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  1. Desert Peak EGS Project

    Energy.gov [DOE]

    Desert Peak EGS Project presentation at the April 2013 peer review meeting held in Denver, Colorado.

  2. DESERT SUNLIGHT | Department of Energy

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

    DESERT SUNLIGHT DESERT SUNLIGHT DESERT SUNLIGHT DESERT SUNLIGHT PROJECT SUMMARY In September 2011, the Department of Energy issued two partial loan guarantees of $1.5 billion in total under the Financial Institution Partnership Program (FIPP) to finance Desert Sunlight, a 550-MW photovoltaic (PV) solar generation plant. The facility is jointly owned by NextEra, General Electric, and Sumitomo of America and reached full commercial operations in January 2015. Desert Sunlight is one of the largest

  3. DESERT SUNLIGHT | Department of Energy

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

    DESERT SUNLIGHT DESERT SUNLIGHT DOE-LPO_Project-Posters_PV_Desert-Sunlight.pdf (249.32 KB) More Documents & Publications Hearing Before the House Natural Resources Subcommittee on Oversight and Investigations DESERT SUNLIGHT Powering New Markets: Utility-scale Photovoltaic Solar GENESIS

  4. Desert Peak Geothermal Area | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Peak Geothermal Area (Redirected from Desert Peak Area) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Desert Peak Geothermal Area Contents 1 Area Overview 2...

  5. Desert Solar | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    search Name: Desert Solar Place: Apple Valley, California Zip: 92308 Sector: Renewable Energy, Solar Product: Selling and installing commercial renewable energy projects, mainly...

  6. Desert Wind Power | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Wind Power Jump to: navigation, search Name Desert Wind Power Facility Desert Wind Power Sector Wind energy Facility Type Commercial Scale Wind Facility Status Proposed Developer...

  7. DOE - NNSA/NFO -- Operation Clean Desert

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

    ZONE > Operation Clean Desert NNSANFO Language Options U.S. DOENNSA - Nevada Field Office Operation Clean Desert FUN FOR ALL AGES Dr. Proton Graphic Adam - Smiling Operation ...

  8. Desert landscape irrigation

    SciTech Connect

    Quinones, R.

    1995-06-01

    Industrialization can take place in an arid environment if a long term, overall water management program is developed. The general rule to follow is that recharge must equal or exceed use. The main problem encountered in landscape projects is that everyone wants a lush jungle setting, tall shade trees, ferns, with a variety of floral arrangements mixed in. What we want, what we can afford, and what we get are not always the same. Vegetation that requires large quantities of water are not native to any desert. Surprisingly; there are various types of fruit trees, and vegetables that will thrive in the desert. Peaches, plums, nut trees, do well with drip irrigation as well as tomatoes. Shaded berry plans will also do well, the strawberry being one. In summary; if we match our landscape to our area, we can then design our irrigation system to maintain our landscape and grow a variety of vegetation in any arid or semiarid environment. The application of science and economics to landscaping has now come of age.

  9. Supersymmetry without the Desert

    SciTech Connect

    Nomura, Yasunori; Poland, David

    2006-09-26

    Naturalness of electroweak symmetry breaking in weak scale supersymmetric theories may suggest the absence of the conventional supersymmetric desert. We present a simple, realistic framework for supersymmetry in which (most of) the virtues of the supersymmetric desert are naturally reproduced without having a large energy interval above the weak scale. The successful supersymmetric prediction for the low-energy gauge couplings is reproduced due to a gauged R symmetry present in the effective theory at the weak scale. The observable sector superpotential naturally takes the form of the next-to-minimal supersymmetric standard model, but without being subject to the Landau pole constraints up to the conventional unification scale. Supersymmetry breaking masses are generated by the F-term and D-term VEVs of singlet and U(1){sub R} gauge fields, as well as by anomaly mediation, at a scale not far above the weak scale. We study the resulting pattern of supersymmetry breaking masses in detail, and find that it can be quite distinct. We construct classes of explicit models within this framework, based on higher dimensional unified theories with TeV-sized extra dimensions. A similar model based on a non-R symmetry is also presented. These models have a rich phenomenology at the TeV scale, and allow for detailed analyses of, e.g., electroweak symmetry breaking.

  10. Desert Sky Wind Farm | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Sky Wind Farm Jump to: navigation, search Name Desert Sky Wind Farm Facility Desert Sky Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service...

  11. Erosion Resistance Index (ERI) to Assess Surface Stability in Desert Environments

    SciTech Connect

    Hamada, Yuki; Grippo, Mark A.

    2015-11-01

    A new spectral index—erosion resistance index (ERI)—was developed to assess erosion risks in desert landscapes. The index was developed by applying trigonometry to the combination of the green/red band-ratio and the red/near infrared band-ratio from very high spatial resolution imagery. The resultant ERI maps showed spatially cohesive distributions of high and low index values across the study areas. High index values were observed over areas that were resistant to erosion (such as desert pavement and dense vegetation), while low index values overlapped with areas likely dominated by loose sandy soils, such as stream beds and access roads. Although further investigation is warranted, this new index, ERI, shows promise for the assessment of erosion risks in desert regions.

  12. Desert Queen Geothermal Project | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    ,"group":"","inlineLabel":"","visitedicon":"" Hide Map Location Fernley, NV County Churchill County, NV Geothermal Area Desert Queen Geothermal Area Geothermal Region Northwest...

  13. Desert Sunlight Solar Power Plant | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Sunlight Solar Power Plant Facility Desert Sunlight Sector Solar Facility Type Photovoltaic Developer First Solar Location Desert Center, California Coordinates 33.7541038,...

  14. Core Analysis At Desert Peak Area (Laney, 2005) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Peak Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Desert Peak Area (Laney, 2005) Exploration...

  15. Gas Flux Sampling At Desert Peak Area (Lechler And Coolbaugh...

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Peak Area (Lechler And Coolbaugh, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Gas Flux Sampling At Desert Peak Area (Lechler And...

  16. Cuttings Analysis At Desert Peak Area (Laney, 2005) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Peak Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Cuttings Analysis At Desert Peak Area (Laney, 2005) Exploration...

  17. BLM California Desert District Office | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    California Desert District Office Jump to: navigation, search Name: California Desert District Office Address: 22835 Calle San Juan De Los Lagos Place: Moreno Valley, CA Zip: 92553...

  18. Desert Hot Springs Space Heating Low Temperature Geothermal Facility...

    OpenEI (Open Energy Information) [EERE & EIA]

    Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Desert Hot Springs Space Heating Low Temperature Geothermal Facility Facility Desert Hot...

  19. EIS-0448: First Solar Desert Sunlight Project in Riverside County...

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

    8: First Solar Desert Sunlight Project in Riverside County, CA EIS-0448: First Solar Desert Sunlight Project in Riverside County, CA June 24, 2011 EIS-0448: Final Environmental ...

  20. California Desert Fish Farm Aquaculture Low Temperature Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Fish Farm Aquaculture Low Temperature Geothermal Facility Jump to: navigation, search Name California Desert Fish Farm Aquaculture Low Temperature Geothermal Facility...

  1. Geothermometry At Desert Queen Area (Garchar & Arehart, 2008...

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Queen Area (Garchar & Arehart, 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Desert Queen Area (Garchar &...

  2. Reflection Survey At San Emidio Desert Area (DOE GTP) | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    San Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At San Emidio Desert Area (DOE GTP)...

  3. Refraction Survey At San Emidio Desert Area (DOE GTP) | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    San Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Refraction Survey At San Emidio Desert Area (DOE GTP)...

  4. Thermal Gradient Holes At San Emidio Desert Area (DOE GTP) |...

    OpenEI (Open Energy Information) [EERE & EIA]

    San Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At San Emidio Desert Area (DOE GTP)...

  5. UNLV DESERT SUNRISE DESERT SUNRISE HOME Project Summary

    Energy.gov [DOE] (indexed site)

    of the Moapa Band of Paiutes of Southern Nevada with contemporary, evidence-based design ... Project Data o Las Vegas, Nevada. o Climate Zone 3. o 1,387 sq. ft. o 2 bedrooms, 2 ...

  6. BLM West Desert District Office | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    West Desert District Office Jump to: navigation, search Name: BLM West Desert District Office Place: Salt Lake City, Utah Phone Number: (801) 977-4300 ParentHolding Organization:...

  7. California Desert Native Plants Act | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    California Desert Native Plants Act Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: California Desert Native Plants ActLegal...

  8. Modeling-Computer Simulations At Desert Peak Area (Wisian & Blackwell...

    OpenEI (Open Energy Information) [EERE & EIA]

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Desert Peak Area (Wisian & Blackwell, 2004) Exploration Activity...

  9. High performance robotic traverse of desert terrain.

    SciTech Connect

    Whittaker, William

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  10. The Palm Desert renewable [hydrogen] transportation system

    SciTech Connect

    Chamberlin, C.E.; Lehman, P.

    1998-08-01

    This paper describes the Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period June 1997 through May 1998. The project began in March 1996. The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project demonstrates the practical utility of hydrogen as a transportation fuel and the proton exchange membrane (PEM) fuel cell as a vehicle power system. The project includes designing and building 4 fuel cell powered vehicles, a solar hydrogen generating and refueling station, and a fuel cell vehicle diagnostic center. Over this last year, SERC has built a fuel cell powered neighborhood electric vehicle and delivered it to the City of Palm Desert. The design of the hydrogen refueling station is near completion and it is anticipated that construction will be complete in the fall of 1998. The vehicles are currently being refueled at a temporary refueling station. The diagnostic center is being designed and maintenance procedures as well as computer diagnostic programs for the fuel cell vehicles are being developed. City employees are driving the vehicles daily and monitoring data are being collected. The drivers are pleased with the performance of the vehicles.

  11. Structural Analysis of the Desert Peak-Brady Geothermal Fields...

    OpenEI (Open Energy Information) [EERE & EIA]

    Structures and Geothermal Reservoirs in the Humboldt Structural Zone Citation James E. Faulds,Larry J. Garside,Gary L. Oppliger. 2003. Structural Analysis of the Desert...

  12. Desert Peak II Geothermal Facility | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Facility Desert Peak II Sector Geothermal energy Location Information Location Churchill, Nevada Coordinates 39.753854931241, -118.95378112793 Loading map......

  13. Desert Peak East EGS Project; 2010 Geothermal Technology Program...

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

    East EGS Project; 2010 Geothermal Technology Program Peer Review Report Desert Peak East EGS Project; 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal...

  14. DOE - NNSA/NFO -- News & Views Camp Desert Rock

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

    Desert Rock Airport, with its 7,500 foot runway, was built ... Military officials declared the maneuvers invaluable for the ... using essential personnel and equipment protection measures. ...

  15. City of Palm Desert - Energy Independence Program | Department...

    Energy.gov [DOE] (indexed site)

    conditioners Windows Doors Other EE Program Info Sector Name Local Administrator Palm Desert Website http:www.cityofpalmdesert.orgIndex.aspx?page484 State California Program...

  16. Palm Desert, California: Energy Resources | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert, California: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 33.7222445, -116.3744556 Show Map Loading map... "minzoom":false,"mappingse...

  17. Desert Hot Springs, California: Energy Resources | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Riverside County, California. It falls under California's 41st congressional district.12 Registered Energy Companies in Desert Hot Springs, California BCL Associates Inc...

  18. America's Atomic Army: The Historical Archaeology of Camp Desert Rock

    SciTech Connect

    Susan R. Edwards

    2007-11-02

    Established in 1951, Camp Desert Rock served as the training ground for America's 'Atomic Army'. For the next six years, U.S. ground troops traveled to the Nevada desert to participate in military maneuvers during atmospheric atomic weapons testing. Nearly 60,000 soldiers received physical and psychological training in atomic warfare. Abandoned when atmospheric testing ended, Camp Desert Rock was dismantled and its buildings moved to other locations. Today, the camp appears as a sterile expanse of desert marked by rock-lined tent platforms, concrete foundations, and trash scatters. Although visually unimposing, the site is rich with the history of America's nuclear testing program.

  19. Desert Hills, Arizona: Energy Resources | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Desert Hills, Arizona: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 34.5538996, -114.3724569 Show Map Loading map... "minzoom":false,"mappin...

  20. InSAR At Desert Peak Area (Laney, 2005) | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    United States by developing basic measurements and interpretations that will assist reservoir management and expansion at Bradys, Desert Peak and the Desert Peak EGS study...

  1. Ground Magnetics At San Emidio Desert Area (DOE GTP) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Magnetics At San Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Magnetics At San Emidio Desert Area (DOE...

  2. Field Mapping At San Emidio Desert Area (DOE GTP) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At San Emidio Desert Area (DOE GTP) Exploration...

  3. Ground Gravity Survey At San Emidio Desert Area (DOE GTP) | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At San Emidio Desert Area (DOE GTP)...

  4. InfiniBand Interconnects

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

    MPICH2 MVAPICH2 Equipment InfiniBand 4x 10 GigE Fujitsu switch NetEffect NIC Equipment & Benchmarks Latency Results Bandwidth Results Bidirectional Bandwidth...

  5. Desert Sunlight is Shining Example of How DOE Loan Guarantees...

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

    LPO issued a 1.46 billion loan guarantee to Desert Sunlight, a 550-MW photovoltaic solar project located in Riverside County, California. | Photo courtesy of NextEra Energy ...

  6. Desert View Highlands, California: Energy Resources | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Hide Map This article is a stub. You can help OpenEI by expanding it. Desert View Highlands is a census-designated place in Los Angeles County, California.1...

  7. Desert Shores, California: Energy Resources | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Hide Map This article is a stub. You can help OpenEI by expanding it. Desert Shores is a census-designated place in Imperial County, California.1 References ...

  8. LPO5-002-Proj-Poster-PV-DesertSunlight

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

    DESERT SUNLIGHT By working with 14 commercial lending partners, Desert Sunlight helped pave the way for future utility-scale photovoltaic solar deals. INVESTING in AMERICAN ENERGY OWNERS NextEra Energy, General Electric & Sumitomo of America LOCATION Riverside County, California LOAN AMOUNT $1.5 Billion ISSUANCE DATE September 2011 GENERATION CAPACITY 550 MW PROJECTED ANNUAL GENERATION 1,060,000 MWh CLIMATE BENEFIT 614,000 Metric Tons of C0 2 Prevented Annually

  9. Desert scientists turn to rainforest for climate answers

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

    Desert scientists turn to rainforest for climate answers Desert scientists turn to rainforest for climate answers Work in Brazil's Amazon Basin should improve climate prediction. May 30, 2014 Curiosity zaps Mars for vital signs: ChemCam, designed by Lab team, looks for elements such as carbon, nitrogen, and oxygen, all of which are crucial for life. Heath-Powers: Los Alamos scientist Heath Powers, foreground, and on-site technician Vagner Castro work on field equipment for measuring carbon

  10. Snails, stable iostopes, and southwestern desert paleoclimates

    SciTech Connect

    Sharpe, S.E.; Whelan, J.F.; Forester, R.M.; Burdett, J.

    1995-09-01

    Modern and fossil molluscs (snails) occur in many localities in and semi-arid regions throughout the desert southwest. Live terrestrial snails are found under rocks and in forest litter and aquatic taxa inhabit springs, seeps, and/or wetlands. Molluscs uptake local water during their growing season (spring and summer) and incorporate its delta 180 signature into their shells. Preliminary 180 analysis of modem shells from the southern Great Basin indicates that the shells probably reflect meteoric water 180 values during the growing season. This provides a way to estimate the delta 180 value of precipitation and, thereby, the source of the moisture-bearing air masses. Significant 180 variability in shells analyzed include geographic location, elevation, taxonomy, and habitat (terrestrial, spring, or wetland). We found a rough inverse correlation with elevation in modem shells from the Spring Range in southern Nevada. The delta 180 values of modem and fossil shells are also very different; modem values in this location are much higher than those from nearby late Pleistocene-age molluscs suggesting that the Pleistocene summers were variously colder and wetter than today or less evaporative (more humid). Assuming shell material directly reflects the 180 of the growing-season environment, comparison of modem and fossil shell delta 180 values can potentially identify changes in air-mass moisture sources and can help to define seasonal precipitation change through time. Comprehension and quantification of community and isotopic variability in modem gastropods is required to create probabilistic valid transfer functions with fossil materials. Valid inferences about past environmental conditions can then be established with known confidence limits.

  11. EA-1912: Midway-Benton No. 1 Rebuild Project, near town of Desert...

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

    Midway-Benton No. 1 Rebuild Project, near town of Desert Aire, Benton County, WA EA-1912: Midway-Benton No. 1 Rebuild Project, near town of Desert Aire, Benton County, WA...

  12. PSInSAR At San Emidio Desert Area (DOE GTP) | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    PSInSAR At San Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: PSInSAR At San Emidio Desert Area (DOE GTP)...

  13. SunLine Tests HHICE Bus in Desert Climate | Department of Energy

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

    Tests HHICE Bus in Desert Climate SunLine Tests HHICE Bus in Desert Climate Fuel Cell Bus Demonstration Projects (Fact Sheet). PDF icon 40107.pdf More Documents & Publications...

  14. EIS-0448: First Solar Desert Sunlight Project in Riverside County, CA |

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

    Department of Energy 8: First Solar Desert Sunlight Project in Riverside County, CA EIS-0448: First Solar Desert Sunlight Project in Riverside County, CA June 24, 2011 EIS-0448: Final Environmental Impact Statement Desert Sunlight Solar Farm Project, California June 24, 2011 EIS-0448: Notice of Adoption of an Environmental Impact Statement First Solar Desert Sunlight Solar Farm Project October 6, 2011 EIS-0448: Record of Decision Issuance of a Loan Guarantee to First Solar, Inc., for the

  15. Science on the Hill: Fragile life underfoot has big impact on desert

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

    Fragile life underfoot has big impact on desert Fragile life underfoot has big impact on desert Anyone who spends time in the high-desert landscape of Northern New Mexico has come across biological soil crusts, or biocrusts. This fragile crust fills a pivotal ecosystem niche. However, its survival is being challenged by threats from climate change and man-made disturbance. June 13, 2016 Science on the Hill: Fragile life underfoot has big impact on desert For years, space scientists thought the

  16. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W.; Gonzales, Aaron A.; Patel, Mahadeo R.; Olich, Eugene E.

    1996-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  17. Banded electromagnetic stator core

    DOEpatents

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1994-04-05

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

  18. Banded electromagnetic stator core

    DOEpatents

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1996-06-11

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

  19. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W.; Gonzales, Aaron A.; Patel, Mahadeo R.; Olich, Eugene E.

    1994-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  20. Broad band waveguide spectrometer

    DOEpatents

    Goldman, Don S.

    1995-01-01

    A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

  1. Dramatic Demand Reduction In The Desert Southwest

    SciTech Connect

    Boehm, Robert; Hsieh, Sean; Lee, Joon; Baghzouz, Yahia; Cross, Andrew; Chatterjee, Sarah

    2015-07-06

    This report summarizes a project that was funded to the University of Nevada Las Vegas (UNLV), with subcontractors Pulte Homes and NV Energy. The project was motivated by the fact that locations in the Desert Southwest portion of the US demonstrate very high peak electrical demands, typically in the late afternoons in the summer. These high demands often require high priced power to supply the needs, and the large loads can cause grid supply problems. An approach was proposed through this contact that would reduce the peak electrical demands to an anticipated 65% of what code-built houses of the similar size would have. It was proposed to achieve energy reduction through four approaches applied to a development of 185 homes in northwest part of Las Vegas named Villa Trieste. First, the homes would all be highly energy efficient. Secondly, each house would have a PV array installed on it. Third, an advanced demand response technique would be developed to allow the resident to have some control over the energy used. Finally, some type of battery storage would be used in the project. Pulte Homes designed the houses. The company considered initial cost vs. long-term savings and chose options that had relatively short paybacks. HERS (Home Energy Rating Service) ratings for the homes are approximately 43 on this scale. On this scale, code-built homes rate at 100, zero energy homes rate a 0, and Energy Star homes are 85. In addition a 1.764 Wp (peak Watt) rated PV array was used on each house. This was made up of solar shakes that were in visual harmony with the roofing material used. A demand response tool was developed to control the amount of electricity used during times of peak demand. While demand response techniques have been used in the utility industry for some time, this particular approach is designed to allow the customer to decide the degree of participation in the response activity. The temperature change in the residence can be decided by the residents by

  2. Desert Peak East EGS Project; 2010 Geothermal Technology Program Peer

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

    Review Report | Department of Energy East EGS Project; 2010 Geothermal Technology Program Peer Review Report Desert Peak East EGS Project; 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal Technologies Program Peer Review egs_008_zemach.pdf (182.67 KB) More Documents & Publications Feasibility of EGS Development at Bradys Hot Springs, Nevada Concept Testing and Development at the Raft River Geothermal Field, Idaho Creation of an Enhanced Geothermal System

  3. The Mystery of the Gun Turret in the Desert

    SciTech Connect

    Hoffman, R. D.

    2015-11-30

    The mystery of the gun turret in the desert began with an ingenious idea: to develop a reusable open-air line of sight diagnostic device to support LLNL’s early nuclear weapons development efforts. Obtained from the Mare Island Navy Shipyard (MINS) in January 1957, the gun turret traveled by ship to the Naval Construction Battalion base at Port Hueneme, California, and then by truck to Area 2 in the Yucca Flats valley at the Nevada Nuclear Security Site (NNSS).

  4. Fire Impacts on the Mojave Desert Ecosystem: Literature Review

    SciTech Connect

    Fenstermaker Lynn

    2012-01-01

    The Nevada National Security Site (NNSS) is located within the Mojave Desert, which is the driest region in North America. Precipitation on the NNSS varies from an annual average of 130 millimeters (mm; 5.1 inches) with a minimum of 47 mm (1.9 inches) and maximum of 328 mm (12.9 inches) over the past 15 year period to an annual average of 205 mm (8.1 inches) with an annual minimum of 89 mm (3.5 inches) and maximum of 391 mm (15.4 inches) for the same time period; for a Frenchman Flat location at 970 meters (m; 3182 feet) and a Pahute Mesa location at 1986 m (6516 feet), respectively. The combination of aridity and temperature extremes has resulted in sparsely vegetated basins (desert shrub plant communities) to moderately vegetated mountains (mixed coniferous forest plant communities); both plant density and precipitation increase with increasing elevation. Whereas some plant communities have evolved under fire regimes and are dependent upon fire for seed germination, plant communities within the Mojave Desert are not dependent on a fire regime and therefore are highly impacted by fire (Brown and Minnich, 1986; Brooks, 1999). As noted by Johansen (2003) natural range fires are not prevalent in the Mojave and Sonoran Deserts because there is not enough vegetation present (too many shrub interspaces) to sustain a fire. Fire research and hence publications addressing fires in the Southwestern United States (U.S.) have therefore focused on forest, shrub-steppe and grassland fires caused by both natural and anthropogenic ignition sources. In the last few decades, however, invasion of mid-elevation shrublands by non-native Bromus madritensis ssp. rubens and Bromus tectorum (Hunter, 1991) have been highly correlated with increased fire frequency (Brooks and Berry, 2006; Brooks and Matchett, 2006). Coupled with the impact of climate change, which has already been shown to be playing a role in increased forest fires (Westerling et al., 2006), it is likely that the fire

  5. 2-M Probe At Desert Peak Area (Sladek, Et Al., 2007) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: 2-M Probe At Desert Peak Area (Sladek, Et Al., 2007) Exploration Activity Details Location...

  6. Stepout-Deepening Wells At San Emidio Desert Area (DOE GTP) ...

    OpenEI (Open Energy Information) [EERE & EIA]

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Stepout-Deepening Wells At San Emidio Desert Area (DOE GTP) Exploration Activity Details Location San Emidio...

  7. Flow Test At San Emidio Desert Area (DOE GTP) | Open Energy Informatio...

    OpenEI (Open Energy Information) [EERE & EIA]

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Flow Test At San Emidio Desert Area (DOE GTP) Exploration Activity Details Location San Emidio...

  8. Band anticrossing in dilute nitrides

    SciTech Connect

    Shan, W.; Yu, K.M.; Walukiewicz, W.; Wu, J.; Ager III, J.W.; Haller, E.E.

    2003-12-23

    Alloying III-V compounds with small amounts of nitrogen leads to dramatic reduction of the fundamental band-gap energy in the resulting dilute nitride alloys. The effect originates from an anti-crossing interaction between the extended conduction-band states and localized N states. The interaction splits the conduction band into two nonparabolic subbands. The downward shift of the lower conduction subband edge is responsible for the N-induced reduction of the fundamental band-gap energy. The changes in the conduction band structure result in significant increase in electron effective mass and decrease in the electron mobility, and lead to a large enhance of the maximum doping level in GaInNAs doped with group VI donors. In addition, a striking asymmetry in the electrical activation of group IV and group VI donors can be attributed to mutual passivation process through formation of the nearest neighbor group-IV donor nitrogen pairs.

  9. EIS-0448: Department of Energy Loan Guarantee to First Solar for the Proposed Desert Sunlight Solar Farm Project, California

    Energy.gov [DOE]

    First Solar Desert Sunlight Solar Farm (DSSF) Project, proposes to develop a 550-megawatt photovoltaic solar project and proposes to facilitate the construction and operation of the Red Bluff Substation, California Desert Conservation Area (CDCA) Plan, Riverside County, California.

  10. CO2 EFFECTS ON MOJAVE DESERT PLANT INTERACTIONS

    SciTech Connect

    L. A. DEFALCO; G. C. FERNANDEZ; S. D. SMITH; R. S. NOWAK

    2004-01-01

    Seasonal and interannual droughts characteristic of deserts have the potential to modify plant interactions as atmospheric CO{sub 2} concentrations continue to rise. At the Nevada Desert FACE (free-air CO{sub 2} enrichment) facility in the northern Mojave Desert, the effects of elevated atmospheric C02 (550 vs. ambient {approx}360 {micro}mol mol{sup -1}) on plant interactions were examined during two years of high and low rainfall. Results suggest that CO{sub 2} effects on the interaction between native species and their understory herbs are dependent on the strength of competition when rainfall is plentiful, but are unimportant during annual drought. Seasonal rainfall for 1999 was 23% the long-term average for the area, and neither elevated CO{sub 2} nor the low production of herbaceous neighbors had an effect on relative growth rate (RGR, d{sup -1}) and reproductive effort (RE, number of flowers g{sup -1}) for Achnatherum hymenoides (early season perennial C{sub 3} grass), Pleuraphis rigida (late season perennial C{sub 4} grass), and Larrea tridentata (evergreen C{sub 3} shrub). In contrast, 1998 received 213% the average rainfall. Consequently, the decrease in RGR and increase in RE for Achnatherum, whose period of growth overlaps directly with that of its neighbors, was exaggerated at elevated CO{sub 2}. However, competitive effects of neighbors on Eriogonum trichopes (a winter annual growing in shrub interspaces), Pleuraphis and Larrea were not affected by elevated CO{sub 2}, and possible explanations are discussed. Contrary to expectations, the invasive annual neighbor Bromus madritensis ssp. rubens had little influence on target plant responses because densities in 1998 and 1999 at this site were well below those found in other studies where it has negatively affected perennial plant growth. The extent that elevated CO{sub 2} reduces the performance of Achnatherum in successive years to cause its loss from the plant community depends more on future pressure

  11. Biotic Processes Regulating the Carbon Balance of Desert Ecosystems - Final Report

    SciTech Connect

    Nowak, Robert S; Smith, Stanley D; Evans, Dave; Ogle, Kiona; Fenstermaker, Lynn

    2012-12-13

    Our results from the 10-year elevated atmospheric CO{sub 2} concentration study at the Nevada Desert FACE (Free-air CO{sub 2} Enrichment) Facility (NDFF) indicate that the Mojave Desert is a dynamic ecosystem with the capacity to respond quickly to environmental changes. The Mojave Desert ecosystem is accumulating carbon (C), and over the 10-year experiment, C accumulation was significantly greater under elevated [CO{sub 2}] than under ambient, despite great fluctuations in C inputs from year to year and even apparent reversals in which [CO{sub 2}] treatment had greater C accumulations.

  12. Project title: Stimulation at Desert Peak and Bradys reservoirs: modeling

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

    with the coupled THM code FEHM | Department of Energy Project title: Stimulation at Desert Peak and Bradys reservoirs: modeling with the coupled THM code FEHM Project title: Stimulation at Desert Peak and Bradys reservoirs: modeling with the coupled THM code FEHM Project title: Stimulation at Desert Peak and Bradys reservoirs: modeling with the coupled THM code FEHM presentation at the April 2013 peer review meeting held in Denver, Colorado. kelkar_peer2013.pdf (496.77 KB) More

  13. First Tracer Test After Circulation in Desert Peak 27-15 (Dataset) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Dataset: First Tracer Test After Circulation in Desert Peak 27-15 Citation Details In-Document Search Title: First Tracer Test After Circulation in Desert Peak 27-15 Following the successful stimulation of Desert Peak target EGS well 27-15, a circulation test was initiated by injecting a conservative tracer (1,5-nds) in combination with a reactive tracer (7-amino-1,3-naphthalene disulfonate). The closest production well 74-21 was monitored over the subsequent several months.

  14. Resistive band for turbomachine blade

    DOEpatents

    Roberts, Herbert Chidsey; Taxacher, Glenn Curtis

    2015-08-25

    A turbomachine system includes a rotor that defines a longitudinal axis of the turbomachine system. A first blade is coupled to the rotor, and the first blade has first and second laminated plies. A first band is coupled to the first blade and is configured to resist separation of the first and second laminated plies.

  15. Broad-band beam buncher

    DOEpatents

    Goldberg, David A.; Flood, William S.; Arthur, Allan A.; Voelker, Ferdinand

    1986-01-01

    A broad-band beam buncher is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-band response and the device as a whole designed to effect broad-band beam coupling, so as to minimize variations of the output across the response band.

  16. Genomic insights into salt adaptation in a desert poplar

    SciTech Connect

    Ma, Tao; Wang, Junyi; Zhou, Gongke; Yue, Zhen; Hu, Quanjun; Chen, Yan; Liu, Bingbing; Qiu, Qiang; Wang, Zhuo; Zhang, Jian; Wang, Kun; Jaing, Dechun; Gou, Caiyun; Yu, Lili; Zhan, Dongliang; Zhou, Ran; Luo, Wenchun; Ma, Hui; Yang, Yongzhi; Pan, Shengkai; Fang, Dongming; Luo, Yadan; Wang, Xia; Wang, Gaini; Wang, Juan; Wang, Qian; Lu, Xu; Chen, Zhe; Liu, Jinchao; Lu, Yao; Yin, Ye; Yang, Huanming; Abbott, Richard; Wu, Yuxia; Wan, Dongshi; Li, Jia; Yin, Tongming; Yin, Tongming; Lascoux, Martin; DiFazio, Steven P; Tuskan, Gerald A; Wang, Jun; Jianquan, Liu

    2013-01-01

    Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to sa lt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.

  17. VP of Transmission System Asset Management for Desert Southwest Region (Maintenance Manager)

    Energy.gov [DOE]

    (See Frequently Asked Questions for more information). Where would I be working? Western Area Power Administration Desert Southwest Region Maintenance (G5000) 615 S. 43rd Avenue Phoenix, AZ 85009...

  18. Desert Peak to Humboldt House and Winnemucca, in: Lane, M.A....

    OpenEI (Open Energy Information) [EERE & EIA]

    to Humboldt House and Winnemucca, in: Lane, M.A., (ed) Nevada geothermal areas: Desert Peak, Humboldt House, Beoware: Guidebook for field trip Jump to: navigation, search OpenEI...

  19. Augustine Band of Cahuilla Mission Indians- 2006 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Deep in the Coachella Valley, the tribe's reservation is a desert environment entirely below sea level, with an average elevation of minus 90 feet. Strong, consistent winds cross the desert floor, indicating that wind power might be viable for this underdeveloped reservation.

  20. Observed 20th Century Desert Dust Variability: Impact on Climate and Biogeochemistry

    SciTech Connect

    Mahowald, Natalie; Kloster, Silvia; Engelstaedter, S.; Moore, Jefferson Keith; Mukhopadhyay, S.; McConnell, J. R.; Albani, S.; Doney, Scott C.; Bhattacharya, A.; Curran, M. A. J.; Flanner, Mark G.; Hoffman, Forrest M; Lawrence, David M.; Lindsay, Keith; Mayewski, P. A.; Neff, Jason; Rothenberg, D.; Thomas, E.; Thornton, Peter E; Zender, Charlie S.

    2010-01-01

    Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry. While we know that desert dust is sensitive to perturbations in climate and human land use, previous studies have been unable to determine whether humans were increasing or decreasing desert dust in the global average. Here we present observational estimates of desert dust based on paleodata proxies showing a doubling of desert dust during the 20th century over much, but not all the globe. Large uncertainties remain in estimates of desert dust variability over 20th century due to limited data. Using these observational estimates of desert dust change in combination with ocean, atmosphere and land models, we calculate the net radiative effect of these observed changes (top of atmosphere) over the 20th century to be -0.14 {+-} 0.11 W/m{sup 2} (1990-1999 vs. 1905-1914). The estimated radiative change due to dust is especially strong between the heavily loaded 1980-1989 and the less heavily loaded 1955-1964 time periods (-0.57 {+-} 0.46 W/m{sup 2}), which model simulations suggest may have reduced the rate of temperature increase between these time periods by 0.11 C. Model simulations also indicate strong regional shifts in precipitation and temperature from desert dust changes, causing 6 ppm (12 PgC) reduction in model carbon uptake by the terrestrial biosphere over the 20th century. Desert dust carries iron, an important micronutrient for ocean biogeochemistry that can modulate ocean carbon storage; here we show that dust deposition trends increase ocean productivity by an estimated 6% over the 20th century, drawing down an additional 4 ppm (8 PgC) of carbon dioxide into the oceans. Thus, perturbations to desert dust over the 20th century inferred from observations are potentially important for climate and biogeochemistry, and our understanding

  1. Campo Band of Mission Indians- 2010 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Campo Band of Mission Indians ("Band") goal is to develop a 300 MW wind energy project ("Kumeyaay Wind II") in two phases over the next two to five years.

  2. Spatiotemporal dynamics of wetted soils across a polar desert landscape

    SciTech Connect

    Langford, Zachary L.; Gooseff, Michael N.; Lampkin, Derrick J.

    2014-10-30

    Liquid water is scarce across the landscape of the McMurdo Dry Valleys (MDV), Antarctica, a 3800 km2 ice-free region, and is chiefly associated with soils that are adjacent to streams and lakes (i.e. wetted margins) during the annual thaw season. However, isolated wetted soils have been observed at locations distal from water bodies. The source of water for the isolated patches of wet soil is potentially generated by a combination of infiltration from melting snowpacks, melting of pore ice at the ice table, and melting of buried segregation ice formed during winter freezing. In this paper, high resolution remote sensing data gathered several times per summer in the MDV region were used to determine the spatial and temporal distribution of wet soils. The spatial consistency with which the wet soils occurred was assessed for the 2009–10 to 2011–12 summers. The remote sensing analyses reveal that cumulative area and number of wet soil patches varies among summers. The 2010–11 summer provided the most wetted soil area (10.21 km2) and 2009–10 covered the least (5.38 km2). Finally, these data suggest that wet soils are a significant component of the MDV cold desert land system and may become more prevalent as regional climate changes.

  3. WIDE BAND REGENERATIVE FREQUENCY DIVIDER AND MULTIPLIER

    DOEpatents

    Laine, E.F.

    1959-11-17

    A regenerative frequency divider and multiplier having wide band input characteristics is presented. The circuit produces output oscillations having frequencies related by a fixed ratio to input oscillations over a wide band of frequencies. In accomplishing this end, the divider-multiplier includes a wide band input circuit coupled by mixer means to a wide band output circuit having a pass band related by a fixed ratio to that of the input circuit. A regenerative feedback circuit derives a fixed frequency ratio feedback signal from the output circuit and applies same to the mixer means in proper phase relation to sustain fixed frequency ratio oscillations in the output circuit.

  4. Photonic band gap structure simulator

    DOEpatents

    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.

  5. Project Reports for Agua Caliente Band of Cahuilla Indians -...

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

    Agua Caliente Band of Cahuilla Indians - 2010 Project Project Reports for Agua Caliente Band of Cahuilla Indians - 2010 Project The Agua Caliente Band of Cahuilla Indians (ACBCI) ...

  6. Countering third world weapons of mass destruction: Desert storm as a prototype. Final report

    SciTech Connect

    Nelson, S.M.

    1993-02-19

    The proliferation of Weapons of Mass Destruction (WMDs)--nuclear, biological, and chemical--is occurring throughout the Third World. Desert Storm offers an excellent case study for assessing the various measures and operations which can be employed to protect U.S.. forces against an adversary possessing a WMD capability. The elements of Desert Storm's successful strategy can be categorized in three broad approaches--deterrence, denial, and defense. All three approaches were necessary and syngergistic. In the future, the ability to quickly deny or destroy an adversary's WMD capability will be increasingly important, due to the unacceptability of exposing forces to any type of NBC agent, the likelihood for increased uncertainty surrounding deterrent threats, and the diplomatic, political, and psychological dilemmas posed by an adversary's first use....Weapons of mass destruction, Desert Storm.

  7. EFFECTS OF ELEVATED CO2 ON ROOT FUNCTION AND SOIL RESPIRATION IN A MOJAVE DESERT ECOSYSTEM

    SciTech Connect

    Nowak, Robert S.

    2007-12-19

    Increases in atmospheric CO{sub 2} concentration during the last 250 years are unequivocal, and CO{sub 2} will continue to increase at least for the next several decades (Houghton et al. 2001, Keeling & Whorf 2002). Arid ecosystems are some of the most important biomes globally on a land surface area basis, are increasing in area at an alarming pace (Dregne 1991), and have a strong coupling with regional climate (Asner & Heidebrecht 2005). These water-limited ecosystems also are predicted to be the most sensitive to elevated CO{sub 2}, in part because they are stressful environments where plant responses to elevated CO{sub 2} may be amplified (Strain & Bazzaz 1983). Indeed, all C{sub 3} species examined at the Nevada Desert FACE Facility (NDFF) have shown increased A{sub net} under elevated CO{sub 2} (Ellsworth et al. 2004, Naumburg et al. 2003, Nowak et al. 2004). Furthermore, increased shoot growth for individual species under elevated CO{sub 2} was spectacular in a very wet year (Smith et al. 2000), although the response in low to average precipitation years has been smaller (Housman et al. 2006). Increases in perennial cover and biomass at the NDFF are consistent with long term trends in the Mojave Desert and elsewhere in the Southwest, indicating C sequestration in woody biomass (Potter et al. 2006). Elevated CO{sub 2} also increases belowground net primary production (BNPP), with average increases of 70%, 21%, and 11% for forests, bogs, and grasslands, respectively (Nowak et al. 2004). Although detailed studies of elevated CO{sub 2} responses for desert root systems were virtually non-existent prior to our research, we anticipated that C sequestration may occur by desert root systems for several reasons. First, desert ecosystems exhibit increases in net photosynthesis and primary production at elevated CO{sub 2}. If large quantities of root litter enter the ecosystem at a time when most decomposers are inactive, significant quantities of carbon may be stored

  8. Desert Sunlight is Shining Example of How DOE Loan Guarantees Helped Launch

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

    Utility-scale PV Solar Market | Department of Energy Desert Sunlight is Shining Example of How DOE Loan Guarantees Helped Launch Utility-scale PV Solar Market Desert Sunlight is Shining Example of How DOE Loan Guarantees Helped Launch Utility-scale PV Solar Market February 9, 2015 - 12:01am Addthis In 2011, LPO issued loan guarantees to the first 5 PV projects larger than 100 MW in the U.S. An additional 17 projects have been financed since without loan guarantees. In 2011, LPO issued loan

  9. X-BAND KLYSTRON DEVELOPMENT AT SLAC

    SciTech Connect

    Vlieks, Arnold E.; /SLAC

    2009-08-03

    The development of X-band klystrons at SLAC originated with the idea of building an X-band Linear Collider in the late 1980's. Since then much effort has been expended in developing a reliable X-band Power source capable of delivering >50 MW RF power in pulse widths >1.5 {micro}s. I will report on some of the technical issues and design strategies which have led to the current SLAC klystron designs.

  10. Radiative Heating in Underexplored Bands Campaign (RHUBC)

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

    Bands Campaign (RHUBC) D. Turner and E. Mlawer RHUBC Breakout Session 2008 ARM Science Team Meeting 13 March, 2008 Norfolk, Virginia Motivation * Radiative heatingcooling in the ...

  11. Aroostook Band of Micmac Indians- 2005 Project

    Energy.gov [DOE]

    The goal of the project is to develop a strategic energy plan in order to reduce energy costs in the Aroostook Band of Micmacs' government buildings and homes.

  12. Eastern Band of Cherokee Indians- 2010 Project

    Energy.gov [DOE]

    The Eastern Band of Cherokee Indians (EBCI) is using the grant funds from the Department of Energy to complete the Energy Efficiency Improvements to seven EBCI facilities.

  13. Broad-band beam buncher

    DOEpatents

    Goldberg, D.A.; Flood, W.S.; Arthur, A.A.; Voelker, F.

    1984-03-20

    A broad-band beam bunther is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-

  14. Photovoltaic at Hollywood and Desert Breeze Recreational Centers

    SciTech Connect

    Ammerman, Shane

    2015-09-24

    Executive Summary Renewable Energy Initiatives for Clark County Parks and Recreation Solar Project DOE grant # DE-EE0003180 In accordance with the goals of the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy for promoting solar energy as clean, carbon-free and cost-effective, the County believed that a recreational center was an ideal place to promote solar energy technologies to the public. This project included the construction of solar electricity generation facilities (40kW) at two Clark County facility sites, Desert Breeze Recreational Center and Hollywood Recreational Center, with educational kiosks and Green Boxes for classroom instruction. The major objectives and goals of this Solar Project include demonstration of state of the art technologies for the generation of electricity from solar technology and the creation of an informative and educational tool in regards to the benefits and process of generating alternative energy. Clark County partnered with Anne Johnson (design architect/consultant), Affiliated Engineers Inc. (AEI), Desert Research Institute (DRI), and Morse Electric. The latest photovoltaic technologies were used in the project to help create the greatest expected energy savings for60443 each recreational center. This coupled with the data created from the monitoring system will help Clark County and NREL further understand the real time outputs from the system. The educational portion created with AEI and DRI incorporates material for all ages with a focus on K - 12. The AEI component is an animated story telling the fundamentals of how sunlight is turned into electricity and DRI‘s creation of Solar Green Boxes brings environmental education into the classroom. In addition to the educational component for the public, the energy that is created through the photovoltaic system also translates into saved money and health benefits for the general public. This project has helped Clark County to further add to its own

  15. Apparatus for loading a band saw blade

    DOEpatents

    Reeves, S.R.

    1990-03-20

    A band saw blade is loaded between pairs of guide wheels upon tensioning the blade by guiding the blade between pairs of spaced guide plates which define converging slots that converge toward the guide wheels. The approach is particularly useful in loading blades on underwater band saw machines used to cut radioactive materials. 2 figs.

  16. Apparatus for loading a band saw blade

    DOEpatents

    Reeves, Steven R.

    1990-01-01

    A band saw blade is loaded between pairs of guide wheels upon tensioning the blade by guiding the blade between pairs of spaced guide plates which define converging slots that converge toward the guide wheels. The approach is particularly useful in loading blades on underwater band saw machines used to cut radioactive materials.

  17. First Tracer Test After Circulation in Desert Peak 27-15

    DOE Data Explorer

    Rose, Peter

    2013-11-16

    Following the successful stimulation of Desert Peak target EGS well 27-15, a circulation test was initiated by injecting a conservative tracer (1,5-nds) in combination with a reactive tracer (7-amino-1,3-naphthalene disulfonate). The closest production well 74-21 was monitored over the subsequent several months.

  18. First Tracer Test After Circulation in Desert Peak 27-15

    DOE Data Explorer

    Rose, Peter

    Following the successful stimulation of Desert Peak target EGS well 27-15, a circulation test was initiated by injecting a conservative tracer (1,5-nds) in combination with a reactive tracer (7-amino-1,3-naphthalene disulfonate). The closest production well 74-21 was monitored over the subsequent several months.

  19. Stimulation at Desert Peak -modeling with the coupled THM code FEHM

    DOE Data Explorer

    kelkar, sharad

    Numerical modeling of the 2011 shear stimulation at the Desert Peak well 27-15. This submission contains the FEHM executable code for a 64-bit PC Windows-7 machine, and the input and output files for the results presented in the included paper from ARMA-213 meeting.

  20. Operation Clean Desert Educates Hundreds of Students on EM Program in Nevada

    Energy.gov [DOE]

    LAS VEGAS – Operation Clean Desert — EM’s effort to educate students on the science of environmental cleanup and other missions at the Nevada National Security Site (NNSS) — kicked into gear with the start of the school year.

  1. Stimulation at Desert Peak -modeling with the coupled THM code FEHM

    SciTech Connect

    kelkar, sharad

    2013-04-30

    Numerical modeling of the 2011 shear stimulation at the Desert Peak well 27-15. This submission contains the FEHM executable code for a 64-bit PC Windows-7 machine, and the input and output files for the results presented in the included paper from ARMA-213 meeting.

  2. Narrow band gap amorphous silicon semiconductors

    DOEpatents

    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.

  3. ARM - Campaign Instrument - s-band-profiler

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

    govInstrumentss-band-profiler Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : NOAA S-band (2835 Mhz) Profiler (S-BAND-PROFILER) Instrument Categories Atmospheric Profiling, Cloud Properties Campaigns CRYSTAL-FACE [ Download Data ] Off Site Campaign : various, including non-ARM sites, 2002.06.26 - 2002.08.01 Midlatitude Continental Convective Clouds Experiment (MC3E) [ Download Data ] Southern Great Plains, 2011.04.22 -

  4. Asymmetric acoustic transmission in multiple frequency bands

    SciTech Connect

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-11-23

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  5. Radiative Heating in Underexplored Bands Campaign (RHUBC)

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

    Underexplored Bands Campaign (RHUBC) Feb 22 - Mar 14, 2007 Dave Turner, Eli Mlawer RHUBC ... at 183 GHz RHUBC Participants * PIs: Dave Turner and Eli Mlawer * Co-Is: - Paul Green, ...

  6. Control Banding and Nanotechnology Synergist

    SciTech Connect

    Zalk, D; Paik, S

    2009-12-15

    The average Industrial Hygienist (IH) loves a challenge, right? Okay, well here is one with more than a few twists. We start by going through the basics of a risk assessment. You have some chemical agents, a few workers, and the makings of your basic exposure characterization. However, you have no occupational exposure limit (OEL), essentially no toxicological basis, and no epidemiology. Now the real handicap is that you cannot use sampling pumps, cassettes, tubes, or any of the media in your toolbox, and the whole concept of mass-to-dose is out the window, even at high exposure levels. Of course, by the title, you knew we were talking about nanomaterials (NM). However, we wonder how many IHs know that this topic takes everything you know about your profession and turns it upside down. It takes the very foundations that you worked so hard in college and in the field to master and pulls it out from underneath you. It even takes the gold standard of our profession, the quantitative science of exposure assessment, and makes it look pretty darn rusty. Now with NM there is the potential to get some aspect of quantitative measurements, but the instruments are generally very expensive and getting an appropriate workplace personal exposure measurement can be very difficult if not impossible. The potential for workers getting exposures, however, is very real, as evidenced by a recent publication reporting worker exposures to polyacrylate nanoparticles in a Chinese factory (Song et al. 2009). With something this complex and challenging, how does a concept as simple as Control Banding (CB) save the day? Although many IHs have heard of CB, most of their knowledge comes from its application in the COSHH Essentials toolkit. While there is conflicting published research on COSHH Essentials and its value for risk assessments, almost all of the experts agree that it can be useful when no OELs are available (Zalk and Nelson 2008). It is this aspect of CB, its utility with

  7. Wood-Producing Sunflower? Mining Genetic Diversity in Desert-Dwelling Wild Species (2010 JGI User Meeting)

    ScienceCinema

    Knapp, Steve

    2016-07-12

    Steve Knapp from Monsanto on "Wood-Producing Sunflower? Mining Genetic Diversity in Desert-Dwelling Wild Species" on March 25, 2010 at the 5th Annual DOE JGI User Meeting

  8. Dipole Bands in {sup 196}Hg

    SciTech Connect

    Lawrie, J. J.; Lawrie, E. A.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D.; Msezane, B.; Benatar, M.; Mabala, G. K.; Mutshena, K. P.; Federke, M.; Mullins, S. M.; Ncapayi, N. J.; Vymers, P.

    2011-10-28

    High spin states in {sup 196}Hg have been populated in the {sup 198}Pt({alpha},6n) reaction at 65 MeV and the level scheme has been extended. A new dipole band has been observed and a previously observed dipole has been confirmed. Excitation energies, spins and parities of these bands were determined from DCO ratio and linear polarization measurements. Possible quasiparticle excitations responsible for these structures are discussed.

  9. ISM band to U-NII band frequency transverter and method of frequency transversion

    DOEpatents

    Stepp, Jeffrey David; Hensley, Dale

    2006-09-12

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  10. ISM band to U-NII band frequency transverter and method of frequency transversion

    DOEpatents

    Stepp, Jeffrey David; Hensley, Dale

    2006-04-04

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz-6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  11. Wind-dependent desert aerosol model: radiative properties. Technical report, November 1986-April 1988

    SciTech Connect

    Longtin, D.R.; Shettle, E.P.; Hummel, J.R.; Pryce, J.D.

    1988-04-19

    This report presents a desert aerosol model that predicts aerosol radiative properties during background and severe dust-storm conditions. The model treats the desert aerosol as an external mixture of natural carbon, water soluble, and sand particles. The sand consists of two kinds of particles, pure quartz and quartz contaminated with a small amount of hematite. Mie calculations are performed using different size distributions and indices of refraction for each type of particle, and then a volume-weighting scheme is used to obtain the radiative properties of the aerosol as a whole. Attenuation coefficients, single scattering albedo, and asymmetry parameter are given for 68 wavelengths between 0.2 and 300 micro. The results indicate that extinction is wavelength-dependent for background conditions, but increases and becomes nearly constant for dust-storm conditions.

  12. Ecological energetics of the desert tortoise (Gopherus Agassizii): Effects of rainfall and drought

    SciTech Connect

    Peterson, C.C.

    1996-09-01

    To elucidate ecological effects of variation in the temporal distribution of a limiting resource (water in the Mojave Desert), energetics of two free-living populations of desert tortoises (Gopherus [=Xerobates] agassizii) were studied concurrently over 18 mo with use of doubly-labeled water. Field metabolic rates (FMR) and feeding rates were highly variable. This variability was manifested at several levels, including seasonal changes within populations, year-to-year differences within populations, and differences between populations. Underlying observed patterns and contrasts was considerable variation among individuals. Much of the variation in energetic variables was associated with a single climatic variable, rainfall. Seasonal, annual, and interpopulation differences in FMR and foraging rates corresponded to differences in availability of free-standing water from rainstorms. Some differences among individuals were apparently due to differences in proclivity or ability to drink. Tortoises had very low FMRs relative to other reptiles, allowed them to tolerate long periods of chronic energy shortage during a drought. Calculations suggested that tortoises experienced a net loss of energy shortage during a drought and tortoises experienced a net loss of energy on their spring diet of succulent annual plants. If so, tortoises require drier forage to accrue an energy profit, emphasizing reliance on drinking rainwater. Further, it suggests that growth (as protein deposition) and net acquisition of energy may be temporally decoupled in desert tortoises, with potential consequences for geographic variation in life history. Energy acquisition and expenditure in desert tortoises are strongly constrained by the contingencies of rainfall, both indirectly through effects on availability and quality of food, and directly through reliance on free-standing water for drinking, which is apparently necessary for achieving a net annual energy profit. 61 refs., 5 figs., 5 tabs.

  13. DOE/NV/10845 IT U S VECAS LIBRARY UC-703 I?. DESERT RESEARCH INSTITUTE

    Office of Legacy Management (LM)

    0845 IT U S VECAS LIBRARY UC-703 I?. DESERT RESEARCH INSTITUTE 3 I 'UNIVERSITY OF . ? .NEVADA SYSTEM Jenny B. Chapman Sam L. Hokett EVALUATION OF GROUNDWATER MONITORING AT O F F S m NUCLEAR TEST AREAS March 1991 WATER RESOURCES CENTER Publication #45085 DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. EVALUATION OF GROUNDWATER MONITORING AT OFFSITE NUCLEAR TEST AREAS b-r Jenny B. Chapman Sam L

  14. Desert architecture for educational buildings, a case study: A center for training university graduates

    SciTech Connect

    Ebeid, M.

    1996-10-01

    A new program for training graduates in desert development is being implemented by the Desert Development Center (DDC) of the American University in Cairo. The facilities consist of fifty bed/sitting rooms for accommodating 100 students. Each unit consists of two rooms and a bathroom for the use of 4 students; a lecture theater which can house 120 students, with adjoining office for trainers as well as necessary facilities; a general cafeteria which can serve 120--150 persons and an adjoining dining room for teaching staff. The cafeteria building also houses the kitchen; a cold storage area; a laundry room, storerooms, sleeping quarters and services for the labor force of the building complex; a system of solar water heaters; and a special sanitary sewage system for treatment of waste water produced by the building`s activities. When designing and implementing this complex, architectural elements and building philosophy based on the concept of integrating with the environment were considered. Elements included orientation heights and building materials suited to the desert environment, thick walls, outer and inner finishing materials, roofs, malkafs, floors, colors, solar heaters, lighting, green areas, windbreaks, terraces, and furniture. The paper includes a general evaluation of this educational building based on the PRA approach (Participatory Rapid Appraisal) involving those living and working in it. As a result of her position with the project, the author was able to evaluate the original designs, recommend modifications, and evaluate their implementation and fulfillment of the original goals of the projects.

  15. Modeling fluid flow in deformation bands with stabilized localization...

    Office of Scientific and Technical Information (OSTI)

    Modeling fluid flow in deformation bands with stabilized localization mixed finite elements. Citation Details In-Document Search Title: Modeling fluid flow in deformation bands...

  16. IR Spectral Bands and Performance | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    2013 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for IR Spectral Bands and Performance Citation Chris Douglass. IR Spectral Bands...

  17. Band structure anisotropy in semiconductor quantum wells

    SciTech Connect

    Novotny, S.J.

    1999-03-01

    The focus of this research is an investigation of energy band anisotropy in simple quantum well structures. This anisotropy results from the asymmetry of the periodic potential within the crystal lattice. For sufficiently high doping levels, band structure anisotropy is expected to play an important role in the evaluation of the electronic and optical properties of the quantum well structures. The analysis uses a model based on a 6x6 Luttinger-Kohn k.p approach for bulk material valence band structure together with the Envelope Function Approximation. The model is used to analyze Si/SiGe, AlGaAs/GaAs, and GaAs/InGaAs quantum wells for the 001 and the 110 growth directions. The resulting band structures show significant anisotropy for materials grown in both the 110 and 001 directions. In all cases the materials grown in the 110 direction show a more pronounced anisotropy than the materials grown in the 001 directions. For the 001 growth directions, the band structures were effectively isotropic for values of k-parallel less than 0.4 inverse angstrom for Si/SiGe, 0.6 inverse angstrom for GaAs/AlGaAs, and 0.5 inverse angstrom for InGaAs/GaAs.

  18. High power W-band klystrons

    SciTech Connect

    Caryotakis, George; Scheitrum, Glenn; Jongewaard, Erik; Vlieks, Arnold; Fowkes, Randy [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States); Li, Jeff [University of California Davis, Davis, California 95616 (United States)

    1999-05-01

    The development of W-band klystrons is discussed. Modeling of the klystron performance predicts 100 kW output power from a single klystron. The permanent magnet focusing and small size of the circuit permit combination of multiple klystrons in a module. A six-klystron module in a single vacuum envelope is expected to produce 500 kW peak power and up to 5 kW average power. The critical issues in the W-band klystron development are the electron beam transport and the fabrication of the klystron circuit. Two microfabrication techniques, EDM and LIGA, are being evaluated to produce the W-band circuit. {copyright} {ital 1999 American Institute of Physics.}

  19. Band filling effects on temperature performance of intermediate band quantum wire solar cells

    SciTech Connect

    Kunets, Vas. P. Furrow, C. S.; Ware, M. E.; Souza, L. D. de; Benamara, M.; Salamo, G. J.; Mortazavi, M.

    2014-08-28

    Detailed studies of solar cell efficiency as a function of temperature were performed for quantum wire intermediate band solar cells grown on the (311)A plane. A remotely doped one-dimensional intermediate band made of self-assembled In{sub 0.4}Ga{sub 0.6}As quantum wires was compared to an undoped intermediate band and a reference p-i-n GaAs sample. These studies indicate that the efficiencies of these solar cells depend on the population of the one-dimensional band by equilibrium free carriers. A change in this population by free electrons under various temperatures affects absorption and carrier transport of non-equilibrium carriers generated by incident light. This results in different efficiencies for both the doped and undoped intermediate band solar cells in comparison with the reference GaAs p-i-n solar cell device.

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

    DOE PAGES [OSTI]

    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

  1. Cabazon Band of Mission Indians- 2011 Project

    Energy.gov [DOE]

    The Cabazon Band of Mission Indians' long-range goals are to become energy self-sufficient, foster economic diversity, grow jobs, and improve the well-being of members of the tribe as well as those in its region of Southern California.

  2. X-Band Photoinjector Beam Dynamics

    SciTech Connect

    Zhou, Feng; Adolphsen, Chris; Ding, Yuantao; Li, Zenghai; Vlieks, Arnold; /SLAC

    2011-12-13

    SLAC is studying the feasibility of using an X-band RF photocathode gun to produce low emittance bunches for applications such as a mono-energetic MeV {gamma} ray source (in collaboration with LLNL) and a photoinjector for a compact FEL. Beam dynamics studies are being done for a configuration consisting of a 5.5-cell X-band gun followed by several 53-cell high-gradient X-band accelerator structures. A fully 3D program, ImpactT, is used to track particles taking into account space charge forces, short-range longitudinal and transverse wakefields, and the 3D rf fields in the structures, including the quadrupole component of the couplers. The effect of misalignments of the various elements, including the drive-laser, gun, solenoid and accelerator structures, are evaluated. This paper presents these results and estimates of the expected bunch emittance vs cathode gradient, and the effects of mixing between the fundamental and off-frequency longitudinal modes. An X-band gun at SLAC has been shown to operate reliably with a 200 MV/m acceleration gradient at the cathode, which is nearly twice the 115 MV/m acceleration gradient in the LCLS gun. The higher gradient should roughly balance the space charge related transverse emittance growth for the same bunch charge but provide a 3-4 times shorter bunch length. The shorter length would make the subsequent bunch compression easier and allow for a more effective use of emittance exchange. Such a gun can also be used with an X-band linac to produce a compact FEL or g ray source that would require rf sources of only one frequency for beam generation and acceleration. The feasibility of using an X-band rf photocathode gun and accelerator structures to generate high quality electron beams for compact FELs and g ray sources is being studied at SLAC. Results from the X-band photoinjector beam dynamics studies are reported in this paper.

  3. A Microcantilever Sensor Array for the Detection and Inventory of Desert Tortoises

    SciTech Connect

    Venedam, R. J.; Dillingham, T. R.

    2008-07-01

    Wehavedesignedandtestedaportableinstrumentconsistingofasmallinfraredcameracoupledwithanarrayofpiezoresistivemicrocantileversensorsthatisusedtoprovidereal-time,non-invasive data on desert tortoise den occupancy. The piezoresistive microcantilever (PMC) sensors are used to obtain a chemical signature of tortoise presence from the air deep within the dens, and provide data in cases where the camera cannot extend deep enough into the den to provide visual evidence of tortoise presence. The infrared camera was used to verify the PMC data during testing, and in many cases, such as shallower dens, may be used to provide exact numbers on den populations.

  4. S-Band Loads for SLAC Linac

    SciTech Connect

    Krasnykh, A.; Decker, F.-J.; LeClair, R.; /INTA Technologies, Santa Clara

    2012-08-28

    The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.

  5. X-Band RF Gun Development

    SciTech Connect

    Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

    2012-06-22

    In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

  6. HIGH CURRENT L-BAND LINAC

    SciTech Connect

    S. RUSSELL; B. CARLSTEN; J. GOETTEE

    2001-02-01

    The Sub-Picosecond Accelerator (SPA) at the Los Alamos National Laboratory is an L-band photoinjector. Using magnetic compression, the SPA routinely compresses 8 MeV, 1 nC per bunch electron beams from an initial temporal FWHM bunch length of 20 ps to less than 1 ps. In recent plasma wakefield accelerator experiments, we have compressed a 2 nC per bunch electron beam to an approximate temporal length of 1 ps.

  7. Permanent magnet focused X-band photoinjector

    DOEpatents

    Yu, David U. L.; Rosenzweig, James

    2002-09-10

    A compact high energy photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injection and the linac. High electron beam brightness is achieved by accelerating a tightly focused electron beam in an integrated, multi-cell, X-band rf linear accelerator (linac). The photoelectron linac employs a Plane-Wave-Transformer (PWT) design which provides strong cell-to-cell coupling, easing manufacturing tolerances and costs.

  8. 12. mu. m band tunable ammonia laser

    SciTech Connect

    Li Yuteh; Kuang Ichung; Hsun Hungtao

    1987-01-01

    The 9.4 ..mu..m R(30) line from a TEA-CO/sub 2/ laser was used to pump a NH/sub 3/ laser. Tunable NH/sub 3/ laser emission in the 12 ..mu..m band has been obtained. The output energy at 12.247, 12.261, and 12.079 ..mu..m is 18.6, 23, and 26 mJ, respectively.

  9. Fabrication of photonic band gap materials

    DOEpatents

    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.

  10. Manzanita Band of Mission Indians- 2002 Project

    Energy.gov [DOE]

    The Manzanita Band of Mission Indians ("the tribe") has long recognized that its reservation has an abundant wind resource that could be commercially utilized to its benefit. The tribe is now investigating the feasibility of commercial scale development of a wind power project on tribal lands. The proposed project is a joint effort between the tribe and its subcontractor and consultant, SeaWest Consulting.

  11. Fermion dynamical symmetry and identical bands

    SciTech Connect

    Guidry, M. |

    1994-10-01

    Recent general attention has been directed to the phenomenon of identical bands in both normally deformed and superdeformed nuclei. This paper discusses the possibility that such behavior results from a dynamical symmetry of the nuclear many-body system. Phenomenology and the basic principles of Lie algebras are used to place conditions on the acceptable properties of a candidate symmetry. We find that quite general arguments require that such a symmetry have a minimum of 21 generators with a microscopic fermion interpretation.

  12. W-Band Sheet Beam Klystron Simulation

    SciTech Connect

    Colby, E.R.; Caryotakis, G.; Fowkes, W.R.; /SLAC; Smithe, D.N.; /Mission Res., Newington

    2005-09-12

    With the development of ever higher energy particle accelerators comes the need for compactness and high gradient, which in turn require very high frequency high power rf sources. Recent development work in W-band accelerating techniques has spurred the development of a high-power W-band source. Axisymmetric sources suffer from fundamental power output limitations (P{sub sat} {approx} {lambda}{sup 2}) brought on by the conflicting requirements of small beam sizes and high beam current. The sheet beam klystron allows for an increase in beam current without substantial increase in the beam current density, allowing for reduced cathode current densities and focusing field strengths. Initial simulations of a 20:1 aspect ratio sheet beam/cavity interaction using the 3 dimensional particle-in-cell code Magic3D have demonstrated a 35% beam-power to RF power extraction efficiency. Calculational work and numerical simulations leading to a prototype W-band sheet beam klystron will be presented, together with preliminary cold test structure studies of a proposed RF cavity geometry.

  13. W-band sheet beam klystron simulation

    SciTech Connect

    Colby, E.R.; Caryotakis, G.; Fowkes, W.R. [Stanford Linear Accelerator Center, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); Smithe, D.N. [Mission Research Corporation, 8560 Cinderbed Road, Ste. 700, Newington, Virginia 22122 (United States)

    1999-05-01

    With the development of ever higher energy particle accelerators comes the need for compactness and high gradient, which in turn require very high frequency high power rf sources. Recent development work in W-band accelerating techniques has spurred the development of a high-power W-band source. Axisymmetric sources suffer from fundamental power output limitations (P{sub sat}{approximately}{lambda}{sup 2}) brought on by the conflicting requirements of small beam sizes and high beam current. The sheet beam klystron allows for an increase in beam current without substantial increase in the beam current density, allowing for reduced cathode current densities and focussing field strengths. Initial simulations of a 20:1 aspect ratio sheet beam/cavity interaction using the 3 dimensional particle-in-cell code Magic3D have demonstrated a 35{percent} beam-power to RF power extraction efficiency. Calculational work and numerical simulations leading to a prototype W-band sheet beam klystron will be presented, together with preliminary cold test structure studies of a proposed RF cavity geometry. {copyright} {ital 1999 American Institute of Physics.}

  14. Project Reports for Augustine Band of Cahuilla Mission Indians- 2006 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Deep in the Coachella Valley, the tribe's reservation is a desert environment entirely below sea level, with an average elevation of minus 90 feet. Strong, consistent winds cross the desert floor, indicating that wind power might be viable for this underdeveloped reservation.

  15. Assessment of damage to the desert surfaces of Kuwait due to the Gulf War

    SciTech Connect

    El-Baz, F. . Center for Remote Sensing); Al-Ajmi, D. . Environmental and Earth Sciences Div.)

    1993-01-01

    This is a preliminary report on a joint research project by Boston University and the Kuwait Institute for Scientific Research that commenced in April 1992. The project aim is to establish the extent and nature of environmental damage to the desert surface and coastal zone of Kuwait due to the Gulf War and its aftermath. Change detection image enhancement techniques were employed to enhance environmental change by comparison of Landsat Thematic Mapper images obtained before the wars and after the cessation of the oil and well fires. Higher resolution SPOT images were also utilized to evaluate the nature of the environmental damage to specific areas. The most prominent changes were due to: (1) the deposition of oil and course-grained soot on the desert surface as a result of oil rain'' from the plume that emanated from the oil well fires; (2) the formation of hundreds of oil lakes, from oil seepage at the damaged oil well heads; (3) the mobilization of sand and dust and (4) the pollution of segments of the coastal zone by the deposition of oil from several oil spills. Interpretation of satellite image data are checked in the field to confirm the observations, and to assess the nature of the damage. Final results will be utilized in establishing the needs for remedial action to counteract the harmful effects of the various types of damage to the environment of Kuwait.

  16. W-band ARM Cloud Radar (WACR) Update and Status

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

    W-band ARM Cloud Radar (WACR) Update and Status PopStefanija, Ivan ProSensing, Inc. Mead, ... Widener, Kevin Pacific Northwest National Laboratory Category: Instruments Two W-band ARM ...

  17. W-Band ARM Cloud Radar - Specifications and Design

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

    W-Band ARM Cloud Radar - Specifications and Design K. B. Widener Pacific Northwest ... to develop and deploy the W-band ARM Cloud Radar (WACR) at the SGP central facility. ...

  18. G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value...

    Office of Scientific and Technical Information (OSTI)

    G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product Citation Details In-Document Search Title: G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) ...

  19. Project Reports for Campo Band of Mission Indians- 2010 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Campo Band of Mission Indians ("Band") goal is to develop a 300 MW wind energy project ("Kumeyaay Wind II") in two phases over the next two to five years.

  20. Project Reports for Soboba Band of Luiseno Indians - 2011 Project...

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

    Project Reports for Soboba Band of Luiseno Indians - 2011 Project The Soboba Band of Luiseno Indians would like to begin to focus on renewable sources for electricity and to ...

  1. Inter-band optoelectronic properties in quantum dot structure of low band gap III-V semiconductors

    SciTech Connect

    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.

  2. Morongo Band of Cahuilla Mission Indians- 2006 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Southwest Tribal Energy Consortium, represented by the Morongo Band, is comprised of tribes in California, Arizona and New Mexico.

  3. Aroostook Band of Micmacs - Strategic Energy Planning Initiative

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

    Initiative Presented by: Fred Corey Environmental Director October 2006 Aroostook Band of Micmacs Overview * About the Aroostook Band of Micmacs * Project Background and Introduction * Project Goals and Objectives * Summary of Report * Vision Statement * Discussion on Vision and Plan * Next Steps Aroostook Band of Micmacs Aroostook Band of Micmacs * Federally Recognized by Congress in 1991 * 1,000 Enrolled Members * Largest Maritime Tribe in Eastern Canada (50,000+ Members, 27 Reserves) * Tribal

  4. W-Band Sheet Beam Klystron Design

    SciTech Connect

    Scheitrum, G.; Caryotakis, G.; Burke, A.; Jensen, A.; Jongewaard, E.a Krasnykh, A.; Neubauer, M.; Phillips, R.; Rauenbuehler, K.; /SLAC

    2011-11-11

    Sheet beam devices provide important advantages for very high power, narrow bandwidth RF sources like accelerator klystrons [1]. Reduced current density and increased surface area result in increased power capabi1ity, reduced magnetic fields for focusing and reduced cathode loading. These advantages are offset by increased complexity, beam formation and transport issues and potential for mode competition in the ovennoded cavities and drift tube. This paper will describe the design issues encountered in developing a 100 kW peak and 2 kW average power sheet beam k1ystron at W-band including beam formation, beam transport, circuit design, circuit fabrication and mode competition.

  5. Universal EUV in-band intensity detector

    DOEpatents

    Berger, Kurt W.

    2004-08-24

    Extreme ultraviolet light is detected using a universal in-band detector for detecting extreme ultraviolet radiation that includes: (a) an EUV sensitive photodiode having a diode active area that generates a current responsive to EUV radiation; (b) one or more mirrors that reflects EUV radiation having a defined wavelength(s) to the diode active area; and (c) a mask defining a pinhole that is positioned above the diode active area, wherein EUV radiation passing through the pinhole is restricted substantially to illuminating the diode active area.

  6. Cabazon Band of Mission Indians- 2003 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Strategic energy planning effort to assist in achieving the tribe's primary goals of economic diversity, economic self-sufficiency, and protecting the health and welfare of tribal members. The Cabazon Band Reservation, located on four sections of non-contiguous land on the eastern half of the Coachella Valley in Riverside County is approximately 25 miles east of Palm Springs, comprises 1500 acres and currently has the seventh highest residential electricity rates among U.S. Native American reservations. The Strategic Energy Plan will enable the tribe to make informed decisions in creating and conducting an effective energy management program for their people.

  7. Band excitation method applicable to scanning probe microscopy

    SciTech Connect

    Jesse, Stephen; Kalinin, Sergei V.

    2015-08-04

    Scanning probe microscopy may include a method for generating a band excitation (BE) signal and simultaneously exciting a probe at a plurality of frequencies within a predetermined frequency band based on the excitation signal. A response of the probe is measured across a subset of frequencies of the predetermined frequency band and the excitation signal is adjusted based on the measured response.

  8. Excitation of Banded Whistler Waves in the Magnetosphere

    SciTech Connect

    Gary, S. Peter; Liu, Kaijun; Winske, Dan

    2012-07-13

    Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.

  9. W-band free-electron masers

    SciTech Connect

    Freund, H. P. [Science Applications International Corp., McLean, Virginia 22102 (United States); Jackson, R. H.; Danly, B. G.; Levush, B. [Naval Research Laboratory, Washington, District of Columbia 20375 (United States)

    1999-05-07

    Theoretical analyses of high power W-band (i.e., {approx_equal}94 GHz) free-electron maser amplifiers are presented for a helical wiggler/cylindrical waveguide configuration using the three-dimensional slow-time-scale ARACHNE simulation code [9]. The geometry treated by ARACHNE is that of an electron beam propagating through the cylindrical waveguide subject to a helical wiggler and an axial guide magnetic field. Two configurations are discussed. The first is the case of a reversed-guide field geometry where the guide field is oriented antiparallel to the helicity of the wiggler field. Using a 330 kV/20 A electron beam, efficiencies of the order of 7% are calculated with a bandwidth (FWHM) of 5 GHz. The second example employs a strong guide field of 20 kG oriented parallel to the helicity of the wiggler. Here, efficiencies of greater than 8% are possible with a FWHM bandwidth of 4.5 GHz using a 300 kV/20 A electron beam. A normalized emittance of 95 mm-mrad is assumed in both cases, and no beam losses are observed for either case. Both cases assume interaction with the fundamental TE{sub 11} mode, which has acceptably low losses in the W-band.

  10. Final Technical Report: Effects of Changing Water and Nitrogen Inputs on a Mojave Desert Ecosystem

    SciTech Connect

    Smith, Stanley, D.; Nowak, Robert S.; Fenstermaker, Lynn, F.; Young, Michael,H.

    2007-11-30

    In order to anticipate the effects of global change on ecosystem function, it is essential that predictive relationships be established linking ecosystem function to global change scenarios. The Mojave Desert is of considerable interest with respect to global change. It contains the driest habitats in North America, and thus most closely approximates the worlds great arid deserts. In order to examine the effects of climate and land use changes, in 2001 we established a long-term manipulative global change experiment, called the Mojave Global Change Facility. Manipulations in this study include the potential effects of (1) increased summer rainfall (75 mm over three discrete 25 mm events), (2) increased nitrogen deposition (10 and 40 kg ha-1), and (3) the disturbance of biological N-fixing crusts . Questions addressed under this grant shared the common hypothesis that plant and ecosystem performance will positively respond to the augmentation of the most limiting resources to plant growth in the Mojave Desert, e.g., water and nitrogen. Specific hypotheses include (1) increased summer rainfall will significantly increase plant production through an alleviation of moisture stress in the dry summer months, (2) N-deposition will increase plant production in this N-limited system, particularly in wet years or in concert with added summer rain, and (3) biological crust disturbance will gradually decrease bio-available N, with concomitant long-term reductions in photosynthesis and ANPP. Individual plant and ecosystem responses to global change may be regulated by biogeochemical processes and natural weather variability, and changes in plant and ecosystem processes may occur rapidly, may occur only after a time lag, or may not occur at all. During the first PER grant period, we observed changes in plant and ecosystem processes that would fall under each of these time-response intervals: plant and ecosystem processes responded rapidly to added summer rain, whereas most

  11. Hybrid Band effects program (Lockheed Martin shared vision CRADA)

    SciTech Connect

    Bacon, L. D.

    2012-03-01

    Hybrid Band{trademark} (H-band) is a Lockheed Martin Missiles and Fire Control (LMMFC) designation for a specific RF modulation that causes disruption of select electronic components and circuits. H-Band enables conventional high-power microwave (HPM) effects (with a center frequency of 1 to 2 GHz, for example) using a higher frequency carrier signal. The primary technical objective of this project was to understand the fundamental physics of Hybrid Band{trademark} Radio Frequency effects on electronic systems. The follow-on objective was to develop and validate a Hybrid Band{trademark} effects analysis process.

  12. Fine structure on the green band in ZnO

    SciTech Connect

    Reynolds, D. C.; Look, D. C.; Jogai, B.

    2001-06-01

    An emission band at 2.4 eV, called the green band, is observed in most ZnO samples, no matter what growth technique is used. Sometimes this band includes fine structure, which consists mainly of doublets, repeated with a longitudinal-optical-phonon-energy spacing (72 meV). We have developed a vibronic model for the green band, based on transitions from two separate shallow donors to a deep acceptor. The donors, at energies 30 and 60 meV from the conduction-band edge, respectively, are also found from Hall-effect measurements. {copyright} 2001 American Institute of Physics.

  13. Coupled Environmental Processes and Long-term Performance of Landfill Covers in the northern Mojave Desert

    SciTech Connect

    David Shafer; Michael Young; Stephen Zitzer; Eric McDonald; Todd Caldwell

    2004-05-12

    Evapotransiration (ET) covers have gained widespread acceptance as a closure feature for waste disposal sites, particularly in the arid and semi-arid regions of the southwestern U.S. But as landforms, ET covers are subject to change over time because of processes such as pedogenesis, hydrologic processes, vegetation establishment and change, and biological processes. To better understand the effects of coupled process changes to ET covers, a series of four primary analog sites in Yucca Flat on the Nevada Test Site, along with measurements and observations from other locations in the Mojave Desert, were selected to evaluate changes in ET covers over time. The analog sites, of varying ages, were selected to address changes in the early post-institutional control period, the 1,000-year compliance period for disposal of low-level and mixed low-level waste, and the 10,000-year compliance period for transuranic waste sites.

  14. Free Air CO2 Enrichment (FACE) Research Data from the Nevada Desert FACE Facility (NDFF)

    DOE Data Explorer

    DOE has conducted trace gas enrichment experiments since the mid 1990s. The FACE Data Management System is a central repository and archive for Free-Air Carbon Dioxide Enrichment (FACE) data, as well as for the related open-top chamber (OTC) experiments. FACE Data Management System is located at the Carbon Dioxide Information Analysis Center (CDIAC). While the data from the various FACE sites, each one a unique user facility, are centralized at CDIAC, each of the FACE sites presents its own view of its activities and information. For that reason, DOE Data Explorer users are advised to see both the central repository at http://public.ornl.gov/face/index.shtml and the individual home pages of each site. NDFF whole-ecosystem manipulation is a flagship experiment of the Terrestrial Carbon Process (TCP) research program of the US Dept. of Energy. It is also a core project of the International Geosphere-Biosphere Program (IGBP) and a contribution to the US Global Change Research Program. The NDFF was developed in conjunction with the National Science Foundation (NSF) and DOE-EPSCoR programs. FACE (Free-Air-Carbon dioxide-Enrichment) technology allows researchers to elevate the carbon dioxide level in large study plots while minimizing ecosystem disturbance. At the NDFF the concentration of CO2 was elevated by 50 percent above the present atmospheric levels in three plots in the Mojave Desert ecosystem, while six other plots remained at the current level. This experimental design provided a large area in which integrated teams of scientists could describe and quantify processes regulating carbon, nutrient, and water balances in desert ecosystems.

  15. Eastern Band of Cherokee Strategic Energy Plan

    SciTech Connect

    Souther Carolina Institute of energy Studies-Robert Leitner

    2009-01-30

    The Eastern Band of Cherokee Indians was awarded a grant under the U.S. Department of Energy Tribal Energy Program (TEP) to develop a Tribal Strategic Energy Plan (SEP). The grant, awarded under the “First Steps” phase of the TEP, supported the development of a SEP that integrates with the Tribe’s plans for economic development, preservation of natural resources and the environment, and perpetuation of Tribal heritage and culture. The Tribe formed an Energy Committee consisting of members from various departments within the Tribal government. This committee, together with its consultant, the South Carolina Institute for Energy Studies, performed the following activities: • Develop the Tribe’s energy goals and objectives • Establish the Tribe’s current energy usage • Identify available renewable energy and energy efficiency options • Assess the available options versus the goals and objectives • Create an action plan for the selected options

  16. Wide band stepped frequency ground penetrating radar

    DOEpatents

    Bashforth, M.B.; Gardner, D.; Patrick, D.; Lewallen, T.A.; Nammath, S.R.; Painter, K.D.; Vadnais, K.G.

    1996-03-12

    A wide band ground penetrating radar system is described embodying a method wherein a series of radio frequency signals is produced by a single radio frequency source and provided to a transmit antenna for transmission to a target and reflection therefrom to a receive antenna. A phase modulator modulates those portions of the radio frequency signals to be transmitted and the reflected modulated signal is combined in a mixer with the original radio frequency signal to produce a resultant signal which is demodulated to produce a series of direct current voltage signals, the envelope of which forms a cosine wave shaped plot which is processed by a Fast Fourier Transform Unit 44 into frequency domain data wherein the position of a preponderant frequency is indicative of distance to the target and magnitude is indicative of the signature of the target. 6 figs.

  17. Wide band stepped frequency ground penetrating radar

    DOEpatents

    Bashforth, Michael B.; Gardner, Duane; Patrick, Douglas; Lewallen, Tricia A.; Nammath, Sharyn R.; Painter, Kelly D.; Vadnais, Kenneth G.

    1996-01-01

    A wide band ground penetrating radar system (10) embodying a method wherein a series of radio frequency signals (60) is produced by a single radio frequency source (16) and provided to a transmit antenna (26) for transmission to a target (54) and reflection therefrom to a receive antenna (28). A phase modulator (18) modulates those portion of the radio frequency signals (62) to be transmitted and the reflected modulated signal (62) is combined in a mixer (34) with the original radio frequency signal (60) to produce a resultant signal (53) which is demodulated to produce a series of direct current voltage signals (66) the envelope of which forms a cosine wave shaped plot (68) which is processed by a Fast Fourier Transform unit 44 into frequency domain data (70) wherein the position of a preponderant frequency is indicative of distance to the target (54) and magnitude is indicative of the signature of the target (54).

  18. Mississippi Band of Choctaw Indians- 2002 Project

    Energy.gov [DOE]

    The Mississippi Band of Choctaw Indians (MBCI) always seeks new opportunities to diversify its economy and create new career opportunities for tribal members, which is the purpose of this feasibility study. The MBCI will study the feasibility of locating a renewable energy installation on tribal lands. The technologies to be utilized in the renewable energy installation will be those that can readily handle poultry litter, either alone or in combination with wood residues. The purpose of the study is to determine whether such an installation can be both economically sustainable and consistent with the cultural, social, and economic goals of the tribe. The feasibility study will result in the development of a thorough business plan that will allow the MBCI to make an informed decision regarding this project.

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

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Continuously controlled optical band gap in oxide semiconductor thin films Citation Details In-Document Search This content will become publicly available on February 2, 2017 Title: Continuously controlled optical band gap in oxide semiconductor thin films 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

  20. Aroostook Band of Micmacs - Strategic Enegy Planning Initiative

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

    Initiative Presented by: Russell Dennis Economic Development Director Presented to: US DOE Tribal Energy Program FY05 Program Review Meeting Aroostook Band of Micmacs Presentation Overview * ABM Background and Demographics * Geographic Area * Energy Perspective * Project Goals and Objectives * Project Activities * Project Partners * Next Steps Aroostook Band of Micmacs ABM Background and Demographics * 1,000 Members in ABM * Micmac Nation: 7 districts of 29 bands with 30,000 members * Federally

  1. Dependence of Band Renormalization Effect on the Number of Copper...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Dependence of Band Renormalization Effect on the Number of Copper-oxide ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  2. Project Reports for Eastern Band of Cherokee Indians- 2010 Project

    Energy.gov [DOE]

    The Eastern Band of Cherokee Indians (EBCI) is using the grant funds from the Department of Energy to complete the Energy Efficiency Improvements to seven EBCI facilities.

  3. Band structure of topological insulators from noise measurements...

    Office of Scientific and Technical Information (OSTI)

    noise measurements in tunnel junctions Citation Details In-Document Search Title: Band structure of topological insulators from noise measurements in tunnel junctions The unique ...

  4. Santa Ynez Band of Chumash Indians- 2011 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Santa Ynez Band of Chumash Indians (SYBCI) will prepare a comprehensive, strategic energy plan that incorporates energy efficiency, renewable energy, and other energy management and development options.

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

    U.S. Department of Energy (DOE) - all 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...

  6. Ramona Band of Cahuilla Mission Indians- 1999 Project

    Energy.gov [DOE]

    The Ramona Band of Cauhilla Indians is establishing an ecotourism facility on their Reservation at the southern end of the San Bernardino National Forest in southern California.

  7. Agua Caliente Band's Pursuit of Energy Self-Sufficiency Gains...

    Office of Environmental Management (EM)

    The Agua Caliente Band of Cahuilla Indians in the Palm Springs area of California is a ... Caliente Resort and Casino in Rancho Mirage, California. View the workshop presentations. ...

  8. High Performance Computing with Harness over InfiniBand

    SciTech Connect

    Valentini, Alessandro; Di Biagio, Christian; Batino, Fabrizio; Pennella, Guido; Palma, Fabrizio; Engelmann, Christian

    2009-01-01

    Harness is an adaptable and plug-in-based middleware framework able to support distributed parallel computing. By now, it is based on the Ethernet protocol which cannot guarantee high performance throughput and real time (determinism) performance. During last years, both, the research and industry environments have developed new network architectures (InfiniBand, Myrinet, iWARP, etc.) to avoid those limits. This paper concerns the integration between Harness and InfiniBand focusing on two solutions: IP over InfiniBand (IPoIB) and Socket Direct Protocol (SDP) technology. They allow the Harness middleware to take advantage of the enhanced features provided by the InfiniBand Architecture.

  9. Project Reports for Aroostook Band of Micmac Indians- 2005 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The goal of the project is to develop a strategic energy plan in order to reduce energy costs in the Aroostook Band of Micmacs' government buildings and homes.

  10. Band excitation method applicable to scanning probe microscopy...

    Office of Scientific and Technical Information (OSTI)

    The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive ...

  11. Minnesota Chippewa Tribe: White Earth Band- 2003 Project

    Energy.gov [DOE]

    Several northern Minnesota tribes interested in building a common foundation for strategic tribal energy capacity have banded together for strategic energy resource planning.

  12. Engineering the Electronic Band Structure for Multiband Solar Cells

    SciTech Connect

    Lopez, N.; Reichertz, L.A.; Yu, K.M.; Campman, K.; Walukiewicz, W.

    2010-07-12

    Using the unique features of the electronic band structure of GaNxAs1-x alloys, we have designed, fabricated and tested a multiband photovoltaic device. The device demonstrates an optical activity of three energy bands that absorb, and convert into electrical current, the crucial part of the solar spectrum. The performance of the device and measurements of electroluminescence, quantum efficiency and photomodulated reflectivity are analyzed in terms of the Band Anticrossing model of the electronic structure of highly mismatched alloys. The results demonstrate the feasibility of using highly mismatched alloys to engineer the semiconductor energy band structure for specific device applications.

  13. Germanium blocked impurity band infrared detectors

    SciTech Connect

    Rossington, C.S.; Haller, E.E.

    1988-08-01

    Germanium blocked impurity band (BIB) photoconductors have been fabricated and characterized for responsivity, dark current, and noise equivalent power. BIB photoconductors theoretically provide an extension of the spectral response, a reduction in sensitivity to cosmic radiation and a reduction in noise characteristics compared with conventional photoconductors. Silicon BIB detectors have been successfully developed by researchers at Rockwell International, which do indeed meet their theoretical potential. In the proper configuration, these same Si BIB detectors are capable of continuous detection of individual photons in the wavelength range from 0.4 to 28 ..mu..m. Until the BIB concept was developed, detection of individual photons was only possible with photomultiplier tubes which detected visible light. Due to the successes of the Si BIB detectors, it seemed natural to extend this concept to Ge detectors, which would then allow an extension of the spectral response over conventional Ge detectors from /approximately/100 ..mu..m to /approximately/200 ..mu..m. 8 refs., 2 figs.

  14. Metallic photonic band-gap materials

    SciTech Connect

    Sigalas, M.M.; Chan, C.T.; Ho, K.M.; Soukoulis, C.M.

    1995-10-15

    We calculate the transmission and absorption of electromagnetic waves propagating in two-dimensional (2D) and 3D periodic metallic photonic band-gap (PBG) structures. For 2D systems, there is substantial difference between the {ital s}- and {ital p}-polarized waves. The {ital p}-polarized waves exhibit behavior similar to the dielectric PBG`s. But, the {ital s}-polarized waves have a cutoff frequency below which there are no propagating modes. For 3D systems, the results are qualitatively the same for both polarizations but there are important differences related to the topology of the structure. For 3D structures with isolated metallic scatterers (cermet topology), the behavior is similar to that of the dielectric PBG`s, while for 3D structures with the metal forming a continuous network (network topology), there is a cutoff frequency below which there are no propagating modes. The systems with the network topology may have some interesting applications for frequencies less than about 1 THz where the absorption can be neglected. We also study the role of the defects in the metallic structures.

  15. PHOTOSYNTHESIS AND RESOURCE ALLOCATION OF THREE MOJAVE DESERT GRASSES IN RESPONSE TO ELEVATED ATMOSPHERIC CO2

    SciTech Connect

    L. A. DEFALCO; C. K. IVANS; P. VIVIN; J. R. SEEMANN; R. S. NOWAK

    2004-01-01

    Gas exchange, biomass and N allocation were compared among three Mojave Desert grasses representing different functional types to determine if photosynthetic responses and the associated allocation of resources within the plant changed after prolonged exposure to elevated CO{sub 2}. Leaf gas exchange characteristics were measured for Bromus madritensis ssp. rubens (C{sub 3} invasive annual), Achnatherum hymenoides (C{sub 3} native perennial) and Pleuraphis rigida (C{sub 4} native perennial) exposed to 360 {micro}mol mol{sup -1} (ambient) and 1000 {micro}mol mol{sup -1} (elevated) CO{sub 2} concentrations in a glasshouse experiment, and tissue biomass and total N pools were quantified from three harvests during development. The maximum rate of carboxylation by the N-rich enzyme Rubisco (Vc{sub max}), which was inferred from the relationship between net CO{sub 2} assimilation (A{sub net}) and intracellular CO{sub 2} concentration (c{sub i}), declined in the C{sub 3} species Bromus and Achnatherum across all sampling dates, but did not change at elevated CO{sub 2} for the C{sub 4} Pleuraphis. Whole plant N remained the same between CO{sub 2} treatments for all species, but patterns of allocation differed for the short- and long-lived C{sub 3} species. For Bromus, leaf N used for photosynthesis was reallocated to reproduction at elevated CO{sub 2} as inferred from the combination of lower Vc{sub max} and N per leaf area (NLA) at elevated CO{sub 2}, but similar specific leaf area (SLA, cm{sup 2} g{sup -1}), and of greater reproductive effort (RE) for the elevated CO{sub 2} treatment. Vc{sub max}, leaf N concentration and NLA declined for the perennial Achnatherum at elevated CO{sub 2} potentially due to accumulation of carbohydrates or changes in leaf morphology inferred from lower SLA and greater total biomass at elevated CO{sub 2}. In contrast, Vc{sub max} for the C{sub 4} perennial Pleuraphis did not change at elevated CO{sub 2}, and tissue biomass and total N were

  16. PLUTONIUM UPTAKE AND BEHAVIOR IN PLANTS OF THE DESERT SOUTHWEST: A PRELIMINARY ASSESSMENT

    SciTech Connect

    Caldwell, E.; Duff, M.; Ferguson, C.

    2011-03-01

    Eight species of desert vegetation and associated soils were collected from the Nevada National Security Site (N2S2) and analyzed for 238Pu and 239+240Pu concentrations. Amongst the plant species sampled were: atmospheric elemental accumulators (moss and lichen), the very slow growing, long-lived creosote bush and the rapidly growing, short-lived cheatgrass brome. The diversity of growth strategies provided insight into the geochemical behavior and bio-availability of Pu at the N2S2. The highest concentrations of Pu were measured in the onion moss (24.27 Bq kg-1 238Pu and 52.78 Bq kg-1 239+240Pu) followed by the rimmed navel lichen (8.18 Bq kg-1 and 18.4 Bq kg-1 respectively), pointing to the importance of eolian transport of Pu. Brome and desert globemallow accumulated between 3 and 9 times higher concentrations of Pu than creosote and sage brush species. These results support the importance of species specific elemental accumulation strategies rather than exposure duration as the dominant variable influencing Pu concentrations in these plants. Total vegetation elemental concentrations of Ce, Fe, Al, Sm and others were also analyzed. Strong correlations were observed between Fe and Pu. This supports the conclusion that Pu was accumulated as a consequence of the active accumulation of Fe and other plant required nutrients. Cerium and Pu are considered to be chemical analogs. Strong correlations observed in plants support the conclusion that these elements displayed similar geochemical behavior in the environment as it related to the biochemical uptake process of vegetation. Soils were also sampled in association with vegetation samples. This allowed for the calculation of a concentration ratio (CR). The CR values for Pu in plants were highly influenced by the heterogeneity of Pu distribution among sites. Results from the naturally occurring elements of concern were more evenly distributed between sample sites. This allowed for the development of a pattern of plant

  17. Shell model description of band structure in 48Cr

    SciTech Connect

    Vargas, Carlos E.; Velazquez, Victor M.

    2007-02-12

    The band structure for normal and abnormal parity bands in 48Cr are described using the m-scheme shell model. In addition to full fp-shell, two particles in the 1d3/2 orbital are allowed in order to describe intruder states. The interaction includes fp-, sd- and mixed matrix elements.

  18. Excited bands in even-even rare-earth nuclei

    SciTech Connect

    Vargas, Carlos E.; Hirsch, Jorge G.

    2004-09-13

    The energetics of states belonging to normal parity bands in even-even dysprosium isotopes, and their B(E2) transition strengths, are studied using an extended pseudo-SU(3) shell model. States with pseudospin 1 are added to the standard pseudospin 0 space, allowing for a proper description of known excited normal parity bands.

  19. The electronic structure of heavy fermions: Narrow temperature independent bands

    SciTech Connect

    Arko, A.J.; Joyce, J.J.; Smith, J.L.; Andrews, A.B.

    1996-08-01

    The electronic structure of both Ce and U heavy fermions appears to consist of extremely narrow temperature independent bands. There is no evidence from photoemission for a collective phenomenon normally referred to as the Kondo resonance. In uranium compounds a small dispersion of the bands is easily measurable.

  20. Band excitation method applicable to scanning probe microscopy

    DOEpatents

    Jesse, Stephen [Knoxville, TN; Kalinin, Sergei V. [Knoxville, TN

    2010-08-17

    Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

  1. Band excitation method applicable to scanning probe microscopy

    DOEpatents

    Jesse, Stephen; Kalinin, Sergei V

    2013-05-28

    Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

  2. Estimating Annual Precipitation in the Fenner Basin of the Eastern Mojave Desert, California

    SciTech Connect

    Davisson, M.L.; Rose, T.P.

    2000-05-15

    Metropolitan Water District (MWD) of southern California and Cadiz Inc. investigated the feasibility of storing Colorado River water in groundwater aquifers of the eastern Mojave Desert as a future drought mitigation strategy. This culminated in the public release of the Cadiz Groundwater Storage and Dry-Year Supply program Draft EIR, which included pilot percolation studies, groundwater modeling, and precipitation/runoff analysis in the Fenner groundwater basin, which overlies the proposed storage site. The project proposes to store and withdrawal Colorado River water over a 50-year period, but will not exceed the natural replenishment rates of the groundwater basin. Several independent analyses were conducted to estimate the rates of natural groundwater replenishment to the Fenner Groundwater Basin which was included in the Draft EIR. The US Geologic Survey, Water Resources Division (WRD) officially submitted comments during public review and concluded that the natural groundwater replenishment rates calculated for the Draft EIR were too high. In the WRD review, they provided a much lower recharge calculation based on a Maxey-Eakin estimation approach. This approach estimates annual precipitation over an entire basin as a function of elevation, followed by calibration against annual recharge rates. Previous attempts to create precipitation-elevation functions in western Nevada have been difficult and result in large uncertainty. In the WRD data analysis, the effect of geographic scale on the precipitation-elevation function was overlooked. This contributed to an erroneous Maxey-Eakin recharge estimate.

  3. Secondary production of benthic insects in three cold-desert streams

    SciTech Connect

    Gaines, W.L.

    1987-07-01

    Aquatic insect production was studied in three cold-desert streams in eastern Washington (Douglas Creek, Snively Springs, and Rattlesnake Springs). The size-frequency method was applied to individual taxa to estimate total insect production. production was also assessed for functional groups and trophic levels in each stream. Optioservus sp. (riffle beetles) and Baetis sp. (mayflies) accounted for 72% of the total insect numbers and 50% of the total biomass in Douglas Creek. Baetis sp. accounted for 42% of the total insect numbers and 25% of the total biomass in Snively Springs. Simulium sp. (blackflies) and Baetis sp. comprised 74% of the total insect numbers and 55% of the total biomass in Rattlesnake Springs. Grazer-scrapers (49%) and collectors (48%) were the most abundant functional groups in Douglas Creek. Collectors were the most abundant functional group in Snively Springs and Rattlesnake Springs. Herbivores and detritivores were the most abundant trophic level in Snively Springs and Rattlesnake Springs. Dipterans (midges and blackflies) were the most productive taxa within the study streams, accounting for 40% to 70% of the total community production. Production by collectors and detritivores was the highest of all functional groups and trophic levels in all study streams.

  4. Corrosion of Uranium in Desert Soil, with Application to GCD Source Term M

    SciTech Connect

    ANDERSON, HOWARD L.; BACA, JULIANNE; KRUMHANSL, JAMES L.; STOCKMAN, HARLAN W.; THOMPSON, MOLLIE E.

    1999-09-01

    Uranium fragments from the Sandia Sled Track were studied as analogues for weapons components and depleted uranium buried at the Greater Confinement Disposal (GCD) site in Nevada. The Sled Track uranium fragments originated as weapons mockups and counterweights impacted on concrete and soil barriers, and experienced heating and fragmentation similar to processes thought to affect the Nuclear Weapons Accident Residues (NWAR) at GCD. Furthermore, the Sandia uranium was buried in unsaturated desert soils for 10 to 40 years, and has undergone weathering processes expected to affect the GCD wastes. Scanning electron microscopy, X-ray diffraction and microprobe analyses of the fragments show rapid alteration from metals to dominantly VI-valent oxy-hydroxides. Leaching studies of the samples give results consistent with published U-oxide dissolution rates, and suggest longer experimental periods (ca. 1 year) would be required to reach equilibrium solution concentrations. Thermochemical modeling with the EQ3/6 code indicates that the uranium concentrations in solutions saturated with becquerelite could increase as the pore waters evaporate, due to changes in carbonate equilibria and increased ionic strength.

  5. Feasibility study of the seismic reflection method in Amargosa Desert, Nye County, Nevada

    SciTech Connect

    Brocher, T.M.; Hart, P.E.; Carle, S.F.

    1990-11-01

    The US Geological Survey (USGS) working under an Interagency agreement with the Department of Energy is engaged in a broad geoscience program to assess and identify a potential repository for high level nuclear waste at Yucca Mountain, Nye County, Nevada. The USGS program, referred to as the Yucca Mountain Project, or YMP, consists of integrated geologic, hydrologic and geophysical studies which range in nature from site specific to regional. This report is an evaluation of different acquisition methods for future regional seismic reflection studies to be conducted in the vicinity of Yucca Mountain, located in the southwestern corner of the Nevada Test Site (NTS). In January 1988, field studies were conducted to investigate the feasibility of using the common-depth point (CDP) seismic reflection method to map subsurface geological horizons within the Amargosa Desert, Nye County, Nevada. The goal of the field study was to investigate which seismic reflection method(s) should be used for mapping shallow to lower-crustal horizons. Therefore, a wide-variety of field acquisition parameters were tested, included point versus linear receiver group arrays; Vibroseis (service and trademark of Conoco, Inc.) versus explosive sources; Vibroseis array patterns; and Vibroseis sweep and frequency range. 31 refs., 33 figs., 8 tabs.

  6. HYDROPHOBIC CHARACTERISTICS OF COMPOSITE INSULATORS IN SIMULATED INLAND ARID DESERT ENVIRONMENT

    SciTech Connect

    Khan, Yasin; Al-Arainy, Abdulrehman Ali; Malik, Nazar Hussain; Qureshi, Muhammad Iqbal

    2010-06-15

    Presently along with traditional insulators i.e. glass and porcelain, etc., the polymeric insulators are also used world widely. These polymeric insulators are very sensitive to various environmental parameters e.g. UV radiations, heat, etc. The UV radiation level in the central region of Saudi Arabia is high as compared to the recommended IEC-61109 standard for the accelerated aging of the composite insulators. In this study, thermoplastic elastomer (TPE) and Ethylene Propylene Diene Monomer (EPDM) insulators were subjected to accelerated aging stress as per IEC standard as well as modified IEC standard simulating the inland arid desert's atmospheric conditions. The hydrophobic characteristics were studied by measuring the contact angle along the insulator surface before and after the accelerated aging of the samples. It was found that TPE loses its hydrophobic properties more as compared to EPDM insulator. This loss was proportional to the intensity of UV irradiation. The rate of recovery is also low for both the tested materials as compared to Silicone Rubber insulators.

  7. Highly Mismatched Alloys for Intermediate Band Solar Cells

    SciTech Connect

    Walukiewicz, W.; Yu, K.M.; Wu, J.; Ager III, J.W.; Shan, W.; Scrapulla, M.A.; Dubon, O.D.; Becla, P.

    2005-03-21

    It has long been recognized that the introduction of a narrow band of states in a semiconductor band gap could be used to achieve improved power conversion efficiency in semiconductor-based solar cells. The intermediate band would serve as a ''stepping stone'' for photons of different energy to excite electrons from the valence to the conduction band. An important advantage of this design is that it requires formation of only a single p-n junction, which is a crucial simplification in comparison to multijunction solar cells. A detailed balance analysis predicts a limiting efficiency of more than 50% for an optimized, single intermediate band solar cell. This is higher than the efficiency of an optimized two junction solar cell. Using ion beam implantation and pulsed laser melting we have synthesized Zn{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys with x<0.03. These highly mismatched alloys have a unique electronic structure with a narrow oxygen-derived intermediate band. The width and the location of the band is described by the Band Anticrossing model and can be varied by controlling the oxygen content. This provides a unique opportunity to optimize the absorption of solar photons for best solar cell performance. We have carried out systematic studies of the effects of the intermediate band on the optical and electrical properties of Zn{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys. We observe an extension of the photovoltaic response towards lower photon energies, which is a clear indication of optical transitions from the valence to the intermediate band.

  8. Physical properties and analytical models of band-to-band tunneling in low-bandgap semiconductors

    SciTech Connect

    Shih, Chun-Hsing Dang Chien, Nguyen

    2014-01-28

    Low-bandgap semiconductors, such as InAs and InSb, are widely considered to be ideal for use in tunnel field-effect transistors to ensure sufficient on-current boosting at low voltages. This work elucidates the physical and mathematical considerations of applying conventional band-to-band tunneling models in low-bandgap semiconductors, and presents a new analytical alternative for practical use. The high-bandgap tunneling generates most at maximum field region with shortest tunnel path, whereas the low-bandgap generations occur dispersedly because of narrow tunnel barrier. The local electrical field associated with tunneling-electron numbers dominates in low-bandgap materials. This work proposes decoupled electric-field terms in the pre-exponential factor and exponential function of generation-rate expressions. Without fitting, the analytical results and approximated forms exhibit great agreements with the sophisticated forms both in high- and low-bandgap semiconductors. Neither nonlocal nor local field is appropriate to be used in numerical simulations for predicting the tunneling generations in a variety of low- and high-bandgap semiconductors.

  9. Fast, narrow-band computer model for radiation calculations

    SciTech Connect

    Yan, Z.; Holmstedt, G.

    1997-01-01

    A fast, narrow-band computer model, FASTNB, which predicts the radiation intensity in a general nonisothermal and nonhomogeneous combustion environment, has been developed. The spectral absorption coefficients of the combustion products, including carbon dioxide, water vapor, and soot, are calculated based on the narrow-band model. FASTNB provides an accurate calculation at reasonably high speed. Compared with Grosshandler`s narrow-band model, RADCAL, which has been verified quite extensively against experimental measurements, FASTNB is more than 20 times faster and gives almost exactly the same results.

  10. Soboba Band of Luiseno Indians - Strategic Tribal Energy Planning Project

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

    Tribal Energy Program Review Denver, CO November, 2 012 By: Erica Helms---Schenk, Environmental Director Soboba Energy Efficiency and ConservaKon Project Soboba Band of Luiseño Indians Soboba Band of Luiseño Indians Soboba Band of Luiseño Indians Our Champions - Who is Involved? Gerald Wilson Soboba Tribal Environmental & Brian McDonald - Department our SCE RepresentaKves Soboba Tribal Council IT --- Steven Nino Public Works - Ken McLaughlin and Summer Willis Project Goals and ObjecKves

  11. Agua Caliente Band of Cahuilla Indians- 2005 Project

    Energy.gov [DOE]

    The Agua Caliente Band of Cahuilla Indians will establish a comprehensive energy strategic plan that captures economic and environmental benefits while continuing to respect tribal cultural practices and traditions.

  12. Agua Caliente Band of Cahuilla Indians- 2012 Project

    Energy.gov [DOE]

    The Agua Caliente Band of Cahuilla Indians (ACBCI) plans to complete a feasibility study to evaluate a combined wind/solar power generation project on its Whitewater Ranch trust lands in southern California.

  13. Little River Band of Ottawa Indians- 2011 Project

    Energy.gov [DOE]

    he main purpose of this project is to increase human capacity of the Little River Band of Ottawa Indians (LRBOI) to understand the components of renewable energy and the importance of energy efficiency.

  14. Scotts Valley Band of Pomo Indians- 2010 Project

    Energy.gov [DOE]

    The Scotts Valley Band of Pomo Indians in Lakeport, California, will establish a Tribal Multi-County Weatherization Energy Program to provide training, outreach, and education on energy assistance and conservation to low-income families.

  15. Linear Scaling of the Exciton Binding Energy versus the Band...

    Office of Scientific and Technical Information (OSTI)

    Linear Scaling of the Exciton Binding Energy versus the Band Gap of Two-Dimensional Materials This content will become publicly available on August 6, 2016 Prev Next Title:...

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

    SciTech Connect

    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.

  17. An X-Band Gun Test Area at SLAC

    SciTech Connect

    Limborg-Deprey, C.; Adolphsen, C.; Chu, T.S.; Dunning, M.P.; Jobe, R.K.; Jongewaard, E.N.; Hast, C.; Vlieks, A.E.; Wang, F.; Walz, D.R.; Marsh, R.A.; Anderson, S.G.; Hartemann, F.V.; Houck, T.L.; /LLNL, Livermore

    2012-09-07

    The X-Band Test Area (XTA) is being assembled in the NLCTA tunnel at SLAC to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200 MV/m peak field X-band gun designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were developed in collaboration with LLNL since the same gun will be used in an injector for a LLNL Gamma-ray Source. Our beamline includes an X-band acceleration section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.

  18. Method for Creating Photonic Band Gap Materials - Energy Innovation Portal

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

    Method for Creating Photonic Band Gap Materials Ames Laboratory Contact AMES About This Technology Technology Marketing Summary Innovative microstructures that can direct light in a manner similar to the way semiconductors can influence electrons can be produced by creating what is termed a photonic band gap. These microstructures have the potential to change the way optoelectronic devices, such as photodiodes, LEDs, and integrated optical circuit elements, are designed and used. Ames Laboratory

  19. Radiative Heating in Underexplored Bands Campaign, Phase II

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

    Bands Campaign, Phase II From August to October 2009, a team of researchers from the United States and Italy are gathering in Chile to obtain precious climate data from the far reaches of Earth's atmosphere. Sponsored by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility, the second phase of the Radiative Heating in Underexplored Bands Campaign (RHUBC-II) takes place on Cerro Toco. This mountain rises from the Chajnantor Plateau in Chile's Atacama

  20. Ramona Band of Cahuilla Mission Indians- 2002 Project

    Energy.gov [DOE]

    The Ramona Band of Cahuilla Mission Indians ("Ramona Band" or "tribe") will be the first tribe to develop its entire reservation off-grid, using renewable energy as the primary power source. The tribe will purchase and install the primary components for a 65-80 kilowatt-hours per day central wind/PV/propane generator hybrid system that will power the reservation's housing, offices, ecotourism, and training businesses. The electricity is planned to be distributed through an underground mini-grid.

  1. Band Excitation Method Applicable to Scanning Probe Microscopy - Energy

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

    Innovation Portal Analysis Energy Analysis Find More Like This Return to Search Band Excitation Method Applicable to Scanning Probe Microscopy Oak Ridge National Laboratory Contact ORNL About This Technology Technology Marketing SummaryUsing adaptive band excitation, ORNL researchers invented new scanning probe microscopy (SPM) techniques that offer improved data acquisition, processing, and control. These techniques enable researchers to carry out functional imaging and manipulation down to

  2. Interface band structure engineering by ferroelectric polarization in

    Office of Scientific and Technical Information (OSTI)

    perovskite solar cells (Journal Article) | DOE PAGES Interface band structure engineering by ferroelectric polarization in perovskite solar cells Title: Interface band structure engineering by ferroelectric polarization in perovskite solar cells Authors: Chen, Bo ; Zheng, Xiaojia ; Yang, Mengjin ; Zhou, Yuan ; Kundu, Souvik ; Shi, Jian ; Zhu, Kai ; Priya, Shashank Publication Date: 2015-04-01 OSTI Identifier: 1252091 Grant/Contract Number: AC36-08-GO28308; FOA-0000990 Type: Publisher's

  3. Battle Mountain Band - Te-Moak: Solar Energy Park

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

    Battle Mountain Band - Te-Moak Chairman Joseph Holley and Vice-chairman Mark Oppenhein, Members Donna Hill, Delbert Holley, Lydia Johnson, and Lydell Oppenhein Solar Energy Park DOE/Te-Moak Grant EE0005632 Tribal Energy Program Review March 26, 2014 Presented By: Brenda Gilbert Program Manager 775-345-5261 Brenda@becnv.com Donna Hill Project Manager Battle Mountain Band 775-635-2004 coordinatorbmbc@hotmail.com Joe Bourg Chief Executive Officer Millennium Energy, LLC 303-526-2972

  4. AN H-BAND SPECTROSCOPIC METALLICITY CALIBRATION FOR M DWARFS

    SciTech Connect

    Terrien, Ryan C.; Mahadevan, Suvrath; Bender, Chad F.; Deshpande, Rohit; Ramsey, Lawrence W.; Bochanski, John J., E-mail: rct151@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2012-03-10

    We present an empirical near-infrared (NIR) spectroscopic method for estimating M dwarf metallicities, based on features in the H band, as well as an implementation of a similar published method in the K band. We obtained R {approx} 2000 NIR spectra of a sample of M dwarfs using the NASA IRTF-SpeX spectrograph, including 22 M dwarf metallicity calibration targets that have FGK companions with known metallicities. The H-band and K-band calibrations provide equivalent fits to the metallicities of these binaries, with an accuracy of {+-}0.12 dex. We derive the first empirically calibrated spectroscopic metallicity estimate for the giant planet-hosting M dwarf GJ 317, confirming its supersolar metallicity. Combining this result with observations of eight other M dwarf planet hosts, we find that M dwarfs with giant planets are preferentially metal-rich compared to those that host less massive planets. Our H-band calibration relies on strongly metallicity-dependent features in the H band, which will be useful in compositional studies using mid- to high-resolution NIR M dwarf spectra, such as those produced by multiplexed surveys like SDSS-III APOGEE. These results will also be immediately useful for ongoing spectroscopic surveys of M dwarfs.

  5. Evaluation of stress experienced by soldiers wearing chemical protective clothing during varying work loads in desert or tropical environments. Final report

    SciTech Connect

    Hudgens, G.A.; Banderet, L.E.; Cadarette, B.S.

    1994-04-01

    A stress evaluation was conducted in a laboratory test in which the physiological and psychological reactions of soldiers were monitored while they wore either the standard battle dress overgarment (MOPPI) or the full complement of chemical protective clothing with mask (MOPPIV) and worked at low, moderate, or high work loads in simulated desert (hot and dry) or tropic (hot and humid) environments. The psychological instruments indicated greater stress responses for soldiers wearing MOPPIV than wearing MOPPI and for soldiers working at a high work load than working at a low work load. Chemical protective clothing, MOPPIV, Tropics, Desert, Psychological stress, Work load, MOPPI, Stress evaluation.

  6. C-Band Scanning ARM Precipitation Radar (C-SAPR) Handbook (Technical...

    Office of Scientific and Technical Information (OSTI)

    C-Band Scanning ARM Precipitation Radar (C-SAPR) Handbook Citation Details In-Document Search Title: C-Band Scanning ARM Precipitation Radar (C-SAPR) Handbook The C-band scanning ...

  7. Table of superdeformed nuclear bands and fission isomers

    SciTech Connect

    Firestone, R.B.; Singh, B.

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in {sup 152}Dy was predicted for {beta}{sub 2}-0.65. Subsequently, a discrete set of {gamma}-ray transitions in {sup 152}DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of {gamma}-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra.

  8. A Calibrated Maxey-Eakin Curve for the Fenner Basin of the Eastern Mojave Desert, California

    SciTech Connect

    Davisson, M.L.; Rose, T.P.

    2000-05-15

    Metropolitan Water District (MWD) of southern California and Cadiz Inc. investigated the feasibility of storing Colorado River water in groundwater aquifers of the eastern Mojave Desert as a future drought mitigation strategy. This culminated in the public release of the Cadiz Groundwater Storage and Dry-Year Supply program Draft EIR, which included pilot percolation studies, groundwater modeling, and precipitation/runoff analysis in the Fenner groundwater basin, which overlies the proposed storage site. The project proposes to store and withdrawal Colorado River water over a 50-year period, but will not exceed the natural replenishment rates of the groundwater basin. Several independent analyses were conducted to estimate the rates of natural groundwater replenishment to the Fenner Groundwater Basin, which was included in the Draft EIR. The US Geologic Survey, Water Resources Division (WRD) officially submitted comments during public review and concluded that the natural groundwater replenishment rates calculated for the Draft EIR were too high. In the WRD review, they provided a much lower recharge calculation based on a Maxey-Eakin estimation approach. This approach estimates annual precipitation over an entire basin as a function of elevation, followed by calibration against annual recharge rates. Recharge rates are estimated on the basis that some fraction of annual precipitation will recharge, and that fraction will increase with increasing elevation. This results in a hypothetical curve relating annual groundwater recharge to annual precipitation. Field validation of recharge rates is critical in order to establish credibility to any estimate. This is due to the fact that the Maxey-Eakin model is empirical. An empirical model is derived from practical experience rather than basic theory. Therefore, a validated Maxey-Eakin model in one groundwater basin does not translate to a different one. In the WRD's Maxey-Eakin model, they used a curve calibrated against

  9. ARBUSCULAR MYCORRHIZAL COLONIZATION OF LARREA TRIDENTATA AND AMBROSIA DUMOSA ROOTS VARIES WITH PRECIPITATION AND SEASON IN THE MOJAVE DESERT

    SciTech Connect

    M. E. APPLE; C. I. THEE; V. L. SMITH-LONGOZO; C. R. COGAR; C. E. WELLS; R. S. NOWAK

    2004-01-01

    The percentage of fine roots colonized by arbuscular mycorrhizal (AM) fungi varied with season and with species in the co-dominant shrubs Lurreu tridentutu and Ambrosia dumosu at a site adjacent to the Nevada Desert FACE (Free-Air CO{sub 2} Enrichment) Facility (NDFF) in the Mojave Desert. We excavated downward and outward from the shrub bases in both species to collect and examine fine roots (< 1.0 mm diameter) at monthly intervals throughout 2001 and from October 2002 to September 2003. Fungal structures became visible in cleared roots stained with trypan blue. We quantified the percent colonization of roots by AM fungi via the line intercept method. In both years and for both species, colonization was highest in fall, relatively low in spring when root growth began, increased in late spring, and decreased during summer drought periods. Increases in colonization during summer and fall reflect corresponding increases in precipitation. Spring mycorrhizal colonization is low despite peaks in soil water availability and precipitation, indicating that precipitation is not the only factor influencing mycorrhizal colonization. Because the spring decrease in mycorrhizal colonization occurs when these shrubs initiate a major flush of fine root growth, other phenological events such as competing demands for carbon by fine root initiation, early season shoot growth, and flowering may reduce carbon availability to the fungus, and hence decrease colonization. Another possibility is that root growth exceeds the rate of mycorrhizal colonization.

  10. Oxygen isotope variability within Nautilus shell growth bands

    DOE PAGES [OSTI]

    Linzmeier, Benjamin J.; Kozdon, Reinhard; Peters, Shanan E.; Valley, John W.

    2016-04-21

    Nautilus is often used as an analogue for the ecology and behavior of extinct externally shelled cephalopods. Nautilus shell grows quickly, has internal growth banding, and is widely believed to precipitate aragonite in oxygen isotope equilibrium with seawater. Pieces of shell from a wild-caught Nautilus macromphalus from New Caledonia and from a Nautilus belauensis reared in an aquarium were cast in epoxy, polished, and then imaged. Growth bands were visible in the outer prismatic layer of both shells. The thicknesses of the bands are consistent with previously reported daily growth rates measured in aquarium reared individuals. In situ analysis ofmore » oxygen isotope ratios using secondary ion mass spectrometry (SIMS) with 10 μm beam-spot size reveals inter- and intra-band δ18O variation. In the wild-caught sample, a traverse crosscutting 45 growth bands yielded δ18O values ranging 2.5‰, from +0.9 to -1.6 ‰ (VPDB), a range that is larger than that observed in many serial sampling of entire shells by conventional methods. The maximum range within a single band (~32 μm) was 1.5‰, and 27 out of 41 bands had a range larger than instrumental precision (±2 SD = 0.6‰). The results from the wild individual suggest depth migration is recorded by the shell, but are not consistent with a simple sinusoidal, diurnal depth change pattern. In addition, to create the observed range of δ18O, however, this Nautilus must have traversed a temperature gradient of at least ~12°C, corresponding to approximately 400 m depth change. Isotopic variation was also measured in the aquarium-reared sample, but the pattern within and between bands likely reflects evaporative enrichment arising from a weekly cycle of refill and replacement of the aquarium water. Overall, this work suggests that depth migration behavior in ancient nektonic mollusks could be elucidated by SIMS analysis across individual growth bands.« less

  11. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Calibration Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Calibration Authors: Dan Nelson ; ...

  12. Fond du Lac Band Leads Climate Resilience Efforts on Lake Superior...

    Energy Saver

    Fond du Lac Band Leads Climate Resilience Efforts on Lake Superior Chippewa Indian Reservation Fond du Lac Band Leads Climate Resilience Efforts on Lake Superior Chippewa Indian ...

  13. Topological system with a twisting edge band: A position-dependent...

    Office of Scientific and Technical Information (OSTI)

    Topological system with a twisting edge band: A position-dependent Hall resistance Citation Details In-Document Search Title: Topological system with a twisting edge band: A ...

  14. Little River Band of Ottawa Indians … First Steps to Human Capacity...

    Energy.gov [DOE] (indexed site)

    Little River Band of Ottawa Indians Melissa Waitner, GPC Grant Writer 375 River Street Manistee, Michigan 49660 mwaitner@lrboi.com The Little River Band of Ottawa Indians ...

  15. The Origin of Lueders's Bands in Deformed Rock

    SciTech Connect

    Olsson, W.A.

    1999-03-31

    Lueders' bands are shear deformation features commonly observed in rock specimens that have been deformed experimentally in the brittle-ductile transition regime. For specimens that contain both faults (shear fractures that separate the specimen) and bands, the bands form earlier in the deformation history and their orientations are often different from the fault These differences pose the question of the relationship between these two structures. Understanding the origin of these features may shed light on the genesis of apparent natural analogues, and on the general process of rock deformation and fracture in the laboratory. This paper presents a hypothesis for the formation of Lueders' bands in laboratory specimens based on deformation localization theory considered in the context of the nonuniform stress distribution of the conventional triaxial experiment Lueders' bands and faults appear to be equivalent reflections of the localization process as it is controlled by nonuniform distributions of stress and evolution of incremental constitutive parameters resulting from increasing damage. To relate conditions for localization in laboratory specimens to natural settings, it will be necessary to design new experiments that create uniform stress and deformation fields, or to extract constitutive data indirectly from standard experiments using computational means.

  16. Blocked impurity band hybrid infrared focal plane arrays for astronomy

    SciTech Connect

    Reynolds, D.B.; Seib, D.H.; Stetson, S.B.; Herter, T.; Rowlands, N.; Schoenwald, J.

    1989-02-01

    High-performance infrared hybrid focal plane arrays using 10 x 50 element Si:As Blocked-Impurity-Band (BIB) detectors (cut-off wavelength = 28 ..mu..m) and matching switched MOSFET multiplexers have been developed and characterized for space astronomy. Use of impurity band conduction technology provides detectors which are nuclear radiation hard and free of the many anomalies associated with conventional silicon photoconductive detectors. Emphasis in this paper is on recent advances in detector material quality which have led to significantly improved detector and hybrid characteristics. Results demonstrating increase quantum efficiency (particular at short wavelength infrared), obtained by varying the Blocked-Impurity-Band detector properties (infrared active layer thickness and arsenic doping profile), are summarized. Read noise and dark current for different temperatures have been measured and are also described. The hybrid array performance achieved clearly demonstrates that BIB detectors are well suited for use in astronomical instrumentation.

  17. Amorphous copper tungsten oxide with tunable band gaps

    SciTech Connect

    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.

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

    DOE PAGES [OSTI]

    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

  19. Robotic end gripper with a band member to engage object

    DOEpatents

    Pollard, R.E.; Robinson, S.C.; Thompson, W.F.; Couture, S.A.; Sutton, B.J.

    1994-05-10

    An end effector for use with robotic arms and like devices is described that utilizes a flexible band to draw an object against an anvil having a concave surface. One typical convex surface is created by a V-block, with an apex of the V being centrally located. If an object to be grasped is fragile, the contour of the concave surface closely matches the surface of the object. Typically the movement of the band is effected by a linear actuator, with the anvil remaining fixed relative to a support base. Several embodiments are described that utilize variations in drawing the band toward the anvil, with one of these embodiments described in detail in the form of a fabricated unit. One embodiment includes a cover element that can be moved over an object after the grasping thereof, with this cover potentially serving various functions. Movement of the cover can be effected with a second linear actuator. 8 figures.

  20. Numerical method for shear bands in ductile metal with inclusions

    SciTech Connect

    Plohr, Jee Yeon N [Los Alamos National Laboratory; Plohr, Bradley J [Los Alamos National Laboratory

    2010-01-01

    A numerical method for mesoscale simulation of high strain-rate loading of ductile metal containing inclusions is described. Because of small-scale inhomogeneities, such a composite material is prone to localized shear deformation (adiabatic shear bands). The modeling framework is the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. /27-139, 1992], which ensures that the micromechanical response of the material is reflected in the behavior of the composite at the mesoscale. To calculate the effective plastic strain rate when shear bands are present, the analytic and numerical analysis of shear bands by Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31-41, 1996] is adapted and extended.

  1. Robotic end gripper with a band member to engage object

    DOEpatents

    Pollard, Roy E.; Robinson, Samuel C.; Thompson, William F.; Couture, Scott A.; Sutton, Bill J.

    1994-01-01

    An end effector for use with robotic arms and like devices that utilizes a flexible band to draw an object against an anvil having a concave surface. One typical convex surface is created by a V-block, with an apex of the V being centrally located. If an object to be grasped is fragile, the contour of the concave surface closely matches the surface of the object. Typically the movement of the band is effected by a linear actuator, with the anvil remaining fixed relative to a support base. Several embodiments are described that utilize variations in drawing the band toward the anvil, with one of these embodiments described in detail in the form of a fabricated unit. One embodiment includes a cover element that can be moved over an object after the grasping thereof, with this cover potentially serving various functions. Movement of the cover can be effected with a second linear actuator.

  2. Draft Genome Sequence of Streptomyces sp. Strain Wb2n-11, a Desert Isolate with Broad-Spectrum Antagonism against Soilborne Phytopathogens

    DOE PAGES [OSTI]

    Köberl, Martina; White, Richard A.; Erschen, Sabine; El-Arabi, Tarek F.; Jansson, Janet K.; Berg, Gabriele

    2015-08-06

    Streptomyces sp. strain Wb2n-11, isolated from native desert soil, exhibited broad-spectrum antagonism against plant pathogenic fungi, bacteria, and nematodes. The 8.2-Mb draft genome reveals genes putatively responsible for its promising biocontrol activity and genes which enable the soil bacterium to directly interact beneficially with plants.

  3. Draft Genome Sequence of Streptomyces sp. Strain Wb2n-11, a Desert Isolate with Broad-Spectrum Antagonism against Soilborne Phytopathogens

    SciTech Connect

    Köberl, Martina; White, Richard A.; Erschen, Sabine; El-Arabi, Tarek F.; Jansson, Janet K.; Berg, Gabriele

    2015-08-06

    Streptomyces sp. strain Wb2n-11, isolated from native desert soil, exhibited broad-spectrum antagonism against plant pathogenic fungi, bacteria, and nematodes. The 8.2-Mb draft genome reveals genes putatively responsible for its promising biocontrol activity and genes which enable the soil bacterium to directly interact beneficially with plants.

  4. Draft genome sequence of Streptomyces sp. strain Wb2n-11, a desert isolate with broad-spectrum antagonism against soilborne phytopathogens

    SciTech Connect

    Koeberl, Martina; White, Richard A.; Erschen, Sabine; El-Arabi, Tarek F.; Jansson, Janet K.; Berg, Gabriele

    2015-08-06

    Streptomyces sp. strain Wb2n-11, isolated from native desert soil, exhibited broad-spectrum antagonism against plant pathogenic fungi, bacteria and nematodes. The 8.2 Mb draft genome reveals genes putatively responsible for its promising biocontrol activity and genes which enable the soil bacterium to directly interact beneficially with plants.

  5. Structure of dipole bands in {sup 106}In

    SciTech Connect

    Deo, A. Y.; Palit, R.; Naik, Z.; Joshi, P. K.; Mazumdar, I.; Sihotra, S.; Mehta, D.; Kumar, S.; Chakrabarti, R.; Kshetri, R.

    2009-06-15

    High spin states in neutron-deficient {sup 106}In were investigated using {sup 78}Se({sup 32}S,p3n) reaction at 125 MeV. The level scheme is extended up to 7 MeV of excitation energy for the negative parity states constituting four dipole bands, and the positive parity states which mainly exhibit single-particle excitations are extended up to 5 MeV. Projected deformed Hartree-Fock calculations were carried out to understand the configurations of different bands in this nucleus.

  6. Cabazon Band of Mission Indians Strategic Energy Plan Presentation

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

    Cabazon Band of Mission Indians Strategic Energy Plan Presentation Prepared by Philip Rentz 11/1/2004 2 Developed for the Cabazon Band of Mission Indians (CBMI) In Cooperation With The Department of Energy 11/1/2004 3 Site Location Maps 11/1/2004 4 Tribal Land 11/1/2004 5 Fantasy Springs Resort and Casino 11/1/2004 6 Cabazon Resource Recovery Park 11/1/2004 7 Organizational Chart 11/1/2004 8 Vision Statement The primary objective of the Strategic energy Plan is to aide in the social and economic

  7. Electronic band structure of magnetic bilayer graphene superlattices

    SciTech Connect

    Pham, C. Huy; Nguyen, T. Thuong

    2014-09-28

    Electronic band structure of the bilayer graphene superlattices with ?-function magnetic barriers and zero average magnetic flux is studied within the four-band continuum model, using the transfer matrix method. The periodic magnetic potential effects on the zero-energy touching point between the lowest conduction and the highest valence minibands of pristine bilayer graphene are exactly analyzed. Magnetic potential is shown also to generate the finite-energy touching points between higher minibands at the edges of Brillouin zone. The positions of these points and the related dispersions are determined in the case of symmetric potentials.

  8. Soboba Band of Luiseno Indians - 2011 Project | Department of Energy

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

    Luiseno Indians - 2011 Project Soboba Band of Luiseno Indians - 2011 Project Summary The Soboba Band of Luiseno Indians would like to begin to focus on renewable sources for electricity and to actively target lowering the energy usage of the community. Based on a past U.S. Department of Energy (DOE)-funded study, it was decided that the tribe would aim to achieve a 5% reduction in energy each year over a five-year period. This would be a total reduction of 25% of the 2009 baseline energy data

  9. Ultra high vacuum broad band high power microwave window

    DOEpatents

    Nguyen-Tuong, Viet; Dylla, III, Henry Frederick

    1997-01-01

    An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost.

  10. Ultra high vacuum broad band high power microwave window

    DOEpatents

    Nguyen-Tuong, V.; Dylla, H.F. III

    1997-11-04

    An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost. 5 figs.

  11. Special purpose modes in photonic band gap fibers

    DOEpatents

    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.

  12. ARM - Field Campaign - Radiative Heating in Underexplored Bands Campaign

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

    (RHUBC) govCampaignsRadiative Heating in Underexplored Bands Campaign (RHUBC) Campaign Links RHUBC Website ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Radiative Heating in Underexplored Bands Campaign (RHUBC) 2007.02.22 - 2007.03.14 Website : http://www.arm.gov/campaigns/rhubc/ Lead Scientist : David Turner For data sets, see below. Abstract Radiative cooling and heating in the mid-to-upper

  13. Center for Inverse Design: Modality 1 - Inverse Band Structure

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

    1: Inverse Band Structure Modality 1 applies to cases where we have a single material system, but an astronomical number of configurations, and where the target properties can be calculated on the fly. The approach is also called Inverse Band Structure (IBS). The IBS approach began a dozen years ago within the Solid-State Theory group at the National Renewable Energy Laboratory (NREL), under support from the U.S. Department of Energy's Office of Basic Energy Sciences. Imagine that you have a

  14. Energy distribution of nonequilibrium electrons and optical phonons in GaAs under band-to-band pumping by intense short pulses of light

    SciTech Connect

    Altybaev, G. S.; Kumekov, S. E. Mahmudov, A. A.

    2009-03-15

    Deviation from the Fermi distribution of nonequilibrium electrons and distribution of 'hot' optical phonons in GaAs under band-to-band pumping by picosecond pulses of light are calculated.

  15. Project Reports for Cabazon Band of Mission Indians- 2011 Project

    Energy.gov [DOE]

    The Cabazon Band of Mission Indians' long-range goals are to become energy self-sufficient, foster economic diversity, grow jobs, and improve the well-being of members of the tribe as well as those in its region of Southern California.

  16. Quantum interference of independently generated telecom-band single photons

    SciTech Connect

    Patel, Monika; Altepeter, Joseph B.; Huang, Yu-Ping; Oza, Neal N.; Kumar, Prem

    2014-12-04

    We report on high-visibility quantum interference of independently generated telecom O-band (1310 nm) single photons using standard single-mode fibers. The experimental data are shown to agree well with the results of simulations using a comprehensive quantum multimode theory without the need for any fitting parameter.

  17. Modeling Multi-Bunch X-band Photoinjector Challenges

    SciTech Connect

    Marsh, R A; Anderson, S G; Gibson, D J; Barty, C J

    2012-05-09

    An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. Of critical import to the functioning of the LLNL X-band system with multiple electron bunches is the performance of the photoinjector. In depth modeling of the Mark 1 LLNL/SLAC X-band rf photoinjector performance will be presented addressing important challenges that must be addressed in order to fabricate a multi-bunch Mark 2 photoinjector. Emittance performance is evaluated under different nominal electron bunch parameters using electrostatic codes such as PARMELA. Wake potential is analyzed using electromagnetic time domain simulations using the ACE3P code T3P. Plans for multi-bunch experiments and implementation of photoinjector advances for the Mark 2 design will also be discussed.

  18. Agua Caliente Band of Cahuilla Indians- 2015 Project

    Energy.gov [DOE]

    The Agua Caliente Band of Cahuilla Indians is seeking to install a 76.9-kilowatt (kW) solar photovoltaic (PV) system to offset the energy costs of the Tribal Education and Family Services offices located at the Heritage Plaza office building.

  19. Grand Traverse Band of Ottawa and Chippewa Indians- 2005 Project

    Energy.gov [DOE]

    The Grand Traverse Band of Ottawa and Chippewa Indians (GTB) will conduct a feasibility study to determine the cost effectiveness and other economic, environmental, cultural, and social benefits of maximizing the diversity of energy sources used at GTB facilities. This includes an assessment of energy conservation measures as well as renewable energy sources such as wind, solar, and biomass.

  20. Mesa Grande Band of Mission Indians- 2004 Project

    Energy.gov [DOE]

    The Mesa Grande Band of Mission Indians, located in northern San Diego County, will conduct a study of the feasibility of reducing air pollution generated on the reservation by an over-reliance on wood-burning stoves, kerosene heaters, and gasoline generators, and to identify the types of renewable energy systems that could be used for residential structures and well-pump systems.

  1. Evidence for hybrid surface metallic band in (4??4) silicene on Ag(111)

    SciTech Connect

    Tsoutsou, D. Xenogiannopoulou, E.; Golias, E.; Tsipas, P.; Dimoulas, A.

    2013-12-02

    The electronic band structure of monolayer (4??4) silicene on Ag(111) is imaged by angle resolved photoelectron spectroscopy. A dominant hybrid surface metallic band is observed to be located near the bulk Ag sp-band which is also faintly visible. The two-dimensional character of the hybrid band has been distinguished against the bulk character of the Ag(111) sp-band by means of photon energy dependence experiments. The surface band exhibits a steep linear dispersion around the K{sup }{sub Ag} point and has a saddle point near the M{sup }{sub Ag} point of Ag(111) resembling the ?-band dispersion in graphene.

  2. David Blackwell’s Forty Years in the Idaho Desert, The Foundation for 21st Century Geothermal Research

    SciTech Connect

    McLing, Travis; McCurry, Mike; Cannon, Cody; Neupane, Ghanashyam; Wood, Thomas; Podgorney, Robert; Welhan, John; Mines, Greg; Mattson, Earl; Wood, Rachel; Palmer, Carl

    2015-04-01

    Dr. David Blackwell has had a profound influence on geo-thermal exploration and R&D in Idaho. Forty years have elapsed since the first Southern Methodist University (SMU) temperature logging truck rolled onto the high desert in Southern Idaho, yet even after so much time has elapsed, most recent and ongoing geothermal R&D can trace its roots to the foundational temperature studies led by Dr. Blackwell. We believe that the best way to honor any scientist is to see their work carried forward by others. As this paper demonstrates, it has been an easy task to find a host of Idaho researchers and students eager to contribute to this tribute paper. We organize this paper by ongoing or recent projects that continue to benefit left to Idaho by Dr. David Blackwell.

  3. [Climate implications of terrestrial paleoclimate]. Quaternary Sciences Center, Desert Research Institute annual report, fiscal year 1994/1995

    SciTech Connect

    Wigand, P.E.

    1995-12-31

    The objective of this study is to collect terrestrial climate indicators for paleoclimate synthesis. The paleobiotic and geomorphic records are being examined for the local and regional impact of past climates to assess Yucca Mountain`s suitability as a high-level nuclear waste repository. In particular these data are being used to provide estimates of the timing, duration and extremes of past periods of moister climate for use in hydrological models of local and regional recharge that are being formulated by USGS and other hydrologists for the Yucca Mountain area. The project includes botanical, faunal, and geomorphic components that will be integrated to accomplish this goal. To this end personnel at the Quaternary Sciences Center of the Desert Research Institute in Reno, Nevada are conducting the following activities: Analyses of packrat middens; Analysis of pollen samples; and Determination of vegetation climate relationships.

  4. Parallel preconditioning for the solution of nonsymmetric banded linear systems

    SciTech Connect

    Amodio, P.; Mazzia, F.

    1994-12-31

    Many computational techniques require the solution of banded linear systems. Common examples derive from the solution of partial differential equations and of boundary value problems. In particular the authors are interested in the parallel solution of block Hessemberg linear systems Gx = f, arising from the solution of ordinary differential equations by means of boundary value methods (BVMs), even if the considered preconditioning may be applied to any block banded linear system. BVMs have been extensively investigated in the last few years and their stability properties give promising results. A new class of BVMs called Reverse Adams, which are BV-A-stable for orders up to 6, and BV-A{sub 0}-stable for orders up to 9, have been studied.

  5. Broad-band characteristics of circular button pickups

    SciTech Connect

    Barry, W.C.

    1992-10-01

    A broad-band.theory of the circular button pickup is presented. Expressions for the longitudinal and transverse transfer impedance of a pair of such pickups are derived in the frequency domain. The broad-band expressions are shown to reduce to the standard electrostatic transfer functions for wavelengths large compared to the button diameter. The theory is shown to be in reasonable agreement with measurements performed on standard LEP button electrodes. In particular, the theory explains a resonance in the response of the LEP buttons which made them unsuitable, in standard form, for their intended application as pickups in the LBL Advanced Light Source feedback system. The buttons were modified to suppress the resonance and subsequently incorporated into the feedback system.

  6. ARM - Radiative Heating in Underexplored Bands Campaign (RHUBC)

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

    Related Links RHUBC Home NSA Home ARM Data Discovery Browse Data Experiment Planning RHUBC Proposal Abstract Full Proposal (pdf, 420kb) Science Plan (pdf) Operations Plan (pdf, 144kb) Instruments Contacts News ARM Press Release (Feb. 26, 2007) Images flickr_dots Radiative Heating in Underexplored Bands Campaign (RHUBC) Now available: RHUBC-II website Between February and March 2007 at the ACRF North Slope of Alaska site in Barrow, high-spectral-resolution observations were collected by two

  7. Lac Courte Oreilles Band of Lake Superior Ojibwe

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

    Oreilles Band of Lake Superior Ojibwe Leslie Isham, Director/Assistant Director Lac Courte Oreilles Energy Project Lac Courte Oreilles Public works Department First Steps towards Tribal Weatherization Assessing the Feasibility of the Hydro Dam About Lac Courte Oreilles (LCO) * Located in Upper Northwest Wisconsin * 76,000 acres and 15 miles wide * 90 miles from Duluth 100 miles from Eau Claire 10 miles from Hayward * Close to 6,000 members, 50% live on or near the reservation * 68% unemployment

  8. Lac Courte Oreilles Lake Superior Band of Ojibwe Energy Projects

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

    OdaawaaZaga'iganing or Lac Courte Oreilles Lake Superior Band Of Ojibwe LCO Energy Department Staff: Director: Leslie Isham Coordinator: Denise Johnson Energy Projects: Assessing Hydro Dam First Steps Toward Tribal Weatherization Lac Courte Oreilles's Mission We, the Anishinaabeg, the people of OdaawaaZaaga'iganing, the Lac Courte Oreilles Tribe, will sustain our heritage by preserving our past, strengthening our present and embracing our future. We will defend our inherent sovereign rights and

  9. Project Reports for Manzanita Band of Mission Indians- 2002 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Manzanita Band of Mission Indians ("the tribe") has long recognized that its reservation has an abundant wind resource that could be commercially utilized to its benefit. The tribe is now investigating the feasibility of commercial scale development of a wind power project on tribal lands. The proposed project is a joint effort between the tribe and its subcontractor and consultant, SeaWest Consulting.

  10. Red Lake Band of Chippewa Indians- 2003 Project

    Energy.gov [DOE]

    The Red Lake Band of Chippewa Indians, located in the northwest corner of Minnesota near the Canadian border, will assess the potential to expand the use of biomass resources for energy autonomy and economic development on tribal lands. Specifically, the tribe will evaluate the technical, market, financial, and cultural aspects of using its extensive, forested lands to create a sustainable bioproducts-based business and will develop a business plan to guide tribal industry development.

  11. Wide band focusing x-ray spectrograph with spatial resolution

    SciTech Connect

    Pikuz, S. A.; Douglass, J. D.; Shelkovenko, T. A.; Sinars, D. B.; Hammer, D. A.

    2008-01-15

    A new, wide spectral bandwidth x-ray spectrograph, the wide-bandwidth focusing spectrograph with spatial resolution (WB-FSSR), based on spherically bent mica crystals, is described. The wide bandwidth is achieved by combining three crystals to form a large aperture dispersive element. Since the WB-FSSR covers a wide spectral band, it is very convenient for application as a routine diagnostic tool in experiments in which the desired spectral coverage is different from one test to the next. The WB-FSSR has been tested in imploding wire-array experiments on a 1 MA pulsed power machine, and x-ray spectra were recorded in the 1-20 A spectral band using different orders of mica crystal reflection. Using a two mirror-symmetrically placed WB-FSSR configuration, it was also possible to distinguish between a real spectral shift and a shift of recorded spectral lines caused by the spatial distribution of the radiating plasma. A spectral resolution of about 2000 was demonstrated and a spatial resolution of {approx}100 {mu}m was achieved in the spectral band of 5-10 A in second order of mica reflection. A simple method of numerical analysis of spectrograph capability is proposed.

  12. Ultrafast band engineering and transient spin currents in antiferromagnetic oxides

    DOE PAGES [OSTI]

    Gu, Mingqiang; Rondinelli, James M.

    2016-04-29

    Here, we report a dynamic structure and band engineering strategy with experimental protocols to induce indirect-to-direct band gap transitions and coherently oscillating pure spin-currents in three-dimensional antiferromagnets (AFM) using selective phononic excitations. In the Mott insulator LaTiO3, we show that a photo-induced nonequilibrium phonon mode amplitude destroys the spin and orbitally degenerate ground state, reduces the band gap by 160 meV and renormalizes the carrier masses. The time scale of this process is a few hundreds of femtoseconds. Then in the hole-doped correlated metallic titanate, we show how pure spin-currents can be achieved to yield spin-polarizations exceeding those observed inmore » classic semiconductors. Last, we demonstrate the generality of the approach by applying it to the non-orbitally degenerate AFM CaMnO3. These results advance our understanding of electron-lattice interactions in structures out-of-equilibrium and establish a rational framework for designing dynamic phases that may be exploited in ultrafast optoelectronic and optospintronic devices.« less

  13. X-band photoinjector for a chirped-pulse FEL

    SciTech Connect

    Landahl, E. C.; Alvis, R. M.; Troha, A. L.; Hartemann, F. V.; Baldis, H. A. [Applied Science Department, University of California, Davis California 95616 (United States); Institute for Laser Science and Applications, LLNL, Livermore, California 94550 (United States); Le Sage, G. P.; White, W. E. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bennett, C. V. [Electrical Engineering Department, University of California, Los Angeles, California 90024 (United States); Li, K.; Heritage, J. P. [Electrical and Computer Engineering Department, University of California, Davis, California (United States); Ho, C. H. [Synchrotron Radiation Research Center, Taiwan (China); Luhmann, N. C. Jr. [Applied Science Department, University of California, Davis California 95616 (United States)

    1999-05-07

    The phase noise and jitter characteristics of the laser and rf systems of a high gradient X-band photoinjector have been measured experimentally. The laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a rf oscillator such as a magnetron or a compact source such as a cross-field amplifier. In particular, the rf gun can play the role of a pulsed rf clock to synchronize the photocathode laser system: direct drive of a synchronously modelocked AlGaAs quantum well laser has been achieved using the X-band gun rf fields. This novel, GHz repetition rate, laser system is being developed to replace the more conventional femtosecond Ti:Al{sub 2}O{sub 3} system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported.

  14. X-band photoinjector for a chirped-pulse FEL

    SciTech Connect

    Landahl, E.C.; Alvis, R.M.; Troha, A.L.; Hartemann, F.V.; Baldis, H.A.; Luhmann, N.C. Jr. [Applied Science Department, University of California, Davis , California 95616 (United States); Landahl, E.C.; Alvis, R.M.; Troha, A.L.; Hartemann, F.V.; Baldis, H.A. [Institute for Laser Science and Applications, LLNL, Livermore, California 94550 (United States); Le Sage, G.P.; White, W.E. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bennett, C.V. [Electrical Engineering Department, University of California, Los Angeles, California 90024 (United States); Li, K.; Heritage, J.P. [Electrical and Computer Engineering Department, University of California, Davis, California (United States); Ho, C.H. [Synchrotron Radiation Research Center (Taiwan)

    1999-05-01

    The phase noise and jitter characteristics of the laser and rf systems of a high gradient X-band photoinjector have been measured experimentally. The laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a rf oscillator such as a magnetron or a compact source such as a cross-field amplifier. In particular, the rf gun can play the role of a pulsed rf clock to synchronize the photocathode laser system: direct drive of a synchronously modelocked AlGaAs quantum well laser has been achieved using the X-band gun rf fields. This novel, GHz repetition rate, laser system is being developed to replace the more conventional femtosecond Ti:Al{sub 2}O{sub 3} system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported. {copyright} {ital 1999 American Institute of Physics.}

  15. Performance Models for the Spike Banded Linear System Solver

    DOE PAGES [OSTI]

    Manguoglu, Murat; Saied, Faisal; Sameh, Ahmed; Grama, Ananth

    2011-01-01

    With availability of large-scale parallel platforms comprised of tens-of-thousands of processors and beyond, there is significant impetus for the development of scalable parallel sparse linear system solvers and preconditioners. An integral part of this design process is the development of performance models capable of predicting performance and providing accurate cost models for the solvers and preconditioners. There has been some work in the past on characterizing performance of the iterative solvers themselves. In this paper, we investigate the problem of characterizing performance and scalability of banded preconditioners. Recent work has demonstrated the superior convergence properties and robustness of banded preconditioners,more » compared to state-of-the-art ILU family of preconditioners as well as algebraic multigrid preconditioners. Furthermore, when used in conjunction with efficient banded solvers, banded preconditioners are capable of significantly faster time-to-solution. Our banded solver, the Truncated Spike algorithm is specifically designed for parallel performance and tolerance to deep memory hierarchies. Its regular structure is also highly amenable to accurate performance characterization. Using these characteristics, we derive the following results in this paper: (i) we develop parallel formulations of the Truncated Spike solver, (ii) we develop a highly accurate pseudo-analytical parallel performance model for our solver, (iii) we show excellent predication capabilities of our model – based on which we argue the high scalability of our solver. Our pseudo-analytical performance model is based on analytical performance characterization of each phase of our solver. These analytical models are then parameterized using actual runtime information on target platforms. An important consequence of our performance models is that they reveal underlying performance bottlenecks in both serial and parallel formulations. All of our results are validated

  16. Effects of microstructure banding on hydrogen assisted fatigue crack growth in X65 pipeline steels

    SciTech Connect

    Ronevich, Joseph A.; Somerday, Brian P.; San Marchi, Chris W.

    2015-09-10

    Banded ferrite-pearlite X65 pipeline steel was tested in high pressure hydrogen gas to evaluate the effects of oriented pearlite on hydrogen assisted fatigue crack growth. Test specimens were oriented in the steel pipe such that cracks propagated either parallel or perpendicular to the banded pearlite. The ferrite-pearlite microstructure exhibited orientation dependent behavior in which fatigue crack growth rates were significantly lower for cracks oriented perpendicular to the banded pearlite compared to cracks oriented parallel to the bands. Thus the reduction of hydrogen assisted fatigue crack growth across the banded pearlite is attributed to a combination of crack-tip branching and impeded hydrogen diffusion across the banded pearlite.

  17. Effects of microstructure banding on hydrogen assisted fatigue crack growth in X65 pipeline steels

    SciTech Connect

    Ronevich, Joseph A.; Somerday, Brian P.; San Marchi, Chris W.

    2015-09-10

    Banded ferritepearlite X65 pipeline steel was tested in high pressure hydrogen gas to evaluate the effects of oriented pearlite on hydrogen assisted fatigue crack growth. Test specimens were oriented in the steel pipe such that cracks propagated either parallel or perpendicular to the banded pearlite. The ferritepearlite microstructure exhibited orientation dependent behavior in which fatigue crack growth rates were significantly lower for cracks oriented perpendicular to the banded pearlite compared to cracks oriented parallel to the bands. Thus the reduction of hydrogen assisted fatigue crack growth across the banded pearlite is attributed to a combination of crack-tip branching and impeded hydrogen diffusion across the banded pearlite.

  18. Determination of Band Offsets between the High-k Dielectric LaAlO3...

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

    found that band gaps of high-k dielectric films are also significantly affected by film growth conditions. Therefore, we can not rely on previously published LaAlO3 band gap...

  19. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Cross-Wind RHI Scan...

    Office of Scientific and Technical Information (OSTI)

    Cross-Wind RHI Scan Title: ARM: X-Band Scanning ARM Cloud Radar (XSACR) Cross-Wind RHI Scan X-Band Scanning ARM Cloud Radar (XSACR) Cross-Wind RHI Scan Authors: Dan Nelson ; Joseph ...

  20. ARM: Marine W-band (95 GHz) ARM Cloud Radar (Dataset) | Data...

    Office of Scientific and Technical Information (OSTI)

    Radar Title: ARM: Marine W-band (95 GHz) ARM Cloud Radar Marine W-band (95 GHz) ARM Cloud Radar Authors: Joseph Hardin ; Bradley Isom ; Alyssa Matthews ; Karen Johnson ; Nitin ...

  1. ARM: X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector...

    Office of Scientific and Technical Information (OSTI)

    W-SACR) Corner Reflector Raster Scan Title: ARM: X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector Raster Scan X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector ...

  2. ARM: Marine W-band (95 GHz) ARM Cloud Radar, filtered spectral...

    Office of Scientific and Technical Information (OSTI)

    Radar, filtered spectral data, co-polarized mode Title: ARM: Marine W-band (95 GHz) ARM Cloud Radar, filtered spectral data, co-polarized mode Marine W-band (95 GHz) ARM Cloud ...

  3. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Raster Scan Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Raster Scan Authors: Dan Nelson ; ...

  4. s d 2 Graphene: Kagome Band in a Hexagonal Lattice (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    s d 2 Graphene: Kagome Band in a Hexagonal Lattice Citation Details In-Document Search Title: s d 2 Graphene: Kagome Band in a Hexagonal Lattice Authors: Zhou, Miao ; Liu, Zheng ; ...

  5. s d 2 Graphene: Kagome Band in a Hexagonal Lattice (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    s d 2 Graphene: Kagome Band in a Hexagonal Lattice Prev Next Title: s d 2 Graphene: Kagome Band in a Hexagonal Lattice Authors: Zhou, Miao ; Liu, Zheng ; Ming, Wenmei ; Wang,...

  6. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Boundary Layer RHI...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: X-Band Scanning ARM Cloud Radar (XSACR) Boundary Layer RHI Scan X-Band Scanning ARM Cloud Radar (XSACR) Boundary Layer RHI Scan Authors: Dan Nelson ; Joseph Hardin ; ...

  7. Optical Absorption and Band Gap Reduction in (Fe 1-x Cr x ) 2...

    Office of Scientific and Technical Information (OSTI)

    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. Authors: Wang, Yong ; Lopata, Kenneth ; ...

  8. High-Efficiency, Wide-Band Three-Phase Rectifiers and Adaptive...

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

    Efficiency, Wide-Band Three-Phase Rectifiers and Adaptive Rectifier Management High-Efficiency, Wide-Band Three-Phase Rectifiers and Adaptive Rectifier Management Higher-Efficiency...

  9. The Band Gap of AlGaN Alloys (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Journal Article: The Band Gap of AlGaN Alloys Citation Details In-Document Search Title: The Band ... Publication Date: 1999-01-29 OSTI Identifier: 3336 Report Number(s): ...

  10. Soboba Band of Luiseño Indians Celebrates Initial Step Toward...

    Energy.gov [DOE] (indexed site)

    Photo from the Soboba Band of Luiseo Indians. The Soboba Band of Luiseo Indians 1-megawatt solar photovoltaic system, which was co-funded by a DOE grant, will help ...

  11. Band alignment and interfacial structure of ZnO/Si heterojunction...

    Office of Scientific and Technical Information (OSTI)

    Band alignment and interfacial structure of ZnOSi heterojunction with Alsub 2Osub 3 and HfOsub 2 as interlayers Citation Details In-Document Search Title: Band alignment and ...

  12. X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook...

    Office of Scientific and Technical Information (OSTI)

    X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook Citation Details In-Document Search Title: X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook ...

  13. Little River Band of Ottawa Indians … First Steps to Human Capacity...

    Energy.gov [DOE] (indexed site)

    Little River Band of Ottawa Indians Melissa Waitner, GPC Grant Writer 375 River Street Manistee, Michigan 49660 mwaitner@lrboi.com - The Little River Band of Ottawa Indians (LRBOI) ...

  14. Deep z-band observations of the coolest Y dwarf

    SciTech Connect

    Kopytova, Taisiya G.; Crossfield, Ian J. M.; Deacon, Niall R.; Brandner, Wolfgang; Buenzli, Esther; Bayo, Amelia; Schlieder, Joshua E.; Manjavacas, Elena; Kopon, Derek; Biller, Beth A.

    2014-12-10

    WISE J085510.83-071442.5 (hereafter, WISE 0855-07) is the coolest Y dwarf known to date and is located at a distance of 2.31 0.08 pc, giving it the fourth largest parallax of any known star or brown dwarf system. We report deep z-band observations of WISE 0855-07 using FORS2 on UT1/Very Large Telescope. We do not detect any counterpart to WISE 0855-07 in our z-band images and estimate a brightness upper limit of AB mag > 24.8 (F {sub ?} < 0.45 ?Jy) at 910 65 nm with 3? confidence. We combine our z-band upper limit with previous near- and mid-infrared photometry to place constraints on the atmospheric properties of WISE 0855-07 via comparison to models which implement water clouds in the atmospheres of T {sub eff} < 300 K substellar objects. We find that none of the available models that implement water clouds can completely reproduce the observed spectral energy distribution of WISE 0855-07. Every model significantly disagrees with the (3.6 ?m/4.5 ?m) flux ratio and at least one other bandpass. Since methane is predicted to be the dominant absorber at 3-4 ?m, these mismatches might point to an incorrect or incomplete treatment of methane in current models. We conclude that (a) WISE0855-07 has T {sub eff} ? 200-250 K, (b) <80% of its surface is covered by clouds, and (c) deeper observations, and improved models of substellar evolution, atmospheres, clouds, and opacities will be necessary to better characterize this object.

  15. History and Evolution of Control Banding: A Review

    SciTech Connect

    Zalk, D; Nelson, D

    2006-07-19

    Control Banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents often encountered in the workplace. The original CB model was developed within the pharmaceutical industry; however, the modern movement involves models developed for non-experts to input hazard and exposure potential information for bulk chemical processes, receiving control advice as a result. The CB approach utilizes these models for the dissemination of qualitative and semi-quantitative risk assessment tools being developed to complement the traditional industrial hygiene model of air sampling and analysis. It is being applied and tested in small and medium size enterprises (SMEs) within developed countries and industrially developing countries; however, large enterprises (LEs) have also incorporated these strategies within chemical safety programs. Existing research of the components of the most available CB model, the Control of Substances Hazardous to Health (COSHH) Essentials, has shown that exposure bands do not always provide adequate margins of safety, that there is a high rate of under-control errors, that it works better with dusts than with vapors, that there is an inherent inaccuracy in estimating variability, and that when taken together the outcomes of this model may lead to potentially inappropriate workplace confidence in chemical exposure reduction in some operations. Alternatively, large-scale comparisons of industry exposure data to this CB model's outcomes have indicated more promising results with a high correlation seen internationally. With the accuracy of the toxicological ratings and hazard band classification currently in question, their proper reevaluation will be of great benefit to the reliability of existing and future CB models. The need for a more complete analysis of CB model components and, most importantly, a more comprehensive prospective research process remains and will be important in understanding implications of the

  16. X-band photoinjector for a chirped-pulse FEL

    SciTech Connect

    Luhmann, Jr., N. C.; Alvis, R. M.; Baldis, H. A.; Hartemann, F. V; Heritage, J. P.; Ho, C. H.; Landahl, E. C.; Li, K.; Troha,A. L.; White, W. E.

    1998-12-15

    The phase noise and jitter characteristics of the laser and rf systems of a high gradient X-band photoinjector have been measured experimentally. When > 100 coherently phased 5 MeV electron bunches are produced in bursts, the photoinjector should be an ideal electron source for a pulsed, pre-bunched free-electron laser (FEL) operating at 100 GHz. The laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT and klystron. A comparison between the klystron and TWT amplifier phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a rf oscillator such as a magnetron or a compact source such as a cross-field amplifier. In particular, the rf gun can play the role of a pulsed rf clock to synchronize the photocathode laser system: direct drive of a synchronously mode-locked AlGaAs quantum well laser has been achieved using the X0-band gun rf fields. This novel, GHz repetition rate, sub-picosecond laser system is being developed to replace the more conventional femtosecond Ti: Al2O3 system. Some advantages include pumping this laser with a stabilized current source instead of a costly, low efficiency pump laser. Finally, dark current measurements and initial photoelectron measurements are reported.

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

    DOEpatents

    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.

  18. Morongo Band of Cahuilla Mission Indians: Southwest Tribal Energy Consortium- 2006 Project

    Energy.gov [DOE]

    The Southwest Tribal Energy Consortium, represented by the Morongo Band, is comprised of tribes in California, Arizona and New Mexico.

  19. Project Reports for Morongo Band of Cahuilla Mission Indians: Southwest Tribal Energy Consortium- 2006 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Southwest Tribal Energy Consortium, represented by the Morongo Band, is comprised of tribes in California, Arizona and New Mexico.

  20. Grand Traverse Band Renewable Energy Feasibility Study in Wind, Biomass and Solar

    SciTech Connect

    Suzanne McSawby, Project Director Steve Smiley, Principle Investigator Grand Traverse Resort, Cost Sharing Partner

    2008-12-31

    Renewable Energy Feasibility Study for wind, biomass, solar on the Grand Traverse Band tribal lands from 2005 - 2008

  1. Project Reports for Cabazon Band of Mission Indians- 2003 Project

    Energy.gov [DOE]

    Strategic energy planning effort to assist in achieving the tribe's primary goals of economic diversity, economic self-sufficiency, and protecting the health and welfare of tribal members. The Cabazon Band Reservation, located on four sections of non-contiguous land on the eastern half of the Coachella Valley in Riverside County is approximately 25 miles east of Palm Springs, comprises 1500 acres and currently has the seventh highest residential electricity rates among U.S. Native American reservations. The Strategic Energy Plan will enable the tribe to make informed decisions in creating and conducting an effective energy management program for their people.

  2. A HIGH-POWER L-BAND RF WINDOW

    SciTech Connect

    R. RIMMER; G. KOEHLER; ET AL

    2001-05-01

    This paper discusses the design, fabrication and testing of a high power alumina disk window in WR1500 waveguide at L Band, suitable for use in the NLC damping ring RF cavities at 714 MHz and the LEDA Accelerator at 700 MHz. The design is based on the fabrication methods used for the successful PEP-II cavity windows. Four prototype windows at 700 MHz have been produced by LBNL for testing at LANL. The RF design and simulation using MAFIA, laboratory cold test measurements, fabrication methods and preliminary high power test results are discussed.

  3. Wide band cryogenic ultra-high vacuum microwave absorber

    DOEpatents

    Campisi, I.E.

    1992-05-12

    An absorber waveguide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the waveguide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the waveguide. 11 figs.

  4. X-BAND TRAVELING WAVE RF DEFLECTOR STRUCTURES

    SciTech Connect

    Wang, J.W.; Tantawi, S.; /SLAC

    2008-12-18

    Design studies on the X-Band transverse RF deflectors operating at HEM{sub ll} mode have been made for two different applications. One is for beam measurement of time-sliced emittance and slice energy spread for the upgraded LCLS project, its optimization in RF efficiency and system design are carefully considered. Another is to design an ultra-fast RF kicker in order to pick up single bunches from the bunch-train of the B-factory storage ring. The challenges are to obtain very short structure filling time with high RF group velocity and good RF efficiency with reasonable transverse shunt impedance. Its RF system will be discussed.

  5. Campo Band of Mission Indians - Renewable Energy Update

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

    Connolly Miskwish November 16, 2012 — Campo is one of twelve Bands o — 50 megawatt facility comprised of 25 2---MW turbines — 25 year lease — Outside owner with tribe receiving a royalty based on gross output — Lease negotiated in 2004 — 160 MW project — Project development began in 2006 MW---hour California Market Price Referent 140 120 100 80 60 40 20 0 2007 2008 2009 2010 2011 2012 2013 — More direct involvement by tribal government — Less reliance on

  6. Ka-Band ARM Zenith Radar (KAZR) Instrument Handbook

    SciTech Connect

    Widener, K; Bharadwaj, N; Johnson, K

    2012-03-06

    The Ka-band ARM zenith radar (KAZR) is a zenith-pointing Doppler cloud radar operating at approximately 35 GHz. The KAZR is an evolutionary follow-on radar to ARM's widely successful millimeter-wavelength cloud radar (MMCR). The main purpose of the KAZR is to provide vertical profiles of clouds by measuring the first three Doppler moments: reflectivity, radial Doppler velocity, and spectra width. At the sites where the dual-polarization measurements are made, the Doppler moments for the cross-polarization channel are also available. In addition to the moments, velocity spectra are also continuously recorded for each range gate.

  7. Narrow-band optical transmission of metallic nanoslit arrays

    SciTech Connect

    Sun Zhijun; Yang Ying; Zuo Xiaoliu

    2012-10-22

    Metallic nanoslit arrays usually demonstrate wide transmission bands for transverse-magnetic-polarized incidence light. Here, we show that by introducing multi-dielectric layers underneath the metallic structure layer on the substrate, a narrow peak is formed, whose bandwidth can be down to a few nanometers. Three types of resonance modes in the region under the metal layer are identified responsible for the formation of the peak, i.e., a two-dimensional cavity resonance mode, which supports optical transmission, and two in-plane hybrid surface plasmon resonance modes locating on both sides of the peak that suppresses the transmission. Such structures can be applied in advanced photonic devices.

  8. Wide band cryogenic ultra-high vacuum microwave absorber

    DOEpatents

    Campisi, Isidoro E. (Newport News, VA)

    1992-01-01

    An absorber wave guide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the wave guide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the wave guide.

  9. Intermediate band solar cells: Recent progress and future directions

    SciTech Connect

    Okada, Y. Tamaki, R.; Farrell, D. J.; Yoshida, K.; Ahsan, N.; Shoji, Y.; Sogabe, T.; Ekins-Daukes, N. J. Yoshida, M.; Pusch, A.; Hess, O.; Phillips, C. C.; Kita, T.; Guillemoles, J.-F.

    2015-06-15

    Extensive literature and publications on intermediate band solar cells (IBSCs) are reviewed. A detailed discussion is given on the thermodynamics of solar energy conversion in IBSCs, the device physics, and the carrier dynamics processes with a particular emphasis on the two-step inter-subband absorption/recombination processes that are of paramount importance in a successful implementation high-efficiency IBSC. The experimental solar cell performance is further discussed, which has been recently demonstrated by using highly mismatched alloys and high-density quantum dot arrays and superlattice. IBSCs having widely different structures, materials, and spectral responses are also covered, as is the optimization of device parameters to achieve maximum performance.

  10. Graded band gap GaInNAs solar cells

    SciTech Connect

    Langer, F.; Perl, S.; Kamp, M.; Höfling, S.

    2015-06-08

    Dilute nitride GaInN(Sb)As with a band gap (E{sub g}) of 1.0 eV is a promising material for the integration in next generation multijunction solar cells. We have investigated the effect of a compositionally graded GaInNAs absorber layer on the spectral response of a GaInNAs sub cell. We produced band gap gradings (ΔE{sub g}) of up to 39 meV across a 1 μm thick GaInNAs layer. Thereby, the external quantum efficiency—compared to reference cells—was increased due to the improved extraction of photo-generated carriers from 34.0% to 36.7% for the wavelength range from 900 nm to 1150 nm. However, this device figure improvement is accompanied by a small decrease in the open circuit voltage of about 20 mV and the shift of the absorption edge to shorter wavelengths.

  11. Band structure of ABC-trilayer graphene superlattice

    SciTech Connect

    Uddin, Salah Chan, K. S.

    2014-11-28

    We investigate the effect of one-dimensional periodic potentials on the low energy band structure of ABC trilayer graphene first by assuming that all the three layers have the same potential. Extra Dirac points having the same electron hole crossing energy as that of the original Dirac point are generated by superlattice potentials with equal well and barrier widths. When the potential height is increased, the numbers of extra Dirac points are increased. The dispersions around the Dirac points are not isotropic. It is noted that the dispersion along the k{sub y} direction for k{sub x}?=?0 oscillates between a non-linear dispersion and a linear dispersion when the potential height is increased. When the well and barrier widths are not identical, the symmetry of the conduction and valence bands is broken. The extra Dirac points are shifted either upward or downward depending on the barrier and well widths from the zero energy, while the position of the central Dirac point oscillates with the superlattice potential height. By considering different potentials for different layers, extra Dirac points are generated not from the original Dirac points but from the valleys formed in the energy spectrum. Two extra Dirac points appear from each pair of touched valleys, so four Dirac points appeared in the spectrum at particular barrier height. By increasing the barrier height of superlattice potential two Dirac points merge into the original Dirac point. This emerging and merging of extra Dirac points is different from the equal potential case.

  12. Alternating-parity collective states of yrast and nonyrast bands in lanthanide and actinide nuclei

    SciTech Connect

    Nadirbekov, M. S. Yuldasheva, G. A.; Denisov, V. Yu.

    2015-03-15

    Excited collective states of even-even nuclei featuring quadrupole and octupole deformations are studied within a nonadiabatic collective model with a Gaussian potential energy. Rotational states of the yrast band and vibrational-rotational states of nonyrast bands are considered in detail. The energies of alternating-parity excited states of the yrast band in the {sup 164}Er, {sup 220}Ra, and {sup 224}Th nuclei; the yrast and first nonyrast bands in the {sup 154}Sm and {sup 160}Gd nuclei; and the yrast, first nonyrast, and second nonyrast bands in the {sup 224}Ra and {sup 240}Pu nuclei are described well on the basis of the proposed model.

  13. Triaxial strongly deformed bands in {sup 164}Hf and the effect of elevated yrast line

    SciTech Connect

    Ma Wenchao

    2012-10-20

    Two exotic rotational bands have been identified in {sup 164}Hf and linked to known states. They are interpreted as being associated with the calculated triaxial strongly deformed (TSD) potential energy minimum. The bands are substantially stronger and are located at much lower spins than the previously discovered TSD bands in {sup 168}Hf. In addition to the proton and neutron shell gaps at large trixiality, it was proposed that the relative excitation energy of TSD bands above the yrast line plays an important role in the population of TSD bands.

  14. Introducing Defects in Photonic Band-Gap (PBG) Crystals

    SciTech Connect

    Johnson, Elliott C.; /North Dakota State U. /SLAC

    2007-11-07

    Photonic Band-Gap (PBG) fibers are a periodic array of optical materials arranged in a lattice called a photonic crystal. The use of PBG fibers for particle acceleration is being studied by the Advanced Accelerator Research Department (AARD) at SLAC. By introducing defects in such fibers, e.g. removing one or more capillaries from a hexagonal lattice, spatially confined modes suitable for particle acceleration may be created. The AARD has acquired several test samples of PBG fiber arrays with varying refractive index, capillary size, and length from an external vendor for testing. The PBGs were inspected with a microscope and characteristics of the capillaries including radii, spacing, and errors in construction were determined. Transmission tests were performed on these samples using a broad-range spectrophotometer. In addition, detailed E-field simulations of different PBG configurations were done using the CUDOS and RSOFT codes. Several accelerating modes for different configurations were found and studied in detail.

  15. Little Traverse Bay Bands of Odawa Indians- 2005 Project

    Energy.gov [DOE]

    The Little Traverse Bay Bands of Odawa Indians is located in the northern part of lower Michigan on approximately 590 acres of land. The tribe originally had no consistent vision or strategic plan concerning its energy use. This project had three objectives. The first objective was to produce a comprehensive energy plan for the tribe. The second objective was to create an energy organization and tribal energy code. The third objective was to increase the capacity of the tribe for better understanding (through active tribal participation), capability, knowledge and awareness of energy issues through bimonthly articles in the tribal newsletter and two energy workshops. The vision, strategic plan, and code will provide the focus, direction and guidelines as the tribe seeks to develop renewable energy and energy efficiency.

  16. Initial assessment of an airborne Ku-band polarimetric SAR.

    SciTech Connect

    Raynal, Ann Marie; Doerry, Armin Walter

    2013-02-01

    Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940's. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analyst's understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.

  17. Toroidal band limiter for a plasma containment device

    DOEpatents

    Kelley, George G.

    1978-01-01

    This invention relates to a toroidal plasma confinement device having poloidal and toroidal magnetic fields for confining a toroidal plasma column with a plasma current induced therein along an endless, circular equilibrium axis in a torus vacuum cavity wherein the improvement comprises the use of a toroidal plasma band limiter mounted within the vacuum cavity in such a manner as to ensure that the plasma energy is distributed more uniformly over the limiter surface thereby avoiding intense local heating of the limiter while at the same time substantially preventing damage to the plasma containment wall of the cavity by the energetic particles diffusing out from the confined plasma. A plurality of poloidal plasma ring limiters are also utilized for containment wall protection during any disruptive instability that might occur during operation of the device.

  18. Project Reports for Mississippi Band of Choctaw Indians- 2002 Project

    Energy.gov [DOE]

    The Mississippi Band of Choctaw Indians (MBCI) always seeks new opportunities to diversify its economy and create new career opportunities for tribal members, which is the purpose of this feasibility study. The MBCI will study the feasibility of locating a renewable energy installation on tribal lands. The technologies to be utilized in the renewable energy installation will be those that can readily handle poultry litter, either alone or in combination with wood residues. The purpose of the study is to determine whether such an installation can be both economically sustainable and consistent with the cultural, social, and economic goals of the tribe. The feasibility study will result in the development of a thorough business plan that will allow the MBCI to make an informed decision regarding this project.

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

    DOEpatents

    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.

  20. G-Band Vapor Radiometer Profiler (GVRP) Handbook

    SciTech Connect

    Caddeau, MP

    2010-06-23

    The G-Band Vapor Radiometer Profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.310 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. Channels between 170.0 and 176.0 GHz are particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from the GVRP instrument are therefore especially useful during low-humidity conditions (PWV < 5 mm). In addition to integrated water vapor and liquid water, the GVRP can provide low-resolution vertical profiles of water vapor in very dry conditions.

  1. W-band ARM Cloud Radar (WACR) Handbook

    SciTech Connect

    Widener, KB; Johnson, K

    2005-01-05

    The W-band Atmospheric Radiation Measurement (ARM) Program Cloud Radar (WACR) systems are zenith pointing Doppler radars that probe the extent and composition of clouds at 95.04 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar reports estimates for the first three spectra moments for each range gate up to 15 km. The 0th moment is reflectivity, the 1st moment is radial velocity, and the 2nd moment is spectral width. Also available are the raw spectra files. Unlike the millimeter wavelength cloud radar (MMCR), the WACR does not use pulse coding and operates in only copolarization and cross-polarization modes.

  2. Out of band radiation effects on resist patterning

    SciTech Connect

    George, Simi A .; Naulleau, Patrick P.

    2011-03-11

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

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

    DOEpatents

    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.

  4. Nitrogen control of 13C enrichment in heterotrophic organs relative to leaves in a landscape-building desert plant species

    DOE PAGES [OSTI]

    Zhang, J.; Gu, L.; Bao, F.; Cao, Y.; Hao, Y.; He, J.; Li, J.; Li, Y.; Ren, Y.; Wang, F.; et al

    2014-09-10

    A longstanding puzzle in isotope studies of C3 plant species is that heterotrophic plant organs (e.g., stems, roots, seeds, and fruits) tend to be enriched in 13C compared to the autotrophic organ (leaves) that provides them with photosynthate. Our inability to explain this puzzle suggests key deficiencies in understanding post-photosynthetic metabolic processes. It also limits the effectiveness of applications of stable carbon isotope analyses in a variety of scientific disciplines ranging from plant physiology to global carbon cycle studies. To gain insight into this puzzle, we excavated whole plant architectures of Nitraria tangutorum Bobrov, a C3 species that has anmore » exceptional capability of fixing sands and building sand dunes, in two deserts in northwestern China. We systematically and simultaneously measured carbon isotope ratios and nitrogen and phosphorous contents of different parts of the excavated plants. We also determined the seasonal variations in leaf carbon isotope ratios on nearby intact plants of N. tangutorum. We found, for the first time, that higher nitrogen contents in heterotrophic organs were significantly correlated with increased heterotrophic 13C enrichment compared to leaves. However, phosphorous contents had no effect on the enrichment. In addition, new leaves had carbon isotope ratios similar to roots but were progressively depleted in 13C as they matured. We concluded that a nitrogen-mediated process, probably the refixation of respiratory CO2 by phosphoenolpyruvate (PEP) carboxylase, was responsible for the differences in 13C enrichment among different heterotrophic organs while processes within leaves or during phloem loading may contribute to the overall autotrophic – heterotrophic difference in carbon isotope compositions.« less

  5. High Bacterial Diversity of Biological Soil Crusts in Water Tracks over Permafrost in the High Arctic Polar Desert

    DOE PAGES [OSTI]

    Steven, Blaire; Lionard, Marie; Kuske, Cheryl R.; Vincent, Warwick F.

    2013-08-13

    In this paper we report the bacterial diversity of biological soil crusts (biocrusts) inhabiting polar desert soils at the northern land limit of the Arctic polar region (83° 05 N). Employing pyrosequencing of bacterial 16S rRNA genes this study demonstrated that these biocrusts harbor diverse bacterial communities, often as diverse as temperate latitude communities. The effect of wetting pulses on the composition of communities was also determined by collecting samples from soils outside and inside of permafrost water tracks, hill slope flow paths that drain permafrost-affected soils. The intermittent flow regime in the water tracks was correlated with altered relativemore » abundance of phylum level taxonomic bins in the bacterial communities, but the alterations varied between individual sampling sites. Bacteria related to the Cyanobacteria and Acidobacteria demonstrated shifts in relative abundance based on their location either inside or outside of the water tracks. Among cyanobacterial sequences, the proportion of sequences belonging to the family Oscillatoriales consistently increased in relative abundance in the samples from inside the water tracks compared to those outside. Acidobacteria showed responses to wetting pulses in the water tracks, increasing in abundance at one site and decreasing at the other two sites. Subdivision 4 acidobacterial sequences tended to follow the trends in the total Acidobacteria relative abundance, suggesting these organisms were largely responsible for the changes observed in the Acidobacteria. Finally, taken together, these data suggest that the bacterial communities of these high latitude polar biocrusts are diverse but do not show a consensus response to intermittent flow in water tracks over high Arctic permafrost.« less

  6. Nitrogen control of 13C enrichment in heterotrophic organs relative to leaves in a landscape-building desert plant species

    SciTech Connect

    Zhang, Jinxin [Chinese Academy of Forestry; Gu, Lianhong [ORNL

    2014-01-01

    A longstanding puzzle in isotopic studies of C3 plant species is that heterotrophic plant organs (e.g., stems, roots, seeds, and fruits) tend to be enriched in 13C compared to the autotrophic organ (leaves) that provides them with photosynthate. Our inability to explain this puzzle suggests key deficiencies in understanding post-photosynthetic metabolic processes. It also limits the effectiveness of applications of stable carbon isotope analyses in a variety of scientific disciplines ranging from plant physiology to global carbon cycle studies. To gain insight into this puzzle, we excavated whole plant architectures of Nitraria tangutorum Bobrov, a C3 species that has an exceptional capability of fixing sands and building sand dunes, in two deserts in northwestern China. We systematically and simultaneously measured carbon isotopic ratios and nitrogen and phosphorous concentrations of different parts of the excavated plants. We also determined the seasonal variations in leaf carbon isotopic ratios on nearby intact plants of N. tangutorum. We found that higher nitrogen concentrations in heterotrophic organs were significantly correlated with increased heterotrophic 13C enrichment compared to leaves. However, phosphorous concentrations had no effect on the enrichment. In addition, new leaves had carbon isotopic ratios similar to roots but were progressively depleted in 13C as they matured. We concluded that a nitrogen-mediated process, probably the refixation of respiratory CO2 by phosphoenolpyruvate (PEP) carboxylase, was responsible for the differences in 13C enrichment among different heterotrophic organs while processes within leaves or during phloem loading may contribute to the overall autotrophic heterotrophic difference in carbon isotopic compositions.

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

    SciTech Connect

    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.

  8. TEMPORAL SPECTRAL SHIFT AND POLARIZATION OF A BAND-SPLITTING SOLAR TYPE II RADIO BURST

    SciTech Connect

    Du, Guohui; Chen, Yao; Lv, Maoshui; Kong, Xiangliang; Feng, Shiwei; Guo, Fan; Li, Gang

    2014-10-01

    In many type II solar radio bursts, the fundamental and/or the harmonic branches of the bursts can split into two almost parallel bands with similar spectral shapes and frequency drifts. However, the mechanisms accounting for this intriguing phenomenon remain elusive. In this study, we report a special band-splitting type II event in which spectral features appear systematically earlier on the upper band (with higher frequencies) than on the lower band (with lower frequencies) by several seconds. Furthermore, the emissions carried by the splitting band are moderately polarized with the left-hand polarized signals stronger than the right-hand ones. The polarization degree varies in a range of 0.3 to 0.6. These novel observational findings provide important constraints on the underlying physical mechanisms of band-splitting of type II radio bursts.

  9. Effects of microstructure banding on hydrogen assisted fatigue crack growth in X65 pipeline steels

    DOE PAGES [OSTI]

    Ronevich, Joseph A.; Somerday, Brian P.; San Marchi, Chris W.

    2015-09-10

    Banded ferrite-pearlite X65 pipeline steel was tested in high pressure hydrogen gas to evaluate the effects of oriented pearlite on hydrogen assisted fatigue crack growth. Test specimens were oriented in the steel pipe such that cracks propagated either parallel or perpendicular to the banded pearlite. The ferrite-pearlite microstructure exhibited orientation dependent behavior in which fatigue crack growth rates were significantly lower for cracks oriented perpendicular to the banded pearlite compared to cracks oriented parallel to the bands. Thus the reduction of hydrogen assisted fatigue crack growth across the banded pearlite is attributed to a combination of crack-tip branching and impededmore » hydrogen diffusion across the banded pearlite.« less

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

    DOE PAGES [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-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. Fond du Lac Band Leads Climate Resilience Efforts on Lake Superior Chippewa

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

    Indian Reservation | Department of Energy Fond du Lac Band Leads Climate Resilience Efforts on Lake Superior Chippewa Indian Reservation Fond du Lac Band Leads Climate Resilience Efforts on Lake Superior Chippewa Indian Reservation September 23, 2014 - 11:24am Addthis From the White House Council on Environmental Quality blog: Last Friday I had the pleasure of visiting the Fond du Lac Band of Lake Superior Chippewa Indian Reservation. I was joined by Raina Thiele, Associate Director of White

  12. Accurate Band-Structure Calculations for the 3d Transition Metal Oxides

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

    has developed a method to calculate accurate band structures and bandgap energies for 3d transition metal oxides using an augmented GW formalism. Significance and Impact This approach provides a computationally viable route for high-throughput prediction of band structures and optical properties in transition metal compounds. Accurate Band-Structure Calculations for the 3d Transition Metal Oxides S. Lany, Phys. Rev. B 87, 085112 (2013). Density of states (DOS) and absorption spectrum, shown for

  13. Nonequilibrium Green's function formulation of intersubband absorption for nonparabolic single-band effective mass Hamiltonian

    SciTech Connect

    Kolek, Andrzej

    2015-05-04

    The formulas are derived that enable calculations of intersubband absorption coefficient within nonequilibrium Green's function method applied to a single-band effective-mass Hamiltonian with the energy dependent effective mass. The derivation provides also the formulas for the virtual valence band components of the two-band Green's functions which can be used for more exact estimation of the density of states and electrons and more reliable treatment of electronic transport in unipolar n-type heterostructure semiconductor devices.

  14. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Zenith Pointing PPI

    Office of Scientific and Technical Information (OSTI)

    (Dataset) | Data Explorer Ka-Band Scanning ARM Cloud Radar (KASACR) Zenith Pointing PPI Title: ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Zenith Pointing PPI Ka-Band Scanning ARM Cloud Radar (KASACR) Zenith Pointing PPI Authors: Joseph Hardin ; Dan Nelson ; Iosif [1] ; Bradley Isom ; Karen Johnson ; Alyssa Matthews ; Nitin Bharadwaj + Show Author Affiliations (Andrei) Lindenmaier Publication Date: 2014-04-14 OSTI Identifier: 1140236 DOE Contract Number: DE-AC05-00OR22725 Resource Type:

  15. Theoretical performance of solar cell based on mini-bands quantum dots

    SciTech Connect

    Aly, Abou El-Maaty M. E-mail: ashraf.nasr@gmail.com; Nasr, A. E-mail: ashraf.nasr@gmail.com

    2014-03-21

    The tremendous amount of research in solar energy is directed toward intermediate band solar cell for its advantages compared with the conventional solar cell. The latter has lower efficiency because the photons have lower energy than the bandgap energy and cannot excite mobile carriers from the valence band to the conduction band. On the other hand, if mini intermediate band is introduced between the valence and conduction bands, then the smaller energy photons can be used to promote charge carriers transfer to the conduction band and thereby the total current increases while maintaining a large open circuit voltage. In this article, the influence of the new band on the power conversion efficiency for structure of quantum dots intermediate band solar cell is theoretically investigated and studied. The time-independent Schrödinger equation is used to determine the optimum width and location of the intermediate band. Accordingly, achievement of a maximum efficiency by changing the width of quantum dots and barrier distances is studied. Theoretical determination of the power conversion efficiency under the two different ranges of QD width is presented. From the obtained results, the maximum power conversion efficiency is about 70.42%. It is carried out for simple cubic quantum dot crystal under fully concentrated light. It is strongly dependent on the width of quantum dots and barrier distances.

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

    DOEpatents

    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.

  17. Project Reports for Minnesota Chippewa Tribe: White Earth Band- 2003 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Several northern Minnesota tribes interested in building a common foundation for strategic tribal energy capacity have banded together for strategic energy resource planning.

  18. ARM: Ka-Band Scanning ARM Cloud Radar, filtered spectral data...

    Office of Scientific and Technical Information (OSTI)

    Ka-Band Scanning ARM Cloud Radar, filtered spectral data, co-polarized mode Authors: Dan Nelson ; Joseph Hardin ; Iosif 1 ; Bradley Isom ; Karen Johnson ; Nitin Bharadwaj + Show ...

  19. ARM: X-Band Scanning ARM Cloud Radar, filtered spectral data...

    Office of Scientific and Technical Information (OSTI)

    X-Band Scanning ARM Cloud Radar, filtered spectral data, co-polarized mode Authors: Dan Nelson ; Joseph Hardin ; Iosif 1 ; Bradley Isom ; Karen Johnson ; Nitin Bharadwaj + Show ...

  20. One-quasiparticle bands in neutron-rich {sup 187}W

    SciTech Connect

    Shizuma, T.; Hayakawa, T.; Ishii, T.; Makii, H.; Matsuda, M.; Shigematsu, S.; Ideguchi, E.; Zheng, Y.; Liu, M.; Morikawa, T.; Oi, M.

    2008-04-15

    Modest spin states in neutron-rich {sup 187}W have been populated by using a {sup 186}W({sup 18}O,{sup 17}O) one-neutron transfer reaction. Negative-parity bands previously known are extended to higher spin, and two positive-parity bands are newly identified. Configurations based on {nu} i{sub 13/2} orbitals are assigned to these bands from an analysis of the level energy systematics as well as the g factors derived from in-band branching ratios.

  1. Project Reports for Ramona Band of Cahuilla Mission Indians- 1999 Project

    Energy.gov [DOE]

    The Ramona Band of Cauhilla Indians is establishing an ecotourism facility on their Reservation at the southern end of the San Bernardino National Forest in southern California.

  2. Project Reports for Santa Ynez Band of Chumash Indians- 2011 Project

    Energy.gov [DOE]

    The Santa Ynez Band of Chumash Indians (SYBCI) will prepare a comprehensive, strategic energy plan that incorporates energy efficiency, renewable energy, and other energy management and development options.

  3. Project Reports for Agua Caliente Band of Cahuilla Indians- 2010 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Agua Caliente Band of Cahuilla Indians (ACBCI) will conduct a feasibility and predevelopment study of potential solar projects on its lands in southern California.

  4. Fully Polarimetric Differential Intensity W-band Imager

    SciTech Connect

    Bernacki, Bruce E.; Tedeschi, Jonathan R.; Kelly, James F.; Sheen, David M.; Hall, Thomas E.; Valdez, Patrick LJ; Lechelt, Wayne M.; McMakin, Douglas L.

    2013-05-31

    We present a novel architecture based upon a Dicke-switched heterodyne radiometer architecture employing two identical input sections consisting of horn and orthomode transducer to detect the difference between the H and V polarization states of two separate object patches imaged by the radiometer. We have constructed and described previously a fully polarimetric W-band passive millimeter wave imager constructed to study the phenomenology of anomaly detection using polarimetric image exploitation of the Stokes images. The heterodyne radiometer used a PIN diode switch between the input millimeter wave energy and that of a reference load in order to eliminate the effects of component drifts and reduce the effects of 1/f noise. The differential approach differs from our previous work by comparing H and V polarization states detected by each of the two input horns instead of a reference load to form signals delta H and delta V from closely adjacent paired object patches. This novel imaging approach reduces common mode noise and enhances detection of small changes between the H and V polarization states of two object patches, now given as difference terms of the fully polarimetric radiometer. We present the theory of operation, initial proof of concept experimental results, and extension of the differential radiometer to a system with a binocular fore optics that allow adjustment of the convergence or shear of the object patches viewed by the differential polarimetric imager.

  5. The role of beryllium in the band structure of MgZnO: Lifting the valence band maximum

    SciTech Connect

    Chen, S. S.; Pan, X. H. E-mail: yezz@zju.edu.cn; Chen, W.; Zhang, H. H.; Dai, W.; Ding, P.; Huang, J. Y.; Lu, B.; Ye, Z. Z. E-mail: yezz@zju.edu.cn

    2014-09-22

    We investigate the effect of Be on the valence band maximum (VBM) of MgZnO by measuring the band offsets of Mg{sub x}Zn{sub 1−x}O/Be{sub x}Mg{sub y}Zn{sub 1−x−y}O heterojunctions using X-ray photoelectron spectroscopy measurements. Mg{sub x}Zn{sub 1−x}O and Be{sub x}Mg{sub y}Zn{sub 1−x−y}O films have been grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The valence band offset (ΔE{sub V}) of Mg{sub 0.15}Zn{sub 0.85}O (E{sub g} = 3.62 eV)/Be{sub 0.005}Mg{sub 0.19}Zn{sub 0.805}O (E{sub g} = 3.73 eV) heterojunction is 0.01 eV and Be{sub 0.005}Mg{sub 0.19}Zn{sub 0.805}O has a lower VBM. The increased Mg composition is the main factor for the reduction of VBM. The VBM of Mg{sub x}Zn{sub 1−x}O is lower by 0.03 eV with the enlargement of E{sub g} from 3.62 eV to 3.73 eV by increasing Mg composition. Considering the effect of increased Mg composition, it is concluded that the little amount of Be makes the VBM go up by 0.02 eV when the E{sub g} of the alloy is 3.73 eV. The ΔE{sub V} of Mg{sub 0.11}Zn{sub 0.89}O (E{sub g} = 3.56 eV)/Be{sub 0.007}Mg{sub 0.12}Zn{sub 0.873}O (E{sub g} = 3.56 eV) heterojunction is calculated to be 0.03 eV and Be{sub 0.007}Mg{sub 0.12}Zn{sub 0.873}O has a higher VBM than Mg{sub 0.11}Zn{sub 0.89}O, which means that a little amount Be lifts the VBM by 0.03 eV when the E{sub g} of the alloy is 3.56 eV. The experimental measurements have offered a strong support for the theoretical research that alloying Be in Mg{sub x}Zn{sub 1−x}O alloys is hopeful to form a higher VBM and to enhance the p-type dopability of MgZnO.

  6. Environmental Assessment and Finding of No Significant Impact: The Nevada Test Site Development Corporations's Desert Rock Sky Park at the Nevada Test Site

    SciTech Connect

    N /A

    2000-03-01

    The United States Department of Energy has prepared an Environmental Assessment (DOE/EA-1300) (EA) which analyzes the potential environmental effects of developing operating and maintaining a commercial/industrial park in Area 22 of the Nevada Test Site, between Mercury Camp and U.S. Highway 95 and east of Desert Rock Airport. The EA evaluates the potential impacts of infrastructure improvements necessary to support fill build out of the 512-acre Desert Rock Sky Park. Two alternative actions were evaluated: (1) Develop, operate and maintain a commercial/industrial park in Area 22 of the Nevada Test Site, and (2) taking no action. The purpose and need for the commercial industrial park are addressed in Section 1.0 of the EA. A detailed description of the proposed action and alternatives is in section 2.0. Section 3.0 describes the affected environment. Section 4.0 the environmental consequences of the proposed action and alternative. Cumulative effects are addressed in Section 5.0. Mitigation measures are addressed in Section 6.0. The Department of Energy determined that the proposed action of developing, operating and maintaining a commercial/industrial park in Area 22 of the Nevada Test Site would best meet the needs of the agency.

  7. Development of a Multi Megawatt Circulator for X Band

    SciTech Connect

    Neilson, J.; Ives, L.; Tantawi, S.G.; /Calabazas Creek Res., Saratoga /SLAC

    2008-03-24

    Research is in progress on a TeV-scale linear collider that will operate at 5-10 times the energy of present-generation accelerators. This will require development of high power RF sources generating of 50-100 MW per source. Transmission of power at this level requires overmoded waveguide to avoid breakdown. In particular, the TE{sub 01} circular waveguide mode is currently the mode of choice for waveguide transmission at Stanford Linear Accelerator Center (SLAC) in the Multimode Delay Line Distribution System (MDLDS). A common device for protecting an RF source from reflected power is the waveguide circulator. A circulator is typically a three-port device that allows low loss power transmission from the source to the load, but diverts power coming from the load (reflected power) to a third terminated port. To achieve a low loss, matched, three port junction requires nonreciprocal behavior. This is achieved using ferrites in a static magnetic field which introduces a propagation constant dependent on RF field direction relative to the static magnetic field. Circulators are currently available at X-Band for power levels up to 1 MW in fundamental rectangular waveguide; however, the next generation of RF sources for TeV-level accelerators will require circulators in the 50-100 MW range. Clearly, conventional technology is not capable of reaching the power level required. In this paper, we discuss the development of an X-Band circulator operating at multi-megawatt power levels in overmoded waveguide. The circulator will employ an innovative coaxial geometry using the TE{sub 01} mode. Difficulties in maintaining mode purity in oversized rectangular guide preclude increasing guide area to allow increasing the power level to the desired 50-100 MW range. The TE{sub 01} mode in circular waveguide is very robust mode for transmission of high power in overmoded waveguide. The mode is ideal for transmission of high power microwaves because of its low-losses, zero tangential

  8. Analysis of the efficiency of intermediate band solar cells based on quantum dot supercrystals

    SciTech Connect

    Heshmati, S; Golmohammadi, S; Abedi, K; Taleb, H

    2014-03-28

    We have studied the influence of the quantum-dot (QD) width and the quantum-dot conduction band (QD-CB) offset on the efficiency of quantum-dot intermediate band solar cells (QD-IBSCs). Simulation results demonstrate that with increasing QD-CB offset and decreasing QD width, the maximum efficiency is achieved. (laser applications and other topics in quantum electronics)

  9. Defect-Band Emission Photoluminescence Imaging on Multi-Crystalline Si Solar Cells: Preprint

    SciTech Connect

    Yan, F.; Johnston, S.; Zaunbrecher, K.; Al-Jassim, M.; Sidelkheir, O.; Blosse, A.

    2011-07-01

    Defect-band photoluminescence (PL) imaging with an InGaAs camera was applied to multicrystalline silicon (mc-Si) wafers, which were taken from different heights of different Si bricks. Neighboring wafers were picked at six different processing steps, from as-cut to post-metallization. By using different cut-off filters, we were able to separate the band-to-band emission images from the defect-band emission images. On the defect-band emission images, the bright regions that originate from the grain boundaries and defect clusters were extracted from the PL images. The area fraction percentage of these regions at various processing stages shows a correlation with the final cell electrical parameters.

  10. Dilute Group III-V nitride intermediate band solar cells with contact blocking layers

    DOEpatents

    Walukiewicz, Wladyslaw; Yu, Kin Man

    2012-07-31

    An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

  11. Dilute group III-V nitride intermediate band solar cells with contact blocking layers

    DOEpatents

    Walukiewicz, Wladyslaw; Yu, Kin Man

    2015-02-24

    An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

  12. DESERT RESEARCH INSTITUTE

    Office of Legacy Management (LM)

    CIRCULAR 1 2 CENTER FOR WATER R E S ~ U R C E ~ REHiARCH GROUND-WATER SERIES C - 1 GEOHYDROLOGIC DATA FROM THE PICEANCE CREEK B A S I N BETWEEN THE WHITE AND COLQRAD.0 RIVERS, NORTHWESTERN COLORADO D . L. C o f f i n , F . A. W e l d e r , R . K. G l a n z m a n , and X. W. D u t t o n U n i t e d S t a t e s G e o l o g i c a l Survey Prepared by T h e U n i t e d S t a t e s G e o l o g i c a l Survey i n c o o p e r a t i o n w i t h . 1 he C o l o r a . d o W a . t e r C o n s e r v a t i o

  13. Desert Peak EGS Project

    Energy.gov [DOE] (indexed site)

    Ethan Chabora GeothermEx, a Schlumberger Company Ezra Zemach Ormat Nevada Inc. ... Collaborations * Project Leader: Ormat Nevada, Inc. - Co-Management: GeothermEx, Inc. - ...

  14. Surviving Operation Desert Storm

    SciTech Connect

    Vice, J. )

    1992-08-01

    The importance of aircraft survivability during the invasion of Iraq is examined detailing anecdotal evidence of susceptibility and vulnerability reduction. Among the aircraft used that were designed to be more survivable than their predecessors were the F-117, A-10, F/A-18, and the AH-64. Reduced vulnerability is incorporated into the aircraft designs in the form of damage tolerant components, redundancy, self-sealing fluid systems, and miniaturization.

  15. Tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge

    SciTech Connect

    Inaoka, Takeshi Furukawa, Takuro; Toma, Ryo; Yanagisawa, Susumu

    2015-09-14

    By means of a hybrid density-functional method, we investigate the tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge. We consider [001], [111], and [110] uniaxial tensility and (001), (111), and (110) biaxial tensility. Under the condition of no normal stress, we determine both normal compression and internal strain, namely, relative displacement of two atoms in the primitive unit cell, by minimizing the total energy. We identify those strain types which can induce the band-gap transition, and evaluate the critical strain coefficient where the gap transition occurs. Either normal compression or internal strain operates unfavorably to induce the gap transition, which raises the critical strain coefficient or even blocks the transition. We also examine how each type of tensile strain decreases the band-gap energy, depending on its orientation. Our analysis clearly shows that synergistic operation of strain orientation and band anisotropy has a great influence on the gap transition and the gap energy.

  16. Band width and multiple-angle valence-state mapping of diamond

    SciTech Connect

    Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J.

    1997-04-01

    The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid`s many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of {+-}1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84{degrees} cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space.

  17. Evidence of ion intercalation mediated band structure modification and opto-ionic coupling in lithium niobite

    SciTech Connect

    Shank, Joshua C.; Tellekamp, M. Brooks; Doolittle, W. Alan

    2015-01-21

    The theoretically suggested band structure of the novel p-type semiconductor lithium niobite (LiNbO{sub 2}), the direct coupling of photons to ion motion, and optically induced band structure modifications are investigated by temperature dependent photoluminescence. LiNbO{sub 2} has previously been used as a memristor material but is shown here to be useful as a sensor owing to the electrical, optical, and chemical ease of lithium removal and insertion. Despite the high concentration of vacancies present in lithium niobite due to the intentional removal of lithium atoms, strong photoluminescence spectra are observed even at room temperature that experimentally confirm the suggested band structure implying transitions from a flat conduction band to a degenerate valence band. Removal of small amounts of lithium significantly modifies the photoluminescence spectra including additional larger than stoichiometric-band gap features. Sufficient removal of lithium results in the elimination of the photoluminescence response supporting the predicted transition from a direct to indirect band gap semiconductor. In addition, non-thermal coupling between the incident laser and lithium ions is observed and results in modulation of the electrical impedance.

  18. Electronic band structure and Kondo coupling in YbRh2Si2

    SciTech Connect

    Wigger, G.A.

    2010-04-15

    The electronic band structure of YbRh2Si2 is calculated in a relativistic framework including correlation corrections and magnetization of the Yb ion and compared to detailed angle-resolved photoemission spectra. The photoemission spectra for LuRh2Si2 are used as reference to identify electronic bands with no f symmetry. The calculated band structure manifests a 4f13 spin-polarized configuration leaving the unoccupied state at 1.4eV above the Fermi energy. At the band theory level, the 4f bands are located far below the Fermi level and the anisotropic Coulomb interaction within the 4f shell spreads the multilevel into broader 4f complexes below -2.5eV . The photoemission spectra obtained on YbRh2Si2 show a clear f -multilevel splitting into j=7/2 and 5/2 excitations. The interaction of the 4f7/2 levels close to the Fermi energy with two conduction bands shows visible hybridization gaps of 45 and 80meV, respectively. We discuss the origin of these excitations and provide an analysis according to Anderson's single-impurity model with parameters suggested by the band-structure calculation and the photoemission spectra. Both experiment and theory indicate nearly identical Fermi surfaces for LuRh2Si2 and YbRh2Si2 . The valency of Yb in YbRh2Si2 is estimated to be close to +3.

  19. RRI-GBT MULTI-BAND RECEIVER: MOTIVATION, DESIGN, AND DEVELOPMENT

    SciTech Connect

    Maan, Yogesh; Deshpande, Avinash A.; Chandrashekar, Vinutha; Chennamangalam, Jayanth; Rao, K. B. Raghavendra; Somashekar, R.; Ezhilarasi, M. S.; Sujatha, S.; Kasturi, S.; Sandhya, P.; Duraichelvan, R.; Amiri, Shahram; Aswathappa, H. A.; Sarabagopalan, G.; Ananda, H. M.; Anderson, Gary; Bauserman, Jonah; Beaudet, Carla; Bloss, Marty; Barve, Indrajit V.; and others

    2013-01-15

    We report the design and development of a self-contained multi-band receiver (MBR) system, intended for use with a single large aperture to facilitate sensitive and high time-resolution observations simultaneously in 10 discrete frequency bands sampling a wide spectral span (100-1500 MHz) in a nearly log-periodic fashion. The development of this system was primarily motivated by need for tomographic studies of pulsar polar emission regions. Although the system design is optimized for the primary goal, it is also suited for several other interesting astronomical investigations. The system consists of a dual-polarization multi-band feed (with discrete responses corresponding to the 10 bands pre-selected as relatively radio frequency interference free), a common wide-band radio frequency front-end, and independent back-end receiver chains for the 10 individual sub-bands. The raw voltage time sequences corresponding to 16 MHz bandwidth each for the two linear polarization channels and the 10 bands are recorded at the Nyquist rate simultaneously. We present the preliminary results from the tests and pulsar observations carried out with the Robert C. Byrd Green Bank Telescope using this receiver. The system performance implied by these results and possible improvements are also briefly discussed.

  20. Band bending at ferroelectric surfaces and interfaces investigated by x-ray photoelectron spectroscopy

    SciTech Connect

    Apostol, Nicoleta Georgiana

    2014-11-24

    This work reports on the use of X-ray photoelectron spectroscopy to quantify band bending at ferroelectric free surfaces and at their interfaces with metals. Surfaces exhibiting out-of-plane ferroelectric polarization are characterized by a band bending, due to the formation of a dipole layer at the surface, composed by the uncompensated polarization charges (due to ionic displacement) and to the depolarization charge sheet of opposite sign, composed by mobile charge carriers, which migrate near surface, owing to the depolarization electric field. To this surface band bending due to out-of-plane polarization states, metal-semiconductor Schottky barriers must be considered additionally when ferroelectrics are covered by metal layers. It is found that the net band bending is not always an algebraic sum of the two effects discussed above, since sometimes the metal is able to provide additional charge carriers, which are able to fully compensate the surface charge of the ferroelectric, up to the vanishing of the ferroelectric band bending. The two cases which will be discussed in more detail are Au and Cu deposited by molecular beam epitaxy on PbZr{sub 0.2}Ti{sub 0.8}O{sub 3}(001) single crystal thin layers, prepared by pulsed laser deposition. Gold forms unconnected nanoparticles, and their effect on the band bending is the apparition of a Schottky band bending additional to the band bending due to the out-of-plane polarization. Copper, starting with a given thickness, forms continuous metal layers connected to the ground of the system, and provide electrons in sufficient quantity to compensate the band bending due to the out-of-plane polarization.

  1. The use of bulk states to accelerate the band edge statecalculation of a semiconductor quantum dot

    SciTech Connect

    Vomel, Christof; Tomov, Stanimire Z.; Wang, Lin-Wang; Marques,Osni A.; Dongarra, Jack J.

    2006-05-10

    We present a new technique to accelerate the convergence of the folded spectrum method in empirical pseudopotential band edge state calculations for colloidal quantum dots. We use bulk band states of the materials constituent of the quantum dot to construct initial vectors and a preconditioner. We apply these to accelerate the convergence of the folded spectrum method for the interior states at the top of the valence and the bottom of the conduction band. For large CdSe quantum dots, the number of iteration steps until convergence decreases by about a factor of 4 compared to previous calculations.

  2. Strain-induced optical band gap variation of SnO2 films (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Strain-induced optical band gap variation of SnO2 films Citation Details In-Document Search This content will become publicly available on June 29, 2017 Title: Strain-induced optical band gap variation of SnO2 films In this paper, thickness dependent strain relaxation effects are utilized to study the impact of crystal anisotropy on the optical band gap of epitaxial SnO2 films grown by pulsed laser deposition on (0001)-oriented sapphire substrates. An X-ray diffraction

  3. ARM: Marine W-band (95 GHz) ARM Cloud Radar, filtered spectral data,

    Office of Scientific and Technical Information (OSTI)

    co-polarized mode (Dataset) | Data Explorer Marine W-band (95 GHz) ARM Cloud Radar, filtered spectral data, co-polarized mode Title: ARM: Marine W-band (95 GHz) ARM Cloud Radar, filtered spectral data, co-polarized mode Marine W-band (95 GHz) ARM Cloud Radar, filtered spectral data, co-polarized mode Authors: Joseph Hardin ; Bradley Isom ; Alyssa Matthews ; Karen Johnson ; Nitin Bharadwaj Publication Date: 2013-06-28 OSTI Identifier: 1150244 DOE Contract Number: DE-AC05-00OR22725 Resource

  4. Band alignment of TiO{sub 2}/FTO interface determined by X-ray

    Office of Scientific and Technical Information (OSTI)

    photoelectron spectroscopy: Effect of annealing (Journal Article) | SciTech Connect Band alignment of TiO{sub 2}/FTO interface determined by X-ray photoelectron spectroscopy: Effect of annealing Citation Details In-Document Search Title: Band alignment of TiO{sub 2}/FTO interface determined by X-ray photoelectron spectroscopy: Effect of annealing The energy band alignment between pulsed-laser-deposited TiO{sub 2} and FTO was firstly characterized using high-resolution X-ray photoelectron

  5. Electronic band structures and photovoltaic properties of MWO{sub 4} (M=Zn,

    Office of Scientific and Technical Information (OSTI)

    Mg, Ca, Sr) compounds (Journal Article) | SciTech Connect Electronic band structures and photovoltaic properties of MWO{sub 4} (M=Zn, Mg, Ca, Sr) compounds Citation Details In-Document Search Title: Electronic band structures and photovoltaic properties of MWO{sub 4} (M=Zn, Mg, Ca, Sr) compounds Divalent metal tungstates, MWO{sub 4}, with wolframite (M=Zn and Mg) and scheelite (M=Ca and Sr) structures were prepared using a conventional solid state reaction method. Their electronic band

  6. SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

    SciTech Connect

    L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK

    2004-01-01

    Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

  7. Dipole bands in high spin states of {sub 57}{sup 135}La{sub 78}

    SciTech Connect

    Garg, Ritika; Kumar, S.; Saxena, Mansi; Goyal, Savi; Siwal, Davinder; Verma, S.; Mandal, S.; Palit, R.; Saha, Sudipta; Sethi, J.; Sharma, Sushil K.; Trivedi, T.; Jadav, S. K.; Donthi, R.; Naidu, B. S.

    2014-08-14

    High spin states of {sup 135}La have been investigated using the reaction {sup 128}Te({sup 11}B,4n){sup 135}La at a beam energy of 50.5 MeV. Two negative parity dipole bands (?I = 1) have been established. Crossover E2 transitions have been observed for the first time in one of the dipole bands. For the Tilted Axis Cranking (TAC) calculations, a three-quasiparticle (3qp) configuration ?(h{sub 11/2}){sup 1}??(h{sub 11/2}){sup ?2} and a five-quasiparticle (5qp) configuration ?(h{sub 11/2}){sup 1}(g{sub 7/2}/d{sub 5/2}){sup 2}??(h{sub 11/2}){sup ?2} have been taken for the two negative parity dipole bands. The comparison of experimental observables with TAC calculations supports the configuration assignments for both the dipole bands.

  8. ARM: Auxiliary data for the Marine W-band (95 GHz) ARM Cloud...

    Office of Scientific and Technical Information (OSTI)

    Auxiliary data for the Marine W-band (95 GHz) ARM Cloud Radar Authors: Joseph Hardin ; Bradley Isom ; Alyssa Matthews ; Karen Johnson ; Nitin Bharadwaj Publication Date: 2012-11-01 ...

  9. Project Reports for Agua Caliente Band of Cahuilla Indians-2015 Project

    Energy.gov [DOE]

    Under this grant, Agua Caliente Band of Cahuilla Indians will install a 76.9-kilowatt (kW) SunEdison solar photovoltaic (PV) system to offset the energy usage costs of the Tribal Education and Family Services offices.

  10. Agua Caliente Band's Pursuit of Energy Self-Sufficiency Gains Momentum

    Energy.gov [DOE]

    The Agua Caliente Band of Cahuilla Indians in the Palm Springs area of California is a shining example of the type of leadership tribes can provide on the clean energy development front.

  11. Extended investigation of superdeformed bands in {sup 151,152}Tb nuclei

    SciTech Connect

    Robin, J.; Byrski, Th.; Duchene, G.; Beck, F. A.; Curien, D.; Dubray, N.; Dudek, J.; Courtin, S.; Dorvaux, O.; France, G. de; Gall, B.; Joshi, P.; Nourredine, A.; Pachoud, E.; Piqueras, I.; Vivien, J. P.; Gozdz, A.; Odahara, A.; Schunck, N.; Adimi, N.

    2008-01-15

    A detailed study of known and new SD bands in Tb isotopes has been performed with the use of the EUROBALL IV {gamma}-ray array. The high-statistics data set has allowed for the extension of known SD bands at low and high spins by new {gamma}-ray transitions. These transitions, as it turns out, correspond to the rotational frequencies where the principal superdeformed gaps (Z=66,N=86) close giving rise to up- or down-bending mechanisms. This enables to attribute the underlying theoretical configurations with much higher confidence as compared to the previous identifications. Five new SD bands have been discovered, three of them assigned to the {sup 152}Tb and the two others to the {sup 151}Tb nuclei. Nuclear mean-field calculations have been used to interpret the structure of known SD bands as well as of the new ones in terms of nucleonic configurations.

  12. ARM: X-Band Scanning ARM Cloud Radar (XSACR) RHI Scans, which...

    Office of Scientific and Technical Information (OSTI)

    X-Band Scanning ARM Cloud Radar (XSACR) RHI Scans, which can vary in elevation range and azimuth Authors: Dan Nelson ; Joseph Hardin ; Iosif 1 ; Bradley Isom ; Karen Johnson ; ...

  13. Band structure effects on resonant tunneling in III-V quantum...

    Office of Scientific and Technical Information (OSTI)

    in III-V quantum wells versus two-dimensional vertical heterostructures Citation Details In-Document Search Title: Band structure effects on resonant tunneling in III-V quantum ...

  14. Project Reports for Little River Band of Ottawa Indians- 2011 Project

    Energy.gov [DOE]

    The main purpose of this project is to increase human capacity of the Little River Band of Ottawa Indians (LRBOI) to understand the components of renewable energy and the importance of energy efficiency.

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

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

    ... The measured energy bands of indium atomic wires in the metallic state (left) and in the ... of indium wires on silicon with the soft x-ray angle-resolved photoemission endstation ...

  16. Ultra-High Gradient Compact S-Band Linac for Laboratory and Industrial Applications

    SciTech Connect

    Faillace, Luigi; Agustsson, Ronald; Frigola, Pedro; Murokh, Alex; Dolgashev, Valery; Rosenzweig, James; /UCLA

    2012-07-03

    There is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The commonly used S-band SLAC-type structure has an operating gradient of only about 20 MV/m; while much higher operating gradients (up to 70 MV/m) have been recently achieved in X-band, as a consequence of the substantial efforts by the Next Linear Collider (NLC) collaboration to push the performance envelope of RF structures towards higher accelerating gradients. Currently however, high power X-band RF sources are not readily available for industrial applications. Therefore, RadiaBeam Technologies is developing a short, standing wave S-band structure which uses frequency scaled NLC design concepts to achieve up to a 50 MV/m operating gradient at 2856 MHz. The design and prototype commissioning plans are presented.

  17. Project Reports for Scotts Valley Band of Pomo Indians- 2010 Project

    Energy.gov [DOE]

    The Scotts Valley Band of Pomo Indians in Lakeport, California, will establish a Tribal Multi-County Weatherization Energy Program to provide training, outreach, and education on energy assistance and conservation to low-income families.

  18. Intrinsic electron and hole bands in electron-doped cuprate superconductors

    SciTech Connect

    Xiang, T.

    2010-02-24

    We propose that the upper Hubbard band (electron-like) and the Zhang-Rice singlet band (holelike) are two essential components in describing low-energy excitations of electron-doped cuprate superconductors. We find that the gap between these two bands is significantly smaller than the charge-transfer gap measured by optics and is further reduced upon doping. This indicates that the charge fluctuation is strong and the system is in the intermediate correlation regime. A two-band model is derived. In the limit that the intraband and interband hopping integrals are equal to each other, this model is equivalent to the unconstrained t-J model with on-site Coulomb repulsions.

  19. Band structure engineering through orbital interaction for enhanced thermoelectric power factor

    SciTech Connect

    Zhu, Hong; Sun, Wenhao; Ceder, Gerbrand; Armiento, Rickard; Lazic, Predrag

    2014-02-24

    Band structure engineering for specific electronic or optical properties is essential for the further development of many important technologies including thermoelectrics, optoelectronics, and microelectronics. In this work, we report orbital interaction as a powerful tool to finetune the band structure and the transport properties of charge carriers in bulk crystalline semiconductors. The proposed mechanism of orbital interaction on band structure is demonstrated for IV-VI thermoelectric semiconductors. For IV-VI materials, we find that the convergence of multiple carrier pockets not only displays a strong correlation with the s-p and spin-orbit coupling but also coincides with the enhancement of power factor. Our results suggest a useful path to engineer the band structure and an enticing solid-solution design principle to enhance thermoelectric performance.

  20. Quasi-phase-matching of the dual-band nonlinear left-handed metamaterial

    SciTech Connect

    Liu, Yahong Song, Kun; Gu, Shuai; Liu, Zhaojun; Guo, Lei; Zhao, Xiaopeng; Zhou, Xin

    2014-11-17

    We demonstrate a type of nonlinear meta-atom creating a dual-band nonlinear left-handed metamaterial (DNLHM). The DNLHM operates at two distinct left-handed frequency bands where there is an interval of one octave between the two center frequencies. Under the illumination of a high-power signal at the first left-handed frequency band corresponding to fundamental frequency (FF), second-harmonic generation (SHG) is observed at the second left-handed band. This means that our DNLHM supports backward-propagating waves both at FF and second-harmonic (SH) frequency. We also experimentally demonstrate quasi-phase-matching configurations for the backward SHG. This fancy parametric process can significantly transmits the SH generated by an incident FF wave.

  1. Project Reports for Agua Caliente Band of Cahuilla Indians- 2012 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Agua Caliente Band of Cahuilla Indians (ACBCI) plans to complete a feasibility study to evaluate a combined wind/solar power generation project on its Whitewater Ranch trust lands in southern California.

  2. Significant Reduction in NiO Band Gap Upon Formation of LixNi1...

    Office of Scientific and Technical Information (OSTI)

    Significant Reduction in NiO Band Gap Upon Formation of LixNi1-xO alloys: Applications To Solar Energy Conversion Citation Details In-Document Search Title: Significant Reduction ...

  3. Project Reports for Agua Caliente Band of Cahuilla Indians- 2005 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Agua Caliente Band of Cahuilla Indians will establish a comprehensive energy strategic plan that captures economic and environmental benefits while continuing to respect tribal cultural practices and traditions.

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

    DOEpatents

    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.

  5. Prompt Proton Decay and Deformed Bands in 56Ni

    SciTech Connect

    Johansson, E. K.; Rudolph, D.; Andersson, L. L.; Torres, D. A.; Ragnarsson, I.; Andreoiu, C.; Baktash, Cyrus; Carpenter, M. P.; Charity, R. J.; Chiara, C. J.; Ekman, J.; Fahlander, C.; Hoel, C.; Pechenaya, O. L.; Reviol, W.; du Rietz, R.; Sarantites, D. G.; Seweryniak, D.; Sobotka, L. G.; Yu, Chang-Hong; Zhu, S.

    2008-06-01

    High-spin states in the doubly magic N=Z nucleus {sup 56}Ni have been investigated with three fusion-evaporation reaction experiments. New {gamma}-ray transitions are added, and a confirmation of a previously suggested prompt proton decay from a rotational band in {sup 56}Ni into the ground state of {sup 55}Co is presented. The rotational bands in {sup 56}Ni are discussed within the framework of cranked Nilsson-Strutinsky calculations.

  6. Solar Project Provides Jobs and Training for Moapa Band of Paiute Indians |

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

    Department of Energy Project Provides Jobs and Training for Moapa Band of Paiute Indians Solar Project Provides Jobs and Training for Moapa Band of Paiute Indians March 29, 2016 - 4:56pm Addthis Touring First Solar's 250-megawatt Moapa Southern Paiute Solar Project located on the Moapa River Reservation. From left to right: Office of Indian Energy Director Chris Deschene, Office of Indian Energy Senior Policy Advisor Doug MacCourt, National Renewable Energy Laboratory Engineer Sherry Stout,

  7. Project Reports for Ramona Band of Cahuilla Mission Indians- 2002 Project

    Energy.gov [DOE]

    The Ramona Band of Cahuilla Mission Indians ("Ramona Band" or "tribe") will be the first tribe to develop its entire reservation off-grid, using renewable energy as the primary power source. The tribe will purchase and install the primary components for a 65-80 kilowatt-hours per day central wind/PV/propane generator hybrid system that will power the reservation's housing, offices, ecotourism, and training businesses. The electricity is planned to be distributed through an underground mini-grid.

  8. Sharp exponential band tails in highly disordered lead sulfide quantum dot

    Office of Scientific and Technical Information (OSTI)

    arrays (Journal Article) | DOE PAGES Sharp exponential band tails in highly disordered lead sulfide quantum dot arrays Title: Sharp exponential band tails in highly disordered lead sulfide quantum dot arrays Authors: Erslev, Peter T. ; Chen, Hsiang-Yu ; Gao, Jianbo ; Beard, Matthew C. ; Frank, Arthur J. ; van de Lagemaat, Jao ; Johnson, Justin C. ; Luther, Joseph M. Publication Date: 2012-10-17 OSTI Identifier: 1101626 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B

  9. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Zenith Pointing PPI (Dataset)

    Office of Scientific and Technical Information (OSTI)

    | Data Explorer XSACR) Zenith Pointing PPI Title: ARM: X-Band Scanning ARM Cloud Radar (XSACR) Zenith Pointing PPI X-Band Scanning ARM Cloud Radar (XSACR) Zenith Pointing PPI Authors: Widener, Kevin ; Nelson, Dan ; Bharadwaj, Nitin ; Lindenmaier, Iosif [1] ; Johnson, Karen + Show Author Affiliations Andrei Publication Date: 2014-04-14 OSTI Identifier: 1150304 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Dataset Data Type: Numeric Data Research Org: Atmospheric Radiation Measurement

  10. Performance characteristics of a perforated shadow band under clear sky conditions

    SciTech Connect

    Brooks, Michael J.

    2010-12-15

    A perforated, non-rotating shadow band is described for separating global solar irradiance into its diffuse and direct normal components using a single pyranometer. Whereas shadow bands are normally solid so as to occult the sensor of a pyranometer throughout the day, the proposed band has apertures cut from its circumference to intermittently expose the instrument sensor at preset intervals. Under clear sky conditions the device produces a saw tooth waveform of irradiance data from which it is possible to reconstruct separate global and diffuse curves. The direct normal irradiance may then be calculated giving a complete breakdown of the irradiance curves without need of a second instrument or rotating shadow band. This paper describes the principle of operation of the band and gives a mathematical model of its shading mask based on the results of an optical ray tracing study. An algorithm for processing the data from the perforated band system is described and evaluated. In an extended trial conducted at NREL's Solar Radiation Research Laboratory, the band coupled with a thermally corrected Eppley PSP produced independent curves for diffuse, global and direct normal irradiance with low mean bias errors of 5.6 W/m{sup 2}, 0.3 W/m{sup 2} and -2.6 W/m{sup 2} respectively, relative to collocated reference instruments. Random uncertainties were 9.7 W/m{sup 2} (diffuse), 17.3 W/m{sup 2} (global) and 19.0 W/m{sup 2} (direct). When the data processing algorithm was modified to include the ray trace model of sensor exposure, uncertainties increased only marginally, confirming the effectiveness of the model. Deployment of the perforated band system can potentially increase the accuracy of data from ground stations in predominantly sunny areas where instrumentation is limited to a single pyranometer. (author)

  11. Grand Traverse Band of Ottawa & Chippewa Indians - Renewable Energy Feasibility Study

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

    DOE Tribal Energy Program Review DOE Tribal Energy Program Review Denver, Colorado Denver, Colorado November 5 November 5 - - 8, 2007 8, 2007 Final Report Final Report December 2007 December 2007 Grand Traverse Band Grand Traverse Band * * 4,023 Members 4,023 Members * * 2,370 Acres 2,370 Acres - - Checkerboard Checkerboard * * Six Six - - County Service Area County Service Area * * EDC: 2 Casinos, Resort (424 Rooms), EDC: 2 Casinos, Resort (424 Rooms), Gas Station, etc. Gas Station, etc. * *

  12. Grand Traverse Band of Ottawa and Chippewa Indians - Renewable Energy Feasibility Study

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

    DOE Tribal Energy Forum DOE Tribal Energy Forum October 25, 2006 October 25, 2006 Grand Traverse Band Grand Traverse Band * * 3,988 Members 3,988 Members * * 2,370 Acres 2,370 Acres - - Checkerboard Checkerboard * * Six Six - - County Service Area County Service Area * * EDC: 2 Casinos, Resort (424 Rooms), Gas EDC: 2 Casinos, Resort (424 Rooms), Gas Station, etc. Station, etc. * * Gov Gov ' ' t: Administration, Housing, Medicine t: Administration, Housing, Medicine Lodge, Strong Heart Center,

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

    SciTech Connect

    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.

  14. Discrete Electronic Bands in Semiconductors and Insulators: Potential High-Light-Yield Scintillators

    SciTech Connect

    Shi, Hongliang; Du, Mao-Hua

    2015-05-12

    Bulk semiconductors and insulators typically have continuous valence and conduction bands. In this paper, we show that valence and conduction bands of a multinary semiconductor or insulator can be split to narrow discrete bands separated by large energy gaps. This unique electronic structure is demonstrated by first-principles calculations in several quaternary elpasolite compounds, i.e., Cs2NaInBr6, Cs2NaBiCl6, and Tl2NaBiCl6. The narrow discrete band structure in these quaternary elpasolites is due to the large electronegativity difference among cations and the large nearest-neighbor distances in cation sublattices. We further use Cs2NaInBr6 as an example to show that the narrow bands can stabilize self-trapped and dopant-bound excitons (in which both the electron and the hole are strongly localized in static positions on adjacent sites) and promote strong exciton emission at room temperature. The discrete band structure should further suppress thermalization of hot carriers and may lead to enhanced impact ionization, which is usually considered inefficient in bulk semiconductors and insulators. Finally, these characteristics can enable efficient room-temperature light emission in low-gap scintillators and may overcome the light-yield bottleneck in current scintillator research.

  15. Electronic structure descriptor for the discovery of narrow-band red-emitting phosphors

    DOE PAGES [OSTI]

    Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; Ong, Shyue Ping

    2016-05-09

    Narrow-band red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-band Eu2+-activated emission identified through a comparison of the electronic structures of known narrow-band and broad-band phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu2+ 4f7 bands. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu2+-activated red-emitting phosphors that are predicted to exhibit goodmore » chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-band emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.« less

  16. Electronic Band Structure And Kondo Coupling in YbRh(2)Si(2)

    SciTech Connect

    Wigger, G.A.; Baumberger, F.; Shen, Z.X.; Yin, Z.P.; Pickett, W.E.; Maquilon, S.; Fisk, Z.; /UC, Davis

    2007-09-26

    The electronic band structure of YbRh{sub 2}Si{sub 2} is calculated in a relativistic framework including correlation corrections and magnetization of the Yb ion and compared to detailed angle-resolved photoemission spectra. The photoemission spectra for LuRh{sub 2}Si{sub 2} are used as reference to identify electronic bands with no f symmetry. The calculated band structure manifests a 4f{sup 13} spin-polarized configuration leaving the unoccupied state at 1.4 eV above the Fermi energy. At the band theory level, the 4f bands are located far below the Fermi level and the anisotropic Coulomb interaction within the 4f shell spreads the multilevel into broader 4f complexes below -2.5 eV. The photoemission spectra obtained on YbRh2Si2 show a clear f-multilevel splitting into j=7/2 and 5/2 excitations. The interaction of the 4f{sub 7/2} levels close to the Fermi energy with two conduction bands shows visible hybridization gaps of 45 and 80 meV, respectively. We discuss the origin of these excitations and provide an analysis according to Anderson's single-impurity model with parameters suggested by the band-structure calculation and the photoemission spectra. Both experiment and theory indicate nearly identical Fermi surfaces for LuRh{sub 2}Si{sub 2} and YbRh{sub 2}Si{sub 2}. The valency of Yb in YbRh{sub 2}Si{sub 2} is estimated to be close to +3.

  17. Preliminary experimental investigation of a complex dual-band high power microwave source

    SciTech Connect

    Zhang, Xiaoping Li, Yangmei; Li, Zhiqiang; Zhong, Huihuang; Qian, Baoliang

    2015-10-15

    In order to promote the power conversion efficiency of a magnetically insulated transmission line oscillator (MILO) and obtain microwaves in dual bands, an axially extracted C-band virtual cathode oscillator (VCO) with multiple resonant cavities is introduced to partially utilize the load current of an S-band MILO. The formed novel dual-band high power microwave source called MILO and VCO is investigated with simulation and experimentally. A dual-band radiation antenna is designed to effectively radiate microwaves generated by the MILO and the VCO, respectively, while avoiding them being influenced by the microwave reflection and diffraction. The preliminary experimental results measured by the dual-band diagnostic system show that both the MILO and the VCO operate normally under repeated shots. A microwave of 2.1 GHz, 1.70 GW is generated from the MILO and a 0.37 GW microwave at frequencies of 4.1 GHz and 3.8 GHz is generated from the VCO under the condition of about 440 kV and 35 kA. Compared with a single MILO (10.6%), a MILO and VCO achieves higher total power and efficiency (13.4%) in both S and C bands, indicating that the load current of the MILO partially couples into the beam-wave interaction in the VCO and then contributes to the output microwaves. However, more works are needed regarding the spectrum purification of the VCO and promotion of the output power of both the MILO and the VCO.

  18. Reading data stored in the state of metastable defects in silicon using band-band photoluminescence: Proof of concept and physical limits to the data storage density

    SciTech Connect

    Rougieux, F. E.; Macdonald, D.

    2014-03-24

    The state of bistable defects in crystalline silicon such as iron-boron pairs or the boron-oxygen defect can be changed at room temperature. In this letter, we experimentally demonstrate that the chemical state of a group of defects can be changed to represent a bit of information. The state can then be read without direct contact via the intensity of the emitted band-band photoluminescence signal of the group of defects, via their impact on the carrier lifetime. The theoretical limit of the information density is then computed. The information density is shown to be low for two-dimensional storage but significant for three-dimensional data storage. Finally, we compute the maximum storage capacity as a function of the lower limit of the photoluminescence detector sensitivity.

  19. J- AND H-BAND IMAGING OF AKARI NORTH ECLIPTIC POLE SURVEY FIELD

    SciTech Connect

    Jeon, Yiseul; Im, Myungshin; Kang, Eugene; Lee, Hyung Mok; Matsuhara, Hideo E-mail: mim@astro.snu.ac.kr

    2014-10-01

    We present the J- and H-band source catalog covering the AKARI North Ecliptic Pole field. Filling the gap between the optical data from other follow-up observations and mid-infrared (MIR) data from AKARI, our near-infrared (NIR) data provides contiguous wavelength coverage from optical to MIR. For the J- and H-band imaging, we used the FLoridA Multi-object Imaging Near-ir Grism Observational Spectrometer on the Kitt Peak National Observatory 2.1m telescope covering a 5.1 deg{sup 2} area down to a 5σ depth of ∼21.6 mag and ∼21.3 mag (AB) for the J and H bands with an astrometric accuracy of 0.''14 and 0.''17 for 1σ in R.A. and decl. directions, respectively. We detected 208,020 sources for the J band and 203,832 sources for the H band. This NIR data is being used for studies including the analysis of the physical properties of infrared sources such as stellar mass and photometric redshifts, and will be a valuable data set for various future missions.

  20. Method for producing a thin sample band in a microchannel device

    DOEpatents

    Griffiths, Stewart K.; Nilson, Robert H.

    2004-08-03

    The present invention improves the performance of microchannel systems for chemical and biological synthesis and analysis by providing a method and apparatus for producing a thin band of a species sample. Thin sample bands improve the resolution of microchannel separation processes, as well as many other processes requiring precise control of sample size and volume. The new method comprises a series of steps in which a species sample is manipulated by controlled transport through a junction formed at the intersection of four or more channels. A sample is first inserted into the end of one of these channels in the vicinity of the junction. Next, this sample is thinned by transport across the junction one or more times. During these thinning steps, flow enters the junction through one of the channels and exists through those remaining, providing a divergent flow field that progressively stretches and thins the band with each traverse of the junction. The thickness of the resulting sample band may be smaller than the channel width. Moreover, the thickness of the band may be varied and controlled by altering the method alone, without modification to the channel or junction geometries. The invention is applicable to both electroosmotic and electrophoretic transport, to combined electrokinetic transport, and to some special cases in which bulk fluid transport is driven by pressure gradients. It is further applicable to channels that are open, filled with a gel or filled with a porous or granular material.

  1. Apparatus for producing a thin sample band in a microchannel system

    DOEpatents

    Griffiths, Stewart K.

    2008-05-13

    The present invention improves the performance of microchannel systems for chemical and biological synthesis and analysis by providing a method and apparatus for producing a thin band of a species sample. Thin sample bands improve the resolution of microchannel separation processes, as well as many other processes requiring precise control of sample size and volume. The new method comprises a series of steps in which a species sample is manipulated by controlled transport through a junction formed at the intersection of four or more channels. A sample is first inserted into the end of one of these channels in the vicinity of the junction. Next, this sample is thinned by transport across the junction one or more times. During these thinning steps, flow enters the junction through one of the channels and exists through those remaining, providing a divergent flow field that progressively stretches and thins the band with each traverse of the junction. The thickness of the resulting sample band may be smaller than the channel width. Moreover, the thickness of the band may be varied and controlled by altering the method alone, without modification to the channel or junction geometries. The invention is applicable to both electroosmotic and electrophoretic transport, to combined electrokinetic transport, and to some special cases in which bulk fluid transport is driven by pressure gradients. It is further applicable to channels that are open, filled with a gel or filled with a porous or granular material.

  2. Band structure engineering and thermoelectric properties of charge-compensated filled skutterudites

    DOE PAGES [OSTI]

    Shi, Xiaoya; Yang, Jiong; Wu, Lijun; Salvador, James R.; Zhang, Cheng; Villaire, William L.; Haddad, Daad; Yang, Jihui; Zhu, Yimei; Li, Qiang

    2015-10-12

    Thermoelectric properties of semiconductors are intimately related to their electronic band structure, which can be engineered via chemical doping. Dopant Ga in the cage-structured skutterudite Co4Sb12 substitutes Sb sites while occupying the void sites. Combining quantitative scanning transmission electron microscopy and first-principles calculations, we show that Ga dual-site occupancy breaks the symmetry of the Sb-Sb network, splits the deep triply-degenerate conduction bands, and drives them downward to the band edge. The charge-compensating nature of the dual occupancy Ga increases overall filling fraction limit. By imparting this unique band structure feature, and judiciously doping the materials by increasing the Yb content,more » we promote the Fermi level to a point where carriers are in energetic proximity to these features. Increased participation of these heavier bands in electronic transport leads to increased thermopower and effective mass. Further, the localized distortion from Ga/Sb substitution enhances the phonon scattering to reduce the thermal conductivity effectively.« less

  3. Band structure engineering and thermoelectric properties of charge-compensated filled skutterudites

    SciTech Connect

    Shi, Xiaoya; Yang, Jiong; Wu, Lijun; Salvador, James R.; Zhang, Cheng; Villaire, William L.; Haddad, Daad; Yang, Jihui; Zhu, Yimei; Li, Qiang

    2015-10-12

    Thermoelectric properties of semiconductors are intimately related to their electronic band structure, which can be engineered via chemical doping. Dopant Ga in the cage-structured skutterudite Co4Sb12 substitutes Sb sites while occupying the void sites. Combining quantitative scanning transmission electron microscopy and first-principles calculations, we show that Ga dual-site occupancy breaks the symmetry of the Sb-Sb network, splits the deep triply-degenerate conduction bands, and drives them downward to the band edge. The charge-compensating nature of the dual occupancy Ga increases overall filling fraction limit. By imparting this unique band structure feature, and judiciously doping the materials by increasing the Yb content, we promote the Fermi level to a point where carriers are in energetic proximity to these features. Increased participation of these heavier bands in electronic transport leads to increased thermopower and effective mass. Further, the localized distortion from Ga/Sb substitution enhances the phonon scattering to reduce the thermal conductivity effectively.

  4. Formation of Bragg band gaps in anisotropic phononic crystals analyzed with the empty lattice model

    DOE PAGES [OSTI]

    Wang, Yan -Feng; Maznev, Alexei; Laude, Vincent

    2016-05-11

    Bragg band gaps of phononic crystals generally, but not always, open at Brillouin zone boundaries. The commonly accepted explanation stems from the empty lattice model: assuming a small material contrast between the constituents of the unit cell, avoided crossings in the phononic band structure appear at frequencies and wavenumbers corresponding to band intersections; for scalar waves the lowest intersections coincide with boundaries of the first Brillouin zone. However, if a phononic crystal contains elastically anisotropic materials, its overall symmetry is not dictated solely by the lattice symmetry. We construct an empty lattice model for phononic crystals made of isotropic andmore » anisotropic materials, based on their slowness curves. We find that, in the anisotropic case, avoided crossings generally do not appear at the boundaries of traditionally defined Brillouin zones. Furthermore, the Bragg "planes" which give rise to phononic band gaps, are generally not flat planes but curved surfaces. Lastly, the same is found to be the case for avoided crossings between shear (transverse) and longitudinal bands in the isotropic case.« less

  5. ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, S-band Radar (williams-s_band)

    DOE Data Explorer

    Williams, Christopher

    2012-11-06

    This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

  6. Valence-band electronic structure evolution of graphene oxide upon thermal annealing for optoelectronics

    DOE PAGES [OSTI]

    Yamaguchi, Hisato; Ogawa, Shuichi; Watanabe, Daiki; Hozumi, Hideaki; Gao, Yongqian; Eda, Goki; Mattevi, Cecilia; Fujita, Takeshi; Yoshigoe, Akitaka; Ishizuka, Shinji; et al

    2016-04-08

    We report valence band electronic structure evolution of graphene oxide (GO) upon its thermal reduction. Degree of oxygen functionalization was controlled by annealing temperatures, and an electronic structure evolution was monitored using real-time ultraviolet photoelectron spectroscopy. We observed a drastic increase in density of states around the Fermi level upon thermal annealing at ~600 °C. The result indicates that while there is an apparent band gap for GO prior to a thermal reduction, the gap closes after an annealing around that temperature. This trend of band gap closure was correlated with electrical, chemical, and structural properties to determine a setmore » of GO material properties that is optimal for optoelectronics. The results revealed that annealing at a temperature of ~500 °C leads to the desired properties, demonstrated by a uniform and an order of magnitude enhanced photocurrent map of an individual GO sheet compared to as-synthesized counterpart.« less

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

    DOEpatents

    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.

  8. A new silicon phase with direct band gap and novel optoelectronic properties

    SciTech Connect

    Guo, Yaguang; Wang, Qian; Kawazoe, Yoshiyuki; Jena, Puru

    2015-09-23

    Due to the compatibility with the well-developed Si-based semiconductor industry, there is considerable interest in developing silicon structures with direct energy band gaps for effective sunlight harvesting. In this paper, using silicon triangles as the building block, we propose a new silicon allotrope with a direct band gap of 0.61 eV, which is dynamically, thermally and mechanically stable. Symmetry group analysis further suggests that dipole transition at the direct band gap is allowed. Additionally, this new allotrope displays large carrier mobility (~104 cm/V · s) at room temperature and a low mass density (1.71 g/cm3), making it a promising material for optoelectronic applications.

  9. A new silicon phase with direct band gap and novel optoelectronic properties

    DOE PAGES [OSTI]

    Guo, Yaguang; Wang, Qian; Kawazoe, Yoshiyuki; Jena, Puru

    2015-09-23

    Due to the compatibility with the well-developed Si-based semiconductor industry, there is considerable interest in developing silicon structures with direct energy band gaps for effective sunlight harvesting. In this paper, using silicon triangles as the building block, we propose a new silicon allotrope with a direct band gap of 0.61 eV, which is dynamically, thermally and mechanically stable. Symmetry group analysis further suggests that dipole transition at the direct band gap is allowed. Additionally, this new allotrope displays large carrier mobility (~104 cm/V · s) at room temperature and a low mass density (1.71 g/cm3), making it a promising materialmore » for optoelectronic applications.« less

  10. Structure and dynamics of shear bands in amorphous–crystalline nanolaminates

    SciTech Connect

    Guo, Wei; Gan, Bin; Molina-Aldareguia, Jon M.; Poplawsky, Jonathan D.; Raabe, Dierk

    2015-01-01

    In this paper, the velocities of shear bands in amorphous CuZr/crystalline Cu nanolaminates were quantified as a function of strain rate and crystalline volume fraction. A rate-dependent transition in flow response was found in a 100 nm CuZr/10 nm Cu nanolaminates. When increasing the Cu layer thickness from 10 nm to 100 nm, the instantaneous velocity of the shear band in these nanolaminates decreases from 11.2 μm/s to <~500 nm/s. Finally, atom probe tomography and transmission election microcopy observation revealed that in post-deformed pillars both grain rotation in the crystalline portion and non-diffusive crystallization in the amorphous layer affect the viscosity of shear bands.

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

    SciTech Connect

    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.

  12. Asymmetric band flipping for time-of-flight neutron diffraction data

    DOE PAGES [OSTI]

    Whitfield, Pamela S.; Coelho, Alan A.

    2016-08-24

    Charge flipping with powder diffraction data is known to produce a result more reliably with high-resolution data,i.e.visible reflections at smalldspacings. This data are readily accessible with the neutron time-of-flight technique but the assumption that negative scattering density is nonphysical is no longer valid where elements with negative scattering lengths are present. The concept of band flipping was introduced in the literature, where a negative threshold is used in addition to a positive threshold during the flipping. But, it was not tested with experimental data at the time. Finallly, band flipping has been implemented inTOPAStogether with the band modification of low-densitymore » elimination and tested with experimental powder and Laue single-crystal neutron data.« less

  13. Effect of Sn on the optical band gap determined using absorption spectrum fitting method

    SciTech Connect

    Heera, Pawan; Kumar, Anup; Sharma, Raman

    2015-05-15

    We report the preparation and the optical studies on tellurium rich glasses thin films. The thin films of Se{sub 30}Te{sub 70-x} Sn{sub x} system for x= 0, 1.5, 2.5 and 4.5 glassy alloys prepared by melt quenching technique are deposited on the glass substrate using vacuum thermal evaporation technique. The analysis of absorption spectra in the spectral range 400nm–4000 nm at room temperature obtained from UV-VIS-NIR spectrophotometer [Perkin Elmer Lamda-750] helps us in the optical characterization of the thin films under study. The absorption spectrum fitting method is applied by using the Tauc’s model for estimating the optical band gap and the width of the band tail of the thin films. The optical band gap is calculated and is found to decrease with the Sn content.

  14. Analysis of several high-resolution infrared bands of spiropentane, C5H8

    SciTech Connect

    Maki, Arthur G.; Price, Joseph E.; Harzan, J.; Nibler, Joseph W.; Weber, Alfons; Masiello, Tony; Blake, Thomas A.

    2015-06-01

    he high-resolution infrared absorption spectrum of spiropentane (C5H8) has been measured from 200 to 4000 cm 1, and a detailed analysis is presented for eight bands in the region from 700 to 2200 cm 1. Two fundamental perpendicular bands were analyzed, m22 and m24 near 1050 and 780 cm 1, respectively, along with two fundamental parallel bands, m14 and m16 near 1540 and 990 cm1, respectively. Two other fundamentals, m17 and m23, are seen as intense overlapping bands near 880 cm*1 and are Coriolis-coupled, producing a complex mixture in which only P-branch transitions could be tentatively assigned for m17. In addition, three binary combination bands were fit at about 1570, 2082, and 2098 cm*1 which are assigned as either 2m24 or m5 + m16 in the first case, m4 + m22 in the second case, and 2m22 in the latter case. The two l-type resonance constants, q+ and q*, were determined for each of the two perpendicular fundamentals m22 and m24. Those two constants were also responsible for splittings observed in the K = 3 levels of m24. For the ground state the order of the split K = 2 B1/B2 levels has been reversed from that reported previously, based on the measurements and assignments for the m24 band. Rovibrational parameters deduced from the analyses are compared with those obtained from density functional Gaussian calculations at the anharmonic level.

  15. Soboba Band of Luiseño Indians Celebrates Initial Step Toward Achieving

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

    Its Tribal Energy Vision | Department of Energy Soboba Band of Luiseño Indians Celebrates Initial Step Toward Achieving Its Tribal Energy Vision Soboba Band of Luiseño Indians Celebrates Initial Step Toward Achieving Its Tribal Energy Vision July 27, 2016 - 2:16pm Addthis On July 25, Office of Indian Energy Director Chris Deschene joined Soboba Tribal Council Vice-Chair Isaiah Vivanco, other members of the tribal council and staff, and partners from Southern California Edison and Optimum

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

    SciTech Connect

    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.

  17. A Minimal Two-band Model for the Superconducting Fe-pnictides

    SciTech Connect

    Raghu, S.

    2010-03-25

    Following the discovery of the Fe-pnictide superconductors, LDA band structure calculations showed that the dominant contributions to the spectral weight near the Fermi energy came from the Fe 3d orbitals. The Fermi surface is characterized by two hole surfaces around the {Lambda} point and two electron surfaces around the M point of the 2 Fe/cell Brillouin zone. Here, we describe a 2-band model that reproduces the topology of the LDA Fermi surface and exhibits both ferromagnetic and q = ({pi}, 0) spin density wave (SDW) fluctuations. We argue that this minimal model contains the essential low energy physics of these materials.

  18. Complex and real unconventional Bose-Einstein condensations in high orbital bands

    SciTech Connect

    Cai Zi; Wu Congjun

    2011-09-15

    We perform a theoretical study on the recently observed unconventional Bose-Einstein condensations (UBEC) in the high bands of optical lattices. These exotic states are characterized by complex-valued condensate wave functions with nodal points or real-valued wave functions with nodal lines; thus, they are beyond the ''no-node'' theorem of conventional BECs. A quantum phase transition is driven by the competition between the single-particle band and interaction energies. The complex UBECs spontaneously break time-reversal symmetry, exhibiting a vortex-antivortex lattice structure.

  19. Defect-band mediated ferromagnetism in Gd-doped ZnO thin films

    SciTech Connect

    Venkatesh, S.; Roqan, I. S.; Franklin, J. B.; Ryan, M. P.; McLachlan, M. A.; Alford, N. M.; Lee, J.-S.; Ohldag, Hendrik

    2015-01-07

    Gd-doped ZnO thin films prepared by pulsed laser deposition with Gd concentrations varying from 0.02–0.45 atomic percent (at. %) showed deposition oxygen pressure controlled ferromagnetism. Thin films prepared with Gd dopant levels (band formed due to oxygen deficiency related defect complexes. Mott's theory of variable range of hopping conduction confirms the formation of the impurity/defect band near the Fermi level.

  20. Development of an L-Band RF Electron Gun for SASE in the Infrared Region

    SciTech Connect

    Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro; Hayano, Hitoshi; Urakawa, Junji

    2010-02-03

    We conduct research on Self-Amplified Spontaneous Emission (SASE) in the infrared region using the 40 MeV, 1.3 GHz L-band linac of Osaka University. The linac equipped with a thermionic electron gun can accelerate a high-intensity single-bunch beam though its normalized emittance is high. In order to advance the research on SASE, we have begun development of an RF gun for the L-band linac in collaboration with KEK. We will report conceptual design of the RF gun and present the status of development of another RF gun for STF at KEK.

  1. Systematic approach for simultaneously correcting the band-gap and p - d

    Office of Scientific and Technical Information (OSTI)

    separation errors of common cation III-V or II-VI binaries in density functional theory calculations within a local density approximation (Journal Article) | SciTech Connect Systematic approach for simultaneously correcting the band-gap and p - d separation errors of common cation III-V or II-VI binaries in density functional theory calculations within a local density approximation Citation Details In-Document Search Title: Systematic approach for simultaneously correcting the band-gap and p

  2. A panel of sequence tagged sites for chromosome band 11q23

    SciTech Connect

    Tunnacliffe, A.; Perry, H. ); Radice, P. Istituto Nazionale Tumori, Milan ); Budarf, M.L.; Emanuel, B.S. )

    1993-09-01

    A panel of sequence tagged sites (STSs) representing 30 markers previously assigned to human chromosome band 11q23 has been assembled. Eleven STSs represent cloned genes, and the remainder are from anonymous DNA segments. The STSs have been used in PCR experiments to localize their cognate sequences further with respect to five translocation breakpoints that define three intervals in 11q23. Two of these translocation breakpoints have been mapped more precisely by the STS assignments. The STS panel will form a useful starting point for the generation of a genomic contig of band 11q23. 32 refs., 1 fig., 1 tab.

  3. Realizing novel accelerator concepts in an X-band photo-injector

    SciTech Connect

    Marsh, R

    2010-04-13

    In this project we propose to investigate the use of novel accelerator structure cell geometry to enhance the performance of X-band photo-injectors. Making novel accelerator concepts possible involves fabrication and testing of components to ensure that the performance predicted by simulation is robustly achievable. This work is important because photo-injectors are increasingly used to provide high brightness electron beams for light sources, pushing their performance to the limits, but also requiring them to be user-facility stable. Careful investigation in both computer simulation and design, and low power testing of piece parts will enable the successful fabrication of an advanced X-band photo-injector.

  4. Leaf seal for gas turbine stator shrouds and a nozzle band

    DOEpatents

    Burdgick, Steven Sebastian; Sexton, Brendan Francis

    2002-01-01

    A leaf seal assembly is secured to the trailing edge of a shroud segment for sealing between the shroud segment and the leading edge side wall of a nozzle outer band. The leaf seal includes a circumferentially elongated seal plate biased by a pair of spring clips disposed in a groove along the trailing edge of the shroud segment to maintain the seal plate in engagement with the flange on the leading edge side wall of the nozzle outer band. The leaf seal plate and spring clips receive pins tack-welded to the shroud segment to secure the leaf seal assembly in place.

  5. ARM: X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector Raster Scan

    Office of Scientific and Technical Information (OSTI)

    (Dataset) | Data Explorer W-SACR) Corner Reflector Raster Scan Title: ARM: X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector Raster Scan X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector Raster Scan Authors: Joseph Hardin ; Dan Nelson ; Iosif [1] ; Bradley Isom ; Karen Johnson ; Alyssa Matthews ; Nitin Bharadwaj + Show Author Affiliations (Andrei) Lindenmaier Publication Date: 2014-03-07 OSTI Identifier: 1150295 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Dataset

  6. ARM: X-Band Scanning ARM Cloud Radar (X-SACR) Side-Looking Radar (Dataset)

    Office of Scientific and Technical Information (OSTI)

    | Data Explorer X-SACR) Side-Looking Radar Title: ARM: X-Band Scanning ARM Cloud Radar (X-SACR) Side-Looking Radar X-Band Scanning ARM Cloud Radar (X-SACR) Side-Looking Radar Authors: Dan Nelson ; Joseph Hardin ; Iosif [1] ; Bradley Isom ; Karen Johnson ; Nitin Bharadwaj + Show Author Affiliations (Andrei) Lindenmaier Publication Date: 2014-01-16 OSTI Identifier: 1150300 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Dataset Data Type: Numeric Data Research Org: Atmospheric Radiation

  7. ARM - Publications: Science Team Meeting Documents: W-Band ARM Cloud Radar

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

    System W-Band ARM Cloud Radar System Mead, James ProSensing Inc. Widener, Kevin Pacific Northwest National Laboratory The W-Band ARM Cloud Radar (WACR) is a dual polarization 95 GHz radar that will be deployed at the SGP CART site in the spring of 2005. The WACR system will be installed in the existing MMCR shelter, and will provide continuous zenith pointing measurements of clouds to compliment measurements provided by MMCR. Built by ProSensing Inc. of Amherst, MA, the WACR system include a

  8. TWO PLANETARY COMPANIONS AROUND THE K7 DWARF GJ 221: A HOT SUPER-EARTH AND A CANDIDATE IN THE SUB-SATURN DESERT RANGE

    SciTech Connect

    Arriagada, Pamela; Minniti, Dante; Anglada-Escude, Guillem; Butler, R. Paul; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian; Wende, Sebastian

    2013-07-01

    We report two low-mass companions orbiting the nearby K7 dwarf GJ 221 that have emerged from reanalyzing 4.4 yr of publicly available HARPS spectra complemented with 2 years of high-precision Doppler measurements with Magellan/PFS. The HARPS measurements alone contain the clear signal of a low-mass companion with a period of 125 days and a minimum mass of 53.2 M{sub Circled-Plus} (GJ 221b), falling in a mass range where very few planet candidates have been found (sub-Saturn desert). The addition of 17 PFS observations allows the confident detection of a second low-mass companion (6.5 M{sub Circled-Plus }) in a hot orbit (3.87 day period, GJ 221c). Spectroscopic and photometric calibrations suggest that GJ 221 is slightly depleted ([Fe/H] {approx} -0.1) compared to the Sun, so the presence of two low-mass companions in the system confirms the trend that slightly reduced stellar metallicity does not prevent the formation of planets in the super-Earth to sub-Saturn mass regime.

  9. Burlap bands as a sampling technique for green anoles (Anolis carolinensis) and other reptiles commonly found on tree boles.

    SciTech Connect

    Horn, Scott; Hanula, James L.

    2006-07-01

    This paper examines the use and successfulness of using burlap bands on tree boles as a sampling technique for green anoles.

  10. Project Reports for Lac Courte Oreilles Band of Lake Superior Chippewa Indians- 2007 Project

    Energy.gov [DOE]

    The Lac Courte Oreilles Band of Lake Superior Chippewa will gather and compile information on the tribe's energy use, conduct energy audits of reservation facilities, identify where conservation efforts would be worthwhile, and evaluate policy changes needed to implement conservation measures.

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

    SciTech Connect

    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. G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product

    SciTech Connect

    Koontz, A; Cadeddu, M

    2012-12-05

    The G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) value-added product (VAP) computes precipitable water vapor using neural network techniques from data measured by the GVR. The GVR reports time-series measurements of brightness temperatures for four channels located at 183.3 ± 1, 3, 7, and 14 GHz.

  13. Lac Courte Oreilles Band of Lake Superior Chippewa Indians- 2007 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Lac Courte Oreilles Band of Lake Superior Chippewa will gather and compile information on the tribe's energy use, conduct energy audits of reservation facilities, identify where conservation efforts would be worthwhile, and evaluate policy changes needed to implement conservation measures.

  14. Discrete decay of the yrast superdeformed band in the {sup 151}Tb nucleus

    SciTech Connect

    Robin, J.; Duchene, G.; Beck, F. A.; Byrski, Th.; Curien, D.; Courtin, S.; Dorvaux, O.; Gall, B.; Nourredine, A.; Pachoud, E.; Piqueras, I.; Vivien, J. P.; Twin, P.; Cullen, D. M.; King, S. L.; Paul, E. S.; Adimi, N.; Appelbe, D. E.; Simpson, J.

    2008-09-15

    The Euroball array has been used to search for linking transitions between the superdeformed (SD) and the normal deformed (ND) wells in {sup 151}Tb. Many {gamma} rays in the energy range 2-4 MeV have been observed in coincidence with the yrast SD band. It is proposed that the highest energy transition of 3748 keV and the strongest line (2818 keV) of the previously observed transitions both decay from the same SD level as their links with the ND states have been identified. The current spectra have insufficient statistics to completely identify the decay point in the SD band. Theoretical calculations covering SD bands in the A{approx_equal}150 region enable the two possible spin assignments to be compared with experimental data on proposed links in {sup 149}Gd and {sup 152}Dy. It is concluded that the energy of the lowest SD band member in {sup 151}Tb has an excitation energy of 12861 keV and a spin of 65/2{sup +}.

  15. Quasi one-dimensional band dispersion and surface metallization in long-range ordered polymeric wires

    DOE PAGES [OSTI]

    Vasseur, Guillaume; Fagot-Revurat, Yannick; Sicot, Muriel; Kierren, Bertrand; Moreau, Luc; Malterre, Daniel; Cardenas, Luis; Galeotti, Gianluca; Lipton-Duffin, Josh; Rosei, Frederico; et al

    2016-01-04

    We study the electronic structure of an ordered array of poly(para-phenylene) chains produced by surface-catalyzed dehalogenative polymerization of 1,4-dibromobenzene on copper (110). The quantization of unoccupied molecular states is measured as a function of oligomer length by scanning tunnelling spectroscopy, with Fermi level crossings observed for chains longer than ten phenyl rings. Angle-resolved photoelectron spectroscopy reveals a quasi-one-dimensional valence band as well as a direct gap of 1.15 eV, as the conduction band is partially filled through adsorption on the surface. Tight-binding modelling and ab initio density functional theory calculations lead to a full description of the organic band-structure, includingmore » the k-dispersion, the gap size and electron charge transfer mechanisms, highlighting a strong substrate-molecule interaction that drives the system into a metallic behaviour. In summary, we have fully characterized the band structure of a carbon-based conducting wire. This model system may be considered as a fingerprint of -conjugation of surface organic frameworks.« less

  16. 3D Band Diagram and Photoexcitation of 2D–3D Semiconductor Heterojunctions

    DOE PAGES [OSTI]

    Li, Bo; Shi, Gang; Lei, Sidong; He, Yongmin; Gao, Weilu; Gong, Yongji; Ye, Gonglan; Zhou, Wu; Keyshar, Kunttal; Hao, Ji; et al

    2015-08-17

    The emergence of a rich variety of two-dimensional (2D) layered semiconductor materials has enabled the creation of atomically thin heterojunction devices. Junctions between atomically thin 2D layers and 3D bulk semiconductors can lead to junctions that are fundamentally electronically different from the covalently bonded conventional semiconductor junctions. In this paper, we propose a new 3D band diagram for the heterojunction formed between n-type monolayer MoS2 and p-type Si, in which the conduction and valence band-edges of the MoS2 monolayer are drawn for both stacked and in-plane directions. This new band diagram helps visualize the flow of charge carriers inside themore » device in a 3D manner. Our detailed wavelength-dependent photocurrent measurements fully support the diagrams and unambiguously show that the band alignment is type I for this 2D-3D heterojunction. Photogenerated electron–hole pairs in the atomically thin monolayer are separated and driven by an external bias and control the “on/off” states of the junction photodetector device. Finally, two photoresponse regimes with fast and slow relaxation are also revealed in time-resolved photocurrent measurements, suggesting the important role played by charge trap states.« less

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

    SciTech Connect

    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.

  18. Study of transmission line attenuation in broad band millimeter wave frequency range

    SciTech Connect

    Pandya, Hitesh Kumar B.; Austin, M. E.; Ellis, R. F.

    2013-10-15

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

  19. Project Reports for Pala Band of Mission Indians – 2015 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Under this grant, the Pala Band of Mission Indians plan on building a 94.8-kilowatt (kW) DC solar system on its fire station. The system will use a combination of rooftop PV and ground-mounted panels that will be installed on land adjacent to the Pala Indian Reservation’s fire station.

  20. X-Band Multi-Beam Klystron Design and Progress Report

    SciTech Connect

    Jensen, Aaron; Neilson, Jeff; Tantawi, Sami

    2015-04-15

    Progress on the development of a 5MW 16 beam x-band multi-beam klystron is presented. The power from each of the 16 klystrons is combined using a matched waveguide network. Mechanical and electric models and simulations are discussed. The status of procuring and assembling parts is presented.

  1. Electronic and thermoelectric properties of van der Waals materials with ring-shaped valence bands

    SciTech Connect

    Wickramaratne, Darshana E-mail: rlake@ece.ucr.edu; Lake, Roger K. E-mail: rlake@ece.ucr.edu; Zahid, Ferdows

    2015-08-21

    The valence band of a variety of few-layer, two-dimensional materials consist of a ring of states in the Brillouin zone. The energy-momentum relation has the form of a “Mexican hat” or a Rashba dispersion. The two-dimensional density of states is singular at or near the band edge, and the band-edge density of modes turns on nearly abruptly as a step function. The large band-edge density of modes enhances the Seebeck coefficient, the power factor, and the thermoelectric figure of merit ZT. Electronic and thermoelectric properties are determined from ab initio calculations for few-layer III–VI materials GaS, GaSe, InS, InSe, for Bi{sub 2}Se{sub 3}, for monolayer Bi, and for bilayer graphene as a function of vertical field. The effect of interlayer coupling on these properties in few-layer III–VI materials and Bi{sub 2}Se{sub 3} is described. Analytical models provide insight into the layer dependent trends that are relatively consistent for all of these few-layer materials. Vertically biased bilayer graphene could serve as an experimental test-bed for measuring these effects.

  2. Probing Xylan-Specific Raman Bands for Label-Free Imaging Xylan in Plant Cell Wall

    SciTech Connect

    Zeng, Yining; Yarbrough, John M.; Mittal, Ashutosh; Tucker, Melvin P.; Vinzant, Todd; Himmel, Michael E.

    2015-06-15

    Xylan constitutes a significant portion of biomass (e.g. 22% in corn stover used in this study). Xylan is also an important source of carbohydrates, besides cellulose, for renewable and sustainable energy applications. Currently used method for the localization of xylan in biomass is to use fluorescence confocal microscope to image the fluorescent dye labeled monoclonal antibody that specifically binds to xylan. With the rapid adoption of the Raman-based label-free chemical imaging techniques in biology, identifying Raman bands that are unique to xylan would be critical for the implementation of the above label-free techniques for in situ xylan imaging. Unlike lignin and cellulose that have long be assigned fingerprint Raman bands, specific Raman bands for xylan remain unclear. The major challenge is the cellulose in plant cell wall, which has chemical units highly similar to that of xylan. Here we report using xylanase to specifically remove xylan from feedstock. Under various degree of xylan removal, with minimum impact to other major cell wall components, i.e. lignin and cellulose, we have identified Raman bands that could be further tested for chemical imaging of xylan in biomass in situ.

  3. Project Reports for Grand Traverse Band of Ottawa and Chippewa Indians- 2005 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Grand Traverse Band of Ottawa and Chippewa Indians (GTB) will conduct a feasibility study to determine the cost effectiveness and other economic, environmental, cultural, and social benefits of maximizing the diversity of energy sources used at GTB facilities. This includes an assessment of energy conservation measures as well as renewable energy sources such as wind, solar, and biomass.

  4. Quasiparticle band structures and thermoelectric transport properties of p-type SnSe

    SciTech Connect

    Shi, Guangsha; Kioupakis, Emmanouil

    2015-02-14

    We used density functional and many-body perturbation theory to calculate the quasiparticle band structures and electronic transport parameters of p-type SnSe both for the low-temperature Pnma and high-temperature Cmcm phases. The Pnma phase has an indirect band gap of 0.829 eV, while the Cmcm has a direct band gap of 0.464 eV. Both phases exhibit multiple local band extrema within an energy range comparable to the thermal energy of carriers from the global extrema. We calculated the electronic transport coefficients as a function of doping concentration and temperature for single-crystal and polycrystalline materials to understand the previous experimental measurements. The electronic transport coefficients are highly anisotropic and are strongly affected by bipolar transport effects at high temperature. Our results indicate that SnSe exhibits optimal thermoelectric performance at high temperature when doped in the 10{sup 19}–10{sup 20 }cm{sup −3} range.

  5. Project Reports for Soboba Band of Luiseño Indians – 2015 Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Under this grant, the Soboba Band of Luiseño Indians plans to install the Soboba Community Solar Energy Project, a 1.0-megawatt (MW) AC ground-mounted photovoltaic (PV) system that, once installed, will generate approximately 1,884,686 kilowatt-hours (kWh)/year, meeting 80% of the annual energy needs of key community facilities.

  6. Band alignment at AlN/Si (111) and (001) interfaces

    SciTech Connect

    King, Sean W. Davis, Robert F.; Nemanich, Robert J.

    2015-07-28

    To advance the development of III-V nitride on silicon heterostructure semiconductor devices, we have utilized in-situ x-ray photoelectron spectroscopy (XPS) to investigate the chemistry and valence band offset (VBO) at interfaces formed by gas source molecular beam epitaxy of AlN on Si (001) and (111) substrates. For the range of growth temperatures (600–1050 °C) and Al pre-exposures (1–15 min) explored, XPS showed the formation of Si-N bonding at the AlN/Si interface in all cases. The AlN/Si VBO was determined to be −3.5 ± 0.3 eV and independent of the Si orientation and degree of interfacial Si-N bond formation. The corresponding AlN/Si conduction band offset (CBO) was calculated to be 1.6 ± 0.3 eV based on the measured VBO and band gap for wurtzite AlN. Utilizing these results, prior reports for the GaN/AlN band alignment, and transitive and commutative rules for VBOs, the VBO and CBO at the GaN/Si interface were determined to be −2.7 ± 0.3 and −0.4 ± 0.3 eV, respectively.

  7. THEORETICAL CEPHEID PERIOD-LUMINOSITY AND PERIOD-COLOR RELATIONS IN SPITZER IRAC BANDS

    SciTech Connect

    Ngeow, Chow-Choong; Marconi, Marcella; Musella, Ilaria; Cignoni, Michele; Kanbur, Shashsi M.

    2012-02-01

    In this paper, the synthetic period-luminosity (P-L) relations in Spitzer's IRAC bands, based on a series of theoretical pulsation models with varying metal and helium abundance, were investigated. Selected sets of these synthetic P-L relations were compared to the empirical IRAC band P-L relations recently determined from Galactic and Magellanic Clouds Cepheids. For the Galactic case, synthetic P-L relations from model sets with (Y = 0.26, Z = 0.01), (Y = 0.26, Z = 0.02), and (Y = 0.28, Z = 0.02) agree with the empirical Galactic P-L relations derived from the Hubble Space Telescope parallaxes. For Magellanic Cloud Cepheids, the synthetic P-L relations from model sets with (Y = 0.25, Z = 0.008) agree with both of the empirical Large Magellanic Cloud (LMC) and Small Magellanic Cloud P-L relations. Analysis of the synthetic P-L relations from all model sets suggested that the IRAC band P-L relations may not be independent of metallicity, as the P-L slopes and intercepts could be affected by the metallicity and/or helium abundance. We also derive the synthetic period-color (P-C) relations in the IRAC bands. Non-vanishing synthetic P-C relations were found for certain combinations of IRAC band filters and metallicity. However, the synthetic P-C relations disagreed with the [3.6]-[8.0] P-C relation recently found for the Galactic Cepheids. The synthetic [3.6]-[4.5] P-C slope from the (Y = 0.25, Z = 0.008) model set, on the other hand, is in excellent agreement to the empirical LMC P-C counterpart, if a period range 1.0 < log (P) < 1.8 is adopted.

  8. Two-band description of resonant superfluidity in atomic Fermi gases

    SciTech Connect

    He, Lianyi; Hu, Hui; Liu, Xia -Ji

    2015-02-23

    Fermionic superfluidity in atomic Fermi gases across a Feshbach resonance is normally described by the atom-molecule theory, which treats the closed channel as a noninteracting point boson. In this work we present a theoretical description of the resonant superfluidity in analogy to the two-band superconductors. We employ the underlying two-channel scattering model of Feshbach resonance where the closed channel is treated as a composite boson with binding energy ε0 and the resonance is triggered by the microscopic interchannel coupling U12. The binding energy ε0 naturally serves as an energy scale of the system, which has been sent to infinity in the atom-molecule theory. We show that the atom-molecule theory can be viewed as a leading-order low-energy effective theory of the underlying fermionic theory in the limit ε0→∞ and U12→0, while keeping the phenomenological atom-molecule coupling finite. The resulting two-band description of the superfluid state is in analogy to the BCS theory of two-band superconductors. In the dilute limit ε0→∞, the two-band description recovers precisely the atom-molecule theory. The two-band theory provides a natural approach to study the corrections because of a finite binding energy ε0 in realistic experimental systems. For broad and moderate resonances, the correction is not important for current experimental densities. However, for extremely narrow resonance, we find that the correction becomes significant. Lastly, the finite binding energy correction could be important for the stability of homogeneous polarized superfluid against phase separation in imbalanced Fermi gases across a narrow Feshbach resonance.

  9. Two-band description of resonant superfluidity in atomic Fermi gases

    DOE PAGES [OSTI]

    He, Lianyi; Hu, Hui; Liu, Xia -Ji

    2015-02-23

    Fermionic superfluidity in atomic Fermi gases across a Feshbach resonance is normally described by the atom-molecule theory, which treats the closed channel as a noninteracting point boson. In this work we present a theoretical description of the resonant superfluidity in analogy to the two-band superconductors. We employ the underlying two-channel scattering model of Feshbach resonance where the closed channel is treated as a composite boson with binding energy ε0 and the resonance is triggered by the microscopic interchannel coupling U12. The binding energy ε0 naturally serves as an energy scale of the system, which has been sent to infinity inmore » the atom-molecule theory. We show that the atom-molecule theory can be viewed as a leading-order low-energy effective theory of the underlying fermionic theory in the limit ε0→∞ and U12→0, while keeping the phenomenological atom-molecule coupling finite. The resulting two-band description of the superfluid state is in analogy to the BCS theory of two-band superconductors. In the dilute limit ε0→∞, the two-band description recovers precisely the atom-molecule theory. The two-band theory provides a natural approach to study the corrections because of a finite binding energy ε0 in realistic experimental systems. For broad and moderate resonances, the correction is not important for current experimental densities. However, for extremely narrow resonance, we find that the correction becomes significant. Lastly, the finite binding energy correction could be important for the stability of homogeneous polarized superfluid against phase separation in imbalanced Fermi gases across a narrow Feshbach resonance.« less

  10. Experimental determination of band offsets of NiO-based thin film heterojunctions

    SciTech Connect

    Kawade, Daisuke; Sugiyama, Mutsumi, E-mail: mutsumi@rs.noda.tus.ac.jp [Faculty of Science and Technology/Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, Shigefusa F. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 9808577 (Japan)

    2014-10-28

    The energy band diagrams of NiO-based solar cell structures that use various n-type oxide semiconductors such as ZnO, Mg{sub 0.3}Zn{sub 0.7}O, Zn{sub 0.5}Sn{sub 0.5}O, In{sub 2}O{sub 3}:Sn (ITO), SnO{sub 2}, and TiO{sub 2} were evaluated by photoelectron yield spectroscopy. The valence band discontinuities were estimated to be 1.6?eV for ZnO/NiO and Mg{sub 0.3}Zn{sub 0.7}O/NiO, 1.7?eV for Zn{sub 0.5}Sn{sub 0.5}O/NiO and ITO/NiO, and 1.8?eV for SnO{sub 2}/NiO and TiO{sub 2}/NiO heterojunctions. By using the valence band discontinuity values and corresponding energy bandgaps of the layers, energy band diagrams were developed. Judging from the band diagram, an appropriate solar cell consisting of p-type NiO and n-type ZnO layers was deposited on ITO, and a slight but noticeable photovoltaic effect was obtained with an open circuit voltage (V{sub oc}) of 0.96?V, short circuit current density (J{sub sc}) of 2.2??A/cm{sup 2}, and fill factor of 0.44.

  11. Roles of nanoclusters in shear banding and plastic deformation of bulk metallic glasses

    SciTech Connect

    Nieh, T.G.

    2012-07-31

    During the course of this research we published 33 papers in various physics/material journals. We select four representing papers in this report and their results are summarized as follows. I. To study shear banding process, it is pertinent to know the intrinsic shear strain rate within a propagating shear band. To this aim, we used nanoindentation technique to probe the mechanical response of a Au49Ag5.5Pd2.3Cu26.9Si16.3 bulk metallic glass in locality and found notable pop-in events associated with shear band emission. Using a free volume model and under the situation when temperature and stress/hardness are fixed result in an equation, which predicts that hardness serration caused by pop-in decreases exponentially with the strain rate. Our data are in good agreement with the prediction. The result also predicts that, when strain rate is higher than a critical strain rate of 1700 s^-1, there will be no hardness serration, thereby no pop-in. In other words, multiple shear bandings will take place and material will flow homogeneously. The critical strain rate of 1700 s^-1 can be treated as the intrinsic strain rate within a shear band. We subsequently carried out a simulation study and showed that, if the imposed strain rate was over , the shear band spacing would become so small that the entire sample would virtually behave like one major shear band. Using the datum strain rate =1700 s^-1 and based on a shear band nucleation model proposed by us, the size of a shear-band nucleus in Au-BMG was estimated to be 3 ???? 10^6 atoms, or a sphere of ~30 nm in diameter. II. Inspired by the peculiar result published in a Science article ?¢????Super Plastic Bulk Metallic Glasses at Room Temperature?¢???, we synthesized the Zr-based bulk metallic glass with a composition identical to that in the paper (Zr64.13Cu15.75Ni10.12Al10) and, subsequently, tested in compression at the same slow strain rate (~10^-4 s^-1). We found that the dominant deformation mode is

  12. Nitrogen control of 13C enrichment in heterotrophic organs relative to leaves in a landscape-building desert plant species

    SciTech Connect

    Zhang, J.; Gu, L.; Bao, F.; Cao, Y.; Hao, Y.; He, J.; Li, J.; Li, Y.; Ren, Y.; Wang, F.; Wu, R.; Yao, B.; Zhao, Y.; Lin, G.; Wu, B.; Lu, Q.; Meng, P.

    2014-09-10

    A longstanding puzzle in isotope studies of C3 plant species is that heterotrophic plant organs (e.g., stems, roots, seeds, and fruits) tend to be enriched in 13C compared to the autotrophic organ (leaves) that provides them with photosynthate. Our inability to explain this puzzle suggests key deficiencies in understanding post-photosynthetic metabolic processes. It also limits the effectiveness of applications of stable carbon isotope analyses in a variety of scientific disciplines ranging from plant physiology to global carbon cycle studies. To gain insight into this puzzle, we excavated whole plant architectures of Nitraria tangutorum Bobrov, a C3 species that has an exceptional capability of fixing sands and building sand dunes, in two deserts in northwestern China. We systematically and simultaneously measured carbon isotope ratios and nitrogen and phosphorous contents of different parts of the excavated plants. We also determined the seasonal variations in leaf carbon isotope ratios on nearby intact plants of N. tangutorum. We found, for the first time, that higher nitrogen contents in heterotrophic organs were significantly correlated with increased heterotrophic 13C enrichment compared to leaves. However, phosphorous contents had no effect on the enrichment. In addition, new leaves had carbon isotope ratios similar to roots but were progressively depleted in 13C as they matured. We concluded that a nitrogen-mediated process, probably the refixation of respiratory CO2 by phosphoenolpyruvate (PEP) carboxylase, was responsible for the differences in 13C enrichment among different heterotrophic organs while processes within leaves or during phloem loading may contribute to the overall autotrophic – heterotrophic difference in carbon isotope compositions.

  13. The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR...

    Office of Scientific and Technical Information (OSTI)

    The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTARSuzaku Observation Citation Details In-Document Search Title: The Broad-band X-ray Spectrum of IC 4329A from a Joint ...

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

    DOEpatents

    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.

  15. Heterojunction band offsets and dipole formation at BaTiO{sub 3}/SrTiO{sub 3} interfaces

    SciTech Connect

    Balaz, Snjezana; Zeng, Zhaoquan; Brillson, Leonard J.; Department of Physics, The Ohio State University, 191 West Woodruff, Columbus, Ohio 43210

    2013-11-14

    We used a complement of photoemission and cathodoluminescence techniques to measure formation of the BaTiO{sub 3} (BTO) on SrTiO{sub 3} (STO) heterojunction band offset grown monolayer by monolayer by molecular beam epitaxy. X-ray photoemission spectroscopy (XPS) provided core level and valence band edge energies to monitor the valence band offset in-situ as the first few crystalline BTO monolayers formed on the STO substrate. Ultraviolet photoemission spectroscopy (UPS) measured Fermi level positions within the band gap, work functions, and ionization potentials of the growing BTO film. Depth-resolved cathodoluminescence spectroscopy measured energies and densities of interface states at the buried heterojunction. Kraut-based XPS heterojunction band offsets provided evidence for STO/BTO heterojunction linearity, i.e., commutativity and transitivity. In contrast, UPS and XPS revealed a large dipole associated either with local charge transfer or strain-induced polarization within the BTO epilayer.

  16. The Effects of Heterogeneity in Magma Water Concentration on the Development of Flow Banding and Spherulites in Rhyolitic Lava

    SciTech Connect

    Seaman, S.; Dyar, D; Marinkovic, N

    2009-01-01

    This study focuses on the origin of flow-banded rhyolites that consist of compositionally similar darker and lighter flow bands of contrasting texture and color. Infrared radiation was used to obtain Fourier transform infrared (FTIR) spectra from which water concentrations were calculated, and to map variations in water concentrations across zones of spherulites and glass from the 23 million year old Sycamore Canyon lava flow of southern Arizona. Lighter-colored, thicker flow bands consist of gray glass, fine-grained quartz, and large (1.0 to 1.5 mm) spherulites. Darker-colored, thinner flow bands consist of orange glass and smaller (0.1 to 0.2 mm) spherulites. The centers of both large and small spherulites are occupied by either (1) a quartz or sanidine crystal, (2) a granophyric intergrowth, or (3) a vesicle. Mapping of water concentration (dominantly OH- in glass and OH- and H2O in sanidine crystals) illustrates fluctuating water availability during quenching of the host melt. Textures of large spherulites in the lighter (gray) bands in some cases indicate complex quenching histories that suggest that local water concentration controlled the generation of glass versus crystals. Small spherulites in darker (orange) bands have only one generation of radiating crystal growth. Both the glass surrounding spherulites, and the crystals in the spherulites contain more water in the gray flow bands than in the orange flow bands. Flow banding in the Sycamore Canyon lava flow may have originated by the stretching of a magma that contained pre-existing zones (vesicles or proto-vesicles) of contrasting water concentration, as the magma flowed in the conduit and on the surface. Variation in the original water concentration in the alternating layers is interpreted to have resulted in differences in undercooling textures in spherulites in the lighter compared to the darker flow bands.

  17. THE FIRST H-BAND SPECTRUM OF THE GIANT PLANET ? PICTORIS b

    SciTech Connect

    Chilcote, Jeffrey; Fitzgerald, Michael P.; Larkin, James E.; Barman, Travis; Graham, James R.; Kalas, Paul; Macintosh, Bruce; Ingraham, Patrick; Bauman, Brian; Burrows, Adam S.; Cardwell, Andrew; Hartung, Markus; Hibon, Pascale; De Rosa, Robert J.; Dillon, Daren; Gavel, Donald; Dunn, Jennifer; Erikson, Darren; Goodsell, Stephen J.; and others

    2015-01-01

    Using the recently installed Gemini Planet Imager (GPI), we have obtained the first H-band spectrum of the planetary companion to the nearby young star ? Pictoris. GPI is designed to image and provide low-resolution spectra of Jupiter-sized, self-luminous planetary companions around young nearby stars. These observations were taken covering the H band (1.65 ?m). The spectrum has a resolving power of ?45 and demonstrates the distinctive triangular shape of a cool substellar object with low surface gravity. Using atmospheric models, we find an effective temperature of 1600-1700 K and a surface gravity of log (g) = 3.5-4.5 (cgs units). These values agree well with ''hot-start'' predictions from planetary evolution models for a gas giant with mass between 10 and 12 M {sub Jup} and age between 10 and 20 Myr.

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

    DOEpatents

    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.

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

    DOEpatents

    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.

  20. Analysis of shear banding in Armco IF iron, tungsten alloy, and depleted uranium

    SciTech Connect

    Barta, R.C.; Kim, C.H.

    1992-03-01

    We study the problem of the initiation and growth of shear bands in three materials by analyzing the thermomechanical deformations of a block of nonuniform thickness undergoing overall simple shearing deformations. Each of these materials is assumed to obey the Johnson-Cook law. It is found that, for each material, the deformations of the block have become nonhomogeneous by the time the shear stress attains its maximum value. For Armco IF iron, a narrow band at the center develops when the shear stress there has dropped to 85% of its peak value, and the same occurs for the tungsten alloy when the shear stress at the specimen center equals 80% of the maximum value. For the depleted uranium satisfactory results could be computed only till the shear stress dropped to 99% of the peak value.

  1. Study of the formation of adiabatic shear bands in mild steel under dynamic loading

    SciTech Connect

    Costin, L.S.

    1982-01-01

    The conditions of strain and temperature under which adiabatic shear bands form were examined using a torsional Kolsky (split-Hopkinson) bar apparatus. Thin walled tubular specimens of 1018 cold rolled steel were tested at an approximately constant strain rate in one of two strain rate regimes. In addition, the initial test temperature was varied from 173/sup 0/K to 300/sup 0/K. The total specimen strain was varied from test to test in order to determine the strain at which localized deformation begins at a given strain-rate and temperature. Using a series of fine lines scribed along the inner surface of the tube parallel to its axis, the strain distribution along the gage length of the specimen was determined by post-test examination. In this way it was determined whether the deformation was homogeneous or localized into a shear band.

  2. The effect of spin-orbit coupling in band structure of few-layer graphene

    SciTech Connect

    Sahdan, Muhammad Fauzi Darma, Yudi

    2014-03-24

    Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have protected conducting states on their edge or surface. This can be happened due to spin-orbit coupling and time-reversal symmetry. Moreover, the edge current flows through their edge or surface depends on its spin orientation and also it is robust against non-magnetic impurities. Therefore, topological insulators are predicted to be useful ranging from spintronics to quantum computation. Graphene was first predicted to be the precursor of topological insulator by Kane-Mele. They developed a Hamiltonian model to describe the gap opening in graphene. In this work, we investigate the band structure of few-layer graphene by using this model with analytical approach. The results of our calculations show that the gap opening occurs at K and K’ point, not only in single layer, but also in bilayer and trilayer graphene.

  3. The origin of 2.7?eV blue luminescence band in zirconium oxide

    SciTech Connect

    Perevalov, T. V. Zhuravlev, K. S.; Gritsenko, V. A.; Gulyaev, D. V.; Aliev, V. S.; Yelisseyev, A. P.

    2014-12-28

    The luminescence spectra of non-stoichiometric zirconium oxide film series with different oxygen vacancies' concentrations show the blue photoluminescence band centered near a 2.7?eV peak. There is a broad band at 5.2?eV in the luminescence excitation spectrum for blue emission. The ab-initio quantum-chemical calculation gives a peak in the optical absorption at 5.1?eV for the oxygen vacancy in cubic ZrO{sub 2}. It was concluded that the 2.7?eV blue luminescence excited near 5.2?eV in a zirconium oxide film is associated with the oxygen vacancy.

  4. Band gaps and internal electric fields in semipolar short period InN/GaN superlattices

    SciTech Connect

    Gorczyca, I.; Skrobas, K.; Suski, T.; Christensen, N. E.; Svane, A.

    2014-06-09

    The electronic structures and internal electric fields of semipolar short-period mInN/nGaN superlattices (SLs) have been calculated for several compositions (m, n). Two types of SL are considered, (112{sup ¯}2) and (202{sup ¯}1), corresponding to growth along the wurtzite s2 and s6 directions, respectively. The results are compared to similar calculations for polar SLs (grown in the c-direction) and nonpolar SLs (grown in the a- and m-directions). The calculated band gaps for the semipolar SLs lie between those calculated for the nonpolar and polar SLs: For s2-SLs they fall slightly below the band gaps of a-plane SLs, whereas for s6-SLs they are considerably smaller.

  5. Superdeformed band up to spin approx. (127/2 in /sup 149/Gd

    SciTech Connect

    Haas, B.; Taras, P.; Flibotte, S.; Banville, F.; Gascon, J.; Cournoyer, S.; Monaro, S.; Nadon, N.; Prevost, D.; Thibault, D.; and others

    1988-02-08

    A rotational band of nineteen transitions, extending to spinapprox.(127/2h-dash-bar and with an average moment of inertia scrI/sup (2)/ of 77 h-dash-bar/sup 2/ MeV/sup -1/, has been observed in /sup 149/Gd. Its intensity accounts for approximately (1/2% of the total fusion cross section. Lifetime measurements yielded an average quadrupole moment of 17 +- 2 e-b, in excellent agreement with the value calculated microscopically for a superdeformed shape. The trends in scrI/sup (1)/ and scrI/sup (2)/ are consistent with very weak pairing effects. The data also suggest that to populate superdeformed bands significantly one must form cold residual nuclei.

  6. High power operation of an X-band coaxial multi-beam relativistic klystron amplifier

    SciTech Connect

    Liu, Zhenbang; Huang, Hua; Jin, Xiao; Zhao, Yucong; He, Hu; Lei, Lurong; Chen, Zhaofu

    2013-11-15

    An X-band coaxial multi-beam relativistic klystron amplifier is designed in order to increase output microwave power and operating frequency of the amplifier tube. The experiment is performed on a Tesla-type accelerator. The amplifier is driven by an electron beam of 2.8 kA at 720 kV, and a microwave power of 30 kW and frequency of 9.384 GHz is injected into an input cavity by means of an external source, then a microwave power of over 800 MW is extracted, the amplifier gain is about 44 dB, and conversion efficiency is 40%. The experiment proves that output power of nearly GWs can be generated with the X-band coaxial multi-beam relativistic klystron amplifier driven by a kW-level input power.

  7. Experimental study of an X-band phase-locked relativistic backward wave oscillator

    SciTech Connect

    Wu, Y.; Li, Z. H.; Xu, Z.

    2015-11-15

    To achieve high power microwave combined with high frequency band, an X-band phase-locked relativistic backward wave oscillator (RBWO) is proposed and investigated theoretically and experimentally using a modulated electron beam. In the device, an overmoded input cavity and a buncher cavity are employed to premodulate the electron beam. Particle-in-cell simulation shows that an input power of 90 kW is sufficient to lock the frequency and phase of 1.5 GW output microwave with the locking bandwidth of 60 MHz. Moreover, phase and frequency locking of an RBWO has been accomplished experimentally with an output power of 1.5 GW. The fluctuation of the relative phase difference between output microwave and input RF signal is less than ±20° with the locking duration of about 50 ns. The input RF power required to lock the oscillator is only 90 kW.

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

    SciTech Connect

    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.

  9. An X-band phase-locked relativistic backward wave oscillator

    SciTech Connect

    Wu, Y.; Li, Z. H.; Xu, Z.; Jin, X.; Ma, Q. S.

    2015-08-15

    For the purpose of coherent high power microwave combining at high frequency band, an X-band phase-locked relativistic backward wave oscillator is presented and investigated. The phase-locking of the oscillator is accomplished by modulation of the electron beam before it reaches the oscillator. To produce a bunched beam with an acceptable injected RF power requirement, an overmoded input cavity is employed to provide initial density modulation. And a buncher cavity is introduced to further increase the modulation depth. When the beam enters the oscillator, the modulation depth is enough to lock the frequency and phase of the output microwave generated by the oscillator. Particle-in-cell simulation shows that an input power of 90 kW is sufficient to lock the frequency and phase of 1.5 GW output microwave with locking bandwidth of 60 MHz.

  10. Intermediate band solar cell simulation use InAs quantum dot in GaAs

    SciTech Connect

    Hendra P, I. B. Rahayu, F.; Sahdan, M. F.; Darma, Y.

    2015-04-16

    Intermediate band solar cell (IBSC) has become a new approach in increasing solar cell efficiency significantly. One way to create intermediate band is by proposing quantum dots (QD) technology. One of the important aspects in utilizing IBSC is the absorption of light. In this work we simulated the influence of QD arrangement in order to increase absorption coefficient and solar cell efficiency. We also simulated the influence of QD size to capture a wider light spectrum. We present a simple calculation method with low computing power demand. Results show that the increasing in quantum dot size can increase in capturing wider spectrum of light. Arrangement InAs QD in bulk material GaAs can capture wider spectrum of light and increase the absorption coefficient. The arrangement InAs QD 2 nm in GaAs bulk can increase solar cell efficiency up to 49.68%.

  11. Support pedestals for interconnecting a cover and nozzle band wall in a gas turbine nozzle segment

    DOEpatents

    Yu, Yufeng Phillip; Itzel, Gary Michael; Webbon, Waylon Willard; Bagepalli, Radhakrishna; Burdgick, Steven Sebastian; Kellock, Iain Robertson

    2002-01-01

    A gas turbine nozzle segment has outer and inner band portions. Each band portion includes a nozzle wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through the apertures of the impingement plate to cool the nozzle wall. Structural pedestals interconnect the cover and nozzle wall and pass through holes in the impingement plate to reduce localized stress otherwise resulting from a difference in pressure within the chamber of the nozzle segment and the hot gas path and the fixed turbine casing surrounding the nozzle stage. The pedestals may be cast or welded to the cover and nozzle wall.

  12. Narrow band wavelength selective filter using grating assisted single ring resonator

    SciTech Connect

    Prabhathan, P. Murukeshan, V. M.

    2014-09-15

    This paper illustrates a filter configuration which uses a single ring resonator of larger radius connected to a grating resonator at its drop port to achieve single wavelength selectivity and switching property with spectral features suitable for on-chip wavelength selection applications. The proposed configuration is expected to find applications in silicon photonics devices such as, on-chip external cavity lasers and multi analytic label-free biosensors. The grating resonator has been designed for a high Q-factor, high transmittivity, and minimum loss so that the wavelength selectivity of the device is improved. The proof-of-concept device has been demonstrated on a Silicon-on-Insulator (SOI) platform through electron beam lithography and Reactive Ion Etching (RIE) process. The transmission spectrum shows narrow band single wavelength selection and switching property with a high Free Spectral Range (FSR) ?60 nm and side band rejection ratio >15 dB.

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

    DOEpatents

    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.

  14. Two-band lasing in epitaxially stacked tunnel-junction semiconductor lasers

    SciTech Connect

    Vinokurov, D. A.; Ladugin, M. A.; Lyutetskii, A. V.; Marmalyuk, A. A.; Petrunov, A. N.; Pikhtin, N. A.; Slipchenko, S. O. Sokolova, Z. N.; Stankevich, A. L.; Fetisova, N. V.; Shashkin, I. S.; Averkiev, N. S.; Tarasov, I. S.

    2010-06-15

    Epitaxially stacked tunnel-junction laser hetero structures were grown by hydride metalorganic vapor-phase epitaxy in the system of AlGaAs/GaAs/In GaAs alloys. Based on such structures, mesa stripe lasers with an aperture of 150 s- 7 m were fabricated. The possibility of controlling the lasing wavelength by varying the active region thickness in each tunnel-junction laser structure was demonstrated. Independent two-band lasing at wavelengths of 914 and 925 nm (the difference frequency is 2.3 THz) was achieved at a maximum optical radiation power of 20 W in each band of the epitaxially stacked tunnel-junction semiconductor laser.

  15. Using Measurements of Fill Factor at High Irradiance to Deduce Heterobarrier Band Offsets: Preprint

    SciTech Connect

    Olson, J. M.; Steiner, M. A.; Kanevce, A.

    2011-07-01

    Using a 2D device simulation tool, we examine the high irradiance behavior of a single junction, GaAs concentrator cell as a function of the doping in the back surface confinement layer. The confinement layer is designed to be a barrier for both holes and electrons in the base of the solar cell. For a p-type base we show that the FF of the cell at high concentrations is a strong function of both the magnitude of the valence band offset and the doping level in the barrier. In short, for a given valence band offset (VBO), there is a critical barrier doping, below which the FF drops rapidly with lower doping. This behavior is confirmed experimentally for a GaInP/GaAs double heterostructure solar cell where the critical doping concentration (at 500 suns) in the back surface confinement layer is ~1e18 cm-3 for a VBO of 300 meV.

  16. X-band RF Photoinjector for Laser Compton X-ray and Gamma-ray Sources

    SciTech Connect

    Marsh, R. A.; Anderson, G. G.; Anderson, S. G.; Gibson, D. J.; Barty, C. J.

    2015-05-06

    Extremely bright narrow bandwidth gamma-ray sources are expanding the application of accelerator technology and light sources in new directions. An X-band test station has been commissioned at LLNL to develop multi-bunch electron beams. This multi-bunch mode will have stringent requirements for the electron bunch properties including low emittance and energy spread, but across multiple bunches. The test station is a unique facility featuring a 200 MV/m 5.59 cell X-band photogun powered by a SLAC XL4 klystron driven by a Scandinova solid-state modulator. This paper focuses on its current status including the generation and initial characterization of first electron beam. Design and installation of the inverse-Compton scattering interaction region and upgrade paths will be discussed along with future applications.

  17. Initial Testing of the Mark-0 X-Band RF Gun at SLAC

    SciTech Connect

    Vlieks, Arnold; Adolphsen, C.; Dolgashev, V.; Lewandowski, J.; Limborg, Cecile; Weathersby, S.; /SLAC

    2012-06-06

    A new X-band RF gun (Mark-0) has been assembled, tuned and was tested in the ASTA facility at SLAC. This gun has been improved from an earlier gun used in Compton-scattering experiments at SLAC by the introduction of a racetrack dual-input coupler to reduce quadrupole fields. Waveguide-to-coupler irises were also redesigned to reduce surface magnetic fields and therefore peak pulse surface heating. Tests of this photocathode gun will allow us to gain early operational experience for beam tests of a new gun with further improvements (Mark-1) being prepared for SLAC's X-Band Test Area (XTA) program and the LLNL MEGa-ray program. Results of current testing up to {approx} 200 MV/m peak surface Electric fields are presented.

  18. Nonlinear optical response of semiconductor-nanocrystals-embedded photonic band gap structure

    SciTech Connect

    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.

  19. Characterization and Simulation of Transient Vibrations Using Band Limited Temporal Moments

    DOE PAGES [OSTI]

    Smallwood, David O.

    1994-01-01

    A method is described to characterize shocks (transient time histories) in terms of the Fourier energy spectrum and the temporal moments of the shock passed through a contiguous set of band pass filters. The product model is then used to generate of a random process as simulations that in the mean will have the same energy and moments as the characterization of the transient event.

  20. Vibration Stabilization of a Mechanical Model of a X-Band Linear Collider Final Focus Magnet

    SciTech Connect

    Frisch, Josef; Chang, Allison; Decker, Valentin; Doyle, Eric; Eriksson, Leif; Hendrickson, Linda; Himel, Thomas; Markiewicz, Thomas; Partridge, Richard; Seryi, Andrei; /SLAC

    2006-09-28

    The small beam sizes at the interaction point of a X-band linear collider require mechanical stabilization of the final focus magnets at the nanometer level. While passive systems provide adequate performance at many potential sites, active mechanical stabilization is useful if the natural or cultural ground vibration is higher than expected. A mechanical model of a room temperature linear collider final focus magnet has been constructed and actively stabilized with an accelerometer based system.

  1. Double-band Electrode Channel Flow DEMS Cell > Research Highlights >

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

    Research > The Energy Materials Center at Cornell Research Highlights In This Section The Structural Evolution and Diffusion During the Chemical Transformation from Cobalt to Cobalt Phosphide Nanoparticles Joint Density-Functional Theory of Electrochemistry Double-band Electrode Channel Flow DEMS Cell Sulfur@Carbon Cathodes for Lithium Sulfur Batteries Better Ham & Cheese: Enhanced Anodes and Cathodes for Fuel Cells Epitaxial Single Crystal Nanostructures for Batteries & PVs High

  2. Magnetic frustration in the three-band Anderson lattice model for high-temperature superconductors

    SciTech Connect

    Ihle, D.; Kasner, M. )

    1990-09-01

    The three-band Anderson lattice model for the CuO{sub 2} planes in high-{Tc} superconductors is established. Treating this model by perturbation theory, the effective spin interactions are derived. The antiferromagnetic superexchange integrals are calculated as functions of the direct oxygen transfer and the hole concentration. It is found that frustration in the superexchange occurs, even in the undoped case, which increases with oxygen trnasfer and decreases with hole concentration.

  3. Little Traverse Bay Bands of Odawa Indians - Renewable Energy Strategic Plan

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

    Strategic Plan Little Traverse Bay Bands Of Odawa Indians Albert Colby Jr. and Steve Smiley Tribal History 1855 Treaty established present reservation boundaries in Northern Michigan. Tribe reaffirmed on September 21, 1994. 1995 Tribe received first BIA contract designed to establish service programs to Tribal members, including Law Enforcement, Tribal Court, Housing, Natural Resources, Human Services and Enrollment Departments. Tribal History 1995 Tribe received first Indian Health Service

  4. DOE/SC-ARM/TR-122 G-Band Vapor Radiometer Precipitable Water

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

    2 G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product A Koontz M Cadeddu December 2012 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States 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 information, apparatus, product, or process disclosed, or represents that

  5. Project Reports for Red Lake Band of Chippewa Indians- 2003 Project

    Energy.gov [DOE]

    The Red Lake Band of Chippewa Indians, located in the northwest corner of Minnesota near the Canadian border, will assess the potential to expand the use of biomass resources for energy autonomy and economic development on tribal lands. Specifically, the tribe will evaluate the technical, market, financial, and cultural aspects of using its extensive, forested lands to create a sustainable bioproducts-based business and will develop a business plan to guide tribal industry development.

  6. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    SciTech Connect

    Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.

    2015-09-14

    Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.

  7. Miniaturized Multi-Band Antenna Design via Element Collocation and Inductive Feed Loading

    SciTech Connect

    Martin, R. P.

    2012-09-12

    In a FY09 SDRD project, four separate antennas were designed to receive signals of interest covering a broad range of frequencies. While the elements exceeded specifications, the array footprint is substantial. Research performed by the CU Microwave Active Antenna Group in collaboration with RSL, showed promise in realizing a reduced structure. This work will expand upon this previous research. This project will result in a prototype quad-band antenna.

  8. Morongo Band of Mission Indians - Southwest Tribal Energy Consortiums Renewable Energy Project

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

    Southwest Tribal Energy Consortium Renewable Energy Feasibility Study U.S. Department of Energy Tribal Energy Program Review Todd Hooks, SWTEC Member, Agua Caliente Band of Cahuilla Indians Carolyn Stewart, Red Mountain Energy Partners October 2006 1 © 2006 All Rights Reserved Discussion Outline 1 Project Overview 2 Project Location 3 Project Participants 4 Project Status 5 Next Steps Project Overview 2 © 2006 All Rights Reserved Project Overview >> Background Feasibility study to

  9. Red Lake Band of Chippewa Indians: Biomass Energy Feasiblity Study Update

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

    Health and Bioenergy: Technology Opportunities and Barriers Scott Haase McNeil Technologies June 20, 2003 Red Lake Band of Chippewa Indians: Biomass Energy Feasibility Study Update Presented to DOE Tribal Energy Program Scott Haase October 19, 2004 * Project overview * Resource assessment * Assess on-site electric and thermal applications * Assess local/regional utility market * Economic analysis * Alternative products Presentation Outline * Evaluate and determine potential options for creating

  10. Augustine Band of Cahuilla Mission Indians - Energy Conservation and Energy Options Analysis

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

    Energy Conservation and Alternative Energy Resources Development October, 2007 AUGUSTINE BAND OF CAHUILLA INDIANS - Eight-member tribe with flat, developable 540 acre reservation in rapidly urbanizing area. Limited management resources. - Reservation undeveloped except for small casino and temporary Tribal offices. - Tribal Chairperson is highly motivated to make the Reservation a model of energy use planning and conservation. - This effort will be assisted by future independence from external

  11. Grand Traverse Band of Ottawa and Chippewa Indians - Renewable Energy Feasibility Study

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

    Renewable Energy & Energy Efficiency Feasibility Study DOE Tribal Energy Program Review Denver, Colorado November 14 - 20, 2008 November 2008 Grand Traverse Band * 3,988 Members * 2,370 Acres - Checkerboard * Six-County Service Area * EDC: 2 Casinos, Resort Hotels (600 Rooms), Gas Station, etc. * Gov't: Administration, Housing, Medicine Lodge, Strong Heart Center, Day Care, etc. Grand Traverse Resort and Spa Turtle Creek Casino Hotel (June 08) GTB Energy Vision & Plan Three Focus Areas:

  12. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    SciTech Connect

    Anand, Naween; Gu, Genda; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Martin, C.

    2014-12-23

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10300 K) reflectance was measured over 407000 cm? (5870 meV) with an extension to 15,500 cm? (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy optical spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.

  13. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    DOE PAGES [OSTI]

    Anand, Naween; Gu, Genda; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Martin, C.

    2014-12-23

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10300 K) reflectance was measured over 407000 cm? (5870 meV) with an extension to 15,500 cm? (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy opticalmorespectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.less

  14. Controlling the conduction band offset for highly efficient ZnO nanorods based perovskite solar cell

    SciTech Connect

    Dong, Juan; Shi, Jiangjian; Li, Dongmei; Luo, Yanhong; Meng, Qingbo

    2015-08-17

    The mechanism of charge recombination at the interface of n-type electron transport layer (n-ETL) and perovskite absorber on the carrier properties in the perovskite solar cell is theoretically studied. By solving the one dimensional diffusion equation with different boundary conditions, it reveals that the interface charge recombination in the perovskite solar cell can be suppressed by adjusting the conduction band offset (ΔE{sub C}) at ZnO ETL/perovskite absorber interface, thus leading to improvements in cell performance. Furthermore, Mg doped ZnO nanorods ETL has been designed to control the energy band levels. By optimizing the doping amount of Mg, the conduction band minimum of the Mg doped ZnO ETL has been raised up by 0.29 eV and a positive ΔE{sub C} of about 0.1 eV is obtained. The photovoltage of the cell is thus significantly increased due to the relatively low charge recombination.

  15. FERROELECTRIC SWITCH FOR A HIGH-POWER Ka-BAND ACTIVE PULSE COMPRESSOR

    SciTech Connect

    Hirshfield, Jay L.

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  16. Energy band alignment and electronic states of amorphous carbon surfaces in vacuo and in aqueous environment

    SciTech Connect

    Caro, Miguel A.; Mtt, Jukka; Lopez-Acevedo, Olga; Laurila, Tomi

    2015-01-21

    In this paper, we obtain the energy band positions of amorphous carbon (aC) surfaces in vacuum and in aqueous environment. The calculations are performed using a combination of (i) classical molecular dynamics (MD), (ii) Kohn-Sham density functional theory with the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional, and (iii) the screened-exchange hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE). PBE allows an accurate generation of a-C and the evaluation of the local electrostatic potential in the a-C/water system, HSE yields an improved description of energetic positions which is critical in this case, and classical MD enables a computationally affordable description of water. Our explicit calculation shows that, both in vacuo and in aqueous environment, the a-C electronic states available in the region comprised between the H{sub 2}/H{sub 2}O and O{sub 2}/H{sub 2}O levels of water correspond to both occupied and unoccupied states within the a-C pseudogap region. These are localized states associated to sp{sup 2} sites in a-C. The band realignment induces a shift of approximately 300?meV of the a-C energy band positions with respect to the redox levels of water.

  17. EXAMINING THE BROADBAND EMISSION SPECTRUM OF WASP-19b: A NEW z-BAND ECLIPSE DETECTION

    SciTech Connect

    Zhou, George; Bayliss, Daniel D. R.; Kedziora-Chudczer, Lucyna; Bailey, Jeremy

    2013-09-10

    WASP-19b is one of the most irradiated hot-Jupiters known. Its secondary eclipse is the deepest of all transiting planets and has been measured in multiple optical and infrared bands. We obtained a z-band eclipse observation with a measured depth of 0.080% {+-} 0.029%, using the 2 m Faulkes Telescope South, which is consistent with the results of previous observations. We combined our measurement of the z-band eclipse with previous observations to explore atmosphere models of WASP-19b that are consistent with its broadband spectrum. We use the VSTAR radiative transfer code to examine the effect of varying pressure-temperature profiles and C/O abundance ratios on the emission spectrum of the planet. We find that models with super-solar carbon enrichment best match the observations, which is consistent with previous model retrieval studies. We also include upper atmosphere haze as another dimension in the interpretation of exoplanet emission spectra and find that particles <0.5 {mu}m in size are unlikely to be present in WASP-19b.

  18. Asymmetric band offsets in silicon heterojunction solar cells: Impact on device performance

    DOE PAGES [OSTI]

    Seif, Johannes Peter; Menda, Deneb; Descoeudres, Antoine; Barraud, Loris; Özdemir, Orhan; Ballif, Christophe; De Wolf, Stefaan

    2016-08-01

    Here, amorphous/crystalline silicon interfaces feature considerably larger valence than conduction band offsets. In this article, we analyze the impact of such band offset asymmetry on the performance of silicon heterojunction solar cells. To this end, we use silicon suboxides as passivation layers -- inserted between substrate and (front or rear) contacts -- since such layers enable intentionally exacerbated band-offset asymmetry. Investigating all topologically possible passivation layer permutations and focussing on light and dark current-voltage characteristics, we confirm that to avoid fill factor losses, wider-bandgap silicon oxide films (of at least several nanometer thin) should be avoided in hole-collecting contacts. Asmore » a consequence, device implementation of such films as window layers -- without degraded carrier collection -- demands electron collection at the front and hole collection at the rear. Furthermore, at elevated operating temperatures, once possible carrier transport barriers are overcome by thermionic (field) emission, the device performance is mainly dictated by the passivation of its surfaces. In this context, compared to the standard amorphous silicon layers, the wide-bandgap oxide layers applied here passivate remarkably better at these temperatures, which may represent an additional benefit under practical operation conditions.« less

  19. Surface-plasmon enhanced photodetection at communication band based on hot electrons

    SciTech Connect

    Wu, Kai; Zhan, Yaohui E-mail: xfli@suda.edu.cn; Wu, Shaolong; Deng, Jiajia; Li, Xiaofeng E-mail: xfli@suda.edu.cn

    2015-08-14

    Surface plasmons can squeeze light into a deep-subwavelength space and generate abundant hot electrons in the nearby metallic regions, enabling a new paradigm of photoconversion by the way of hot electron collection. Unlike the visible spectral range concerned in previous literatures, we focus on the communication band and design the infrared hot-electron photodetectors with plasmonic metal-insulator-metal configuration by using full-wave finite-element method. Titanium dioxide-silver Schottky interface is employed to boost the low-energy infrared photodetection. The photodetection sensitivity is strongly improved by enhancing the plasmonic excitation from a rationally engineered metallic grating, which enables a strong unidirectional photocurrent. With a five-step electrical simulation, the optimized device exhibits an unbiased responsivity of ∼0.1 mA/W and an ultra-narrow response band (FWHM = 4.66 meV), which promises to be a candidate as the compact photodetector operating in communication band.

  20. The occurrence and wave properties of H?-, He?-, and O?-band EMIC waves observed by the Van Allen Probes

    SciTech Connect

    Saikin, A. A.; Zhang, J. -C.; Allen, R. C.; Smith, C. W.; Kistler, L. M.; Spence, H. E.; Torbert, R. B.; Kletzing, C. A.; Jordanova, Vania K.

    2015-09-26

    We perform a statistical study of electromagnetic ion cyclotron (EMIC) waves detected by the Van Allen Probes mission to investigate the spatial distribution of their occurrence, wave power, ellipticity, and normal angle. The Van Allen Probes have been used which allow us to explore the inner magnetosphere (1.1 to 5.8 RE). Magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes are used to identify EMIC wave events for the first 22 months of the mission operation (8 September 2012 to 30 June 2014). EMIC waves are examined in H?-, He?-, and O?-bands. Over 700 EMIC wave events have been identified over the three different wave bands (265 H?-band events, 438 He?-band events, and 68 O?-band events). EMIC wave events are observed between L = 2 8, with over 140 EMIC wave events observed below L = 4. The results show that H?-band EMIC waves have two peak magnetic local time (MLT) occurrence regions: pre-noon (09:00 < MLT ? 12:00) and afternoon (15:00 < MLT ? 17:00) sectors. He?-band EMIC waves feature an overall stronger dayside occurrence. O?-band EMIC waves have one peak region located in the morning sector at lower L shells (L < 4). He?-band EMIC waves average the highest wave power overall (>0.1 nT/Hz), especially in the afternoon sector. Ellipticity observations reveal that linearly polarized EMIC waves dominate in lower L shells.

  1. The use of bulk states to accelerate the band edge state calculation of a semiconductor quantum dot

    SciTech Connect

    Voemel, Christof . E-mail: voemel@eecs.berkeley.edu; Tomov, Stanimire Z. . E-mail: tomov@cs.utk.edu; Wang, Lin-Wang . E-mail: LWWang@lbl.gov; Marques, Osni A. . E-mail: OAMarques@lbl.gov; Dongarra, Jack J. . E-mail: dongarra@cs.utk.edu

    2007-05-01

    We present a new technique to accelerate the convergence of the folded spectrum method in empirical pseudopotential band edge state calculations for colloidal quantum dots. We use bulk band states of the materials constituent of the quantum dot to construct initial vectors and a preconditioner. We apply these to accelerate the convergence of the folded spectrum method for the interior states at the top of the valence and the bottom of the conduction band. For large CdSe quantum dots, the number of iteration steps until convergence decreases by about a factor of 4 compared to previous calculations.

  2. Renormalization of optical transition strengths in semiconductor nanoparticles due to band mixing

    DOE PAGES [OSTI]

    Velizhanin, Kirill A.

    2016-05-25

    We report that unique optical properties of semiconductor nanoparticles (SN) make them very promising in the multitude of applications including lasing, light emission and photovoltaics. In many of these applications it is imperative to understand the physics of interaction of electrons in a SN with external electromagnetic fields on the quantitative level. In particular, the strength of electron–photon coupling determines such important SN parameters as the radiative lifetime and absorption cross section. This strength is often assumed to be fully encoded by the so called Kane momentum matrix element. This parameter, however, pertains to a bulk semiconductor material and, asmore » such, is not sensitive to the quantum confinement effects in SNs. In this work we demonstrate that the quantum confinement, via the so called band mixing, can result in a significant suppression of the strength of electron interaction with electromagnetic field. Within the envelope function formalism we show how this suppression can be described by introducing an effective energy-dependent Kane momentum. Then, the effect of band mixing on the efficiencies of various photoinduced processes can be fully captured by the conventional formulae (e.g., spontaneous emission rate), once the conventional Kane momentum is substituted with the renormalized energy-dependent Kane momentum introduced in here. Lastly, as an example, we evaluate the energy-dependent Kane momentum for spherical PbSe and PbS SNs (i.e., quantum dots) and show that neglecting band mixing in these systems can result in the overestimation of absorption cross sections and emission rates by a factor of ~2.« less

  3. Carrier Multiplication in Semiconductor Nanocrystals: Theoretical Screening of Candidate Materials Based on Band-Structure Effects

    SciTech Connect

    Luo, J. W.; Franceschetti, A.; Zunger, A.

    2008-01-01

    Direct carrier multiplication (DCM) occurs when a highly excited electron-hole pair decays by transferring its excess energy to the electrons rather than to the lattice, possibly exciting additional electron-hole pairs. Atomistic electronic structure calculations have shown that DCM can be induced by electron-hole Coulomb interactions, in an impact-ionization-like process whose rate is proportional to the density of biexciton states {rho}{sub XX}. Here we introduce a DCM 'figure of merit' R{sub 2}(E) which is proportional to the ratio between the biexciton density of states {rho}{sub XX} and the single-exciton density of states {rho}{sub x}, restricted to single-exciton and biexciton states that are coupled by Coulomb interactions. Using R{sub 2}(E), we consider GaAs, InAs, InP, GaSb, InSb, CdSe, Ge, Si, and PbSe nanocrystals of different sizes. Although DCM can be affected by both quantum-confinement effects (reflecting the underly electronic structure of the confined dot-interior states) and surface effects, here we are interested to isolate the former. To this end the nanocrystal energy levels are obtained from the corresponding bulk band structure via the truncated crystal approximation. We find that PbSe, Si, GaAs, CdSe, and InP nanocrystals have larger DCM figure of merit than the other nanocrystals. Our calculations suggest that high DCM efficiency requires high degeneracy of the corresponding bulk band-edge states. Interestingly, by considering band structure effects we find that as the dot size increases the DCM critical energy E{sub 0} (the energy at which R{sub 2}(E) becomes {ge}1) is reduced, suggesting improved DCM. However, whether the normalized E{sub 0}/{var_epsilon}{sub g} increases or decreases as the dot size increases depends on dot material.

  4. Origin of multi-band emission from the microquasar Cygnus X-1

    SciTech Connect

    Zhang, Jianfu; Lu, Jufu; Xu, Bing

    2014-06-20

    We study the origin of non-thermal emissions from the Galactic black hole X-ray binary Cygnus X-1, which is a confirmed high-mass microquasar. By analogy with the methods used in studies of active galactic nuclei, we propose a two-dimensional, time-dependent radiation model from the microquasar Cygnus X-1. In this model, the evolution equation for relativistic electrons in a conical jet are numerically solved by including escape, adiabatic, and various radiative losses. The radiative processes involved are synchrotron emission, its self-Compton scattering, and inverse Compton scatterings of an accretion disk and its surrounding stellar companion. This model also includes an electromagnetic cascade process of an anisotropic ?-? interaction. We study the spectral properties of electron evolution and its emission spectral characteristic at different heights of the emission region located in the jet. We find that radio data from Cygnus X-1 are reproduced by the synchrotron emission, the Fermi Large Area Telescope measurements by the synchrotron emission and Comptonization of photons of the stellar companion, and the TeV band emission fluxes by the Comptonization of the stellar photons. Our results show the following. (1) The radio emission region extends from the binary system scales to the termination of the jet. (2) The GeV band emissions should originate from the distance close to the binary system scales. (3) The TeV band emissions could be inside the binary system, and these emissions could be probed by the upcoming Cherenkov Telescope Array. (4) The MeV tail emissions, which produce a strongly linearly polarized signal, are emitted inside the binary system. The location of the emissions is very close to the inner region of the jet.

  5. Fully Polarimetric Passive W-band Millimeter Wave Imager for Wide Area Search

    SciTech Connect

    Tedeschi, Jonathan R.; Bernacki, Bruce E.; Sheen, David M.; Kelly, James F.; McMakin, Douglas L.

    2013-09-27

    We describe the design and phenomenology imaging results of a fully polarimetric W-band millimeter wave (MMW) radiometer developed by Pacific Northwest National Laboratory for wide-area search. Operating from 92 - 94 GHz, the W-band radiometer employs a Dicke switching heterodyne design isolating the horizontal and vertical mm-wave components with 40 dB of polarization isolation. Design results are presented for both infinite conjugate off-axis parabolic and finite conjugate off-axis elliptical fore-optics using optical ray tracing and diffraction calculations. The received linear polarizations are down-converted to a microwave frequency band and recombined in a phase-shifting network to produce all six orthogonal polarization states of light simultaneously, which are used to calculate the Stokes parameters for display and analysis. The resulting system performance produces a heterodyne receiver noise equivalent delta temperature (NEDT) of less than 150m Kelvin. The radiometer provides novel imaging capability by producing all four of the Stokes parameters of light, which are used to create imagery based on the polarization states associated with unique scattering geometries and their interaction with the down welling MMW energy. The polarization states can be exploited in such a way that man-made objects can be located and highlighted in a cluttered scene using methods such as image comparison, color encoding of Stokes parameters, multivariate image analysis, and image fusion with visible and infrared imagery. We also present initial results using a differential imaging approach used to highlight polarization features and reduce common-mode noise. Persistent monitoring of a scene using the polarimetric passive mm-wave technique shows great promise for anomaly detection caused by human activity.

  6. MODELING THE NEAR-ULTRAVIOLET BAND OF GK STARS. I. LOCAL THERMODYNAMIC EQUILIBRIUM MODELS

    SciTech Connect

    Short, C. Ian; Hauschildt, P. H. E-mail: yeti@hs.uni-hamburg.d

    2010-08-01

    We present a grid of LTE atmospheric models and synthetic spectra that covers the spectral class range from mid-G to mid-K, and luminosity classes from V to III, that is dense in T{sub eff} sampling ({Delta}T {sub eff} = 62.5 K), for stars of solar metallicity and moderately metal-poor scaled solar abundance ([A/H]=0.0 and -0.5). All models have been computed with two choices of atomic line list: (1) the 'big' line lists of Kurucz that best reproduce the broadband solar blue and near-UV f{sub {lambda}} level, and (2) the 'small' lists of Kurucz and Peytremann that provide the best fit to the high-resolution solar blue and near-UV spectrum. We compare our model spectral energy distributions to a sample of stars carefully selected from the large catalog of uniformly re-calibrated spectrophotometry of Burnashev with the goal of determining how the quality of fit varies with stellar parameters, especially in the historically troublesome blue and near-UV bands. We confirm that our models computed with the 'big' line list recover the derived T {sub eff} values of the PHOENIX NextGen grid, but find that the models computed with the 'small' line list provide greater internal self-consistency among different spectral bands, and closer agreement with the empirical T{sub eff} scale of Ramirez and Melendez, but not to the interferometrically derived T{sub eff} values of Baines et al. We find no evidence that the near-UV band discrepancy between models and observations for Arcturus ({alpha} Boo) reported in two works by Short and Hauschildt is pervasive, and that Arcturus may be peculiar in this regard.

  7. Observation of nonlinear bands in near-field scanning optical microscopy of a photonic-crystal waveguide

    SciTech Connect

    Singh, A.; Huisman, S. R.; Ctistis, G. Mosk, A. P.; Pinkse, P. W. H.; Korterik, J. P.; Herek, J. L.

    2015-01-21

    We have measured the photonic bandstructure of GaAs photonic-crystal waveguides with high resolution in energy as well as in momentum using near-field scanning optical microscopy. Intriguingly, we observe additional bands that are not predicted by eigenmode solvers, as was recently demonstrated by Huisman et al. [Phys. Rev. B 86, 155154 (2012)]. We study the presence of these additional bands by performing measurements of these bands while varying the incident light power, revealing a non-linear power dependence. Here, we demonstrate experimentally and theoretically that the observed additional bands are caused by a waveguide-specific near-field tip effect not previously reported, which can significantly phase-modulate the detected field.

  8. First-principles study of direct and narrow band gap semiconducting β -CuGaO2

    DOE PAGES [OSTI]

    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

  9. Apparatus and methods for relieving thermally induced stresses in inner and outer bands of thermally cooled turbine nozzle stages

    DOEpatents

    Yu, Yufeng Phillip; Itzel, Gary Michael; Correia, Victor H. S.

    2002-01-01

    To control the temperature mismatch between the inner and outer bands and covers forming plenums with the inner and outer bands on sides thereof remote from the hot gas path, passages extend from the leading edge of the covers in communication with the hot gases of combustion to the trailing edge of the covers in communication with the hot gas flowpath. A mixing chamber is provided in each passage in communication with compressor discharge air for mixing the hot gases of combustion and compressor discharge air for flow through the passage, thereby heating the cover and minimizing the temperature differential between the inner and outer bands and their respective covers. The passages are particularly useful adjacent the welded or brazed joints between the covers and inner band portions.

  10. Relativistically parametrized extended Hueckel calculations. 11. Energy bands for elemental tellurium and polonium

    SciTech Connect

    Lohr, L.L.

    1987-06-17

    An extension of the REX relativistically parametrized extended Hueckel LCAO molecular orbital method to periodic solids is outlined. The method provides a simple and systematic approach to the description of the spin-orbit splitting of energy bands. The method is illustrated with results for the main-group elements tellurium and polonium, with trigonal-helical and simple-cubic structures, respectively. The helical structure of tellurium is described as a distortion of a simple-cubic structure, with the distortion being quenched in the case of polonium by its very large spin-orbit coupling. 36 references, 10 figures, 1 table.

  11. Winter Hydroelectric Dam Feasibility Assessment: The Lac Courte Oreilles Band of Lake Superior Ojibwe

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

    WINTER HYDROELECTRIC DAM FEASIBILITY ASSESSMENT THE LAC COURTE OREILLES BAND OF LAKE SUPERIOR OJIBWE PRESENTED BY JASON WEAVER LAC COURTE OREILLES HISTORY * WE ARE LOCATED IN SAWYER COUNTY IN THE NORTHWESTERN REGION OF WISCONSIN. * WE HAVE 7,310 ENROLLED TRIBAL MEMBERS * THE RESERVATION CONSIST OF 76,465 ACRES, ABOUT 10,500 ACRES ARE WATER * WE HAVE ENTERED 4 SOVEREIGN TREATIES WITH THE U.S. GOVERNMENT. 1825, 1837, 1842 AND THE LA POINTE TREATY OF 1854 WHICH ESTABLISHED THE CURRENT RESERVATIONS

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

    SciTech Connect

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

    2013-11-18

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

  13. Recent experimental results from a long-pulse J-band relativistic klystron amplifier developmental effort

    SciTech Connect

    Kato, K.G.; Crouch, D.D.; Sar, D.R.; Speciale, R.A.; Carlsten, B.E.; Fazio, M.V.; Haynes, W.B.; Stringfield, R.M.

    1994-12-31

    Recent experimental results, supporting simulations, and design modeling are presented from a developmental effort to a produce a long pulse ({approximately}1{mu}s) J-band (5.85-8.2 GHz) relativistic klystron amplifier (RKA) of the high current NRL genealogy. This RKA is designed to operate at approximately 6.6 GHz, with a desired RF output {approximately}700 MW. Conversion of electron beam energy to microwave energy is obtained by a mock magnetically insulated coaxial converter which, in various incarnations, can be made to be either a cavity gap extractor or an inverse cathode.

  14. First principles electronic band structure and phonon dispersion curves for zinc blend beryllium chalcogenide

    SciTech Connect

    Dabhi, Shweta Mankad, Venu Jha, Prafulla K.

    2014-04-24

    A detailed theoretical study of structural, electronic and Vibrational properties of BeX compound is presented by performing ab-initio calculations based on density-functional theory using the Espresso package. The calculated value of lattice constant and bulk modulus are compared with the available experimental and other theoretical data and agree reasonably well. BeX (X = S,Se,Te) compounds in the ZB phase are indirect wide band gap semiconductors with an ionic contribution. The phonon dispersion curves are represented which shows that these compounds are dynamically stable in ZB phase.

  15. Lac Courte Oreilles Band of Lake Superior Chippewa Indians - Energy Analysis

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

    Oreilles Band of Lake Superior Ojibwe Location of Lac Courte Oreilles About Lac Courte Oreilles (LCO) * The reservation is presently 76,465 acres and is 15 miles wide. * We have a seven member Tribal Governing Board with four year terms. * LCO's membership is about 7,000 with nearly half of its members residing on or near the reservation * There are 25 distinctly different communities within the reservation for a total of 1,019 households (2000 Census). * LCO operates two casinos; recently

  16. A simplified scheme for generating narrow-band mid-ultraviolet laser radiation

    SciTech Connect

    Almog, G.; Scholz, M. Weber, W.; Leisching, P.; Kaenders, W.; Udem, Th.

    2015-03-15

    We report on the development and characterization of continuous, narrow-band, and tunable laser systems that use direct second-harmonic generation from blue and green diode lasers with an output power level of up to 11.1 mW in the mid-ultraviolet. One of our laser systems was tuned to the mercury 6{sup 1}S{sub 0} → 6{sup 3}P{sub 1} intercombination line at 253.7 nm. We could perform Doppler-free saturation spectroscopy on this line and were able to lock our laser to the transition frequency on long time scales.

  17. Effects of subconduction band excitations on thermal conductance at metal-metal interfaces

    SciTech Connect

    Hopkins, Patrick E.; Beechem, Thomas E.; Duda, John C.; Smoyer, Justin L.; Norris, Pamela M.

    2010-01-04

    Increased power densities combined with the decreased length scales of nanosystems give rise to large thermal excitations that can drastically affect the electron population near the Fermi surface. In light of such conditions, a model is developed for electron thermal boundary conductance (eTBC) that accounts for significant changes in the electron and hole populations around the Fermi level that occur at heightened temperatures. By including the contribution of subconduction band electrons to transport and evaluating the transmission coefficient based upon the total number of available states, an extension of eTBC predictions to high temperatures is made possible.

  18. X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook

    SciTech Connect

    Widener, K; Bharadwaj, N

    2012-10-29

    The X-band scanning ARM cloud radar (X-SAPR) is a full-hemispherical scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 200 kW magnetron transmitter, this puts 100 kW of transmitted power for each polarization. The receiver for the X-SAPR is a Vaisala Sigmet RVP-900 operating in a coherent-on-receive mode. Three X-SAPRs are deployed around the Southern Great Plains (SGP) Central Facility in a triangular array. A fourth X-SAPR is deployed near Barrow, Alaska on top of the Barrow Arctic Research Center.

  19. Complete active space self-consistent field calculations of the vibrational band strengths for C3

    SciTech Connect

    Jorgensen, U.G.; Almlof, J.; Siegbahn, P.E.M.; Minnesota Univ., Minneapolis; Stockholm Universitet )

    1989-08-01

    Complete active space self-consistent calculations of the energy and dipole moment functions were carried out for C3 in its electronic ground state. The absorption coefficient between 0.7 and 75 microns is calculated on the basis of the vibrational band strength of transitions between the 800 lowest states with v less than or equal to (4, 39, 3). In cool carbon stars with a high C/O ratio, C3 is found to be the most prevalent of the known opacity sources. 49 refs.

  20. Monolayer-induced band shifts at Si(100) and Si(111) surfaces

    SciTech Connect

    Mkinen, A. J. Kim, Chul-Soo; Kushto, G. P.

    2014-01-27

    We report our study of the interfacial electronic structure of Si(100) and Si(111) surfaces that have been chemically modified with various organic monolayers, including octadecene and two para-substituted benzene derivatives. X-ray photoelectron spectroscopy reveals an upward band shift, associated with the assembly of these organic monolayers on the Si substrates, that does not correlate with either the dipole moment or the electron withdrawing/donating character of the molecular moieties. This suggests that the nature and quality of the self-assembled monolayer and the intrinsic electronic structure of the semiconductor material define the interfacial electronic structure of the functionalized Si(100) and Si(111) surfaces.