National Library of Energy BETA

Sample records for transportation dot research

  1. NREL: Transportation Research - DOE, DOT Announce Collaboration to Advance

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

    Smart Transportation Systems DOE, DOT Announce Collaboration to Advance Smart Transportation Systems May 17, 2016 The U.S. Department of Energy (DOE) and U.S. Department of Transportation (DOT) recently announced their collaboration to accelerate research, demonstration, and deployment of innovative transportation and alternative fuel technologies. The agencies made their formal Memorandum of Understanding known at an electric vehicle workshop in Berkeley, California. The initiative will tap

  2. DOT Awards University Transportation Centers $63 Million

    Broader source: Energy.gov [DOE]

    The U.S. Department of Transportation's (DOT) announced approximately $63 million in grants to 33 University Transportation Centers to advance research and education programs that address critical transportation challenges.

  3. Transportation Research

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

    transportation-research TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling Transportation Research Current Research Overview The U.S. Department of Transportation (USDOT) has established its only high-performance computing and engineering analysis research facility at Argonne National Laboratory to provide applications support in key areas of applied research and development for the USDOT community. The Transportation Research and

  4. Expansion of DOE-DOT Tight Oil Research Work

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

    Expansion of DOE-DOT Tight Oil Research Work - Sandia Energy Energy Search Icon Sandia ... Twitter Google + Vimeo Newsletter Signup SlideShare Expansion of DOE-DOT Tight Oil ...

  5. NREL: Transportation Research - Transportation News

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

    Transportation News The following news stories highlight transportation research at NREL. August 25, 2016 NREL and NASA Receive Regional FLC Award for Notable Technology NASA Johnson Space Center (JSC) and the National Renewable Energy Laboratory (NREL) were selected as 2016 recipients of a Federal Laboratory Consortium (FLC) Mid-Continent Regional Award, for their notable technology development of the patented Battery Internal Short-Circuit (ISC) Device. August 25, 2016 NREL Helps the National

  6. NREL: Transportation Research - News

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

    News NREL provides a number of transportation and hydrogen news sources. Transportation News Find news stories that highlight NREL's transportation research, development, and deployment (RD&D) activities, including work on vehicles and fuels. Hydrogen and Fuel Cells News Find news stories that highlight NREL's hydrogen RD&D activities, including work on fuel cell electric vehicle technologies. Transportation and Hydrogen Newsletter Stay up to date on NREL's RD&D of transportation and

  7. Los Alamos researchers unravel the mystery of quantum dot blinking

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

    Researchers unravel the mystery of quantum dot blinking Los Alamos researchers unravel the mystery of quantum dot blinking Most exciting is that the Los Alamos researchers have shown that blinking can be controlled and even completely suppressed electrochemically. November 9, 2011 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy

  8. Nontoxic quantum dot research improves solar cells

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

    Solar cells made with low-cost, nontoxic copper-based quantum dots can achieve ... LOS ALAMOS, N.M., Dec. 10, 2013-Solar cells made with low-cost, nontoxic copper-based ...

  9. NREL: Transportation Research - Projects

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

    Projects Illustration of aerodynamic light-, medium, and heavy-duty vehicles. NREL research helps optimize the energy efficiency of a wide range of vehicle technologies and applications. NREL's innovative transportation research, development, and deployment projects accelerate widespread adoption of high-performance, low-emission, energy-efficient passenger and freight vehicles, as well as alternative fuels and related infrastructure. The following NREL transportation projects are propelling

  10. NREL: Transportation Research - Capabilities

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

    Capabilities A Vision for Sustainable Transportation Line graph illustrating three pathways (biofuel, hydrogen, and electric vehicle) to reduce energy use and greenhouse gas emissions. Electric Vehicle Technologies & Targets 3-D illustration of electric car diagramming energy storage, power electronics, and climate control components. NREL uses 100% of its considerable transportation research, development, and deployment (RD&D) capabilities to pursue sustainable solutions that deliver

  11. Research Challenge 2: Quantum Dots and Phosphors

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

    2: Quantum Dots and Phosphors - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs

  12. NREL: Transportation Research - Webmaster

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

    Webmaster Please enter your name and email address in the boxes provided, then type your message below. When you are finished, click "Send Message." NOTE: If you enter your e-mail address incorrectly, we will be unable to reply. Your name: Your email address: Your message: Send Message Printable Version Transportation Research Home Capabilities Projects

  13. Research Challenge 2: Quantum Dots and Phosphors

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

    Energy Frontier Research Centers: Solid-State Lighting Science Center for Frontiers of ... HomeEnergy ResearchEFRCsSolid-State Lighting Science EFRCOur SSLS EFRC's Scientific ...

  14. NREL: Transportation Research - Transportation and Hydrogen Newsletter

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

    Transportation and Hydrogen Newsletter The Transportation and Hydrogen Newsletter is a monthly electronic newsletter that provides information on NREL's research, development, and deployment of transportation and hydrogen technologies. Photo of a stack of newspapers July 2016 Issue Hydrogen Fuel Cells Read the latest issue of the newsletter. Subscribe: To receive new issues by email, subscribe to the newsletter. Archives: For past issues, read the newsletter archives. Printable Version

  15. NREL: Transportation Research - Sustainable Transportation Basics

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

    Transportation Basics Compare Vehicle Technologies 3-D illustration of electric car diagramming energy storage, power electronics, and climate control components. The following links to the U.S. Department of Energy's Alternative Fuels Data Center (AFDC) provide an introduction to sustainable transportation. NREL research supports development of electric, hybrid, hydrogen fuel cell, biofuel, natural gas, and propane vehicle technologies. Learn more about vehicles, fuels, and transportation

  16. the-transportation-research-board

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

    January 22-26, 2012 The Transportation Research Board (TRB) 91st Annual Meeting will be held in Washington, D.C. at the Washington Marriott Wardman Park, Omni Shoreham, and Washington Hilton hotels. The information-packed program will attract more than 11,000 transportation professionals from around the world to Washington, D.C., January 22-26, 2012. The Transportation Research and Analysis Computing Center (TRACC) team will showcase current projects at the upcoming Transportation Research Board

  17. NREL: Transportation Research Home Page

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

    Transportation Research Silver Toyota Prius being driven in front of NREL entrance sign. NREL helps industry partners develop the next generation of energy efficient, high performance vehicles and fuels. Thermal image of two men standing in front of tractor trailer cab. NREL conducts research on the full range of vehicle types, from light-duty passenger cars to heavy-duty freight trucks. Female researcher holding coin cell battery. NREL's transportation research spans from the materials to the

  18. Exciton dissociation and interdot transport in CdSe quantum-dot molecules

    SciTech Connect (OSTI)

    Franceschetti, Alberto; Zunger, Alex

    2001-04-15

    One of the most important parameters that determine the transport properties of a quantum dot array is the exciton dissociation energy, i.e., the energy {Delta}E required to dissociate an exciton into an electron and a hole localized in different dots. We show that a pseudopotential calculation for a dot molecule, coupled with a basic configuration interaction calculation of the exciton energy levels, provides directly the exciton dissociation energy, including the effects of wave function overlap, screened Coulomb attraction between the electron and the hole in different dots, and polarization effects. We find that {Delta}E decreases as the interdot distance decreases and as the dielectric constant of the medium increases.

  19. NREL: Transportation Research - Facilities

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

    Facilities NREL conducts vehicles and fuels research in laboratories and test sites on its 327-acre main campus in Golden, Colorado, and at specialized facilities within the region. Industry, government, and university partners benefit from access to NREL equipment and facilities tailored to analyze a broad spectrum of energy-efficient vehicle and fuel technologies and innovations. NREL engineers and researchers work closely with a wide variety of partners to research and develop advanced

  20. Transport Research Laboratory | Open Energy Information

    Open Energy Info (EERE)

    Research Laboratory Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Transport Research Laboratory AgencyCompany Organization: Transport Research Laboratory Focus Area:...

  1. NREL: Transportation Research - Success Stories

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

    Success Stories NREL understands real-world factors impacting industry and consumer adoption of sustainable transportation solutions, resulting in an impressive record of breaking down barriers to accelerate development and deployment of new transportation technologies. The success stories below provide a snapshot of how NREL research, development, and deployment activities translate into more energy-efficient vehicles and cleaner burning fuels, providing viable options to meet the needs of

  2. NREL: Transportation Research - Energy Storage

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

    Energy Storage Transportation Research Cutaway image of an automobile showing the location of energy storage components (battery and inverter), as well as electric motor, power electronics controller, and heat exchangers. Blowout shows the image of an individual battery pack. NREL research is pointing the way toward affordable, high-performing, long-lasting batteries for the next generation of electric-drive vehicles. Researcher holding cables and standing in front of an open equipment chamber.

  3. Cornell dots research collaboration leads to $10M cancer center...

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

    at MSKCC in New York City - will focus on melanoma (skin) and malignant brain cancers. ... Assessment of particles in brain tumors for cancer therapy. C dots successfully have ...

  4. The impact of disorder on charge transport in three dimensional quantum dot resonant tunneling structures

    SciTech Connect (OSTI)

    Puthen-Veettil, B. Patterson, R.; Knig, D.; Conibeer, G.; Green, M. A.

    2014-10-28

    Efficient iso-entropic energy filtering of electronic waves can be realized through nanostructures with three dimensional confinement, such as quantum dot resonant tunneling structures. Large-area deployment of such structures is useful for energy selective contacts but such configuration is susceptible to structural disorders. In this work, the transport properties of quantum-dot-based wide-area resonant tunneling structures, subject to realistic disorder mechanisms, are studied. Positional variations of the quantum dots are shown to reduce the resonant transmission peaks while size variations in the device are shown to reduce as well as broaden the peaks. Increased quantum dot size distribution also results in a peak shift to lower energy which is attributed to large dots dominating transmission. A decrease in barrier thickness reduces the relative peak height while the overall transmission increases dramatically due to lower series resistance. While any shift away from ideality can be intuitively expected to reduce the resonance peak, quantification allows better understanding of the tolerances required for fabricating structures based on resonant tunneling phenomena/.

  5. Cornell dots research collaboration leads to $10M cancer center > EMC2 News

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

    > The Energy Materials Center at Cornell dots research collaboration leads to $10M cancer center September 24th, 2015 › Provided/Wiesner Lab A rendering of the molecular structure of a Cornell dot, which is smaller than 10 nanometers. Provided/Wiesner Lab A transmission electron microscope image of Cornell dots. C dots, which are injected into patients, are designed to either adhere to and light up cancer cells or quickly leave the body. Cornell University, in partnership with Memorial

  6. NREL: Transportation Research - Transportation Deployment Support

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

    Transportation Deployment Support Photo of a car parked in front of a monument. A plug-in electric vehicle charges near the Thomas Jefferson Memorial in Washington, D.C. Photo from Julie Sutor, NREL NREL's transportation deployment team works with vehicle fleets, fuel providers, and other transportation stakeholders to help deploy alternative and renewable fuels, advanced vehicles, fuel economy improvements, and fleet-level efficiencies that reduce emissions and petroleum dependence. In

  7. Charge transport and memristive properties of graphene quantum dots embedded in poly(3-hexylthiophene) matrix

    SciTech Connect (OSTI)

    Cosmin Obreja, Alexandru; Cristea, Dana; Radoi, Antonio; Gavrila, Raluca; Comanescu, Florin; Kusko, Cristian; Mihalache, Iuliana

    2014-08-25

    We show that graphene quantum dots (GQD) embedded in a semiconducting poly(3-hexylthiophene) polymeric matrix act as charge trapping nanomaterials. In plane current-voltage (I-V) measurements of thin films realized from this nanocomposite deposited on gold interdigitated electrodes revealed that the GQD enhanced dramatically the hole transport. I-V characteristics exhibited a strong nonlinear behavior and a pinched hysteresis loop, a signature of a memristive response. The transport properties of this nanocomposite were explained in terms of a trap controlled space charge limited current mechanism.

  8. Elastic tunneling charge transport mechanisms in silicon quantum dots /SiO{sub 2} thin films and superlattices

    SciTech Connect (OSTI)

    Illera, S. Prades, J. D.; Cirera, A.

    2015-05-07

    The role of different charge transport mechanisms in Si/SiO{sub 2} structures has been studied. A theoretical model based on the Transfer Hamiltonian Formalism has been developed to explain experimental current trends in terms of three different elastic tunneling processes: (1) trap assisted tunneling; (2) transport through an intermediate quantum dot; and (3) direct tunneling between leads. In general, at low fields carrier transport is dominated by the quantum dots whereas, for moderate and high fields, transport through deep traps inherent to the SiO{sub 2} is the most relevant process. Besides, current trends in Si/SiO{sub 2} superlattice structure have been properly reproduced.

  9. NREL: Transportation Research - Transportation and Hydrogen Newsletter...

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

    This is the May 2015 issue of the Transportation and Hydrogen Newsletter. May 28, 2015 Photo of a car refueling at a hydrogen dispensing station. DOE's H2FIRST project focuses on ...

  10. NREL: Transportation Research - Transportation and Hydrogen Newsletter...

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

    Energy Storage This is the November 2015 issue of the Transportation and Hydrogen ... kind in the national lab system, and one of just a few to be found in the entire country. ...

  11. Resonant electronic transport through a triple quantum-dot with Λ-type level structure under dual radiation fields

    SciTech Connect (OSTI)

    Guan, Chun; Xing, Yunhui; Zhang, Chao; Ma, Zhongshui

    2014-08-14

    Due to quantum interference, light can transmit through dense atomic media, a phenomenon known as electromagnetically induced transparency (EIT). We propose that EIT is not limited to light transmission and there is an electronic analog where resonant transparency in charge transport in an opaque structure can be induced by electromagnetic radiation. A triple-quantum-dots system with Λ-type level structure is generally opaque due to the level in the center dot being significantly higher and therefore hopping from the left dot to the center dot is almost forbidden. We demonstrate that an electromagnetically induced electron transparency (EIET) in charge of transport can indeed occur in the Λ-type system. The direct evidence of EIET is that an electron can travel from the left dot to the right dot, while the center dot apparently becomes invisible. We analyze EIET and the related shot noise in both the zero and strong Coulomb blockade regimes. It is found that the EIET (position, height, and symmetry) can be tuned by several controllable parameters of the radiation fields, such as the Rabi frequencies and detuning frequencies. The result offers a transparency/opaque tuning technique in charge transport using interfering radiation fields.

  12. NREL: Transportation Research - Transportation and Hydrogen Newsletter...

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

    ... and university researchers to support improved motor designs. Although the research focused on electric machines for electric-drive vehicle applications, the results are applicable ...

  13. Low-temperature transport in ac-driven quantum dots in the Kondo regime

    SciTech Connect (OSTI)

    Lopez, Rosa; Aguado, Ramon; Platero, Gloria; Tejedor, Carlos

    2001-08-15

    We present a fully nonequilibrium calculation of the low-temperature transport properties of a quantum dot in the Kondo regime when an ac potential is applied to the gate. We solve a time-dependent Anderson model with finite on-site Coulomb interaction. The interaction self-energy is calculated up to second order in perturbation theory in the on-site interaction, in the context of the Keldysh nonequilibrium technique, and the effect of the ac voltage is taken into account exactly for all ranges of ac frequencies and ac intensities. The obtained linear conductance and time-averaged density of states of the quantum dot evolve in a nontrivial way as a function of the ac frequency and ac intensity of the harmonic modulation.

  14. A commentary on the 1995 DOT/NRC amendments to the U.S. nuclear transportation regulations

    SciTech Connect (OSTI)

    Grella, A.

    1996-07-01

    This article discusses the major revisions (1995 DOT/NRC ammendments) to the US Nuclear Transportation regulations and their probable impacts on transportation. Areas covered include the following: the LSA and SCO definitions and packaging; radiation protection programs; mandatory use of SI units; changes an additions to the table of A1/A2 radionuclide values; and additional type B package hypothetical accident parameters.

  15. NREL: Transportation Research - Transportation and Hydrogen Newsletter:

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

    Market Impact Hydrogen Fuel Cells This is the July 2016 issue of the Transportation and Hydrogen Newsletter. July 28, 2016 A photo of a public hydrogen fuel cell bus parked in a parking lot. Fuel cell electric buses (FCEBs), such as this one operating in Oakland, California, are providing data to compare FCEB performance with that of buses using conventional technology. Photo by Leslie Eudy, NREL NREL Helps Pave Way for H2 Technologies As deployment of hydrogen fueling stations increases to

  16. Center for Transportation Research | Argonne National Laboratory

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

    Center for Transportation Research Argonne's Center for Transportation Research (CTR) provides innovative solutions to challenges involving fuel efficiency, emissions, durability, safety, design and operating efficiency, petroleum dependence, interoperability, compatibility and codes/standards compliance and harmonization. The CTR is home to a well-balanced transportation research program staffed by world-class researchers and engineers, who are well known in the technical community and within

  17. Transportation Research Board 94th Annual Meeting

    Broader source: Energy.gov [DOE]

    The Transportation Research Board 94th Annual Meeting will be held January 11–15, 2015, in Washington, D.C. at the Walter E. Washington Convention Center. The event covers the entire transportation...

  18. NREL: Transportation Research - E-Roadway Animation

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

    extend the operational range of electric vehicles. Plus, e-roadway power can come from renewable sources. Text version. Printable Version Transportation Research Home...

  19. NREL: Transportation Research - Fuel Chemistry Research

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

    Chemistry Research Photo of a hand holding a beaker containing a clear yellow liquid. NREL ... Photo by Dennis Schroeder, NREL NREL's fuel chemistry research explores how biofuels, ...

  20. NREL: Transportation Research - Subscribe to the Transportation and

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

    Hydrogen Newsletter Subscribe to the Transportation and Hydrogen Newsletter To subscribe to or unsubscribe from the Transportation and Hydrogen Newsletter, complete one of the forms below. Subscribe To subscribe to the newsletter, submit your email address. Email: Submit Unsubscribe To unsubscribe from the newsletter, submit your email address. Email: Submit Printable Version Transportation Research Home Capabilities Projects Success Stories Facilities Working with Us Publications Data &

  1. Kondo-type transport through a quantum dot under magnetic fields

    SciTech Connect (OSTI)

    Dong, Bing; Lei, X. L.

    2001-06-15

    In this paper, we investigate the Kondo correlation effects on linear and nonlinear transport in a quantum dot connected to reservoirs under finite magnetic fields, using the slave-boson mean field approach suggested by Kotliar and Ruckenstein [Phys. Rev. Lett. >57, 1362 (1986)]. A brief comparison between the present formulation and other slave-boson formulation is presented to justify this approach. The numerical results show that the linear conductance near electron-hole symmetry is suppressed by the application of the magnetic fields, but an anomalous enhancement is predicted in the nonsymmetry regime. The effect of external magnetic fields on the nonlinear differential conductances is discussed for the Kondo system. A significant reduction of the peak splitting is observed due to the strong Kondo correlation, which agrees well with experimental data.

  2. 1995 revisions to the DOT/NRC transport regulations and their impact on nuclear power plants

    SciTech Connect (OSTI)

    Grella, A.W.

    1996-10-01

    On September 28, 1995, the U.S. Department of Transportation (DOT) and the U.S. Nuclear Regulatory Commission (NRC) published major amendments to the nuclear transportation regulations of the US. The amendments culminated an approximate 8-year effort of the two agencies to conform US regulations (to the extent practicable) to the international transport standards of the International Atomic Energy Agency (IAEA) Safety Series N. 6, {open_quotes}Regulations For The Safe Transport of Radioactive Material{close_quotes}, 1985 Edition (Revised 1990). This paper identifies the major revisions to the regulations which have taken place and discusses not only their probable future impacts but also identifies certain issues and early impacts which have been emerging since publication of the final rules late in 1995. The discussion is summarized with respect to these impacts and issues on transportation of radioactive material by the nuclear power industry. Many of the revisions which are more minor in nature are also identified. The generic effective date for mandatory compliance with the revised regulations was April 1, 1996, however two of the major revisions of interest to the utilities have later effective dates for mandatory compliance. The use of the so-called {open_quotes}NRC-Certified Type A LSA Packages{close_quotes} are authorized until April 1, 1999 and mandatory compliance with the new radiation protection program requirements of 49 CFR 172 Subpart I is not until October 1, 1997. This paper is based to a large extent on the EPRI report bearing the same title as this paper, which is currently in draft.

  3. New Transportation Technology | GE Global Research

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

    Transportation We're working with railroads and heavy industries to create hybrid systems, batteries and first-in-class transportation solutions. Home > Innovation > Transportation Silicon Carbide Applications: Small Device, Broad Impact in Power Electronics It's not every day that the engineers at GE Global Research get their hands on a material that's literally revolutionizing an... Read More » Data Science Makes Trains More Efficient In this Special Report, GE's Creator-in-Residence,

  4. Transportation Secure Data Center: Real-World Data for Value Pricing and Tolling Research (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-01-01

    The National Renewable Energy Laboratory (NREL) and the U.S. Department of Transportation (DOT) have launched the free, web-based Transportation Secure Data Center (TSDC). The TSDC (www.nrel.gov/tsdc) preserves respondent anonymity while making vital transportation data available to a broad group of users through secure, online access. The TSDC database provides free-of-charge web-based access to valuable transportation data that can be used for: Location and time-of-day variable tolling research, Mileage-based fee analysis, Travel demand modeling and transit planning, Congestion mitigation research, and Validating transportation data from other sources. The TSDC's two levels of access make composite data available with simple online registration, and allow researchers to use detailed spatial data after completing a straight forward application process.

  5. NREL: Transportation Research - Working with Us

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

    Working with Us Partnerships Drive Transportation Solutions Photo of two men standing in front of a large solar panel and an electric vehicle. NREL offers industry, academia, and government agencies opportunities to work with us and leverage our research expertise and capabilities. There are several ways for your organization to get involved with us: Partner with NREL through a Cooperative Research and Development Agreement or a Work-for-Others Agreement. License NREL-developed technologies. The

  6. The role of transport processes of nonequilibrium charge carriers in radiative properties of arrays of InAs/GaAs quantum dots

    SciTech Connect (OSTI)

    Shkolnik, A. S. Savelyev, A. V.; Karachinsky, L. Ya.; Gordeev, N. Yu.; Seisyan, R. P.; Zegrya, G. G.; Pellegrini, S.; Buller, G. S.; Evtikhiev, V. P.

    2008-03-15

    The results of time-resolved photoluminescence studies of heterostructures containing monolayer arrays of InAs/GaAs quantum dots are presented. A two-component time dependence of intensity of photoluminescence from the ground state of quantum dots, with characteristic times of the slow component up to hundreds of nanoseconds and those of rapid one several nanoseconds, is studied. It is shown that the slow component is determined by the transport of nonequilibrium charge carriers between the quantum dots. At low temperatures, the time of the slow component is determined by tunneling, and at high temperatures by thermal escape of nonequilibrium charge carriers. The ratio of the contributions of tunneling and thermal escape is determined by the degree of isolation of quantum dots. A theoretical model is constructed that describes the effect of the dynamics of carrier transport on the emergence and decay of the slow component of photoluminescence.

  7. Cost-effectiveness analysis of TxDOT LPG fleet conversion. Volume 1. Interim research report

    SciTech Connect (OSTI)

    Euritt, M.A.; Taylor, D.B.; Mahmassani, H.

    1992-10-01

    Increased emphasis on energy efficiency and air quality has resulted in a number of state and federal initiatives examining the use of alternative fuels for motor vehicles. Texas' program for alternate fuels includes liquefied petroleum gas (LPG). Based on an analysis of 30-year life-cycle costs, development of a propane vehicle program for the Texas Department of Transportation (TxDOT) would cost about $24.3 million (in 1991 dollars). These costs include savings from lower-priced LPG and differentials between propane and gasoline/diesel in infrastructure costs for a fueling station, vehicle costs, and operating costs. The 30-year life-cycle costs translate into an average annual vehicle cost increase of $308, or about 2.5 cents more per vehicle mile of travel. Sensitivity analyses are performed on the discount rate, price of propane, maintenance savings, vehicle utilization, diesel vehicles, extended vehicle life, original equipment manufacturer (OEM) vehicles, and operating and infrastructure costs. The best results are obtained when not converting diesel vehicles, converting only large fleets, and extending the period the vehicle is kept in service. Combining these factors yields results that are most cost-effective for TxDOT. This is volume one of two volumes.

  8. Cost-effectiveness analysis of TxDOT LPG fleet conversion. Volume 2. Interim research report

    SciTech Connect (OSTI)

    Euritt, M.A.; Taylor, D.B.; Mahmassani, H.

    1992-11-01

    Increased emphasis on energy efficiency and air quality has resulted in a number of state and federal initiatives examining the use of alternative fuels for motor vehicles. Texas' program for alternate fuels includes liquefied petroleum gas (LPG), commonly called propane. Based on an analysis of 30-year life-cycle costs, development of a propane vehicle program for the Texas Department of Transportation (TxDOT) would cost about $24.3 million (in 1991 dollars). These costs include savings from lower-priced propane and differentials between propane and gasoline/diesel in infrastructure costs, vehicle costs, and operating costs. The 30-year life-cycle costs translate into an average annual vehicle cost increase of $308, or about 2.5 cents more per vehicle mile of travel. Based on the cost-effectiveness analysis and assumptions, there are currently no TxDOT locations that can be converted to propane without additional financial outlays. This is volume two of two volumes.

  9. 'Giant' Nanocrystal Quantum Dots

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

    Energy Frontier Research Centers: Solid-State Lighting Science Center for Frontiers of ... 'Giant' Nanocrystal Quantum Dots HomeEnergy ResearchEFRCsSolid-State Lighting Science ...

  10. Transportation Research and Analysis Computing Center Fact Sheet | Argonne

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

    National Laboratory Transportation Research and Analysis Computing Center Fact Sheet The Transportation Research and Analysis Computing Center (TRACC) is the intersection of state-of-the-art computing and critical science and engineering research that is improving how the nation plans, builds, and secures a transportation system for the 21st Century. PDF icon TRACC

  11. NREL Researchers Demonstrate External Quantum Efficiency Surpassing 100% in a Quantum Dot Solar Cell (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-12-01

    A new device that produces and collects multiple electrons per photon could yield inexpensive, high-efficiency photovoltaics. A new device developed through research at the National Renewable Energy Laboratory (NREL) reduces conventional losses in photovoltaic (PV) solar cells, potentially increasing the power conversion efficiency-but not the cost-of the solar cells. Solar cells convert optical energy from the sun into usable electricity; however, almost 50% of the incident energy is lost as heat with present-day technologies. High-efficiency, multi-junction cells reduce this heat loss, but their cost is significantly higher. NREL's new device uses excess energy in solar photons to create extra charges rather than heat. This was achieved using 5-nanometer-diameter quantum dots of lead selenide (PbSe) tightly packed into a film. The researchers chemically treated the film, and then fabricated a device that yielded an external quantum efficiency (number of electrons produced per incident photon) exceeding 100%, a value beyond that of all current solar cells for any incident photon. Quantum dots are known to efficiently generate multiple excitons (a bound electron-hole pair) per absorbed high-energy photon, and this device definitively demonstrates the collection of multiple electrons per photon in a PV cell. The internal quantum efficiency corrects for photons that are not absorbed in the photoactive layer and shows that the PbSe film generates 30% to 40% more electrons in the high-energy spectral region than is possible with a conventional solar cell. While the unoptimized overall power conversion efficiency is still low (less than 5%), the results have important implications for PV because such high quantum efficiency can lead to more electrical current produced than possible using present technologies. Furthermore, this fabrication is also amenable to inexpensive, high-throughput roll-to-roll manufacturing.

  12. UC Berkeley-Transportation Sustainability Research Center | Open...

    Open Energy Info (EERE)

    Sustainability Research Center Jump to: navigation, search Name: UC Berkeley-Transportation Sustainability Research Center Address: 2614 Dwight Way Place: Berkeley, California Zip:...

  13. Transport properties and Kondo correlations in nanostructures: Time-dependent DMRG method applied to quantum dots coupled to Wilson chains

    SciTech Connect (OSTI)

    Dias Da Silva, Luis G; Heidrich-Meisner, Fabian; Feiguin, Adrian E; Busser, C. A.; Martins, G. B.; Anda, E. V.; Dagotto, Elbio R

    2008-01-01

    We apply the adaptive time-dependent density-matrix renormalization-group method tDMRG to the study of transport properties of quantum-dot systems connected to metallic leads. Finite-size effects make the usual tDMRG description of the Kondo regime a numerically demanding task. We show that such effects can be attenuated by describing the leads by Wilson chains, in which the hopping matrix elements decay exponentially away from the impurity tn n/2. For a given system size and in the linear-response regime, results for 1 show several improvements over the undamped =1 case: perfect conductance is obtained deeper in the strongly interacting regime and current plateaus remain well defined for longer time scales. Similar improvements were obtained in the finite-bias regime up to bias voltages of the order of the Kondo temperature. These results show that with the proposed modification, the tDMRG characterization of Kondo correlations in the transport properties can be substantially improved, while it turns out to be sufficient to work with much smaller system sizes. We discuss the numerical cost of this approach with respect to the necessary system sizes and the entanglement growth during the time evolution.

  14. NREL: Transportation Research - Vehicle Thermal Management

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

    transported across the United States each year. Idling these vehicles to heat and cool cabsleeper spaces improves driver comfort and safety, but consumes large quantities of...

  15. NREL: Transportation Research - Successful Transportation Lab-Industry

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

    Collaborations Spotlighted at Summit Successful Transportation Lab-Industry Collaborations Spotlighted at Summit Five men stand outside in front of passenger car and white modular building. On display at the National Lab Impact Summit, a Toyota Mirai fuel cell electric vehicle from NREL paired with a 3D-printed building from ORNL can work together to produce and store renewable energy. Image Dennis Schroeder, NREL. May 18, 2016 On May 4, NREL hosted leaders from the business, government, and

  16. Superconducting transport in single and parallel double InAs quantum dot Josephson junctions with Nb-based superconducting electrodes

    SciTech Connect (OSTI)

    Baba, Shoji Sailer, Juergen; Deacon, Russell S.; Oiwa, Akira; Shibata, Kenji; Hirakawa, Kazuhiko; Tarucha, Seigo

    2015-11-30

    We report conductance and supercurrent measurements for InAs single and parallel double quantum dot Josephson junctions contacted with Nb or NbTiN superconducting electrodes. Large superconducting gap energy, high critical field, and large switching current are observed, all reflecting the features of Nb-based electrodes. For the parallel double dots, we observe an enhanced supercurrent when both dots are on resonance, which may reflect split Cooper pair tunneling.

  17. DOE and the Department of Transportation Announce Collaboration to Support Smart Transportation Systems and Alternative Fuel Technologies

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy (DOE) and the U.S. Department of Transportation (DOT) announced a collaboration to accelerate research, development, demonstration, and deployment of innovative smart transportation systems and alternative fuel technologies.

  18. NREL: Transportation Research - News Release Archives

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

    2 December 28, 2012 Clean Cities YouTube Channel Offers Videos on Alternative Fuels and Advanced Vehicles The NREL-developed Clean Cities YouTube channel offers informative videos that can help vehicle fleet managers and transportation decision makers reduce petroleum use by gleaning insight from a variety of alternative transportation topics. December 21, 2012 NREL Names New Executive The U.S. Department of Energy's National Renewable Energy Laboratory today named Barbara Goodman as Associate

  19. NREL: Transportation Research - Sustainable Mobility Initiative

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

    Mobility Initiative Graphic of four concentric circles starting with the traveler and branching out to encompass the vehicle, transport system, and built environment. NREL's Sustainable Mobility Initiative approaches sustainable transportation as a network of travelers, services, and environments-rather than just vehicles and roads-using connectivity and automation to optimize mobility and significantly reduce related energy consumption. This concept of an intelligent, integrated, and dynamic

  20. NREL: Transportation Research - News Release Archives

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

    NREL researchers will gather with U.S. Department of Energy program directors and technology ... February 14, 2013 NREL Helps Communities Assess Their Readiness for Electric Vehicles ...

  1. NREL: Transportation Research - Power Electronics Packaging Reliabilit...

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

    Packaging Reliability A photo of a piece of power electronics testing equipment. NREL power electronics packaging reliability research investigates the performance and reliability ...

  2. Center for Transportation Research | Argonne National Laboratory

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

    Advanced Vehicle Technologies Friction, Wear, and Lubrication Technologies Fuel Spray Analysis Multi-Dimensional Modeling Vehicle-Grid Interoperability CTR research occurs in...

  3. New Transportation Technology | GE Global Research

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

    Read More GE, MIT Build Crowdsourcing Software Platform GE (NYSE: GE), with the Massachusetts Institute of Technology (MIT) and the Defense Advanced Research Agency (DARPA), ...

  4. Research in transportation: the shape of the future

    SciTech Connect (OSTI)

    Chenea, P.F.

    1981-01-01

    The individual mobility now enjoyed due to advancements in the transportation sector is being threatened by higher fuel costs and declining petroleum resources. Transportation research approaches must address these problems. Automotive engineers must redesign existing vehicles to make them smaller, lighter, and so more fuel efficient. Alternatives to the gasoline engine, such as gas turbine and stratified charge engines, must be commercialized.

  5. Vehicle Technologies Office: Data and Analysis for Transportation Research

    Office of Energy Efficiency and Renewable Energy (EERE)

    The U.S. Department of Energy (DOE) — in conjunction with the national laboratories — conducts a wide range of statistical research on energy use, economics, and trends in transportation.

  6. NREL: Transportation Research - NREL Researcher Jason Lustbader Recognized

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

    with SAE Excellence in Oral Presentation Award NREL Researcher Jason Lustbader Recognized with SAE Excellence in Oral Presentation Award Man with dark hair in blue shirt with arms crossed. NREL Senior Research Engineer Jason Lustbader. July 27, 2016 On July 14, 2016, National Renewable Energy Laboratory (NREL) Senior Research Engineer Jason Lustbader was recognized with an SAE Excellence in Oral Presentation Award. The award honors individuals who make outstanding presentations at the SAE

  7. NREL: Transportation Research - Compare Vehicle Technologies

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

    Compare Vehicle Technologies NREL researchers are simultaneously exploring ways to optimize the legacy internal combustion technology that makes up the vast majority of vehicles on today's roads, while developing the electric, fuel cell, and biofuel technologies needed to transition to a virtually net-zero emissions, non-polluting fleet. See how electric, hybrid, and fuel cell vehicles compare to traditional internal combustion vehicles in the slideshow below. 3-D illustration of electric car

  8. NREL: Transportation Research - Power Electronics Thermal Management

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

    Power Electronics Thermal Management A photo of water boiling in liquid cooling lab equipment. Power electronics thermal management research aims to help lower the cost and improve the performance of electric-drive vehicles. Photo by Dennis Schroeder, NREL NREL investigates and develops thermal management strategies for power electronics systems that use wide-bandgap technology, which enables the development of devices that are smaller than those based on other materials, demonstrating

  9. NREL: Transportation Research - Alternative Fuels Characterization

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

    Alternative Fuels Characterization Find out about other biomass research projects at NREL. NREL alternative fuels projects help overcome technical barriers and expand markets for renewable, biodegradable vehicle fuels. These liquid fuels include higher-level ethanol blends, butanol, biodiesel, renewable diesel, other biomass-derived fuels, and natural gas. By studying the fuel chemistry as well as combustion and emissions impacts of alternative fuels, NREL helps improve engine efficiency, reduce

  10. Promising future of quantum dots explored in conference

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

    Promising future of quantum dots explored Promising future of quantum dots explored in conference Researchers are gathering to reflect on two decades of quantum dot research at a special topical conference, "20 Years of Quantum Dots at Los Alamos" April 13, 2015 Quantum dot LSC devices under ultraviolet illumination. Quantum dot LSC devices under ultraviolet illumination. Contact Los Alamos National Laboratory Nancy Ambrosiano Communications Office (505) 667-0471 Email "This

  11. DOT specification packages evaluation

    SciTech Connect (OSTI)

    Ratledge, J.E.; Rawl, R.R. )

    1991-01-01

    During the late 1960s and early 1970s, the Department of Transportation (DOT) specification package system was implemented to serve as a useful and equivalent alternative to the Nuclear Regulatory Commission (NRC) and the Bureau of Explosives approval systems for Type B and fissile radioactive material package designs. When a package design was used by a large number of organizations, the package design was added to the DOT regulations as a specification package authorized for use by any shipper. In the mid-1970s, the NRC revised its package design certification system to the one in use today. This paper reports that, while the NRC and DOT transportation regulations have evolved over the years, the DOT specification package designs have remained largely unchanged. Questions have been raised as to whether these designs meet the current and proposed regulations. In order to enable the NRC and DOT to develop a regulatory analysis that will support appropriate action regarding the specification packages, a study is being performed to compile all available design, testing, and analysis information on these packages.

  12. NREL: Transportation Research - Driverless Cars and Fuel Efficiency

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

    Spotlighted in Scientific American Driverless Cars and Fuel Efficiency Spotlighted in Scientific American January 25, 2016 The potential to slow pollution through deployment of automated vehicles is gaining more and more traction in the news. In a recent Scientific American article, reporter Camille von Kaenel asked NREL's Jeff Gonder for a transportation researcher's thoughts on both the sustainability benefits and uncertainties that will accompany an increase in driverless cars. "The

  13. NREL: Transportation Research - NREL Kicks Off Next Phase of Advanced

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

    Computer-Aided Battery Engineering NREL Kicks Off Next Phase of Advanced Computer-Aided Battery Engineering March 16, 2016 NREL researcher looks across table at meeting Ahmad Pesaran, Energy Storage Group Manager for NREL's Transportation and Hydrogen Systems Center, led the kickoff meeting for CAEBAT-3 On March 8, NREL hosted the first review meeting of the Advanced Computer-Aided Battery Engineering Consortium, initiating phase three of the collaborative Computer Aided Engineering for

  14. Sandia Paper Wins Recognition by the Transportation Research Board

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

    Paper Wins Recognition by the Transportation Research Board - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense

  15. Transportable Heavy Duty Emissions Testing Laboratory and Research Program

    SciTech Connect (OSTI)

    David Lyons

    2008-03-31

    The objective of this program was to quantify the emissions from heavy-duty vehicles operating on alternative fuels or advanced fuel blends, often with novel engine technology or aftertreatment. In the first year of the program West Virginia University (WVU) researchers determined that a transportable chassis dynamometer emissions measurement approach was required so that fleets of trucks and buses did not need to be ferried across the nation to a fixed facility. A Transportable Heavy-Duty Vehicle Emissions Testing Laboratory (Translab) was designed, constructed and verified. This laboratory consisted of a chassis dynamometer semi-trailer and an analytic trailer housing a full scale exhaust dilution tunnel and sampling system which mimicked closely the system described in the Code of Federal Regulations for engine certification. The Translab was first used to quantify emissions from natural gas and methanol fueled transit buses, and a second Translab unit was constructed to satisfy research demand. Subsequent emissions measurement was performed on trucks and buses using ethanol, Fischer-Tropsch fuel, and biodiesel. A medium-duty chassis dynamometer was also designed and constructed to facilitate research on delivery vehicles in the 10,000 to 20,000lb range. The Translab participated in major programs to evaluate low-sulfur diesel in conjunction with passively regenerating exhaust particulate filtration technology, and substantial reductions in particulate matter were recorded. The researchers also participated in programs to evaluate emissions from advanced natural gas engines with closed loop feedback control. These natural gas engines showed substantially reduced levels of oxides of nitrogen. For all of the trucks and buses characterized, the levels of carbon monoxide, oxides of nitrogen, hydrocarbons, carbon dioxide and particulate matter were quantified, and in many cases non-regulated species such as aldehydes were also sampled. Particle size was also

  16. Chemistry and Transport - Combustion Energy Frontier Research Center

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

    Chemistry and Transport Chemistry and Transport The overall goal of the flame chemistry working group is to obtain fundamental combustion and emission properties of low and high pressure flames, to validate kinetic and transport models, and to develop accurate and computationally efficient models capable of predicting turbulent combustion of future transportation fuels. Experimental data of laminar and turbulent flame speeds, flame structures, extinction/ignition limits, and soot/NOx emissions

  17. Texas Department of Transportation | Open Energy Information

    Open Energy Info (EERE)

    Texas Department of Transportation Jump to: navigation, search Logo: Texas Department of Transportation Name: Texas Department of Transportation Abbreviation: TxDOT Place: Austin,...

  18. NREL: Hydrogen and Fuel Cells Research - Successful Transportation...

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

    On display at the National Lab Impact Summit, a Toyota Mirai fuel cell electric vehicle from ... needs," said NREL Transportation and Hydrogen Systems Center Director Chris Gearhart. ...

  19. Fuel Cells for Transportation- Research and Development: Program Abstracts

    Broader source: Energy.gov [DOE]

    Remarkable progress has been achieved in the development of proton-exchange-membrane(PEM) fuel cell technology since the U.S. Department of Energy (DOE) initiated a significant developmental program in the early 1990s. This progress has stimulated enormous interest worldwide in developing fuel cell products for transportation as well as for stationary and portable power applications. The potential markets are huge, but so are the R&D risks. Given the potential for PEM fuel cells to deliver large economic and environmental benefits to the Nation, DOE continues to take a leadership role in developing and validating this technology. DOE’s strategy to implement its Fuel Cells for Transportation program has three components: an R&D strategy, a fuels strategy, and a management strategy.

  20. Pipeline Safety Research, Development and Technology

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

    Pipeline and Hazardous Materials Safety Administration Pipeline Safety Research, Development and Technology Natural Gas Infrastructure R&D and Methane Emissions Mitigation Workshop Nov 2014 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Thank You! * We appreciate the opportunity to share! * Much to share about DOT natural gas infrastructure R&D * Many facets to the fugitive methane issue * DOT/DOE - We would like to restart the practice of

  1. NREL: Transportation Research - NREL's Campus EV Charging Stations...

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

    NREL's Campus EV Charging Stations are Now More Integrated with the Grid Researcher looks at computer in parking garage standing near electric vehicle charging station. Myungsoo ...

  2. NREL: Transportation Research - NREL Serves as the Energy Department...

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

    Serves as the Energy Department's Showcase for Cutting-Edge Fuel Cell Cars Research Studies Fueling System, Driver Behavior, and Vehicle Performance January 25, 2016 The Energy ...

  3. NREL: Transportation Research - NREL Engineer Recognized for Leadership in

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

    Motor Thermal Management NREL Engineer Recognized for Leadership in Motor Thermal Management Photo of Kevin Bennion with award June 16, 2016 NREL senior engineer and researcher Kevin Bennion received a special recognition award from the U.S. Department of Energy's Vehicle Technologies Office for expertise and leadership in the thermal management of motor designs in electric drive technologies research. The award was presented at a Vehicle Technologies Office ceremony on June 6, 2016, in

  4. NREL: Transportation Research - Power Electronics and Electric Machines

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

    Facilities and Electric Machines Facilities NREL's power electronics and electric machines thermal management test facilities feature a wide range of equipment and enable world-class experimental and modeling capabilities. NREL researchers excel at testing and measurement in the areas of heat transfer, reliability characterization, and thermal and thermomechanical modeling. The following list describes NREL's innovative testing capabilities and equipment. A photo of four researchers in

  5. NREL: Transportation Research - Fuel Combustion and Engine Performance

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

    Fuel Combustion and Engine Performance Photo of a gasoline direct injection piston with injector. NREL studies the effects of new fuel properties on performance and emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and development bridges fundamental chemical kinetics and applied engine research to investigate how new engine technologies can be co-developed with fuels and lubricants to maximize energy-efficient vehicle performance. Through

  6. NREL: Transportation Research - Power Electronics and Electric Machines

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

    Power Electronics and Electric Machines A photo of a researcher using testing equipment in a lab. NREL R&D is making wide-scale adoption of electric-drive vehicles more feasible by developing technologies and components with superior reliability, efficiency, and durability, while dramatically decreasing costs. Photo by Dennis Schroeder, NREL NREL's power electronics and electric machines research focuses on systems for electric-drive vehicles (EDVs) that control the flow of electricity

  7. Basic Research Needs for Clean and Efficient Combustion of 21st Century Transportation Fuels

    SciTech Connect (OSTI)

    McIlroy, A.; McRae, G.; Sick, V.; Siebers, D. L.; Westbrook, C. K.; Smith, P. J.; Taatjes, C.; Trouve, A.; Wagner, A. F.; Rohlfing, E.; Manley, D.; Tully, F.; Hilderbrandt, R.; Green, W.; Marceau, D.; O'Neal, J.; Lyday, M.; Cebulski, F.; Garcia, T. R.; Strong, D.

    2006-11-01

    To identify basic research needs and opportunities underlying utilization of evolving transportation fuels, with a focus on new or emerging science challenges that have the potential for significant long-term impact on fuel efficiency and emissions.

  8. Addressing transportation energy and environmental impacts: technical and policy research directions

    SciTech Connect (OSTI)

    Weissenberger, S.; Pasternak, A.; Smith, J.R.; Wallman, H.

    1995-08-01

    The Lawrence Livermore National Laboratory (LLNL) is establishing a local chapter of the University of California Energy Institute (UCEI). In order to most effectively contribute to the Institute, LLNL sponsored a workshop on energy and environmental issues in transportation. This workshop took place in Livermore on August 10 and brought together researchers from throughout the UC systems in order to establish a joint LLNL-UC research program in transportation, with a focus on energy and environmental impacts.

  9. Lessons learned from bacterial transport research at the South Oyster Site

    SciTech Connect (OSTI)

    Scheibe, T.; Hubbard, S.S.; Onstott, T.C.; DeFlaun, M.F.

    2011-04-01

    This paper provides a review of bacterial transport experiments conducted by a multi-investigator, multi-institution, multi-disciplinary team of researchers under the auspices of the U. S. Department of Energy (DOE). The experiments were conducted during the time period 1999-2001 at a field site near the town of Oyster, Virginia known as the South Oyster Site, and included four major experimental campaigns aimed at understanding and quantifying bacterial transport in the subsurface environment. Several key elements of the research are discussed here: (1) quantification of bacterial transport in physically, chemically and biologically heterogeneous aquifers, (2) evaluation of the efficacy of conventional colloid filtration theory, (3) scale effects in bacterial transport, (4) development of new methods for microbial enumeration and screening for low adhesion strains, (5) application of novel hydrogeophysical techniques for aquifer characterization, and (6) experiences regarding management of a large field research effort. Lessons learned are summarized in each of these areas. The body of literature resulting from South Oyster Site research has been widely cited and continues to influence research into the controls exerted by aquifer heterogeneity on reactive transport (including microbial transport). It also served as a model (and provided valuable experience) for subsequent and ongoing highly-instrumented field research efforts conducted by DOE-sponsored investigators.

  10. AUTHORIZING THE DOT SPECIFICATION 6M PACKAGING FOR CONTINUED USE AT THE SAVANNAH RIVER SITE

    SciTech Connect (OSTI)

    Watkins, R.; Loftin, B.; Hoang, D.

    2010-03-04

    The U.S. Department of Transportation (DOT) Specification 6M packaging was in extensive use for more than 40 years for in-commerce shipments of Type B quantities of fissile and radioactive material (RAM) across the USA, among the Department of Energy (DOE) laboratories, and between facilities in the DOE production complex. In January 2004, the DOT Research and Special Programs Administration (RSPA) Agency issued a final rule in the Federal Register to ammend requirements in the Hazardous Materials Regulations (HMR) pertaining to the transportation of radioactive materials. The final rule became effective on October 1, 2004. One of those changes discontinued the use of the DOT specification 6M, along with other DOT specification packagings, on October 1, 2008. A main driver for the change was due to the fact that 6M specification packagings were not supported by a Safety Analysis Report for Packagings (SARP) that was compliant with Title 10 of the Code of Federal Regulations (CFR) Part 71 (10 CFR 71). The regulatory rules for the discontinued use have been edited in Title 49 of the CFR Parts 100-185, 2004 edition and thereafter. Prior to October 1, 2008, the use of the 6M within the boundaries of the Savannah River Site (SRS), called an onsite transfer, was governed by an onsite transportation document that referenced 49 CFR Parts 100-185. SRS had to develop an Onsite Safety Assessment (OSA) which was independent of 49 CFR in order to justify the continued use of the DOT Specification 6M for the transfer of radioactive material (RAM) at the SRS after October 1, 2008. This paper will discuss the methodology for and difficulties associated with authorizing the DOT Specification 6M Packaging for continued use at the Savannah River Site.

  11. NREL: Transportation Research - Light-Duty Vehicle Thermal Management

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

    Light-Duty Vehicle Thermal Management Image of a semi-transparent car with parts of the engine highlighted in green. NREL evaluates technologies and methods such as advanced window glazing, cooling heat-pipe systems, parked car ventilation, and direct energy recovery. Illustration by Josh Bauer, NREL National Renewable Energy Laboratory (NREL) researchers are focused on improving the thermal efficiency of light-duty vehicles (LDVs) while maintaining the thermal comfort that drivers expect.

  12. NREL: Transportation Research - Vehicle Thermal Management Models and Tools

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

    Models and Tools image of three models of semi truck cabs. Truck cab models drawn from CAD geometry using CoolCalc (left and center), and a model with overlay of computational fluid dynamics flow (right) indicate areas of heat absorption and loss. Illustrations by Jason Lustbader, Matt Jeffers, and Larry Chaney, NREL The National Renewable Energy Laboratory's (NREL's) vehicle thermal management modeling tools allow researchers to assess the trade-offs and calculate the potential benefits of

  13. NREL: Transportation Research - New Funds to Help NREL Commercialize

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

    Compact, Power-Dense Inverters for Electric-Drive Vehicles New Funds to Help NREL Commercialize Compact, Power-Dense Inverters for Electric-Drive Vehicles August 2, 2016 As part of the new Technology Commercialization Fund (TCF), the U.S. Department of Energy (DOE) has awarded funding to the National Renewable Energy Laboratory (NREL) to lead a vehicle research and development (R&D) project in collaboration with John Deere Electronic Solutions (JDES). The funds will be used to apply

  14. RKKY interaction in a chirally coupled double quantum dot system

    SciTech Connect (OSTI)

    Heine, A. W.; Tutuc, D.; Haug, R. J.; Zwicknagl, G.; Schuh, D.; Wegscheider, W.

    2013-12-04

    The competition between the Kondo effect and the Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction is investigated in a double quantum dots system, coupled via a central open conducting region. A perpendicular magnetic field induces the formation of Landau Levels which in turn give rise to the so-called Kondo chessboard pattern in the transport through the quantum dots. The two quantum dots become therefore chirally coupled via the edge channels formed in the open conducting area. In regions where both quantum dots exhibit Kondo transport the presence of the RKKY exchange interaction is probed by an analysis of the temperature dependence. The thus obtained Kondo temperature of one dot shows an abrupt increase at the onset of Kondo transport in the other, independent of the magnetic field polarity, i.e. edge state chirality in the central region.

  15. Tuning Into the Right Wavelength: Quantum Dot Rainbow Increases...

    Office of Science (SC) Website

    Tuning Into the Right Wavelength: Quantum Dot Rainbow Increases Solar Cell Efficiency Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of ...

  16. Quantum Dot Materials Can Reduce Heat, Boost Electrical Output...

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

    Golden, Colo. - Researchers at the U.S. Department of Energy's National Renewable Energy ... dots," produce as many as three electrons from one high energy photon of sunlight. ...

  17. Summary of the FY 2005 Batteries for Advanced Transportation Technologies (BATT) Research Program Annual Review

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

    the FY 2005 Batteries for Advanced Transportation Technologies (BATT) Research Program Annual Review May 31-June 2, 2005 Berkeley, CA August 2005 U.S. Department of Energy Office of FreedomCAR and Vehicle Technologies August 8, 2005 Dear Colleague: This document presents a summary of the evaluation and comments provided by the review panel for the FY 2005 Department of Energy (DOE) Batteries for Advanced Transportation Technologies (BATT) program annual review. The review was held at the

  18. Test and evaluation document for DOT Specification 7A type A packaging. Volume 1

    SciTech Connect (OSTI)

    Kelly, D L

    1997-08-04

    The US Department of Energy (DOE) has been conducting, through several of its operating contractors, an evaluation and testing program to qualify Type A radioactive material packagings per US Department of Transportation (DOT) Specification 7A (DOT-7A) of the Code of Federal Regulations (CFR), Title 49, Part 178 (49 CFR 178). This document summarizes the evaluation and testing performed for all of the packagings successfully qualified in this program. This document supersedes DOE Evaluation Document for DOT-7A Type A Packaging (Edling 1987), originally issued in 1987 by Monsanto Research Corporation Mound Laboratory (MLM), Miamisburg, Ohio, for the Department of Energy, Security Evaluation Program (I)P-4. Mound Laboratory issued four revisions to the document between November 1988 and December 1989. In September 1989, the program was transferred to Westinghouse Hanford Company (Westinghouse Hanford) in Richland, Washington. One additional revision was issued in March 1990 by Westinghouse Hanford. This revision reflects the earlier material and incorporates a number of changes. Evaluation and testing activities on 1208 three DOT-7A Program Dockets resulted in the qualification of three new packaging configurations, which are incorporated herein and summarized. This document presents approximately 300 different packagings that have been determined to meet the requirements for a DOT-7A, type A packaging per 49 CFR 178.350.

  19. Scalable quantum computer architecture with coupled donor-quantum dot qubits

    SciTech Connect (OSTI)

    Schenkel, Thomas; Lo, Cheuk Chi; Weis, Christoph; Lyon, Stephen; Tyryshkin, Alexei; Bokor, Jeffrey

    2014-08-26

    A quantum bit computing architecture includes a plurality of single spin memory donor atoms embedded in a semiconductor layer, a plurality of quantum dots arranged with the semiconductor layer and aligned with the donor atoms, wherein a first voltage applied across at least one pair of the aligned quantum dot and donor atom controls a donor-quantum dot coupling. A method of performing quantum computing in a scalable architecture quantum computing apparatus includes arranging a pattern of single spin memory donor atoms in a semiconductor layer, forming a plurality of quantum dots arranged with the semiconductor layer and aligned with the donor atoms, applying a first voltage across at least one aligned pair of a quantum dot and donor atom to control a donor-quantum dot coupling, and applying a second voltage between one or more quantum dots to control a Heisenberg exchange J coupling between quantum dots and to cause transport of a single spin polarized electron between quantum dots.

  20. Nanoscale engineering boosts performance of quantum dot light emitting

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

    diodes Quantum dot light emitting diodes Nanoscale engineering boosts performance of quantum dot light emitting diodes Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by simply changing their dimensions. October 25, 2013 Postdoctoral researcher Young-Shin Park characterizing emission spectra of LEDs in the Los Alamos National Laboratory optical laboratory. Postdoctoral researcher Young-Shin Park characterizing emission spectra of LEDs in the Los Alamos

  1. Chevron and NREL to Collaborate on Research to Produce Transportation Fuels

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

    using Algae - News Releases | NREL Chevron and NREL to Collaborate on Research to Produce Transportation Fuels using Algae Joint effort to identify and develop algae strains for feedstock in next-generation biofuels October 31, 2007 Chevron Corporation (NYSE: CVX) and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) announced today that they have entered into a collaborative research and development agreement to study and advance technology to produce liquid

  2. Research and Development Program for transportation packagings at Sandia National Laboratories

    SciTech Connect (OSTI)

    Hohnstreiter, G.F.; Sorenson, K.B.

    1995-02-01

    This document contains information about the research and development programs dealing with waste transport at Sandia National Laboratories. This paper discusses topics such as: Why new packaging is needed; analytical methodologies and design codes;evaluation of packaging components; materials characterization; creative packaging concepts; packaging engineering and analysis; testing; and certification support.

  3. transportation

    National Nuclear Security Administration (NNSA)

    security missions undertaken by the U.S. government.

    Pantex Plant's Calvin Nelson honored as Analyst of the Year for Transportation Security http:nnsa.energy.gov...

  4. Quantum Dots: Theory

    SciTech Connect (OSTI)

    Vukmirovic, Nenad; Wang, Lin-Wang

    2009-11-10

    This review covers the description of the methodologies typically used for the calculation of the electronic structure of self-assembled and colloidal quantum dots. These are illustrated by the results of their application to a selected set of physical effects in quantum dots.

  5. Letter to Science from Michael Wang, Center for Transportation Research, Argonne National Laboratory

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Letter to Science (Original version submitted to Science on Feb. 14 th , 2008; revised on March 14 th , 2008) Michael Wang Center for Transportation Research Argonne National Laboratory Zia Haq Office of Biomass Program Office of Energy Efficiency and Renewable Energy U.S. Department of Energy The article by Searchinger et al. in Sciencexpress ("Use of U.S. Croplands for Biofuels Increases Greenhouse Gases through Emissions from Land Use Change," February 7, 2008) provides a timely

  6. Improvement in carrier transport properties by mild thermal annealing...

    Office of Scientific and Technical Information (OSTI)

    quantum dot solar cells Citation Details In-Document Search Title: Improvement in carrier transport properties by mild thermal annealing of PbS quantum dot solar cells Authors: ...

  7. WIPP Documents - Transportation

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

    Transportation

  8. Operational guidance for using DOT-6M/2R packaging

    SciTech Connect (OSTI)

    Kelly, D.L.; Hummer, J.H.

    1994-03-01

    The purpose of this paper is to describe a new US Department of Energy (DOE), Transportation Management Division task to create a US Department of Transportation (DOT) Specification 6M/2R packaging configuration user`s guide. The need for a user`s guide was identified because the DOT-6M/2R packaging configuration is widely used by DOE site contractors, and DOE receives many questions about the approved packaging configurations. Currently, two DOE organizations have the authority to approve new DOT-6M/2R configurations. For Defense Programs, the Transportation and Packaging Safety Division (EH-332) administers the program. For Environmental Restoration and Waste Management, the Transportation Management Division (EM-261) administers the program.

  9. Testing of a Transport Cask for Research Reactor Spent Fuel - 13003

    SciTech Connect (OSTI)

    Mourao, Rogerio P.; Leite da Silva, Luiz; Miranda, Carlos A.; Mattar Neto, Miguel; Quintana, Jose F.A.; Saliba, Roberto O.; Novara, Oscar E.

    2013-07-01

    Since the beginning of the last decade three Latin American countries that operate research reactors - Argentina, Brazil and Chile - have been joining efforts to improve the regional capability in the management of spent fuel elements from the TRIGA and MTR reactors operated in the region. A main drive in this initiative, sponsored by the International Atomic Energy Agency, is the fact that no definite solution regarding the back end of the research reactor fuel cycle has been taken by any of the participating country. However, any long-term solution - either disposition in a repository or storage away from reactor - will involve at some stage the transportation of the spent fuel through public roads. Therefore, a licensed cask that provides adequate shielding, assurance of subcriticality, and conformance to internationally accepted safety, security and safeguards regimes is considered a strategic part of any future solution to be adopted at a regional level. As a step in this direction, a packaging for the transport of irradiated fuel for MTR and TRIGA research reactors was designed by the tri-national team and a half-scale model equipped with the MTR version of the internal basket was constructed in Argentina and Brazil and tested in Brazil. Three test campaigns have been carried out so far, covering both normal conditions of transportation and hypothetical accident conditions. After failing the tests in the first two test series, the specimen successfully underwent the last test sequence. A second specimen, incorporating the structural improvements in view of the previous tests results, will be tested in the near future. Numerical simulations of the free drop and thermal tests are being carried out in parallel, in order to validate the computational modeling that is going to be used as a support for the package certification. (authors)

  10. US Department of Transportation (DOT) Spec 7A Type A evaluation document: Spec 17C 55-gal steel drum with RWMC/SWEPP drum venting system carbon filter assembly

    SciTech Connect (OSTI)

    Edling, D.A.

    1986-09-15

    As part of MRC-Mound's responsibility to coordinate DOE Spec 7A Type A Packaging testing, evaluation, and utilization, this document evaluates per 49CFR 173.415(a) the SWEPP packaging system: DOT Spec 17C steel drums - 30, 55 and 83-gal; High Density Polyethylene (HDPE) liners; and SWEPP DVS Filter Assemblies (two configurations) as a US DOT Spec 7A Type A packaging. A variety of Type A performance testing was done on: DOT Spec 17C 55-gal steel drums; DOT Spec 17C 55-gal steel drums with HDPE liners; and DOT Spec 17C 55-gal steel drums with ''Nucfil'' filters as part of MRC-Mound's Type A Packaging Evaluation Program funded by DOE/HQ, DP-4, Security Evaluations. The subject SWEPP packaging incorporates modifications to the ''Nucfil'' filter and installation assembly previously tested in conjunction with the Spec 17C 55-gal drums. Thus, additional testing was required on the new filter installation in order to evaluate the entire packaging system. This document presents the test data to demonstrate the SWEPP packaging system's performance against the DOT 7A Type A requirements.

  11. NRC Technical Research Program to Evaluate Extended Storage and Transportation of Spent Nuclear Fuel - 12547

    SciTech Connect (OSTI)

    Einziger, R.E.; Compton, K.; Gordon, M.; Ahn, T.; Gonzales, H.; Pan, Y.

    2012-07-01

    Any new direction proposed for the back-end of spent nuclear fuel (SNF) cycle will require storage of SNF beyond the current licensing periods. The Nuclear Regulatory Commission (NRC) has established a technical research program to determine if any changes in the 10 CFR part 71, and 72 requirements, and associated guidance might be necessary to regulate the safety of anticipated extended storage, and subsequent transport of SNF. This three part program of: 1) analysis of knowledge gaps in the potential degradation of materials, 2) short-term research and modeling, and 3) long-term demonstration of systems, will allow the NRC to make informed regulatory changes, and determine when and if additional monitoring and inspection of the systems is necessary. The NRC has started a research program to obtain data necessary to determine if the current regulatory guidance is sufficient if interim dry storage has to be extended beyond the currently approved licensing periods. The three-phased approach consists of: - the identification and prioritization of potential degradation of the components related to the safe operation of a dry cask storage system, - short-term research to determine if the initial analysis was correct, and - a long-term prototypic demonstration project to confirm the models and results obtained in the short-term research. The gap analysis has identified issues with the SCC of the stainless steel canisters, and SNF behavior. Issues impacting the SNF and canister internal performance such as high and low temperature distributions, and drying have also been identified. Research to evaluate these issues is underway. Evaluations have been conducted to determine the relative values that various types of long-term demonstration projects might provide. These projects or follow-on work is expected to continue over the next five years. (authors)

  12. DOT-7A packaging test procedure

    SciTech Connect (OSTI)

    Kelly, D.L.

    1995-01-23

    This test procedure documents the steps involved with performance testing of Department of Transportation Specification 7A (DOT-7A) Type A packages. It includes description of the performance tests, the personnel involved, appropriate safety considerations, and the procedures to be followed while performing the tests. Westinghouse Hanford Company (WHC) is conducting the evaluation and testing discussed herein for the Department of Energy-Headquarters, Division of Quality Verification and Transportation Safety (EH-321). Please note that this report is not in WHC format. This report is being submitted through the Engineering Documentation System so that it may be used for reference and information purposes.

  13. Surface Transportation Research and Development Act of 1997. House of Representatives, One Hundred Fifth Congress, Second Session

    SciTech Connect (OSTI)

    1998-12-31

    Mr. Sensenbrenner, from the Committee on Science, submitted this report together with additional views. The Committee on Science, to whom was referred the bill (H.R. 860) to authorize appropriations to the Department of Transportation for surface transportation research and development, and for other purposes, having considered the same, report favorably thereon with an amendment and recommend that the bill as amended do pass.

  14. Geometric spin manipulation in semiconductor quantum dots

    SciTech Connect (OSTI)

    Prabhakar, Sanjay Melnik, Roderick; Inomata, Akira

    2014-04-07

    We propose a method to flip the spin completely by an adiabatic transport of quantum dots. We show that it is possible to flip the spin by inducing a geometric phase on the spin state of a quantum dot. We estimate the geometric spin flip time (approximately 2 ps) which turned out to be much shorter than the experimentally reported decoherence time (approximately 100 ns) that would provide an alternative means of fliping the spin before reaching decoherence. It is important that both the Rashba coupling and the Dresselhaus coupling are present for inducing a phase necessary for spin flip. If one of them is absent, the induced phase is trivial and irrelevant for spin-flip.

  15. Quality Assurance Plan for Transportation Management Division Transportation Training Programs

    SciTech Connect (OSTI)

    Not Available

    1994-10-01

    The U.S. Department of Transportation (DOT) implemented new rules requiring minimum levels of training for certain key individuals who handle, package, transport, or otherwise prepare hazardous materials for transportation. In response to these rules, the U.S. Department of Energy (DOE), Transportation Management Division (TMD), has developed a transportation safety training program. This program supplies designed instructional methodology and course materials to provide basic levels of DOT training to personnel for whom training has become mandatory. In addition, this program provides advanced hazardous waste and radioactive material packaging and transportation training to help personnel achieve proficiency and/or certification as hazardous waste and radioactive material shippers. This training program does not include site-specific or task-specific training beyond DOT requirements.

  16. The effect of Coulomb interactions on thermoelectric properties of quantum dots

    SciTech Connect (OSTI)

    Zimbovskaya, Natalya A.

    2014-03-14

    Thermoelectric effects in a quantum dot coupled to the source and drain charge reservoirs are explored using a nonequilibrium Green's functions formalism beyond the Hartree-Fock approximation. Thermal transport is analyzed within a linear response regime. A transition from Coulomb blockade regime to Kondo regime in thermoelectric transport through a single-level quantum dot is traced using unified approximations for the relevant Green's functions.

  17. NREL: Transportation Research - NREL Describes to U.S. Senate Role National

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

    Labs Play in Sustainable Transportation Innovation Describes to U.S. Senate Role National Labs Play in Sustainable Transportation Innovation January 26, 2016 On Thursday, January 21, 2016, NREL's Transportation and Hydrogen Systems Center Director Chris Gearhart provided a testimony on new technologies in the automobile industry before the U.S. Senate Energy and Natural Resources Committee. Members of the committee are currently evaluating a bipartisan bill that will include several

  18. 'Giant' Nanocrystal Quantum Dots

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

    'Giant' Nanocrystal Quantum Dots - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs

  19. Relaxation dynamics in correlated quantum dots

    SciTech Connect (OSTI)

    Andergassen, S.; Schuricht, D.; Pletyukhov, M.; Schoeller, H.

    2014-12-04

    We study quantum many-body effects on the real-time evolution of the current through quantum dots. By using a non-equilibrium renormalization group approach, we provide analytic results for the relaxation dynamics into the stationary state and identify the microscopic cutoff scales that determine the transport rates. We find rich non-equilibrium physics induced by the interplay of the different energy scales. While the short-time limit is governed by universal dynamics, the long-time behavior features characteristic oscillations as well as an interplay of exponential and power-law decay.

  20. NREL Certifies First All-Quantum-Dot Photovoltaic Cell; Demonstrates Stability, Performance (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) have certified the first all-quantum-dot photovoltaic cell, which was based on lead sulfide and demonstrated reasonable quantum dot solar cell performance for an initial efficiency measurement along with good stability. The certified open-circuit voltage of the quantum dot cell is greater than that possible from bulk lead sulfide because of quantum confinement.

  1. Towards the future: The promise of intermodal and multimodal transportation systems. Research report

    SciTech Connect (OSTI)

    Anderson, S.E.; Easley, R.B.; Fowler, T.M.; Gabler, W.L.; Govind, S.

    1995-02-01

    Issues relating to intermodal and multimodal transportation systems are introduced and defined. Intermodal and multimodal transportation solutions are assessed within the framework of legislative efforts such as Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA), Clean Air Act Amendments of 1990 (CAAA), and North American Free Trade Agreement (NAFTA). Federal involvement in state intermodal transportation systems, and state responses to the growing intermodal and multimodal trends are also reviewed. The roles and responsibilities of the Metropolitan Planning Organizations (MPO) in the post-ISTEA world is examined and the impacts of legislative mandates considered. As a case study, the workings of the Houston MPO are examined. Private sector intermodal and multimodal involvement is addressed, including issues in management, regulatory, financial, economical, environmental, and even physical constraints. Effects of regulation on private sector intermodalism are discussed, as are case studies in partnering and management.

  2. Summary of the FY 2005 Batteries for Advanced Transportation Technologies (BATT) research program annual review

    SciTech Connect (OSTI)

    None, None

    2005-08-01

    This document presents a summary of the evaluation and comments provided by the review panel for the FY 2005 Department of Energy (DOE) Batteries for Advanced Transportation Technologies (BATT) program annual review.

  3. Transportation Secure Data Center: Real-World Data for Transportation Planning and Land Use Analysis (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-01-01

    The National Renewable Energy Laboratory (NREL) and the U.S. Department of Transportation (DOT) have launched the free, web-based Transportation Secure Data Center (TSDC). The TSDC (www.nrel.gov/tsdc) preserves respondent anonymity while making vital transportation data available to a broad group of users through secure, online access. The TSDC database provides free-of-charge web-based access to valuable transportation data that can be used for: Transit planning, Travel demand modeling, Homeland Security evacuation planning, Alternative fuel station planning, and Validating transportation data from other sources. The TSDC's two levels of access make composite data available with simple online registration, and allow researchers to use detailed spatial data after completing a straight forward application process.

  4. Dallas area-wide intelligent transportation system plan. Draft research report, August 1992-August 1996

    SciTech Connect (OSTI)

    Carvell, J.D.; Seymour, E.J.; Walters, C.H.; Starr, T.R.; Balke, K.

    1996-07-01

    This report documents the development of a comprehensive plan for implementation of Intelligent Transportation Systems (ITS) in the Dallas Urban Area. The contract defined objectives: Develop a Broadly Based Steering Committee; Assess Existing Transportation Management Systems and Potential ITS Technology; Identify Institutional Issues and Legal Barriers; Develop an Implementable, Area-Wide Multi-Jurisdictional ITS Plan; and Develop Cost, Benefits, and an Implementation Plan.

  5. Out-of-Equilibrium Kondo Effect in Double Quantum Dots

    SciTech Connect (OSTI)

    Aguado, Ramon; Langreth, David C.

    2000-08-28

    The out-of-equilibrium transport properties of a double quantum dot system in the Kondo regime are studied theoretically by means of a two-impurity Anderson Hamiltonian with interimpurity hopping. The Hamiltonian is solved by means of a nonequilibrium generalization of the slave-boson mean-field theory. It is demonstrated that measurements of the differential conductance dI/dV , for appropriate values of voltages and tunneling couplings, can give a direct observation of the coherent superposition between the many-body Kondo states of each dot. For large voltages and arbitrarily large interdot tunneling, there is a critical voltage above which the physical behavior of the system again resembles that of two decoupled quantum dots. (c) 2000 The American Physical Society.

  6. A prototype silicon double quantum dot with dispersive microwave readout

    SciTech Connect (OSTI)

    Schmidt, A. R. Henry, E.; Namaan, O.; Siddiqi, I.; Lo, C. C.; Wang, Y.-T.; Bokor, J.; Yablonovitch, E.; Li, H.; Greenman, L.; Whaley, K. B.; Schenkel, T.

    2014-07-28

    We present a unique design and fabrication process for a lateral, gate-confined double quantum dot in an accumulation mode metal-oxide-semiconductor (MOS) structure coupled to an integrated microwave resonator. All electrostatic gates for the double quantum dot are contained in a single metal layer, and use of the MOS structure allows for control of the location of the two-dimensional electron gas via the location of the accumulation gates. Numerical simulations of the electrostatic confinement potential are performed along with an estimate of the coupling of the double quantum dot to the microwave resonator. Prototype devices are fabricated and characterized by transport measurements of electron confinement and reflectometry measurements of the microwave resonator.

  7. DOT-7A Type A packaging design guide

    SciTech Connect (OSTI)

    Kelly, D.L.

    1995-01-23

    The purpose of this Design Guide is to provide instruction for designing a U.S. Department of Transportation Specification 7A (DOT-7A) Type A packaging. Another purpose for this Design Guide is to support the evaluation and testing activities that are performed on new designs by a U.S. Department of Energy (DOE) test facility. This evaluation and testing program is called the DOT-7A Program. When an applicant has determined that a DOT-7A packaging is needed and not commercially available, a design may be created according to this document. The design should include a packaging drawing, specifications, analysis report, operating instructions, and a Packaging Qualification Checklist; all of which should be forwarded to a DOE/HQ approved test facility for evaluation and testing. This report is being submitted through the Engineering Documentation System so that it may be used for reference and information purposes.

  8. Chamber transport

    SciTech Connect (OSTI)

    OLSON,CRAIG L.

    2000-05-17

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

  9. NREL: Transportation Research - NREL Leads Effort to Get Traffic Moving in

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

    the Right Direction NREL Leads Effort to Get Traffic Moving in the Right Direction Connected Traveler project will guide travelers in energy-efficient manner August 17, 2015 The Energy Department's National Renewable Energy Laboratory (NREL) will serve as the lead organization in developing a tool travelers and transportation officials can use in helping guide people through a city in the most energy-efficient way possible. "Using real-time traffic and GPS data, along with simulations

  10. Few Electron Quantum Dot coupling ...

    Office of Scientific and Technical Information (OSTI)

    Electron Quantum Dot coupling to Donor Implanted Electron Spins Martin Rudolph1. P. Harvey-Collard12, E. Nielson1, J.K. Gamble1, R. Muller1, T. Jacobson1, G. Ten-Eyck1, J. ...

  11. Regulatory compliance guide for DOT-7A type A packaging design

    SciTech Connect (OSTI)

    Kelly, D.L.

    1996-06-04

    The purpose of this guide is to provide instruction for assuring that the regulatory design requirements for a DOT-7A Type A packaging are met. This guide also supports the testing and evaluation activities that are performed on new packaging designs by a DOE-approved test facility through the DOE`s DOT-7A Test Program. This Guide was updated to incorporate regulatory changes implemented by HM-169A (49 CFR, `Transportation`).

  12. Enforcement Guidance Supplement 98-02: DOE Enforcement Activities where Off-site Transportation Issues are also Present.

    Broader source: Energy.gov [DOE]

    Recently several questions have arisen regarding the scope of Price-Anderson enforcement when transportation issues are directly or indirectly involved in an incident. These questions can be separated into two areas, (1) transportation issues that involve on-site transportation typically not regulated by the Department of Transportation (DOT), and (2) transportation issues that involve off-site transportation. This guidance addresses off-site transportation that is regulated by DOT and other state and federal agencies.

  13. Computational models for the berry phase in semiconductor quantum dots

    SciTech Connect (OSTI)

    Prabhakar, S. Melnik, R. V. N.; Sebetci, A.

    2014-10-06

    By developing a new model and its finite element implementation, we analyze the Berry phase low-dimensional semiconductor nanostructures, focusing on quantum dots (QDs). In particular, we solve the Schrdinger equation and investigate the evolution of the spin dynamics during the adiabatic transport of the QDs in the 2D plane along circular trajectory. Based on this study, we reveal that the Berry phase is highly sensitive to the Rashba and Dresselhaus spin-orbit lengths.

  14. Transportation Energy

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

    Energy Home/Transportation Energy CRF_climatechange Permalink Gallery Understanding Hazardous Combustion Byproducts Reduces Factors Impacting Climate Change CRF, Global Climate & Energy, News, News & Events, Transportation Energy Understanding Hazardous Combustion Byproducts Reduces Factors Impacting Climate Change By Micheal Padilla Researchers at Sandia's Combustion Research Facility are developing the understanding necessary to build cleaner combustion technologies that will in turn

  15. Reaction-based Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center

    SciTech Connect (OSTI)

    Tsyh Yeh, Gour

    2007-12-21

    This research sought to examine biogeochemical processes likely to take place in the less conductive materials above and below the gravel during the in situ ethanol biostimulation experiment conducted at Area 2 during 2005-2006. The in situ experiment in turn examined the hypothesis that injection of electron donor into this layer would induce formation of a redox barrier in the less conductive materials, resulting in decreased mass transfer of uranium out these materials and attendant declines in groundwater U(VI) concentration. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This report summarizes research activities conducted at The University of Central Florida (2004-2007), the development of biogeochemical and reactive transport models and the conduction of numerical simulations at laboratory, column, and field scales.

  16. Nontoxic quantum dot research improves solar cells

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

    Nonproliferation Policy Challenge: Address evolving threats/challenges to the nonproliferation and arms control regimes. Solution: Develop programs and strategies to address emerging nonproliferation and arms control challenges and opportunities. Learn More 10 CFR Part 810 Related Topics international security international security policy NIS nuclear controls safeguards safeguards and security verification Related News Nuclear Verification International Nuclear Safeguards Nonproliferation and

  17. Transportation Systems Modeling

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

    TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling TRANSPORTATION SYSTEMS MODELING Overview of TSM Transportation systems modeling research at TRACC uses the TRANSIMS (Transportation Analysis SIMulation System) traffic micro simulation code developed by the U.S. Department of Transportation (USDOT). The TRANSIMS code represents the latest generation of traffic simulation codes developed jointly under multiyear programs by USDOT, the

  18. Photocurrent extraction efficiency in colloidal quantum dot photovoltaics

    SciTech Connect (OSTI)

    Kemp, K. W.; Wong, C. T. O.; Hoogland, S. H.; Sargent, E. H.

    2013-11-18

    The efficiency of photocurrent extraction was studied directly inside operating Colloidal Quantum Dot (CQD) photovoltaic devices. A model was derived from first principles for a thin film p-n junction with a linearly spatially dependent electric field. Using this model, we were able to clarify the origins of recent improvement in CQD solar cell performance. From current-voltage diode characteristics under 1 sun conditions, we extracted transport lengths ranging from 39 nm to 86 nm for these materials. Characterization of the intensity dependence of photocurrent extraction revealed that the dominant loss mechanism limiting the transport length is trap-mediated recombination.

  19. Hazardous Materials Transportation Authorization Act of 1993. Introduced in the Senate of the United States. Report of the Senate Committee on Commerce, Science, and Transportation, One Hundred Third Congress, First Session

    SciTech Connect (OSTI)

    1993-12-31

    The report addresses a bill (S. 1640) to amend the Hazardous Materials Transportation Act (HMTA). The bill authorizes appropriations. This legislation would authorized funding of the HMTA by the Department of Transportation (DOT) as program manager. The DOT is required to take a number of significant steps to improve hazmat transportation safety. The legislative text of the Bill is summarized with amendments.

  20. Transportation Secure Data Center: Real-World Data for Environmental and Air Quality Analysis (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-01-01

    The National Renewable Energy Laboratory (NREL) and the U.S. Department of Transportation (DOT) have launched the free, web-based Transportation Secure Data Center (TSDC). The TSDC (www.nrel.gov/tsdc) preserves respondent anonymity while making vital transportation data available to a broad group of users through secure, online access. The TSDC database provides free-of-charge web-based access to valuable transportation data that can be used for: Emissions and air pollution modeling, Vehicle energy and power analysis, Climate change impact studies, Alternative fuel station planning, and Validating transportation data from other sources. The TSDC's two levels of access make composite data available with simple online registration, and allow researchers to use detailed spatial data after completing a straight forward application process.

  1. Induced spin-accumulation and spin-polarization in a quantum-dot ring by using magnetic quantum dots and Rashba spin-orbit effect

    SciTech Connect (OSTI)

    Eslami, L., E-mail: Leslami@iust.ac.ir; Faizabadi, E. [School of Physics, Iran University of Science and Technology, Tehran 16846 (Iran, Islamic Republic of)

    2014-05-28

    The effect of magnetic contacts on spin-dependent electron transport and spin-accumulation in a quantum ring, which is threaded by a magnetic flux, is studied. The quantum ring is made up of four quantum dots, where two of them possess magnetic structure and other ones are subjected to the Rashba spin-orbit coupling. The magnetic quantum dots, referred to as magnetic quantum contacts, are connected to two external leads. Two different configurations of magnetic moments of the quantum contacts are considered; the parallel and the anti-parallel ones. When the magnetic moments are parallel, the degeneracy between the transmission coefficients of spin-up and spin-down electrons is lifted and the system can be adjusted to operate as a spin-filter. In addition, the accumulation of spin-up and spin-down electrons in non-magnetic quantum dots are different in the case of parallel magnetic moments. When the intra-dot Coulomb interaction is taken into account, we find that the electron interactions participate in separation between the accumulations of electrons with different spin directions in non-magnetic quantum dots. Furthermore, the spin-accumulation in non-magnetic quantum dots can be tuned in the both parallel and anti-parallel magnetic moments by adjusting the Rashba spin-orbit strength and the magnetic flux. Thus, the quantum ring with magnetic quantum contacts could be utilized to create tunable local magnetic moments which can be used in designing optimized nanodevices.

  2. Photo-induced conductance fluctuations in mesoscopic Ge/Si systems with quantum dots

    SciTech Connect (OSTI)

    Stepina, N. P.; Dvurechenskii, A. V.; Nikiforov, A. I.; Moers, J.; Gruetzmacher, D.

    2014-08-20

    We study the evolution of electron transport in strongly localized mesoscopic system with quantum dots under small photon flux. Exploring devices with narrow transport channels lead to the observation of giant fluctuations of the photoconductance, which is attributed to the strong dependence of hopping current on the filling of dots by holes. In our experiments, single-photon mode operation is indicated by the linear dependence of the frequency of photo-induced fluctuations on the light intensity and the step-like response of conductance on the pulse excitation. The effect of the light wavelength, measurement temperature, size of the conductive channel on the device efficiency are considered.

  3. Safety analysis report for packaging: the ORNL DOT specification 6M - special form package

    SciTech Connect (OSTI)

    Schaich, R.W.

    1982-07-01

    The ORNL DOT Specification 6M - Special Form Package was fabricated at the Oak Ridge Nation al Laboratory (ORNL) for the transport of Type B solid non-fissile radioactive materials in special form. The package was evaluated on the basis of tests performed by the Dow Chemical Company, Rocky Flats Division, on the DOT-6M container and special form tests performed on a variety of stainless steel capsules at ORNL by Operations Division personnel. The results of these evaluations demonstrate that the package is in compliance with the applicable regulations for the transport of Type B quantities in special form of non-fissile radioactive materials.

  4. Modeling of the quantum dot filling and the dark current of quantum dot infrared photodetectors

    SciTech Connect (OSTI)

    Ameen, Tarek A.; El-Batawy, Yasser M.; Abouelsaood, A. A.

    2014-02-14

    A generalized drift-diffusion model for the calculation of both the quantum dot filling profile and the dark current of quantum dot infrared photodetectors is proposed. The confined electrons inside the quantum dots produce a space-charge potential barrier between the two contacts, which controls the quantum dot filling and limits the dark current in the device. The results of the model reasonably agree with a published experimental work. It is found that increasing either the doping level or the temperature results in an exponential increase of the dark current. The quantum dot filling turns out to be nonuniform, with a dot near the contacts containing more electrons than one in the middle of the device where the dot occupation approximately equals the number of doping atoms per dot, which means that quantum dots away from contacts will be nearly unoccupied if the active region is undoped.

  5. Caged Quantum Dots

    ScienceCinema (OSTI)

    Cohen, Bruce

    2013-05-29

    Berkeley Lab scientists have developed a nanosized crystal that lights up on command, a feat that could allow researchers to more easily observe individual proteins inside cells. http://newscenter.lbl.gov/feature-stories/2008/11/18/cagedquantumdots/

  6. Tunnel magnetoresistance and linear conductance of double quantum dots strongly coupled to ferromagnetic leads

    SciTech Connect (OSTI)

    Weymann, Ireneusz

    2015-05-07

    We analyze the spin-dependent linear-response transport properties of double quantum dots strongly coupled to external ferromagnetic leads. By using the numerical renormalization group method, we determine the dependence of the linear conductance and tunnel magnetoresistance on the degree of spin polarization of the leads and the position of the double dot levels. We focus on the transport regime where the system exhibits the SU(4) Kondo effect. It is shown that the presence of ferromagnets generally leads the suppression of the linear conductance due to the presence of an exchange field. Moreover, the exchange field gives rise to a transition from the SU(4) to the orbital SU(2) Kondo effect. We also analyze the dependence of the tunnel magnetoresistance on the double dot levels' positions and show that it exhibits a very nontrivial behavior.

  7. DOE TMD transportation training module 14 transportation of explosives

    SciTech Connect (OSTI)

    Griffith, R.L. Jr.

    1994-07-01

    The Department of Energy Transportation Management Division has developed training module 14, entitled {open_quotes}Transportation of Explosives{close_quotes} to compliment the basic {open_quotes}core ten{close_quotes} training modules of the Hazardous Materials Modular Training Program. The purpose of this training module is to increase awareness of the Department of Transportation (DOT) requirements concerning the packaging and transportation of explosives. Topics covered in module 14 include the classification of explosives, approval and registration of explosives, packaging requirements, hazard communication requirements, separation and segregation compatibility requirements, loading and unloading operations, as well as safety measures required in the event of a vehicle accident involving explosives.

  8. Final Progress Report for Project Entitled: Quantum Dot Tracers for Use in Engineered Geothermal Systems

    SciTech Connect (OSTI)

    Rose, Peter; Bartl, Michael; Reimus, Paul; Williams, Mark; Mella, Mike

    2015-09-12

    The objective of this project was to develop and demonstrate a new class of tracers that offer great promise for use in characterizing fracture networks in EGS reservoirs. From laboratory synthesis and testing through numerical modeling and field demonstrations, we have demonstrated the amazing versatility and applicability of quantum dot tracers. This report summarizes the results of four years of research into the design, synthesis, and characterization of semiconductor nanocrystals (quantum dots) for use as geothermal tracers.

  9. NREL: Transportation Research - Publications

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

    publications related to our vehicles and fuels projects: Clean Cities Electric Vehicle Grid Integration Energy Storage Fleet Test and Evaluation Fuels Performance Power...

  10. Quantitative multiplexed quantum dot immunohistochemistry

    SciTech Connect (OSTI)

    Sweeney, E.; Ward, T.H.; Gray, N.; Womack, C.; Jayson, G.; Hughes, A.; Dive, C.; Byers, R.

    2008-09-19

    Quantum dots are photostable fluorescent semiconductor nanocrystals possessing wide excitation and bright narrow, symmetrical, emission spectra. These characteristics have engendered considerable interest in their application in multiplex immunohistochemistry for biomarker quantification and co-localisation in clinical samples. Robust quantitation allows biomarker validation, and there is growing need for multiplex staining due to limited quantity of clinical samples. Most reported multiplexed quantum dot staining used sequential methods that are laborious and impractical in a high-throughput setting. Problems associated with sequential multiplex staining have been investigated and a method developed using QDs conjugated to biotinylated primary antibodies, enabling simultaneous multiplex staining with three antibodies. CD34, Cytokeratin 18 and cleaved Caspase 3 were triplexed in tonsillar tissue using an 8 h protocol, each localised to separate cellular compartments. This demonstrates utility of the method for biomarker measurement enabling rapid measurement of multiple co-localised biomarkers on single paraffin tissue sections, of importance for clinical trial studies.

  11. Quantum Dot Light Emitting Diode

    SciTech Connect (OSTI)

    Keith Kahen

    2008-07-31

    The project objective is to create low cost coatable inorganic light emitting diodes, composed of quantum dot emitters and inorganic nanoparticles, which have the potential for efficiencies equivalent to that of LEDs and OLEDs and lifetime, brightness, and environmental stability between that of LEDs and OLEDs. At the end of the project the Recipient shall gain an understanding of the device physics and properties of Quantum-Dot LEDs (QD-LEDs), have reliable and accurate nanocrystal synthesis routines, and have formed green-yellow emitting QD-LEDs with a device efficiency greater than 3 lumens/W, a brightness greater than 400 cd/m2, and a device operational lifetime of more than 1000 hours. Thus the aim of the project is to break the current cost-efficiency paradigm by creating novel low cost inorganic LEDs composed of inorganic nanoparticles.

  12. Quantum Dot Light Emitting Diode

    SciTech Connect (OSTI)

    Kahen, Keith

    2008-07-31

    The project objective is to create low cost coatable inorganic light emitting diodes, composed of quantum dot emitters and inorganic nanoparticles, which have the potential for efficiencies equivalent to that of LEDs and OLEDs and lifetime, brightness, and environmental stability between that of LEDs and OLEDs. At the end of the project the Recipient shall gain an understanding of the device physics and properties of Quantum-Dot LEDs (QD-LEDs), have reliable and accurate nanocrystal synthesis routines, and have formed green-yellow emitting QD-LEDs with a device efficiency greater than 3 lumens/W, a brightness greater than 400 cd/m{sup 2}, and a device operational lifetime of more than 1000 hours. Thus the aim of the project is to break the current cost-efficiency paradigm by creating novel low cost inorganic LEDs composed of inorganic nanoparticles.

  13. Research and development of proton-exchange membrane (PEM) fuel cell system for transportation applications. Phase I final report

    SciTech Connect (OSTI)

    1996-01-01

    Objective during Phase I was to develop a methanol-fueled 10-kW fuel cell power source and evaluate its feasibility for transportation applications. This report documents research on component (fuel cell stack, fuel processor, power source ancillaries and system sensors) development and the 10-kW power source system integration and test. The conceptual design study for a PEM fuel cell powered vehicle was documented in an earlier report (DOE/CH/10435-01) and is summarized herein. Major achievements in the program include development of advanced membrane and thin-film low Pt-loaded electrode assemblies that in reference cell testing with reformate-air reactants yielded performance exceeding the program target (0.7 V at 1000 amps/ft{sup 2}); identification of oxidation catalysts and operating conditions that routinely result in very low CO levels ({le} 10 ppm) in the fuel processor reformate, thus avoiding degradation of the fuel cell stack performance; and successful integrated operation of a 10-kW fuel cell stack on reformate from the fuel processor.

  14. Transportation Secure Data Center: Real-World Data for Planning, Modeling and Analysis (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-01-01

    The National Renewable Energy Laboratory (NREL) and the U.S. Department of Transportation (DOT) have launched the free, web-based Transportation Secure Data Center (TSDC). The TSDC (www.nrel.gov/tsdc) preserves respondent anonymity while making vital transportation data available to a broad group of users through secure, online access. The TSDC database gives, metropolitan planning organizations, universities, national laboratories, air quality management districts, disaster planning agencies and auto manufacturers free-of-charge web-based access to valuable transportation data. The TSDC's two levels of access make composite data available with simple online registration, and allow researchers to use detailed spatial data after completing a straight forward application process.

  15. Quantum Dot Tracers for Use in Engineered Geothermal

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

    Quantum Dot Tracers for Use in Engineered Geothermal Systems DE-EE0002768 Peter Rose, EGI/University of Utah Michael Bartl, Department of Chemistry at the University of Utah Paul Reimus, Los Alamos National Lab Project Officer: Lauren Boyd Total Project Funding: $1,238,499 April 23, 2013 This presentation does not contain any proprietary confidential, or otherwise restricted information. 2 | US DOE Geothermal Office eere.energy.gov Relevance/Impact of Research The objective of this project is to

  16. Controlling thermal conductance through quantum dot roughening...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Controlling thermal conductance through quantum dot roughening at interfaces. Citation Details ... Publication Date: 2011-01-01 OSTI Identifier: 1110382 Report ...

  17. The dosimetric consequences of the new DOT LSA definition

    SciTech Connect (OSTI)

    Mis, F.J.

    1996-10-01

    As a result of the new regulations for the transportation of radioactive materials, the DOT and the NRC have implemented a rule designed to limit the activity in an LSA container. This is a new regulation designed to insure that the spirit of the law as well as the letter of the law are followed for LSA shipments. Specifically, it limits the dose rate at any location on an unshielded LSA container to less than 1 rem/hr at 3 meters. Other possible alternatives had been discussed prior to the implementation of this regulation including multiples of A{sub 2} values, as implemented by the French.

  18. Generation of even harmonics in coupled quantum dots (Journal...

    Office of Scientific and Technical Information (OSTI)

    Generation of even harmonics in coupled quantum dots Citation Details In-Document Search Title: Generation of even harmonics in coupled quantum dots Using the spatial-temporal...

  19. Mastermind Session: Connecting the Dots Between the Real Estate...

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

    Connecting the Dots Between the Real Estate Market and Residential Energy Efficiency Mastermind Session: Connecting the Dots Between the Real Estate Market and Residential Energy ...

  20. Test and evaluation document for DOT Specification 7A Type A Packaging. Revision 3

    SciTech Connect (OSTI)

    1996-01-30

    The US Department of Energy (DOE) has been conducting, through several of its operating contractors, an evaluation and testing program to qualify Type A radioactive material packagings per US Department of Transportation (DOT) Specification 7A (DOT-7A) of the Code of Federal Regulations (CFR), Title 49, Part 178 (49 CFR 178). The program is currently administered by the DOE, Office of Facility Safety Analysis, DOE/EH-32, at DOE-Headquarters (DOE-HQ) in Germantown, Maryland. This document summarizes the evaluation and testing performed for all of the packagings successfully qualified in this program.

  1. Single-dot optical emission from ultralow density well-isolated InP quantum dots

    SciTech Connect (OSTI)

    Ugur, A.; Hatami, F.; Masselink, W. T.; Vamivakas, A. N.; Lombez, L.; Atatuere, M.

    2008-10-06

    We demonstrate a straightforward way to obtain single well-isolated quantum dots emitting in the visible part of the spectrum and characterize the optical emission from single quantum dots using this method. Self-assembled InP quantum dots are grown using gas-source molecular-beam epitaxy over a wide range of InP deposition rates, using an ultralow growth rate of about 0.01 atomic monolayers/s, a quantum-dot density of 1 dot/{mu}m{sup 2} is realized. The resulting isolated InP quantum dots embedded in an InGaP matrix are individually characterized without the need for lithographical patterning and masks on the substrate. Such low-density quantum dots show excitonic emission at around 670 nm with a linewidth limited by instrument resolution. This system is applicable as a single-photon source for applications such as quantum cryptography.

  2. HMPT: Hazardous Waste Transportation Live 27928, Test 27929 (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect HMPT: Hazardous Waste Transportation Live 27928, Test 27929 Citation Details In-Document Search Title: HMPT: Hazardous Waste Transportation Live 27928, Test 27929 HMPT: Hazardous Waste Transportation (Live 27928, suggested one time and associated Test 27929, required initially and every 36 months) addresses the Department of Transportation (DOT) function-specific training requirements of the hazardous materials packagings and transportation (HMPT) Los Alamos

  3. Thick-shell nanocrystal quantum dots

    SciTech Connect (OSTI)

    Hollingsworth, Jennifer A.; Chen, Yongfen; Klimov, Victor I.; Htoon, Han; Vela, Javier

    2011-05-03

    Colloidal nanocrystal quantum dots comprising an inner core having an average diameter of at least 1.5 nm and an outer shell, where said outer shell comprises multiple monolayers, wherein at least 30% of the quantum dots have an on-time fraction of 0.80 or greater under continuous excitation conditions for a period of time of at least 10 minutes.

  4. Theory Of Alkyl Terminated Silicon Quantum Dots

    SciTech Connect (OSTI)

    Reboredo, F; Galli, G

    2004-08-19

    We have carried out a series of ab-initio calculations to investigate changes in the optical properties of Si quantum dots as a function of surface passivation. In particular, we have compared hydrogen passivated dots with those having alkyl groups at the surface. We find that, while on clusters with reconstructed surfaces a complete alkyl passivation is possible, steric repulsion prevents full passivation of Si dots with unreconstructed surfaces. In addition, our calculations show that steric repulsion may have a dominant effect in determining the surface structure, and eventually the stability of alkyl passivated clusters, with results dependent on the length of the carbon chain. Alkyl passivation weakly affects optical gaps of silicon quantum dots, while it substantially decreases ionization potentials and electron affinities and affect their excited state properties. On the basis of our results we propose that alkyl terminated quantum dots may be size selected taking advantage of the change in ionization potential as a function of the cluster size.

  5. Sustainable Transportation - Continuum Magazine | NREL

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

    A Closer Look Slideshow: Sustainable Transportation NREL research, development, and ... Continuum Sustainable Transportation Fall 2013 Issue 5 Download the print version. RSS ...

  6. Shiny quantum dots brighten future of solar cells

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

    Shiny quantum dots brighten future of solar cells Shiny quantum dots brighten future of solar cells The project demonstrates that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight. April 14, 2014 Quantum dot LSC devices under ultraviolet illumination. Quantum dot LSC devices under ultraviolet illumination. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email "The key accomplishment is the

  7. Tungsten impurity transport experiments in Alcator C-Mod to address high priority research and development for ITER

    SciTech Connect (OSTI)

    Loarte, A.; Polevoi, A. R.; Hosokawa, M.; Reinke, M. L.; Chilenski, M.; Howard, N.; Hubbard, A.; Hughes, J. W.; Rice, J. E.; Walk, J.; Köchl, F.; Pütterich, T.; Dux, R.; Zhogolev, V. E.

    2015-05-15

    Experiments in Alcator C-Mod tokamak plasmas in the Enhanced D-alpha H-mode regime with ITER-like mid-radius plasma density peaking and Ion Cyclotron Resonant heating, in which tungsten is introduced by the laser blow-off technique, have demonstrated that accumulation of tungsten in the central region of the plasma does not take place in these conditions. The measurements obtained are consistent with anomalous transport dominating tungsten transport except in the central region of the plasma where tungsten transport is neoclassical, as previously observed in other devices with dominant neutral beam injection heating, such as JET and ASDEX Upgrade. In contrast to such results, however, the measured scale lengths for plasma temperature and density in the central region of these Alcator C-Mod plasmas, with density profiles relatively flat in the core region due to the lack of core fuelling, are favourable to prevent inter and intra sawtooth tungsten accumulation in this region under dominance of neoclassical transport. Simulations of ITER H-mode plasmas, including both anomalous (modelled by the Gyro-Landau-Fluid code GLF23) and neoclassical transport for main ions and tungsten and with density profiles of similar peaking to those obtained in Alcator C-Mod show that accumulation of tungsten in the central plasma region is also unlikely to occur in stationary ITER H-mode plasmas due to the low fuelling source by the neutral beam injection (injection energy ∼ 1 MeV), which is in good agreement with findings in the Alcator C-Mod experiments.

  8. The Fluid Interface Reactions Structures and Transport (FIRST) EFRC (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    SciTech Connect (OSTI)

    Wesolowski, David J.; FIRST Staff

    2011-05-01

    'The Fluid Interface Reactions Structures and Transport (FIRST) EFRC' was submitted by FIRST to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. FIRST, an EFRC directed by David J. Wesolowski at the Oak Ridge National Laboratory is a partnership of scientists from nine institutions: Oak Ridge National Laboratory (lead), Argonne National Laboratory, Drexel University, Georgia State University, Northwestern University, Pennsylvania State University, Suffolk University, Vanderbilt University, and University of Virginia. The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of Fluid Interface Reactions, Structures and Transport Center is 'to develop quantitative and predictive models of the unique nanoscale environment at fluid-solid interfaces that will enable transformational advances in electrical energy storage and heterogeneous catalysis for solar fuels.' Research topics are: catalysis (biomass, CO{sub 2}, water), electrocatalysis, photocatalysis, photoelectrocatalysis, solar fuels, solar electrodes, electrical energy storage, batteries, capacitors, battery electrodes, electrolytes, extreme environment, CO{sub 2} (convert), greenhouse gas, microelectromechanical systems (MEMS), interfacial characterization, matter by design, novel materials synthesis, and charge transport.

  9. The Fluid Interface Reactions Structures and Transport (FIRST) EFRC (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    ScienceCinema (OSTI)

    Wesolowski, David J. (Director, FIRST - Fluid Interface Reactions, Structures, and Transport Center); FIRST Staff

    2011-11-02

    'The Fluid Interface Reactions Structures and Transport (FIRST) EFRC' was submitted by FIRST to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. FIRST, an EFRC directed by David J. Wesolowski at the Oak Ridge National Laboratory is a partnership of scientists from nine institutions: Oak Ridge National Laboratory (lead), Argonne National Laboratory, Drexel University, Georgia State University, Northwestern University, Pennsylvania State University, Suffolk University, Vanderbilt University, and University of Virginia. The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of Fluid Interface Reactions, Structures and Transport Center is 'to develop quantitative and predictive models of the unique nanoscale environment at fluid-solid interfaces that will enable transformational advances in electrical energy storage and heterogeneous catalysis for solar fuels.' Research topics are: catalysis (biomass, CO{sub 2}, water), electrocatalysis, photocatalysis, photoelectrocatalysis, solar fuels, solar electrodes, electrical energy storage, batteries, capacitors, battery electrodes, electrolytes, extreme environment, CO{sub 2} (convert), greenhouse gas, microelectromechanical systems (MEMS), interfacial characterization, matter by design, novel materials synthesis, and charge transport.

  10. What the Blank Makes Quantum Dots Blink?

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

    if scientists can stop them blinking. (Photo by Antipoff, CC BY-SA 3.0) Quantum dots are nanoparticles of semiconductor that can be tuned to glow in a rainbow of colors. ...

  11. First principle thousand atom quantum dot calculations

    SciTech Connect (OSTI)

    Wang, Lin-Wang; Li, Jingbo

    2004-03-30

    A charge patching method and an idealized surface passivation are used to calculate the single electronic states of IV-IV, III-V, II-VI semiconductor quantum dots up to a thousand atoms. This approach scales linearly and has a 1000 fold speed-up compared to direct first principle methods with a cost of eigen energy error of about 20 meV. The calculated quantum dot band gaps are parametrized for future references.

  12. Electron Spin Dynamics in Semiconductor Quantum Dots

    SciTech Connect (OSTI)

    Marie, X.; Belhadj, T.; Urbaszek, B.; Amand, T.; Krebs, O.; Lemaitre, A.; Voisin, P.

    2011-07-15

    An electron spin confined to a semiconductor quantum dot is not subject to the classical spin relaxation mechanisms known for free carriers but it strongly interacts with the nuclear spin system via the hyperfine interaction. We show in time resolved photoluminescence spectroscopy experiments on ensembles of self assembled InAs quantum dots in GaAs that this interaction leads to strong electron spin dephasing.

  13. Investigation of size dependent structural and optical properties of thin films of CdSe quantum dots

    SciTech Connect (OSTI)

    Sharma, Madhulika; Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay, Powai, Mumbai 400076 ; Sharma, A.B.; Mishra, N.; Pandey, R.K.

    2011-03-15

    Research highlights: {yields} CdSe q-dots have been synthesized using simple chemical synthesis route. {yields} Thin film of CdSe quantum dots exhibited self-organized growth. {yields} Size dependent blue shift observed in the absorption edge of CdSe nanocrystallites. {yields} PL emission band corresponds to band edge luminescence and defect luminescence. {yields} Organized growth led to enhancement in luminescence yield of smaller size Q-dots. -- Abstract: Cadmium selenide (CdSe) quantum dots were grown on indium tin oxide substrate using wet chemical technique for possible application as light emitting devices. The structural, morphological and luminescence properties of the as deposited thin films of CdSe Q-dot have been investigated, using X-ray diffraction, transmission electron microscopy, atomic force microscopy and optical and luminescence spectroscopy. The quantum dots have been shown to deposit in an organized array on ITO/glass substrate. The as grown Q-dots exhibited size dependent blue shift in the absorption edge. The effect of quantum confinement also manifested as a blue shift of photoluminescence emission. It is shown that the nanocrystalline CdSe exhibits intense photoluminescence as compared to the large grained polycrystalline CdSe films.

  14. ARPA-E Announces $40 Million for Research Projects to Develop Cleaner and Cheaper Transportation Choices for Consumers

    Broader source: Energy.gov [DOE]

    Two New ARPA-E Programs Will Engage Nation’s Brightest Scientists, Engineers and Entrepreneurs in Research Competition to Improve Vehicle Manufacturing Techniques and Natural Gas Conversion

  15. Research Highlight

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

    Black Carbon Reduction of Snow Albedo Submitter: Kirchstetter, T. W., Lawrence Berkeley National Laboratory Area of Research: Radiation Processes Working Group(s): Aerosol Life Cycle Journal Reference: Hadley OL and TW Kirchstetter. 2012. "Black carbon reduction of snow albedo." Nature Climate Change, , doi:10.1038/nclimate1433. Spectrally weighted snow albedo over the 300-2,500 nm solar spectrum: derived from our experiments (dots, 1 standard deviation) and modelled using SNICAR

  16. Research Highlight

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

    Initial Aerosol Concentration Is Key Contributor to Low-Level Cloud Reflectivity Submitter: Penner, J. E., University of Michigan Area of Research: Aerosol Properties Working Group(s): Aerosol Journal Reference: Penner, J., Dong, X., Chen. Y., Observational evidence of a change in radiative forcing due to the indirect aerosol effect, Nature, Vol. 427, 15 January 2004. Cloud optical depth, as determined from the parcel model, is indicated by the dots. Red lines show best fit data of cloud liquid

  17. Approaches to Future Generation Photovoltaics and Solar Fuels: Quantum Dots, Arrays, and Quantum Dot Solar Cells

    SciTech Connect (OSTI)

    Semonin, O.; Luther, J.; Beard, M.; Johnson, J.; Gao, J.; Nozik, A.

    2012-01-01

    One potential, long-term approach to more efficient and lower cost future generation solar cells for solar electricity and solar fuels is to utilize the unique properties of quantum dots (QDs) to control the relaxation pathways of excited states to enhance multiple exciton generation (MEG). We have studied MEG in close-packed PbSe QD arrays where the QDs are electronically coupled in the films and thus exhibit good transport while still maintaining quantization and MEG. We have developed simple, all-inorganic solution-processable QD solar cells that produce large short-circuit photocurrents and power conversion efficiencies above 5% via nanocrystalline p-n junctions. These solar cells show QYs for photocurrent that exceed 100% in the photon energy regions where MEG is possible; the photocurrent MEG QYs as a function of photon energy match those determined via time-resolved spectroscopy Recent analyses of the major effect of MEG combined with solar concentration on the conversion efficiency of solar cells will also be discussed.

  18. Research and Development of Proton-Exchange Membrane (PEM) Fuel Cell System for Transportation Applications: Initial Conceptual Design Report

    SciTech Connect (OSTI)

    Not Available

    1993-11-30

    This report addresses Task 1.1, model development and application, and Task 1.2, vehicle mission definition. Overall intent is to produce a methanol-fueled 10-kW power source, and to evaluate electrochemical engine (ECE) use in transportation. Major achievements include development of an ECE power source model and its integration into a comprehensive power source/electric vehicle propulsion model, establishment of candidate FCV (fuel cell powered electric vehicle) mission requirements, initial FCV studies, and a candidate FCV recommendation for further study.

  19. Research

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

    Research Research Isotopes produced at Los Alamos National Laboratory are saving lives, advancing cutting-edge research and keeping the U.S. safe. Research thorium test foil A thorium test foil target for proof-of-concept actinium-225 production In addition to our routine isotope products, the LANL Isotope Program is focused on developing the next suite of isotopes and services to meet the Nation's emerging needs. The LANL Isotope Program's R&D strategy is focused on four main areas (see

  20. Energy Department Welcomes Department of Transportation as New Workplace Charging Challenge Partner

    Broader source: Energy.gov [DOE]

    Today, the Energy Department is welcoming the Department of Transportation (DOT) as a partner in its Workplace Charging Challenge, which aims to make workplace charging for plug-in electric vehicles available to employees across the country.

  1. NREL: Transportation Research - Archives for the Transportation...

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

    Durability, and Safety July 2014 - Big Data, Models & Tools May 2014 - Medium- and Heavy-Duty Vehicles March 2014 - NREL in the News January 2014 - 2013 Year in Review ...

  2. NREL: Transportation Research - Transportation and Hydrogen Newsletter...

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

    partners, including original equipment manufacturers, suppliers, fleets, national labs, Clean Cities coalitions, the Energy Department, the Federal Highway Administration, the...

  3. NREL: Transportation Research - Transportation Secure Data Center

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

    of miles of travel, along with vehicle characteristics and survey participant demographics. NREL screens the initial data for quality control, translates each data set into a...

  4. Carrier multiplication detected through transient photocurrent in device-grade films of lead selenide quantum dots

    SciTech Connect (OSTI)

    Gao, Jianbo; Fidler, Andrew F.; Klimov, Victor I.

    2015-09-08

    In carrier multiplication, the absorption of a single photon results in two or more electron–hole pairs. Quantum dots are promising materials for implementing carrier multiplication principles in real-life technologies. So far, however, most of research in this area has focused on optical studies of solution samples with yet to be proven relevance to practical devices. We report ultra-fast electro-optical studies of device-grade films of electronically coupled quantum dots that allow us to observe multiplication directly in the photocurrent. Our studies help rationalize previous results from both optical spectroscopy and steady-state photocurrent measurements and also provide new insights into effects of electric field and ligand treatments on multiexciton yields. Importantly, we demonstrate that using appropriate chemical treatments of the films, extra charges produced by carrier multiplication can be extracted from the quantum dots before they are lost to Auger recombination and hence can contribute to photocurrent of practical devices.

  5. Research

    SciTech Connect (OSTI)

    1999-10-01

    Subjects covered in this section are: (1) PCAST panel promotes energy research cooperation; (2) Letter issued by ANS urges funding balance in FFTF restart consideration and (3) FESAC panel releases report on priorities and balance.

  6. Research

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

    The LANL Isotope Program's R&D strategy is focused on four main areas (see article list below for recent efforts in these areas): Medical Applications are a key focus for research ...

  7. Promising future of quantum dots explored in conference

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

    ... Los Alamos Quantum Dots for Solar, Display Technology 2:55 Los Alamos Quantum Dots for Solar, Display Technology Two for the price of one An important breakthrough reported by the ...

  8. Nanoscale engineering boosts performance of quantum dot light...

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

    Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by ... Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by ...

  9. Next-Generation "Giant" Quantum Dots: Performance-Engineered...

    Energy Savers [EERE]

    This project seeks to develop quantum-dot downconverters to be used in LED lighting. The focus will be on synthesizing red-emitting quantum dots, revealing their failure ...

  10. Surface treatment of nanocrystal quantum dots after film deposition

    DOE Patents [OSTI]

    Sykora, Milan; Koposov, Alexey; Fuke, Nobuhiro

    2015-02-03

    Provided are methods of surface treatment of nanocrystal quantum dots after film deposition so as to exchange the native ligands of the quantum dots for exchange ligands that result in improvement in charge extraction from the nanocrystals.

  11. Quantum Dot Tracers for Use in Engineered Geothermal

    Broader source: Energy.gov [DOE]

    Quantum Dot Tracers for Use in Engineered Geothermal presentation at the April 2013 peer review meeting held in Denver, Colorado.

  12. Exciton binding energy in semiconductor quantum dots

    SciTech Connect (OSTI)

    Pokutnii, S. I.

    2010-04-15

    In the adiabatic approximation in the context of the modified effective mass approach, in which the reduced exciton effective mass {mu} = {mu}(a) is a function of the radius a of the semiconductor quantum dot, an expression for the exciton binding energy E{sub ex}(a) in the quantum dot is derived. It is found that, in the CdSe and CdS quantum dots with the radii a comparable to the Bohr exciton radii a{sub ex}, the exciton binding energy E{sub ex}(a) is substantially (respectively, 7.4 and 4.5 times) higher than the exciton binding energy in the CdSe and CdS single crystals.

  13. Quantum Dot-Based Cell Motility Assay

    SciTech Connect (OSTI)

    Gu, Weiwei; Pellegrino, Teresa; Parak Wolfgang J; Boudreau,Rosanne; Le Gros, Mark A.; Gerion, Daniele; Alivisatos, A. Paul; Larabell, Carolyn A.

    2005-06-06

    Because of their favorable physical and photochemical properties, colloidal CdSe/ZnS-semiconductor nanocrystals (commonly known as quantum dots) have enormous potential for use in biological imaging. In this report, we present an assay that uses quantum dots as markers to quantify cell motility. Cells that are seeded onto a homogeneous layer of quantum dots engulf and absorb the nanocrystals and, as a consequence, leave behind a fluorescence-free trail. By subsequently determining the ratio of cell area to fluorescence-free track area, we show that it is possible to differentiate between invasive and noninvasive cancer cells. Because this assay uses simple fluorescence detection, requires no significant data processing, and can be used in live-cell studies, it has the potential to be a powerful new tool for discriminating between invasive and noninvasive cancer cell lines or for studying cell signaling events involved in migration.

  14. US Department of Transportation specification packages evaluation

    SciTech Connect (OSTI)

    Ratledge, J.E.; Rawl, R.R.

    1992-01-01

    Specification packages are broad families of package designs and approved by the Department of Transportation (DOT) for transport of certain classes of radioactive materials, with each specification containing a number of designs of various sizes. Many of the individual package designs are not supported by reasonably current safety analyses. The Nuclear Regulatory Commission (NRC) asked Oak Ridge National Laboratory (ORNL) staff to collect all related information, perform analyses, and identify alternative actions that will enable NRC and DOT to make informed decisions on whether to retain, withdraw, or modify the existing regulatory permission for the use of specification packages to transport radioactive and fissile materials. This paper presents the background, issues, and progress made in this activity.

  15. US Department of Transportation specification packages evaluation

    SciTech Connect (OSTI)

    Ratledge, J.E.; Rawl, R.R.

    1992-03-01

    Specification packages are broad families of package designs and approved by the Department of Transportation (DOT) for transport of certain classes of radioactive materials, with each specification containing a number of designs of various sizes. Many of the individual package designs are not supported by reasonably current safety analyses. The Nuclear Regulatory Commission (NRC) asked Oak Ridge National Laboratory (ORNL) staff to collect all related information, perform analyses, and identify alternative actions that will enable NRC and DOT to make informed decisions on whether to retain, withdraw, or modify the existing regulatory permission for the use of specification packages to transport radioactive and fissile materials. This paper presents the background, issues, and progress made in this activity.

  16. Nonradiative Recombination Pathways in Noncarcinogenic Quantum Dot

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

    Composites | Department of Energy Lead Performer: UbiQD, LLC - Los Alamos, NM DOE Total Funding: $150,000 Project Term: February 22, 2016 - November 21, 2016 Funding Type: SBIR PROJECT OBJECTIVE Quantum dots composed of I-III-VI materials such as CuInS2 offer a compelling alternative to typical semiconductor quantum-dot systems, because they have no known toxicity and can be manufactured at a much lower cost. The project proposes to evaluate the commercial viability of CuInS2/ZnS quantum

  17. Bilayer graphene quantum dot defined by topgates

    SciTech Connect (OSTI)

    Müller, André; Kaestner, Bernd; Hohls, Frank; Weimann, Thomas; Pierz, Klaus; Schumacher, Hans W.

    2014-06-21

    We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK, the conductance underneath the grounded gates is suppressed, which we attribute to nearest neighbour hopping and strain-induced piezoelectric fields. The gate-layout can thus be used to define resistive regions by tuning into the corresponding temperature range. We use this method to define a quantum dot structure in bilayer graphene showing Coulomb blockade oscillations consistent with the gate layout.

  18. TEST & EVALUATION REPORT FOR THE HEDGEHOG-II PACKAGING SYSTEMS DOT-7A TYPE A CONTAINER

    SciTech Connect (OSTI)

    KELLY, D.L.

    2003-12-29

    This report documents the US. Department of Transportation Specification 7A (DOT-7A) Type A compliance test and evaluation results for the Hedgehog-II packaging systems. The approved Hedgehog-II packaging configurations provide primary and secondary containment. The approved packaging configurations described within this report are designed to ship Type A quantities of radioactive materials, normal form. Contents may be in solid or liquid form. Liquids transported in the approved 1 L glass bottle assembly shall have a specific gravity of less than or equal to 1.6. Liquids transported in all other approved configurations shall have a specific gravity of less than or equal to 2.0. The solid contents, including packaging, are limited in weight to the gross weight of the as-tested liquids and bottles. The approved Hedgehog-II packaging configurations described in this report may be transported by air, and have been evaluated as meeting the applicable International Air Transport Association/International Civil Aviation Organization (IATA/ICAO) Dangerous Goods Regulations in addition to the DOT requirements.

  19. Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center

    SciTech Connect (OSTI)

    Burgos, W.D.

    2009-09-02

    This report summarizes research conducted in conjunction with a project entitled “Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center”, which was funded through the Integrative Studies Element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. William Burgos (The Pennsylvania State University) was the overall PI/PD for the project, which included Brian Dempsey (Penn State), Gour-Tsyh (George) Yeh (Central Florida University), and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The project focused on development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. The work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and was directly aligned with the Scheibe et al. ORNL FRC Field Project at Area 2.

  20. Reaction-Based Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center

    SciTech Connect (OSTI)

    Yeh, Gour-Tsyh

    2006-06-01

    This research project (started Fall 2004) was funded by a grant to The Pennsylvania State University, University of Central Florida, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Dr. Eric Roden, formerly at The University of Alabama, is now at the University of Wisconsin - Madison. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

  1. Kondo and mixed-valence regimes in multilevel quantum dots

    SciTech Connect (OSTI)

    Chudnovskiy, A. L.; Ulloa, S. E.

    2001-04-15

    We investigate the dependence of the ground state of a multilevel quantum dot on the coupling to an external fermionic system and on the interactions in the dot. As the coupling to the external system increases, the rearrangement of the effective energy levels in the dot signals the transition from the Kondo regime to a mixed-valence (MV) regime. The MV regime in a two-level dot is characterized by an intrinsic mixing of the levels in the dot, resulting in nonperturbative subtunneling and supertunneling phenomena that strongly influence the Kondo effect.

  2. Current status, research needs, and opportunities in applications of surface processing to transportation and utilities technologies. Proceedings of a December 1991 workshop

    SciTech Connect (OSTI)

    Czanderna, A.W.; Landgrebe, A.R.

    1992-09-01

    Goal of surface processing is to develop innovative methods of surface modification and characterization for optimum performance and environmental protection for cost-effective operational lifetimes of systems, materials, and components used in transportation and utilities. These proceedings document the principal discussions and conclusions reached at the workshop; they document chapters about the current status of surface characterization with focus on composition, structure, bonding, and atomic-scale topography of surfaces. Also documented are chapters on the current status of surface modification techniques: electrochemical, plasma-aided, reactive and nonreactive physical vapor deposition, sol-gel coatings, high-energy ion implantation, ion-assisted deposition, organized molecular assemblies, solar energy. Brief chapters in the appendices document basic research in surface science by NSF, Air Force, and DOE. Participants at the workshop were invited to serve on 10 working groups. Separate abstracts were prepared for the data base where appropriate.

  3. Location deterministic biosensing from quantum-dot-nanowire assemblies

    SciTech Connect (OSTI)

    Liu, Chao; Kim, Kwanoh; Fan, D. L.

    2014-08-25

    Semiconductor quantum dots (QDs) with high fluorescent brightness, stability, and tunable sizes, have received considerable interest for imaging, sensing, and delivery of biomolecules. In this research, we demonstrate location deterministic biochemical detection from arrays of QD-nanowire hybrid assemblies. QDs with diameters less than 10 nm are manipulated and precisely positioned on the tips of the assembled Gold (Au) nanowires. The manipulation mechanisms are quantitatively understood as the synergetic effects of dielectrophoretic (DEP) and alternating current electroosmosis (ACEO) due to AC electric fields. The QD-nanowire hybrid sensors operate uniquely by concentrating bioanalytes to QDs on the tips of nanowires before detection, offering much enhanced efficiency and sensitivity, in addition to the position-predictable rationality. This research could result in advances in QD-based biomedical detection and inspires an innovative approach for fabricating various QD-based nanodevices.

  4. Synthesis of CdSe quantum dots for quantum dot sensitized solar cell

    SciTech Connect (OSTI)

    Singh, Neetu Kapoor, Avinashi; Kumar, Vinod; Mehra, R. M.

    2014-04-24

    CdSe Quantum Dots (QDs) of size 0.85 nm were synthesized using chemical route. ZnO based Quantum Dot Sensitized Solar Cell (QDSSC) was fabricated using CdSe QDs as sensitizer. The Pre-synthesized QDs were found to be successfully adsorbed on front ZnO electrode and had potential to replace organic dyes in Dye Sensitized Solar Cells (DSSCs). The efficiency of QDSSC was obtained to be 2.06 % at AM 1.5.

  5. Transportation Safety Excellence in Operations Through Improved Transportation Safety Document

    SciTech Connect (OSTI)

    Dr. Michael A. Lehto; MAL

    2007-05-01

    A recent accomplishment of the Idaho National Laboratory (INL) Materials and Fuels Complex (MFC) Nuclear Safety analysis group was to obtain DOE-ID approval for the inter-facility transfer of greater-than-Hazard-Category-3 quantity radioactive/fissionable waste in Department of Transportation (DOT) Type A drums at MFC. This accomplishment supported excellence in operations through safety analysis by better integrating nuclear safety requirements with waste requirements in the Transportation Safety Document (TSD); reducing container and transport costs; and making facility operations more efficient. The MFC TSD governs and controls the inter-facility transfer of greater-than-Hazard-Category-3 radioactive and/or fissionable materials in non-DOT approved containers. Previously, the TSD did not include the capability to transfer payloads of greater-than-Hazard-Category-3 radioactive and/or fissionable materials using DOT Type A drums. Previous practice was to package the waste materials to less-than-Hazard-Category-3 quantities when loading DOT Type A drums for transfer out of facilities to reduce facility waste accumulations. This practice allowed operations to proceed, but resulted in drums being loaded to less than the Waste Isolation Pilot Plant (WIPP) waste acceptance criteria (WAC) waste limits, which was not cost effective or operations friendly. An improved and revised safety analysis was used to gain DOE-ID approval for adding this container configuration to the MFC TSD safety basis. In the process of obtaining approval of the revised safety basis, safety analysis practices were used effectively to directly support excellence in operations. Several factors contributed to the success of MFCs effort to obtain approval for the use of DOT Type A drums, including two practices that could help in future safety basis changes at other facilities. 1) The process of incorporating the DOT Type A drums into the TSD at MFC helped to better integrate nuclear safety

  6. Tunable Quantum Dot Solids: Impact of Interparticle Interactions on Bulk Properties

    SciTech Connect (OSTI)

    Sinclair, Michael B.; Fan, Hongyou; Brener, Igal; Liu, Sheng; Luk, Ting S.; Li, Binsong

    2015-09-01

    QD-solids comprising self-assembled semiconductor nanocrystals such as CdSe are currently under investigation for use in a wide array of applications including light emitting diodes, solar cells, field effect transistors, photodetectors, and biosensors. The goal of this LDRD project was develop a fundamental understanding of the relationship between nanoparticle interactions and the different regimes of charge and energy transport in semiconductor quantum dot (QD) solids. Interparticle spacing was tuned through the application of hydrostatic pressure in a diamond anvil cell, and the impact on interparticle interactions was probed using x-ray scattering and a variety of static and transient optical spectroscopies. During the course of this LDRD, we discovered a new, previously unknown, route to synthesize semiconductor quantum wires using high pressure sintering of self-assembled quantum dot crystals. We believe that this new, pressure driven synthesis approach holds great potential as a new tool for nanomaterials synthesis and engineering.

  7. Fuel Cell Demonstration Project - 200 kW - Phosphoric Acid Fuel Cell Power Plant Located at the National Transportation Research Center: FINAL REPORT

    SciTech Connect (OSTI)

    Berry, JB

    2005-05-06

    Oak Ridge National Laboratory (ORNL) researches and develops distributed generation technology for the Department of Energy, Energy Efficiency and Renewable Energy Distributed Energy Program. This report describes installation and operation of one such distributed generation system, a United Technology Corporation fuel cell located at the National Transportation Research Center in Knoxville, Tennessee. Data collected from June 2003 to June of 2004, provides valuable insight regarding fuel cell-grid compatibility and the cost-benefit of the fuel cell operation. The NTRC fuel cell included a high-heat recovery option so that use of thermal energy improves project economics and improves system efficiency to 59% year round. During the year the fuel cell supplied a total of 834MWh to the NTRC and provided 300MBtu of hot water. Installation of the NTRC fuel cell was funded by the Distributed Energy Program with partial funding from the Department of Defense's Climate Change Fuel Cell Buy Down Program, administered by the National Energy Technology Laboratory. On-going operational expenses are funded by ORNL's utility budget and are paid from operational cost savings. Technical information and the benefit-cost of the fuel cell are both evaluated in this report and sister reports.

  8. Coupling of Time-Dependent Neutron Transport Theory with the Thermal Hydraulics Code ATHLET and Application to the Research Reactor FRM-II

    SciTech Connect (OSTI)

    Pautz, Andreas; Birkhofer, Adolf

    2003-11-15

    We introduce a new coupled neutronics/thermal hydraulics code system for analyzing transients of nuclear power plants and research reactors, based on a neutron transport theory approach. For the neutron kinetics, we have developed the code DORT-TD, a time-dependent extension of the well-known discrete ordinates code DORT. DORT-TD uses a fully implicit time integration scheme and is coupled via a general interface to the thermal hydraulics system code ATHLET, a generally applicable code for the analyses of LWR accident scenarios. Feedback is accounted for by interpolating multigroup cross sections from precalculated libraries, which are generated in advance for user-specified, discrete sets of thermal hydraulic parameters, e.g., fuel and coolant temperature. The coupled code system is applied to the high-flux research reactor FRM-II (Germany). Several design basis accidents are considered, namely the unintended control rod withdrawal, the loss of offsite power, and the loss of the secondary heat sink as well as a hypothetical transient with large reactivity insertion.

  9. Proposed mechanism to represent the suppression of dark current density by four orders with low energy light ion (H{sup ?}) implantation in quaternary alloy-capped InAs/GaAs quantum dot infrared photodetectors

    SciTech Connect (OSTI)

    Mandal, A.; Ghadi, H.; Mathur, K.L.; Basu, A.; Subrahmanyam, N.B.V.; Singh, P.; Chakrabarti, S.

    2013-08-01

    Graphical abstract: - Abstract: Here we propose a carrier transport mechanism for low energy H{sup ?} ions implanted InAs/GaAs quantum dot infrared photodetectors supportive of the experimental results obtained. Dark current density suppression of up to four orders was observed in the implanted quantum dot infrared photodetectors, which further demonstrates that they are effectively operational. We concentrated on determining how defect-related material and structural changes attributed to implantation helped in dark current density reduction for InAs/GaAs quantum dot infrared photodetectors. This is the first study to report the electrical carrier transport mechanism of H{sup ?} ion-implanted InAs/GaAs quantum dot infrared photodetectors.

  10. Copenhagen Accord NAMA Submissions Implications for the Transport...

    Open Energy Info (EERE)

    Organization: GTZ, Institute for Transportation and Development Policy (ITDP), Transport Research Laboratory(TRL), International Association for Public Transport (UITP), Veolia...

  11. Current Research

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

    Current Research The U.S. Department of Transportation (USDOT) has established its only high-performance computing and engineering analysis research facility at Argonne National Laboratory to provide applications support in key areas of applied research and development for the USDOT community. The Transportation Research and Analysis Computing Center (TRACC) features a state-of-the-art massively parallel computer system, advanced scientific visualization capability, high-speed network

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

    SciTech Connect (OSTI)

    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 Schrdinger 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.

  13. The Oak Ridge Field Research Center : Advancing Scientific Understanding of the Transportation, Fate, and Remediation of Subsurface Contamination Sources and Plumes

    SciTech Connect (OSTI)

    David Watson

    2005-04-18

    Historical research, development, and testing of nuclear materials across this country resulted in subsurface contamination that has been identified at over 7,000 discrete sites across the U.S. Department of Energy (DOE) complex. With the end of the Cold War threat, DOE has shifted its emphasis to remediation, decommissioning, and decontamination of the immense volumes of contaminated groundwater, sediments, and structures at its sites. DOE currently is responsible for remediating 1.7 trillion gallons of contaminated groundwater, an amount equal to approximately four times the daily U.S. water consumption, and 40 million cubic meters of contaminated soil, enough to fill approximately 17 professional sports stadiums.* DOE also sponsors research intended to improve or develop remediation technologies, especially for difficult, currently intractable contaminants or conditions. The Oak Ridge FRC is representative of some difficult sites, contaminants, and conditions. Buried wastes in contact with a shallow water table have created huge reservoirs of contamination. Rainfall patterns affect the water table level seasonally and over time. Further, the hydrogeology of the area, with its fractures and karst geology, affects the movement of contaminant plumes. Plumes have migrated long distances and to surface discharge points through ill-defined preferred flowpaths created by the fractures and karst conditions. From the standpoint of technical effectiveness, remediation options are limited, especially for contaminated groundwater. Moreover, current remediation practices for the source areas, such as capping, can affect coupled processes that, in turn, may affect the movement of subsurface contaminants in unknown ways. Research conducted at the FRC or with FRC samples therefore promotes understanding of the processes that influence the transport and fate of subsurface contaminants, the effectiveness and long-term consequences of extant remediation options, and the

  14. ARM - Research Highlights

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

    CenterResearch Highlights Media Contact Hanna Goss hanna-dot-goss-at-pnnl-dot-gov @armnewsteam Field Notes Blog Topics Field Notes117 AGU 3 AMIE 10 ARM Aerial Facility 2 ARM Mobile Facility 1 7 ARM Mobile Facility 2 47 ARM Mobile Facility 3 1 BAECC 1 BBOP 4 CARES 1 Data Quality Office 2 ENA 2 GOAMAZON 7 HI-SCALE 4 LASIC 3 MAGIC 15 MC3E 17 PECAN 3 SGP 8 STORMVEX 29 TCAP 3 Search News Search Blog News Center All Categories What's this? Social Media Guidance News Center All Categories Features and

  15. Enhancing efficiency and power of quantum-dots resonant tunneling thermoelectrics in three-terminal geometry by cooperative effects

    SciTech Connect (OSTI)

    Jiang, Jian-Hua

    2014-11-21

    We propose a scheme of multilayer thermoelectric engine where one electric current is coupled to two temperature gradients in three-terminal geometry. This is realized by resonant tunneling through quantum dots embedded in two thermal and electrical resisting polymer matrix layers between highly conducting semiconductor layers. There are two thermoelectric effects, one of which is pertaining to inelastic transport processes (if energies of quantum dots in the two layers are different), while the other exists also for elastic transport processes. These two correspond to the transverse and longitudinal thermoelectric effects, respectively, and are associated with different temperature gradients. We show that cooperation between the two thermoelectric effects leads to markedly improved figure of merit and power factor, which is confirmed by numerical calculation using material parameters. Such enhancement is robust against phonon heat conduction and energy level broadening. Therefore, we demonstrated cooperative effect as an additional way to effectively improve performance of thermoelectrics in three-terminal geometry.

  16. The operation mechanism of poly(9,9-dioctylfluorenyl-2,7-diyl) dots in high efficiency polymer solar cells

    SciTech Connect (OSTI)

    Liu, Chunyu; He, Yeyuan; Zhang, Xinyuan; Li, Zhiqi; Li, Jinfeng; Zhang, Zhihui; Guo, Wenbin Ruan, Shengping; Shen, Liang

    2015-05-11

    The highly efficient polymer solar cells were realized by doping poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO) dots into active layer. The dependence of doping amount on devices performance was investigated and a high efficiency of 7.15% was obtained at an optimal concentration, accounting for a 22.4% enhancement. The incorporation of PFO dots (Pdots) is conducted to the improvement of J{sub sc} and fill factor mainly due to the enhancement of light absorption and charge transport property. Pdots blended in active layer provides an interface for charge transfer and enables the formation of percolation pathways for electron transport. The introduction of Pdots was proven an effective way to improve optical and electrical properties of solar cells.

  17. NREL: Transportation Research - Fuels Performance

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

    Fuels Performance Photo of a man working with laboratory equipment. NREL fuel performance chemists evaluate a broad range of performance criteria, including storage stability. ...

  18. Controlling quantum dot energies using submonolayer bandstructure engineering

    SciTech Connect (OSTI)

    Yu, L.; Law, S.; Wasserman, D.; Jung, D.; Lee, M. L.; Shen, J.; Cha, J. J.

    2014-08-25

    We demonstrate control of energy states in epitaxially-grown quantum dot structures formed by stacked submonolayer InAs depositions via engineering of the internal bandstructure of the dots. Transmission electron microscopy of the stacked sub-monolayer regions shows compositional inhomogeneity, indicative of the presence of quantum dots. The quantum dot ground state is manipulated not only by the number of deposited InAs layers, but also by control of the thickness and material composition of the spacing layers between submonolayer InAs depositions. In this manner, we demonstrate the ability to shift the quantum dot ground state energy at 77?K from 1.38?eV to 1.88?eV. The results presented offer a potential avenue towards enhanced control of dot energies for a variety of optoelectronic applications.

  19. Radiation Transport

    SciTech Connect (OSTI)

    Urbatsch, Todd James

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  20. Safety-analysis report for packaging - corrugated steel container (SAND Box) for DOT specification 7A packaging

    SciTech Connect (OSTI)

    Brugger, R.P.

    1983-05-16

    Department of Transportation (DOT) Specification 7A, Type A corrugated steel containers for shipment and storage of Transuranic (TRU) solid waste have been developed. The containers are made entirely of 14 gauge (0.0747-in.) low carbon steel. All seams including the closure are welded to produce a leak-tight container. Four sizes of the SAND Box container have successfully met all Specification 7A, Type A requirements.

  1. Safety analysis report for packaging-corrugated steel container (SAND Box) for DOT Specification 7A packaging

    SciTech Connect (OSTI)

    Brugger, R.P.

    1983-01-24

    Department of Transportation (DOT) Specification 7A, Type A corrugated steel containers for shipment and storage of Transuranic (TRU) solid waste have been developed. The containers are made entirely of 14 gauge (0.0747-in.) low carbon steel. All seams including the closure are welded to produce a leaktight container. Four sizes of the SAND Box container have successfully met all Specification 7A, Type A requirements.

  2. Solution-Processed Solar Cells using Colloidal Quantum Dots | MIT-Harvard

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

    Center for Excitonics Solution-Processed Solar Cells using Colloidal Quantum Dots September 27, 2012 at 3pm/36-428 Ted Sargent Department of Electrical and Computer Engineering - Canada Research Chair in Nanotechnology, University of Toronto, Canada sargent001_000 Abstract: Solution-processed photovoltaics offer a cost-effective path to harvesting the abundant resource that is solar energy. The organic and polymer semiconductors at the heart of these devices generally absorb visible light;

  3. Geological Sequestration Training and Research Program in Capture and Transport: Development of the Most Economical Separation Method for CO2 Capture

    SciTech Connect (OSTI)

    Vahdat, Nader

    2013-09-30

    The project provided hands-on training and networking opportunities to undergraduate students in the area of carbon dioxide (CO2) capture and transport, through fundamental research study focused on advanced separation methods that can be applied to the capture of CO2 resulting from the combustion of fossil-fuels for power generation . The project team’s approach to achieve its objectives was to leverage existing Carbon Capture and Storage (CCS) course materials and teaching methods to create and implement an annual CCS short course for the Tuskegee University community; conduct a survey of CO2 separation and capture methods; utilize data to verify and develop computer models for CO2 capture and build CCS networks and hands-on training experiences. The objectives accomplished as a result of this project were: (1) A comprehensive survey of CO2 capture methods was conducted and mathematical models were developed to compare the potential economics of the different methods based on the total cost per year per unit of CO2 avoidance; and (2) Training was provided to introduce the latest CO2 capture technologies and deployment issues to the university community.

  4. Interdot Coulomb correlation effects and spin-orbit coupling in two carbon nanotube quantum dots

    SciTech Connect (OSTI)

    Wang, Zhen-Hua; Kuang, Xiao-Yu Zhong, Ming-Min; Shao, Peng; Li, Hui

    2014-01-28

    Transport properties of the two-level Kondo effect involving spin, orbital, and pseudospin degrees of freedom are examined in a parallel carbon nanotube double quantum dot with a sufficient interdot Coulomb interaction and small interdot tunneling. The interdot Coulomb correlation effects are taken into account, and it plays an important role in forming bonding and antibonding states. Attached to ferromagnetic leads, the Kondo effect is observed at the interdot Coulomb blockade region with degeneracy of spin, orbital, and pseudospin degrees of freedom. A crossover from a two-level Kondo state involving the fivefold degeneracy of the double quantum dots to an SU(4) spin-orbit Kondo state and to an SU(2) spin-Kondo effect is demonstrated. At finite magnetic field, the splitting of the spin, orbital, and pseudospin Kondo resonance can be restored. For finite intradot Coulomb interaction U, there is a competition between the single-dot Kondo effect and the antiferromagnetic exchange coupling J{sub AFM}, resulting in the suppression of the Kondo resonance. Moreover, both the J{sub AFM} and the Zeeman interactions compete, leading to need a much higher value of the magnetic field to compensate for the Kondo splitting.

  5. Few Electron Quantum Dot coupling to Donor Implanted Electron...

    Office of Scientific and Technical Information (OSTI)

    Title: Few Electron Quantum Dot coupling to Donor Implanted Electron Spins. Abstract not provided. Authors: Rudolph, Martin ; Patrick Harvey-Collard ; Nielsen, Erik ; Gamble, John ...

  6. Spin filtering in a double quantum dot device: Numerical renormalizati...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; MATHEMATICAL MODELS; MATHEMATICAL SOLUTIONS; QUANTUM DOTS; ...

  7. Quantum Dot Tracers for Use in Engineered Geothermal Systems...

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

    Project objective: To develop and demonstrate a new class of tracerssemiconductor nanoparticles(quantum dots)that offer great promise for use in characterizing fracture ...

  8. Kondo time scales for quantum dots: Response to pulsed bias potentials

    SciTech Connect (OSTI)

    Plihal, Martin; Langreth, David C.; Nordlander, Peter

    2000-05-15

    The response of a quantum dot in the Kondo regime to rectangular pulsed bias potentials of various strengths and durations is studied theoretically. It is found that the rise time is faster than the fall time, and also faster than time scales normally associated with the Kondo problem. For larger values of the pulsed bias, one can induce dramatic oscillations in the induced current with a frequency approximating the splitting between the Kondo peaks that would be present in steady state. The effect persists in the total charge transported per pulse, which should facilitate the experimental observation of the phenomenon. (c) 2000 The American Physical Society.

  9. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

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

    DeVore, Matthew S.; Werner, James H.; Goodwin, Peter M.; Keller, Aaron M.; Hollingsworth, Jennifer A.; Wilson, Bridget S.; Cleyrat, Cedric; Lidke, Diane S.; Ghosh, Yagnaseni; Stewart, Michael H.; et al

    2015-03-12

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. As a result, signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection.

  10. Packaging and Transportation for Offsite Shipment of Materials of National Security Interest

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2016-07-20

    The purpose of this Order is to make clear that the packaging and transportation of all offsite shipments of Materials of National Security Interest (MNSI) for DOE must be conducted in accordance with Department of Transportation (DOT) and Nuclear Regulatory Commission (NRC) regulations that would be applicable to comparable commercial shipments, except where an alternative course of action is identified in this Order.

  11. Applicability of the {bold k}{center_dot}{bold p} method to the electronic structure of quantum dots

    SciTech Connect (OSTI)

    Fu, H.; Wang, L.; Zunger, A.

    1998-04-01

    The {bold k}{center_dot}{bold p} method has become the {open_quotes}standard model{close_quotes} for describing the electronic structure of nanometer-size quantum dots. In this paper we perform parallel {bold k}{center_dot}{bold p} (6{times}6 and 8{times}8) and direct-diagonalization pseudopotential studies on spherical quantum dots of an ionic material{emdash}CdSe, and a covalent material{emdash}InP. By using an equivalent input in both approaches, i.e., starting from a given atomic pseudopotential and deriving from it the Luttinger parameters in {bold k}{center_dot}{bold p} calculation, we investigate the effect of the different underlying wave-function representations used in {bold k}{center_dot}{bold p} and in the more exact pseudopotential direct diagonalization. We find that (i) the 6{times}6{bold k}{center_dot}{bold p} envelope function has a distinct (odd or even) parity, while atomistic wave function is parity-mixed. The 6{times}6{bold k}{center_dot}{bold p} approach produces an incorrect order of the highest valence states for both InP and CdSe dots: the p-like level is above the s-like level. (ii) It fails to reveal that the second conduction state in small InP dots is folded from the L point in the Brillouin zone. Instead, all states in {bold k}{center_dot}{bold p} are described as {Gamma}-like. (iii) The {bold k}{center_dot}{bold p} overestimates the confinement energies of both valence states and conduction states. A wave-function projection analysis shows that the principal reasons for these {bold k}{center_dot}{bold p} errors in dots are (a) use of restricted basis set, and (b) incorrect {ital bulk} dispersion relation. Error (a) can be reduced only by increasing the number of basis functions. Error (b) can be reduced by altering the {bold k}{center_dot}{bold p} implementation so as to bend upwards the second lowest bulk band, and to couple the conduction band into the s-like dot valence state. Our direct diagonalization approach provides an

  12. Sustainable Transportation: Accelerating Widespread Adoption...

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

    and reduce GHG emissions, a truly sustainable solution will require more than just ... NREL's sustainable transportation research, development, and deployment (RD&D) efforts are ...

  13. ISSUES ASSOCIATED WITH SAFE PACKAGING AND TRANSPORT OF NANOPARTICLES

    SciTech Connect (OSTI)

    Gupta, N.; Smith, A.

    2011-02-14

    Nanoparticles have long been recognized a hazardous substances by personnel working in the field. They are not, however, listed as a separate, distinct category of dangerous goods at present. As dangerous goods or hazardous substances, they require packaging and transportation practices which parallel the established practices for hazardous materials transport. Pending establishment of a distinct category for such materials by the Department of Transportation, existing consensus or industrial protocols must be followed. Action by DOT to establish appropriate packaging and transport requirements is recommended.

  14. NREL: Biomass Research - Facilities

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

    Facilities At NREL's state-of-the-art biomass research facilities, researchers design and optimize processes to convert renewable biomass feedstocks into transportation fuels and...

  15. Going the Distance? NRC's Response to the National Academy of Science's Transportation Study

    SciTech Connect (OSTI)

    Easton, E.P.; Bajwa, C.S.

    2008-07-01

    In February 2006, the National Academy of Sciences (NAS) published the results of a 3 1/2-year study, titled Going the Distance, that examined the safety of transporting spent nuclear fuel (SNF) and high level waste (HLW) in the United States. NAS initiated this study to address what it perceived to be a national need for an independent, objective, and authoritative analysis of SNF and HLW transport in the United States. The study was co-sponsored by the U.S. Nuclear Regulatory Commission (NRC), the U.S. Department of Energy (DOE), the U.S. Department of Transportation (DOT), the Electric Power Research Institute and the National Cooperative Highway Research Program. This paper addresses some of the recommendations made in the NAS study related to the performance of SNF transportation casks in long duration fires, the use of full-scale package testing, and the need for an independent review of transportation security prior to the commencement of large scale shipping campaigns to an interim storage site or geologic repository. In conclusion: The NRC believes that the current regulations in 10 CFR Part 71 for the design of SNF and HLW transportation packages provide a very high level of protection to the public for very severe accidents and credible threat scenarios. As recommended by the NAS study, additional studies of accidents involving severe fires have been completed. These studies have confirmed that spent fuel casks would be expected to withstand very severe fires without the release of any fission products from the spent fuel. Additionally, changes in rail operating procedures such as the use of dedicated trains and prohibition on the co-location of SNF and flammable liquids in rail tunnels can further reduce the already low probability of severe rail accident fires involving SNF and HLW. (authors)

  16. Kondo effect in coupled quantum dots under magnetic fields

    SciTech Connect (OSTI)

    Aono, Tomosuke; Eto, Mikio

    2001-08-15

    The Kondo effect in coupled quantum dots is investigated theoretically under magnetic fields. We show that the magnetoconductance (MC) illustrates the peak structures of Kondo resonant spectra. When the dot-dot tunneling coupling V{sub C} is smaller than the dot-lead coupling {Delta} (level broadening), Kondo resonant levels appear at the Fermi level (E{sub F}). The Zeeman splitting of the levels weakens the Kondo effect, which results in a negative MC. When V{sub C} is larger than {Delta}, the Kondo resonances form bonding and antibonding levels, located below and above E{sub F}, respectively. We observe a positive MC since the Zeeman splitting increases the overlap between the levels at E{sub F}. In the presence of antiferromagnetic spin coupling between the dots, the sign of the MC can change as a function of the gate voltage.

  17. Numerical simulation of optical feedback on a quantum dot lasers

    SciTech Connect (OSTI)

    Al-Khursan, Amin H.; Ghalib, Basim Abdullattif; Al-Obaidi, Sabri J.

    2012-02-15

    We use multi-population rate equations model to study feedback oscillations in the quantum dot laser. This model takes into account all peculiar characteristics in the quantum dots such as inhomogeneous broadening of the gain spectrum, the presence of the excited states on the quantum dot and the non-confined states due to the presence of wetting layer and the barrier. The contribution of quantum dot groups, which cannot follow by other models, is simulated. The results obtained from this model show the feedback oscillations, the periodic oscillations which evolves to chaos at higher injection current of higher feedback levels. The frequency fluctuation is attributed mainly to wetting layer with a considerable contribution from excited states. The simulation shows that is must be not using simple rate equation models to express quantum dots working at excited state transition.

  18. Approaches to Future Generation Photovoltaics and Solar Fuels: Multiple Exciton Generation in Quantum Dots, Quantum Dot Arrays, Molecular Singlet Fission, and Quantum Dot Solar Cells

    SciTech Connect (OSTI)

    Nozik, A. J.; Beard, M. C.; Johnson, J. C.; Hanna, M. C.; Luther, J. M.; Midgett, A.; Semonin, O.; Michel, J.

    2012-01-01

    One potential, long-term approach to more efficient future generation solar cells is to utilize the unique properties of quantum dots (QDs) and unique molecular chromophores to control the relaxation pathways of excited states to produce enhanced conversion efficiency through efficient multiple electron-hole pair generation from single photons . We have observed efficient multiple exciton generation (MEG) in PbSe, PbS, PbTe, and Si QDs and efficient singlet fission (SF) in molecules that satisfy specific requirements for their excited state energy level structure to achieve carrier multiplication. We have studied MEG in close-packed QD arrays where the QDs are electronically coupled in the films and thus exhibit good transport while still maintaining quantization and MEG. We have developed simple, all-inorganic QD solar cells that produce large short-circuit photocurrents and power conversion efficiencies in the 3-5% range via both nanocrystalline Schottky junctions and nanocrystalline p-n junctions. These solar cells also show QYs for photocurrent that exceed 100% in the photon energy regions where MEG is possible; the photocurrent MEG QYs as a function of photon energy match those determined via time-resolved spectroscopy. We have also observed very efficient SF in thin films of molecular crystals of 1,3 diphenylisobenzofuran with quantum yields of 200% at the optimum SF threshold of 2Eg (HOMO-LUMO for S{sub 0}-S{sub 1}), reflecting the creation of two excited triplet states from the first excited singlet state. Various possible configurations for novel solar cells based on MEG in QDs and SF in molecules that could produce high conversion efficiencies will be presented, along with progress in developing such new types of solar cells. Recent analyses of the effect of MEG or SF combined with solar concentration on the conversion efficiency of solar cells will be discussed.

  19. Competing interactions in semiconductor quantum dots

    SciTech Connect (OSTI)

    van den Berg, R.; Brandino, G. P.; El Araby, O.; Konik, R. M.; Gritsev, V.; Caux, J. -S.

    2014-10-14

    In this study, we introduce an integrability-based method enabling the study of semiconductor quantum dot models incorporating both the full hyperfine interaction as well as a mean-field treatment of dipole-dipole interactions in the nuclear spin bath. By performing free induction decay and spin echo simulations we characterize the combined effect of both types of interactions on the decoherence of the electron spin, for external fields ranging from low to high values. We show that for spin echo simulations the hyperfine interaction is the dominant source of decoherence at short times for low fields, and competes with the dipole-dipole interactions at longer times. On the contrary, at high fields the main source of decay is due to the dipole-dipole interactions. In the latter regime an asymmetry in the echo is observed. Furthermore, the non-decaying fraction previously observed for zero field free induction decay simulations in quantum dots with only hyperfine interactions, is destroyed for longer times by the mean-field treatment of the dipolar interactions.

  20. Competing interactions in semiconductor quantum dots

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

    van den Berg, R.; Brandino, G. P.; El Araby, O.; Konik, R. M.; Gritsev, V.; Caux, J. -S.

    2014-10-14

    In this study, we introduce an integrability-based method enabling the study of semiconductor quantum dot models incorporating both the full hyperfine interaction as well as a mean-field treatment of dipole-dipole interactions in the nuclear spin bath. By performing free induction decay and spin echo simulations we characterize the combined effect of both types of interactions on the decoherence of the electron spin, for external fields ranging from low to high values. We show that for spin echo simulations the hyperfine interaction is the dominant source of decoherence at short times for low fields, and competes with the dipole-dipole interactions atmore » longer times. On the contrary, at high fields the main source of decay is due to the dipole-dipole interactions. In the latter regime an asymmetry in the echo is observed. Furthermore, the non-decaying fraction previously observed for zero field free induction decay simulations in quantum dots with only hyperfine interactions, is destroyed for longer times by the mean-field treatment of the dipolar interactions.« less

  1. Beam Transport

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

    Beam Transport A simplified drawing of the beam transport system from the linac to Target-1 (Lujan Center), Target-2 (Blue Room) and Target-4 is shown below. In usual operation ...

  2. New Research Projects > Research > The Energy Materials Center...

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

    - Coates Research Initiative - Abrua Research Initiative - Schlom New Research Projects Transport Dynamics and Carbonation Tolerance in Solution Processable Ionomers: Enabling a...

  3. WIPP Transportation

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

    Transuranic Waste Transportation Container Documents Documents related to transuranic waste containers and packages. CBFO Tribal Program Information about WIPP shipments across tribal lands. Transportation Centralized Procurement Program - The Centralized Procurement Program provides a common method to procure standard items used in the packaging and handling of transuranic wasted destined for WIPP. Transuranic Waste Transportation Routes - A map showing transuranic waste generator sites and

  4. Safety analysis report for packaging a DOT 7A specification container for tritiated liquid wastes

    SciTech Connect (OSTI)

    Alford, E.

    1980-08-01

    This Safety Analysis Report for Packaging (SARP) was prepared in accordance with ERDA (DOE) Appendix 5201 for DOE/ALO review and approval of packaging of tritiated liquid wastes to be shipped from Sandia National Laboratories, Livermore, (SNLL) California. This report presents information pertinent to the construction of tritiated liquid waste shipping containers. It contains design and development considerations, explains tests and evaluations required to prove the container can withstand normal transportation conditions, and demonstrates that the Sandia container-and-radioactive-material shipment package is in compliance with DOE and Department of Transportation (DOT) safety requirements. An internal review of this SARP has been performed in compliance with the ERDA (DOE) Manual, 5201 Appendix V.

  5. Status report on the Small Secure Transportable Autonomous Reactor (SSTAR) /Lead-cooled Fast Reactor (LFR) and supporting research and development.

    SciTech Connect (OSTI)

    Sienicki, J. J.; Moisseytsev, A.; Yang, W. S.; Wade, D. C.; Nikiforova, A.; Hanania, P.; Ryu, H. J.; Kulesza, K. P.; Kim, S. J.; Halsey, W. G.; Smith, C. F.; Brown, N. W.; Greenspan, E.; de Caro, M.; Li, N.; Hosemann, P.; Zhang, J.; Yu, H.; Nuclear Engineering Division; LLNL; LANL; Massachusetts Inst. of Tech.; Ecole des Mines de Paris; Oregon State Univ.; Univ.of California at Berkley

    2008-06-23

    This report provides an update on development of a pre-conceptual design for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) plant concept and supporting research and development activities. SSTAR is a small, 20 MWe (45 MWt), natural circulation, fast reactor plant for international deployment concept incorporating proliferation resistance for deployment in non-fuel cycle states and developing nations, fissile self-sufficiency for efficient utilization of uranium resources, autonomous load following making it suitable for small or immature grid applications, and a high degree of passive safety further supporting deployment in developing nations. In FY 2006, improvements have been made at ANL to the pre-conceptual design of both the reactor system and the energy converter which incorporates a supercritical carbon dioxide Brayton cycle providing higher plant efficiency (44 %) and improved economic competitiveness. The supercritical CO2 Brayton cycle technology is also applicable to Sodium-Cooled Fast Reactors providing the same benefits. One key accomplishment has been the development of a control strategy for automatic control of the supercritical CO2 Brayton cycle in principle enabling autonomous load following over the full power range between nominal and essentially zero power. Under autonomous load following operation, the reactor core power adjusts itself to equal the heat removal from the reactor system to the power converter through the large reactivity feedback of the fast spectrum core without the need for motion of control rods, while the automatic control of the power converter matches the heat removal from the reactor to the grid load. The report includes early calculations for an international benchmarking problem for a LBE-cooled, nitride-fueled fast reactor core organized by the IAEA as part of a Coordinated Research Project on Small Reactors without Onsite Refueling; the calculations use the same neutronics

  6. Carrier multiplication detected through transient photocurrent in device-grade films of lead selenide quantum dots

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

    Gao, Jianbo; Fidler, Andrew F.; Klimov, Victor I.

    2015-09-08

    In carrier multiplication, the absorption of a single photon results in two or more electron–hole pairs. Quantum dots are promising materials for implementing carrier multiplication principles in real-life technologies. So far, however, most of research in this area has focused on optical studies of solution samples with yet to be proven relevance to practical devices. We report ultra-fast electro-optical studies of device-grade films of electronically coupled quantum dots that allow us to observe multiplication directly in the photocurrent. Our studies help rationalize previous results from both optical spectroscopy and steady-state photocurrent measurements and also provide new insights into effects ofmore » electric field and ligand treatments on multiexciton yields. Importantly, we demonstrate that using appropriate chemical treatments of the films, extra charges produced by carrier multiplication can be extracted from the quantum dots before they are lost to Auger recombination and hence can contribute to photocurrent of practical devices.« less

  7. Generation of even harmonics in coupled quantum dots

    SciTech Connect (OSTI)

    Guo Shifang; Duan Suqing; Yang Ning; Chu Weidong; Zhang Wei

    2011-07-15

    Using the spatial-temporal symmetry principle we developed recently, we propose an effective scheme for even-harmonics generation in coupled quantum dots. The relative intensity of odd and even harmonic components in the emission spectrum can be controlled by tuning the dipole couplings among the dots, which can be realized in experiments by careful design of the nanostructures. In particular, pure 2nth harmonics and (2n+1)th harmonics (where n is an integer) can be generated simultaneously with polarizations in two mutual perpendicular directions in our systems. An experimental design of the coupled dots system is presented.

  8. Zeno-logic applications of semiconductor quantum dots

    SciTech Connect (OSTI)

    Schneebeli, L.; Peyghambarian, N.; Feldtmann, T.; Kira, M.; Koch, S. W.

    2010-05-15

    Microscopic calculations show that CdSe-based semiconductor quantum dots with confined exciton and biexciton states are suitable candidates for Zeno-logic applications. The frequencies of the control and signal fields are chosen to guarantee very high transmission of the individual beams. If both fields are present simultaneously, they are strongly absorbed due to efficient ground-state-to-biexciton transitions. The optical Bloch equations for a three-level quantum-dot model with self-consistent light-matter coupling are solved numerically. The influence of dephasing and/or inhomogeneous dot distributions is analyzed and the conditions for satisfactory device operation are identified.

  9. Electron states in semiconductor quantum dots

    SciTech Connect (OSTI)

    Dhayal, Suman S.; Ramaniah, Lavanya M.; Ruda, Harry E.; Nair, Selvakumar V.

    2014-11-28

    In this work, the electronic structures of quantum dots (QDs) of nine direct band gap semiconductor materials belonging to the group II-VI and III-V families are investigated, within the empirical tight-binding framework, in the effective bond orbital model. This methodology is shown to accurately describe these systems, yielding, at the same time, qualitative insights into their electronic properties. Various features of the bulk band structure such as band-gaps, band curvature, and band widths around symmetry points affect the quantum confinement of electrons and holes. These effects are identified and quantified. A comparison with experimental data yields good agreement with the calculations. These theoretical results would help quantify the optical response of QDs of these materials and provide useful input for applications.

  10. DOT Beyond Traffic Smart City Challenge

    Broader source: Energy.gov [DOE]

    The U.S. Department of Transportation is accepting applications for the Smart City Challenge to one mid-sized city that can demonstrate how advanced data and intelligent transportation system technologies and applications can be used to reduce congestion, protect the environment, respond to climate change, and support economic vitality.