982-08-31

    Spark gap apparatus for use as an electric switch operating at high voltage, high current and high repetition rate. Mounted inside a housing are an anode, cathode and ion plate. An ionizable fluid is pumped through the chamber of the housing. A pulse of current to the ion plate causes ions to be emitted by the ion plate, which ions move into and ionize the fluid. Electric current supplied to the anode discharges through the ionized fluid and flows to the cathode. Current stops flowing when the current source has been drained. The ionized fluid recombines into its initial dielectric ionizable state. The switch is now open and ready for another cycle.

  4. Low pressure spark gap triggered by an ion diode

    DOE Patents [OSTI]

    Prono, Daniel S.

    1985-01-01

    Spark gap apparatus for use as an electric switch operating at high voltage, high current and high repetition rate. Mounted inside a housing are an anode, cathode and ion plate. An ionizable fluid is pumped through the chamber of the housing. A pulse of current to the ion plate causes ions to be emitted by the ion plate, which ions move into and ionize the fluid. Electric current supplied to the anode discharges through the ionized fluid and flows to the cathode. Current stops flowing when the current source has been drained. The ionized fluid recombines into its initial dielectric ionizable state. The switch is now open and ready for another cycle.

  5. Prediction of a strain-induced conduction-band minimum in embedded quantum dots

    SciTech Connect (OSTI)

    Williamson, A.J.; Zunger, A.; Canning, A.

    1998-02-01

    Free-standing InP quantum dots have previously been theoretically and experimentally shown to have a direct band gap across a large range of experimentally accessible sizes. We demonstrated that when these dots are embedded coherently within a GaP barrier material, the effects of quantum confinement in conjunction with coherent strain suggest there will be a critical diameter of dot ({approx}60 {Angstrom}), above which the dot is direct, type I, and below which it is indirect, type II. However, the strain in the system acts to produce another conduction state with an even lower energy, in which electrons are localized in small pockets at the interface between the InP dot and the GaP barrier. Since this conduction state is GaP X{sub 1c} derived and the highest occupied valence state is InP, {Gamma} derived, the fundamental transition is predicted to be indirect in both real and reciprocal space ({open_quotes}type II{close_quotes}) for all dot sizes. This effect is peculiar to the strained dot, and is absent in the freestanding dot. {copyright} {ital 1998} {ital The American Physical Society}

  6. Thermally triggered phononic gaps in liquids at THz scale

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

    Bolmatov, Dima; Zhernenkov, Mikhail; Zavyalov, Dmitry; Stoupin, Stanislav; Cunsolo, Alessandro; Cai, Yong Q.

    2016-01-14

    In this study we present inelastic X-ray scattering experiments in a diamond anvil cell and molecular dynamic simulations to investigate the behavior of phononic excitations in liquid Ar. The spectra calculated using molecular dynamics were found to be in a good agreement with the experimental data. Furthermore, we observe that, upon temperature increases, a low-frequency transverse phononic gap emerges while high-frequency propagating modes become evanescent at the THz scale. The effect of strong localization of a longitudinal phononic mode in the supercritical phase is observed for the first time. The evidence for the high-frequency transverse phononic gap due to themore » transition from an oscillatory to a ballistic dynamic regimes of motion is presented and supported by molecular dynamics simulations. This transition takes place across the Frenkel line thermodynamic limit which demarcates compressed liquid and non-compressed fluid domains on the phase diagram and is supported by calculations within the Green-Kubo phenomenological formalism. These results are crucial to advance the development of novel terahertz thermal devices, phononic lenses, mirrors, and other THz metamaterials.« less

  7. Method and radial gap machine for high strength undiffused brushless operation

    DOE Patents [OSTI]

    Hsu, John S.

    2006-10-31

    A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from the pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). A method of non-diffused flux enhancement and flux weakening for a radial gap machine is also disclosed.

  8. THE TURBULENT CASCADE AND PROTON HEATING IN THE SOLAR WIND DURING SOLAR MINIMUM

    SciTech Connect (OSTI)

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A. E-mail: Charles.Smith@unh.edu E-mail: Joshua.Stawarz@Colorado.edu

    2012-08-01

    The recently protracted solar minimum provided years of interplanetary data that were largely absent in any association with observed large-scale transient behavior on the Sun. With large-scale shear at 1 AU generally isolated to corotating interaction regions, it is reasonable to ask whether the solar wind is significantly turbulent at this time. We perform a series of third-moment analyses using data from the Advanced Composition Explorer. We show that the solar wind at 1 AU is just as turbulent as at any other time in the solar cycle. Specifically, the turbulent cascade of energy scales in the same manner proportional to the product of wind speed and temperature. Energy cascade rates during solar minimum average a factor of 2-4 higher than during solar maximum, but we contend that this is likely the result of having a different admixture of high-latitude sources.

  9. Estimate of Technical Potential for Minimum Efficiency Performance Standards in 13 Major World Economies

    SciTech Connect (OSTI)

    Letschert, Virginie; Desroches, Louis-Benoit; Ke, Jing; McNeil, Michael

    2012-07-01

    As part of the ongoing effort to estimate the foreseeable impacts of aggressive minimum efficiency performance standards (MEPS) programs in the worlds major economies, Lawrence Berkeley National Laboratory (LBNL) has developed a scenario to analyze the technical potential of MEPS in 13 major economies around the world1 . The best available technology (BAT) scenario seeks to determine the maximum potential savings that would result from diffusion of the most efficient available technologies in these major economies.

  10. Voltage-Matched, Monolithic, Multi-Band-Gap Devices

    DOE Patents [OSTI]

    Wanlass, M. W.; Mascarenhas, A.

    2006-08-22

    Monolithic, tandem, photonic cells include at least a first semiconductor layer and a second semiconductor layer, wherein each semiconductor layer includes an n-type region, a p-type region, and a given band-gap energy. Formed within each semiconductor layer is a string of electrically connected photonic sub-cells. By carefully selecting the numbers of photonic sub-cells in the first and second layer photonic sub-cell string(s), and by carefully selecting the manner in which the sub-cells in a first and second layer photonic sub-cell string(s) are electrically connected, each of the first and second layer sub-cell strings may be made to achieve one or more substantially identical electrical characteristics.

  11. Voltage-matched, monolithic, multi-band-gap devices

    DOE Patents [OSTI]

    Wanlass, Mark W.; Mascarenhas, Angelo

    2006-08-22

    Monolithic, tandem, photonic cells include at least a first semiconductor layer and a second semiconductor layer, wherein each semiconductor layer includes an n-type region, a p-type region, and a given band-gap energy. Formed within each semiconductor layer is a sting of electrically connected photonic sub-cells. By carefully selecting the numbers of photonic sub-cells in the first and second layer photonic sub-cell string(s), and by carefully selecting the manner in which the sub-cells in a first and second layer photonic sub-cell string(s) are electrically connected, each of the first and second layer sub-cell strings may be made to achieve one or more substantially identical electrical characteristics.

  12. Abrupt Onset of a Second Energy Gap at the Superconducting Transition of

    Office of Scientific and Technical Information (OSTI)

    Underdoped Bi2212 (Journal Article) | SciTech Connect Abrupt Onset of a Second Energy Gap at the Superconducting Transition of Underdoped Bi2212 Citation Details In-Document Search Title: Abrupt Onset of a Second Energy Gap at the Superconducting Transition of Underdoped Bi2212 The superconducting gap--an energy scale tied to the superconducting phenomena--opens on the Fermi surface at the superconducting transition temperature ({Tc}) in conventional BCS superconductors. In underdoped

  13. WORKSHOP REPORT:Light-Duty Vehicles Technical Requirements and Gaps for

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

    Lightweight and Propulsion Materials | Department of Energy Light-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials WORKSHOP REPORT:Light-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials PDF icon wr_ldvehicles.pdf More Documents & Publications WORKSHOP REPORT: Trucks and Heavy-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials Summary of the Output from the VTP Advanced

  14. Review of Used Nuclear Fuel Storage and Transportation Technical Gap Analysis

    Broader source: Energy.gov [DOE]

    While both wet and dry storage have been shown to be safe options for storing UNF, the focus of the program is on dry storage of commercial UNF at reactor or centralized locations. This report focuses on the knowledge gaps concerning extended storage identified in numerous domestic and international investigations and provides the UFDC’s gap description, any alternate gap descriptions, the rankings by the various organizations, evaluation of the priority assignment, and UFDC-recommended action based on the comparison.

  15. Technical Standards, MACCS2, Gap Analysis - May 3, 2004 | Department of

    Office of Environmental Management (EM)

    Energy MACCS2, Gap Analysis - May 3, 2004 Technical Standards, MACCS2, Gap Analysis - May 3, 2004 May 3, 2004 Software Quality Assurance Improvement Plan: MACCS2 Gap Analysis The MACCS2 software, for radiological dispersion and consequence analysis, is one of the codes designated for the toolbox. To determine the actions needed to bring the MACCS2 code into compliance with the SQA qualification criteria, and develop an estimate of the resources required to perform the upgrade, the

  16. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, Mark W.

    1994-01-01

    A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

  17. GALACTIC COSMIC-RAY ENERGY SPECTRA AND COMPOSITION DURING THE 2009-2010 SOLAR MINIMUM PERIOD

    SciTech Connect (OSTI)

    Lave, K. A.; Binns, W. R.; Israel, M. H.; Wiedenbeck, M. E.; Christian, E. R.; De Nolfo, G. A.; Von Rosenvinge, T. T.; Cummings, A. C.; Davis, A. J.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.

    2013-06-20

    We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 {<=} Z {<=} 28 in the energy range {approx}50-550 MeV nucleon{sup -1}. Several recent improvements have been made to the earlier CRIS data analysis, and therefore updates of our previous observations for the 1997-1998 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than {approx}7%, and the relative abundances changed by less than {approx}4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2{sigma}, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple ''leaky-box'' galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium.

  18. Exotic equilibria of Harary graphs and a new minimum degree lower bound for synchronization

    SciTech Connect (OSTI)

    Canale, Eduardo A.; Monzn, Pablo

    2015-02-15

    This work is concerned with stability of equilibria in the homogeneous (equal frequencies) Kuramoto model of weakly coupled oscillators. In 2012 [R. Taylor, J. Phys. A: Math. Theor. 45, 115 (2012)], a sufficient condition for almost global synchronization was found in terms of the minimum degreeorder ratio of the graph. In this work, a new lower bound for this ratio is given. The improvement is achieved by a concrete infinite sequence of regular graphs. Besides, non standard unstable equilibria of the graphs studied in Wiley et al. [Chaos 16, 015103 (2006)] are shown to exist as conjectured in that work.

  19. Confronting Regulatory Cost and Quality Expectations. An Exploration of Technical Change in Minimum Efficiency Performance Standards

    SciTech Connect (OSTI)

    Taylor, Margaret; Spurlock, C. Anna; Yang, Hung-Chia

    2015-09-21

    The dual purpose of this project was to contribute to basic knowledge about the interaction between regulation and innovation and to inform the cost and benefit expectations related to technical change which are embedded in the rulemaking process of an important area of national regulation. The area of regulation focused on here is minimum efficiency performance standards (MEPS) for appliances and other energy-using products. Relevant both to U.S. climate policy and energy policy for buildings, MEPS remove certain product models from the market that do not meet specified efficiency thresholds.

  20. ECOR VAP Flux Corrections, Gap-filling, and Results David R....

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

    ECOR VAP Flux Corrections, Gap-filling, and Results David R. Cook, Meredith Franklin, Donna J. Holdridge Argonne National Laboratory, Argonne, IL This work was supported by the...

  1. Stationary Fuel Cell Application Codes and Standards: Overview and Gap Analysis

    SciTech Connect (OSTI)

    Blake, C. W.; Rivkin, C. H.

    2010-09-01

    This report provides an overview of codes and standards related to stationary fuel cell applications and identifies gaps and resolutions associated with relative codes and standards.

  2. Fact #837: September 8, Gap between Net Imports and Total Imports...

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

    Net Imports and Total Imports of Petroleum is Widening Fact 837: September 8, Gap between Net Imports and Total Imports of Petroleum is Widening Net imports of petroleum ...

  3. Experimental investigation of breakdown voltage characteristics of single-gap and multigap pseudosparks

    SciTech Connect (OSTI)

    Liu, C.J.; Rhee, M.J.

    1995-06-01

    Simple empirical scaling laws that can be applied universally are determined for breakdown voltage characteristics of single-gap and multigap pseudosparks. For the single-gap pseudospark, the breakdown voltage is found to be a function of the product of the gas pressure squared, the anode-cathode gap distance, and the hollow cavity diameter, p{sup 2}dD, and a function of the product pd for a gap distance less than and greater than three times the cavity diameter, respectively. For the multigap pseudospark, however, the breakdown voltage is found to be only a function of the product p{sup 2}dD.

  4. Millimeter image of the HL Tau Disk: gaps opened by planets?...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Millimeter image of the HL Tau Disk: gaps opened by planets? Authors: Li, Hui 1 + Show Author Affiliations Los Alamos National ...

  5. Fact #850: December 8, 2014 Automatic Transmissions have closed the Fuel Economy Gap with Manual Transmissions

    Broader source: Energy.gov [DOE]

    Historically, manual transmissions have delivered better fuel economy than automatic transmissions. However, improvements in the efficiency of automatic transmissions have closed that gap in recent...

  6. Bridging the Gap-The Outcome of the Climate Conference in Copehagen...

    Open Energy Info (EERE)

    the Land Transport Sector AgencyCompany Organization: Bridging the Gap Sector: Energy, Land Focus Area: Transportation Topics: Policiesdeployment programs Resource Type:...

  7. Mass gap for gravity localized on Weyl thick branes

    SciTech Connect (OSTI)

    Barbosa-Cendejas, N.; Santos, M. A. Reyes; Herrera-Aguilar, A.; Schubert, C.

    2008-06-15

    We consider thick brane configurations in a pure geometric Weyl integrable 5D space-time, a non-Riemannian generalization of Kaluza-Klein (KK) theory involving a geometric scalar field. Thus, the 5D theory describes gravity coupled to a self-interacting scalar field which gives rise to the structure of the thick branes. We continue the study of the properties of a previously found family of solutions which is smooth at the position of the brane but involves naked singularities in the fifth dimension. Analyzing their graviton spectrum, we find that a particularly interesting situation arises for a special case in which the 4D graviton is separated from the KK gravitons by a mass gap. The corresponding effective Schroedinger equation has a modified Poeschl-Teller potential and can be solved exactly. Apart from the massless 4D graviton, it contains one massive KK bound state, and the continuum spectrum of delocalized KK modes. We also discuss the mass hierarchy problem, and explicitly compute the corrections to Newton's law in the thin brane limit.

  8. Minimum separation distances for natural gas pipeline and boilers in the 300 area, Hanford Site

    SciTech Connect (OSTI)

    Daling, P.M.; Graham, T.M.

    1997-08-01

    The U.S. Department of Energy (DOE) is proposing actions to reduce energy expenditures and improve energy system reliability at the 300 Area of the Hanford Site. These actions include replacing the centralized heating system with heating units for individual buildings or groups of buildings, constructing a new natural gas distribution system to provide a fuel source for many of these units, and constructing a central control building to operate and maintain the system. The individual heating units will include steam boilers that are to be housed in individual annex buildings located at some distance away from nearby 300 Area nuclear facilities. This analysis develops the basis for siting the package boilers and natural gas distribution systems to be used to supply steam to 300 Area nuclear facilities. The effects of four potential fire and explosion scenarios involving the boiler and natural gas pipeline were quantified to determine minimum separation distances that would reduce the risks to nearby nuclear facilities. The resulting minimum separation distances are shown in Table ES.1.

  9. Apparatus and method for closed-loop control of reactor power in minimum time

    DOE Patents [OSTI]

    Bernard, Jr., John A.

    1988-11-01

    Closed-loop control law for altering the power level of nuclear reactors in a safe manner and without overshoot and in minimum time. Apparatus is provided for moving a fast-acting control element such as a control rod or a control drum for altering the nuclear reactor power level. A computer computes at short time intervals either the function: .rho.=(.beta.-.rho.).omega.-.lambda..sub.e '.rho.-.SIGMA..beta..sub.i (.lambda..sub.i -.lambda..sub.e ')+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e '.omega.] or the function: .rho.=(.beta.-.rho.).omega.-.lambda..sub.e .rho.-(.lambda..sub.e /.lambda..sub.e)(.beta.-.rho.)+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e .omega.-(.lambda..sub.e /.lambda..sub.e).omega.] These functions each specify the rate of change of reactivity that is necessary to achieve a specified rate of change of reactor power. The direction and speed of motion of the control element is altered so as to provide the rate of reactivity change calculated using either or both of these functions thereby resulting in the attainment of a new power level without overshoot and in minimum time. These functions are computed at intervals of approximately 0.01-1.0 seconds depending on the specific application.

  10. Filling Knowledge Gaps with Five Fuel Cycle Studies

    SciTech Connect (OSTI)

    Steven J. Piet; Jess Gehin; William Halsey; Temitope Taiwo

    2010-11-01

    During FY 2010, five studies were conducted of technology families applicability to various fuel cycle strategies to fill in knowledge gaps in option space and to better understand trends and patterns. Here, a technology family is considered to be defined by a type of reactor and by selection of which actinides provide fuel. This report summarizes the higher-level findings; the detailed analyses and results are documented in five individual reports, as follows: Advanced once through with uranium fuel in fast reactors (SFR), Advanced once through (uranium fuel) or single recycle (TRU fuel) in high temperature gas cooled reactors (HTGR), Sustained recycle with Th/U-233 in light water reactors (LWRs), Sustained recycle with Th/U-233 in molten salt reactors (MSR), and Several fuel cycle missions with Fusion-Fission Hybrid (FFH). Each study examined how the designated technology family could serve one or more designated fuel cycle missions, filling in gaps in overall option space. Each study contains one or more illustrative cases that show how the technology family could be used to meet a fuel cycle mission, as well as broader information on the technology family such as other potential fuel cycle missions for which insufficient information was available to include with an illustrative case. None of the illustrative cases can be considered as a reference, baseline, or nominal set of parameters for judging performance; the assessments were designed to assess areas of option space and were not meant to be optimized. There is no implication that any of the cases or technology families are necessarily the best way to meet a given fuel cycle mission. The studies provide five examples of 1-year fuel cycle assessments of technology families. There is reasonable coverage in the five studies of the performance areas of waste management and uranium utilization. The coverage of economics, safety, and proliferation resistance and physical protection in the five studies was spotty. Some studies did not have existing or past work to draw on in one or more of these areas. Resource constraints limited the amount of new analyses that could be performed. Little or no assessment was done of how soon any of the technologies could be deployed and therefore how quickly they could impact domestic or international fuel cycle performance. There were six common R&D needs, such as the value of advanced fuels, cladding, coating, and structure that would survive high neutron fluence. When a technology family is considered for use in a new fuel cycle mission, fuel cycle performance characteristics are dependent on both the design choices and the fuel cycle approach. For example, the use of the sodium-cooled fast reactor to provide recycle in either breeder or burner mode has been studied for decades, but the SFR could be considered for once-through fuel cycle with the physical reactor design and fuel management parameters changed. In addition, the sustained recycle with Th/U-233 in LWR could be achieved with a heterogeneous assembly and derated power density. Therefore, it may or may not be adjustable for other fuel cycle missions although a reactor intended for one fuel cycle mission is built. Simple parameter adjustment in applying a technology family to a new fuel cycle mission should be avoided and, if observed, the results viewed with caution.

  11. Bridging the PSI Knowledge Gap: A Multi-Scale Approach

    SciTech Connect (OSTI)

    Wirth, Brian D

    2015-01-08

    Plasma-surface interactions (PSI) pose an immense scientific hurdle in magnetic confinement fusion and our present understanding of PSI in confinement environments is highly inadequate; indeed, a recent Fusion Energy Sciences Advisory Committee report found that 4 out of the 5 top five fusion knowledge gaps were related to PSI. The time is appropriate to develop a concentrated and synergistic science effort that would expand, exploit and integrate the wealth of laboratory ion-beam and plasma research, as well as exciting new computational tools, towards the goal of bridging the PSI knowledge gap. This effort would broadly advance plasma and material sciences, while providing critical knowledge towards progress in fusion PSI. This project involves the development of a Science Center focused on a new approach to PSI science; an approach that both exploits access to state-of-the-art PSI experiments and modeling, as well as confinement devices. The organizing principle is to develop synergistic experimental and modeling tools that treat the truly coupled multi-scale aspect of the PSI issues in confinement devices. This is motivated by the simple observation that while typical lab experiments and models allow independent manipulation of controlling variables, the confinement PSI environment is essentially self-determined with few outside controls. This means that processes that may be treated independently in laboratory experiments, because they involve vastly different physical and time scales, will now affect one another in the confinement environment. Also, lab experiments cannot simultaneously match all exposure conditions found in confinement devices typically forcing a linear extrapolation of lab results. At the same time programmatic limitations prevent confinement experiments alone from answering many key PSI questions. The resolution to this problem is to usefully exploit access to PSI science in lab devices, while retooling our thinking from a linear and de-coupled extrapolation to a multi-scale, coupled approach. The PSI Plasma Center consisted of three equal co-centers; one located at the MIT Plasma Science and Fusion Center, one at UC San Diego Center for Energy Research and one at the UC Berkeley Department of Nuclear Engineering, which moved to the University of Tennessee, Knoxville (UTK) with Professor Brian Wirth in July 2010. The Center had three co-directors: Prof. Dennis Whyte led the MIT co-center, the UCSD co-center was led by Dr. Russell Doerner, and Prof. Brian Wirth led the UCB/UTK center. The directors have extensive experience in PSI and material research, and have been internationally recognized in the magnetic fusion, materials and plasma research fields. The co-centers feature keystone PSI experimental and modeling facilities dedicated to PSI science: the DIONISOS/CLASS facility at MIT, the PISCES facility at UCSD, and the state-of-the-art numerical modeling capabilities at UCB/UTK. A collaborative partner in the center is Sandia National Laboratory at Livermore (SNL/CA), which has extensive capabilities with low energy ion beams and surface diagnostics, as well as supporting plasma facilities, including the Tritium Plasma Experiment, all of which significantly augment the Center. Interpretive, continuum material models are available through SNL/CA, UCSD and MIT. The participating institutions of MIT, UCSD, UCB/UTK, SNL/CA and LLNL brought a formidable array of experimental tools and personnel abilities into the PSI Plasma Center. Our work has focused on modeling activities associated with plasma surface interactions that are involved in effects of He and H plasma bombardment on tungsten surfaces. This involved performing computational material modeling of the surface evolution during plasma bombardment using molecular dynamics modeling. The principal outcomes of the research efforts within the combined experimental – modeling PSI center are to provide a knowledgebase of the mechanisms of surface degradation, and the influence of the surface on plasma conditions.

  12. Method and apparatus for controlling electrode gap during vacuum consumable arc remelting

    DOE Patents [OSTI]

    Fisher, R.W.; Maroone, J.P.; Tipping, D.W.; Zanner, F.J.

    During vacuum consumable arc remelting the electrode gap between a consumable electrode and a pool of molten metal is difficult to control. The present invention monitors drop shorts by detecting a decrease in the voltage between the consumable electrode and molten pool. The drop shorts and their associated voltage reductions occur as repetitive pulses which are closely correlated to the electrode gap. Thus, the method and apparatus of the present invention controls electrode gap based upon drop shorts detected from the monitored anode-cathode voltage. The number of drop shorts are accumulated, and each time the number of drop shorts reach a predetermined number, the average period between drop shorts is calculated from this predetermined number and the time in which this number is accumulated. This average drop short period is used in a drop short period electrode gap model which determines the actual electrode gap from the drop short. The actual electrode gap is then compared with a desired electrode gap which is selected to produce optimum operating conditions and the velocity of the consumable error is varied based upon the gap error. The consumable electrode is driven according to any prior art system at this velocity. In the preferred embodiment, a microprocessor system is utilized to perform the necessary calculations and further to monitor the duration of each drop short. If any drop short exceeds a preset duration period, the consumable electrode is rapidly retracted a predetermined distance to prevent bonding of the consumable electrode to the molten remelt.

  13. Analysis of Minimum Efficiency Performance Standards for Residential General Service Lighting in Chile

    SciTech Connect (OSTI)

    Letschert, Virginie E.; McNeil, Michael A.; Leiva Ibanez, Francisco Humberto; Ruiz, Ana Maria; Pavon, Mariana; Hall, Stephen

    2011-06-01

    Minimum Efficiency Performance Standards (MEPS) have been chosen as part of Chile's national energy efficiency action plan. As a first MEPS, the Ministry of Energy has decided to focus on a regulation for lighting that would ban the sale of inefficient bulbs, effectively phasing out the use of incandescent lamps. Following major economies such as the US (EISA, 2007) , the EU (Ecodesign, 2009) and Australia (AS/NZS, 2008) who planned a phase out based on minimum efficacy requirements, the Ministry of Energy has undertaken the impact analysis of a MEPS on the residential lighting sector. Fundacion Chile (FC) and Lawrence Berkeley National Laboratory (LBNL) collaborated with the Ministry of Energy and the National Energy Efficiency Program (Programa Pais de Eficiencia Energetica, or PPEE) in order to produce a techno-economic analysis of this future policy measure. LBNL has developed for CLASP (CLASP, 2007) a spreadsheet tool called the Policy Analysis Modeling System (PAMS) that allows for evaluation of costs and benefits at the consumer level but also a wide range of impacts at the national level, such as energy savings, net present value of savings, greenhouse gas (CO2) emission reductions and avoided capacity generation due to a specific policy. Because historically Chile has followed European schemes in energy efficiency programs (test procedures, labelling program definitions), we take the Ecodesign commission regulation No 244/2009 as a starting point when defining our phase out program, which means a tiered phase out based on minimum efficacy per lumen category. The following data were collected in order to perform the techno-economic analysis: (1) Retail prices, efficiency and wattage category in the current market, (2) Usage data (hours of lamp use per day), and (3) Stock data, penetration of efficient lamps in the market. Using these data, PAMS calculates the costs and benefits of efficiency standards from two distinct but related perspectives: (1) The Life-Cycle Cost (LCC) calculation examines costs and benefits from the perspective of the individual household; and (2) The National Perspective projects the total national costs and benefits including both financial benefits, and energy savings and environmental benefits. The national perspective calculations are called the National Energy Savings (NES) and the Net Present Value (NPV) calculations. PAMS also calculate total emission mitigation and avoided generation capacity. This paper describes the data and methodology used in PAMS and presents the results of the proposed phase out of incandescent bulbs in Chile.

  14. 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.

  15. Minimum Fisher regularization of image reconstruction for infrared imaging bolometer on HL-2A

    SciTech Connect (OSTI)

    Gao, J. M.; Liu, Y.; Li, W.; Lu, J.; Dong, Y. B.; Xia, Z. W.; Yi, P.; Yang, Q. W.

    2013-09-15

    An infrared imaging bolometer diagnostic has been developed recently for the HL-2A tokamak to measure the temporal and spatial distribution of plasma radiation. The three-dimensional tomography, reduced to a two-dimensional problem by the assumption of plasma radiation toroidal symmetry, has been performed. A three-dimensional geometry matrix is calculated with the one-dimensional pencil beam approximation. The solid angles viewed by the detector elements are taken into account in defining the chord brightness. And the local plasma emission is obtained by inverting the measured brightness with the minimum Fisher regularization method. A typical HL-2A plasma radiation model was chosen to optimize a regularization parameter on the criterion of generalized cross validation. Finally, this method was applied to HL-2A experiments, demonstrating the plasma radiated power density distribution in limiter and divertor discharges.

  16. A fast tomographic method for searching the minimum free energy path

    SciTech Connect (OSTI)

    Chen, Changjun; Huang, Yanzhao; Xiao, Yi; Jiang, Xuewei

    2014-10-21

    Minimum Free Energy Path (MFEP) provides a lot of important information about the chemical reactions, like the free energy barrier, the location of the transition state, and the relative stability between reactant and product. With MFEP, one can study the mechanisms of the reaction in an efficient way. Due to a large number of degrees of freedom, searching the MFEP is a very time-consuming process. Here, we present a fast tomographic method to perform the search. Our approach first calculates the free energy surfaces in a sequence of hyperplanes perpendicular to a transition path. Based on an objective function and the free energy gradient, the transition path is optimized in the collective variable space iteratively. Applications of the present method to model systems show that our method is practical. It can be an alternative approach for finding the state-to-state MFEP.

  17. The turbulent cascade and proton heating in the solar wind during solar minimum

    SciTech Connect (OSTI)

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

    2013-06-13

    Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

  18. Observed Minimum Illuminance Threshold for Night Market Vendors in Kenya who use LED Lamps

    SciTech Connect (OSTI)

    Johnstone, Peter; Jacobson, Arne; Mills, Evan; Radecsky, Kristen

    2009-03-21

    Creation of light for work, socializing, and general illumination is a fundamental application of technology around the world. For those who lack access to electricity, an emerging and diverse range of LED based lighting products hold promise for replacing and/or augmenting their current fuel-based lighting sources that are costly and dirty. Along with analysis of environmental factors, economic models for total cost-ofownership of LED lighting products are an important tool for studying the impacts of these products as they emerge in markets of developing countries. One important metric in those models is the minimum illuminance demanded by end-users for a given task before recharging the lamp or replacing batteries. It impacts the lighting service cost per unit time if charging is done with purchased electricity, batteries, or charging services. The concept is illustrated in figure 1: LED lighting products are generally brightest immediately after the battery is charged or replaced and the illuminance degrades as the battery is discharged. When a minimum threshold level of illuminance is reached, the operational time for the battery charge cycle is over. The cost to recharge depends on the method utilized; these include charging at a shop at a fixed price per charge, charging on personal grid connections, using solar chargers, and purchasing dry cell batteries. This Research Note reports on the observed"charge-triggering" illuminance level threshold for night market vendors who use LED lighting products to provide general and task oriented illumination. All the study participants charged with AC power, either at a fixed-price charge shop or with electricity at their home.

  19. Thirty-Year Solid Waste Generation Maximum and Minimum Forecast for SRS

    SciTech Connect (OSTI)

    Thomas, L.C.

    1994-10-01

    This report is the third phase (Phase III) of the Thirty-Year Solid Waste Generation Forecast for Facilities at the Savannah River Site (SRS). Phase I of the forecast, Thirty-Year Solid Waste Generation Forecast for Facilities at SRS, forecasts the yearly quantities of low-level waste (LLW), hazardous waste, mixed waste, and transuranic (TRU) wastes generated over the next 30 years by operations, decontamination and decommissioning and environmental restoration (ER) activities at the Savannah River Site. The Phase II report, Thirty-Year Solid Waste Generation Forecast by Treatability Group (U), provides a 30-year forecast by waste treatability group for operations, decontamination and decommissioning, and ER activities. In addition, a 30-year forecast by waste stream has been provided for operations in Appendix A of the Phase II report. The solid wastes stored or generated at SRS must be treated and disposed of in accordance with federal, state, and local laws and regulations. To evaluate, select, and justify the use of promising treatment technologies and to evaluate the potential impact to the environment, the generic waste categories described in the Phase I report were divided into smaller classifications with similar physical, chemical, and radiological characteristics. These smaller classifications, defined within the Phase II report as treatability groups, can then be used in the Waste Management Environmental Impact Statement process to evaluate treatment options. The waste generation forecasts in the Phase II report includes existing waste inventories. Existing waste inventories, which include waste streams from continuing operations and stored wastes from discontinued operations, were not included in the Phase I report. Maximum and minimum forecasts serve as upper and lower boundaries for waste generation. This report provides the maximum and minimum forecast by waste treatability group for operation, decontamination and decommissioning, and ER activities.

  20. NEWLY DISCOVERED GLOBAL TEMPERATURE STRUCTURES IN THE QUIET SUN AT SOLAR MINIMUM

    SciTech Connect (OSTI)

    Huang Zhenguang; Frazin, Richard A.; Landi, Enrico; Manchester, Ward B.; Gombosi, Tamas I.; Vasquez, Alberto M.

    2012-08-20

    Magnetic loops are building blocks of the closed-field corona. While active region loops are readily seen in images taken at EUV and X-ray wavelengths, quiet-Sun (QS) loops are seldom identifiable and are therefore difficult to study on an individual basis. The first analysis of solar minimum (Carrington Rotation 2077) QS coronal loops utilizing a novel technique called the Michigan Loop Diagnostic Technique (MLDT) is presented. This technique combines Differential Emission Measure Tomography and a potential field source surface (PFSS) model, and consists of tracing PFSS field lines through the tomographic grid on which the local differential emission measure is determined. As a result, the electron temperature T{sub e} and density N{sub e} at each point along each individual field line can be obtained. Using data from STEREO/EUVI and SOHO/MDI, the MLDT identifies two types of QS loops in the corona: so-called up loops in which the temperature increases with height and so-called down loops in which the temperature decreases with height. Up loops are expected, however, down loops are a surprise, and furthermore, they are ubiquitous in the low-latitude corona. Up loops dominate the QS at higher latitudes. The MLDT allows independent determination of the empirical pressure and density scale heights, and the differences between the two remain to be explained. The down loops appear to be a newly discovered property of the solar minimum corona that may shed light on the physics of coronal heating. The results are shown to be robust to the calibration uncertainties of the EUVI instrument.

  1. Efficient Computation of Info-Gap Robustness for Finite Element Models

    SciTech Connect (OSTI)

    Stull, Christopher J.; Hemez, Francois M.; Williams, Brian J.

    2012-07-05

    A recent research effort at LANL proposed info-gap decision theory as a framework by which to measure the predictive maturity of numerical models. Info-gap theory explores the trade-offs between accuracy, that is, the extent to which predictions reproduce the physical measurements, and robustness, that is, the extent to which predictions are insensitive to modeling assumptions. Both accuracy and robustness are necessary to demonstrate predictive maturity. However, conducting an info-gap analysis can present a formidable challenge, from the standpoint of the required computational resources. This is because a robustness function requires the resolution of multiple optimization problems. This report offers an alternative, adjoint methodology to assess the info-gap robustness of Ax = b-like numerical models solved for a solution x. Two situations that can arise in structural analysis and design are briefly described and contextualized within the info-gap decision theory framework. The treatments of the info-gap problems, using the adjoint methodology are outlined in detail, and the latter problem is solved for four separate finite element models. As compared to statistical sampling, the proposed methodology offers highly accurate approximations of info-gap robustness functions for the finite element models considered in the report, at a small fraction of the computational cost. It is noted that this report considers only linear systems; a natural follow-on study would extend the methodologies described herein to include nonlinear systems.

  2. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

    SciTech Connect (OSTI)

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl

    2014-09-15

    A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

  3. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods

    Office of Scientific and Technical Information (OSTI)

    and nanowires (Journal Article) | SciTech Connect Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires Citation Details In-Document Search This content will become publicly available on November 6, 2016 Title: Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of

  4. Direct band gaps in multiferroic h-LuFeO{sub 3}

    SciTech Connect (OSTI)

    Holinsworth, B. S.; Mazumdar, D.; Musfeldt, J. L.; Brooks, C. M.; Mundy, J. A.; Das, H.; Fennie, C. J.; Cherian, J. G.; McGill, S. A.; Schlom, D. G.

    2015-02-23

    We measured the optical properties of epitaxial thin films of the metastable hexagonal polymorph of LuFeO{sub 3} by absorption spectroscopy, magnetic circular dichroism, and photoconductivity. Comparison with complementary electronic structure calculations reveals a 1.1 eV direct gap involving hybridized Fe 3d{sub z{sup 2}}+O 2p{sub z}→Fe d excitations at the Γ and A points, with a higher energy direct gap at 2.0 eV. Both charge gaps nicely overlap the solar spectrum.

  5. Vacancy defects in as-grown and neutron irradiated GaP studied by positrons

    SciTech Connect (OSTI)

    Dlubek, G.; Bruemmer, O.; Polity, A.

    1986-08-18

    Positron lifetime and Doppler-broadening measurements have been used to study vacancy defects in n-italic-type GaP. Vacancies in the P sublattice with a concentration of some 10/sup 17/ cm/sup -3/ were observed in as-grwon GaP. The vacancies disappear during annealing at 500--800 /sup 0/C. In neutron-irradiated GaP positrons are trapped by Ga vacancies which anneal out in two stages situated at 300--550 /sup 0/C and 550--700 /sup 0/C.

  6. "Bridging the Gaps on Prepaid Utility Service" Report Now Available |

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

    Department of Energy "Bridging the Gaps on Prepaid Utility Service" Report Now Available "Bridging the Gaps on Prepaid Utility Service" Report Now Available November 13, 2015 - 5:12pm Addthis The Office of Electricity Delivery and Energy Reliability has released a report entitled "Bridging the Gaps on Prepaid Utility Service" that examines utilities' and consumers' experiences with prepay which is an alternative payment option in which consumers buy a dollar

  7. Generation of full polarization in ferromagnetic graphene with spin energy gap

    SciTech Connect (OSTI)

    Wu, Qing-Ping; Liu, Zheng-Fang E-mail: aixichen@ecjtu.edu.cn; Liu, Zhi-Min; Chen, Ai-Xi E-mail: aixichen@ecjtu.edu.cn; Xiao, Xian-Bo

    2014-12-22

    We propose a workable scheme for the generation of full spin polarization in ferromagnetic graphene system with strain or Rashba spin-orbit interaction. A spin energy gap can be opened in ferromagnetic graphene system in the presence of strain or Rashba spin-orbit interaction, leading to the full polarization in the spin energy gap. In addition, under the combined modulation of strain and Rashba spin-orbit interaction, the ferromagnetic graphene system can generate significantly large spin-polarized current with a full polarization in the spin energy gap. It is anticipated to apply such a phenomenon to design the electron spin devices based on the graphene.

  8. Nonlinear sub-cyclotron resonance as a formation mechanism for gaps in banded chorus

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

    Fu, Xiangrong; Guo, Zehua; Dong, Chuanfei; Gary, S. Peter

    2015-05-14

    An interesting characteristic of magnetospheric chorus is the presence of a frequency gap at ω ≃ 0.5Ωe, where Ωe is the electron cyclotron angular frequency. Recent chorus observations sometimes show additional gaps near 0.3Ωe and 0.6Ωe. Here we present a novel nonlinear mechanism for the formation of these gaps using Hamiltonian theory and test particle simulations in a homogeneous, magnetized, collisionless plasma. We find that an oblique whistler wave with frequency at a fraction of the electron cyclotron frequency can resonate with electrons, leading to effective energy exchange between the wave and particles.

  9. Nonlinear sub-cyclotron resonance as a formation mechanism for gaps in banded chorus

    SciTech Connect (OSTI)

    Fu, Xiangrong; Guo, Zehua; Dong, Chuanfei; Gary, S. Peter

    2015-05-14

    An interesting characteristic of magnetospheric chorus is the presence of a frequency gap at ? ? 0.5?e, where ?e is the electron cyclotron angular frequency. Recent chorus observations sometimes show additional gaps near 0.3?e and 0.6?e. Here we present a novel nonlinear mechanism for the formation of these gaps using Hamiltonian theory and test particle simulations in a homogeneous, magnetized, collisionless plasma. We find that an oblique whistler wave with frequency at a fraction of the electron cyclotron frequency can resonate with electrons, leading to effective energy exchange between the wave and particles.

  10. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, M.W.

    1994-12-27

    A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

  11. The transition from the open minimum to the ring minimum on the ground state and on the lowest excited state of like symmetry in ozone: A configuration interaction study

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

    Theis, Daniel; Ivanic, Joseph; Windus, Theresa L.; Ruedenberg, Klaus

    2016-03-10

    The metastable ring structure of the ozone 11A1 ground state, which theoretical calculations have shown to exist, has so far eluded experimental detection. An accurate prediction for the energy difference between this isomer and the lower open structure is therefore of interest, as is a prediction for the isomerization barrier between them, which results from interactions between the lowest two 1A1 states. In the present work, valence correlated energies of the 11A1 state and the 21A1 state were calculated at the 11A1 open minimum, the 11A1 ring minimum, the transition state between these two minima, the minimum of the 21A1more » state, and the conical intersection between the two states. The geometries were determined at the full-valence multi-configuration self-consistent-field level. Configuration interaction (CI) expansions up to quadruple excitations were calculated with triple-zeta atomic basis sets. The CI expansions based on eight different reference configuration spaces were explored. To obtain some of the quadruple excitation energies, the method of CorrelationEnergy Extrapolation by Intrinsic Scaling was generalized to the simultaneous extrapolation for two states. This extrapolation method was shown to be very accurate. On the other hand, none of the CI expansions were found to have converged to millihartree (mh) accuracy at the quadruple excitation level. The data suggest that convergence to mh accuracy is probably attained at the sextuple excitation level. On the 11A1 state, the present calculations yield the estimates of (ring minimum—open minimum) ~45–50 mh and (transition state—open minimum) ~85–90 mh. For the (21A1–1A1) excitation energy, the estimate of ~130–170 mh is found at the open minimum and 270–310 mh at the ring minimum. At the transition state, the difference (21A1–1A1) is found to be between 1 and 10 mh. The geometry of the transition state on the 11A1 surface and that of the minimum on the 21A1 surface nearly coincide. More accurate predictions of the energydifferences also require CI expansions to at least sextuple excitations with respect to the valence space. Furthermore, for every wave function considered, the omission of the correlations of the 2s oxygen orbitals, which is a widely used approximation, was found to cause errors of about ±10 mh with respect to the energy differences.« less

  12. Effects of minimum monitor unit threshold on spot scanning proton plan quality

    SciTech Connect (OSTI)

    Howard, Michelle Beltran, Chris; Mayo, Charles S.; Herman, Michael G.

    2014-09-15

    Purpose: To investigate the influence of the minimum monitor unit (MU) on the quality of clinical treatment plans for scanned proton therapy. Methods: Delivery system characteristics limit the minimum number of protons that can be delivered per spot, resulting in a min-MU limit. Plan quality can be impacted by the min-MU limit. Two sites were used to investigate the impact of min-MU on treatment plans: pediatric brain tumor at a depth of 5–10 cm; a head and neck tumor at a depth of 1–20 cm. Three-field, intensity modulated spot scanning proton plans were created for each site with the following parameter variations: min-MU limit range of 0.0000–0.0060; and spot spacing range of 2–8 mm. Comparisons were based on target homogeneity and normal tissue sparing. For the pediatric brain, two versions of the treatment planning system were also compared to judge the effects of the min-MU limit based on when it is accounted for in the optimization process (Eclipse v.10 and v.13, Varian Medical Systems, Palo Alto, CA). Results: The increase of the min-MU limit with a fixed spot spacing decreases plan quality both in homogeneous target coverage and in the avoidance of critical structures. Both head and neck and pediatric brain plans show a 20% increase in relative dose for the hot spot in the CTV and 10% increase in key critical structures when comparing min-MU limits of 0.0000 and 0.0060 with a fixed spot spacing of 4 mm. The DVHs of CTVs show min-MU limits of 0.0000 and 0.0010 produce similar plan quality and quality decreases as the min-MU limit increases beyond 0.0020. As spot spacing approaches 8 mm, degradation in plan quality is observed when no min-MU limit is imposed. Conclusions: Given a fixed spot spacing of ≤4 mm, plan quality decreases as min-MU increased beyond 0.0020. The effect of min-MU needs to be taken into consideration while planning proton therapy treatments.

  13. Fact #837: September 8, 2014 Gap between Net Imports and Total Imports of Petroleum is Widening – Dataset

    Broader source: Energy.gov [DOE]

    Excel file with dataset for Fact #837: Gap between Net Imports and Total Imports of Petroleum is Widening

  14. WORKSHOP REPORT: Trucks and Heavy-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials

    Broader source: Energy.gov [DOE]

    WORKSHOP REPORT: Trucks and Heavy-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials

  15. Photonic band gap of a graphene-embedded quarter-wave stack

    SciTech Connect (OSTI)

    Fan, Yuancheng; Wei, Zeyong; Li, Hongqiang; Chen, Hong; Soukoulis, Costas M

    2013-12-10

    Here, we present a mechanism for tailoring the photonic band structure of a quarter-wave stack without changing its physical periods by embedding conductive sheets. Graphene is utilized and studied as a realistic, two-dimensional conductive sheet. In a graphene-embedded quarter-wave stack, the synergic actions of Bragg scattering and graphene conductance contributions open photonic gaps at the center of the reduced Brillouin zone that are nonexistent in conventional quarter-wave stacks. Such photonic gaps show giant, loss-independent density of optical states at the fixed lower-gap edges, of even-multiple characteristic frequency of the quarter-wave stack. The conductive sheet-induced photonic gaps provide a platform for the enhancement of light-matter interactions.

  16. Contrasting Behavior of GaP(001) and InP(001) at the Interface...

    Office of Scientific and Technical Information (OSTI)

    at the Interface with Water Citation Details In-Document Search Title: Contrasting Behavior of GaP(001) and InP(001) at the Interface with Water Authors: Wood, B C ; ...

  17. Developing Secure Power Systems Professional Competence: Alignment and Gaps in Workforce Development Programs—Summary Report

    SciTech Connect (OSTI)

    O'Neil, Lori Ross; Assante, Michael; Tobey, D. H.; Conway, T. J.; Vanderhorst, Jr, T. J.; Januszewski, III, J.; Leo, R.; Perman, K.

    2013-07-01

    This document is a summarization of the report, Developing Secure Power Systems Professional Competence: Alignment and Gaps in Workforce Development Programs, the final report for phase 2 of the SPSP (DOE workforce study) project.

  18. Fact #837: September 8, 2014 Gap between Net Imports and Total...

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

    Excel file with dataset for Fact 837: Gap between Net Imports and Total Imports of ... were Only 33% of U.S. Consumption in 2013 - Dataset Fact 839: September 22, 2014 ...

  19. Fact #837: September 8, Gap between Net Imports and Total Imports of Petroleum is Widening

    Broader source: Energy.gov [DOE]

    Net imports of petroleum (total imports minus exports) were 6.2 million barrels per day in 2013 – the lowest since the 1980's (dark blue line). The widening gap between total imports (light blue...

  20. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    the third opens a band-gap in the normal way. Low-dimensional metals have attracted much attention because of their unique electronic properties, which often lead to exotic...

  1. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying...

  2. Technical Barriers, Gaps,and Opportunities Related to Home Energy Upgrade Market Delivery

    SciTech Connect (OSTI)

    Bianchi, Marcus V.A.

    2011-11-01

    This report outlines the technical barriers, gaps, and opportunities that arise in executing home energy upgrade market delivery approaches, as identified through research conducted by the U.S. Department of Energy's Building America program.

  3. Molten Carbonate and Phosphoric Acid Stationary Fuel Cells: Overview and Gap Analysis

    Fuel Cell Technologies Publication and Product Library (EERE)

    This report details technical and cost gap analyses of molten carbonate fuel cell and phosphoric acid fuel cell stationary fuel cell power plants and identifies pathways for reducing costs.

  4. Codes and Standards Gap Analysis Helps DOE Define Research Priorities (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-11-01

    This fact sheet describes NREL's accomplishments in analyzing gaps in codes and standards for alternative vehicle fuels, including hydrogen. Work was performed by the Hydrogen Technologies and Systems Center.

  5. Molten Carbonate and Phosphoric Acid Stationary Fuel Cells: Overview and Gap Analysis

    Broader source: Energy.gov [DOE]

    This report describes the technical and cost gap analysis performed to identify pathways for reducing the costs of molten carbonate fuel cell (MCFC) and phosphoric acid fuel cell (PAFC) stationary fuel cell power plants.

  6. Molten Carbonate and Phosphoric Acid Stationary Fuel Cells. Overview and Gap Analysis

    SciTech Connect (OSTI)

    Remick, Robert; Wheeler, Douglas

    2010-09-01

    This report details technical and cost gap analyses of molten carbonate fuel cell and phosphoric acid fuel cell stationary fuel cell power plants and identifies pathways for reducing costs.

  7. Molten Carbonate and Phosphoric Acid Stationary Fuel Cells: Overview and Gap Analysis

    SciTech Connect (OSTI)

    Remick, R.; Wheeler, D.

    2010-09-01

    This report describes the technical and cost gap analysis performed to identify pathways for reducing the costs of molten carbonate fuel cell (MCFC) and phosphoric acid fuel cell (PAFC) stationary fuel cell power plants.

  8. Aerodynamic drag reduction apparatus for gap-divided bluff bodies such as tractor-trailers

    DOE Patents [OSTI]

    Ortega, Jason M.; Salari, Kambiz

    2006-07-11

    An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

  9. Two color laser fields for studying the Cooper minimum with phase-matched high-order harmonic generation

    SciTech Connect (OSTI)

    Ba Dinh, Khuong Vu Le, Hoang; Hannaford, Peter; Van Dao, Lap

    2014-05-28

    We experimentally study the observation of the Cooper minimum in a semi-infinite argon-filled gas cell using two-color laser fields at wavelengths of 1400 nm and 800 nm. The experimental results show that the additional 800 nm field can change the macroscopic phase-matching condition through change of the atomic dipole phase associated with the electron in the continuum state and that this approach can be used to control the appearance of the Cooper minimum in the high-order harmonic spectrum in order to study the electronic structure of atoms and molecules.

  10. Metaproteomics reveals differential modes of metabolic coupling among ubiquitous oxygen minimum zone microbes

    SciTech Connect (OSTI)

    Hawley, Alyse K.; Brewer, Heather M.; Norbeck, Angela D.; Pasa-Tolic, Ljiljana; Hallam, Steven J.

    2014-08-05

    Oxygen minimum zones (OMZs) are intrinsic water column features arising from respiratory oxygen demand during organic matter degradation in stratified marine waters. Currently OMZs are expanding due to global climate change. This expansion alters marine ecosystem function and the productivity of fisheries due to habitat compression and changes in biogeochemical cycling leading to fixed nitrogen loss and greenhouse gas production. Here we use metaproteomics to chart spatial and temporal patterns of gene expression along defined redox gradients in a seasonally anoxic fjord, Saanich Inlet to better understand microbial community responses to OMZ expansion. The expression of metabolic pathway components for nitrification, anaerobic ammonium oxidation (anammox), denitrification and inorganic carbon fixation predominantly co-varied with abundance and distribution patterns of Thaumarchaeota, Nitrospira, Planctomycetes and SUP05/ARCTIC96BD-19 Gammaproteobacteria. Within these groups, pathways mediating inorganic carbon fixation and nitrogen and sulfur transformations were differentially expressed across the redoxcline. Nitrification and inorganic carbon fixation pathways affiliated with Thaumarchaeota dominated dysoxic waters and denitrification, sulfur-oxidation and inorganic carbon fixation pathways affiliated with SUP05 dominated suboxic and anoxic waters. Nitrite-oxidation and anammox pathways affiliated with Nitrospina and Planctomycetes respectively, also exhibited redox partitioning between dysoxic and suboxic waters. The differential expression of these pathways under changing water column redox conditions has quantitative implications for coupled biogeochemical cycling linking different modes of inorganic carbon fixation with distributed nitrogen and sulfur-based energy metabolism extensible to coastal and open ocean OMZs.

  11. Use of finite volume radiation for predicting the Knudsen minimum in 2D channel flow

    SciTech Connect (OSTI)

    Malhotra, Chetan P.; Mahajan, Roop L.

    2014-12-09

    In an earlier paper we employed an analogy between surface-to-surface radiation and free-molecular flow to model Knudsen flow through tubes and onto planes. In the current paper we extend the analogy between thermal radiation and molecular flow to model the flow of a gas in a 2D channel across all regimes of rarefaction. To accomplish this, we break down the problem of gaseous flow into three sub-problems (self-diffusion, mass-motion and generation of pressure gradient) and use the finite volume method for modeling radiation through participating media to model the transport in each sub-problem as a radiation problem. We first model molecular self-diffusion in the stationary gas by modeling the transport of the molecular number density through the gas starting from the analytical asymptote for free-molecular flow to the kinetic theory limit of gaseous self-diffusion. We then model the transport of momentum through the gas at unit pressure gradient to predict Poiseuille flow and slip flow in the 2D gas. Lastly, we predict the generation of pressure gradient within the gas due to molecular collisions by modeling the transport of the forces generated due to collisions per unit volume of gas. We then proceed to combine the three radiation problems to predict flow of the gas over the entire Knudsen number regime from free-molecular to transition to continuum flow and successfully capture the Knudsen minimum at Kn ? 1.

  12. Designing a minimum-functionality neutron and gamma measurement instrument with a focus on authentication

    SciTech Connect (OSTI)

    Karpius, Peter J; Williams, Richard B

    2009-01-01

    During the design and construction of the Next-Generation Attribute-Measurement System, which included a largely commercial off-the-shelf (COTS), nondestructive assay (NDA) system, we realized that commercial NDA equipment tends to include numerous features that are not required for an attribute-measurement system. Authentication of the hardware, firmware, and software in these instruments is still required, even for those features not used in this application. However, such a process adds to the complexity, cost, and time required for authentication. To avoid these added authenticat ion difficulties, we began to design NDA systems capable of performing neutron multiplicity and gamma-ray spectrometry measurements by using simplified hardware and software that avoids unused features and complexity. This paper discusses one possible approach to this design: A hardware-centric system that attempts to perform signal analysis as much as possible in the hardware. Simpler processors and minimal firmware are used because computational requirements are kept to a bare minimum. By hard-coding the majority of the device's operational parameters, we could cull large sections of flexible, configurable hardware and software found in COTS instruments, thus yielding a functional core that is more straightforward to authenticate.

  13. Minimum 186 Basin levels required for operation of ECS and CWS pumps

    SciTech Connect (OSTI)

    Reeves, K.K.; Barbour, K.L.

    1992-10-01

    Operation of K Reactor with a cooling tower requires that 186 Basin loss of inventory transients be considered during Design Basis Accident analyses requiring ECS injection, such as the LOCA and LOPA. Since the cooling tower systems are not considered safety systems, credit is not taken for their continued operation during a LOPA or LOCA even though they would likely continue to operate as designed. Without the continued circulation of cooling water to the 186 Basin by the cooling tower pumps, the 186 Basin will lose inventory until additional make-up can be obtained from the river water supply system. Increasing the make-up to the 186 Basin from the river water system may require the opening of manually operated valves, the starting of additional river water pumps, and adjustments of the flow to L Area. In the time required for these actions a loss of basin inventory could occur. The ECS and CWS pumps are supplied by the 186 Basin. A reduction in the basin level will result in decreased pump suction head. This reduction in suction head will result in decreased output from the pumps and, if severe enough, could lead to pump cavitation for some configurations. The subject of this report is the minimum 186 Basin level required to prevent ECS and CWS pump cavitation. The reduction in ECS flow due to a reduced 186 Basin level without cavitation is part of a separate study.

  14. Searching for Minimum in Dependence of Squared Speed-of-Sound on Collision Energy

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

    Liu, Fu-Hu; Gao, Li-Na; Lacey, Roy A.

    2016-01-01

    Experimore » mental results of the rapidity distributions of negatively charged pions produced in proton-proton ( p - p ) and beryllium-beryllium (Be-Be) collisions at different beam momentums, measured by the NA61/SHINE Collaboration at the super proton synchrotron (SPS), are described by a revised (three-source) Landau hydrodynamic model. The squared speed-of-sound parameter c s 2 is then extracted from the width of rapidity distribution. There is a local minimum (knee point) which indicates a softest point in the equation of state (EoS) appearing at about 40 A  GeV/ c (or 8.8 GeV) in c s 2 excitation function (the dependence of c s 2 on incident beam momentum (or center-of-mass energy)). This knee point should be related to the searching for the onset of quark deconfinement and the critical point of quark-gluon plasma (QGP) phase transition.« less

  15. Approaching the Minimum Thermal Conductivity in Rhenium-Substituted Higher Manganese Silicides

    SciTech Connect (OSTI)

    Chen, Xi [University of Texas at Austin] [University of Texas at Austin; Girard, S. N. [University of Wisconsin, Madison] [University of Wisconsin, Madison; Meng, F. [University of Wisconsin, Madison] [University of Wisconsin, Madison; Lara-Curzio, Edgar [ORNL] [ORNL; Jin, S [University of Wisconsin, Madison] [University of Wisconsin, Madison; Goodenough, J. B. [University of Texas at Austin] [University of Texas at Austin; Zhou, J. S. [University of Texas at Austin] [University of Texas at Austin; Shi, L [University of Texas at Austin] [University of Texas at Austin

    2014-01-01

    Higher manganese silicides (HMS) made of earth-abundant and non-toxic elements are regarded as promising p-type thermoelectric materials because their complex crystal structure results in low lattice thermal conductivity. It is shown here that the already low thermal conductivity of HMS can be reduced further to approach the minimum thermal conductivity via partial substitu- tion of Mn with heavier rhenium (Re) to increase point defect scattering. The solubility limit of Re in the obtained RexMn1 xSi1.8 is determined to be about x = 0.18. Elemental inhomogeneity and the formation of ReSi1.75 inclusions with 50 200 nm size are found within the HMS matrix. It is found that the power factor does not change markedly at low Re content of x 0.04 before it drops considerably at higher Re contents. Compared to pure HMS, the reduced lattice thermal conductivity in RexMn1 xSi1.8 results in a 25% increase of the peak figure of merit ZT to reach 0.57 0.08 at 800 K for x = 0.04. The suppressed thermal conductivity in the pure RexMn1 xSi1.8 can enable further investigations of the ZT limit of this system by exploring different impurity doping strategies to optimize the carrier concentration and power factor.

  16. Vacuum gaps with small tunnel currents at large electric field and its

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

    potential applications for energy storage, charge storage and power supplies. | Stanford Synchrotron Radiation Lightsource Vacuum gaps with small tunnel currents at large electric field and its potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm SSRL Conference Room 137-226 Alfred Hubler, Department of Physics, University of Illinois, Urbana-Champaign We study tunnel currents and electric break down in vacuum gaps experimentally and

  17. Interactions and the θ term in one-dimensional gapped systems (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Interactions and the θ term in one-dimensional gapped systems Citation Details In-Document Search Title: Interactions and the θ term in one-dimensional gapped systems Authors: Mulligan, Michael Publication Date: 2011-05-17 OSTI Identifier: 1099376 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 83; Journal Issue: 20; Journal ID: ISSN 1098-0121 Publisher: American Physical Society Sponsoring

  18. Bridging the Gap: Helping Small Businesses With Big Ideas Develop New

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

    Industries | Department of Energy Bridging the Gap: Helping Small Businesses With Big Ideas Develop New Industries Bridging the Gap: Helping Small Businesses With Big Ideas Develop New Industries October 25, 2011 - 3:59pm Addthis Semprius, solar panels shown above, announced that it is building a factory in Henderson, NC to manufacture its high concentration photovoltaic (HCPV) solar modules and is expected to create more than 250 full-time jobs over the next five years. Semprius, solar

  19. Active Power Controls from Wind Power: Bridging the Gaps | Department of

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

    Energy Active Power Controls from Wind Power: Bridging the Gaps Active Power Controls from Wind Power: Bridging the Gaps This report evaluates how wind power can support power system reliability, and do so economically. The study includes a number of different power system simulations, control simulations, and actual field tests using turbines at the National Renewable Energy Laboratory's (NREL's) National Wind Technology Center (NWTC). PDF icon Active Power Controls from Wind Power.pdf More

  20. Antiferromagnetism in the spin-gap system NaV2O5: Muon spin rotation

    Office of Scientific and Technical Information (OSTI)

    measurements (Journal Article) | SciTech Connect Journal Article: Antiferromagnetism in the spin-gap system NaV2O5: Muon spin rotation measurements Citation Details In-Document Search Title: Antiferromagnetism in the spin-gap system NaV2O5: Muon spin rotation measurements Authors: Storchak, Vyacheslav G. ; Parfenov, Oleg E. ; Eshchenko, Dmitry G. ; Lichti, Roger L. ; Mengyan, Patrick W. ; Isobe, Masahiko ; Ueda, Yutaka Publication Date: 2012-03-05 OSTI Identifier: 1099289 Type: Publisher's

  1. Thermophotovoltaic conversion using selective infrared line emitters and large band gap photovoltaic devices

    DOE Patents [OSTI]

    Brandhorst, Jr., Henry W.; Chen, Zheng

    2000-01-01

    Efficient thermophotovoltaic conversion can be performed using photovoltaic devices with a band gap in the 0.75-1.4 electron volt range, and selective infrared emitters chosen from among the rare earth oxides which are thermally stimulated to emit infrared radiation whose energy very largely corresponds to the aforementioned band gap. It is possible to use thermovoltaic devices operating at relatively high temperatures, up to about 300.degree. C., without seriously impairing the efficiency of energy conversion.

  2. Ultrashort pulse laser-triggering of long gap high voltage switches.

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: Ultrashort pulse laser-triggering of long gap high voltage switches. Citation Details In-Document Search Title: Ultrashort pulse laser-triggering of long gap high voltage switches. Authors: Rambo, Patrick K. ; Schwarz, Jens ; Kimmel, Mark W. ; Van Tassle, Aaron J. ; Urayama, Junji ; Welch, Dale Robert [1] ; Rose, David V. [1] ; Thoma, Carsten [1] ; Clark, Robert E. [1] ; Miller, Craig [1] ; Zimmerman, William R. [1] ; Pitts, Todd Alan ;

  3. Fundamental gaps with approximate density functionals: The derivative discontinuity revealed from ensemble considerations

    SciTech Connect (OSTI)

    Kraisler, Eli; Kronik, Leeor

    2014-05-14

    The fundamental gap is a central quantity in the electronic structure of matter. Unfortunately, the fundamental gap is not generally equal to the Kohn-Sham gap of density functional theory (DFT), even in principle. The two gaps differ precisely by the derivative discontinuity, namely, an abrupt change in slope of the exchange-correlation energy as a function of electron number, expected across an integer-electron point. Popular approximate functionals are thought to be devoid of a derivative discontinuity, strongly compromising their performance for prediction of spectroscopic properties. Here we show that, in fact, all exchange-correlation functionals possess a derivative discontinuity, which arises naturally from the application of ensemble considerations within DFT, without any empiricism. This derivative discontinuity can be expressed in closed form using only quantities obtained in the course of a standard DFT calculation of the neutral system. For small, finite systems, addition of this derivative discontinuity indeed results in a greatly improved prediction for the fundamental gap, even when based on the most simple approximate exchange-correlation density functional the local density approximation (LDA). For solids, the same scheme is exact in principle, but when applied to LDA it results in a vanishing derivative discontinuity correction. This failure is shown to be directly related to the failure of LDA in predicting fundamental gaps from total energy differences in extended systems.

  4. Discrete monotron oscillator having one-half wavelength coaxial resonator with one-quarter wavelength gap spacing

    DOE Patents [OSTI]

    Carlsten, B.E.; Haynes, W.B.

    1998-02-03

    A discrete monotron oscillator for use in a high power microwave device is formed with a microwave oscillator having a half-wavelength resonant coaxial microwave cavity operating in fundamental TEM mode for microwave oscillation with an inner conductor defining a drift tube for propagating an electron beam and an outer conductor coaxial with the inner conductor. The inner conductor defines a modulating gap and an extraction gap downstream of the modulating gap. The modulating gap and the extraction gap connect the coaxial microwave cavity with the drift tube so that energy for the microwave oscillation is extracted from the electron beam at the extraction gap and modulates the electron beam at the modulating gap. For high power operation, an annular electron beam is used. 8 figs.

  5. Discrete monotron oscillator having one-half wavelength coaxial resonator with one-quarter wavelength gap spacing

    DOE Patents [OSTI]

    Carlsten, Bruce E.; Haynes, William B.

    1998-01-01

    A discrete monotron oscillator for use in a high power microwave device is formed with a microwave oscillator having a half-wavelength resonant coaxial microwave cavity operating in fundamental TEM mode for microwave oscillation with an inner conductor defining a drift tube for propagating an electron beam and an outer conductor coaxial with the inner conductor. The inner conductor defines a modulating gap and an extraction gap downstream of the modulating gap. The modulating gap and the extraction gap connect the coaxial microwave cavity with the drift tube so that energy for the microwave oscillation is extracted from the electron beam at the extraction gap and modulates the electron beam at the modulating gap. For high power operation, an annular electron beam is used.

  6. ANALYSIS OF THE AXIAL GAP VS FIBERBOARD MOISTURE CONTENT IN A 9975 SHIPPING PACKAGE

    SciTech Connect (OSTI)

    Daugherty, W.

    2013-09-30

    The fiberboard assembly within a 9975 shipping package contains a modest amount of moisture, which can migrate to the cooler regions of the package when an internal heat load is present. Typically, this leads to increased moisture levels in the bottom fiberboard layers, along with elevated chloride levels which can leach from the fiberboard. Concerns have been raised that this condition could lead to corrosion of the stainless steel drum. It has been postulated that checking the axial gap at the top of the package against the current 1 inch maximum criterion provides a sufficient indication regarding the integrity of the fiberboard and drum. This report estimates the increase in axial gap that might be expected for a given moisture increase in the bottom fiberboard layers, and the likelihood that the increase will create a nonconforming condition that will lead to identification of the moisture increase. Using data relating the fiberboard moisture content with the degree of compaction under load, the present analysis indicates that the axial gap will increase by 0.282 inch as the bottom fiberboard layers approach the saturation point. This increase will cause approximately 58% of packages with otherwise nominal package component dimensions to fail the axial gap criterion, based on a survey of axial gap values recorded in K-Area surveillance activities. As the moisture content increases above saturation, the predicted increase in axial gap jumps to 0.405 inch, which would result in 92% or more of all packages failing the axial gap criterion. The data and analysis described in this report are specific to cane fiberboard. While it is expected that softwood fiberboard will behave similarly, such behavior has not yet been demonstrated.

  7. Shock Desensitization Effect in the STANAG 4363 Confined Explosive Component Water Gap Test

    SciTech Connect (OSTI)

    Lefrancois, A S; Lee, R S; Tarver, C M

    2006-06-07

    The Explosive Component Water Gap Test (ECWGT) in the Stanag 4363 has been recently investigated to assess the shock sensitivity of lead and booster components having a diameter less than 5 mm. For that purpose, Pentaerythritol Tetranitrate (PETN) based pellets having a height and diameter of 3 mm have been confined by a steel annulus of wall thickness 1-3.5 mm and with the same height as the pellet. 1-mm wall thickness makes the component more sensitive (larger gap). As the wall thickness is increased to 2-mm, the gap increases a lesser amount, but when the wall thickness is increased to 3.5-mm a decrease in sensitivity is observed (smaller gap). This decrease of the water gap has been reproduced experimentally by many nations. Numerical simulations using Ignition and Growth model have been performed in this paper and have reproduced the experimental results for the steel confinement up to 2 mm thick and aluminum confinement. A stronger re-shock following the first input shock from the water is focusing on the axis due to the confinement. The double shock configuration is well-known to lead in some cases to shock desensitization.

  8. Band gap engineering for graphene by using Na{sup +} ions

    SciTech Connect (OSTI)

    Sung, S. J.; Lee, P. R.; Kim, J. G.; Ryu, M. T.; Park, H. M.; Chung, J. W.

    2014-08-25

    Despite the noble electronic properties of graphene, its industrial application has been hindered mainly by the absence of a stable means of producing a band gap at the Dirac point (DP). We report a new route to open a band gap (E{sub g}) at DP in a controlled way by depositing positively charged Na{sup +} ions on single layer graphene formed on 6H-SiC(0001) surface. The doping of low energy Na{sup +} ions is found to deplete the ?* band of graphene above the DP, and simultaneously shift the DP downward away from Fermi energy indicating the opening of E{sub g}. The band gap increases with increasing Na{sup +} coverage with a maximum E{sub g}?0.70?eV. Our core-level data, C 1s, Na 2p, and Si 2p, consistently suggest that Na{sup +} ions do not intercalate through graphene, but produce a significant charge asymmetry among the carbon atoms of graphene to cause the opening of a band gap. We thus provide a reliable way of producing and tuning the band gap of graphene by using Na{sup +} ions, which may play a vital role in utilizing graphene in future nano-electronic devices.

  9. Gap solitons in rocking optical lattices and waveguides with undulating gratings

    SciTech Connect (OSTI)

    Mayteevarunyoo, Thawatchai; Malomed, Boris A.

    2009-07-15

    We report results of a systematic analysis of the stability of one-dimensional solitons in a model including the self-repulsive or attractive cubic nonlinearity and a linear potential represented by a periodically shaking lattice, which was recently implemented in experiments with Bose-Einstein condensates. In optics, the same model applies to undulated waveguiding arrays, which are also available to the experiment. In the case of the repulsive nonlinearity, stability regions are presented, in relevant parameter planes, for fundamental gap solitons and their two-peak and three-peak bound complexes, in the first and second finite band gaps. In the model with the attractive nonlinearity, stability regions are produced for fundamental solitons and their bound states populating the semi-infinite gap. In the first finite and semi-infinite gaps, unstable solitons gradually decay into radiation, while, in the second finite band gap, they are transformed into more complex states, which may represent new species of solitons. For a large amplitude of the rocking-lattice drive, the model is tantamount to that with a 'flashing' lattice potential, which is controlled by periodic sequences of instantaneous kicks. Using this correspondence, we explain generic features of the stability diagrams for the solitons. We also derive a limit case of the latter system, in the form of coupled-mode equations with a 'flashing' linear coupling.

  10. Band-Gap Engineering at a Semiconductor-Crystalline Oxide Interface

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

    Jahangir-Moghadam, Mohammadreza; Ahmadi-Majlan, Kamyar; Shen, Xuan; Droubay, Timothy; Bowden, Mark; Chrysler, Matthew; Su, Dong; Chambers, Scott A.; Ngai, Joseph H.

    2015-02-09

    The epitaxial growth of crystalline oxides on semiconductors provides a pathway to introduce new functionalities to semiconductor devices. Key to integrating the functionalities of oxides onto semiconductors is controlling the band alignment at interfaces between the two materials. Here we apply principles of band gap engineering traditionally used at heterojunctions between conventional semiconductors to control the band offset between a single crystalline oxide and a semiconductor. Reactive molecular beam epitaxy is used to realize atomically abrupt and structurally coherent interfaces between SrZrxTi1-xO₃ and Ge, in which the band gap of the former is enhanced with Zr content x. We presentmore » structural and electrical characterization of SrZrxTi1-xO₃-Ge heterojunctions and demonstrate a type-I band offset can be achieved. These results demonstrate that band gap engineering can be exploited to realize functional semiconductor crystalline oxide heterojunctions.« less

  11. Reactor Safety Gap Evaluation of Accident Tolerant Components and Severe Accident Analysis

    SciTech Connect (OSTI)

    Farmer, Mitchell T.; Bunt, R.; Corradini, M.; Ellison, Paul B.; Francis, M.; Gabor, John D.; Gauntt, R.; Henry, C.; Linthicum, R.; Luangdilok, W.; Lutz, R.; Paik, C.; Plys, M.; Rabiti, Cristian; Rempe, J.; Robb, K.; Wachowiak, R.

    2015-01-31

    The overall objective of this study was to conduct a technology gap evaluation on accident tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist, given the current state of light water reactor (LWR) severe accident research, and additionally augmented by insights obtained from the Fukushima accident. The ultimate benefit of this activity is that the results can be used to refine the Department of Energy’s (DOE) Reactor Safety Technology (RST) research and development (R&D) program plan to address key knowledge gaps in severe accident phenomena and analyses that affect reactor safety and that are not currently being addressed by the industry or the Nuclear Regulatory Commission (NRC).

  12. CHARACTERIZING DETONATING LX-17 CHARGES CROSSING A TRANSVERSE AIR GAP WITH EXPERIMENTS AND MODELING

    SciTech Connect (OSTI)

    Lauderbach, L M; Souers, P C; Garcia, F; Vitello, P; Vandersall, K S

    2009-06-26

    Experiments were performed using detonating LX-17 (92.5% TATB, 7.5% Kel-F by weight) charges with various width transverse air gaps with manganin peizoresistive in-situ gauges present. The experiments, performed with 25 mm diameter by 25 mm long LX-17 pellets with the transverse air gap in between, showed that transverse gaps up to about 3 mm could be present without causing the detonation wave to fail to continue as a detonation. The Tarantula/JWL{sup ++} code was utilized to model the results and compare with the in-situ gauge records with some agreement to the experimental data with additional work needed for a better match to the data. This work will present the experimental details as well as comparison to the model results.

  13. Band-Gap Engineering at a Semiconductor-Crystalline Oxide Interface

    SciTech Connect (OSTI)

    Jahangir-Moghadam, Mohammadreza; Ahmadi-Majlan, Kamyar; Shen, Xuan; Droubay, Timothy; Bowden, Mark; Chrysler, Matthew; Su, Dong; Chambers, Scott A.; Ngai, Joseph H.

    2015-02-09

    The epitaxial growth of crystalline oxides on semiconductors provides a pathway to introduce new functionalities to semiconductor devices. Key to integrating the functionalities of oxides onto semiconductors is controlling the band alignment at interfaces between the two materials. Here we apply principles of band gap engineering traditionally used at heterojunctions between conventional semiconductors to control the band offset between a single crystalline oxide and a semiconductor. Reactive molecular beam epitaxy is used to realize atomically abrupt and structurally coherent interfaces between SrZrxTi1-xO? and Ge, in which the band gap of the former is enhanced with Zr content x. We present structural and electrical characterization of SrZrxTi1-xO?-Ge heterojunctions and demonstrate a type-I band offset can be achieved. These results demonstrate that band gap engineering can be exploited to realize functional semiconductor crystalline oxide heterojunctions.

  14. Local strain effect on the band gap engineering of graphene by a first-principles study

    SciTech Connect (OSTI)

    Gui, Gui; Booske, John; Ma, Zhenqiang E-mail: mazq@engr.wisc.edu; Morgan, Dane; Zhong, Jianxin E-mail: mazq@engr.wisc.edu

    2015-02-02

    We have systematically investigated the effect of local strain on electronic properties of graphene by first-principles calculations. Two major types of local strain, oriented along the zigzag and the armchair directions, have been studied. We find that local strain with a proper range and strength along the zigzag direction results in opening of significant band gaps in graphene, on the order of 10{sup ?1?}eV; whereas, local strain along the armchair direction cannot open a significant band gap in graphene. Our results show that appropriate local strain can effectively open and tune the band gap in graphene; therefore, the electronic and transport properties of graphene can also be modified.

  15. Dome – like variation of the superconducting gap anisotropy in Fe-based superconductors

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

    Prozorov, R.; Cho, K.; Kim, H.; Tanatar, M. A.

    2013-07-17

    Experiments performed on different iron-based superconductors suggest a variety of possible structures of the superconducting energy gap, both nodeless and nodal. To understand the pairing mechanisms, it is important to identify common features in the behavior of different materials. Measurements of the temperature - dependent London penetration depth provide important information on the structure of the superconducting gap. We show that despite significant differences between different iron - based superconductors, there is a universal trend: the gap is least anisotropic at the optimal doping and its anisotropy increases upon the departure towards underdoped and overdoped ends of the ''superconducting dome''.more » As a result, this trend is not related to the presence of the long-range magnetic order in the underdoped state.« less

  16. Method of manufacturing flexible metallic photonic band gap structures, and structures resulting therefrom

    DOE Patents [OSTI]

    Gupta, Sandhya; Tuttle, Gary L.; Sigalas, Mihail; McCalmont, Jonathan S.; Ho, Kai-Ming

    2001-08-14

    A method of manufacturing a flexible metallic photonic band gap structure operable in the infrared region, comprises the steps of spinning on a first layer of dielectric on a GaAs substrate, imidizing this first layer of dielectric, forming a first metal pattern on this first layer of dielectric, spinning on and imidizing a second layer of dielectric, and then removing the GaAs substrate. This method results in a flexible metallic photonic band gap structure operable with various filter characteristics in the infrared region. This method may be used to construct multi-layer flexible metallic photonic band gap structures. Metal grid defects and dielectric separation layer thicknesses are adjusted to control filter parameters.

  17. Formation of quantum spin Hall state on Si surface and energy gap scaling

    Office of Scientific and Technical Information (OSTI)

    with strength of spin orbit coupling (Journal Article) | SciTech Connect Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling Citation Details In-Document Search Title: Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling For potential applications in spintronics and quantum computing, it is desirable to place a quantum spin Hall insulator [i.e., a 2D topological insulator

  18. Interface Ferroelectric Transition near the Gap-Opening Temperature in a

    Office of Scientific and Technical Information (OSTI)

    Single-Unit-Cell FeSe Film Grown on Nb-Doped SrTiO 3 Substrate (Journal Article) | SciTech Connect Interface Ferroelectric Transition near the Gap-Opening Temperature in a Single-Unit-Cell FeSe Film Grown on Nb-Doped SrTiO 3 Substrate Citation Details In-Document Search Title: Interface Ferroelectric Transition near the Gap-Opening Temperature in a Single-Unit-Cell FeSe Film Grown on Nb-Doped SrTiO 3 Substrate Authors: Cui, Y.-T. ; Moore, R. G. ; Zhang, A.-M. ; Tian, Y. ; Lee, J. J. ;

  19. Structural studies and band gap tuning of Cr doped ZnO nanoparticles

    SciTech Connect (OSTI)

    Srinet, Gunjan Kumar, Ravindra Sajal, Vivek

    2014-04-24

    Structural and optical properties of Cr doped ZnO nanoparticles prepared by the thermal decomposition method are presented. X-ray diffraction studies confirmed the substitution of Cr on Zn sites without changing the wurtzite structure of ZnO. Modified form of W-H equations was used to calculate various physical parameters and their variation with Cr doping is discussed. Significant red shift was observed in band gap, i.e., a band gap tuning is achieved by Cr doping which could eventually be useful for optoelectronic applications.

  20. Influence of discharge gap on the discharge stability in a short vacuum arc ion source

    SciTech Connect (OSTI)

    Chen, L.; Zhang, G. L.; Jin, D. Z.; Dai, J. Y.; Yang, L.

    2012-02-15

    The influence of the discharge gap between cathode and anode on the discharge stability in a short vacuum arc (SVA) ion source is presented in this paper. Planar cathode and cylindrical hollow anode made of titanium are investigated. There is a great need in present accelerator injection research for SVA source to produce the small deviation of the ion current beam. Current research shows that increasing the short discharge gap can reduce the level of ion current deviation and ion charge deviation from 29% and 31% to 15% and 17%, respectively. A microplasma plume generation mechanism in SVA and scanning electron microscopic results can be used to explain this interesting phenomenon.

  1. Coexistence of a pseudogap and a superconducting gap for the high - T c

    Office of Scientific and Technical Information (OSTI)

    superconductor La 2 - x Sr x CuO 4 studied by angle-resolved photoemission spectroscopy (Journal Article) | SciTech Connect Coexistence of a pseudogap and a superconducting gap for the high - T c superconductor La 2 - x Sr x CuO 4 studied by angle-resolved photoemission spectroscopy Citation Details In-Document Search This content will become publicly available on January 18, 2017 Title: Coexistence of a pseudogap and a superconducting gap for the high - T c superconductor La 2 - x Sr x CuO

  2. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal A New Gap-Opening Mechanism in a Triple-Band Metal Print Wednesday, 23 February 2005 00:00 A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to

  3. Direct Observation of Energy-Gap Scaling Law in CdSe Quantum Dots with Positrons

    SciTech Connect (OSTI)

    Denison, Arthur Blanchard; Weber, M. H.; Lynn, K. G.; Barbiellini, B.; Sterne, P. A.

    2002-07-01

    CdSe quantum dot samples with sizes in the range of 1.8~6 nm in diameter were examined by positron annihilation spectroscopy. The results were compared to data obtained for single-crystal bulk CdSe. Evidence is provided that the positrons annihilate within the nanospheres. The annihilation line shape shows a smearing at the boundary of the Jones zone proportional to the widening of the band gap due to a reduction in the size of the quantum dots. The data confirm that the change in the band gap is inversely proportional to the square of the quantum dot diameter.

  4. Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc

    Office of Scientific and Technical Information (OSTI)

    Cuprate Superconductors: Angle-Resolved Photoemission Study of La2-xSrxCuO4 (Journal Article) | SciTech Connect Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc Cuprate Superconductors: Angle-Resolved Photoemission Study of La2-xSrxCuO4 Citation Details In-Document Search Title: Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc Cuprate Superconductors: Angle-Resolved Photoemission Study of La2-xSrxCuO4 We have investigated the doping and temperature

  5. Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc

    Office of Scientific and Technical Information (OSTI)

    Cuprate Superconductors: Angle-Resolved Photoemission Study of La2-xSrxCuO4 (Journal Article) | SciTech Connect Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc Cuprate Superconductors: Angle-Resolved Photoemission Study of La2-xSrxCuO4 Citation Details In-Document Search Title: Universal versus Materials-Dependent Two-Gap Behaviour of the High-Tc Cuprate Superconductors: Angle-Resolved Photoemission Study of La2-xSrxCuO4 × You are accessing a document from the

  6. Multi-gap Resistive Plate Chambers as a Time-of-Flight System for the PHENIX Experiment

    SciTech Connect (OSTI)

    Velkovska, Julia

    2013-12-08

    In this project a Time-of-Flight detector based on multi-gap resistive plate chambers was built and installed for the PHENIX experiment at RHIC.

  7. Fact #850: December 8, 2014 Automatic Transmissions have closed the Fuel Economy Gap with Manual Transmissions- Dataset

    Broader source: Energy.gov [DOE]

    Excel file with dataset for Fact #850: December 8, 2014 Automatic Transmissions have closed the Fuel Economy Gap with Manual Transmissions

  8. GaNPAs Solar Cells Lattice-Matched To GaP: Preprint

    SciTech Connect (OSTI)

    Geisz, J. F.; Friedman, D. J.; Kurtz, S.

    2002-05-01

    This conference paper describes the III-V semiconductors grown on silicon substrates are very attractive for lower-cost, high-efficiency multijunction solar cells, but lattice-mismatched alloys that result in high dislocation densities have been unable to achieve satisfactory performance. GaNxP1-x-yAsy is a direct-gap III-V alloy that can be grown lattice-matched to Si when y= 4.7x - 0.1. We propose the use of lattice-matched GaNPAs on silicon for high-efficiency multijunction solar cells. We have grown GaNxP1-x-yAsy on GaP (with a similar lattice constant to silicon) by metal-organic chemical vapor phase epitaxy with direct band-gaps in the range of 1.5 to 2.0 eV. We demonstrate the performance of single-junction GaNxP1-x-yAsy solar cells grown on GaP substrates and discuss the prospects for the development of monolithic high-efficiency multijunction solar cells based on silicon substrates.

  9. Continuum absorption in the vicinity of the toroidicity-induced Alfvén gap

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

    Li, M.; Breizman, B. N.; Zheng, L. J.; Chen, Eugene Y.

    2015-12-04

    Excitation of Alfvén modes is commonly viewed as a concern for energetic particle confinement in burning plasmas. The 3.5 MeValpha particles produced by fusion may be affected as well as other fast ions in both present and future devices. Continuum damping of such modes is one of the key factors that determine their excitation thresholds and saturation levels. This work examines the resonant dissipative response of the Alfvén continuum to an oscillating driving current when the driving frequency is slightly outside the edges of the toroidicity-induced spectral gap. The problem is largely motivated by the need to describe the continuummore » absorption in the frequency sweeping events. Akey element of this problem is the negative interference of the two closely spaced continuum crossing points.Weexplain why the lower and upper edges of the gap can have very different continuum absorption features. Lastly, the difference is associated with an eigenmode whose frequency can be arbitrarily close to the upper edge of the gap whereas the lower edge of the gap is always a finite distance away from the closest eigenmode.« less

  10. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    SciTech Connect (OSTI)

    Souers, P C; Hernandez, A; Cabacungan, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2008-02-05

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in 0 reactive flow JWL++ and Linked Cheetah V4, mostly at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. The physical basis of the input parameters is considered.

  11. Electronegativity calculation of bulk modulus and band gap of ternary ZnO-based alloys

    SciTech Connect (OSTI)

    Li, Keyan; Kang, Congying [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)] [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Xue, Dongfeng, E-mail: dongfeng@ciac.jl.cn [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China) [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-10-15

    In this work, the bulk moduli and band gaps of M{sub x}Zn{sub 1?x}O (M = Be, Mg, Ca, Cd) alloys in the whole composition range were quantitatively calculated by using the electronegativity-related models for bulk modulus and band gap, respectively. We found that the change trends of bulk modulus and band gap with an increase of M concentration x are same for Be{sub x}Zn{sub 1?x}O and Cd{sub x}Zn{sub 1?x}O, while the change trends are reverse for Mg{sub x}Zn{sub 1?x}O and Ca{sub x}Zn{sub 1?x}O. It was revealed that the bulk modulus is related to the valence electron density of atoms whereas the band gap is strongly influenced by the detailed chemical bonding behaviors of constituent atoms. The current work provides us a useful guide to compositionally design advanced alloy materials with both good mechanical and optoelectronic properties.

  12. Band-gap tailoring of ZnO by means of heavy Al doping

    SciTech Connect (OSTI)

    Sernelius, B.E.; Berggren, K.; Jin, Z.; Hamberg, I.; Granqvist, C.G.

    1988-06-15

    Films of ZnO:Al were produced by weakly reactive dual-target magnetron sputtering. Optical band gaps, evaluated from spectrophotometric data, were widened in proportion to the Al doping. The widening could be quantitatively reconciled with an effective-mass model for n-doped semiconductors, provided the polar character of ZnO was accounted for.

  13. Continuum absorption in the vicinity of the toroidicity-induced Alfvén gap

    SciTech Connect (OSTI)

    Li, M.; Breizman, B. N.; Zheng, L. J.; Chen, Eugene Y.

    2015-12-04

    Excitation of Alfvén modes is commonly viewed as a concern for energetic particle confinement in burning plasmas. The 3.5 MeValpha particles produced by fusion may be affected as well as other fast ions in both present and future devices. Continuum damping of such modes is one of the key factors that determine their excitation thresholds and saturation levels. This work examines the resonant dissipative response of the Alfvén continuum to an oscillating driving current when the driving frequency is slightly outside the edges of the toroidicity-induced spectral gap. The problem is largely motivated by the need to describe the continuum absorption in the frequency sweeping events. Akey element of this problem is the negative interference of the two closely spaced continuum crossing points.Weexplain why the lower and upper edges of the gap can have very different continuum absorption features. Lastly, the difference is associated with an eigenmode whose frequency can be arbitrarily close to the upper edge of the gap whereas the lower edge of the gap is always a finite distance away from the closest eigenmode.

  14. Summary of Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies

    SciTech Connect (OSTI)

    Not Available

    2010-08-01

    This report presents the key gaps and barriers to implementing residential energy efficiency strategies in the U.S. market, as identified in sessions at the U.S. Department of Energy's Building America 2010 Residential Energy Efficiency Meeting held in Denver, Colorado, on July 20-22, 2010.

  15. Stability of S and Se induced reconstructions on GaP(001)(21) surface

    SciTech Connect (OSTI)

    Li , D. F.; Guo, Zhi C.; Xiao, Hai Yan; Zu, Xiaotao T.; Gao, Fei

    2010-10-15

    The structural and electronic properties of S- and Se- passivated GaP(001)(21) surfaces were studied using first-principles simulations. Our calculations showed that the most stable structure consists of a single chalcogen atom (S or Se) in the first crystal layer, which is bonded to two Ga atoms of the second layer, and the third P layer replaced by chalcogen atoms, similar to the passivation of GaAs(001)(21) surface by chalcogen atoms. The structural parameters were determined and the surface band characters and the local density of states were also analyzed. The results showed that the preferable structure has no surface states in the bulk band gap, but the energy band gaps of the S- and Se-adsorbed GaP(001) surfaces are 1.83eV and 1.63eV, respectively. The passivation effects for the S- and Se-adsorbed surfaces are similar to each other.

  16. Summary of Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies

    Broader source: Energy.gov [DOE]

    This report presents the key gaps and barriers to implementing residential energy efficiency strategies in the U.S. market, as identified in sessions at the U.S. Department of Energy's Building America 2010 Residential Energy Efficiency Meeting held in Denver, Colorado, on July 20-22, 2010.

  17. Correlation of pulsar radio emission spectrum with peculiarities of particle acceleration in a polar gap

    SciTech Connect (OSTI)

    Kontorovich, V. M. Flanchik, A. B.

    2013-01-15

    The analytical expression for the frequency of radio emission intensity maximum in pulsars with free electron emission from the stellar surface has been found. Peculiarities of the electron acceleration in a polar gap are considered. The correlation between the high-frequency cutoff and low-frequency turnover in the radio emission spectrum of pulsars known from observations has been explained.

  18. Likelihood-based gene annotations for gap filling and quality assessment in genome-scale metabolic models

    SciTech Connect (OSTI)

    Benedict, Matthew N.; Mundy, Michael B.; Henry, Christopher S.; Chia, Nicholas; Price, Nathan D.; Maranas, Costas D.

    2014-10-16

    Genome-scale metabolic models provide a powerful means to harness information from genomes to deepen biological insights. With exponentially increasing sequencing capacity, there is an enormous need for automated reconstruction techniques that can provide more accurate models in a short time frame. Current methods for automated metabolic network reconstruction rely on gene and reaction annotations to build draft metabolic networks and algorithms to fill gaps in these networks. However, automated reconstruction is hampered by database inconsistencies, incorrect annotations, and gap filling largely without considering genomic information. Here we develop an approach for applying genomic information to predict alternative functions for genes and estimate their likelihoods from sequence homology. We show that computed likelihood values were significantly higher for annotations found in manually curated metabolic networks than those that were not. We then apply these alternative functional predictions to estimate reaction likelihoods, which are used in a new gap filling approach called likelihood-based gap filling to predict more genomically consistent solutions. To validate the likelihood-based gap filling approach, we applied it to models where essential pathways were removed, finding that likelihood-based gap filling identified more biologically relevant solutions than parsimony-based gap filling approaches. We also demonstrate that models gap filled using likelihood-based gap filling provide greater coverage and genomic consistency with metabolic gene functions compared to parsimony-based approaches. Interestingly, despite these findings, we found that likelihoods did not significantly affect consistency of gap filled models with Biolog and knockout lethality data. This indicates that the phenotype data alone cannot necessarily be used to discriminate between alternative solutions for gap filling and therefore, that the use of other information is necessary to obtain a more accurate network. All described workflows are implemented as part of the DOE Systems Biology Knowledgebase (KBase) and are publicly available via API or command-line web interface.

  19. Likelihood-based gene annotations for gap filling and quality assessment in genome-scale metabolic models

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

    Benedict, Matthew N.; Mundy, Michael B.; Henry, Christopher S.; Chia, Nicholas; Price, Nathan D.; Maranas, Costas D.

    2014-10-16

    Genome-scale metabolic models provide a powerful means to harness information from genomes to deepen biological insights. With exponentially increasing sequencing capacity, there is an enormous need for automated reconstruction techniques that can provide more accurate models in a short time frame. Current methods for automated metabolic network reconstruction rely on gene and reaction annotations to build draft metabolic networks and algorithms to fill gaps in these networks. However, automated reconstruction is hampered by database inconsistencies, incorrect annotations, and gap filling largely without considering genomic information. Here we develop an approach for applying genomic information to predict alternative functions for genesmore » and estimate their likelihoods from sequence homology. We show that computed likelihood values were significantly higher for annotations found in manually curated metabolic networks than those that were not. We then apply these alternative functional predictions to estimate reaction likelihoods, which are used in a new gap filling approach called likelihood-based gap filling to predict more genomically consistent solutions. To validate the likelihood-based gap filling approach, we applied it to models where essential pathways were removed, finding that likelihood-based gap filling identified more biologically relevant solutions than parsimony-based gap filling approaches. We also demonstrate that models gap filled using likelihood-based gap filling provide greater coverage and genomic consistency with metabolic gene functions compared to parsimony-based approaches. Interestingly, despite these findings, we found that likelihoods did not significantly affect consistency of gap filled models with Biolog and knockout lethality data. This indicates that the phenotype data alone cannot necessarily be used to discriminate between alternative solutions for gap filling and therefore, that the use of other information is necessary to obtain a more accurate network. All described workflows are implemented as part of the DOE Systems Biology Knowledgebase (KBase) and are publicly available via API or command-line web interface.« less

  20. P and n-type microcrystalline semiconductor alloy material including band gap widening elements, devices utilizing same

    DOE Patents [OSTI]

    Guha, Subhendu; Ovshinsky, Stanford R.

    1988-10-04

    An n-type microcrystalline semiconductor alloy material including a band gap widening element; a method of fabricating p-type microcrystalline semiconductor alloy material including a band gap widening element; and electronic and photovoltaic devices incorporating said n-type and p-type materials.

  1. Fabrication of Ceramic Layer-by-Layer Infrared Wavelength Photonic Band Gap Crystals

    SciTech Connect (OSTI)

    Henry Hao-Chuan Kang

    2004-12-19

    Photonic band gap (PBG) crystals, also known as photonic crystals, are periodic dielectric structures which form a photonic band gap that prohibit the propagation of electromagnetic (EM) waves of certain frequencies at any incident angles. Photonic crystals have several potential applications including zero-threshold semiconductor lasers, the inhibition of spontaneous emission, dielectric mirrors, and wavelength filters. If defect states are introduced in the crystals, light can be guided from one location to another or even a sharp bending of light in micron scale can be achieved. This generates the potential for optical waveguide and optical circuits, which will contribute to the improvement in the fiber-optic communications and the development of high-speed computers.

  2. Oxygen miscibility gap and spin glass formation in the pyrochlore Lu{sub

    Office of Scientific and Technical Information (OSTI)

    2}Mo{sub 2}O{sub 7} (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Oxygen miscibility gap and spin glass formation in the pyrochlore Lu{sub 2}Mo{sub 2}O{sub 7} Citation Details In-Document Search Title: Oxygen miscibility gap and spin glass formation in the pyrochlore Lu{sub 2}Mo{sub 2}O{sub 7} Rare earth (R) molybdate pyrochlores, R{sub 2}Mo{sub 2}O{sub 7}, are of interest as frustrated magnets. Polycrystalline samples of Lu{sub 2}Mo{sub 2}O{sub 7-x}

  3. Simulation of impact of the Generic Accident-Resistant Packaging (GAP)

    SciTech Connect (OSTI)

    Slavin, A.M.

    1994-10-01

    Finite element simulations modelling impact of the Generic Accident-Resistant Packaging (GAP) have been performed. The GAP is a nuclear weapon shipping container that will be used by accident response groups from both the United States and the United Kingdom. The package is a thin-walled steel structure filled with rigid polyurethane foam and weighs approximately 5100 lbs when loaded. The simulations examined 250 ft/s impacts onto a rigid target at several orientations. The development of the finite element model included studies of modelling assumptions and material parameters. Upon completion of the simulation series, three full-scale impact tests were performed. A comparison of the simulation results to the test data is given. Differences between the results and data are examined, and possible explanations for the differences are discussed.

  4. Bridging a gap between continuum-QCD and ab initio predictions of hadron observables

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

    Binosi, Daniele; Chang, Lei; Papavassiliou, Joannis; Roberts, Craig D.

    2015-01-23

    Within contemporary hadron physics there are two common methods for determining the momentum-dependence of the interaction between quarks: the top-down approach, which works toward an ab initio computation of the interaction via direct analysis of the gauge-sector gap equations; and the bottom-up scheme, which aims to infer the interaction by fitting data within a well-defined truncation of those equations in the matter sector that are relevant to bound-state properties. We unite these two approaches by demonstrating that the renormalisation-group-invariant running-interaction predicted by contemporary analyses of QCDs gauge sector coincides with that required in order to describe ground-state hadron observables usingmorea nonperturbative truncation of QCDs DysonSchwinger equations in the matter sector. This bridges a gap that had lain between nonperturbative continuum-QCD and the ab initio prediction of bound-state properties.less

  5. Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

    SciTech Connect (OSTI)

    Piepel, Gregory F.; Amidan, Brett G.; Hu, Rebecca

    2011-11-28

    This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the (1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and (2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed and recommendations are given for future studies.

  6. Emergence of robust gaps in two-dimensional antiferromagnets via additional spin-1/2 probes

    SciTech Connect (OSTI)

    Ferreira, Aires; Lopes, J. Viana; Lopes dos Santos, J. M. B.

    2010-08-15

    We study the capacity of antiferromagnetic lattices of varying geometries to entangle two additional spin-1/2 probes. Analytical modeling of the quantum Monte Carlo data shows the appearance of a robust gap, allowing a description of entanglement in terms of probe-only states, even in cases where the coupling to the probes is larger than the gap of the spin lattice and cannot be treated perturbatively. We find a considerable enhancement of the temperature at which probe entanglement disappears as we vary the geometry of the bus and the coupling to the probes. In particular, the square Heisenberg antiferromagnet exhibits the best thermal robustness of all systems, whereas the three-leg ladder chain shows the best performance in the natural quantum ground state.

  7. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires

    SciTech Connect (OSTI)

    Guo, Shaojun; Andrew F. Fidler; He, Kai; Su, Dong; Chen, Gen; Lin, Qianglu; Pietryga, Jeffrey M.; Klimov, Victor I.

    2015-11-06

    In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead to elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.

  8. Periodic dielectric structure for production of photonic band gap and method for fabricating the same

    DOE Patents [OSTI]

    Ozbay, Ekmel; Tuttle, Gary; Michel, Erick; Ho, Kai-Ming; Biswas, Rana; Chan, Che-Ting; Soukoulis, Costas

    1995-01-01

    A method for fabricating a periodic dielectric structure which exhibits a photonic band gap. Alignment holes are formed in a wafer of dielectric material having a given crystal orientation. A planar layer of elongate rods is then formed in a section of the wafer. The formation of the rods includes the step of selectively removing the dielectric material of the wafer between the rods. The formation of alignment holes and layers of elongate rods and wafers is then repeated to form a plurality of patterned wafers. A stack of patterned wafers is then formed by rotating each successive wafer with respect to the next-previous wafer, and then placing the successive wafer on the stack. This stacking results in a stack of patterned wafers having a four-layer periodicity exhibiting a photonic band gap.

  9. Band gap tuning in transition metal oxides by site-specific substitution

    DOE Patents [OSTI]

    Lee, Ho Nyung; Chisholm, Jr., Matthew F; Jellison, Jr., Gerald Earle; Singh, David J; Choi, Woo Seok

    2013-12-24

    A transition metal oxide insulator composition having a tuned band gap includes a transition metal oxide having a perovskite or a perovskite-like crystalline structure. The transition metal oxide includes at least one first element selected form the group of Bi, Ca, Ba, Sr, Li, Na, Mg, K, Pb, and Pr; and at least one second element selected from the group of Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Hf, Ta, W, Re, Os, Ir, and Pt. At least one correlated insulator is integrated into the crystalline structure, including REMO.sub.3, wherein RE is at least one Rare Earth element, and wherein M is at least one element selected from the group of Co, V, Cr, Ni, Mn, and Fe. The composition is characterized by a band gap of less of 4.5 eV.

  10. Periodic dielectric structure for production of photonic band gap and method for fabricating the same

    DOE Patents [OSTI]

    Ozbay, E.; Tuttle, G.; Michel, E.; Ho, K.M.; Biswas, R.; Chan, C.T.; Soukoulis, C.

    1995-04-11

    A method is disclosed for fabricating a periodic dielectric structure which exhibits a photonic band gap. Alignment holes are formed in a wafer of dielectric material having a given crystal orientation. A planar layer of elongate rods is then formed in a section of the wafer. The formation of the rods includes the step of selectively removing the dielectric material of the wafer between the rods. The formation of alignment holes and layers of elongate rods and wafers is then repeated to form a plurality of patterned wafers. A stack of patterned wafers is then formed by rotating each successive wafer with respect to the next-previous wafer, and then placing the successive wafer on the stack. This stacking results in a stack of patterned wafers having a four-layer periodicity exhibiting a photonic band gap. 42 figures.

  11. WORKSHOP REPORT:Light-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials

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

    VEHICLES TECHNOLOGIES OFFICE WORKSHOP REPORT: Light-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials February 2013 FINAL REPORT This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any

  12. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    SciTech Connect (OSTI)

    Souers, P C; Hernandez, A; Cabacungen, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2007-05-30

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in the Linked Cheetah V4.0 reactive flow code at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. A report card of 25 tests run with the same settings on LX-17 is shown, possibly the most extensive simultaneous calibration yet tried with an explosive. The physical basis of some of the input parameters is considered.

  13. NREL Study Suggests Cost Gap for Western Renewables Could Narrow by 2025 -

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

    News Releases | NREL NREL Study Suggests Cost Gap for Western Renewables Could Narrow by 2025 August 23, 2013 A new Energy Department study conducted by the National Renewable Energy Laboratory (NREL) indicates that by 2025 wind and solar power electricity generation could become cost-competitive without federal subsidies, if new renewable energy development occurs in the most productive locations. The report, "Beyond Renewable Portfolio Standards: An Assessment of Regional Supply and

  14. Catalysis by Design: Bridging the Gap Between Theory and Experiments at

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

    Nanoscale Level | Department of Energy Studies on a simple platinum-alumina system constitute a first step toward a "catalyst by design" approach. PDF icon deer08_narula.pdf More Documents & Publications Catalysis by Design: Bridging the Gap between Theory and Experiments Catalyst by Design - Theoretical, Nanostructural, and Experimental Studies of Oxidation Catalyst for Diesel Engine Emission Treatment

  15. THE MIGRATION OF GAP-OPENING PLANETS IS NOT LOCKED TO VISCOUS DISK EVOLUTION

    SciTech Connect (OSTI)

    Duffell, Paul C.; MacFadyen, Andrew I.; Farris, Brian D.; Haiman, Zoltan; D'Orazio, Daniel J.

    2014-09-01

    Most standard descriptions of TypeII migration state that massive, gap-opening planets must migrate at the viscous drift rate. This is based on the idea that the disk is separated into an inner and outer region and gas is considered unable to cross the gap. In fact, gas easily crosses the gap on horseshoe orbits, nullifying this necessary premise which would set the migration rate. In this work, it is demonstrated using highly accurate numerical calculations that the actual migration rate is dependent on disk and planet parameters, and can be significantly larger or smaller than the viscous drift rate. In the limiting case of a disk much more massive than the secondary, the migration rate saturates to a constant that is sensitive to disk parameters and is not necessarily of the order of the viscous rate. In the opposite limit of a low-mass disk, the migration rate decreases linearly with disk mass. Steady-state solutions in the low disk mass limit show no pile-up outside the secondary's orbit, and no corresponding drainage of the inner disk.

  16. HUD (Housing and Urban Development) Intermediate Minimum Property Standards Supplement 4930. 2 (1989 edition). Solar heating and domestic hot water systems

    SciTech Connect (OSTI)

    Not Available

    1989-12-01

    The Minimum Property Standards for Housing 4910.1 were developed to provide a sound technical basis for housing under numerous programs of the Department of Housing and Urban Development (HUD). These Intermediate Minimum Property Standards for Solar Heating and Domestic Hot Water Systems are intended to provide a companion technical basis for the planning and design of solar heating and domestic hot water systems. These standards have been prepared as a supplement to the Minimum Property Standards (MPS) and deal only with aspects of planning and design that are different from conventional housing by reason of the solar systems under consideration. The document contains requirements and standards applicable to one- and two-family dwellings, multifamily housing, and nursing homes and intermediate care facilities references made in the text to the MPS refer to the same section in the Minimum Property Standards for Housing 4910.1.

  17. Webinar: America's Next Top Energy Innovator Runner-Up Presents...

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

    ... I am going to try something here to show a video; we will see if I can. Embedded Video This video shows our thin-film sensor. You can see it is a mixture of 10 percent hydrogen ...

  18. Impact of Rate Design Alternatives on Residential Solar Customer Bills. Increased Fixed Charges, Minimum Bills and Demand-based Rates

    SciTech Connect (OSTI)

    Bird, Lori; Davidson, Carolyn; McLaren, Joyce; Miller, John

    2015-09-01

    With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset, on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.

  19. High pressures and the Kondo gap in Ce{sub 3}Bi{sub 4}Pt{sub 3}

    SciTech Connect (OSTI)

    Cooley, J.C.; Aronson, M.C.; Canfield, P.C.

    1997-03-01

    We have measured the electrical resistivity {rho}(T) of single crystals of Ce{sub 3}Bi{sub 4}Pt{sub 3} for temperatures from 1.2 to 300 K, and pressures from 1 bar to 145 kbar. The transport is dominated at high temperatures by excitations across a small activation gap {Delta}, which increases rapidly with pressure. The low-temperature transport involves variable range hopping among extrinsic states in the gap. The spatial extent of the in-gap states reflects coupling to conduction-electron states, and is strongly modified as pressure enhances {Delta}. Despite the strong pressure dependence of {Delta}, a direct correspondence between single-ion energetics and the measured gap is maintained, and the role of valence fluctuations is minimal even at the highest pressures. {copyright} {ital 1997} {ital The American Physical Society}

  20. Determing Degradation Of Fiberboard In The 9975 Shipping Package By Measuring Axial Gap

    SciTech Connect (OSTI)

    Hackney, E. R.; Dougherty, W. L.; Dunn, K. A.; Stefek, T. M

    2013-08-01

    Currently, thousands of model 9975 transportation packages are in use by the US Department of Energy (DOE); the design of which has been certified by DOE for shipment of Type B radioactive and fissile materials in accordance with Part 71, Title 10 Code of Federal Regulations (CFR), or 10 CFR 71, Packaging and Transportation of Radioactive Material. These transportation packages are also approved for the storage of DOE-STD-3013 containers at the Savannah River Site (SRS). As such, the 9975 has been continuously exposed to the service environment for a period of time greater than the approved transportation service life. In order to ensure the material integrity as specified in the safety basis, an extensive surveillance program is in place in K-Area Complex (KAC) to monitor the structural and thermal properties of the fiberboard of the 9975 shipping packages. The surveillance approach uses a combination of Non-Destructive Examination (NDE) field surveillance and Destructive Examination (DE) lab testing to validate the 9975 performance assumptions. The fiberboard in the 9975 is credited with thermal insulation, criticality control and resistance to crushing. During surveillance monitoring in KAC, an increased axial gap of the fiberboard was discovered on selected items packaged at Rocky Flats Environmental Technology Site (RFETS). Many of these packages were later found to contain excess moisture. Savannah River National Laboratory (SRNL) testing has resulted in a better understanding of the relationship between the fiberboard moisture level and compaction of the fiberboard under storage conditions and during transport. In laboratory testing, the higher moisture content has been shown to correspond to higher total compaction of fiberboard material and compaction rate. The fiberboard height is reduced by compression of the layers. This change is observed directly in the axial gap between the flange and the air shield. The axial gap measurement is made during the pre-use inspection or during the annual recertification process and is a screening measurement for changes in the fiberboard.

  1. Technical Barriers, Gaps, and Opportunities Related to Home Energy Upgrade Market Delivery

    SciTech Connect (OSTI)

    Bianchi, M. V. A.

    2011-11-01

    This report outlines the technical barriers, gaps, and opportunities that arise in executing home energy upgrade market delivery approaches, as identified through research conducted by the U.S. Department of Energy's Building America program. The objective of this report is to outline the technical1 barriers, gaps, and opportunities that arise in executing home energy upgrade market delivery approaches, as identified through research conducted by the U.S. Department of Energy's (DOE) Building America program. This information will be used to provide guidance for new research necessary to enable the success of the approaches. Investigation for this report was conducted via publications related to home energy upgrade market delivery approaches, and a series of interviews with subject matter experts (contractors, consultants, program managers, manufacturers, trade organization representatives, and real estate agents). These experts specified technical barriers and gaps, and offered suggestions for how the technical community might address them. The potential benefits of home energy upgrades are many and varied: reduced energy use and costs; improved comfort, durability, and safety; increased property value; and job creation. Nevertheless, home energy upgrades do not comprise a large part of the overall home improvement market. Residential energy efficiency is the most complex climate intervention option to deliver because the market failures are many and transaction costs are high (Climate Change Capital 2009). The key reasons that energy efficiency investment is not being delivered are: (1) The opportunity is highly fragmented; and (2) The energy efficiency assets are nonstatus, low-visibility investments that are not properly valued. There are significant barriers to mobilizing the investment in home energy upgrades, including the 'hassle factor' (the time and effort required to identify and secure improvement works), access to financing, and the opportunity cost of capital and split incentives.

  2. Low jitter spark gap switch for repetitively pulsed parallel capacitor banks

    SciTech Connect (OSTI)

    Rohwein, G. J.

    1980-01-01

    A two-section air insulated spark gap has been developed for switching multi-kilojoule plus-minus charged parallel capacitor banks which operate continuously at pulse rates up to 20 pps. The switch operates with less than 2 ns jitter, recovers its dielectric strength within 2 to 5 ms and has not shown degraded performance in sequential test runs totaling over a million shots. Its estimated life with copper electrodes is > 10/sup 7/ shots. All preliminary tests indicate that the switch is suitable for continuous running multi-kilojoule systems operating to at least 20 pps.

  3. Photonic band gaps in three-dimensional network structures with short-range order

    SciTech Connect (OSTI)

    Liew, Seng Fatt; Noh, Heeso; Yang, Jin-Kyu; Schreck, Carl F.; Dufresne, Eric R.; O'Hern, Corey S.; Cao, Hui

    2011-12-15

    We present a systematic study of photonic band gaps (PBGs) in three-dimensional (3D) photonic amorphous structures (PASs) with short-range order. From calculations of the density of optical states (DOS) for PASs with different topologies, we find that tetrahedrally connected dielectric networks produce the largest isotropic PBGs. Local uniformity and tetrahedral order are essential to the formation of PBGs in PASs, in addition to short-range geometric order. This work demonstrates that it is possible to create broad, isotropic PBGs for vector light fields in 3D PASs without long-range order.

  4. Note: The design of thin gap chamber simulation signal source based on field programmable gate array

    SciTech Connect (OSTI)

    Hu, Kun; Wang, Xu; Li, Feng; Jin, Ge; Lu, Houbing; Liang, Futian

    2015-01-15

    The Thin Gap Chamber (TGC) is an important part of ATLAS detector and LHC accelerator. Targeting the feature of the output signal of TGC detector, we have designed a simulation signal source. The core of the design is based on field programmable gate array, randomly outputting 256-channel simulation signals. The signal is generated by true random number generator. The source of randomness originates from the timing jitter in ring oscillators. The experimental results show that the random number is uniform in histogram, and the whole system has high reliability.

  5. Analysis of plasma-magnetic photonic crystal with a tunable band gap

    SciTech Connect (OSTI)

    Mehdian, H.; Mohammadzahery, Z.; Hasanbeigi, A. [Department of Physics and Plasma Research Institute of Tarbiat Moallem University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)

    2013-04-15

    In this paper, electromagnetic wave propagation through the one-dimensional plasma-magnetic photonic crystal in the presence of external magnetic field has been analyzed. The dispersion relation, transmission and reflection coefficients have been obtained by using the transfer matrix method. It is investigated how photonic band gap of photonic crystals will be tuned when both dielectric function {epsilon} and magnetic permeability {mu} of the constitutive materials, depend on applied magnetic field. This is shown by one dimensional photonic crystals consisting of plasma and ferrite material layers stacked alternately.

  6. U.S. Gap Analysis to Support Extended Storage of Used Nuclear Fuel

    SciTech Connect (OSTI)

    Hanson, Brady D.; Alsaed, Abdelhalim -.; Stockman, Christine T.; Sorenson, Ken B.

    2012-06-27

    Dry storage of used nuclear fuel in the United States will continue until a disposition pathway is chosen and implemented. As such, the duration of dry storage will be much longer than originally anticipated. This paper reviews the methodology used in and the results of an analysis to determine the technical data gaps that need to be addressed to assure the continued safe and secure storage of used nuclear fuel for extended periods. Six high priority and eleven medium priority mechanisms were identified that may degrade the safety functions of the dry storage structures, systems, and components.

  7. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface

  8. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface

  9. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface

  10. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface

  11. A New Gap-Opening Mechanism in a Triple-Band Metal

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

    A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface

  12. Bridging the Gap between Scientific Data Producers and Consumers: A Provenance Approach

    SciTech Connect (OSTI)

    Stephan, Eric G.; Pinheiro da Silva, Paulo; Kleese van Dam, Kerstin

    2013-06-03

    Despite the methodical and painstaking efforts made by scientists to record their scientific findings and protocols, a knowledge gap problem continues to persist today between producers of scientific results and consumers because technology is performing the exchange of data as opposed to scientists making direct contact. Provenance is a means to formalize how this knowledge is transferred. However, for it to be meaningful to scientists, the provenance research community needs continued contributions from the scientific community to extend and leverage provenance-based vocabularies and technology from the provenance community. Going forward the provenance community must also be vigilant to meet scalability needs of data intensive science

  13. Inverse Design of Mn-based ternary p-type wide-gap oxides

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

    ZnO is an important prototypical wide-gap oxide semiconductor. The discrepancy between band- structure theory and ARPES is removed by a correction for the Zn-d band energy in GW calculations. Significance and Impact The present approach improves the capability for property prediction and design of energy materials. Benchmarking Band-Structure Calculations Against Angular-Resolved Photoemission Spectroscopy (ARPES) for ZnO L.Y. Lim, S. Lany, Y.J. Chang, E. Rotenberg, A. Zunger, M.F. Toney,

  14. DOE Hydropower Program Annual Report for FY 2001

    SciTech Connect (OSTI)

    Sale, M. J.; Cada, G. F.; Carlson, T. J.; Dauble, D. D.; Hunt, R. T.; Sommers, G. L.; Rinehart, B. N.; Flynn, J. V.; Brookshier, P. A.

    2002-04-01

    This annual report describes the various projects supported by the hydropower program in FY 2001. The program’s focus for FY 2002 was on improving the environmental performance of hydropower projects by addressing problems such as fish mortality during passage through turbines, alteration of instream habitat, and water quality in tailwaters. A primary goal of this research was to develop new, environmentally friendly technology. DOE-funded projects have produced new conceptual designs for turbine systems, and these were tested in pilot-scale laboratory tests and in the field. New design approaches range from totally new turbine runners (e.g., work by Alden Research Laboratory and Concepts NREC) to modifications to existing designs (e.g., Voith Siemens work on Minimum Gap Runners). Biological criteria have also been developed in controlled laboratory tests of fish response to physical stresses, such as hydraulic shear and pressure changes. These biocriteria were combined with computational design tools to locate and eliminate damaging areas inside turbine systems.

  15. Techno-Economic Analysis of the Deacetylation and Disk Refining Process. Characterizing the Effect of Refining Energy and Enzyme Usage on Minimum Sugar Selling Price and Minimum Ethanol Selling Price

    SciTech Connect (OSTI)

    Chen, Xiaowen; Shekiro, Joseph; Pschorn, Thomas; Sabourin, Marc; Tucker, Melvin P.; Tao, Ling

    2015-10-29

    A novel, highly efficient deacetylation and disk refining (DDR) process to liberate fermentable sugars from biomass was recently developed at the National Renewable Energy Laboratory (NREL). The DDR process consists of a mild, dilute alkaline deacetylation step followed by low-energy-consumption disk refining. The DDR corn stover substrates achieved high process sugar conversion yields, at low to modest enzyme loadings, and also produced high sugar concentration syrups at high initial insoluble solid loadings. The sugar syrups derived from corn stover are highly fermentable due to low concentrations of fermentation inhibitors. The objective of this work is to evaluate the economic feasibility of the DDR process through a techno-economic analysis (TEA). A large array of experiments designed using a response surface methodology was carried out to investigate the two major cost-driven operational parameters of the novel DDR process: refining energy and enzyme loadings. The boundary conditions for refining energy (128–468 kWh/ODMT), cellulase (Novozyme’s CTec3) loading (11.6–28.4 mg total protein/g of cellulose), and hemicellulase (Novozyme’s HTec3) loading (0–5 mg total protein/g of cellulose) were chosen to cover the most commercially practical operating conditions. The sugar and ethanol yields were modeled with good adequacy, showing a positive linear correlation between those yields and refining energy and enzyme loadings. The ethanol yields ranged from 77 to 89 gallons/ODMT of corn stover. The minimum sugar selling price (MSSP) ranged from $0.191 to $0.212 per lb of 50 % concentrated monomeric sugars, while the minimum ethanol selling price (MESP) ranged from $2.24 to $2.54 per gallon of ethanol. The DDR process concept is evaluated for economic feasibility through TEA. The MSSP and MESP of the DDR process falls within a range similar to that found with the deacetylation/dilute acid pretreatment process modeled in NREL’s 2011 design report. The DDR process is a much simpler process that requires less capital and maintenance costs when compared to conventional chemical pretreatments with pressure vessels. As a result, we feel the DDR process should be considered as an option for future biorefineries with great potential to be more cost-effective.

  16. Techno-Economic Analysis of the Deacetylation and Disk Refining Process. Characterizing the Effect of Refining Energy and Enzyme Usage on Minimum Sugar Selling Price and Minimum Ethanol Selling Price

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

    Chen, Xiaowen; Shekiro, Joseph; Pschorn, Thomas; Sabourin, Marc; Tucker, Melvin P.; Tao, Ling

    2015-10-29

    A novel, highly efficient deacetylation and disk refining (DDR) process to liberate fermentable sugars from biomass was recently developed at the National Renewable Energy Laboratory (NREL). The DDR process consists of a mild, dilute alkaline deacetylation step followed by low-energy-consumption disk refining. The DDR corn stover substrates achieved high process sugar conversion yields, at low to modest enzyme loadings, and also produced high sugar concentration syrups at high initial insoluble solid loadings. The sugar syrups derived from corn stover are highly fermentable due to low concentrations of fermentation inhibitors. The objective of this work is to evaluate the economic feasibilitymore » of the DDR process through a techno-economic analysis (TEA). A large array of experiments designed using a response surface methodology was carried out to investigate the two major cost-driven operational parameters of the novel DDR process: refining energy and enzyme loadings. The boundary conditions for refining energy (128–468 kWh/ODMT), cellulase (Novozyme’s CTec3) loading (11.6–28.4 mg total protein/g of cellulose), and hemicellulase (Novozyme’s HTec3) loading (0–5 mg total protein/g of cellulose) were chosen to cover the most commercially practical operating conditions. The sugar and ethanol yields were modeled with good adequacy, showing a positive linear correlation between those yields and refining energy and enzyme loadings. The ethanol yields ranged from 77 to 89 gallons/ODMT of corn stover. The minimum sugar selling price (MSSP) ranged from $0.191 to $0.212 per lb of 50 % concentrated monomeric sugars, while the minimum ethanol selling price (MESP) ranged from $2.24 to $2.54 per gallon of ethanol. The DDR process concept is evaluated for economic feasibility through TEA. The MSSP and MESP of the DDR process falls within a range similar to that found with the deacetylation/dilute acid pretreatment process modeled in NREL’s 2011 design report. The DDR process is a much simpler process that requires less capital and maintenance costs when compared to conventional chemical pretreatments with pressure vessels. As a result, we feel the DDR process should be considered as an option for future biorefineries with great potential to be more cost-effective.« less

  17. Superconducting gap evolution in overdoped BaFe₂(As1-xPx)₂ single crystals through nanocalorimetry

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

    Campanini, D.; Diao, Z.; Fang, L.; Kwok, W.-K.; Welp, U.; Rydh, A.

    2015-06-18

    We report on specific heat measurements on clean overdoped BaFe₂(As1-xPx)₂ single crystals performed with a high resolution membrane-based nanocalorimeter. A nonzero residual electronic specific heat coefficient at zero temperature γr=C/T|T→0 is seen for all doping compositions, indicating a considerable fraction of the Fermi surface ungapped or having very deep minima. The remaining superconducting electronic specific heat is analyzed through a two-band s-wave α model in order to investigate the gap structure. Close to optimal doping we detect a single zero-temperature gap of Δ₀~5.3 me V, corresponding to Δ₀/kBTc ~ 2.2. Increasing the phosphorus concentration x, the main gap reduces tillmore » a value of Δ₀ ~ 1.9 meV for x = 0.55 and a second weaker gap becomes evident. From the magnetic field effect on γr, all samples however show similar behavior [γr(H) - γr (H = 0)∝ Hn, with n between 0.6 and 0.7]. This indicates that, despite a considerable redistribution of the gap weights, the total degree of gap anisotropy does not change drastically with doping.« less

  18. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires

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

    Guo, Shaojun; Andrew F. Fidler; He, Kai; Su, Dong; Chen, Gen; Lin, Qianglu; Pietryga, Jeffrey M.; Klimov, Victor I.

    2015-11-06

    In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead tomore » elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.« less

  19. Low temperature synthesis of Ru–Cu alloy nanoparticles with the compositions in the miscibility gap

    SciTech Connect (OSTI)

    Martynova, S.A.; Filatov, E.Yu.; Korenev, S.V.; Kuratieva, N.V.; Sheludyakova, L.A.; Plusnin, P.E.; Shubin, Yu.V.; Slavinskaya, E.M.; Boronin, A.I.

    2014-04-01

    A complex salt [Ru(NH{sub 3}){sub 5}Cl][Cu(C{sub 2}O{sub 4}){sub 2}H{sub 2}O]—the precursor of nanoalloys combining ruthenium and copper was prepared. It crystallizes in the monoclinic space group P2{sub 1}/n. Thermal properties of the prepared salt were examined in different atmospheres (helium, hydrogen, oxygen). Thermal decomposition of the precursor in inert atmosphere was thoroughly examined and the intermediate products were characterized. Experimental conditions for preparation of copper-rich (up to 12 at% of copper) metastable solid solution Cu{sub x}Ru{sub 1−x} (based on Ru structure) were optimized, what is in sharp contrast to the bimetallic miscibility gap known for the bulk counterparts in a wide composition range. Catalytic properties of copper–ruthenium oxide composite were tested in catalytic oxidation of CO. - Highlights: • We synthesized new precursor of CuRu metastable nanoalloys. • Thermal properties of the prepared salt were examined in different atmospheres. • Thermodestruction mechanism of precursor are studied. • Cu{sub 0.12}Ru{sub 0.88} nanoalloy with the compositions in the miscibility gap is obtained. • Catalytic conversion of CO on copper–ruthenium oxide composite were examined.

  20. Simulating Interface Growth and Defect Generation in CZT Simulation State of the Art and Known Gaps

    SciTech Connect (OSTI)

    Henager, Charles H.; Gao, Fei; Hu, Shenyang Y.; Lin, Guang; Bylaska, Eric J.; Zabaras, Nicholas

    2012-11-01

    This one-year, study topic project will survey and investigate the known state-of-the-art of modeling and simulation methods suitable for performing fine-scale, fully 3-D modeling, of the growth of CZT crystals at the melt-solid interface, and correlating physical growth and post-growth conditions with generation and incorporation of defects into the solid CZT crystal. In the course of this study, this project will also identify the critical gaps in our knowledge of modeling and simulation techniques in terms of what would be needed to be developed in order to perform accurate physical simulations of defect generation in melt-grown CZT. The transformational nature of this study will be, for the first time, an investigation of modeling and simulation methods for describing microstructural evolution during crystal growth and the identification of the critical gaps in our knowledge of such methods, which is recognized as having tremendous scientific impacts for future model developments in a wide variety of materials science areas.

  1. ACCRETION OF GAS ONTO GAP-OPENING PLANETS AND CIRCUMPLANETARY FLOW STRUCTURE IN MAGNETIZED TURBULENT DISKS

    SciTech Connect (OSTI)

    Uribe, A. L. [University of Chicago, Chicago, IL 60637 (United States); Klahr, H.; Henning, Th., E-mail: uribe@oddjob.uchicago.edu [Max-Planck-Institut fuer Astronomie, Heidelberg (Germany)

    2013-06-01

    We have performed three-dimensional magnetohydrodynamical simulations of stellar accretion disks, using the PLUTO code, and studied the accretion of gas onto a Jupiter-mass planet and the structure of the circumplanetary gas flow after opening a gap in the disk. We compare our results with simulations of laminar, yet viscous disks with different levels of an {alpha}-type viscosity. In all cases, we find that the accretion flow across the surface of the Hill sphere of the planet is not spherically or azimuthally symmetric, and is predominantly restricted to the mid-plane region of the disk. Even in the turbulent case, we find no significant vertical flow of mass into the Hill sphere. The outer parts of the circumplanetary disk are shown to rotate significantly below Keplerian speed, independent of viscosity, while the circumplanetary disk density (therefore the angular momentum) increases with viscosity. For a simulation of a magnetized turbulent disk, where the global averaged alpha stress is {alpha}{sub MHD} = 10{sup -3}, we find the accretion rate onto the planet to be M-dot {approx}2 Multiplication-Sign 10{sup -6}M{sub J} yr{sup -1} for a gap surface density of 12 g cm{sup -2}. This is about a third of the accretion rate obtained in a laminar viscous simulation with equivalent {alpha} parameter.

  2. Mid-Gap Electronic States in Zn1 xMnxO

    SciTech Connect (OSTI)

    Johnson, Claire A.; Kittilstved, Kevin R.; Kaspar, Tiffany C.; Droubay, Timothy C.; Chambers, Scott A.; Salley, G. Mackay; Gamelin, Daniel R.

    2010-09-02

    Electronic absorption, magnetic circular dichroism, photoconductivity, and valence-band X-ray photoelectron (XPS) spectroscopic measurements were performed on epitaxial Zn1 xMnxO films to investigate the origin of the new mid-gap band that appears upon introduction of Mn2+ into the ZnO lattice. Absorption and MCD spectroscopies reveal Mn2+-related intensity at energies below the first excitonic transition of ZnO, tailing well into the visible energy region, with an onset at ~2.2 eV. Photoconductivity measurements show that excitation into this visible band generates mobile charge carriers, consistent with assignment as a Mn2+/3+ photoionization transition. XPS measurements reveal the presence of occupied Mn2+ levels just above the valence-band edge, supporting this assignment. Magnetic circular dichroism measurements additionally show a change in sign and large increase in magnitude of the excitonic Zeeman splitting in Zn1 xMnxO relative to ZnO, suggesting that sp-d exchange in Zn1 xMnxO is not as qualitatively different from those in other II-VI diluted magnetic semiconductors as has been suggested. The singular electronic structure feature of Zn1 xMnxO is its Mn2+/3+ ionization level within the gap, and the influence of this level on other physical properties of Zn1 xMnxO is discussed.

  3. Laboratory studies on surface sampling of Bacillus anthracis contamination: summary, gaps, and recommendations

    SciTech Connect (OSTI)

    Piepel, Gregory F.; Amidan, Brett G.; Hu, Rebecca

    2012-12-01

    This article summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the 1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and 2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed. Recommendations are given for future evaluations of data from existing studies and possible new studies.

  4. Periodic dielectric structure for production of photonic band gap and devices incorporating the same

    DOE Patents [OSTI]

    Ho, Kai-Ming; Chan, Che-Ting; Soukoulis, Costas

    1994-08-02

    A periodic dielectric structure which is capable of producing a photonic band gap and which is capable of practical construction. The periodic structure is formed of a plurality of layers, each layer being formed of a plurality of rods separated by a given spacing. The material of the rods contrasts with the material between the rods to have a refractive index contrast of at least two. The rods in each layer are arranged with their axes parallel and at a given spacing. Adjacent layers are rotated by 90.degree., such that the axes of the rods in any given layer are perpendicular to the axes in its neighbor. Alternating layers (that is, successive layers of rods having their axes parallel such as the first and third layers) are offset such that the rods of one are about at the midpoint between the rods of the other. A four-layer periocity is thus produced, and successive layers are stacked to form a three-dimensional structure which exhibits a photonic band gap. By virtue of forming the device in layers of elongate members, it is found that the device is susceptible of practical construction.

  5. Feasibility study for lowering the minimum gas pressure in solution-mined caverns based on geomechanical analyses of creep-induced damage and healing

    SciTech Connect (OSTI)

    Ratigan, J.L.; Nieland, J.D.; Devries, K.L.

    1998-12-31

    Geomechanical analyses were made to determine the minimum gas pressure allowable based on an existing stress-based criterion (Damage Potential) and an advanced constitutive model (MDCF model) capable of quantifying the level of damage and healing in rock salt. The MDCF model is a constitutive model developed for the WIPP to provide a continuum description of the dislocation and damage deformation of salt. The purpose of this study was to determine if the MDCF model is applicable for evaluating the minimum gas pressure of CNG storage caverns. Specifically, it was to be determined if this model would predict that the minimum gas pressure in the caverns could be lowered without compromising the stability of the cavern. Additionally, the healing behavior of the salt was analyzed to determine if complete healing of the damaged rock zone would occur during the period the cavern was at maximum gas pressure. Significant findings of this study are reported.

  6. A NEW SUB-PERIOD-MINIMUM CATACLYSMIC VARIABLE WITH PARTIAL HYDROGEN DEPLETION AND EVIDENCE OF SPIRAL DISK STRUCTURE

    SciTech Connect (OSTI)

    Littlefield, C.; Garnavich, P.; Magno, K.; Applegate, A.; Pogge, R.; Irwin, J.; Marion, G. H.; Kirshner, R.; Vinko, J.

    2013-06-15

    We present time-resolved spectroscopy and photometry of CSS 120422:111127+571239 (=SBS 1108+574), a recently discovered SU UMa-type dwarf nova whose 55 minute orbital period is well below the cataclysmic variable (CV) period minimum of {approx}78 minutes. In contrast with most other known CVs, its spectrum features He I emission of comparable strength to the Balmer lines, implying a hydrogen abundance less than 0.1 of long-period CVs-but still at least 10 times higher than that in AM CVn stars. Together, the short orbital period and remarkable helium-to-hydrogen ratio suggest that mass transfer in CSS 120422 began near the end of the donor star's main-sequence lifetime, meaning that this CV is a strong candidate progenitor of an AM CVn system as described by Podsiadlowski et al. Moreover, a Doppler tomogram of the H{alpha} line reveals two distinct regions of enhanced emission. While one is the result of the stream-disk impact, the other is probably attributable to spiral disk structure generated when material in the outer disk achieves a 2:1 orbital resonance with respect to the donor.

  7. A study of the minimum wetting rate of isothermal films flowing down on outer surface of vertical pipes

    SciTech Connect (OSTI)

    Koizumi, Yasuo; Ohtake, Hiroyasu; Ueda, Tatsuhiro

    1999-07-01

    The minimum wetting rate (MWR) was investigated experimentally with an isothermal water film flowing down on the outer surface of test pipes arranged vertically. A dry patch was generated by blowing a small air jet onto the film temporally, and observation was made to discriminate whether the dry patch was rewetted or not. The contact angle of the film at the top edge of the dry patch and the amplitude, length and velocity of large waves on the film were measured. The MWR decreased rapidly as the film flowed down and reached a nearly constant value at a position around 0.6 m down from the film inlet. There were large waves on the film. The tendency of the variation of MWR with the distance coincided well with the growth of the amplitude of large waves with the distance. The contact angle at the top edge of the dry patch varied periodically in a range synchronizing with the arrival of the waves. When the contact angle exceeded the maximum advancing contact angle, the rewetting of the dry patch was initiated. The existing correlations where the smooth surface film was assumed considerably over-predicted the MWR. The MWR was properly given by supposing that the dry patch is rewetted when the maximum of the fluctuating dynamic pressure of the film exceeds the upward component of the surface tension corresponding to the maximum advancing contact angle at the top edge of the dry patch.

  8. Inter-band optoelectronic properties in quantum dot structure of low band gap III-V semiconductors

    SciTech Connect (OSTI)

    Dey, Anup; Maiti, Biswajit; Chanda, Debasree

    2014-04-14

    A generalized theory is developed to study inter-band optical absorption coefficient (IOAC) and material gain (MG) in quantum dot structures of narrow gap III-V compound semiconductor considering the wave-vector (k{sup ?}) dependence of the optical transition matrix element. The band structures of these low band gap semiconducting materials with sufficiently separated split-off valance band are frequently described by the three energy band model of Kane. This has been adopted for analysis of the IOAC and MG taking InAs, InSb, Hg{sub 1?x}Cd{sub x}Te, and In{sub 1?x}Ga{sub x}As{sub y}P{sub 1?y} lattice matched to InP, as example of IIIV compound semiconductors, having varied split-off energy band compared to their bulk band gap energy. It has been found that magnitude of the IOAC for quantum dots increases with increasing incident photon energy and the lines of absorption are more closely spaced in the three band model of Kane than those with parabolic energy band approximations reflecting the direct the influence of energy band parameters. The results show a significant deviation to the MG spectrum of narrow-gap materials having band nonparabolicity compared to the parabolic band model approximations. The results reflect the important role of valence band split-off energies in these narrow gap semiconductors.

  9. Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling

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

    Zhou, Miao; Ming, Wenmei; Liu, Zheng; Wang, Zhengfei; Yao, Yugui; Liu, Feng

    2014-11-19

    For potential applications in spintronics and quantum computing, it is desirable to place a quantum spin Hall insulator [i.e., a 2D topological insulator (TI)] on a substrate while maintaining a large energy gap. Here, we demonstrate a unique approach to create the large-gap 2D TI state on a semiconductor surface, based on first-principles calculations and effective Hamiltonian analysis. We show that when heavy elements with strong spin orbit coupling (SOC) such as Bi and Pb atoms are deposited on a patterned H-Si(111) surface into a hexagonal lattice, they exhibit a 2D TI state with a large energy gap of ≥0.5more » eV. The TI state arises from an intriguing substrate orbital filtering effect that selects a suitable orbital composition around the Fermi level, so that the system can be matched onto a four-band effective model Hamiltonian. Furthermore, it is found that within this model, the SOC gap does not increase monotonically with the increasing strength of SOC. These interesting results may shed new light in future design and fabrication of large-gap topological quantum states.« less

  10. Analysis of photonic band gaps in two-dimensional photonic crystals with rods covered by a thin interfacial layer

    SciTech Connect (OSTI)

    Trifonov, T.; Marsal, L.F.; Pallares, J.; Rodriguez, A.; Alcubilla, R.

    2004-11-15

    We investigate different aspects of the absolute photonic band gap (PBG) formation in two-dimensional photonic structures consisting of rods covered with a thin dielectric film. Specifically, triangular and honeycomb lattices in both complementary arrangements, i.e., air rods drilled in silicon matrix and silicon rods in air, are studied. We consider that the rods are formed of a dielectric core (silicon or air) surrounded by a cladding layer of silicon dioxide (SiO{sub 2}), silicon nitride (Si{sub 3}N{sub 4}), or germanium (Ge). Such photonic lattices present absolute photonic band gaps, and we study the evolution of these gaps as functions of the cladding material and thickness. Our results show that in the case of air rods in dielectric media the existence of dielectric cladding reduces the absolute gap width and may cause complete closure of the gap if thick layers are considered. For the case of dielectric rods in air, however, the existence of a cladding layer can be advantageous and larger absolute PBG's can be achieved.

  11. Airflow-terrain interactions through a mountain gap, with an example of eolian activity beneath an atmospheric hydraulic jump

    SciTech Connect (OSTI)

    Gaylord, D.R.; Dawson, P.J.

    1987-09-01

    The integration of atmospheric soundings from a fully instrumented aircraft with detailed sedimentary and geomorphic analyses of eolian features in the Ferris dune field of south-central Wyoming lends insight into the manner in which topography interacts with airflow to modify eolian activity. Topographically modified airflow results in zones of airflow deceleration, acceleration, and enhanced atmospheric turbulence, all of which influence the surface morphology and sedimentology. Extreme lateral confluence of prevailing airflow produces accelerated, unidirectional winds. These winds correlate with unusually continuous and elongate parabolic dunes that extend into a mountain gap (Windy Gap). Persistently heightened winds produced at the entrance to Windy Gap have resulted in a concentration of active sand dunes that lack slipfaces. Common development of a strongly amplified atmospheric wave analogous to a hydraulic jump in the gap contributes to the formation of a variety of eolian features that mantle the surface of Windy Gap and the Ferris dune field tail. Heightened, unidirectional winds in this zone promote grain-size segregation, the formation of elongated and aligned sand drifts, climbing and falling dunes, elongate scour streaks, and parabolic dunes that have low-angle (< 20/sup 0/) cross-stratification. Deflation of bedrock and loose sediment has been enhanced in the zone of maximum turbulence beneath the hydraulic jump.

  12. Air-gap gating of MgZnO/ZnO heterostructures

    SciTech Connect (OSTI)

    Tambo, T.; Falson, J. Kozuka, Y.; Maryenko, D.; Tsukazaki, A.; Kawasaki, M.

    2014-08-28

    The adaptation of air-gap dielectric based field-effect transistor technology to controlling the MgZnO/ZnO heterointerface confined two-dimensional electron system (2DES) is reported. We find it possible to tune the charge density of the 2DES via a gate electrode spatially separated from the heterostructure surface by a distance of 5??m. Under static gating, the observation of the quantum Hall effect suggests that the charge carrier density remains homogeneous, with the 2DES in the 3?mm square sample the sole conductor. The availability of this technology enables the exploration of the charge carrier density degree of freedom in the pristine sample limit.

  13. Photonic-band-gap effects in two-dimensional polycrystalline and amorphous structures

    SciTech Connect (OSTI)

    Yang, Jin-Kyu; Noh, Heeso; Liew, Seng-Fatt; Schreck, Carl; Guy, Mikhael I.; O'Hern, Corey S.; Cao, Hui

    2010-11-15

    We study numerically the density of optical states (DOS) in two-dimensional photonic structures with short-range positional order and observe a transition from polycrystalline to amorphous photonic systems. In polycrystals, photonic band gaps (PBGs) are formed within individual domains, which leads to a depletion of the DOS similar to that in periodic structures. In amorphous photonic media, the domain sizes are too small to form PBGs, thus the depletion of the DOS is weakened significantly. The critical domain size that separates the polycrystalline and amorphous regimes is determined by the attenuation length of Bragg scattering, which depends not only on the degree of positional order but also the refractive-index contrast of the photonic material. Even with relatively low-refractive-index contrast, we find that modest short-range positional order in photonic structures enhances light confinement via collective scattering and interference.

  14. 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.

  15. Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties

    SciTech Connect (OSTI)

    Strikman, Mark; Weiss, Christian

    2009-01-01

    We summarize our understanding of the dynamical mechanisms governing rapidity gap survival in central exclusive diffraction, pp -> p + H + p (H = high-mass system), and discuss the uncertainties in present estimates of the survival probability. The main suppression of diffractive scattering is due to inelastic soft spectator interactions at small pp impact parameters and can be described in a mean-field approximation (independent hard and soft interactions). Moderate extra suppression results from fluctuations of the partonic configurations of the colliding protons. At LHC energies absorptive interactions of hard spectator partons associated with the gg -> H process reach the black-disk regime and cause substantial additional suppression, pushing the survival probability below 0.01.

  16. Band gap narrowing in zinc oxide-based semiconductor thin films

    SciTech Connect (OSTI)

    Kumar, Jitendra E-mail: akrsri@gmail.com; Kumar Srivastava, Amit E-mail: akrsri@gmail.com

    2014-04-07

    A simple expression is proposed for the band gap narrowing (or shrinkage) in semiconductors using optical absorption measurements of spin coated 1 at. % Ga-doped ZnO (with additional 0–1.5 at. % zinc species) thin films as ΔE{sub BGN} = Bn{sup 1/3} [1 − (n{sub c}/n){sup 1/3}], where B is the fitting parameter, n is carrier concentration, and n{sub c} is the critical density required for shrinkage onset. Its uniqueness lies in not only describing variation of ΔE{sub BGN} correctly but also allowing deduction of n{sub c} automatically for several M-doped ZnO (M: Ga, Al, In, B, Mo) systems. The physical significance of the term [1 − (n{sub c}/n){sup 1/3}] is discussed in terms of carrier separation.

  17. Glide-plane symmetry and superconducting gap structure of iron-based superconductors

    SciTech Connect (OSTI)

    Wang, Yan; Berlijn, Tom; Hirschfeld, Peter J.; Scalapino, Douglas J.; Maier, Thomas A.

    2015-03-10

    We consider the effect of glide-plane symmetry of the Fe-pnictogen/chalcogen layer in Fe-based superconductors on pairing in spin fluctuation models. Recent theories propose that so-called η-pairing states with nonzero total momentum can be realized and possess such exotic properties as odd parity spin singlet symmetry and time-reversal symmetry breaking. Here we show that when there is orbital weight at the Fermi level from orbitals with even and odd mirror reflection symmetry in z, η pairing is inevitable; however, we conclude from explicit calculation that the gap function appearing in observable quantities is identical to that found in earlier pseudocrystal momentum calculations with 1 Fe per unit cell.

  18. Research Gaps and Technology Needs in Development of PHM for Passive AdvSMR Components

    SciTech Connect (OSTI)

    Meyer, Ryan M.; Ramuhalli, Pradeep; Coble, Jamie B.; Hirt, Evelyn H.; Mitchell, Mark R.; Wootan, David W.; Berglin, Eric J.; Bond, Leonard J.; Henager, Charles H.

    2014-01-01

    Advanced small modular reactors (AdvSMRs), which are based on modularization of advanced reactor concepts, may provide a longer-term alternative to traditional light-water reactors and near term small modular reactors (SMRs), which are based on integral pressurized water reactor (iPWR) concepts. SMRs are challenged economically due to losses in economy of scale, thus, there is increased motivation to reduce the controllable operations and maintenance (O&M) costs through automation technologies including prognostics health management (PHM) systems. In this regard, PHM systems have the potential to play a vital role in supporting the deployment of AdvSMRs and face several unique challenges with respect to implementation for passive AdvSMR components. This paper presents a summary of a research gaps and technical needs assessment performed for implementation of PHM for passive AdvSMR components. state-of-the-art in PHM.

  19. Research gaps and technology needs in development of PHM for passive AdvSMR components

    SciTech Connect (OSTI)

    Meyer, Ryan M.; Ramuhalli, Pradeep; Hirt, Evelyn H.; Mitchell, Mark R.; Wootan, David W.; Berglin, Eric J.; Henagar, Chuck H. Jr.; Coble, Jamie B.; Bond, Leonard J.

    2014-02-18

    Advanced small modular reactors (AdvSMRs), which are based on modularization of advanced reactor concepts, may provide a longer-term alternative to traditional light-water reactors and near-term small modular reactors (SMRs), which are based on integral pressurized water reactor (iPWR) concepts. SMRs are challenged economically because of losses in economy of scale; thus, there is increased motivation to reduce the controllable operations and maintenance costs through automation technologies including prognostics health management (PHM) systems. In this regard, PHM systems have the potential to play a vital role in supporting the deployment of AdvSMRs and face several unique challenges with respect to implementation for passive AdvSMR components. This paper presents a summary of a research gaps and technical needs assessment performed for implementation of PHM for passive AdvSMR components.

  20. The recovery of glow-plasma structure in atmospheric radio frequency microplasmas at very small gaps

    SciTech Connect (OSTI)

    Zhang Yuantao; Shang Wanli

    2011-11-15

    In atmospheric radio frequency discharges at 13.56 MHz, with the electrode gap reduced, the sheath region eventually occupies a main portion of the electrode spacing and the bulk plasma region is significantly compressed. The computational results in this letter based on a one-dimensional fluid model show that by increasing the excitation frequency over 13.56 MHz, the traditional glow-plasma structure could gradually recover even at very small sizes with a well defined quasineutral plasma region, and the electron density is improved but the electric fields in sheath region are reduced. This study indicates that the excitation frequency can be used to modulate the discharge structure and then tailor the plasma-surface interaction in atmospheric microplasmas.

  1. Diffraction limited focusing and routing of gap plasmons by a metal-dielectric-metal lens

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

    Dennis, Brian S.; Czaplewski, David A.; Haftel, Michael I.; Lopez, Daniel; Blumberg, Girsh; Aksyuk, Vladimir

    2015-08-12

    Passive optical elements can play key roles in photonic applications such as plasmonic integrated circuits. Here we experimentally demonstrate passive gap-plasmon focusing and routing in two-dimensions. This is accomplished using a high numerical-aperture metal-dielectric-metal lens incorporated into a planar-waveguide device. Fabrication via metal sputtering, oxide deposition, electron- and focused-ion- beam lithography, and argon ion-milling is reported on in detail. Diffraction-limited focusing is optically characterized by sampling out-coupled light with a microscope. The measured focal distance and full-width-half-maximum spot size agree well with the calculated lens performance. The surface plasmon polariton propagation length is measured by sampling light from multiple out-couplermoreslits.less

  2. Glide-plane symmetry and superconducting gap structure of iron-based superconductors

    SciTech Connect (OSTI)

    Wang, Yan; Berlijn, Tom; Hirschfeld, Peter J.; Scalapino, Douglas J.; Maier, Thomas A.

    2015-03-10

    We consider the effect of glide-plane symmetry of the Fe-pnictogen/chalcogen layer in Fe-based superconductors on pairing in spin fluctuation models. Recent theories propose that so-called ?-pairing states with nonzero total momentum can be realized and possess such exotic properties as odd parity spin singlet symmetry and time-reversal symmetry breaking. Here we show that when there is orbital weight at the Fermi level from orbitals with even and odd mirror reflection symmetry in z, ? pairing is inevitable; however, we conclude from explicit calculation that the gap function appearing in observable quantities is identical to that found in earlier pseudocrystal momentum calculations with 1 Fe per unit cell.

  3. Glide-plane symmetry and superconducting gap structure of iron-based superconductors

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

    Wang, Yan; Berlijn, Tom; Hirschfeld, Peter J.; Scalapino, Douglas J.; Maier, Thomas A.

    2015-03-10

    We consider the effect of glide-plane symmetry of the Fe-pnictogen/chalcogen layer in Fe-based superconductors on pairing in spin fluctuation models. Recent theories propose that so-called η-pairing states with nonzero total momentum can be realized and possess such exotic properties as odd parity spin singlet symmetry and time-reversal symmetry breaking. Here we show that when there is orbital weight at the Fermi level from orbitals with even and odd mirror reflection symmetry in z, η pairing is inevitable; however, we conclude from explicit calculation that the gap function appearing in observable quantities is identical to that found in earlier pseudocrystal momentummore » calculations with 1 Fe per unit cell.« less

  4. Strategies to Address Identified Education Gaps in the Preparation of a National Security Workforce

    SciTech Connect (OSTI)

    2008-06-30

    This report will discuss strategies available to address identified gaps and weaknesses in education efforts aimed at the preparation of a skilled and properly trained national security workforce.The need to adequately train and educate a national security workforce is at a critical juncture. Even though there are an increasing number of college graduates in the appropriate fields, many of these graduates choose to work in the private sector because of more desirable salary and benefit packages. This is contributing to an inability to fill vacant positions at NNSA resulting from high personnel turnover from the large number of retirements. Further, many of the retirees are practically irreplaceable because they are Cold War scientists that have experience and expertise with nuclear weapons.

  5. Measurement of positive direct current corona pulse in coaxial wire-cylinder gap

    SciTech Connect (OSTI)

    Yin, Han Zhang, Bo He, Jinliang Wang, Wenzhuo

    2014-03-15

    In this paper, a system is designed and developed to measure the positive corona current in coaxial wire-cylinder gaps. The characteristic parameters of corona current pulses, such as the amplitude, rise time, half-wave time, and repetition frequency, are statistically analyzed and a new set of empirical formulas are derived by numerical fitting. The influence of space charges on corona currents is tested by using three corona cages with different radii. A numerical method is used to solve a simplified ion-flow model to explain the influence of space charges. Based on the statistical results, a stochastic model is developed to simulate the corona pulse trains. And this model is verified by comparing the simulated frequency-domain responses with the measured ones.

  6. A versatile optical junction using photonic band-gap guidance and self collimation

    SciTech Connect (OSTI)

    Gupta, Man Mohan; Medhekar, Sarang

    2014-09-29

    We show that it is possible to design two photonic crystal (PC) structures such that an optical beam of desired wavelength gets guided within the line defect of the first structure (photonic band gap guidance) and the same beam gets guided in the second structure by self-collimation. Using two dimensional simulation of a design made of the combination of these two structures, we propose an optical junction that allows for crossing of two optical signals of same wavelength and same polarization with very low crosstalk. Moreover, the junction can be operated at number of frequencies in a wide range. Crossing of multiple beams with very low cross talk is also possible. The proposed junction should be important in future integrated photonic circuits.

  7. Nonlinear optical response of semiconductor-nanocrystals-embedded photonic band gap structure

    SciTech Connect (OSTI)

    Liao, Chen; Zhang, Huichao; Tang, Luping; Zhou, Zhiqiang; Lv, Changgui; Cui, Yiping; Zhang, Jiayu

    2014-04-28

    Colloidal CdSe/ZnS core/shell nanocrystals (NCs), which were dispersed in SiO{sub 2} sol, were utilized to fabricate a SiO{sub 2}:NCs/TiO{sub 2} all-dielectric photonic band gap (PBG) structure. The third-order nonlinear refractive index (n{sub 2}) of the PBG structure was nearly triple of that of the SiO{sub 2}:NCs film due to the local field enhancement in the PBG structure. The photoinduced change in refractive index (Δn) could shift the PBG band edge, so the PBG structure would show significant transmission modification, whose transmission change was ∼17 folds of that of the SiO{sub 2}:NCs film. Under excitation of a 30 GW/cm{sup 2} femtosecond laser beam, a transmission decrease of 80% was realized.

  8. Gap Analysis of Material Properties Data for Ferritic/Martensitic HT-9 Steel

    SciTech Connect (OSTI)

    Brown, Neil R.; Serrano De Caro, Magdalena; Rodriguez, Edward A.

    2012-08-28

    The US Department of Energy (DOE), Office of Nuclear Energy (NE), is supporting the development of an ASME Code Case for adoption of 12Cr-1Mo-VW ferritic/martensitic (F/M) steel, commonly known as HT-9, primarily for use in elevated temperature design of liquid-metal fast reactors (LMFR) and components. In 2011, Los Alamos National Laboratory (LANL) nuclear engineering staff began assisting in the development of a small modular reactor (SMR) design concept, previously known as the Hyperion Module, now called the Gen4 Module. LANL staff immediately proposed HT-9 for the reactor vessel and components, as well as fuel clad and ducting, due to its superior thermal qualities. Although the ASME material Code Case, for adoption of HT-9 as an approved elevated temperature material for LMFR service, is the ultimate goal of this project, there are several key deliverables that must first be successfully accomplished. The most important key deliverable is the research, accumulation, and documentation of specific material parameters; physical, mechanical, and environmental, which becomes the basis for an ASME Code Case. Time-independent tensile and ductility data and time-dependent creep and creep-rupture behavior are some of the material properties required for a successful ASME Code case. Although this report provides a cursory review of the available data, a much more comprehensive study of open-source data would be necessary. This report serves three purposes: (a) provides a list of already existing material data information that could ultimately be made available to the ASME Code, (b) determines the HT-9 material properties data missing from available sources that would be required and (c) estimates the necessary material testing required to close the gap. Ultimately, the gap analysis demonstrates that certain material properties testing will be required to fulfill the necessary information package for an ASME Code Case.

  9. Sodium fast reactor gaps analysis of computer codes and models for accident analysis and reactor safety.

    SciTech Connect (OSTI)

    Carbajo, Juan; Jeong, Hae-Yong; Wigeland, Roald; Corradini, Michael; Schmidt, Rodney Cannon; Thomas, Justin; Wei, Tom; Sofu, Tanju; Ludewig, Hans; Tobita, Yoshiharu; Ohshima, Hiroyuki; Serre, Frederic

    2011-06-01

    This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and identify important gaps. During the review, panel members identified over 60 computer codes that are currently available in the international community to perform different aspects of SFR safety analysis for various event scenarios and accident categories. A brief description of each of these codes together with references (when available) is provided. An adaptation of the Predictive Capability Maturity Model (PCMM) for computational modeling and simulation is described for use in this work. The panel's assessment of the available US codes is presented in the form of nine tables, organized into groups of three for each of three risk categories considered: anticipated operational occurrences (AOOs), design basis accidents (DBA), and beyond design basis accidents (BDBA). A set of summary conclusions are drawn from the results obtained. At the highest level, the panel judged that current US code capabilities are adequate for licensing given reasonable margins, but expressed concern that US code development activities had stagnated and that the experienced user-base and the experimental validation base was decaying away quickly.

  10. Filling the gaps in meteorological continuous data measured at FLUXNET sites with ERA-Interim reanalysis

    SciTech Connect (OSTI)

    Vuichard, N.

    2015-07-13

    In this study, exchanges of carbon, water and energy between the land surface and the atmosphere are monitored by eddy covariance technique at the ecosystem level. Currently, the FLUXNET database contains more than 500 registered sites, and up to 250 of them share data (free fair-use data set). Many modelling groups use the FLUXNET data set for evaluating ecosystem models' performance, but this requires uninterrupted time series for the meteorological variables used as input. Because original in situ data often contain gaps, from very short (few hours) up to relatively long (some months) ones, we develop a new and robust method for filling the gaps in meteorological data measured at site level. Our approach has the benefit of making use of continuous data available globally (ERA-Interim) and a high temporal resolution spanning from 1989 to today. These data are, however, not measured at site level, and for this reason a method to downscale and correct the ERA-Interim data is needed. We apply this method to the level 4 data (L4) from the La Thuile collection, freely available after registration under a fair-use policy. The performance of the developed method varies across sites and is also function of the meteorological variable. On average over all sites, applying the bias correction method to the ERA-Interim data reduced the mismatch with the in situ data by 10 to 36 %, depending on the meteorological variable considered. In comparison to the internal variability of the in situ data, the root mean square error (RMSE) between the in situ data and the unbiased ERA-I (ERA-Interim) data remains relatively large (on average over all sites, from 27 to 76 % of the standard deviation of in situ data, depending on the meteorological variable considered). The performance of the method remains poor for the wind speed field, in particular regarding its capacity to conserve a standard deviation similar to the one measured at FLUXNET stations.

  11. THE EVOLUTION OF PLASMA PARAMETERS ON A CORONAL SOURCE SURFACE AT 2.3 R{sub Sun} DURING SOLAR MINIMUM

    SciTech Connect (OSTI)

    Strachan, L.; Panasyuk, A. V.; Kohl, J. L.; Lamy, P.

    2012-01-20

    We analyze data from the Solar and Heliospheric Observatory to produce global maps of coronal outflow velocities and densities in the regions where the solar wind is undergoing acceleration. The maps use UV and white light coronal data obtained from the Ultraviolet Coronagraph Spectrometer and the Large Angle Spectroscopic Coronagraph, respectively, and a Doppler dimming analysis to determine the mean outflow velocities. The outflow velocities are defined on a sphere at 2.3 R{sub Sun} from Sun-center and are organized by Carrington Rotations during the solar minimum period at the start of solar cycle 23. We use the outflow velocity and density maps to show that while the solar minimum corona is relatively stable during its early stages, the shrinkage of the north polar hole in the later stages leads to changes in both the global areal expansion of the coronal hole and the derived internal flux tube expansion factors of the solar wind. The polar hole areal expansion factor and the flux tube expansion factors (between the coronal base and 2.3 R{sub Sun }) start out as super-radial but then they become more nearly radial as the corona progresses away from solar minimum. The results also support the idea that the largest flux tube expansion factors are located near the coronal hole/streamer interface, at least during the deepest part of the solar minimum period.

  12. Expedited site characterization (ESC) using the M{sup 3} approach, M{sup 3} = massive, moderate, minimum

    SciTech Connect (OSTI)

    Tindall, S.

    1995-12-31

    The main objective of this approach is to quickly and cost effectively identify and classify potential Areas of Concern (AOCS) as clean or contaminated, thus allowing potentially responsible parties (PRPS) to save limited resources by ceasing costly investigations and undertaking removal type actions expeditiously. The ESC M{sup 3} approach also overcomes the high degree of uncertainty typically associated with traditional site investigations resulting from a lack of comprehensive scoping. Thus, EPA Region 9 has agreed to accept and use, for risk assessment purposes, the data generated from the ESC M{sup 3} approach, providing the data quality is known and confirmation analyses are performed. The extraordinary benefit will be to eliminate any further action on those AOCs found to be clean using this approach. Finally this approach reduces the large number of non-detect samples that are customarily submitted for CLP-type (i.e., Contract Laboratory Program) analyses. The ESC M{sup 3} approach consists of the following three steps: (1) a massive sampling effort is first conducted at an AOC (e.g., 200 samples are collected using a grid approach); the samples are analyzed on a daily basis using real time onsite methods and field screening (FS)-type data are generated; (2) a moderate sampling effort is then conducted to provide onsite verification of the FS-type data; the samples are analyzed using onsite CLP-type methods and field quantitation (FQ)-type data are generated with an agreed upon level of QC; and finally, (3) a minimum sampling effort is conducted to provide verification of the FQ-type data; these confirmation samples are sent to an offsite laboratory for analysis, and CLP-type data are generated.

  13. Potential Impact of Adopting Maximum Technologies as Minimum Efficiency Performance Standards in the U.S. Residential Sector

    SciTech Connect (OSTI)

    Letschert, Virginie; Desroches, Louis-Benoit; McNeil, Michael; Saheb, Yamina

    2010-05-03

    The US Department of Energy (US DOE) has placed lighting and appliance standards at a very high priority of the U.S. energy policy. However, the maximum energy savings and CO2 emissions reduction achievable via minimum efficiency performance standards (MEPS) has not yet been fully characterized. The Bottom Up Energy Analysis System (BUENAS), first developed in 2007, is a global, generic, and modular tool designed to provide policy makers with estimates of potential impacts resulting from MEPS for a variety of products, at the international and/or regional level. Using the BUENAS framework, we estimated potential national energy savings and CO2 emissions mitigation in the US residential sector that would result from the most aggressive policy foreseeable: standards effective in 2014 set at the current maximum technology (Max Tech) available on the market. This represents the most likely characterization of what can be maximally achieved through MEPS in the US. The authors rely on the latest Technical Support Documents and Analytical Tools published by the U.S. Department of Energy as a source to determine appliance stock turnover and projected efficiency scenarios of what would occur in the absence of policy. In our analysis, national impacts are determined for the following end uses: lighting, television, refrigerator-freezers, central air conditioning, room air conditioning, residential furnaces, and water heating. The analyzed end uses cover approximately 65percent of site energy consumption in the residential sector (50percent of the electricity consumption and 80percent of the natural gas and LPG consumption). This paper uses this BUENAS methodology to calculate that energy savings from Max Tech for the U.S. residential sector products covered in this paper will reach an 18percent reduction in electricity demand compared to the base case and 11percent in Natural Gas and LPG consumption by 2030 The methodology results in reductions in CO2 emissions of a similar magnitude.

  14. CONSTRAINTS ON THE MINIMUM ELECTRON LORENTZ FACTOR AND MATTER CONTENT OF JETS FOR A SAMPLE OF BRIGHT FERMI BLAZARS

    SciTech Connect (OSTI)

    Kang, Shi-Ju; Wu, Qingwen; Chen, Liang

    2014-11-01

    We fit (quasi-)simultaneous multi-waveband spectral energy distributions for a sample of low-synchrotron-peaked (LSP) blazars with a one-zone leptonic model. The seed photons that predominantly come from the broad line region (BLR) and infrared (IR) molecular torus are considered in the context of an external Compton process. We find that modeling with IR seed photons is systematically better than that with BLR photons based on a ?{sup 2} test, which suggests that ?-ray-emitting regions are most likely found outside the BLR. The minimum electron Lorentz factor, ?{sub min}, is constrained from the modeling of these LSP blazars with good soft X-ray data (ranging from 5 to 160 with a median value of 55), which plays a key role in jet power estimation. Assuming a one-to-one ratio of protons to electrons, we find that the jet power for LSP blazars is systematically higher than that of FR II radio galaxies at a 151 MHz radio luminosity, L {sub 151} {sub MHz} even though FR IIs are regarded as the same as LSP blazars in a unification scheme except at the jet viewing angle. A possible reason for this is that there are some e {sup } pairs in the jets of these blazars. If this is the case, we find that the number density of e {sup } pairs should be several times higher than that of e {sup }-p pairs by assuming the jet power is the same for LSP blazars and FR IIs at the given L {sub 151} {sub MHz}.

  15. First-principles study of direct and narrow band gap semiconducting β -CuGaO2

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

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai-Zhuang; Ho, Kai-Ming

    2015-04-16

    Semiconducting oxides have attracted much attention due to their great stability in air or water and the abundance of oxygen. Recent success in synthesizing a metastable phase of CuGaO2 with direct narrow band gap opens up new applications of semiconducting oxides as absorber layer for photovoltaics. Using first-principles density functional theory calculations, we investigate the thermodynamic and mechanical stabilities as well as the structural and electronic properties of the β-CuGaO2 phase. Our calculations show that the β-CuGaO2 structure is dynamically and mechanically stable. The energy band gap is confirmed to be direct at the Γ point of Brillouin zone. Inmore » conclusion, the optical absorption occurs right at the band gap edge and the density of states near the valance band maximum is large, inducing an intense absorption of light as observed in experiment.« less

  16. Surface Chemistry of GaP(001) and InP(001) in Contact with Water (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Surface Chemistry of GaP(001) and InP(001) in Contact with Water Citation Details In-Document Search Title: Surface Chemistry of GaP(001) and InP(001) in Contact with Water Authors: Wood, B C ; Schwegler, E ; Choi, W ; Ogitsu, T Publication Date: 2013-09-20 OSTI Identifier: 1130018 Report Number(s): LLNL-JRNL-644315 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal Name: Journal of Physical Chemistry C, vol. 118, no. 2,

  17. CEPAN method of analyzing creep collapse of oval cladding. Volume 5. Evaluation of interpellet gap formation and clad collapse in modern PWR fuel rods

    SciTech Connect (OSTI)

    Adams, W.M.; Fisher, H.D.; Litke, H.J.; Mordarski, W.J.

    1985-04-01

    This report presents the results from a review of interpellet-gap formation, ovality, creepdown and clad collapse data in modern PWR fuel rods. Conclusions are reached regarding the propensity of modern PWR fuel to form such gaps and to undergo clad collapse. CEPAN, a creep-collapse predictor approved by the NRC in 1976, has been reformulated to include the creep analysis of cladding with finite interpellet gaps. The basis for this reformulation is discussed in detail. The model previously used in the calculation of the augmentation factor, a peak linear heat rate penalty due to the presence of interpellet gaps within the fuel rod, has been modified to incorporate gap-formation statistics from modern fuel. Finnally, the benefits of the limited gap formation and the CEPAN reformulation for the licensing of modern PWR fuel rods are evaluated.

  18. Spatial variation of dosimetric leaf gap and its impact on dose delivery

    SciTech Connect (OSTI)

    Kumaraswamy, Lalith K.; Schmitt, Jonathan D.; Bailey, Daniel W.; Xu, Zheng Zheng; Podgorsak, Matthew B.

    2014-11-01

    Purpose: During dose calculation, the Eclipse treatment planning system (TPS) retracts the multileaf collimator (MLC) leaf positions by half of the dosimetric leaf gap (DLG) value (measured at central axis) for all leaf positions in a dynamic MLC plan to accurately model the rounded leaf ends. The aim of this study is to map the variation of DLG along the travel path of each MLC leaf pair and quantify how this variation impacts delivered dose. Methods: 6 MV DLG values were measured for all MLC leaf pairs in increments of 1.0 cm (from the line intersecting the CAX and perpendicular to MLC motion) to 13.0 cm off axis distance at dmax. The measurements were performed on two Varian linear accelerators, both employing the Millennium 120-leaf MLCs. The measurements were performed at several locations in the beam with both a Sun Nuclear MapCHECK device and a PTW pinpoint ion chamber. Results: The measured DLGs for the middle 40 MLC leaf pairs (each 0.5 cm width) at positions along a line through the CAX and perpendicular to MLC leaf travel direction were very similar, varying maximally by only 0.2 mm. The outer 20 MLC leaf pairs (each 1.0 cm width) have much lower DLG values, about 0.30.5 mm lower than the central MLC leaf pair, at their respective central line position. Overall, the mean and the maximum variation between the 0.5 cm width leaves and the 1.0 cm width leaf pairs are 0.32 and 0.65 mm, respectively. Conclusions: The spatial variation in DLG is caused by the variation of intraleaf transmission through MLC leaves. Fluences centered on the CAX would not be affected since DLG does not vary; but any fluences residing significantly off axis with narrow sweeping leaves may exhibit significant dose differences. This is due to the fact that there are differences in DLG between the true DLG exhibited by the 1.0 cm width outer leaves and the constant DLG value utilized by the TPS for dose calculation. Since there are large differences in DLG between the 0.5 cm width leaf pairs and 1.0 cm width leaf pairs, there is a need to correct the TPS plans, especially those with high modulation (narrow dynamic MLC gap), with 2D variation of DLG.

  19. Technology gap analysis on sodium-cooled reactor fuel handling system supporting advanced burner reactor development.

    SciTech Connect (OSTI)

    Chikazawa, Y.; Farmer, M.; Grandy, C.; Nuclear Engineering Division

    2009-03-01

    The goals of the Global Nuclear Energy Partnership (GNEP) are to expand the use of nuclear energy to meet increasing global energy demand in an environmentally sustainable manner, to address nuclear waste management issues without making separated plutonium, and to address nonproliferation concerns. The advanced burner reactor (ABR) is a fast reactor concept which supports the GNEP fuel cycle system. Since the integral fast reactor (IFR) and advanced liquid-metal reactor (ALMR) projects were terminated in 1994, there has been no major development on sodium-cooled fast reactors in the United States. Therefore, in support of the GNEP fast reactor program, the history of sodium-cooled reactor development was reviewed to support the initiation of this technology within the United States and to gain an understanding of the technology gaps that may still remain for sodium fast reactor technology. The fuel-handling system is a key element of any fast reactor design. The major functions of this system are to receive, test, store, and then load fresh fuel into the core; unload from the core; then clean, test, store, and ship spent fuel. Major requirements are that the system must be reliable and relatively easy to maintain. In addition, the system should be designed so that it does not adversely impact plant economics from the viewpoints of capital investment or plant operations. In this gap analysis, information on fuel-handling operating experiences in the following reactor plants was carefully reviewed: EBR-I, SRE, HNPF, Fermi, SEFOR, FFTF, CRBR, EBR-II, DFR, PFR, Rapsodie, Phenix, Superphenix, KNK, SNR-300, Joyo, and Monju. The results of this evaluation indicate that a standardized fuel-handling system for a commercial fast reactor is yet to be established. However, in the past sodium-cooled reactor plants, most major fuel-handling components-such as the rotatable plug, in-vessel fuel-handling machine, ex-vessel fuel transportation cask, ex-vessel sodium-cooled storage, and cleaning stations-have accumulated satisfactory construction and operation experiences. In addition, two special issues for future development are described in this report: large capacity interim storage and transuranic-bearing fuel handling.

  20. Filling the gaps in meteorological continuous data measured at FLUXNET sites with ERA-Interim reanalysis

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

    Vuichard, N.; Papale, D.

    2015-07-13

    In this study, exchanges of carbon, water and energy between the land surface and the atmosphere are monitored by eddy covariance technique at the ecosystem level. Currently, the FLUXNET database contains more than 500 registered sites, and up to 250 of them share data (free fair-use data set). Many modelling groups use the FLUXNET data set for evaluating ecosystem models' performance, but this requires uninterrupted time series for the meteorological variables used as input. Because original in situ data often contain gaps, from very short (few hours) up to relatively long (some months) ones, we develop a new and robustmore » method for filling the gaps in meteorological data measured at site level. Our approach has the benefit of making use of continuous data available globally (ERA-Interim) and a high temporal resolution spanning from 1989 to today. These data are, however, not measured at site level, and for this reason a method to downscale and correct the ERA-Interim data is needed. We apply this method to the level 4 data (L4) from the La Thuile collection, freely available after registration under a fair-use policy. The performance of the developed method varies across sites and is also function of the meteorological variable. On average over all sites, applying the bias correction method to the ERA-Interim data reduced the mismatch with the in situ data by 10 to 36 %, depending on the meteorological variable considered. In comparison to the internal variability of the in situ data, the root mean square error (RMSE) between the in situ data and the unbiased ERA-I (ERA-Interim) data remains relatively large (on average over all sites, from 27 to 76 % of the standard deviation of in situ data, depending on the meteorological variable considered). The performance of the method remains poor for the wind speed field, in particular regarding its capacity to conserve a standard deviation similar to the one measured at FLUXNET stations.« less

  1. The benzene metabolite trans,trans-muconaldehyde blocks gap junction intercellular communication by cross-linking connexin43

    SciTech Connect (OSTI)

    Rivedal, Edgar Leithe, Edward

    2008-11-01

    Benzene is used at large volumes in many different human activities. Hematotoxicity and cancer-causation as a result of benzene exposure was recognized many years ago, but the mechanisms involved remain unclear. Aberrant regulation of gap junction intercellular communication (GJIC) has been linked to both cancer induction and interference with normal hematopoietic development. We have previously suggested that inhibition of GJIC may play a role in benzene toxicity since benzene metabolites were found to block GJIC, the ring-opened trans,trans-muconaldehyde (MUC) being the most potent metabolite. In the present work we have studied the molecular mechanisms underlying the MUC-induced inhibition of gap junctional communication. We show that MUC induces cross-linking of the gap junction protein connexin43 and that this is likely to be responsible for the induced inhibition of GJIC, as well as the loss of connexin43 observed in Western blots. We also show that glutaraldehyde possesses similar effects as MUC, and we compare the effects to that of formaldehyde. The fact that glutaraldehyde and formaldehyde have been associated with induction of leukemia as well as disturbance of hematopoiesis, strengthens the possible link between the effect of MUC on gap junctions, and the toxic effects of benzene.

  2. Fully gapped superconductivity in In-doped topological crystalline insulator Pb0.5Sn0.5Te

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

    Du, Guan; Gu, G. D.; Du, Zengyi; Fang, Delong; Yang, Huan; Zhong, R. D.; Schneeloch, J.; Wen, Hai -Hu

    2015-07-27

    In this study, superconductors derived from topological insulators and topological crystalline insulators by chemical doping have long been considered to be candidates as topological superconductors. Pb0.5Sn0.5Te is a topological crystalline insulator with mirror symmetry protected surface states on (001)-, (011)-, and (111)-oriented surfaces. The superconductor (Pb0.5Sn0.5)0.7In0.3Te is produced by In doping in Pb0.5Sn0.5Te, and is thought to be a topological superconductor. Here we report scanning tunneling spectroscopy measurements of the superconducting state as well as the superconducting energy gap in (Pb0.5Sn0.5)0.7In0.3Te on a (001)-oriented surface. The spectrum can be well fitted by an anisotropic s-wave gap function of Δ =more » 0.72 + 0.18cos4θ meV using Dynes model. The results show that the superconductor seems to be a fully gapped one without any in-gap states, in contradiction with the expectation of a topological superconductor.« less

  3. Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer

    SciTech Connect (OSTI)

    Ito, Kota; Miura, Atsushi; Iizuka, Hideo; Toshiyoshi, Hiroshi

    2015-02-23

    Near-field radiative heat transfer has been a subject of great interest due to the applicability to thermal management and energy conversion. In this letter, a submicron gap between a pair of diced fused quartz substrates is formed by using micromachined low-density pillars to obtain both the parallelism and small parasitic heat conduction. The gap uniformity is validated by the optical interferometry at four corners of the substrates. The heat flux across the gap is measured in a steady-state and is no greater than twice of theoretically predicted radiative heat flux, which indicates that the parasitic heat conduction is suppressed to the level of the radiative heat transfer or less. The heat conduction through the pillars is modeled, and it is found to be limited by the thermal contact resistance between the pillar top and the opposing substrate surface. The methodology to form and evaluate the gap promotes the near-field radiative heat transfer to various applications such as thermal rectification, thermal modulation, and thermophotovoltaics.

  4. Method of fabricating n-type and p-type microcrystalline semiconductor alloy material including band gap widening elements

    DOE Patents [OSTI]

    Guha, Subhendu; Ovshinsky, Stanford R.

    1990-02-02

    A method of fabricating doped microcrystalline semiconductor alloy material which includes a band gap widening element through a glow discharge deposition process by subjecting a precursor mixture which includes a diluent gas to an a.c. glow discharge in the absence of a magnetic field of sufficient strength to induce electron cyclotron resonance.

  5. L-asparagine crystals with wide gap semiconductor features: Optical absorption measurements and density functional theory computations

    SciTech Connect (OSTI)

    Zanatta, G.; Gottfried, C.; Silva, A. M.; Caetano, E. W. S.; Sales, F. A. M.; Freire, V. N.

    2014-03-28

    Results of optical absorption measurements are presented together with calculated structural, electronic, and optical properties for the anhydrous monoclinic L-asparagine crystal. Density functional theory (DFT) within the generalized gradient approximation (GGA) including dispersion effects (TS, Grimme) was employed to perform the calculations. The optical absorption measurements revealed that the anhydrous monoclinic L-asparagine crystal is a wide band gap material with 4.95 eV main gap energy. DFT-GGA+TS simulations, on the other hand, produced structural parameters in very good agreement with X-ray data. The lattice parameter differences ?a, ?b, ?c between theory and experiment were as small as 0.020, 0.051, and 0.022, respectively. The calculated band gap energy is smaller than the experimental data by about 15%, with a 4.23 eV indirect band gap corresponding to Z???? and Z???? transitions. Three other indirect band gaps of 4.30 eV, 4.32 eV, and 4.36 eV are assigned to ?3 ???, ?1 ???, and ?2 ??? transitions, respectively. ?-sol computations, on the other hand, predict a main band gap of 5.00 eV, just 50 meV above the experimental value. Electronic wavefunctions mainly originating from O 2pcarboxyl, C 2pside chain, and C 2pcarboxyl orbitals contribute most significantly to the highest valence and lowest conduction energy bands, respectively. By varying the lattice parameters from their converged equilibrium values, we show that the unit cell is less stiff along the b direction than for the a and c directions. Effective mass calculations suggest that hole transport behavior is more anisotropic than electron transport, but the mass values allow for some charge mobility except along a direction perpendicular to the molecular layers of L-asparagine which form the crystal, so anhydrous monoclinic L-asparagine crystals could behave as wide gap semiconductors. Finally, the calculations point to a high degree of optical anisotropy for the absorption and complex dielectric function, with more structured curves for incident light polarized along the 100 and 101 directions.

  6. Supercondutivity at 9K in Mo5PB2 with evidence for multiple gaps

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

    McGuire, Michael A.; Parker, David S.

    2016-02-09

    Superconductivity is observed with critical temperatures near 9 K in the tetragonal compound Mo5PB2. This material adopts the Cr5B3 structure type common to superconducting Nb5Si3–xBx, Mo5SiB2, and W5SiB2, which have critical temperatures of 5.8–7.8 K. We have synthesized polycrystalline samples of the compound, made measurements of electrical resistivity, magnetic susceptibility, and heat capacity, and performed first-principles electronic structure calculations. The highest Tc value (9.2 K) occurs in slightly phosphorus rich samples, with composition near Mo5P1.1B1.9, and the upper critical field Hc2 at T = 0 is estimated to be ≈17 kOe. Together, the measurements and band-structure calculations indicate intermediate couplingmore » (λ=1.0), phonon mediated superconductivity. Here, the temperature dependence of the heat capacity and upper critical field Hc2 below Tc suggest multiple superconducting gaps may be present.« less

  7. Bayesian-information-gap decision theory with an application to CO2 sequestration

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

    O'Malley, D.; Vesselinov, V. V.

    2015-09-04

    Decisions related to subsurface engineering problems such as groundwater management, fossil fuel production, and geologic carbon sequestration are frequently challenging because of an overabundance of uncertainties (related to conceptualizations, parameters, observations, etc.). Because of the importance of these problems to agriculture, energy, and the climate (respectively), good decisions that are scientifically defensible must be made despite the uncertainties. We describe a general approach to making decisions for challenging problems such as these in the presence of severe uncertainties that combines probabilistic and non-probabilistic methods. The approach uses Bayesian sampling to assess parametric uncertainty and Information-Gap Decision Theory (IGDT) to addressmore » model inadequacy. The combined approach also resolves an issue that frequently arises when applying Bayesian methods to real-world engineering problems related to the enumeration of possible outcomes. In the case of zero non-probabilistic uncertainty, the method reduces to a Bayesian method. Lastly, to illustrate the approach, we apply it to a site-selection decision for geologic CO2 sequestration.« less

  8. Bayesian-information-gap decision theory with an application to CO2 sequestration

    SciTech Connect (OSTI)

    O'Malley, D.; Vesselinov, V. V.

    2015-09-04

    Decisions related to subsurface engineering problems such as groundwater management, fossil fuel production, and geologic carbon sequestration are frequently challenging because of an overabundance of uncertainties (related to conceptualizations, parameters, observations, etc.). Because of the importance of these problems to agriculture, energy, and the climate (respectively), good decisions that are scientifically defensible must be made despite the uncertainties. We describe a general approach to making decisions for challenging problems such as these in the presence of severe uncertainties that combines probabilistic and non-probabilistic methods. The approach uses Bayesian sampling to assess parametric uncertainty and Information-Gap Decision Theory (IGDT) to address model inadequacy. The combined approach also resolves an issue that frequently arises when applying Bayesian methods to real-world engineering problems related to the enumeration of possible outcomes. In the case of zero non-probabilistic uncertainty, the method reduces to a Bayesian method. Lastly, to illustrate the approach, we apply it to a site-selection decision for geologic CO2 sequestration.

  9. Method for implantation of high dopant concentrations in wide band gap materials

    DOE Patents [OSTI]

    Usov, Igor; Arendt, Paul N.

    2009-09-15

    A method that combines alternate low/medium ion dose implantation with rapid thermal annealing at relatively low temperatures. At least one dopant is implanted in one of a single crystal and an epitaxial film of the wide band gap compound by a plurality of implantation cycles. The number of implantation cycles is sufficient to implant a predetermined concentration of the dopant in one of the single crystal and the epitaxial film. Each of the implantation cycles includes the steps of: implanting a portion of the predetermined concentration of the one dopant in one of the single crystal and the epitaxial film; annealing one of the single crystal and the epitaxial film and implanted portion at a predetermined temperature for a predetermined time to repair damage to one of the single crystal and the epitaxial film caused by implantation and activates the implanted dopant; and cooling the annealed single crystal and implanted portion to a temperature of less than about 100.degree. C. This combination produces high concentrations of dopants, while minimizing the defect concentration.

  10. Ultra-high speed permanent magnet axial gap alternator with multiple stators

    DOE Patents [OSTI]

    Hawsey, Robert A.; Bailey, J. Milton

    1991-01-01

    An ultra-high speed, axial gap alternator that can provide an output to a plurality of loads, the alternator providing magnetic isolation such that operating conditions in one load will not affect operating conditions of another load. This improved alternator uses a rotor member disposed between a pair of stator members, with magnets disposed in each of the rotor member surfaces facing the stator members. The magnets in one surface of the rotor member, which alternate in polarity, are isolated from the magnets in the other surface of the rotor member by a disk of magnetic material disposed between the two sets of magents. In the preferred embodiment, this disk of magnetic material is laminated between two layers of non-magnetic material that support the magnets, and the magnetic material has a peripheral rim that extends to both surfaces of the rotor member to enhance the structural integrity. The stator members are substantially conventional in construction in that equally-spaced and radially-oriented slots are provided, and winding members are laid in these slots. A unit with multiple rotor members and stator members is also described.

  11. Geometric phase and entanglement of Raman photon pairs in the presence of photonic band gap

    SciTech Connect (OSTI)

    Berrada, K.; Ooi, C. H. Raymond; Abdel-Khalek, S.

    2015-03-28

    Robustness of the geometric phase (GP) with respect to different noise effects is a basic condition for an effective quantum computation. Here, we propose a useful quantum system with real physical parameters by studying the GP of a pair of Stokes and anti-Stokes photons, involving Raman emission processes with and without photonic band gap (PBG) effect. We show that the properties of GP are very sensitive to the change of the Rabi frequency and time, exhibiting collapse phenomenon as the time becomes significantly large. The system allows us to obtain a state which remains with zero GP for longer times. This result plays a significant role to enhance the stabilization and control of the system dynamics. Finally, we investigate the nonlocal correlation (entanglement) between the pair photons by taking into account the effect of different parameters. An interesting correlation between the GP and entanglement is observed showing that the PBG stabilizes the fluctuations in the system and makes the entanglement more robust against the change of time and frequency.

  12. Nearest Neighbor Averaging and its Effect on the Critical Level and Minimum Detectable Concentration for Scanning Radiological Survey Instruments that Perform Facility Release Surveys.

    SciTech Connect (OSTI)

    Fournier, Sean Donovan; Beall, Patrick S; Miller, Mark L.

    2014-08-01

    Through the SNL New Mexico Small Business Assistance (NMSBA) program, several Sandia engineers worked with the Environmental Restoration Group (ERG) Inc. to verify and validate a novel algorithm used to determine the scanning Critical Level (L c ) and Minimum Detectable Concentration (MDC) (or Minimum Detectable Areal Activity) for the 102F scanning system. Through the use of Monte Carlo statistical simulations the algorithm mathematically demonstrates accuracy in determining the L c and MDC when a nearest-neighbor averaging (NNA) technique was used. To empirically validate this approach, SNL prepared several spiked sources and ran a test with the ERG 102F instrument on a bare concrete floor known to have no radiological contamination other than background naturally occurring radioactive material (NORM). The tests conclude that the NNA technique increases the sensitivity (decreases the L c and MDC) for high-density data maps that are obtained by scanning radiological survey instruments.

  13. INVESTIGATING THE MINIMUM ENERGY PRINCIPLE IN SEARCHES FOR NEW MOLECULAR SPECIESTHE CASE OF H{sub 2}C{sub 3}O ISOMERS

    SciTech Connect (OSTI)

    Loomis, Ryan A.; McGuire, Brett A.; Remijan, Anthony J.; Shingledecker, Christopher; Johnson, Chelen H.; Blair, Samantha; Robertson, Amy

    2015-01-20

    Recently, Lattelais et al. have interpreted aggregated observations of molecular isomers to suggest that there exists a ''minimum energy principle'', such that molecular formation will favor more stable molecular isomers for thermodynamic reasons. To test the predictive power of this principle, we have fully characterized the spectra of the three isomers of C{sub 3}H{sub 2}O toward the well-known molecular region SgrB2(N). Evidence for the detection of the isomers cyclopropenone (c-C{sub 3}H{sub 2}O) and propynal (HCCCHO) is presented, along with evidence for the non-detection of the lowest zero-point energy isomer, propadienone (CH{sub 2}CCO). We interpret these observations as evidence that chemical formation pathways, which may be under kinetic control, have a more pronounced effect on final isomer abundances than thermodynamic effects such as the minimum energy principle.

  14. Moderate forest disturbance as a stringent test for gap and big-leaf models

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

    Bond-Lamberty, Benjamin; Fisk, Justin P.; Holm, Jennifer; Bailey, Vanessa L.; Bohrer, Gil; Gough, Christopher

    2015-01-27

    Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. It is thus unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models – Biome-BGC (BioGeochemical Cycles), a classic big-leaf model, and the ZELIG and ED (Ecosystem Demography) gap-oriented models – could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experimentmore » in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ZELIG and ED correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes, in particular gross primary production or net primary production (NPP). Biome-BGC NPP was correctly resilient but for the wrong reasons, and could not match the absolute observational values. ZELIG and ED, in contrast, exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. It is thus an open question whether most ecosystem models will simulate correctly the gradual and less extensive tree mortality characteristic of moderate disturbances.« less

  15. Modeling of Gap Closure in Uranium-Zirconium Alloy Metal Fuel - A Test Problem

    SciTech Connect (OSTI)

    Simunovic, Srdjan; Ott, Larry J; Gorti, Sarma B; Nukala, Phani K; Radhakrishnan, Balasubramaniam; Turner, John A

    2009-10-01

    Uranium based binary and ternary alloy fuel is a possible candidate for advanced fast spectrum reactors with long refueling intervals and reduced liner heat rating [1]. An important metal fuel issue that can impact the fuel performance is the fuel-cladding gap closure, and fuel axial growth. The dimensional change in the fuel during irradiation is due to a superposition of the thermal expansion of the fuel due to heating, volumetric changes due to possible phase transformations that occur during heating and the swelling due to fission gas retention. The volumetric changes due to phase transformation depend both on the thermodynamics of the alloy system and the kinetics of phase change reactions that occur at the operating temperature. The nucleation and growth of fission gas bubbles that contributes to fuel swelling is also influenced by the local fuel chemistry and the microstructure. Once the fuel expands and contacts the clad, expansion in the radial direction is constrained by the clad, and the overall deformation of the fuel clad assembly depends upon the dynamics of the contact problem. The neutronics portion of the problem is also inherently coupled with microstructural evolution in terms of constituent redistribution and phase transformation. Because of the complex nature of the problem, a series of test problems have been defined with increasing complexity with the objective of capturing the fuel-clad interaction in complex fuels subjected to a wide range of irradiation and temperature conditions. The abstract, if short, is inserted here before the introduction section. If the abstract is long, it should be inserted with the front material and page numbered as such, then this page would begin with the introduction section.

  16. Moderate forest disturbance as a stringent test for gap and big-leaf models

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin; Fisk, Justin P.; Holm, Jennifer; Bailey, Vanessa L.; Bohrer, Gil; Gough, Christopher

    2015-01-27

    Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. It is thus unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models – Biome-BGC (BioGeochemical Cycles), a classic big-leaf model, and the ZELIG and ED (Ecosystem Demography) gap-oriented models – could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experiment in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ZELIG and ED correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes, in particular gross primary production or net primary production (NPP). Biome-BGC NPP was correctly resilient but for the wrong reasons, and could not match the absolute observational values. ZELIG and ED, in contrast, exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. It is thus an open question whether most ecosystem models will simulate correctly the gradual and less extensive tree mortality characteristic of moderate disturbances.

  17. Calibration Monitoring for Sensor Calibration Interval Extension: Gaps in the Current Science Base

    SciTech Connect (OSTI)

    Coble, Jamie B.; Ramuhalli, Pradeep; Meyer, Ryan M.; Hashemian, Hash; Shumaker, Brent; Cummins, Dara

    2012-10-09

    Currently in the United States, periodic sensor recalibration is required for all safety-related sensors, typically occurring at every refueling outage, and it has emerged as a critical path item for shortening outage duration in some plants. International application of calibration monitoring has shown that sensors may operate for longer periods within calibration tolerances. This issue is expected to also be important as the United States looks to the next generation of reactor designs (such as small modular reactors and advanced concepts), given the anticipated longer refueling cycles, proposed advanced sensors, and digital instrumentation and control systems. Online monitoring (OLM) can be employed to identify those sensors that require calibration, allowing for calibration of only those sensors that need it. The U.S. Nuclear Regulatory Commission (NRC) accepted the general concept of OLM for sensor calibration monitoring in 2000, but no U.S. plants have been granted the necessary license amendment to apply it. This paper summarizes a recent state-of-the-art assessment of online calibration monitoring in the nuclear power industry, including sensors, calibration practice, and OLM algorithms. This assessment identifies key research needs and gaps that prohibit integration of the NRC-approved online calibration monitoring system in the U.S. nuclear industry. Several technical needs were identified, including an understanding of the impacts of sensor degradation on measurements for both conventional and emerging sensors; the quantification of uncertainty in online calibration assessment; determination of calibration acceptance criteria and quantification of the effect of acceptance criteria variability on system performance; and assessment of the feasibility of using virtual sensor estimates to replace identified faulty sensors in order to extend operation to the next convenient maintenance opportunity.

  18. Halftoning band gap of InAs/InP quantum dots using inductively coupled argon plasma-enhanced intermixing

    SciTech Connect (OSTI)

    Nie, D.; Mei, T.; Xu, C. D.; Dong, J. R.

    2006-09-25

    Inductively coupled argon plasma-enhanced intermixing of InAs/InP quantum dots grown on InP substrate is investigated. Intermixing is promoted by the near-surface defects generated by plasma exposure in annealing at a temperature of 600 deg. C for 30 s. The annealing results in a maximum differential band-gap blueshift of 106 nm but a thermal shift of only 10 nm. Band-gap halftones are obtained by controlling the amount of near-surface defects via wet chemical etching on the plasma-exposed InP cap layer. No degradation of quantum-dot crystal quality due to the process has been observed as evidenced by photoluminescence intensity.

  19. The change in dielectric constant, AC conductivity and optical band gaps of polymer electrolyte film: Gamma irradiation

    SciTech Connect (OSTI)

    Raghu, S. Subramanya, K. Sharanappa, C. Mini, V. Archana, K. Sanjeev, Ganesh Devendrappa, H.

    2014-04-24

    The effects of gamma (γ) irradiation on dielectric and optical properties of polymer electrolyte film were investigated. The dielectric constant and ac conductivity increases with γ dose. Also optical band gap decreased from 4.23 to 3.78ev after irradiation. A large dependence of the polymer properties on the irradiation dose was noticed. This suggests that there is a possibility of improving polymer electrolyte properties on gamma irradiation.

  20. Strategy and gaps for modeling, simulation, and control of hybrid systems

    SciTech Connect (OSTI)

    Rabiti, Cristian; Garcia, Humberto E.; Hovsapian, Rob; Kinoshita, Robert; Mesina, George L.; Bragg-Sitton, Shannon M.; Boardman, Richard D.

    2015-04-01

    The purpose of this report is to establish a strategy for modeling and simulation of candidate hybrid energy systems. Modeling and simulation is necessary to design, evaluate, and optimize the system technical and economic performance. Accordingly, this report first establishes the simulation requirements to analysis candidate hybrid systems. Simulation fidelity levels are established based on the temporal scale, real and synthetic data availability or needs, solution accuracy, and output parameters needed to evaluate case-specific figures of merit. Accordingly, the associated computational and co-simulation resources needed are established; including physical models when needed, code assembly and integrated solutions platforms, mathematical solvers, and data processing. This report first attempts to describe the figures of merit, systems requirements, and constraints that are necessary and sufficient to characterize the grid and hybrid systems behavior and market interactions. Loss of Load Probability (LOLP) and effective cost of Effective Cost of Energy (ECE), as opposed to the standard Levelized Cost of Electricty (LCOE), are introduced as technical and economical indices for integrated energy system evaluations. Financial assessment methods are subsequently introduced for evaluation of non-traditional, hybrid energy systems. Algorithms for coupled and iterative evaluation of the technical and economic performance are subsequently discussed. This report further defines modeling objectives, computational tools, solution approaches, and real-time data collection and processing (in some cases using real test units) that will be required to model, co-simulate, and optimize; (a) an energy system components (e.g., power generation unit, chemical process, electricity management unit), (b) system domains (e.g., thermal, electrical or chemical energy generation, conversion, and transport), and (c) systems control modules. Co-simulation of complex, tightly coupled, dynamic energy systems requires multiple simulation tools, potentially developed in several programming languages and resolved on separate time scales. Whereas further investigation and development of hybrid concepts will provide a more complete understanding of the joint computational and physical modeling needs, this report highlights areas in which co-simulation capabilities are warranted. The current development status, quality assurance, availability and maintainability of simulation tools that are currently available for hybrid systems modeling is presented. Existing gaps in the modeling and simulation toolsets and development needs are subsequently discussed. This effort will feed into a broader Roadmap activity for designing, developing, and demonstrating hybrid energy systems.

  1. Structurally Distinct Bacterial TBC-like GAPs Link Arf GTPase to Rab1 Inactivation to Counteract Host Defenses

    SciTech Connect (OSTI)

    Dong, Na; Zhu, Yongqun; Lu, Qiuhe; Hu, Liyan; Zheng, Yuqing; Shao, Feng

    2012-10-10

    Rab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses.

  2. The effects of gaps between bridge foils and PETN as a function of PETN density and specific surface area

    SciTech Connect (OSTI)

    Phillips, D; Roeske, F; Burnham, A

    2007-06-26

    X-ray computer tomography scans of artificially aged PETN seem to indicate shrinkage of material and, by extension, an increased high explosive density, resulting in potential separation of the HE from the header/bridge foil. We have investigated these phenomena by mimicking this shrinkage of material (load density). Thus, we have evaluated various induced gaps between the exploding bridge foil and the PETN in our custom detonators by changing both specific surface area - recognizing crystal morphology changes - and load density. Analyses for these data include absolute function time relative to bridge burst and careful evaluation of the detonation wave breakout curvature, using an electronic streak camera for wave capture, in cases where the bridge foil (exploding bridge wire - EBW style) initiation successfully traverses the gap (a 'go' condition). In addition, a fireset with subnanosecond trigger jitter was used for these tests allowing easy comparison of relative 'go' function times. Using the same test matrix and fine-tuning the induced gap, a second, smaller subset of these experiments were performed to provide additional insight as to what conditions we might expect detonator anomalies/failure.

  3. Sedimentology of the Mesaverde Formation at Rifle Gap, Colorado and implications for gas-bearing intervals in the subsurface

    SciTech Connect (OSTI)

    Lorenz, J.C.

    1982-03-01

    The exposures of the Mesaverde Formation at Rifle Gap, Colorado, are of a regressive series of marine to fluvial deposits about 1650 m (5000 ft) thick. Grading up out of the marine Mancos Shale, the blanket shoreline sandstones of the Corcoran, Cozzette, and Rollins Sandstones record substages of the regression as delta lobes were activated and abandoned in northwestern Colorado during Late Cretaceous time. The overlying coals, sandstones, and carbonaceous mudstones were deposited on the paludal lower delta plain behind the shoreline. Meandering fluvial systems prograded over the paludal deposits. These systems deposited point-bar sandstones and overbank mudstones and siltstones in composite meander-belt trends, some of which are now gas-bearing, low-permeability reservoirs. Reorientation of the paleogeography during the Laramide orogeny (contemporaneous with fluvial deposition) probably changed the orientation of the meander belt trends. The uppermost sandstones at Rifle Gap, including the Ohio Creek conglomerate, are interpreted as shoreline deposits of a transgression that has been previously unrecognized in the area. Most of the record of this transgression has been destroyed by pre-Eocene erosion. The outcrops at Rifle Gap provide a basis for interpreting subsurface deposis in the Department of Energy's Western Gas Sands Project Multi-Well Experiment, 12 miles away.

  4. Percolation Cooling of the Three Mile Island Unit 2 Lower Head by Way of Thermal Cracking and Gap Formation

    SciTech Connect (OSTI)

    Thomsen, K.L.

    2002-01-15

    Two partial models have been developed to elucidate the Three Mile Island Unit 2 lower head coolability by water percolation from above into the thermally cracking debris bed and into a gap between the debris and the wall. The bulk permeability of the cracked top crust is estimated based on simple fracture mechanics and application of Poiseuille's law to the fractures. The gap is considered as an abstraction representing an initially rugged interface, which probably expanded by thermal deformation and cracking in connection with the water ingress. The coupled flow and heat conduction problem for the top crust is solved in slab geometry based on the two-phase Darcy equations together with quasi-steady mass and energy conservation equations. The resulting water penetration depth is in good agreement with the depth of the so-called loose debris bed. The lower-head and bottom-crust problem is treated analogously by a two-dimensional axisymmetric model. The notion of a gap is maintained as a useful concept in the flow analysis. Simulations show that a central hot spot with a peak wall temperature of 1075 to 1100 deg. C can be obtained, but the quenching rates are not satisfactory. It is concluded that a three-dimensional model with an additional mechanism to explain the sudden water ingress to the hot spot center would be more appropriate.

  5. SU-F-18C-01: Minimum Detectability Analysis for Comprehensive Sized Based Optimization of Image Quality and Radiation Dose Across CT Protocols

    SciTech Connect (OSTI)

    Smitherman, C; Chen, B; Samei, E

    2014-06-15

    Purpose: This work involved a comprehensive modeling of task-based performance of CT across a wide range of protocols. The approach was used for optimization and consistency of dose and image quality within a large multi-vendor clinical facility. Methods: 150 adult protocols from the Duke University Medical Center were grouped into sub-protocols with similar acquisition characteristics. A size based image quality phantom (Duke Mercury Phantom) was imaged using these sub-protocols for a range of clinically relevant doses on two CT manufacturer platforms (Siemens, GE). The images were analyzed to extract task-based image quality metrics such as the Task Transfer Function (TTF), Noise Power Spectrum, and Az based on designer nodule task functions. The data were analyzed in terms of the detectability of a lesion size/contrast as a function of dose, patient size, and protocol. A graphical user interface (GUI) was developed to predict image quality and dose to achieve a minimum level of detectability. Results: Image quality trends with variations in dose, patient size, and lesion contrast/size were evaluated and calculated data behaved as predicted. The GUI proved effective to predict the Az values representing radiologist confidence for a targeted lesion, patient size, and dose. As an example, an abdomen pelvis exam for the GE scanner, with a task size/contrast of 5-mm/50-HU, and an Az of 0.9 requires a dose of 4.0, 8.9, and 16.9 mGy for patient diameters of 25, 30, and 35 cm, respectively. For a constant patient diameter of 30 cm, the minimum detected lesion size at those dose levels would be 8.4, 5, and 3.9 mm, respectively. Conclusion: The designed CT protocol optimization platform can be used to evaluate minimum detectability across dose levels and patient diameters. The method can be used to improve individual protocols as well as to improve protocol consistency across CT scanners.

  6. Estimate of Cost-Effective Potential for Minimum Efficiency Performance Standards in 13 Major World Economies Energy Savings, Environmental and Financial Impacts

    SciTech Connect (OSTI)

    Letschert, Virginie E.; Bojda, Nicholas; Ke, Jing; McNeil, Michael A.

    2012-07-01

    This study analyzes the financial impacts on consumers of minimum efficiency performance standards (MEPS) for appliances that could be implemented in 13 major economies around the world. We use the Bottom-Up Energy Analysis System (BUENAS), developed at Lawrence Berkeley National Laboratory (LBNL), to analyze various appliance efficiency target levels to estimate the net present value (NPV) of policies designed to provide maximum energy savings while not penalizing consumers financially. These policies constitute what we call the cost-effective potential (CEP) scenario. The CEP scenario is designed to answer the question: How high can we raise the efficiency bar in mandatory programs while still saving consumers money?

  7. Housing standards: change to HUD 4930. 2 Intermediate Minimum Property Standard (IMPS) supplement for solar heating and domestic hot water systems

    SciTech Connect (OSTI)

    Not Available

    1982-08-17

    This rule is made to provide an updating, clarification, and improvement of requirements contained in HUD Handbook 4930.2, Intermediate Minimum Property Standards (IMPS) Supplement concerning solar heating and domestic hot water systems. Changes pertain to fire protection, penetration, roof covering, conditions of use, thermal stability, rain resistance, ultraviolet stability, and compatibility with transfer medium. Additional changes cover applicable standards, labeling, flash point, chemical and physical commpatibility, flame spread classification, lightening protection, and parts of a solar energy system. Altogether, there are over 50 changes, some of which apply to tables and worksheets. Footnotes are included.

  8. Technical Readiness and Gaps Analysis of Commercial Optical Materials and Measurement Systems for Advanced Small Modular Reactors

    SciTech Connect (OSTI)

    Anheier, Norman C.; Suter, Jonathan D.; Qiao, Hong; Andersen, Eric S.; Berglin, Eric J.; Bliss, Mary; Cannon, Bret D.; Devanathan, Ramaswami; Mendoza, Albert; Sheen, David M.

    2013-08-06

    This report intends to support Department of Energy’s Office of Nuclear Energy (DOE-NE) Nuclear Energy Research and Development Roadmap and industry stakeholders by evaluating optical-based instrumentation and control (I&C) concepts for advanced small modular reactor (AdvSMR) applications. These advanced designs will require innovative thinking in terms of engineering approaches, materials integration, and I&C concepts to realize their eventual viability and deployability. The primary goals of this report include: 1. Establish preliminary I&C needs, performance requirements, and possible gaps for AdvSMR designs based on best available published design data. 2. Document commercial off-the-shelf (COTS) optical sensors, components, and materials in terms of their technical readiness to support essential AdvSMR in-vessel I&C systems. 3. Identify technology gaps by comparing the in-vessel monitoring requirements and environmental constraints to COTS optical sensor and materials performance specifications. 4. Outline a future research, development, and demonstration (RD&D) program plan that addresses these gaps and develops optical-based I&C systems that enhance the viability of future AdvSMR designs. The development of clean, affordable, safe, and proliferation-resistant nuclear power is a key goal that is documented in the Nuclear Energy Research and Development Roadmap. This roadmap outlines RD&D activities intended to overcome technical, economic, and other barriers, which currently limit advances in nuclear energy. These activities will ensure that nuclear energy remains a viable component to this nation’s energy security.

  9. Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge

    DOE Patents [OSTI]

    Olson, Jerry M.; Kurtz, Sarah R.; Friedman, Daniel J.

    2001-01-01

    A multi-junction, monolithic, photovoltaic solar cell device is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The solar cell device comprises a plurality of semiconductor cells, i.e., active p/n junctions, connected in tandem and deposited on a substrate fabricated from GaAs or Ge. To increase efficiency, each semiconductor cell is fabricated from a crystalline material with a lattice constant substantially equivalent to the lattice constant of the substrate material. Additionally, the semiconductor cells are selected with appropriate band gaps to efficiently create photovoltage from a larger portion of the solar spectrum. In this regard, one semiconductor cell in each embodiment of the solar cell device has a band gap between that of Ge and GaAs. To achieve desired band gaps and lattice constants, the semiconductor cells may be fabricated from a number of materials including Ge, GaInP, GaAs, GaInAsP, GaInAsN, GaAsGe, BGaInAs, (GaAs)Ge, CuInSSe, CuAsSSe, and GaInAsNP. To further increase efficiency, the thickness of each semiconductor cell is controlled to match the photocurrent generated in each cell. To facilitate photocurrent flow, a plurality of tunnel junctions of low-resistivity material are included between each adjacent semiconductor cell. The conductivity or direction of photocurrent in the solar cell device may be selected by controlling the specific p-type or n-type characteristics for each active junction.

  10. June 11, 2009, HSS/Union Task Meeting on 2009 HSS/Union Task Progress - Assessing Training Gaps in ORPS

    Energy Savers [EERE]

    Assessing Training Gaps Using DOE's Occurrence Reporting and Processing System (ORPS) HSS/Union Meeting June 11, 2009 2 Highlights Training is a contributing cause in about 15% of DOE operational events (about 150 per year) * Poor management practices are the most common training cause * Poor training programs are next (cited about 50 times per year) Of ORPS-reported injuries, about 17% had training as a contributing cause (101 of 594) * About 30 per year HS-30 will develop a report with a few

  11. Plasmon-polariton and ⟨n⟨ = 0 non-Bragg gaps in 1D Cantor photonic superlattices

    SciTech Connect (OSTI)

    Meja-Salazar, J. R.; Porras-Montenegro, N.; Reyes-Gmez, E.; Cavalcanti, S. B.; Oliveira, L. E.

    2014-05-15

    We have used the transfer-matrix approach for one-dimensional Cantor photonic superlattices, and studied the plasmon-polariton modes for a multilayered system composed by alternating layers of positive and dispersive materials. Results indicate that the corresponding plasmon-polariton modes, which show up for oblique incidence, strongly depend on the Cantor step, and the plasmon-polariton subbands are associated with the number of metamaterial layers contained in the elementary cell. Moreover, we have studied the ⟨n⟩ = 0 non-Bragg gap in such fractal photonic superlattices and characterized its behavior as function of the steps of the Cantor series.

  12. In situ study of atomic layer deposition Al{sub 2}O{sub 3} on GaP (100)

    SciTech Connect (OSTI)

    Dong, H.; Brennan, B.; Qin, X.; Hinkle, C. L.; Kim, J.; Wallace, R. M.; Zhernokletov, D. M.

    2013-09-16

    The interfacial chemistry of atomic layer deposition (ALD) of Al{sub 2}O{sub 3} on chemically treated GaP (100) has been studied using in situ X-ray photoelectron spectroscopy. A “self-cleaning” effect for Ga-oxide upon exposure to trimethylaluminum is seen to be efficient on the native oxide and chemically treated surfaces. The phosphorus oxide chemical states are seen to change during the ALD process, but the total concentration of P-oxides is seen to remain constant throughout the ALD process.

  13. Band gap estimation from temperature dependent Seebeck measurementDeviations from the 2e|S|{sub max}T{sub max} relation

    SciTech Connect (OSTI)

    Gibbs, Zachary M.; Kim, Hyun-Sik; Wang, Heng; Snyder, G. Jeffrey

    2015-01-12

    In characterizing thermoelectric materials, electrical and thermal transport measurements are often used to estimate electronic band structure properties such as the effective mass and band gap. The Goldsmid-Sharp band gap, E{sub g}?=?2e|S|{sub max}T{sub max}, is a tool widely employed to estimate the band gap from temperature dependent Seebeck coefficient measurements. However, significant deviations of more than a factor of two are now known to occur. We find that this is when either the majority-to-minority weighted mobility ratio (A) becomes very different from 1.0 or as the band gap (E{sub g}) becomes significantly smaller than 10 k{sub B}T. For narrow gaps (E{sub g}???6 k{sub B}T), the Maxwell-Boltzmann statistics applied by Goldsmid-Sharp break down and Fermi-Dirac statistics are required. We generate a chart that can be used to quickly estimate the expected correction to the Goldsmid-Sharp band gap depending on A and S{sub max}; however, additional errors can occur for S?

  14. Effect of surface viscosity, anchoring energy, and cell gap on the response time of nematic liquid crystals

    SciTech Connect (OSTI)

    Souza, R.F. de; Yang, D.-Ke; Lenzi, E.K.; Evangelista, L.R.; Zola, R.S.

    2014-07-15

    An analytical expression for the relaxation time of a nematic liquid crystal is obtained for the first time by considering the influence of surface viscosity, anchoring energy strength and cell gap, validated numerically by using the so-called relaxation method. This general equation for the molecular response time (?{sub 0}) was derived for a vertical aligned cell and by solving an eigenvalue equation coming from the usual balance of torque equation in the Derzhanskii and Petrov formulation, recovering the usual equations in the appropriate limit. The results show that ??d{sup b}, where b=2 is observed only for strongly anchored cells, while for moderate to weak anchored cells, the exponent lies between 1 and 2, depending on both, surface viscosity and anchoring strength. We found that the surface viscosity is important when calculating the response time, specially for thin cells, critical for liquid crystal devices. The surface viscositys effect on the optical response time with pretilt is also explored. Our results bring new insights about the role of surface viscosity and its effects in applied physics. - Highlights: The relaxation of nematic liquid crystals is calculated by taking the surface viscosity into account. An analytical expression for the relaxation time depending on surface viscosity, anchoring strength and cell gap is obtained. The results are numerically verified. Surface viscosity is crucial for thin and weak anchored cells. The effect on optical time and pretilt angle is also studied.

  15. Electronic Structures, Bonding Configurations, and Band-Gap-Opening Properties of Graphene Binding with Low-Concentration Fluorine

    SciTech Connect (OSTI)

    Duan, Yuhua; Stinespring, Charter D.; Chorpening, Benjamin

    2015-06-18

    To better understand the effects of low-level fluorine in graphene-based sensors, first-principles density functional theory (DFT) with van der Waals dispersion interactions has been employed to investigate the structure and impact of fluorine defects on the electrical properties of single-layer graphene films. The results show that both graphite-2H and graphene have zero band gaps. When fluorine bonds to a carbon atom, the carbon atom is pulled slightly above the graphene plane, creating what is referred to as a CF defect. The lowest-binding energy state is found to correspond to two CF defects on nearest neighbor sites, with one fluorine above the carbon plane and the other below the plane. Overall this has the effect of buckling the graphene. The results further show that the addition of fluorine to graphene leads to the formation of an energy band (BF) near the Fermi level, contributed mainly from the 2p orbitals of fluorine with a small contribution from the porbitals of the carbon. Among the 11 binding configurations studied, our results show that only in two cases does the BF serve as a conduction band and open a band gap of 0.37 eV and 0.24 eV respectively. The binding energy decreases with decreasing fluorine concentration due to the interaction between neighboring fluorine atoms. The obtained results are useful for sensor development and nanoelectronics.

  16. Wide band gap p-type nanocrystalline CuBO{sub 2} as a novel UV photocatalyst

    SciTech Connect (OSTI)

    Santra, S.; Das, N.S.; Chattopadhyay, K.K.

    2013-07-15

    Graphical abstract: - Highlights: CuBO{sub 2} nanocrystals were synthesized by solgel route. The products have been characterized to confirm the formation of CuBO{sub 2}. Photocatalytic activity of this material is reported for the first time. - Abstract: Wide band gap copper based delafossite CuBO{sub 2} nanocrystalline powders of different particle sizes were synthesized via solgel route. Structural characterization was performed using X-ray diffraction (XRD) and transmission electron microscopy (TEM) which confirmed good crystallinity and proper phase formation of the samples. Compositional analysis was carried out by energy dispersive X-ray studies (EDX), whereas field emission scanning electron microscopy revealed morphological information of the samples. The photocatalytic performance of this delafossite material was studied for the first time with a standard photocatalytic set-up and the photocatalytic efficiency was found to increase with decreasing particle size. The LangmuirHinshelwood photocatalytic rate constants increased considerably for the samples synthesized at different pH from 2.75 to 0.5; which eventually varied particle size. The efficient photocatalytic performance, found for the first time here, will make this novel p-type wide band gap semiconductor a truly multifunctional material.

  17. Two-dimensional topological crystalline insulator phase in Sb/Bi planar honeycomb with tunable Dirac gap

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

    Hsu, Chia -Hsiu; Huang, Zhi -Quan; Crisostomo, Christian P.; Yao, Liang -Zi; Chuang, Feng -Chuan; Liu, Yu -Tzu; Wang, Baokai; Hsu, Chuang -Han; Lee, Chi -Cheng; Lin, Hsin; et al

    2016-01-14

    We predict planar Sb/Bi honeycomb to harbor a two-dimensional (2D) topological crystalline insulator (TCI) phase based on first-principles computations. Although buckled Sb and Bi honeycombs support 2D topological insulator (TI) phases, their structure becomes planar under tensile strain. The planar Sb/Bi honeycomb structure restores the mirror symmetry, and is shown to exhibit non-zero mirror Chern numbers, indicating that the system can host topologically protected edge states. Our computations show that the electronic spectrum of a planar Sb/Bi nanoribbon with armchair or zigzag edges contains two Dirac cones within the band gap and an even number of edge bands crossing themore » Fermi level. Lattice constant of the planar Sb honeycomb is found to nearly match that of hexagonal-BN. As a result, the Sb nanoribbon on hexagonal-BN exhibits gapped edge states, which we show to be tunable by an out-of the-plane electric field, providing controllable gating of edge state important for device applications.« less

  18. Numerical Simulation of the Performance Characteristics, Instability, and Effects of Band Gap Grading in Cadmium Telluride Based Photovoltaic Devices

    SciTech Connect (OSTI)

    Michael David Petersen

    2001-05-01

    Using computer simulations, the performance of several CdTe based photovoltaic structures has been studied. The advantages and disadvantages of band gap grading, through the use of (Zn,Cd)Te, have also been investigated in these structures. Grading at the front interface between a CdS window layer and a CdTe absorber layer, can arise due to interdiffusion between the materials during growth or due to the intentional variation of the material composition. This grading has been shown to improve certain performance metrics, such as the open-circuit voltage, while degrading others, such as the fill factor, depending on the amount and distance of the grading. The presence of a Schottky barrier as the back contact has also been shown to degrade the photovoltaic performance of the device, resulting in a characteristic IV curve. However, with the appropriate band gap grading at the back interface, it has been shown that the performance can be enhanced through more efficient carrier collection. These results were then correlated with experimental observations of the performance degradation in devices subjected to light and heat stress.

  19. Numerical Simulation of the Performance Characteristics, Instability, and Effects of Band Gap Grading in Cadmium Telluride Based Photovoltaic Devices

    SciTech Connect (OSTI)

    Michael David Petersen

    2001-06-27

    Using computer simulations, the performance of several CdTe based photovoltaic structures has been studied. The advantages and disadvantages of band gap grading, through the use of (Zn, Cd)Te, have also been investigated in these structures. Grading at the front interface between a CdS window layer and a CdTe absorber layer, can arise due to interdiffusion between the materials during growth or due to the intentional variation of the material composition. This grading has been shown to improve certain performance metrics, such as the open-circuit voltage, while degrading others, such as the fill factor, depending on the amount and distance of the grading. The presence of a Schottky barrier as the back contact has also been shown to degrade the photovoltaic performance of the device, resulting in a characteristic IV curve. However, with the appropriate band gap grading at the back interface, it has been shown that the performance can be enhanced through more efficient carrier collection. These results were then correlated with experimental observations of the performance degradation in devices subjected to light and heat stress.

  20. Design and 3D simulation of a two-cavity wide-gap relativistic klystron amplifier with high power injection

    SciTech Connect (OSTI)

    Bai Xianchen; Yang Jianhua; Zhang Jiande [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2012-08-15

    By using an electromagnetic particle-in-cell (PIC) code, an S-band two-cavity wide-gap klystron amplifier (WKA) loaded with washers/rods structure is designed and investigated for high power injection application. Influences of the washers/rods structure on the high frequency characteristics and the basic operation of the amplifier are presented. Generally, the rod structure has great impacts on the space-charge potential depression and the resonant frequency of the cavities. Nevertheless, if only the resonant frequency is tuned to the desired operation frequency, effects of the rod size on the basic operation of the amplifier are expected to be very weak. The 3-dimension (3-D) PIC simulation results show an output power of 0.98 GW corresponding to an efficiency of 33% for the WKA, with a 594 keV, 5 kA electron beam guided by an external magnetic field of 1.5 Tesla. Moreover, if a conductive plane is placed near the output gap, such as the electron collector, the beam potential energy can be further released, and the RF power can be increased to about 1.07 GW with the conversion efficiency of about 36%.

  1. Electronic Structures, Bonding Configurations, and Band-Gap-Opening Properties of Graphene Binding with Low-Concentration Fluorine

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

    Duan, Yuhua; Stinespring, Charter D.; Chorpening, Benjamin

    2015-06-18

    To better understand the effects of low-level fluorine in graphene-based sensors, first-principles density functional theory (DFT) with van der Waals dispersion interactions has been employed to investigate the structure and impact of fluorine defects on the electrical properties of single-layer graphene films. The results show that both graphite-2H and graphene have zero band gaps. When fluorine bonds to a carbon atom, the carbon atom is pulled slightly above the graphene plane, creating what is referred to as a CF defect. The lowest-binding energy state is found to correspond to two CF defects on nearest neighbor sites, with one fluorine abovemore » the carbon plane and the other below the plane. Overall this has the effect of buckling the graphene. The results further show that the addition of fluorine to graphene leads to the formation of an energy band (BF) near the Fermi level, contributed mainly from the 2p orbitals of fluorine with a small contribution from the porbitals of the carbon. Among the 11 binding configurations studied, our results show that only in two cases does the BF serve as a conduction band and open a band gap of 0.37 eV and 0.24 eV respectively. The binding energy decreases with decreasing fluorine concentration due to the interaction between neighboring fluorine atoms. The obtained results are useful for sensor development and nanoelectronics.« less

  2. Properties of Wide-Gap Chalcopyrite Semiconductors for Photovoltaic Applications: Final Report, 8 July 1998 -- 17 October 2001

    SciTech Connect (OSTI)

    Rockett, A.

    2003-07-01

    The objectives of this project were to obtain a fundamental understanding of wide-gap chalcopyrite semiconductors and photovoltaic devices. Information to be gathered included significant new fundamental materials data necessary for accurate modeling of single- and tandem-junction devices, basic materials science of wider-gap chalcopyrite semiconductors to be used in next-generation devices, and practical information on the operation of devices incorporating these materials. Deposition used a hybrid sputtering and evaporation method shown previously to produce high-quality epitaxial layers of Cu(In,Ga)Se2 (CIGS). Materials analysis was also provided to assist members of the National CIS Team, of which, through this contract, we were a member. Solar cells produced from resulting single-crystal epitaxial layers in collaboration with various members of the CIS Team were used to determine the factors limiting performance of the devices based on analysis of the results. Because epitaxial growth allows us to determine the surface orientation of our films specifically by choice of the substrate surface on which the film is grown, a major focus of the project concerned the nature of (110)-oriented CIGS films and the performance of solar cells produced from these films. We begin this summary with a description of the results for growth on (110) GaAs, which formed a basis for much of the work ultimately conducted under the program.

  3. System and method employing a minimum distance and a load feature database to identify electric load types of different electric loads

    DOE Patents [OSTI]

    Lu, Bin; Yang, Yi; Sharma, Santosh K; Zambare, Prachi; Madane, Mayura A

    2014-12-23

    A method identifies electric load types of a plurality of different electric loads. The method includes providing a load feature database of a plurality of different electric load types, each of the different electric load types including a first load feature vector having at least four different load features; sensing a voltage signal and a current signal for each of the different electric loads; determining a second load feature vector comprising at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the different electric loads; and identifying by a processor one of the different electric load types by determining a minimum distance of the second load feature vector to the first load feature vector of the different electric load types of the load feature database.

  4. A Mechanistic Study of CO2 Reduction at the Interface of a Gallium Phosphide (GaP) Surface using Core-level Spectroscopy

    SciTech Connect (OSTI)

    Flynn, Kristen

    2015-08-18

    Carbon dioxide (CO2) emission into the atmosphere has increased tremendously through burning of fossil fuels, forestry, etc.. The increased concentration has made CO2 reductions very attractive though the reaction is considered uphill. Utilizing the sun as a potential energy source, CO2 has the possibility to undergo six electron and four proton transfers to produce methanol, a useable resource. This reaction has been shown to occur selectively in an aqueous pyridinium solution with a gallium phosphide (GaP) electrode. Though this reaction has a high faradaic efficiency, it was unclear as to what role the GaP surface played during the reaction. In this work, we aim to address the fundamental role of GaP during the catalytic conversion, by investigating the interaction between a clean GaP surface with the reactants, products, and intermediates of this reaction using X-ray photoelectron spectroscopy. We have determined a procedure to prepare atomically clean GaP and our initial CO2 adsorption studies have shown that there is evidence of chemisorption and reaction to form carbonate on the clean surface at LN2 temperatures (80K), in contrast to previous theoretical calculations. These findings will enable future studies on CO2 catalysis.

  5. A Mechanistic Study of CO2 Reduction at the Interface of a Gallium Phosphide (GaP) Surface using Core-level Spectroscopy - Oral Presentation

    SciTech Connect (OSTI)

    Flynn, Kristen

    2015-08-19

    Carbon dioxide (CO2) emission into the atmosphere has increased tremendously through burning of fossil fuels, forestry, etc.. The increased concentration has made CO2 reductions very attractive though the reaction is considered uphill. Utilizing the sun as a potential energy source, CO2 has the possibility to undergo six electron and four proton transfers to produce methanol, a useable resource. This reaction has been shown to occur selectively in an aqueous pyridinium solution with a gallium phosphide (GaP) electrode. Though this reaction has a high faradaic efficiency, it was unclear as to what role the GaP surface played during the reaction. In this work, we aim to address the fundamental role of GaP during the catalytic conversion, by investigating the interaction between a clean GaP surface with the reactants, products, and intermediates of this reaction using X-ray photoelectron spectroscopy. We have determined a procedure to prepare atomically clean GaP and our initial CO2 adsorption studies have shown that there is evidence of chemisorption and reaction to form carbonate on the clean surface at LN2 temperatures (80K), in contrast to previous theoretical calculations. These findings will enable future studies on CO2 catalysis.

  6. Conductivity and optical band gaps of polyethylene oxide doped with Li{sub 2}SO{sub 4} salt

    SciTech Connect (OSTI)

    Chapi, Sharanappa Raghu, S. Subramanya, K. Archana, K. Mini, V. Devendrappa, H.

    2014-04-24

    The conductivity and optical properties of Li{sub 2}SO{sub 4} doped polyethylene oxide (PEO) films were studied. The polymer electrolyte films are prepared using solution casting technique. The material phase change was confirmed by X-ray diffraction (XRD) technique. Optical absorption study was conducted using UV- Vis. Spectroscopy in the wavelength range 190–1100nm on pure and doped PEO films. The direct and indirect optical band gaps were found decreased from 5.81–4.51eV and 4.84–3.43eV respectively with increasing the Li{sub 2}SO{sub 4}. The conductivity found to increases with increasing the dopant concentration due to strong hopping mechanism at room temperature.

  7. Physics of band-gap formation and its evolution in the pillar-based phononic crystal structures

    SciTech Connect (OSTI)

    Pourabolghasem, Reza; Mohammadi, Saeed; Eftekhar, Ali Asghar; Adibi, Ali; Khelif, Abdelkrim

    2014-07-07

    In this paper, the interplay of Bragg scattering and local resonance is theoretically studied in a phononic crystal (PnC) structure composed of a silicon membrane with periodic tungsten pillars. The comparison of phononic band gaps (PnBGs) in three different lattice types (i.e., square, triangular, and honeycomb) with different pillar geometries shows that different PnBGs have varying degrees of dependency on the lattice symmetry based on the interplay of the local resonances and the Bragg effect. The details of this interplay is discussed. The significance of locally resonating pillars, specially in the case of tall pillars, on PnBGs is discussed and verified by examining the PnBG position and width in perturbed lattices via Monte Carlo simulations. It is shown that the PnBGs caused by the local resonance of the pillars are more resilient to the lattice perturbations than those caused by Bragg scattering.

  8. Accumulation capacitance frequency dispersion of III-V metal-insulator-semiconductor devices due to disorder induced gap states

    SciTech Connect (OSTI)

    Galatage, R. V.; Zhernokletov, D. M.; Dong, H.; Brennan, B.; Hinkle, C. L.; Wallace, R. M.; Vogel, E. M.

    2014-07-07

    The origin of the anomalous frequency dispersion in accumulation capacitance of metal-insulator-semiconductor devices on InGaAs and InP substrates is investigated using modeling, electrical characterization, and chemical characterization. A comparison of the border trap model and the disorder induced gap state model for frequency dispersion is performed. The fitting of both models to experimental data indicate that the defects responsible for the measured dispersion are within approximately 0.8 nm of the surface of the crystalline semiconductor. The correlation between the spectroscopically detected bonding states at the dielectric/III-V interface, the interfacial defect density determined using capacitance-voltage, and modeled capacitance-voltage response strongly suggests that these defects are associated with the disruption of the III-V atomic bonding and not border traps associated with bonding defects within the high-k dielectric.

  9. Band-gap nonlinear optical generation: The structure of internal optical field and the structural light focusing

    SciTech Connect (OSTI)

    Zaytsev, Kirill I. Katyba, Gleb M.; Yakovlev, Egor V.; Yurchenko, Stanislav O.; Gorelik, Vladimir S.

    2014-06-07

    A novel approach for the enhancement of nonlinear optical effects inside globular photonic crystals (PCs) is proposed and systematically studied via numerical simulations. The enhanced optical harmonic generation is associated with two- and three-dimensional PC pumping with the wavelength corresponding to different PC band-gaps. The interactions between light and the PC are numerically simulated using the finite-difference time-domain technique for solving the Maxwell's equations. Both empty and infiltrated two-dimensional PC structures are considered. A significant enhancement of harmonic generation is predicted owing to the highly efficient PC pumping based on the structural light focusing effect inside the PC structure. It is shown that a highly efficient harmonic generation could be attained for both the empty and infiltrated two- and three-dimensional PCs. We are demonstrating the ability for two times enhancement of the parametric decay efficiency, one order enhancement of the second harmonic generation, and two order enhancement of the third harmonic generation in PC structures in comparison to the nonlinear generations in appropriate homogenous media. Obviously, the nonlinear processes should be allowed by the molecular symmetry. The criteria of the nonlinear process efficiency are specified and calculated as a function of pumping wavelength position towards the PC globule diameter. Obtained criterion curves exhibit oscillating characteristics, which indicates that the highly efficient generation corresponds to the various PC band-gap pumping. The highest efficiency of nonlinear conversions could be reached for PC pumping with femtosecond optical pulses; thus, the local peak intensity would be maximized. Possible applications of the observed phenomenon are also discussed.

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

    SciTech Connect (OSTI)

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

    2014-01-01

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

  11. SU-E-T-552: Minimum Monitor Unit Effects On Plan Quality for Multi-Field Optimized Spot Scanning Proton Therapy

    SciTech Connect (OSTI)

    Howard, M; Beltran, C; Herman, M

    2014-06-01

    Purpose: To investigate the influence of the minimum monitor unit (MU) on the quality of clinical treatment plans for scanned proton therapy. Methods: Delivery system characteristics limit the minimum number of protons that can be delivered per spot, resulting in a min-MU limit. Plan quality can be impacted by the min-MU limit. Two sites were used to investigate the impact of min-MU on treatment plans: pediatric brain tumor at a depth of 5-10 cm; a head and neck tumor at a depth of 1-20 cm. Three field intensity modulated spot scanning proton plans were created for each site with the following parameter variations: min-MU limit range of 0.0000-0.0060; and spot spacing range of 0.5-2.0σ of the nominal spot size at isocenter in water (σ=4mm in this work). Comparisons were based on target homogeneity and normal tissue sparing. Results: The increase of the min-MU with a fixed spot spacing decreases plan quality both in homogeneous target coverage and in the avoidance of critical structures. Both head and neck and pediatric brain plans show a 20% increase in relative dose for the hot spot in the CTV and 10% increase in key critical structures when comparing min-MU limits of 0.0000 and 0.0060 with a fixed spot spacing of 1σ. The DVHs of CTVs show min-MU limits of 0.0000 and 0.0010 produce similar plan quality and quality decreases as the min-MU limit increases beyond 0.0020. As spot spacing approaches 2σ, degradation in plan quality is observed when no min-MU limit is imposed. Conclusion: Given a fixed spot spacing of ≤ 1σ of the spot size in water, plan quality decreases as min- MU increases greater than 0.0020. The effect of min-MU should be taken into consideration while planning spot scanning proton therapy treatments to realize its full potential.

  12. GaP ring-like nanostructures on GaAs (100) with In{sub 0.15}Ga{sub 0.85}As compensation layers

    SciTech Connect (OSTI)

    Prongjit, Patchareewan Pankaow, Naraporn Boonpeng, Poonyasiri Thainoi, Supachok Panyakeow, Somsak Ratanathammaphan, Somchai

    2013-12-04

    We present the fabrication of GaP ring-like nanostructures on GaAs (100) substrates with inserted In{sub 0.15}Ga{sub 0.85}As compensation layers. The samples are grown by droplet epitaxy using solid-source molecular beam epitaxy. The dependency of nanostructural and optical properties of GaP nanostructures on In{sub 0.15}Ga{sub 0.85}As layer thickness is investigated by ex-situ atomic force microscope (AFM) and photoluminescence (PL). It is found that the characteristics of GaP ring-like structures on GaAs strongly depend on the In{sub 0.15}Ga{sub 0.85}As layer thickness.

  13. THE ROCHE LIMIT FOR CLOSE-ORBITING PLANETS: MINIMUM DENSITY, COMPOSITION CONSTRAINTS, AND APPLICATION TO THE 4.2 hr PLANET KOI 1843.03

    SciTech Connect (OSTI)

    Rappaport, Saul; Sanchis-Ojeda, Roberto; Winn, Joshua N.; Rogers, Leslie A.; Levine, Alan E-mail: sar@mit.edu E-mail: larogers@caltech.edu

    2013-08-10

    The requirement that a planet must orbit outside of its Roche limit gives a lower limit on the planet's mean density. The minimum density depends almost entirely on the orbital period and is immune to systematic errors in the stellar properties. We consider the implications of this density constraint for the newly identified class of small planets with periods shorter than half a day. When the planet's radius is accurately known, this lower limit to the density can be used to restrict the possible combinations of iron and rock within the planet. Applied to KOI 1843.03, a 0.6 R{sub Circled-Plus} planet with the shortest known orbital period of 4.245 hr, the planet's mean density must be {approx}> 7 g cm{sup -3}. By modeling the planetary interior subject to this constraint, we find that the composition of the planet must be mostly iron, with at most a modest fraction of silicates ({approx}< 30% by mass)

  14. Optimizing minimum free-energy crossing points in solution: Linear-response free energy/spin-flip density functional theory approach

    SciTech Connect (OSTI)

    Minezawa, Noriyuki

    2014-10-28

    Examining photochemical processes in solution requires understanding the solvent effects on the potential energy profiles near conical intersections (CIs). For that purpose, the CI point in solution is determined as the crossing between nonequilibrium free energy surfaces. In this work, the nonequilibrium free energy is described using the combined method of linear-response free energy and collinear spin-flip time-dependent density functional theory. The proposed approach reveals the solvent effects on the CI geometries of stilbene in an acetonitrile solution and those of thymine in water. Polar acetonitrile decreases the energy difference between the twisted minimum and twisted-pyramidalized CI of stilbene. For thymine in water, the hydrogen bond formation stabilizes significantly the CI puckered at the carbonyl carbon atom. The result is consistent with the recent simulation showing that the reaction path via this geometry is open in water. Therefore, the present method is a promising way of identifying the free-energy crossing points that play an essential role in photochemistry of solvated molecules.

  15. Revisions included in HUD Intermediate Minimum Property Standards Supplement 4930. 2, 1977 edition: solar heating and domestic hot-water systems

    SciTech Connect (OSTI)

    Not Available

    1984-04-01

    This addendum to a 1977 HUD publication contains revisions and additions to the existing intermediate minimum property standards supplment for solar heating and cooling systems. Building design revisions cover fire protection, penetrations, and roof coverings. Changes to guidelines for materials, such as those for thermal and ultraviolet stability and moisture resistance, are detailed. Flash points of toxic and combustive fluids, chemical and physical compatibility, and flame spread and resistance of insulation materials are also explained. Construction standards were revised for hail loads; waterproofing insulated exterior storage containers, pipes, and ducts; and for passive systems. Standards also were revised for power-operated protection, dust and dirt prevention, and chimney and vent heights. Radiation temperature, draft control, and thermal energy storage and loss standards were deleted. Other standards for insulation values for thermal devices, lighting protection, and sealing and testing air distribution systems were added. Appended materials contain revisions to calculation procedures for determining the thermal performance of active, solar space heating, and domestic hot water systems. A revised materials list for properties of typical cover materials, absorptive coatings, thermal storage unit containers, and heat-transfer liquids is provided. Revisions to acceptable engineering practice standards are also included.

  16. SU-E-T-628: Effect of Dose Rate and Leakage Correction for Dosimetric Leaf Gap Measurement

    SciTech Connect (OSTI)

    Feng, W; Chu, A; Chi, Y; Hu, J

    2014-06-15

    Purpose: To study the dose rate response of Mapcheck and quantify/correct dose rate/leakage effect on IMRT QA. Evaluate the dose rate/leakage effect on dosimetric leaf gap (DLG) measurement. Methods: Varian Truebeam Linac with HD120 MLC was used for all measurement, it is capable to adjust dose rate from 600MU/min to 5MU/min. Fluke Advanced Therapy Doisemter and PTW 30013 Farmer chamber for chamber measurement; SunNuclear Mapcheck2 with 5cm total buildup for diode measurement. DLG was measured with both chamber and diode.Diode response was measured by varies dose rate, while fixed mapcheck setup and total MU. MLC Leakage was measured with both chamber and diode. Mapcheck measurement was saved as movie file (mcm file), which include measurement updated every 50mSec. The difference between intervals can be converted to dose and dose rate and leakage response correction can be applied to them. Results: DLG measurement results with chamber and diode were showed as follows, the DLG value is 0.36 vs. 0.24mm respectively. Diode dose rate response drops from 100% at 600MU/min to 95.5% at 5MU/min as follows. MLC Leakage measured with diode is 1.021%, which is 9% smaller than 1.112% from chamber measurement. By apply the dose rate and leakage correction, the residue error reduced 2/3. Conclusions: Diode has lower response at lower dose rate, as low as 4.5% for 5MU/min; diode has lower energy response for low energy too, 5% lower for Co-60 than 6MV. It partially explains the leakage difference of 9% between chamber and diode. Lower DLG with diode is because of the lower response at narrower gap, in Eclipse however DLG need to increase to makeup lower response, which is over correction for chamber though. Correction can reduce error by 2/3, the rest 1/3 can be corrected by scatter effect, which is under study.

  17. Significant Reduction in NiO Band Gap upon Formation of LixNi1?xO Alloys: Applications to Solar Energy Conversion

    SciTech Connect (OSTI)

    Alidoust, Nima; Toroker, Maytal; Keith, John A.; Carter, Emily A.

    2014-01-01

    Long-term sustainable solar energy conversion relies on identifying economical and versatile semiconductor materials with appropriate band structures for photovoltaic and photocatalytic applications (e.g., band gaps of ?1.52.0 eV). Nickel oxide (NiO) is an inexpensive yet highly promising candidate. Its charge-transfer character may lead to longer carrier lifetimes needed for higher efficiencies, and its conduction band edge is suitable for driving hydrogen evolution via water-splitting. However, NiOs large band gap (?4 eV) severely limits its use in practical applications. Our first-principles quantum mechanics calculations show band gaps dramatically decrease to ?2.0 eV when NiO is alloyed with Li2O. We show that LixNi1?xO alloys (with x=0.125 and 0.25) are p-type semiconductors, contain states with no impurity levels in the gap and maintain NiOs desirable charge-transfer character. Lastly, we show that the alloys have potential for photoelectrochemical applications, with band edges well-placed for photocatalytic hydrogen production and CO2 reduction, as well as in tandem dye-sensitized solar cells as a photocathode.

  18. Experimental test of whether electrostatically charged micro-organisms and their spores contribute to the onset of arcs across vacuum gaps

    SciTech Connect (OSTI)

    Grisham, L. R.; Halle, A. von; Carpe, A. F.; Gilton, K. R.; Rossi, Guy; Stevenson, T. N.

    2013-12-15

    Recently it was proposed [L. R. Grisham et al. Phys. Plasmas 19, 023107 (2012)] that one of the initiators of vacuum voltage breakdown between conducting electrodes might be micro-organisms and their spores, previously deposited during exposure to air, which then become electrostatically charged when an electric potential is applied across the vacuum gap. This note describes a simple experiment to compare the number of voltage-conditioning pulses required to reach the nominal maximum operating voltage across a gap between two metallic conductors in a vacuum, comparing cases in which biological cleaning was done just prior to pump-down with cases where this was not done, with each case preceded by exposure to ambient air for three days. Based upon these results, it does not appear that air-deposited microbes and their spores constitute a major pathway for arc initiation, at least for exposure periods of a few days, and for vacuum gaps of a few millimeters, in the regime where voltage holding is usually observed to vary linearly with gap distance.

  19. Experimental Test Of Whether Electrostatically Charged Micro-organisms And Their Spores Contribute To The Onset Of Arcs Across Vacuum Gaps

    SciTech Connect (OSTI)

    none,; Grisham, Larry R.

    2014-02-24

    Recently it was proposed [L.R. Grisham, A. vonHalle, A.F. Carpe, Guy Rossi, K.R. Gilton, E.D. McBride, E.P. Gilson, A. Stepanov, T.N. Stevenson, Physics of Plasma 19 023107 (2012)] that one of the initiators of vacuum voltage breakdown between condu cting electrodes might be micro-organisms and their spores, previously deposited during exposure to air, which tnen become electrostatically charged when an electric potential is applied across the vacuum gap. The note describes a simple experiment to compare the number of voltage-conditioning pulses required to reach the nominal maxium operating voltage across a gap between two metallic conductors in a vacuum, comparing cases in which biological cleaning was done just prior to pump-down with cases where this was not done, with each preceded by exposure to ambient air for three days. Based upon these results, it does not appear that air-deposited microbes and their spores constitute a major pathway for arc initiation, at least for exposure periods of a few days, and for vacuum gaps of a few millimeters, in the regime where voltage holding is usually observed to vary linearly with gap distance

  20. Research on high-efficiency, multiple-gap, multijunction, amorphous-silicon-based alloy thin-film solar cells

    SciTech Connect (OSTI)

    Guha, S. )

    1989-06-01

    This report presents results of research on advancing our understanding of amorphous-silicon-based alloys and their use in small-area multijunction solar cells. The principal objectives of the program are to develop a broad scientific base for the chemical, structural, optical, and electronic properties of amorphous-silicon-based alloys; to determine the optimum properties of these alloy materials as they relate to high-efficiency cells; to determine the optimum device configuration for multijunction cells; and to demonstrate proof-of-concept, multijunction, a-Si-alloy-based solar cells with 18% efficiency under standard AM1.5 global insolation conditions and with an area of at least 1 cm{sup 2}. A major focus of the work done during this reporting period was the optimization of a novel, multiple-graded structure that enhances cell efficiency through band-gap profiling. The principles of the operation of devices incorporating such a structure, computer simulations of those, and experimental results for both single- and multijunction cells prepared by using the novel structure are discussed in detail. 14 refs., 35 figs., 7 tabs.

  1. First-principles study of band gap engineering via oxygen vacancy doping in perovskite ABB'O₃ solid solutions

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

    Qi, Tingting; Curnan, Matthew T.; Kim, Seungchul; Bennett, Joseph W.; Grinberg, Ilya; Rappe, Andrew M.

    2011-12-15

    Oxygen vacancies in perovskite oxide solid solutions are fundamentally interesting and technologically important. However, experimental characterization of the vacancy locations and their impact on electronic structure is challenging. We have carried out first-principles calculations on two Zr-modified solid solutions, Pb(Zn1/3Nb2/3)O₃ and Pb(Mg1/3Nb2/3)O₃, in which vacancies are present. We find that the vacancies are more likely to reside between low-valent cation-cation pairs than high-valent cation-cation pairs. Based on the analysis of our results, we formulate guidelines that can be used to predict the location of oxygen vacancies in perovskite solid solutions. Our results show that vacancies can have a significant impactmore » on both the conduction and valence band energies, in some cases lowering the band gap by ≈0.5 eV. The effects of vacancies on the electronic band structure can be understood within the framework of crystal field theory.« less

  2. Toward Photochemical Water Splitting Using Band-Gap-Narrowed Semiconductors and Transition-Metal Based Molecular Catalysts

    SciTech Connect (OSTI)

    Muckerman,J.T.; Rodriguez, J.A.; Fujita, E.

    2009-06-07

    We are carrying out coordinated theoretical and experimental studies of toward photochemical water splitting using band-gap-narrowed semiconductors (BGNSCs) with attached multi-electron molecular water oxidation and hydrogen production catalysts. We focus on the coupling between the materials properties and the H{sub 2}O redox chemistry, with an emphasis on attaining a fundamental understanding of the individual elementary steps in the following four processes: (1) Light-harvesting and charge-separation of stable oxide or oxide-derived semiconductors for solar-driven water splitting, including the discovery and characterization of the behavior of such materials at the aqueous interface; (2) The catalysis of the four-electron water oxidation by dinuclear hydroxo transition-metal complexes with quinonoid ligands, and the rational search for improved catalysts; (3) Transfer of the design principles learned from the elucidation of the DuBois-type hydrogenase model catalysts in acetonitrile to the rational design of two-electron hydrogen production catalysts for aqueous solution; (4) Combining these three elements to examine the function of oxidation catalysts on BGNSC photoanode surfaces and hydrogen production catalysts on cathode surfaces at the aqueous interface to understand the challenges to the efficient coupling of the materials functions.

  3. Empirical determination of the energy band gap narrowing in p{sup +} silicon heavily doped with boron

    SciTech Connect (OSTI)

    Yan, Di Cuevas, Andres

    2014-11-21

    In the analysis of highly doped silicon, energy band gap narrowing (BGN) and degeneracy effects may be accounted for separately, as a net BGN in conjunction with Fermi-Dirac statistics, or lumped together in an apparent BGN used with Boltzmann statistics. This paper presents an experimental study of silicon highly doped with boron, with the aim of evaluating the applicability of previously reported BGN models. Different boron diffusions covering a broad range of dopant densities were prepared, and their characteristic recombination current parameters J{sub 0} were measured using a contactless photoconductance technique. The BGN was subsequently extracted by matching theoretical simulations of carrier transport and recombination in each of the boron diffused regions and the measured J{sub 0} values. An evaluation of two different minority carrier mobility models indicates that their impact on the extraction of the BGN is relatively small. After considering possible uncertainties, it can be concluded that the BGN is slightly larger in p{sup +} silicon than in n{sup +} silicon, in qualitative agreement with theoretical predictions by Schenk. Nevertheless, in quantitative terms that theoretical model is found to slightly underestimate the BGN in p{sup +} silicon. With the two different parameterizations derived in this paper for the BGN in p{sup +} silicon, both statistical approaches, Boltzmann and Fermi-Dirac, provide a good agreement with the experimental data.

  4. Radiation response analysis of wide-gap p-AlInGaP for superhigh-efficiency space photovoltaics

    SciTech Connect (OSTI)

    Khan, Aurangzeb; Marupaduga, S.; Anandakrishnan, S.S.; Alam, M.; Ekins-Daukes, N.J.; Lee, H.S.; Sasaki, T.; Yamaguchi, M.; Takamoto, T.; Agui, T.; Kamimura, K.; Kaneiwa, M.; Imazumi, M.

    2004-11-29

    We present here the direct observation of the majority and minority carrier defects generation from wide-band-gap (2.04 eV) and thick (2 {mu}m) p-AlInGaP diodes and solar cells structures before and after 1 MeV electron irradiation by deep level transient spectroscopy (DLTS). One dominant hole-emitting trap H1 (E{sub V}+0.37{+-}0.05 eV) and two electron-emitting traps, E1 (E{sub C}-0.22{+-}0.04 eV) and E3 (E{sub C}-0.78{+-}0.05 eV) have been observed in the temperature range, which we could scan by DLTS. Detailed analysis of the minority carrier injection annealing experiment reveals that the H1 center has shown the same annealing characteristics, which has been previously observed in all phosphide-based materials such as InP, InGaP, and InGaAsP. The annealing property of the radiation-induced defects in p-AlInGaP reveals that multijunction solar cells and other optoelectronic devices such as light-emitting diodes based on this material could be considerably better to Si and GaAs in a radiation environment.

  5. Migration of Nuclear Shell Gaps Studied in the d({sup 24}Ne,p{gamma}){sup 25}Ne Reaction

    SciTech Connect (OSTI)

    Catford, W. N.; Timis, C. N.; Baldwin, T. D.; Gelletly, W.; Pain, S. D.; Lemmon, R. C.; Pucknell, V. P. E.; Warner, D. D.; Labiche, M.; Orr, N. A.; Achouri, N. L.; Chapman, R.; Amzal, N.; Burns, M.; Liang, X.; Spohr, K.; Freer, M.; Ashwood, N. I.

    2010-05-14

    The transfer of neutrons onto {sup 24}Ne has been measured using a reaccelerated radioactive beam of {sup 24}Ne to study the (d,p) reaction in inverse kinematics. The unusual raising of the first 3/2{sup +} level in {sup 25}Ne and its significance in terms of the migration of the neutron magic number from N=20 to N=16 is put on a firm footing by confirmation of this state's identity. The raised 3/2{sup +} level is observed simultaneously with the intruder negative parity 7/2{sup -} and 3/2{sup -} levels, providing evidence for the reduction in the N=20 gap. The coincident gamma-ray decays allowed the assignment of spins as well as the transferred orbital angular momentum. The excitation energy of the 3/2{sup +} state shows that the established USD shell model breaks down well within the sd model space and requires a revised treatment of the proton-neutron monopole interaction.

  6. Narrow gap laser welding

    DOE Patents [OSTI]

    Milewski, J.O.; Sklar, E.

    1998-06-02

    A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables. 34 figs.

  7. Narrow gap laser welding

    DOE Patents [OSTI]

    Milewski, John O.; Sklar, Edward

    1998-01-01

    A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables.

  8. Ability of the Confined Explosive Component Water Gap Test STANAG 4363 to Assess the Shock Sensitivity of MM-Scale Detonators

    SciTech Connect (OSTI)

    Lefrancois, A S; Roeske, F; Benterou, J; Tarver, C M; Lee, R S; Hannah, B

    2006-02-10

    The Explosive Component Water Gap Test (ECWGT) has been validated to assess the shock sensitivity of lead and booster components having a diameter larger than 5 mm. Several countries have investigated by experiments and numerical simulations the effect of confinement on the go/no go threshold for Pentaerythritol Tetranitrate (PETN) pellets having a height and diameter of 3 mm, confined by a steel annulus of wall thickness 1-3.5 mm. Confinement of the PETN by a steel annulus of the same height of the pellet with 1-mm wall thickness makes the component more sensitive (larger gap). As the wall thickness is increased to 2-mm, the gap increases a lesser amount, but when the wall thickness is increased to 3.5-mm a decrease in sensitivity is observed (smaller gap). This decrease of the water gap has been reproduced experimentally. Recent numerical simulations using Ignition and Growth model [1] for the PETN Pellet have reproduced the experimental results for the steel confinement up to 2 mm thick [2]. The presence of a stronger re-shock following the first input shock from the water and focusing on the axis have been identified in the pellet due to the steel confinement. The double shock configuration is well-known to lead in some cases to shock desensitization. This work presents the numerical simulations using Ignition and Growth model for LX16 (PETN based HE) and LX19 (CL20 based HE) Pellets [3] in order to assess the shock sensitivity of mm-scale detonators. The pellets are 0.6 mm in diameter and 3 mm length with different type of steel confinement 2.2 mm thick and 4.7 mm thick. The influence of an aluminum confinement is calculated for the standard LX 16 pellet 3 mm in diameter and 3 mm in height. The question of reducing the size of the donor charge is also investigated to small scale the test itself.

  9. Structure and band gap determination of irradiation-induced amorphous nano-channels in LiNbO{sub 3}

    SciTech Connect (OSTI)

    Sachan, R. Pakarinen, O. H.; Chisholm, M. F.; Liu, P.; Patel, M. K.; Zhang, Y.; Wang, X. L.; Weber, W. J.

    2015-04-07

    The irradiation of lithium niobate with swift heavy ions results in the creation of amorphous nano-sized channels along the incident ion path. These nano-channels are on the order of a hundred microns in length and could be useful for photonic applications. However, there are two major challenges in these nano-channels characterization: (i) it is difficult to investigate the structural characteristics of these nano-channels due to their very long length and (ii) the analytical electron microscopic analysis of individual ion track is complicated due to electron beam sensitive nature of lithium niobate. Here, we report the first high resolution microscopic characterization of these amorphous nano-channels, widely known as ion-tracks, by direct imaging them at different depths in the material, and subsequently correlating the key characteristics with electronic energy loss of ions. Energetic Kr ions ({sup 84}Kr{sup 22} with 1.98?GeV energy) are used to irradiate single crystal lithium niobate with a fluence of 2 10{sup 10} ions/cm{sup 2}, which results in the formation of individual ion tracks with a penetration depth of ?180??m. Along the ion path, electron energy loss of the ions, which is responsible for creating the ion tracks, increases with depth under these conditions in LiNbO{sub 3}, resulting in increases in track diameter of a factor of ?2 with depth. This diameter increase with electronic energy loss is consistent with predictions of the inelastic thermal spike model. We also show a new method to measure the band gap in individual ion track by using electron energy-loss spectroscopy.

  10. Bridging the Gap between Theory and Experiments - Nano-structural Changes in Supported Catalysts under Operating Conditions

    SciTech Connect (OSTI)

    Narula, Chaitanya Kumar; Allard Jr, Lawrence Frederick; Blom, Douglas Allen; Debusk, Melanie Moses

    2008-01-01

    Computational approaches have been limited to examining catalytic processes using models that have been greatly simplified in comparison to real catalysts. Experimental studies, especially on emission treatment catalysts, have primarily focused on fully formulated systems. Thus, there remains a knowledge gap between theory and experiments. We combine the power of theory and experiment for atomistic design of catalytically active sites that can translate the fundamental insights gained directly to a catalyst system suitable for technical deployment. In this article, we describe our results on a model platinum-alumina catalyst that is a common constituent of emission treatment catalysts such as three-way, NO/dx trap, oxidation, and HC-SCR catalysts. We present theoretical and experimental studies of the oxidation and reactivity of Pt catalyst clusters towards O, CO, and NO/dx. Our theoretical studies indicate that the reaction energetics are strongly dependent on the size of the clusters as well as the extent of oxidation of the clusters, and the energetics of CO and NO oxidation may be more favorable on the oxidized clusters than metallic clusters because of the weakened adsorption of O, CO and NO. Experimentally, we have observed that the aberration-corrected HA-ADF STEM images of Pt/gg-alumina support show that there are single atoms, 2-3 atom clusters, and several 10-20 atom clusters of Pt. We also found that the Pt particles size has an impact on CO oxidation initiation and completion temperatures. Substrate effects were studied for equivalent Pt particle size distributions on both gu-alumina and gg-alumina supports. Particle size effects were investigated on Pt/gg-alumina catalysts with Pt particle size distribution centered at 1 nm and 12 nm, respectively. We will describe our results on substrate and Pt particle size effects. In addition, we will also present our study of nano-structural changes in model catalysts on exposure to various reaction conditions.

  11. Slide 1

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

    and lamination production * Turbine runner parts and wicket gates casting production * Testing casting coupons Wicket Gate Unit 2 Turbine Runner Crown Unit 3 Turbine Runner ...

  12. Visible-light absorption and large band-gap bowing of GaN1-xSbx from first principles

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

    Sheetz, R. Michael; Richter, Ernst; Andriotis, Antonis N.; Lisenkov, Sergey; Pendyala, Chandrashekhar; Sunkara, Mahendra K.; Menon, Madhu

    2011-08-01

    Applicability of the Ga(Sbx)N1-x alloys for practical realization of photoelectrochemical water splitting is investigated using first-principles density functional theory incorporating the local density approximation and generalized gradient approximation plus the Hubbard U parameter formalism. Our calculations reveal that a relatively small concentration of Sb impurities is sufficient to achieve a significant narrowing of the band gap, enabling absorption of visible light. Theoretical results predict that Ga(Sbx)N1-x alloys with 2-eV band gaps straddle the potential window at moderate to low pH values, thus indicating that dilute Ga(Sbx)N1-x alloys could be potential candidates for splitting water under visible light irradiation.

  13. V-203: HP LoadRunner Multiple Bugs Let Remote Users Deny Service...

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

    V-171: Apple Safari Bugs Let Remote Users Execute Arbitrary Code and Conduct Cross-Site Scripting Attacks V-110: Adobe Flash Player Bugs Let Remote Users Execute Arbitrary Code...

  14. Frequencies of the geodesic acoustic mode and Alfvn gap modes in high-q{sup 2}? plasmas with non-circular cross section

    SciTech Connect (OSTI)

    Fesenyuk, O. P.; Kolesnichenko, Ya. I.; Yakovenko, Yu. V.; National University of Kyiv Mohyla Academy, Vul. Skovorody 2, Kyiv 04070

    2013-12-15

    This work generalizes recent results [O. P. Fesenyuk et al., Plasma Phys. Controlled Fusion 54, 085014 (2012)] to plasmas with elongated cross section. It suggests new expressions for the frequencies of the geodesic acoustic mode and Alfvn gap modes in tokamaks, with a large ratio of the plasma pressure to the magnetic field pressure and a large safety factor (q?1, which takes place in discharges with reversed-shear configuration and, especially, in hollow-current discharges)

  15. Optical absorption and band gap reduction in (Fe1-xCrx)2O3 solid solutions: A first-principles study

    SciTech Connect (OSTI)

    Wang, Yong; Lopata, Kenneth A.; Chambers, Scott A.; Govind, Niranjan; Sushko, Petr V.

    2013-12-02

    We provide a detailed theoretical analysis of the character of optical transitions and band gap reduction in (Fe1-xCrx)2O3 solid solutions using extensive periodic model and embedded cluster calculations. Optical absorption bands for x = 0.0, 0.5, and 1.0 are assigned on the basis of timedependent density functional theory (TDDFT) calculations. A band-gap reduction of as much as 0.7 eV with respect to that of pure ?-Fe2O3 is found. This result can be attributed to predominantly two effects: (i) the higher valence band edge for x ? 0.5, as compared to those in pure ?-Fe2O3 and ?-Cr2O3, and, (ii) the appearance of Cr ? Fe dd transitions in the solid solutions. Broadening of the valence band due to hybridization of the O 2p states with Fe and Cr 3d states also contributes to band gap reduction.

  16. Near-edge band structures and band gaps of Cu-based semiconductors predicted by the modified Becke-Johnson potential plus an on-site Coulomb U

    SciTech Connect (OSTI)

    Zhang, Yubo; Zhang, Jiawei; Wang, Youwei; Gao, Weiwei; Abtew, Tesfaye A.; Zhang, Peihong E-mail: wqzhang@mail.sic.ac.cn; Beijing Computational Science Research Center, Beijing 100084 ; Zhang, Wenqing E-mail: wqzhang@mail.sic.ac.cn; School of Chemistry and Chemical Engineering and Sate Key Laboratory of Coordination Chemistry, Nanjing University, Jiangsu 210093

    2013-11-14

    Diamond-like Cu-based multinary semiconductors are a rich family of materials that hold promise in a wide range of applications. Unfortunately, accurate theoretical understanding of the electronic properties of these materials is hindered by the involvement of Cu d electrons. Density functional theory (DFT) based calculations using the local density approximation or generalized gradient approximation often give qualitative wrong electronic properties of these materials, especially for narrow-gap systems. The modified Becke-Johnson (mBJ) method has been shown to be a promising alternative to more elaborate theory such as the GW approximation for fast materials screening and predictions. However, straightforward applications of the mBJ method to these materials still encounter significant difficulties because of the insufficient treatment of the localized d electrons. We show that combining the promise of mBJ potential and the spirit of the well-established DFT + U method leads to a much improved description of the electronic structures, including the most challenging narrow-gap systems. A survey of the band gaps of about 20 Cu-based semiconductors calculated using the mBJ + U method shows that the results agree with reliable values to within 0.2 eV.

  17. Synthesis of cadmium telluride quantum wires and the similarity of their band gaps to those of equidiameter cadmium telluride quantum dots

    SciTech Connect (OSTI)

    Wang, Lin-Wang; Sun, Jianwei; Wang, Lin-Wang; Buhro, William E.

    2008-07-11

    High-quality colloidal CdTe quantum wires having purposefully controlled diameters in the range of 5-11 nm are grown by the solution-liquid-solid (SLS) method, using Bi-nanoparticle catalysts, cadmium octadecylphosphonate and trioctylphosphine telluride as precursors, and a TOPO solvent. The wires adopt the wurtzite structure, and grow along the [002] direction (parallel to the c axis). The size dependence of the band gaps in the wires are determined from the absorption spectra, and compared to the experimental results for high-quality CdTe quantum dots. In contrast to the predictions of an effective-mass approximation, particle-in-a-box model, and previous experimental results from CdSe and InP dot-wire comparisons, the band gaps of CdTe dots and wires of like diameter are found to be experimentally indistinguishable. The present results are analyzed using density functional theory under the local-density approximation by implementing a charge-patching method. The higher-level theoretical analysis finds the general existence of a threshold diameter, above which dot and wire band gaps converge. The origin and magnitude of this threshold diameter is discussed.

  18. A non-uniform three-gap buncher cavity with suppression of transverse-electromagnetic mode leakage in the triaxial klystron amplifier

    SciTech Connect (OSTI)

    Qi, Zumin; Zhang, Jun Zhong, Huihuang; Zhu, Danni; Qiu, Yongfeng

    2014-01-15

    The triaxial klystron amplifier is an efficient high power relativistic klystron amplifier operating at high frequencies due to its coaxial structure with large radius. However, the coaxial structures result in coupling problems among the cavities as the TEM mode is not cut-off in the coaxial tube. Therefore, the suppression of the TEM mode leakage, especially the leakage from the buncher cavity to the input cavity, is crucial in the design of a triaxial klystron amplifier. In this paper, a non-uniform three-gap buncher cavity is proposed to suppress the TEM mode leakage. The cold cavity analysis shows that the non-uniform three-gap buncher cavity can significantly suppress the TEM mode generation compared to a uniform three-gap buncher cavity. Particle-in-cell simulation shows that the power leakage to the input cavity is less than 1.5 of the negative power in the buncher cavity and the buncher cavity can efficiently modulate an intense relativistic electron beam free of self-oscillations. A fundamental current modulation depth of 117% is achieved by employing the proposed non-uniform buncher cavity into an X-band triaxial amplifier, which results in the high efficiency generation of high power microwave.

  19. Universal heat conduction in Ce1-xYbxCoIn5: Evidence for robust nodal d-wave superconducting gap

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

    Xu, Y.; Petrovic, C.; Dong, J. K.; Lum, I. K.; Zhang, J.; Hong, X. C.; He, L. P.; Wang, K. F.; Ma, Y. C.; Maple, M. B.; et al

    2016-02-01

    In the heavy-fermion superconductor Ce1-xYbxCoIn5, Yb doping was reported to cause a possible change from nodal d-wave superconductivity to a fully gapped d-wave molecular superfluid of composite pairs near x ≈ 0.07 (nominal value xnom = 0.2). Here we present systematic thermal conductivity measurements on Ce1-xYbxCoIn5 (x = 0.013, 0.084, and 0.163) single crystals. The observed finite residual linear term κ0/T is insensitive to Yb doping, verifying the universal heat conduction of the nodal d-wave superconducting gap in Ce1-xYbxCoIn5. Similar universal heat conduction is also observed in the CeCo(In1–yCdy)5 system. Furthermore, these results reveal a robust nodal d-wave gap inmore » CeCoIn5 upon Yb or Cd doping.« less

  20. Band offset determination of mixed As/Sb type-II staggered gap heterostructure for n-channel tunnel field effect transistor application

    SciTech Connect (OSTI)

    Zhu, Y.; Jain, N.; Hudait, M. K.; Mohata, D. K.; Datta, S.; Lubyshev, D.; Fastenau, J. M.; Liu, A. K.

    2013-01-14

    The experimental study of the valence band offset ({Delta}E{sub v}) of a mixed As/Sb type-II staggered gap GaAs{sub 0.35}Sb{sub 0.65}/In{sub 0.7}Ga{sub 0.3}As heterostructure used as source/channel junction of n-channel tunnel field effect transistor (TFET) grown by molecular beam epitaxy was investigated by x-ray photoelectron spectroscopy (XPS). Cross-sectional transmission electron micrograph shows high crystalline quality at the source/channel heterointerface. XPS results demonstrate a {Delta}E{sub v} of 0.39 {+-} 0.05 eV at the GaAs{sub 0.35}Sb{sub 0.65}/In{sub 0.7}Ga{sub 0.3}As heterointerface. The conduction band offset was calculated to be {approx}0.49 eV using the band gap values of source and channel materials and the measured valence band offset. An effective tunneling barrier height of 0.21 eV was extracted, suggesting a great promise for designing a metamorphic mixed As/Sb type-II staggered gap TFET device structure for low-power logic applications.

  1. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    SciTech Connect (OSTI)

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are needed for repository modeling are severely lacking. In addition, most of existing reactive transport codes were developed for non-radioactive contaminants, and they need to be adapted to account for radionuclide decay and in-growth. The accessibility to the source codes is generally limited. Because the problems of interest for the Waste IPSC are likely to result in relatively large computational models, a compact memory-usage footprint and a fast/robust solution procedure will be needed. A robust massively parallel processing (MPP) capability will also be required to provide reasonable turnaround times on the analyses that will be performed with the code. A performance assessment (PA) calculation for a waste disposal system generally requires a large number (hundreds to thousands) of model simulations to quantify the effect of model parameter uncertainties on the predicted repository performance. A set of codes for a PA calculation must be sufficiently robust and fast in terms of code execution. A PA system as a whole must be able to provide multiple alternative models for a specific set of physical/chemical processes, so that the users can choose various levels of modeling complexity based on their modeling needs. This requires PA codes, preferably, to be highly modularized. Most of the existing codes have difficulties meeting these requirements. Based on the gap analysis results, we have made the following recommendations for the code selection and code development for the NEAMS waste IPSC: (1) build fully coupled high-fidelity THCMBR codes using the existing SIERRA codes (e.g., ARIA and ADAGIO) and platform, (2) use DAKOTA to build an enhanced performance assessment system (EPAS), and build a modular code architecture and key code modules for performance assessments. The key chemical calculation modules will be built by expanding the existing CANTERA capabilities as well as by extracting useful components from other existing codes.

  2. Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

    SciTech Connect (OSTI)

    Hare, D E; Chandler, J B; Compton, S M; Garza, R G; Grimsley, D A; Hernandez, A; Villafana, R J; Wade, J T; Weber, S R; Wong, B M; Souers, P C

    2008-01-16

    The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins.

  3. Quantum-Size Effects on the Pressure-Induced Direct-to-Indirect Band-Gap Transition in InP Quantum Dots

    SciTech Connect (OSTI)

    Fu, H.; Zunger, A.

    1998-06-01

    We predict that the difference in quantum confinement energies of {Gamma} -like and X -like conduction states in a covalent quantum dot will cause the direct-to-indirect transition to occur at substantially lower pressure than in the bulk material. Furthermore, the first-order transition in the bulk is predicted to become, for certain dot sizes, a second-order transition. Measurements of the {open_quotes}anticrossing gap{close_quotes} could thus be used to obtain unique information on the {Gamma}-X- L intervalley coupling, predicted here to be surprisingly large (50{endash}100thinspthinspmeV). {copyright} {ital 1998} {ital The American Physical Society}

  4. Effect of thermal annealing on structure and optical band gap of Se{sub 66}Te{sub 25}In{sub 9} thin films

    SciTech Connect (OSTI)

    Dwivedi, D. K.; Pathak, H. P.; Shukla, Nitesh; Kumar, Vipin

    2015-05-15

    Thin films of a-Se{sub 66}Te{sub 25}In{sub 9} have been deposited onto a chemically cleaned glass substrate by thermal evaporation technique under vacuum. Glassy nature of the films has been ascertained by X-ray diffraction pattern. The analysis of absorption spectra, measured at normal incidence, in the spectral range 400-1100 nm has been used for the optical characterization of thin films under investigation. The effect of thermal annealing on structure and optical band gap (E{sub g}) of a-Se{sub 66}Te{sub 25}In{sub 9} have been studied.

  5. Localization of metal-induced gap states at the metal-insulator interface: Origin of flux noise in SQUIDs and superconducting qubits

    SciTech Connect (OSTI)

    Choi, SangKook; Lee, Dung-Hai; Louie, Steven G.; Clarke, John

    2009-10-10

    The origin of magnetic flux noise in Superconducting Quantum Interference Devices with a power spectrum scaling as 1/f (f is frequency) has been a puzzle for over 20 years. This noise limits the decoherence time of superconducting qubits. A consensus has emerged that the noise arises from fluctuating spins of localized electrons with an areal density of 5 x 10(17)m(-2). We show that, in the presence of potential disorder at the metal-insulator interface, some of the metal-induced gap states become localized and produce local moments. A modest level of disorder yields the observed areal density.

  6. Short gamma-ray burst formation rate from BATSE data using E{sub p} -L{sub p} correlation and the minimum gravitational-wave event rate of a coalescing compact binary

    SciTech Connect (OSTI)

    Yonetoku, Daisuke; Sawano, Tatsuya; Toyanago, Asuka [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192 (Japan); Nakamura, Takashi [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Takahashi, Keitaro, E-mail: yonetoku@astro.s.kanazawa-u.ac.jp, E-mail: takashi@tap.scphys.kyoto-u.ac.jp [Faculty of Science, Kumamoto University, Kurokami, Kumamoto 860-8555 (Japan)

    2014-07-01

    Using 72 short gamma-ray bursts (SGRBs) with well determined spectral data observed by BATSE, we determine their redshift and luminosity by applying the E{sub p} -L{sub p} correlation for SGRBs found by Tsutsui et al. For 53 SGRBs with an observed flux brighter than 4 10{sup 6} erg cm{sup 2} s{sup 1}, the cumulative redshift distribution up to z = 1 agrees well with that of 22 Swift SGRBs. This suggests that the redshift determination by the E{sub p} -L{sub p} correlation for SGRBs works well. The minimum event rate at z = 0 is estimated as R{sub on?axis}{sup min}=6.3{sub ?3.9}{sup +3.1} 10{sup ?10} events Mpc{sup ?3} yr{sup ?1}, so that the minimum beaming angle is 0.6-7.8 assuming a merging rate of 10{sup 7}- 4 10{sup 6} events Mpc{sup 3} yr{sup 1} suggested from the binary pulsar data. Interestingly, this angle is consistent with that for SGRB 130603B of ?4-8. On the other hand, if we assume a beaming angle of ?6 suggested from four SGRBs with the observed beaming angle value, then the minimum event rate including off-axis SGRBs is estimated as R{sub all}{sup min}=1.15{sub ?0.66}{sup +0.56} 10{sup ?7} events Mpc{sup ?3} yr{sup ?1}. If SGRBs are induced by the coalescence of binary neutron stars (NSs) and/or black holes (BHs), then this event rate leads to a minimum gravitational-wave detection rate of 3.8{sub ?2.2}{sup +1.8} (146{sub ?83}{sup +71}) events yr{sup ?1} for an NS-NS (NS-BH) binary, respectively, by a worldwide network with KAGRA, advanced-LIGO, advanced-VIRGO, and GEO.

  7. Forward energy flow, central charged-particle multiplicities, and pseudorapidity gaps in W and Z boson events from pp collisions at $\\sqrt{s}= 7$ TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-01-01

    A study of forward energy flow and central charged-particle multiplicity in events with W and Z bosons decaying into leptons is presented. The analysis uses a sample of 7 TeV pp collisions, corresponding to an integrated luminosity of 36 inverse picobarns, recorded by the CMS experiment at the LHC. The observed forward energy depositions, their correlations, and the central charged-particle multiplicities are not well described by the available non-diffractive soft-hadron production models. A study of about 300 events with no significant energy deposited in one of the forward calorimeters, corresponding to a pseudorapidity gap of at least 1.9 units, is also presented. An indication for a diffractive component in these events comes from the observation that the majority of the charged leptons from the (W/Z) decays are found in the hemisphere opposite to the gap. When fitting the signed lepton pseudorapidity distribution of these events with predicted distributions from an admixture of diffractive (POMPYT) and non-diffractive (PYTHIA) Monte Carlo simulations, the diffractive component is determined to be (50.0 +/- 9.3 (stat.) +/- 5.2 (syst.))%.

  8. Direct evidence for a pressure-induced nodal superconducting gap in the Ba0.65Rb0.35Fe2As2 superconductor

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

    Guguchia, Z.; Amato, A.; Kang, J.; Luetkens, H.; Biswas, P. K.; Prando, G.; von Rohr, F.; Bukowski, Z.; Shengelaya, A.; Keller, H.; et al

    2015-11-09

    The superconducting gap structure in iron-based high-temperature superconductors (Fe-HTSs) is non-universal. Contrasting with other unconventional superconductors, in the Fe-HTSs both d-wave and extended s-wave pairing symmetries are close in energy. Probing the proximity between these very different superconducting states and identifying experimental parameters that can tune them is of central interest. Here we report high-pressure muon spin rotation experiments on the temperature-dependent magnetic penetration depth in the optimally doped nodeless s-wave Fe-HTS Ba0.65Rb0.35Fe2As2. Upon pressure, a strong decrease of the penetration depth in the zero-temperature limit is observed, while the superconducting transition temperature remains nearly constant. More importantly, the low-temperaturemore » behaviour of the inverse-squared magnetic penetration depth, which is a direct measure of the superfluid density, changes qualitatively from an exponential saturation at zero pressure to a linear-in-temperature behaviour at higher pressures, indicating that hydrostatic pressure promotes the appearance of nodes in the superconducting gap.« less

  9. Structural distortions in the spin-gap regime of the quantum antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}

    SciTech Connect (OSTI)

    Vecchini, C.; Adamopoulos, O.; Chapon, L.C.; Lappas, A.; Kageyama, H.; Ueda, Y.; Zorko, A.

    2009-12-15

    We report the first crystallographic study within the low-temperature (<40 K) spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. The crystal system does not deviate from the tetragonal I-42m space group symmetry. However, our high-resolution neutron powder diffraction measurements uncover subtle structural modifications below 34 K, concomitant to the formation of the dimer singlet ground state. Intimate spin-lattice coupling leads to negative thermal expansion of the tetragonal structure, which reflects into particular local lattice adjustments. The extracted structural parameters suggest the reduction of the buckling found in the copper-borate planes and the strengthening of the leading, in-plane intra-dimer superexchange interaction. The observed contraction along the c-axis, associated with the inter-dimer exchange in adjacent layers, indicates the involvement of weaker three-dimensional interactions in the magnetic properties. The rules posed by the crystal symmetry do not preclude Dzyaloshinsky-Moriya interactions, which therefore remain as an important source of spin anisotropy necessary to rationalise the ground state behaviour. - Abstract: We report the first crystallographic study within the low-temperature spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. Subtle spin-lattice coupling was unveiled in the low-temperature region. Display Omitted

  10. Structural properties and band offset determination of p-channel mixed As/Sb type-II staggered gap tunnel field-effect transistor structure

    SciTech Connect (OSTI)

    Zhu, Y.; Jain, N.; Hudait, M. K.; Mohata, D. K.; Datta, S.; Lubyshev, D.; Fastenau, J. M.; Liu, A. K.

    2012-09-10

    The structural properties and band offset determination of p-channel staggered gap In{sub 0.7}Ga{sub 0.3}As/GaAs{sub 0.35}Sb{sub 0.65} heterostructure tunnel field-effect transistor (TFET) grown by molecular beam epitaxy (MBE) were investigated. High resolution x-ray diffraction revealed that the active layers are strained with respect to 'virtual substrate.' Dynamic secondary ion mass spectrometry confirmed an abrupt junction profile at the In{sub 0.7}Ga{sub 0.3}As/GaAs{sub 0.35}Sb{sub 0.65} heterointerface and minimal level of intermixing between As and Sb atoms. The valence band offset of 0.37 {+-} 0.05 eV was extracted from x-ray photoelectron spectroscopy. A staggered band lineup was confirmed at the heterointerface with an effective tunneling barrier height of 0.13 eV. Thus, MBE-grown staggered gap In{sub 0.7}Ga{sub 0.3}As/GaAs{sub 0.35}Sb{sub 0.65} TFET structures are a promising p-channel option to provide critical guidance for the future design of mixed As/Sb type-II based complementary logic and low power devices.

  11. Experimental and theoretical studies of band gap alignment in GaAs{sub 1?x}Bi{sub x}/GaAs quantum wells

    SciTech Connect (OSTI)

    Kudrawiec, R. Kopaczek, J.; Polak, M. P.; Scharoch, P.; Gladysiewicz, M.; Misiewicz, J.; Richards, R. D.; Bastiman, F.; David, J. P. R.

    2014-12-21

    Band gap alignment in GaAs{sub 1?x}Bi{sub x}/GaAs quantum wells (QWs) was studied experimentally by photoreflectance (PR) and theoretically, ab initio, within the density functional theory in which the supercell based calculations are combined with the alchemical mixing approximation applied to a single atom in a supercell. In PR spectra, the optical transitions related to the excited states in the QW (i.e., the transition between the second heavy-hole and the second electron subband) were clearly observed in addition to the ground state QW transition and the GaAs barrier transition. This observation is clear experimental evidence that this is a type I QW with a deep quantum confinement in the conduction and valence bands. From the comparison of PR data with calculations of optical transitions in GaAs{sub 1?x}Bi{sub x}/GaAs QW performed for various band gap alignments, the best agreement between experimental data and theoretical calculations has been found for the valence band offset of 52??5%. A very similar valence band offset was obtained from ab initio calculations. These calculations show that the incorporation of Bi atoms into GaAs host modifies both the conduction and the valence band. For GaAs{sub 1?x}Bi{sub x} with 0?gap is parabolic and the reduction rates change from ?84 to ?53?meV per % Bi for lower and higher Bi concentrations, respectively. The calculated shifts of valence and conduction bands give the variation of valence (conduction) band offset between GaAs{sub 1?x}Bi{sub x} and GaAs in the range of ?60%40% (?40%60%), which is in good agreement with our conclusion derived from PR measurements.

  12. Nodal to nodeless superconducting energy gap structure change concomitant with Fermi surface reconstruction in the heavy-fermion CeCoIn?

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

    Kim, Hyunsoo; Petrovic, C.; Tanatar, M. A.; Flint, R.; Hu, Rongwei; White, B. D.; Lum, I. K.; Maple, M. B.; Prozorov, R.

    2015-01-15

    The London penetration depth ?(T) was measured in single crystals of Ce1xRxCoIn?, R=La, Nd, and Yb down to Tmin ? 50 mK (Tc/Tmin ~50) using a tunnel-diode resonator. In the cleanest samples ??(T) is best described by the power law, ??(T) ? Tn, with n ~ 1, consistent with line nodes. Substitutions of Ce with La, Nd, and Yb lead to similar monotonic suppressions of Tc, however, the effects on ??(T) differ. While La and Nd dopings lead to increase of the exponent n and saturation at n ~ 2, as expected for a dirty nodal superconductor, Yb doping leadsmoreto n > 3, suggesting a change from nodal to nodeless superconductivity. This superconducting gap structure change happens in the same doping range where changes of the Fermi surface topology were reported, implying that the nodal structure and Fermi surface topology are closely linked.less

  13. Minimum Day Time Load Calculation and Screening

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

    Electric Grid Using a Dynamically Controlled Battery Bank for Peak Load Shaving (Conference) | SciTech Connect Minimization of Impact from Electric Vehicle Supply Equipment to the Electric Grid Using a Dynamically Controlled Battery Bank for Peak Load Shaving Citation Details In-Document Search Title: Minimization of Impact from Electric Vehicle Supply Equipment to the Electric Grid Using a Dynamically Controlled Battery Bank for Peak Load Shaving This research presents a comparison of two

  14. Minimum Day Time Load Calculation and Screening

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

    ... It says that total harmonic distortion was not mentioned. Is it measured and is it ... small and the impact on, the impact on the grid is very minor so we spend less time on ...

  15. Minimum Day Time Load Calculation and Screening

    Energy Savers [EERE]

    Minimizing User Burden in Building Energy Analysis Minimizing User Burden in Building Energy Analysis Lead Performer: ThermoAnalytics Inc. - Calumet, MI DOE Funding: $145,684 Cost Share: N/A Project Term: June 2014 - March 2015 Funding Opportunity: Small Business Innovation Research FY 2014 Phase 1 Release 2 Awards Project Objective ThermoAnalytics Inc. (TAI), in partnership with Skidmore, Owings, & amp; Merrill LLP (SOM), will develop an integrated workflow for constructing energy models of

  16. Program Evaluation: Minimum EERE Requirements | Department of...

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

    ... Program Manager Review and Response. Before the report is finalized and goes to senior management, the office leadership will add written responses to peer reviewer findings and ...

  17. Minimum Day Time Load Calculation and Screening

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

    ... type of load? (Residential, Commercial, Industrial, mix)? Find nearby feeders (Feeder 2) of similar type and determine the ratio of Feeder 2 peak to capture profile shape ...

  18. Neutron scattering studies of spin-phonon hybridization and superconducting spin gaps in the high temperature superconductor La2-x(Sr;Ba)xCuO4

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

    Wagman, J. J.; Carlo, Jeremy P.; Gaudet, J.; Van Gastel, G. J.; Abernathy, Douglas L.; Stone, Matthew B.; Granroth, Garrett E.; Kolesnikov, Alexander I.; Savici, Andrei T.; Kim, Young -June; et al

    2016-03-14

    We present time-of-flight neutron-scattering measurements on single crystals of La2-xBaxCuO4 (LBCO) with 0 ≤ x ≤ 0.095 and La2-xSrxCuO4 (LSCO) with x = 0.08 and 0.11. This range of dopings spans much of the phase diagram relevant to high temperature cuprate superconductivity, ranging from insulating, three dimensional commensurate long range antiferromagnetic order for x ≤ 0.02 to two dimensional (2D) incommensurate antiferromagnetism co-existing with superconductivity for x ≥ 0.05. Previous work on lightly doped LBCO with x = 0.035 showed a clear resonant enhancement of the inelastic scattering coincident with the low energy crossings of the highly dispersive spin excitationsmore » and quasi-2D optic phonons. The present work extends these measurements across the phase diagram and shows this enhancement to be a common feature to this family of layered quantum magnets. Furthermore we show that the low temperature, low energy magnetic spectral weight is substantially larger for samples with non-superconducting ground states relative to any of the samples with superconducting ground states. Lastly spin gaps, suppression of low energy magnetic spectral weight, are observed in both superconducting LBCO and LSCO samples, consistent with previous observations for superconducting LSCO« less

  19. Band-Gap Reduction and Dopant Interaction in Epitaxial La,Cr Co-doped SrTiO3 Thin Films

    SciTech Connect (OSTI)

    Comes, Ryan B.; Sushko, Petr; Heald, Steve M.; Colby, Robert J.; Bowden, Mark E.; Chambers, Scott A.

    2014-12-03

    We show that by co-doping SrTiO3 (STO) epitaxial thin films with equal amounts of La and Cr it is possible to produce films with an optical band gap ~0.9 eV lower than that of undoped STO. Sr1-xLaxTi1-xCrxO3 thin films were deposited by molecular beam epitaxy and characterized using x-ray photoelectron spectroscopy and x-ray absorption near-edge spectroscopy to show that the Cr dopants are almost exclusively in the Cr3+ oxidation state. Extended x-ray absorption fine structure measurements and theoretical modeling suggest that it is thermodynamically preferred for La and Cr dopants to occupy nearest neighbor A- and B-sites in the lattice. Transport measurements show that the material exhibits variable-range hopping conductivity with high resistivity. These results create new opportunities for the use of doped STO films in photovoltaic and photocatalytic applications.

  20. Fabrication and testing of diamond-machined gratings in ZnSe, GaP, and bismuth germanate for the near infrared and visible

    SciTech Connect (OSTI)

    Kuzmenko, P J; Little, S L; Ikeda, Y; Kobayashi, N

    2008-06-22

    High quality immersion gratings for infrared applications have been demonstrated in silicon and germanium. To extend this technology to shorter wavelengths other materials must be investigated. We selected three materials, zinc selenide, gallium phosphide and bismuth germanate (Bi{sub 4}Ge{sub 3}O{sub 12}), based on high refractive index, good visible transmission and commercial availability in useful sizes. Crystal samples were diamond turned on an ultra-precision lathe to identify preferred cutting directions. Using this information we diamond-flycut test gratings over a range of feed rates to determine the optimal cutting conditions. For both ZnSe and GaP good surface quality was achieved at feed rates up to 1.0 cm/minute using a special compound angle diamond tool with negative rake angles on both cutting surfaces. The surface roughness of the groove facets was about 4 nm. A Zygo interferometer measured grating wavefront errors in reflection. For the ZnSe the RMS error was < {lambda}/20 at 633nm. More extensive testing was performed with a HeNe laser source and a cooled CCD camera. These measurements demonstrated high relative diffraction efficiency (> 80%), low random groove error (2.0 nm rms), and Rowland ghost intensities at < 0.1%. Preliminary tests on bismuth germanate show high tool wear.