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Sample records for energy grand junction

  1. Environmental assessment of facility operations at the U.S. Department of Energy Grand Junction Projects Office, Grand Junction, Colorado

    SciTech Connect

    1996-06-01

    The US Department of Energy (DOE) has prepared a sitewide environmental assessment (EA) of the proposed action to continue and expand present-day activities on the DOE Grand Junction Projects Office (GJPO) facility in Grand Junction, Colorado. Because DOE-GJPO regularly proposes and conducts many different on-site activities, DOE decided to evaluate these activities in one sitewide EA rather than in multiple, activity-specific documents. On the basis of the information and analyses presented in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, as defined by the National Environmental Policy Act (NEPA) of 1969. Therefore, preparation of an environmental impact statement is not required for facility operations, and DOE is issuing this Finding of No Significant Impact (FONSI).

  2. US Department of Energy Grand Junction Projects Office Remedial Action Project. Final report of the decontamination and decommissioning of Building 52 at the Grand Junction Projects Office Facility

    SciTech Connect

    Krabacher, J.E.

    1996-08-01

    The U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore and mill tailings during uranium refining activities of the Manhattan Engineer District and during pilot milling experiments conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJPO Remedial Action Project to clean up and restore the facility lands, improvements, and the underlying aquifer. The site contractor for the facility, Rust Geotech, also was the remedial action contractor. Building 52 was found to be radiologically contaminated and was demolished in 1994. The soil area within the footprint of the building has been remediated in accordance with the identified standards and the area can be released for unlimited exposure and unrestricted use. This document was prepared in response to a DOE request for an individual final report for each contaminated GJPO building.

  3. Overview of the Grand Junction Office from Bluff east of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview of the Grand Junction Office from Bluff east of facility. Note Buildings #35. #33 and #31A in lower left of photograph. VIEW WEST - Department of Energy, Grand Junction Office, 2597 B3/4 Road, Grand Junction, Mesa County, CO

  4. U.S. Department of Energy Grand Junction Projects Office site environmental report for calendar year 1995

    SciTech Connect

    1996-05-01

    This report presents information pertaining to environmental activities conducted during calendar year 1995 at the US Department of Energy (DOE) Grand Junction Projects Office (GJPO) facility in Grand Junction, Colorado. Environmental activities conducted at the GJPO facility during 1995 were associated with mixed-waste treatment, site remediation, off-site dose modeling, and radiological and nonradiological monitoring. As part of the GJPO Mixed-Waste Treatment Program, on-site treatability studies were conducted in 1995 that made use of pilot-scale evaporative-oxidation and thermal-desorption units and bench-scale stabilization. DOE-GJPO used some of its own mixed-waste as well as samples received from other DOE sites for these treatability studies. These studies are expected to conclude in 1996. Removal of radiologically contaminated materials from GJPO facility buildings was conducted under the provisions of the Grand Junction Projects Office Remedial Action Project. Remediation activities included the removal of 394 metric tons of contaminated material from Buildings 18 and 28 and revegetation activities on the GJPO site; remediation was conducted in compliance with applicable permits.

  5. Environmental Audit of the Grand Junction Projects Office

    SciTech Connect

    Not Available

    1991-08-01

    The Grand Junction Projects Office (GJPO) is located in Mesa County, Colorado, immediately south and west of the Grand Junction city limits. The US Atomic Energy Commission (AEC) established the Colorado Raw Materials Office at the present-day Grand Junction Projects Office in 1947, to aid in the development of a viable domestic uranium industry. Activities at the site included sampling uranium concentrate; pilot-plant milling research, including testing and processing of uranium ores; and operation of a uranium mill pilot plant from 1954 to 1958. The last shipment of uranium concentrate was sent from GJPO in January, 1975. Since that time the site has been utilized to support various DOE programs, such as the former National Uranium Resource Evaluation (NURE) Program, the Uranium Mill Tailings Remedial Action Project (UMTRAP), the Surplus Facilities Management Program (SFMP), and the Technical Measurements Center (TMC). All known contamination at GJPO is believed to be the result of the past uranium milling, analyses, and storage activities. Hazards associated with the wastes impounded at GJPO include surface and ground-water contamination and potential radon and gamma-radiation exposure. This report documents the results of the Baseline Environmental Audit conducted at Grand Junction Projects Office (GJPO) located in Grand Junction, Colorado. The Grand Junction Baseline Environmental Audit was conducted from May 28 to June 12, 1991, by the Office of Environmental Audit (EH-24). This Audit evaluated environmental programs and activities at GJPO, as well as GJPO activities at the State-Owned Temporary Repository. 4 figs., 12 tabs.

  6. 75 FR 6094 - Modification of Class E Airspace; Grand Junction, CO

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... Federal Register a notice of proposed rulemaking to amend Class E airspace at Grand Junction, CO (74 FR... Junction, CO Grand Junction Regional, Grand Junction, CO (Lat. 39 07'21'' N., long. 108 31'36'' W.) Grand Junction VORTAC (Lat. 39 03'34'' N., long. 108 47'33'' W.) Grand Junction Localizer (Lat. 39 07'04''...

  7. 24. VIEW SHOWING WASTE GATES ON GRAND CANAL AT JUNCTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. VIEW SHOWING WASTE GATES ON GRAND CANAL AT JUNCTION WITH OLD CROSSCUT NE/4, Sec. 7, TIN, R4E; LOOKING WEST. OLD CROSSCUT CANAL ENTERS FROM RIGHT. WASTE GATE ON LEFT EMPTIES INTO SALT RIVER BED Photographer: Kevin Kreisel-Coons, May 1990 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  8. Site observational work plan for the UMTRA Project Site at Grand Junction, Colorado

    SciTech Connect

    1996-03-01

    The U.S. Department of Energy (DOE) has prepared this initial site observational work plan (SOWP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project site in Grand Junction, Colorado. This SOWP is one of the first UMTRA Ground Water Project documents developed to select a compliance strategy that meets the UMTRA ground water standards (40 CFR Part 192, as amended by 60 FR 2854) for the Grand Junction site. This SOWP applies information about the Grand Junction site to the compliance strategy selection framework developed in the UMTRA Ground Water Project draft programmatic environmental impact statement (PEIS). This risk-based, decision-making framework identifies the decision logic for selecting compliance strategies that could be used to meet the ground water standards. The DOE goal is to use the observational method to implement a cost-effective site strategy that complies with the ground water standards and protects human health and the environment. Based on an evaluation of the site characterization and risk assessment data available for the preparation of this SOWP, DOE proposes that the most likely compliance strategy for the Grand Junction site is no remediation based on the application of supplemental standards. This proposed strategy is based on a conceptual site model that indicates site-related contamination is confined to a limited-use aquifer as defined in the ground water standards.

  9. Environmental Assessment and Finding of No Significant Impact: Transfer of the Department of Energy Grand Junction Office to Non-DOE Ownership

    SciTech Connect

    N /A

    2000-04-25

    The scope of this environmental assessment (EA) is to analyze the potential consequences of the Proposed Action on human health and the environment. Accordingly, this EA contains an introduction to the site and the history of the Grand Junction Office (Chapter One), a description of the Purpose and Need for Agency Action (Chapter Two), a description of the Proposed Action and Alternatives (Chapter Three), and the description of the Affected Environment and the Environmental Consequences (Chapter Four). Resource categories addressed in this EA include geology, soils and topography, groundwater and surface water, floodplains and wetlands, land use and infrastructure, human health, ecological resources, cultural resources, air quality, noise, visual resources, solid and hazardous waste management, transportation, and socioeconomic and environmental justice.

  10. Final report of the radiological release survey of Building 54 at the Grand Junction Office Facility

    SciTech Connect

    Johnson, R.K.; Corle, S.G.

    1997-09-01

    The U.S. Department of Energy (DOE) Grand Junction Office (GJO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore concentrates and mill tailings during vanadium refining activities of the Manhattan Engineer District, and during sampling, assaying, pilot milling, storage, and brokerage activities conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJO Remedial Action Project (GJORAP) to clean up and restore the facility lands, improvements, and underlying aquifer. WASTREN-Grand Junction is the site contractor for the facility and the remedial action contractor for GJORAP. Building 54 and the underlying soil were found not to be radiologically contaminated, and can be released for unrestricted use. Placards have been placed at the building entrances indicating the completion of the radiological release survey and prohibiting the introduction of any radioactive materials within the building without written approvals from the GJO Facilities Operations Manager. This document was prepared in response to a DOE-GJO request for an individual release report for each GJO building.

  11. Final report of the radiological release survey of Building 11 at the Grand Junction Office Facility

    SciTech Connect

    Johnson, R.K.; Corle, S.G.

    1997-09-01

    The U.S. Department of Energy (DOE) Grand Junction Office (GJO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore concentrates and mill tailings during vanadium refining activities of the Manhattan Engineer District, and during sampling, assaying, pilot milling, storage, and brokerage activities conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJO Remedial Action Project (GJORAP) to clean up and restore the facility lands, improvements, and underlying aquifer. WASTREN-Grand Junction is the site contractor for the facility and the remedial action contractor for GJORAP. Building 11 and the underlying soil were found not to be radiologically contaminated; therefore, the building can be released for unrestricted use. Placards have been placed at the building entrances indicating the completion of the radiological release survey and prohibiting the introduction of any radioactive materials within the building without written approvals from the GJO Facilities Operations Manager. This document was prepared in response to a DOE-GJO request for an individual final release report for each GJO building.

  12. National Uranium Resource Evaluation. Bibliographic index of Grand Junction office uranium reports

    SciTech Connect

    Johnson, J.B.

    1981-05-01

    In October 1978, Mesa College entered into subcontract with Bendix Field Engineering Corporation (BFEC) to prepare a bibliographic index of the uranium raw materials reports issued by the Grand Junction Office of the US Department of Energy (DOE). Bendix, prime contractor to the Grand Junction Office, operates the Technical Library at the DOE facility. Since the early 1950s, approximately 2700 reports have been issued by the Grand Junction Office. These reports were the results of uranium investigations conducted by federal agencies and their subcontractors. The majority of the reports cover geology, mineralogy, and metallurgy of uranium and/or thorium. No single, complete list of these reports existed. The purpose of this subcontract was to compile a comprehensive index to these reports. The Mesa College geology faculty worked with the BFEC and DOE staffs to develop the format for the index. Undergraduate geology students from Mesa compiled a master record sheet for each report. All reports issued up to January 1, 1979 were included in the bibliography. The bibliography is in preliminary, unedited form. It is being open-filed at this time, on microfiche, to make the information available to the public on a timely basis. The bibliography is divided into a master record list arranged in alpha-numeric order by report identification number, with separate indices arranged by title, author, state and county, 1/sup 0/ x 2/sup 0/ NTMS quadrangle, key words, and exploration area.

  13. Final audit report of remedial action construction at the UMTRA Project, Grand Junction, Colorado, processing site

    SciTech Connect

    1995-02-01

    This final audit report (FAR) for remedial action at the Grand Junction, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project processing site consists of a summary of the radiological surveillances/ audits, the quality assurance (QA) in-process surveillances, and the QA final close-out inspection performed by the US Department of Energy (DOE) and Technical Assistance Contractor (TAC). The FAR also summarizes other surveillances performed by the US Nuclear Regulatory Commission (NRC). To summarize, a total of one finding and 127 observations were noted during DOE/TAC audit and surveillance activities. The NRC noted general site-related observations during the OSCRs. Follow-up to responses required from MK-Ferguson for the DOE/TAC finding and observations indicated that all issues related to the Grand Junction processing site were resolved and closed out to the DOE`s satisfaction. The NRC OSCRs resulted in no issues related to the Grand Junction processing site requiring a response from MK-Ferguson.

  14. Site observational work plan for the UMTRA project site at Grand Junction, Colorado

    SciTech Connect

    1996-01-01

    This site observational work plan (SOWP) is one of the first Uranium Mill Tailings Remedial Action (UMTRA) Ground Water Project documents developed to select a compliance strategy that meets the UMTRA ground water standards for the Grand Junction site. This SOWP applies information about the Grand Junction site to the compliance strategy selection framework developed in the UMTRA Ground Water Project draft programmatic environmental impact statement. This risk-based, decision-making framework identifies the decision logic for selecting compliance strategies that could be used to meet the ground water standards. The US Department of Energy (DOE) goal is to implement a cost-effective site strategy that complies with the ground water standards and protects human health and the environment. Based on an evaluation of the site characterization and risk assessment data available for the preparation of this SOWP, DOE proposes that the most likely compliance strategy for the Grand Junction site is no remediation with the application of supplemental standards. This proposed strategy is based on a conceptual site model that indicates site-related contamination is confined to a limited-use aquifer as defined in the ground water standards. The conceptual model demonstrates that the uranium processing-related contamination at the site has affected the unconfined alluvial aquifer, but not the deeper confined aquifer.

  15. 76 FR 2412 - Notice of Intent To Amend the Grand Junction Resource Management Plan, Prepare an Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ...The Grand Junction, Colorado, Regional Airport Authority has requested the Bureau of Land Management (BLM) Grand Junction Field Office (GJFO) to consider the transfer of title to approximately 720 acres of public land for airport improvements, including relocation and construction of the main runway for the Grand Junction Regional Airport. Public Land Order No. 7027 (59 FR 3000 January 20,......

  16. Long-term surveillance plan for the Cheney disposal site near Grand Junction, Colorado

    SciTech Connect

    1997-07-01

    This long-term surveillance plan (LTSP) describes the U.S. Department of Energy`s (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Cheney Disposal Site near Grand Junction, Colorado. This LSTP describes the long-term surveillance program the DOE will implement to ensure the Cheney Disposal Site performs as designed and is cared for in a manner that protects the public health and safety and the environment. Before each disposal site is licensed for custody and long-term care, the Nuclear Regulatory Commission (NRC) requires the DOE to submit such a site-specific LTSP.

  17. Interim long-term surveillance plan for the Cheney disposal site near, Grand Junction, Colorado

    SciTech Connect

    1997-08-01

    This interim long-term surveillance plan (LTSP) describes the U.S. Department of Energy`s (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Cheney Disposal Site in Mesa County near Grand Junction, Colorado. This LSTP describes the long-term surveillance program the DOE will implement to ensure the Cheney disposal site performs as designed and is cared for in a manner that protects the public health and safety and the environment. Before each disposal site is licensed for custody and long-term care, the Nuclear Regulatory Commission (NRC) requires the DOE to submit such a site-specific LTSP.

  18. Environmental Audit, Rifle, Gunnison and Grand Junction UMTRA Project Sites

    SciTech Connect

    Not Available

    1991-08-01

    This report documents the results of the comprehensive baseline Environmental Audit completed for the Uranium Mill Tailings Remedial Action (UMTRA) sites at Grand Junction, Rifle, and Gunnison, Colorado. Included in the Audit were the actual abandoned mill sites, associated transportation and disposal cell facilities, and representative examples of the more than 4,000 known vicinity properties. Sites investigated include: Climax Mill Site, Truck/Train Haul Route, Cotter Transfer Station, Cheney Disposal Cell, Rifle Mill Sites (Old and New Rifle), Gunnison Mill Site, Vicinity Properties, and Estes Gulch and Proposed Landfill Site No. 1 Disposal Cells. The UMTRA Audit was a comprehensive baseline audit which considered all environmental programs and the activities associated with ongoing and planned remediation at the UMTRA sites listed above. Compliance with the National Environmental Policy Act (NEPA) was not considered during this investigation. The Audit Team looked at the following technical disciplines: air, surface water/drinking water, groundwater, soil/sediment/biota, waste management, toxic and chemical materials, quality assurance, radiation, inactive waste sites, and environmental management. 6 figs., 12 tabs.

  19. 76 FR 56966 - Amendment of Class D and Modification of Class E Airspace; Grand Junction, CO

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-15

    ...), 40103, 40113, 40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec. 71.1 0 2. The... Junction Regional Airport, CO (Lat. 39 07'21'' N., long. 108 31'36'' W.) Within a 4.7-mile radius of Grand.... 39 07'21'' N., long. 108 31'36'' W.) Grand Junction Localizer (Lat. 39 07'04'' N., long. 108...

  20. Technical basis for radiological release of Grand Junction Office Building 2. Volume 2, dose assessment supporting data

    SciTech Connect

    1997-07-01

    The second volume of the Grand Junction Office Action Program Technical Basis for Radiological Release of Grand Junction Office Building 2 report includes the data quality objectives (DQO), sampling plan, collected data, and analysis used to model future radiation doses to members of the public occupying Building 2 on the U.S. Department of Energy (DOE) Grand Junction Office (GJO) site. This volume was assembled by extracting relevant components of the Grand Junction Projects Office Remedial Action Project Building 2 Public Dose Evaluation (DOE 1996) and inserting recent additional data that was gathered and dose pathway modeling that was performed. The intent of this document is to provide all derived guidance decisions, assumptions, measured data, testing results, and pathway modeling software input and output data that supports the discussion and determinations presented in Volume 1 of this report. For constructive employment of this document, the reader is encouraged to closely follow Volume 1 for proper association with the segment of information being examined.

  1. Lessons Learned: The Grand Junction Office Site Transfer to Private Ownership

    SciTech Connect

    none,

    2001-02-01

    The U.S. Department of Energy Grand Junction Office (DOE-GJO) in Grand Junction, Colorado, has played an integral role within the DOE complex for many years. GJO has a reputation for outstanding quality in the performance of complex environmental restoration projects, utilizing state-of-the-art technology. Many of the GJO missions have been completed in recent years. In 1998, DOE Headquarters directed GJO to reduce its mortgage costs by transferring ownership of the site and to lease space at a reasonable rate for its ongoing work. A local community group and GJO have entered into a sales contract; signing of the Quitclaim Deed is planned for February 16, 2001. Site transfer tasks were organized as a project with a critical-path schedule to track activities and a Site Transition Decision Plan was prepared that included a decision process flow chart, key tasks, and responsibilities. Specifically, GJO identified the end state with affected parties early on, successfully dealt with site contamination issues, and negotiated a lease-back arrangement, resulting in an estimated savings of more than 60 percent of facility maintenance costs annually. Lessons learned regarding these transition activities could be beneficial to many other sites.

  2. Grand Junction Projects Office site environmental report for calendar year 1992

    SciTech Connect

    Not Available

    1993-05-01

    This report presents information pertaining to environmental activities conducted during calendar year 1992 at the US Department of Energy Grand Junction Projects Office (DOE-GJPO) facility in Colorado. Environmental activities conducted at the GJPO facility during 1992 included those associated with environmental compliance, site remediation, off-site dose modeling, and radiological and nonradiological monitoring. Four phases of the on-site Grand Junction Projects Office Remedial Action Project were completed in 1992. Remediation activities, which included the removal of 161,589 tons of uranium-mill-tailings-contaminated material from the facility, were conducted in compliance with all applicable permits. Off-site dose modeling for the GJPO was conducted to determine compliance with current National Emission Standards for Hazardous Air Pollutants, Subpart H, and applicable DOE Orders (5400.1 and 5400.5). The total off-site EDE to the public from all sources of radiation emanating from the facility (radon, air particulates, gamma) was calculated as 9 mrem/yr, which is well below the DOE dose limit of 100 mrem/yr above background. The radiological and nonradiological monitoring program at the GJPO facility included monitoring of activities that generate potentially hazardous or toxic wastes and monitoring of ambient air, surface water, and ground water.

  3. 76 FR 40293 - Proposed Amendment of Class D and Modification of Class E Airspace; Grand Junction, CO

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-08

    ...: Authority: 49 U.S.C. 106(g), 40103, 40113, 40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389..., CO Grand Junction Regional Airport, CO (Lat. 39 07'21''N., long. 108 31'36''W.) That airspace.... * * * * * ANM CO E2 Grand Junction, CO Grand Junction Regional Airport, CO (Lat. 39 07'21''N., long. 108...

  4. UMTRA Project water sampling and analysis plan, Grand Junction, Colorado. Revision 1, Version 6

    SciTech Connect

    1995-09-01

    This water sampling and analysis plan describes the planned, routine ground water sampling activities at the Grand Junction US DOE Uranium Mill Tailings Remedial Action (UMTRA) Project site (GRJ-01) in Grand Junction, Colorado, and at the Cheney Disposal Site (GRJ-03) near Grand Junction. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequencies for the routine monitoring stations at the sites. Regulatory basis is in the US EPA regulations in 40 CFR Part 192 (1994) and EPA ground water quality standards of 1995 (60 FR 2854). This plan summarizes results of past water sampling activities, details water sampling activities planned for the next 2 years, and projects sampling activities for the next 5 years.

  5. Final report of the decontamination and decommissioning of the exterior land areas at the Grand Junction Projects Office facility

    SciTech Connect

    Widdop, M.R.

    1995-09-01

    The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) facility occupies approximately 56.4 acres (22.8 hectares) along the Gunnison River near Grand Junction, Colorado. The site was contaminated with uranium ore and mill tailings during uranium-refining activities conducted by the Manhattan Engineer District and during pilot-milling experiments conducted for the US Atomic Energy Commission`s (AEC`s) domestic uranium procurement program. The GJPO facility was the collection and assay point for AEC uranium and vanadium oxide purchases until the early 1970s. The DOE Decontamination and Decommissioning Program sponsored the Grand Junction Projects Office Remedial Action Project (GJPORAP) to remediate the facility lands, site improvements, and the underlying aquifer. The site contractor, Rust Geotech, was the Remedial Action Contractor for GJPORAP. The exterior land areas of the facility assessed as contaminated have been remediated in accordance with identified standards and can be released for unrestricted use. Restoration of the aquifer will be accomplished through the natural flushing action of the aquifer during the next 50 to 80 years. The remediation of the DOE-GJPO facility buildings is ongoing and will be described in a separate report.

  6. Final report of the decontamination and decommissioning of Building 34 at the Grand Junction Projects Office Facility

    SciTech Connect

    Widdop, M.R.

    1996-08-01

    The U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) occupies a 61.7 acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore and mill tailings during uranium refining activities of the Manhattan Engineer District and during pilot milling experiments conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the Grand Junction Projects Office Remedial Action Project to clean up and restore the facility lands, improvements, and the underlying aquifer. The site contractor for the facility, Rust Geotech, was also the remedial action contractor. Building 34 was radiologically contaminated and the building was demolished in 1996. The soil area within the footprint of the building was analyzed and found to be not contaminated. The area can be released for unlimited exposure and unrestricted use. This document was prepared in response to a DOE request for an individual closeout report for each contaminated GJPO building.

  7. The Grand Junction Report: Issues of Equality in the Mesa Valley.

    ERIC Educational Resources Information Center

    Commission on Civil Rights, Washington, DC.

    The Grand Junction Metropolitan Statistical Area is the fifth largest metropolitan area in Colorado and the 12th fastest-growing in the Southwest. Latinos make up approximately 8 percent of total population and 15 percent of school enrollment; these numbers are increased by migrant farmworkers and their families. In May 2001, a public forum was…

  8. Josephson junctions and dark energy

    NASA Astrophysics Data System (ADS)

    Jetzer, Philippe; Straumann, Norbert

    2006-08-01

    In a recent paper Beck and Mackey [C. Beck, M.C. Mackey, astro-ph/0603397] argue that the argument we gave in our paper [Ph. Jetzer, N. Straumann, Phys. Lett. B 606 (2005) 77, astro-ph/0411034] to disprove their claim that dark energy can be discovered in the Lab through noise measurements of Josephson junctions is incorrect. In particular, they emphasize that the measured noise spectrum in Josephson junctions is a consequence of the fluctuation dissipation theorem, while our argument was based on equilibrium statistical mechanics. In this note we show that the fluctuation dissipation relation does not depend upon any shift of vacuum (zero-point) energies, and therefore, as already concluded in our previous paper, dark energy has nothing to do with the proposed measurements.

  9. Long-term surveillance plan for the Cheney disposal site near Grand Junction, Colorado

    SciTech Connect

    1997-04-01

    This long-term surveillance plan (LTSP) describes the U.S. Department of Energy`s (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Cheney disposal site. The site is in Mesa County near Grand Junction, Colorado. The U.S. Nuclear Regulatory Commission (NRC) has developed regulations for the issuance of a general license for the custody and long-term care of UMTRA Project disposal sites in 10 CFR Part 40. The purpose of this general license is to ensure that the UMTRA Project disposal sites are cared for in a manner that protects public health and safety and the environment. Before each disposal site may be licensed, the NRC requires the DOE to submit a site-specific LTSP. The DOE prepared this LTSP to meet this requirement for the Cheney disposal site. The general license becomes effective when the NRC concurs with the DOE`s determination that remedial action is complete and the NRC formally accepts this plan. This document describes the long-term surveillance program the DOE will implement to ensure that the Cheney disposal site performs as designed. The program is based on site inspections to identify potential threats to disposal cell integrity. The LTSP is based on the UMTRA Project long-term surveillance program guidance and meets the requirements of 10 CFR {section}40.27(b) and 40 CFR {section}192.03.

  10. Work plan for ground water elevation data recorder/monitor well injection at Grand Junction, Colorado

    SciTech Connect

    Not Available

    1994-07-18

    The purpose of this document is to describe the work that will be performed and the procedures that will be followed during installation of ground water monitor wells and ground water elevation data recorders (data loggers) at the Grand Junction, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project site. The monitor wells and data loggers will be used to gather required time-dependent data to investigate the interaction between the shallow aquifer and the Colorado River. Data collection objectives (DCO) identify reasons for collecting data. The following are DCOs for the Grand Junction ground water elevation data recorder/monitor well installation project: long-term continuous ground water level data and periodic ground water samples will be collected to better understand the relationship between surface and ground water at the site; water level and water quality data will eventually be used in future ground water modeling to more firmly establish boundary conditions in the vicinity of the Grand Junction processing site; modeling results will be used to demonstrate and document the potential remedial alternative of natural flushing.

  11. Technical basis for radiological release of Grand Junction Office Building 2. Volume 1, dose assessment

    SciTech Connect

    Morris, R.; Warga, J.; Thorne, D.

    1997-07-01

    Building 2 on the US Department of Energy (DOE) Grand Junction Office (GJO) site is part of the GJO Remedial Action Program (GJORAP). During evaluation of Building 2 for determination of radiological release disposition, some inaccessible surface contamination measurements were detected to be greater than the generic surface contamination guidelines of DOE Order 5400.5 (which are functionally equivalent to US Nuclear Regulatory Commission [NRC] Regulatory Guide 1.86). Although the building is nominal in size, it houses the site telecommunications system, that is critical to continued GJO operations, and demolition is estimated at $1.9 million. Because unrestricted release under generic surface contamination guidelines is cost-prohibitive, supplemental standards consistent with DOE Order 5400.5 are being pursued. This report describes measurements and dose analysis modeling efforts to evaluate the radiation dose to members of the public who might occupy or demolish Building 2, a 2,480 square-foot (ft) building constructed in 1944. The north portion of the building was used as a shower facility for Manhattan Project uranium-processing mill workers and the south portion was a warehouse. Many originally exposed surfaces are no longer accessible for contamination surveys because expensive telecommunications equipment have been installed on the floors and mounted on panels covering the walls. These inaccessible surfaces are contaminated above generic contamination limits.

  12. Grand Junction Projects Office Remedial Action Project Building 2 public dose evaluation. Final report

    SciTech Connect

    Morris, R.

    1996-05-01

    Building 2 on the U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) site, which is operated by Rust Geotech, is part of the GJPO Remedial Action Program. This report describes measurements and modeling efforts to evaluate the radiation dose to members of the public who might someday occupy or tear down Building 2. The assessment of future doses to those occupying or demolishing Building 2 is based on assumptions about future uses of the building, measured data when available, and predictive modeling when necessary. Future use of the building is likely to be as an office facility. The DOE sponsored program, RESRAD-BUILD, Version. 1.5 was chosen for the modeling tool. Releasing the building for unrestricted use instead of demolishing it now could save a substantial amount of money compared with the baseline cost estimate because the site telecommunications system, housed in Building 2, would not be disabled and replaced. The information developed in this analysis may be used as part of an as low as reasonably achievable (ALARA) cost/benefit determination regarding disposition of Building 2.

  13. Final report of the decontamination and decommissioning of Building 18 at the Grand Junction Projects Office Facility

    SciTech Connect

    Widdop, M.R.

    1996-08-01

    The U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore and mill tailings during uranium refining activities of the Manhattan Engineer District and during pilot milling experiments conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJPO Remedial Action Project to clean up and restore the facility lands, improvements, and the underlying aquifer. The site contractor for the facility, Rust Geotech, also is the remedial action contractor. The soil beneath Building 18 was found to be radiologically contaminated; the building was not contaminated. The soil was remediated in accordance with identified standards. Building 18 and the underlying soil can be released for unlimited exposure and unrestricted use. This document was prepared in response to a DOE request for an individual final report for each contaminated GJPO building.

  14. PCB usage at the Grand Junction Area Office Facility. Final report

    SciTech Connect

    Miller, M.E.; Donivan, S.

    1982-06-01

    The development, implementation, and results of the polychlorinated biphenyl (PCB) identification project at the Grand Junction Area Office (GJAO) are summarized. Methodology for the PCB analysis is described, and results are tabulated. Of the 51 transformers and disconnects in use at GJAO, 15 unites were determined to be PCB-contaminated or filled with PCBs. This number falls within EPA's estimate of 25 to 40 percent of all transformers in use being at least contaminated. Approximately 324 gallons of PCBs and 515 gallons of PCB-contaminated fluids are being used currently. No contaminated transformers or disconnects are in a position to contaminate food or feed products at the facility.

  15. Assessment of cover systems at the Grand Junction, Colorado, uranium mill tailings pile: 1987 field measurements

    SciTech Connect

    Gee, G.W.; Campbell, M.D.; Freeman, H.D.; Cline, J.F.

    1989-02-01

    Four Pacific Northwest Laboratory (PNL) scientists and a technician conducted an onsite evaluation of radon gas exhalation, water content profiles, and plant and animal intrusion for a series of cover systems located on the uranium mill tailings pile at Grand Junction, Colorado. These six plots were sampled extensively down to the radon control layer (e.g., asphalt or wet clay) for soil moisture content and permeability. Radon gas emission through the surface was measured. Soil samples were collected and analyzed in the lab for particle-size distribution, particle density, bulk density, and ambient water content. Prairie dog burrows were excavated to discover the extent to which they penetrated the barriers. Plant type, density, and cover characteristics were measured.

  16. 75 FR 57024 - Decision To Evaluate a Petition To Designate a Class of Employees From the Grand Junction...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Decision To Evaluate a Petition To Designate a Class of Employees From the Grand Junction... Institute for Occupational Safety and Health (NIOSH), Department of Health and Human Services (HHS)....

  17. Radiological audit of remedial action activities at the processing site, transfer site, and Cheney disposal site Grand Junction, Colorado: Audit date, August 9--11, 1993. Final report

    SciTech Connect

    Not Available

    1993-08-01

    The Uranium Mill Tailing Remedial Action (UMTRA) Project`s Technical Assistance Contractor (TAC) performed a radiological audit of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing site, transfer site, and Cheney disposal site in Grand Junction, Colorado. Jim Hylko and Bill James of the TAC conducted this audit August 9 through 11, 1993. Bob Cornish and Frank Bosiljevec represented the US Department of Energy (DOE). This report presents one programmatic finding, eleven site-specific observations, one good practice, and four programmatic observations.

  18. Neutrino dark energy in grand unified theories

    NASA Astrophysics Data System (ADS)

    Bhatt, Jitesh R.; Gu, Pei-Hong; Sarkar, Utpal; Singh, Santosh K.

    2009-10-01

    We studied a left-right symmetric model that can accommodate the neutrino dark energy (νDE) proposal. The type-III seesaw mechanism is implemented to give masses to the neutrinos. After explaining the model, we study the consistency of the model by minimizing the scalar potential and obtaining the conditions for the required vacuum expectation values of the different scalar fields. This model is then embedded in an SO(10) grand unified theory and the allowed symmetry breaking scales are determined by the condition of the gauge coupling unification. Although SU(2)R breaking is required to be high, its Abelian subgroup U(1)R is broken in the TeV range, which can then give the required neutrino masses and predicts new gauge bosons that could be detected at LHC. The neutrino masses are studied in detail in this model, which shows that at least 3 singlet fermions are required.

  19. Neutrino dark energy in grand unified theories

    SciTech Connect

    Bhatt, Jitesh R.; Sarkar, Utpal; Singh, Santosh K.; Gu, P.-H.

    2009-10-01

    We studied a left-right symmetric model that can accommodate the neutrino dark energy ({nu}DE) proposal. The type-III seesaw mechanism is implemented to give masses to the neutrinos. After explaining the model, we study the consistency of the model by minimizing the scalar potential and obtaining the conditions for the required vacuum expectation values of the different scalar fields. This model is then embedded in an SO(10) grand unified theory and the allowed symmetry breaking scales are determined by the condition of the gauge coupling unification. Although SU(2){sub R} breaking is required to be high, its Abelian subgroup U(1){sub R} is broken in the TeV range, which can then give the required neutrino masses and predicts new gauge bosons that could be detected at LHC. The neutrino masses are studied in detail in this model, which shows that at least 3 singlet fermions are required.

  20. Health-hazard evaluation report HETA 92-152-2214, Mesa County Courthouse, Grand Junction, Colorado

    SciTech Connect

    McCammon, C.S.

    1992-05-01

    In response to a request from the Facilities Manager of Mesa County Support Services Department concerning the Mesa County Courthouse and Annex (SIC-9222), Grand Junction, Colorado, an evaluation was undertaken of indoor air quality as employees had been suffering with itchy watery eyes, chronic sinus problems, headaches, and other symptoms. Over the past 5 years each of the four courtrooms in the Annex had its own ventilation (heating and air conditioning) system installed. The areas of the Annex building which had a central HVAC system were the source of most complaints. No carbon-dioxide (124389) levels were recorded above 1000 parts per million (ppm) in any section of the building. Temperatures inside ranged from 72 to 79 degrees-F and relative humidity was 17 to 20%. Carbon-monoxide (630080) levels were less than 1 ppm. There were times when the amount of outside air mixed in were inadequate. The author concludes that no airborne contaminant which would constitute a health hazard was identified; however, there were defciencies in the ventilation system. The author recommends measures to improve the ventilation system.

  1. Work plan for ground water elevation data recorder/monitor well installation at Grand Junction, Colorado. Revision 1

    SciTech Connect

    Not Available

    1994-08-01

    The purpose of this document is to describe the work that will be performed and the procedures that will be followed during installation of ground water monitor wells and ground water elevation data recorders (data loggers) at the Grand Junction, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project site. The monitor wells and data loggers will be used to gather required time-dependent data to investigate the interaction between the shallow aquifer and the Colorado River.

  2. Confirmatory radiological survey of the Grand Junction Projects Office Remedial Action Project exterior portions, 1989-1995

    SciTech Connect

    Forbes, G.H.; Egidi, P.V.

    1997-04-01

    The purpose of this independent assessment was to provide the U.S. Department of Energy (DOE) with an independent verification (IV) that the soil at the Grand Junction Projects Office (GJPO) complies with applicable DOE guidelines. Oak Ridge National Laboratory/ Environmental Technology Section (ORNL/ETS) which is also located at the GJPO, was assigned by DOE as the Independent Verification Contractor (IVC). The assessment included reviews of the decontamination and decommissioning plan, annual environmental monitoring reports, data in the pre- and post-remedial action reports, reassessment reports and IV surveys. Procedures and field methods used during the remediation were reviewed, commented on, and amended as needed. The IV surveys included beta-gamma and gamma radiation scans, soil sampling and analyses. Based on the data presented in the post-remedial action report and the results of the IV surveys, the remediation of the outdoor portions of the GJPO has achieved the objectives. Residual deposits of uranium contamination may exist under asphalt because the original characterization was not designed to identify uranium and subsequent investigations were limited. The IVC recommends that this be addressed with the additional remediation. The IVC is working with the remedial action contractor (RAC) to assure that final documentation WM be sufficient for certification. The IVC will address additional remediation of buildings, associated utilities, and groundwater in separate reports. Therefore, this is considered a partial verification.

  3. Grand Junction remedial action program. Analysis of currently approved and proposed procedures for establishing eligibility for remedial action. Final report

    SciTech Connect

    1980-12-01

    This analysis of the Grand Junction Remedial Action Program has been undertaken at the request of the Department of Energy (DOE) in response to proposals submitted by the Colorado Department of Health (CHD). In essence those proposals are for approval by DOE of alternative procedures for establishing the eligibility of structures for remedial action. Regardless of the preeminence accorded the RPISU method in the regulation, it is appropriate to question the assumption that this method gives better estimates of average long-term exposure than other potential methods of evaluation. The objectives here are to (1) review the reliability of the methods of measurement authorized by 10 CFR 12, i.e. the RPISU 6 sample method for determining RDC and the presumptive tests based on the indoor net average gamma exposure rate; (2) evaluate the reliability of the alternative measurement methods proposed by the CDH for determining eligibility for remedial action; and (3) recommend for DOE approval specific methods and applicable procedures that may be used to determine eligibility for remedial action with at least the same reliability as presently achieved with the RPISU 6 sample method.

  4. Alpha Schottky junction energy source

    NASA Astrophysics Data System (ADS)

    Litz, Marc S.; Fan, Zhaoyang; Carroll, James J.; Bayne, Stephen

    2012-06-01

    Isotope batteries offer solutions for long-lived low-power sensor requirements. Alpha emitting isotopes have energy per decay 103 times that of beta emitters. Alpha particles are absorbed within 20 μm of most materials reducing shielding mitigation. However, damage to materials from the alphas limits their practical use. A Schottky Barrier Diode (SBD) geometry is considered with an alpha emitting contact-layer on a diamond-like crystal semiconductor region. The radiation tolerance of diamond, the safety of alpha particles, combined with the internal field of the SBD is expected to generate current useful for low-power electronic devices over decades. Device design parameters and calculations of the expected current are described.

  5. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Grand Junction, Colorado

    SciTech Connect

    Not Available

    1994-06-01

    This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site Near Grand Junction, Colorado evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site. This risk assessment follows an approach outlined by the EPA. the first step is to evaluate ground water data collected from monitor wells at the site. Evaluation of these data showed that the contaminants of potential concern in the ground water are arsenic, cadmium, cobalt, fluoride, iron, manganese, molybdenum, nickel, sulfate, uranium, vanadium, zinc, and radium-226. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if they drank from a well installed in the contaminated ground water at the former processing site.

  6. Remedial actions at the former Climax Uranium Company, Uranium Mill site, Grand Junction, Mesa County, Colorado. Volume 1, Text: Final environmental impact statement

    SciTech Connect

    1986-12-01

    This statement evaluates and compares the environmental impacts associated with the remedial actions of the residual radioactive materials remaining at the inactive uranium processing site and associated vicinity properties at Grand Junction, Mesa County, Colorado. This statement is also intended to aid the BLM in amending their management framework plans and final resource management plan, as well as assisting in compliance with the withdrawal application as appropriate. The site is a 114-acre tract of private and state owned land which contains approximately 3.1 million cubic yards of tailings and associated contaminated soils. The vicinity properties are homes, businesses, public buildings, and vacant lots which may have been contaminated during construction by the use of tailings as building material. An estimated 3465 vicinity properties would be cleaned up during remedial action of the tailings pile. The tailings were produced by the former Climax Uranium Company which processed uranium ore, which it sold to the US Atomic Energy Commission from 1951 to 1966 and to private sources from 1966 to 1970. This statement evaluates six alternatives for stabilization and disposal of the tailings and other contaminated materials: (1) No action. (2) Stabilization at the Grand Junction site. (3) Disposal at the Cheney Reservoir site with truck transport. (4) Disposal at the Cheney Reservoir site with train and truck transport. (5) Disposal at the Two Road site with truck transport. (6) Disposal at the Two Road site with train and truck transport. All of the alternatives except no action include remedial action at an estimated 3465 vicinity properties. Alternative 3 is DOE`s preferred alternative.

  7. Grand challenges of inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Nuckolls, J. H.

    2010-08-01

    As soon as practical, Earth's low-cost, abundant, environmentally attractive fusion energy resources should be applied to the urgent global challenges of climate change, energy supply, economic growth, and the developing world. A National Ignition Campaign is under way at the recently completed National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) to ignite high-gain inertial fusion targets in the 2010-2012 time frame. Achieving ignition on NIF could be the catalyst for national and global leaders to support the development of inertial fusion energy (IFE) to meet the future's worldwide electric power demand. With sustained, high-priority funding could practical IFE be possible by the 2020 timeframe? The answer lies in how well can the community address and solve technical challenges in four key areas: achieving ignition, producing advanced targets and drivers, creating a practical fusion engine, and developing economical fusion power plants.

  8. Work plan for phase 1A paleochannel studies at the Cheney disposal cell, Grand Junction, Colorado: Draft

    SciTech Connect

    1996-11-01

    This document will serve as a Work Plan for continuing paleochannel characterization activities at the Cheney disposal site near Grand Junction, Colorado. Elevated levels of nitrate were encountered in ground water from two monitor wells installed in alluvial paleochannels near the Cheney disposal cell in 1994. This triggered a series of investigations (Phase 1) designed to determine the source of nitrate and other chemical constituents in ground water at the site. A comprehensive summary of the Phase 1 field investigations (limited to passive monitoring and modeling studies) conducted by the Remedial Action Contractor (RAC) and Technical Assistance Contractor (TAC) to date is provided in Section 2.0 of this document. Results of Phase 1 were inconclusive regarding the potential interaction between the disposal cell and the paleochannels, so additional Phase 1A investigations are planned. Recommendations for Phase 1A tasks and possible future activities are discussed in Section 3.0. Detailed information on the implementation of the proposed Phase 1A tasks appears in Section 4.0 and will provide the basis for Statements of Work (SOW) for each of these tasks. A detailed sampling plan is provided to ensure quality and a consistency with previous data collection efforts.

  9. An Energy Management Programme for Grande Prairie Public School District. Energy Conservation: Energy Management.

    ERIC Educational Resources Information Center

    Calgary Univ. (Alberta).

    This report describes a pilot energy conservation project in Grande Prairie (Alberta) School District No. 2357. Extensive data collection and analysis were undertaken to provide a sound, quantitative basis for evaluation of the program. Energy conserving measures requiring capital outlays were not considered. During the project, electric demand…

  10. 77 FR 51983 - Availability of Department of Energy EV Everywhere Grand Challenge Initial Framing Document and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-28

    .... SUMMARY: The EV Everywhere Grand Challenge is a U.S. Department of Energy ``Clean Energy Grand Challenge... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Availability of Department of Energy EV Everywhere...

  11. Low-energy theory of transport in Majorana wire junctions

    NASA Astrophysics Data System (ADS)

    Zazunov, A.; Egger, R.; Levy Yeyati, A.

    2016-07-01

    We formulate and apply a low-energy transport theory for hybrid quantum devices containing junctions of topological superconductor (TS) wires and conventional normal (N) or superconducting (S) leads. We model TS wires as spinless p -wave superconductors and derive their boundary Keldysh Green's function, capturing both the Majorana end state and continuum quasiparticle excitations in a unified manner. We also specify this Green's function for a finite-length TS wire. Junctions connecting different parts of the device are described by the standard tunneling Hamiltonian. Using this Hamiltonian approach, one also has the option to include many-body interactions in a systematic manner. For N-TS junctions, we provide the current-voltage (I -V ) characteristics at arbitrary junction transparency and give exact results for the shot-noise power and the excess current. For TS-TS junctions, analytical results for the thermal noise spectrum and for the I -V curve in the high-transparency low-bias regime are presented. For S-TS junctions, we compute the entire I -V curve and clarify the conditions for having a finite Josephson current.

  12. Work plan for monitor well/groundwater elevation data recorder installation at the Cheney Disposal site, Grand Junction, Colorado

    SciTech Connect

    Not Available

    1994-09-01

    In May 1990, during the excavation for the Grand Junction, Colorado, Cheney Reservoir disposal cell (Cheney), a water bearing paleochannel was encountered along the northern boundary of the excavation (designated the Northwest Paleochannel). To ensure the long-term integrity of the disposal embankment, remedial actions were taken including the excavation of the paleochannel and underlying material to bedrock, backfilling of the trapezoidal trench with granular material, and placement of a geotextile liner above the granular material. Compacted clay backfill was placed above the reconstructed paleochannel trench, and the northwest corner was restored to the designated grade. Investigation of other paleochannels determined that ground water flow terminated before it migrated as far west as the disposal cell. Therefore, flow in these paleochannels would have no impact on the disposal cell. Although characterization efforts did not indicate the presence of a ground water-bearing paleochannel south of the disposal cell, the potential could not be ruled out. As a best management practice for long-term monitoring at Cheney, two monitor wells will be installed within the paleochannels. One well will be installed within 50 feet (ft) west of the reconstructed Northwest Paleochannel. The second well will be installed near the southwestern (downgradient) corner of the disposal cell. The purposes of these wells are to characterize ground water flow (if any) within the paleochannels and to monitor the potential for water movement (seepage) into or out of the disposal cell. Initial monitoring of the paleochannels will consist of water level elevation measurement collection and trend analysis to evaluate fluctuations in storage. The purpose of this document is to describe the work that will be performed and the procedures that will be followed during installation of two ground water monitor wells and two ground water elevation data recorders (data loggers) at Cheney.

  13. Length and energy gap dependences of thermoelectricity in nanostructured junctions.

    PubMed

    Asai, Yoshihiro

    2013-04-17

    The possibilities of an enhanced thermoelectric figure of merit value, ZT, in a nanostructured junction are examined for a wide range of parameter values in a theoretical model. Our research shows that the figure of merit can take a very large maximum, which depends both on the length and the energy gap values. The maximum of ZT is achieved when the Fermi level of the electrodes is aligned to the edge of the electronic transmission function of the junction, where both the conductance and the Seebeck constant are significantly enhanced. On the basis of our results, we conclude that nanowires and molecular junctions form a special class of systems where a large ZT can be expected in some cases. PMID:23528878

  14. 27 CFR 9.137 - Grand Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 1973. (3) “Grand Junction Quadrangle, Colorado,” edition of 1962, photorevised 1973. (4) “Colorado... map to the Canal's junction with the Gunnison River on the Grand Junction quadrangle map (western part... Gunnison River to its junction with the Colorado River in section 22, T. 1 S., R. 1 W.; (10)...

  15. 27 CFR 9.137 - Grand Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 1973. (3) “Grand Junction Quadrangle, Colorado,” edition of 1962, photorevised 1973. (4) “Colorado... map to the Canal's junction with the Gunnison River on the Grand Junction quadrangle map (western part... Gunnison River to its junction with the Colorado River in section 22, T. 1 S., R. 1 W.; (10)...

  16. Grand Forks - East Grand Forks Urban Water Resources Study. Energy conservation and recreation appendix, public involvement appendix. Final report

    SciTech Connect

    Not Available

    1981-07-01

    The goal of the Corps of Engineers Urban Study Program is to provide planning assistance to local interests in a variety of water resource areas. The St. Paul District conducted the Grand Forks-East Grand Forks (GF/EGF) Urban Water Resources Study which was a cooperative effort among local, state and federal agencies. Primary attention was given to flood control, water supply and wastewater management; supporting investigations addressed recreation and energy conservation. The recreation investigation consists of the leisure time analysis conducted in stage 2 of the urban study by the Heritage Conservation and Recreation Service, Department of the Interior. The leisure time analysis compared the study area's recreational needs to the available and planned facilities and identified unsatisfied needs. The thermography investigation was conducted in spring 1978 in response to the public's growing awareness of energy conservation and the Corps' desire to make the public aware of the urban study in a meaningful, useful fashion. The investigation consisted of aerial infrared photography, public displays of photographs, and distribution of information on energy saving practices. This investigation was a one-time effort with no plans for follow-up.

  17. Multiple-junction quantum cascade photodetectors for thermophotovoltaic energy conversion.

    PubMed

    Yin, Jian; Paiella, Roberto

    2010-01-18

    The use of intersubband transitions in quantum cascade structures for thermophotovoltaic energy conversion is investigated numerically. The intrinsic cascading scheme, spectral agility, and design flexibility of these structures make them ideally suited to the development of high efficiency multiple-junction thermophotovoltaic detectors. A specific implementation of this device concept is designed, based on bound-to-continuum intersubband transitions in large-conduction-band-offset In(0.7)Ga(0.3)As/AlAs(0.8)Sb(0.2) quantum wells. The device electrical characteristics in the presence of thermal radiation from a blackbody source at 1300 K are calculated, from which a maximum extracted power density of 1.4 W/cm(2) is determined. This value compares favorably with the present state-of-the-art in interband thermophotovoltaic energy conversion, indicating that quantum cascade photodetectors may provide a promising approach to improve energy extraction from thermal sources. PMID:20173989

  18. Alt-Energy Grand Prix Inspires an "I Can" Attitude

    ERIC Educational Resources Information Center

    Tessmer, Al; Trzeciak, Mark

    2010-01-01

    This article describes how a team comprised largely of high school students builds and races an E85-fueled car and takes first place at the Bowling Green (Ohio) State University (BGSU) Grand Prix. Free and open to the public, the event features student drivers and crews, racing go-karts powered by renewable, ethanol-based E85 fuel. The track is a…

  19. Minimization of the energy costs for operating magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Farhat, Ilyas A. H.; Gale, E.; Isakovic, A. F.

    2015-03-01

    Increasing prospects of utilizing the STT-MRAM calls for the re-assessment of the overall energy (power) cost of operating magnetic tunnel junctions and related elements. This motivates our design, nanofabrication and characterization of simple tri-layer magnetic tunnel junctions which show measurable decrease in the operating energy cost. The MTJs we report about rely on nanoengineering interfaces between the insulating and magnetic layers in such a way that the area of the hysteresis loops can be controlled in one or both magnetic layers. Our TMR coefficient ranges from 45% to 130%, depending on the MTJ layer materials, and can be anticipated to be further increased. We also report the study of the TMR dependence on the RA product, as an important interface parameter. Lastly, we present an analysis of MTJ parameters affected by our approach and a perspective on further improvements, focusing on the device design parameters relevant for the integration of this type of MTJs. This work is supported by the SRC-ATIC Grant 2012-VJ-2335. A part of this work is being performed at Cornell University CNF, a member of NNIN. We thank CNF staff for the support.

  20. Refined lateral energy correction functions for the KASCADE-Grande experiment based on Geant4 simulations

    NASA Astrophysics Data System (ADS)

    Gherghel-Lascu, A.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2015-02-01

    In previous studies of KASCADE-Grande data, a Monte Carlo simulation code based on the GEANT3 program has been developed to describe the energy deposited by EAS particles in the detector stations. In an attempt to decrease the simulation time and ensure compatibility with the geometry description in standard KASCADE-Grande analysis software, several structural elements have been neglected in the implementation of the Grande station geometry. To improve the agreement between experimental and simulated data, a more accurate simulation of the response of the KASCADE-Grande detector is necessary. A new simulation code has been developed based on the GEANT4 program, including a realistic geometry of the detector station with structural elements that have not been considered in previous studies. The new code is used to study the influence of a realistic detector geometry on the energy deposited in the Grande detector stations by particles from EAS events simulated by CORSIKA. Lateral Energy Correction Functions are determined and compared with previous results based on GEANT3.

  1. Chemical control over the energy-level alignment in a two-terminal junction

    NASA Astrophysics Data System (ADS)

    Yuan, Li; Franco, Carlos; Crivillers, Núria; Mas-Torrent, Marta; Cao, Liang; Sangeeth, C. S. Suchand; Rovira, Concepció; Veciana, Jaume; Nijhuis, Christian A.

    2016-07-01

    The energy-level alignment of molecular transistors can be controlled by external gating to move molecular orbitals with respect to the Fermi levels of the source and drain electrodes. Two-terminal molecular tunnelling junctions, however, lack a gate electrode and suffer from Fermi-level pinning, making it difficult to control the energy-level alignment of the system. Here we report an enhancement of 2 orders of magnitude of the tunnelling current in a two-terminal junction via chemical molecular orbital control, changing chemically the molecular component between a stable radical and its non-radical form without altering the supramolecular structure of the junction. Our findings demonstrate that the energy-level alignment in self-assembled monolayer-based junctions can be regulated by purely chemical modifications, which seems an attractive alternative to control the electrical properties of two-terminal junctions.

  2. Chemical control over the energy-level alignment in a two-terminal junction.

    PubMed

    Yuan, Li; Franco, Carlos; Crivillers, Núria; Mas-Torrent, Marta; Cao, Liang; Sangeeth, C S Suchand; Rovira, Concepció; Veciana, Jaume; Nijhuis, Christian A

    2016-01-01

    The energy-level alignment of molecular transistors can be controlled by external gating to move molecular orbitals with respect to the Fermi levels of the source and drain electrodes. Two-terminal molecular tunnelling junctions, however, lack a gate electrode and suffer from Fermi-level pinning, making it difficult to control the energy-level alignment of the system. Here we report an enhancement of 2 orders of magnitude of the tunnelling current in a two-terminal junction via chemical molecular orbital control, changing chemically the molecular component between a stable radical and its non-radical form without altering the supramolecular structure of the junction. Our findings demonstrate that the energy-level alignment in self-assembled monolayer-based junctions can be regulated by purely chemical modifications, which seems an attractive alternative to control the electrical properties of two-terminal junctions. PMID:27456200

  3. Chemical control over the energy-level alignment in a two-terminal junction

    PubMed Central

    Yuan, Li; Franco, Carlos; Crivillers, Núria; Mas-Torrent, Marta; Cao, Liang; Sangeeth, C. S. Suchand; Rovira, Concepció; Veciana, Jaume; Nijhuis, Christian A.

    2016-01-01

    The energy-level alignment of molecular transistors can be controlled by external gating to move molecular orbitals with respect to the Fermi levels of the source and drain electrodes. Two-terminal molecular tunnelling junctions, however, lack a gate electrode and suffer from Fermi-level pinning, making it difficult to control the energy-level alignment of the system. Here we report an enhancement of 2 orders of magnitude of the tunnelling current in a two-terminal junction via chemical molecular orbital control, changing chemically the molecular component between a stable radical and its non-radical form without altering the supramolecular structure of the junction. Our findings demonstrate that the energy-level alignment in self-assembled monolayer-based junctions can be regulated by purely chemical modifications, which seems an attractive alternative to control the electrical properties of two-terminal junctions. PMID:27456200

  4. Toward Net Energy Buildings: Design, Construction, and Performance of the Grand Canyon House

    SciTech Connect

    C. Edward Hancock; Greg Barker; J. Douglas Balcomb.

    1999-06-23

    The Grand Canyon house is a joint project of the DOE's National Renewable Energy Laboratory and the U.S. National Park Service and is part of the International Energy Agency Solar Heating and Cooling Programme Task 13 (Advanced Solar Low-Energy Buildings). Energy consumption of the house, designed using a whole-building low-energy approach, was reduced by 75% compared to an equivalent house built in accordance with American Building Officials Model Energy Code and the Home Energy Rating System criteria.

  5. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site at Grand Junction, Colorado. Revision 1

    SciTech Connect

    Not Available

    1994-09-01

    This risk assessment evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site.

  6. Three-dimensional models of conventional and vertical junction laser-photovoltaic energy converters

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Walker, Gilbert H.

    1988-01-01

    Three-dimensional models of both conventional planar junction and vertical junction photovoltaic energy converters have been constructed. The models are a set of linear partial differential equations and take into account many photoconverter design parameters. The model is applied to Si photoconverters; however, the model may be used with other semiconductors. When used with a Nd laser, the conversion efficiency of the Si vertical junction photoconverter is 47 percent, whereas the efficiency for the conventional planar Si photoconverter is only 17 percent. A parametric study of the Si vertical junction photoconverter is then done in order to describe the optimum converter for use with the 1.06-micron Nd laser. The efficiency of this optimized vertical junction converter is 44 percent at 1 kW/sq cm.

  7. Multiphoton transitions between energy levels in a current-biased Josephson tunnel junction.

    PubMed

    Wallraff, A; Duty, T; Lukashenko, A; Ustinov, A V

    2003-01-24

    The escape of a current-biased Josephson tunnel junction from the zero-voltage state in the presence of weak microwave radiation is investigated experimentally at low temperatures. The measurements of the junction switching current distribution indicate the macroscopic quantum tunneling of the phase below a crossover temperature of T small star, filled approximately 280 mK. At temperatures below T small star, filled we observe both single-photon and multiphoton transitions between the junction energy levels by applying microwave radiation in the frequency range between 10 and 38 GHz to the junction. These observations reflect the anharmonicity of the junction potential containing only a small number of levels. PMID:12570519

  8. Primary Energy Spectrum as Reconstructed from S(500) Measurements by KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Toma, G.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2010-01-01

    In cosmic ray investigations by observations of extensive air showers (EAS) the general question arises how to relate the registered EAS observables to the energy of the primary particle from the cosmos entering into the atmosphere. We present results on the reconstruction of the primary energy spectrum of cosmic rays from the experimentally recorded S(500) observable using the KASCADE-Grande detector array. The KASCADE-Grande experiment is installed in Forschungszentrum Karlsruhe, Germany, and driven by an international collaboration. Previous EAS investigations have shown that for a fixed energy the charged particle density becomes independent of the primary mass at certain distances from the shower core. This feature can be used as an estimator for the primary energy. The particular radial distance from the shower core where this effect shows up is a characteristic of the detector. For the KASCADE-Grande experiment it was shown to be around 500 m, hence a notation S(500). Extensive simulation studies have shown that S(500) is mapping the primary energy. The constant intensity cut (CIC) method is applied to evaluate the attenuation of the S(500) observable with the zenith angle. An attenuation correction is applied and all recorded S(500) values are corrected for attenuation. A calibration of S(500) values with the primary energy has been worked out by simulations and was used for conversion providing the possibility to obtain the primary energy spectrum (in the energy range accessible to KASCADE-Grande 1010-1018 eV). The systematic uncertainties induced by different factors are considered.

  9. Grand Valley State University Checks Out Energy Savings at New Mary Idema Pew Library

    SciTech Connect

    none,

    2013-03-01

    Grand Valley State University (GVSU) partnered with the Department of Energy (DOE) to develop and implement solutions to build new, low-energy buildings that are at least 50% below Standard 90.1-2007 of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the American National Standards Institute (ANSI), and the Illuminating Engineering Society of North America (IESNA) as part of DOE’s Commercial Building Partnerships (CBP) Program.

  10. Grand Junction projects office mixed-waste treatment program, VAC*TRAX mobile treatment unit process hazards analysis

    SciTech Connect

    Bloom, R.R.

    1996-04-01

    The objective of this report is to demonstrate that a thorough assessment of the risks associated with the operation of the Rust Geotech patented VAC*TRAX mobile treatment unit (MTU) has been performed and documented. The MTU was developed to treat mixed wastes at the US Department of Energy (DOE) Albuquerque Operations Office sites. The MTU uses an indirectly heated, batch vacuum dryer to thermally desorb organic compounds from mixed wastes. This process hazards analysis evaluated 102 potential hazards. The three significant hazards identified involved the inclusion of oxygen in a process that also included an ignition source and fuel. Changes to the design of the MTU were made concurrent with the hazard identification and analysis; all hazards with initial risk rankings of 1 or 2 were reduced to acceptable risk rankings of 3 or 4. The overall risk to any population group from operation of the MTU was determined to be very low; the MTU is classified as a Radiological Facility with low hazards.

  11. Grand Challenge Portfolio: Driving Innovation in Industrial Energy Efficiency

    SciTech Connect

    2011-01-04

    Under the Recovery Act, AMO provided cost-shared funding for early-stage, low-cost, "concept definition studies" of 47 promising innovations for next-generation manufacturing, energy-intensive processes, advanced materials, and greenhouse gas emissions reduction. The brochure provides information on each of these projects.

  12. Measurement of energy relaxation time in a microwave-driven Josephson junction

    NASA Astrophysics Data System (ADS)

    Sun, Guozhu; Wang, Yiwen; Cao, Junyu; Chen, Jian; Ji, Zhengming; Kang, Lin; Xu, Weiwei; Yu, Yang; Han, Siyuan

    2007-11-01

    The switching current distributions P(I) with different sweep rates are obtained in microwave-driven current-biased Josephson tunnel junctions. We observe the resonant peak caused by microwave-assisted tunneling in P(I). By measuring the magnitude of the microwave resonant peak as a function of the sweep rate, we develop a novel method of extracting the energy relaxation time T1 of the junction. With this simple method, it is determined that T1 of a Nb/AlOx/Nb Josephson junction is approximately 0.5 µs.

  13. CERN and high energy physics, the grand picture

    ScienceCinema

    None

    2011-10-06

    The lecture will touch on several topics, to illustrate the role of CERN in the present and future of high-energy physics: how does CERN work? What is the role of the scientific community, of bodies like Council and SPC, and of international cooperation, in the definition of CERN's scientific programme? What are the plans for the future of the LHC and of the non-LHC physics programme? What is the role of R&D; and technology transfer at CERN?

  14. CERN and high energy physics, the grand picture

    SciTech Connect

    2010-06-21

    The lecture will touch on several topics, to illustrate the role of CERN in the present and future of high-energy physics: how does CERN work? What is the role of the scientific community, of bodies like Council and SPC, and of international cooperation, in the definition of CERN's scientific programme? What are the plans for the future of the LHC and of the non-LHC physics programme? What is the role of R&D; and technology transfer at CERN?

  15. The KASCADE-Grande observatory and the composition of very high-energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Arteaga-Velázquez, J. C.; Apel, W. D.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2015-11-01

    KASCADE-Grande is an air-shower observatory devoted to the detection of cosmic rays with energies in the range of 1016 to 1018 eV. This energy region is of particular interest for the cosmic ray astrophysics, since it is the place where some models predict the existence of a transition from galactic to extragalactic origin of cosmic rays and the presence of a break in the flux of its heavy component. The detection of these features requires detailed and simultaneous measurements of the energy and composition of cosmic rays with sufficient statistics. These kinds of studies are possible for the first time in KASCADE-Grande due to the accurate measurements of several air-shower observables, i.e., the number of charged particles, electrons and muons in the shower, using the different detector systems of the observatory. In this contribution, a detailed look into the composition of 1016 — 1018 eV cosmic rays with KASCADE-Grande is presented.

  16. Evaluation of Streamflow Losses Along the Gunnison River from Whitewater Downstream to the Redlands Canal Diversion Dam, near Grand Junction, Colorado, Water Years 1995-2003

    USGS Publications Warehouse

    Kuhn, Gerhard; Williams, Cory A.

    2004-01-01

    In 2003, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, Upper Colorado River Endangered Fish Recovery Program, Colorado River Water Conservation District, Colorado Division of Water Resources, and Bureau of Reclamation, initiated a study to characterize streamflow losses along a reach of the Gunnison River from the town of Whitewater downstream to the Redlands Canal diversion dam. This describes the methods and results of the study that include: (1) a detailed mass-balance analysis of historical discharge records that were available for the three streamflow-gaging stations along the study reach; and (2) two sets of discharge measurements that were made at the three stations and at four additional locations. Data for these existing streamflow-gaging stations were compiled and analyzed: (1) Gunnison River near Grand Junction (Whitewater station); (2) Gunnison River below Redlands Canal diversion dam (below-Redlands-dam station); and (3) Redlands Canal near Grand Junction (Redlands-Canal station). Data for water years 1995-2003 were used for the mass-balance analysis. Four intermediate sites (M1, M2, M3, and M4) were selected for discharge measurements in addition to the existing stations. The study reach is the approximate 12-mile reach of the Gunnison River from the Whitewater station downstream to the Redlands Canal diversion dam, which is about 3 miles upstream from the confluence with the Colorado River. For the mass-balance analysis, differences between the sum of the annual cumulative daily mean discharge at the two downstream stations and the annual cumulative daily mean discharges at the upstream station ranged from about -8,700 to -69,800 acre-feet (about -.8 to -1.1 percent), indicating that the downstream discharges generally were less than the upstream discharges. Moving 3-day daily mean discharge averages also were computed for each of the three stations to smooth out some of the abrupt differences between the

  17. Building a Course on Global Sustainability using the grand challenges of Energy-Water-Climate

    NASA Astrophysics Data System (ADS)

    Myers, J. D.

    2012-12-01

    GEOL1600: Global Sustainability: Managing the Earth's Resources is a lower division integrated science course at the University of Wyoming that fulfills the university's science requirement. Course content and context has been developed using the grand challenge nexus of energy-water-and climate (EWC). The interconnection of these issues, their social relevance and timeliness has provided a framework that gives students an opportunity to recognize why STEM is relevant to their lives regardless of their ultimate professional career choices. The EWC nexus provides the filter to sieve the course's STEM content. It also provides an ideal mechanism by which the non-STEM perspectives important in grand challenge solutions can be seamlessly incorporated in the course. Through a combination of content and context, the relevance of these issues engage students in their own learning. Development of the course followed the Grand Challenge Scientific Literacy (GCSL) model independently developed by the author and two colleagues at the University of Wyoming. This course model stresses science principles centered on the nature of science (e.g., fundamental premises, habits of mind, critical thinking) and unifying scientific concepts (e.g., methods and tools, experimentation, modeling). Grand challenge principles identify the STEM and non-STEM concepts needed to understand the grand challenges, drawing on multiple STEM and non-STEM disciplines and subjects (i.e., economics, politics, unintended consequences, roles of stakeholders). Using the EWC nexus filter and building on the Grand Challenge Principles, specific content included in the course is selected is that most relevant to understanding the Grand Challenges, thereby stressing content depth over breadth. Because quantitative data and reasoning is critical to effectively evaluating challenge solutions, QR is a component of nearly all class activities, while engineering and technology aspects of grand challenges are

  18. 78 FR 69410 - Grand Tower Energy Center, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Grand Tower Energy Center, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding, of...

  19. The energy barrier at noble metal/TiO{sub 2} junctions

    SciTech Connect

    Hossein-Babaei, F. E-mail: fhbabaei@yahoo.com; Lajvardi, Mehdi M. Alaei-Sheini, Navid

    2015-02-23

    Nobel metal/TiO{sub 2} structures are used as catalysts in chemical reactors, active components in TiO{sub 2}-based electronic devices, and connections between such devices and the outside circuitry. Here, we investigate the energy barrier at the junctions between vacuum-deposited Ag, Au, and Pt thin films and TiO{sub 2} layers by recording their electrical current vs. voltage diagrams and spectra of optical responses. Deposited Au/, Pt/, and Ag/TiO{sub 2} behave like contacts with zero junction energy barriers, but the thermal annealing of the reverse-biased devices for an hour at 523 K in air converts them to Schottky diodes with high junction energy barriers, decreasing their reverse electric currents up to 10{sup 6} times. Similar thermal processing in vacuum or pure argon proved ineffective. The highest energy barrier and the lowest reverse current among the devices examined belong to the annealed Ag/TiO{sub 2} contacts. The observed electronic features are described based on the physicochemical parameters of the constituting materials. The formation of higher junction barriers with rutile than with anatase is demonstrated.

  20. XPS quantification of the hetero-junction interface energy

    NASA Astrophysics Data System (ADS)

    Ma, Z. S.; Wang, Yan; Huang, Y. L.; Zhou, Z. F.; Zhou, Y. C.; Zheng, Weitao; Sun, Chang Q.

    2013-01-01

    We present an approach for quantifying the heterogeneous interface bond energy using X-ray photoelectron spectroscopy (XPS). Firstly, from analyzing the XPS core-level shift of the elemental surfaces we obtained the energy levels of an isolated atom and their bulk shifts of the constituent elements for reference; then we measured the energy shifts of the specific energy levels upon interface alloy formation. Subtracting the referential spectrum from that collected from the alloy, we can distil the interface effect on the binding energy. Calibrated based on the energy levels and their bulk shifts derived from elemental surfaces, we can derive the bond energy, energy density, atomic cohesive energy, and free energy at the interface region. This approach has enabled us to clarify the dominance of quantum entrapment at CuPd interface and the dominance of polarization at AgPd and BeW interfaces, as the origin of interface energy change. Developed approach not only enhances the power of XPS but also enables the quantification of the interface energy at the atomic scale that has been an issue of long challenge.

  1. Electron Transport, Energy Transfer, and Optical Response in Single Molecule Junctions

    NASA Astrophysics Data System (ADS)

    White, Alexander James

    The last decade has seen incredible growth in the quality of experiments being done on single molecule junctions. Contemporary experimental measurements have expanded far beyond simple electron transport. Measurement of vibronic eects, quantum interference and decoherence eects, molecular optical response (Raman spectroscopy), and molecular spintronics are just some of the continuing areas of research in single molecule junctions. Experimental advancements demand advanced theoretical treatments, which can be used accurately within appropriate physical regimes, in order to understand measured phenomena and predict interesting directions for future study. In this dissertation we will study systems with strong intra-system interactions using a many-body states based approach. We will be focused on three related processes in molecular junctions: electron transport, electronic energy transfer, and molecular excitation. Inelastic electron transport in the regime of strong and nonlinear electron-vibration coupling within and outside of the Born-Oppenheimer regime will be investigated. To understand their appropriateness, we will compare simple semi-classical approximations in molecular redox junctions and electron-counting devices to fully quantum calculations based on many-body system states. The role of coherence and quantum interference in energy and electron transfer in molecular junctions is explored. Experiments that simultaneously measure surface enhanced Raman scattering and electron conduction have revealed a strong interaction between conducting electrons and molecular excitation. We investigate the role of the molecular response to a classical surface plasmon enhanced electric eld considering the back action of the oscillating molecular dipole. Raman scattering is quantum mechanical by nature and involves strong interaction between surface plasmons in the contacts and the molecular excitation. We develop a scheme for treating strong plasmon-molecular excitation

  2. Beyond the Lorentzian Model in Quantum Transport: Energy-Dependent Resonance Broadening in Molecular Junctions

    NASA Astrophysics Data System (ADS)

    Liu, Zhenfei; Neaton, Jeffrey B.

    In quantum transport calculations, transmission functions of molecular junctions, as well as spectral functions of metal-organic interfaces, often feature peaks originating from molecular resonances. These resonance peaks are often assumed to be Lorentzian, with an energy-independent broadening function Γ. However, in the general case, the wide-band-limit breaks down, and the Lorentzian approximation is no longer valid. Here, we develop a new energy-dependent broadening function Γ (E) , based on diagonalization of non-Hermitian matrices within a non-equilbrium Green's function (NEGF) formalism. As defined, Γ (E) can describe resonances of non-Lorentzian nature and can be decomposed into components associated with the left and right leads, respectively; and it is particularly useful in understanding transport properties in terms of molecular orbitals in asymmetric junctions. We compute this quantity via an ab initio NEGF approach based on density functional theory and illustrate its utility with several junctions of experimental relevance, including recent work on rectification in Au-graphite junctions. This work is supported by the DOE, and computational resources are provided by NERSC.

  3. Surface Passivation and Junction Formation Using Low Energy Hydrogen Implants

    NASA Technical Reports Server (NTRS)

    Fonash, S. J.

    1985-01-01

    New applications for high current, low energy hydrogen ion implants on single crystal and polycrystal silicon grain boundaries are discussed. The effects of low energy hydrogen ion beams on crystalline Si surfaces are considered. The effect of these beams on bulk defects in crystalline Si is addressed. Specific applications of H+ implants to crystalline Si processing are discussed. In all of the situations reported on, the hydrogen beams were produced using a high current Kaufman ion source.

  4. Probing the Ion Binding Site in a DNA Holliday Junction Using Förster Resonance Energy Transfer (FRET)

    PubMed Central

    Litke, Jacob L.; Li, Yan; Nocka, Laura M.; Mukerji, Ishita

    2016-01-01

    Holliday Junctions are critical DNA intermediates central to double strand break repair and homologous recombination. The junctions can adopt two general forms: open and stacked-X, which are induced by protein or ion binding. In this work, fluorescence spectroscopy, metal ion luminescence and thermodynamic measurements are used to elucidate the ion binding site and the mechanism of junction conformational change. Förster resonance energy transfer measurements of end-labeled junctions monitored junction conformation and ion binding affinity, and reported higher affinities for multi-valent ions. Thermodynamic measurements provided evidence for two classes of binding sites. The higher affinity ion-binding interaction is an enthalpy driven process with an apparent stoichiometry of 2.1 ± 0.2. As revealed by Eu3+ luminescence, this binding class is homogeneous, and results in slight dehydration of the ion with one direct coordination site to the junction. Luminescence resonance energy transfer experiments confirmed the presence of two ions and indicated they are 6–7 Å apart. These findings are in good agreement with previous molecular dynamics simulations, which identified two symmetrical regions of high ion density in the center of stacked junctions. These results support a model in which site-specific binding of two ions in close proximity is required for folding of DNA Holliday junctions into the stacked-X conformation. PMID:26978349

  5. Observing tunnel magnetoresistance in junctions comprising of superconductors with Zeeman-split energy bands

    NASA Astrophysics Data System (ADS)

    Li, Bin; Miao, Guo-Xing; Moodera, Jagadeesh S.

    2014-03-01

    The spin-splitting of the quasiparticle density of states (DOS) in a superconductor due to Zeeman energy can lead to a highly field responsive spintronic device. We present our magnetotunneling studies in superconductor/insulator/ferromagnet tunnel junctions in which the superconducting quasiparticle DOS is energy split by an internal exchange field at the interface from an adjacent ferromagnetic insulator EuS layer. A tunnel magnetoresistance (TMR) as large as 36% is observed, and that only occurs in the superconducting state. Tunnel conductance simulation suggests that the TMR originates from the conductance variation resulting from spin selective quasiparticle tunneling. Our results show that in addition to the naturally existent spin imbalance at Fermi level in ferromagnets that gives rise to conventional TMR in standard magnetic junction (MTJs), we can manipulate tunnel conductance by tailoring spin dependent density of states with interfacial exchange fields. Furthermore, a similar TMR is also observed even with a tunnel junction with both superconducting electrodes that have exchange split DOS. [B. Li, G.-X. Miao, and J. S. Moodera, Phys. Rev. B 88, 161105(R) (2013)] The work was supported by NSF Grant No. DMR-1207469 and ONR Grant No. N00014-13-1-0301.

  6. Direct structural observation of a molecular junction by high-energy x-ray reflectometry

    PubMed Central

    Lefenfeld, Michael; Baumert, Julian; Sloutskin, Eli; Kuzmenko, Ivan; Pershan, Peter; Deutsch, Moshe; Nuckolls, Colin; Ocko, Benjamin M.

    2006-01-01

    We report a direct angstrom resolution measurement of the structure of a molecular-size electronic junction comprising a single (or a double) layer of alkyl-thiol and alkyl-silane molecules at the buried interface between solid silicon and liquid mercury. The high-energy synchrotron x-ray measurements reveal densely packed layers comprising roughly interface-normal molecules. The monolayer’s thickness is found to be 3–4 Å larger than that of similar layers at the free surfaces of both mercury and silicon. The origins of this and the other unusual features detected are discussed in this article. Measurements of the bilayer junction with an applied potential did not show visible changes in the surface normal structure. PMID:16467139

  7. Direct Structural Observation of a Molecular Junction by High-Energy X-ray Reflectometry

    SciTech Connect

    Lefenfeld,M.; Baumert, J.; Sloutskin, E.; Kuzmenko, I.; Pershan, P.; Deutsch, M.; Nuckolls, C.; Ocko, B.

    2006-01-01

    We report a direct angstrom resolution measurement of the structure of a molecular-size electronic junction comprising a single (or a double) layer of alkyl-thiol and alkyl-silane molecules at the buried interface between solid silicon and liquid mercury. The high-energy synchrotron x-ray measurements reveal densely packed layers comprising roughly interface-normal molecule . The monolayer's thickness is found to be 3-4 Angstroms larger than that of similar layers at the free surfaces of both mercury and silicon. The origins of this and the other unusual features detected are discussed in this article. Measurements of the bilayer junction with an applied potential did not show visible changes in the surface normal structure.

  8. Maps of zeros of the grand canonical partition function in a statistical model of high energy collisions

    NASA Astrophysics Data System (ADS)

    Brambilla, M.; Giovannini, A.; Ugoccioni, R.

    2006-06-01

    Theorems on zeros of the truncated generating function in the complex plane are reviewed. When examined in the framework of a statistical model of high energy collisions based on the negative binomial (Pascal) multiplicity distribution, these results lead to maps of zeros of the grand canonical partition function which allow us to interpret in a novel way different classes of events in pp collisions at LHC c.m. energies.

  9. Grand Canyon

    Atmospheric Science Data Center

    2014-05-15

    article title:  The Grand Canyon     View Larger Image Northern Arizona and the Grand Canyon are captured in this pair of Multi-angle Imaging SpectroRadiometer ... formats available at JPL December 31, 2000 - Grand Canyon and Lake Powell. project:  MISR ...

  10. Voltage tuning of vibrational mode energies in single-molecule junctions

    PubMed Central

    Li, Yajing; Doak, Peter; Kronik, Leeor; Neaton, Jeffrey B.; Natelson, Douglas

    2014-01-01

    Vibrational modes of molecules are fundamental properties determined by intramolecular bonding, atomic masses, and molecular geometry, and often serve as important channels for dissipation in nanoscale processes. Although single-molecule junctions have been used to manipulate electronic structure and related functional properties of molecules, electrical control of vibrational mode energies has remained elusive. Here we use simultaneous transport and surface-enhanced Raman spectroscopy measurements to demonstrate large, reversible, voltage-driven shifts of vibrational mode energies of C60 molecules in gold junctions. C60 mode energies are found to vary approximately quadratically with bias, but in a manner inconsistent with a simple vibrational Stark effect. Our theoretical model instead suggests that the mode shifts are a signature of bias-driven addition of electronic charge to the molecule. These results imply that voltage-controlled tuning of vibrational modes is a general phenomenon at metal–molecule interfaces and is a means of achieving significant shifts in vibrational energies relative to a pure Stark effect. PMID:24474749

  11. THE "MUD VOLCANO," A STINKY THERMAL FEATURE ON THE GRAND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    THE "MUD VOLCANO," A STINKY THERMAL FEATURE ON THE GRAND LOOP ROAD. ACIDIC HOT SPRINGS HAVE REDUCED THE UNDERLYING LAVA TO A FINE CLAY, PRODUCING AN AREA OF BOILING MUD. THE ODOR OF ROTTEN EGGS IS FROM HYDROGEN SULFIDE GAS. - Grand Loop Road, Forming circuit between Mammoth Hot Springs, Norris Junction, Madison Junction, Old Faithful, Mammoth, Park County, WY

  12. Three-junction solar cell

    DOEpatents

    Ludowise, Michael J.

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  13. Grand Challenges of Advanced Computing for Energy Innovation Report from the Workshop Held July 31-August 2, 2012

    SciTech Connect

    Larzelere, Alex R.; Ashby, Steven F.; Christensen, Dana C.; Crawford, Dona L.; Khaleel, Mohammad A.; John, Grosh; Stults, B. Ray; Lee, Steven L.; Hammond, Steven W.; Grover, Benjamin T.; Neely, Rob; Dudney, Lee Ann; Goldstein, Noah C.; Wells, Jack; Peltz, Jim

    2013-03-06

    On July 31-August 2 of 2012, the U.S. Department of Energy (DOE) held a workshop entitled Grand Challenges of Advanced Computing for Energy Innovation. This workshop built on three earlier workshops that clearly identified the potential for the Department and its national laboratories to enable energy innovation. The specific goal of the workshop was to identify the key challenges that the nation must overcome to apply the full benefit of taxpayer-funded advanced computing technologies to U.S. energy innovation in the ways that the country produces, moves, stores, and uses energy. Perhaps more importantly, the workshop also developed a set of recommendations to help the Department overcome those challenges. These recommendations provide an action plan for what the Department can do in the coming years to improve the nation’s energy future.

  14. Modification of Layer Structures of Superconducting Tunnel Junctions to Improve X-ray Energy Resolution

    NASA Astrophysics Data System (ADS)

    Ukibe, Masahiro; Fujii, Go; Shiki, Shigetomo; Kitajima, Yoshinori; Ohkubo, Masataka

    2016-07-01

    The layer structure of a Nb/Al-based superconducting tunnel junction (STJ) X-ray detector was modified to improve the energy resolution (Δ E) of STJ X-ray detectors by suppressing the recombination of excited quasiparticles in the electrodes. A 100-pixel array of 100 × 100 \\upmu m STJs with a symmetric layer structure of Nb (300 nm)/Al-AlOx(70 nm)/Al (70 nm)/Nb (300 nm) was fabricated. Fabrication yields of the 100 pixels were more than 90 %. The average leak current of the STJ array was 8 nA. The mean Δ E of the STJ array was 6.7 ± 1.0 eV for 400 eV X-rays. This Δ E is the best value reported for Nb/Al STJs.

  15. Cosmic ray energy reconstruction from the S(500) observable recorded in the KASCADE-Grande air shower experiment

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2016-04-01

    The energy reconstruction at KASCADE-Grande is based on a combination of the shower size and the total muon number, which are both estimated for each individual air shower event. We present investigations where we employed a second method to reconstruct the primary energy using S(500), which are the charged particle densities inferred with the KASCADE-Grande detector at a distance of 500 m from the shower axis. We considered the attenuation of inclined showers by applying the "Constant Intensity Cut" method and we employed a simulation-derived calibration to convert the recorded S(500) into primary energy. We observed a systematic shift in the S(500)-derived energy compared with previously reported results obtained using the standard reconstruction technique. However, a comparison of the two methods based on simulated and measured data showed that this shift only appeared in the measured data. Our investigations showed that this shift was caused mainly by the inadequate description of the shape of the lateral density distribution in the simulations.

  16. Environmental assessment of remedial action at vicinity properties associated with the former Climax Uranium Company Uranium Mill Site, Grand Junction, Mesa County, Colorado

    SciTech Connect

    1986-07-01

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the UMTRA Project vicinity properties in Mesa County, Colorado. Vicinity properties are homes, businesses, public buildings, and vacant lots which may have been contaminated during construction by the use of tailings as a building material or as fill material before the hazards associated with this material were known. It is estimated that 3585 contaminated properties remain to be formally included on the vicinity property list and thereby require remedial action. The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law 95-604, authorized the US Department of Energy to perform remedial action at these properties. The US Environmental Protection Agency promulqated standards for remedial action (40 CRF Part 192). The alternatives addressed in this environmental assessment (EA) including taking no action toward remedial action at the vicinity properties, conducting remedial action at a rate of 500 properties per year, and conducting remedial action at a rate of 800 properties per year. 3 figs., 4 tabs.

  17. A comparison between fine grain and epitaxial superconducting tunneling junctions for use as high energy resolution x-ray detectors

    NASA Astrophysics Data System (ADS)

    Saulnier, Gregory Gerard

    1994-01-01

    Superconducting tunneling junctions (STJ) show great promise in high energy resolution x-ray spectroscopy for use in x-ray astrophysics. An STJ is a sandwich of an insulator between two superconductors (S-I-S). Such a device has an intrinsic energy resolution an order of magnitude better than any existing semiconductor device, including the charge coupled device (CCD). The potential impact on x-ray astrophysics is enormous, with possible future use on sounding rockets and other as yet undefined satellite missions. This thesis compares two STJ's that have been fabricated using Nb/Al/Al2O3/Nb in the same ultra-high vacuum chamber with the same layer thicknesses with the only difference being that the base layers are either fine grain (polycrystalline) or epitaxial. The testing was done at temperatures between 0.4 K and 4.2 K. The comparison included subgap spectra from an Fe-55 x-ray source. The findings showed that the fine grain junction had a tunnel barrier of much higher quality and yielded higher energy resolution. It was determined that the epitaxial junction was much more sensitive to substrate events. Two peaks were found in the x-ray spectra. Each peak was attributed to x-ray interactions within one or the other superconducting films of the junction.

  18. Energy resolution and high count rate performance of superconducting tunnel junction x-ray spectrometers

    SciTech Connect

    Frank, M.; Hiller, L.J.; le Grand, J.B.; Mears, C.A.; Labov, S.E.; Lindeman, M.A.; Netel, H.; Chow, D.; Barfknecht, A.

    1998-01-01

    We present experimental results obtained with a cryogenically cooled, high-resolution x-ray spectrometer based on a 141{mu}m{times}141{mu}m Nb-Al-Al{sub 2}O{sub 3}-Al-Nb superconducting tunnel junction (STJ) detector in a demonstration experiment. Using monochromatized synchrotron radiation we studied the energy resolution of this energy-dispersive spectrometer for soft x rays with energies between 70 and 700 eV and investigated its performance at count rates up to nearly 60000 cps. At count rates of several 100 cps we achieved an energy resolution of 5.9 eV (FWHM) and an electronic noise of 4.5 eV for 277 eV x rays (the energy corresponding to C K). Increasing the count rate, the resolution 277 eV remained below 10 eV for count rates up to {approximately}10000cps and then degraded to 13 eV at 23000 cps and 20 eV at 50000 cps. These results were achieved using a commercially available spectroscopy amplifier with a baseline restorer. No pile-up rejection was applied in these measurements. Our results show that STJ detectors can operate at count rates approaching those of semiconductor detectors while still providing a significantly better energy resolution for soft x rays. Thus STJ detectors may prove very useful in microanalysis, synchrotron x-ray fluorescence (XRF) applications, and XRF analysis of light elements (K lines) and transition elements (L lines). {copyright} {ital 1998 American Institute of Physics.}

  19. Self-energy-corrected electronic energy level alignment in molecular junctions and at interfaces with hybrid functionals

    NASA Astrophysics Data System (ADS)

    Kotiuga, Michele; Egger, David; Kronik, Leeor; Neaton, Jeffrey B.

    2015-03-01

    Accurate calculations of energy level alignment at complex interfaces are imperative for understanding a variety of transport and spectroscopy measurements, as well as for elucidating new interfacial electronic structure phenomena. However, standard approaches to such calculations, based on density functional theory (DFT), are well known to be deficient. In prior work on molecular junctions and physisorbed molecules on surfaces, an approximate GW approach, DFT+ Σ, has been successful in describing the conductance and level alignment of amine and pyridine terminated molecules on gold surfaces and in junctions. Here, via the use of hybrid functionals, we preform quantitative studies of the level alignment of thiol- and carbon-terminated phenyls on gold, where the formation of a strong chemical bond and presence of gateway states limit the validity of the DFT+ Σ approximation as currently formulated. We contrast these systems to prior work on weakly-coupled molecules, including bipyridine or phenyl-diamines. Additionally, we compute transmission functions using both DFT-PBE and DFT-HSE starting points and predict conductance and thermopower with these methods, comparing to experiments where possible. We acknowledge DOE, DOD, NERSC, ERC, ISF, and FWF.

  20. Low frequency noise peak near magnon emission energy in magnetic tunnel junctions

    SciTech Connect

    Liu, Liang; Xiang, Li; Guo, Huiqiang; Wei, Jian; Li, D. L.; Yuan, Z. H.; Feng, J. F. Han, X. F.; Coey, J. M. D.

    2014-12-15

    We report on the low frequency (LF) noise measurements in magnetic tunnel junctions (MTJs) below 4 K and at low bias, where the transport is strongly affected by scattering with magnons emitted by hot tunnelling electrons, as thermal activation of magnons from the environment is suppressed. For both CoFeB/MgO/CoFeB and CoFeB/AlO{sub x}/CoFeB MTJs, enhanced LF noise is observed at bias voltage around magnon emission energy, forming a peak in the bias dependence of noise power spectra density, independent of magnetic configurations. The noise peak is much higher and broader for unannealed AlO{sub x}-based MTJ, and besides Lorentzian shape noise spectra in the frequency domain, random telegraph noise (RTN) is visible in the time traces. During repeated measurements the noise peak reduces and the RTN becomes difficult to resolve, suggesting defects being annealed. The Lorentzian shape noise spectra can be fitted with bias-dependent activation of RTN, with the attempt frequency in the MHz range, consistent with magnon dynamics. These findings suggest magnon-assisted activation of defects as the origin of the enhanced LF noise.

  1. Quasiparticle energies and lifetimes in a metallic chain model of a tunnel junction.

    PubMed

    Szepieniec, Mark; Yeriskin, Irene; Greer, J C

    2013-04-14

    As electronics devices scale to sub-10 nm lengths, the distinction between "device" and "electrodes" becomes blurred. Here, we study a simple model of a molecular tunnel junction, consisting of an atomic gold chain partitioned into left and right electrodes, and a central "molecule." Using a complex absorbing potential, we are able to reproduce the single-particle energy levels of the device region including a description of the effects of the semi-infinite electrodes. We then use the method of configuration interaction to explore the effect of correlations on the system's quasiparticle peaks. We find that when excitations on the leads are excluded, the device's highest occupied molecular orbital and lowest unoccupied molecular orbital quasiparticle states when including correlation are bracketed by their respective values in the Hartree-Fock (Koopmans) and ΔSCF approximations. In contrast, when excitations on the leads are included, the bracketing property no longer holds, and both the positions and the lifetimes of the quasiparticle levels change considerably, indicating that the combined effect of coupling and correlation is to alter the quasiparticle spectrum significantly relative to an isolated molecule. PMID:24981526

  2. Nano-welding and junction formation in hydrogen titanate nanowires by low-energy nitrogen ion irradiation.

    PubMed

    Dhal, Satyanarayan; Chatterjee, Shyamal; Sarkar, Subhrangsu; Tribedi, Lokesh C; Bapat, Rudheer; Ayyub, Pushan

    2015-06-12

    Crystalline hydrogen titanate (H2Ti3O7) nanowires were irradiated with N(+) ions of different energies and fluences. Scanning electron microscopy reveals that at relatively lower fluence the nanowires are bent and start to adhere strongly to one another as well as to the silicon substrate. At higher fluence, the nanowires show large-scale welding and form a network of mainly 'X' and 'Y' junctions. Transmission electron microscopy and Raman scattering studies confirm a high degree of amorphization of the nanowire surface after irradiation. We suggest that while ion-irradiation induced defect formation and dangling bonds may lead to chemical bonding between nanowires, the large scale nano-welding and junction network formation can be ascribed to localized surface melting due to heat spike. Our results demonstrate that low energy ion irradiation with suitable choice of fluence may provide an attractive route to the formation and manipulation of large-area nanowire-based devices. PMID:25990259

  3. Nano-welding and junction formation in hydrogen titanate nanowires by low-energy nitrogen ion irradiation

    NASA Astrophysics Data System (ADS)

    Dhal, Satyanarayan; Chatterjee, Shyamal; Sarkar, Subhrangsu; Tribedi, Lokesh C.; Bapat, Rudheer; Ayyub, Pushan

    2015-06-01

    Crystalline hydrogen titanate (H2Ti3O7) nanowires were irradiated with N+ ions of different energies and fluences. Scanning electron microscopy reveals that at relatively lower fluence the nanowires are bent and start to adhere strongly to one another as well as to the silicon substrate. At higher fluence, the nanowires show large-scale welding and form a network of mainly ‘X’ and ‘Y’ junctions. Transmission electron microscopy and Raman scattering studies confirm a high degree of amorphization of the nanowire surface after irradiation. We suggest that while ion-irradiation induced defect formation and dangling bonds may lead to chemical bonding between nanowires, the large scale nano-welding and junction network formation can be ascribed to localized surface melting due to heat spike. Our results demonstrate that low energy ion irradiation with suitable choice of fluence may provide an attractive route to the formation and manipulation of large-area nanowire-based devices.

  4. Nanotube junctions

    DOEpatents

    Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon; Zettl, Alexander Karlwalte

    2004-12-28

    The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

  5. Nanotube junctions

    DOEpatents

    Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon Sheng; Zettl, Alexander Karlwalter

    2003-01-01

    The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

  6. Nuclear Proliferation and Grand Challenges

    SciTech Connect

    McCarthy, Kathy

    2009-01-01

    Nuclear engineer Dr. Kathy McCarthy leads systems analysis. She talks about proliferation and the grand challenges of nuclear R&D. For more information about INL energy research, visit http://www.facebook.com/idahonationallaboratory.

  7. Nuclear Proliferation and Grand Challenges

    ScienceCinema

    McCarthy, Kathy

    2013-05-28

    Nuclear engineer Dr. Kathy McCarthy leads systems analysis. She talks about proliferation and the grand challenges of nuclear R&D. For more information about INL energy research, visit http://www.facebook.com/idahonationallaboratory.

  8. Petit Grand Tour: Mission Concepts to Outer Planet Satellites Using Non-Conic Low Energy Trajectories

    NASA Technical Reports Server (NTRS)

    Lo, M. W.

    2001-01-01

    Our Solar System is connected by a vast Interplanetary Superhighway System (ISSys) providing low energy transport throughout. The Outer Planets with their satellites and rings are smaller replicas of the Solar System with their own ISSys, also providing low energy transport within their own satellite systems. This low energy transport system is generated by all of the Lagrange points of the planets and satellites within the Solar System. Figures show the tubular passage-ways near L1 of Jupiter and the ISSys of Jupiter schematically. These delicate and resilient dynamics may be used to great effect to produce free temporary captures of a spacecraft by a planet or satellite, low energy interplanetary and inter-satellite transfers, as well as precision impact orbits onto the surface of the satellites. Additional information is contained in the original extended abstract.

  9. Grand unified theories, topological defects and ultrahigh-energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Bhattacharjee, Pijushpani; Hill, Christopher T.; Schramm, David N.

    1991-01-01

    The ultrahigh-energy (UHE) proton and neutrino spectra resulting from collapse or annihilations of topological defects surviving from the GUT era are calculated. Irrespective of the specific process under consideration (which determines the overall normalization of the spectrum), the UHE proton spectrum always 'recovers' at approximately 1.8 x 10 exp 11 GeV after a partial Greisen-Zatsepin-Kuz'min 'cutoff' at approximately 5 x 10 exp 10 GeV and continues to a GUT-scale energy with a universal shape determined by the physics of hadronic jet fragmentation. Implications of our results are discussed.

  10. Grand unified theories, topological defects, and ultrahigh-energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Bhattacharjee, Pijushpani; Hill, Christopher T.; Schramm, David N.

    1992-01-01

    The ultrahigh-energy (UHE) proton and neutrino spectra resulting from collapse or annihilations of topological defects surviving from the GUT era are calculated. Irrespective of the specific process under consideration (which determines the overall normalization of the spectrum), the UHE proton spectrum always 'recovers' at approximately 1.8 x 10 exp 11 GeV after a partial Greisen-Zatsepin-Kuz'min 'cutoff' at approximately 5 x 10 exp 10 GeV and continues to a GUT-scale energy with a universal shape determined by the physics of hadronic jet fragmentation. Implications of the results are discussed.

  11. On a coherent investigation of the spectrum of cosmic rays in the energy range of 1014 - 1018 eV with KASCADE and KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Schoo, S.; Apel, W. D.; Arteaga-Velázquez, J. C.; Beck, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K. H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2015-08-01

    The KASCADE experiment and its extension KASCADE-Grande have significantly contributed to the current knowledge about the energy spectrum and composition of cosmic rays (CRs) with energies between the knee and the ankle. However, the data of both experiments were analysed separately, although Grande used the muon information of the KASCADE-array. A coherent analysis based on the combined data of both arrays is expected to profit from reconstructed shower observables with even higher accuracy compared to the stand-alone analyses. In addition, a significantly larger fiducial area is available. The aim of this analysis is to obtain the spectrum and composition of CRs in the range from 1014 to 1018 eV with a larger number of events and further reduced uncertainties using one unique reconstruction procedure for the entire energy range. This contribution will describe the motivation, the concept, and the current status of the combined analysis.

  12. Octagonal Defects at Carbon Nanotube Junctions

    PubMed Central

    Jaskólski, W.; Pelc, M.; Chico, Leonor; Ayuela, A.

    2013-01-01

    We investigate knee-shaped junctions of semiconductor zigzag carbon nanotubes. Two dissimilar octagons appear at such junctions; one of them can reconstruct into a pair of pentagons. The junction with two octagons presents two degenerate localized states at Fermi energy (EF). The reconstructed junction has only one state near EF, indicating that these localized states are related to the octagonal defects. The inclusion of Coulomb interaction splits the localized states in the junction with two octagons, yielding an antiferromagnetic system. PMID:24089604

  13. Next-Generation Photon Sources for Grand Challenges in Science and Energy

    SciTech Connect

    2009-05-01

    The next generation of sustainable energy technologies will revolve around transformational new materials and chemical processes that convert energy efficiently among photons, electrons, and chemical bonds. New materials that tap sunlight, store electricity, or make fuel from splitting water or recycling carbon dioxide will need to be much smarter and more functional than today's commodity-based energy materials. To control and catalyze chemical reactions or to convert a solar photon to an electron requires coordination of multiple steps, each carried out by customized materials and interfaces with designed nanoscale structures. Such advanced materials are not found in nature the way we find fossil fuels; they must be designed and fabricated to exacting standards, using principles revealed by basic science. Success in this endeavor requires probing, and ultimately controlling, the interactions among photons, electrons, and chemical bonds on their natural length and time scales. Control science - the application of knowledge at the frontier of science to control phenomena and create new functionality - realized through the next generation of ultraviolet and X-ray photon sources, has the potential to be transformational for the life sciences and information technology, as well as for sustainable energy. Current synchrotron-based light sources have revolutionized macromolecular crystallography. The insights thus obtained are largely in the domain of static structure. The opportunity is for next generation light sources to extend these insights to the control of dynamic phenomena through ultrafast pump-probe experiments, time-resolved coherent imaging, and high-resolution spectroscopic imaging. Similarly, control of spin and charge degrees of freedom in complex functional materials has the potential not only to reveal the fundamental mechanisms of high-temperature superconductivity, but also to lay the foundation for future generations of information science. This

  14. Ankle-like feature in the energy spectrum of light elements of cosmic rays observed with KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga-Velàzquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2013-04-01

    Recent results of the KASCADE-Grande experiment provided evidence for a mild knee-like structure in the all-particle spectrum of cosmic rays at E=1016.92±0.10eV, which was found to be due to a steepening in the flux of heavy primary particles. The spectrum of the combined components of light and intermediate masses was found to be compatible with a single power law in the energy range from 1016.3 to 1018eV. In this paper, we present an update of this analysis by using data with increased statistics, originating both from a larger data set including more recent measurements and by using a larger fiducial area. In addition, optimized selection criteria for enhancing light primaries are applied. We find a spectral feature for light elements, namely, a hardening at E=1017.08±0.08eV with a change of the power law index from -3.25±0.05 to -2.79±0.08.

  15. Josephson junction

    DOEpatents

    Wendt, Joel R.; Plut, Thomas A.; Martens, Jon S.

    1995-01-01

    A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material.

  16. Josephson junction

    DOEpatents

    Wendt, J.R.; Plut, T.A.; Martens, J.S.

    1995-05-02

    A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material. 10 figs.

  17. Bimetallic junctions

    NASA Technical Reports Server (NTRS)

    Arcella, F. G.; Lessmann, G. G.; Lindberg, R. A. (Inventor)

    1977-01-01

    The formation of voids through interdiffusion in bimetallic welded structures exposed to high operating temperatures is inhibited by utilizing an alloy of the parent materials in the junction of the parent materials or by preannealing the junction at an ultrahigh temperature. These methods are also used to reduce the concentration gradient of a hardening agent.

  18. Gap Junctions

    PubMed Central

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2013-01-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

  19. The solution structure of the four-way DNA junction at low-salt conditions: a fluorescence resonance energy transfer analysis.

    PubMed Central

    Clegg, R M; Murchie, A I; Lilley, D M

    1994-01-01

    The four-way DNA (Holliday) junction is an important postulated intermediate in the process of genetic recombination. Earlier studies have suggested that the junction exists in two alternative conformations, depending upon the salt concentration present. At high salt concentrations the junction folds into a stacked X structure, while at low salt concentrations the data indicate an extended unstacked conformation. The stereochemical conformation of the four-way DNA junction at low salt (low alkali ion concentration and no alkaline earth ions) was established by comparing the efficiency of fluorescence resonance energy transfer (FRET) between donor and acceptor molecules attached pairwise in three permutations to the 5' termini of the duplex arms. A new variation of FRET was implemented based upon a systematic variation of the fraction of donor labeled single strands. The FRET results indicate that the structure of the four-way DNA junction at low salt exists as an unstacked, extended, square arrangement of the four duplex arms. The donor titration measurements made in the presence of magnesium ions clearly show the folding of the junction into the X stacked structure. In addition, the FRET efficiency can be measured. The fluorescence anisotropy of the acceptor in the presence of Mg2+ during donor titrations was also measured; the FRET efficiency can be calculated from the anisotropy data and the results are consistent with the folded, stacked X structure. PMID:8130350

  20. Comparison of evapotranspiration estimates from the Surface Energy Balance Algorithm (SEBAL) and flux tower data, middle Rio Grande Basin

    NASA Astrophysics Data System (ADS)

    Xie, H.; Hendrickx, J.; Kurc, S.; Small, E.

    2002-12-01

    Evapotranspiration (ET) is one of the most important components of the water balance, but also one of the most difficult to measure. Field techniques such as soil water balances and Bowen ratio or eddy covariance techniques are local, ranging from point to field scale. SEBAL (Surface Energy Balance Algorithm for Land) is an image-processing model that calculates ET and other energy exchanges at the earth's surface. SEBAL uses satellite image data (TM/ETM+, MODIS, AVHRR, ASTER, and so on) measuring visible, near-infrared, and thermal infrared radiation. SEBAL algorithms predict a complete radiation and energy balance for the surface along with fluxes of sensible heat and aerodynamic surface roughness (Bastiaanssen et al, 1998; and Allen et al. 2001). We are constructing a GIS based database that includes spatially-distributed estimates of ET from remote-sensed data at a resolution of about 30 m. The SEBAL code will be optimized for this region via comparison of surface based observations of ET, reference ET (from windspeed, solar radiation, humidity, air temperature, and rainfall records), surface temperature, albedo, and so on. The observed data is collected at a series of tower in the middle Rio Grande Basin. The satellite image provides the instantaneous ET (ET_inst) only. Therefore, estimating 24 hour ET (ET_24) requires some assumptions. Two of these assumptions, which are (1) by assuming the instantaneous evaporative fraction (EF) is equal to the 24-hour averaged value, and (2) by assuming the instantaneous ETrF (same as `crop coefficient', and equal to instantaneous ET divided by instantaneous reference ET) is equal to the 24 hour averaged value, will be evaluated for the study area. Seasonal ET will be estimated by expanding the 24-hour ET proportionally to a reference ET that is derived from weather data. References: Bastiaanssen,W.G.M., M.Menenti, R.A. Feddes, and A.A.M. Holtslag, 1998, A remote sensing surface energy balance algorithm for land (SEBAL): 1

  1. Communication: energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach.

    PubMed

    Liu, Zhen-Fei; Neaton, Jeffrey B

    2014-10-01

    The electronic structure of organic-inorganic interfaces often features resonances originating from discrete molecular orbitals coupled to continuum lead states. An example is molecular junction, individual molecules bridging electrodes, where the shape and peak energy of such resonances dictate junction conductance, thermopower, I-V characteristics, and related transport properties. In molecular junctions where off-resonance coherent tunneling dominates transport, resonance peaks in the transmission function are often assumed to be Lorentzian functions with an energy-independent broadening parameter Γ. Here we define a new energy-dependent resonance broadening function, Γ(E), based on diagonalization of non-Hermitian matrices, which can describe resonances of a more complex, non-Lorentzian nature and can be decomposed into components associated with the left and right leads, respectively. We compute this quantity via an ab initio non-equilibrium Green's function (NEGF) approach based on density functional theory (DFT) for both symmetric and asymmetric molecular junctions, and show that our definition of Γ(E), when combined with Breit-Wigner formula, reproduces the transmission calculated from DFT-NEGF. Through a series of examples, we illustrate how this approach can shed new light on experiments and understanding of junction transport properties in terms of molecular orbitals. PMID:25296777

  2. Communication: Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach

    SciTech Connect

    Liu, Zhen-Fei; Neaton, Jeffrey B.

    2014-10-07

    The electronic structure of organic-inorganic interfaces often features resonances originating from discrete molecular orbitals coupled to continuum lead states. An example is molecular junction, individual molecules bridging electrodes, where the shape and peak energy of such resonances dictate junction conductance, thermopower, I-V characteristics, and related transport properties. In molecular junctions where off-resonance coherent tunneling dominates transport, resonance peaks in the transmission function are often assumed to be Lorentzian functions with an energy-independent broadening parameter Γ. Here we define a new energy-dependent resonance broadening function, Γ(E), based on diagonalization of non-Hermitian matrices, which can describe resonances of a more complex, non-Lorentzian nature and can be decomposed into components associated with the left and right leads, respectively. We compute this quantity via an ab initio non-equilibrium Green's function (NEGF) approach based on density functional theory (DFT) for both symmetric and asymmetric molecular junctions, and show that our definition of Γ(E), when combined with Breit-Wigner formula, reproduces the transmission calculated from DFT-NEGF. Through a series of examples, we illustrate how this approach can shed new light on experiments and understanding of junction transport properties in terms of molecular orbitals.

  3. Communication: Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach

    NASA Astrophysics Data System (ADS)

    Liu, Zhen-Fei; Neaton, Jeffrey B.

    2014-10-01

    The electronic structure of organic-inorganic interfaces often features resonances originating from discrete molecular orbitals coupled to continuum lead states. An example is molecular junction, individual molecules bridging electrodes, where the shape and peak energy of such resonances dictate junction conductance, thermopower, I-V characteristics, and related transport properties. In molecular junctions where off-resonance coherent tunneling dominates transport, resonance peaks in the transmission function are often assumed to be Lorentzian functions with an energy-independent broadening parameter Γ. Here we define a new energy-dependent resonance broadening function, Γ(E), based on diagonalization of non-Hermitian matrices, which can describe resonances of a more complex, non-Lorentzian nature and can be decomposed into components associated with the left and right leads, respectively. We compute this quantity via an ab initio non-equilibrium Green's function (NEGF) approach based on density functional theory (DFT) for both symmetric and asymmetric molecular junctions, and show that our definition of Γ(E), when combined with Breit-Wigner formula, reproduces the transmission calculated from DFT-NEGF. Through a series of examples, we illustrate how this approach can shed new light on experiments and understanding of junction transport properties in terms of molecular orbitals.

  4. Primary Energy Reconstruction from the Charged Particle Densities Recorded with the KASCADE-Grande Detector at 500 m Distance from Shower Core

    NASA Astrophysics Data System (ADS)

    Toma, G.; Apel, W. D.; Arteaga, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2010-11-01

    Previous EAS investigations have shown that for a fixed primary energy the charged particle density becomes independent of the primary mass at certain (fixed) distances from the shower core. This feature can be used as an estimator for the primary energy. We present results on the reconstruction of the primary energy spectrum of cosmic rays from the experimentally recorded S(500) observable (the density of charged particles at 500 m distance to the shower core) using the KASCADE-Grande detector array. The KASCADE-Grande experiment is hosted by the Karlsruhe Institute for Technology-Campus North, Karlsruhe, Germany, and operated by an international collaboration. The constant intensity cut (CIC) method is applied to evaluate the attenuation of the S(500) observable with the zenith angle and is corrected for. A calibration of S(500) values with the primary energy has been worked out by simulations and was applied to the data to obtain the primary energy spectrum (in the energy range log10[E0/GeV]∈[7.5,9]). The systematic uncertainties induced by different sources are considered. In addition, a correction based on a response matrix is applied to account for the effects of shower-to-shower fluctuations on the spectral index of the reconstructed energy spectrum.

  5. Basic aspects for improving the energy conversion efficiency of hetero-junction organic photovoltaic cells.

    PubMed

    Ryuzaki, Sou; Onoe, Jun

    2013-01-01

    Hetero-junction organic photovoltaic (OPV) cells consisting of donor (D) and acceptor (A) layers have been regarded as next-generation PV cells, because of their fascinating advantages, such as lightweight, low fabrication cost, resource free, and flexibility, when compared to those of conventional PV cells based on silicon and semiconductor compounds. However, the power conversion efficiency (η) of the OPV cells has been still around 8%, though more than 10% efficiency has been required for their practical use. To fully optimize these OPV cells, it is necessary that the low mobility of carriers/excitons in the OPV cells and the open circuit voltage (V OC), of which origin has not been understood well, should be improved. In this review, we address an improvement of the mobility of carriers/excitons by controlling the crystal structure of a donor layer and address how to increase the V OC for zinc octaethylporphyrin [Zn(OEP)]/C60 hetero-junction OPV cells [ITO/Zn(OEP)/C60/Al]. It was found that crystallization of Zn(OEP) films increases the number of inter-molecular charge transfer (IMCT) excitons and enlarges the mobility of carriers and IMCT excitons, thus significantly improving the external quantum efficiency (EQE) under illumination of the photoabsorption band due to the IMCT excitons. Conversely, charge accumulation of photo-generated carriers in the vicinity of the donor/acceptor (D/A) interface was found to play a key role in determining the V OC for the OPV cells. PMID:23853702

  6. Energy level alignment and quantum conductance of functionalized metal-molecule junctions: Density functional theory versus GW calculations

    SciTech Connect

    Jin, Chengjun; Markussen, Troels; Thygesen, Kristian S.; Strange, Mikkel; Solomon, Gemma C.

    2013-11-14

    We study the effect of functional groups (CH{sub 3}*4, OCH{sub 3}, CH{sub 3}, Cl, CN, F*4) on the electronic transport properties of 1,4-benzenediamine molecular junctions using the non-equilibrium Green function method. Exchange and correlation effects are included at various levels of theory, namely density functional theory (DFT), energy level-corrected DFT (DFT+Σ), Hartree-Fock and the many-body GW approximation. All methods reproduce the expected trends for the energy of the frontier orbitals according to the electron donating or withdrawing character of the substituent group. However, only the GW method predicts the correct ordering of the conductance amongst the molecules. The absolute GW (DFT) conductance is within a factor of two (three) of the experimental values. Correcting the DFT orbital energies by a simple physically motivated scissors operator, Σ, can bring the DFT conductances close to experiments, but does not improve on the relative ordering. We ascribe this to a too strong pinning of the molecular energy levels to the metal Fermi level by DFT which suppresses the variation in orbital energy with functional group.

  7. The importance of surface recombination and energy-bandgap narrowing in p-n-junction silicon solar cells

    NASA Technical Reports Server (NTRS)

    Fossum, J. G.; Lindholm, F. A.; Shibib, M. A.

    1979-01-01

    Experimental data demonstrating the sensitivity of open-circuit voltage to front-surface conditions are presented for a variety of p-n-junction silicon solar cells. Analytical models accounting for the data are defined and supported by additional experiments. The models and the data imply that a) surface recombination significantly limits the open-circuit voltage (and the short-circuit current) of typical silicon cells, and b) energy-bandgap narrowing is important in the manifestation of these limitations. The models suggest modifications in both the structural design and the fabrication processing of the cells that would result in substantial improvements in cell performance. The benefits of one such modification - the addition of a thin thermal silicon-dioxide layer on the front surface - are indicated experimentally.

  8. Self-assembled molecular p/n junctions for applications in dye-sensitized solar energy conversion.

    PubMed

    Farnum, Byron H; Wee, Kyung-Ryang; Meyer, Thomas J

    2016-09-01

    The achievement of long-lived photoinduced redox separation lifetimes has long been a central goal of molecular-based solar energy conversion strategies. The longer the redox-separation lifetime, the more time available for useful work to be extracted from the absorbed photon energy. Here we describe a novel strategy for dye-sensitized solar energy applications in which redox-separated lifetimes on the order of milliseconds to seconds can be achieved based on a simple toolkit of molecular components. Specifically, molecular chromophores (C), electron acceptors (A) and electron donors (D) were self-assembled on the surfaces of mesoporous, transparent conducting indium tin oxide nanoparticle (nanoITO) electrodes to prepare both photoanode (nanoITO|-A-C-D) and photocathode (nanoITO|-D-C-A) assemblies. Nanosecond transient-absorption and steady-state photolysis measurements show that the electrodes function microscopically as molecular analogues of semiconductor p/n junctions. These results point to a new chemical strategy for dye-sensitized solar energy conversion based on molecular excited states and electron acceptors/donors on the surfaces of transparent conducting oxide nanoparticle electrodes. PMID:27554411

  9. Squeezable electron tunneling junctions

    NASA Astrophysics Data System (ADS)

    Moreland, J.; Alexander, S.; Cox, M.; Sonnenfeld, R.; Hansma, P. K.

    1983-09-01

    We report a versatile new technique for constructing electron tunneling junctions with mechanically-adjusted artificial barriers. I-V curves are presented for tunneling between Ag electrodes with vacuum, gas, liquid or solid in the barrier. An energy gap is apparent in the measured I-V curve when tunneling occurs between superconducting Pb electrodes.

  10. Simulation of neutron displacement damage in bipolar junction transistors using high-energy heavy ion beams.

    SciTech Connect

    Doyle, Barney Lee; Buller, Daniel L.; Hjalmarson, Harold Paul; Fleming, Robert M; Bielejec, Edward Salvador; Vizkelethy, Gyorgy

    2006-12-01

    Electronic components such as bipolar junction transistors (BJTs) are damaged when they are exposed to radiation and, as a result, their performance can significantly degrade. In certain environments the radiation consists of short, high flux pulses of neutrons. Electronics components have traditionally been tested against short neutron pulses in pulsed nuclear reactors. These reactors are becoming less and less available; many of them were shut down permanently in the past few years. Therefore, new methods using radiation sources other than pulsed nuclear reactors needed to be developed. Neutrons affect semiconductors such as Si by causing atomic displacements of Si atoms. The recoiled Si atom creates a collision cascade which leads to displacements in Si. Since heavy ions create similar cascades in Si we can use them to create similar damage to what neutrons create. This LDRD successfully developed a new technique using easily available particle accelerators to provide an alternative to pulsed nuclear reactors to study the displacement damage and subsequent transient annealing that occurs in various transistor devices and potentially qualify them against radiation effects caused by pulsed neutrons.

  11. T-Junction Benchmark

    SciTech Connect

    2010-01-01

    Part 1: Two different volume renderings of fluid temperatures in a turbulent T-junction mixing problem at Reynolds number Re=40,000. Part 2: Volume rendering of fluid temperatures in a turbulent T-junction mixing problem at Reynolds number Re=40,000, simulated using Nek5000 at three different resolutions. Part 3: Temperature distribution for a turbulent T-junction mixing problem at Reynolds number Re=40,000, simulated using Nek5000 with 89056 spectral elements of order N=9 (65 million grid points). Credits: Science: Aleks Obabko and Paul Fisher, Argonne National Laboratory
 Visualization: Hank Childs, Lawrence Berkeley National Laboratory

 This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357

  12. OBSIDIAN CLIFF OVERLOOKS THE EAST SIDE OF THE GRAND LOOP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBSIDIAN CLIFF OVERLOOKS THE EAST SIDE OF THE GRAND LOOP ROAD. THE OBSIDIAN, A BLACK VOLCANIC GLASS, FORMED WHEN A LAVA FLOW CONTACTED GLACIAL ICE. IN THE CONSTRUCTION OF THE ROAD BY THE U.S. ARMY CORPS OF ENGINEERS, WORKERS CREATED THE LEDGE FOR THE ROAD BY BUILDING LARGE BONFIRES AGAINST THE CLIFF, THEN DASHING THE HEATED ROCK WITH COLD WATER, CAUSING IT TO SHATTER. - Grand Loop Road, Forming circuit between Mammoth Hot Springs, Norris Junction, Madison Junction, Old Faithful, Mammoth, Park County, WY

  13. Compact-device model development for the energy-delay analysis of magneto-electric magnetic tunnel junction structures

    NASA Astrophysics Data System (ADS)

    Sharma, N.; Bird, J. P.; Dowben, P. A.; Marshall, A.

    2016-06-01

    We discuss the application of a novel class of device, the magneto-electric magnetic tunnel junction (ME-MTJ) to realize a variety of computational functions, including majority logic and the XNOR/XOR gate. We also develop a compact model to describe the operation of these devices, which function by utilizing the phenomenon of ‘voltage-controlled magnetism’ to switch the operational state of MTJs. The model breaks down the switching process into three key stages of operation: electrical-to-magnetic conversion, magnetization transfer, and final-state readout. Estimates for the switching energy and delay of these devices, obtained from this compact model, reveal significant improvements in both of these parameters when compared to conventional MTJs switched by spin-transfer-torque. In fact, the capacity to use the ME-MTJ to implement complex logical operations within a single device allows its energy costs to even approach those of low-power CMOS. The added benefits of non-volatility and compact circuit footprint, combined with their potential for heterogeneous integration with CMOS, make the ME devices of considerable interest for post-CMOS technology.

  14. Josephson junction Q-spoiler

    DOEpatents

    Clarke, John; Hilbert, Claude; Hahn, Erwin L.; Sleator, Tycho

    1988-01-01

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  15. Josephson junction Q-spoiler

    DOEpatents

    Clarke, J.; Hilbert, C.; Hahn, E.L.; Sleator, T.

    1986-03-25

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  16. Results from KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Bertaina, M.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2012-11-01

    The KASCADE-Grande experiment, located at Karlsruhe Institute of Technology (Germany) is a multi-component extensive air-shower experiment devoted to the study of cosmic rays and their interactions at primary energies 1014-1018 eV. Main goals of the experiment are the measurement of the all-particle energy spectrum and mass composition in the 1016-1018 eV range by sampling charged (Nch) and muon (Nμ) components of the air shower. The method to derive the energy spectrum and its uncertainties, as well as the implications of the obtained result, is discussed. An overview of the analyses performed by KASCADE-Grande to derive the mass composition of the measured high-energy comic rays is presented as well.

  17. Rationally designed graphene-nanotube 3D architectures with a seamless nodal junction for efficient energy conversion and storage

    PubMed Central

    Xue, Yuhua; Ding, Yong; Niu, Jianbing; Xia, Zhenhai; Roy, Ajit; Chen, Hao; Qu, Jia; Wang, Zhong Lin; Dai, Liming

    2015-01-01

    One-dimensional (1D) carbon nanotubes (CNTs) and 2D single-atomic layer graphene have superior thermal, electrical, and mechanical properties. However, these nanomaterials exhibit poor out-of-plane properties due to the weak van der Waals interaction in the transverse direction between graphitic layers. Recent theoretical studies indicate that rationally designed 3D architectures could have desirable out-of-plane properties while maintaining in-plane properties by growing CNTs and graphene into 3D architectures with a seamless nodal junction. However, the experimental realization of seamlessly-bonded architectures remains a challenge. We developed a strategy of creating 3D graphene-CNT hollow fibers with radially aligned CNTs (RACNTs) seamlessly sheathed by a cylindrical graphene layer through a one-step chemical vapor deposition using an anodized aluminum wire template. By controlling the aluminum wire diameter and anodization time, the length of the RACNTs and diameter of the graphene hollow fiber can be tuned, enabling efficient energy conversion and storage. These fibers, with a controllable surface area, meso-/micropores, and superior electrical properties, are excellent electrode materials for all-solid-state wire-shaped supercapacitors with poly(vinyl alcohol)/H2SO4 as the electrolyte and binder, exhibiting a surface-specific capacitance of 89.4 mF/cm2 and length-specific capacitance up to 23.9 mF/cm, — one to four times the corresponding record-high capacities reported for other fiber-like supercapacitors. Dye-sensitized solar cells, fabricated using the fiber as a counter electrode, showed a power conversion efficiency of 6.8% and outperformed their counterparts with an expensive Pt wire counter electrode by a factor of 2.5. These novel fiber-shaped graphene-RACNT energy conversion and storage devices are so flexible they can be woven into fabrics as power sources. PMID:26601246

  18. Rationally designed graphene-nanotube 3D architectures with a seamless nodal junction for efficient energy conversion and storage.

    PubMed

    Xue, Yuhua; Ding, Yong; Niu, Jianbing; Xia, Zhenhai; Roy, Ajit; Chen, Hao; Qu, Jia; Wang, Zhong Lin; Dai, Liming

    2015-09-01

    One-dimensional (1D) carbon nanotubes (CNTs) and 2D single-atomic layer graphene have superior thermal, electrical, and mechanical properties. However, these nanomaterials exhibit poor out-of-plane properties due to the weak van der Waals interaction in the transverse direction between graphitic layers. Recent theoretical studies indicate that rationally designed 3D architectures could have desirable out-of-plane properties while maintaining in-plane properties by growing CNTs and graphene into 3D architectures with a seamless nodal junction. However, the experimental realization of seamlessly-bonded architectures remains a challenge. We developed a strategy of creating 3D graphene-CNT hollow fibers with radially aligned CNTs (RACNTs) seamlessly sheathed by a cylindrical graphene layer through a one-step chemical vapor deposition using an anodized aluminum wire template. By controlling the aluminum wire diameter and anodization time, the length of the RACNTs and diameter of the graphene hollow fiber can be tuned, enabling efficient energy conversion and storage. These fibers, with a controllable surface area, meso-/micropores, and superior electrical properties, are excellent electrode materials for all-solid-state wire-shaped supercapacitors with poly(vinyl alcohol)/H2SO4 as the electrolyte and binder, exhibiting a surface-specific capacitance of 89.4 mF/cm(2) and length-specific capacitance up to 23.9 mF/cm, - one to four times the corresponding record-high capacities reported for other fiber-like supercapacitors. Dye-sensitized solar cells, fabricated using the fiber as a counter electrode, showed a power conversion efficiency of 6.8% and outperformed their counterparts with an expensive Pt wire counter electrode by a factor of 2.5. These novel fiber-shaped graphene-RACNT energy conversion and storage devices are so flexible they can be woven into fabrics as power sources. PMID:26601246

  19. Tunneling in Al/Al2 O3 /Al junctions and its direct link with energy gap and tunneling time across the barrier

    NASA Astrophysics Data System (ADS)

    Patino, Edgar; Kelkar, Neelima

    Quantum tunneling has been widely used in order to investigate the density of states of the materials across the barrier and magnetoresistance in magnetic tunnel junctions (MTJs). In spite of the possible applications there is no clear understanding of the barrier parameters as a function of temperature. Measurements of current-voltage (I-V) characteristics of a high quality Al/Al2O3/Al junction at temperatures ranging from 3.5 K to 300 K have been used to extract the barrier properties. Fitting results using Simmons' model led to a constant value of barrier width s ~20.8 Å and a continuous increase in the barrier height with decreasing temperature. The latter is used to determine the energy band gap temperature dependence and average phonon frequency ω = 2.05 × 1013 sec-1 in Al2O3. Finally from the experimentally extracted barrier height and width parameters we calculate the tunneling time for a solid state tunnel junction. The order of magnitude of this time corresponds to the one obtained in sophisticated experiments.The barrier parameters are used to extract the temperature dependent dwell times in tunneling (τD = 3.6 × 10-16 sec at mid-barrier energies) and locate resonances above the barrier.

  20. Comparative life-cycle energy payback analysis of multi-junction a-SiGe and nanocrystalline/a-Si modules

    SciTech Connect

    Fthenakis, V.; Kim, H.

    2010-07-15

    Despite the publicity of nanotechnologies in high tech industries including the photovoltaic sector, their life-cycle energy use and related environmental impacts are understood only to a limited degree as their production is mostly immature. We investigated the life-cycle energy implications of amorphous silicon (a-Si) PV designs using a nanocrystalline silicon (nc-Si) bottom layer in the context of a comparative, prospective life-cycle analysis framework. Three R and D options using nc-Si bottom layer were evaluated and compared to the current triple-junction a-Si design, i.e., a-Si/a-SiGe/a-SiGe. The life-cycle energy demand to deposit nc-Si was estimated from parametric analyses of film thickness, deposition rate, precursor gas usage, and power for generating gas plasma. We found that extended deposition time and increased gas usages associated to the relatively high thickness of nc-Si lead to a larger primary energy demand for the nc-Si bottom layer designs, than the current triple-junction a-Si. Assuming an 8% conversion efficiency, the energy payback time of those R and D designs will be 0.7-0.9 years, close to that of currently commercial triple-junction a-Si design, 0.8 years. Future scenario analyses show that if nc-Si film is deposited at a higher rate (i.e., 2-3 nm/s), and at the same time the conversion efficiency reaches 10%, the energy-payback time could drop by 30%.

  1. Gaugino mass nonuniversality in an SO(10) supersymmetric grand unified theory: Low-energy spectra and collider signals

    SciTech Connect

    Bhattacharya, Subhaditya; Chakrabortty, Joydeep

    2010-01-01

    We derive the nonuniversal gaugino mass ratios in a supergravity (SUGRA) framework where the Higgs superfields belong to the nonsinglet representations 54 and 770 in an SO(10) grand unified theory (GUT). We evaluate the ratios for the phenomenologically viable intermediate breaking chain SU(4){sub C}xSU(2){sub L}xSU(2){sub R}(G{sub 422}). After a full calculation of the gaugino mass ratios, noting some errors in the earlier calculation for 54, we obtain, using the renormalization group equations, interesting low scale phenomenology of such breaking patterns. Here, we assume the breaking of the SO(10) GUT group to the intermediate gauge group and that to the standard model take place at the GUT scale itself. We also study the collider signatures in multilepton channels at the Large Hadron Collider (LHC) for some selected benchmark points allowed by the cold dark-matter relic density constraint provided by the WMAP data and compare these results with the minimal supergravity (mSUGRA) framework with similar gluino masses indicating their distinguishability in this regard.

  2. Thermoelectricity in molecular junctions.

    PubMed

    Reddy, Pramod; Jang, Sung-Yeon; Segalman, Rachel A; Majumdar, Arun

    2007-03-16

    By trapping molecules between two gold electrodes with a temperature difference across them, the junction Seebeck coefficients of 1,4-benzenedithiol (BDT), 4,4'-dibenzenedithiol, and 4,4''-tribenzenedithiol in contact with gold were measured at room temperature to be +8.7 +/- 2.1 microvolts per kelvin (muV/K), +12.9 +/- 2.2 muV/K, and +14.2 +/- 3.2 muV/K, respectively (where the error is the full width half maximum of the statistical distributions). The positive sign unambiguously indicates p-type (hole) conduction in these heterojunctions, whereas the Au Fermi level position for Au-BDT-Au junctions was identified to be 1.2 eV above the highest occupied molecular orbital level of BDT. The ability to study thermoelectricity in molecular junctions provides the opportunity to address these fundamental unanswered questions about their electronic structure and to begin exploring molecular thermoelectric energy conversion. PMID:17303718

  3. Peculiarities of the capacitance-voltage characteristic of a photoelectric solar energy convertor based on a silicon p- n junction with a porous silicon antireflection coating

    NASA Astrophysics Data System (ADS)

    Tregulov, V. V.

    2014-09-01

    Experimental results on the high-frequency capacitance-voltage characteristic of a photoelectric solar energy converter based on the n +- p junction with a thin porous silicon film on the frontal surface are considered. It is shown that the capacitance-voltage characteristic is determined by the surface metal-insulator-semiconductor (MIS) structure formed as a result of growing of a porous silicon layer by electrochemical anode etching. The effective thickness of the insulator layer of the MIS structure, the impurity concentration in its semiconductor region, and the density of surface states are determined.

  4. Nanoscience Research for Energy Needs. Report of the National Nanotechnology Initiative Grand Challenge Workshop, March 16-18, 2004

    SciTech Connect

    Alivisatos, P.; Cummings, P.; De Yoreo, J.; Fichthorn, K.; Gates, B.; Hwang, R.; Lowndes, D.; Majumdar, A.; Makowski, L.; Michalske, T.; Misewich, J.; Murray, C.; Sibener, S.; Teague, C.; Williams, E.

    2004-03-18

    This document is the report of a workshop held under NSET auspices in March 2004 aimed at identifying and articulating the relationship of nanoscale science and technology to the Nation's energy future.

  5. Magnetic-tunnel-junction based low-energy nonvolatile flip-flop using an area-efficient self-terminated write driver

    NASA Astrophysics Data System (ADS)

    Suzuki, Daisuke; Hanyu, Takahiro

    2015-05-01

    A nonvolatile flip-flop (NV-FF) that makes it possible to minimize the backup energy before power-off is proposed. The use of a self-terminated write driver with continuous voltage monitoring enables automatic write-current termination to be performed immediately after the desired data are written, resulting in great energy saving. Moreover, by utilizing single-ended circuitry together with a symmetrical write current path structure, both a nonvolatile storage function and self-termination are compactly embedded in the NV-FF without performance degradation. As a result, the backup energy is reduced by 83% compared to that of the average of conventional magnetic tunnel junction (MTJ)-based NV-FFs with no self-termination. It is also demonstrated that total transistor counts are reduced by 43% compared to a conventional MTJ-based NV-FF with self-termination.

  6. Anomalous tunneling in carbon/alkane/TiO(2)/gold molecular electronic junctions: energy level alignment at the metal/semiconductor interface.

    PubMed

    Yan, Haijun; McCreery, Richard L

    2009-02-01

    Carbon/TiO(2)/gold electronic junctions show slightly asymmetric electronic behavior, with higher current observed in current density (J)/voltage (V) curves when carbon is biased negative with respect to the gold top contact. When a approximately 1-nm-thick alkane film is deposited between the carbon and TiO(2), resulting in a carbon/alkane/TiO(2)/gold junction, the current increases significantly for negative bias and decreases for positive bias, thus creating a much less symmetric J/V response. Similar results were obtained when SiO(2) was substituted for the alkane layer, but Al(2)O(3) did not produce the effect. The observation that, by the addition of an insulating material between carbon and TiO(2), the junction becomes more conductive is unexpected and counterintuitive. Kelvin probe measurements revealed that while the apparent work function of the pyrolyzed photoresist film electrode is modulated by surface dipoles of different surface-bound molecular layers, the anomalous effect is independent of the direction of the surface dipole. We propose that by using a nanometer-thick film with a low dielectric constant as an insertion layer, most of the applied potential is dropped across this thin film, thus permitting alignment between the carbon Fermi level and the TiO(2) conduction band. Provided that the alkane layer is sufficiently thin, electrons can directly tunnel from carbon to the TiO(2) conduction band. Therefore, the electron injection barrier at the carbon/TiO(2) interface is effectively reduced by this energy-level alignment, resulting in an increased current when carbon is biased negative. The modulation of injection barriers by a low-kappa molecular layer should be generally applicable to a variety of materials used in micro- and nanoelectronic fabrication. PMID:20353235

  7. Star junctions and watermelons of pure or random quantum Ising chains: finite-size properties of the energy gap at criticality

    NASA Astrophysics Data System (ADS)

    Monthus, Cécile

    2015-06-01

    We consider M  ⩾  2 pure or random quantum Ising chains of N spins when they are coupled via a single star junction at their origins or when they are coupled via two star junctions at the their two ends leading to the watermelon geometry. The energy gap is studied via a sequential self-dual real-space renormalization procedure that can be explicitly solved in terms of Kesten variables containing the initial couplings and and the initial transverse fields. In the pure case at criticality, the gap is found to decay as a power-law {ΔM}\\propto {{N}-z(M)} with the dynamical exponent z(M)=\\frac{M}{2} for the single star junction (the case M   =   2 corresponds to z   =   1 for a single chain with free boundary conditions) and z(M)   =   M  -  1 for the watermelon (the case M   =   2 corresponds to z   =   1 for a single chain with periodic boundary conditions). In the random case at criticality, the gap follows the Infinite Disorder Fixed Point scaling \\ln {ΔM}=-{{N}\\psi}g with the same activated exponent \\psi =\\frac{1}{2} as the single chain corresponding to M   =   2, and where g is an O(1) random positive variable, whose distribution depends upon the number M of chains and upon the geometry (star or watermelon).

  8. A power balance model for converging and diverging flow junctions

    SciTech Connect

    Guffey, S.E. ); Fraser, D.A. )

    1989-01-01

    The authors propose that pressures across a junction of flows are best described by potential, kinetic, and dissipated (lost) power. It is demonstrated that differences in Bernoulli constants up- and downstream of junctions are not proportional to energy losses even in the trivial case of zero junction losses.

  9. Solar energy conversion through the interaction of plasmons with tunnel junctions. Part A: Solar cell analysis. Part B: Photoconductor analysis

    NASA Technical Reports Server (NTRS)

    Welsh, P. E.; Schwartz, R. J.

    1988-01-01

    A solar cell utilizing guided optical waves and tunnel junctions was analyzed to determine its feasibility. From this analysis, it appears that the limits imposed upon conventional multiple cell systems also limit this solar cell. Due to this limitation, it appears that the relative simplicity of the conventional multiple cell systems over the solar cell make the conventional multiple cell systems the more promising candidate for improvement. It was discovered that some superlattice structures studied could be incorporated into an infrared photodetector. This photoconductor appears to be promising as a high speed, sensitive (high D sup star sub BLIP) detector in the wavelength range from 15 to over 100 micrometers.

  10. The KASCADE-Grande Experiment

    NASA Astrophysics Data System (ADS)

    de Souza, V.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; van Buren, J.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2009-04-01

    KASCADE-Grande is a multi-component detector located at Karlsruhe, Germany. It was optimized to measure cosmic ray air showers with energies between 5×1016 and 1018 eV. Its capabilities are based on the use of several techniques to measure the electromagnetic and muon components of the shower in an independent way which allows a direct comparison to hadronic interaction models and a good estimation of the primary cosmic ray composition. In this paper, we present the status of the experiment, an update of the data analysis and the latest results.

  11. 6 x 6-cm fully depleted pn-junction CCD for high-resolution spectroscopy in the 0.1- to 15-keV photon energy range

    NASA Astrophysics Data System (ADS)

    von Zanthier, Christoph; Holl, Peter; Kemmer, Josef; Lechner, Peter; Maier, B.; Soltau, Heike; Stoetter, R.; Braeuninger, Heinrich W.; Dennerl, Konrad; Haberl, Frank; Hartmann, R.; Hartner, Gisela D.; Hippmann, H.; Kastelic, E.; Kink, W.; Krause, N.; Meidinger, Norbert; Metzner, G.; Pfeffermann, Elmar; Popp, M.; Reppin, Claus; Stoetter, Diana; Strueder, Lothar; Truemper, Joachim; Weber, U.; Carathanassis, D.; Engelhard, S.; Gebhart, Th.; Hauff, D.; Lutz, G.; Richter, R. H.; Seitz, H.; Solc, P.; Bihler, Edgar; Boettcher, H.; Kendziorra, Eckhard; Kraemer, J.; Pflueger, Bernhard; Staubert, Ruediger

    1998-04-01

    The concept and performance of the fully depleted pn- junction CCD system, developed for the European XMM- and the German ABRIXAS-satellite missions for soft x-ray imaging and spectroscopy in the 0.1 keV to 15 keV photon range, is presented. The 58 mm X 60 mm large pn-CCD array uses pn- junctions for registers and for the backside instead of MOS registers. This concept naturally allows to fully deplete the detector volume to make it an efficient detector to photons with energies up to 15 keV. For high detection efficiency in the soft x-ray region down to 100 eV, an ultrathin pn-CCD backside deadlayer has been realized. Each pn-CCD-channel is equipped with an on-chip JFET amplifier which, in combination with the CAMEX-amplifier and multiplexing chip, facilitates parallel readout with a pixel read rate of 3 MHz and an electronic noise floor of ENC < e-. With the complete parallel readout, very fast pn-CCD readout modi can be implemented in the system which allow for high resolution photon spectroscopy of even the brightest x-ray sources in the sky.

  12. Solitons in Josephson junctions

    NASA Astrophysics Data System (ADS)

    Ustinov, A. V.

    1998-11-01

    Magnetic flux quanta in Josephson junctions, often called fluxons, in many cases behave as solitons. A review of recent experiments and modelling of fluxon dynamics in Josephson circuits is presented. Classic quasi-one-dimensional junctions, stacked junctions (Josephson superlattices), and discrete Josephson transmission lines (JTLs) are discussed. Applications of fluxon devices as high-frequency oscillators and digital circuits are also addressed.

  13. Transverse section through the Grand Lodge and Grand Chapter rooms ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Transverse section through the Grand Lodge and Grand Chapter rooms of James H. Windrim and George Summers’s neoclassical competition design for the New Masonic Temple, Philadelphia, 1867 - Masonic Temple, 1 North Broad Street, Philadelphia, Philadelphia County, PA

  14. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device

    SciTech Connect

    Abboud, A.; Send, S.; Pashniak, N.; Pietsch, U.; Kirchlechner, C.; Micha, J. S.; Ulrich, O.; Keckes, J.

    2014-11-15

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots’ energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the “3D detector method” as a promising tool for material investigations to separate bending and strain for technical materials.

  15. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device.

    PubMed

    Abboud, A; Kirchlechner, C; Send, S; Micha, J S; Ulrich, O; Pashniak, N; Strüder, L; Keckes, J; Pietsch, U

    2014-11-01

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots' energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the "3D detector method" as a promising tool for material investigations to separate bending and strain for technical materials. PMID:25430118

  16. A GRAND affair

    NASA Astrophysics Data System (ADS)

    tima2014; tomandersen; mugundhan; toadgreen

    2015-10-01

    In reply to the physicsworld.com news story “GRAND plans for new neutrino observatory”, which called for a new detector made up of hundreds of thousands of antennas spread over an area slightly smaller than the UK (18 August, http://owl.ly/R5N6u).

  17. High-energy x-ray scattering quantification of in-situ-loading-related strain gradients spanning the dentinoenamel junction (DEJ) in bovine tooth specimens.

    SciTech Connect

    Almer, J. D.; Stock, S. R.; Northeastern Univ.

    2010-08-26

    High energy X-ray scattering (80.7keV photons) at station 1-ID of the Advanced Photon Source quantified internal strains as a function of applied stress in mature bovine tooth. These strains were mapped from dentin through the dentinoenamel junction (DEJ) into enamel as a function of applied compressive stress in two small parallelepiped specimens. One specimen was loaded perpendicular to the DEJ and the second parallel to the DEJ. Internal strains in enamel and dentin increased and, as expected from the relative values of the Young's modulus, the observed strains were much higher in dentin than in enamel. Large strain gradients were observed across the DEJ, and the data suggest that the mantle dentin-DEJ-aprismatic enamel structure may shield the near-surface volume of the enamel from large strains. In the enamel, drops in internal strain for applied stresses above 40MPa also suggest that this structure had cracked.

  18. State transition analysis of spontaneous branch migration of the Holliday junction by photon-based single-molecule fluorescence resonance energy transfer.

    PubMed

    Okamoto, Kenji; Sako, Yasushi

    2016-02-01

    Branch migration of Holliday junction (HJ) DNA in solution is a spontaneous conformational change between multiple discrete states. We applied single-molecule fluorescence resonance energy transfer (smFRET) measurement to three-state branch migration. The photon-based variational Bayes-hidden Markov model (VB-HMM) method was applied to fluorescence signals to reproduce the state transition trajectories and evaluate the transition parameters, such as transition rate. The upper limit of time resolution suggested in simulation was nearly achieved for the state dynamics with relatively small FRET changes, and the distinctions in the populations of different states were successfully retrieved. We also discuss the suitability of the HJ as a standard sample for smFRET dynamics measurements and data analysis. PMID:26687325

  19. Disordered graphene Josephson junctions

    NASA Astrophysics Data System (ADS)

    Muñoz, W. A.; Covaci, L.; Peeters, F. M.

    2015-02-01

    A tight-binding approach based on the Chebyshev-Bogoliubov-de Gennes method is used to describe disordered single-layer graphene Josephson junctions. Scattering by vacancies, ripples, or charged impurities is included. We compute the Josephson current and investigate the nature of multiple Andreev reflections, which induce bound states appearing as peaks in the density of states for energies below the superconducting gap. In the presence of single-atom vacancies, we observe a strong suppression of the supercurrent, which is a consequence of strong intervalley scattering. Although lattice deformations should not induce intervalley scattering, we find that the supercurrent is still suppressed, which is due to the presence of pseudomagnetic barriers. For charged impurities, we consider two cases depending on whether the average doping is zero, i.e., existence of electron-hole puddles, or finite. In both cases, short-range impurities strongly affect the supercurrent, similar to the vacancies scenario.

  20. Grand and Semigrand Canonical Basin-Hopping

    PubMed Central

    2015-01-01

    We introduce grand and semigrand canonical global optimization approaches using basin-hopping with an acceptance criterion based on the local contribution of each potential energy minimum to the (semi)grand potential. The method is tested using local harmonic vibrational densities of states for atomic clusters as a function of temperature and chemical potential. The predicted global minima switch from dissociated states to clusters for larger values of the chemical potential and lower temperatures, in agreement with the predictions of a model fitted to heat capacity data for selected clusters. Semigrand canonical optimization allows us to identify particularly stable compositions in multicomponent nanoalloys as a function of increasing temperature, whereas the grand canonical potential can produce a useful survey of favorable structures as a byproduct of the global optimization search. PMID:26669731

  1. Electrostatic control of thermoelectricity in molecular junctions.

    PubMed

    Kim, Youngsang; Jeong, Wonho; Kim, Kyeongtae; Lee, Woochul; Reddy, Pramod

    2014-11-01

    Molecular junctions hold significant promise for efficient and high-power-output thermoelectric energy conversion. Recent experiments have probed the thermoelectric properties of molecular junctions. However, electrostatic control of thermoelectric properties via a gate electrode has not been possible due to technical challenges in creating temperature differentials in three-terminal devices. Here, we show that extremely large temperature gradients (exceeding 1 × 10(9) K m(-1)) can be established in nanoscale gaps bridged by molecules, while simultaneously controlling their electronic structure via a gate electrode. Using this platform, we study prototypical Au-biphenyl-4,4'-dithiol-Au and Au-fullerene-Au junctions to demonstrate that the Seebeck coefficient and the electrical conductance of molecular junctions can be simultaneously increased by electrostatic control. Moreover, from our studies of fullerene junctions, we show that thermoelectric properties can be significantly enhanced when the dominant transport orbital is located close to the chemical potential (Fermi level) of the electrodes. These results illustrate the intimate relationship between the thermoelectric properties and charge transmission characteristics of molecular junctions and should enable systematic exploration of the recent computational predictions that promise extremely efficient thermoelectric energy conversion in molecular junctions. PMID:25282046

  2. Temperature dependence of thermopower in molecular junctions

    NASA Astrophysics Data System (ADS)

    Kim, Youngsang; Lenert, Andrej; Meyhofer, Edgar; Reddy, Pramod

    2016-07-01

    The thermoelectric properties of molecular junctions are of considerable interest due to their promise for efficient energy conversion. While the dependence of thermoelectric properties of junctions on molecular structure has been recently studied, their temperature dependence remains unexplored. Using a custom built variable temperature scanning tunneling microscope, we measured the thermopower and electrical conductance of individual benzenedithiol junctions over a range of temperatures (100 K-300 K). We find that while the electrical conductance is independent of temperature, the thermopower increases linearly with temperature, confirming the predictions of the Landauer theory.

  3. Spectroscopy Measurements of Magnesium Diboride Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Mlack, J. T.; Lambert, J. G.; Carabello, S. A.; Thrailkill, Z. E.; Galwaduge, P. T.; Ramos, R. C.

    2010-03-01

    MgB2 has the highest Tc of the conventional superconductors at 39K and exhibits two superconducting energy bands. This material is also inexpensive to produce and has been utilized in new designs for MRI, RF cavities, and Josephson junctions. We report results of recent spectroscopy and transport measurements of Josephson junctions made of MgB2 obtained from our collaborators. We investigate its transport characteristics at sub-kelvin temperatures as well as its responses to resonant microwave activation.

  4. 77 FR 31344 - Grand Valley Irrigation Company; Notice of Application Accepted for Filing and Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-25

    ... Energy Regulatory Commission Grand Valley Irrigation Company; Notice of Application Accepted for Filing.... Date filed: March 26, 2012. d. Applicant: Grand Valley Irrigation District. e. Name of Project... on the Grand Valley Irrigation Canal where the Mainline canal splits into the Highline and the...

  5. 76 FR 9341 - Grand River Dam Authority; Notice of Application Accepted for Filing, Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... Federal Energy Regulatory Commission Grand River Dam Authority; Notice of Application Accepted for Filing..., 2011. d. Applicant: Grand River Dam Authority (GRDA). e. Name of Project: Pensacola Project. f... Counsel, Grand River Dam Authority, P.O. Box 409, Vinita, OK 74301; 918-256- 5545; tjahnke@gdra.com ....

  6. 77 FR 58820 - Grand River Dam Authority; Notice of Application Accepted for Filing, Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-24

    ... Energy Regulatory Commission Grand River Dam Authority; Notice of Application Accepted for Filing.... Applicant: Grand River Dam Authority. e. Name of Project: Pensacola Hydroelectric Project. f. Location: The.... Jahnke, Assistant General Counsel, Grand River Dam Authority, P.O. Box 409, Vinita, Oklahoma 74301,...

  7. Triboelectric-Potential-Regulated Charge Transport Through p-n Junctions for Area-Scalable Conversion of Mechanical Energy.

    PubMed

    Meng, Xian Song; Wang, Zhong Lin; Zhu, Guang

    2016-01-27

    Regulation of charge-transport direction is realized through the coupling of triboelectrification, electrostatic induction, and semiconducting properties for area-scalable conversion of mechanical energy. The output current from each unit triboelectric generator can always constructively add up due to the unidirectional flow of electrons. This work proposes a practical and general route to area-scalable applications of the triboelectric generator and other energy-harvesting techniques. PMID:26611707

  8. Superconducting switch made of graphene nanoribbon junctions

    NASA Astrophysics Data System (ADS)

    Liang, Qifeng; Dong, Jinming

    2008-09-01

    The transmission of superconductor-graphene nanoribbon-superconductor junctions (SGS) has been studied by the non-equilibrium Green's function method. It is found that the on-site potential U in the center zigzag graphene nanoribbon (ZGNR) of the SGS junction plays an important role in the magnitude of the supercurrent Ic. As the effective Fermi energy μeff (μeff = μF-U) goes from negative to positive, the SGS junction would suddenly transform from an 'OFF' state to an 'ON' state. And, as μeff increases further, the Ic will continue to increase. This switching behavior of the SGS junction shares the same origin with the zigzag GNR valley-isospin valve (Rycerz et al 2007 Nat. Phys. 3 172). Besides the valley-isospin, the density of states will also have an effect on the suppression of Ic.

  9. Energy level alignment in polymer organic solar cells at donor-acceptor planar junction formed by electrospray vacuum deposition

    SciTech Connect

    Kim, Ji-Hoon; Hong, Jong-Am; Kwon, Dae-Gyeon; Seo, Jaewon; Park, Yongsup

    2014-04-21

    Using ultraviolet photoelectron spectroscopy (UPS), we have measured the energy level offset at the planar interface between poly(3-hexylthiophene) (P3HT) and C{sub 61}-butyric acid methylester (PCBM). Gradual deposition of PCBM onto spin-coated P3HT in high vacuum was made possible by using electrospray vacuum deposition (EVD). The UPS measurement of EVD-prepared planar interface resulted in the energy level offset of 0.91 eV between P3HT HOMO and PCBM LUMO, which is considered as the upper limit of V{sub oc} of the organic photovoltaic cells.

  10. Perfect spin filtering controlled by an electric field in a bilayer graphene junction: Effect of layer-dependent exchange energy

    NASA Astrophysics Data System (ADS)

    Kitakorn, Jatiyanon; I-Ming, Tang; Bumned, Soodchomshom

    2016-07-01

    Magneto transport of carriers with a spin-dependent gap in a ferromagnetic-gated bilayer of graphene is investigated. We focus on the effect of an energy gap induced by the mismatch of the exchange fields in the top and bottom layers of an AB-stacked graphene bilayer. The interplay of the electric and exchange fields causes the electron to acquire a spin-dependent energy gap. We find that, only in the case of the anti-parallel configuration, the effect of a magnetic-induced gap will give rise to perfect spin filtering controlled by the electric field. The resolution of the spin filter may be enhanced by varying the bias voltage. Perfect switching of the spin polarization from + 100% to ‑100% by reversing the direction of electric field is predicted. Giant magnetoresistance is predicted to be easily realized when the applied electric field is smaller than the magnetic energy gap. It should be pointed out that the perfect spin filter is due to the layer-dependent exchange energy. This work points to the potential application of bilayer graphene in spintronics. Project supported by the Kasetsart University Research and Development Institute (KURDI) and Thailand Research Fund (TRF) (Grant No. TRG5780274).

  11. Doped semiconductor nanocrystal junctions

    NASA Astrophysics Data System (ADS)

    Borowik, Ł.; Nguyen-Tran, T.; Roca i Cabarrocas, P.; Mélin, T.

    2013-11-01

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (ND≈1020-1021cm-3) silicon nanocrystals (NCs) in the 2-50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as ND-1/3, and depleted charge linearly increasing with the NC diameter and varying as ND1/3. We thus establish a "nanocrystal counterpart" of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

  12. Quantum junction solar cells.

    PubMed

    Tang, Jiang; Liu, Huan; Zhitomirsky, David; Hoogland, Sjoerd; Wang, Xihua; Furukawa, Melissa; Levina, Larissa; Sargent, Edward H

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO(2)); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. PMID:22881834

  13. Introduction to Grand Unified Theories

    NASA Astrophysics Data System (ADS)

    Masiero, Antonio

    The following sections are included: * THE STANDARD MODEL: A CRITICAL APPRAISAL * The "Low Energy" Limit of Renormalizable Gauge Theories * The Standard Model: its purity * The Standard Model: its impurity * Vices and Virtues of the Standard Model * INTRODUCTION TO GRAND UNIFIED THEORIES * When "Strong" and "Weak" Merge Together * The "Big Desert" Picture of the World * A Persistent Cloud: the hierarchy problem * PHENOMENOLOGICAL CONSEQUENCES OF GUTs * What is New in GUTs * General Features of the B and L Violating Processes * A FIRST GLIMPSE AT THE SU(5) MODEL * Why SU(5)? * The Higgs Sector and the Hierarchy Nightmare * LOW ENERGY PHENOMENOLOGICAL CONSEQUENCES OF SU(5) * The Successful sin2θW Prediction of SU(5) * Fermion Masses in SU(5) * Mixing Angles and Phases * Proton Lifetime: A Death Blow to the SU(5) Model? * B-L and Neutrino Masses in SU(5) * SU(5): A Final Score * NEW PHYSICS NOT FAR FROM THE FERMI SCALE? * L-Right Symmetry: A Fundamental Symmetry? * Massive Majorana Neutrinos * Neutron -Antineutron Oscillations * Lepton Number as a Fourth Colour * THE SO(10) MODEL * Few Generalities on the Orthogonal Groups * The SO(10) Gauge Interactions * Patterns of Symmetry Breaking in the SO(10) Model * The Fermion Mass Spectrum * The Question of the Neutrino Mass * PHENOMENOLOGY OF THE INTERMEDIATE MASS SCALES * Renormalization Group Equations in the Presence of IMS * MI and MX in IMS models * Higgs Contributions to the β-Functions * Phenomenological Consequences of IMS * A GENERAL OUTLOOK ON GUTs * General Constraints on GUTs * Major Unsolved Questions in GUTs * Bibliography * References

  14. The critical power to maintain thermally stable molecular junctions

    NASA Astrophysics Data System (ADS)

    Wang, Yanlei; Xu, Zhiping

    2014-07-01

    With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 109 kW-1. Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design.

  15. The critical power to maintain thermally stable molecular junctions.

    PubMed

    Wang, Yanlei; Xu, Zhiping

    2014-01-01

    With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 10(9) kW(-1). Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design. PMID:25005801

  16. Lateral distributions of EAS muons (Eμ > 800 MeV) measured with the KASCADE-Grande Muon Tracking Detector in the primary energy range 1016 -1017 eV

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2015-05-01

    The KASCADE-Grande large area (128 m2) Muon Tracking Detector has been built with the aim to identify muons ( Eμthr = 800 MeV) in Extensive Air Showers by track measurements under 18 r.l. shielding. This detector provides high-accuracy angular information (approx. 0.3 °) for muons up to 700 m distance from the shower core. In this work we present the lateral density distributions of muons in EAS measured with the Muon Tracking Detector of the KASCADE-Grande experiment. The density is calculated by counting muon tracks in a muon-to-shower-axis distance range from 100 m to 610 m from showers with reconstructed energy of 1016 -1017 eV and zenith angle θ < 18 ° . In the distance range covered by the experiment, these distributions are well described by functions phenomenologically determined already in the fifties (of the last century) by Greisen. They are compared also with the distributions obtained with the KASCADE scintillator array (Eμthr = 230 MeV) and with distributions obtained using simulated showers.

  17. Thermoelectric effects in nanoscale junctions.

    PubMed

    Dubi, Yonatan; Di Ventra, Massimiliano

    2009-01-01

    Despite its intrinsic nonequilibrium origin, thermoelectricity in nanoscale systems is usually described within a static scattering approach which disregards the dynamical interaction with the thermal baths that maintain energy flow. Using the theory of open quantum systems, we show instead that unexpected properties, such as a resonant structure and large sign sensitivity, emerge if the nonequilibrium nature of this problem is considered. Our approach also allows us to define and study a local temperature, which shows hot spots and oscillations along the system according to the coupling of the latter to the electrodes. This demonstrates that Fourier's lawa paradigm of statistical mechanicsis generally violated in nanoscale junctions. PMID:19072125

  18. Mapping the Transmission Functions of Single-Molecule Junctions.

    PubMed

    Capozzi, Brian; Low, Jonathan Z; Xia, Jianlong; Liu, Zhen-Fei; Neaton, Jeffrey B; Campos, Luis M; Venkataraman, Latha

    2016-06-01

    Charge transport phenomena in single-molecule junctions are often dominated by tunneling, with a transmission function dictating the probability that electrons or holes tunnel through the junction. Here, we present a new and simple technique for measuring the transmission functions of molecular junctions in the coherent tunneling limit, over an energy range of 1.5 eV around the Fermi energy. We create molecular junctions in an ionic environment with electrodes having different exposed areas, which results in the formation of electric double layers of dissimilar density on the two electrodes. This allows us to electrostatically shift the molecular resonance relative to the junction Fermi levels in a manner that depends on the sign of the applied bias, enabling us to map out the junction's transmission function and determine the dominant orbital for charge transport in the molecular junction. We demonstrate this technique using two groups of molecules: one group having molecular resonance energies relatively far from EF and one group having molecular resonance energies within the accessible bias window. Our results compare well with previous electrochemical gating data and with transmission functions computed from first principles. Furthermore, with the second group of molecules, we are able to examine the behavior of a molecular junction as a resonance shifts into the bias window. This work provides a new, experimentally simple route for exploring the fundamentals of charge transport at the nanoscale. PMID:27186894

  19. Grand slam on cancer.

    PubMed

    Gartrell, Nanette

    2014-01-01

    A winner of 59 Grand Slam championships including a record 9 Wimbledon singles titles, Martina Navratilova is the most successful woman tennis player of the modern era. Martina was inducted into the International Tennis Hall of Fame, named "Tour Player of the Year" seven times by the Women's Tennis Association, declared "Female Athlete of the Year" by the Associated Press, and ranked one of the "Top Forty Athletes of All-Time" by Sports Illustrated. Equally accomplished off the court, Martina is an author, philanthropist, TV commentator, and activist who has dedicated her life to educating people about prejudice and stereotypes. After coming out as a lesbian in 1981, Martina became a tireless advocate of equal rights for lesbian, gay, bisexual, and transgender (LGBT) people, and she has contributed generously to the LGBT community. Martina is the author of seven books, including most recently Shape Your Self: My 6-Step Diet and Fitness Plan to Achieve the Best Shape of your Life, an inspiring guide to healthy living and personal fitness. Martina was diagnosed with breast cancer in 2010. PMID:24400624

  20. Carbon nanotube intramolecular junctions

    NASA Astrophysics Data System (ADS)

    Yao, Zhen; Postma, Henk W. Ch.; Balents, Leon; Dekker, Cees

    1999-11-01

    The ultimate device miniaturization would be to use individual molecules as functional devices. Single-wall carbon nanotubes (SWNTs) are promising candidates for achieving this: depending on their diameter and chirality, they are either one-dimensional metals or semiconductors. Single-electron transistors employing metallic nanotubes and field-effect transistors employing semiconducting nanotubes have been demonstrated. Intramolecular devices have also been proposed which should display a range of other device functions. For example, by introducing a pentagon and a heptagon into the hexagonal carbon lattice, two tube segments with different atomic and electronic structures can be seamlessly fused together to create intramolecular metal-metal, metal-semiconductor, or semiconductor-semiconductor junctions. Here we report electrical transport measurements on SWNTs with intramolecular junctions. We find that a metal-semiconductor junction behaves like a rectifying diode with nonlinear transport characteristics that are strongly asymmetric with respect to bias polarity. In the case of a metal-metal junction, the conductance appears to be strongly suppressed and it displays a power-law dependence on temperatures and applied voltage, consistent with tunnelling between the ends of two Luttinger liquids. Our results emphasize the need to consider screening and electron interactions when designing and modelling molecular devices. Realization of carbon-based molecular electronics will require future efforts in the controlled production of these intramolecular nanotube junctions.

  1. String junctions and holographic interfaces

    SciTech Connect

    Chiodaroli, Marco; Gutperle, Michael; Hung, Ling-Yan; Krym, Darya

    2011-01-15

    In this paper we study half-BPS type IIB supergravity solutions with multiple AdS{sub 3}xS{sup 3}xM{sub 4} asymptotic regions, where M{sub 4} is either T{sup 4} or K{sub 3}. These solutions were first constructed in [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] and have geometries given by the warped product of AdS{sub 2}xS{sup 2}xM{sub 4} over {Sigma}, where {Sigma} is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. n half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] are constructed introducing two meromorphic and two harmonic functions defined on {Sigma}. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.

  2. Four-junction superconducting circuit

    NASA Astrophysics Data System (ADS)

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

    2016-06-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit.

  3. Four-junction superconducting circuit.

    PubMed

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J Q

    2016-01-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

  4. Four-junction superconducting circuit

    PubMed Central

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

    2016-01-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

  5. Mixing Hot and Cold Water Streams at a T-Junction

    ERIC Educational Resources Information Center

    Sharp, David; Zhang, Mingqian; Xu, Zhenghe; Ryan, Jim; Wanke, Sieghard; Afacan, Artin

    2008-01-01

    A simple mixing of a hot- and cold-water stream at a T-junction was investigated. The main objective was to use mass and energy balance equations to predict mass low rates and the temperature of the mixed stream after the T-junction, and then compare these with the measured values. Furthermore, the thermocouple location after the T-junction and…

  6. 75 FR 16090 - Grand River Dam Authority; Notice of Application for Amendment of License and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-31

    ... Energy Regulatory Commission Grand River Dam Authority; Notice of Application for Amendment of License.... Date Filed: March 11, 2010, supplemented on March 17, 2010. d. Applicant: Grand River Dam Authority. e.... 791a-825r. h. Applicant Contact: Ms. Tamara E. Jahnke, Assistant General Council, Grand Dam...

  7. 78 FR 30914 - Grand River Dam Authority Notice of Application for Temporary Variance of License and Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ... Federal Energy Regulatory Commission Grand River Dam Authority Notice of Application for Temporary...: March 20, 2013, and supplemented on May 3, 2013, and May 16, 2013. d. Applicant: Grand River Dam..., Grand River Dam Authority, P.O. Box 409, Vinita, OK 74301; telephone: (918) 256-5545. i. FERC Contact:...

  8. 76 FR 7831 - Grand River Dam Authority; Notice of Application for Amendment of License and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... Energy Regulatory Commission Grand River Dam Authority; Notice of Application for Amendment of License...: Grand River Dam Authority. e. Name of Project: Markham Ferry Project. f. Location: The project is..., Grand River Dam Authority, P.O. Box 409, Vinita, OK 73401-0409. Tel: (918) 256-5545. i. FERC...

  9. 75 FR 4363 - Grand River Dam Authority; Notice of Application for Amendment of License and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... Energy Regulatory Commission Grand River Dam Authority; Notice of Application for Amendment of License..., 2009. d. Applicant: Grand River Dam Authority. e. Name of Project: Markham Ferry Hydroelectric Project... Contact: D. Casey Davis, Grand River Dam Authority, P.O. Box 409, 226 West Dwain Willis Avenue,...

  10. 75 FR 74700 - Grand River Dam Authority; Notice of Application for Amendment of License and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-01

    ... Energy Regulatory Commission Grand River Dam Authority; Notice of Application for Amendment of License.... Date Filed: October 26, 2010. d. Applicant: Grand River Dam Authority. e. Name of Project: Markham.... 791(a)-825(r). h. Applicant Contact: Tamara E. Jahnke, Grand River Dam Authority, P.O. Box 409,...

  11. Electrostatic model of radial pn junction nanowires

    NASA Astrophysics Data System (ADS)

    Chia, A. C. E.; LaPierre, R. R.

    2013-08-01

    Poisson's equation is solved for a radial pn junction nanowire (NW) with surface depletion. This resulted in a model capable of giving radial energy band and electric field profiles for any arbitrary core/shell doping density, core/shell dimensions, and surface state density. Specific cases were analyzed to extract pertinent underlying physics, while the relationship between NW specifications and the depletion of the NW were examined to optimize the built-in potential across the junction. Additionally, the model results were compared with experimental results in literature to good agreement. Finally, an optimum device design is proposed to satisfy material, optical, and electrostatic constraints in high efficiency NW solar cells.

  12. Fluctuation of heat current in Josephson junctions

    SciTech Connect

    Virtanen, P.; Giazotto, F.

    2015-02-15

    We discuss the statistics of heat current between two superconductors at different temperatures connected by a generic weak link. As the electronic heat in superconductors is carried by Bogoliubov quasiparticles, the heat transport fluctuations follow the Levitov–Lesovik relation. We identify the energy-dependent quasiparticle transmission probabilities and discuss the resulting probability density and fluctuation relations of the heat current. We consider multichannel junctions, and find that heat transport in diffusive junctions is unique in that its statistics is independent of the phase difference between the superconductors.

  13. Rio Grande pipeline introduces LPG to Mexico

    SciTech Connect

    1997-06-01

    Rio Grande Pipeline, a joint venture between Mid-America Pipeline Co., Amoco Pipeline Co. and Navajo Pipeline Co., has broken new ground in the energy industry as the first LPG pipeline to cross the US-Mexico border. Plans for the project were announced in November 1995 and first deliveries started three months ago on March 21, 1997. The 8-inch, 265-mile pipeline originates near Odessa, TX, where it receives an 85-15 propane-butane mix via a connection to Mid-America Pipeline. From Odessa, product moves west through the Texas desert and crosses the Rio Grande River about 15 miles south of El Paso near Clint, TX and extends 20 miles into Mexico. Capacity of the line is 24,000 bpd and it has been averaging about 22,000 bpd since line-fill. All in all, it sounded like a reasonably feasible, routine project. But perceptions can be deceiving, or at least misleading. In other words, the project can be summarized as follows: one river, two cultures and a world of difference. The official border crossing for pipeline construction took place on Dec. 2, 1996, with a directional drill under the Rio Grande River, but in actuality, the joint venture partners were continually bridging differences in language, laws, customs and norms with Pemex and contracted workers from Mexico.

  14. Semiconductor Lasers Containing Quantum Wells in Junctions

    NASA Technical Reports Server (NTRS)

    Yang, Rui Q.; Qiu, Yueming

    2004-01-01

    In a recent improvement upon In(x)Ga(1-x)As/InP semiconductor lasers of the bipolar cascade type, quantum wells are added to Esaki tunnel junctions, which are standard parts of such lasers. The energy depths and the geometric locations and thicknesses of the wells are tailored to exploit quantum tunneling such that, as described below, electrical resistances of junctions and concentrations of dopants can be reduced while laser performances can be improved. In(x)Ga(1-x)As/InP bipolar cascade lasers have been investigated as sources of near-infrared radiation (specifically, at wavelengths of about 980 and 1,550 nm) for photonic communication systems. The Esaki tunnel junctions in these lasers have been used to connect adjacent cascade stages and to enable transport of charge carriers between them. Typically, large concentrations of both n (electron-donor) and p (electron-acceptor) dopants have been necessary to impart low electrical resistances to Esaki tunnel junctions. Unfortunately, high doping contributes free-carrier absorption, thereby contributing to optical loss and thereby, further, degrading laser performance. In accordance with the present innovation, quantum wells are incorporated into the Esaki tunnel junctions so that the effective heights of barriers to quantum tunneling are reduced (see figure).

  15. Phonon Josephson junction with nanomechanical resonators

    NASA Astrophysics Data System (ADS)

    Barzanjeh, Shabir; Vitali, David

    2016-03-01

    We study coherent phonon oscillations and tunneling between two coupled nonlinear nanomechanical resonators. We show that the coupling between two nanomechanical resonators creates an effective phonon Josephson junction, which exhibits two different dynamical behaviors: Josephson oscillation (phonon-Rabi oscillation) and macroscopic self-trapping (phonon blockade). Self-trapping originates from mechanical nonlinearities, meaning that when the nonlinearity exceeds its critical value, the energy exchange between the two resonators is suppressed, and phonon Josephson oscillations between them are completely blocked. An effective classical Hamiltonian for the phonon Josephson junction is derived and its mean-field dynamics is studied in phase space. Finally, we study the phonon-phonon coherence quantified by the mean fringe visibility, and show that the interaction between the two resonators may lead to the loss of coherence in the phononic junction.

  16. Junction-side illuminated silicon detector arrays

    DOEpatents

    Iwanczyk, Jan S.; Patt, Bradley E.; Tull, Carolyn

    2004-03-30

    A junction-side illuminated detector array of pixelated detectors is constructed on a silicon wafer. A junction contact on the front-side may cover the whole detector array, and may be used as an entrance window for light, x-ray, gamma ray and/or other particles. The back-side has an array of individual ohmic contact pixels. Each of the ohmic contact pixels on the back-side may be surrounded by a grid or a ring of junction separation implants. Effective pixel size may be changed by separately biasing different sections of the grid. A scintillator may be coupled directly to the entrance window while readout electronics may be coupled directly to the ohmic contact pixels. The detector array may be used as a radiation hardened detector for high-energy physics research or as avalanche imaging arrays.

  17. Electric-field-induced magnetization switching in CoFeB/MgO magnetic tunnel junctions with high junction resistance

    NASA Astrophysics Data System (ADS)

    Kanai, S.; Matsukura, F.; Ohno, H.

    2016-05-01

    We show the electric-field induced magnetization switching for CoFeB/MgO magnetic tunnel junctions with thick MgO barrier layer of 2.8 nm, whose resistance-area product is 176 kΩ μm2, and achieve the small switching energy of 6.3 fJ/bit. The increase of the junction resistance is expected to suppress the energy consumption due to the Joule heating during the switching; however, the energy is still dominated by the Joule energy rather than the charging energy. This is because the junction resistance decreases more rapidly for junctions with thicker MgO as bias voltage increases.

  18. 13(a) assessment of the Rio Grande Region. Final report

    SciTech Connect

    Not Available

    1981-09-01

    The report summarizes results of an assessment of water requirements, water availability and other water implications of the development of emerging, nonnuclear energy technologies in the Rio Grande Region. The technologies assessed include advanced coal combustion, geothermal energy, small-scale/low-head hydropower, and enhanced oil recovery.

  19. Doped semiconductor nanocrystal junctions

    SciTech Connect

    Borowik, Ł.; Mélin, T.; Nguyen-Tran, T.; Roca i Cabarrocas, P.

    2013-11-28

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (N{sub D}≈10{sup 20}−10{sup 21}cm{sup −3}) silicon nanocrystals (NCs) in the 2–50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as N{sub D}{sup −1/3}, and depleted charge linearly increasing with the NC diameter and varying as N{sub D}{sup 1/3}. We thus establish a “nanocrystal counterpart” of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

  20. Victory Junction Gang Camp

    ERIC Educational Resources Information Center

    Shell, Ryan

    2007-01-01

    This article describes the Victory Junction Gang Camp, a not-for-profit, NASCAR-themed camp for children with chronic medical conditions that serves 24 different disease groups. The mission of the camp is to give children life-changing camping experiences that are exciting, fun, and empowering in a safe and medically sound environment. While doing…

  1. Josephson junction mixing.

    NASA Technical Reports Server (NTRS)

    Thompson, E. D.

    1973-01-01

    A theory is presented which, though too simple to explain quantitative details in the Josephson junction mixing response, is sufficient for explaining qualitatively the results observed. Crucial to the theory presented, and that which differentiates it from earlier ones, is the inclusion of harmonic voltages across the ideal Josephson element.

  2. Brain barriers: Crosstalk between complex tight junctions and adherens junctions

    PubMed Central

    Tietz, Silvia

    2015-01-01

    Unique intercellular junctional complexes between the central nervous system (CNS) microvascular endothelial cells and the choroid plexus epithelial cells form the endothelial blood–brain barrier (BBB) and the epithelial blood–cerebrospinal fluid barrier (BCSFB), respectively. These barriers inhibit paracellular diffusion, thereby protecting the CNS from fluctuations in the blood. Studies of brain barrier integrity during development, normal physiology, and disease have focused on BBB and BCSFB tight junctions but not the corresponding endothelial and epithelial adherens junctions. The crosstalk between adherens junctions and tight junctions in maintaining barrier integrity is an understudied area that may represent a promising target for influencing brain barrier function. PMID:26008742

  3. Direct characterization of the energy level alignments and molecular components in an organic hetero-junction by integrated photoemission spectroscopy and reflection electron energy loss spectroscopy analysis.

    PubMed

    Yun, Dong-Jin; Shin, Weon-Ho; Bulliard, Xavier; Park, Jong Hwan; Kim, Seyun; Chung, Jae Gwan; Kim, Yongsu; Heo, Sung; Kim, Seong Heon

    2016-08-26

    A novel, direct method for the characterization of the energy level alignments at bulk-heterojunction (BHJ)/electrode interfaces on the basis of electronic spectroscopy measurements is proposed. The home-made in situ photoemission system is used to perform x-ray/ultraviolet photoemission spectroscopy (XPS/UPS), reflection electron energy loss spectroscopy (REELS) and inverse photoemission spectroscopy of organic-semiconductors (OSCs) deposited onto a Au substrate. Through this analysis system, we are able to obtain the electronic structures of a boron subphthalocyanine chloride:fullerene (SubPC:C60) BHJ and those of the separate OSC/electrode structures (SubPC/Au and C60/Au). Morphology and chemical composition analyses confirm that the original SubPC and C60 electronic structures remain unchanged in the electrodes prepared. Using this technique, we ascertain that the position and area of the nearest peak to the Fermi energy (EF = 0 eV) in the UPS (REELS) spectra of SubPC:C60 BHJ provide information on the highest occupied molecular orbital level (optical band gap) and combination ratio of the materials, respectively. Thus, extracting the adjusted spectrum from the corresponding SubPC:C60 BHJ UPS (REELS) spectrum reveals its electronic structure, equivalent to that of the C60 materials. This novel analytical approach allows complete energy-level determination for each combination ratio by separating its electronic structure information from the BHJ spectrum. PMID:27420635

  4. Direct characterization of the energy level alignments and molecular components in an organic hetero-junction by integrated photoemission spectroscopy and reflection electron energy loss spectroscopy analysis

    NASA Astrophysics Data System (ADS)

    Yun, Dong-Jin; Shin, Weon-Ho; Bulliard, Xavier; Park, Jong Hwan; Kim, Seyun; Chung, Jae Gwan; Kim, Yongsu; Heo, Sung; Kim, Seong Heon

    2016-08-01

    A novel, direct method for the characterization of the energy level alignments at bulk-heterojunction (BHJ)/electrode interfaces on the basis of electronic spectroscopy measurements is proposed. The home-made in situ photoemission system is used to perform x-ray/ultraviolet photoemission spectroscopy (XPS/UPS), reflection electron energy loss spectroscopy (REELS) and inverse photoemission spectroscopy of organic-semiconductors (OSCs) deposited onto a Au substrate. Through this analysis system, we are able to obtain the electronic structures of a boron subphthalocyanine chloride:fullerene (SubPC:C60) BHJ and those of the separate OSC/electrode structures (SubPC/Au and C60/Au). Morphology and chemical composition analyses confirm that the original SubPC and C60 electronic structures remain unchanged in the electrodes prepared. Using this technique, we ascertain that the position and area of the nearest peak to the Fermi energy (EF = 0 eV) in the UPS (REELS) spectra of SubPC:C60 BHJ provide information on the highest occupied molecular orbital level (optical band gap) and combination ratio of the materials, respectively. Thus, extracting the adjusted spectrum from the corresponding SubPC:C60 BHJ UPS (REELS) spectrum reveals its electronic structure, equivalent to that of the C60 materials. This novel analytical approach allows complete energy-level determination for each combination ratio by separating its electronic structure information from the BHJ spectrum.

  5. Local Grand Unification and String Theory

    SciTech Connect

    Nilles, Hans Peter; Ramos-Sanchez, Saul; Vaudrevange, Patrick K. S.

    2010-02-10

    The low energy effective action of string theory depends strongly on the process of compactification and the localization of fields in extra dimensions. Explicit string constructions towards the minimal supersymmetric standard model (MSSM) reveal interesting results leading to the concept of local grand unification. Properties of the MSSM indicate that we might live at a special location close to an orbifold fixed point rather than a generic point in Calabi-Yau moduli space. We observe an enhancement of (discrete) symmetries that have various implications for the properties of the MSSM such as proton stability as well as solutions to the flavor problem, the mu-problem and the strong CP-problem.

  6. The Air-Shower Experiment KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Haungs, A.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; KASCADE-Grande Collaboration

    2009-12-01

    KASCADE-Grande is an extensive air shower experiment at the Forschungszentrum Karlsruhe, Germany. Main parts of the experiment are the Grande array spread over an area of 700×700 m, the original KASCADE array covering 200×200 m with unshielded and shielded detectors, and additional muon tracking devices. This multi-detector system allows to investigate the energy spectrum, composition, and anisotropies of cosmic rays in the energy range up to 1 EeV. An overview on the performance of the apparatus and first results will be given.

  7. Break junction under electrochemical gating: testbed for single-molecule electronics.

    PubMed

    Huang, Cancan; Rudnev, Alexander V; Hong, Wenjing; Wandlowski, Thomas

    2015-02-21

    Molecular electronics aims to construct functional molecular devices at the single-molecule scale. One of the major challenges is to construct a single-molecule junction and to further manipulate the charge transport through the molecular junction. Break junction techniques, including STM break junctions and mechanically controllable break junctions are considered as testbed to investigate and control the charge transport on a single-molecule scale. Moreover, additional electrochemical gating provides a unique opportunity to manipulate the energy alignment and molecular redox processes for a single-molecule junction. In this review, we start from the technical aspects of the break junction technique, then discuss the molecular structure-conductance correlation derived from break junction studies, and, finally, emphasize electrochemical gating as a promising method for the functional molecular devices. PMID:25560965

  8. Observation of short ballistic Josephson effect in vertical graphene junctions

    NASA Astrophysics Data System (ADS)

    Lee, Gil-Ho; Lee, Hu-Jong

    2014-03-01

    The current-phase relation (CPR) of vertical graphene Josephson junctions (vGJJs) was measured using phase-sensitive dc-SQUID interferometry. A vGJJ, realized by vertically sandwiching a monolayer graphene between two Al electrodes, had an atomically short channel with transparent contacts for the highly coherent junction nature. The measured CPR was almost perfectly skewed, which rigorously confirmed the short ballisticity of the vGJJs. The short ballistic character of a Josephson junction has been predicted since 1970's but has never been realized in scalable hybrid systems. The CPR also provided energy spectrum of Andreev levels formed inside the junction, which offered a promising prospect for scalable quantum information devices such as Andreev-level qubits. This vertical-junction scheme is also readily applicable to the other cleavable materials such as three-dimensional topological insulators or transition metal dichalcogenides, opening a new pathway for uncovering exotic coherence phenomena arising in an atomic scale.

  9. Electronic Properties of Carbon Nanotubes and Junctions

    NASA Technical Reports Server (NTRS)

    Anantram, M. P.; Han, Jie; Yang, Liu; Govindan, T. R.; Jaffe, R.; Saini, Subhash (Technical Monitor)

    1998-01-01

    Metallic and semiconducting Single Wall Carbon Nanotubes (CNT) have recently been characterized using scanning tunneling microscopy (STM) and the manipulation of individual CNT has been demonstrated. These developments make the prospect of using CNT as molecular wires and possibly as electronic devices an even more interesting one. We have been modeling various electronic properties such as the density of states and the transmission coefficient of CNT wires and junctions. These studies involve first calculating the stability of junctions using molecular dynamics simulations and then calculating the electronic properties using a pi-electron tight binding Hamiltonian. We have developed the expertise to calculate the electronic properties of both finite-sized CNT and CNT systems with semi-infinite boundary conditions. In this poster, we will present an overview of some of our results. The electronic application of CNT that is most promising at this time is their use as molecular wires. The conductance can however be greatly reduced because of reflection due to defects and contacts. We have modeled the transmission through CNT in the presence of two types of defects: weak uniform disorder and strong isolated scatterers. We find that the conductance is affected in significantly different manners due to these defects Junctions of CNT have also been imaged using STM. This makes it essential to derive rules for the formation of junctions between tubes of different chirality, study their relative energies and electronic properties. We have generalized the rules for connecting two different CNT and have calculated the transmission and density of states through CNT junctions. Metallic and semiconducting CNT can be joined to form a stable junction and their current versus voltage characteristics are asymmetric. CNT are deformed by the application of external forces including interactions with a substrate or other CNT. In many experiments, these deformation are expected to

  10. Holliday Junction Resolvases

    PubMed Central

    Wyatt, Haley D.M.; West, Stephen C.

    2014-01-01

    Four-way DNA intermediates, called Holliday junctions (HJs), can form during meiotic and mitotic recombination, and their removal is crucial for chromosome segregation. A group of ubiquitous and highly specialized structure-selective endonucleases catalyze the cleavage of HJs into two disconnected DNA duplexes in a reaction called HJ resolution. These enzymes, called HJ resolvases, have been identified in bacteria and their bacteriophages, archaea, and eukaryotes. In this review, we discuss fundamental aspects of the HJ structure and their interaction with junction-resolving enzymes. This is followed by a brief discussion of the eubacterial RuvABC enzymes, which provide the paradigm for HJ resolvases in other organisms. Finally, we review the biochemical and structural properties of some well-characterized resolvases from archaea, bacteriophage, and eukaryotes. PMID:25183833

  11. Wireless Josephson Junction Arrays

    NASA Astrophysics Data System (ADS)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

  12. Fractional order junctions

    NASA Astrophysics Data System (ADS)

    Machado, J. Tenreiro

    2015-01-01

    Gottfried Leibniz generalized the derivation and integration, extending the operators from integer up to real, or even complex, orders. It is presently recognized that the resulting models capture long term memory effects difficult to describe by classical tools. Leon Chua generalized the set of lumped electrical elements that provide the building blocks in mathematical models. His proposal of the memristor and of higher order elements broadened the scope of variables and relationships embedded in the development of models. This paper follows the two directions and proposes a new logical step, by generalizing the concept of junction. Classical junctions interconnect system elements using simple algebraic restrictions. Nevertheless, this simplistic approach may be misleading in the presence of unexpected dynamical phenomena and requires including additional "parasitic" elements. The novel γ -junction includes, as special cases, the standard series and parallel connections and allows a new degree of freedom when building models. The proposal motivates the search for experimental and real world manifestations of the abstract conjectures.

  13. Thomas Moran: "The Grand Canyon."

    ERIC Educational Resources Information Center

    Brubaker, Ann

    1986-01-01

    Presents a lesson plan for introducing students in grades four through six to Thomas Moran's painting, "The Grand Canyon." The goal of the lesson is to illustrate the importance of the American West as a subject for artists in the nineteenth century. (JDH)

  14. Giving a grand rounds presentation.

    PubMed

    Morrison, Laura J; Portenoy, Russell

    2010-12-01

    Giving a Grand Rounds presentation provides the hospice and palliative medicine subspecialist with the occasion to participate in a time-honored and respected event. It remains an opportunity to promote the discipline, support institutional culture change, and favorably influence the attitudes, knowledge, skills, and performance of colleagues. For those pursuing academic careers, it also is a chance to establish academic currency and develop teaching and presentation skills. In most academic settings, the format of Grand Rounds has shifted over time from a patient and problem-based discussion to a didactic, topic-focused lecture. A body of literature questions the value of this shift toward a more passive learner. Limited evidence prevents a definitive answer but many advocate for the integration of more interactive methods to improve the effectiveness of Grand Rounds. This article provides a flexible framework to guide those preparing to give a Grand Rounds and those teaching and supporting others to do so. To do this well, adult learning principles must be thoughtfully incorporated into a presentation style and method appropriate to the venue. The approach emphasizes learner-centeredness, interactive strategies, and evaluation. Room for creativity exists at every step and can add enjoyment and challenge along the way. PMID:21155643

  15. Designing a Virtual Grand Tour

    ERIC Educational Resources Information Center

    Hansen, Per Skafte

    2004-01-01

    The Virtual Grand Tour (VGT) is a paradigm for integrating a presentation of an overview of a larger subject with the possibility of launching at any time an exploratory study of a given sub-topic. The name derives from the paradigm's emulation of those 18th-century travels intended to educate (especially) young, affluent British men; today, with…

  16. The periodicity of Grand Solar Minimum

    NASA Astrophysics Data System (ADS)

    Velasco Herrera, Victor Manuel

    2016-07-01

    The sunspot number is the most used index to quantify the solar activity. Nevertheless, the sunspot is a syn- thetic index and not a physical index. Therefore, we should be careful to use the sunspot number to quantify the low (high) solar activity. One of the major problems of using sunspot to quantify solar activity is that its minimum value is zero. This zero value hinders the reconstruction of the solar cycle during the Maunder minimum. All solar indexes can be used as analog signals, which can be easily converted into digital signals. In con- trast, the conversion of a digital signal into an analog signal is not in general a simple task. The sunspot number during the Maunder minimum can be studied as a digital signal of the solar activity In 1894, Maunder published a discovery that has maintained the Solar Physics in an impasse. In his fa- mous work on "A Prolonged Sunspot Minimum" Maunder wrote: "The sequence of maximum and minimum has, in fact, been unfailing during the present century [..] and yet there [..], the ordinary solar cycle was once interrupted, and one long period of almost unbroken quiescence prevailed". The search of new historical Grand solar minima has been one of the most important questions in Solar Physics. However, the possibility of estimating a new Grand solar minimum is even more valuable. Since solar activity is the result of electromagnetic processes; we propose to employ the power to quantify solar activity: this is a fundamental physics concept in electrodynamics. Total Solar Irradiance is the primary energy source of the Earth's climate system and therefore its variations can contribute to natural climate change. In this work, we propose to consider the fluctuations in the power of the Total Solar Irradiance as a physical measure of the energy released by the solar dynamo, which contributes to understanding the nature of "profound solar magnetic field in calm". Using a new reconstruction of the Total Solar Irradiance we found the

  17. Gold plasmonic effects on charge transport through single molecule junctions

    NASA Astrophysics Data System (ADS)

    Adak, Olgun; Venkataraman, Latha

    2014-03-01

    We study the impact of surface plasmon polaritons, the coupling of electromagnetic waves to collective electron oscillations on metal surfaces, on the conductance of single-molecule junctions. We use a scanning-tunneling microscope based break junction setup that is built into an optical microscope to form molecular junctions. Coherent 685nm light is used to illuminate the molecular junctions formed with 4,4'-bipyridine with diffraction limited focusing performance. We employ a lock-in type technique to measure currents induced by light. Furthermore, the thermal expansion due to laser heating is mimicked by mechanically modulating inter-electrode separation. For each junction studied, we measure current, and use AC techniques to determine molecular junction resonance levels and coupling strengths. We use a cross correlations analysis technique to analyze and compare the effect of light to that of the mechanical modulation. Our results show that junction transmission characteristics are not altered under illumination, within the resolution of our instrument. We argue that photo-currents measured with lock-in techniques in these kinds of structures are due to thermal effects. This work was funded by the Center for Re-Defining Photovoltaic Efficiency through Molecule Scale Control, an EFRC funded by the US Department of Energy, Office of Basic Energy Sciences under Contract No. DESC0001085.

  18. 78 FR 55249 - Grand Valley Rural Power Lines, Inc., Holy Cross Electric Association, Inc., Intermountain Rural...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ... Energy Regulatory Commission Grand Valley Rural Power Lines, Inc., Holy Cross Electric Association, Inc., Intermountain Rural Electric Association, Inc., Yampa Valley Electric Association, Inc. v. Public Service.... 824, 824(e) and 825(e) 2013, Grand Valley Rural Power Lines, Inc., Holy Cross Electric...

  19. Radiation comb generation with extended Josephson junctions

    SciTech Connect

    Solinas, P.; Bosisio, R.; Giazotto, F.

    2015-09-21

    We propose the implementation of a Josephson radiation comb generator based on an extended Josephson junction subject to a time dependent magnetic field. The junction critical current shows known diffraction patterns and determines the position of the critical nodes when it vanishes. When the magnetic flux passes through one of such critical nodes, the superconducting phase must undergo a π-jump to minimize the Josephson energy. Correspondingly, a voltage pulse is generated at the extremes of the junction. Under periodic driving, this allows us to produce a comb-like voltage pulses sequence. In the frequency domain, it is possible to generate up to hundreds of harmonics of the fundamental driving frequency, thus mimicking the frequency comb used in optics and metrology. We discuss several implementations through a rectangular, cylindrical, and annular junction geometries, allowing us to generate different radiation spectra and to produce an output power up to 10 pW at 50 GHz for a driving frequency of 100 MHz.

  20. Heat Transport in Graphene Ferromagnet-Insulator-Superconductor Junctions

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Wei

    2011-04-01

    We study heat transport in a graphene ferromagnet-insulator-superconducting junction. It is found that the thermal conductance of the graphene ferromagnet-insulator-superconductor (FIS) junction is an oscillatory function of the barrier strength χ in the thin-barrier limit. The gate potential U0 decreases the amplitude of thermal conductance oscillation. Both the amplitude and phase of the thermal conductance oscillation varies with the exchange energy Eh. The thermal conductance of a graphene FIS junction displays the usual exponential dependence on temperature, reflecting the s-wave symmetry of superconducting graphene.

  1. Suppression of Andreev conductance in a topological insulator-superconductor nanostep junction

    NASA Astrophysics Data System (ADS)

    Yi-Jie, Zheng; Jun-Tao, Song; Yu-Xian, Li

    2016-03-01

    When two three-dimensional topological insulators (TIs) are brought close to each other with their surfaces aligned, the surfaces form a line junction. Similarly, three TI surfaces, not lying in a single plane, can form an atomic-scale nanostep junction. In this paper, Andreev reflection in a TI-TI-superconductor nanostep junction is investigated theoretically. Because of the existence of edge states along each line junction, the conductance for a nanostep junction is suppressed. When the incident energy (ɛ) of an electron is larger than the superconductor gap (Δ), the Andreev conductance in a step junction is less than unity while for a plane junction it is unity. The Andreev conductance is found to depend on the height of the step junction. The Andreev conductance exhibits oscillatory behavior as a function of the junction height with the amplitude of the oscillations remaining unchanged when ɛ = 0, but decreasing for ɛ = Δ, which is different from the case of the plane junction. The height of the step is therefore an important parameter for Andreev reflection in nanostep junctions, and plays a role similar to that of the delta potential barrier in normal metal-superconductor plane junctions. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204065 and 11474085) and the Natural Science Foundation of Hebei Province, China (Grant Nos. A2013205168 and A2014205005).

  2. Signatures of topological Josephson junctions

    NASA Astrophysics Data System (ADS)

    Peng, Yang; Pientka, Falko; Berg, Erez; Oreg, Yuval; von Oppen, Felix

    2016-08-01

    Quasiparticle poisoning and diabatic transitions may significantly narrow the window for the experimental observation of the 4 π -periodic dc Josephson effect predicted for topological Josephson junctions. Here, we show that switching-current measurements provide accessible and robust signatures for topological superconductivity which persist in the presence of quasiparticle poisoning processes. Such measurements provide access to the phase-dependent subgap spectrum and Josephson currents of the topological junction when incorporating it into an asymmetric SQUID together with a conventional Josephson junction with large critical current. We also argue that pump-probe experiments with multiple current pulses can be used to measure the quasiparticle poisoning rates of the topological junction. The proposed signatures are particularly robust, even in the presence of Zeeman fields and spin-orbit coupling, when focusing on short Josephson junctions. Finally, we also consider microwave excitations of short topological Josephson junctions which may complement switching-current measurements.

  3. [Gap junction and diabetic foot].

    PubMed

    Zou, Xiao-rong; Tao, Jian; Wang, Yun-kai

    2015-11-01

    Gap junctions play a critical role in electrical synchronization and exchange of small molecules between neighboring cells; connexins are a family of structurally related transmembrane proteins that assemble to form vertebrate gap junctions. Hyperglycemia changes the structure gap junction proteins and their expression, resulting in obstruction of neural regeneration, vascular function and wound healing, and also promoting vascular atherosclerosis. These pathogenic factors would cause diabetic foot ulcers. This article reviews the involvement of connexins in pathogenesis of diabetic foot. PMID:26822053

  4. Rio Grande Wetbacks: Mexican Migrant Workers.

    ERIC Educational Resources Information Center

    Norquest, Carrol

    Farmers in the Lower Rio Grande Valley of Texas saw a rise of wetback labor in the 1930s and 40s. The wetback laborers were Mexicans who had crossed the Rio Grande and were in the United States illegally to work. Carrol Norquest, a farmer in the Lower Rio Grande Valley, employed wetbacks regularly. In this book, Mr. Norquest writes about the…

  5. SNOW: THE REAL WATER SUPPLY FOR THE RIO GRANDE BASIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rio Grande basin in Colorado, New Mexico, Texas, and Mexico is an important drainage in southwestern North America, vital for water consumption by a rapidly growing population, irrigated agriculture, economic development, preservation of endangered species, and energy generation. The most impor...

  6. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  7. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  8. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  9. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  10. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  11. 75 FR 37308 - Drawbridge Operation Regulations; Grand River, Grand Haven, MI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Grand River, Grand Haven, MI AGENCY....S. 31 Bridge at Mile 2.89 over the Grand River, at Grand Haven, MI. This deviation temporarily.... on July 5, 2010 and again from 10 p.m. on August 7, 2010 to 2 a.m. on August 8, 2010....

  12. Josephson junction simulation of neurons

    NASA Astrophysics Data System (ADS)

    Crotty, Patrick; Schult, Dan; Segall, Ken

    2010-07-01

    With the goal of understanding the intricate behavior and dynamics of collections of neurons, we present superconducting circuits containing Josephson junctions that model biologically realistic neurons. These “Josephson junction neurons” reproduce many characteristic behaviors of biological neurons such as action potentials, refractory periods, and firing thresholds. They can be coupled together in ways that mimic electrical and chemical synapses. Using existing fabrication technologies, large interconnected networks of Josephson junction neurons would operate fully in parallel. They would be orders of magnitude faster than both traditional computer simulations and biological neural networks. Josephson junction neurons provide a new tool for exploring long-term large-scale dynamics for networks of neurons.

  13. An induced junction photovoltaic cell

    NASA Technical Reports Server (NTRS)

    Call, R. L.

    1974-01-01

    Silicon solar cells operating with induced junctions rather than diffused junctions have been fabricated and tested. Induced junctions were created by forming an inversion layer near the surface of the silicon by supplying a sheet of positive charge above the surface. Measurements of the response of the inversion layer cell to light of different wavelengths indicated it to be more sensitive to the shorter wavelengths of the sun's spectrum than conventional cells. The greater sensitivity occurs because of the shallow junction and the strong electric field at the surface.

  14. Scientific Grand Challenges: Discovery In Basic Energy Sciences: The Role of Computing at the Extreme Scale - August 13-15, 2009, Washington, D.C.

    SciTech Connect

    Galli, Giulia; Dunning, Thom

    2009-08-13

    The U.S. Department of Energy’s (DOE) Office of Basic Energy Sciences (BES) and Office of Advanced Scientific Computing Research (ASCR) workshop in August 2009 on extreme-scale computing provided a forum for more than 130 researchers to explore the needs and opportunities that will arise due to expected dramatic advances in computing power over the next decade. This scientific community firmly believes that the development of advanced theoretical tools within chemistry, physics, and materials science—combined with the development of efficient computational techniques and algorithms—has the potential to revolutionize the discovery process for materials and molecules with desirable properties. Doing so is necessary to meet the energy and environmental challenges of the 21st century as described in various DOE BES Basic Research Needs reports. Furthermore, computational modeling and simulation are a crucial complement to experimental studies, particularly when quantum mechanical processes controlling energy production, transformations, and storage are not directly observable and/or controllable. Many processes related to the Earth’s climate and subsurface need better modeling capabilities at the molecular level, which will be enabled by extreme-scale computing.

  15. GRAND DITCH VIEW, FROM FARVIEW CURVE OVERLOOK, VIEWING WEST. DITCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GRAND DITCH VIEW, FROM FARVIEW CURVE OVERLOOK, VIEWING WEST. DITCH IS INDICATED BY HORIZONTAL LINE NEAR TOP OF CLOUD COVERED PEAKS - Grand Ditch, Baker Creek to LaPoudre Pass Creek, Grand Lake, Grand County, CO

  16. Topographic view of the Grande Ronde River Bridge, view looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Topographic view of the Grande Ronde River Bridge, view looking south - Grande Ronde River Bridge, Sprnning Grande Ronde River on Old Oregon Trail Highway (Oregon Route 6), La Grande, Union County, OR

  17. General perspective view of the Grande Ronde River Bridge, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General perspective view of the Grande Ronde River Bridge, view looking southwest - Grande Ronde River Bridge, Sprnning Grande Ronde River on Old Oregon Trail Highway (Oregon Route 6), La Grande, Union County, OR

  18. General perspective view of the Grande Ronde River Bridge, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General perspective view of the Grande Ronde River Bridge, view looking southeast - Grande Ronde River Bridge, Sprnning Grande Ronde River on Old Oregon Trail Highway (Oregon Route 6), La Grande, Union County, OR

  19. View of downstream face of Grand Coulee Dam (from just ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of downstream face of Grand Coulee Dam (from just below No. 3 Powerhouse), looking southwest. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  20. View of upstream face of Grand Coulee Dam, looking west. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of Grand Coulee Dam, looking west. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  1. View of upstream face of Grand Coulee Dam, looking northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of Grand Coulee Dam, looking northeast from the Pumping Plant. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  2. View of upstream face of Grand Coulee Dam, looking northeast. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of Grand Coulee Dam, looking northeast. This image features a cloudless sky.) - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  3. City of Grand Rapids Building Solar Roof Demonstration

    SciTech Connect

    DeClercq, Mark; Martinez, Imelda

    2012-08-31

    Grand Rapids, Michigan is striving to reduce it environmental footprint. The municipal government organization has established environmental sustainability policies with the goal of securing 100% of its energy from renewable sources by 2020. This report describes the process by which the City of Grand Rapids evaluated, selected and installed solar panels on the Water/Environmental Services Building. The solar panels are the first to be placed on a municipal building. Its new power monitoring system provides output data to assess energy efficiency and utilization. It is expected to generate enough clean solar energy to power 25 percent of the building. The benefit to the public includes the economic savings from reduced operational costs for the building; an improved environmentally sustainable area in which to live and work; and increased knowledge about the use of solar energy. It will serve as a model for future energy saving applications.

  4. GUARD RING SEMICONDUCTOR JUNCTION

    DOEpatents

    Goulding, F.S.; Hansen, W.L.

    1963-12-01

    A semiconductor diode having a very low noise characteristic when used under reverse bias is described. Surface leakage currents, which in conventional diodes greatly contribute to noise, are prevented from mixing with the desired signal currents. A p-n junction is formed with a thin layer of heavily doped semiconductor material disposed on a lightly doped, physically thick base material. An annular groove cuts through the thin layer and into the base for a short distance, dividing the thin layer into a peripheral guard ring that encircles the central region. Noise signal currents are shunted through the guard ring, leaving the central region free from such currents. (AEC)

  5. Spatial updating in the great grand canonical ensemble

    NASA Astrophysics Data System (ADS)

    Orkoulas, G.; Noon, Daniel P.

    2009-10-01

    In spatial updating grand canonical Monte Carlo, particle transfers are implemented by examining the local environment around a point in space. In the present work, these algorithms are extended to very high densities by allowing the volume to fluctuate, thus forming a great grand canonical ensemble. Since fluctuations are unbounded, a constraint must be imposed. The constrained ensemble may be viewed as a superposition of either constant-pressure or grand canonical ensembles. Each simulation of the constrained ensemble requires a set of weights that must be determined iteratively. The outcome of a single simulation is the density of states in terms of all its independent variables. Since all extensive variables fluctuate, it is also possible to estimate absolute free energies and entropies from a single simulation. The method is tested on a system of hard spheres and the transition from the fluid to a face-centered cubic crystal is located with high precision.

  6. Graphene/silicon nanowire Schottky junction for enhanced light harvesting.

    PubMed

    Fan, Guifeng; Zhu, Hongwei; Wang, Kunlin; Wei, Jinquan; Li, Xinming; Shu, Qinke; Guo, Ning; Wu, Dehai

    2011-03-01

    Schottky junction solar cells are assembled by directly coating graphene films on n-type silicon nanowire (SiNW) arrays. The graphene/SiNW junction shows enhanced light trapping and faster carrier transport compared to the graphene/planar Si structure. With chemical doping, the SiNW-based solar cells showed energy conversion efficiencies of up to 2.86% at AM1.5 condition, opening a possibility of using graphene/semiconductor nanostructures in photovoltaic application. PMID:21323376

  7. Evidence for a minigap in YBCO grain boundary Josephson junctions.

    PubMed

    Lucignano, P; Stornaiuolo, D; Tafuri, F; Altshuler, B L; Tagliacozzo, A

    2010-10-01

    Self-assembled YBaCuO diffusive grain boundary submicron Josephson junctions offer a realization of a special regime of the proximity effect, where normal state coherence prevails on the superconducting coherence in the barrier region. Resistance oscillations from the current-voltage characteristic encode mesoscopic information on the junction and more specifically on the minigap induced in the barrier. Their persistence at large voltages is evidence of the long lifetime of the antinodal (high energy) quasiparticles. PMID:21230860

  8. [Obstetric characteristics of a grand multipara].

    PubMed

    Raudaskoski, Tytti; Gissler, Mika

    2014-01-01

    Finnish grand multiparae (4 to 7 previous childbirths) use maternal care services to the same extent, weigh more and smoke less compared with primigravidae and multiparae (1 to 3 previous childbirths). Problems in pregnancy and delivery are least common in multiparae. Frequency of the hypertension problem in grand grand multiparae (8 or more previous childbirths) is 1.3-fold and the risk of ablation in all grand multiparae approximately 1.5-fold higher in comparison with multiparae. Compared with primigravidae and multiparae, childbirths by grand multiparae proceed in a more regular manner, although the number of induced labors is higher with the latter. PMID:25095478

  9. SU(9) grand unified theory

    SciTech Connect

    Fujimoto, Y.; Sodano, P.

    1981-04-01

    Frampton's SU(9) model is considered in detail as a grand unified theory with SU(4) horizontal symmetry. We find a correlation among neutrino, horizontal-gauge-boson, and new-fermion masses. With neutrino mass around 10 eV, the horizontal gauge boson is estimated to be as heavy as 6 x 10/sup 10/ GeV. The theory also contains new charged-current processes, which are B+L conserving and ..delta..L=2.

  10. Light emission from statistically rough Ag tunnel junctions

    NASA Astrophysics Data System (ADS)

    Dawson, P.; Walmsley, D. G.

    1986-05-01

    Observation of both narrowband 3.8 eV emission and broadband, mostly visible emission from single, statistically rough CaF 2AlAl 2O 3Ag tunnel junction structures under high applied bias (> 4 V) is reported. Resolution between the two components of the output is much superior in the tunnel junction arrangement than in experiments where high energy (keV) electron beams impinge on rough Ag films. Importantly, we find that the broadband emission cuts off at 3.5 eV even when the applied bias exceeds 4 V. This cut-off energy is higher than that reported elsewhere and confirms that for Ag junctions the bulk of the broadband output is indeed mediated by the fast surface plasmon polariton mode (which has a maximum energy of 3.5 eV) and not by the slow or junction mode. Both components of the output are found to be most intense in the direction normal to the junction surface and to be substantially unpolarised. For the broadband emission these features are consistent with results of theoretical calculation; for the narrowband 3.8 eV emission they contrast sharply with the observed characteristics of the 3.8 eV emission from smooth Ag junctions.