Sample records for atmospherically emitted radiance

  1. Atmospheric Emitted Radiance Interferometer (AERI) Archived Data at the University of Wisconsin Space Science and Engineering Center (SSEC)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The AERI instrument is an advanced version of the high spectral resolution interferometer sounder (HIS) designed and fabricated at the University of Wisconsin (Revercomb et al. 1988) to measure upwelling infrared radiances from an aircraft. The AERI is a fully automated ground-based passive infrared interferometer that measures downwelling atmospheric radiance from 3.3 - 18.2 mm (550 - 3000 cm-1) at less than 10-minute temporal resolution with a spectral resolution of one wavenumber. It has been used in DOEĆs Atmospheric Radiation Measurement (ARM) program. Much of the data available here at the Cooperative Institute for Meteorological Satellite Studies (CIMSS), an institute within the University of Wisconsin’s Space Science and Engineering Center, may also be available in the ARM Archive. On this website, data and images from six different field experiments are available, along with AERIPLUS realtime data for the Madison, Wisconsin location. Realtime data includes temperature and water vapor time-height cross sections, SKEWT diagrams, convective stability indices, and displays from a rooftop Lidar instrument. The field experiments took place in Oaklahoma and Wisconsin with the AERI prototype.

  2. Semianalytic Monte Carlo calculation of reflected and transmitted radiance in a plane parallel atmosphere

    E-Print Network [OSTI]

    Moffitt, John Russell

    1972-01-01T23:59:59.000Z

    SEMIANALYTIC MONTE CARLO CALCULATION OF REFLECTED AND TRANSMITTED RADIANCE IN A PLANE PARALLEL ATMOSPHERE A Thesis by JOHN RUSSELL MOFFITT Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1972 Major Subject: Physics SEMIANALYTIC MONTE CARLO CALCULATION OF REFLECTED AND TRANSMITTED RADIANCE IN A PLANE PARALLEL ATMOSPHERE A Thesis by JOHN RUSSELL MOFFITT Approved as to style and content by: (Cha...

  3. atmospheric emitted radiance: Topics by E-print Network

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

    mesoscales (wavelengths of 64-957 km) were obtained potential energy by differential solar heating. This is converted to eddy available potential energy 11 The horizontal...

  4. Posters Atmospheric Emitted Radiance Interferometer Data Analysis Methods

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah Project Office PressPostdoctoraldecadal observations71 Posters A513

  5. The ARM Atmospheric Emitted Radiance Interferometer (AERI): Status and

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructureProposedPAGESafetyTed Donat

  6. Numerical calculation of reflected and transmitted radiance in a plane parallel atmosphere by doubling very thin layers

    E-Print Network [OSTI]

    Entrekin, Robert David

    1976-01-01T23:59:59.000Z

    NUMERICAL CALCULATION OF REFLECTED AND TRANSMITTED RADIANCE IN A PLANE PARALLEL ATMOSPHERE BY DOUBLING VERY THIN LAYERS A Thesis by ROBERT DAVID ENTREKIN Submitted to the Graduate College of Texas ASM University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE December 1976 Major Subject: Physics NUMERICAL CALCULATION OF REFLECTED AND TRANSMITTED RADIANCE IN A PLANE PARALLEL ATMOSPHERE BY DOUBLING VERY THIN LAYERS A Thesis by ROBERT DAVID ENTREKIN Approved...

  7. Semianalytic Monte Carlo calculation of reflected and transmitted radiance in a plane parallel atmosphere 

    E-Print Network [OSTI]

    Moffitt, John Russell

    1972-01-01T23:59:59.000Z

    thickness. Both Rayleigh and isotropic scattering are considered and examples are included for r = 1, m = 1, n = -1, m ' o ' 1 and A = 0. The method is also extended to include non-zero ground albedos and an example is included. A method... scattering for = 1 m = 1 n = -1 and A = 0. The continuous m o 1 10 curve is Matrix Operator Theory result 27 INTROBNCTION 1. Current and Past Methods for Calculating Reflected and Trans- mitted Radiance Early work in calculating the reflected...

  8. Posters Atmospheric Emitted Radiance Interferometer: Status and Water Vapor Continuum Results

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah Project Office PressPostdoctoraldecadal observations71 Posters

  9. Electron density and temperature measurement by continuum radiation emitted from weakly ionized atmospheric pressure plasmas

    SciTech Connect (OSTI)

    Park, Sanghoo; Choe, Wonho, E-mail: wchoe@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Youn Moon, Se [High-enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 561-756 (Korea, Republic of); Park, Jaeyoung [5771 La Jolla Corona Drive, La Jolla, CA 92037 (United States)

    2014-02-24T23:59:59.000Z

    The electron-atom neutral bremsstrahlung continuum radiation emitted from weakly ionized plasmas is investigated for electron density and temperature diagnostics. The continuum spectrum in 450–1000?nm emitted from the argon atmospheric pressure plasma is found to be in excellent agreement with the neutral bremsstrahlung formula with the electron-atom momentum transfer cross-section given by Popovi?. In 280–450?nm, however, a large discrepancy between the measured and the neutral bremsstrahlung emissivities is observed. We find that without accounting for the radiative H{sub 2} dissociation continuum, the temperature, and density measurements would be largely wrong, so that it should be taken into account for accurate measurement.

  10. Radiance | Department of Energy

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

    retrofit of the New York Times offices in New York.
    Image credit: Andrew McNeil, LBNL. Radiance rendering of daylighting and electric lighting for the retrofit of the New...

  11. Absolute spectral radiance responsivity calibration of sun photometers

    SciTech Connect (OSTI)

    Xu Qiuyun; Zheng Xiaobing; Zhang Wei; Wang Xianhua; Li Jianjun; Li Xin [Key Laboratory of Optical Calibration and Characterization, Chinese Academy of Sciences, Hefei 230031 (China); Li Zhengqiang [Laboratoire d'Optique Atmospherique, Universite Lille 1, Villeneuve d'Ascq 59655 (France) and State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 100101 (China)

    2010-03-15T23:59:59.000Z

    Sun photometers are designed to measure direct solar irradiance and diffused sky radiance for the purpose of atmospheric parameters characterization. A sun photometer is usually calibrated by using a lamp-illuminated integrating sphere source for its band-averaged radiance responsivity, which normally has an uncertainty of 3%-5% at present. Considering the calibration coefficients may also change with time, a regular high precision calibration is important to maintain data quality. In this paper, a tunable-laser-based facility for spectral radiance responsivity calibration has been developed at the Key Laboratory of Optical Calibration and Characterization, Chinese Academy of Sciences. A reference standard radiance radiometer, calibrated against cryogenic radiometer, is used to determine the radiance from a laser-illuminated integrating sphere source. Spectral radiance responsivity of CIMEL CE318-2 sun photometer is calibrated using this new calibration system with a combined standard uncertainty of about 0.8%. As a validation, the derived band-averaged radiance responsivity are compared to that from a Goddard Space Flight Center lamp-based sphere calibration and good agreements (difference <1.4%) are found from 675 to 1020 nm bands.

  12. On the filling factor of emitting material in the upper atmosphere of Epsilon Eri (K2 V)

    E-Print Network [OSTI]

    S. A. Sim; C. Jordan

    2003-08-28T23:59:59.000Z

    The emission measure distribution in the upper transition region and corona of Epsilon Eri is derived from observed emission line fluxes. Theoretical emission measure distributions are calculated assuming that the radiation losses are balanced by the net conductive flux. We discuss how the area factor of the emitting regions as a function of temperature can be derived from a comparison between these emission measure distributions. It is found that the filling factor varies from ~0.2 in the mid transition region to ~1.0 in the inner corona. The sensitivity of these results to the adopted ion fractions, the iron abundance and other parameters is discussed. The area factors found are qualitatively similar to the observed structure of the solar atmosphere, and can be used to constrain two-component models of the chromosphere. Given further observations, the method could be applied to investigate the trends in filling factors with indicators of stellar activity.

  13. The Radiance Process: Water and Chemical Free Cleaning 

    E-Print Network [OSTI]

    Robison, J. H.

    1998-01-01T23:59:59.000Z

    Radiance Services Company manages a new technology called the Radiance Process®, a dry non-toxic technology for surface cleaning. The Radiance Process received the National Pollution Prevention Roundtable's 1997 Most Valuable Pollution Prevention...

  14. Horizon brightness revisited: measurements and a model of clear-sky radiances

    E-Print Network [OSTI]

    Lee Jr., Raymond L.

    from solar energy engineering2 ,3 to atmospheric optics4'5 have repeatedly measured and modeled. Second, before the advent of narrow field-of-view (FOV) radiometers8 and photographic analysis tech explanation of the phenomenon. High-Resolution Measurements of Clear-Sky Radiances We beginby electronically

  15. Modelling TOVS radiances of synoptic systems

    E-Print Network [OSTI]

    Coe, Thomas Eddy

    1992-01-01T23:59:59.000Z

    MODELLING TOVS RADIANCES OF SYNOPTIC SYSTEMS A Thesis THOMAS EDDY COE Submitted to the Office of Graduate Studies of TBxBs AFxM Unlvezs&ty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1992 Major... Subject: Meteorology MODELLING TOVS RADIANCES OF SYNOPTIC SYSTEMS THOMAS EDDY COE Approved as to style and content by: James P. McGairk (Chair of Committee) gW('. Denrus M. Driscoll (~) J B. Valdes ~) ~ J. Zi (Head of Deparbrent) Decemter 1992...

  16. A Gentle Introduction to Precomputed Radiance Transfer

    E-Print Network [OSTI]

    Oliveira, Manuel M.

    in computer graphics, and many algorithms have been developed to try to reproduce the visual complexity with the support of modern graphics hardware. Precomputed Radiance Transfer (PRT) is a new graphics technique of the rendering equation to a subset of the light transport paths that handle only energy exchange among diffuse

  17. Bright Light-Emitting Diodes based on Organometal Halide Perovskite

    E-Print Network [OSTI]

    Tan, Zhi-Kuang; Moghaddam, Reza Saberi; Lai, May Ling; Docampo, Pablo; Higler, Ruben; Deschler, Felix; Price, Michael; Sadhanala, Aditya; Pazos, Luis M.; Credgington, Dan; Hanusch, Fabian; Bein, Thomas; Snaith, Henry J.; Friend, Richard H.

    2014-08-03T23:59:59.000Z

    a Keithley 2400 Source Measure Unit (SMU). Photon flux was measured simultaneously using a calibrated silicon photodiode centered over the light-emitting pixel. Radiance in W sr-1 m-2 and luminance in cd m-2 10 were calculated based...

  18. Acceleration of the matrix multiplication of Radiance three phase daylighting simulations

    E-Print Network [OSTI]

    LBNL-6461E Acceleration of the matrix multiplication of Radiance three phase daylighting multiplication of Radiance three phase daylighting simulations with parallel computing on heterogeneous hardware. Radiance, a lighting simulation program, has been used to conduct daylighting simulations for complex

  19. Estimating atmospheric parameters and reducing noise for multispectral imaging

    DOE Patents [OSTI]

    Conger, James Lynn

    2014-02-25T23:59:59.000Z

    A method and system for estimating atmospheric radiance and transmittance. An atmospheric estimation system is divided into a first phase and a second phase. The first phase inputs an observed multispectral image and an initial estimate of the atmospheric radiance and transmittance for each spectral band and calculates the atmospheric radiance and transmittance for each spectral band, which can be used to generate a "corrected" multispectral image that is an estimate of the surface multispectral image. The second phase inputs the observed multispectral image and the surface multispectral image that was generated by the first phase and removes noise from the surface multispectral image by smoothing out change in average deviations of temperatures.

  20. Measuring absolute infrared spectral radiance with correlated photons: new arrangements

    E-Print Network [OSTI]

    Migdall, Alan

    metrologia Measuring absolute infrared spectral radiance with correlated photons: new arrangements must be created in pairs, the VIS channel is also stimulated. In this Metrologia, 1998, 35, 295-300 295

  1. Porous light-emitting compositions

    DOE Patents [OSTI]

    Burrell, Anthony K. (Los Alamos, NM); McCleskey, Thomas Mark (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Bauer, Eve (Los Alamos, NM); Mueller, Alexander H. (Los Alamos, NM)

    2012-04-17T23:59:59.000Z

    Light-emitting devices are prepared by coating a porous substrate using a polymer-assisted deposition process. Solutions of metal precursor and soluble polymers having binding properties for metal precursor were coated onto porous substrates. The coated substrates were heated at high temperatures under a suitable atmosphere. The result was a substrate with a conformal coating that did not substantially block the pores of the substrate.

  2. Analytical Green's function of the radiative transfer radiance for the infinite medium

    SciTech Connect (OSTI)

    Liemert, Andre; Kienle, Alwin [Institut fuer Lasertechnologien in der Medizin und Messtechnik, Helmholtzstrasse12, D-89081 Ulm (Germany)

    2011-03-15T23:59:59.000Z

    An analytical solution of the radiative transfer equation for the radiance caused by an isotropic source which is located in an infinitely extended medium was derived using the P{sub N} method. The results were compared with Monte Carlo simulations and excellent agreement was found. In addition, the radiance of the SP{sub N} approximation for the same geometry was derived. Comparison with Monte Carlo simulations showed that the SP{sub N} radiance, although being more exact than the radiance derived from diffusion theory, has relatively large errors in many relevant cases.

  3. Precomputed Radiance Transfer for Real-Time Rendering in Dynamic, Low-Frequency Lighting Environments

    E-Print Network [OSTI]

    O'Brien, James F.

    Precomputed Radiance Transfer for Real-Time Rendering in Dynamic, Low-Frequency Lighting a new, real-time method for rendering diffuse and glossy objects in low-frequency lighting environments-frequency incident lighting into transferred radiance which includes global effects like shadows and interreflections

  4. A comparison of model-generated and satellite-observed radiances

    E-Print Network [OSTI]

    Smith, Donna Ellen Woolley

    1989-01-01T23:59:59.000Z

    periods in January: Every 12 hours between 21 January at 12 GMT and 29 January at 00 GMT. 2. Ten time periods in May: Every 12 hours between 12 May at 12 GMT and 17 May at 00 GMT, B. TIROS-N HIRS/MSU Radiances Channel radiances used as ground truth... are discussed in Chapter IV. Detailed information is described by Smith et al. (1979). Satellite radiances are not observed synoptically at 00 GMT and 12 GMT. Therefore, measurements made during satellite passes within three hours of Sponsored...

  5. Direct radiative effect of aerosols emitted by transport from road, shipping and

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Direct radiative effect of aerosols emitted by transport from road, shipping and aviation 1234567.0 License. Atmospheric Chemistry and Physics Direct radiative effect of aerosols emitted by transport: from ­ Published: 17 May 2010 Abstract. Aerosols and their precursors are emitted abun- dantly by transport

  6. Light-emitting diode spherical packages: an equation for the light transmission efficiency

    E-Print Network [OSTI]

    Moreno, Ivan; Avendano-Alejo, Maximino; 10.1364/AO.49.000012

    2011-01-01T23:59:59.000Z

    Virtually all light-emitting diodes (LEDs) are encapsulated with a transparent epoxy or silicone-gel. In this paper we analyze the optical efficiency of spherical encapsulants. We develop a quasi-radiometric equation for the light transmission efficiency, which incorporates some ideas of Monte-Carlo ray tracing into the context of radiometry. The approach includes the extended source nature of the LED chip, and the chip radiance distribution. The equation is an explicit function of the size and the refractive index of the package, and also of several chip parameters such as shape, size, radiance, and location inside the package. To illustrate the use of this equation, we analyze several packaging configurations of practical interest; for example, a hemispherical dome with multiple chips, a flat encapsulation as a special case of the spherical package, and approximate calculations of an encapsulant with a photonic crystal LED or with a photonic quasi crystal LED. These calculations are compared with Monte-Carl...

  7. BTRAM: An Interactive Atmospheric Radiative Transfer Model I.M. Chapman1

    E-Print Network [OSTI]

    Naylor, David A.

    radiance incident on the spectrometer/radiometer. Computer simulations, known as radiative transfer models source of opacity at submillimetre wavelengths where many objects emit most of their energy. Although high altitude observatories (such as the James Clerk Maxwell Telescope (JCMT) in Hawaii and the Atacama

  8. Light emitting ceramic device

    DOE Patents [OSTI]

    Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

    2010-05-18T23:59:59.000Z

    A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, is herein claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

  9. Mesoscale Spectra of Mars's Atmosphere Derived from MGS TES Infrared Radiances TAKESHI IMAMURA

    E-Print Network [OSTI]

    Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa FUKUHARA Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara potential energy by differential solar heating. This is converted to eddy available potential energy

  10. Method of making organic light emitting devices

    DOE Patents [OSTI]

    Shiang, Joseph John (Niskayuna, NY); Janora, Kevin Henry (Schenectady, NY); Parthasarathy, Gautam (Saratoga Springs, NY); Cella, James Anthony (Clifton Park, NY); Chichak, Kelly Scott (Clifton Park, NY)

    2011-03-22T23:59:59.000Z

    The present invention provides a method for the preparation of organic light-emitting devices comprising a bilayer structure made by forming a first film layer comprising an electroactive material and an INP precursor material, and exposing the first film layer to a radiation source under an inert atmosphere to generate an interpenetrating network polymer composition comprising the electroactive material. At least one additional layer is disposed on the reacted first film layer to complete the bilayer structure. The bilayer structure is comprised within an organic light-emitting device comprising standard features such as electrodes and optionally one or more additional layers serving as a bipolar emission layer, a hole injection layer, an electron injection layer, an electron transport layer, a hole transport layer, exciton-hole transporting layer, exciton-electron transporting layer, a hole transporting emission layer, or an electron transporting emission layer.

  11. Solar Energy, 2006, 80, 3, 361-367 SIMULATING METEOSAT-7 BROADBAND RADIANCES USING TWO

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Solar Energy, 2006, 80, 3, 361-367 SIMULATING METEOSAT-7 BROADBAND RADIANCES USING TWO VISIBLE-00361360,version1-13Feb2009 Author manuscript, published in "Solar Energy 80, 3 (2006) 361-367" DOI : 10.1016/j.solener.2005.01.012 #12;Solar Energy, 2006, 80, 3, 361-367 · Imet-7 the maximum irradiance

  12. The Five-Phase Method for Simulating Complex Fenestration with Radiance

    E-Print Network [OSTI]

    series of illuminance or luminance result V = View matrix, relating outgoing directions on window the sun luminance (no sky luminance) Ssun = Direct sun matrix containing the radiance and position of the luminance contributions that are used in the five-phase for a space with clear glazing. E3ph - Eds-3ph + Eds

  13. The impact of explicit cloud boundary information on ice cloud microphysical property retrievals from infrared radiances

    E-Print Network [OSTI]

    Stephens, Graeme L.

    from infrared radiances Steven J. Cooper, Tristan S. L'Ecuyer, and Graeme L. Stephens Department inclusion of explicit cloud boundary information from complementary sensors as well as providing a suite of diagnostic tools for evaluating the dominant sources of uncertainty in all retrieved quantities. Errors

  14. Modeling Wildland Fire Radiance in Synthetic Remote Sensing B.S. Beijing Institute of Technology, 1996

    E-Print Network [OSTI]

    Salvaggio, Carl

    efforts in phenomenology studies, algorithm development, and sensor evaluation. Synthetic scenes are also and op- tical properties of wildfire and burn area in an infrared remote sensing system will assist look like as seen by the airborne sensor. Radiance scene rendering of the 3D flame iv #12;v includes 2D

  15. Remote sensing of Greenland ice sheet using multispectral near-infrared and visible radiances

    E-Print Network [OSTI]

    Dozier, Jeff

    Remote sensing of Greenland ice sheet using multispectral near-infrared and visible radiances Petr microwave methods. The method should be useful for long-term monitoring of the melt area of the Greenland of MODIS retrievals of the western portion of the Greenland ice sheet over the period 2000 to 2006

  16. Process of preparing metal parts to be heated by means of infrared radiance

    DOE Patents [OSTI]

    Mayer, Howard Robinson (Cincinnati, OH); Blue, Craig A. (Knoxville, TN)

    2009-06-09T23:59:59.000Z

    A method for preparing metal for heating by infrared radiance to enable uniform and consistent heating. The surface of one or more metal parts, such as aluminum or aluminum alloy parts, is treated to alter the surface finish to affect the reflectivity of the surface. The surface reflectivity is evaluated, such as by taking measurements at one or more points on the surface, to determine if a desired reflectivity has been achieved. The treating and measuring are performed until the measuring indicates that the desired reflectivity has been achieved. Once the treating has altered the surface finish to achieve the desired reflectivity, the metal part may then be exposed to infrared radiance to heat the metal part to a desired temperature, and that heating will be substantially consistent throughout by virtue of the desired reflectivity.

  17. IEEE TRANSACTIONS ON VISUALIZATION & COMPUTER GRAPHICS 1 Radiance Transfer Biclustering for Real-time

    E-Print Network [OSTI]

    Zhou, Kun

    --We present a real-time algorithm to render all-frequency radiance transfer at both macro-scale and meso-scale. At a meso-scale, the shading is computed on a per-pixel basis by integrating the product of the local inci in a meso-scale, densely sampled at each pixel and mapped over the object. The bi-scale transfer

  18. Extracting High Temperature Event radiance from satellite images and correcting for saturation using Independent Component Analysis

    E-Print Network [OSTI]

    Barnie, Talfan; Oppenheimer, Clive

    2014-12-01T23:59:59.000Z

    radiance from other sources, such as reflected sunlight and thermal emission from ground, clouds and atmo- sphere as well as instrument response effects such as stray light image pixel size and irregular acquisition intervals which make analysing data from... sources are strongly non-Gaussian and will tend to give more Gaussian signals when mixed with radiative signals from other environmental processes (the diurnal cycle, cloud cover, etc.). Given volcanic thermal signals tend to be isolated discrete events...

  19. Final Scientific/Technical Report Grant title: Use of ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction This is a collaborative project with the NASA GSFC project of Dr. A. Marshak and W. Wiscombe (PIs). This report covers BU activities from February 2011 to June 2011 and BU "Â?no-cost extension" activities from June 2011 to June 2012. This report summarizes results that complement a final technical report submitted by the PIs in 2011.

    SciTech Connect (OSTI)

    Knyazikhin, Y

    2012-09-10T23:59:59.000Z

    Main results are summarized for work in these areas: spectrally-invariant approximation within atmospheric radiative transfer; spectral invariance of single scattering albedo for water droplets and ice crystals at weakly absorbing wavelengths; seasonal changes in leaf area of Amazon forests from leaf flushing and abscission; and Cloud droplet size and liquid water path retrievals from zenith radiance measurements.

  20. Toward ZnO Light Emitting Diode

    E-Print Network [OSTI]

    Liu, Jianlin

    2008-01-01T23:59:59.000Z

    applications such as light emitting diodes (LEDs) and laser009 "Toward ZnO Light Emitting Diode" Jianlin Liu July 2008Title: “Toward ZnO Light Emitting Diode” Sponsor: UC Energy

  1. A validation of the Radiance three-phase simulation method for modeling annual daylight performance of optically-complex fenestration systems

    E-Print Network [OSTI]

    McNeil, Andrew

    2013-01-01T23:59:59.000Z

    J. , 2011. Simulating the Daylight Performance of Complexof dynamic RADIANCE-based daylight simulations for a testS.E. , 1998. Energy and Daylight Performance of Angular

  2. Infrared emitting device and method

    DOE Patents [OSTI]

    Kurtz, Steven R. (Albuquerque, NM); Biefeld, Robert M. (Albuquerque, NM); Dawson, L. Ralph (Albuquerque, NM); Howard, Arnold J. (Albuquerque, NM); Baucom, Kevin C. (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    An infrared emitting device and method. The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region. Examples have been set forth showing embodiments of the present invention as surface- and edge-emitting light emitting diodes (LEDs), an optically-pumped semiconductor laser, and an electrically-injected semiconductor diode laser. The light emission from each of the infrared emitting devices of the present invention is in the midwave infrared region of the spectrum from about 2 to 6 microns.

  3. Acceleration of Radiance for Lighting Simulation by Using Parallel Computing with OpenCL

    SciTech Connect (OSTI)

    Zuo, Wangda; McNeil, Andrew; Wetter, Michael; Lee, Eleanor

    2011-09-06T23:59:59.000Z

    We report on the acceleration of annual daylighting simulations for fenestration systems in the Radiance ray-tracing program. The algorithm was optimized to reduce both the redundant data input/output operations and the floating-point operations. To further accelerate the simulation speed, the calculation for matrix multiplications was implemented using parallel computing on a graphics processing unit. We used OpenCL, which is a cross-platform parallel programming language. Numerical experiments show that the combination of the above measures can speed up the annual daylighting simulations 101.7 times or 28.6 times when the sky vector has 146 or 2306 elements, respectively.

  4. Simulating the Daylight Performance of Complex Fenestration Systems Using Bidirectional Scattering Distribution Functions within Radiance

    SciTech Connect (OSTI)

    Ward, Gregory; Mistrick, Ph.D., Richard; Lee, Eleanor; McNeil, Andrew; Jonsson, Ph.D., Jacob

    2011-01-21T23:59:59.000Z

    We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies of glazing, shading, and other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual performance evaluations of CFS, and b) accurate renderings of CFS despite the loss of spatial resolution associated with low-resolution BSDF datasets for inhomogeneous systems. Validation, accuracy, and limitations of the methods are discussed.

  5. Blue light emitting thiogallate phosphor

    DOE Patents [OSTI]

    Dye, Robert C. (Los Alamos, NM); Smith, David C. (Los Alamos, NM); King, Christopher N. (Portland, OR); Tuenge, Richard T. (Hillsboro, OR)

    1998-01-01T23:59:59.000Z

    A crystalline blue emitting thiogallate phosphor of the formula RGa.sub.2 S.sub.4 :Ce.sub.x where R is selected from the group consisting of calcium, strontium, barium and zinc, and x is from about 1 to 10 atomic percent, the phosphor characterized as having a crystalline microstructure on the size order of from about 100 .ANG. to about 10,000 .ANG. is provided together with a process of preparing a crystalline blue emitting thiogallate phosphor by depositing on a substrate by CVD and resultant thin film electroluminescent devices including a layer of such deposited phosphor on an ordinary glass substrate.

  6. Acceleration of the matrix multiplication of Radiance three phase daylighting simulations with parallel computing on heterogeneous hardware of personal computer

    SciTech Connect (OSTI)

    University of Miami; Zuo, Wangda; McNeil, Andrew; Wetter, Michael; Lee, Eleanor S.

    2013-04-30T23:59:59.000Z

    Building designers are increasingly relying on complex fenestration systems to reduce energy consumed for lighting and HVAC in low energy buildings. Radiance, a lighting simulation program, has been used to conduct daylighting simulations for complex fenestration systems. Depending on the configurations, the simulation can take hours or even days using a personal computer. This paper describes how to accelerate the matrix multiplication portion of a Radiance three-phase daylight simulation by conducting parallel computing on heterogeneous hardware of a personal computer. The algorithm was optimized and the computational part was implemented in parallel using OpenCL. The speed of new approach was evaluated using various daylighting simulation cases on a multicore central processing unit and a graphics processing unit. Based on the measurements and analysis of the time usage for the Radiance daylighting simulation, further speedups can be achieved by using fast I/O devices and storing the data in a binary format.

  7. A model for the directional distribution of the diffuse sky radiance with an application to a CPC collector

    SciTech Connect (OSTI)

    Siala, F.M.F. (Center for Solar Energy Studies, Tripoli (Libya)); Hooper, F.C. (Univ. of Toronto, Ontario (Canada))

    1990-01-01T23:59:59.000Z

    The development of a new, semi-empirical model for the directional distribution of the diffuse radiance is reported. The proposed regression-type model, with the form of its base functions obtained from physical principles, is based on a combination of the purely physical reasoning approach and the purely empirical approach. Direct multiple-scattering calculations are circumvented through the use of the method of successive orders of scattering. The model is calibrated for the mean diffuse radiance estimated under all sky conditions reported in a large and comprehensive diffuse radiance data set. It is found that only a small increase in accuracy is gained by including higher orders of scattering, and this increase does not justify the complexity of the resulting model. Therefore, the single scattering approximation is recommended. The use of the model is illustrated in a typical application, in which the fraction of diffuse radiation intercepted by the receive of a compound parabolic concentrator is computed.

  8. Hawking-Unruh Thermal Radiance as Relativistic Exponential Scaling of Quantum Noise

    E-Print Network [OSTI]

    B. L. Hu

    1996-06-26T23:59:59.000Z

    The Hawking-Unruh effect of thermal radiance from a black hole or observed by an accelerated detector is usually viewed as a geometric effect related to the existence of an event horizon. Here we propose a new viewpoint, that the detection of thermal radiance in these systems is a local, kinematic effect arising from the vacuum being subjected to a relativistic exponential scale transformation. This kinematic effect alters the relative weight of quantum versus thermal fluctuations (noise) between the two vacua. This approach can treat conditions which the geometric approach cannot, such as systems which do not even have an event horizon. An example is the case of an observer whose acceleration is nonuniform or only asymptotically uniform. Since this approach is based on concepts and techniques of non-equilibrium statistical mechanics, it is more adept to dynamical problems, such as the dissipation, fluctuation, and entropy aspects of particle creation and phase transitions in black hole collapse and in the early universe.

  9. Broadband light-emitting diode

    DOE Patents [OSTI]

    Fritz, Ian J. (Albuquerque, NM); Klem, John F. (Sandia Park, NM); Hafich, Michael J. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A broadband light-emitting diode. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3-2 .mu.m. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-division-multiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft.

  10. Broadband light-emitting diode

    DOE Patents [OSTI]

    Fritz, I.J.; Klem, J.F.; Hafich, M.J.

    1998-07-14T23:59:59.000Z

    A broadband light-emitting diode is disclosed. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3--2 {micro}m. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-divisionmultiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft. 10 figs.

  11. Infrared emitting device and method

    DOE Patents [OSTI]

    Kurtz, S.R.; Biefeld, R.M.; Dawson, L.R.; Howard, A.J.; Baucom, K.C.

    1997-04-29T23:59:59.000Z

    The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region. Examples have been set forth showing embodiments of the present invention as surface- and edge-emitting light emitting diodes (LEDs), an optically-pumped semiconductor laser, and an electrically-injected semiconductor diode laser. The light emission from each of the infrared emitting devices of the present invention is in the midwave infrared region of the spectrum from about 2 to 6 microns. 8 figs.

  12. A comparison of cloud top heights computed from airborne lidar and MAS radiance data using CO2 slicing

    E-Print Network [OSTI]

    Sheridan, Jennifer

    A comparison of cloud top heights computed from airborne lidar and MAS radiance data using CO2 in assessing the accuracy of the CO2-slicing cloud height algorithm. Infrared measurements of upwelling which included various single- layer and multilayer cloud conditions. Overall, the CO2-slicing method

  13. To appear in the ACM SIGGRAPH conference proceedings Precomputed Local Radiance Transfer for Real-Time Lighting Design

    E-Print Network [OSTI]

    Jensen, Henrik Wann

    -Time Lighting Design Anders Wang Kristensen UCSD Tomas Akenine-M¨oller Lund University Henrik Wann Jensen UCSD Abstract This paper introduces a new method for real-time relight- ing of scenes illuminated by local light sources. We extend previous work on precomputed radiance transfer for distant lighting to local lighting

  14. Radiative interactions: I. Light scattering and emission from irregular particles. II. Time dependent radiative coupling of an atmosphere-ocean system

    E-Print Network [OSTI]

    Li, Changhui

    2006-10-30T23:59:59.000Z

    and fluorescence. In the second part of the dissertation, we study radiative interactions in an atmosphere-ocean system. By using the so called Matrix operator method, not only the radiance of the radiation field, but also the polarization of the radiation field...

  15. Quantum Dot Light Emitting Diode

    SciTech Connect (OSTI)

    Kahen, Keith

    2008-07-31T23:59:59.000Z

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

  16. Quantum Dot Light Emitting Diode

    SciTech Connect (OSTI)

    Keith Kahen

    2008-07-31T23:59:59.000Z

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

  17. White light-emitting organic electroluminescent devices

    DOE Patents [OSTI]

    Shiang, Joseph John; Duggal, Anil Raj; Parthasarathy, Gautam

    2006-06-20T23:59:59.000Z

    A light-emitting device comprises a light-emitting member, which comprises two electrodes, at least two organic electroluminescent ("EL") materials disposed between the electrodes, a charge blocking material disposed between the electrodes, and at least one photoluminescent ("PL") material. The light-emitting member emits electromagnetic ("EM") radiation having a first spectrum in response to a voltage applied across the two electrodes. The PL material absorbs a portion of the EM radiation emitted by the light-emitting member and emits EM radiation having second spectrum different than the first spectrum. Each of the organic EL materials emits EM radiation having a wavelength range selected from the group consisting of blue and red wavelength ranges.

  18. A nanoflare model for active region radiance: application of artificial neural networks

    E-Print Network [OSTI]

    M. Bazarghan; H. Safari; D. E. Innes; E. Karami; S. K. Solanki

    2008-12-20T23:59:59.000Z

    Context. Nanoflares are small impulsive bursts of energy that blend with and possibly make up much of the solar background emission. Determining their frequency and energy input is central to understanding the heating of the solar corona. One method is to extrapolate the energy frequency distribution of larger individually observed flares to lower energies. Only if the power law exponent is greater than 2, is it considered possible that nanoflares contribute significantly to the energy input. Aims. Time sequences of ultraviolet line radiances observed in the corona of an active region are modelled with the aim of determining the power law exponent of the nanoflare energy distribution. Methods. A simple nanoflare model based on three key parameters (the flare rate, the flare duration time, and the power law exponent of the flare energy frequency distribution) is used to simulate emission line radiances from the ions Fe XIX, Ca XIII, and Si iii, observed by SUMER in the corona of an active region as it rotates around the east limb of the Sun. Light curve pattern recognition by an Artificial Neural Network (ANN) scheme is used to determine the values. Results. The power law exponents, alpha 2.8, 2.8, and 2.6 for Fe XIX, Ca XIII, and Si iii respectively. Conclusions. The light curve simulations imply a power law exponent greater than the critical value of 2 for all ion species. This implies that if the energy of flare-like events is extrapolated to low energies, nanoflares could provide a significant contribution to the heating of active region coronae.

  19. White emitting polyfluorene functionalized with azide hybridized on near-UV light emitting diode

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    White emitting polyfluorene functionalized with azide hybridized on near-UV light emitting diode generation using CdSe/ZnS core-shell nanocrystals hybridized with InGaN/GaN light emitting diodesGaN/conjugated polymer hybrid light-emitting diodes," Appl. Phys. Lett. 70, 2664-2666 (1997). 9. H. V. Demir, S

  20. Visible light emitting vertical cavity surface emitting lasers

    DOE Patents [OSTI]

    Bryan, R.P.; Olbright, G.R.; Lott, J.A.; Schneider, R.P. Jr.

    1995-06-27T23:59:59.000Z

    A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of {lambda}/2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In{sub z}(Al{sub y}Ga{sub 1{minus}y}){sub 1{minus}z}P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m {lambda}/2n{sub eff} where m is an integer and n{sub eff} is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of {lambda}/n, typically within the green to red portion of the visible spectrum. 10 figs.

  1. Visible light emitting vertical cavity surface emitting lasers

    DOE Patents [OSTI]

    Bryan, Robert P. (Boulder, CO); Olbright, Gregory R. (Boulder, CO); Lott, James A. (Albuquerque, NM); Schneider, Jr., Richard P. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of .lambda./2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In.sub.z (Al.sub.y Ga.sub.1-y).sub.1-z P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m .lambda./2n.sub.eff where m is an integer and n.sub.eff is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of .lambda./n, typically within the green to red portion of the visible spectrum.

  2. Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region

    E-Print Network [OSTI]

    Slanker, Julie Marie

    2009-05-15T23:59:59.000Z

    Three investigations were conducted on the nature of the radiance field in clear ocean water. It is important to understand the sunlight intensity below the sea surface because this leads to an understanding of how ocean creatures navigate...

  3. Microwave emissivity of fresh water ice--Lake ice and Antarctic ice pack--Radiative transfer simulations versus satellite radiances

    E-Print Network [OSTI]

    Mills, Peter

    2012-01-01T23:59:59.000Z

    Microwave emissivity models of sea ice are poorly validated empirically. Typical validation studies involve using averaged or stereotyped profiles of ice parameters against averaged radiance measurements. Measurement sites are rarely matched and even less often point-by-point. Because of saline content, complex permittivity of sea ice is highly variable and difficult to predict. Therefore, to check the validity of a typical, plane-parallel, radiative-transfer-based ice emissivity model, we apply it to fresh water ice instead of salt-water ice. Radiance simulations for lake ice are compared with measurements over Lake Superior from the Advanced Microwave Scanning Radiometer on EOS (AMSR-E). AMSR-E measurements are also collected over Antarctic icepack. For each pixel, a thermodynamic model is driven by four years of European Center for Medium Range Weather Forecasts (ECMWF) reanalysis data and the resulting temperature profiles used to drive the emissivity model. The results suggest that the relatively simple ...

  4. Sandia National Laboratories: light-emitting diode

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

    light-emitting diode Sandian Receives the Illuminating Engineering Society of North America, South Region Technical Award On December 12, 2014, in Capabilities, Energy, Energy...

  5. Atmospheric Neutrinos

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2006-12-11T23:59:59.000Z

    This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

  6. Green emitting phosphors and blends thereof

    DOE Patents [OSTI]

    Setlur, Anant Achyut (Niskayuna, NY); Siclovan, Oltea Puica (Rexford, NY); Nammalwar, Prasanth Kumar (Bangalore, IN); Sathyanarayan, Ramesh Rao (Bangalore, IN); Porob, Digamber G. (Goa, IN); Chandran, Ramachandran Gopi (Bangalore, IN); Heward, William Jordan (Saratoga Springs, NY); Radkov, Emil Vergilov (Euclid, OH); Briel, Linda Jane Valyou (Niskayuna, NY)

    2010-12-28T23:59:59.000Z

    Phosphor compositions, blends thereof and light emitting devices including white light emitting LED based devices, and backlights, based on such phosphor compositions. The devices include a light source and a phosphor material as described. Also disclosed are phosphor blends including such a phosphor and devices made therefrom.

  7. Light emitting device having peripheral emissive region

    DOE Patents [OSTI]

    Forrest, Stephen R

    2013-05-28T23:59:59.000Z

    Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.

  8. AN EMPIRICAL METHOD FOR ESTIMATING THE THERMAL RADIANCE OF CLEAR SKIES

    E-Print Network [OSTI]

    Berdahl, Paul

    2012-01-01T23:59:59.000Z

    Cloud cover has a strong effect on the atmos- pheric radiationeffect of clouds upon the spectrum of atmospheric radiationclouds will not be detected, but their effect on the sky radiation

  9. Carbonation of alkaline paper mill waste to reduce CO2 greenhouse gas emissions into the atmosphere

    E-Print Network [OSTI]

    Montes-Hernandez, German

    Carbonation of alkaline paper mill waste to reduce CO2 greenhouse gas emissions into the atmosphere of anthropogenic emission of greenhouse gases into the atmosphere such as CO2, CH4, N2O and CFCs. The CO2 emissions to reflect, adsorb and emit the solar energy. However, the continuous emissions of CO2 into the atmosphere

  10. Stable blue phosphorescent organic light emitting devices

    DOE Patents [OSTI]

    Forrest, Stephen R.; Thompson, Mark; Giebink, Noel

    2014-08-26T23:59:59.000Z

    Novel combination of materials and device architectures for organic light emitting devices is provided. An organic light emitting device, is provided, having an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer includes a host and a phosphorescent emissive dopant having a peak emissive wavelength less than 500 nm, and a radiative phosphorescent lifetime less than 1 microsecond. Preferably, the phosphorescent emissive dopant includes a ligand having a carbazole group.

  11. Demonstration Assessment of Light Emitting Diode (LED) Street...

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

    Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Final Report Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Final Report This...

  12. Demonstration Assessment of Light-Emitting Diode (LED) Freezer...

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

    Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case Lighting Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case Lighting This document is a report...

  13. Highly efficient blue organic light emitting devices with indium...

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

    efficient blue organic light emitting devices with indium-free transparent anode on flexible substrates. Highly efficient blue organic light emitting devices with indium-free...

  14. An Infrared Spectral Database for Detection of Gases Emitted...

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

    Database for Detection of Gases Emitted by Biomass Burning. An Infrared Spectral Database for Detection of Gases Emitted by Biomass Burning. Abstract: We report the construction of...

  15. array lasers emitting: Topics by E-print Network

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

    Array and Graphene Hybrid Light Emitting Diodes Jung Min Lee, Jae a class of light emitting diode (LED) with interesting mechanical, optical, and electrical characteristics,...

  16. Analyzing Black Hole super-radiance Emission of Particles/Energy from a Black Hole as a Gedankenexperiment to get bounds on the mass of a Graviton

    E-Print Network [OSTI]

    Andrew Beckwith

    2014-04-15T23:59:59.000Z

    Use of super-radiance in BH physics, so dE/dt past the planet Mercury.The present document makes a given differentiation between super-radiance in the case of conventional BHs and Braneworld BH super-radiance, which may delineate if Braneworlds contribute to an admissible massive graviton in terms of removing the usual problem of the 3/4th the bending of light past the planet Mercury which is normally associated with massive gravitons. This leads to a fork in the road, between two alternatives with the possibility of needing a multiverse containment of BH structure, or embracing what Hawkings wrote up recently, namely a re do of the Event Horizon hypothesis as we know it.

  17. GROUND-BASED CLOUD IMAGES AND SKY RADIANCES IN THE VISIBLE AND NEAR INFRARED REGION FROM

    E-Print Network [OSTI]

    Shields, Janet

    the atmospheric heating rates as well as the amount of solar radiation including biologically effective UV preliminary comparisons with model calculations and cloud cover data both from another type of sky imager data are of specific importance to study the role of clouds on the radiation balance of the earth

  18. Side-emitting fiber optic position sensor

    DOE Patents [OSTI]

    Weiss, Jonathan D. (Albuquerque, NM)

    2008-02-12T23:59:59.000Z

    A side-emitting fiber optic position sensor and method of determining an unknown position of an object by using the sensor. In one embodiment, a concentrated beam of light source illuminates the side of a side-emitting fiber optic at an unknown axial position along the fiber's length. Some of this side-illuminated light is in-scattered into the fiber and captured. As the captured light is guided down the fiber, its intensity decreases due to loss from side-emission away from the fiber and from bulk absorption within the fiber. By measuring the intensity of light emitted from one (or both) ends of the fiber with a photodetector(s), the axial position of the light source is determined by comparing the photodetector's signal to a calibrated response curve, look-up table, or by using a mathematical model. Alternatively, the side-emitting fiber is illuminated at one end, while a photodetector measures the intensity of light emitted from the side of the fiber, at an unknown position. As the photodetector moves further away from the illuminated end, the detector's signal strength decreases due to loss from side-emission and/or bulk absorption. As before, the detector's signal is correlated to a unique position along the fiber.

  19. Visible light surface emitting semiconductor laser

    DOE Patents [OSTI]

    Olbright, Gregory R. (Boulder, CO); Jewell, Jack L. (Bridgewater, NJ)

    1993-01-01T23:59:59.000Z

    A vertical-cavity surface-emitting laser is disclosed comprising a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. Specific embodiments of the invention for generating red, green, and blue radiation are described.

  20. Atmospheric Aerosols Workshop | EMSL

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

    Atmospheric Aerosols Workshop Atmospheric Aerosols Workshop EMSL Science Theme Advisory Panel Workshop - Atmospheric Aerosol Chemistry, Climate Change, and Air Quality. Baer DR, BJ...

  1. Solar radius determination from SODISM/PICARD and HMI/SDO observations of the decrease of the spectral solar radiance during the June

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Solar radius determination from SODISM/PICARD and HMI/SDO observations of the decrease of the spectral solar radiance during the June 2012 Venus transit A. Hauchecorne1 , M. Meftah1 , A. Irbah1 , S of Venus provided a rare opportunity to determine the radius of the Sun using solar imagers observing

  2. Atmospheric Aerosol Systems | EMSL

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

    Science Themes Atmospheric Aerosol Systems Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems...

  3. Conference on Atmospheric Radiation, 6th, Williamsburg, VA, May 13-16, 1986, Extended Abstracts

    SciTech Connect (OSTI)

    Not Available

    1986-01-01T23:59:59.000Z

    Numerous topics of interest for measurements and modeling of radiation in the atmosphere are discussed, with emphasis on satellite remote sensing capabilities, data analysis techniques and climatological impact. Attention is devoted to aerosols at all levels of the atmosphere, the current understanding of potential nuclear winter scenarios, and to instruments which are used for sensing radiance in the atmosphere. Consideration is also given to spectroscopy and band models, radiative transfer calculations, earth radiation budget (ERB) models and their interaction with GCMs, and to climate models. In-depth analyses are performed of data from the ERB instruments on the Nimbus-7 spacecraft and to validation procedures being developed for data collected by the ERB satellite.

  4. Spectroscopic Studies of Atmospheric Relevant Air-Aqueous Interfaces DISSERTATION

    E-Print Network [OSTI]

    Spectroscopic Studies of Atmospheric Relevant Air-Aqueous Interfaces DISSERTATION Presented The Ohio State University 2010 Dissertation Committee: Heather C. Allen, Advisor Anne Carey Harold Walker in this dissertation as proxies of organic coated aerosols. Since a number of organic compounds are emitted

  5. The Global Anthropogenic Lead Experiment Earth, Atmospheric and Planetary Sciences

    E-Print Network [OSTI]

    Einat, Aharonov

    The Global Anthropogenic Lead Experiment Ed Boyle Earth, Atmospheric and Planetary Sciences Reuer Rick Kayser Boyle Lab, arriving in Rio at the end of EN 367 #12;The Global Anthropogenic Lead Experiment · Lead is a volatile element and it is emitted by high temperature industrial activities (smelting

  6. Highly Efficient Silicon Light Emitting Diode

    E-Print Network [OSTI]

    Leminh Holleman Wallinga; P. Leminh; J. Holleman; H. Wallinga

    2000-01-01T23:59:59.000Z

    In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a local strain field that is formed by dislocation loop arrays. The dependence of device electroluminescent properties on the annealing conditions is carefully examined as a high temperature process has profound influence on these dislocations. Increased luminescent intensity at higher device temperature, together with pure diffusion current conduction mechanism evidently shows the influence of the dislocation loops. The electrical properties of the diode are reasonable with low leakage reverse current.

  7. Thermo-electrically pumped semiconductor light emitting diodes

    E-Print Network [OSTI]

    Santhanam, Parthiban

    2014-01-01T23:59:59.000Z

    Thermo-electric heat exchange in semiconductor light emitting diodes (LEDs) allows these devices to emit optical power in excess of the electrical power used to drive them, with the remaining power drawn from ambient heat. ...

  8. Water Cooling of High Power Light Emitting Diode Henrik Srensen

    E-Print Network [OSTI]

    Berning, Torsten

    Water Cooling of High Power Light Emitting Diode Henrik Sřrensen Department of Energy Technology and product lifetime. The high power Light Emitting Diodes (LED) belongs to the group of electronics

  9. High-Performance Organic Light-Emitting Diodes Using ITO

    E-Print Network [OSTI]

    Ho, Seng-Tiong

    High-Performance Organic Light-Emitting Diodes Using ITO Anodes Grown on Plastic by Room,* Mark E. Madsen, Antonio DiVenere, and Seng-Tiong Ho Organic light-emitting diodes (OLEDs) fabricated

  10. Habitability of waterworlds: runaway greenhouses, atmospheric expansion and multiple climate states of pure water atmospheres

    E-Print Network [OSTI]

    Goldblatt, Colin

    2015-01-01T23:59:59.000Z

    There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds". I map these as a function of solar constant for planets ranging in size from Mars size to 10 Earth-mass. The states are: globally ice covered (Tsnet absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surfa...

  11. Photochemistry in Terrestrial Exoplanet Atmospheres II: H2S and SO2 Photochemistry in Anoxic Atmospheres

    E-Print Network [OSTI]

    Hu, Renyu; Bains, William

    2013-01-01T23:59:59.000Z

    Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H2S and SO2) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative transfer model to investigate the sulfur chemistry in atmospheres ranging from reducing to oxidizing. The most important finding is that both H2S and SO2 are chemically short-lived in virtually all types of atmospheres on terrestrial exoplanets, based on models of H2, N2, and CO2 atmospheres. This implies that direct detection of surface sulfur emission is unlikely, as their surface emission rates need to be extremely high (>1000 times Earth's volcanic sulfur emission) for these gases to build up to a detectable level. We also find that sulfur compounds emitted from the surface lead to photochemical formation of element...

  12. INTRODUCTIONTOTHE SOLAR ATMOSPHERE

    E-Print Network [OSTI]

    ? #12;WHAT ISTHE SOLAR ATMOSPHERE? #12;#12;1-D MODEL ATMOSPHERE · Averaged over space and time · GoodINTRODUCTIONTOTHE SOLAR ATMOSPHERE D. Shaun Bloomfield Trinity College Dublin #12;OUTLINE · What is the solar atmosphere? · How is the solar atmosphere observed? · What structures exist and how do they evolve

  13. Microchemical investigations of dust emitted by a lead smelter

    SciTech Connect (OSTI)

    Sobanska, S.; Ricq, N. [Ecole des Mines de Douai (France). Dept. Chimie et Environnement] [Ecole des Mines de Douai (France). Dept. Chimie et Environnement; [Univ. de Lille I, Villeneuve d`Ascq (France); Laboudigue, A.; Guillermo, R. [Ecole des Mines de Douai (France). Dept. Chimie et Environnement] [Ecole des Mines de Douai (France). Dept. Chimie et Environnement; Bremard, C.; Laureyns, J.; Merlin, J.C.; Wignacourt, J.P. [Univ. de Lille I, Villeneuve d`Ascq (France)] [Univ. de Lille I, Villeneuve d`Ascq (France)

    1999-05-01T23:59:59.000Z

    Dusts emitted by an important pyrometallurgical lead smelter have been sampled within the pipes of the grilling and furnace working units before and after the filtering systems, respectively. Particle size distribution, elementary analyses, and X-ray powder diffraction analysis indicate PbS, PbSO{sub 4}, PbSO{sub 4}{center_dot}PbO, Pb, ZnS small particles less than 5 {micro}m in size to contribute mainly to the current atmospheric pollution. Although at least 90% of dust are retained on the filters, the amounts of the respirable smaller particles are significantly larger in the current emission. The average chemical speciation was found to be analogous for the dust samples collected before and after the filters. The scanning electron microscopy associated with energy-dispersive X-ray analysis and Raman microspectrometry established the morphology and chemical composition at the level of individual particles. A lot of minor compounds were found as small heterogeneous individual particles in the heterogeneous particles of grilling dust. Among the homogeneous particles of furnace dust, amorphous C, {beta}-PbO, PbO-PbCl{sub 2}, FeO, CdS, CdSO{sub 4} were often detected as homogeneous mixtures with the major compounds within the particles.

  14. A micrometer-size movable light emitting area in a resonant tunneling light emitting diode

    SciTech Connect (OSTI)

    Pettinari, G., E-mail: giorgio.pettinari@cnr.it [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); National Research Council (CNR), Institute for Photonics and Nanotechnologies (IFN-CNR), Via Cineto Romano 42, 00156 Roma (Italy); Balakrishnan, N.; Makarovsky, O.; Campion, R. P.; Patanč, A. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Polimeni, A.; Capizzi, M. [CNISM-Dipartimento di Fisica, Sapienza Universitŕ di Roma, P.le A. Moro 2, 00185 Roma (Italy)] [CNISM-Dipartimento di Fisica, Sapienza Universitŕ di Roma, P.le A. Moro 2, 00185 Roma (Italy)

    2013-12-09T23:59:59.000Z

    We report on the fabrication of a micrometer-size movable light emitting area in a GaAs/AlAs quantum well resonant tunneling p-i-n diode. The spatial position of the micrometer-size light emitting area shifts linearly with increasing applied bias, up to 30??m for a bias increment of 0.2?V. Also, the simultaneous resonant tunneling injection of both electrons and holes into the quantum well states is achieved at specific positions of the diode, thus resulting in a tenfold increase of the electroluminescence intensity.

  15. Tunable, superconducting, surface-emitting teraherz source

    DOE Patents [OSTI]

    Welp, Ulrich; Koshelev, Alexei E.; Gray, Kenneth E.; Kwok, Wai-Kwong; Vlasko-Vlasov, Vitalii

    2010-05-11T23:59:59.000Z

    A compact, solid-state THz source based on the driven Josephson vortex lattice in a highly anisotropic superconductor such as Bi.sub.2Sr.sub.2CaCu.sub.2O.sub.8 that allows cw emission at tunable frequency. A second order metallic Bragg grating is used to achieve impedance matching and to induce surface emission of THz-radiation from a Bi.sub.2Sr.sub.2CaCu.sub.2O.sub.8 sample. Steering of the emitted THz beam is accomplished by tuning the Josephson vortex spacing around the grating period using a superimposed magnetic control field.

  16. Tunable, superconducting, surface-emitting teraherz source

    DOE Patents [OSTI]

    Welp, Ulrich (Lisle, IL); Koshelev, Alexei E. (Bolingbrook, IL); Gray, Kenneth E. (Evanston, IL); Kwok, Wai-Kwong (Evanston, IL); Vlasko-Vlasov, Vitalii (Downers Grove, IL)

    2009-10-27T23:59:59.000Z

    A compact, solid-state THz source based on the driven Josephson vortex lattice in a highly anisotropic superconductor such as Bi.sub.2Sr.sub.2CaCu.sub.2O.sub.8 that allows cw emission at tunable frequency. A second order metallic Bragg grating is used to achieve impedance matching and to induce surface emission of THz-radiation from a Bi.sub.2Sr.sub.2CaCu.sub.2O.sub.8 sample. Steering of the emitted THz beam is accomplished by tuning the Josephson vortex spacing around the grating period using a superimposed magnetic control field.

  17. White organic light-emitting diodes with an ultra-thin premixed emitting layer

    E-Print Network [OSTI]

    Jeon, T; Tondelier, Denis; Bonnassieux, Yvan; Forget, Sebastien; Chenais, Sebastien; Ishow, Elena

    2014-01-01T23:59:59.000Z

    We described an approach to achieve fine color control of fluorescent White Organic Light-Emitting Diodes (OLED), based on an Ultra-thin Premixed emitting Layer (UPL). The UPL consists of a mixture of two dyes (red-emitting 4-di(4'-tert-butylbiphenyl-4-yl)amino-4'-dicyanovinylbenzene or fvin and green-emitting 4-di(4'-tert-butylbiphenyl-4-yl)aminobenzaldehyde or fcho) premixed in a single evaporation cell: since these two molecules have comparable structures and similar melting temperatures, a blend can be evaporated, giving rise to thin films of identical and reproducible composition compared to those of the pre-mixture. The principle of fine color tuning is demonstrated by evaporating a 1-nm-thick layer of this blend within the hole-transport layer (4,4'-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (\\alpha-NPB)) of a standard fluorescent OLED structure. Upon playing on the position of the UPL inside the hole-transport layer, as well as on the premix composition, two independent parameters are available to finel...

  18. Policy for Permitting Low-Emitting Sources  (West Virginia)

    Broader source: Energy.gov [DOE]

    While this policy alleviates some requirements on low-emitting emission sources, it does not change the policy of requiring applicants to submit reasonable information concerning all potential...

  19. alingap light emitting: Topics by E-print Network

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

    show a low threshold voltage for light emission of Potma, Eric Olaf 4 LIGHT EMITTING DIODE CHARACTERISTICS (SAMPLE LAB WRITEUP) Engineering Websites Summary: , 1997...

  20. active compounds emitted: Topics by E-print Network

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

    switching occurs even Rocca, Jorge J. 5 Transparent Active Matrix Organic Light-Emitting Diode Displays Driven by Chemistry Websites Summary: and portable electronics. In...

  1. airborne noise emitted: Topics by E-print Network

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

    The light intensity noise was measured as a function of wavelength within the light emitting diode spectral emission line. The spectral noise density is found to increase Wetzel,...

  2. auger electron emitting: Topics by E-print Network

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

    diodes constructed from an electron online 30 September 2013 Keywords: Organic light-emitting diode Alternating current AC driving Color- and brightness-tunable organic...

  3. Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate...

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

    semipolar light-emitting diodes (LEDs) on low-defect bulk gallium nitride (GaN) substrates. Peak internal quantum efficiency (IQE) values of greater than 80% are...

  4. Light emitting device comprising phosphorescent materials for white light generation

    DOE Patents [OSTI]

    Thompson, Mark E.; Dapkus, P. Daniel

    2014-07-22T23:59:59.000Z

    The present invention relates to phosphors for energy downconversion of high energy light to generate a broadband light spectrum, which emit light of different emission wavelengths.

  5. Impact of assumption of log-normal distribution on monthly rainfall estimation from TMI

    E-Print Network [OSTI]

    Lee, Dong Heon

    2001-01-01T23:59:59.000Z

    of the raining atmosphere in order to predict brightness temperature for a given rainfall rate. This method was first explored by Wilheit et al. (1977), who developed a theoretical model for quantitatively relating the microwave radiance to rain rate over... the oceans. Wu and Weinman (1984) developed a microwave radiative transfer model of the radiance emitted by precipitating clouds containing ice, combined ice, and water hydrometeors. They found that intense storms produced ice-scattering signatures...

  6. TRICOLOR LIGHT EMITTING DIODE DOT MATRIX DISPLAY SYSTEM WITHAUDIO OUTPUT

    E-Print Network [OSTI]

    Pang, Grantham

    1 TRICOLOR LIGHT EMITTING DIODE DOT MATRIX DISPLAY SYSTEM WITHAUDIO OUTPUT Grantham Pang, Chi emitting diodes; tricolor display; audio communication. I. Introduction This paper relates to a tricolor broadcasting through the visible light rays transmitted by the display panel or assembly. Keywords: light

  7. Effects of emitted electron temperature on the plasma sheath

    SciTech Connect (OSTI)

    Sheehan, J. P., E-mail: sheehanj@umich.edu [Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Kaganovich, I. D.; Wang, H.; Raitses, Y. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Sydorenko, D. [Physics Department, University of Alberta, Edmonton, Alberta T6G 2E9 (Canada); Hershkowitz, N. [Department of Engineering Physics, University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States)

    2014-06-15T23:59:59.000Z

    It has long been known that electron emission from a surface significantly affects the sheath surrounding that surface. Typical fluid theory of a planar sheath with emitted electrons assumes that the plasma electrons follow the Boltzmann relation and the emitted electrons are emitted with zero energy and predicts a potential drop of 1.03T{sub e}/e across the sheath in the floating condition. By considering the modified velocity distribution function caused by plasma electrons lost to the wall and the half-Maxwellian distribution of the emitted electrons, it is shown that ratio of plasma electron temperature to emitted electron temperature significantly affects the sheath potential when the plasma electron temperature is within an order of magnitude of the emitted electron temperature. When the plasma electron temperature equals the emitted electron temperature the emissive sheath potential goes to zero. One dimensional particle-in-cell simulations corroborate the predictions made by this theory. The effects of the addition of a monoenergetic electron beam to the Maxwellian plasma electrons were explored, showing that the emissive sheath potential is close to the beam energy only when the emitted electron flux is less than the beam flux.

  8. Efficient semiconductor light-emitting device and method

    DOE Patents [OSTI]

    Choquette, Kent D. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM); Schneider, Jr., Richard P. (Albuquerque, NM)

    1996-01-01T23:59:59.000Z

    A semiconductor light-emitting device and method. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL).

  9. Efficient semiconductor light-emitting device and method

    DOE Patents [OSTI]

    Choquette, K.D.; Lear, K.L.; Schneider, R.P. Jr.

    1996-02-20T23:59:59.000Z

    A semiconductor light-emitting device and method are disclosed. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL). 12 figs.

  10. Atmospheric Transport of Radionuclides

    SciTech Connect (OSTI)

    Crawford, T.V.

    2003-03-03T23:59:59.000Z

    The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

  11. Top-emitting Organic Light-Emitting Diode with a Cap Layer Chengfeng Qiu, Huajun Peng, Haiying Chen, Zhilang Xie,

    E-Print Network [OSTI]

    Kwok, Hoi S.

    , Kowloon, Hong Kong, China ABSTRACT For top emitting Organic Light-Emitting Diodes (OLED), the study of top layer is very important aiming to acquire good device performance. In this report, Pt as anode for Cu coated on glass as anode, copper (II) phthalocyanine (CuPc) as organic buffer layer, N,N'- diphenyl

  12. Organic Light-Emitting Diodes and Organic Light-emitting Electrochemical Cells Based on Silole-Fluorene Derivatives

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and to stop the well known spectral shift degradation occurring in fluorene based materials. In this paper we1 Organic Light-Emitting Diodes and Organic Light-emitting Electrochemical Cells Based on Silole-Fluorene, copolymerization of siloles with fluorene was aimed at improving electron injection into the polymer layer and so

  13. How atmospheric ice forms | EMSL

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

    atmospheric ice forms How atmospheric ice forms Released: September 08, 2014 New insights into atmospheric ice formation could improve climate models This study advances our...

  14. Atmospheric Pressure Reactor System | EMSL

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

    Atmospheric Pressure Reactor System Atmospheric Pressure Reactor System The atmospheric pressure reactor system is designed for testing the efficiency of various catalysts for the...

  15. Climate Sciences: Atmospheric Thermodynamics

    E-Print Network [OSTI]

    Russell, Lynn

    1 Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http://aerosol.ucsd.edu/courses.html Text: Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http

  16. Cloudy sounding and cloud-top height retrieval from AIRS alone single field-of-view radiance measurements

    E-Print Network [OSTI]

    Li, Jun

    to 15.4 mm). The spectral coverage includes strong CO2 absorption necessary for temperature profile and Ping Yang4 Received 3 April 2007; accepted 16 May 2007; published 20 June 2007. [1] High) Aqua satellite provide unique information about atmospheric state, surface and cloud properties

  17. Growths of staggered InGaN quantum wells light-emitting diodes emitting at 520525 nm employing graded growth-temperature profile

    E-Print Network [OSTI]

    Gilchrist, James F.

    Growths of staggered InGaN quantum wells light-emitting diodes emitting at 520­525 nm employing current spreading and light extraction in GaN-based light emitting diodes Appl. Phys. Lett. 100, 061107 (2012) Electrically driven nanopyramid green light emitting diode Appl. Phys. Lett. 100, 061106 (2012

  18. Terrestrial Planet Atmospheres. The Moon's Sodium Atmosphere

    E-Print Network [OSTI]

    Walter, Frederick M.

    ;Origins of Atmospheres · Outgassing ­ Volcanoes expel water, CO2, N2, H2S, SO2 removed by the Fme convecFon reaches deserts #12;Water and Ice Clouds #12;H2SO4

  19. Development of ZnO Based Light Emitting Diodes and Laser Diodes

    E-Print Network [OSTI]

    Kong, Jieying

    2012-01-01T23:59:59.000Z

    E. Fred Schubert, Light-Emitting Diodes, New York (2006) [8]ZnO homojunction light emitting diode 3. 1. Motivation ofAlGaAs red light-emitting diodes, in: G.B. Stringfellow, M.

  20. Electrophoretic Deposition of Highly Efficient Phosphors for White Solid State Lighting using near UV-Emitting LEDs /

    E-Print Network [OSTI]

    Choi, Jae Ik

    2014-01-01T23:59:59.000Z

    application in white light emitting diode,” J. Mater. Res. ,phosphors for white light emitting diodes (LEDs)”, 220 thconverted white light emitting diodes by electrophoretic

  1. White light emitting diode as liquid crystal display backlight

    E-Print Network [OSTI]

    Soon, Chian Myau

    2007-01-01T23:59:59.000Z

    The discovery of high brightness (white) light emitting diode (LED) is considered as a real threat to the current lighting industry in various applications. One of the most promising sectors would be using white LED to ...

  2. Metal-halide perovskites for photovoltaic and light-emitting...

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

    Metal-halide perovskites for photovoltaic and light-emitting devices September 15, 2015 at 4:30 pm36-428 Sam Stranks Massachusetts Institute of Technology peopleStranks...

  3. alpha emitting radionuclides: Topics by E-print Network

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

    on the response function of a TeO2 bolometer to alpha's emitted by 147Sm dissolved in the crystal at the growth phase. A Quenching Factor of (1.0076pm...

  4. White organic light-emitting diodes: Status and perspective

    E-Print Network [OSTI]

    Reineke, Sebastian

    White organic light-emitting diodes (OLEDs) are ultrathin, large-area light sources made from organic semiconductor materials. Over the past decades, much research has been spent on finding suitable materials to realize ...

  5. Organic light emitting device structure for obtaining chromaticity stability

    DOE Patents [OSTI]

    Tung, Yeh-Jiun (Princeton, NJ); Ngo, Tan (Levittown, PA)

    2007-05-01T23:59:59.000Z

    The present invention relates to organic light emitting devices (OLEDs). The devices of the present invention are efficient white or multicolored phosphorescent OLEDs which have a high color stability over a wide range of luminances. The devices of the present invention comprise an emissive region having at least two emissive layers, with each emissive layer comprising a different host and emissive dopant, wherein at least one of the emissive dopants emits by phosphorescence.

  6. Interference of Cooper Pairs Emitted from Independent Superconductors

    E-Print Network [OSTI]

    Mauro Iazzi; Kazuya Yuasa

    2010-05-16T23:59:59.000Z

    We discuss the interference in the two-particle distribution of the electrons emitted from two independent superconductors. It is clarified that, while the interference appearing in the antibunching correlation is due to the Hanbury Brown and Twiss effect, that in the positive correlation due to superconductivity is intrinsically different and is nothing but the first-order interference of Cooper pairs emitted from different sources. This is the equivalent of the interference of two independent Bose-Einstein condensates.

  7. High power light emitting diode based setup for photobleaching fluorescent impurities

    E-Print Network [OSTI]

    Kaufman, Laura

    High power light emitting diode based setup for photobleaching fluorescent impurities Tobias K be photobleached before final sample preparation. The instrument consists of high power light emitting diodes

  8. Low-Cost Light-Emitting Diode Luminaire for General Illumination...

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

    Cost Light-Emitting Diode Luminaire for General Illumination Low-Cost Light-Emitting Diode Luminaire for General Illumination Presenter: Paul Fini, CREE Santa Barbara Technology...

  9. EMSL - Atmospheric Aerosol Systems

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

    scienceatmospheric The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model...

  10. Atmospheric Neutrino Fluxes

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2005-02-18T23:59:59.000Z

    Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

  11. Dynamics of planetary atmospheres

    E-Print Network [OSTI]

    Read, Peter L.

    705810Sound speed (m s-1) 3920Scale height (km) 300400Emission-space pressure (hPa) 95124Emission temperature (K) 1.81.7Emitted/absorbed power 26.73.1Orbital inclination(o) 6901310Mean density (kg m-3) 10) Science #12;Jovian Jets · - uyy winds

  12. Optical Simulation of Top-emitting Organic Light Emitting Diodes H. J. Peng, C.F. Qiu, Z. L. Xie, H. Y. Chen, M. Wong and H. S. Kwok

    E-Print Network [OSTI]

    Kwok, Hoi S.

    8.3.3-89 Optical Simulation of Top-emitting Organic Light Emitting Diodes H. J. Peng, C.F. Qiu, Z the optical effects for the top-emitting organic light emitting diodes. The optical performance of the devices with experiments Keywords: Top-emitting organic light emitting diode, optical modeling, microcavity INTRODUCTION

  13. Atmospheric Dynamics II Instructor

    E-Print Network [OSTI]

    AT602 Atmospheric Dynamics II 2 credits Instructor: David W. J. Thompson davet: An Introduction to Dynamic Meteorology, 5th Edition, Academic Press (recommended) · Marshall, J., and Plumb, R. A., 2008: Atmosphere, Ocean, and Climate Dynamics: An Introductory Text, Academic Press. · Vallis, G. K

  14. Atmospheric Thermodynamics Composition

    E-Print Network [OSTI]

    Russell, Lynn

    1 Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 EnergyBalance Ch4 Water Ch Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http #12;2 Review from Ch. 1 · Thermodynamic quantities · Composition · Pressure · Density · Temperature

  15. Light emitting ceramic device and method for fabricating the same

    DOE Patents [OSTI]

    Valentine, Paul; Edwards, Doreen D.; Walker Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

    2004-11-30T23:59:59.000Z

    A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, and alternative methods of fabrication for the same are claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

  16. Flip-chip light emitting diode with resonant optical microcavity

    SciTech Connect (OSTI)

    Gee, James M.; Bogart, Katherine H.A.; Fischer, Arthur J.

    2005-11-29T23:59:59.000Z

    A flip-chip light emitting diode with enhanced efficiency. The device structure employs a microcavity structure in a flip-chip configuration. The microcavity enhances the light emission in vertical modes, which are readily extracted from the device. Most of the rest of the light is emitted into waveguided lateral modes. Flip-chip configuration is advantageous for light emitting diodes (LEDs) grown on dielectric substrates (e.g., gallium nitride LEDs grown on sapphire substrates) in general due to better thermal dissipation and lower series resistance. Flip-chip configuration is advantageous for microcavity LEDs in particular because (a) one of the reflectors is a high-reflectivity metal ohmic contact that is already part of the flip-chip configuration, and (b) current conduction is only required through a single distributed Bragg reflector. Some of the waveguided lateral modes can also be extracted with angled sidewalls used for the interdigitated contacts in the flip-chip configuration.

  17. Close-packed array of light emitting devices

    SciTech Connect (OSTI)

    Ivanov, Ilia N.; Simpson, John T.

    2013-04-09T23:59:59.000Z

    A close-packed array of light emitting diodes includes a nonconductive substrate having a plurality of elongate channels extending therethrough from a first side to a second side, where each of the elongate channels in at least a portion of the substrate includes a conductive rod therein. The conductive rods have a density over the substrate of at least about 1,000 rods per square centimeter and include first conductive rods and second conductive rods. The close-packed array further includes a plurality of light emitting diodes on the first side of the substrate, where each light emitting diode is in physical contact with at least one first conductive rod and in electrical contact with at least one second conductive rod.

  18. Oxycarbonitride phosphors and light emitting devices using the same

    DOE Patents [OSTI]

    Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

    2014-07-08T23:59:59.000Z

    Disclosed herein is a novel family of oxycarbonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

  19. Oxycarbonitride phosphors and light emitting devices using the same

    DOE Patents [OSTI]

    Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

    2013-10-08T23:59:59.000Z

    Disclosed herein is a novel family of oxycarbidonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbidonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

  20. alpha-particle emitting radiopharmaceuticals: Topics by E-print...

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

    44 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  1. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

    1988-01-01T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  2. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

  3. The dynamic behavior of thin-film ionic transition metal complex-based light-emitting electrochemical cells

    SciTech Connect (OSTI)

    Meier, Sebastian B., E-mail: sebastian.meier@belectric.com, E-mail: wiebke.sarfert@siemens.com [Department of Materials Science VI: Materials for Electronics and Energy Technology, Friedrich-Alexander-University of Erlangen-Nuremberg, 91058 Erlangen (Germany); Siemens AG, Corporate Technology, CT RTC MAT IEC-DE, 91058 Erlangen (Germany); Hartmann, David; Sarfert, Wiebke, E-mail: sebastian.meier@belectric.com, E-mail: wiebke.sarfert@siemens.com [Siemens AG, Corporate Technology, CT RTC MAT IEC-DE, 91058 Erlangen (Germany); Winnacker, Albrecht [Department of Materials Science VI: Materials for Electronics and Energy Technology, Friedrich-Alexander-University of Erlangen-Nuremberg, 91058 Erlangen (Germany)

    2014-09-14T23:59:59.000Z

    Light-emitting electrochemical cells (LECs) have received increasing attention during recent years due to their simple architecture, based on solely air-stabile materials, and ease of manufacture in ambient atmosphere, using solution-based technologies. The LEC's active layer offers semiconducting, luminescent as well as ionic functionality resulting in device physical processes fundamentally different as compared with organic light-emitting diodes. During operation, electrical double layers (EDLs) form at the electrode interfaces as a consequence of ion accumulation and electrochemical doping sets in leading to the in situ development of a light-emitting p-i-n junction. In this paper, we comment on the use of impedance spectroscopy in combination with complex nonlinear squares fitting to derive key information about the latter events in thin-film ionic transition metal complex-based light-emitting electrochemical cells based on the model compound bis-2-phenylpyridine 6-phenyl-2,2?-bipyridine iridium(III) hexafluoridophosphate ([Ir(ppy){sub 2}(pbpy)][PF{sub 6}]). At operating voltages below the bandgap potential of the ionic complex used, we obtain the dielectric constant of the active layer, the conductivity of mobile ions, the transference numbers of electrons and ions, and the thickness of the EDLs, whereas the transient thickness of the p-i-n junction is determined at voltages above the bandgap potential. Most importantly, we find that charge transport is dominated by the ions when carrier injection from the electrodes is prohibited, that ion movement is limited by the presence of transverse internal interfaces and that the width of the intrinsic region constitutes almost 60% of the total active layer thickness in steady state at a low operating voltage.

  4. Thermoelectrically Pumped Light-Emitting Diodes Operating above Unity Efficiency

    E-Print Network [OSTI]

    Santhanam, Parthiban

    A heated semiconductor light-emitting diode at low forward bias voltage V

  5. Lighting affects appearance LightSource emits photons

    E-Print Network [OSTI]

    Jacobs, David

    1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line). And then some reach the eye/camera. #12;3 Basic fact: Light is linear Double intensity of sources, double photons reaching eye. Turn on two lights, and photons reaching eye are same as sum of number when each

  6. Lighting affects appearance LightSource emits photons

    E-Print Network [OSTI]

    Jacobs, David

    1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line). And then some reach the eye/camera. #12;3 Reflectance Model how objects reflect light. Model light sources Algorithms for computing Shading: computing intensities within polygons Determine what light strikes what

  7. Atmospheric Science: An introductory survey 1. Introduction to the atmosphere

    E-Print Network [OSTI]

    Folkins, Ian

    Sound Convergence Zone #12;Terrain effects #12;Von Karman vortex streets #12;Atmosphere in Earth system

  8. Strategy Implementation for the CTA Atmospheric Monitoring Program

    E-Print Network [OSTI]

    Doro, M; Reyes, R de los; Gaug, M; Maccarone, M C

    2015-01-01T23:59:59.000Z

    The Cherenkov Telescope Array (CTA) is the next generation facility of Imaging Atmospheric Cherenkov Telescopes. It will reach unprecedented sensitivity and energy resolution in very-high-energy gamma-ray astronomy. CTA will detect Cherenkov light emitted within an atmospheric shower of particles initiated by cosmic-gamma rays or cosmic rays entering the Earth's atmosphere. From the combination of images the Cherenkov light produces in the telescopes, one is able to infer the primary particle energy and direction. A correct energy estimation can be thus performed only if the local atmosphere is well characterized. The atmosphere not only affects the shower development itself, but also the Cherenkov photon transmission from the emission point in the particle shower, at about 10-20 km above the ground, to the detector. Cherenkov light on the ground is peaked in the UV-blue region, and therefore molecular and aerosol extinction phenomena are important. The goal of CTA is to control systematics in energy reconstr...

  9. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOE Patents [OSTI]

    Karl, Jr., Robert R. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  10. Use of the ARM Measurement of Spectral Zenith Radiance For Better Understanding Of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction

    SciTech Connect (OSTI)

    D. Jui-Yuan Chiu

    2010-10-19T23:59:59.000Z

    Our proposal focuses on cloud-radiation processes in a general 3D cloud situation, with particular emphasis on cloud optical depth and effective particle size. We also focus on zenith radiance measurements, both active and passive. The proposal has three main parts. Part One exploits the �¢����solar-background�¢��� mode of ARM lidars to allow them to retrieve cloud optical depth not just for thin clouds but for all clouds. This also enables the study of aerosol cloud interactions with a single instrument. Part Two exploits the large number of new wavelengths offered by ARM�¢����s zenith-pointing ShortWave Spectrometer (SWS), especially during CLASIC, to develop better retrievals not only of cloud optical depth but also of cloud particle size. We also propose to take advantage of the SWS�¢���� 1 Hz sampling to study the �¢����twilight zone�¢��� around clouds where strong aerosol-cloud interactions are taking place. Part Three involves continuing our cloud optical depth and cloud fraction retrieval research with ARM�¢����s 2NFOV instrument by, first, analyzing its data from the AMF-COPS/CLOWD deployment, and second, making our algorithms part of ARM�¢����s operational data processing.

  11. PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. II. H{sub 2}S AND SO{sub 2} PHOTOCHEMISTRY IN ANOXIC ATMOSPHERES

    SciTech Connect (OSTI)

    Hu Renyu; Seager, Sara; Bains, William, E-mail: hury@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-05-20T23:59:59.000Z

    Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H{sub 2}S and SO{sub 2}) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative transfer model to investigate the sulfur chemistry in atmospheres ranging from reducing to oxidizing. The most important finding is that both H{sub 2}S and SO{sub 2} are chemically short-lived in virtually all types of atmospheres on terrestrial exoplanets, based on models of H{sub 2}, N{sub 2}, and CO{sub 2} atmospheres. This implies that direct detection of surface sulfur emission is unlikely, as their surface emission rates need to be extremely high (>1000 times Earth's volcanic sulfur emission) for these gases to build up to a detectable level. We also find that sulfur compounds emitted from the surface lead to photochemical formation of elemental sulfur and sulfuric acid in the atmosphere, which would condense to form aerosols if saturated. For terrestrial exoplanets in the habitable zone of Sun-like stars or M stars, Earth-like sulfur emission rates result in optically thick haze composed of elemental sulfur in reducing H{sub 2}-dominated atmospheres for a wide range of particle diameters (0.1-1 {mu}m), which is assumed as a free parameter in our simulations. In oxidized atmospheres composed of N{sub 2} and CO{sub 2}, optically thick haze, composed of elemental sulfur aerosols (S{sub 8}) or sulfuric acid aerosols (H{sub 2}SO{sub 4}), will form if the surface sulfur emission is two orders of magnitude more than the volcanic sulfur emission of Earth. Although direct detection of H{sub 2}S and SO{sub 2} by their spectral features is unlikely, their emission might be inferred by observing aerosol-related features in reflected light with future generation space telescopes.

  12. Luminescence and Squeezing of a Superconducting Light Emitting Diode

    E-Print Network [OSTI]

    Patrik Hlobil; Peter P. Orth

    2015-05-11T23:59:59.000Z

    We investigate a semiconductor $p$-$n$ junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the electroluminescence in a certain frequency window. We demonstrate that the tunneling of Cooper pairs induces an additional luminescence peak on resonance. There is a transfer of superconducting to photonic coherence which results in the emission of entangled photon pairs and squeezing of the fluctuations in the quadrature amplitudes of the emitted light. The squeezing angle can be electrically manipulated by changing the relative phase of the order parameters in the superconductors. We finally derive the conditions for lasing in the system and show that the laser threshold is reduced due to superconductivity. This shows how macroscopic coherence of a superconductor can be used to control the properties of light.

  13. Luminescence and Squeezing of a Superconducting Light Emitting Diode

    E-Print Network [OSTI]

    Hlobil, Patrik

    2015-01-01T23:59:59.000Z

    We investigate a semiconductor $p$-$n$ junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the electroluminescence in a certain frequency window. We demonstrate that the tunneling of Cooper pairs induces an additional luminescence peak on resonance. There is a transfer of superconducting to photonic coherence which results in the emission of entangled photon pairs and squeezing of the fluctuations in the quadrature amplitudes of the emitted light. The squeezing angle can be electrically manipulated by changing the relative phase of the order parameters in the superconductors. We finally derive the conditions for lasing in the system and show that the laser threshold is reduced due to superconductivity. This shows how macroscopic coherence of a superconductor can be used to control the properties of light.

  14. Organic light-emitting diodes from homoleptic square planar complexes

    DOE Patents [OSTI]

    Omary, Mohammad A

    2013-11-12T23:59:59.000Z

    Homoleptic square planar complexes [M(N.LAMBDA.N).sub.2], wherein two identical N.LAMBDA.N bidentate anionic ligands are coordinated to the M(II) metal center, including bidentate square planar complexes of triazolates, possess optical and electrical properties that make them useful for a wide variety of optical and electrical devices and applications. In particular, the complexes are useful for obtaining white or monochromatic organic light-emitting diodes ("OLEDs"). Improved white organic light emitting diode ("WOLED") designs have improved efficacy and/or color stability at high brightness in single- or two-emitter white or monochrome OLEDs that utilize homoleptic square planar complexes, including bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) ("Pt(ptp).sub.2").

  15. Luminescence and Squeezing of a Superconducting Light Emitting Diode

    E-Print Network [OSTI]

    Patrik Hlobil; Peter P. Orth

    2015-02-17T23:59:59.000Z

    We investigate a semiconductor $p$-$n$ junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the electroluminescence in a certain frequency window. We demonstrate that the tunneling of Cooper pairs induces an additional luminescence peak on resonance. There is a transfer of superconducting to photonic coherence which results in the emission of entangled photon pairs and squeezing of the fluctuations in the quadrature amplitudes of the emitted light. The squeezing angle can be electrically manipulated by changing the relative phase of the order parameters in the superconductors. We finally derive the conditions for lasing in the system and show that the laser threshold is reduced due to superconductivity. This shows how macroscopic coherence of a superconductor can be used to control the properties of light.

  16. Concave-hemisphere-patterned organic top-light emitting device

    DOE Patents [OSTI]

    Forrest, Stephen R; Slootsky, Michael; Lunt, Richard

    2014-01-21T23:59:59.000Z

    A first device is provided. The first device includes an organic light emitting device, which further comprises a first electrode, a second electrode, and an organic emissive layer disposed between the first and second electrode. Preferably, the second electrode is more transparent than the first electrode. The organic emissive layer has a first portion shaped to form an indentation in the direction of the first electrode, and a second portion shaped to form a protrusion in the direction of the second electrode. The first device may include a plurality of organic light emitting devices. The indentation may have a shape that is formed from a partial sphere, a partial cylinder, a pyramid, or a pyramid with a mesa, among others. The protrusions may be formed between adjoining indentations or between an indentation and a surface parallel to the substrate.

  17. Electrically injected visible vertical cavity surface emitting laser diodes

    DOE Patents [OSTI]

    Schneider, R.P.; Lott, J.A.

    1994-09-27T23:59:59.000Z

    Visible laser light output from an electrically injected vertical cavity surface emitting laser (VSCEL) diode is enabled by the addition of phase-matching spacer layers on either side of the active region to form the optical cavity. The spacer layers comprise InAlP which act as charge carrier confinement means. Distributed Bragg reflector layers are formed on either side of the optical cavity to act as mirrors. 5 figs.

  18. Coherent flash of light emitted by a cold atomic cloud

    SciTech Connect (OSTI)

    Chalony, M. [Institut Non Lineaire de Nice, Universite de Nice Sophia-Antipolis, CNRS, F-06560 Valbonne (France); Pierrat, R. [Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, 10 rue Vauquelin, F-75005 Paris (France); Delande, D. [Laboratoire Kastler Brossel, UPMC-Paris 6, ENS, CNRS, 4 Place Jussieu, F-75005 Paris (France); Wilkowski, D. [Institut Non Lineaire de Nice, Universite de Nice Sophia-Antipolis, CNRS, F-06560 Valbonne (France); Centre for Quantum Technologies, National University of Singapore, 117543 Singapore (Singapore)

    2011-07-15T23:59:59.000Z

    When a resonant laser sent on an optically thick cold atomic cloud is abruptly switched off, a coherent flash of light is emitted in the forward direction. This transient phenomenon is observed due to the highly resonant character of the atomic scatterers. We analyze quantitatively its temporal properties and show very good agreement with theoretical predictions. Based on complementary experiments, the phase of the coherent field is reconstructed without interferometric tools.

  19. Organic light emitting device having multiple separate emissive layers

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI)

    2012-03-27T23:59:59.000Z

    An organic light emitting device having multiple separate emissive layers is provided. Each emissive layer may define an exciton formation region, allowing exciton formation to occur across the entire emissive region. By aligning the energy levels of each emissive layer with the adjacent emissive layers, exciton formation in each layer may be improved. Devices incorporating multiple emissive layers with multiple exciton formation regions may exhibit improved performance, including internal quantum efficiencies of up to 100%.

  20. Multispectral imaging of the ocular fundus using light emitting diode illumination

    E-Print Network [OSTI]

    Claridge, Ela

    Multispectral imaging of the ocular fundus using light emitting diode illumination N. L. Everdell,1 on light emitting diode LED illumination that produces multispectral optical images of the human ocular

  1. High-Efficiency and Stable White Organic Light-Emitting Diode...

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

    Efficiency and Stable White Organic Light-Emitting Diode Using a Single Emitter High-Efficiency and Stable White Organic Light-Emitting Diode Using a Single Emitter Presenter: Jian...

  2. Injection and transport processes in organic light emitting diodes based on N. Huby a,b

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Injection and transport processes in organic light emitting diodes based on a silole. N. Huby a- conductors in light emitting diodes1 . The different fields of research around the organic electronic allowed

  3. Green exciplex emission from a bilayer light-emitting diode containing a rare earth ternary complex

    E-Print Network [OSTI]

    Huang, Yanyi

    Green exciplex emission from a bilayer light-emitting diode containing a rare earth ternary complex form 18 October 2001 Abstract A bilayer organic light-emitting diode using a blue-fluorescent yttrium

  4. auger-electron emitting estrogen: Topics by E-print Network

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

    Ag as anode Institute of Physics. DOI: 10.10631.2172734 Active-matrix organic light-emitting diode AMOLED displays have 63 Interference of spontaneously emitted photons Quantum...

  5. advanced semiconductor light-emitting: Topics by E-print Network

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

    vertical radiation using a two-dimensional photonic crystal in a semiconductor light-emitting diode Engineering Websites Summary: light-emitting diode Alexei A. Erchak,a) Daniel...

  6. alpha-particle emitting 211at: Topics by E-print Network

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

    Ag as anode Institute of Physics. DOI: 10.10631.2172734 Active-matrix organic light-emitting diode AMOLED displays have 108 Interference of spontaneously emitted photons Quantum...

  7. Evaluation of potential applications for templated arrays of heterostructural semiconductor nanowires as light emitting devices

    E-Print Network [OSTI]

    Zou, Ting, M. Eng. Massachusetts Institute of Technology

    2006-01-01T23:59:59.000Z

    While light emitting devices, such as laser diodes (LDs) and light emitting diodes (LEDs), were first introduced decades ago, they have been the subject of continuing research and improvements due to their relatively poor ...

  8. Light extraction enhanced white light-emitting diodes with multi-layered phosphor configuration

    E-Print Network [OSTI]

    You, Jiun Pyng; Tran, Nguyen T.; Shi, Frank G.

    2010-01-01T23:59:59.000Z

    and J. K. Kim, “Solid-state light sources getting smart,”power phosphor-converted light-emitting diodes based on III-for phosphor- based white-light-emitting diodes,” Appl.

  9. Process development for the fabrication of light emitting vacuum field emission triodes

    E-Print Network [OSTI]

    Williams, Roger T.

    1994-01-01T23:59:59.000Z

    . Light emitting diodes and triodes are also fabricated to address the feasibility of their application to flat panel displays....

  10. Dynamics of Atmospheres

    E-Print Network [OSTI]

    Read, Peter L.

    transfer ­ Solar heating of surface, and atmosphere via dust absorption ­ Infrared CO2 band cooling (especially around 667 cm-1) ­ nonLTE near-infrared heating of CO2 and nonLTE cooling effects above ~60-80 km. Baroclinic waves, scales, heat and momentum transport, seasonal occurrence. Qualitative treatment

  11. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    . Along with this growth came a new building on campus and a new name: the Laboratory for Atmospheric of the Sun to the outermost fringes of the solar system. With LASP's continuing operations role in the planet traditional and stable approach based on federal agency funding of research grant

  12. Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle

    SciTech Connect (OSTI)

    Kim, Jung-Bum; Lee, Jeong-Hwan; Moon, Chang-Ki; Kim, Jang-Joo, E-mail: jjkim@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-02-17T23:59:59.000Z

    We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000?cd/m{sup 2} corresponding to a current efficiency of 110?cd/A, low efficiency roll-off with 21% at 10?000?cd/m{sup 2} and low turn on voltage of 2.4?V. Especially, the device showed very small color change with the variation of ?x?=?0.02, ?y?=?0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.

  13. Enhanced light emission from top-emitting organic light-emitting diodes by optimizing surface plasmon polariton losses

    E-Print Network [OSTI]

    Fuchs, Cornelius; Wieczorek, Martin; Gather, Malte C; Hofmann, Simone; Reineke, Sebastian; Leo, Karl; Scholz, Reinhard

    2015-01-01T23:59:59.000Z

    We demonstrate enhanced light extraction for monochrome top-emitting organic light-emitting diodes (OLEDs). The enhancement by a factor of 1.2 compared to a reference sample is caused by the use of a hole transport layer (HTL) material possessing a low refractive index (1.52). The low refractive index reduces the in-plane wave vector of the surface plasmon polariton (SPP) excited at the interface between the bottom opaque metallic electrode (anode) and the HTL. The shift of the SPP dispersion relation decreases the power dissipated into lost evanescent excitations and thus increases the outcoupling efficiency, although the SPP remains constant in intensity. The proposed method is suitable for emitter materials owning isotropic orientation of the transition dipole moments as well as anisotropic, preferentially horizontal orientation, resulting in comparable enhancement factors. Furthermore, for sufficiently low refractive indices of the HTL material, the SPP can be modeled as a propagating plane wave within ot...

  14. Space charge spectroscopy of integrated quantum well infrared photodetectorlight emitting diode

    E-Print Network [OSTI]

    Perera, A. G. Unil

    Space charge spectroscopy of integrated quantum well infrared photodetector±light emitting diode M ± light emitting diode (QWIP-LED). Quasistatic capacitance±voltage (C±V ) characteristics under reverse.V. All rights reserved. Keywords: Quantum-well infrared photodetector; Light-emitting diode; Space charge

  15. Enhancement of Barrier Properties Using Ultrathin Hybrid Passivation Layer for Organic Light Emitting Diodes

    E-Print Network [OSTI]

    Hwang, Sung Woo

    acrylate layer and MS-31 (MgO : SiO2 Ľ 3 : 1 wt %) layer was adopted in organic light emitting diode (OLED the penetrations of oxygen and moisture. [DOI: 10.1143/JJAP.45.5970] KEYWORDS: organic light emitting diode (OLED. Introduction As a next generation display, the organic light emitting diode (OLED) has to great performances

  16. Light extraction analysis and enhancement in a quantum dot light emitting diode

    E-Print Network [OSTI]

    Wu, Shin-Tson

    Light extraction analysis and enhancement in a quantum dot light emitting diode Ruidong Zhu outcoupling and angular performance of quantum dot light emitting diode (QLED). To illustrate the design principles, we use a red QLED as an example and compare its performance with an organic light emitting diode

  17. Enhanced coupling of light from organic light emitting diodes using nanoporous films

    E-Print Network [OSTI]

    Enhanced coupling of light from organic light emitting diodes using nanoporous films H. J. Peng, Y the light extraction efficiency for organic light emitting diode OLED . Nanoporous alumina film was used by Bragg scattering. The corrugated light- emitting diode had two-times the efficiency as compared

  18. Depth of cure and compressive strength of dental composites cured with blue light emitting diodes (LEDs)

    E-Print Network [OSTI]

    Ashworth, Stephen H.

    Depth of cure and compressive strength of dental composites cured with blue light emitting diodes with either a light emitting diode (LED) based light curing unit (LCU) or a conventional halogen LCU do reserved. Keywords: Blue light emitting diodes; Light curing unit; Composites; Irradiance; Spectrum; Depth

  19. Correlation between the Indium Tin Oxide morphology and the performances of polymer light-emitting diodes

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : This paper reports on performance enhancement of polymer light-emitting diodes (PLEDs) based on poly(2,5-bis. Keywords : Polymer light emitting diode; Indium tin oxide; Atomic force microscopy; Rutherford backscattering spectroscopy 1. Introduction Polymer light-emitting diodes (PLEDs) have received worldwide

  20. Point defect engineered Si sub-bandgap light-emitting diode

    E-Print Network [OSTI]

    Bao, Jiming

    Point defect engineered Si sub-bandgap light-emitting diode Jiming Bao1 , Malek Tabbal1,2 , Taegon light emission in Si and demonstrate a sub-bandgap light emitting diode based on the introduction OCIS codes: (230.3670) Light-emitting diodes; (160.6000) Semiconductors; (130-0250) Optoelectronics

  1. High efficiency light emitting diode with anisotropically etched GaN-sapphire interface

    E-Print Network [OSTI]

    High efficiency light emitting diode with anisotropically etched GaN- sapphire interface M. H. Lo and optimization of a light-emitting diode projection micro-stereolithography three-dimensional manufacturingGaN micro-light emitting diodes Appl. Phys. Lett. 101, 231110 (2012) A bright cadmium-free, hybrid organic

  2. spectroscopic techniques A Multi-Source Portable Light Emitting Diode Spectrofluorometer

    E-Print Network [OSTI]

    spectroscopic techniques A Multi-Source Portable Light Emitting Diode Spectrofluorometer SAFWAN only 1.5 kg that uses multiple light emitting diodes (LEDs) as excitation sources was developed emitting diodes; LEDs; Animal forage; Excitation-emission matrices; EEM. INTRODUCTION Movement of chemical

  3. Room temperature 1.6 m electroluminescence from Ge light emitting diode on Si substrate

    E-Print Network [OSTI]

    Vuckovic, Jelena

    Room temperature 1.6 µm electroluminescence from Ge light emitting diode on Si substrate Szu n+/p light emitting diode on a Si substrate. Unlike normal electrically pumped devices, this device.4670) Optical materials; (230.3670) Light-emitting diodes. References and links 1. L. C. Kimerling, "Silicon

  4. Poly(p-phenylene vinylene)/tris(8-hydroxy) quinoline aluminum heterostructure light emitting diode

    E-Print Network [OSTI]

    Poly(p-phenylene vinylene)/tris(8-hydroxy) quinoline aluminum heterostructure light emitting diode are presented from polymer/molecular organic heterostructure light emitting diodes composed of a layer,2 organic light emitting diodes OLEDs utilizing fluorescent molecules have attracted considerable interest

  5. Vertical Pillar-Superlattice Array and Graphene Hybrid Light Emitting Diodes

    E-Print Network [OSTI]

    Rogers, John A.

    Vertical Pillar-Superlattice Array and Graphene Hybrid Light Emitting Diodes Jung Min Lee, Jae a class of light emitting diode (LED) with interesting mechanical, optical, and electrical characteristics, light-emitting diodes, 3D architectures, transparent electrodes V ertical arrays of one-dimensional (1D

  6. Coupled optical and electronic simulations of electrically pumped photonic-crystal-based light-emitting diodes

    E-Print Network [OSTI]

    Dutton, Robert W.

    trade-offs in electrically pumped photonic-crystal-based light-emitting diodes. A finite- toelectronic devices, such as light-emitting diodes LEDs and lasers. It has been suggested that a thin slabCoupled optical and electronic simulations of electrically pumped photonic-crystal-based light-emitting

  7. Efficient blue organic light-emitting diodes employing thermally activated delayed

    E-Print Network [OSTI]

    Cai, Long

    Efficient blue organic light-emitting diodes employing thermally activated delayed fluorescence,2 * Organic light-emitting diodes (OLEDs) employing thermally activated delayed fluorescence (TADF) have energy is high enough and the 3 LE state is higher than the 3 CT state. O rganic light-emitting diodes

  8. A description and evaluation of light-emitting diode displays for generation of visual stimuli*

    E-Print Network [OSTI]

    Massaro, Dominic

    A description and evaluation of light-emitting diode displays for generation of visual stimuli 53706 A description of the design and function of light-emitting diode (LED) display modules is given (Time, April 1972). Light-emitting diodes (L~Ds) are examples of these spin-offs, LED display devices

  9. High performance flexible top-emitting warm-white organic light-emitting devices and chromaticity shift mechanism

    SciTech Connect (OSTI)

    Shi, Hongying; Deng, Lingling; Chen, Shufen, E-mail: iamsfchen@njupt.edu.cn, E-mail: wei-huang@njupt.edu.cn; Xu, Ying; Zhao, Xiaofei; Cheng, Fan [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China)] [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China); Huang, Wei, E-mail: iamsfchen@njupt.edu.cn, E-mail: wei-huang@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China) [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China); Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Technology, Nanjing 211816 (China)

    2014-04-15T23:59:59.000Z

    Flexible warm-white top-emitting organic light-emitting devices (TEOLEDs) are fabricated onto PET substrates with a simple semi-transparent cathode Sm/Ag and two-color phosphors respectively doped into a single host material TCTA. By adjusting the relative position of the orange-red EML sandwiched between the blue emitting layers, the optimized device exhibits the highest power/current efficiency of 8.07 lm/W and near 13 cd/A, with a correlated color temperature (CCT) of 4105 K and a color rendering index (CRI) of 70. In addition, a moderate chromaticity variation of (-0.025, +0.008) around warm white illumination coordinates (0.45, 0.44) is obtained over a large luminance range of 1000 to 10000 cd/m{sup 2}. The emission mechanism is discussed via delta-doping method and single-carrier device, which is summarized that the carrier trapping, the exciton quenching, the mobility change and the recombination zone alteration are negative to color stability while the energy transfer process and the blue/red/blue sandwiched structure are contributed to the color stability in our flexible white TEOLEDs.

  10. SIO 217a Atmospheric and Climate Sciences I: Atmospheric Thermodynamics

    E-Print Network [OSTI]

    Russell, Lynn

    SIO 217a Atmospheric and Climate Sciences I: Atmospheric Thermodynamics Course Syllabus and Lecture Schedule Instructor: Lynn Russell, 343 NH, 534-4852, lmrussell@ucsd.edu Text: Thermodynamics of Atmospheres of Thermodynamics (Work, Heat, First Law, Second Law, Heat Capacity, Adiabatic Processes) 5-Oct F Hurricane Example

  11. LARGE ABUNDANCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN TITAN'S UPPER ATMOSPHERE

    SciTech Connect (OSTI)

    Lopez-Puertas, M.; Funke, B.; Garcia-Comas, M. [Instituto de Astrofisica de Andalucia (CSIC), E-18080 Granada (Spain); Dinelli, B. M. [ISAC-CNR, I-40129 Bologna (Italy); Adriani, A.; D'Aversa, E. [IAPS-INAF, I-00133 Rome (Italy); Moriconi, M. L. [ISAC-CNR, I-00133 Rome (Italy); Boersma, C.; Allamandola, L. J., E-mail: puertas@iaa.es [NASA Ames Research Center, Moffett Field, CA 94035-1000 (United States)

    2013-06-20T23:59:59.000Z

    In this paper, we analyze the strong unidentified emission near 3.28 {mu}m in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 {mu}m. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) Multiplication-Sign 10{sup 4} particles cm{sup -3}. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is {approx}430 u; the mean area is about 0.53 nm{sup 2}; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

  12. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008

    SciTech Connect (OSTI)

    LR Roeder

    2008-12-01T23:59:59.000Z

    The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

  13. Pluto's Atmosphere Does Not Collapse

    E-Print Network [OSTI]

    Olkin, C B; Borncamp, D; Pickles, A; Sicardy, B; Assafin, M; Bianco, F B; Buie, M W; de Oliveira, A Dias; Gillon, M; French, R G; Gomes, A Ramos; Jehin, E; Morales, N; Opitom, C; Ortiz, J L; Maury, A; Norbury, M; Ribas, F B; Smith, R; Wasserman, L H; Young, E F; Zacharias, M; Zacharias, N

    2013-01-01T23:59:59.000Z

    Combining stellar occultation observations probing Pluto's atmosphere from 1988 to 2013 and models of energy balance between Pluto's surface and atmosphere, we conclude that Pluto's atmosphere does not collapse at any point in its 248-year orbit. The occultation results show an increasing atmospheric pressure with time in the current epoch, a trend present only in models with a high thermal inertia and a permanent N2 ice cap at Pluto's north rotational pole.

  14. Recipient luminophoric mediums having narrow spectrum luminescent materials and related semiconductor light emitting devices and methods

    DOE Patents [OSTI]

    LeToquin, Ronan P; Tong, Tao; Glass, Robert C

    2014-12-30T23:59:59.000Z

    Light emitting devices include a light emitting diode ("LED") and a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED. In some embodiments, the recipient luminophoric medium includes a first broad-spectrum luminescent material and a narrow-spectrum luminescent material. The broad-spectrum luminescent material may down-convert radiation emitted by the LED to radiation having a peak wavelength in the red color range. The narrow-spectrum luminescent material may also down-convert radiation emitted by the LED into the cyan, green or red color range.

  15. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, O.A.; Stencel, J.R.

    1987-10-02T23:59:59.000Z

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The moisture then passes through a combustion chamber where hydrogen gas in the form of H/sub 2/ or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  16. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, Otto A. (Langhorne, PA); Stencel, Joseph R. (Skillman, NJ)

    1990-01-01T23:59:59.000Z

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The mixture then passes through a combustion chamber where hydrogen gas in the form of H.sub.2 or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  17. Poly (p-phenyleneneacetylene) light-emitting diodes

    DOE Patents [OSTI]

    Shinar, Joseph (Ames, IA); Swanson, Leland S. (Ames, IA); Lu, Feng (Ames, IA); Ding, Yiwei (Ames, IA); Barton, Thomas J. (Ames, IA); Vardeny, Zeev V. (Salt Lake City, UT)

    1994-10-04T23:59:59.000Z

    Acetylene containing poly(p-phenyleneacetylene) (PPA) - based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as Al or Al/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes.

  18. Fabrication of poly(p-phenyleneacetylene) light-emitting diodes

    DOE Patents [OSTI]

    Shinar, Joseph (Ames, IA); Swanson, Leland S. (Ames, IA); Lu, Feng (Ames, IA); Ding, Yiwei (Ames, IA)

    1994-08-02T23:59:59.000Z

    Acetylene containing poly(p-phenyleneacetylene) (PPA) - based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as A1 or A1/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes.

  19. Efficient bottom cathodes for organic light-emitting devices

    SciTech Connect (OSTI)

    Liu Jie; Duggal, Anil R.; Shiang, Joseph J.; Heller, Christian M. [General Electric Global Research, 1 Research Circle, Niskayuna, New York 12309 (United States)

    2004-08-02T23:59:59.000Z

    Bilayers of aluminum and an alkali fluoride are well-known top cathode contacts for organic light-emitting devices but have never been successfully applied as bottom contacts. We describe a bilayer bottom cathode contact for organic electronic devices based on reversing the well-known top cathode structure such that the aluminum, rather than the alkali fluoride, contacts the organic material. Electron-only devices were fabricated showing enhanced electron injection from this bottom contact. Kelvin probe, x-ray photoelectron spectroscopy experiments, and thermodynamic calculations suggest that the enhancement results from n doping of the organic material by dissociated alkali metals.

  20. High efficiency III-nitride light-emitting diodes

    DOE Patents [OSTI]

    Crawford, Mary; Koleske, Daniel; Cho, Jaehee; Zhu, Di; Noemaun, Ahmed; Schubert, Martin F; Schubert, E. Fred

    2013-05-28T23:59:59.000Z

    Tailored doping of barrier layers enables balancing of the radiative recombination among the multiple-quantum-wells in III-Nitride light-emitting diodes. This tailored doping enables more symmetric carrier transport and uniform carrier distribution which help to reduce electron leakage and thus reduce the efficiency droop in high-power III-Nitride LEDs. Mitigation of the efficiency droop in III-Nitride LEDs may enable the pervasive market penetration of solid-state-lighting technologies in high-power lighting and illumination.

  1. Poly (p-phenyleneacetylene) light-emitting diodes

    DOE Patents [OSTI]

    Shinar, J.; Swanson, L.S.; Lu, F.; Ding, Y.; Barton, T.J.; Vardeny, Z.V.

    1994-10-04T23:59:59.000Z

    Acetylene containing poly(p-phenyleneacetylene) (PPA) - based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as Al or Al/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes. 8 figs.

  2. Fabrication of poly(p-phenyleneacetylene) light-emitting diodes

    DOE Patents [OSTI]

    Shinar, J.; Swanson, L.S.; Lu, F.; Ding, Y.

    1994-08-02T23:59:59.000Z

    Acetylene-containing poly(p-phenyleneacetylene) (PPA)-based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as Al or Al/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes. 8 figs.

  3. Graphene surface emitting terahertz laser: Diffusion pumping concept

    SciTech Connect (OSTI)

    Davoyan, Arthur R., E-mail: davoyan@seas.upenn.edu [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019, Russia and Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Morozov, Mikhail Yu.; Popov, Vyacheslav V. [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019 (Russian Federation)] [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019 (Russian Federation); Satou, Akira; Otsuji, Taiichi [Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai, Miyagi 980-8577 (Japan)] [Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai, Miyagi 980-8577 (Japan)

    2013-12-16T23:59:59.000Z

    We suggest a concept of a tunable graphene-based terahertz (THz) surface emitting laser with diffusion pumping. We employ significant difference in the electronic energy gap of graphene and a typical wide-gap semiconductor, and demonstrate that carriers generated in the semiconductor can be efficiently captured by graphene resulting in population inversion and corresponding?THz lasing from graphene. We develop design principles for such a laser and estimate its performance. We predict up to 50?W/cm{sup 2} terahertz power output for 100?kW/cm{sup 2} pump power at frequency around 10?THz at room temperature.

  4. Solid-state radiation-emitting compositions and devices

    DOE Patents [OSTI]

    Ashley, Carol S. (Albuquerque, NM); Brinker, C. Jeffrey (Albuquerque, NM); Reed, Scott (Albuquerque, NM); Walko, Robert J. (Albuquerque, NM)

    1992-01-01T23:59:59.000Z

    The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. Preferably, the composition is an aerogel substrate loaded with both a source of exciting radiation, such as tritium, and a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce radiation of a second energy.

  5. Solid-state radiation-emitting compositions and devices

    DOE Patents [OSTI]

    Ashley, C.S.; Brinker, C.J.; Reed, S.; Walko, R.J.

    1992-08-11T23:59:59.000Z

    The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. Preferably, the composition is an aerogel substrate loaded with both a source of exciting radiation, such as tritium, and a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce radiation of a second energy. 4 figs.

  6. Organic light-emitting devices using spin-dependent processes

    DOE Patents [OSTI]

    Vardeny, Z. Valy (Salt Lake City, UT); Wohlgenannt, Markus (Salt Lake City, UT)

    2010-03-23T23:59:59.000Z

    The maximum luminous efficiency of organic light-emitting materials is increased through spin-dependent processing. The technique is applicable to all electro-luminescent processes in which light is produced by singlet exciton decay, and all devices which use such effects, including LEDs, super-radiant devices, amplified stimulated emission devices, lasers, other optical microcavity devices, electrically pumped optical amplifiers, and phosphorescence (Ph) based light emitting devices. In preferred embodiments, the emissive material is doped with an impurity, or otherwise modified, to increase the spin-lattice relaxation rate (i.e., decrease the spin-lattice time), and hence raise the efficiency of the device. The material may be a polymer, oligomer, small molecule, single crystal, molecular crystal, or fullerene. The impurity is preferably a magnetic or paramagnetic substance. The invention is applicable to IR, UV, and other electromagnetic radiation generation and is thus not limited to the visible region of the spectrum. The methods of the invention may also be combined with other techniques used to improve device performance.

  7. Monitoring lensed starlight emitted close to the Galactic Center

    E-Print Network [OSTI]

    Adi Nusser; Tom Broadhurst

    2004-07-12T23:59:59.000Z

    We describe the feasibility of detecting the gravitational deflection of light emitted by stars moving under the influence of the massive object at the Galactic center. Light emitted by a star orbiting behind the central mass has a smaller impact parameter than the star itself, and suffers the effect of gravitational lensing, providing a closer probe of the central mass distribution and hence a stricter test of the black hole hypothesis. A mass of $4.3\\times 10^{6} M_{\\odot}$ causes a $0.1-2\\rm mas$ deviation in the apparent position of orbiting stars projected within $10^{\\circ}$ of the line of sight to the galactic center. In addtion, we may uniquely constrain the distance to the center of the galaxy because lensing deflections constrain the ratio $\\rg/R_{0}$ of the Schwarzschild radius to the distance to the black hole, $R_{o}$, whereas the ratio $\\rg/R_{o}^{3}$ is obtained by fitting the orbit.

  8. ARM - Atmospheric Heat Budget

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric Heat

  9. ARM - Atmospheric Pressure

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric

  10. Atmospheric PSF Interpolation

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR SEPARATION BYAbrasion andArticle)Atmospheric

  11. ARM - Measurement - Longwave narrowband radiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC

  12. ARM - Measurement - Longwave spectral radiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwelling irradiance ARM Data Discovery Browsespectral

  13. ARM - Measurement - Shortwave broadband radiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarization ARMdownwelling

  14. ARM - Measurement - Shortwave narrowband radiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarizationupwelling irradiance

  15. ARM - Measurement - Shortwave spectral radiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarizationupwellingdiffuse

  16. Radiance Solar | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎ | Roadmap Jump to:b <RGS Development BV JumpRTEVRadiance

  17. atmospheres thin atmospheres: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  18. Solid-state radiation-emitting compositions and devices

    DOE Patents [OSTI]

    Ashley, Carol S. (14316 Bauer Rd., NE., Albuquerque, NM 87123); Brinker, C. Jeffrey (14 Eagle Nest Dr., NE., Albuquerque, NM 87122); Reed, Scott (10308 Leymon Ct., NW., Albuquerque, NM 87114); Shepodd, Timothy J. (1838 Broadmore St., Livermore, CA 94550); Leonard, Leroy E. (4944 Ten Oaks Rd., Dayton, MD 21036); Ellefson, Robert E. (193 Elmwood Dr., Centerville, OH 45459); Gill, John T. (906 E. Linden Ave., Miamisburg, OH 45342); Walko, Robert J. (3215 Blume, NE., Albuquerque, NM 87111); Renschler, Clifford L. (7 Lagarto Rd., Tijeras, NM 87059)

    1992-01-01T23:59:59.000Z

    The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. In the composition, a composite is formed from a carrier material and at least one of the source of the exciting radiation or the component which is capable of interacting with the exciting radiation. The composite is then employed for loading a porous substrate, preferably an aerogel substrate.

  19. Electroluminescence property of organic light emitting diode (OLED)

    SciTech Connect (OSTI)

    Özdemir, Orhan; Kavak, Pelin; Saatci, A. Evrim; Gökdemir, F. P?nar; Menda, U. Deneb; Can, Nursel; Kutlu, Kubilay [Y?ld?z Technical University, Department of Physics, Esenler, Istanbul (Turkey); Tekin, Emine; Pravadal?, Selin [National Metrology Inst?tute of Turkey (TUB?TAK-UME), Kocaeli (Turkey)

    2013-12-16T23:59:59.000Z

    Transport properties of electrons and holes were investigated not only in a anthracene-containing poly(p-phenylene-ethynylene)- alt - poly(p-phenylene-vinylene) (PPE-PPV) polymer (AnE-PVstat) light emitting diodes (OLED) but also in an ITO/Ag/polymer/Ag electron and ITO/PEDOT:PSS/polymer/Au hole only devices. Mobility of injected carriers followed the Poole-Frenkel type conduction mechanism and distinguished in the frequency range due to the difference of transit times in admittance measurement. Beginning of light output took place at the turn-on voltage (or flat band voltage), 1.8 V, which was the difference of energy band gap of polymer and two barrier offsets between metals and polymer.

  20. Thermal properties of organic light-emitting diodes

    SciTech Connect (OSTI)

    Bergemann, Kevin; Krasny, Robert; Forrest, Stephen R.

    2012-01-01T23:59:59.000Z

    Thermal management is important for the efficient operation of organic light-emitting diodes (OLED, or PHOLED) at high brightness, with the device operating temperature influencing both lifetime and performance. We apply a transmission-matrix approach to analytically model the effects of thermal conduction, convection and radiation on OLED temperature. The model predictions match experiment without requiring the use of fitting parameters. This allows for the simulation of the thermal response of various device architectures, materials combinations and environmental factors under a variety of operating conditions. Using these simulations, we find that 87% of the heat is dissipated through the air space adjacent to the glass package cap. Furthermore, an air gap between the device cathode and cap provides a significant thermal impedance. Minimizing the thickness of the internal air gap can lead to nearly room temperature operation, even at very high brightness.

  1. Mid-ultraviolet light-emitting diode detects dipicolinic acid.

    SciTech Connect (OSTI)

    Bogart, Katherine Huderle Andersen; Lee, Stephen Roger; Temkin, Henryk (Texas Tech University, Lubbock, TX); Crawford, Mary Hagerott; Dasgupta, Purnendu K. (Texas Tech University, Lubbock, TX); Li, Qingyang (Texas Tech University, Lubbock, TX); Allerman, Andrew Alan; Fischer, Arthur Joseph

    2005-06-01T23:59:59.000Z

    Dipicolinic acid (DPA, 2,6-pyridinedicarboxylic acid) is a substance uniquely present in bacterial spores such as that from anthrax (B. anthracis). It is known that DPA can be detected by the long-lived fluorescence of its terbium chelate; the best limit of detection (LOD) reported thus far using a large benchtop gated fluorescence instrument using a pulsed Xe lamp is 2 nM. We use a novel AlGaN light-emitting diode (LED) fabricated on a sapphire substrate that has peak emission at 291 nm. Although the overlap of the emission band of this LED with the absorption band of Tb-DPA ({lambda}{sub max} doublet: 273, 279 nm) is not ideal, we demonstrate that a compact detector based on this LED and an off-the-shelf gated photodetection module can provide an LOD of 0.4 nM, thus providing a basis for convenient early warning detectors.

  2. Method of electroplating a conversion electron emitting source on implant

    DOE Patents [OSTI]

    Srivastava, Suresh C. (Setauket, NY); Gonzales, Gilbert R. (New York, NY); Adzic, Radoslav (East Setauket, NY); Meinken, George E. (Middle Island, NY)

    2012-02-14T23:59:59.000Z

    Methods for preparing an implant coated with a conversion electron emitting source (CEES) are disclosed. The typical method includes cleaning the surface of the implant; placing the implant in an activating solution comprising hydrochloric acid to activate the surface; reducing the surface by H.sub.2 evolution in H.sub.2SO.sub.4 solution; and placing the implant in an electroplating solution that includes ions of the CEES, HCl, H.sub.2SO.sub.4, and resorcinol, gelatin, or a combination thereof. Alternatively, before tin plating, a seed layer is formed on the surface. The electroplated CEES coating can be further protected and stabilized by annealing in a heated oven, by passivation, or by being covered with a protective film. The invention also relates to a holding device for holding an implant, wherein the device selectively prevents electrodeposition on the portions of the implant contacting the device.

  3. Model for Triplet State Engineering in Organic Light Emitting Diodes

    E-Print Network [OSTI]

    Prodhan, Suryoday; Ramasesha, S

    2014-01-01T23:59:59.000Z

    Engineering the position of the lowest triplet state (T1) relative to the first excited singlet state (S1) is of great importance in improving the efficiencies of organic light emitting diodes and organic photovoltaic cells. We have carried out model exact calculations of substituted polyene chains to understand the factors that affect the energy gap between S1 and T1. The factors studied are backbone dimerisation, different donor-acceptor substitutions and twisted geometry. The largest system studied is an eighteen carbon polyene which spans a Hilbert space of about 991 million. We show that for reverse intersystem crossing (RISC) process, the best system involves substituting all carbon sites on one half of the polyene with donors and the other half with acceptors.

  4. White organic light-emitting diodes: Status and perspective

    E-Print Network [OSTI]

    Reineke, Sebastian; Lüssem, Björn; Leo, Karl

    2013-01-01T23:59:59.000Z

    White organic light-emitting diodes (OLEDs) are ultra-thin, large-area light sources made from organic semiconductor materials. Over the last decades, much research has been spent on finding the suitable materials to realize highly efficient monochrome and white OLEDs. With their high efficiency, color-tunability, and color-quality, white OLEDs are emerging to become one of the next generation light sources. In this review, we discuss the physics of a variety of device concepts that are introduced to realize white OLEDs based on both polymer and small molecule organic materi als. Owing to the fact that about 80 % of the internally generated photons are trapped within the thin-film layer structure, we put a second focus on reviewing promising concepts for improved light outcoupling.

  5. Low Voltage, Low Power Organic Light Emitting Transistors for AMOLED Displays

    SciTech Connect (OSTI)

    McCarthy, M. A. [University of Florida, Gainesville; Liu, B. [University of Florida, Gainesville; Donoghue, E. P. [University of Florida, Gainesville; Kravchenko, Ivan I [ORNL; Kim, D. Y. [University of Florida, Gainesville; Reynolds, J. R. [University of Florida, Gainesville; So, Franky [University of Florida, Gainesville; Rinzler, A. G. [University of Florida, Gainesville

    2011-01-01T23:59:59.000Z

    Low voltage, low power dissipation, high aperture ratio organic light emitting transistors are demonstrated. The high level of performance is enabled by a carbon nanotube source electrode that permits integration of the drive transistor and the organic light emitting diode into an efficient single stacked device. Given the demonstrated performance, this technology could break the technical logjam holding back widespread deployment of active matrix organic light emitting displays at flat panel screen sizes.

  6. Organic light-emitting device with a phosphor-sensitized fluorescent emission layer

    DOE Patents [OSTI]

    Forrest, Stephen (Ann Arbor, MI); Kanno, Hiroshi (Osaka, JP)

    2009-08-25T23:59:59.000Z

    The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters. The emissive region of the devices of the present invention comprise at least one phosphor-sensitized layer which has a combined emission from a phosphorescent emitter and a fluorescent emitter. In preferred embodiments, the invention relates to white-emitting OLEDS (WOLEDs).

  7. Sandia National Laboratories: atmospheric chemistry

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

    and atmospheric chemistry that is expected to benefit auto and engine manufacturers, oil and gas utilities, and other industries that employ combustion models. A paper...

  8. 2014-05-16 Issuance: Test Procedures for Integrated Light-Emitting...

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

    16 Issuance: Test Procedures for Integrated Light-Emitting Diode Lamps; Supplemental Notice of Proposed Rulemaking 2014-05-16 Issuance: Test Procedures for Integrated...

  9. algainp light-emitting diodes: Topics by E-print Network

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

    materials for different organic layers, which compose the standard organic light emitting diode (OLED) architecture.; Chapter one introduces (more) Borek, Carsten 2008-01-01...

  10. Wire-shaped semiconductor light-emitting diodes for general-purpose lighting

    SciTech Connect (OSTI)

    Mauk, Michael G.

    2002-10-28T23:59:59.000Z

    The object of this work is to develop and optimize a new type of light-emitting diode (LED) with a wire-shaped, cylindrical geometry.

  11. 2014-06-18 Issuance: Test Procedure for Integrated Light-Emitting...

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

    6-18 Issuance: Test Procedure for Integrated Light-Emitting Diode Lamps; Supplemental Notice of Proposed Rulemaking 2014-06-18 Issuance: Test Procedure for Integrated...

  12. ELSEVIER AtmosphericResearch 38 (1995) 207-235 ATMOSPHERIC

    E-Print Network [OSTI]

    Moelders, Nicole

    ELSEVIER AtmosphericResearch 38 (1995) 207-235 ATMOSPHERIC RESEARCH On the parameterization of ice and water substance mixing ratio fields were only strongly altered by turning off the ice phase of these schemes includes ice processes. But in mid- latitudes and also in tropics the ice phase is an important

  13. ATMOSPHERIC ELSEVIER AtmosphericResearch 44 (1997) 231-241

    E-Print Network [OSTI]

    Reading, University of

    ATMOSPHERIC RESEARCH ELSEVIER AtmosphericResearch 44 (1997) 231-241 Error analysis of backscatter;accepted 14 February 1997 Abstract Ice sphere backscatter has been calculated using both Mie theory as a reasonable approximation for rv 1997 Elsevier Science B.V. 1. Introduction Cirrus clouds play

  14. Soot aerosol properties in laminar soot-emitting microgravity nonpremixed flames

    SciTech Connect (OSTI)

    Konsur, B.; Megaridis, C.M.; Griffin, D.W.

    1999-09-01T23:59:59.000Z

    The spatial distributions and morphological properties of the soot aerosol are examined experimentally in a series of 0-g laminar gas-jet nonpremixed flames. The methodology deploys round jet diffusion flames of nitrogen-diluted acetylene fuel burning in quiescent air at atmospheric pressure. Full-field laser-light extinction is utilized to determine transient soot spatial distributions within the flames. Thermophoretic sampling is employed in conjunction with transmission electron microscopy to define soot microstructure within the soot-emitting 0-g flames. The microgravity tests indicate that the 0-g flames attain a quasi-steady state roughly 0.7 s after ignition, and sustain their annular structure even beyond their luminous flame tip. The measured peak soot volume fractions show a complex dependence on burner exit conditions, and decrease in a nonlinear fashion with decreasing characteristic flow residence times. Fuel preheat by {approximately}140K appears to accelerate the formation of soot near the flame axis via enhanced field pyrolysis rates. The increased soot presence caused by the elevated fuel injection temperatures triggers higher flame radiative losses, which may account for the premature suppression of soot growth observed along the annular region of preheated-fuel flames. Electron micrographs of soot aggregates collected in 0-g reveal the presence of soot precursor particles near the symmetry axis at midflame height. The observations also verify that soot primary particle sizes are nearly uniform among aggregates present at the same flame location, but vary considerably with radius at a fixed distance from the burner. The maximum primary size in 0-g is found to be by 40% larger than in 1-g, under the same burner exit conditions. Estimates of the number concentration of primary particles and surface area of soot particulate phase per unit volume of the combustion gases are also made for selected in-flame locations.

  15. Space Science : Atmosphere Greenhouse Effect

    E-Print Network [OSTI]

    Johnson, Robert E.

    Space Science : Atmosphere Greenhouse Effect Part-5a Solar + Earth Spectrum IR Absorbers Grey Atmosphere Greenhouse Effect #12;Radiation: Solar and Earth Surface B"(T) Planck Ideal Emission Integrate at the carbon cycle #12;However, #12;Greenhouse Effect is Complex #12;PLANETARY ENERGY BALANCE G+W fig 3-5

  16. Ch4. Atmosphere and Surface Energy Balances

    E-Print Network [OSTI]

    Pan, Feifei

    ;Energy Pathways #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Atmosphere or performing any work. #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Transmission or water. #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Transmission Atmosphere

  17. Saturated and efficient blue phosphorescent organic light emitting devices with Lambertian angular emission

    E-Print Network [OSTI]

    Saturated and efficient blue phosphorescent organic light emitting devices with Lambertian angular a microcavity to optimize the color of a phosphorescent organic light emitting device OLED based on the-sky blue.1063/1.2742577 The development of a stable, efficient, and saturated blue remains an important goal for phosphorescent organic

  18. Hydrocarbons emitted by waggle-dancing honey bees stimulate colony foraging activity by causing experienced

    E-Print Network [OSTI]

    Hydrocarbons emitted by waggle-dancing honey bees stimulate colony foraging activity by causing of the hydrocarbons emitted by waggle-dancing bees are investigated in this study. First, we test the hypothesis itself. waggle dance / cuticular hydrocarbon / nectar foraging / semiochemical / pheromone 1

  19. Method to generate high efficient devices which emit high quality light for illumination

    DOE Patents [OSTI]

    Krummacher, Benjamin C. (Sunnyvale, CA); Mathai, Mathew (Santa Clara, CA); Choong, Vi-En (San Jose, CA); Choulis, Stelios A. (San Jose, CA)

    2009-06-30T23:59:59.000Z

    An electroluminescent apparatus includes an OLED device emitting light in the blue and green spectrums, and at least one down conversion layer. The down conversion layer absorbs at least part of the green spectrum light and emits light in at least one of the orange spectra and red spectra.

  20. Proton implanted singlemode holey vertical-cavity surface-emitting lasers

    E-Print Network [OSTI]

    Choquette, Kent

    Proton implanted singlemode holey vertical-cavity surface-emitting lasers P.O. Leisher, A.J. Danner of proton implant confined vertical-cavity surface-emitting lasers. The index confinement and selective loss (both fundamental and non-fundamental) operation [9]. Although proton implantation for current

  1. Emitting gas regions in Mrk 493: An extensive Fe II line emission region

    E-Print Network [OSTI]

    L. C. Popovic; A. Smirnova; D. Ilic; A. Moiseev; J. Kovacevic; V. Afanasiev

    2007-01-24T23:59:59.000Z

    We performed 3D spectroscopic observations of Mrk 493 in order to investigate the Fe II emitting region and their possible connection with the Hydrogen emitting region. We found that there is a strong Fe II emission in an extensive region ~ 4" x 4" around Sy 1 nucleus. The Fe II line width indicates that these lines are originated in an intermediate line region.

  2. Modeling Population Exposures to Pollutants Emitted from Natural Gas Cooking Burners

    E-Print Network [OSTI]

    iPage | i Modeling Population Exposures to Pollutants Emitted from Natural Gas Cooking. LBNL4885E #12;Modeling Population Exposures to Pollutants Emitted from Natural Gas Cooking Burners distributions resulting from use of natural gas cooking appliances across households in California. The model

  3. Efficiency improvement of phosphorescent organic light-emitting diodes using semitransparent Ag as anode

    E-Print Network [OSTI]

    Efficiency improvement of phosphorescent organic light-emitting diodes using semitransparent Ag The emission efficiency in an organic light-emitting diode OLED based on fac tris phenyl pyridine iridium Ir current efficiency of 81 cd/A and a power efficiency of 79 lm/W, compared with 46 cd/A and 39 lm

  4. Light extraction efficiency enhancement of InGaN quantum wells light-emitting diodes with

    E-Print Network [OSTI]

    Gilchrist, James F.

    Light extraction efficiency enhancement of InGaN quantum wells light-emitting diodes@lehigh.edu Abstract: Improvement of light extraction efficiency of InGaN light emitting diodes (LEDs) using microstructures on the light extraction efficiency of III-Nitride LEDs was studied. Depending on the size

  5. Light extraction from organic light-emitting diodes for lighting applications by sand-blasting

    E-Print Network [OSTI]

    Light extraction from organic light-emitting diodes for lighting applications by sand@ust.hk Abstract: Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost

  6. Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors

    E-Print Network [OSTI]

    Mayer, Alexandre

    Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors developed for the optimization of light-emitting diodes (LED) and solar thermal collectors. The surface a light-extraction efficiency of only 3.7%). The solar thermal collector we considered consists

  7. Semiconductor lasers with broad tunnel-coupled waveguides, emitting at a wavelength of 980 nm

    SciTech Connect (OSTI)

    Zvonkov, N B; Ershov, A V; Zvonkov, B N; Maksimov, G A; Uskova, E A [Scientific-Research Physicotechnical Institute at the Nizhnii Novgorod State University, Nizhnii Novgorod (Russian Federation); Akhlestina, S A [Research Insitute of Chemistry, N.I. Lobachevskii Nizhnii Novgorod State University, Nizhnii Novgorod (Russian Federation)

    1999-03-31T23:59:59.000Z

    InGaP/GaAs/InGaAs semiconductor lasers with broad tunnel-coupled waveguides were developed and investigated experimentally. Output radiation power of 5.2 - 5.8 W was obtained from an emitting region 100 {mu}m wide with a 36{sup 0} divergence of the emitted radiation in a plane perpendicular to the p - n junction. (lasers)

  8. GaN light-emitting diodes with Archimedean lattice photonic crystals Aurlien David,a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    GaN light-emitting diodes with Archimedean lattice photonic crystals Aurélien David,a Tetsuo Fujii 2005; published online 16 February 2006 We study GaN-based light emitting diodes incorporating the semiconductor due to its index contrast with air.1­6 Recently, PhCs were used as out- coupling gratings in GaN

  9. Constraints on the ionizing flux emitted by T Tauri stars

    E-Print Network [OSTI]

    R. D. Alexander; C. J. Clarke; J. E. Pringle

    2005-01-06T23:59:59.000Z

    We present the results of an analysis of ultraviolet observations of T Tauri Stars (TTS). By analysing emission measures taken from the literature we derive rates of ionizing photons from the chromospheres of 5 classical TTS in the range ~10^41-10^44 photons/s, although these values are subject to large uncertainties. We propose that the HeII/CIV line ratio can be used as a reddening-independent indicator of the hardness of the ultraviolet spectrum emitted by TTS. By studying this line ratio in a much larger sample of objects we find evidence for an ionizing flux which does not decrease, and may even increase, as TTS evolve. This implies that a significant fraction of the ionizing flux from TTS is not powered by the accretion of disc material onto the central object, and we discuss the significance of this result and its implications for models of disc evolution. The presence of a significant ionizing flux in the later stages of circumstellar disc evolution provides an important new constraint on disc photoevaporation models.

  10. White Light Emitting Diode Development for General Illumination Applications

    SciTech Connect (OSTI)

    James Ibbetson

    2006-05-01T23:59:59.000Z

    This report contains a summary of technical achievements during a 3-year project aimed at developing the chip and packaging technology necessary to demonstrate efficient, high flux light-emitting diode (LED) arrays using Cree's gallium nitride/silicon carbide (GaN/SiC) LED technology as the starting point. Novel chip designs and fabrication processes are described that led to high power blue LEDs that achieved 310 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 32.5% and 26.5%, respectively. When combined with phosphor, high power white LEDs with luminous output of 67 lumens and efficacy of 57 lumens per watt were also demonstrated. Advances in packaging technology are described that enabled compact, multi-chip white LED lamp modules with 800-1000 lumens output at efficacies of up to 55 lumens per watt. Lamp modules with junction-to-ambient thermal resistance as low as 1.7 C/watt have also been demonstrated.

  11. Modeling Atmospheric Aerosols V. Rao Kotamarthi

    E-Print Network [OSTI]

    Modeling Atmospheric Aerosols V. Rao Kotamarthi and Yan Feng Climate Research Section Environmental Science Division Argonne National Laboratory #12;Outline Atmospheric Aerosols and gas phase heterogeneous reactions Regional Scales and Atmospheric Aerosols Regional Scale Aerosols: Ganges Valley Aerosol

  12. Fragmentation Energetics of Clusters Relevant to Atmospheric...

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

    of Clusters Relevant to Atmospheric New Particle Formation. Fragmentation Energetics of Clusters Relevant to Atmospheric New Particle Formation. Abstract: The exact mechanisms by...

  13. Environmental Chemistry II (Atmospheric Chemistry)

    E-Print Network [OSTI]

    Dibble, Theodore

    SYLLABUS FOR Environmental Chemistry II (Atmospheric Chemistry) FCH 511 Fall 2013 Theodore S/explaining the trends in J as a function of altitude and solar zenith angle. The second involves analyzing real

  14. THE MARTIAN ATMOSPHERIC BOUNDARY LAYER

    E-Print Network [OSTI]

    Spiga, Aymeric

    THE MARTIAN ATMOSPHERIC BOUNDARY LAYER A. Petrosyan,1 B. Galperin,2 S. E. Larsen,3 S. R. Lewis,4 A [Haberle et al., 1993a; Larsen et al., 2002; Hinson et al., 2008]. At night, convection is inhibited

  15. Carbonitride based phosphors and light emitting devices using the same

    DOE Patents [OSTI]

    Li, Yuanqiang; Tian, Yongchi; Romanelli, Michael Dennis

    2013-08-20T23:59:59.000Z

    Disclosed herein is a novel group of carbidonitride phosphors and light emitting devices which utilize these phosphors. In certain embodiments, the present invention is directed to a novel family of carbidonitride-based phosphors expressed as follows: Ca.sub.1-xAl.sub.x-xySi.sub.1-x+xyN.sub.2-x-xyC.sub.xy:A; (1) Ca.sub.1-x-zNa.sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xyC.sub.xy:- A; (2) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x- -xyC.sub.xy:A; (3) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xy-2w/- 3C.sub.xyO.sub.w-v/2H.sub.v:A; and (4) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xy-2w/- 3-v/3C.sub.xyO.sub.wH.sub.v:A, (4a) wherein 0xy+z, and 0

  16. Atmospheric science and power production

    SciTech Connect (OSTI)

    Randerson, D. (ed.)

    1984-07-01T23:59:59.000Z

    This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

  17. Laser Atmospheric Studies with VERITAS

    E-Print Network [OSTI]

    C. M. Hui; for the VERITAS collaboration

    2007-09-25T23:59:59.000Z

    As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.

  18. Organic light emitting device architecture for reducing the number of organic materials

    DOE Patents [OSTI]

    D'Andrade, Brian (Westampton, NJ); Esler, James (Levittown, PA)

    2011-10-18T23:59:59.000Z

    An organic light emitting device is provided. The device includes an anode and a cathode. A first emissive layer is disposed between the anode and the cathode. The first emissive layer includes a first non-emitting organic material, which is an organometallic material present in the first emissive layer in a concentration of at least 50 wt %. The first emissive layer also includes a first emitting organic material. A second emissive layer is disposed between the first emissive layer and the cathode, preferably, in direct contact with the first emissive layer. The second emissive material includes a second non-emitting organic material and a second emitting organic material. The first and second non-emitting materials, and the first and second emitting materials, are all different materials. A first non-emissive layer is disposed between the first emissive layer and the anode, and in direct contact with the first emissive layer. The first non- emissive layer comprises the first non-emissive organic material.

  19. Wavelength-resolved low-frequency noise of GaInN/GaN green light emitting diodes

    E-Print Network [OSTI]

    Wetzel, Christian M.

    Wavelength-resolved low-frequency noise of GaInN/GaN green light emitting diodes S. L. Rumyantseva well light emitting diodes. The light intensity noise was measured as a function of wavelength within the light emitting diode spectral emission line. The spectral noise density is found to increase

  20. High-density organic light emitting diodes by nanoimprint technology Krutarth Trivedi, Caleb Nelson, Li Tao, Mathew Goeckner, Walter Hua)

    E-Print Network [OSTI]

    Hu, Wenchuang "Walter"

    High-density organic light emitting diodes by nanoimprint technology Krutarth Trivedi, Caleb Nelson sources. Despite the considerable development of inorganic semiconductor based light emitting diodes of miniaturization to nanoscale. Organic light emitting diode (OLED) technology is immune to quantum confinement

  1. Journal of Crystal Growth 298 (2007) 272275 Dislocation analysis in homoepitaxial GaInN/GaN light emitting

    E-Print Network [OSTI]

    Wetzel, Christian M.

    2007-01-01T23:59:59.000Z

    of GaInN/GaN-based light emitting diodes (LED) on quasi-bulk GaN with an atomically flat polished were much improved. The optical output power of the light emitting diode increased by more than one. Cathodoluminescence; A1. Threading dislocation density; A2. Homoepitaxial growth; B1. GaInN; B3. Light emitting diode

  2. Junction temperature, spectral shift, and efficiency in GaInN-based blue and green light emitting diodes

    E-Print Network [OSTI]

    Wetzel, Christian M.

    Keywords: GaInN/GaN Light emitting diode temperature Micro-Raman Photoluminescence Electroluminescence well light emitting diode (LED) dies is analyzed by micro-Raman, photoluminescence, cathodoluminescenceJunction temperature, spectral shift, and efficiency in GaInN-based blue and green light emitting

  3. 4.2: Design of an Improved Pixel for a Polysilicon Active Matrix Organic Light Emitting Diode Display

    E-Print Network [OSTI]

    4.2: Design of an Improved Pixel for a Polysilicon Active Matrix Organic Light Emitting Diode active matrix organic light emitting diode (AMOLED) pixel with high pixel to pixel luminance uniformity such as organic light emitting diodes (OLEDs) are presently of great interest due to their potential application

  4. Thickness-dependent changes in the optical properties of PPV-and PF-based polymer light emitting diodes

    E-Print Network [OSTI]

    Carter, Sue

    the thickness-dependent optical properties of single layer polymer light emitting diodes for two materials, poly the electronic and optical properties of these materials in light emitting diode LED structures.2 OurThickness-dependent changes in the optical properties of PPV- and PF-based polymer light emitting

  5. Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design

    E-Print Network [OSTI]

    Boyer, Edmond

    Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes Light Emitting Diode (OLED), intermolecular p­p interactions should be usually suppressed to avoid any Emitting Diodes (SMOLEDs) is almost absent from the literature. In this work, three aryl-substituted Di

  6. Vacuum-free lamination of low work function cathode for efficient solution-processed organic light-emitting diodes

    E-Print Network [OSTI]

    Meng, Hsin-Fei

    -coated organic light-emitting diode is transferred from a soft polydimethylsiloxane (PDMS) mold by lamination, or blade coating [1,2] for organic light emitting diode (OLED) as well as solar cell. The top electrodeVacuum-free lamination of low work function cathode for efficient solution-processed organic light-emitting

  7. Efficiency enhancement in a light-emitting diode with a two-dimensional surface grating photonic crystal

    E-Print Network [OSTI]

    Baba, Toshihiko

    Efficiency enhancement in a light-emitting diode with a two-dimensional surface grating photonic 21 November 2003 We demonstrate a light-emitting diode exhibiting 1.7­2.7-fold enhancement in light light emitting diode LED , the ef- ficiency is limited to several percents by a low light extrac- tion

  8. Polarization engineering via staggered InGaN quantum wells for radiative efficiency enhancement of light emitting diodes

    E-Print Network [OSTI]

    Gilchrist, James F.

    of light emitting diodes Ronald A. Arif, Yik-Khoon Ee, and Nelson Tansu Citation: Appl. Phys. Lett. 91 extraction in GaN-based light emitting diodes Appl. Phys. Lett. 100, 061107 (2012) Electrically driven nanopyramid green light emitting diode Appl. Phys. Lett. 100, 061106 (2012) Ultraviolet electroluminescence

  9. Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract--Semiconductor nanocrystal quantum dots (NQD)

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract-- Semiconductor nanocrystal convertors integrated on light-emitting diodes (LEDs). The use of nonradiative energy transfer, also known-LEDs for lighting applications. Index Terms-- Förster resonance energy transfer, light emitting diode, nanocrystal

  10. Interface electronic structures of organic light-emitting diodes with WO3 interlayer: A study by photoelectron spectroscopy

    E-Print Network [OSTI]

    Kim, Sehun

    Interface electronic structures of organic light-emitting diodes with WO3 interlayer: A study injec- tion and transport layers in an organic light-emitting diode (OLED) structure has been studied B.V. All rights reserved. 1. Introduction OLEDs (organic light-emitting diodes) are display de

  11. Atmospheric Circulation and Tides of "51Peg b-like" Planets

    E-Print Network [OSTI]

    Adam P. Showman; Tristan Guillot

    2002-02-12T23:59:59.000Z

    We examine the properties of the atmospheres of extrasolar giant planets at orbital distances smaller than 0.1 AU from their stars. We show that these ``51Peg b-like'' planets are rapidly synchronized by tidal interactions, but that small departures from synchronous rotation can occur because of fluid-dynamical torques within these planets. Previous radiative-transfer and evolution models of such planets assume a homogeneous atmosphere. Nevertheless, we show using simple arguments that, at the photosphere, the day-night temperature difference and characteristic wind speeds may reach ~500 K and ~2 km/s, respectively. Substantial departures from chemical equilibrium are expected. The cloud coverage depends sensitively on the dynamics; clouds could exist predominantly either on the dayside or nightside, depending on the circulation regime. Radiative-transfer models that assume homogeneous conditions are therefore inadequate in describing the atmospheric properties of 51Peg b-like planets. We present preliminary three-dimensional, nonlinear simulations of the atmospheric circulation of HD209458b that indicate plausible patterns for the circulation and generally agree with our simpler estimates. Furthermore, we show that kinetic energy production in the atmosphere can lead to the deposition of substantial energy in the interior, with crucial consequences for the evolution of these planets. Future measurements of reflected and thermally-emitted radiation from these planets will help test our ideas.

  12. Surface Plasmon Enhanced Phosphorescent Organic Light Emitting Diodes

    SciTech Connect (OSTI)

    Guillermo Bazan; Alexander Mikhailovsky

    2008-08-01T23:59:59.000Z

    The objective of the proposed work was to develop the fundamental understanding and practical techniques for enhancement of Phosphorescent Organic Light Emitting Diodes (PhOLEDs) performance by utilizing radiative decay control technology. Briefly, the main technical goal is the acceleration of radiative recombination rate in organometallic triplet emitters by using the interaction with surface plasmon resonances in noble metal nanostructures. Increased photonic output will enable one to eliminate constraints imposed on PhOLED efficiency by triplet-triplet annihilation, triplet-polaron annihilation, and saturation of chromophores with long radiative decay times. Surface plasmon enhanced (SPE) PhOLEDs will operate more efficiently at high injection current densities and will be less prone to degradation mechanisms. Additionally, introduction of metal nanostructures into PhOLEDs may improve their performance due to the improvement of the charge transport through organic layers via multiple possible mechanisms ('electrical bridging' effects, doping-like phenomena, etc.). SPE PhOLED technology is particularly beneficial for solution-fabricated electrophosphorescent devices. Small transition moment of triplet emitters allows achieving a significant enhancement of the emission rate while keeping undesirable quenching processes introduced by the metal nanostructures at a reasonably low level. Plasmonic structures can be introduced easily into solution-fabricated PhOLEDs by blending and spin coating techniques and can be used for enhancement of performance in existing device architectures. This constitutes a significant benefit for a large scale fabrication of PhOLEDs, e.g. by roll-to-roll fabrication techniques. Besides multieexciton annihilation, the power efficacy of PhOLEDs is often limited by high operational bias voltages required for overcoming built-in potential barriers to injection and transport of electrical charges through a device. This problem is especially pronounced in solution processed OLEDs lacking the accuracy and precision of fabrication found in their small molecule counterparts. From this point of view, it seems beneficial to develop materials allowing reduction of the operation bias voltage via improvement of the charge injection. The materials sought have to be compatible with solution-based fabrication process and allow easy incorporation of metal nanostructures.

  13. Atmospheric optical measurements in western Florida, Flight 112, Part II: Sky luminances

    E-Print Network [OSTI]

    Boileau, Almerian R

    1960-01-01T23:59:59.000Z

    by which the sky luminance and radiance distributions wereRecording schedule. Sky luminance distribution data wereof Data Lines used for Sky Luminance P l o t s , Figure 4

  14. Use of the ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes & Aerosol-Cloud Interaction

    SciTech Connect (OSTI)

    Chiu, Jui-Yuan Christine [University of Reading] [University of Reading

    2014-04-10T23:59:59.000Z

    This project focuses on cloud-radiation processes in a general three-dimensional cloud situation, with particular emphasis on cloud optical depth and effective particle size. The proposal has two main parts. Part one exploits the large number of new wavelengths offered by the Atmospheric Radiation Measurement (ARM) zenith-pointing ShortWave Spectrometer (SWS), to develop better retrievals not only of cloud optical depth but also of cloud particle size. We also take advantage of the SWS’ high sampling resolution to study the “twilight zone” around clouds where strong aerosol-cloud interactions are taking place. Part two involves continuing our cloud optical depth and cloud fraction retrieval research with ARM’s 2-channel narrow vield-of-view radiometer and sunphotometer instrument by, first, analyzing its data from the ARM Mobile Facility deployments, and second, making our algorithms part of ARM’s operational data processing.

  15. Climate effects of seasonally varying Biomass Burning emitted Carbonaceous Aerosols (BBCA)

    E-Print Network [OSTI]

    Jeong, Gill-Ran

    The climate impact of the seasonality of Biomass Burning emitted Carbonaceous Aerosols (BBCA) is studied using an aerosol-climate model coupled with a slab ocean model in a set of 60-year long simulations, driven by BBCA ...

  16. Development of monolithic CMOS-compatible visible light emitting diode arrays on silicon

    E-Print Network [OSTI]

    Chilukuri, Kamesh

    2006-01-01T23:59:59.000Z

    The synergies associated with integrating Si-based CMOS ICs and III-V-material-based light-emitting devices are very exciting and such integration has been an active area of research and development for quite some time ...

  17. Diffusion injected multi-quantum well light-emitting diode structure

    SciTech Connect (OSTI)

    Riuttanen, L., E-mail: lauri.riuttanen@aalto.fi; Nykänen, H.; Svensk, O.; Suihkonen, S.; Sopanen, M. [Department of Micro- and Nanosciences, Aalto University, P.O. Box 13500, FI-00076 Aalto (Finland); Kivisaari, P.; Oksanen, J.; Tulkki, J. [Department of Biomedical Engineering and Computational Science, Aalto University, P.O. Box 12200, FI-00076 Aalto (Finland)

    2014-02-24T23:59:59.000Z

    The attention towards light-emitting diode (LED) structures based on nanowires, surface plasmon coupled LEDs, and large-area high-power LEDs has been increasing for their potential in increasing the optical output power and efficiency of LEDs. In this work we demonstrate an alternative way to inject charge carriers into the active region of an LED, which is based on completely different current transport mechanism compared to conventional current injection approaches. The demonstrated structure is expected to help overcoming some of the challenges related to current injection with conventional structures. A functioning III-nitride diffusion injected light-emitting diode structure, in which the light-emitting active region is located outside the pn-junction, is realized and characterized. In this device design, the charge carriers are injected into the active region by bipolar diffusion, which could also be utilized to excite otherwise challenging to realize light-emitting structures.

  18. Method and apparatus for improving the performance of light emitting diodes

    DOE Patents [OSTI]

    Lowery, Christopher H. (Fremont, CA); McElfresh, David K. (Union City, CA); Burchet, Steve (Cedar Crest, NM); Adolf, Douglas B. (Albuquerque, NM); Martin, James (Tijeras, NM)

    1996-01-01T23:59:59.000Z

    A method for increasing the resistance of a light emitting diode and other semiconductor devices to extremes of temperature is disclosed. During the manufacture of the light emitting diode, a liquid coating is applied to the light emitting die after the die has been placed in its lead frame. After the liquid coating has been placed on the die and its lead frames, a thermosetting encapsulant material is placed over the coating. The operation that cures the thermosetting material leaves the coating liquid intact. As the die and the encapsulant expand and contract at different rates with respect to changes in temperature, and as in known light emitting diodes the encapsulating material adheres to the die and lead frames, this liquid coating reduces the stresses that these different rates of expansion and contraction normally cause by eliminating the adherence of the encapsulating material to the die and frame.

  19. Collisionless ion collection by non-emitting spherical bodies in E x B fields

    E-Print Network [OSTI]

    Patacchini, Leonardo

    2010-01-01T23:59:59.000Z

    The three-dimensional interaction of a magnetized, collisionless flowing plasma with a non-emitting conducting sphere is solved in the entire range of physically allowed parameters, in the ion-collecting regime. This can ...

  20. Components, production processes, and recommendations for future research in organic light emitting diodes

    E-Print Network [OSTI]

    Hunting, Lindsay (Lindsay E.)

    2009-01-01T23:59:59.000Z

    Organic Light Emitting Diodes (OLEDs) are small, optoelectronic devices that can be used in the production of energy-efficient, high definition displays in cell phones, computers, and televisions. These devices have great ...

  1. Room-temperature direct bandgap electroluminesence from Ge-on-Si light-emitting diodes

    E-Print Network [OSTI]

    Sun, Xiaochen

    We report what we believe to be the first demonstration of direct bandgap electroluminescence (EL) from Ge/Si heterojunction light-emitting diodes (LEDs) at room temperature. In-plane biaxial tensile strain is used to ...

  2. Storage of charge carriers on emitter molecules in organic light-emitting diodes

    E-Print Network [OSTI]

    Reineke, Sebastian

    Organic light-emitting diodes (OLEDs) using the red phosphorescent emitter iridium(III)bis(2-methyldibenzo[f,h]quinoxaline) (acetylacetonate) [Ir(MDQ)[subscript 2](acac)] are studied by time-resolved electroluminescence ...

  3. Fabrication and optimization of light emitting devices with core-shell quantum dots

    E-Print Network [OSTI]

    Song, Katherine Wei

    2013-01-01T23:59:59.000Z

    Quantum dot light emitting devices (QD-LEDs) are promising options for the next generation of solid state lighting, color displays, and other optoelectronic applications. Overcoating quantum dots (QDs) -- semiconducting ...

  4. active-matrix organic light-emitting: Topics by E-print Network

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

    22 23 24 25 Next Page Last Page Topic Index 1 Transparent Active Matrix Organic Light-Emitting Diode Displays Driven by Chemistry Websites Summary: and portable electronics. In...

  5. Fiber Fabry-Perot interferometer (FFPI) sensor using vertical cavity surface emitting laser (VCSEL) 

    E-Print Network [OSTI]

    Lee, Kyung-Woo

    2006-10-30T23:59:59.000Z

    This research represents the first effort to apply vertical cavity surface emitting lasers (VCSELs) to the monitoring of interferometric fiber optic sensors. Modulation of the drive current causes thermal tuning of the laser light frequency...

  6. Efficiency loss mechanisms in colloidal quantum-dot light-emitting diodes

    E-Print Network [OSTI]

    Shirasaki, Yasuhiro

    2013-01-01T23:59:59.000Z

    Saturated and tunable emission colors make colloidal quantum-dot light-emitting diodes (QD-LEDs) interesting for the next generation of display and lighting technologies. However, there still remain various hurdles to the ...

  7. A strategy for the use of light emitting diodes by autonomous underwater vehicles

    E-Print Network [OSTI]

    Curran, Joseph R. (Joseph Robinson)

    2004-01-01T23:59:59.000Z

    Light Emitting Diode (LED) technology has advanced dramatically in a few short years. An expensive and difficult to manufacture LED array containing nearly 100 individual LEDs and measuring at least 5 cm˛ can now be replaced ...

  8. Physical properties and design of light-emitting devices based on organic materials and nanoparticles

    E-Print Network [OSTI]

    Anikeeva, Polina Olegovna

    2009-01-01T23:59:59.000Z

    This thesis presents the detailed experimental and theoretical characterization of light-emitting devices (LEDs) based on organic semiconductors and colloidal quantum dots (QDs). This hybrid material system has several ...

  9. Fiber Fabry-Perot interferometer (FFPI) sensor using vertical cavity surface emitting laser (VCSEL)

    E-Print Network [OSTI]

    Lee, Kyung-Woo

    2006-10-30T23:59:59.000Z

    to achieve PD Coupler Terminated 6 internal mirror reflectances as high as 86% [11]. Low coherent interferometery (LCI) using broadband light sources such as light emitting diodes (LEDs) has been researched [12,13]. FFPI sensor systems have been...

  10. Energy Policy Seminar Series: Climate impacts of methane-emitting energy technologies

    E-Print Network [OSTI]

    Chen, Kuang-Yu

    of greenhouse gases, most notably methane and carbon dioxide, and these gases have dissimilar properties. This research finds that methane-emitting energy such as natural gas becomes significantly more carbon dioxide

  11. Colloidal semiconductor nanocrystals as nanoscale emissive probes in light emitting diodes and cell biology

    E-Print Network [OSTI]

    Huang, Hao, Ph. D. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    This thesis employs colloidal semiconductor nanocrystals (NCs) as nanoscale emissive probes to investigate the physics of light emitting diodes (LEDs), as well as to unveil properties of cells that conventional imaging ...

  12. Aspects of charge recombination and charge transport in organic solar cells and light-emitting devices

    E-Print Network [OSTI]

    Difley, Seth

    2010-01-01T23:59:59.000Z

    In this thesis, aspects of charge reconbination and charge transport in organic solar cells and light-emitting devices are presented. These devices show promise relative to traditional inorganic semiconductors. We show ...

  13. An evaluation of styrene levels emitted during cast polymer production of cultured marble building materials

    E-Print Network [OSTI]

    Bell, Lewis Ray

    1994-01-01T23:59:59.000Z

    emitted into the surrounding facility and outside ambient air. These concentrations were tabulated and compared against styrene levels from each major process in the fabrication of cultured marble. Additionally, the removal effectiveness of the ventilation...

  14. Adhesion in flexible organic and hybrid organic/inorganic light emitting device and solar cells

    SciTech Connect (OSTI)

    Yu, D.; Kwabi, D.; Akogwu, O.; Du, J. [Princeton Institute of Science and Technology of Materials, Princeton University, 70 Prospect Street, Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544 (United States); Oyewole, O. K. [Department of Theoretical and Applied Physics, African University of Science and Technology, Km 10, Airport Road, Galadimawa, Abuja, Federal Capital Territory (Nigeria); Department of Materials Science and Engineering, Kwara State University, Malete, Kwara State (Nigeria); Tong, T. [Princeton Institute of Science and Technology of Materials, Princeton University, 70 Prospect Street, Princeton, New Jersey 08544 (United States); Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544 (United States); Anye, V. C.; Rwenyagila, E. [Department of Materials Science and Engineering, African University of Science and Technology, Km 10, Airport Road, Galadimawa, Abuja, Federal Capital Territory (Nigeria); Asare, J.; Fashina, A. [Department of Theoretical and Applied Physics, African University of Science and Technology, Km 10, Airport Road, Galadimawa, Abuja, Federal Capital Territory (Nigeria); Soboyejo, W. O. [Princeton Institute of Science and Technology of Materials, Princeton University, 70 Prospect Street, Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544 (United States); Department of Materials Science and Engineering, African University of Science and Technology, Km 10, Airport Road, Galadimawa, Abuja, Federal Capital Territory (Nigeria)

    2014-08-21T23:59:59.000Z

    This paper presents the results of an experimental study of the adhesion between bi-material pairs that are relevant to organic light emitting devices, hybrid organic/inorganic light emitting devices, organic bulk heterojunction solar cells, and hybrid organic/inorganic solar cells on flexible substrates. Adhesion between the possible bi-material pairs is measured using force microscopy (AFM) techniques. These include: interfaces that are relevant to organic light emitting devices, hybrid organic/inorganic light emitting devices, bulk heterojunction solar cells, and hybrid combinations of titanium dioxide (TiO{sub 2}) and poly(3-hexylthiophene). The results of AFM measurements are incorporated into the Derjaguin-Muller-Toporov model for the determination of adhesion energies. The implications of the results are then discussed for the design of robust organic and hybrid organic/inorganic electronic devices.

  15. Integration of photoactive and electroactive components with vertical cavity surface emitting lasers

    DOE Patents [OSTI]

    Bryan, R.P.; Esherick, P.; Jewell, J.L.; Lear, K.L.; Olbright, G.R.

    1997-04-29T23:59:59.000Z

    A monolithically integrated optoelectronic device is provided which integrates a vertical cavity surface emitting laser and either a photosensitive or an electrosensitive device either as input or output to the vertical cavity surface emitting laser either in parallel or series connection. Both vertical and side-by-side arrangements are disclosed, and optical and electronic feedback means are provided. Arrays of these devices can be configured to enable optical computing and neural network applications. 9 figs.

  16. Integration of photoactive and electroactive components with vertical cavity surface emitting lasers

    DOE Patents [OSTI]

    Bryan, Robert P. (12700 Indian School Rd. NE., Apt. 604, Albuquerque, NM 87112); Esherick, Peter (1105 Sagebrush Trail SE., Albuquerque, NM 87123); Jewell, Jack L. (12 Timberline Dr., Bridgewater, NJ 08807); Lear, Kevin L. (13713 Vic Rd. NE., Albuquerque, NM 87112); Olbright, Gregory R. (3875 Orange Ct., Boulder, CO 80304)

    1997-01-01T23:59:59.000Z

    A monolithically integrated optoelectronic device is provided which integrates a vertical cavity surface emitting laser and either a photosensitive or an electrosensitive device either as input or output to the vertical cavity surface emitting laser either in parallel or series connection. Both vertical and side-by-side arrangements are disclosed, and optical and electronic feedback means are provided. Arrays of these devices can be configured to enable optical computing and neural network applications.

  17. Light-Emitting Diodes in the Solid-State Lighting Systems

    E-Print Network [OSTI]

    Sparavigna, Amelia Carolina

    2014-01-01T23:59:59.000Z

    Red and green light-emitting diodes (LEDs) had been produced for several decades before blue emitting diodes, suitable for lighting applications, were widely available. Today, we have the possibility of combining the three fundamental colours to have a bright white light. And therefore, a new form of lighting, the solid-state lighting, has now become a reality. Here we discuss LEDs and some of their applications in displays and lamps.

  18. Radiative transfer in the earth's atmosphere-ocean system using Monte Carlo techniques

    E-Print Network [OSTI]

    Bradley, Paul Andrew

    1987-01-01T23:59:59.000Z

    TRANSFER PROBLEM MONTE CARLO METHOD Assumptions of the Model Photon Pathlength Emulation Techniques Sampling Scattering Functions: Angles and Probabilities Emulation of an Interface Computing the Radiance by Statistical Estimation Determination... of Direction Cosines After Scattering Flux Estimation into Detectors Determination of a New Scattering Point Photon Trajectories Direct Flux and Radiance From the Ocean Bottonr Accounting for Multiple Orders of Scattering With the Bottom Computation...

  19. The influence of atmospheric pressure on landfill methane emissions

    SciTech Connect (OSTI)

    Czepiel, P.M.; Shorter, J.H.; Mosher, B.; Allwine, E.; McManus, J.B.; Harriss, R.C.; Kolb, C.E.; Lamb, B.K

    2003-07-01T23:59:59.000Z

    Landfills are the largest source of anthropogenic methane (CH{sub 4}) emissions to the atmosphere in the United States. However, few measurements of whole landfill CH{sub 4} emissions have been reported. Here, we present the results of a multi-season study of whole landfill CH{sub 4} emissions using atmospheric tracer methods at the Nashua, New Hampshire Municipal landfill in the northeastern United States. The measurement data include 12 individual emission tests, each test consisting of 5-8 plume measurements. Measured emissions were negatively correlated with surface atmospheric pressure and ranged from 7.3 to 26.5 m{sup 3} CH{sub 4} min{sup -1}. A simple regression model of our results was used to calculate an annual emission rate of 8.4x10{sup 6} m{sup 3} CH{sub 4} year{sup -1}. These data, along with CH{sub 4} oxidation estimates based on emitted landfill gas isotopic characteristics and gas collection data, were used to estimate annual CH{sub 4} generation at this landfill. A reported gas collection rate of 7.1x10{sup 6} m{sup 3} CH{sub 4} year{sup -1} and an estimated annual rate of CH{sub 4} oxidation by cover soils of 1.2x10{sup 6} m{sup 3} CH{sub 4} year{sup -1} resulted in a calculated annual CH{sub 4} generation rate of 16.7x10{sup 6} m{sup 3} CH{sub 4} year{sup -1}. These results underscore the necessity of understanding a landfill's dynamic environment before assessing long-term emissions potential.

  20. Demonstration of a semipolar (10(1)over-bar(3)over-bar) InGaN/GaN green light emitting diode

    E-Print Network [OSTI]

    2005-01-01T23:59:59.000Z

    InGaN / GaN green light emitting diode R. Sharma, a? P. M.green ??525 nm? light emitting diode ?LED?. The fabricated

  1. Oscillations of solar atmosphere neutrinos

    E-Print Network [OSTI]

    G. L. Fogli; E. Lisi; A. Mirizzi; D. Montanino; P. D. Serpico

    2006-11-10T23:59:59.000Z

    The Sun is a source of high energy neutrinos (E > 10 GeV) produced by cosmic ray interactions in the solar atmosphere. We study the impact of three-flavor oscillations (in vacuum and in matter) on solar atmosphere neutrinos, and calculate their observable fluxes at Earth, as well as their event rates in a kilometer-scale detector in water or ice. We find that peculiar three-flavor oscillation effects in matter, which can occur in the energy range probed by solar atmosphere neutrinos, are significantly suppressed by averaging over the production region and over the neutrino and antineutrino components. In particular, we find that the relation between the neutrino fluxes at the Sun and at the Earth can be approximately expressed in terms of phase-averaged ``vacuum'' oscillations, dominated by a single mixing parameter (the angle theta_23).

  2. Cumulant expansions for atmospheric flows

    E-Print Network [OSTI]

    Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B

    2015-01-01T23:59:59.000Z

    The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...

  3. Chandra X-ray Observations of the Hydra A Cluster: An Interaction Between the Radio Source and the X-Ray-Emitting Gas

    E-Print Network [OSTI]

    B. R. McNamara; M. Wise; P. E. J. Nulsen; L. P. David; C. L. Sarazin; M. Bautz; M. Markevitch; A. Vikhlinin; W. R. Forman; C. Jones; D. E. Harris

    2000-01-25T23:59:59.000Z

    We present Chandra X-ray Observations of the Hydra A cluster of galaxies, and we report the discovery of structure in the central 80 kpc of the cluster's X-ray-emitting gas. The most remarkable structures are depressions in the X-ray surface brightness, $\\sim 25-35$ kpc diameter, that are coincident with Hydra A's radio lobes. The depressions are nearly devoid of X-ray-emitting gas, and there is no evidence for shock-heated gas surrounding the radio lobes. We suggest the gas within the surface brightness depressions was displaced as the radio lobes expanded subsonically, leaving cavities in the hot atmosphere. The gas temperature declines from 4 keV at 70 kpc to 3 keV in the inner 20 kpc of the brightest cluster galaxy (BCG), and the cooling time of the gas is $\\sim 600$ Myr in the inner 10 kpc. These properties are consistent with the presence of a $\\sim 34 \\msunyr$ cooling flow within a 70 kpc radius. Bright X-ray emission is present in the BCG surrounding a recently-accreted disk of nebular emission and young stars. The star formation rate is commensurate with the cooling rate of the hot gas within the volume of the disk, although the sink for the material cooling at larger radii remains elusive.

  4. HEATING THE ATMOSPHERE ABOVE SUNSPOTS

    E-Print Network [OSTI]

    Rucklidge, Alastair

    become fragmented and twisted, and where they generate the necessary energy to heat the solar coronaHEATING THE ATMOSPHERE ABOVE SUNSPOTS David Alexander and Neal E. Hurlburt Lockheed Martin Solar, University of Cambridge, Cambridge, CB3 9EW, UK Abstract We present our results of a hybrid model of sunspots

  5. Space Science: Atmosphere Thermal Structure

    E-Print Network [OSTI]

    Johnson, Robert E.

    Space Science: Atmosphere Part -2 Thermal Structure Review tropospheres Absorption of Radiation Adiabatic Lapse Rate ~ 9 K/km Slightly smaller than our estimate Pressure ~3000ft under ocean surface thickness (positive up) is the solar zenith angle Fs is the solar energy flux at frequency (when

  6. Climate Impacts of Atmospheric Sulfate and Black Carbon Aerosols

    SciTech Connect (OSTI)

    Qian, Yun; Song, Qingyuan; Menon, Surabi; Yu, Shaocai; Liu, Shaw C.; Shi, Guangyu; Leung, Lai R.; Luo, Yunfeng

    2008-09-19T23:59:59.000Z

    Although the global average surface temperature has increased by about 0.6°C during the last century (IPCC, 2001), some regions such as East Asia, Eastern North America, and Western Europe have cooled rather than warmed during the past decades (Jones, 1988; Qian and Giorgi, 2000). Coherent changes at the regional scale may reflect responses to different climate forcings that need to be understood in order to predict the future net climate response at the global and regional scales under different emission scenarios. Atmospheric aerosols play an important role in global climate change (IPCC 2001). They perturb the earth’s radiative budget directly by scattering and absorbing solar and long wave radiation, and indirectly by changing cloud reflectivity, lifetime, and precipitation efficiency via their role as cloud condensation nuclei. Because aerosols have much shorter lifetime (days to weeks) compared to most greenhouse gases, they tend to concentrate near their emission sources and distribute very unevenly both in time and space. This non-uniform distribution of aerosols, in conjunction with the greenhouse effect, may lead to differential net heating in some areas and net cooling in others (Penner et al. 1994). Sulfate aerosols come mainly from the oxidation of sulfur dioxide (SO2) emitted from fossil fuel burning. Black carbon aerosols are directly emitted during incomplete combustion of biomass, coal, and diesel derived sources. Due to the different optical properties, sulfate and black carbon affect climate in different ways. Because of the massive emissions of sulfur and black carbon that accompany the rapid economic expansions in East Asia, understanding the effects of aerosols on climate is particularly important scientifically and politically in order to develop adaptation and mitigation strategies.

  7. Simulation of radio emission from air showers in atmospheric electric fields

    SciTech Connect (OSTI)

    Buitink, S.; Huege, T.; Falcke, H; Kuijpers, J.

    2010-02-25T23:59:59.000Z

    We study the effect of atmospheric electric fields on the radio pulse emitted by cos- mic ray air showers. Under fair weather conditions the dominant part of the radio emission is driven by the geomagnetic field. When the shower charges are accelerated and deflected in an electric field additional radiation is emitted. We simulate this effect with the Monte Carlo code REAS2, using CORSIKA-simulated showers as input. In both codes a routine has been implemented that treats the effect of the electric field on the shower particles. We find that the radio pulse is significantly altered in background fields of the order of ~100 V/cm and higher. Practically, this means that air showers passing through thunderstorms emit radio pulses that are not a reliable measure for the shower energy. Under other weather circumstances significant electric field effects are expected to occur rarely, but nimbostratus clouds can harbor fields that are large enough. In general, the contribution of the electric field to the radio pulse has polarization properties that are different from the geomagnetic pulse. In order to filter out radio pulses that have been affected by electric field effects, radio air shower experiments should keep weatherinformation and perform full polarization measurements of the radio signal.

  8. Pacific Northwest Laboratory annual report for 1993 to the DOE Office of Energy Research. Part 3: Atmospheric and climate research

    SciTech Connect (OSTI)

    Not Available

    1994-05-01T23:59:59.000Z

    The US Department of Energy`s (DOE`s) Office of Health and Environmental Research (OHER) atmospheric sciences and carbon dioxide research programs provide the DOE with scientifically defensible information on the local, regional, and global distributions of energy-related pollutants and their effects on climate. PNL has had a long history of technical leadership in the atmospheric sciences research programs within OHER. Within the Environmental Sciences Division of OHER, the Atmospheric Chemistry Program continues DOE`s long-term commitment to understanding the local, regional, and global effects of energy-related air pollutants. Research through direct measurement, numerical modeling, and analytical studies in the Atmospheric Chemistry Program emphasizes the long-range transport, chemical transformation, and removal of emitted pollutants, photochemically produced oxidant species, nitrogen-reservoir species, and aerosols. The atmospheric studies in Complex Terrain Program applies basic research on atmospheric boundary layer structure and evolution over inhomogeneous terrain to DOE`s site-specific and generic mission needs in site safety, air quality, and climate change. Research at PNL provides basic scientific underpinnings to DOE`s program of global climate research. Research projects within the core carbon dioxide and ocean research programs are now integrated with those in the Atmospheric Radiation Measurements, the Computer Hardware, Advanced Mathematics and Model Physics, and Quantitative Links program to form DOE`s contribution to the US Global Change Research Program. The description of ongoing atmospheric and climate research at PNL is organized in two broad research areas: atmospheric research; and climate research. This report describes the progress in fiscal year 1993 in each of these areas. Individual papers have been processed separately for inclusion in the appropriate data bases.

  9. A Cloud Detection Algorithm using the Downwelling Infrared Radiance Measured by an Infrared Pyrometer of the Ground-based Microwave Radiometer

    SciTech Connect (OSTI)

    Ahn, M. H.; Han, D.; Won, H. Y.; Morris, Victor R.

    2015-01-01T23:59:59.000Z

    For a better utilization of the ground-based microwave radiometer, it is important to detect the cloud presence in the measured data. Here, we introduce a simple and fast cloud detection algorithm by using the optical characteristics of the clouds in the infrared atmospheric window region. The new algorithm utilizes the brightness temperature (Tb) measured by an infrared radiometer installed on top of a microwave radiometer. The two step algorithm consists of a spectral test followed by a temporal test. The measured Tb is first compared with a predicted clear sky Tb obtained by an empirical formula as a function of surface air temperature and water vapor pressure. For the temporal test, the temporal variability of the measured Tb during one minute compares with a dynamic threshold value, representing the variability of the clear sky condition. It is designated as cloud free data only when both the spectral and temporal tests confirm a cloud free data. Overall, most of the thick and uniform clouds are successfully screened out by the spectral test, while the broken and fast-varying clouds are screened out by the temporal test. The algorithm is validated by comparison with the collocated ceilometer data for 6 months, from January 2013 to June 2013. The overall proportion correct is about 88.3% and the probability of detection is 90.8 %, which are comparable with or better than those of previous similar approaches. Two thirds of failures occur when the new algorithm detects clouds while the ceilometer does not detect, resulting in different values of the probability of detection with different cloud base altitude, 93.8, 90.3, and 82.8% for low, mid, and high clouds, respectively. Finally, due to the characteristics of the spectral range, the new algorithm is found to be insensitive to the presence of inversion layers.

  10. A cloud detection algorithm using the downwelling infrared radiance measured by an infrared pyrometer of the ground-based microwave radiometer

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

    Ahn, M.-H.; Han, D.; Won, H. Y.; Morris, V.

    2015-01-01T23:59:59.000Z

    For better utilization of the ground-based microwave radiometer, it is important to detect the cloud presence in the measured data. Here, we introduce a simple and fast cloud detection algorithm by using the optical characteristics of the clouds in the infrared atmospheric window region. The new algorithm utilizes the brightness temperature (Tb) measured by an infrared radiometer installed on top of a microwave radiometer. The two-step algorithm consists of a spectral test followed by a temporal test. The measured Tb is first compared with a predicted clear-sky Tb obtained by an empirical formula as a function of surface air temperaturemore »and water vapor pressure. For the temporal test, the temporal variability of the measured Tb during one minute compares with a dynamic threshold value, representing the variability of clear-sky conditions. It is designated as cloud-free data only when both the spectral and temporal tests confirm cloud-free data. Overall, most of the thick and uniform clouds are successfully detected by the spectral test, while the broken and fast-varying clouds are detected by the temporal test. The algorithm is validated by comparison with the collocated ceilometer data for six months, from January to June 2013. The overall proportion of correctness is about 88.3% and the probability of detection is 90.8%, which are comparable with or better than those of previous similar approaches. Two thirds of discrepancies occur when the new algorithm detects clouds while the ceilometer does not, resulting in different values of the probability of detection with different cloud-base altitude, 93.8, 90.3, and 82.8% for low, mid, and high clouds, respectively. Finally, due to the characteristics of the spectral range, the new algorithm is found to be insensitive to the presence of inversion layers.« less

  11. Synthesis and optical properties of cadmium selenide quantum dots for white light-emitting diode application

    SciTech Connect (OSTI)

    Xu, Xianmei; Wang, Yilin; Gule, Teri; Luo, Qiang [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Zhou, Liya, E-mail: zhouliyatf@163.com [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Gong, Fuzhong [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China)

    2013-03-15T23:59:59.000Z

    Highlights: ? Stable CdSe QDs were synthesized by the one-step and two-level process respectively. ? The fabricated white LEDs show good white balance. ? CdSe QDs present well green to yellow band luminescence. ? CdSe QDs displayed a broad excitation band. - Abstract: Yellow light-emitting cadmium selenide quantum dots were synthesized using one-step and two-step methods in an aqueous medium. The structural luminescent properties of these quantum dots were investigated. The obtained cadmium selenide quantum dots displayed a broad excitation band suitable for blue or near-ultraviolet light-emitting diode applications. White light-emitting diodes were fabricated by coating the cadmium selenide samples onto a 460 nm-emitting indium gallium nitrite chip. Both samples exhibited good white balance. Under a 20 mA working current, the white light-emitting diode fabricated via the one-step and two-step methods showed Commission Internationale de l’Éclairage coordinates at (0.27, 0.23) and (0.27, 0.33), respectively, and a color rendering index equal to 41 and 37, respectively. The one-step approach was simpler, greener, and more effective than the two-step approach. The one-step approach can be enhanced by combining cadmium selenide quantum dots with proper phosphors.

  12. THE SPATIALLY RESOLVED H{alpha}-EMITTING WIND STRUCTURE OF P CYGNI

    SciTech Connect (OSTI)

    Balan, Aurelian; Tycner, C. [Department of Physics, Central Michigan University, Mount Pleasant, MI 48859 (United States); Zavala, R. T.; Benson, J. A.; Hutter, D. J. [US Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Rd., Flagstaff, AZ 86001 (United States); Templeton, M., E-mail: abalan@delta.ed, E-mail: c.tycner@cmich.ed, E-mail: bzavala@nofs.navy.mi, E-mail: jbenson@nofs.navy.mi, E-mail: djh@nofs.navy.mi, E-mail: matthewt@aavso.or [American Association of Variable Star Observers, 49 Bay State Road, Cambridge, MA 02138 (United States)

    2010-06-15T23:59:59.000Z

    High spatial resolution observations of the H{alpha}-emitting wind structure associated with the luminous blue variable star P Cygni were obtained with the Navy Prototype Optical Interferometer. These observations represent the most comprehensive interferometric data set on P Cyg to date. We demonstrate how the apparent size of the H{alpha}-emitting region of the wind structure of P Cyg compares between the 2005, 2007, and 2008 observing seasons and how this relates to the H{alpha} line spectroscopy. Using the data sets from 2005, 2007, and 2008 observing seasons, we fit a circularly symmetric Gaussian model to the interferometric signature from the H{alpha}-emitting wind structure of P Cyg. Based on our results, we conclude that the radial extent of the H{alpha}-emitting wind structure around P Cyg is stable at the 10% level. We also show how the radial distribution of the H{alpha} flux from the wind structure deviates from a Gaussian shape, whereas a two-component Gaussian model is sufficient to fully describe the H{alpha}-emitting region around P Cyg.

  13. Sulfuryl fluoride in the global atmosphere

    E-Print Network [OSTI]

    Muhle, J.

    The first calibrated high-frequency, high-precision, in situ atmospheric and archived air measurements of the fumigant sulfuryl fluoride (SO[subscript 2]F[subscript 2]) have been made as part of the Advanced Global Atmospheric ...

  14. ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2012)

    E-Print Network [OSTI]

    Gerber, Edwin

    2012-01-01T23:59:59.000Z

    ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2012) Published online in Wiley Online Library using National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP) concentrations and sea- surface temperatures (SSTs). These integrations enable the relative role of ozone

  15. 1997 Atmospheric Chemistry Colloquium for Emerging Senior Scientists

    SciTech Connect (OSTI)

    Paul H. Wine

    1998-11-23T23:59:59.000Z

    DOE's Atmospheric Chemistry Program is providing partial funding for the Atmospheric Chemistry Colloquium for Emerging Senior Scientists (ACCESS) and FY 1997 Gordon Research Conference in Atmospheric Chemistry

  16. atmospheric nitrogen fluorescence: Topics by E-print Network

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

    Websites Summary: Greenhouse Effect and Atmospheric Warming Atmosphere absorbs heat energy A real greenhouse traps heatCh4. Atmosphere and Surface Energy Balances...

  17. atmospheric energy redistribution: Topics by E-print Network

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

    16 Ch4. Atmosphere and Surface Energy Balances Geosciences Websites Summary: Greenhouse Effect and Atmospheric Warming Atmosphere absorbs heat energy A real greenhouse traps...

  18. atmospheric pressure surface: Topics by E-print Network

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

    K. 27 Ch4. Atmosphere and Surface Energy Balances Geosciences Websites Summary: Greenhouse Effect and Atmospheric Warming Atmosphere absorbs heat energy A real greenhouse traps...

  19. Radar range measurements in the atmosphere.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2013-02-01T23:59:59.000Z

    The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

  20. Proof of the Atmospheric Greenhouse Effect

    E-Print Network [OSTI]

    Smith, Arthur P

    2008-01-01T23:59:59.000Z

    A recently advanced argument against the atmospheric greenhouse effect is refuted. A planet without an infrared absorbing atmosphere is mathematically constrained to have an average temperature less than or equal to the effective radiating temperature. Observed parameters for Earth prove that without infrared absorption by the atmosphere, the average temperature of Earth's surface would be at least 33 K lower than what is observed.

  1. Atmospheric Lifetime of Fossil Fuel Carbon Dioxide

    E-Print Network [OSTI]

    Scherer, Norbert F.

    Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial

  2. Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming

    DOE Patents [OSTI]

    Li, Ting (Ventura, CA)

    2011-04-26T23:59:59.000Z

    The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

  3. Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming

    DOE Patents [OSTI]

    Li, Ting

    2013-08-13T23:59:59.000Z

    The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

  4. Orbital Angular Momentum (OAM) Vertical-Cavity Surface-Emitting Lasers

    E-Print Network [OSTI]

    Li, Huanlu; Wang, Xuyang; Ho, Daniel; Chen, Lifeng; Zhou, Xiaoqi; Zhu, Jiangbo; Yu, Siyuan; Cai, Xinlun

    2015-01-01T23:59:59.000Z

    Harnessing the Orbital Angular Momentum (OAM) of light is an appealing approach to developing photonic technologies for future applications in optical communications and high- dimensional Quantum Key Distributions (QKD). An outstanding challenge to the widespread uptake of the OAM resource is its efficient generation. We design a new device which can directly emit an OAM-carrying light beam. By fabricating micro-scale Spiral Phase Plates (SPPs) within the aperture of a Vertical-Cavity Surface-Emitting Laser (VCSELs), the linearly polarized Gaussian beam emitted by the VCSEL is converted into a beam carrying specific OAM modes and their superposition states with high efficiency and high beam quality. The innovative OAM emitter opens a new horizon in the field of OAM-based optical and quantum communications, especially for short reach data interconnects and Quantum Key Distribution (QKD).

  5. Atmospheric-pressure plasma jet

    DOE Patents [OSTI]

    Selwyn, Gary S. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.

  6. Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes

    E-Print Network [OSTI]

    Gilchrist, James F.

    Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes Keywords: III-Nitride InGaN QWs Light-emitting diodes Efficiency-droop a b s t r a c t Current injection efficiency and its impact on efficiency-droop in InGaN single quantum well (QW) based light-emitting diodes

  7. New red phosphor for near-ultraviolet light-emitting diodes with high color-purity

    SciTech Connect (OSTI)

    Wang, Zhengliang, E-mail: wzhl_ww@yahoo.com.cn [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China)] [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China); He, Pei; Wang, Rui [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)] [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China); Zhao, Jishou [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China)] [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China); Gong, Menglian [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)] [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)

    2010-02-15T23:59:59.000Z

    New red phosphors, Na{sub 5}Eu(MoO{sub 4}){sub 4} doped with boron oxide were prepared by the solid-state reaction. Their structure and photo-luminescent properties were investigated. With the introduction of boron oxide, the red emission intensity of the phosphors under 395 nm excitation is strengthened, with high color-purity (x = 0.673, y = 0.327). The single red light-emitting diode was obtained by combining InGaN chip with the red phosphor, bright red light can be observed by naked eyes from the red light-emitting diodes under a forward bias of 20 mA.

  8. Cooperative accumulation of coherent undulator radiation emitted from periodic electron bunches

    SciTech Connect (OSTI)

    Seo, Y. H. [Department of Electrophysics, Kwangwoon University, Seoul 139-701 (Korea, Republic of)

    2013-01-15T23:59:59.000Z

    Cavity build-up of coherent undulator synchrotron radiation emitted by periodic electron bunches is investigated. At the optimal off-grazing resonance, the bunch slippage relative to the radiation pulse introduces an initial transient period during which radiation accumulates cooperatively as if it is emitted by a single bunch. The power growth during the period is quadratic to the number of bunches. The number of cooperative bunches is {approx}2 Script-Small-L {sub s}{sup 2}, where Script-Small-L {sub s} denotes the slippage length in units of the resonant wavelength.

  9. Printed assemblies of ultrathin, microscale inorganic light emitting diodes for deformable and semitransparent displays

    DOE Patents [OSTI]

    Rogers, John A; Nuzzo, Ralph; Kim, Hoon-sik; Brueckner, Eric; Park, Sang Il; Kim, Rak Hwan

    2014-10-21T23:59:59.000Z

    Described herein are printable structures and methods for making, assembling and arranging electronic devices. A number of the methods described herein are useful for assembling electronic devices where one or more device components are embedded in a polymer which is patterned during the embedding process with trenches for electrical interconnects between device components. Some methods described herein are useful for assembling electronic devices by printing methods, such as by dry transfer contact printing methods. Also described herein are GaN light emitting diodes and methods for making and arranging GaN light emitting diodes, for example for display or lighting systems.

  10. Enhancing the emission directionality of organic light-emitting diodes by using photonic microstructures

    SciTech Connect (OSTI)

    Zhang, Shuyu; Turnbull, Graham A., E-mail: gat@st-andrews.ac.uk, E-mail: idws@st-andrews.ac.uk; Samuel, Ifor D. W., E-mail: gat@st-andrews.ac.uk, E-mail: idws@st-andrews.ac.uk [Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)] [Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

    2013-11-18T23:59:59.000Z

    We report microstructured organic light-emitting diodes (OLEDs) with directional emission based on efficient solution-processable europium-OLEDs patterned by solvent assisted microcontact molding. The angle dependence of the light emission is characterized for OLEDs with square-array photonic crystals with periods between 275?nm and 335?nm. The microstructured devices have emission patterns strongly modified from the Lambertian emission of planar OLEDs and can approximately double the emitted power in a desired angle range in both s- and p-polarizations. The modified emission is attributed to light diffracted out of the waveguide modes of the OLEDs.

  11. Green Light-Emitting Diode Makes Highly Efficient White Light; The Spectrum of Clean Energy Innovation (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-06-01T23:59:59.000Z

    Fact sheet describing NREL's green light emitting diode that can lead to higher efficiency white light used in indoor lighting applications.

  12. Demonstration Assessment of Light-Emitting Diode Roadway Lighting on the FDR Drive in New York, New York

    SciTech Connect (OSTI)

    Myer, Michael; Hazra, Oindrila; Kinzey, Bruce R.

    2011-12-01T23:59:59.000Z

    This a report about a field study of light-emitting diodes street lights by four different manufacturers installed on the FDR Drive in New York City, NY.

  13. Low threshold vertical cavity surface emitting lasers integrated onto Si-CMOS ICs using novel hybrid assembly techniques

    E-Print Network [OSTI]

    Perkins, James Michael, 1978-

    2007-01-01T23:59:59.000Z

    A new heterogeneous integration technique has been developed and demonstrated to integrate vertical cavity surface emitting lasers (VCSELs) on silicon CMOS integrated circuits for optical interconnect applications. Individual ...

  14. An Infrared Spectral Library for Atmospheric Environmental Monitoring...

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

    An Infrared Spectral Library for Atmospheric Environmental Monitoring. An Infrared Spectral Library for Atmospheric Environmental Monitoring. Abstract: Infrared (IR) spectroscopy...

  15. atmospheric research community: Topics by E-print Network

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

    University Corporation for Atmospheric Research Geosciences Websites Summary: University Corporation for Atmospheric Research CIGNA DENTAL PREFERRED PROVIDER INSURANCE EFFECTIVE...

  16. Hanbury BrownTwiss Correlations to Probe the Population Statistics of GHz Photons Emitted by Conductors

    E-Print Network [OSTI]

    Plaçais, Bernard

    Hanbury Brown­Twiss Correlations to Probe the Population Statistics of GHz Photons Emitted of GHz photons in quantum circuits, using Hanbury Brown and Twiss correlations. The super The seminal experiment of Hanbury Brown and Twiss (HBT) [1], consisted in two detectors correlating the power

  17. Red emitting photonic devices using InGaP/InGaAlP material system

    E-Print Network [OSTI]

    Kangude, Yamini

    2005-01-01T23:59:59.000Z

    In this thesis, two red emitting photonic devices are presented using the InGaP/InGaAlP material system. InGaP/InGaAlP material system provides large flexibility in the band gap energy while being lattice matched to GaAs ...

  18. Antennas in the optical range will improve the efficiency of light-emitting devices.

    E-Print Network [OSTI]

    Novotny, Lukas

    Antennas in the optical range will improve the efficiency of light-emitting devices. The purpose of optical antennas is to convert the energy of free propagat- ing radiation to localized energy, and vice versa. Although this is similar to what radio wave and microwave antennas do, optical antennas exploit

  19. Ultrafast shift and injection currents observed in wurtzite semiconductors via emitted terahertz radiation

    E-Print Network [OSTI]

    Van Driel, Henry M.

    Ultrafast shift and injection currents observed in wurtzite semiconductors via emitted terahertz; published online 18 November 2005 Shift and injection currents are generated in the wurtzite semiconductors in the wurtzite structure. The largest shift currents are generated along the optical axis for light polarized

  20. The Spectrum of Clean Energy Innovationinnovati nGreen Light-Emitting Diode Makes

    E-Print Network [OSTI]

    in the indoor lighting world. LEDs are fundamentally solar cells operating in reverse--that is, when of light generated far outweighs the amount of heat produced. But at the moment, LEDs that emit white light are produced using an inefficient process known as phosphor conversion. In this process, light from a blue

  1. Ultra-thin ohmic contacts for p-type nitride light emitting devices

    DOE Patents [OSTI]

    Raffetto, Mark (Raleigh, NC); Bharathan, Jayesh (Cary, NC); Haberern, Kevin (Cary, NC); Bergmann, Michael (Chapel Hill, NC); Emerson, David (Chapel Hill, NC); Ibbetson, James (Santa Barbara, CA); Li, Ting (Ventura, CA)

    2012-01-03T23:59:59.000Z

    A semiconductor based Light Emitting Device (LED) can include a p-type nitride layer and a metal ohmic contact, on the p-type nitride layer. The metal ohmic contact can have an average thickness of less than about 25 .ANG. and a specific contact resistivity less than about 10.sup.-3 ohm-cm.sup.2.

  2. Warm-white light-emitting diodes integrated with colloidal quantum dots for high luminous

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Warm-white light-emitting diodes integrated with colloidal quantum dots for high luminous efficacy NQD-LED design with both high luminous efficacy of optical radiation and CRI is presented to have luminous efficacy of optical ra- diation (LER), which is challenging using conventional phosphors

  3. Bright red electroluminescent devices using novel second-ligand-contained europium complexes as emitting layers

    E-Print Network [OSTI]

    Huang, Yanyi

    Bright red electroluminescent devices using novel second-ligand- contained europium complexes) and 1-ethyl-2-(2-pyridyl)benzimidazole (EPBM), two europium complexes, Eu(DBM)3HPBM and Eu(DBM)3EPBM/TPD/Eu(DBM)3EPBM/AlQ/Al emit red light originating from the europium complexes. The EL luminance of Eu(DBM)3

  4. High-K Based Non-Volatile Memory Devices with the Light Emitting Application

    E-Print Network [OSTI]

    Lin, Chi-Chou

    2014-09-05T23:59:59.000Z

    The zirconium-doped hafnium oxide (ZrHfO) high-k gate dielectric films with and without the embedded nanocrystals have been studied for the applications of the nonvolatile memory and light emitting devices. By replacing the polycrystalline Si...

  5. Pulse atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1989-03-01T23:59:59.000Z

    The overall objective of the program is the development of a pulsed atmospheric fluidized-bed combustion (PAFBC) technology to burn coal and to provide heat and steam to commercial, institutional, and small industrial applications at a reasonable price in an environmentally acceptable manner. During this reporting period, a total of eight shakedown and debugging coal combustion tests were performed in the AFBC. A start-up procedure was established, system improvements implemented, and preliminary material and heat balances made based on these tests. The pulse combustor for the AFBC system was fabricated and installed and a series of tests was conducted on the system. 17 figs., 5 tabs.

  6. NETL SOFC: Atmospheric Pressure Systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Saleshttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gif Directorate -AdvancedMIRTBD525AdaptingWaterTerryAtmospheric

  7. Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store

    E-Print Network [OSTI]

    Burke, Peter

    Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store scanners, construction tools, and laser pointers are generally lower powered lasers emit high-intensity, directional light beams that vary in strength, they are a particular hazard

  8. Seeding of a titanium sapphire osctllator by a vertical-cavity surface-emitting laser in the nanosecond range

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Seeding of a titanium sapphire osctllator by a vertical-cavity surface- emitting laser-emitting laser was used to seed a titanium-sapphire laser oscillator. Both lasers were pumped synchronously. The transmission of the plane output coupler M2 is 40%. The energy of the pump pulses is a few mJ, their temporal

  9. Yellow-green strained-InGaP quantum-well epitaxial-transparent-substrate light emitting diodes

    E-Print Network [OSTI]

    Yellow-green strained-InGaP quantum-well epitaxial-transparent-substrate light emitting diodes L March 2004 We present a strained-InGaP quantum-well light emitting diode LED operating in the green that InGaP alloys in this composition range are not lattice-matched to any traditional substrate material

  10. Atmospheric neutrino flux at INO site

    SciTech Connect (OSTI)

    Honda, Morihiro [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8582 (Japan)

    2011-11-23T23:59:59.000Z

    To illustrate the calculation of the atmospheric neutrino flux, we briefly explain our calculation scheme and important components, such as primary cosmic ray spectra, interaction model, and geomagnetic model. Then, we calculate the atmospheric neutrino flux at INO site in our calculation scheme. We compare the calculated atmospheric neutrino fluxes predicted at INO with those at other major neutrino detector sites, especially that at SK site.

  11. Toxicity of atmospheric aerosols on marine phytoplankton

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    metals added from these aerosols to the bioassay incubationsreleased to seawater from the aerosol filters after Author4605 CHEMISTRY Atmospheric aerosol deposition CHEMISTRY

  12. Urban Atmospheres captures a unique, synergistic moment

    E-Print Network [OSTI]

    Paulos, Eric

    Urban Atmospheres captures a unique, synergistic moment ­ expanding urban populations, rapid EDITORS Eric Paulos Intel Research eric@paulos.net Tom Jenkins Royal College of Art thomas

  13. Characterizing orbit uncertainty due to atmospheric uncertainty

    E-Print Network [OSTI]

    Wilkins, Matthew Paul

    2000-01-01T23:59:59.000Z

    is implemented to model errors in the atmospheric density model. This study shows that the Kalman filter computes a believable and more realistic covariance....

  14. Atmospheric Radiation Measurement Climate Research Facility ...

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

    improving our understanding of how clouds and atmospheric moisture interact with solar radiation and the effects of these interactions on climate. Photo courtesy Argonne National...

  15. Physics Potential of Future Atmospheric Neutrino Searches

    E-Print Network [OSTI]

    Thomas Schwetz

    2008-12-12T23:59:59.000Z

    The potential of future high statistics atmospheric neutrino experiments is considered, having in mind currently discussed huge detectors of various technologies (water Cerekov, magnetized iron, liquid Argon). I focus on the possibility to use atmospheric data to determine the octant of $\\theta_{23}$ and the neutrino mass hierarchy. The sensitivity to the $\\theta_{23}$-octant of atmospheric neutrinos is competitive (or even superior) to long-baseline experiments. I discuss the ideal properties of a fictitious atmospheric neutrino detector to determine the neutrino mass hierarchy.

  16. Super-Kamiokande atmospheric neutrino results

    E-Print Network [OSTI]

    Toshiyuki Toshito; the Super-Kamiokande collaboration

    2001-05-14T23:59:59.000Z

    We present atmospheric neutrino results from a 79 kiloton year (1289 days) exposure of the Super-Kamiokande detector. Our data are well explained by $\

  17. atmospheres: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  18. atmosphere: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  19. atmospherics: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  20. Laboratory Studies of Processing of Carbonaceous Aerosols by Atmospheric Oxidants/Hygroscopicity and CCN Activity of Secondary & Processed Primary Organic Aerosols

    SciTech Connect (OSTI)

    Ziemann, P.J.; Arey, J.; Atkinson, R.; Kreidenweis, S.M.; Petters, M.D.

    2012-06-13T23:59:59.000Z

    The atmosphere is composed of a complex mixture of gases and suspended microscopic aerosol particles. The ability of these particles to take up water (hygroscopicity) and to act as nuclei for cloud droplet formation significantly impacts aerosol light scattering and absorption, and cloud formation, thereby influencing air quality, visibility, and climate in important ways. A substantial, yet poorly characterized component of the atmospheric aerosol is organic matter. Its major sources are direct emissions from combustion processes, which are referred to as primary organic aerosol (POA), or in situ processes in which volatile organic compounds (VOCs) are oxidized in the atmosphere to low volatility reaction products that subsequent condense to form particles that are referred to as secondary organic aerosol (SOA). POA and VOCs are emitted to the atmosphere from both anthropogenic and natural (biogenic) sources. The overall goal of this experimental research project was to conduct laboratory studies under simulated atmospheric conditions to investigate the effects of the chemical composition of organic aerosol particles on their hygroscopicity and cloud condensation nucleation (CCN) activity, in order to develop quantitative relationships that could be used to more accurately incorporate aerosol-cloud interactions into regional and global atmospheric models. More specifically, the project aimed to determine the products, mechanisms, and rates of chemical reactions involved in the processing of organic aerosol particles by atmospheric oxidants and to investigate the relationships between the chemical composition of organic particles (as represented by molecule sizes and the specific functional groups that are present) and the hygroscopicity and CCN activity of oxidized POA and SOA formed from the oxidation of the major classes of anthropogenic and biogenic VOCs that are emitted to the atmosphere, as well as model hydrocarbons. The general approach for this project was to carry out reactions of representative anthropogenic and biogenic VOCs and organic particles with ozone (O3), and hydroxyl (OH), nitrate (NO3), and chlorine (Cl) radicals, which are the major atmospheric oxidants, under simulated atmospheric conditions in large-volume environmental chambers. A combination of on-line and off-line analytical techniques were used to monitor the chemical and physical properties of the particles including their hygroscopicity and CCN activity. The results of the studies were used to (1) improve scientific understanding of the relationships between the chemical composition of organic particles and their hygroscopicity and CCN activity, (2) develop an improved molecular level theoretical framework for describing these relationships, and (3) establish a large database that is being used to develop parameterizations relating organic aerosol chemical properties and SOA sources to particle hygroscopicity and CCN activity for use in regional and global atmospheric air quality and climate models.

  1. Response of global soil consumption of atmospheric methane to changes in atmospheric climate and nitrogen deposition

    E-Print Network [OSTI]

    Zhuang, Qianlai

    Soil consumption of atmospheric methane plays an important secondary role in regulating the atmospheric CH4 budget, next to the dominant loss mechanism involving reaction with the hydroxyl radical (OH). Here we used a ...

  2. Parallization of Stellar Atmosphere Codes

    E-Print Network [OSTI]

    P. Hoeflich

    2002-09-19T23:59:59.000Z

    Parallel computing has turned out to be the enabling technology to solve complex physical systems. However, the transition from shared memory, vector computers to massively parallel, distributed memory systems and, recently, to hybrid systems poses new challenges to the scientist. We want to present a cook-book (with a very strong, personal bias) based on our experience with parallization of our existing codes. Some of the general tools and communication libraries are discussed. Our approach includes a mixture of algorithm, domain and physical module based parallization. The advantages, scalability and limitations of each are discussed at some examples. We want show that it becomes easier to write parallel code with increasing complexity of the physical problem making stellar atmosphere codes beyond the classical assumptions very suitable.

  3. Limits to the lunar atmosphere

    SciTech Connect (OSTI)

    Morgan, T.H. (National Aeronautics and Space Administration, Washington, D.C. (USA)); Shemansky, D.E. (Univ. of Arizona, Tucson (USA))

    1991-02-01T23:59:59.000Z

    The presence of sodium and potassium on the Moon implies that other more abundant species should be present. Volatile molecules like H{sub 2}O are significantly more abundant than sodium in any of the proposed external atmospheric sources. Source mechanisms which derive atoms from the surface should favor abundant elements in the regolith. It is therefore puzzling that the Apollo ultraviolet spectrometer experiment set limits on the density of oxygen of N{sub O} < 5 {times} 10{sup 2} cm{sup {minus}3}, and that the Apollo Lunar Atmospheric Composition Experiment data imply N{sub O} < 50 cm{sup {minus}3} above the subsolar point. These limits are surprisingly small relative to the measured value for sodium. A simple consideration of sources and sinks predicts significantly greater densities of oxygen. It is possible but doubtful that the Apollo measurements occur ed during an epoch in which source rates were small. A preferential loss process for oxygen on the darkside of the Moon is considered in which ionization by electron capture in surface collisions leads to escape through acceleration in the local electric field. Cold trapping in permanently shadowed regions as a net sink is considered and discounted, but the episodic nature of cometary insertion may allow formation of ice layers which act as a stablized source of OH. On the basis of an assumed meteoroid impact source, the authors predict a possible emission brightness of {approximately} 50 R in the OH(A {minus} X)(0,0) band above the lunar bright limb. A very uncertain small comet source of H{sub 2}O could raise this value by more than two orders of magnitude.

  4. Light emitting diode with porous SiC substrate and method for fabricating

    DOE Patents [OSTI]

    Li, Ting; Ibbetson, James; Keller, Bernd

    2005-12-06T23:59:59.000Z

    A method and apparatus for forming a porous layer on the surface of a semiconductor material wherein an electrolyte is provided and is placed in contact with one or more surfaces of a layer of semiconductor material. The electrolyte is heated and a bias is introduced across said electrolyte and the semiconductor material causing a current to flow between the electrolyte and the semiconductor material. The current forms a porous layer on the one or more surfaces of the semiconductor material in contact with the electrolyte. The semiconductor material with its porous layer can serve as a substrate for a light emitter. A semiconductor emission region can be formed on the substrate. The emission region is capable of emitting light omnidirectionally in response to a bias, with the porous layer enhancing extraction of the emitting region light passing through the substrate.

  5. Broadband visible light source based on AllnGaN light emitting diodes

    SciTech Connect (OSTI)

    Crawford, Mary H.; Nelson, Jeffrey S.

    2003-12-16T23:59:59.000Z

    A visible light source device is described based on a light emitting diode and a nanocluster-based film. The light emitting diode utilizes a semiconductor quantum well structure between n-type and p-type semiconductor materials on the top surface a substrate such as sapphire. The nanocluster-based film is deposited on the bottom surface of the substrate and can be derived from a solution of MoS.sub.2, MoSe.sub.2, WS.sub.2, and WSe.sub.2 particles of size greater than approximately 2 nm in diameter and less than approximately 15 nm in diameter, having an absorption wavelength greater than approximately 300 nm and less than approximately 650 nm.

  6. Soft lithography microlens fabrication and array for enhanced light extraction from organic light emitting diodes (OLEDs)

    SciTech Connect (OSTI)

    Leung, Wai Y.; Park, Joong-Mok; Gan, Zhengqing; Constant, Kristen P.; Shinar, Joseph; Shinar, Ruth; ho, Kai-Ming

    2014-06-03T23:59:59.000Z

    Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.

  7. Amber light-emitting diode comprising a group III-nitride nanowire active region

    DOE Patents [OSTI]

    Wang, George T.; Li, Qiming; Wierer, Jr., Jonathan J.; Koleske, Daniel

    2014-07-22T23:59:59.000Z

    A temperature stable (color and efficiency) III-nitride based amber (585 nm) light-emitting diode is based on a novel hybrid nanowire-planar structure. The arrays of GaN nanowires enable radial InGaN/GaN quantum well LED structures with high indium content and high material quality. The high efficiency and temperature stable direct yellow and red phosphor-free emitters enable high efficiency white LEDs based on the RGYB color-mixing approach.

  8. Photoionization of optically trapped ultracold atoms with a high-power light-emitting diode

    SciTech Connect (OSTI)

    Goetz, Simone; Hoeltkemeier, Bastian; Amthor, Thomas; Weidemueller, Matthias [Physikalisches Institut, Universitaet Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg (Germany)

    2013-04-15T23:59:59.000Z

    Photoionization of laser-cooled atoms using short pulses of a high-power light-emitting diode (LED) is demonstrated. Light pulses as short as 30 ns have been realized with the simple LED driver circuit. We measure the ionization cross section of {sup 85}Rb atoms in the first excited state, and show how this technique can be used for calibrating efficiencies of ion detector assemblies.

  9. Observation of slow light in the noise spectrum of a vertical external cavity surface emitting laser

    E-Print Network [OSTI]

    A. El Amili; B. -X. Miranda; F. Goldfarb; G. Baili; G. Beaudoin; I. Sagnes; F. Bretenaker; M. Alouini

    2010-10-27T23:59:59.000Z

    The role of coherent population oscillations is evidenced in the noise spectrum of an ultra-low noise lasers. This effect is isolated in the intensity noise spectrum of an optimized single-frequency vertical external cavity surface emitting laser. The coherent population oscillations induced by the lasing mode manifest themselves through their associated dispersion that leads to slow light effects probed by the spontaneous emission present in the non-lasing side modes.

  10. Improved light extraction from white organic light-emitting devices using a binary random phase array

    SciTech Connect (OSTI)

    Inada, Yasuhisa, E-mail: inada.yasuhisa@jp.panasonic.com; Nishiwaki, Seiji; Hirasawa, Taku; Nakamura, Yoshitaka; Hashiya, Akira; Wakabayashi, Shin-ichi; Suzuki, Masa-aki [R and D Division, Panasonic Corporation, 1006 Kadoma, Kadoma City, Osaka 571-8501 (Japan); Matsuzaki, Jumpei [Device Development Center, Eco Solutions Company, Panasonic Corporation, 1048 Kadoma, Osaka 571-8686 Japan (Japan)

    2014-02-10T23:59:59.000Z

    We have developed a binary random phase array (BRPA) to improve the light extraction performance of white organic light-emitting devices (WOLEDs). We demonstrated that the scattering of incoming light can be controlled by employing diffraction optics to modify the structural parameters of the BRPA. Applying a BRPA to the substrate of the WOLED leads to enhanced extraction efficiency and suppression of angle-dependent color changes. Our systematic study clarifies the effect of scattering on the light extraction of WOLEDs.

  11. Epitaxial Growth of InGaN Nanowire Arrays for Light Emitting Diodes

    E-Print Network [OSTI]

    Yang, Peidong

    from the substrate. Ni/Au (20 nm / 20 nm) contacts were deposited on the p-GaN substrate in a geometryS1 Epitaxial Growth of InGaN Nanowire Arrays for Light Emitting Diodes Christopher Hahn, Zhaoyu. The straight line represents the Vegard's law correlation between GaN (c = 5.188 Ĺ) and InN (c = 5.709 Ĺ). (b

  12. Doctoral Programs Atmospheric, Oceanic & Space Sciences

    E-Print Network [OSTI]

    Eustice, Ryan

    University of Michigan Space Research Building 2455 Hayward Street Ann Arbor, MI 48109-2143 aoss Katherine E. White, Ann Arbor ©The Regents of the University of Michigan Research areas Atmospheric Science Atmospheric Dynamics Climate, Climate Modeling & Climate Change Clouds & Precipitation Paleoclimate, Ice

  13. Human effects on the global atmosphere

    SciTech Connect (OSTI)

    Johnston, H.S.

    1984-01-01T23:59:59.000Z

    This review considers whether human activities can significantly change important functions of the global atmosphere by altering the amount or distribution of certain trace species. It deals with three specific topics: stratopheric ozone, the role of species other than carbon dioxide on the greenhouse effect, and certain recently recognized atmospheric consequences of a large scale nuclear war. 64 references, 10 figures, 2 tables.

  14. ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2013)

    E-Print Network [OSTI]

    Lee, Sukyoung

    2013-01-01T23:59:59.000Z

    ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2013) Published online in Wiley Online Library Sciences, Seoul National University, Seoul, South Korea *Correspondence to: C. Yoo, Center for Atmosphere). A number of studies have shown that the MJO plays an important role in modulating the extratropical cir

  15. ATOMIC IONIZATION AND OPACITIES IN PULSAR ATMOSPHERES

    E-Print Network [OSTI]

    ATOMIC IONIZATION AND OPACITIES IN PULSAR ATMOSPHERES Hydrogen Atmospheres J. VENTURA Physics.g. Pavlov et al., 1995; Zavlin et al., 1995, 1996; #12; 2 J. VENTURA ET AL. Rajagopal and Romani, 1996 the past three years. As is well known (Canuto and Ventura, 1977; Ruder et al., 1994), the external strong

  16. Measurements of the Cerenkov light emitted by a TeO2 crystal

    E-Print Network [OSTI]

    F. Bellini; N. Casali; I. Dafinei; M. Marafini; S. Morganti; F. Orio; D. Pinci; M. Vignati; C. Voena

    2012-12-12T23:59:59.000Z

    Bolometers have proven to be good instruments to search for rare processes because of their excellent energy resolution and their extremely low intrinsic background. In this kind of detectors, the capability of discriminating alpha particles from electrons represents an important aspect for the background reduction. One possibility for obtaining such a discrimination is provided by the detection of the Cerenkov light which, at the low energies of the natural radioactivity, is only emitted by electrons. In this paper, the results of the analysis of the light emitted by a TeO2 crystal at room temperature when transversed by a cosmic ray are reported. Light is promptly emitted after the particle crossing and a clear evidence of its directionality is also found. These results represent a strong indication that Cerenkov light is the main, if not even the only, component of the light signal in a TeO2 crystal. They open the possibility to make large improvements in the performance of experiments based on this kind of materials

  17. Atmospheric neutrino flux calculation using the NRLMSISE00 atmospheric model

    E-Print Network [OSTI]

    Honda, M; Kajita, T; Kasahara, K; Midorikawa, S

    2015-01-01T23:59:59.000Z

    In this paper, we extend the calculation of the atmospheric neutrino flux~\\cite{hkkm2004,hkkms2006,hkkm2011} to the sites in polar and tropical regions. In our earliest full 3D-calculation~\\cite{hkkm2004}, we used DPMJET-III~\\cite{dpm} for the hadronic interaction model above 5~GeV, and NUCRIN~\\cite{nucrin} below 5~GeV. We modified DPMJET-III as in Ref.~\\cite{hkkms2006} to reproduce the experimental muon spectra better, mainly using the data observed by BESS group~\\cite{BESSTeVpHemu}. In a recent work~\\cite{hkkm2011}, we introduced JAM interaction model for the low energy hadronic interactions. JAM is a nuclear interaction model developed with PHITS (Particle and Heavy-Ion Transport code System)~\\cite{phits}. In Ref.~\\cite{hkkm2011}, we could reproduce the observed muon flux at the low energies at balloon altitude with DPMJET-III above 32 GeV and JAM below that better than the combination of DPMJET-III above 5~GeV and NUCRIN below that. Besides the interaction model, we have also improved the calculation sche...

  18. Atmospheric sampling glow discharge ionization source

    DOE Patents [OSTI]

    McLuckey, S.A.; Glish, G.L.

    1989-07-18T23:59:59.000Z

    An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

  19. Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    GaN light-emitting diodes: Efficiency-limiting processes at high injection J. Vac. Sci. Technol. A 31

  20. ISSUANCE 2015-06-25: Energy Conservation Program: Test Procedures for Integrated Light-Emitting Diode Lamps, Supplemental Notice of Proposed Rulemaking

    Broader source: Energy.gov [DOE]

    Energy Conservation Program: Test Procedures for Integrated Light-Emitting Diode Lamps, Supplemental Notice of Proposed Rulemaking

  1. DIRSIG Cloud Modeling Capabilities; A Parametric Study

    E-Print Network [OSTI]

    Salvaggio, Carl

    1 DIRSIG Cloud Modeling Capabilities; A Parametric Study Kristen Powers powers:................................................................................................................... 13 Calculation of Sensor Reaching Radiance Truth Values for Cloudless & Stratus Cloud Scenes and Atmospheric Database Creation for Stratus Cloud Scene & Calculation of Associated Sensor Reaching Radiance

  2. C. Wetzel et al MRS Internet J. Nitride Semicond. Res. 10, 2 (2005) 1 Development of High Power Green Light Emitting Diode Chips

    E-Print Network [OSTI]

    Wetzel, Christian M.

    2005-01-01T23:59:59.000Z

    Power Green Light Emitting Diode Chips C. Wetzel and T. Detchprohm Future Chips Constellation Abstract The development of high emission power green light emitting diodes chips using GaInN/GaN multi production-scale implementation of this green LED die process. Keywords: nitrides, light emitting diode

  3. InP-Based Oxide-Confined 16 p.m Microcavity Light Emitting Diodes Weidong Zhou, Omar Qasaimeh, and Pallab Bhattacharya

    E-Print Network [OSTI]

    Zhou, Weidong

    InP-Based Oxide-Confined 16 p.m Microcavity Light Emitting Diodes Weidong Zhou, Omar Qasaimeh light emitting diodes (MCLEDs) have been designed, fabricated and characterized. Oxide- confined MCLEDs region emission peak and cavity resonance peak. Key words: Microcavity light emitting diode (MCLED), wet

  4. Microcavity enhanced vertical-cavity light-emitting diodes U. Keller, G. R. Jacobovitz-Veselka, J. E. Cunningham, W. Y. Jan, B. Tell,

    E-Print Network [OSTI]

    Keller, Ursula

    Microcavity enhanced vertical-cavity light-emitting diodes U. Keller, G. R. Jacobovitz-Veselka, J-cavity light-emitting diode (LED) by continuously changing the microcavity resonance with respect for optical interconnects seems to be the light emitting diode (LED), or better yet, the microcavity en

  5. Synthesis and luminescence properties of rare earth activated phosphors for near UV-emitting LEDs for efficacious generation of white light

    E-Print Network [OSTI]

    Han, Jinkyu

    2013-01-01T23:59:59.000Z

    Luo, S. Lu. ?White light emitting diode by using a-Ca 2 P 2silicates for near-UV light emitting diode applications,? J.S.Y. Choi. ?White light-emitting diodes of GaN-based Sr 2

  6. Conference 5739, SPIE International Symposium Integrated Optoelectronic Devices, 22-27 Jan 2005, San Jose, CA Development of high power green light emitting diode dies in

    E-Print Network [OSTI]

    Wetzel, Christian M.

    , San Jose, CA Development of high power green light emitting diode dies in piezoelectric Ga in green light emitting diodes is one of the big challenges towards all-solid- state lighting. The prime,3], and commercialization [4,5] of high brightness light emitting diodes LEDs has led to a 1.82 Billion-$/year world market

  7. SPECTRAL MEASUREMENTS OF INFRARED SKY RADIANCE

    E-Print Network [OSTI]

    Berdahl, P.

    2014-01-01T23:59:59.000Z

    displace conventional air conditioning. In order to computeduring periods of high air conditioning load. SAMPLES OF THE

  8. Zenith Radiance Retrieval of Cloud Properties

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhatY-12 recognizedThesisZero-KnowledgeStatus

  9. Radiance: Synthetic Imaging System | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I GeothermalPotentialBiopowerSolidGenerationMethodInformationeNevada <RECServices,RYPOSRadiance:

  10. atmospheric nitrogen dioxide: Topics by E-print Network

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

    Introduction Greenhouse gas emissions have been identified as the major source of global warming. Among the greenhouse gases emitted1 Clathrate hydrate equilibrium data for...

  11. Environmental chamber studies of atmospheric reactivities of volatile organic compounds: Effects of varying chamber and light source

    SciTech Connect (OSTI)

    Carter, W.; Luo, D.; Malkina, I.; Pierce, J. [California Univ., Riverside, CA (United States)

    1995-05-01T23:59:59.000Z

    Photochemical oxidant models are essential tools for assessing effects of emissions changes on ground-level ozone formation. Such models are needed for predicting the ozone impacts of increased alternative fuel use. The gas-phase photochemical mechanism is an important component of these models because ozone is not emitted directly, but is formed from the gas-phase photochemical reactions of the emitted volatile organic compounds (VOCs) and oxides of nitrogen (NO{sub x}) in air. The chemistry of ground level ozone formation is complex; hundreds of types of VOCs being emitted into the atmosphere, and most of their atmospheric reactions are not completely understood. Because of this, no chemical model can be relied upon to give even approximately accurate predictions unless it has been evaluated by comparing its predictions with experimental data. Therefore an experimental and modeling study was conducted to assess how chemical mechanism evaluations using environmental chamber data are affected by the light source and other chamber characteristics. Xenon arc lights appear to give the best artificial representation of sunlight currently available, and experiments were conducted in a new Teflon chamber constructed using such a light source. Experiments were also conducted in an outdoor Teflon Chamber using new procedures to improve the light characterization, and in Teflon chambers using blacklights. These results, and results of previous runs other chambers, were compared with model predictions using an updated detailed chemical mechanism. The magnitude of the chamber radical source assumed when modeling the previous runs were found to be too high; this has implications in previous mechanism evaluations. Temperature dependencies of chamber effects can explain temperature dependencies in chamber experiments when Ta-300{degree}K, but not at temperatures below that.

  12. The Upper Atmosphere of HD17156b

    E-Print Network [OSTI]

    T. T. Koskinen; A. D. Aylward; S. Miller

    2008-11-28T23:59:59.000Z

    HD17156b is a newly-found transiting extrasolar giant planet (EGP) that orbits its G-type host star in a highly eccentric orbit (e~0.67) with an orbital semi-major axis of 0.16 AU. Its period, 21.2 Earth days, is the longest among the known transiting planets. The atmosphere of the planet undergoes a 27-fold variation in stellar irradiation during each orbit, making it an interesting subject for atmospheric modelling. We have used a three-dimensional model of the upper atmosphere and ionosphere for extrasolar gas giants in order to simulate the progress of HD17156b along its eccentric orbit. Here we present the results of these simulations and discuss the stability, circulation, and composition in its upper atmosphere. Contrary to the well-known transiting planet HD209458b, we find that the atmosphere of HD17156b is unlikely to escape hydrodynamically at any point along the orbit, even if the upper atmosphere is almost entirely composed of atomic hydrogen and H+, and infrared cooling by H3+ ions is negligible. The nature of the upper atmosphere is sensitive to to the composition of the thermosphere, and in particular to the mixing ratio of H2, as the availability of H2 regulates radiative cooling. In light of different simulations we make specific predictions about the thermosphere-ionosphere system of HD17156b that can potentially be verified by observations.

  13. Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical. Atmospheric aerosols have profound effects on the environment through several physicochemical processes on the respiratory and cardiovascular systems. Understanding aerosol atmospheric chemistry and its environmental

  14. Demonstration Assessment of Light-Emitting Diode (LED) Accent Lighting at the Field Museum in Chicago, IL

    SciTech Connect (OSTI)

    Myer, Michael; Kinzey, Bruce R.

    2010-12-10T23:59:59.000Z

    This report reviews a demonstration of light-emitting diode (LED) accent lighting compared to halogen (typical) accent lighting in a gallery of the Field Museum in Chicago, IL.

  15. Monolithic phosphor-free InGaN/GaN quantum dot wavelength converter white light emitting diodes

    SciTech Connect (OSTI)

    Jahangir, Shafat; Bhattacharya, Pallab, E-mail: pkb@eecs.umich.edu [Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States); Pietzonka, Ines; Strassburg, Martin [OSRAM Opto Semiconductors GmbH, Leibnizstrasse 4, Regensburg (Germany)

    2014-09-15T23:59:59.000Z

    We report the characteristics of phosphor-free self-organized InGaN/GaN quantum dot wavelength converter white light emitting diodes grown by plasma assisted molecular beam epitaxy. The exciting quantum dots, in which electrically injected carriers recombine, are blue-emitting and the converter dots are red-emitting. We have studied the effect of tuning the number of dot layers and the peak emission wavelength of the exciting and converter dots on the nature of the emitted white light, in terms of the chromaticity coordinates and correlated color temperature. Depending on the values of these wavelengths, color temperatures in the range of 4420–6700?K have been derived at a current density of 45?A/cm{sup 2} across multiple devices. The variation of the color temperature with change in injection current is found to be very small.

  16. Improved Cognitive Function After Transcranial, Light-Emitting Diode Treatments in Chronic, Traumatic Brain Injury: Two Case Reports

    E-Print Network [OSTI]

    Naeser, Margaret A.

    Objective: Two chronic, traumatic brain injury (TBI) cases, where cognition improved following treatment with red and near-infrared light-emitting diodes (LEDs), applied transcranially to forehead and scalp areas, are ...

  17. Experimental determination of the statistics of photons emitted by a tunnel junction Eva Zakka-Bajjani, J. Dufouleur,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ) We report on a microwave Hanbury-Brown Twiss experiment probing the statistics of GHz photons emitted based on Hanbury-Brown Twiss (HBT) microwave photon correlation is found to provide a di- rect

  18. The synthesis of inorganic semiconductor nanocrystalline materials for the purpose of creating hybrid organic/inorganic light-emitting devices

    E-Print Network [OSTI]

    Steckel, Jonathan S. (Jonathan Stephen)

    2006-01-01T23:59:59.000Z

    Colloidal semiconductor nanocrystals (NCs) or quantum dots (QDs) can be synthesized to efficiently emit light from the ultraviolet, across the entire visible spectrum, and into the near infrared. This is now possible due ...

  19. activity and diversity of particle-emitting orga-nisms seem likely to play important roles in Earth

    E-Print Network [OSTI]

    activity and diversity of particle-emitting orga- nisms seem likely to play important roles at BESSY II. We thank the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, and the ATTO team

  20. Atmospheric Mercury Concentrations Near Salmon Falls Creek Reservoir - Phase 1

    SciTech Connect (OSTI)

    M. L. Abbott

    2005-10-01T23:59:59.000Z

    Elemental and reactive gaseous mercury (EGM/RGM) were measured in ambient air concentrations over a two-week period in July/August 2005 near Salmon Falls Creek Reservoir, a popular fishery located 50 km southwest of Twin Falls, Idaho. A fish consumption advisory for mercury was posted at the reservoir in 2002 by the Idaho Department of Health and Welfare. The air measurements were part of a multi-media (water, sediment, precipitation, air) study initiated by the Idaho Department of Environmental Quality and the U.S. Environmental Protection Agency (EPA) Region 10 to identify potential sources of mercury contamination to the reservoir. The sampling site is located about 150 km northeast of large gold mining operations in Nevada, which are known to emit large amounts of mercury to the atmosphere (est. 2,200 kg/y from EPA 2003 Toxic Release Inventory). The work was co-funded by the Idaho National Laboratory’s Community Assistance Program and has a secondary objective to better understand mercury inputs to the environment near the INL, which lies approximately 230 km to the northeast. Sampling results showed that both EGM and RGM concentrations were significantly elevated (~ 30 – 70%, P<0.05) compared to known regional background concentrations. Elevated short-term RGM concentrations (the primary form that deposits) were likely due to atmospheric oxidation of high EGM concentrations, which suggests that EGM loading from upwind sources could increase Hg deposition in the area. Back-trajectory analyses indicated that elevated EGM and RGM occurred when air parcels came out of north-central and northeastern Nevada. One EGM peak occurred when the air parcels came out of northwestern Utah. Background concentrations occurred when the air was from upwind locations in Idaho (both northwest and northeast). Based on 2003 EPA Toxic Release Inventory data, it is likely that most of the observed peaks were from Nevada gold mine sources. Emissions from known large natural mercury sources in that area cannot account for the observed EGM peaks due to their diffuse source geometry and the large (170 km) transport distance involved. The EGM peak originating from northwestern Utah air may be from three known mercury sources west of Salt Lake City (Kennecott, US Magnesium, Clean Harbors Aragonite) and/or the 1600 MW coal-fired Intermountain Power plant near Delta. However, the relative importance of these short-term peaks for long-term watershed mercury loading (critical factor affecting fish concentrations) is not known, and there is a need to better quantify the annual frequency and magnitude of these different inputs over a longer period of time.

  1. Atmospheric science encompasses meteorology and climatology, as well as fields such as atmospheric chemistry and remote sensing.Atmospheric

    E-Print Network [OSTI]

    Oceanography and Meteorology Building.The Doppler weather radar on the roof of the building is a campus Mobile Atmospheric Research and Teaching Radar (SMART-R).This radar is used in national and international

  2. Pulsed atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1989-11-01T23:59:59.000Z

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  3. atmospheric pressure ionization: Topics by E-print Network

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

    for Atmospheric Pressure, in Vivo, and Imaging Mass. For example, atmospheric pressure infrared MALDI (AP IR-MALDI), capable of producing ions from small ionization (DESI),5...

  4. atmospheric carbon emissions: Topics by E-print Network

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

    oxide (N2O) 13 Paris-Sud XI, Universit de 13 Atmospheric Lifetime of Fossil Fuel Carbon Dioxide Geosciences Websites Summary: Atmospheric Lifetime of Fossil Fuel Carbon...

  5. atmospheric oxygenation recorded: Topics by E-print Network

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

    cores may contain high quality records of atmospheric deposition. The qualitative Short, Daniel 3 Bistability of atmospheric oxygen and the Great Oxidation Geosciences Websites...

  6. atmospheric optical turbulence: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 Atmospheric Turbulence and its Influence on Adaptive Optics Physics Websites Summary: Atmospheric Turbulence and its Influence on Adaptive Optics...

  7. atmospheric ion measurements: Topics by E-print Network

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

    the Atmospheric CERN Preprints Summary: We report the first observation in a high energy neutrino telescope of cascades induced by atmospheric electron neutrinos and by...

  8. Comparative Analysis of Urban Atmospheric Aerosol by Particle...

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

    Analysis of Urban Atmospheric Aerosol by Particle-Induced X-ray Emission (PIXE), Proton Elastic Scattering Analysis Comparative Analysis of Urban Atmospheric Aerosol by...

  9. Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach...

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

    Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne Particle Analysis. Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne...

  10. A Volcanologist'S Review Of Atmospheric Hazards Of Volcanic Activity...

    Open Energy Info (EERE)

    atmospheric hazards caused by explosive volcanic activity. The hazard posed by fine silicate ash with long residence time in the atmosphere is probably much less serious than...

  11. Diesel and Gasoline Engine Emissions: Characterization of Atmosphere...

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

    Characterization of Atmosphere Composition and Health Responses to Inhaled Emissions Diesel and Gasoline Engine Emissions: Characterization of Atmosphere Composition and Health...

  12. Fehner and Gosling, Atmospheric Nuclear Weapons Testing, 1951...

    Energy Savers [EERE]

    Atmospheric Nuclear Weapons Testing, 1951-1963. Battlefield of the Cold War: The Nevada Test Site, Volume I Fehner and Gosling, Atmospheric Nuclear Weapons Testing, 1951-1963....

  13. atmospheric global electric: Topics by E-print Network

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

    global atmospheric iron cycle, and combustion this paper. Key Words aerosol deposition, climate change, deserts Abstract Atmospheric inputs of iron sources of iron are...

  14. atmospheric dispersion coefficient: Topics by E-print Network

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

    the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 3 A GIS-based atmospheric dispersion model Computer...

  15. atmospheric dispersion calculations: Topics by E-print Network

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

    the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 4 A GIS-based atmospheric dispersion model Computer...

  16. atmospheric dispersion experiment: Topics by E-print Network

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

    the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 2 A GIS-based atmospheric dispersion model Computer...

  17. atmospheric climate model: Topics by E-print Network

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

    Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Russell, Lynn 10 Climate Sciences: Atmospheric Thermodynamics Environmental...

  18. atmosphere box model: Topics by E-print Network

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

    GloveBoxes Glove boxes allow the user to perform operations in an atmosphere 8 University Corporation for Atmospheric Research PO Box 3000 Boulder, Colorado 80307 Geosciences...

  19. Oxygen detected in atmosphere of Saturn's moon Dione

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

    Oxygen detected in atmosphere of Saturn's moon Dione Oxygen detected in atmosphere of Saturn's moon Dione Scientists and an international research team have announced discovery of...

  20. atmospheric modeling system: Topics by E-print Network

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

    14 Causes and implications of persistent atmospheric carbon dioxide biases in Earth System Models University of California eScholarship Repository Summary: Atmosphere and Ocean...

  1. atmospheric co2 content: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  2. atmospheric chemistry simulations: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  3. atmospheric sciences exposure: Topics by E-print Network

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

    annual reviews of faculty performance in accordance 8 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  4. atmospheric chemistry project: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  5. atmospheric co2 concentrations: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  6. atmospheric co2 concentration: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  7. atmospheric co2 laser: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  8. atmospheric loading effects: Topics by E-print Network

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

    large solar proton Paris-Sud XI, Universit de 7 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  9. atmospheric chemistry programme: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  10. atmospheric co2 measurements: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  11. atmospheric co2 variations: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  12. atmospheric chemistry experiment: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  13. atmospheric science people: Topics by E-print Network

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

    annual reviews of faculty performance in accordance 9 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  14. atmospheric chemistry: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  15. atmospheric sciences: Topics by E-print Network

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

    annual reviews of faculty performance in accordance 8 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  16. atmospheric co2 mixing: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  17. atmospheric aerosols basic: Topics by E-print Network

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

    of atmospheric aerosol. Aplin, KL 2012-01-01 13 1. Introduction The atmospheric greenhouse effect is the basic mechanism Environmental Sciences and Ecology Websites Summary: 1....

  18. atmospheric deposition microbial: Topics by E-print Network

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

    Mercury in the Global Atmosphere: Chemistry, deposition, and land-atmosphere interactions Environmental Management and Restoration Websites Summary: Mercury in the Global...

  19. atmospheric deposition nutrient: Topics by E-print Network

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

    Mercury in the Global Atmosphere: Chemistry, deposition, and land-atmosphere interactions Environmental Management and Restoration Websites Summary: Mercury in the Global...

  20. Visualizing Storms from NCAR's Atmosphere Model at NERSC

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

    Atmosphere Model Visualizing Storms from NCAR's Atmosphere Model CCSM-sprabhat.png Global warming will likely change the statistics of tropical cyclones and hurricanes. In this...

  1. Laboratory Experiments and Instrument Development for the Study of Atmospheric Aerosols

    SciTech Connect (OSTI)

    Davidovits, Paul

    2011-12-10T23:59:59.000Z

    Soot particles are generated by incomplete combustion of fossil and biomass fuels. Through direct effects clear air aerosols containing black carbon (BC) such as soot aerosols, absorb incoming light heating the atmosphere, while most other aerosols scatter light and produce cooling. Even though BC represents only 1-2% of the total annual emissions of particulate mass to the atmosphere, it has been estimated that the direct radiative effect of BC is the second-most important contributor to global warming after absorption by CO2. Ongoing studies continue to underscore the climate forcing importance of black carbon. However, estimates of the radiative effects of black carbon on climate remain highly uncertain due to the complexity of particles containing black carbon. Quantitative measurement of BC is challenging because BC often occurs in highly non-spherical soot particles of complex morphology. Freshly emitted soot particles are typically fractal hydrophobic aggregates. The aggregates consist of black carbon spherules with diameters typically in the range of about 15-40 nm, and they are usually coated by adsorbed polyaromatic hydrocarbons (PAHs) produced during combustion. Diesel-generated soot particles are often emitted with an organic coating composed primarily of lubricating oil and unburned fuel, as well as well as PAH compounds. Sulfuric acid has also been detected in diesel and aircraft-emitted soot particles. In the course of aging, these particle coatings may be substantially altered by chemical reactions and/or the deposition of other materials. Such processes transform the optical and CCN properties of the soot aerosols in ways that are not yet well understood. Our work over the past seven years consisted of laboratory research, instrument development and characterization, and field studies with the central focus of improving our understanding of the black carbon aerosol climate impacts. During the sixth year as well as during this seventh year (no-cost extension period) of our grant, we extended our studies to perform experiments on the controlled production and characterization of secondary organic aerosol.

  2. Cool X-ray emitting gas in the core of the Centaurus cluster of galaxies

    E-Print Network [OSTI]

    J. S. Sanders; A. C. Fabian; S. W. Allen; R. G. Morris; J. Graham; R. M. Johnstone

    2008-01-10T23:59:59.000Z

    We use a deep XMM-Newton Reflection Grating Spectrometer observation to examine the X-ray emission from the core of the Centaurus cluster of galaxies. We clearly detect Fe-XVII emission at four separate wavelengths, indicating the presence of cool X-ray emitting gas in the core of the cluster. Fe ions from Fe-XVII to XXIV are observed. The ratio of the Fe-XVII 17.1A lines to 15.0A line and limits on O-VII emission indicate a lowest detected temperature in the emitting region of 0.3 to 0.45 keV (3.5 to 5.2x10^6 K). The cluster also exhibits strong N-VII emission, making it apparent that the N abundance is supersolar in its very central regions. Comparison of the strength of the Fe-XVII lines with a Solar metallicity cooling flow model in the inner 17 kpc radius gives mass deposition rates in the absence of heating of 1.6-3 Msun/yr. Spectral fitting implies an upper limit of 0.8 Msun/yr below 0.4 keV, 4 Msun/yr below 0.8 keV and 8 Msun/yr below 1.6 keV. The cluster contains X-ray emitting gas over at least the range of 0.35 to 3.7 keV, a factor of more than 10 in temperature. We find that the best fitting metallicity of the cooler components is smaller than the hotter ones, confirming that the apparent metallicity does decline within the inner 1 arcmin radius.

  3. REMOTE SENSING OF ENVIRONMENT 11 191-205 (1981) Atmospheric Corrections to Satellite

    E-Print Network [OSTI]

    Dozier, Jeff

    spaceborne radiometers (e g, Landsat multlspectral scanner, NOAA advanced very high resolution radiome- ter radiometers which measure upwelhng radiance in the solar portion of the electromagnetic spectrum can be used to estimate the spatial distnbuhon of surface parameters which are useful m calculating the surface energy

  4. Adaptive control for Mars atmospheric flight

    E-Print Network [OSTI]

    Restrepo, Carolina Isabel

    2009-05-15T23:59:59.000Z

    landing accuracy requirements for a manned space vehicle make it necessary to ?y a controlled entry trajectory rather than a more robust ballistic entry trajectory used for some robotic missions. The large variations in Mars atmospheric properties make a...

  5. Composition and Reactions of Atmospheric Aerosol Particles

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

    large portion of the microscopic particles floating in the air originate from incomplete combustion of coal and oil and from dust storms. Once in the atmosphere, they can have...

  6. HYPERsensarium : an archive of atmospheric conditions

    E-Print Network [OSTI]

    Shaw, Kelly E. (Kelly Evelyn)

    2013-01-01T23:59:59.000Z

    HYPERsensarium proposes a tangible interface of atmospheres for public experience through an archive of historical and projected weathers. While architecture's purpose has long been to act as the technical boundary between ...

  7. The porous atmosphere of eta Carinae

    E-Print Network [OSTI]

    Nir J. Shaviv

    2000-02-09T23:59:59.000Z

    We analyze the wind generated by the great 20 year long super-Eddington outburst of eta-Carinae. We show that using classical stellar atmospheres and winds theory, it is impossible to construct a consistent wind model in which a sufficiently small amount of mass, like the one observed, is shed. One expects the super-Eddington luminosity to drive a thick wind with a mass loss rate substantially higher than the observed one. The easiest way to resolve the inconsistency is if we alleviate the implicit notion that atmospheres are homogeneous. An inhomogeneous atmosphere, or "porous", allows more radiation to escape while exerting a smaller average force. Consequently, such an atmosphere yields a considerably lower mass loss rate for the same total luminosity. Moreover, all the applications of the Eddington Luminosity as a strict luminosity limit should be revised, or at least reanalyzed carefully.

  8. Space Science: Atmospheres Evolution of planets

    E-Print Network [OSTI]

    Johnson, Robert E.

    ;Atmospheres / Evolution Heat Sources Compressional Energy Trapped Radioactive Material Tidal Interactions, same A) the surface temperature,Tg, increases. WOW! Simple #12;Temperature vs. time in an Early Epoch

  9. MIDDLE ATMOSPHERE DYNAMICS AT707 (3 credits)

    E-Print Network [OSTI]

    ., Holton, J. R., Leovy, C. B., Academic Press, 489 pp. · Atmospheric and Oceanic Fluid Dynamics, 2006 Review Articles: · Haynes, P. H., 2005: Stratospheric Dynamics. Annu. Rev. Fluid Mech., 37, 263­ 293

  10. Detecting special nuclear materials in containers using high-energy gamma rays emitted by fission products

    DOE Patents [OSTI]

    Norman, Eric B. (Oakland, CA); Prussin, Stanley G. (Kensington, CA)

    2007-10-02T23:59:59.000Z

    A method and a system for detecting the presence of special nuclear materials in a container. The system and its method include irradiating the container with an energetic beam, so as to induce a fission in the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  11. Internal efficiency of InGaN light-emitting diodes: Beyond a quasiequilibrium model

    SciTech Connect (OSTI)

    Chow, Weng W.; Crawford, Mary H.; Tsao, Jeffrey Y.; Kneissl, Michael

    2010-01-01T23:59:59.000Z

    We propose a model to better investigate InGaN light-emitting diode (LED) internal efficiency by extending beyond the usual total carrier density rate equation approach. To illustrate its capability, the model is applied to study intrinsic performance differences between violet and green LEDs. The simulations show performance differences, at different current densities and temperatures, arising from variations in spontaneous emission and heat loss rates. By tracking the momentum-resolved carrier populations, these rate changes are, in turn, traced to differences in bandstructure and plasma heating. The latter leads to carrier distributions that deviate from the quasiequilibrium ones at lattice temperature.

  12. Temperature-dependent efficiency droop of blue InGaN micro-light emitting diodes

    SciTech Connect (OSTI)

    Tian, Pengfei; McKendry, Jonathan J. D.; Herrnsdorf, Johannes; Ferreira, Ricardo; Watson, Ian M.; Gu, Erdan, E-mail: erdan.gu@strath.ac.uk; Dawson, Martin D. [Institute of Photonics, University of Strathclyde, 106 Rottenrow, Glasgow G4 0NW (United Kingdom); Watson, Scott; Kelly, Anthony E. [School of Engineering, University of Glasgow, James Watt South Building, Glasgow G12 8LT (United Kingdom)

    2014-10-27T23:59:59.000Z

    Temperature-dependent trends in radiative and Auger recombination coefficients have been determined at different injection carrier concentrations using InGaN micro-light emitting diodes 40 ?m in diameter. The differential lifetime was obtained first from the measured modulation bandwidth and was then employed to calculate the carrier concentration in the quantum well active region. When the temperature increases, the carrier concentration increases, but both the radiative and Auger recombination coefficients decrease. In addition, the temperature dependence of radiative and Auger recombination coefficients is weaker at a higher injection carrier concentration, which is strongly related to phase space filling.

  13. Gravitational waves emitted by solar-type stars excited by orbiting planets

    E-Print Network [OSTI]

    Emanuele Berti; Valeria Ferrari

    2000-11-30T23:59:59.000Z

    The possibility of exciting the g-modes of a solar-type star as a consequence of the gravitational interaction with a close companion (a planet or a brown dwarf) is studied by a perturbative approach. The amplitude of the emitted gravitational wave is computed and compared with the quadrupole emission of the system, showing that in some cases it can be considerably larger. The effects of radiation reaction are considered to evaluate the timescale of the emission process, and a Roche lobe analysis is used to establish the region where the companion can orbit without being disrupted by tidal interactions with the star.

  14. Even-odd effects in Z and N distributions of fragments emitted at intermediate energies

    SciTech Connect (OSTI)

    Lombardo, I.; Lanzalone, G. [INFN-Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Facolta di Ingegneria ed Architettura, Universita' 'Kore'' di Enna, Enna (Italy); Agodi, C.; Amorini, F.; Anzalone, A.; Han, J.; Maiolino, C. [INFN-Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Auditore, L.; Loria, D.; Trifiro, A.; Trimarchi, M. [Dipartimento di Fisica, Universita di Messina and INFN-Gruppo Collegato, Messina (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Cardella, G.; De Filippo, E.; Pagano, A.; Papa, M.; Pirrone, S. [INFN-Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Cavallaro, S.; Porto, F.; Rizzo, F. [INFN-Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia, Catania (Italy)

    2011-08-15T23:59:59.000Z

    Even-odd effects in Z and N distributions of light fragments emitted at forward angles in nuclear collisions {sup 40}Ca + {sup 40}Ca, {sup 40}Ca + {sup 48}Ca, and {sup 48}Ca + {sup 48}Ca at 25 MeV/nucleon and identified in charge and mass with the Chimera multidetector have been analyzed. The amplitude of even-odd staggering effects seems to be related to the neutron to proton ratio N/Z of the entrance channels. A qualitative explanation of this effect, taking into account the deexcitation phase of primary excited fragments, is discussed.

  15. The Interaction of Radio Sources and X-ray-Emitting Gas in Cooling Flows

    E-Print Network [OSTI]

    Elizabeth L. Blanton

    2004-02-13T23:59:59.000Z

    Recent observations of the interactions between radio sources and the X-ray-emitting gas in cooling flows in the cores of clusters of galaxies are reviewed. The radio sources inflate bubbles in the X-ray gas, which then rise buoyantly outward in the clusters transporting energy to the intracluster medium (ICM). The bright rims of gas around the radio bubbles are cool, rather than hot, and do not show signs of being strongly shocked. Energy deposited into the ICM over the lifetime of a cluster through several outbursts of a radio source helps to account for at least some of the gas that is missing in cooling flows at low temperatures.

  16. Suzaku Reveals Helium-burning Products in the X-ray Emitting Planetary Nebula BD+303639

    E-Print Network [OSTI]

    M. Murashima; M. Kokubun; K. Makishima; J. Kotoku; H. Murakami; K. Matsushita; K. Hayashida; K. Arnaud; K. Hamaguchi; H. Matsumoto

    2006-07-07T23:59:59.000Z

    BD+303639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K-lines from C VI, O VII, and O VIII were resolved for the first time, and C/O, N/O, and Ne/O abundance ratios determined. The C/O and Ne/O abundance ratios exceed the solar value by a factor of at least 30 and 5, respectively. These results indicate that the X-rays are emitted mainly by helium shell-burning products.

  17. Suzaku Reveals Helium-burning Products in the X-ray Emitting Planetary Nebula BD+303639

    E-Print Network [OSTI]

    Murashima, M; Makishima, K; Kotoku, J; Murakami, H; Matsushita, K; Hayashida, K; Arnaud, K; Hamaguchi, K; Matsumoto, H

    2006-01-01T23:59:59.000Z

    BD+303639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K-lines from C VI, O VII, and O VIII were resolved for the first time, and C/O, N/O, and Ne/O abundance ratios determined. The C/O and Ne/O abundance ratios exceed the solar value by a factor of at least 30 and 5, respectively. These results indicate that the X-rays are emitted mainly by helium shell-burning products.

  18. Method for accurate growth of vertical-cavity surface-emitting lasers

    DOE Patents [OSTI]

    Chalmers, S.A.; Killeen, K.P.; Lear, K.L.

    1995-03-14T23:59:59.000Z

    The authors report a method for accurate growth of vertical-cavity surface-emitting lasers (VCSELs). The method uses a single reflectivity spectrum measurement to determine the structure of the partially completed VCSEL at a critical point of growth. This information, along with the extracted growth rates, allows imprecisions in growth parameters to be compensated for during growth of the remaining structure, which can then be completed with very accurate critical dimensions. Using this method, they can now routinely grow lasing VCSELs with Fabry-Perot cavity resonance wavelengths controlled to within 0.5%. 4 figs.

  19. Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in atmospheric chemistry

    E-Print Network [OSTI]

    Dimitra Atri; Adrian L. Melott; Brian C. Thomas

    2010-05-03T23:59:59.000Z

    A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV . An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV - 1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.

  20. Air Activation Following an Atmospheric Explosion

    SciTech Connect (OSTI)

    Lowrey, Justin D.; McIntyre, Justin I.; Prichard, Andrew W.; Gesh, Christopher J.

    2013-03-13T23:59:59.000Z

    In addition to thermal radiation and fission products, nuclear explosions result in a very high flux of unfissioned neutrons. Within an atmospheric nuclear explosion, these neutrons can activate the various elemental components of natural air, potentially adding to the radioactive signature of the event as a whole. The goal of this work is to make an order-of-magnitude estimate of the total amount of air activation products that can result from an atmospheric nuclear explosion.

  1. Trace analysis of atmospheric organic bases

    E-Print Network [OSTI]

    Clark, Dwayne C.

    1984-01-01T23:59:59.000Z

    chromatographic fractions for NS analyses ( 121) and its use as a thin layer chromatography (TLC) adsorbent ( 122). The National Institute of Occupational Safety and Health (NIOSH) recommends its use in the analysis of many industrial vapors ( 113 - 120... analysis of atmospheric organic bases were investigated; the study included (1) the analysis of submarine charcoal filter bed samples for nitrogen bases and (2) the use of metallic tetraphenylporphines (TPP) as specific adsorbents for atmospheric...

  2. Quantum light in the turbulent atmosphere

    E-Print Network [OSTI]

    A. A. Semenov; W. Vogel

    2009-08-12T23:59:59.000Z

    Nonclassical properties of light propagating through the turbulent atmosphere are studied. We demonstrate by numerical simulation that the probability distribution of the transmission coefficient, which characterizes the effects of the atmosphere on the quantum state of light, can be reconstructed by homodyne detection. Nonclassical photon-statistics and, more generally, nonclassical Glauber-Sudarshan functions appear to be more robust against turbulence for weak light fields rather than for bright ones.

  3. Atmospheric State, Cloud Microphysics and Radiative Flux

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mace, Gerald

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  4. Regulation of hazardous air pollutants emitted from fossil-fired boilers

    SciTech Connect (OSTI)

    Hendrickson, P.L.; Daellenbach, K.K.

    1993-12-01T23:59:59.000Z

    The changes made in {section}112 of the Clean Air Act by the 1990 Amendments to the Act will affect the regulation of hazardous air pollutants (HAPs) emitted by fossil-fired boilers. The 1990 Amendments designated 189 chemicals/compounds as HAPS. Major and area sources of these pollutants in categories designated by the Environmental Protection Agency (EPA) will be subject to emission standards set by EPA. Industrial and institutional/commercial boilers are two such categories of HAPs designated by EPA for which emission standards will be issued. Fossil-fired boilers can emit a variety of HAPS. All or a portion of such emissions that exceed designated thresholds are likely to be regulated. This paper discusses how the 1990 amendments impact fossil-fired boilers. The steps are outlined which can be taken by owners of industrial and institutional/commercial boilers before the final emission standards are issued. These steps include participation in EPA`s standard setting process, participation in EPA`s early reduction program to delay the time when compliance with the maximum achievable control technology (MACT) standard is required, and consideration of any planned modifications to a facility which might subject that facility to a MACT standard set in advance of the EPA-set standard.

  5. On the origin of ionising photons emitted by T Tauri stars

    E-Print Network [OSTI]

    R. D. Alexander; C. J. Clarke; J. E. Pringle

    2003-11-12T23:59:59.000Z

    We address the issue of the production of Lyman continuum photons by T Tauri stars, in an attempt to provide constraints on theoretical models of disc photoionisation. By treating the accretion shock as a hotspot on the stellar surface we show that Lyman continuum photons are produced at a rate approximately three orders of magnitude lower than that produced by a corresponding black body, and that a strong Lyman continuum is only emitted for high mass accretion rates. When our models are extended to include a column of material accreting on to the hotspot we find that the accretion column is extremely optically thick to Lyman continuum photons. Further, we find that radiative recombination of hydrogen atoms within the column is not an efficient means of producing photons with energies greater than 13.6eV, and find that an accretion column of any conceivable height suppresses the emission of Lyman continuum photons to a level below or comparable to that expected from the stellar photosphere. The photospheric Lyman continuum is itself much too weak to affect disc evolution significantly, and we find that the Lyman continuum emitted by an accretion shock is similarly unable to influence disc evolution significantly. This result has important consequences for models which use photoionisation as a mechanism to drive the dispersal of circumstellar discs, essentially proving that an additional source of Lyman continuum photons must exist if disc photoionisation is to be significant.

  6. Light emitting diode package element with internal meniscus for bubble free lens placement

    SciTech Connect (OSTI)

    Tarsa, Eric; Yuan, Thomas C.; Becerra, Maryanne; Yadev, Praveen

    2010-09-28T23:59:59.000Z

    A method for fabricating a light emitting diode (LED) package comprising providing an LED chip and covering at least part of the LED chip with a liquid encapsulant having a radius of curvature. An optical element is provided having a bottom surface with at least a portion having a radius of curvature larger than the liquid encapsulant. The larger radius of curvature portion of the optical element is brought into contact with the liquid encapsulant. The optical element is then moved closer to the LED chip, growing the contact area between said optical element and said liquid encapsulant. The liquid encapsulant is then cured. A light emitting diode comprising a substrate with an LED chip mounted to it. A meniscus ring is on the substrate around the LED chip with the meniscus ring having a meniscus holding feature. An inner encapsulant is provided over the LED chip with the inner encapsulant having a contacting surface on the substrate, with the meniscus holding feature which defines the edge of the contacting surface. An optical element is included having a bottom surface with at least a portion that is concave. The optical element is arranged on the substrate with the concave portion over the LED chip. A contacting encapsulant is included between the inner encapsulant and optical element.

  7. Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)] [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

    2013-01-28T23:59:59.000Z

    We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can mitigate losses incurred in hot-carrier injection in light emitting heterostructures. To achieve tunnel injection, relatively low composition AlGaN is used for n- and p-type layers to simultaneously take advantage of effective band alignment and efficient doping. The small height of the quantum dots results in short-wavelength emission and are simultaneously an effective tool to fight the reduction of oscillator strength from quantum-confined Stark effect due to polarization fields. The strong quantum confinement results in room-temperature electroluminescence peaks at 261 and 340 nm, well above the 365 nm bandgap of bulk GaN. The demonstration opens the doorway to exploit many varied features of quantum dot physics to realize high-efficiency short-wavelength light sources.

  8. Unique light-induced degradation in yellow-emitting K?SiF?:Mn˛? phosphor

    SciTech Connect (OSTI)

    Oyama, Takuya; Adachi, Sadao, E-mail: adachi@el.gunma-u.ac.jp [Division of Electronics and Informatics, Faculty of Science and Technology, Gunma University, Kiryu-shi, Gunma 376-8515 (Japan)

    2014-10-07T23:59:59.000Z

    Photo-induced luminescence intensity degradation in yellow-emitting K?SiF?:Mn˛? phosphor is studied using x-ray diffraction measurement, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, PL decay analysis, and electron spin resonance (ESR) measurement. The yellow-emitting K?SiF?:Mn˛? phosphor exhibits remarkable degradation in the PL intensity under Xe lamp exposure. Coherent laser irradiation also induces degradation and its degree is in the order of He–Cd (? = 325 nm) > Ar? (488 nm) > He–Ne laser (632.8 nm). The degradation mechanism is proposed to be due to change in the valence state of manganese ions from Mn˛? to Mnł? by the photooxidation (Mn˛? ? Mnł?) or disproportionation reaction (2Mn˛? ? Mn? + Mnł?). The ESR measurement confirms the decreased Mn˛? spin density in the sample exposed with Xe lamp. The PLE spectrum suggests that the excitation of Mnł? ions occurs through energy transfer upon absorption of exciting radiation by the Mn˛? ions. Thermal annealing of the degraded samples at ?200 °C causes a blueshift in the PL emission band with an appearance of the Mn??-related sharp red emission lines.

  9. Quantitative method for measuring heat flux emitted from a cryogenic object

    DOE Patents [OSTI]

    Duncan, R.V.

    1993-03-16T23:59:59.000Z

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

  10. Surface-emitting superconductor laser spectroscopy for characterizing normal and sickled red blood cells

    SciTech Connect (OSTI)

    Gourley, P.L.; Meissner, K.E.; Brennan, T.M.; Hammons, B.E. [Sandia National Labs., Albuquerque, NM (United States); Gourley, M.F. [National Institutes of Health, Bethesda, MD (United States)

    1995-02-01T23:59:59.000Z

    We have developed a new intracavity laser technique that uses a living or a fixed cell as an integral component of the laser. The cells are placed on an AlGaAs/GaAs surface-emitting semiconductor wafer and covered with a glass dielectric mirror to form a laser resonator. In this arrangement, the cells serve as optical waveguides (or lens elements) to confine (or focus) light generated in the resonator by the semiconductor. Because of the high transparency, the cells aid the lasing process to generate laser light. This ultra sensitive laser provides a novel imaging/spectroscopic technique for histologic examination which we demonstrate with normal and sickled human red blood cells. Extremely high contrast microscopic images of the cells are observed near 830-850 nm. These images correspond to electromagnetic modes of cell structures and are sensitive to shape of the cell. Using a high resolution spectrometer, we resolve the light emitted from these images into very narrow spectral peaks associated with the lasing modes. Analysis of the spectra reveals that the distribution of peaks is quite different for normal and sickled red blood cells. This technique, in a more developed form, may be useful for the rapid analysis of other kinds of normal and abnormal cells.

  11. Properties of the Radio-Emitting Gas Around SgrA*

    E-Print Network [OSTI]

    Abraham Loeb; Eli Waxman

    2007-02-25T23:59:59.000Z

    We show that the radial profiles of the temperature and density of the electrons as well as the magnetic field strength around the massive black hole at the Galactic center, SgrA*, may be constrained directly from existing radio data without any need to make prior assumptions about the dynamics of the emitting gas. The observed spectrum and wavelength-dependent angular size of SgrA* indicate that the synchrotron emission originates from an optically-thick plasma of quasi-thermal electrons. We find that the electron temperature rises above the virial temperature within tens of Schwarzschild radii from the black hole, suggesting that the emitting plasma may be outflowing. Constraints on the electron density profile are derived from polarization measurements. Our best-fit results differ from expectations based on existing theoretical models. However, these models cannot be ruled out as of yet due to uncertainties in the source size measurements. Our constraints could tighten considerably with future improvements in the size determination and simultaneous polarization measurements at multiple wavelengths.

  12. Quantitative method for measuring heat flux emitted from a cryogenic object

    DOE Patents [OSTI]

    Duncan, Robert V. (Tijeras, NM)

    1993-01-01T23:59:59.000Z

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infra-red sensing devices.

  13. P-doping-free III-nitride high electron mobility light-emitting diodes and transistors

    SciTech Connect (OSTI)

    Li, Baikui; Tang, Xi; Chen, Kevin J., E-mail: eekjchen@ust.hk [Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Wang, Jiannong [Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2014-07-21T23:59:59.000Z

    We report that a simple metal-AlGaN/GaN Schottky diode is capable of producing GaN band-edge ultraviolet emission at 3.4?eV at a small forward bias larger than ?2?V at room temperature. Based on the surface states distribution of AlGaN, a mature impact-ionization-induced Fermi-level de-pinning model is proposed to explain the underlying mechanism of the electroluminescence (EL) process. By experimenting with different Schottky metals, Ni/Au and Pt/Au, we demonstrated that this EL phenomenon is a “universal” property of metal-AlGaN/GaN Schottky diodes. Since this light-emitting Schottky diode shares the same active structure and fabrication processes as the AlGaN/GaN high electron mobility transistors, straight-forward and seamless integration of photonic and electronic functional devices has been demonstrated on doping-free III-nitride heterostructures. Using a semitransparent Schottky drain electrode, an AlGaN/GaN high electron mobility light-emitting transistor is demonstrated.

  14. Methane emission by termites: Impacts on the self-cleansing mechanisms of the atmosphere

    SciTech Connect (OSTI)

    Mugedo, J.Z.A. [Maseno Univ. College (Kenya)

    1996-12-31T23:59:59.000Z

    Termites are reported to emit large quantities of methane, carbon dioxide, carbon monoxide, hydrogen and dimethyl sulfide. The emission of other trace gases, namely C{sub 2} to C{sub 10} hydrocarbons, is also documented. We have carried out, both in the field and in the laboratory, measurements of methane emissions by Macrotermes subhyalinus (Macrotermitinae), Trinervitermes bettonianus (Termitinae), and unidentified Cubitermes and Microcerotermes species. Measured CH{sub 4} field flux rates ranged from 3.66 to 98.25g per m{sup 2} of termite mound per year. Laboratory measurements gave emission rates that ranged from 14.61 to 165.05 mg CH{sub 4} per termite per year. Gaseous production in all species sampled varied both within species and from species to species. Recalculated global emission of methane from termites was found to be 14.0 x 10{sup 12} g CH{sub 4}, per year. From our study, termites contribution to atmospheric methane content is between 1.11% and 4.25% per year. This study discusses the greenhouse effects as well as photochemical disposal of methane in the lower atmosphere in the tropics and the impacts on the chemistry of HO{sub x} systems and CL{sub x} cycles.

  15. Upper atmospheric effects of the hf active auroral research program ionospheric research instrument (HAARP IRI)

    SciTech Connect (OSTI)

    Eccles, V.; Armstrong, R.

    1993-05-01T23:59:59.000Z

    The earth's ozone layer occurs in the stratosphere, primarily between 10 and 30 miles altitude. The amount of ozone, O3, present is the result of a balance between production and destruction processes. Experiments have shown that natural processes such as auroras create molecules that destroy O. One family of such molecules is called odd nitrogen of which nitric oxide (NO) is an example. Because the HAARP (HF Active Auroral Research Program) facility is designed to mimic and investigate certain natural processes, a study of possible effects of HAARP on the ozone layer was conducted. The study used a detailed model of the thermal and chemical effects of the high power HF beam, which interacts with free electrons in the upper atmosphere above 50 miles altitude. It was found only a small fraction of the beam energy goes into the production of odd nitrogen molecules, whereas odd nitrogen is efficiently produced by auroras. Since the total energy emitted by HAARP in the year is some 200,000 times less than the energy deposited in the upper atmosphere by auroras, the study demonstrates that HAARP HF beam experiments will cause no measurable depletion of the earth's ozone layer.... Ozone, Ozone depletion, Ozone layer, Odd nitrogen, Nitric oxide, HAARP Emitter characteristics.

  16. Effect of atmospheric conditions on operation of terahertz systems for remote detection of ionizing materials

    SciTech Connect (OSTI)

    Nusinovich, Gregory S.; Kashyn, Dmytro G. [IREAP, University of Maryland, College Park, Maryland 20742-3511 (United States)] [IREAP, University of Maryland, College Park, Maryland 20742-3511 (United States); Tatematsu, Yoshinori; Idehara, Toshitaka [FIR Center, University of Fukui, Fukui 910-8507 (Japan)] [FIR Center, University of Fukui, Fukui 910-8507 (Japan)

    2014-01-15T23:59:59.000Z

    This study was motivated by a new concept of remote detection of concealed radioactive materials by using a high power terahertz (THz) wave beam, which can be focused in a small spot where the wave electric field exceeds the breakdown threshold. In the presence of seed electrons in such a volume, this focusing can initiate the avalanche breakdown. Typically, an ambient density of free electrons is assumed to be at the level of one particle per cubic centimeter. So, when a breakdown-prone volume is smaller than 1 cm{sup 3}, there should be significant difference between the breakdown rates in the case of presence of additional sources of ionization versus its absence. Since the flux density of gamma rays emitted by radioactive materials rapidly falls with the distance from the source, while the intensity of THz waves also decreases with the distance due to wave attenuation in the atmosphere, it is important to find an optimal location of the breakdown to be initiated for a given distance between a radioactive material and a THz antenna. This problem is analyzed in a given paper with the account for not only atmospheric attenuation of THz waves but also the air turbulence.

  17. ZnO PN Junctions for Highly-Efficient, Low-Cost Light Emitting Diodes

    SciTech Connect (OSTI)

    David P. Norton; Stephen Pearton; Fan Ren

    2007-09-30T23:59:59.000Z

    By 2015, the US Department of Energy has set as a goal the development of advanced solid state lighting technologies that are more energy efficient, longer lasting, and more cost-effective than current technology. One approach that is most attractive is to utilize light-emitting diode technologies. Although III-V compound semiconductors have been the primary focus in pursuing this objective, ZnO-based materials present some distinct advantages that could yield success in meeting this objective. As with the nitrides, ZnO is a direct bandgap semiconductor whose gap energy (3.2 eV) can be tuned from 3.0 to 4 eV with substitution of Mg for higher bandgap, Cd for lower bandgap. ZnO has an exciton binding energy of 60 meV, which is larger than that for the nitrides, indicating that it should be a superior light emitting semiconductor. Furthermore, ZnO thin films can be deposited at temperatures on the order of 400-600 C, which is significantly lower than that for the nitrides and should lead to lower manufacturing costs. It has also been demonstrated that functional ZnO electronic devices can be fabricated on inexpensive substrates, such as glass. Therefore, for the large-area photonic application of solid state lighting, ZnO holds unique potential. A significant impediment to exploiting ZnO in light-emitting applications has been the absence of effective p-type carrier doping. However, the recent realization of acceptor-doped ZnO material overcomes this impediment, opening the door to ZnO light emitting diode development In this project, the synthesis and properties of ZnO-based pn junctions for light emitting diodes was investigated. The focus was on three issues most pertinent to realizing a ZnO-based solid state lighting technology, namely (1) achieving high p-type carrier concentrations in epitaxial and polycrystalline films, (2) realizing band edge emission from pn homojunctions, and (3) investigating pn heterojunction constructs that should yield efficient light emission. The project engaged established expertise at the University of Florida in ZnO film growth (D. Norton), device fabrication (F. Ren) and wide bandgap photonics (S. Pearton). It addressed p-type doping and junction formation in (Zn,Mg)O alloy thin films. The project employed pulsed laser deposition for film growth. The p-type dopant of interest was primarily phosphorus, given the recent results in our laboratory and elsewhere that this anions can yield p-type ZnO-based materials. The role of Zn interstitials, oxygen vacancies, and/or hydrogen complexes in forming compensating shallow donor levels imposes the need to simultaneously consider the role of in situ and post-growth processing conditions. Temperature-dependent Hall, Seebeck, C-V, and resistivity measurements was used to determine conduction mechanisms, carrier type, and doping. Temperature-dependent photoluminescence was used to determine the location of the acceptor level, injection efficiency, and optical properties of the structures. X-ray diffraction will used to characterize film crystallinity. Using these materials, the fabrication and characterization of (Zn,Mg)O pn homojunction and heterojunction devices was pursued. Electrical characterization of the junction capacitance and I-V behavior was used to extract junction profile and minority carrier lifetime. Electroluminescence from biased junctions was the primary property of interest.

  18. New nonlinear mechanisms of midlatitude atmospheric low-frequency variability

    E-Print Network [OSTI]

    and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands Abstract

  19. Numerical solutions of sheath structures in front of an electron-emitting electrode immersed in a low-density plasma

    SciTech Connect (OSTI)

    Din, Alif [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, 44000 Islamabad (Pakistan)] [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, 44000 Islamabad (Pakistan)

    2013-09-15T23:59:59.000Z

    The exact theoretical expressions involved in the formation of sheath in front of an electron emitting electrode immersed in a low-density plasma have been derived. The potential profile in the sheath region has been calculated for subcritical, critical, and supercritical emissions. The potential profiles of critical and supercritical emissions reveals that we must take into account a small, instead of zero, electric field at the sheath edge to satisfy the boundary conditions used to integrate the Poisson's equation. The I-V curves for critical emission shows that only high values of plasma-electron to emitted-electron temperature ratio can meet the floating potential of the emissive electrode. A one-dimensional fluid like model is assumed for ions, while the electron species are treated as kinetic. The distribution of emitted-electron from the electrode is assumed to be half Maxwellian. The plasma-electron enters the sheath region at sheath edge with half Maxwellian velocity distribution, while the reflected ones have cut-off velocity distribution due to the absorption of super thermal electrons by the electrode. The effect of varying emitted-electron current on the sheath structure has been studied with the help of a parameter G (the ratio of emitted-electron to plasma-electron densities)

  20. Green route synthesis of high quality CdSe quantum dots for applications in light emitting devices

    SciTech Connect (OSTI)

    Bera, Susnata, E-mail: susnata.bera@gmail.com [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Singh, Shashi B. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Ray, S.K., E-mail: physkr@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2012-05-15T23:59:59.000Z

    Investigation was made on light emitting diodes fabricated using CdSe quantum dots. CdSe quantum dots were synthesized chemically using olive oil as the capping agent, instead of toxic phosphine. Room temperature photoluminescence investigation showed sharp 1st excitonic emission peak at 568 nm. Bi-layer organic/inorganic (P3HT/CdSe) hybrid light emitting devices were fabricated by solution process. The electroluminescence study showed low turn on voltage ({approx}2.2 V) .The EL peak intensity was found to increase by increasing the operating current. - Graphical abstract: Light emitting diode was fabricated using CdSe quantum dots using olive oil as the capping agent, instead of toxic phosphine. Bi-layer organic/inorganic (P3HT/CdSe) hybrid light emitting device shows strong electroluminescence in the range 630-661 nm. Highlights: Black-Right-Pointing-Pointer CdSe Quantum dots were synthesized using olive oil as the capping agent. Black-Right-Pointing-Pointer Light emitting device was fabricated using CdSe QDs/P3HT polymer heterojunction. Black-Right-Pointing-Pointer The I-V characteristics study showed low turn on voltage at {approx}2.2 V. Black-Right-Pointing-Pointer The EL peak intensity increases with increasing the operating current.

  1. Magnetized Atmospheres around Accreting Neutron Stars

    E-Print Network [OSTI]

    S. Zane; R. Turolla; A. Treves

    2000-02-01T23:59:59.000Z

    We present a detailed investigation of atmospheres around accreting neutron stars with high magnetic field ($B\\gtrsim 10^{12}$ G) and low luminosity ($L\\lesssim 10^{33}$ erg/s). We compute the atmospheric structure, intensity and emergent spectrum for a plane-parallel, pure hydrogen medium by solving the transfer equations for the normal modes coupled to the hydrostatic and energy balance equations. The hard tail found in previous investigations for accreting, non-magnetic neutron stars with comparable luminosity is suppressed and the X-ray spectrum, although still harder than a blackbody at the star effective temperature, is nearly planckian in shape. Spectra from accreting atmospheres, both with high and low fields, are found to exhibit a significant excess at optical wavelengths above the Rayleigh-Jeans tail of the X-ray continuum.

  2. Atmospheric Pressure Plasma Process And Applications

    SciTech Connect (OSTI)

    Peter C. Kong; Myrtle

    2006-09-01T23:59:59.000Z

    This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those produced in high intensity arcs, plasma torches, or in high intensity, high frequency discharges. Although nonthermal plasmas are at room temperatures, they are extremely effective in producing activated species, e.g., free radicals and excited state atoms. Thus, both thermal and nonthermal atmosphericpressure plasmas are finding applications in a wide variety of industrial processes, e.g. waste destruction, material recovery, extractive metallurgy, powder synthesis, and energy conversion. A brief discussion of recent plasma technology research and development activities at the Idaho National Laboratory is included.

  3. Super Kamiokande results: atmospheric and solar neutrinos

    E-Print Network [OSTI]

    M. Ishitsuka; for the Super-Kamiokande Collaboration

    2004-06-28T23:59:59.000Z

    Atmospheric neutrino and solar neutrino data from the first phase of Super-Kamiokande (SK-I) are presented. The observed data are used to study atmospheric and solar neutrino oscillations. Zenith angle distributions from various atmospheric neutrino data samples are used to estimate the neutrino oscillation parameter region. In addition, a new result of the $L/E$ measurement is presented. A dip in the $L/E$ distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The energy spectrum and the time variation such as day/night and seasonal differences of solar neutrino flux are measured in Super-Kamiokande. The neutrino oscillation parameters are strongly constrained from those measurements.

  4. Lifetime and Spectral Evolution of a Magma Ocean with a Steam Atmosphere: Its Detectability by Future Direct Imaging

    E-Print Network [OSTI]

    Hamano, Keiko; Abe, Yutaka; Onishi, Masanori; Hashimoto, George L

    2015-01-01T23:59:59.000Z

    We present the thermal evolution and emergent spectra of solidifying terrestrial planets along with the formation of steam atmospheres. The lifetime of a magma ocean and its spectra through a steam atmosphere depends on the orbital distance of the planet from the host star. For a type-I planet, which is formed beyond a certain critical distance from the host star, the thermal emission declines on a timescale shorter than approximately $10^6$ years. Therefore, young stars should be targets when searching for molten planets in this orbital region. In contrast, a type-II planet, which is formed inside the critical distance, will emit significant thermal radiation from near-infrared atmospheric windows during the entire lifetime of the magma ocean. The Ks and L bands will be favorable for future direct imaging because the planet-to-star contrasts of these bands are higher than approximately 10$^{-7}$-10$^{-8}$. Our model predicts that, in the type-II orbital region, molten planets would be present over the main s...

  5. Fabrication and Characterization of New Hybrid Organic Light Emitting Diode (OLED): Europium-picrate-triethylene oxide Complex

    SciTech Connect (OSTI)

    Sarjidan, M. A. Mohd; Abu Zakaria, N. Z. A.; Abd. Majid, W. H. [Solid State Research Laboratory, Department of Physics, University of Malaya, 50603, Kuala Lumpur (Malaysia); Kusrini, Eny; Saleh, M. I. [School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2009-07-07T23:59:59.000Z

    Thin-film light emitting devices based on organic materials have attracted vast interest in applications such as light emitting diode (LED) and flat-panel display. The organic material can be attached with inorganic material to enhance the performance of the light emitting device. A hybrid OLED based on a new complex of europium picrate (Eu-pic) with triethylene oxide (EO3) ligand is fabricated. The OLED is fabricated by using spin coating technique with acetone as the solvent and aluminum as the top electrode. The optical, photoluminescence (PL) and electrical properties of the sample are carried out by UV-Vis spectroscopy (Jasco V-750), luminescence spectroscopy (Perkin Elmer LS-500) and source measure unit (SMU)(Keithly), respectively.

  6. A Community Atmosphere Model with Superparameterized Clouds

    SciTech Connect (OSTI)

    Randall, David; Branson, Mark; Wang, Minghuai; Ghan, Steven J.; Craig, Cheryl; Gettelman, A.; Edwards, Jim

    2013-06-18T23:59:59.000Z

    In 1999, National Center for Atmospheric Research (NCAR) scientists Wojciech Grabowski and Piotr Smolarkiewicz created a "multiscale" atmospheric model in which the physical processes associated with clouds were represented by running a simple high-resolution model within each grid column of a lowresolution global model. In idealized experiments, they found that the multiscale model produced promising simulations of organized tropical convection, which other models had struggled to produce. Inspired by their results, Colorado State University (CSU) scientists Marat Khairoutdinov and David Randall created a multiscale version of the Community Atmosphere Model (CAM). They removed the cloud parameterizations of the CAM, and replaced them with Khairoutdinov's high-resolution cloud model. They dubbed the embedded cloud model a "super-parameterization," and the modified CAM is now called the "SP-CAM." Over the next several years, many scientists, from many institutions, have explored the ability of the SP-CAM to simulate tropical weather systems, the day-night changes of precipitation, the Asian and African monsoons, and a number of other climate processes. Cristiana Stan of the Center for Ocean-Land-Atmosphere Interactions found that the SP-CAM gives improved results when coupled to an ocean model, and follow-on studies have explored the SP-CAM's utility when used as the atmospheric component of the Community Earth System Model. Much of this research has been performed under the auspices of the Center for Multiscale Modeling of Atmospheric Processes, a National Science Foundation (NSF) Science and Technology Center for which the lead institution is CSU.

  7. Monte Carlo Simulation of Indoor External Exposure due to Gamma-emitting Radionuclides in Building Materials

    E-Print Network [OSTI]

    Jun Deng; Lei Cao; Xu Su

    2014-01-14T23:59:59.000Z

    The use of building materials containing naturally occurring radionuclides,such as K-40, U-238 and Th-232 and their progeny, could lead to external exposures of the residents of such buildings. In this paper, a set of models are set up to calculate the specific effective dose rates(the effective dose rate per Bq/kg of K-40, U-238 series, and Th-232 series) imposed to residents by building materials with MCNPX code. Effect of chemical composition, position concerned in the room and thickness as well as density of material is analyzed. In order to facilitate more precise assessment of indoor external dose due to gamma emitting radionuclides in building materials, three regressive expressions are proposed and validated by measured data to calculate specific effective rate for K-40, U-238 series and Th-232 series, respectively.

  8. Sidewall passivation for InGaN/GaN nanopillar light emitting diodes

    SciTech Connect (OSTI)

    Choi, Won Hyuck; Abraham, Michael; Yu, Shih-Ying [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); You, Guanjun; Liu, Jie; Wang, Li; Xu, Jian, E-mail: jianxu@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Mohney, Suzanne E., E-mail: mohney@ems.psu.edu [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-07-07T23:59:59.000Z

    We studied the effect of sidewall passivation on InGaN/GaN multiquantum well-based nanopillar light emitting diode (LED) performance. In this research, the effects of varying etch rate, KOH treatment, and sulfur passivation were studied for reducing nanopillar sidewall damage and improving device efficiency. Nanopillars prepared under optimal etching conditions showed higher photoluminescence intensity compared with starting planar epilayers. Furthermore, nanopillar LEDs with and without sulfur passivation were compared through electrical and optical characterization. Suppressed leakage current under reverse bias and four times higher electroluminescence (EL) intensity were observed for passivated nanopillar LEDs compared with unpassivated nanopillar LEDs. The suppressed leakage current and EL intensity enhancement reflect the reduction of non-radiative recombination at the nanopillar sidewalls. In addition, the effect of sulfur passivation was found to be very stable, and further insight into its mechanism was gained through transmission electron microscopy.

  9. Room-temperature spin-polarized organic light-emitting diodes with a single ferromagnetic electrode

    SciTech Connect (OSTI)

    Ding, Baofu, E-mail: b.ding@ecu.edu.au; Alameh, Kamal, E-mail: k.alameh@ecu.edu.au [Electron Science Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup WA 6027 Australia (Australia); Song, Qunliang [Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China)

    2014-05-19T23:59:59.000Z

    In this paper, we demonstrate the concept of a room-temperature spin-polarized organic light-emitting diode (Spin-OLED) structure based on (i) the deposition of an ultra-thin p-type organic buffer layer on the surface of the ferromagnetic electrode of the Spin-OLED and (ii) the use of oxygen plasma treatment to modify the surface of that electrode. Experimental results demonstrate that the brightness of the developed Spin-OLED can be increased by 110% and that a magneto-electroluminescence of 12% can be attained for a 150?mT in-plane magnetic field, at room temperature. This is attributed to enhanced hole and room-temperature spin-polarized injection from the ferromagnetic electrode, respectively.

  10. Green cubic GaInN/GaN light-emitting diode on microstructured silicon (100)

    SciTech Connect (OSTI)

    Stark, Christoph J. M.; Detchprohm, Theeradetch; Wetzel, Christian, E-mail: wetzel@ieee.org [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States) [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Future Chips Constellation, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States); Lee, S. C.; Brueck, S. R. J. [Department of Electrical and Computer Engineering and Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 (United States)] [Department of Electrical and Computer Engineering and Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 (United States); Jiang, Y.-B. [Department of Earth and Planetary Science, University of New Mexico, Albuquerque, New Mexico 87131 (United States)] [Department of Earth and Planetary Science, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2013-12-02T23:59:59.000Z

    GaInN/GaN light-emitting diodes free of piezoelectric polarization were prepared on standard electronic-grade Si(100) substrates. Micro-stripes of GaN and GaInN/GaN quantum wells in the cubic crystal structure were grown on intersecting (111) planes of microscale V-grooved Si in metal-organic vapor phase epitaxy, covering over 50% of the wafer surface area. Crystal phases were identified in electron back-scattering diffraction. A cross-sectional analysis reveals a cubic structure virtually free of line defects. Electroluminescence over 20 to 100??A is found fixed at 487?nm (peak), 516?nm (dominant). Such structures therefore should allow higher efficiency, wavelength-stable light emitters throughout the visible spectrum.

  11. Photonic crystal light emitting diode based on Er and Si nanoclusters co-doped slot waveguide

    SciTech Connect (OSTI)

    Lo Savio, R.; Galli, M.; Liscidini, M.; Andreani, L. C. [Dipartimento di Fisica, Universitŕ di Pavia, Via Bassi 6, 27100 Pavia (Italy); Franzň, G.; Iacona, F.; Miritello, M. [MATIS-IMM CNR and Dipartimento di Fisica e Astronomia, Universitŕ di Catania, via S. Sofia 64, 95123 Catania (Italy); Irrera, A. [CNR-IPCF, Viale Ferdinando Stagno d'Alcontres 37, 98158 Messina (Italy); Sanfilippo, D.; Piana, A. [ST Microelectronics, Stradale Primosole 50, 95121 Catania (Italy); Priolo, F. [MATIS-IMM CNR and Dipartimento di Fisica e Astronomia, Universitŕ di Catania, via S. Sofia 64, 95123 Catania (Italy); Scuola Superiore di Catania, Universitŕ di Catania, Via Valdisavoia 9, 95123 Catania (Italy)

    2014-03-24T23:59:59.000Z

    We report on the design, fabrication, and electro-optical characterization of a light emitting device operating at 1.54??m, whose active layer consists of silicon oxide containing Er-doped Si nanoclusters. A photonic crystal (PhC) is fabricated on the top-electrode to enhance the light extraction in the vertical direction, and thus the external efficiency of the device. This occurs if a photonic mode of the PhC slab is resonant with the Er emission energy, as confirmed by theoretical calculations and experimental analyses. We measure an increase of the extraction efficiency by a factor of 3 with a high directionality of light emission in a narrow vertical cone. External quantum efficiency and power efficiency are among the highest reported for this kind of material. These results are important for the realization of CMOS-compatible efficient light emitters at telecom wavelengths.

  12. Ultrastrong light-matter coupling in electrically doped microcavity organic light emitting diodes

    SciTech Connect (OSTI)

    Mazzeo, M., E-mail: marco.mazzeo@unisalento.it [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Universitŕ del Salento, Via Monteroni, 73100 Lecce (Italy); NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); Genco, A. [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Universitŕ del Salento, Via Monteroni, 73100 Lecce (Italy); Gambino, S. [NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); CBN, Istituto Italiano Tecnologia, Via Barsanti 1, 73010 Lecce (Italy); Ballarini, D.; Mangione, F.; Sanvitto, D. [NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); Di Stefano, O.; Patanč, S.; Savasta, S. [Dipartimento di Fisica e Scienze della Terra, Universitŕ di Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina (Italy); Gigli, G. [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Universitŕ del Salento, Via Monteroni, 73100 Lecce (Italy); NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); CBN, Istituto Italiano Tecnologia, Via Barsanti 1, 73010 Lecce (Italy)

    2014-06-09T23:59:59.000Z

    The coupling of the electromagnetic field with an electronic transition gives rise, for strong enough light-matter interactions, to hybrid states called exciton-polaritons. When the energy exchanged between light and matter becomes a significant fraction of the material transition energy an extreme optical regime called ultrastrong coupling (USC) is achieved. We report a microcavity embedded p-i-n monolithic organic light emitting diode working in USC, employing a thin film of squaraine dye as active layer. A normalized coupling ratio of 30% has been achieved at room temperature. These USC devices exhibit a dispersion-less angle-resolved electroluminescence that can be exploited for the realization of innovative optoelectronic devices. Our results may open the way towards electrically pumped polariton lasers.

  13. A spin light emitting diode incorporating ability of electrical helicity switching

    SciTech Connect (OSTI)

    Nishizawa, N., E-mail: nishizawa@isl.titech.ac.jp; Nishibayashi, K.; Munekata, H. [Imaging Science and Engineering Laboratory, Tokyo Institute of Technology, 4259-J3-15 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

    2014-03-17T23:59:59.000Z

    Fabrication and optical characteristics of a spin light-emitting-diode (spin-LED) having dual spin-injection electrodes with anti-parallel magnetization configuration are reported. Alternating a current between the two electrodes using a computer-driven current source has led us to the observation of helicity switching of circular polarization at the frequency of 1 kHz. Neither external magnetic fields nor optical delay modulators were used. Sending dc-currents to both electrodes with appropriate ratio has resulted in continuous variation of circular polarization between the two opposite helicity, including the null polarization. These results suggest that the tested spin-LED has the feasibility of a monolithic light source whose circular polarization can be switched or continuously tuned all electrically.

  14. Frequency-doubled vertical-external-cavity surface-emitting laser

    DOE Patents [OSTI]

    Raymond, Thomas D. (Edgewood, NM); Alford, William J. (Albuquerque, NM); Crawford, Mary H. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A frequency-doubled semiconductor vertical-external-cavity surface-emitting laser (VECSEL) is disclosed for generating light at a wavelength in the range of 300-550 nanometers. The VECSEL includes a semiconductor multi-quantum-well active region that is electrically or optically pumped to generate lasing at a fundamental wavelength in the range of 600-1100 nanometers. An intracavity nonlinear frequency-doubling crystal then converts the fundamental lasing into a second-harmonic output beam. With optical pumping with 330 milliWatts from a semiconductor diode pump laser, about 5 milliWatts or more of blue light can be generated at 490 nm. The device has applications for high-density optical data storage and retrieval, laser printing, optical image projection, chemical-sensing, materials processing and optical metrology.

  15. Microwave-emitting rotor, separator apparatus including same, methods of operation and design thereof

    DOE Patents [OSTI]

    Meikrantz, David H.

    2006-12-19T23:59:59.000Z

    An apparatus for use in separating, at least in part, a mixture, including at least one chamber and at least one microwave generation device configured for communicating microwave energy into the at least one chamber is disclosed. The rotor assembly may comprise an electric generator for generating electricity for operating the microwave generation device. At least one microwave generation device may be positioned within a tubular interior shaft extending within the rotor assembly. At least a portion of the tubular interior shaft may be substantially transparent to microwave energy. Microwave energy may be emitted in an outward radial direction or toward an anticipated boundary surface defined between a mixture and a separated constituent thereof. A method including flowing a mixture through at least one chamber and communicating microwave energy into the at least one chamber while rotating same is disclosed. Methods of operating a centrifugal separator and design thereof are disclosed.

  16. Amorphous silicon as electron transport layer for colloidal semiconductor nanocrystals light emitting diode

    SciTech Connect (OSTI)

    Song Tao; Shen Xiaojuan; Sun Baoquan [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Functional Nano and Soft Materials Laboratory (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123 (China); Zhang Fute [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Functional Nano and Soft Materials Laboratory (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123 (China); Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering, Soochow University, Suzhou 215123 (China); Zhang Xiaohong [Nano-Organic Photoelectronic Laboratory and Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Zhu Xiulin [Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering, Soochow University, Suzhou 215123 (China)

    2009-12-07T23:59:59.000Z

    We demonstrate the fabrication of light-emitting diodes (LEDs) made from all-inorganic colloidal semiconducting nanocrystals (NCs). The diode utilizes a sandwich structure formed by placing CdSe/CdS NCs between two layers of Si and Ag{sub x}O, which act as electron- and hole-transporting materials, respectively. The photoluminescence properties of NCs are rendered less dependent upon surface chemistry and chemical environment by growing a thick CdS shell. It also enhances stability of the NCs during the process of magnetron sputtering for silicon deposition. The resulting LED device exhibits a low turn-on voltage of 2.5 V and the maximum external quantum efficiency of nearly 0.08%.

  17. Thermal And Mechanical Analysis of High-power Light-emitting Diodes with Ceramic Packages

    E-Print Network [OSTI]

    J. Hu; L. Yang; M. -W. Shin

    2008-01-07T23:59:59.000Z

    In this paper we present the thermal and mechanical analysis of high-power light-emitting diodes (LEDs) with ceramic packages. Transient thermal measurements and thermo-mechanical simulation were performed to study the thermal and mechanical characteristics of ceramic packages. Thermal resistance from the junction to the ambient was decreased from 76.1 oC/W to 45.3 oC/W by replacing plastic mould to ceramic mould for LED packages. Higher level of thermo-mechanical stresses in the chip were found for LEDs with ceramic packages despite of less mismatching coefficients of thermal expansion comparing with plastic packages. The results suggest that the thermal performance of LEDs can be improved by using ceramic packages, but the mounting process of the high power LEDs with ceramic packages is critically important and should be in charge of delaminating interface layers in the packages.

  18. Adhesion and degradation of organic and hybrid organic-inorganic light-emitting devices

    SciTech Connect (OSTI)

    Momodu, D. Y.; Chioh, A. V. [Department of Materials Science and Engineering, African University of Science and Technology, Federal Capital Territory, Abuja (Nigeria); Tong, T. [Department of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Princeton Institute of Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey 08544 (United States); Zebaze Kana, M. G. [Physics Advanced Laboratory, Sheda Science and Technology Complex, Abuja (Nigeria); Department of Materials Science and Engineering, Kwara State University, Malete (Nigeria); Soboyejo, W. O. [Department of Materials Science and Engineering, African University of Science and Technology, Federal Capital Territory, Abuja (Nigeria); Princeton Institute of Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-02-28T23:59:59.000Z

    This paper presents the results of a combined analytical, computational, and experimental study of adhesion and degradation of Organic Light Emitting Devices (OLEDs). The adhesion between layers that are relevant to OLEDs is studied using an atomic force microscopy technique. The interfacial failure mechanisms associated with blister formation in OLEDs and those due to the addition of TiO{sub 2} nanoparticles into the active regions are then elucidated using a combination of fracture mechanics, finite element modeling and experiments. The blisters observed in the models are shown to be consistent with the results from adhesion, interfacial fracture mechanics models, and prior reports of diffusion-assisted phenomena. The implications of the work are then discussed for the design of OLED structures with improved lifetimes and robustness.

  19. Ultra-thin ohmic contacts for p-type nitride light emitting devices

    DOE Patents [OSTI]

    Raffetto, Mark; Bharathan, Jayesh; Haberern, Kevin; Bergmann, Michael; Emerson, David; Ibbetson, James; Li, Ting

    2014-06-24T23:59:59.000Z

    A flip-chip semiconductor based Light Emitting Device (LED) can include an n-type semiconductor substrate and an n-type GaN epi-layer on the substrate. A p-type GaN epi-layer can be on the n-type GaN epi-layer and a metal ohmic contact p-electrode can be on the p-type GaN epi-layer, where the metal ohmic contact p-electrode can have an average thickness less than about 25 .ANG.. A reflector can be on the metal ohmic contact p-electrode and a metal stack can be on the reflector. An n-electrode can be on the substrate opposite the n-type GaN epi-layer and a bonding pad can be on the n-electrode.

  20. Characterizing Ion Profiles in Dynamic Junction Light-Emitting Electrochemical Cells

    SciTech Connect (OSTI)

    Shoji, Tyko D.; Zhu, Zihua; Leger, Janelle M.

    2013-11-27T23:59:59.000Z

    Organic semiconductors have the unique ability to conduct both ionic and electronic charge carriers in thin films, an emerging advantage in applications such as light-emitting devices, transistors, and electrochromic devices, among others. Evidence suggests that the profiles of ions and electrochemical doping in the polymer film during operation significantly impact the performance and stability of the device. However, few studies have directly characterized ion profiles within LECs. Here, we present profiles of ion distributions in LECs following application of voltage, via time-of-flight secondary ion mass spectrometry. Ion distributions were characterized with regard to film thickness, salt concentration, applied voltage, and relaxation over time. Results provide insight into the correlation between ion profiles and device performance, as well as potential approaches to tuning electrochemical doping processes in LECs.