Sample records for high brightness led

  1. Sandia National Laboratories: high-brightness LED

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

    Partnership, Research & Capabilities, Solid-State Lighting Solid state lighting (SSL), which uses light-emitting diodes (LEDs), has the potential to be 10 times more energy...

  2. Low Cost Lithography Tool for High Brightness LED Manufacturing

    SciTech Connect (OSTI)

    Andrew Hawryluk; Emily True

    2012-06-30T23:59:59.000Z

    The objective of this activity was to address the need for improved manufacturing tools for LEDs. Improvements include lower cost (both capital equipment cost reductions and cost-ofownership reductions), better automation and better yields. To meet the DOE objective of $1- 2/kilolumen, it will be necessary to develop these highly automated manufacturing tools. Lithography is used extensively in the fabrication of high-brightness LEDs, but the tools used to date are not scalable to high-volume manufacturing. This activity addressed the LED lithography process. During R&D and low volume manufacturing, most LED companies use contact-printers. However, several industries have shown that these printers are incompatible with high volume manufacturing and the LED industry needs to evolve to projection steppers. The need for projection lithography tools for LED manufacturing is identified in the Solid State Lighting Manufacturing Roadmap Draft, June 2009. The Roadmap states that Projection tools are needed by 2011. This work will modify a stepper, originally designed for semiconductor manufacturing, for use in LED manufacturing. This work addresses improvements to yield, material handling, automation and throughput for LED manufacturing while reducing the capital equipment cost.

  3. LED Record Efficacy and Brightness

    Broader source: Energy.gov [DOE]

    Designed for general lighting applications such as street, industrial, and parking garage lighting, the Cree XLamp® power LED sets new records for LED brightness and efficacy, up to 85 lm/W at 350 mA. The XLamp utilizes Cree's performance breakthrough EZBright™ LED chip; both products include technology that was developed in part with R&D funding support from DOE.

  4. Optical Wireless based on High Brightness Visible LEDs Grantham Pang, Thomas Kwan, Hugh Liu, Chi-Ho Chan

    E-Print Network [OSTI]

    Pang, Grantham

    and encoded with audio or data signal. Hence, an LED indicator lamp or traffic light can become an information for incandescent lamps [3,4]. This advancement has led to the production of large- area full-color LED displaysOptical Wireless based on High Brightness Visible LEDs Grantham Pang, Thomas Kwan, Hugh Liu, Chi

  5. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 17, NO. 4, JULY/AUGUST 2011 971 Highly Efficient and Bright LEDs Overgrown

    E-Print Network [OSTI]

    Efficient and Bright LEDs Overgrown on GaN Nanopillar Substrates Ching-Hsueh Chiu, Po-Min Tu, Chien emitting diodes (LEDs) using a GaN nanopillars (NPs) structure grown on sapphire substrate by integrating. However, lack of a suitable, inexpensive substrate restrains the improve- ment of GaN-based devices. Even

  6. High brightness electron accelerator

    DOE Patents [OSTI]

    Sheffield, Richard L. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM); Young, Lloyd M. (Los Alamos, NM)

    1994-01-01T23:59:59.000Z

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  7. Cree Sets New Benchmarks for LED Efficacy and Brightness

    Broader source: Energy.gov [DOE]

    Cree has successfully created a cool white LED prototype that delivers 107 lm/W at 350mA. This achievement builds on the Cree EZBright® LED chip platform, developed in part with prior funding support from DOE. Cree made the prototype LED under their DOE project focused on developing LED chips incorporating photonic crystal elements for improved light extraction and novel package technology for higher down-conversion efficiency compared to conventional LEDs. Based on a 1 millimeter-square chip, the new prototype LED produces white light with a CCT of 5500K and a CRI of 73. Integration of four of these prototype LEDs can produce luminous flux of more than 450 lumens.

  8. Multicolor, High Efficiency, Nanotextured LEDs

    SciTech Connect (OSTI)

    Jung Han; Arto Nurmikko

    2011-09-30T23:59:59.000Z

    We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and green for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) heteroepitaxy of nitrogen-polar LEDs on sapphire, (ii) heteroepitaxy of semipolar (11{bar 2}2) green LEDs on sapphire, (iii) synthesis of quantum-dot loaded nanoporous GaN that emits white light without phosphor conversion, (iv) demonstration of the highest quality semipolar (11{bar 2}2) GaN on sapphire using orientation-controlled epitaxy, (v) synthesis of nanoscale GaN and InGaN medium, and (vi) development of a novel liftoff process for manufacturing GaN thin-film vertical LEDs. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

  9. High Power UV LED Industrial Curing Systems

    SciTech Connect (OSTI)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14T23:59:59.000Z

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  10. White LED with High Package Extraction Efficiency

    SciTech Connect (OSTI)

    Yi Zheng; Matthew Stough

    2008-09-30T23:59:59.000Z

    The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W{sub e} using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat generated in the package may cause a deterioration of encapsulant materials, affecting the performance of both the LED die and phosphor, leading to a decrease in the luminous efficacy over lifetime. Recent studies from research groups at Rensselaer Polytechnic Institute found that, under the condition to obtain a white light, about 40% of the light is transmitted outward of the phosphor layer and 60% of the light is reflected inward.1,2 It is claimed that using scattered photon extraction (SPE) technique, luminous efficacy is increased by 60%. In this project, a transparent/translucent monolithic phosphor was used to replace the powdered phosphor layer. In the normal pcLED package, the powdered phosphor is mixed with silicone either to be deposited on the top of LED die forming a chip level conversion (CLC) white LED or to be casted in the package forming a volume conversion white LED. In the monolithic phosphors there are no phosphor powder/silicone interfaces so it can reduce the light scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is inserted in the white LED package between the blue LED die and phosphor layer. It will selectively transmit the blue light from the LED die and reflect the phosphor's yellow inward emission outward. The two technologies try to recover backward light to the outward direction in the pcLED package thereby improving the package extraction efficiency.

  11. High output lamp with high brightness

    DOE Patents [OSTI]

    Kirkpatrick, Douglas A. (Great Falls, VA); Bass, Gary K. (Mt. Airy, MD); Copsey, Jesse F. (Germantown, MD); Garber, Jr., William E. (Poolesville, MD); Kwong, Vincent H. (Vancouver, CA); Levin, Izrail (Silver Spring, MD); MacLennan, Donald A. (Gaithersburg, MD); Roy, Robert J. (Frederick, MD); Steiner, Paul E. (Olney, MD); Tsai, Peter (Olney, MD); Turner, Brian P. (Damascus, MD)

    2002-01-01T23:59:59.000Z

    An ultra bright, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.

  12. White LED with High Package Extraction Efficiency

    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 item youTheWSRC-TR-97-0100WHITE LED WITH HIGH PACKAGE

  13. New and Underutilized Technology: High Bay LED Lighting

    Broader source: Energy.gov [DOE]

    The following information outlines key deployment considerations for high bay LED lighting within the Federal sector.

  14. High Performance Green LEDs by Homoepitaxial

    SciTech Connect (OSTI)

    Wetzel, Christian; Schubert, E Fred

    2009-11-22T23:59:59.000Z

    This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.

  15. New Family of Tiny Crystals Glow Bright in LED Lights | Advanced...

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

    crystals that glow different colors may be the missing ingredient for white light-emitting diode (LED) lighting that illuminates homes and offices as effectively as natural...

  16. Veeco Develops a Tool to Reduce Epitaxy Costs and Increase LED Brightness

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, Veeco is working on reducing epitaxy costs and increasing LED efficiency by developing a physical vapor deposition (PVD) tool for depositing aluminum nitride buffer layers on LED substrates. PVD, also known as "sputtering," is an alternative to metal-organic chemical vapor deposition (MOCVD). PVD is a purely physical process that involves plasma sputter bombardment rather than a chemical reaction at the surface to be coated, as in MOCVD.

  17. A high brightness field emission display

    SciTech Connect (OSTI)

    Palevsky, A. [Raytheon Co., Quincy, MA (United States)

    1996-12-31T23:59:59.000Z

    The military requirement for avionics display performance requires that displays be legible with 10,000 foot-candles (fc) bright light shining into the pilot`s eyes, or 10,000 fc shining directly on the display. The contrast ratio under these conditions must be at least 4.66:1. In addition, instant-on operation is sought for temperatures as low as {minus}54 C. Currently these specifications can barely be met by monochrome CRTs whose use is counter-indicated by other factors. No color display can achieve optimum performance in the areas mentioned, nor do any current contenders, primarily AMLCD`s, have any prospects of achieving full compliance. The FED being developed by Raytheon shows strong promise of being able to achieve the brightness and contrast ratios desired. The FED is also inherently able to provide instant-on functionality at any terrestrial temperature and does not require any heating at low temperatures. The technical objective of the Raytheon development program is to develop a high performance, full color, FED Panel that meets the performance and environmental operating condition requirements specified for military and other high performance display applications.

  18. High-Throughput, High-Precision Hot Testing Tool for High-Brightness...

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

    Throughput, High-Precision Hot Testing Tool for High-Brightness Light-Emitting Diode Testing High-Throughput, High-Precision Hot Testing Tool for High-Brightness Light-Emitting...

  19. Building highly efficient LEDs in the yellow-green spectrum

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    Argonne and Purdue researchers are peering deep into the atomic structure and composition of LED lights in order to build highly efficient LEDs in the yellow-green spectrum.

  20. New GATEWAY Report Monitors LED System Performance in a High...

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

    the light. The Yuma site is an extreme environment: high ambient temperatures and direct solar radiation heat up the luminaires throughout the day, and at sunset the LED...

  1. Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes

    SciTech Connect (OSTI)

    Dr. Anatoly Shteynberg, PhD

    2006-08-17T23:59:59.000Z

    This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

  2. Extremely High Current, High-Brightness Energy Recovery Linac

    SciTech Connect (OSTI)

    I. Ben-Zvi; D.S. Barton; D.B. Beavis; M. Blaskiewicz; J.M. Brennan; A. Burrill; R. Calaga; P. Cameron; X.Y. Chang; R. Connolly; D.M. Gassner; J.G. Grimes; H. Hahn; A. Hershcovitch; H.-C. Hseuh; P.D.J. Johnson; D. Kayran; J. Kewisch; R.F. Lambiase; V. Litvinenko; G.T. McIntyre; W. Meng; T.C.N. Nehring; T. Nicoletti; B. Oerter; D. Pate; J. Rank; T. Rao; T. Roser; T. Russo; J. Scaduto; Z. Segalov; K. Smith; N.W.W. Williams; K.-C. Wu; V. Yakimenko; K. Yip; A. Zaltsman; Y. Zhao; H. Bluem; A. Burger; M.D. Cole; A.J. Favale; D. Holmes; J. Rathke; T. Schultheiss; A.M.M. Todd; J.R. Delayen; L. W. Funk; P. Kneisel; H.L. Phillips; J.P. Preble

    2005-05-16T23:59:59.000Z

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  3. Proposal for a High-Brightness Pulsed Electron Source

    SciTech Connect (OSTI)

    Zolotorev, Max; Commins, Eugene D.; Heifets, Sam; Sannibale,Fernando

    2006-03-15T23:59:59.000Z

    We propose a novel scheme for a high-brightness pulsedelectron source, which has the potential for many useful applications inelectron microscopy, inverse photo-emission, low energy electronscattering experiments, and electron holography. A description of theproposed scheme is presented.

  4. High Brightness Beam Applications: Energy Recovered Linacs

    SciTech Connect (OSTI)

    Geoffrey A. Krafft

    2005-09-01T23:59:59.000Z

    In the first part of the paper some general statements are made regarding applications suitable for utilizing energy recovered linacs (ERLs) by contrasting their potential performance to that of single pass linacs and storage rings. As a result of their potential for extremely good beam quality in combination with high average beam current, ERLs have been used and considered as drivers of both free electron laser and partially coherent photon sources, from THz through X-rays; as a suitable technology for high energy electron cooling; and as a continuous or semi-continuous electron beam source for high energy colliders. At present, beam requirements tend to be highly matched to end use requirements. By reviewing some of the many examples which have either been reduced to practice, or are being explored presently, one can develop an appreciation for the wide range of parameters being considered in ERL applications.

  5. OSRAM SYLVANIA Develops High-Efficiency LED Troffer Replacement

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, OSRAM SYLVANIA is developing a high-efficiency LED 2'x2' troffer replacement that is expected to be commercially available in the spring of 2012 and to be cost-competitive with existing troffers of that size. It is projected to have a light output of up to 4,000 lumens, an efficacy of more than 100 lm/W, and a CCT of 3500K.

  6. Proposal for a High-Brightness Pulsed Electron Source

    SciTech Connect (OSTI)

    Zolotorev, M.; Commins, E.D.; Heifets, S.; Sannibale, F.; /LBL, Berkeley /UC, Berkeley /SLAC

    2006-10-16T23:59:59.000Z

    We propose a novel scheme for a high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography. A description of the proposed scheme is presented.

  7. High Efficacy Green LEDs by Polarization Controlled MOVPE

    SciTech Connect (OSTI)

    Wetzel, Christian

    2013-03-31T23:59:59.000Z

    Amazing performance in GaInN/GaN based LEDs has become possible by advanced epitaxial growth on a wide variety of substrates over the last decade. An immediate push towards product development and worldwide competition for market share have effectively reduced production cost and generated substantial primary energy savings on a worldwide scale. At all times of the development, this economic pressure forced very fundamental decisions that would shape huge industrial investment. One of those major aspects is the choice of epitaxial growth substrate. The natural questions are to what extend a decision for a certain substrate will limit the ultimate performance and to what extent, the choice of a currently more expensive substrate such as native GaN could overcome any of the remaining performance limitations. Therefore, this project has set out to explore what performance characteristic could be achieved under the utilization of bulk GaN substrate. Our work was guided by the hypotheses that line defects such as threading dislocations in the active region should be avoided and the huge piezoelectric polarization needs to be attenuated – if not turned off – for higher performing LEDs, particularly in the longer wavelength green and deep green portions of the visible spectrum. At their relatively lower performance level, deep green LEDs are a stronger indicator of relative performance improvements and seem particular sensitive to the challenges at hand. The project therefore made use of recently developed non-polar and semipolar bulk GaN substrates that were made available at Kyma Technologies by crystallographic cuts from thick polar growth of GaN. This approach naturally leads to rather small pieces of substrates, cm along the long side while mm along the short one. Small size and limited volume of sample material therefore set the limits of the ensuing development work. During the course of the project we achieved green and deep green LEDs in all those crystal growth orientations: polar c-plane, non- polar a-plane, non-polar m-plane, and semipolar planes. The active region in those structures shows dramatically reduced densities of threading dislocations unless the wavelength was extended as far as 510 nm and beyond. With the appearance of such defects, the light output power dropped precipitously supporting the necessity to avoid any and all of such defects to reach the active region. Further aspects of the non-polar growth orientation proved extremely promising for the development of such structures. Chief among them is our success to achieve extremely uniform quantum wells in these various crystal orientations that prove devoid of any alloy fluctuation beyond the theoretical limit of a binominal distribution. This became very Rensselaer Wetzel DE?EE0000627 3 directly apparent in highly advanced atom probe tomography performed in collaboration at Northwestern University. Furthermore, under reduced or absence of piezoelectric polarization, green emitters in those growth geometries exhibit an unsurpassed wavelength stability over very wide excitation and drive current ranges. Such a performance had not been possible in any polar c-plane growth and now places green LEDs in terms of wavelength stability up par with typical 450 nm blue emitters. The project also incorporated enabling opportunities in the development of micro and nano- patterned substrate technologies. Originally developped as a means to enhance generated light extraction we have demonstrated that the method of nano-patterning, in contrast to micro- patterning also results in a substantial reduction of threading dislocation generation. In green LEDs, we thereby see equal contributions of enhanced light extraction and reduced defect generation to a threefold enhancement of the green light output power. These results have opened entirely new approaches for future rapid and low cost epitaxial material development by avoidance of thick defect accommodation layers. All methods developed within this project have meanwhile widely been publicized by the members o

  8. Solid-State Lighting with High Brightness, High Efficiency, and Low Cost

    E-Print Network [OSTI]

    Gilchrist, James F.

    -based lamp for lighthouse application were discussed at the system level ("Implementation and test of a LED- based lamp for a lighthouse" by L. Mercatelli et al.). Such applications of LED in lighthouse have-emitting diode (LED) is the most popular technique due to its advantages of small volume, long lifetime, high

  9. Proceedings of the third ICFA mini-workshop on high intensity, high brightness hadron accelerators

    SciTech Connect (OSTI)

    Roser, T.

    1997-11-01T23:59:59.000Z

    The third mini-workshop on high intensity, high brightness hadron accelerators was held at Brookhaven National Laboratory on May 7-9, 1997 and had about 30 participants. The workshop focussed on rf and longitudinal dynamics issues relevant to intense and/or bright hadron synchrotrons. A plenary session was followed by four sessions on particular topics. This document contains copies of the viewgraphs used as well as summaries written by the session chairs.

  10. High Brightness Plasmon-Enhanced Nanostructured Gold Photoemitters

    SciTech Connect (OSTI)

    Gong, Yu; Joly, Alan G.; Kong, Lingmei; El-Khoury, Patrick Z.; Hess, Wayne P.

    2014-12-30T23:59:59.000Z

    Plasmonic nanohole arrays are fabricated in gold thin films by focused ion beam (FIB) lithography. Subsequent heat treatment creates sub 100 nm nanometric structures including tips, rods and flakes, all localized in the nanohole array region. The combined nanohole array and nanostructured surface comprise an efficient photoemitter. High brightness photoemission is observed from this construct using photoemission electron microscopy (PEEM), following 780 nm femtosecond (fs) laser irradiation. By comparing our observables to results of finite difference time domain (FDTD) calculations, we demonstrate that photoemission from the sub-100 nm structures is enhanced in the region of propagating surface plasmons launched from the nanohole arrays. Additionally, by tuning hole diameter and separation in the nanohole array, the photoemission intensity of nanostructured photoemitters can be controlled. We observe a photoemission enhancement of over 108, relative to photoemission from the flat region of the gold substrate at laser intensities well below the ablation threshold.

  11. UV-LED LITHOGRAPHY FOR 3-D HIGH ASPECT RATIO MICROSTRUCTURE PATTERNING

    E-Print Network [OSTI]

    in microfabrication. Table 1 compares the performance of UV-LEDs with a mercury lamp for several key parametersUV-LED LITHOGRAPHY FOR 3-D HIGH ASPECT RATIO MICROSTRUCTURE PATTERNING Jungkwun `JK' Kim*, Seung of Technology, Atlanta, GA, USA ABSTRACT This paper presents a UV lithography method that utilizes a UV-LED

  12. Fabrication of a High-Brightness Blue-Light-Emitting Diode Using a ZnO-Nanowire Array Grown on p-GaN

    E-Print Network [OSTI]

    Wang, Zhong L.

    Fabrication of a High-Brightness Blue-Light-Emitting Diode Using a ZnO-Nanowire Array Grown on p-GaN of metal organic chemical vapor deposition (MOCVD), gallium nitride (GaN) has become the most important GaN nanowires (NWs) have also been fabricated, and nanoLEDs are an active field of research.[5

  13. Scalable Light Module for Low-Cost, High Efficiency LED Luminaires...

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

    Low-Cost, High Efficiency LED Luminaires More Documents & Publications Low-Cost Light-Emitting Diode Luminaire for General Illumination 2015 Project Portfolio 2014 Solid-State...

  14. Concepts for Phosphorescent Organic LEDs at High Brightness | MIT-Harvard

    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 3,625govInstrumentstdmadapInactiveVisiting theCommercialization andComputer SimulationsConcentrating Solar

  15. OPTICS FOR HIGH BRIGHTNESS AND HIGH CURRENT ERL PROJECT AT BNL.

    SciTech Connect (OSTI)

    KAYRAN, D.; BEN-ZVI, I.; CALAGA, R.; CHANG, X.Y.; ET AL.

    2005-05-16T23:59:59.000Z

    An energy recovery linac (ERL), under development at Brookhaven National Laboratory [1,2], will push ERLs further towards high current and high brightness beams. This R&D ERL will operate in two modes: a high current mode and a high charge mode. In this paper we present a lattice of the machine and PARMELA simulations from the cathode to the beam dump. We discuss the design considerations and present main parameters for various modes of operation.

  16. Department of Mechanical Engineering Spring 2013 Lumax Lighting 2: LED Industrial High Bay Light Fixture

    E-Print Network [OSTI]

    Demirel, Melik C.

    PENNSTATE Department of Mechanical Engineering Spring 2013 Lumax Lighting 2: LED Industrial High Bay Light Fixture Overview The problem that our sponsor, Rich Taylor, presented to the team was to design a light fixture for an industrial setting using high power LED lights. The challenge

  17. High Efficiency LED Lamp for Solid-State Lighting

    SciTech Connect (OSTI)

    James Ibbetson

    2006-12-31T23:59:59.000Z

    This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency, solid-state lamps based on gallium nitride/silicon carbide light-emitting diodes. Novel chip designs and fabrication processes are described for a new type of nitride light-emitting diode with the potential for very high efficiency. This work resulted in the demonstration of blue light-emitting diodes in the one watt class that achieved up to 495 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 51% and 45%, respectively. When combined with a phosphor in Cree's 7090 XLamp package, these advanced blue-emitting devices resulted in white light-emitting diodes whose efficacy exceeded 85 lumens per watt. In addition, up to 1040 lumens at greater than 85 lumens per watt was achieved by combining multiple devices to make a compact white lamp module with high optical efficiency.

  18. High-brightness switchable multiwavelength remote laser in air

    SciTech Connect (OSTI)

    Yao Jinping; Cheng Ya; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Zeng Bin; Li Guihua; Chu Wei; Ni Jielei; Zhang Haisu [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100080 (China); Xu Huailiang [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Chin, See Leang [Center for Optics, Universite Laval, Quebec City, Quebec G1V 0A6 (Canada)

    2011-11-15T23:59:59.000Z

    We demonstrate a harmonic-seeded switchable multiwavelength laser in air driven by intense midinfrared femtosecond laser pulses, in which population inversion occurs at an ultrafast time scale (i.e., less than {approx}200 fs) owing to direct formation of excited molecular nitrogen ions by strong-field ionization of inner-valence electrons. The bright multiwavelength laser in air opens the perspective for remote detection of multiple pollutants based on nonlinear optical spectroscopy.

  19. Cree's High-Power White LED Delivers 121 lm/W

    Broader source: Energy.gov [DOE]

    Cree's commercial high-power white LEDs can now deliver 121 lm/W at 35A/cm2 current density. These particular Cree XLamp® XP-G LEDs deliver 267 lumens at a drive current of 700 mA and an operating...

  20. Compact radiation sources for increased access to high brightness x-rays

    E-Print Network [OSTI]

    O'Shea, Finn Henry

    2012-01-01T23:59:59.000Z

    results for the 4.5 GeV LCLS beam. . . . . . . . . . .148 Simulation of a 13.65 GeV LCLS beam . . . . . . . . . .142 LCLS ultra-low charge, high brightness beam

  1. High Efficiency m-plane LEDs on Low Defect Density Bulk GaN Substrates

    SciTech Connect (OSTI)

    David, Aurelien

    2012-10-15T23:59:59.000Z

    Solid-state lighting is a key technology for reduction of energy consumption in the US and worldwide. In principle, by replacing standard incandescent bulbs and other light sources with sources based on light-emitting diodes (LEDs), ultimate energy efficiency can be achieved. The efficiency of LEDs has improved tremendously over the past two decades, however further progress is required for solid- state lighting to reach its full potential. The ability of an LED at converting electricity to light is quantified by its internal quantum efficiency (IQE). The material of choice for visible LEDs is Gallium Nitride (GaN), which is at the basis of blue-emitting LEDs. A key factor limiting the performance of GaN LEDs is the so-called efficiency droop, whereby the IQE of the LED decreases significantly at high current density. Despite decades of research, efficiency droop remains a major issue. Since high-current operation is necessary for practical lighting applications, reducing droop is a major challenge for the scientific community and the LED industry. Our approach to solving the droop issue is the use of newly available low-defect-density bulk GaN non-polar substrates. In contrast to the standard foreign substrates (sapphire, silicon carbide, silicon) used in the industry, we have employed native bulk GaN substrates with very low defect density, thus ensuring exquisite material quality and high IQE. Whereas all commercial LEDs are grown along the c-plane crystal direction of GaN, we have used m-plane non-polar substrates; these drastically modify the physical properties of the LED and enable a reduction of droop. With this approach, we have demonstrated very high IQE performance and low droop. Our results focused on violet and blue LEDs. For these, we have demonstrated very high peak IQEs and current droops of 6% and 10% respectively (up to a high current density of 200A.cm-2). All these results were obtained under electrical operation. These high IQE and low droop values are in line with the program’s milestones. They demonstrate that bulk non-polar GaN substrates represent a disruptive technology for LED performance. Application of this technology to real-world products is feasible, provided that the cost of GaN substrates is compatible with the market’s requirement.

  2. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    for material removal in ultra- fast pulsed laser ablation ofspecifically the ultra- fast laser-induced melting of gold.of an ultra- short, high intensity laser pulse pumping a

  3. Low-Cost Substrates for High-Performance Nanorod Array LEDs

    SciTech Connect (OSTI)

    Sands, Timothy; Stach, Eric; Garcia, Edwin

    2009-04-30T23:59:59.000Z

    The completed project, entitled â??Low-Cost Substrates for High-Performance Nanorod LEDs,â?ť targeted the goal of a phosphor-free nanorod-based white LED with IQE > 50% across the spectrum from 450 nm to 600 nm on metallized silicon substrates. The principal achievements of this project included: â?˘ Demonstration of (In,Ga)N nanopyramid heterostructures by a conventional OMVPE process. â?˘ Verification of complete filtering of threading dislocations to yield dislocation-free pyramidal heterostructures. â?˘ Demonstration of electroluminescence with a peak wavelength of ~600 nm from an (In,Ga)N nanopyramid array LED. â?˘ Development of a reflective ZrN/AlN buffer layer for epitaxial growth of GaN films and GaN nanopyramid arrays on (111)Si.

  4. High brightness diode-pumped organic solid-state laser

    E-Print Network [OSTI]

    Zhao, Zhuang; Nafa, Malik; Chénais, Sébastien; Forget, Sébastien

    2015-01-01T23:59:59.000Z

    High-power, diffraction-limited organic solid-state laser operation has been achieved in a vertical external cavity surface-emitting organic laser (VECSOL), pumped by a low-cost compact blue laser diode. The diode-pumped VECSOLs were demonstrated with various dyes in a polymer matrix, leading to laser emissions from 540 nm to 660 nm. Optimization of both the pump pulse duration and output coupling leads to a pump slope efficiency of 11% for a DCM based VECSOLs. We report output pulse energy up to 280 nJ with 100 ns long pump pulses, leading to a peak power of 3.5 W in a circularly symmetric, diffraction-limited beam.

  5. High-power LEDs based on InGaAsP/InP heterostructures

    SciTech Connect (OSTI)

    Rakovics, V. [Hungarian Academy of Sciences, Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences (Hungary); Imenkov, A. N.; Sherstnev, V. V.; Serebrennikova, O. Yu.; Il’inskaya, N. D.; Yakovlev, Yu. P., E-mail: Yak@iropt1.ioffe.ru [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2014-12-15T23:59:59.000Z

    High-power light-emitting diodes (LEDs) with mesa diameters of 100, 200, and 300 ?m are developed on the basis of InGaAsP/InP heterostructures. The mesas are close in shape to a truncated cone with a generatrix inclination angle of ?45° in the vicinity of the active region of the LED, with a ring etched around the mesa serving as a reflector. The emission spectra and directivity patterns of these LEDs are studied in a wide range of current densities and it is shown that radiative recombination is dominant to a current density of ?5000 A/cm{sup 2}, which makes these structures promising for the development of high-power LEDs. An emission power of ?14 mW is obtained in the continuous-wave mode (I = 0.2 A, ? = 1.1 ?m), and that of 77 mW, in the pulsed mode (I = 2 A, ? = 1.1 ?m), which corresponds to external quantum efficiencies of 6.2 and 3.4%, respectively.

  6. High-Efficiency Non-Polar GaN-Based LEDs

    SciTech Connect (OSTI)

    Paul Fini

    2010-11-30T23:59:59.000Z

    Inlustra Technologies with subcontractor U.C. Santa Barbara conducted a project with the principle goal of demonstrating high internal quantum efficiency blue (430 nm) and green (540nm) light emitting diodes (LEDs) on low-defect density non-polar GaN wafers. Inlustra pursued the fabrication of smooth thick a-plane and m-plane GaN films, as well as defect reduction techniques such as lateral epitaxial overgrowth (LEO) to uniformly lower dislocation density in these films. Limited free-standing wafers were produced as well. By the end of the reporting period, Inlustra had met its milestone of dislocation reduction to < 5 x 10{sup 6} cm{sup -2}. Stacking faults were still present in appreciable density ({approx} 1 x 10{sup 5} cm{sup -1}), but were not the primary focus of defect reduction since there have been no published studies establishing their detrimental effects on LED performance. Inlustra's LEO progress built a solid foundation upon which further commercial development of GaN substrates will occur. UCSB encountered multiple delays in its LED growth and fabrication efforts due to unavoidable facilities outages imposed by ongoing construction in an area adjacent to the metalorganic chemical vapor deposition (MOCVD) laboratory. This, combined with the large amount of ab initio optimization required for the MOCVD system used during the project, resulted in unsatisfactory LED progress. Although numerous blue-green photoluminescence results were obtained, only a few LED structures exhibited electroluminescence at appreciable levels. UCSB also conducting extensive modeling (led by Prof. Van de Walle) on the problem of non-radiative Auger recombination in GaN-based LED structures, which has been posited to contribute to LED efficiency 'droop' at elevated current density. Unlike previous modeling efforts, UCSB's approach was truly a first-principles ab initio methodology. Building on solid numerical foundations, the Auger recombination rates of In{sub x}Ga{sub 1-x}N alloys were calculated from first-principles density-functional and many-body-perturbation theory. The differing mechanisms of inter- and intra-band recombination were found to affect different parts of the emission spectrum. In the blue to green spectral region and at room temperature the Auger coefficient was calculated to be as large as 2 x 10{sup -30} cm{sup 6} s{sup -1}; in the infrared it is even larger. These results indicated that Auger recombination may be responsible for the loss of quantum efficiency that affects InGaN-based light emitters, whether on non-polar or polar crystal planes.

  7. High-Power Warm-White Hybrid LED Package for Illumination

    SciTech Connect (OSTI)

    Soer, Wouter

    2013-09-19T23:59:59.000Z

    In this project, an integrated warm-white hybrid light engine was developed. The hybrid approach involves combining phosphor-converted off-white InGaN LEDs and direct-emitting red AlInGaP LEDs in a single light engine to achieve high efficacy together with high color rendering index. We developed and integrated technology improvements in InGaN and AlInGaP die technology, phosphor technology, package architecture and encapsulation, to realize a hybrid warm-white LED package with an efficacy of 140 lm/W at a correlated color temperature of 3000K and a color rendering index of 90, measured under representative operating conditions. This efficacy is 26% higher than the best warm-white LEDs of similar specification that are commercially available at the end of the project. Since the InGaN- and AlInGaP-based LEDs used in the hybrid engine show different behavior as a function of current and temperature, a control system needs to be in place to ensure a stable color point over all operating conditions. In this project, we developed an electronic control circuit that is fully integrated into the light engine in such a way that the module can simply be driven by a conventional single-channel driver. The integrated control circuit uses a switch-mode boost converter topology to control the LED drive currents based on the temperature and the input current of the light engine. A color control performance of 5 SDCM was demonstrated, and improvement to 3 SDCM is considered well within reach. The combination of high efficacy and ease of integration with existing single-channel drivers is expected to facilitate the adoption of the hybrid technology and accelerate the energy savings associated with solid-state lighting. In the product commercialization plan, downlights and indirect-lit troffers have been selected as the first target applications for this product concept. Fully functional integrated prototypes have been developed for both applications, and the business case evaluation is ongoing as of the end of the project.

  8. Much Ado about Microbunching: Coherent Bunching in High Brightness Electron Beams

    SciTech Connect (OSTI)

    Ratner, Daniel; /Stanford U. /SLAC

    2012-05-25T23:59:59.000Z

    The push to provide ever brighter coherent radiation sources has led to the creation of correspondingly bright electron beams. With billions of electrons packed into normalized emittances (phase space) below one micron, collective effects may dominate both the preservation and use of such ultra-bright beams. An important class of collective effects is due to density modulations within the bunch, or microbunching. Microbunching may be deleterious, as in the case of the Microbunching Instability (MBI), or it may drive radiation sources of unprecedented intensity, as in the case of Free Electron Lasers (FELs). In this work we begin by describing models of microbunching due to inherent beam shot noise, which sparks both the MBI as well as SLAC's Linac Coherent Light Source, the world's first hard X-ray laser. We first use this model to propose a mechanism for reducing the inherent beam shot noise as well as for predicting MBI effects. We then describe experimental measurements of the resulting microbunching at LCLS, including optical radiation from the MBI, as well as the first gain length and harmonic measurements from a hard X-ray FEL. In the final chapters, we describe schemes that use external laser modulations to microbunch light sources of the future. In these sections we describe coherent light source schemes for both both linacs and storage rings.

  9. Head-on beam-beam tune shifts with high brightness beams in the LHC

    E-Print Network [OSTI]

    Alemany, R; Calaga, R; Cornelis, K; Fitterer, M; Giachino, R; Herr, W; McPherson, A; Miyamoto, R; Papotti, G; Pieloni, T; Redaelli, S; Roncarolo, F; Schaumann, M; Suykerbuyk, R; Trad, G; Paret, S

    2011-01-01T23:59:59.000Z

    In this experiment (fills 1765, 1766) we have collided bunches with highest brightness, i.e. small emittances and high intensities, to explore the achievable beam-beam tune shift for head-on collisions. Different parameters and filling schemes have been used for this experiment and tune shifts above 0.015 have been achieved in single collisions and above 0.030 for two collision points.

  10. Volume-scalable high-brightness three-dimensional visible light source

    DOE Patents [OSTI]

    Subramania, Ganapathi; Fischer, Arthur J; Wang, George T; Li, Qiming

    2014-02-18T23:59:59.000Z

    A volume-scalable, high-brightness, electrically driven visible light source comprises a three-dimensional photonic crystal (3DPC) comprising one or more direct bandgap semiconductors. The improved light emission performance of the invention is achieved based on the enhancement of radiative emission of light emitters placed inside a 3DPC due to the strong modification of the photonic density-of-states engendered by the 3DPC.

  11. Nice, Cte d'Azur, France, 27-29 September 2006 THERMAL MODELING OF HIGH POWER LED MODULES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    generation a part of the input electric power is converted into light, which is described by the wall plugNice, Côte d'Azur, France, 27-29 September 2006 THERMAL MODELING OF HIGH POWER LED MODULES D a study of accuracy issues in thermal modeling of high power LED modules on system level. Both physical

  12. Evolution of laser-produced Sn extreme ultraviolet source diameter for high-brightness source

    SciTech Connect (OSTI)

    Roy, Amitava, E-mail: roy@fzu.cz, E-mail: aroy@barc.gov.in [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), Utsunomiya University, Utsunomiya, Tochigi 321-8585 (Japan); HiLASE Centre, Institute of Physics ASCR, v.v.i., Za Radnicí 828, 25241 Dolní B?ežany (Czech Republic); Arai, Goki; Hara, Hiroyuki; Higashiguchi, Takeshi, E-mail: higashi@cc.utsunomiya-u.ac.jp [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), Utsunomiya University, Utsunomiya, Tochigi 321-8585 (Japan); Ohashi, Hayato [Graduate School of Science and Engineering for Research, University of Toyama, Toyama, Toyama 930-8555 (Japan); Sunahara, Atsushi [Institute for Laser Technology, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Li, Bowen [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Dunne, Padraig; O'Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Miura, Taisuke; Mocek, Tomas; Endo, Akira [HiLASE Centre, Institute of Physics ASCR, v.v.i., Za Radnicí 828, 25241 Dolní B?ežany (Czech Republic)

    2014-08-18T23:59:59.000Z

    We have investigated the effect of irradiation of solid Sn targets with laser pulses of sub-ns duration and sub-mJ energy on the diameter of the extreme ultraviolet (EUV) emitting region and source conversion efficiency. It was found that an in-band EUV source diameter as low as 18??m was produced due to the short scale length of a plasma produced by a sub-ns laser. Most of the EUV emission occurs in a narrow region with a plasma density close to the critical density value. Such EUV sources are suitable for high brightness and high repetition rate metrology applications.

  13. Digital Architecture for Driving Large LED Arrays with Dynamic Bus Voltage Regulation and Phase Shifted PWM

    E-Print Network [OSTI]

    Emitting Diodes (HB-LEDs) with improved system efficiency and reduced EMI. Key advantages are achieved - This paper introduces a digital architecture suitable for driving a large number of High Brightness Light

  14. Computational and experimental characterization of high-brightness beams for femtosecond electron imaging and spectroscopy

    SciTech Connect (OSTI)

    Portman, J.; Zhang, H.; Tao, Z.; Makino, K.; Berz, M.; Duxbury, P. M.; Ruan, C.-Y. [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States)] [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States)

    2013-12-16T23:59:59.000Z

    Using a multilevel fast multipole method, coupled with the shadow imaging of femtosecond photoelectron pulses for validation, we quantitatively elucidate the photocathode, space charge, and virtual cathode physics, which fundamentally limit the spatiotemporal and spectroscopic resolution and throughput of ultrafast electron microscope (UEM) systems. We present a simple microscopic description to capture the nonlinear beam dynamics based on a two-fluid picture and elucidate an unexpected dominant role of image potential pinning in accelerating the emittance growth process. These calculations set theoretical limits on the performance of UEM systems and provide useful guides for photocathode design for high-brightness electron beam systems.

  15. Philips Lumileds Develops a Low-Cost, High-Power, Warm-White LED Package

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, Philips Lumileds has developed a low-cost, high-power, warm-white LED package for general illumination. During the course of the two-year project, this package was used to commercialize a series of products with correlated color temperatures (CCTs) ranging from 2700 to 5700 K, under the product name LUXEON M. A record efficacy of nearly 125 lm/W was demonstrated at a flux of 1023 lumens, a CCT of 3435 K, and a color rendering index (CRI) of more than 80 at room temperature in the productized package. In an R&D package, a record efficacy of more than 133 lm/W at a flux of 1015 lumens, a CCT of 3475 K, and a CRI greater than 80 at room temperature were demonstrated.

  16. Design and fabrication of high-index-contrast self-assembled texture for light extraction enhancement in LEDs

    E-Print Network [OSTI]

    Sheng, Xing

    We developed a high-index-contrast photonic structure for improving the light extraction efficiency of light-emitting diodes (LEDs) by a self-assembly approach. In this approach, a two-dimensional grating can be ...

  17. Fundamental Studies and Development of III-N Visible LEDs for High-Power Solid-State Lighting Applications

    SciTech Connect (OSTI)

    Dupuis, Russell

    2012-02-29T23:59:59.000Z

    The goal of this program is to understand in a fundamental way the impact of strain, defects, polarization, and Stokes loss in relation to unique device structures upon the internal quantum efficiency (IQE) and efficiency droop (ED) of III-nitride (III-N) light-emitting diodes (LEDs) and to employ this understanding in the design and growth of high-efficiency LEDs capable of highly-reliable, high-current, high-power operation. This knowledge will be the basis for our advanced device epitaxial designs that lead to improved device performance. The primary approach we will employ is to exploit new scientific and engineering knowledge generated through the application of a set of unique advanced growth and characterization tools to develop new concepts in strain-, polarization-, and carrier dynamics-engineered and low-defect materials and device designs having reduced dislocations and improved carrier collection followed by efficient photon generation. We studied the effects of crystalline defect, polarizations, hole transport, electron-spillover, electron blocking layer, underlying layer below the multiplequantum- well active region, and developed high-efficiency and efficiency-droop-mitigated blue LEDs with a new LED epitaxial structures. We believe new LEDs developed in this program will make a breakthrough in the development of high-efficiency high-power visible III-N LEDs from violet to green spectral region.

  18. High brightness--multiple beamlets source for patterned X-ray production

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Ji, Qing (Albany, CA); Barletta, William A. (Oakland, CA); Jiang, Ximan (El Cerrito, CA); Ji, Lili (Albany, CA)

    2009-10-27T23:59:59.000Z

    Techniques for controllably directing beamlets to a target substrate are disclosed. The beamlets may be either positive ions or electrons. It has been shown that beamlets may be produced with a diameter of 1 .mu.m, with inter-aperture spacings of 12 .mu.m. An array of such beamlets, may be used for maskless lithography. By step-wise movement of the beamlets relative to the target substrate, individual devices may be directly e-beam written. Ion beams may be directly written as well. Due to the high brightness of the beamlets from extraction from a multicusp source, exposure times for lithographic exposure are thought to be minimized. Alternatively, the beamlets may be electrons striking a high Z material for X-ray production, thereafter collimated to provide patterned X-ray exposures such as those used in CAT scans. Such a device may be used for remote detection of explosives.

  19. Ultratech Develops an Improved Lithography Tool for LED Wafer Manufacturing

    Broader source: Energy.gov [DOE]

    Ultratech modified an existing lithography tool used for semiconductor manufacturing to better meet the cost and performance targets of the high-brightness LED manufacturing industry. The goal was to make the equipment compatible with the wide range of substrate diameters and thicknesses prevalent in the industry while reducing the capital cost and the overall cost of ownership (COO).

  20. Advanced X-Band Test Accelerator for High Brightness Electron and Gamma Ray Beams

    SciTech Connect (OSTI)

    Marsh, Roark; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Chu, Tak Sum; /LLNL, Livermore; Ebbers, Chris; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

    2012-07-03T23:59:59.000Z

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  1. ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS

    SciTech Connect (OSTI)

    Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

    2010-05-12T23:59:59.000Z

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  2. LED Update

    SciTech Connect (OSTI)

    Johnson, Mark L.; Gordon, Kelly L.

    2006-09-01T23:59:59.000Z

    This article, which will appear in RESIDENTIAL LIGHTING MAGAZINE, interviews PNNL's Kelly Gordon and presents the interview in question and answer format. The topic is a light emitting diode (LED) lighting also known as solid state lighting. Solid state lighting will be a new category in an energy efficient lighting fixture design competition called Lighting for Tomorrow sponsored by the US Department of Energy Emerging Technologies Office, the American Institute for Lighting, and the Consortium for Energy Efficiency. LED technology has been around since the ’60s, but it has been used mostly for indicator lights on electronics equipment. The big breakthrough was the development in the 1990s of blue LEDs which can be combined with the red and green LEDs that already existed to make white light. LEDs produce 25 to 40 lumens of light per watt of energy used, almost as much as a CFL (50 lumens per watt) and much more efficient than incandescent sources, which are around 15 lumens per watt. They are much longer lived and practical in harsh environments unsuitable for incandescent lighting. They are ready for niche applications now, like under-counter lighting and may be practical for additional applications as technological challenges are worked out and the technology is advancing in leaps and bounds.

  3. LED lamp

    DOE Patents [OSTI]

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12T23:59:59.000Z

    There is herein described a lamp for providing white light comprising a plurality of light sources positioned on a substrate. Each of said light sources comprises a blue light emitting diode (LED) and a dome that substantially covers said LED. A first portion of said blue light from said LEDs is transmitted through said domes and a second portion of said blue light is converted into a red light by a first phosphor contained in said domes. A cover is disposed over all of said light sources that transmits at least a portion of said red and blue light emitted by said light sources. The cover contains a second phosphor that emits a yellow light in response to said blue light. The red, blue and yellow light combining to form the white light and the white light having a color rendering index (CRI) of at least about 80.

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

    SciTech Connect (OSTI)

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl [Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States)

    2014-09-15T23:59:59.000Z

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

  5. LED Traffic Light as a Communications Device Grantham Pang, Thomas Kwan, Chi-Ho Chan, Hugh Liu.

    E-Print Network [OSTI]

    Pang, Grantham

    :http://www.eee.hku.hk/~gpang Abstract The visible light from an LED (light emitting diode) traffic light can be modulated and encoded on the description of an audio information system made up of high brightness, visible light emitting diodes (LEDs messages 1. Introduction Recently, high intensity light emitting diodes for traffic signals are available

  6. High-brightness electron beam evolution following laser-based cleaning of a photocathode

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

    Zhou, F.; Brachmann, A.; Decker, F-J.; Emma, P.; Gilevich, S.; Iverson, R.; Stefan, P.; Turner, J.

    2012-09-01T23:59:59.000Z

    Laser-based techniques have been widely used for cleaning metal photocathodes to increase quantum efficiency (QE). However, the impact of laser cleaning on cathode uniformity and thereby on electron beam quality are less understood. We are evaluating whether this technique can be applied to revive photocathodes used for high-brightness electron sources in advanced x-ray free-electron laser (FEL) facilities, such as the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. The laser-based cleaning was applied to two separate areas of the current LCLS photocathode on July 4 and July 26, 2011, respectively. The QE was increased by 8–10 times upon the laser cleaning. Since the cleaning, routine operation has exhibited a slow evolution of the QE improvement and comparatively rapid improvement of transverse emittance, with a factor of 3 QE enhancement over five months, and a significant emittance improvement over the initial 2–3 weeks following the cleaning. Currently, the QE of the LCLS photocathode is holding constant at about 1.2×10?4 , with a normalized injector emittance of about 0.3???m for a 150-pC bunch charge. With the proper procedures, the laser-cleaning technique appears to be a viable tool to revive the LCLS photocathode. We present observations and analyses for the QE and emittance evolution in time following the laser-based cleaning of the LCLS photocathode, and comparison to the previous studies, the measured thermal emittance versus the QE and comparison to the theoretical model.

  7. High Spatial Resolution KAO Far-Infrared Observations of the Central Regions of Infrared-Bright Galaxies

    E-Print Network [OSTI]

    Beverly J. Smith; P. M. Harvey

    1996-05-06T23:59:59.000Z

    We present new high spatial resolution Kuiper Airborne Observatory 50 micron and/or 100 micron data for 11 infrared-bright galaxies. We also tabulate previously published KAO data for 11 other galaxies, along with the IRAS data for the bulges of M 31 and M 81. We find that L(FIR)/L(B) and L(FIR)/L(H) correlate with CO (1 - 0) intensity and tau(100). Galaxies with optical or near-infrared signatures of OB stars in their central regions have higher values of I(CO) and tau(100), as well as higher far-infrared surface brightnesses and L(FIR)/L(B) and L(FIR)/L(H) ratios. L(FIR)/L(H(alpha)) does not correlate strongly with CO and tau(100). These results support a scenario in which OB stars dominate dust heating in the more active galaxies and older stars are important in quiescent bulges.

  8. Untangling the contributions of image charge and laser profile for optimal photoemission of high-brightness electron beams

    SciTech Connect (OSTI)

    Portman, J.; Zhang, H.; Makino, K.; Ruan, C. Y.; Berz, M.; Duxbury, P. M. [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-11-07T23:59:59.000Z

    Using our model for the simulation of photoemission of high brightness electron beams, we investigate the virtual cathode physics and the limits to spatio-temporal and spectroscopic resolution originating from the image charge on the surface and from the profile of the exciting laser pulse. By contrasting the effect of varying surface properties (leading to expanding or pinned image charge), laser profiles (Gaussian, uniform, and elliptical), and aspect ratios (pancake- and cigar-like) under different extraction field strengths and numbers of generated electrons, we quantify the effect of these experimental parameters on macroscopic pulse properties such as emittance, brightness (4D and 6D), coherence length, and energy spread. Based on our results, we outline optimal conditions of pulse generation for ultrafast electron microscope systems that take into account constraints on the number of generated electrons and on the required time resolution.

  9. Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs - Energy

    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 for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5LetLooking5investsLouisPrepared:

  10. Broadband Spectral Properties of Bright High-Energy Gamma-Ray Bursts Observed with BATSE and EGRET

    E-Print Network [OSTI]

    Kaneko, Y; Preece, R; Dingus, B L; Briggs, M S

    2008-01-01T23:59:59.000Z

    We present the spectral analysis of duration-integrated broadband spectra (in $\\sim30 $keV$-200 $MeV) of 15 bright BATSE gamma-ray bursts (GRBs). Some GRB spectra are very hard, with their spectral peak energies being above the BATSE LAD passband limit of $\\sim$2 MeV. In such cases, their high-energy spectral parameters (peak energy and high-energy power-law indices) cannot be adequately constrained by BATSE LAD data alone. A few dozen bright BATSE GRBs were also observed with EGRET's calorimeter, TASC, in multi-MeV energy band, with a large effective area and fine energy resolution. Combining the BATSE and TASC data, therefore, affords spectra that span four decades of energy ($30 $keV$-200 $MeV), allowing for a broadband spectral analysis with good statistics. Studying such broadband high-energy spectra of GRB prompt emission is crucial, as they provide key clues to understanding its gamma-ray emission mechanism. Among the 15 GRB spectra, we found two cases with a significant high-energy excess, and another...

  11. Light-emitting diodes (LEDs), with high efficiency, dimmabil-ity, long life, and directional light output, could be the ideal

    E-Print Network [OSTI]

    The Issue Light-emitting diodes (LEDs), with high efficiency, dimmabil- ity, long life, and directional light output, could be the ideal light source for the common recessed-can downlight. How- ever, many existing LED downlight products fail to live up to expectations, providing poor light distribution

  12. AlGaN UV LED and Photodiodes Radiation Hardness and Space Qualifications and Their Applications in Space Science and High Energy Density Physics

    SciTech Connect (OSTI)

    Sun, K. X.

    2011-05-31T23:59:59.000Z

    This presentation provides an overview of robust, radiation hard AlGaN optoelectronic devices and their applications in space exploration & high energy density physics. Particularly, deep UV LED and deep UV photodiodes are discussed with regard to their applications, radiation hardness and space qualification. AC charge management of UV LED satellite payload instruments, which were to be launched in late 2012, is covered.

  13. First results from the high-brightness x-ray spectroscopy beamline 9. 3.1 at ALS

    SciTech Connect (OSTI)

    Ng, W.; Jones, G.; Perera, R.C.C.

    1995-10-01T23:59:59.000Z

    Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range. This beamline is designed to achieve the goal of high brightness at the sample for use in the X-ray Atomic and Molecular Spectroscopy (XAMS) science, surface and interface science, biology, and x-ray optical development programs at ALS. X-ray absorption and time of flight photoemission measurements in 2 - 5 keV photon energy along with the flux, resolution, spot size and stability of the beamline will be discussed. Prospects for future XAMS measurements will also be presented.

  14. Broadband Spectral Properties of Bright High-Energy Gamma-Ray Bursts Observed with BATSE and EGRET

    E-Print Network [OSTI]

    Y. Kaneko; M. M. Gonzalez; R. Preece; B. L. Dingus; M. S. Briggs

    2008-01-12T23:59:59.000Z

    We present the spectral analysis of duration-integrated broadband spectra (in $\\sim30 $keV$-200 $MeV) of 15 bright BATSE gamma-ray bursts (GRBs). Some GRB spectra are very hard, with their spectral peak energies being above the BATSE LAD passband limit of $\\sim$2 MeV. In such cases, their high-energy spectral parameters (peak energy and high-energy power-law indices) cannot be adequately constrained by BATSE LAD data alone. A few dozen bright BATSE GRBs were also observed with EGRET's calorimeter, TASC, in multi-MeV energy band, with a large effective area and fine energy resolution. Combining the BATSE and TASC data, therefore, affords spectra that span four decades of energy ($30 $keV$-200 $MeV), allowing for a broadband spectral analysis with good statistics. Studying such broadband high-energy spectra of GRB prompt emission is crucial, as they provide key clues to understanding its gamma-ray emission mechanism. Among the 15 GRB spectra, we found two cases with a significant high-energy excess, and another case with a extremely high peak energy (\\epeak $\\gtrsim$ 170 MeV). There have been very limited number of GRBs observed at MeV energies and above, and only a few instruments have been capable of observing GRBs in this energy band with such high sensitivity. Thus, our analysis results presented here should also help predict GRB observations with current and future high-energy instruments such as AGILE and GLAST, as well as with ground-based very-high-energy telescopes.

  15. NOVEL TECHNOLOGIES DEVELOPED BY CREE LOWER THE COST OF HIGH-PERFORMANCE LED TROFFERS ON THE MARKET

    Broader source: Energy.gov [DOE]

    Cree used a comprehensive approach to reduce the costs of various optical, thermal, and electrical subsystems without impacting performance, resulting in an LED troffer luminaire platform emitting...

  16. 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

  17. LOW-COST LED LUMINAIRE FOR GENERAL ILLUMINATION

    SciTech Connect (OSTI)

    Lowes, Ted

    2014-07-31T23:59:59.000Z

    During this two-year Solid-State Lighting (SSL) Manufacturing R&D project Cree developed novel light emitting diode (LED) technologies contributing to a cost-optimized, efficient LED troffer luminaire platform emitting at ~3500K correlated color temperature (CCT) at a color rendering index (CRI) of >90. To successfully achieve program goals, Cree used a comprehensive approach to address cost reduction of the various optical, thermal and electrical subsystems in the luminaire without impacting performance. These developments built on Cree’s high- brightness, low-cost LED platforms to design a novel LED component architecture that will enable low-cost troffer luminaire designs with high total system efficacy. The project scope included cost reductions to nearly all major troffer subsystems as well as assembly costs. For example, no thermal management components were included in the troffer, owing to the optimized distribution of compact low- to mid-power LEDs. It is estimated that a significant manufacturing cost savings will result relative to Cree’s conventional troffers at the start of the project. A chief project accomplishment was the successful development of a new compact, high-efficacy LED component geometry with a broad far-field intensity distribution and even color point vs. emission angle. After further optimization and testing for production, the Cree XQ series of LEDs resulted. XQ LEDs are currently utilized in Cree’s AR series troffers, and they are being considered for use in other platforms. The XQ lens geometry influenced the independent development of Cree’s XB-E and XB-G high-voltage LEDs, which also have a broad intensity distribution at high efficacy, and are finding wide implementation in Cree’s omnidirectional A-lamps.

  18. Driving Down HB-LED Costs: Implementation of Process Simulation Tools and Temperature Control Methods of High Yield MOCVD Growth

    SciTech Connect (OSTI)

    William Quinn

    2012-04-30T23:59:59.000Z

    The overall objective of this multi-faceted program is to develop epitaxial growth systems that meet a goal of 75% (4X) cost reduction in the epitaxy phase of HB-LED manufacture. A 75% reduction in yielded epitaxy cost is necessary in order to achieve the cost goals for widespread penetration of HB-LEDâ??s into back-lighting units (BLU) for LCD panels and ultimately for solid-state lighting (SSL). To do this, the program will address significant improvements in overall equipment Cost of Ownership, or CoO. CoO is a model that includes all costs associated with the epitaxy portion of production. These aspects include cost of yield, capital cost, operational costs, and maintenance costs. We divide the program into three phases where later phases will incorporate the gains of prior phases. Phase one activities are enabling technologies. In collaboration with Sandia National Laboratories we develop a Fluent-compatible chemistry predictive model and a set of mid-infrared and near-ultraviolet pyrometer monitoring tools. Where previously the modeling of the reactor dynamics were studied within FLUENT alone, here, FLUENT and Chemkin are integrated into a comprehensive model of fluid dynamics and the most advanced transport equations developed for Chemkin. Specifically, the Chemkin model offered the key reaction terms for gas-phase nucleation, a key consideration in the optimization of the MOCVD process. This new predictive model is used to design new MOCVD reactors with optimized growth conditions and the newly developed pyrometers are used monitor and control the MOCVD process temperature to within 0.5°C run-to-run and within each wafer. This portion of the grant is in collaboration with partners at Sandia National Laboratories. Phase two activities are continuous improvement projects which extend the current reactor platform along the lines of improved operational efficiency, improved systems control for throughput, and carrier modifications for increased yield. Programmatically, improvements made in Phase I are applied to developments of Phase II when applicable. Phase three is the culmination of the individual tasks from both phases one and two applied to proposed production platforms. We selectively combine previously demonstrated tasks and other options to develop a high-volume production-worthy MOCVD system demonstrating >3x throughput, 1.3x capital efficiency, and 0.7x cost of ownership. In a parallel demonstration we validate the concept of an improved, larger deposition system which utilizes the predictive modeling of chemistry-based flow analysis and extensions of the improvements demonstrated on the current platforms. This validation includes the build and testing of a prototype version of the hardware and demonstration of 69% reduction in the cost of ownership. Also, in this phase we present a stand-alone project to develop a high-temperature system which improves source efficiency by 30% while concurrently increasing growth rate by 1.3x. The material quality is held to the same material quality specifications of our existing baseline processes. The merits of other line item tasks in phase three are discussed for inclusion on next-generation platforms.

  19. High brightness microwave lamp

    DOE Patents [OSTI]

    Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

    2003-09-09T23:59:59.000Z

    An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

  20. LED Market Intelligence Report

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

    early adopters of LED technologies, particularly around dimming capabilities. 16 LED Market Intelligence Report Home Depot Walmart Cree Philips TCP GE LSG Osram Feit Costco...

  1. Issues, Models and Solutions for Triac Modulated Phase Dimming of LED Lamps

    E-Print Network [OSTI]

    Lehman, Brad

    Issues, Models and Solutions for Triac Modulated Phase Dimming of LED Lamps Dustin Rand (Raytheon Edison socket LED lamps directly from residential phase modulated dimmer switches. In order to explain brightness "White Light" LEDs have experts predicting that the "bright white replacement lamp" could trigger

  2. HIGH CURRENT AND HIGH BRIGHTNESS ELECTRON SOURCES , I. Bazarov, S. Belomestnykh, M. Billing, E. Chojnacki, Z. Conway,

    E-Print Network [OSTI]

    Gruner, Sol M.

    will review the technical requirements of such projects and the status of on-going research through- out and longitudinally shaped laser pulse, in RF cavities with very high electrical fields of up to 120 MV/m [1] to beam to a significant heating of the cavity surfaces due to resistive energy losses which causes thermal stress

  3. Monash researchers led by Dr. Dan Li have developed a novel method for converting natural graphite into highly porous

    E-Print Network [OSTI]

    Albrecht, David

    natural graphite into highly porous graphene film for advanced applications. Figure 1: illustrates the conversion of inexpensive & abundant graphite into highly porous, mechanically robust conductive films (eg capacitors, batteries and fuel cells) n LCD displays and photovoltaic devices n Composites

  4. A Practical Primer to LED Technology

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

    heatsink is what allows the high flux LED to generate much more light An LED (Light Emitting Diode) consists of a chip of semiconducting material treated to create a structure...

  5. LEDs_3LEDs_3 current efficiency

    E-Print Network [OSTI]

    Pulfrey, David L.

    efficiencySec. 8.2 From our toolbox Current efficiency #12;4 Light extraction efficiencyLight extraction extraction efficiencyDesign to improve extraction efficiencySec. 8.4 What are the features of this LED from;6 Various efficienciesVarious efficienciesSecs. 8.4, 8.5 Present record is 56%Wall-plug efficiency Wall

  6. LED Lighting Retrofit

    E-Print Network [OSTI]

    Shaw-Meadow, N.

    2011-01-01T23:59:59.000Z

    ? Municipal Street Lighting Consortium ? American Public Power Association (APPA) ? Demonstration in Energy Efficiency Development (DEED) ? Source of funding and database of completed LED roadway projects 6 Rules of the Road ESL-KT-11-11-57 CATEE 2011..., 2011 ? 9 Solar-Assisted LED Case Study LaQuinta Hotel, Cedar Park, Texas ? Utilizes 18 - ActiveLED Solar-Assisted Parking Lot Lights ? Utilizes ?power management? to extend battery life while handling light output ? Reduces load which reduces PV...

  7. LED Lighting Basics

    Broader source: Energy.gov [DOE]

    Light-Emitting diodes (LEDs) efficiently produce light in a fundamentally different way than any legacy or traditional source of light.

  8. High dynamic range measurement of spectral responsivity and linearity of a radiation thermometer using a super-continuum laser and LEDs

    SciTech Connect (OSTI)

    Yoo, Y. S.; Lee, D. H.; Park, C. W.; Park, S. N. [Korea Research Institute of Standards and Science 209 Gajeong-Ro, Yuseong-Gu, Daejon 305-340 (Korea, Republic of)] [Korea Research Institute of Standards and Science 209 Gajeong-Ro, Yuseong-Gu, Daejon 305-340 (Korea, Republic of)

    2013-09-11T23:59:59.000Z

    To realize the temperature scale above the freezing point of silver according to the definition of ITS-90, the dynamic range of the spectral responsivity is one of the most important factors which limit its uncertainty. When the residual spectral response at both side bands of a spectral band is not negligible, a significant uncertainty can be caused by a low dynamic range of the spectral responsivity measurement. In general, incandescent lamps are used to measure the spectral responsivity and the linearity. The dynamic range of the spectral responsivity measurement is often limited by a trade-off with the desired spectral resolution, which is less than 6 decades. Nonlinearity is another limiting fact of uncertainties of the temperature scale. Tungsten lamps have disadvantage in the nonlinearity measurements in terms of adjustability of radiance level and spectral selectivity. We report spectral responsivity measurements of which the measurable dynamic range is enhanced 50 times after replacing a QTH lamp with a super continuum laser. We also present a spectrally selected linearity measurement over a wide dynamic range using high-brightness light emitting diode arrays to observe a slight saturation of linearity.

  9. Ammothermal Growth of Gan Substrates For Leds: High-Pressure Ammonothermal Process for Bulk Gallium Nitride Crystal Growth for Energy Efficient Commercially Competitive Lighting

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    Broad Funding Opportunity Announcement Project: The new GaN crystal growth method is adapted from that used to grow quartz crystals, which are very inexpensive and represent the second-largest market for single crystals for electronic applications (after silicon). More extreme conditions are required to grow GaN crystals and therefore a new type of chemical growth chamber was invented that is suitable for large-scale manufacturing. A new process was developed that grows GaN crystals at a rate that is more than double that of current processes. The new technology will enable GaN substrates with best-in-world quality at lowest-in-world prices, which in turn will enable new generations of white LEDs, lasers for full-color displays, and high-performance power electronics.

  10. Sandia National Laboratories: LED

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

    electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

  11. Series Input Modular Architecture for Driving Multiple LEDs

    E-Print Network [OSTI]

    , where each cell drives four 700 mA LEDs. Keywords ­ solid-state lighting, light emitting diodes, LED have been achieved over the past decade in solid state light emitting diodes (LEDs), leading to high

  12. 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

    high-color-rendering LED lamps using oxyfluoride andin white LED. (a) Typical LED lamp package. (b) Uniformin white LED. (a) Typical LED lamp package. (b) Uniform

  13. LED MR16 Lamps

    Broader source: Energy.gov [DOE]

    The following CALiPER report provides detailed analysis of LED MR16 lamp performance, covering basic performance characteristics as well as subjective evaluation of beam, shadow, and color quality. Pending reports will offer analysis on performance attributes that are not captured by LM-79 testing. These reports are intended to educate the industry on market trends, potential issues, and important areas for improvement.

  14. Global LED Manufacturing

    Energy Savers [EERE]

    0.20.5W 5630 PPA 0.51.0W 7030 PCT XVGA HDMI UHD 4K2K UHD 8K4K 0.81.2W 3030 EMC 1.22.0W 3535 EMC w Flip-Chip 0.50.8W 2835 PCT ? 1.01.5 W ???? Revolution of LED...

  15. Government-led performance standard and high-tech innovation in China : a case study of Zhongguancun high-tech development zone

    E-Print Network [OSTI]

    Chen, Yang, M.C.P. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    The object of the thesis is to gain an understanding of the role that Chinese government has played in promoting high-tech industries through performance standards and the output the policy generates. As a latecomer in the ...

  16. LED Price Tracking Form

    Broader source: Energy.gov [DOE]

    DOE intends to update the SSL Pricing and Efficacy Trend Analysis for Utility Program Planning report on an annual basis, but doing so requires that we have sufficient product and purchase data including acquisition date, purchase price, product category, and rated initial lumens. Those interested in helping collect this data are asked to use the LED Price Tracking FormMicrosoft Excel and follow the instructions for submitting data.

  17. LED PAR38 Lamps

    Broader source: Energy.gov [DOE]

    The following CALiPER reports provide detailed analysis of LED PAR38 lamp performance, covering basic performance characteristics as well as subjective evaluation of beam, shadow, and color quality. Pending reports will offer analysis on flicker, dimming and power quality characteristics; stress testing; and lumen and chromaticity maintenance. These reports are intended to educate the industry on market trends, potential issues, and important areas for improvement.

  18. LED ProspectsLED Prospects photometric units

    E-Print Network [OSTI]

    Pulfrey, David L.

    Illuminated by: (a) high-CRI source (b) low-CRI source EFS #12;6 http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/ #12;7 http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/ #12;8 http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/ #12;9 http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/ #12;10 http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes

  19. Solving the 'Green Gap' in LED Technology

    Broader source: Energy.gov [DOE]

    One long-standing high-priority research area for DOE is to increase the efficiency of deep green LEDs. Although most products today use phosphor conversion (PC) to produce white light from a blue LED, having a good green source could lead to color-mixed white sources that would avoid the losses associated with the PC approach.

  20. LED Manufacturing Process Modifications Will Boost Quality and

    E-Print Network [OSTI]

    2012 The Issue Highly energyefficient LightEmitting Diode (LED) lighting products have made great process that will enable LED manufacturers to produce higher quality, energyefficient products at lower

  1. 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

  2. LED Market Intelligence Report

    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 for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 1 2 3 4 5 6 7 8 9LDRD, What does

  3. Detection of solar-like oscillations in the bright red giant stars $\\gamma$ Psc and $\\theta^1$ Tau from a 190-day high-precision spectroscopic multisite campaign

    E-Print Network [OSTI]

    Beck, P G; Hillen, M; Corsaro, E; Van Winckel, H; Moravveji, E; De Ridder, J; Bloemen, S; Saesen, S; Mathias, P; Degroote, P; Kallinger, T; Verhoelst, T; Ando, H; Carrier, F; Acke, B; Oreiro, R; Miglio, A; Eggenberger, P; Sato, B; Zwintz, K; Pápics, P I; Marcos-Arenal, P; Fuentes, S A Sans; Schmid, V S; Waelkens, C; Řstensen, R; Matthews, J M; Yoshida, M; Izumiura, H; Koyano, H; Nagayama, S; Shimizu, Y; Okada, N; Okita, K; Sakamoto, A; Yamamuro, T; Aerts, C

    2014-01-01T23:59:59.000Z

    Red giants are evolved stars which exhibit solar-like oscillations. Although a multitude of stars have been observed with space telescopes, only a handful of red-giant stars were targets of spectroscopic asteroseismic observing projects. We search for solar-like oscillations in the two bright red-giant stars $\\gamma$ Psc and $\\theta^1$ Tau from time series of ground-based spectroscopy and determine the frequency of the excess of oscillation power $\

  4. Ongoing LED RD Challenges (LED droop still challenge)

    Energy Savers [EERE]

    and Nonpolar GaN Semi polar GaN SOLUTION New GaN Crystal Planes * Semipolar planes for blue, green and yellow LEDs A. Romanov et al. : J. Appl. Phys. 100 (2006) 023533. (1122)...

  5. Metacapacitors for LED Lighting: Metacapacitors

    SciTech Connect (OSTI)

    None

    2010-09-02T23:59:59.000Z

    ADEPT Project: The CUNY Energy Institute is developing less expensive, more efficient, smaller, and longer-lasting power converters for energy-efficient LED lights. LEDs produce light more efficiently than incandescent lights and last significantly longer than compact fluorescent bulbs, but they require more sophisticated power converter technology, which increases their cost. LEDs need more sophisticated converters because they require a different type of power (low voltage direct current, or DC) than what's generally supplied by power outlets. The CUNY Energy Institute is developing sophisticated power converters for LEDs that contain capacitors made from new, nanoscale materials. Capacitors are electrical components that are used to store energy. CUNY's unique capacitors are configured with advanced power circuits to more efficiently control and convert power to the LED lighting source. They also eliminate the need for large magnetic components, instead relying on networks of capacitors that can be easily printed on plastic substrate. CUNY's prototype LED power converter already meets DOE's 2020 projections for the energy efficiency of LED power converters.

  6. LEDs for Energy Efficient Greenhouse Lighting

    E-Print Network [OSTI]

    Singh, Devesh; Meinhardt-Wollweber, Merve; Roth, Bernhard

    2014-01-01T23:59:59.000Z

    Light energy is an important factor for plant growth. In regions where the natural light source, i.e. solar radiation, is not sufficient for growth optimization, additional light sources are being used. Traditional light sources such as high pressure sodium lamps and other metal halide lamps are not very efficient and generate high radiant heat. Therefore, new sustainable solutions should be developed for energy efficient greenhouse lighting. Recent developments in the field of light source technologies have opened up new perspectives for sustainable and highly efficient light sources in the form of light-emitting diodes, i.e. LEDs, for greenhouse lighting. This review focuses on the potential of LEDs to replace traditional light sources in the greenhouse. In a comparative economic analysis of traditional vs. LED lighting, we show that the introduction of LEDs allows reduction of the production cost of vegetables in the long-run of several years, due to the high energy efficiency, low maintenance cost and lon...

  7. Sandia National Laboratories: white LED

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

    electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

  8. Sandia National Laboratories: Red LED

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

    electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

  9. Sandia National Laboratories: Blue LED

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

    electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

  10. Maintenance Practices for LED Streetlights

    Broader source: Energy.gov [DOE]

    This April 14, 2014 webinar answered important questions about the maintenance and reliability of LED streetlights, and how to take these issues into account when planning and preparing for a...

  11. LED Lighting Facts®

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED Lighting Facts LEDLED

  12. LED lamp power management system and method

    DOE Patents [OSTI]

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19T23:59:59.000Z

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  13. LED lamp color control system and method

    DOE Patents [OSTI]

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05T23:59:59.000Z

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  14. LED structure with enhanced mirror reflectivity

    DOE Patents [OSTI]

    Bergmann, Michael; Donofrio, Matthew; Heikman, Sten; Schneider, Kevin S; Haberern, Kevin W; Edmond, John A

    2014-04-01T23:59:59.000Z

    Embodiments of the present invention are generally related to LED chips having improved overall emission by reducing the light-absorbing effects of barrier layers adjacent mirror contacts. In one embodiment, a LED chip comprises one or more LEDs, with each LED having an active region, a first contact under the active region having a highly reflective mirror, and a barrier layer adjacent the mirror. The barrier layer is smaller than the mirror such that it does not extend beyond the periphery of the mirror. In another possible embodiment, an insulator is further provided, with the insulator adjacent the barrier layer and adjacent portions of the mirror not contacted by the active region or by the barrier layer. In yet another embodiment, a second contact is provided on the active region. In a further embodiment, the barrier layer is smaller than the mirror such that the periphery of the mirror is at least 40% free of the barrier layer, and the second contact is below the first contact and accessible from the bottom of the chip.

  15. Development of Advanced LED Phosphors by Spray-based Processes for Solid State Lighting

    SciTech Connect (OSTI)

    Cabot Corporation

    2007-09-30T23:59:59.000Z

    The overarching goal of the project was to develop luminescent materials using aerosol processes for making improved LED devices for solid state lighting. In essence this means improving white light emitting phosphor based LEDs by improvement of the phosphor and phosphor layer. The structure of these types of light sources, displayed in Figure 1, comprises of a blue or UV LED under a phosphor layer that converts the blue or UV light to a broad visible (white) light. Traditionally, this is done with a blue emitting diode combined with a blue absorbing, broadly yellow emitting phosphor such as Y{sub 3}Al{sub 5}O{sub 12}:Ce (YAG). A similar result may be achieved by combining a UV emitting diode and at least three different UV absorbing phosphors: red, green, and blue emitting. These emitted colors mix to make white light. The efficiency of these LEDs is based on the combined efficiency of the LED, phosphor, and the interaction between the two. The Cabot SSL project attempted to improve the over all efficiency of the LED light source be improving the efficiency of the phosphor and the interaction between the LED light and the phosphor. Cabot's spray based process for producing phosphor powders is able to improve the brightness of the powder itself by increasing the activator (the species that emits the light) concentration without adverse quenching effects compared to conventional synthesis. This will allow less phosphor powder to be used, and will decrease the cost of the light source; thus lowering the barrier of entry to the lighting market. Cabot's process also allows for chemical flexibility of the phosphor particles, which may result in tunable emission spectra and so light sources with improved color rendering. Another benefit of Cabot's process is the resulting spherical morphology of the particles. Less light scattering results when spherical particles are used in the phosphor layer (Figure 1) compared to when conventional, irregular shaped phosphor particles are used. This spherical morphology will result in better light extraction and so an improvement of efficiency in the overall device. Cabot is a 2.5 billion dollar company that makes specialized materials using propriety spray based technologies. It is a core competency of Cabot's to exploit the spray based technology and resulting material/morphology advantages. Once a business opportunity is clearly identified, Cabot is positioned to increase the scale of the production to meet opportunity's need. Cabot has demonstrated the capability to make spherical morphology micron-sized phosphor powders by spray based routes for PDP and CRT applications, but the value proposition is still unproven for LED applications. Cabot believes that the improvements in phosphor powders yielded by their process will result in a commercial advantage over existing technologies. Through the SSL project, Cabot has produced a number of different compositions in a spherical morphology that may be useful for solid state lights, as well as demonstrated processes that are able to produce particles from 10 nanometers to 3 micrometers. Towards the end of the project we demonstrated that our process produces YAG:Ce powder that has both higher internal quantum efficiency (0.6 compared to 0.45) and external quantum efficiency (0.85 compared to 0.6) than the commercial standard (see section 3.4.4.3). We, however, only produced these highly bright materials in research and development quantities, and were never able to produce high quantum efficiency materials in a reproducible manner at a commercial scale.

  16. New family of tiny crystals glow bright in LED lights | ornl.gov

    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 for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOE Project Taps HPCNew User and DataNew companiesNewNew

  17. Low Emission Development Strategies (LEDS): Technical, Institutional...

    Open Energy Info (EERE)

    Strategies (LEDS): Technical, Institutional and Policy Lessons Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Low Emission Development Strategies (LEDS): Technical,...

  18. Low-Cost Illumination-Grade LEDs

    SciTech Connect (OSTI)

    Epler, John

    2013-08-31T23:59:59.000Z

    Solid State Lighting is a cost-effective, energy-conserving technology serving a rapidly expand- ing multi-billion dollar market. This program was designed to accelerate this lighting revolution by reducing the manufacturing cost of Illumination-Grade LEDs. The technical strategy was to investigate growth substrate alternatives to standard planar sapphire, select the most effective and compatible option, and demonstrate a significant increase in Lumen/$ with a marketable LED. The most obvious alternate substrate, silicon, was extensively studied in the first two years of the program. The superior thermal and mechanical properties of Si were expected to improve wavelength uniformity and hence color yield in the manufacture of high-power illumination- grade LEDs. However, improvements in efficiency and epitaxy uniformity on standard c-plane sapphire diminished the advantages of switching to Si. Furthermore, the cost of sapphire decreased significantly and the cost of processing Si devices using our thin film process was higher than expected. We concluded that GaN on Si was a viable technology but not a practical option for Philips Lumileds. Therefore in 2012 and 2013, we sought and received amendments which broadened the scope to include other substrates and extended the time of execution. Proprietary engineered substrates, off-axis (non-c-plane) sapphire, and c-plane patterned sapphire substrates (PSS) were all investigated in the final 18 months of this program. Excellent epitaxy quality was achieved on all three candidates; however we eliminated engineered substrates and non-c-plane sapphire because of their higher combined cost of substrate, device fabrication and packaging. Ultimately, by fabricating a flip-chip (FC) LED based upon c-plane PSS we attained a 42% reduction in LED manufacturing cost relative to our LUXEON Rebel product (Q1-2012). Combined with a flux gain from 85 to 102 Lm, the LUXEON Q delivered a 210% increase in Lm/$ over this time period. The technology was commercialized in our LUXEON Q product in Sept., 2013. Also, the retention of the sapphire increased the robustness of the device, enabling sales of low-cost submount-free chips to lighting manufacturers. Thus, blue LED die sales were initiated in the form of a PSS-FC in February, 2013.

  19. A NEW LED-LED PORTABLE CO2 GAS SENSOR BASED ON AN INTERCHANGEABLE MEMBRANE SYSTEM FOR INDUSTRIAL APPLICATIONS

    E-Print Network [OSTI]

    Lee, Hyowon

    to oxygen scavenging [5]. High CO2 levels (10- 80 %) are desirable for foods such as meat and poultryA NEW LED-LED PORTABLE CO2 GAS SENSOR BASED ON AN INTERCHANGEABLE MEMBRANE SYSTEM FOR INDUSTRIAL APPLICATIONS Abstract A new system for CO2 measurement (0-100%) by based on a paired emitter-detector diode

  20. Lighting the Great Outdoors: LEDs in Exterior Applications

    SciTech Connect (OSTI)

    Cook, Tyson D. S.; Bryan, Mary M.; Kinzey, Bruce R.; Myer, Michael

    2008-08-17T23:59:59.000Z

    Recent progress in the development of white light LEDs promises great impact by opening up the huge potential for LED illumination in new areas. One such area is general illumination for exterior applications. For example, there are an estimated combined 60.5 million roadway and parking installations in the U.S. These lights account for an estimated 53.3 TWh of electricity usage annually -- nearly 7% of all lighting. If LEDs could provide the same light performance with just 25% greater efficiency, savings of over 13 TWh could be achieved. In 2007, the authors assessed emerging LED lighting technologies in a parking garage and on a city street. The purpose of these tests was to enable a utility to determine whether energy efficiency programs promoting white light LED products might be justified. The results have supported the great promise of LEDs in exterior applications, while also highlighting the barriers that continue to hinder their widespread adoption. Such barriers include 1) inconsistent product quality across manufacturers; 2) lack of key metrics for comparing LEDs to conventional sources; and 3) high upfront cost of LED luminaires compared to conventional luminaires. This paper examines these barriers, ways in which energy-efficiency programs could help to overcome them, and the potential for energy and financial savings from LED lighting in these two exterior applications.

  1. LED Chips and Packaging for 120 LPW SSL Component

    SciTech Connect (OSTI)

    James Ibbetson

    2009-09-30T23:59:59.000Z

    Cree has developed a new, high-efficiency, low-cost, light emitting diode (LED) lamp module that should be capable of replacing standard, halogen, fluorescent and metal halide lamps based on the total cost of ownership. White LEDs are produced by combining one or more saturated color LEDs with a phosphor or other light down-converting media to achieve white broad-band illumination. This two year project addressed LED chip and package efficiency improvements to establish a technology platform suitable for low-cost, high-efficiency commercial luminaires. Novel photonic-crystal LEDs were developed to improve the light extraction efficiency of blue GaN-based LEDs compared to the baseline technology. Improved packaging designs that reduced down-conversion and absorption related light losses, led to a higher overall LED efficiency. Specifically, blue LEDs were demonstrated with light output nearing 600 mW and an external quantum efficiency greater than 60 percent (using 1 mm2 chips at an operating current of 350 mA). The results were achieved using a novel, production capable photonic-crystal LED fabrication process. These LEDs formed the basis for a multi-chip white lamp module prototype, which provided 510 lumens light output at a correlated color temperature (CCT) of 3875 K and an operating current of 350 mA per 1mm2 chip. The overall conversion efficiency at 4100 K improved to ~ 65%. The resulting efficacy is 112 lumens per watt (LPW) â?? a 33% improvement over the start of the project. In addition, a proof-of-concept luminaire was demonstrated that provided a flux of 1700 lumens at a 3842 K CCT.

  2. LED North America - Energy Innovation Portal

    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 for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 1 2 3 4 5 6 7 8 9LDRD, What doesLED

  3. MOF Coating a Promising Path to White LEDs

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

    (MOF); the structure was determined at Beamline 11.3.1. Coating a blue light-emitting diode (LED) with this compound readily generates white light with high luminous...

  4. Advances in Chip Technology, Packaging Enable White LED Breakthroughs

    Broader source: Energy.gov [DOE]

    Significant advances in chip technology have enabled Cree, Inc.'s Santa Barbara Technology Center to demonstrate white LEDs with record efficacies as high as 74 lumens per watt - on par with...

  5. Optimized Phosphors for Warm White LED Light Engines

    SciTech Connect (OSTI)

    Setlur, Anant; Brewster, Megan; Garcia, Florencio; Hill, M. Christine; Lyons, Robert; Murphy, James; Stecher, Tom; Stoklosa, Stan; Weaver, Stan; Happek, Uwe; Aesram, Danny; Deshpande, Anirudha

    2012-07-30T23:59:59.000Z

    The objective of this program is to develop phosphor systems and LED light engines that have steady-state LED efficacies (using LEDs with a 60% wall-plug efficiency) of 105–120 lm/W with correlated color temperatures (CCT) ~3000 K, color rendering indices (CRI) >85, <0.003 distance from the blackbody curve (dbb), and <2% loss in phosphor efficiency under high temperature, high humidity conditions. In order to reach these goals, this involves the composition and processing optimization of phosphors previously developed by GE in combination with light engine package modification.

  6. Integrated LED-based luminare for general lighting

    DOE Patents [OSTI]

    Dowling, Kevin J.; Lys, Ihor A.; Roberge, Brian; Williamson, Ryan C.; Roberts, Ron; Datta, Michael; Mollnow, Tomas; Morgan, Frederick M.

    2013-03-05T23:59:59.000Z

    Lighting apparatus and methods employing LED light sources are described. The LED light sources are integrated with other components in the form of a luminaire or other general purpose lighting structure. Some of the lighting structures are formed as Parabolic Aluminum Reflector (PAR) luminaires, allowing them to be inserted into conventional sockets. The lighting structures display beneficial operating characteristics, such as efficient operation, high thermal dissipation, high output, and good color mixing.

  7. Demonstration Assessment of Light Emitting Diode (LED) Residential Downlights and Undercabinet Lights in the Lane County Tour of Homes, Eugene, Oregon

    SciTech Connect (OSTI)

    Ton, My K.; Richman, Eric E.; Gilbride, Theresa L.

    2008-11-10T23:59:59.000Z

    In August 2008 the Pacific Northwest National Laboratory (PNNL) conducted a light emitting diode (LED) residential lighting demonstration project for the U.S. Department of Energy (DOE), Office of Building Technologies, as part of DOE’s Solid State Lighting (SSL) Technology Demonstration Gateway Program. Two lighting technologies, an LED replacement for downlight lamps (bulbs) and an LED undercabinet lighting fixture, were tested in the demonstration which was conducted in two homes built for the 2008 Tour of Homes in Eugene, Oregon. The homes were built by the Lane County Home Builders Association (HBA), and Future B Homes. The Energy Trust of Oregon (ETO) also participated in the demonstration project. The LED downlight product, the LR6, made by Cree LED Lighting Solutions acts as a screw-in replacement for incandescent and halogen bulbs in recessed can downlights. The second product tested is Phillips/Color Kinetics’ eW® Profile Powercore undercabinet fixture designed to mount under kitchen cabinets to illuminate the countertop and backsplash surfaces. Quantitative and qualitative measurements of light performance and electrical power usage were taken at each site before and after initially installed halogen and incandescent lamps were replaced with the LED products. Energy savings and simple paybacks were also calculated and builders who toured the homes were surveyed for their responses to the LED products. The LED downlight product drew 12 Watts of power, cutting energy use by 82% compared to the 65W incandescent lamp and by 84% compared to the 75W halogen lamp. The LED undercabinet fixture drew 10 watts, cutting energy use by 83% to 90% compared to the halogen product, which was tested at two power settings: a low power 60W setting and a high power 105W setting. The LED downlight consistently provided more light than the halogen and incandescent lamps in horizontal measurements at counter height and floor level. It also outperformed in vertical illuminance measurements taken on the walls, indicating better lateral dispersion of the light. The undercabinet fixture’s light output was midway between the low and high power halogen undercabinet fixture light outputs (35.8 foot candle versus 13.4 fc and 53.4 fc) but it produced a more uniform light (max/min ratio of 7.0 versus 10.8). The color correlated temperature (CCT, the blue or yellowness) of the LED light correlated well with the halogen and incandescent lights (2675 K vs 2700 K). The color rendering of the LED downlight also correlated well at 92 CRI compared to 100 CRI for the halogen and incandescent lamps. The LED undercabinet fixture had measures of 2880 K CCT and 71 CRI compared to the 2700 K and 100 CRI scores for the halogen undercabinet fixture. Builders who toured the homes were surveyed; they gave the LED downlight high marks for brightness, said the undercabinet improved shadows and glare and said both products improved overall visibility, home appearance, and home value. Paybacks on the LED downlight ranged from 7.6 years (assuming electricity cost of 11 c/kWh) to 13.5 years (at 5C/kWh). Paybacks on the LED undercabinet fixture in a new home ranged from 4.4 years (11c/kWh electricity) to 7.6 years (5c/kWh) based on product costs of $95 per LED downlight and $140 per LED undercabinet fixture at 3 hrs per day of usage for the downlight and 2 hrs per day for the undercabinet lighting.

  8. LED Watch: The Outlook for OLEDs

    Broader source: Energy.gov [DOE]

    December 2014 LED Watch: The Outlook for OLEDs James Brodrick, U.S. Department of Energy LD+A Magazine

  9. Bright Future NW Energy Coalition

    E-Print Network [OSTI]

    quickly set CO2 emission limits and establish mechanisms to meet them. But the Northwest must not waitAs Usual We have two choices for providing our electrical needs by 2050. We can either develop more of ourCoal Energy Efficiency/CHP 6˘/kWh With this extra 1,500 aMW in Bright Future we can power more electric

  10. The XMM-Newton X-ray Spectra of the Most X-ray Luminous Radio-quiet ROSAT Bright Survey-QSOs: A Reference Sample for the Interpretation of High-redshift QSO Spectra

    E-Print Network [OSTI]

    Krumpe, Mirko; Markowitz, Alex; Corral, Amalia; 10.1088/0004-637X/725/1/1

    2010-01-01T23:59:59.000Z

    We present the broadband X-ray properties of four of the most X-ray luminous (L_X >= 10^{45} erg/s in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe K-alpha fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe K-alpha centroids and the line widths indicate emission from neutral Fe (E=6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at...

  11. White LED Benchmark of 65 Lumens Per Watt Achieved

    Broader source: Energy.gov [DOE]

    Novel chip design and the balance of multiple interrelated design parameters have enabled Cree, Inc.'s Santa Barbara Technology Center to demonstrate white LEDs with efficacies greater than 65 lumens per watt at 350 mA. The results are particularly significant because they were achieved with a pre-production prototype chip using the same package used in Cree's commercially available XLamp® 7090 high power LED, rather than a laboratory device.

  12. Dual LED/incandescent security fixture

    DOE Patents [OSTI]

    Gauna, Kevin Wayne

    2005-06-21T23:59:59.000Z

    A dual LED and incandescent security lighting system uses a hybrid approach to LED illumination. It combines an ambient LED illuminator with a standard incandescent lamp on a motion control sensor. The LED illuminator will activate with the onset of darkness (daylight control) and typically remain on during the course of the night ("always on"). The LED illumination, typically amber, is sufficient to provide low to moderate level lighting coverage to the wall and ground area adjacent to and under the fixture. The incandescent lamp is integrated with a motion control circuit and sensor. When movement in the field of view is detected (after darkness), the incandescent lamp is switched on, providing an increased level of illumination to the area. Instead of an "always on" LED illuminator, the LEDs may also be switched off when the incandescent lamp is switched on.

  13. An Integrated Solid-State LED Luminaire for General Lighting

    SciTech Connect (OSTI)

    Kevin Dowling; Fritz Morgan Ihor Lys; Mike Datta; Bernd Keller; Thomas Yuan

    2009-03-31T23:59:59.000Z

    A strong systems approach to designing and building practical LED-based replacement lamps is lacking. The general method of taking high-performance LEDs and marrying them to standard printed circuit boards, drivers and a heat sink has fallen short of the promise of LED lighting. In this program, a top-down assessment of requirements and a bottom-up reinvention of LED sources, electronics, optics and mechanics have resulted in the highest performance lamp possible. The team, comprised of Color Kinetics, the leaders in LED lighting and Cree, the leaders in LED devices took an approach to reinvent the package, the driver and the overall form and aesthetic of a replacement source. The challenge was to create a new benchmark in LED lighting - the resultant lamp, a PAR38 equivalent, met the light output, color, color quality and efficacy marks set out in the program as well as being dimmable, which is important for market acceptance. The approach combined the use of multiple source die, a chip-on-board approach, a very efficient driver topology, the use of both direct emission and phosphor conversion, and a unique faceted optic to avoid the losses, artifacts and hotspots of lensed approaches. The integral heat sink provided a mechanical base and airflow using a chimney-effect for use in a wide variety of locations and orientations. These research results led to a much better understanding of the system effects of component level technologies. It was clear that best-of-breed sub-system results do not necessarily result in the best end result for the complete system. In doing this work, we did not neglect the practical aspects of these systems. These were not rarified results and commercially impractical but lent themselves to eventual commercial products in the marketplace. The end result - a high performance replacement lamp - will save significant energy while providing a high-quality light source.

  14. THE XMM-NEWTON X-RAY SPECTRA OF THE MOST X-RAY LUMINOUS RADIO-QUIET ROSAT BRIGHT SURVEY-QSOs: A REFERENCE SAMPLE FOR THE INTERPRETATION OF HIGH-REDSHIFT QSO SPECTRA

    SciTech Connect (OSTI)

    Krumpe, M.; Markowitz, A. [University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, La Jolla, CA 92093-0424 (United States); Lamer, G. [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam (Germany); Corral, A., E-mail: mkrumpe@ucsd.ed [INAF-Osservatorio Astronomico di Brera, via Brera 28, 20121 Milan (Italy)

    2010-12-20T23:59:59.000Z

    We present the broadband X-ray properties of four of the most X-ray luminous (L{sub X} {>=} 10{sup 45} erg s{sup -1} in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe K{alpha} fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe K{alpha} centroids and the line widths indicate emission from neutral Fe (E = 6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at very high luminosities. Taking into account our individual EW measurements, we show that the X-ray Baldwin effect flattens above L{sub X} {approx} 10{sup 44} erg s{sup -1} (2-10 keV band) where an almost constant (EW) of {approx}100 eV is found. We confirm the assumption of having very similar X-ray active galactic nucleus properties when interpreting stacked X-ray spectra. Our stacked spectrum serves as a superb reference for the interpretation of low S/N spectra of radio-quiet QSOs with similar luminosities at higher redshifts routinely detected by XMM-Newton and Chandra surveys.

  15. An Brief Overview Of Using LEDs In Lab

    E-Print Network [OSTI]

    Baas, Bevan

    Diodes · A Light-Emitting Diode (LED) is a special type of diode that emits photons (light) when current ­ Forward biased Diode Operation 0 V 5 V Current ~0 high (too high)5 V 0 V I anode cathode #12;3 Light-Emitting

  16. LED Linear Lamps and Troffer Lighting

    Broader source: Energy.gov [DOE]

    The CALiPER program performed a series of investigations on linear LED lamps. Each report in the series covers the performance of up to 31 linear LED lamps, which were purchased in late 2012 or 2013. The first report focuses on bare lamp performance of LED T8 replacement lamps and subsequent reports examine performance in various troffers, as well as cost-effectiveness. There is also a concise guidance document that describes the findings of the Series 21 studies and provides practical advice to manufacturers, specifiers, and consumers (Report 21.4: Summary of Linear (T8) LED Lamp Testing , 5 pages, June 2014).

  17. LED Replacements for Linear Fluorescent Lamps Webcast

    Broader source: Energy.gov [DOE]

    In this June 20, 2011 webcast on LED products marketed as replacements for linear fluorescent lamps, Jason Tuenge of the Pacific Northwest National Laboratory (PNNL) discussed current Lighting...

  18. LED Street Lighting Conversion Workshop Presentations

    Broader source: Energy.gov [DOE]

    This page provides links to the presentations given at the National League of Cities Mobile Workshop, LED Street Lighting Conversion: Saving Your Community Money, While Improving Public Safety,...

  19. Sandia National Laboratories: efficient LED lighting

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

    Partnership, Research & Capabilities, Solid-State Lighting Solid state lighting (SSL), which uses light-emitting diodes (LEDs), has the potential to be 10 times more energy...

  20. Challenges in LED Research and Development

    Broader source: Energy.gov [DOE]

    View the video about LED lighting technology, where it is headed, and the DOE’s role in its continued R&D.

  1. Municipal Consortium LED Street Lighting Workshop Presentations...

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

    Controls Norma Isahakian, City of Los Angeles Bureau of Street Lighting San Jose's "Smart" LED Streetlights: Controlled Amy Olay, City of San Jose Adaptive Lighting Controls...

  2. Bright three-band white light generated from CdSe/ZnSe quantum dot-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode with high color rendering index

    SciTech Connect (OSTI)

    Jang, Ho Seong; Kwon, Byoung-Hwa; Jeon, Duk Young [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yang, Heesun [Department of Materials Science and Engineering, Hongik University, 72-1, Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of)

    2009-10-19T23:59:59.000Z

    In this study, bright three-band white light was generated from the CdSe/ZnSe quantum dot (QD)-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode (WLED). The CdSe/ZnSe core/shell structure was confirmed by energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The CdSe/ZnSe QDs showed high quantum efficiency (79%) and contributed to the high luminous efficiency ({eta}{sub L}) of the fabricated WLED. The WLED showed bright natural white with excellent color rendering property ({eta}{sub L}=26.8 lm/W, color temperature=6140 K, and color rendering index=85) and high stability against the increase in forward bias currents from 20 to 70 mA.

  3. Today LED Holiday Lights, Tomorrow the World?

    SciTech Connect (OSTI)

    Gordon, Kelly L.

    2004-12-20T23:59:59.000Z

    This article for The APEM Advantage, the quarterly newsletter of the Association of Professional Energy Managers (APEM) describes the recent increase in the popularity of light emitting diode (LED) lighting and compares LED light output with that of incandescent and compact fluorescent lighting.

  4. Locally Led Conservation The Local Work Group

    E-Print Network [OSTI]

    Grants ­ Conservation Stewardship Program ­ Environmental Quality Incentive Program ­ Farm & Ranch Lands1 Locally Led Conservation & The Local Work Group Mark Habiger NRCS #12;2 What Is "Locally Led Conservation"? · Community Stakeholders ­ 1. Assessing their natural resource conservation needs ­ 2. Setting

  5. LED Light Sources for Projection Display Applications

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    LED Light Sources for Projection Display Applications By Chenhui Peng 04-13-2012 #12;Outline · 1. · The first practical LED is in red color and it is made with gallium arsenide (GaAs). 4http://en.wikipedia.org/wiki/Light with holes and release energy in the form of photons. 5http://en.wikipedia.org/wiki/Light-emitting_diode #12

  6. Financing Guidance for LED Street Lighting Programs

    Broader source: Energy.gov [DOE]

    Financing an LED street lighting replacement program can present a hurdle for many system owners, even if the planned transition offers very favorable economics. Replacing the existing system requires a significant budget, particularly as the scope of the program increases. Cities such as Los Angeles and Seattle have invested many millions of dollars into their (very successful) LED street lighting replacement programs.

  7. An LED pulser for measuring photomultiplier linearity

    E-Print Network [OSTI]

    Friend, M; Quinn, B

    2011-01-01T23:59:59.000Z

    A light-emitting diode (LED) pulser for testing the low-rate response of a photomultiplier tube (PMT) to scintillator-like pulses has been designed, developed, and implemented. This pulser is intended to simulate 80 ns full width at half maximum photon pulses over the dynamic range of the PMT, in order to precisely determine PMT linearity. This particular design has the advantage that, unlike many LED test rigs, it does not require the use of multiple calibrated LEDs, making it insensitive to LED gain drifts. Instead, a finite-difference measurement is made using two LEDs which need not be calibrated with respect to one another. These measurements give a better than 1% mapping of the response function, allowing for the testing and development of particularly linear PMT bases.

  8. LED Lighting Facts | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED Lighting Facts LED

  9. Ultra-bright pulsed electron beam with low longitudinal emittance

    DOE Patents [OSTI]

    Zolotorev, Max (Oakland, CA)

    2010-07-13T23:59:59.000Z

    A high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography has been described. The source makes use of Cs atoms in an atomic beam. The source is cycled beginning with a laser pulse that excites a single Cs atom on average to a band of high-lying Rydberg nP states. The resulting valence electron Rydberg wave packet evolves in a nearly classical Kepler orbit. When the electron reaches apogee, an electric field pulse is applied that ionizes the atom and accelerates the electron away from its parent ion. The collection of electron wave packets thus generated in a series of cycles can occupy a phase volume near the quantum limit and it can possess very high brightness. Each wave packet can exhibit a considerable degree of coherence.

  10. Decisions that led to Y-12

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

    German physicists Otto Hahn and Fritz Strass- mann's claim that they had achieved nuclear fission. He led a team that included Alfred O. C. Nier who was an expert on mass...

  11. LED Essentials- Technology, Applications, Advantages, Disadvantages

    Broader source: Energy.gov [DOE]

    On October 11, 2007, Kevin Dowling, VP of Innovation for Philips Solid-State Lighting Solutions, presented a broad introduction to LED technology, and discussed the technology status, advantages...

  12. LED Color Stability: 10 Important Questions

    Broader source: Energy.gov [DOE]

    This April 15, 2014 webinar examined the causes of color shift, and took a look at existing metrics used to describe color shift/color stability in LED lighting. The lumen maintenance lifetime of...

  13. Text-Alternative Version LED Lighting Forecast

    Broader source: Energy.gov [DOE]

    The DOE report Energy Savings Forecast of Solid-State Lighting in General Illumination Applications estimates the energy savings of LED white-light sources over the analysis period of 2013 to 2030....

  14. LEDS GP Success Story: Fostering Coordinated LEDS Support in Kenya (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-03-01T23:59:59.000Z

    The LEDS Global Partnership (LEDS GP) strives to advance climate-resilient, low-emission development through catalyzing collaboration, information exchange, and action on the ground. The Government of Kenya is a key LEDS GP member and offers an inspiring example of how LEDS GP is having an impact globally. The 2012 LEDS Collaboration in Action workshop in London provided an interactive space for members to share experiences on cross-ministerial LEDS leadership and to learn about concrete development impacts of LEDS around the world. Inspired by these stories, the Kenya's Ministry of State for Planning, National Development and Vision 2030 (MPND) began to collaborate closely with the Ministry of Environment and Mineral Resources to create strong links between climate change action and development in the country, culminating in the integration of Kenya's National Climate Change Action Plan and the country's Medium Term Development Plan.

  15. Pittsburgh LED Street Lighting Research Project Performance Criteria

    Broader source: Energy.gov [DOE]

    A Pittsburgh LED Street Lighting Research Project document on Technical and Aesthetic Performance for Business District LED Lighting.

  16. WhiteOptics' Low-Cost Reflector Composite Boosts LED Fixture Efficiency

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, WhiteOptics has developed a composite coating that can be used to improve efficiency in backlit, indirect, and cavity-mixing LED luminaire designs by maximizing light reflection and output. The highly diffuse coating, which is based on a novel high-reflectance particle technology, allows for uniform distribution of light without exaggerating the point-source nature of the LEDs, and is intended to offer an overall system cost-improving solution for LED optics.

  17. 130 LPW 1000 Lm Warm White LED for Illumination

    SciTech Connect (OSTI)

    Soer, Wouter

    2012-06-14T23:59:59.000Z

    An illumination-grade warm-white LED, having correlated color temperature (CCT) between 2700 and 3500 K and capable of producing 1000 lm output at over 130 lm/W at room temperature, has been developed in this program. The high-power warm-white LED is an ideal source for use in indoor and outdoor lighting applications. Over the two year period, we have made the following accomplishments: • Developed a low-cost high-power white LED package and commercialized a series of products with CCT ranging from 2700 to 5700 K under the product name LUXEON M; • Demonstrated a record efficacy of 124.8 lm/W at a flux of 1023 lm, CCT of 3435 K and color rendering index (CRI) over 80 at room temperature in the productized package; • Demonstrated a record efficacy of 133.1 lm/W at a flux of 1015 lm, CCT of 3475 K and CRI over 80 at room temperature in an R&D package. The new high-power LED package is a die-on-ceramic surface mountable LED package. It has four 2 mm2 InGaN pump dice, flip-chip attached to a ceramic submount in a 2x2 array configuration. The submount design utilizes a design approach that combines a high-thermal- conductivity ceramic core for die attach and a low-cost and low-thermal-conductivity ceramic frame for mechanical support and as optical lens carrier. The LED package has a thermal resistance of less than 1.25 K/W. The white LED fabrication also adopts a new batch level (instead of die-by-die) phosphor deposition process with precision layer thickness and composition control, which provides not only tight color control, but also low cost. The efficacy performance goal was achieved through the progress in following key areas: (1) high-efficiency royal blue pump LED development through active region design and epitaxial growth quality improvement (funded by internal programs); (2) improvement in extraction efficiency from the LED package through improvement of InGaN-die-level and package-level optical extraction efficiency; and (3) improvement in phosphor system efficiency by improving the lumen equivalent (LE) and phosphor package efficiency (PPE) through improvement in phosphor-package interactions. The high-power warm-white LED product developed has been proven to have good reliability through extensive reliability tests. The new kilo-lumen package has been commercialized under the product name LUXEON M. As of the end of the program, the LUXEON M product has been released in the following CCT/CRI combinations: 3000K/70, 4000K/70, 5000K/70, 5700K/70, 2700K/80, 3000K/80 and 4000K/80. LM-80 tests for the products with CCTs of 4000 K and higher have reached 8500 hours, and per IESNA TM-21-11 have established an L70 lumen maintenance value of >51,000 hours at A drive current and up to 120 °C board temperature.

  18. Small Area Array-Based LED Luminaire Design

    SciTech Connect (OSTI)

    Thomas Yuan

    2008-01-09T23:59:59.000Z

    This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency LED luminaire designs based on small area array-based gallium nitride diodes. Novel GaN-based LED array designs are described, specifically addressing the thermal, optical, electrical and mechanical requirements for the incorporation of such arrays into viable solid-state LED luminaires. This work resulted in the demonstration of an integrated luminaire prototype of 1000 lumens cool white light output with reflector shaped beams and efficacy of 89.4 lm/W at CCT of 6000oK and CRI of 73; and performance of 903 lumens warm white light output with reflector shaped beams and efficacy of 63.0 lm/W at CCT of 2800oK and CRI of 82. In addition, up to 1275 lumens cool white light output at 114.2 lm/W and 1156 lumens warm white light output at 76.5 lm/W were achieved if the reflector was not used. The success to integrate small area array-based LED designs and address thermal, optical, electrical and mechanical requirements was clearly achieved in these luminaire prototypes with outstanding performance and high efficiency.

  19. Microwave generated electrodeless lamp for producing bright output

    SciTech Connect (OSTI)

    Wood, Ch. H.; Ury, M. G.

    1985-03-26T23:59:59.000Z

    A microwave generated electrodeless light source for producing a bright output comprising a lamp structure including a microwave chamber and a plasma medium-containing lamp envelope having a maximum dimension which is substantially less than a wavelength disposed therein. To provide the desired radiation output the interior of the chamber is coated with a UV-reflective material and the chamber has an opening for allowing UV radiation to exit, which is covered with a metallic mesh. The chamber is arranged to be near-resonant at a single wavelength, and the lamp envelope has a fill including mercury at an operating pressure of 1-2 atmospheres, while a power density of at least 250-300 (watts/cm/sup 3/) is coupled to the envelope to result in a relatively high deep UV output at a relatively high brightness.

  20. Batse observations of gamma-ray burst spectra; 2, peak energy evolution in bright, long bursts

    E-Print Network [OSTI]

    Ford, L A; Matteson, J L; Briggs, M S; Pendleton, G N; Preece, R D; Paciesas, W S; Teegarden, B J; Palmer, D M; Schaefer, B E; Cline, T L; Fishman, G J; Kouveliotou, C; Meegan, C A; Wilson, R B; Lestrade, J P

    1994-01-01T23:59:59.000Z

    Abstract We investigate spectral evolution in 37 bright, long gamma-ray bursts observed with the BATSE Spectroscopy Detectors. High resolution spectra are characterized by the energy of the peak of \

  1. LED Lighting Forecast | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED Lighting Facts

  2. LED Outdoor Area Lighting Fact Sheet

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED LightingOutdoor Area

  3. Surface Brightness Profiles of Seyfert Galaxies

    E-Print Network [OSTI]

    Tugay, A V

    2014-01-01T23:59:59.000Z

    We built r-band surface brightness profiles by SDSS data for 16 Seyfert galaxies observed in Crimean Astrophysical Observatory. Obtained profiles can be used for finding more accurate lightcurves for these galaxies.

  4. PublicationsmailagreementNo.40014024 Bright minds and

    E-Print Network [OSTI]

    Victoria, University of

    PublicationsmailagreementNo.40014024 Bright minds and organic matter THE 80% Amount by which-friendly behaviour Psychology grad student Reuven Sussman (centre) at the Hillside Centre food court where he

  5. Philips Lumileds Achieves 139 lm/W in a Neutral White LED

    Broader source: Energy.gov [DOE]

    Philips Lumileds' LUXEON Rebel LED can now deliver 139 lm/W in a neutral white LED. The top bin LED, developed with a single InGaN die and phosphor conversion, shows high-performance characteristics up to 139 lm/W and 138 lumens at 350 mA, with a forward voltage of 2.83 V. The CCT of the device is 5385K and the CRI is 70.

  6. Sustainable LED Fluorescent Light Replacement Technology

    SciTech Connect (OSTI)

    None

    2011-06-30T23:59:59.000Z

    Ilumisys and the National Center for Manufacturing Sciences (NCMS) partnered on a three-year project awarded by the United States (U.S.) Department of Energy (DOE), to quantify the impacts of LED lamps, incandescent lamps and fluorescent benchmark lamps over a product lifecycle – i.e. to develop a sustainable design and manufacturing strategy that addresses product manufacturing, use, recycling and disposal scenarios for LED-based lighting. Based on the knowledge gained from extensive product tear-down studies of fluorescent and screw-in lighting products, lifecycle assessment tools, and accelerated lifecycle testing protocols, an interactive Sustainable LED Design Guide has been developed to aid architectural and lighting designers and engineers in making design decisions that consider three important environmental impacts (greenhouse gas emissions, energy use and mercury emission) across all phases of the life of an LED lighting product. Critical information developed for the lifecycle analysis and product feature comparisons is the useful life of the lighting product as well as its performance. The Design Guide is available at www.ncms.org, and was developed based on operational and durability testing of a variety of lighting products including power consumption, light output, and useful life of a lamp in order to allow a more realistic comparison of lamp designs. This report describes the main project tasks, results and innovative features of the lifecycle assessment (LCA)-based design tools, and the key considerations driving the sustainable design of LED lighting systems. The Design Guide incorporates the following three novel features for efficiently evaluating LED lighting features in value-chains: • Bill-of-Materials (BOM) Builder – Designers may import process data for each component and supply functional data for the product, including power, consumption, lumen output and expected useful life. • Environmental Impact Review – Designs are comparable across lifecycle phases, subsystems, and environmental impact category, and can be normalized to a userdefined functional unit. • Drill-down Review – These provide an indepth look at individual lamp designs with the ability to review across subsystem or lifecycle phase.

  7. The Deconvolution of Lunar Brightness Temperature based on Maximum Entropy Method using Chang'E-2 Microwave Data

    E-Print Network [OSTI]

    Xing, Shuguo; Feng, Jianqing; Li, Chunlai

    2014-01-01T23:59:59.000Z

    A passive and multi-channel microwave sounder onboard Chang'E-2 orbiter has successfully performed microwave observation of the lunar surface and subsurface structure. Compared with Chang'E-1 orbiter, Chang'E-2 orbiter obtained more accurate and comprehensive microwave brightness temperature data which is helpful for further research. Since there is a close relationship between microwave brightness temperature data and some related properties of the lunar regolith, such as the thickness, temperature and dielectric constant, so precise and high resolution brightness temperature is necessary for such research. However, through the detection mechanism of the microwave sounder, the brightness temperature data acquired from the microwave sounder is weighted by the antenna radiation pattern, so the data is the convolution of the antenna radiation pattern and the lunar brightness temperature. In order to obtain the real lunar brightness temperature, a deconvolution method is needed. The aim of this paper is to solve...

  8. Massive Disks in Low Surface Brightness Galaxies

    E-Print Network [OSTI]

    B. Fuchs

    2002-09-09T23:59:59.000Z

    An update of the set of low surface brightness galaxies is presented which can be used to set constraints on the otherwise ambiguous decompositions of their rotation curves into contributions due to the various components of the galaxies. The selected galaxies show all clear spiral structure and arguments of density wave theory of galactic spiral arms are used to estimate the masses of the galactic disks. Again these estimates seem to indicate that the disks of low surface brightness galaxies might be much more massive than currently thought. This puzzling result contradicts stellar population synthesis models. This would mean also that low surface brightness galaxies are not dominated by dark matter in their inner parts.

  9. 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...

  10. 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...

  11. (Expired) Nationwide Limited Public Interest Waiver for LED Lighting...

    Energy Savers [EERE]

    (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC Units: February 11, 2010 (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC...

  12. Energy Department Announces New University-Led Projects to Create...

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

    University-Led Projects to Create More Efficient, Lower Cost Concentrating Solar Power Systems Energy Department Announces New University-Led Projects to Create More Efficient,...

  13. Research Led by Sandia Reveals Leading-Edge Erosion Significantly...

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

    Research Led by Sandia Reveals Leading-Edge Erosion Significantly Reduces Wind Turbine Performance Research Led by Sandia Reveals Leading-Edge Erosion Significantly Reduces Wind...

  14. Application Summary Report 22: LED MR16 Lamps

    SciTech Connect (OSTI)

    Royer, Michael P.

    2014-07-23T23:59:59.000Z

    This report analyzes the independently tested photometric performance of 27 LED MR16 lamps. It describes initial performance based on light output, efficacy, distribution, color quality, electrical characteristics, and form factor, with comparisons to a selection of benchmark halogen MR16s and ENERGY STAR qualification thresholds. Three types of products were targeted. First, CALiPER sought 3000 K lamps with the highest rated lumen output (i.e., at least 500 lm) or a claim of equivalency to a 50 W halogen MR16 or higher. The test results indicate that while the initial performance of LED MR16s has improved across the board, market-available products still do not produce the lumen output and center beam intensity of typical 50 W halogen MR16 lamps. In fact, most of the 18 lamps in this category had lower lumen output and center beam intensity than a typical 35 W halogen MR16 lamp. Second, CALiPER sought lamps with a CRI of 90 or greater. Only four manufacturers were identified with a product in this category. CALiPER testing confirmed the performance of these lamps, which are a good option for applications where high color fidelity is needed. A vast majority of the LED MR16 lamps have a CRI in the low 80s; this is generally acceptable for ambient lighting, but may not always be acceptable for focal lighting. For typical LED packages, there is a fundamental tradeoff between CRI and efficacy, but the lamps in the high-CRI group in this report still offer comparable performance to the rest of the Series 22 products in other performance areas. Finally, CALiPER sought lamps with a narrow distribution, denoted as a beam angle less than 15°. Five such lamps were purchased. Notably, no lamp was identified as having high lumen output (500 lumens or greater), high CRI (90 or greater), a narrow distribution (15° or less), and an efficacy greater than 60 lm/W. This would be an important achievement for LED MR16s especially if output could reach approximately 700 800 lumens, or the approximate equivalent of a 50 W halogen MR16 lamp. Many factors beyond photometric performance should be considered during specification. For example, performance over time, transformer and dimmer compatibility, and total system performance are all critical to a successful installation. Subsequent CALiPER reports will investigate more complex issues.

  15. Dark and bright photovoltaic spatial solitons

    SciTech Connect (OSTI)

    Valley, G.C. (Hughes Research Laboratories, Malibu, California 90265 (United States)); Segev, M.; Crosignani, B.; Yariv, A. (California Institute of Technology, Pasadena, California 91125 (United States)); Fejer, M.M.; Bashaw, M.C. (Stanford University, Stanford, California 94305 (United States))

    1994-12-01T23:59:59.000Z

    Dark (bright) planar spatial solitons are predicted for photovoltaic photorefractive materials when the diffraction of an optical beam is exactly compensated by nonlinear self-defocusing (focusing) due to the photovoltaic field and electro-optic effect. These solitons may have steady-state irradiances of microwatts to milliwatts per square centimeter and widths as small as 10 [mu]m in lithium niobate. Optical control is provided by incoherent illumination, and the nonlinear index of a dark soliton may be used to trap a bright soliton by rotating the plane of polarization of the soliton field.

  16. SemiLEDs | 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 |Rippey JumpAir JumpCalifornia | OpenSelawik|SemiLEDs Jump

  17. SunLed Technologies | 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 IRaghuraji Agro Industries PvtStratosolar Jump to: navigation,SunElectra Jump to: navigation,SunLed

  18. Recessed LED Downlights | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin of ContaminationHubs+18, 2012 Qualified11Department ofMeetingSynthetic DieselRecessed LED

  19. The siting record: An account of the programs of federal agencies and events that have led to the selection of a potential site for a geologic respository for high-level radioactive waste

    SciTech Connect (OSTI)

    Lomenick, T.F.

    1996-03-01T23:59:59.000Z

    This record of siting a geologic repository for high-level radioactive wastes (HLW) and spent fuel describes the many investigations that culminated on December 22, 1987 in the designation of Yucca Mountain (YM), as the site to undergo detailed geologic characterization. It recounts the important issues and events that have been instrumental in shaping the course of siting over the last three and one half decades. In this long task, which was initiated in 1954, more than 60 regions, areas, or sites involving nine different rock types have been investigated. This effort became sharply focused in 1983 with the identification of nine potentially suitable sites for the first repository. From these nine sites, five were subsequently nominated by the U.S. Department of Energy (DOE) as suitable for characterization and then, in 1986, as required by the Nuclear Waste Policy Act of 1982 (NWPA), three of these five were recommended to the President as candidates for site characterization. President Reagan approved the recommendation on May 28, 1986. DOE was preparing site characterization plans for the three candidate sites, namely Deaf Smith County, Texas; Hanford Site, Washington; and YM. As a consequence of the 1987 Amendment to the NWPA, only the latter was authorized to undergo detailed characterization. A final Site Characterization Plan for Yucca Mountain was published in 1988. Prior to 1954, there was no program for the siting of disposal facilities for high-level waste (HLW). In the 1940s and 1950s, the volume of waste, which was small and which resulted entirely from military weapons and research programs, was stored as a liquid in large steel tanks buried at geographically remote government installations principally in Washington and Tennessee.

  20. Business Honors Program A Bright Business Future

    E-Print Network [OSTI]

    de Lijser, Peter

    Business Honors Program Achieve! #12;2page A Bright Business Future If you are a talented no further. The Business Honors Program at Mihaylo College of Business and Economics provides a socially and professionally stimulating academic environment to a select group of business administration students. As you

  1. Laser Power Meter Large, bright, backlit LCD

    E-Print Network [OSTI]

    Woodall, Jerry M.

    Laser Power Meter FEATURES · Large, bright, backlit LCD display · Digital accuracy with analog-like movement for laser tuning · Works with thermopile and optical sensors · Intuitive button-driven user COMPATIBILITY · PowerMax® thermal sensors · Optical sensors FieldMaxII-TO Coherent Laser Measurement and Control

  2. Surface brightness in plasma-redshift cosmology

    E-Print Network [OSTI]

    Ari Brynjolfsson

    2006-05-31T23:59:59.000Z

    In 2001 Lori M. Lubin and Allan Sandage, using big-bang cosmology for interpreting the data, found the surface brightness of galaxies to be inversely proportional to about the third power of (1+z), while the contemporary big-bang cosmology predicts that the surface brightness is inversely proportional to the fourth power of (1+z). In contrast, these surface brightness observations are in agreement with the predictions of the plasma-redshift cosmology. Lubin and Sandage (2001) and Barden et al. (2005), who surmised the big-bang expansion, interpreted the observations to indicate that the diameters of galaxies are inversely proportional to (1+z). In contrast, when assuming plasma-redshift cosmology, the diameters of galaxies are observed to be constant independent of redshift and any expansion. Lubin and Sandage (2001) and Barden et al. (2005), when using big-bang cosmology, observed the average absolute magnitude of galaxies to decrease with redshift; while in plasma redshift cosmology it is a constant. Lubin and Sandage and Barden et al. suggested that a coherent evolution could explain the discrepancy between the observed relations and those predicted in the big-bang cosmology. We have failed to find support for this explanation. We consider the observed relations between the redshift and the surface-brightness, the galaxy diameter, and the absolute magnitude to be robust confirmations of plasma-redshift cosmology.

  3. An Efficient LED System-in-Module for General Lighting Applications

    SciTech Connect (OSTI)

    None

    2008-09-14T23:59:59.000Z

    The objective of the project was to realize an LED-based lighting technology platform for general illumination, starting with LED chips, and integrating the necessary technologies to make compact, user-friendly, high-efficiency, energy-saving sources of controlled white (or variable-colored) light. The project is to build the system around the LEDs, and not to work on the LEDs themselves, in order that working products can be introduced soon after the LEDs reach suitable efficiency for mass-production of high-power light sources for general illumination. Because the light sources are intended for general illumination, color must be accurately maintained, requiring feedback control in the electronics. The project objective has been realized and screw base demonstrators, based on the technology developed in the project, have been built.

  4. Text-Alternative Version: LED Essentials- Technology, Applications, Advantages, Disadvantages

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the LED Essentials - Technology, Applications, Advantages, Disadvantages webcast.

  5. LED exit signs: Improved technology leads the way to energy savings

    SciTech Connect (OSTI)

    Sardinsky, R.; Hawthorne, S.

    1994-12-31T23:59:59.000Z

    Recent innovations in light-emitting diode (LED) exit signs may make LED signs the best choice among the energy efficient options available. In the past, LED signs have offered low power consumption, projected long lamp life, and low maintenance requirements. Now, the best of the LED signs also offer improved optical designs that reduce their already low power consumption while improving visibility and appearance, and even reduce their cost. LED exit signs are gaining market share, and E Source expects this technology to eventually dominate over incandescent, compact fluorescent, and electroluminescent signs. More research is needed, however, to confirm manufacturers` claims of 20-year operating lives for LED signs. Conservative estimates place the number of exit signs in US buildings at about 40 million. Although each sign represents a very small part of a building`s load, exit signs are ready targets for energy efficiency upgrades -- they operate continuously and most use inefficient incandescent sources. With an LED sign, annual energy and maintenance costs can be reduced by more than 90 percent compared to a typical incandescent sign. Low annual costs help to offset the LED sign`s relatively high first cost. More than 25 utilities offer DSM incentives for energy efficient exit signs, and efficient alternatives are becoming more readily available. Recent improvements in optical designs enable many LED signs to visually out perform other sources. In addition to these benefits, LED exit signs have lower life cycle cost than most other options. The biggest barrier to their success, however, is that their first cost has been considerably higher than competing technologies. LED sign prices are falling rapidly, though, because manufacturers are continually improving optical designs of the fixtures to use fewer LEDs and thus even less energy while providing better performance.

  6. Psychophysical evaluations of modulated color rendering for energy performance of LED-based architectural lighting

    E-Print Network [OSTI]

    Thompson, Maria do Rosário

    2007-01-01T23:59:59.000Z

    This thesis is focused on the visual perception evaluation of colors within an environment of a highly automated lighting control strategy. Digitally controlled lighting systems equipped with light emitting diodes, LEDs, ...

  7. Feedback-Controlled LED Photobioreactor for Photophysiological Studies of Cyanobacteria

    SciTech Connect (OSTI)

    Melnicki, Matthew R.; Pinchuk, Grigoriy E.; Hill, Eric A.; Kucek, Leo A.; Stolyar, Sergey; Fredrickson, Jim K.; Konopka, Allan; Beliaev, Alex S.

    2013-04-09T23:59:59.000Z

    A custom photobioreactor (PBR) was designed to enable automatic light adjustments using computerized feedback control. A black anodized aluminum enclosure, constructed to surround the borosilicate reactor vessel, prevents the transmission of ambient light and serves as a mount for arrays of light-emitting diodes (LEDs). The high-output LEDs provide narrow-band light of either 630 or 680 nm for preferential excitation of the cyanobacterial light-harvesting pigments, phycobilin or chlorophyll a, respectively. Custom developed software BioLume provides automatic control of optical properties and a computer feedback loop can automatically adjust the incident irradiance as necessary to maintain a fixed transmitted light through the culture, based on user-determined set points. This feedback control serves to compensate for culture dynamics which have optical effects, (e.g., changing cell density, pigment adaptations) and thus can determine the appropriate light conditions for physiological comparisons or to cultivate light-sensitive strains, without prior analyses. The LED PBR may also be controlled as a turbidostat, using a feedback loop to continuously adjust the rate of media-dilution based on the transmitted light measurements, with a fast and precise response. This cultivation system gains further merit as a high-performance analytical device, using non-invasive tools (e.g., dissolved gas sensors, online mass spectrometry) to automate real-time measurements, thus permitting unsupervised experiments to search for optimal growth conditions, to monitor physiological responses to perturbations, as well as to quantitate photophysiological parameters using an in situ light-saturation response routine.

  8. High Bandgap Phosphide Approaches for LED Applications - Energy Innovation

    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 for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm) Harmonicbet WhenHiggs Boson May Be WithinPortal

  9. High Efficiency Driving Electronics for General Illumination LED Luminaires

    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 for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartmentInnovation Portal 130221326| SciTech

  10. An ultra-bright atom laser

    E-Print Network [OSTI]

    V. Bolpasi; N. K. Efremidis; M. J. Morrissey; P. Condylis; D. Sahagun; M. Baker; W. von Klitzing

    2013-11-25T23:59:59.000Z

    We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just below the condensate. As opposed to traditional atom lasers based on weak coupling, this technique allows us to outcouple atoms at an arbitrarily large rate. We demonstrate an increase in flux per atom in the BEC by a factor of sixteen compared to the brightest quasi-continuous atom laser. Furthermore, we produce by two orders of magnitude the coldest thermal atom beam to date (200 nK).

  11. EECBG Success Story: Bright Green Spot: Fort Worth Library |...

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

    Bright Green Spot: Fort Worth Library EECBG Success Story: Bright Green Spot: Fort Worth Library September 30, 2010 - 9:53am Addthis Fort Worth's Central Library is seeing...

  12. Bright Green Spot: Fort Worth Library | Department of Energy

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

    Bright Green Spot: Fort Worth Library Bright Green Spot: Fort Worth Library September 30, 2010 - 4:07pm Addthis Lindsay Gsell Fort Worth's Central Library is seeing tremendous...

  13. Search for bright stars with infrared excess

    SciTech Connect (OSTI)

    Raharto, Moedji, E-mail: moedji@as.itb.ac.id [Astronomy Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24T23:59:59.000Z

    Bright stars, stars with visual magnitude smaller than 6.5, can be studied using small telescope. In general, if stars are assumed as black body radiator, then the color in infrared (IR) region is usually equal to zero. Infrared data from IRAS observations at 12 and 25?m (micron) with good flux quality are used to search for bright stars (from Bright Stars Catalogues) with infrared excess. In magnitude scale, stars with IR excess is defined as stars with IR color m{sub 12}?m{sub 25}>0; where m{sub 12}?m{sub 25}?=??2.5log(F{sub 12}/F{sub 25})+1.56, where F{sub 12} and F{sub 25} are flux density in Jansky at 12 and 25?m, respectively. Stars with similar spectral type are expected to have similar color. The existence of infrared excess in the same spectral type indicates the existence of circum-stellar dust, the origin of which is probably due to the remnant of pre main-sequence evolution during star formation or post AGB evolution or due to physical process such as the rotation of those stars.

  14. 2002 AUGUST 24 LIMB FLARE LOOP: DYNAMICS OF MICROWAVE BRIGHTNESS DISTRIBUTION

    SciTech Connect (OSTI)

    Reznikova, V. E.; Ji, H. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); Melnikov, V. F.; Gorbikov, S. P.; Pyatakov, N. P. [Radiophysical Research Institute (NIRFI), Nizhny Novgorod 603950 (Russian Federation); Shibasaki, K. [Nobeyama Solar Radio Observatory/NAOJ, Nagano 384-1305 (Japan); Myagkova, I. N. [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation)], E-mail: vreznikova@nirfi.sci-nnov.ru

    2009-05-20T23:59:59.000Z

    High-resolution radio observation of Nobeyama Radioheliograph at 17 and 34 GHz allowed studying the dynamics of microwave brightness distribution along the giant limb flaring loop in the event of 2002 August 24. It is found that on the rising phase of the radio burst the brightness distribution was highly asymmetric, with a strong maximum near the southern footpoint (SFP) and much weaker brightness enhancements near the loop top (LT) and northern footpoint. On the decay phase, the LT gradually became most bright. The similar dynamics of brightness distribution are shown to happen for all major temporal subpeaks of the burst. Results of our diagnostics show two important properties: (1) the number density of mildly relativistic electrons in the LT is much higher than near the footpoints (FPs) during rise, maximum and decay of each major peak; and (2) the ratio of the electron number densities in the LT and an FP increases from the maximum to decay phase. Model simulations with making use of the nonstationary Fokker-Planck equation have allowed us to find the model explaining the major properties of the microwave brightness distribution and dynamics. The model is characterized by a compact source of electrons located near the center of an asymmetric magnetic loop; the source is nonstationary, long lasting, and injecting high-energy electrons with the pitch-angle distribution mostly directed toward the SFP but also having a very weak isotropic component. This easily explains the observed brightness asymmetry. The observed dynamics comes due to two reasons: faster precipitation of electrons having their mirror points near the ends of the magnetic trap, and relatively faster decay of the lower energy electrons responsible for the gyrosynchrotron emission near the FPs with higher magnetic field.

  15. MC-CAM Research Topics Organic LEDs

    E-Print Network [OSTI]

    Bigelow, Stephen

    materials with highly- controlled microstructures Next generation optical storage media Products based applications Novel conjugated polymers and high-conductivity organics Nanostructured materials with unique electronic, magnetic, and optical properties Chemically modified fullerenes and fullerene devices Materials

  16. Regenerative braking on bicycles to power LED safety flashers

    E-Print Network [OSTI]

    Collier, Ian M

    2005-01-01T23:59:59.000Z

    This work develops a method for capturing some of the kinetic energy ordinarily lost during braking on bicycles to power LED safety flashers. The system is designed to eliminate: (a) battery changing in popular LED flashers, ...

  17. EECBG Success Story: Small Nebraska Town Welcomes LEDs and Energy...

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

    historic square, built in the 1850's, is about to become home to something new: LED lights. Learn more. Addthis Related Articles Tecumseh is installing 95 new LED light fixtures...

  18. LEDs Go Ivy League: Princeton’s Dillon Gymnasium

    Broader source: Energy.gov [DOE]

    View the video about LED lighting in Dillon Gymnasium, a focal point of sports and recreation at Princeton since 1947. William Evans discusses measurable benefits of LED lighting in the gym and...

  19. Text-Alternative Version: Challenges in LED Research and Development

    Broader source: Energy.gov [DOE]

    Narrator: LEDs have made remarkable progress in the past decade and gained a strong foothold in the US marketplace. In 2012, LED lighting saved an estimated 71 trillion BTUs, equivalent to annual...

  20. The redshifts of bright sub-mm sources

    E-Print Network [OSTI]

    James S. Dunlop

    2001-01-17T23:59:59.000Z

    One of the key goals in observational cosmology over the next few years will be to establish the redshift distribution of the recently-discovered sub-mm source population. In this brief review I discuss and summarize the redshift information which has been gleaned to date for the ~ 50 bright sub-mm sources which have been uncovered via the six main classes of survey performed with SCUBA on the JCMT over the last 2-3 years. Despite the biases inherent in some of these surveys, and the crudeness of the redshift information available in others, I conclude that all current information suggests that only 10-15 % of luminous sub-mm sources lie at z < 2, and that the median redshift of this population is z ~ 3. I suggest that such a high median redshift is arguably not unexpected given current theories designed to explain the correlation between black-hole mass and spheroid mass found at low redshift. In such scenarios, peak AGN emission is expected to correspond to, or even to cause termination of major star-formation activity in the host spheroid. In contrast, maximum dust emission is expected to occur roughly half-way through the star-formation process. Given that optical emission from bright quasars peaks at z = 2.5, dust-emission from massive ellipticals might be reasonably expected to peak at some point in the preceding ~ 1 Gyr, at z ~ 3. Confirmation or refutation of this picture requires significantly-improved redshift information on bright samples of SCUBA sources.

  1. Text-Alternative Version: LED Replacements for Linear Fluorescent Lamps

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "LED Replacements for Linear Fluorescent Lamps" webcast, held June 20, 2011.

  2. Text-Alternative Version: LEDs for Interior Office Applications

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the LEDs for Interior Office Applications webcast, held March 18, 2010.

  3. Text-Alternative Version: Evaluating LED Street Lighting Solutions

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the Evaluating LED Street Lighting Solutions webcast, held July 20, 2010.

  4. Mann LED Elevator Ligh ng: ECI Savings Table Cost (billed)

    E-Print Network [OSTI]

    Lipson, Michal

    the elevators, deter mined an LED replace ment lamp for the ex is ng halogen lamps, cal culated a cost benefitMann LED Elevator Ligh ng: ECI Savings Table Utility Historical Energy Use (MMBtu) Est. FY 2012,000 2 Energy Conservation Initiative (ECI) Project Summary Mann LED Elevator Ligh ng, Facility 1027 Mann

  5. Philips Lumileds Is Exploring the Use of Silicon Substrates to Lower the Cost of LEDs

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, Philips Lumileds is exploring the use of nitride epitaxy on 150mm silicon substrates to produce low-cost, warm-white, high-performance general-illumination LEDs. Most LEDs are made with C-plane sapphire substrates, but silicon—at roughly half a penny per square millimeter—is much cheaper, and it's also easier to obtain. Philips Lumileds is attempting to adapt the use of silicon to the manufacture of LEDs, drawing upon the knowledge base and depreciated equipment of the computer industry, which has been using silicon substrates for decades.

  6. BrightPhase Energy | 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:EzfeedflagBiomassSustainable and Innovative Energy Technologies | OpenBrigham CityBrightPhase

  7. BrightSource Energy | 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 being directedAnnual Siteof Energy 2,AUDIT REPORT Americium/CuriumAguaBBBWind- GeradoraBorealBradBrightSource

  8. Bright Automotive Inc | 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 being directedAnnual Siteof EnergyInnovation in CarbonofBiotinsBostonBridger Valley Elec Assn, Inc (Utah)Bright

  9. Ultra-Compact High-Efficiency Luminaire for General Illumination

    SciTech Connect (OSTI)

    Ted Lowes

    2012-04-08T23:59:59.000Z

    Cree has developed a new ultra-compact light emitting diode (LED) luminaire capable of providing high efficacy with excellent color quality that can lead to significant energy savings in todayâ??s commercial and retail applications. This success was based on an integrated development effort tailoring the LED component characteristics, optics, thermal management and driver design for the small footprint to achieve an overall system efficiency of â?Ą 70%. A new LED component was designed to provide high brightness and efficacy in a form factor that allowed for a small directional beam with a luminaire housing design able to dissipate the heat effectively using a small physical envelope. A very compact, 90% efficient driver was developed to meet the system performance while not taking away any thermal mass from the heat sink. A 91% efficient secondary optics was designed to maximize efficiency while providing a smooth beam. The reliability of the new LED component was robust under accelerated testing conditions. Luminaires were assembled integrating the novel LED component, secondary optics, heat sink and driver technology to demonstrate the system improvement. Cree has successfully completed this project by developing an ultra-compact LED luminaire that provided 380 lumens at a correlated color temperature (CCT) of 2822 K and color rendering index (CRI) of 94 with an efficacy of 94 lumens per watt (LPW) when operating at 4 W input power (steady state) with an overall system efficiency of 81%. At a higher input power of 9 Watts, the lamp provided 658 lumens at 71 LPW.

  10. Asymmetric Surface Brightness Distribution of Altair Observed with the Navy Prototype Optical Interferometer

    E-Print Network [OSTI]

    Naoko Ohishi; Tyler E. Nordgren; Donald J. Hutter

    2004-05-16T23:59:59.000Z

    An asymmetric surface brightness distribution of the rapidly rotating A7IV-V star, Altair, has been measured by the Navy Prototype Optical Interferometer (NPOI). The observations were recorded simultaneously using a triangle of three long baselines of 30m, 37m, and 64m, on 19 spectral channels, covering the wavelength range of 520nm to 850nm. The outstanding characteristics of these observations are (a) high resolution with the minimum fringe spacing of 1.7mas, easily resolving the 3-milliarcsecond (mas) stellar disk, and (b) the measurement of closure phase which is a sensitive indicator to the asymmetry of the brightness distribution of the source. Uniform disk diameters fit to the measured squared visibility amplitudes confirms the Altair's oblate shape due to its rapid rotation. The measured observables of Altair showed two features which are inconsistent with both the uniform-disk and limb-darkened disk models, while the measured observable of the comparison star, Vega, are consistent with the limb-darkened disk model. The first feature is that measured squared visibility amplitudes at the first minimum do not reach 0.0 but rather remain at about 0.02, indicating the existence of a small bright region on the stellar disk. The other is that the measured closure phases show non-zero/180 degrees at all spectral channels, which requires an asymmetric surface brightness distribution. We fitted the measured observables to a model with a bright spot on a limb-darkened disk and found the observations are well reproduced by a bright spot, which has relative intensity of 4.7%, on a 3.38 mas limb-darkened stellar disk. Rapid rotation of Altair indicates that this bright region is a pole, which is brighter than other part of the star owing to gravity darkening.

  11. The IRAS Revised Bright Galaxy Sample (RBGS)

    E-Print Network [OSTI]

    Sanders, D B; Kim, D C; Surace, J A; Soifer, B T

    2003-01-01T23:59:59.000Z

    IRAS flux densities, redshifts, and infrared luminosities are reported for all sources identified in the IRAS Revised Bright Galaxy Sample (RBGS), a complete flux-limited survey of all extragalactic objects with total 60 micron flux density greater than 5.24 Jy, covering the entire sky surveyed by IRAS at Galactic latitude |b| > 5 degrees. The RBGS includes 629 objects, with a median (mean) sample redshift of 0.0082 (0.0126) and a maximum redshift of 0.0876. The RBGS supersedes the previous two-part IRAS Bright Galaxy Samples, which were compiled before the final ("Pass 3") calibration of the IRAS Level 1 Archive in May 1990. The RBGS also makes use of more accurate and consistent automated methods to measure the flux of objects with extended emission. Basic properties of the RBGS sources are summarized, including estimated total infrared luminosities, as well as updates to cross-identifications with sources from optical galaxy catalogs established using the NASA/IPAC Extragalactic Database (NED). In addition...

  12. Development of Production PVD-AIN Buffer Layer System and Processes to Reduce Epitaxy Costs and Increase LED Efficiency

    SciTech Connect (OSTI)

    Cerio, Frank

    2013-09-14T23:59:59.000Z

    The DOE has set aggressive goals for solid state lighting (SSL) adoption, which require manufacturing and quality improvements for virtually all process steps leading to an LED luminaire product. The goals pertinent to this proposed project are to reduce the cost and improve the quality of the epitaxial growth processes used to build LED structures. The objectives outlined in this proposal focus on achieving cost reduction and performance improvements over state-of-the-art, using technologies that are low in cost and amenable to high efficiency manufacturing. The objectives of the outlined proposal focus on cost reductions in epitaxial growth by reducing epitaxy layer thickness and hetero-epitaxial strain, and by enabling the use of larger, less expensive silicon substrates and would be accomplished through the introduction of a high productivity reactive sputtering system and an effective sputtered aluminum-nitride (AlN) buffer/nucleation layer process. Success of the proposed project could enable efficient adoption of GaN on-silicon (GaN/Si) epitaxial technology on 150mm silicon substrates. The reduction in epitaxy cost per cm{sup 2} using 150mm GaN-on-Si technology derives from (1) a reduction in cost of ownership and increase in throughput for the buffer deposition process via the elimination of MOCVD buffer layers and other throughput and CoO enhancements, (2) improvement in brightness through reductions in defect density, (3) reduction in substrate cost through the replacement of sapphire with silicon, and (4) reduction in non-ESD yield loss through reductions in wafer bow and temperature variation. The adoption of 150mm GaN/Si processing will also facilitate significant cost reductions in subsequent wafer fabrication manufacturing costs. There were three phases to this project. These three phases overlap in order to aggressively facilitate a commercially available production GaN/Si capability. In Phase I of the project, the repeatability of the performance was analyzed and improvements implemented to the Veeco PVD-AlN prototype system to establish a specification and baseline PVD-AlN films on sapphire and in parallel the evaluation of PVD AlN on silicon substrates began. In Phase II of the project a Beta tool based on a scaled-up process module capable of depositing uniform films on batches of 4”or 6” diameter substrates in a production worthy operation was developed and qualified. In Phase III, the means to increase the throughput of the PVD-AlN system was evaluated and focused primarily on minimizing the impact of the substrate heating and cooling times that dominated the overall cycle time.

  13. Quality and Performance of LED Flashlights in Kenya: Common End User Preferences and Complaints

    SciTech Connect (OSTI)

    Tracy, Jenny; Jacobson, Arne; Mills, Evan

    2009-09-14T23:59:59.000Z

    Flashlights that use LED technology have quickly emerged as the dominant source of portable lighting in Kenya. While flashlights do not normally provide a substitute for kerosene and other highly inefficient fuels, they are an important early manifestation of LED lighting in the developing world that can serve as a platform - or deterrent - to the diffusion of the technology into the broader off-grid lighting market. The lead acid batteries embedded in flashlights also represent an important source of hazardous waste, and flashlight durability is thus an important determinant of the rate of waste disposal. Low-cost LED flashlights with prices from $1 to $4 are now widely available in shops and markets throughout Kenya. The increased penetration of LED technology in the flashlight market is significant, as over half of all Kenyan households report owning a flashlight (Kamfor, 2002). While this shift from conventional incandescent technology to modern LEDs may appear to be a promising development, end users that our research team interviewed expressed a number of complaints about the quality and performance of these new flashlights. This raises concerns about the interests of low-income flashlight users, and it may also indicate the onset of a broader market spoiling effect for off-grid lighting products based on LED technology (Mills and Jacobson, 2008; Lighting Africa, 2007). The quality of low-cost LED flashlights can contribute to market spoiling because these products appear to represent the first contact that most Kenyans have with LED technology. In this report, our team uses interviews with 46 end users of flashlights to collect information about their experiences, perceptions, and preferences. We focus especially on highlighting common complaints from respondents about the flashlights that they have used, as well as on noting the features that they indicated were important when evaluating the quality of a flashlight. In previous laboratory tests, researchers from our team found a wide range of quality and performance among battery powered LED lights (Granderson, et al. 2008).

  14. Bright tunable femtosecond x-ray emission from laser irradiated micro-droplets

    SciTech Connect (OSTI)

    Yu, Tong-Pu, E-mail: tongpu@nudt.edu.cn; Hu, Li-Xiang; Yin, Yan; Shao, Fu-Qiu; Zhuo, Hong-Bin; Ma, Yan-Yun; Yang, Xiao-Hu [College of Science, National University of Defense Technology, Changsha 410073 (China); Luo, Wen [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Pukhov, Alexander [Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf (Germany)

    2014-09-15T23:59:59.000Z

    It is demonstrated that bright femtosecond X-rays can be obtained by irradiating a moderate laser onto a helium micro-droplet. The laser ponderomotive force continuously sweeps electrons from the droplets and accelerates them forward. The electrons exposed in the outrunning laser field oscillate transversely and emit photons in the forward direction. The total flux of photons with energies above 1?keV is as high as 10{sup 9}/shot which is about 10-fold enhancement compared with betatron oscillation under similar laser conditions. The maximum achieved peak brightness is up to 10{sup 21} photons/s/mm{sup 2}/mrad{sup 2}/0.1%BW. By adjusting laser and droplet parameters, we can get tunable X-rays with required brightness and energy.

  15. AN ALL-SKY CATALOG OF BRIGHT M DWARFS

    SciTech Connect (OSTI)

    Lepine, Sebastien [Department of Astrophysics, Division of Physical Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, 1680 East-West Road, Honolulu, HI 96822 (United States)

    2011-10-15T23:59:59.000Z

    We present an all-sky catalog of M dwarf stars with apparent infrared magnitude J < 10. The 8889 stars are selected from the ongoing SUPERBLINK survey of stars with proper motion {mu} > 40 mas yr{sup -1}, supplemented on the bright end with the Tycho-2 catalog. Completeness tests which account for kinematic (proper motion) bias suggest that our catalog represents {approx}75% of the estimated {approx}11, 900 M dwarfs with J < 10 expected to populate the entire sky. Our catalog is, however, significantly more complete for the northern sky ({approx}90%) than it is for the south ({approx}60%). Stars are identified as cool, red M dwarfs from a combination of optical and infrared color cuts, and are distinguished from background M giants and highly reddened stars using either existing parallax measurements or, if such measurements are lacking, using their location in an optical-to-infrared reduced proper motion diagram. These bright M dwarfs are all prime targets for exoplanet surveys using the Doppler radial velocity or transit methods; the combination of low-mass and bright apparent magnitude should make possible the detection of Earth-size planets on short-period orbits using currently available techniques. Parallax measurements, when available, and photometric distance estimates are provided for all stars, and these place most systems within 60 pc of the Sun. Spectral type estimated from V - J color shows that most of the stars range from K7 to M4, with only a few late M dwarfs, all within 20 pc. Proximity to the Sun also makes these stars good targets for high-resolution exoplanet imaging searches, especially if younger objects can be identified on the basis of X-ray or UV excess. For that purpose, we include X-ray flux from ROSAT and FUV/NUV ultraviolet magnitudes from GALEX for all stars for which a counterpart can be identified in those catalogs. Additional photometric data include optical magnitudes from Digitized Sky Survey plates and infrared magnitudes from the Two Micron All Sky Survey.

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

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

    where LED efficiency plunges, simulations at the U.S. Department of Energy's National Energy Research Scientific Computing Center (NERSC) have shown. Using NERSC's Cray XC30...

  17. LED Luminaire Lifetime: Recommendations for Testing and Reporting

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

    product life, and many relied on the gradual lumen depreciation of the LED (light-emitting diode) source as the best indicator- resulting, on occasion, in unrealistic claims...

  18. LED Provides Effective and Efficient Parking Area Lighting at...

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

    White Light Options for Parking Area Lighting Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Final Report Guide to FEMP-Designated Parking Lot...

  19. The City of Los Angeles LED Streetlight Program

    Broader source: Energy.gov [DOE]

    View the video about the Los Angeles LED streetlight program, featuring an interview with City of Los Angeles Bureau of Street Lighting Director, Ed Ebrahimian.

  20. ORNL-led team demonstrates desalination with nanoporous graphene...

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

    Communications 865.576.6448 ORNL-led team demonstrates desalination with nanoporous graphene membrane Researchers created nanopores in graphene (red, and enlarged in the circle...

  1. Article Published on LED Lumen Maintenance and Light Loss Factors...

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

    of a comprehensive lifetime rating - as well as the problematic relationship between SSL lifetime and lumen maintenance - determining an appropriate LLD factor for LED products...

  2. CBEA LED Site Lighting Specification - Version 1.3, Released...

    Energy Savers [EERE]

    Applications Outdoor Area Lighting Home About the Solid-State Lighting Program R&D Program Market-Based Programs SSL Basics Using LEDs Information Resources Financial Opportunities...

  3. LEDs Go Ivy League: Princeton University and DOE GATEWAY Demonstrations

    Broader source: Energy.gov [DOE]

    View the video about LED lighting at Princeton University, which has dramatically reduced energy costs in a number of installations around campus. William Evans, electrical engineer, describes the...

  4. Adopting LED Technology: What Federal Facility Managers Need to Know

    Broader source: Energy.gov [DOE]

    This document describes the presentation slides for the "Adopting LED Technology: What Federal Facility Managers Need to Know" webinar that took place on September 11, 2014.

  5. Cooking Up New Nanoribbons to Make Better White LEDs | Advanced...

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

    appealing white phosphors based on LEDs. The materials combine the rare-earth element europium with aluminum oxide to form europium aluminate nanoribbons. Powders of europium oxide...

  6. automated local bright: Topics by E-print Network

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

    with the penumbral features. The bright points are not uniformly distributed over the umbra but preferentially located around the penumbral boundary and in the fast decaying...

  7. artificial sky brightness: Topics by E-print Network

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

    with the penumbral features. The bright points are not uniformly distributed over the umbra but preferentially located around the penumbral boundary and in the fast decaying...

  8. average brightness thomson: Topics by E-print Network

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

    with the penumbral features. The bright points are not uniformly distributed over the umbra but preferentially located around the penumbral boundary and in the fast decaying...

  9. area telescope bright: Topics by E-print Network

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

    with the penumbral features. The bright points are not uniformly distributed over the umbra but preferentially located around the penumbral boundary and in the fast decaying...

  10. albeit ultraviolet bright: Topics by E-print Network

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

    with the penumbral features. The bright points are not uniformly distributed over the umbra but preferentially located around the penumbral boundary and in the fast decaying...

  11. CALiPER Report 21.3: Cost-Effectiveness of Linear (T8) LED Lamps

    SciTech Connect (OSTI)

    Miller, Naomi J.; Perrin, Tess E.; Royer, Michael P.

    2014-05-27T23:59:59.000Z

    Meeting performance expectations is important for driving adoption of linear LED lamps, but cost-effectiveness may be an overriding factor in many cases. Linear LED lamps cost more initially than fluorescent lamps, but energy and maintenance savings may mean that the life-cycle cost is lower. This report details a series of life-cycle cost simulations that compared a two-lamp troffer using LED lamps (38 W total power draw) or fluorescent lamps (51 W total power draw) over a 10-year study period. Variables included LED system cost ($40, $80, or $120), annual operating hours (2,000 hours or 4,000 hours), LED installation time (15 minutes or 30 minutes), and melded electricity rate ($0.06/kWh, $0.12/kWh, $0.18/kWh, or $0.24/kWh). A full factorial of simulations allows users to interpolate between these values to aid in making rough estimates of economic feasibility for their own projects. In general, while their initial cost premium remains high, linear LED lamps are more likely to be cost-effective when electric utility rates are higher than average and hours of operation are long, and if their installation time is shorter.

  12. Assessment of LED Technology in Ornamental Post-Top Luminaires (Host Site: Sacramento, CA)

    SciTech Connect (OSTI)

    Tuenge, Jason R.

    2011-12-01T23:59:59.000Z

    The DOE Municipal Solid-State Street Lighting Consortium has evaluated four different LED replacements for existing ornamental post-top street lights in Sacramento, California. The project team was composed of the City and its consultant, PNNL (representing the Consortium), and the Sacramento Municipal Utility District. Product selection was finalized in March 2011, yielding one complete luminaire replacement and three lamp-ballast retrofit kits. Computer simulations, field measurements, and laboratory testing were performed to compare the performance and cost-effectiveness of the LED products relative to the existing luminaire with 100 W high-pressure sodium lamp. After it was confirmed the LED products were not equivalent to HPS in terms of initial photopic illumination, the following parameters were scaled proportionally to enable equitable (albeit hypothetical) comparisons: light output, input wattage, and pricing. Four replacement scenarios were considered for each LED product, incorporating new IES guidance for mesopic multipliers and lumen maintenance extrapolation, but life cycle analysis indicated cost effectiveness was also unacceptable. Although LED efficacy and pricing continue to improve, this project serves as a timely and objective notice that LED technology may not be quite ready yet for such applications.

  13. Research on optimization of cooling structure of LED element (The 2nd report)

    SciTech Connect (OSTI)

    Kobayashi, T.; Sakate, Y. [Department of Electronics and Control Engineering, Tsuyama National College of Technology, Okayama (Japan); Hashimoto, R. [Collaborative Research Center, Hiroshima University, Hiroshima (Japan); Takashina, T. [International Industry Academia Collaboration Division, Hiroshima University, Hiroshima (Japan); Kanematsu, H. [Department of Materials Science and Engineering, Suzuka National College of Technology, Mie (Japan); Utsumi, Y. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Hyogo (Japan)

    2014-02-20T23:59:59.000Z

    This report shows a design guideline on the parts dimension of LED light bulb for heat transfer. LED light bulb is popular owing to the high efficiency and long life. However, LED element is a point heat source. Therefore, LED light bulb has some problems about heat transfer when it is used for lighting. It sometimes causes deterioration by the raise of local temperature, resulting in lowering of efficiency and shorter life. Thus the thermal analysis focused on the number of element, all parts thickness, length, and radiant heat was studied, as systematic report on the points has not been found. In this report, heat radiation was taken into account in the thermal analysis in addition to natural heat convection. Furthermore the temperature of a heat sink model for LED light bulb was measured with thermocouples and thermo-viewer to verify the calculation. The emissivity of aluminum used for the calculation was 0.4. As the result of analysis, it was found that the maximum temperature was mainly influenced by ring length, ring diameter and disk thickness as a design guideline. Concretely, longer length, larger diameter and thicker disk gave lower temperature of LED element. The temperatures of the best and worst model were around 70 °C and 120 °C respectively in the above condition. The temperatures calculated were consistent with those in experiment.

  14. Semiconductors 4-bit I2C LED dimmer

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    with SMBus · Internal power-on reset · Noise filter on SCL/SDA inputs · 4 open drain outputs directly drive for dimming LEDs in 256 discrete steps for Red/Green/Blue (RGB) color mixing and back light applications to 1.69 second. The open drain outputs directly drive the LEDs with maximum output sink current of 25 m

  15. Epitaxial Growth of GaN-based LEDs on Simple Sacrificial Substrates

    SciTech Connect (OSTI)

    Ian Ferguson; Chris Summers

    2009-12-31T23:59:59.000Z

    The objective of this project is to produce alternative substrate technologies for GaN-based LEDs by developing an ALD interlayer of Al{sub 2}O{sub 3} on sacrificial substrates such as ZnO and Si. A sacrificial substrate is used for device growth that can easily be removed using a wet chemical etchant leaving only the thin GaN epi-layer. After substrate removal, the GaN LED chip can then be mounted in several different ways to a metal heat sink/reflector and light extraction techniques can then be applied to the chip and compared for performance. Success in this work will lead to high efficiency LED devices with a simple low cost fabrication method and high product yield as stated by DOE goals for its solid state lighting portfolio.

  16. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    LCLSprobe experiments at the lcls. Opt. Express, 18(17):17620–probe experiments at the LCLS. Optics express, 18(17):17620–

  17. High-brightness beam diagnostics for the APS linac.

    SciTech Connect (OSTI)

    Lumpkin, A. H.

    1999-04-20T23:59:59.000Z

    The Advanced Photon Source (APS) injector includes an S-band linac with the capability to accelerate beams to 650 MeV. The linac has recently been upgraded with the installation of an rf thermionic gun in addition to the standard DC thermionic gun. The rf gun is predicted to have lower emittance (5{pi}mm mrad) and may be used to support the APS self-amplified spontaneous emission (SASE) experiments. The critical characterization of this gun's beam has begun with a beam diagnostics station at the end of the linac that can address beam transverse size, emittance, and bunch length (peak current). This station uses both an optical transition radiation (OTR) screen at 45{degree} to the beam direction and a Ce-doped YAG single crystal normal to the beam with a 45{degree} mirror behind it. The visible light images are detected by a Vicon CCD camera and a Hamamatsu C5680 synchroscan streak camera. Spatial resolution of about 30 {micro}m ({sigma}) and temporal resolution of 1 ps ({sigma}) have been demonstrated. Examples of rf gun beam characterization at 220 MeV are reported.

  18. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    1989. [96] A. Yariv and P. Yeh. Optical Waves in Crystals:Mar 2008. [95] Amnon Yariv. Quantum electronics. Wiley,

  19. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    Hartmann, D. Rolles, A. Rudenko, C. Schmidt, L. Foucar, N.R. Hartmann, D. Rolles, A. Rudenko, L. Fou- car, N. Kimmel,

  20. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    Hoegen, and D. von der Linde. Femtosecond X-ray measurementTh. Tschentscher, D. von der Linde, and J. B. Hastings.Tinten, P. Tsu, D. von der Linde, S. I. Anisimov, S. I.

  1. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    field lines as the electromagnetic pulse travels into thepulses 117 Femtosecond probing of transient electromagneticlaser pulses and the evolution of electromagnetic fields in

  2. LED Lights for All Occasions | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED Lighting FactsLED

  3. Impact of photonic crystals on LED light extraction efficiency: approaches and limits to vertical structure designs

    SciTech Connect (OSTI)

    Matioli, Elison; Weisbuch, Claude

    2010-01-01T23:59:59.000Z

    The enhancement of the extraction efficiency in light emitting diodes (LEDs) through the use of photonic crystals (PhCs) requires a structure design that optimizes the interaction of the guided modes with the PhCs. The main optimization parameters are related to the vertical structure of the LED, such as the thickness of layers, depth of the PhCs, position of the quantum wells as well as the PhC period and fill factor. We review the impact of the vertical design of different approaches of PhC LEDs through a theoretical and experimental standpoint, assessing quantitatively the competing mechanisms that act over each guided mode. Three approaches are described to overcome the main limitation of LEDs with surface PhCs, i.e. the insufficient interaction of low order guided modes with the PhCs. The introduction of an AlGaN confining layer in such structure is shown to be effective in extracting a fraction of the optical energy of low order modes; however, this approach is limited by the growth of the lattice mismatched AlGaN layer on GaN. The second approach, based on thin-film LEDs with PhCs, is limited by the presence of an absorbing reflective metal layer close to the guided modes that plays a major role in the competition between PhC extraction and metal dissipation. Finally, we demonstrate both experimentally and theoretically the superior extraction of the guided light in embedded PhC LEDs due to the higher interaction between all optical modes and the PhCs, which resulted in a close to unity extraction efficiency for this device. The use of high-resolution angle-resolved measurements to experimentally determine the PhC extraction parameters was an essential tool for corroborating the theoretical models and quantifying the competing absorption and extraction mechanisms in LEDs.

  4. 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

    LEDs is the significant current droop at high current, whicha binning problem and current droop problems [9]. Thus, theinvestigated due to less current droop and improved binning

  5. Team Led by Argonne National Lab Selected as DOE's Batteries...

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

    Team Led by Argonne National Lab Selected as DOE's Batteries and Energy Storage Hub On November 30, 2012 In features Energy Department Announces Team to Receive up to 120...

  6. WEBINAR: CAN LEDS PERFORM IN A PERFORMING ARTS BUILDING? | Department...

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

    the Nadine McGuire Theatre + Dance Pavilion at the University of Florida. Can LEDs render skin tones and makeup accurately in a dressing room? Can they provide the vertical...

  7. EECBG Success Story: Solar LED Light Pilot Project Illuminates...

    Energy Savers [EERE]

    courtesy of Lionel Green, Sand Mountain Reporter. A strip of new solar-powered light emitting-diode (LED) streetlights in Boaz, Alabama were installed with grant funds from the...

  8. Text-Alternative Version: LED Color Stability Webinar

    Broader source: Energy.gov [DOE]

    Michael Royer: All right, welcome ladies and gentleman. I'm Michael Royer of Pacific Northwest National Laboratory, and I'd like to welcome you to today's webinar on LED Color Stability, Ten...

  9. Measured Off-Grid LED Lighting System Performance

    E-Print Network [OSTI]

    Granderson, Jessica

    2009-01-01T23:59:59.000Z

    Budget: The Economics of Off-Grid Lighting for SmallA. Jacobson. 2007. "The Off-Grid Lighting Market in WesternTesting for Emerging Off-grid White-LED Illumination Systems

  10. Implementing and Sustaining Operator Led Energy Efficiency Improvements

    E-Print Network [OSTI]

    Hoyle, A.; Knight, N.; Rutkowski, M.

    2011-01-01T23:59:59.000Z

    , to significantly reduce energy consumption, the site must focus on a strategic approach which involves developing, implementing and sustaining a client specific program of energy optimization. We discuss ways of sustaining energy performance through operator led...

  11. Sandia National Laboratories: AlGaAs LEDs

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

    electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

  12. Laboratory Evaluation of LED T8 Replacement Lamp Products

    SciTech Connect (OSTI)

    Richman, Eric E.; Kinzey, Bruce R.; Miller, Naomi J.

    2011-05-23T23:59:59.000Z

    A report on a lab setting analysis involving LED lamps intended to directly replace T8 fluorescent lamps (4') showing light output, power, and economic comparisons with other fluorescent options.

  13. WEBINAR: LED LIGHTING IN A PERFORMING ARTS BUILDING

    Broader source: Energy.gov [DOE]

    Can LEDs render skin tones and makeup accurately in a dressing room? Can they provide the vertical footcandles in a studio to make dancers' bodies visible, or deliver acting studio lighting to...

  14. Demonstrating LED and Fiber Optic Lighting in Commissary Applications

    Broader source: Energy.gov [DOE]

    Presentation—given at the Federal Utility Partnership Working Group (FUPWG) Fall 2008 meeting—covers goals of the project and applications for light-emitting diodes (LEDs) and fiber optic lighting.

  15. af led lyskilder: Topics by E-print Network

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

    Effective Fabrication of a Solar PV Panel for LED Lighting CiteSeer Summary: Abstract Solar cells are very fragile so they need a encapsulant and encasing for protection and...

  16. The Problem Conventional office lighting typically consists of bright fluo-

    E-Print Network [OSTI]

    by delamping--result in lower power consump- tion. The PLS, which features light-emitting diode (LED lighting is reduced and three light-emitting diode (LED) task lights (two desk lamps and one undercabinet

  17. S 1.1.1 Highly Polarized Non-polar GaN-based LED Unpolarized LED

    E-Print Network [OSTI]

    LĂĽ, James Jian-Qiang

    Jiaxiang Zhang Solution: Smart Lighting Solid state lighting + Control theory + Animal experiments are advancing solid state devices to move lighting beyond the Bulb and improve human health." Drinking WaterN-based power electronics. Common Vision ­ · Incorporate smart lighting features in everyday lighting fixtures

  18. Emission Line Properties of the Large Bright Quasar Survey

    E-Print Network [OSTI]

    Karl Forster; Paul J. Green; Thomas L. Aldcroft; Marianne Vestergaard; Craig B. Foltz; Paul C. Hewett

    2000-11-20T23:59:59.000Z

    We present measurements of the optical/UV emission lines for a large homogeneous sample of 993 quasars from the Large Bright Quasar Survey. Our largely automated technique accounts for continuum breaks and galactic reddening, and we perform multicomponent fits to emission line profiles, including the effects of blended iron emission, and of absorption lines both galactic and intrinsic. Here we describe the fitting algorithm and present the results of line fits to the LBQS sample, including upper limits to line equivalent widths when warranted. The distribution of measured line parameters, principally equivalent width and FWHM, are detailed for a variety of lines, including upper limits. We thus initiate a large-scale investigation of correlations between the high energy continuum and emission lines in quasars, to be extended to complementary samples using similar techniques. High quality, reproducible measurements of emission lines for uniformly selected samples will advance our understanding of active galaxies, especially in a new era of large surveys selected by a variety of complementary methods.

  19. Dim Matter in the Disks of Low Surface Brightness Galaxies

    E-Print Network [OSTI]

    B. Fuchs

    2002-04-23T23:59:59.000Z

    An attempt is made to set constraints on the otherwise ambiguous decomposition of the rotation curves of low surface brightness galaxies into contributions due to the various components of the galaxies. For this purpose galaxies are selected which show clear spiral structure. Arguments of density wave theory of galactic spiral arms are then used to estimate the masses of the galactic disks. These estimates seem to indicate that the disks of low surface brightness galaxies might be much more massive than currently thought. This unexpected result contradicts stellar population synthesis models. This would also mean that low surface brightness galaxies are not dominated by dark matter in their inner parts.

  20. Infrared Brightness Temperature of Mars, 1983-2103

    E-Print Network [OSTI]

    E. L. Wright

    2007-03-25T23:59:59.000Z

    The predicted infrared brightness temperature of Mars using the 1976 model of Wright is tabulated here for the period 1983 to 2103. This model was developed for far-infrared calibration, and is still being used for JCMT calibration.

  1. On the relationship between brightness temperature and thunderstorm evolution

    E-Print Network [OSTI]

    Rapp, Anita Denise

    2013-02-22T23:59:59.000Z

    ON THE RELATIONSHIP BETWEEN BRIGHTNESS TEMPERATURE AND THUNDERSTORM EVOLUTION A Senior Honors Thesis By ANITA DENISE RAPP Submitted to the Office of Honors Programs 4 Academic Scholarslnps Texas A&M University In partial fulfillment... of the requirements of the UNIVERSITY UNDERGRADUATE RESEARCH FELLOWS April 2000 Group: Physical Sciences ON THE RELATIONSHIP BETWEEN BRIGHTNESS TEMPERATURE AND THUNDERSTORM EVOLUTION A Senior Honors Thesis By ANITA DENlSE RAPP Submitted to the OIIice...

  2. Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting in Leavenworth, KS

    SciTech Connect (OSTI)

    Myer, Michael; Kinzey, Bruce R.; Curry, Ku'uipo

    2011-05-06T23:59:59.000Z

    This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a commercial parking lot lighting application, under the U.S. Department of Energy (DOE) Solid-State Lighting Technology GATEWAY Demonstration Program. The parking lot is for customers and employees of a Walmart Supercenter in Leavenworth, Kansas and this installation represents the first use of the LED Parking Lot Performance Specification developed by the DOE’s Commercial Building Energy Alliance. The application is a parking lot covering more than a half million square feet, lighted primarily by light-emitting diodes (LEDs). Metal halide wall packs were installed along the building facade. This site is new construction, so the installed baseline(s) were hypothetical designs. It was acknowledged early on that deviating from Walmart’s typical design would reduce the illuminance on the site. Walmart primarily uses 1000W pulse-start metal halide (PMH) lamps. In order to provide a comparison between both typical design and a design using conventional luminaires providing a lower illuminance, a 400W PMH design was also considered. As mentioned already, the illuminance would be reduced by shifting from the PMH system to the LED system. The Illuminating Engineering Society of North America (IES) provides recommended minimum illuminance values for parking lots. All designs exceeded the recommended illuminance values in IES RP-20, some by a wider margin than others. Energy savings from installing the LED system compared to the different PMH systems varied. Compared to the 1000W PMH system, the LED system would save 63 percent of the energy. However, this corresponds to a 68 percent reduction in illuminance as well. In comparison to the 400W PMH system, the LED system would save 44 percent of the energy and provide similar minimum illuminance values at the time of relamping. The LED system cost more than either of the PMH systems when comparing initial costs. However, when the life-cycle costs from energy and maintenance were factored into the scenario, the LED system had lower costs at the end of a 10-year analysis period. The LED system had a 6.1 year payback compared to the 1000W PMH system and a 7.5 year payback versus the 400W PMH system. The costs reflect high initial cost for the LED luminaire, plus more luminaires and (subsequently) more poles for the LED system. The other major issue affecting cost effectiveness was that Leavenworth, Kansas has very low electricity costs. The melded rate for this site was $0.056 per kWh for electricity. However, if the national electricity rate of $0.1022/kWh was used the payback would change to between four and five years for the LED system. This demonstration met the GATEWAY requirements of saving energy, matching or improving illumination, and being cost effective. The project also demonstrated that the Commercial Building Energy Alliance (CBEA) specification works in practice. Walmart appreciated having an entire site lighted by LEDs to gain more experience with the technology. Walmart is reviewing the results of the demonstration as they consider their entire real estate portfolio.

  3. An LED-based Flasher System for VERITAS

    E-Print Network [OSTI]

    Hanna, D; McCutcheon, M; Nikkinen, L; 10.1016/j.nima.2009.10.107

    2009-01-01T23:59:59.000Z

    We describe a flasher system designed for use in monitoring the gains of the photomultiplier tubes used in the VERITAS gamma-ray telescopes. This system uses blue light-emitting diodes (LEDs) so it can be operated at much higher rates than a traditional laser-based system. Calibration information can be obtained with better statistical precision with reduced loss of observing time. The LEDs are also much less expensive than a laser. The design features of the new system are presented, along with measurements made with a prototype mounted on one of the VERITAS telescopes.

  4. Global Rebalancing: US Protection versus Europe-led reflation

    E-Print Network [OSTI]

    Irvin, George; Izurieta, Alex

    2006-01-01T23:59:59.000Z

    impact of a Europe-led reflation is re-enforced by the strong income and trade linkages with middle- income and poor regions of the world (eg, Eastern Europe, Latin America and Africa)18. An EU-led reflation supposes a set of demand... switching on the required scale within an acceptable time frame. The central point is that the extra growth cannot come entirely or even chiefly from Asia (where resources are already stretched to the limit), but must come from a combination of renewed EU...

  5. LED Luminaire Lifetime: Recommendations For Testing and Reporting |

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED Lighting

  6. LED Performance Specification Series: T8 Replacement Lamps

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED LightingOutdoor

  7. LED T8 Replacement Lamps | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED LightingOutdoorLEDT8

  8. LEDs Ready for Takeoff at Louisiana Airport | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED

  9. Phosphors for near UV-Emitting LED's for Efficacious Generation of White Light

    SciTech Connect (OSTI)

    McKittrick, Joanna

    2013-09-30T23:59:59.000Z

    1) We studied phosphors for near-UV (nUV) LED application as an alternative to blue LEDs currently being used in SSL systems. We have shown that nUV light sources could be very efficient at high current and will have significantly less binning at both the chip and phosphor levels. We identified phosphor blends that could yield 4100K lamps with a CRI of approximately 80 and LPWnUV,opt equal to 179 for the best performing phosphor blend. Considering the fact that the lamps were not optimized for light coupling, the results are quite impressive. The main bottleneck is an optimum blue phosphor with a peak near 440 nm with a full width half maximum of about 25 nm and a quantum efficiency of >95%. Unfortunately, that may be a very difficult task when we want to excite a phosphor at ~400 nm with a very small margin for Stokes shift. Another way is to have all the phosphors in the blend having the excitation peak at 400 nm or slightly shorter wavelength. This could lead to a white light source with no body color and optimum efficacy due to no self-absorption effects by phosphors in the blend. This is even harder than finding an ideal blue phosphor, but not necessarily impossible. 2) With the phosphor blends identified, light sources using nUV LEDs at high current could be designed with comparable efficacy to those using blue LEDs. It will allow us to design light sources with multiple wattages using the same chips and phosphor blends simply by varying the input current. In the case of blue LEDs, this is not currently possible because varying the current will lower the efficacy at high current and alter the color point. With improvement of phosphor blends, control over CRI could improve. Less binning at the chip level and also at the phosphor blend level could reduce the cost of SSL light sources. 3) This study provided a deeper understanding of phosphor characteristics needed for LEDs in general and nUV LEDs in particular. Two students received Ph.D. degrees and three undergraduates participated in this work. Two of the undergraduate students are now in graduate school. The results were widely disseminated – 20 archival journal publications (published, accepted or in preparation) and three conference proceedings resulted. The students presented their work at 11 different national/international conferences (32 oral or poster presentations) and the PI’s delivered 12 invited, keynote or plenary lectures.

  10. GaN-Ready Aluminum Nitride Substrates for Cost-Effective, Very Low Dislocation Density III-Nitride LED's

    SciTech Connect (OSTI)

    Sandra Schujman; Leo Schowalter

    2010-10-15T23:59:59.000Z

    The objective of this project was to develop and then demonstrate the efficacy of a costeffective approach for a low defect density substrate on which AlInGaN LEDs can be fabricated. The efficacy of this “GaN-ready” substrate would then be tested by growing high efficiency, long lifetime InxGa1-xN blue LEDs. The approach used to meet the project objectives was to start with low dislocation density AlN single-crystal substrates and grow graded AlxGa1-xN layers on top. Pseudomorphic AlxGa1-xN epitaxial layers grown on bulk AlN substrates were used to fabricate light emitting diodes and demonstrate better device performance as a result of the low defect density in these layers when benched marked against state-of-the-art LEDs fabricated on sapphire substrates. The pseudomorphic LEDs showed excellent output powers compared to similar wavelength devices grown on sapphire substrates, with lifetimes exceeding 10,000 hours (which was the longest time that could reliably be estimated). In addition, high internal quantum efficiencies were demonstrated at high driving current densities even though the external quantum efficiencies were low due to poor photon extraction. Unfortunately, these pseudomorphic LEDs require high Al content so they emit in the ultraviolet. Sapphire based LEDs typically have threading dislocation densities (TDD) > 108 cm-2 while the pseudomorphic LEDs have TDD ? 105 cm-2. The resulting TDD, when grading the AlxGa1-xN layer all the way to pure GaN to produce a “GaN-ready” substrate, has varied between the mid 108 down to the 106 cm-2. These inconsistencies are not well understood. Finally, an approach to improve the LED structures on AlN substrates for light extraction efficiency was developed by thinning and roughening the substrate.

  11. Controlling a superconducting nanowire single-photon detector using tailored bright illumination

    E-Print Network [OSTI]

    Lars Lydersen; Mohsen K. Akhlaghi; A. Hamed Majedi; Johannes Skaar; Vadim Makarov

    2011-11-16T23:59:59.000Z

    We experimentally demonstrate that a superconducting nanowire single-photon detector is deterministically controllable by bright illumination. We found that bright light can temporarily make a large fraction of the nanowire length normally-conductive, can extend deadtime after a normal photon detection, and can cause a hotspot formation during the deadtime with a highly nonlinear sensitivity. In result, although based on different physics, the superconducting detector turns out to be controllable by virtually the same techniques as avalanche photodiode detectors. As demonstrated earlier, when such detectors are used in a quantum key distribution system, this allows an eavesdropper to launch a detector control attack to capture the full secret key without being revealed by to many errors in the key.

  12. Development and Evaluation of an Advanced LED Warning System for

    E-Print Network [OSTI]

    Minnesota, University of

    .dot.state.mn.us/stateaid/sa_traffic_safety.html #12;Project Need · ITS Safety Plan: ITS Critical Strategy 5: Use Intersection Collision Warning.g. radar) · Utilize alternative energy source (solar and/or wind) · Utilize LED blinker signs #12;Before;Stop Case 2: #12;Roll-through Case: #12;Acknowledgments and Special Thanks · Local Road Research Board

  13. Biofuels in the ASEAN Low Emission Development Strategies (LEDS) Forum

    E-Print Network [OSTI]

    9/20/2012 1 Biofuels in the ASEAN Low Emission Development Strategies (LEDS) Forum Bangkok, Thailand 19-21 September 2012 Biofuel Policy Group Asian Institute of Technology Outline of the Presentation 1. Objectives of this Presentation 2. Background 3. Status of Biofuel Development in ASEAN 4

  14. Heterostructures for Increased Quantum Efficiency in Nitride LEDs

    SciTech Connect (OSTI)

    Davis, Robert

    2010-09-30T23:59:59.000Z

    Task 1. Development of an advanced LED simulator useful for the design of efficient nitride-based devices. Simulator will contain graphical interface software that can be used to specify the device structure, the material parameters, the operating conditions and the desired output results. I-4 Task 2. Theoretical and experimental investigations regarding the influence on the microstructure, defect concentration, mechanical stress and strain and IQE of controlled changes in the chemistry and process route of deposition of the buffer layer underlying the active region of nitride-based blue- and greenemitting LEDs. I-9 Task 3. Theoretical and experimental investigations regarding the influence on the physical properties including polarization and IQE of controlled changes in the geometry, chemistry, defect density, and microstructure of components in the active region of nitride-based blue- and green-emitting LEDs. II-37 Task 4. Theoretical and experimental investigations regarding the influence on IQE of novel heterostructure designs to funnel carriers into the active region for enhanced recombination efficiency and elimination of diffusion beyond this region. II-52 Task 5. Theoretical and experimental investigations regarding the influence of enhanced p-type doping on the chemical, electrical, and microstructural characteristics of the acceptor-doped layers, the hole injection levels at Ohmic contacts, the specific contact resistivity and the IQE of nitride-based blue- and green-emitting LEDs. Development and optical and electrical characterization of reflective Ohmic contacts to n- and p-type GaN films. I

  15. Advanced method for increasing the efficiency of white light quantum dot LEDs

    SciTech Connect (OSTI)

    Duty, Chad E [ORNL; Bennett, Charlee J C [ORNL; Sabau, Adrian S [ORNL; Jellison Jr, Gerald Earle [ORNL; Boudreaux, Philip R [ORNL; Walker, Steven C [ORNL; Ott, Ronald D [ORNL

    2011-01-01T23:59:59.000Z

    Covering a light-emitting diode (LED) with quantum dots (QDs) can produce a broad spectrum of white light. However, current techniques for applying QDs to LEDs suffer from a high density of defects and a non-uniform distribution of QDs, which, respectively, diminish the efficiency and quality of emitted light. Oak Ridge National Laboratory (ORNL) has the unique capability to thermally anneal QD structures at extremely high power densities for very short durations. This process, called pulse thermal processing (PTP), reduces the number of point defects while maintaining the size and shape of the original QD nanostructure. Therefore, the efficiency of the QD wavelength conversion layer is improved without altering the emission spectrum defined by the size distribution of theQD nanoparticles. The current research uses a thermal model to predict annealing temperatures during PTP and demonstrates up to a 300% increase in photoluminescence for QDs on passive substrates.

  16. average brightness of moonlight as a function

    E-Print Network [OSTI]

    Peletier, Reynier

    figures from Roach & Gordon: `The Light of the Night Sky' (1973) #12;many different reactions contribute to nightglow: tables from Roach & Gordon: `The Light of the Night Sky' (1973) nightglow lines can be very upper atmosphere emissions (Roach & Gordon 1973) aurora is transient emission driven by high

  17. A Touch Panel using Silicone Rubber with embedded IR-LEDs Yuichiro Sakamoto,

    E-Print Network [OSTI]

    Tanaka, Jiro

    LED LED FTIR FTIR FTIR FTIR FTIR LED LED A Touch Panel using Silicone Rubber with embedded Shizuki and Jiro Tanaka In this paper, we present a novel touch panel using silicone rubber with embedded are difficult to detect for one made of acryl panel Moreover, it integrates IR-LEDs silicone rubber for multi

  18. Long-term Testing Results for the 2008 Installation of LED Luminaires at the I-35 West Bridge in Minneapolis

    SciTech Connect (OSTI)

    Kinzey, Bruce R.; Davis, Robert G.

    2014-09-30T23:59:59.000Z

    This document reports the long-term testing results from an extended GATEWAY project that was first reported in “Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, in Minneapolis, MN,” August 2009. That original report presented the results of lighting the newly reconstructed I 35W Bridge using LEDs in place of conventional high-pressure sodium (HPS) roadway luminaires, comparing energy use and illuminance levels with a simulated baseline condition. That installation was an early stage implementation of LED lighting and remains one of the oldest installations in continued operation today. This document provides an update of the LED system’s performance since its installation in September 2008.

  19. THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY. I. BRIGHT UV STARS IN THE BULGE OF M31

    SciTech Connect (OSTI)

    Rosenfield, Philip; Johnson, L. Clifton; Dalcanton, Julianne J.; Williams, Benjamin F.; Gilbert, Karoline M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Girardi, Leo [Osservatorio Astronomico di Padova-INAF, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Bressan, Alessandro [SISSA, Via Bonomea 265, 34136 Trieste (Italy); Lang, Dustin [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Guhathakurta, Puragra; Dorman, Claire E. [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Howley, Kirsten M. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Lauer, Tod R.; Olsen, Knut A. G. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Bianchi, Luciana [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street Cambridge, MA 02138 (United States); Dolphin, Andrew [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Kalirai, Jason [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Larsen, Soren S. [Astronomical Institute, University of Utrecht, Princetonplein 5, 3584 CC Utrecht (Netherlands); Rix, Hans-Walter [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); and others

    2012-08-20T23:59:59.000Z

    As part of the Panchromatic Hubble Andromeda Treasury multi-cycle program, we observed a 12' Multiplication-Sign 6.'5 area of the bulge of M31 with the WFC3/UVIS filters F275W and F336W. From these data we have assembled a sample of {approx}4000 UV-bright, old stars, vastly larger than previously available. We use updated Padova stellar evolutionary tracks to classify these hot stars into three classes: Post-AGB stars (P-AGB), Post-Early AGB (PE-AGB) stars, and AGB-manque stars. P-AGB stars are the end result of the asymptotic giant branch (AGB) phase and are expected in a wide range of stellar populations, whereas PE-AGB and AGB-manque (together referred to as the hot post-horizontal branch; HP-HB) stars are the result of insufficient envelope masses to allow a full AGB phase, and are expected to be particularly prominent at high helium or {alpha} abundances when the mass loss on the red giant branch is high. Our data support previous claims that most UV-bright sources in the bulge are likely hot (extreme) horizontal branch (EHB) stars and their progeny. We construct the first radial profiles of these stellar populations and show that they are highly centrally concentrated, even more so than the integrated UV or optical light. However, we find that this UV-bright population does not dominate the total UV luminosity at any radius, as we are detecting only the progeny of the EHB stars that are the likely source of the UV excess. We calculate that only a few percent of main-sequence stars in the central bulge can have gone through the HP-HB phase and that this percentage decreases strongly with distance from the center. We also find that the surface density of hot UV-bright stars has the same radial variation as that of low-mass X-ray binaries. We discuss age, metallicity, and abundance variations as possible explanations for the observed radial variation in the UV-bright population.

  20. LED Retrofit Project in TSH Basement On July 14 2014, McMaster Facilities Services completed an energy conservation lighting

    E-Print Network [OSTI]

    Haykin, Simon

    replaced with the new LED (light emitting diode) tubes. LEDs have better lighting quality, lower energy

  1. High-Throughput, High-Precision Hot Testing Tool for High-Brightness

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

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking of Blythe Solar PowerCommercial Cold Climate HeatEnergy

  2. KLA-Tencor's Inspection Tool Reduces LED Manufacturing Costs

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, KLA-Tencor is developing an improved inspection tool for LED manufacturing that promises to significantly increase overall process yields and minimize expensive waste. The power of the inspection tool lies in optical detection techniques coupled with defect source analysis software to statistically correlate front-end geometric anomalies in the substrate to killer defects on the back end of the manufacturing line, which give rise to an undesirable or unusable end product.

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

    E-Print Network [OSTI]

    Johnstone, Peter

    2009-01-01T23:59:59.000Z

    data logger equipped rechargeable LED lamps, monitoring theadoption of the LED lamps, and a follow-up survey.s kiosk illuminated by an LED lamp Radecsky, K. , P.

  4. Assessing the Performance of 5mm White LED Light Sources for Developing-Country Applications

    E-Print Network [OSTI]

    Mills, Evan

    2007-01-01T23:59:59.000Z

    lamp calibrated by Labsphere Spectral measurements - LEDs inLEDs we tested is exceptionally good (as good or better than many compact fluorescent lamps),lamp. Off-grid lighting products using the poorer LEDs would

  5. LED Site Lighting in the Commercial Building Sector: Opportunities, Challenges, and the CBEA Performance Specification

    Broader source: Energy.gov [DOE]

    This March 26, 2009 webcast presented information about the Commercial Building Energy Alliances' (CBEA) efforts to explore the viability of LED site lighting in commercial parking lots. LED...

  6. Bright X-ray galaxies in SDSS filaments

    E-Print Network [OSTI]

    Tugay, A V

    2013-01-01T23:59:59.000Z

    Eighteen bright X-ray emitting galaxies were found in nearby filaments within SDSS region. Basic X-ray spectral parameters were estimated for these galaxies using power law model with photoelectric absorption. A close pair of X-ray galaxies was found.

  7. Bright Spots in the South Carolina the Economy

    E-Print Network [OSTI]

    Almor, Amit

    Bright Spots in the South Carolina the Economy 2012 African American Economic Summit Doug Woodward Professor of Economics #12;Overview · Why we should worry. ­ Global economy and financial contagion. ­ U.S. economy and political uncertainty. · Why we should be happy. ­ South Carolina economy healing. · Robust

  8. SC-RISE LECTURE SERIES BRIGHT HORIZONS IN SOLAR ENERGY

    E-Print Network [OSTI]

    SC-RISE LECTURE SERIES BRIGHT HORIZONS IN SOLAR ENERGY Sustainable Energy Opportunities, Options are being developed including biomass, geothermal, hydropower, ocean thermal energy conversion, solar electric, solar thermal, and wind. However, such aspects as low energy density, siting, and temporal

  9. A photometric investigation of ultra-efficient LEDs with high color rendering index and high

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    and distribution temperature," J. Opt. Soc. Am. 58(11), 1528­1535 (1968). #119158 - $15.00 USD Received 27 Oct 2009 Sun2 and Hilmi Volkan Demir1,2* 1 Department of Electrical and Electronics Engineering, Department temperature of 3000 K are shown to be achieved using nanocrystal luminophores. ©2009 Optical Society

  10. A portable time-domain LED fluorimeter for nanosecond fluorescence lifetime measurements

    SciTech Connect (OSTI)

    Wang, Hongtao; Salthouse, Christopher D., E-mail: salthouse@ecs.umass.edu [Electrical and Computer Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Qi, Ying; Mountziaris, T. J. [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States) [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Chemical Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States)

    2014-05-15T23:59:59.000Z

    Fluorescence lifetime measurements are becoming increasingly important in chemical and biological research. Time-domain lifetime measurements offer fluorescence multiplexing and improved handling of interferers compared with the frequency-domain technique. In this paper, an all solid-state, filterless, and highly portable light-emitting-diode based time-domain fluorimeter (LED TDF) is reported for the measurement of nanosecond fluorescence lifetimes. LED based excitation provides more wavelengths options compared to laser diode based excitation, but the excitation is less effective due to the uncollimated beam, less optical power, and longer latency in state transition. Pulse triggering and pre-bias techniques were implemented in our LED TDF to improve the peak optical power to over 100 mW. The proposed pulsing circuit achieved an excitation light fall time of less than 2 ns. Electrical resetting technique realized a time-gated photo-detector to remove the interference of the excitation light with fluorescence. These techniques allow the LED fluorimeter to accurately measure the fluorescence lifetime of fluorescein down to concentration of 0.5 ?M. In addition, all filters required in traditional instruments are eliminated for the non-attenuated excitation/emission light power. These achievements make the reported device attractive to biochemical laboratories seeking for highly portable lifetime detection devices for developing sensors based on fluorescence lifetime changes. The device was initially validated by measuring the lifetimes of three commercial fluorophores and comparing them with reported lifetime data. It was subsequently used to characterize a ZnSe quantum dot based DNA sensor.

  11. The Future Looks Bright for Teraflop Computing

    SciTech Connect (OSTI)

    Farber, Rob

    2007-11-01T23:59:59.000Z

    Wouldn’t it be great to have a teraflop of computing power sitting in your lab, desktop workstation, or remote instrument server? Talk about simplifying workflows, eliminating competition for HPC resources, and allowing more scientists and technicians to get more work done! Well, the computer industry is marketing that capability now in the form of high-end video cards – and for a bargain price – with more and better technology on the market horizon. As the industry evolves to become more oriented toward multi-core and multi-threaded hardware; video card manufacturers are attempting to transition from a niche to multi-purpose market. One of the products currently getting attention is the Nvidia Tesla family of products based on the Tesla GPGPU (general purpose graphics processing unit). This card contains 128 processor computing core engines advertised as having the ability to deliver an aggregate 518 billion single-precision floating operations per second (518 Gflop), which is being introduced at a $1499 MSRP price-point. Nvidia also offers other commodity graphics cards, such as the GeForce 8800, which appear on paper to have roughly the same performance for roughly half the price – although with half the memory (768M vs the Tesla 1.5 GB). This highlights how the Tesla GPGPUs are essentially redesigned graphics cards (with no video capability, increased memory, and clock changes) that fit into PCI-Express slots in your motherboard. If you believe Nvidia’s claims, two Tesla cards will - for the right applications - turn your lab workstation into a teraflop capable supercomputer. Double-precision versions are projected for a late 2007 introduction with expected 2008 delivery. The Nvidia Tesla GPGPU is one step forward in the many-core revolution that is happening in the computer industry. Instead of making two or four processing cores available to the user, many-core processors offer tens or hundreds of processing cores. Many-core processors promise to provide very high performance-per-dollar and performance-per-watt for many computational workloads. Intel is working on their version of many-core processors but delivery dates appear to be several years in the future. Last year Intel made a large splash with their proof-of-concept teraflop 80-core chip, which they announced might be available sometime in 2011. Intel is also working on something similar to the Nvidia Tesla – codename Larrabee – which will perform in the teraflop range and has a release date of sometime around 2009 or 2010. Larrabee is supposed to have 16 – 24 cores and several nice features. Bottom line: A teraflop lab computer is feasible today as the programmable Nvidia GeForce 8 and Quadro family of graphics cards are available now, Tesla cards will be shipping, and exciting many-core architectures are on the horizon from a number of vendors. Definitely, the potential for parallel processing systems is huge, and GPGPUs certainly provide parallel processing, but are there enough applications out there to take them mainstream and make it more appealing to businesses other than just research firms? Only time will tell as more applications are developed to utilize this computational capability. Right now, programming is required. Recently Google purchased PeakStream, a firm that engaged in abstracting the task of running multiple threads to software with specific GPGPU applicability. However, Google is a visionary software company. Instrument vendors and much of the software industry are still in the early stages of the transition to multi-threaded many-core data processing. Applications that exploit the full potential of parallel processing systems, and GPGPUs in particular, really don’t exist in today’s market. The development of Matlab plug-ins is a very positive sign for the future of GPGPUs and is indicative of Nvidia’s sense of where the market is headed.

  12. Considerations When Comparing LED and Conventional Lighting | Department of

    Office of Environmental Management (EM)

    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 1,006 492 742 33 1112011AT&T, Inc.'sEnergyTexas1.SpaceFluor Federal Services -Energy Using LEDs »

  13. LED Holiday Lights: Festive, Safe, and Efficient! | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM to 2:05PMDOE-STD-1107-97LSEED:LDVFrequentlyLED

  14. LEDs: The Future of Lighting is Here | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LEDLEDs on Semipolar

  15. LED Lighting on the National Mall | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking ofOil & Gas » MethaneJohnsonKristina Pflanz About Us KristinaLED

  16. #AskEnergySaver: LED Lights | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of Bad CholesteroliManage#AskEnergySaver: LED Lights #AskEnergySaver:

  17. Reducing LED Costs Through Innovation | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMay 2015 < prevQuick Guide:U.N.June 8,PastRadiationReducing LED Costs

  18. LED Traffic Lights Get Buy American Stamp | Department of Energy

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

    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 742Energy ChinaofSchaeferApril 1, 1999 InspectionVolunteersKarenThisDepartment ofLED traffic lights

  19. Abbreviated epitaxial growth mode (AGM) method for reducing cost and improving quality of LEDs and lasers

    SciTech Connect (OSTI)

    Tansu, Nelson; Chan, Helen M; Vinci, Richard P; Ee, Yik-Khoon; Biser, Jeffrey

    2013-09-24T23:59:59.000Z

    The use of an abbreviated GaN growth mode on nano-patterned AGOG sapphire substrates, which utilizes a process of using 15 nm low temperature GaN buffer and bypassing etch-back and recovery processes during epitaxy, enables the growth of high-quality GaN template on nano-patterned AGOG sapphire. The GaN template grown on nano-patterned AGOG sapphire by employing abbreviated growth mode has two orders of magnitude lower threading dislocation density than that of conventional GaN template grown on planar sapphire. The use of abbreviated growth mode also leads to significant reduction in cost of the epitaxy. The growths and characteristics of InGaN quantum wells (QWs) light emitting diodes (LEDs) on both templates were compared. The InGaN QWs LEDs grown on the nano-patterned AGOG sapphire demonstrated at least a 24% enhancement of output power enhancement over that of LEDs grown on conventional GaN templates.

  20. Slutrapport for PSO 337-068 Udvikling af LED lyskilder og lamper

    E-Print Network [OSTI]

    bulb. - two LED pendants/lamps, a LED table lamp and a chair with LED lighting developed by designers Cluster lampe 13 Teknisk design af Cluster 15 Konklusion 16 Lysflyder 17 Hvordan opstod ideen om en LEDSlutrapport for PSO 337-068 Udvikling af LED lyskilder og lamper Carsten Dam-Hansen, Paul Michael

  1. Ultra-bright, ultra-broadband hard x-ray driven by laser-produced energetic electron beams

    SciTech Connect (OSTI)

    Shi, Yin; Shen, Baifei; Zhang, Xiaomei; Wang, Wenpeng; Ji, Liangliang; Zhang, Lingang; Xu, Jiancai; Yu, Yahong; Zhao, Xueyan; Wang, Xiaofeng; Yi, Longqing; Xu, Tongjun; Xu, Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)] [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

    2013-09-15T23:59:59.000Z

    We propose a new method of obtaining a compact ultra-bright, ultra-broadband hard X-ray source. This X-ray source has a high peak brightness in the order of 10{sup 22} photons/(s mm{sup 2} mrad{sup 2} 0.1\\%BW), an ultrashort duration (10 fs), and a broadband spectrum (flat distribution from 0.1 MeV to 4 MeV), and thus has wide-ranging potential applications, such as in ultrafast Laue diffraction experiments. In our scheme, laser-plasma accelerators (LPAs) provide driven electron beams. A foil target is placed oblique to the beam direction so that the target normal sheath field (TNSF) is used to provide a bending force. Using this TNSF-kick scheme, we can fully utilize the advantages of current LPAs, including their high charge, high energy, and low emittance.

  2. Argonne is a partner in the Argonne-Northwestern Solar Energy Research Center led by Northwestern University. Argonne is a partner in the Center for Emergent Superconductivity led by Brookhaven National Laboratory.

    E-Print Network [OSTI]

    Kemner, Ken

    Argonne is a partner in the Argonne-Northwestern Solar Energy Research Center led by Northwestern Conductivity (CES) W. Kwok (MSD) Argonne-Northwestern Solar Energy Research (ANSER) M. Pellin (MSD) #12; Administrative Support J. Hogan and G. Cutinello Chemical Sciences & Engineering (CSE) E.E. Bunel High Energy

  3. THE SLOAN BRIGHT ARCS SURVEY: DISCOVERY OF SEVEN NEW STRONGLY LENSED GALAXIES FROM z = 0.66-2.94

    SciTech Connect (OSTI)

    Kubo, Jeffrey M.; Allam, Sahar S.; Drabek, Emily; Lin, Huan; Tucker, Douglas; Buckley-Geer, Elizabeth J.; Diehl, H. Thomas; Soares-Santos, Marcelle; Hao Jiangang; Kubik, Donna; Annis, James; Frieman, Joshua A. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Wiesner, Matthew [Department of Physics, Northern Illinois University, DeKalb, IL 60115 (United States); West, Anderson [The Illinois Math and Science Academy, Aurora, IL 60506 (United States)

    2010-12-01T23:59:59.000Z

    We report the discovery of seven new, very bright gravitational lens systems from our ongoing gravitational lens search, the Sloan Bright Arcs Survey (SBAS). Two of the systems are confirmed to have high source redshifts z = 2.19 and z = 2.94. Three other systems lie at intermediate redshift with z = 1.33, 1.82, 1.93 and two systems are at low redshift z = 0.66, 0.86. The lensed source galaxies in all of these systems are bright, with i-band magnitudes ranging from 19.73 to 22.06. We present the spectrum of each of the source galaxies in these systems along with estimates of the Einstein radius for each system. The foreground lens in most systems is identified by a red sequence based cluster finder as a galaxy group; one system is identified as a moderately rich cluster. In total, SBAS has now discovered 19 strong lens systems in the SDSS imaging data, 8 of which are among the highest surface brightness z {approx_equal} 2-3 galaxies known.

  4. A statistical study of bright spot reflection parameters

    E-Print Network [OSTI]

    Godwin, David Lee

    1981-01-01T23:59:59.000Z

    cal Study of Bright Spot Reflection Parameters. (December 1981) David Lee Godwin, B. S. , Pepperdine University Chairman of Adv1sory Committee: Dr. T. W. Spencer A data set consisting of two seismic lines served as the basis of study... obtained from each of the seismic lines were compared to deter- mine if the presence of commercial quantities of gas could be identified. The measurement process revealed that the interval travel time measurements between the marker horizons...

  5. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, Minneapolis, MN

    SciTech Connect (OSTI)

    Kinzey, Bruce R.; Myer, Michael

    2009-08-31T23:59:59.000Z

    This report describes the process and results of a demonstration of solid-state lighting (SSL) technology conducted in 2009 at the recently reconstructed I-35W bridge in Minneapolis, MN. The project was supported under the U.S. Department of Energy (DOE) Solid-State Lighting GATEWAY Technology Demonstration Program. Other participants in the demonstration project included the Minnesota Department of Transportation (Mn/DOT), Federal Highways Administration (FHWA), and BetaLED™ (a division of Ruud Lighting). Pacific Northwest National Laboratory (PNNL) conducted the measurements and analysis of the results. DOE has implemented a three-year evaluation of the LED luminaires in this installation in order to develop new longitudinal field data on LED performance in a challenging, real-world environment. This document provides information through the initial phase of the I-35W bridge project, up to and including the opening of the bridge to the public and the initial feedback received on the LED lighting installation from bridge users. Initial findings of the evaluation are favorable, with minimum energy savings level of 13% for the LED installation relative to the simulated base case using 250W high-pressure sodium (HPS) fixtures. The LEDs had an average illuminance level of 0.91 foot candles compared to 1.29 fc for the HPS lamps. The LED luminaires cost $38,000 more than HPS lamps, yielding a lengthy payback period, however the bridge contractor had offered to include the LED luminaires as part of the construction package at no additional cost. One potentially significant benefit of the LEDs in this installation is avoiding rolling lane closures on the heavily-traveled interstate bridge for the purpose of relamping the HPS fixtures. Rolling lane closures involve multiple crew members and various maintenance and safety vehicles, diversion of traffic, as well as related administrative tasks (e.g., approvals, scheduling, etc.). Mn/DOT records show an average cost of relamping fixtures along interstate roadways of between $130-150 per pole. The previous bridge saw a lamp mortality rate of approximately 50% every two years, though the new bridge was designed to minimize many of the vibration issues. A voluntary Web-based feedback survey of nearly 500 self-described bridge users showed strong preference for the LED lighting - positive comments outnumbered negative ones by about five-to-one.

  6. Structure of Bright 2MASS Galaxies: 2D Fits to the Ks-band Surface Brightness Profiles

    E-Print Network [OSTI]

    Daniel H. McIntosh; Ari H. Maller; Neal Katz; Martin D. Weinberg

    2002-09-01T23:59:59.000Z

    The unprecedented sky coverage and photometric uniformity of the Two Micron All Sky Survey (2MASS) provides a rich resource for obtaining a detailed understanding of the galaxies populating our local (z<0.1) Universe. A full characterization of the physical structure of nearby galaxies is essential for theoretical and observational studies of galaxy evolution and structure formation. We have begun a quantified description of the internal structure and morphology of 10,000 bright (10brightness profiles using GIM2D. From our initial Monte Carlo tests on 77 galaxies drawn at random from the RC3, we find that the model derived structural parameter errors due to sky uncertainies are typically less than 10%.

  7. The Dark Bursts population in a complete sample of bright Swift Long Gamma-Ray Bursts

    E-Print Network [OSTI]

    A. Melandri; B. Sbarufatti; P. D'Avanzo; R. Salvaterra; S. Campana; S. Covino; S. D. Vergani; L. Nava; G. Ghisellini; G. Ghirlanda; D. Fugazza; V. Mangano; M. Capalbi; G. Tagliaferri

    2012-02-14T23:59:59.000Z

    We study the properties of the population of optically dark events present in a carefully selected complete sample of bright Swift long gamma-ray bursts. The high level of completeness in redshift of our sample (52 objects out of 58) allow us to establish the existence of a genuine dark population and we are able to estimate the maximum fraction of dark burst events (~30%) expected for the whole class of long gamma-ray burst. The redshift distribution of this population of dark bursts is similar to the one of the whole sample. Interestingly, the rest-frame X-ray luminosity (and the de-absorbed X-ray flux) of the sub-class of dark bursts is slightly higher than the average luminosity of the non-dark events. At the same time the prompt properties do not differ and the optical flux of dark events is at the lower tail of the optical flux distribution, corrected for Galactic absorption. All these properties suggest that dark bursts events generate in much denser environments with respect to normal bright events. We can therefore exclude the high-z and the low-density scenarios and conclude that the major cause of the origin of optically dark events is the dust extinction.

  8. Raman-free, noble-gas-filled PCF source for ultrafast, very bright twin-beam squeezed vacuum

    E-Print Network [OSTI]

    Finger, Martin A; Joly, Nicolas Y; Chekhova, Maria V; Russell, Philip St J

    2015-01-01T23:59:59.000Z

    We report a novel source of twin beams based on modulational instability in high-pressure argon-filled hollow-core kagom\\'e-style photonic-crystal fibre. The source is Raman-free and manifests strong photon-number correlations for femtosecond pulses of squeezed vacuum with a record brightness of ~2500 photons per mode. The ultra-broadband (~50 THz) twin beams are frequency tunable and contain one spatial and less than 5 frequency modes.

  9. Revolutionary Method for Increasing the Efficiency of White Light Quantum Dot LEDs

    SciTech Connect (OSTI)

    Duty, Chad E [ORNL; Bennett, Charlee J C [ORNL; Sabau, Adrian S [ORNL; Jellison Jr, Gerald Earle [ORNL; Boudreaux, Philip R [ORNL; Walker, Steven C [ORNL; Ott, Ronald D [ORNL

    2011-01-01T23:59:59.000Z

    Covering a light-emitting diode (LED) with quantum dots (QDs) can produce a broad spectrum of white light. However, current techniques for applying QDs to LEDs suffer from a high density of defects and a non-uniform distribution of QDs, which respec-tively diminish the efficiency and quality of emitted light. Oak Ridge National Laboratory (ORNL) has the unique capability to thermally anneal QD structures at extremely high power densities for very short durations. This process, called pulse thermal proc-essing (PTP), reduces the number of point defects while main-taining the size and shape of the original QD nanostructure. Therefore, the efficiency of the QD wavelength conversion layer is improved without altering the emission spectrum defined by the size distribution of the quantum dot nanoparticles. The cur-rent research uses a thermal model to predict annealing tempera-tures during PTP and demonstrates up to a 300% increase in pho-toluminescence for QDs on passive substrates

  10. Development of substrate-removal-free vertical ultraviolet light-emitting diode (RefV-LED)

    SciTech Connect (OSTI)

    Kurose, N., E-mail: kurose@fc.ritsumei.ac.jp; Aoyagi, Y. [The Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)] [The Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan); Shibano, K.; Araki, T. [Department of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)] [Department of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)

    2014-02-15T23:59:59.000Z

    A vertical ultraviolet (UV) light-emitting diode (LED) that does not require substrate removal is developed. Spontaneous via holes are formed in n-AlN layer epitaxially grown on a high conductive n+Si substrate and the injected current flows directly from the p-electrode to high doped n{sup +} Si substrate through p-AlGaN, multi-quantum wells, n-AlGaN and spontaneous via holes in n-AlN. The spontaneous via holes were formed by controlling feeding-sequence of metal-organic gas sources and NH{sub 3} and growth temperature in MOCVD. The via holes make insulating n-AlN to be conductive. We measured the current-voltage, current-light intensity and emission characteristics of this device. It exhibited a built-in voltage of 3.8 V and emission was stated at 350 nm from quantum wells with successive emission centered at 400?nm. This UV LED can be produced, including formation of n and p electrodes, without any resist process.

  11. Vehicle Traffic Control Signal Heads— Light Emitting Diode Circular Signal Supplement (VTCSH-LED). This replaced the so-called Interim LED Purchase Specifications,

    E-Print Network [OSTI]

    S. Behura

    Engineers ’ (ITE) specification for light-emitting diode (LED) circular traffic signals recently was updated (June 27, 2005) and published under the name

  12. On the Origin of Low-Surface-Brightness Galaxies

    E-Print Network [OSTI]

    V. Antonuccio-Delogu

    1994-12-16T23:59:59.000Z

    We reconsider the problem of the origin of Low-Surface-Brightness (LSB) galaxies within the standard Cold Dark Matter (CDM) cosmological model ($\\Omega =1, h=0.5$). Taking into account the effect of substructure on the collapse times of low overdensity peaks, we show that the abundance of these peaks is larger than previously expected because of the dragging caused by dynamical friction induced by the presence of small-scale substructure. The number density of these shallow, low-density peaks turns out to be in good agreement with the observed overdensity of the blue LSB galaxies found during recent surveys.

  13. Bright Lights and Even Brighter Ideas | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Future of CSP: ChallengesEnergy For PersonsBright Lights and

  14. NanoBright Technologies Pte Ltd | 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 Geothermal Pwer PlantMunhall, Pennsylvania: Energy ResourcesOcean EnergyEnergyNance County,WasteNanoBright

  15. Asymmetric Surface Brightness Distribution of Altair Observed with the Navy Prototype Optical Interferometer

    E-Print Network [OSTI]

    Ohishi, N; Hutter, D J; Ohishi, Naoko; Nordgren, Tyler E.; Hutter, Donald J.

    2004-01-01T23:59:59.000Z

    An asymmetric surface brightness distribution of the rapidly rotating A7IV-V star, Altair, has been measured by the Navy Prototype Optical Interferometer (NPOI). The observations were recorded simultaneously using a triangle of three long baselines of 30m, 37m, and 64m, on 19 spectral channels, covering the wavelength range of 520nm to 850nm. The outstanding characteristics of these observations are (a) high resolution with the minimum fringe spacing of 1.7mas, easily resolving the 3-milliarcsecond (mas) stellar disk, and (b) the measurement of closure phase which is a sensitive indicator to the asymmetry of the brightness distribution of the source. Uniform disk diameters fit to the measured squared visibility amplitudes confirms the Altair's oblate shape due to its rapid rotation. The measured observables of Altair showed two features which are inconsistent with both the uniform-disk and limb-darkened disk models, while the measured observable of the comparison star, Vega, are consistent with the limb-darke...

  16. Intel Led OpenMP Training Session at NERSC This Wednesday March...

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

    Led OpenMP Training Session at NERSC This Wednesday March 25 Intel Led OpenMP Training Session at NERSC This Wednesday March 25 March 24, 2015 by Katie Antypas (0 Comments) This...

  17. Fabrication of InGaP LEDs on a graded buffer substrate

    E-Print Network [OSTI]

    Martínez, Josué F

    2007-01-01T23:59:59.000Z

    Introduction: Computer display panels create a vast color palette by combining color from three light emitting diodes (LEDs), each producing red, green, or blue light. The light from these three LEDs is chosen so that the ...

  18. Have You Used LED Lighting? Tell Us About It. | Department of...

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

    It. May 7, 2009 - 5:00am Addthis This week, John shared his experiences with light-emitting diode (LED) lighting. In a future blog, he'll share more about LED lighting. Have you...

  19. An Investigation into the Perception of Color under LED White Composite Spectra with Modulated Color Rendering

    E-Print Network [OSTI]

    O'Reilly, Una-May

    emitting diodes, LEDs. We examined seven LED white composite spectra with different color rendering of a pilot study that evaluates the perceptual impact of modulation of color rendering using multi-chip light

  20. Development and Industrialization of InGaN/GaN LEDs on Patterned...

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

    of InGaNGaN LEDs on Patterned Sapphire Substrates for Low Cost Emitter Architecture Development and Industrialization of InGaNGaN LEDs on Patterned Sapphire...

  1. LED Lighting in a Performing Arts Building at the University of Florida

    SciTech Connect (OSTI)

    Miller, Naomi J.; Kaye, Stan; Coleman, Patricia; Wilkerson, Andrea M.; Perrin, Tess E.; Sullivan, Gregory P.

    2014-07-01T23:59:59.000Z

    The U.S. DOE GATEWAY Demonstration Program supports demonstrations of high-performance solid-state lighting (SSL) products in order to develop empirical data and experience with the in-the-field applications of this advanced lighting technology. This report describes the process and results of the 2013 - 2014 GATEWAY demonstration of SSL technology in the Nadine McGuire Theatre and Dance Pavilion at the University of Florida, Gainesville, FL. The LED solutions combined with dimming controls utilized in four interior spaces - the Acting Studio, Dance Studio, Scene Shop, and Dressing Room - received high marks from instructors, students/performers, and reduced energy use in all cases. The report discusses in depth and detail of each project area including specifications, energy savings, and user observations. The report concludes with lessons learned during the demonstration.

  2. Text-Alternative Version: Model Specification for LED Roadway Luminaires Webcast

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "Model Specification for LED Roadway Luminaires" webcast, held November 15, 2011.

  3. Text-Alternative Version: Successful Selection of LED Streetlight Luminaires Webcast

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "Successful Selection of LED Streetlight Luminaires" webcast, held March 6, 2013.

  4. TESLA-FEL 2007-03 Application of low cost GaAs LED as neutron

    E-Print Network [OSTI]

    neutrons in unbiased Gallium Arsenide (GaAs) Light Emitting Diodes (LED) resulted in a reduction Keywords: COTS components, Displacement damage, Electron Linear Accelerator, GaAs Light emitting diode (LED) Gallium Arsenide (GaAs) light emitting diode (LED) for the assessment of integrated neutron fluence

  5. Color shift reduction of a multi-domain IPS-LCD using RGB-LED backlight

    E-Print Network [OSTI]

    Wu, Shin-Tson

    -emitting diodes (LEDs) and cold-cathode fluorescent lamp (CCFL) backlights. Simulation results indicateColor shift reduction of a multi-domain IPS- LCD using RGB-LED backlight Ruibo Lu, Qi Hong, Zhibing that the LED backlight exhibits a wider color gamut, better angular color uniformity, and 2-4X smaller static

  6. Novel Structured LED and OLED Devices - Energy Innovation Portal

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

    to achieve a semiconductor island structure of high crystalline quality for covering the substrate. Similarly, light extraction, particularly for OLEDs, remains an obstacle to...

  7. The angular size of the Cepheid L Car: a comparison of the interferometric and surface brightness techniques

    E-Print Network [OSTI]

    P. Kervella; P. Fouque; J. Storm; W. P. Gieren; D. Bersier; D. Mourard; N. Nardetto; V. Coude du Foresto

    2004-02-11T23:59:59.000Z

    Recent interferometric observations of the brightest and angularly largest classical Cepheid, L Carinae, with ESO's VLT Interferometer (VLTI) have resolved with high precision the variation of its angular diameter with phase. We compare the measured angular diameter curve to the one we derive by an application of the Baade-Wesselink type infrared surface brightness technique, and find a near-perfect agreement between the two curves. The mean angular diameters of L Car from the two techniques agree very well within their total error bars (1.5 %), as do the derived distances (4 %). This result is an indication that the calibration of the surface brightness relations used in the distance determination of far away Cepheids is not affected by large biases.

  8. Demonstration Assessment of Light-Emitting Diode (LED) Street Lighting Host Site: Lija Loop, Portland, Oregon

    SciTech Connect (OSTI)

    Kinzey, Bruce R.; Myer, Michael

    2009-11-01T23:59:59.000Z

    This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a residential street lighting application, under the U.S. Department of Energy GATEWAY Solid-State Lighting Technology Demonstration Program. In this project, eight 100W (nominal) high-pressure sodium cobra head fixtures were replaced with a like number of LED street light luminaires manufactured by Leotek, Inc. The Leotek product achieved an estimated payback in the Lija Loop installation of about 20 years for replacement scenarios and a much shorter 7.6 years for new installations. Much of the associated energy savings (55%) supporting these payback periods, however, were achieved by reducing average horizontal photopic illuminance a similar amount (53%). Examined from a different perspective, the measured performance suggests that the Leotek product is at approximate parity with the HPS cobra head in terms of average delivered photopic illumination for a given power consumption. HPS comprises the second most efficacious street lighting technology available, exceeded only by low pressure sodium (LPS). LPS technology is not considered suitable for most street lighting applications due to its monochromatic spectral output and poor color rendering ability; therefore, this LED product is performing at an efficiency level comparable to its primary competition in this application.

  9. Comparative Analysis of a Transition Region Bright Point with a Blinker and Coronal Bright Point Using Multiple EIS Emission Lines

    E-Print Network [OSTI]

    Orange, N Brice; Chesny, David L; Patel, Maulik; Hesterly, Katie; Preuss, Lauren; Neira, Chantale; Turner, Niescja E

    2015-01-01T23:59:59.000Z

    Since their discovery twenty year ago, transition region bright points (TRBPs) have never been observed spectroscopically. Bright point properties have not been compared with similar transition region and coronal structures. In this work we have investigated three transient quiet Sun brightenings including a TRBP, a coronal BP (CBP) and a blinker. We use time-series observations of the extreme ultraviolet emission lines of a wide range of temperature T (log T = 5.3 - 6.4) from the EUV imaging spectrometer (EIS) onboard the Hinode satellite. We present the EIS temperature maps and Doppler maps, which are compared with magnetograms from the Michelson Doppler Imager (MDI) onboard the SOHO satellite. Doppler velocities of the TR BP and blinker are <,25 km s$^{-1}$, which is typical of transient TR phenomena. The Dopper velocities of the CBP were found to be < 20 km s^{-1} with exception of those measured at log T = 6.2 where a distinct bi-directional jet is observed. From an EM loci analysis we find evidenc...

  10. Homogeneous spectroscopic parameters for bright planet host stars from the northern hemisphere

    E-Print Network [OSTI]

    Sousa, S G; Mortier, A; Tsantaki, M; Adibekyan, V; Mena, E Delgado; Israelian, G; Rojas-Ayala, B; Neves, V

    2015-01-01T23:59:59.000Z

    Aims. In this work we derive new precise and homogeneous parameters for 37 stars with planets. For this purpose, we analyze high resolution spectra obtained by the NARVAL spectrograph for a sample composed of bright planet host stars in the northern hemisphere. The new parameters are included in the SWEET-Cat online catalogue. Methods. To ensure that the catalogue is homogeneous, we use our standard spectroscopic analysis procedure, ARES+MOOG, to derive effective temperatures, surface gravities, and metallicities. These spectroscopic stellar parameters are then used as input to compute the stellar mass and radius, which are fundamental for the derivation of the planetary mass and radius. Results. We show that the spectroscopic parameters, masses, and radii are generally in good agreement with the values available in online databases of exoplanets. There are some exceptions, especially for the evolved stars. These are analyzed in detail focusing on the effect of the stellar mass on the derived planetary mass. ...

  11. Bright Stars in the Galactic Globular M5

    E-Print Network [OSTI]

    E. Brocato; V. Castellani; V. Ripepi

    1994-07-07T23:59:59.000Z

    We present a CCD investigation of the galactic globular M5 aimed to increase the statistical relevance of the available sample of evolving bright stars. Previous investigations, limited to the outer cluster region, have been extended toward the cluster center, more than doubling the number of observed luminous stars. On this basis, we discuss a statistically relevant sample, rich of 415 HB stars. The occurrence of a gap in the blue side of the HB is suggested. Comparison to the current evolutionary scenario discloses a good agreement concerning both the C-M diagram location and the relative abundance of stars in the advanced evolutionary phases, supporting our present knowledge of the evolution of low mass stars. Determination of the amount of the original helium content through the ratio R N(HB)/N(RGB) gives $Y = 0.22 \\pm 0.02$.

  12. V and R-band Galaxy Luminosity Functions and Low Surface Brightness Galaxies in the Century Survey

    E-Print Network [OSTI]

    Warren R. Brown; Margaret J. Geller; Daniel G. Fabricant; Michael J. Kurtz

    2001-05-11T23:59:59.000Z

    We use 64 square degrees of deep V and R CCD images to measure the local V and R band luminosity function of galaxies. The V_0<16.7 and R_0<16.2 redshift samples contain 1250 galaxies and are 98% complete. We apply k-corrections before the magnitude selection so that the completeness is to the same depth for all spectral types. The V and R faint end slopes are surprisingly identical: alpha = -1.07+-0.09. Representative Schechter function parameters for H_0=100 are: M^*_R = -20.88+-0.09, phi^*_R = 0.016+-0.003 Mpc^-3 and M^*_V = -20.23+-0.09, phi^*_V = 0.020+-0.003 Mpc^-3. The V and R local luminosity densities, j_R = (1.9+-0.6)x10^8 and j_V = (2.2+-0.7)x10^8 L_sun, are in essential agreement with the recent 2dF and SDSS determinations. All low surface brightness (LSB) galaxies fall in the large scale structure delineated by high surface brightness galaxies. The properties and surface number density of our LSB galaxies are consistent with the LSB galaxy catalog of O'Neil, Bothun & Cornell, suggesting that our samples are complete for LSB galaxies to the magnitude limits. We measure colors, surface brightnesses, and luminosities for our samples, and find strong correlations among these galaxy properties.

  13. A closer look at the fluctuations in the brightness of SN 2009IP during its late 2012 eruption

    SciTech Connect (OSTI)

    Martin, J. C. [Barber Observatory, University of Illinois Springfield, Springfield, IL 62704 (United States); Hambsch, F.-J. [Remote Observatory, Atacama Desert, Chile Vereniging Voor Sterrenkunde (VVS), Oude Bleken 12, B-2400 Mol (Belgium); Margutti, R.; Soderberg, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02318 (United States); Tan, T. G. [Perth Exoplanet Survey Telescope, Perth (Australia); Curtis, I., E-mail: jmart5@uis.edu [Adelaide (Australia)

    2015-01-01T23:59:59.000Z

    The supernova (SN) impostor SN 2009ip has re-brightened several times since its initial discovery in 2009 August. During its last outburst in late 2012 September, it reached a peak brightness of m{sub v} ?13.5 (M{sub v} brighter than ?18), causing some to speculate that it had undergone a terminal core-collapse SN. Relatively high-cadence multi-wavelength photometry of the post-peak decline revealed bumps in brightness infrequently observed in other SNe IIn. These bumps occurred synchronously in all ultraviolet (UV) and optical bands with amplitudes of 0.1–0.4 mag at intervals of 10–30 days. Episodic continuum brightening and dimming in the UV and optical with these characteristics is not easily explained within the context of models that have been proposed for the late September 2012 outburst of SN 2009ip. We also present evidence that the post-peak fluctuations in brightness occur at regular intervals and raise more questions about their origin.

  14. DUAL USE OF LEDS: SIGNALING AND COMMUNICATIONS IN ITS Grantham Pang, Chi-ho Chan, Hugh Liu, Thomas Kwan

    E-Print Network [OSTI]

    Pang, Grantham

    of an incandescent lamp is 800 hours while the life expectancy of LED is 10-23 years. This result shows that LED has : · LED indicator lamps (as in some dashboard, traffic signals, card readers). · LED displays (1 DUAL USE OF LEDS: SIGNALING AND COMMUNICATIONS IN ITS Grantham Pang, Chi-ho Chan, Hugh Liu

  15. Measured Off-Grid LED Lighting System Performance

    SciTech Connect (OSTI)

    Granderson, Jessica; Galvin, James; Bolotov, Dmitriy; Clear, Robert; Jacobson, Arne; Mills, Evan

    2008-12-18T23:59:59.000Z

    This report is a product of our ongoing effort to support the development of high-quality yet affordable products for off-grid lighting in the developing world that have good potential to succeed in the market. The effort includes work to develop low-cost testing procedures, to identify useful performance metrics, and to facilitate the development of industry standards and product rating protocols. We conducted laboratory testing of nine distinct product lines. In some cases we also tested multiple generations of a single product line and/or operating modes for a product. The resultsare summarized in Table 1. We found that power consumption and light output varied by nearly a factor of 12, with efficacy varying by a factor of more than six. Of particular note, overall luminous efficacy varied from 8.2 to 53.1 lumens per watt. Color quality indices variedmaterially, especially for correlated color temperature. Maximum illuminance, beamcandlepower, and luminance varied by 8x, 32x, and 61x respectively, suggesting considerable differences among products in terms of service levels and visual comfort. Glare varied by1.4x, and was above acceptable thresholds in most cases. Optical losses play a role in overall performance, varying by a factor of 3.2 and ranging as high as 24percent. These findings collectively indicate considerable potential for improved product design.

  16. Text-Alternative Version: MSSLC Member Case Studies- LED Street Lighting Programs Webinar

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "MSSLC Member Case Studies - LED Street Lighting Programs" webcast, held May 8, 2013.

  17. Text Alternative Version: Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products" webcast, held March 28, 2013.

  18. Text-Alternative Version: CALiPER Series 21 on LED Linear Lamps and Troffer Lighting

    Broader source: Energy.gov [DOE]

    Following is a text version of a video about CALiPER Application Report Series 21 on LED Linear Lamps and Troffer Lighting.

  19. Text-Alternative Version: LED Replacement Lamps: Current Performance and the Latest on ENERGY STAR®

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the LED Replacement Lamps: Current Performance and the Latest on ENERGY STAR® webcast.

  20. LED Linear Lamps and Troffer Lighting: CALiPER Report Series 21

    ScienceCinema (OSTI)

    Beeson, Tracy; Miller, Naomi

    2014-06-23T23:59:59.000Z

    Video about CALiPER Report Series 21 on LED Linear Lamps and Troffer Lighting, featuring interviews with Tracy Beeson and Naomi Miller of Pacific Northwest National Laboratory.

  1. Researchers Say They've Solved the Mystery of LED Lighting "Droop...

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

    Sciences Team. Despite being cool, ultra-efficient and long lasting, the light-emitting diode (LED) faces a problem called "efficiency droop." New findings from simulations...

  2. LEDS Tool: Step-By-Step Guidance to a Long-Term Framework for...

    Open Energy Info (EERE)

    OpenEI Keyword(s): LEDS Guidance Developing Implementing Process Language: "English, Spanish; Castilian" is not in the list of possible values (Abkhazian, Achinese, Acoli,...

  3. 2015 DOE SSL R&D Workshop LED Topic Table Questions to Consider

    Broader source: Energy.gov [DOE]

    This document was distributed during the LED Topic Table portion of the DOE SSL R&D Workshop and aimed to prompt discussion on the following topics:

  4. DOE Publishes GATEWAY Report on High-Luminous-Flux LED Lighting...

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

    of the lighting system, despite the reduction in pole height. The combination of the optics and lower pole height reduced stray light considerably. The expected annual...

  5. High performance drive circuits for integrated microLED/CMOS arrays for visible light communication (VLC) 

    E-Print Network [OSTI]

    Mahmood Zuhdi, Ahmad Wafi; Zuhdi, Ahmad

    2015-06-29T23:59:59.000Z

    Wireless communication is a form of communication that has been around for over hundreds of years and is the fastest growing segment of the communication industry. Today, wireless communication has become an essential ...

  6. Scalable Light Module for Low-Cost, High Efficiency LED Luminaires |

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin ofEnergy atLLC - FE DKT. 10-160-LNG -EnergyProcess HeatingatSaw What? Saw

  7. DOE Publishes GATEWAY Report on High-Luminous-Flux LED Lighting in a

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof"WaveInteractions and Policy (2009)| Department ofofShort

  8. New GATEWAY Report Monitors LED System Performance in a High-Temperature

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

    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 742Energy China 2015of 2005 attheMohammed Khan -DepartmentDepartment ofDevelopment | Department

  9. New GATEWAY Report Monitors LED System Performance in a High-Temperature

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

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking ofOilNEW HAMPSHIREof Energy InvestigatesEnvironment | Department of

  10. How Many CASTLE Bulbs Would You Need To Match the Brightness of the Sun?

    E-Print Network [OSTI]

    Collar, Juan I.

    How Many CASTLE Bulbs Would You Need To Match the Brightness of the Sun? = × ? Please do all million miles), so if we were to try to build the Sun out of light bulbs, we'd need a bunch! But, how many objects: the Sun, and a CASTLE light bulb. What do we mean by "brightness?" The electromagnetic (EM

  11. Exploring Infrared Properties of Giant Low Surface Brightness Galaxies

    E-Print Network [OSTI]

    Nurur Rahman; Justin H. Howell; George Helou; Joseph M. Mazzarella; Brent Buckalew

    2007-04-11T23:59:59.000Z

    Abridged: We present analysis of Spitzer Space Telescope observations of the three low surface brightness (LSB) optical giant galaxies Malin 1, UGC 6614 and UGC 9024. Mid- and far-infrared morphology, spectral energy distributions, and integrated colors are used to derive the dust mass, dust-to-gas mass ratio, total infrared luminosity, and star formation rate (SFR). The 8 micron images indicate that polycyclic aromatic hydrocarbon molecules are present in the central regions of all three metal-poor LSB galaxies. The diffuse optical disks of Malin 1 and UGC 9024 remain undetected at mid- and far-infrared wavelengths. The dustiest of the three LSB galaxies, UGC 6614, has infrared morphology that varies significantly with wavelength. The 8 and 24 micron emission is co-spatial with H\\alpha emission previously observed in the outer ring of UGC 6614. The estimated dust-to-gas ratios, from less than 10^{-3} to 10^{-2}, support previous indications that the LSB galaxies are relatively dust poor compared to the HSB galaxies. The total infrared luminosities are approximately 1/3 to 1/2 the blue band luminosities, suggesting that old stellar populations are the primary source of dust heating in these LSB objects. The SFR estimated from the infrared data ranges ~0.01-0.88 M_sun yr^{-1}, consistent with results from optical studies.

  12. Discovery of a Nearby Low-Surface-Brightness Spiral Galaxy

    E-Print Network [OSTI]

    W. B. Burton; R. Braun; R. A. M. Walterbos; C. G. Hoopes

    1998-10-27T23:59:59.000Z

    During the course of a search for compact, isolated gas clouds moving with anomalous velocities in or near our own Galaxy (Braun and Burton 1998 A&A, in press), we have discovered, in the data of the Leiden/Dwingeloo survey (Hartmann and Burton 1997, Atlas of Galactic Neutral Hydrogen, CUP) of Galactic hydrogen, the HI signature of a large galaxy, moving at a recession velocity of 282 km/s, with respect to our Galaxy. Deep multicolor and spectroscopic optical observations show the presence of star formation in scattered HII regions; radio HI synthesis interferometry confirms that the galaxy is rich in HI and has the rotation signature of a spiral galaxy; a submillimeter observation failed to detect the CO molecule. The radio and optical evidence combined suggest its classification as a low-surface-brightness spiral galaxy. It is located in close spatial and kinematic proximity to the galaxy NGC 6946. The newly-discovered galaxy, which we call Cepheus 1, is at a distance of about 6 Mpc. It is probably to be numbered amongst the nearest few LSB spirals.

  13. TRUE COLORS: LEDS AND THE RELATIONSHIP BETWEEN CCT, CRI, OPTICAL SAFETY, MATERIAL DEGRADATION, AND PHOTOBIOLOGICAL STIMULATION

    SciTech Connect (OSTI)

    Royer, Michael P.

    2014-08-30T23:59:59.000Z

    This document analyzes the optical, material, and photobiological hazards of LED light sources compared to conventional light sources. It documents that LEDs generally produce the same amount of blue light, which is the primary contributor to the risks, as other sources at the same CCT. Duv may have some effect on the amount of blue light, but CRI does not.

  14. The evolving price of household LED lamps: Recent trends and historical comparisons for the US market

    SciTech Connect (OSTI)

    Gerke, Brian F.; Ngo, Allison T.; Alstone, Andrea L.; Fisseha, Kibret S.

    2014-10-14T23:59:59.000Z

    In recent years, household LED light bulbs (LED A lamps) have undergone a dramatic price decline. Since late 2011, we have been collecting data, on a weekly basis, for retail offerings of LED A lamps on the Internet. The resulting data set allows us to track the recent price decline in detail. LED A lamp prices declined roughly exponentially with time in 2011-2014, with decline rates of 28percent to 44percent per year depending on lumen output, and with higher-lumen lamps exhibiting more rapid price declines. By combining the Internet price data with publicly available lamp shipments indices for the US market, it is also possible to correlate LED A lamp prices against cumulative production, yielding an experience curve for LED A lamps. In 2012-2013, LED A lamp prices declined by 20-25percent for each doubling in cumulative shipments. Similar analysis of historical data for other lighting technologies reveals that LED prices have fallen significantly more rapidly with cumulative production than did their technological predecessors, which exhibited a historical decline of 14-15percent per doubling of production.

  15. CONSTRUCTING AN ELASTIC TOUCH PANEL WITH EMBEDDED IR-LEDS USING SILICONE RUBBER

    E-Print Network [OSTI]

    Tanaka, Jiro

    CONSTRUCTING AN ELASTIC TOUCH PANEL WITH EMBEDDED IR-LEDS USING SILICONE RUBBER Yuichiro Sakamoto a technique for the construction of an elastic touch panel using silicone rubber. The technique is similar is made of transparent silicone rubber rather than acrylic. Moreover, we embedded infrared LEDs within

  16. LED Lighting Flicker and Potential Health Concerns: IEEE Standard PAR1789 Update

    E-Print Network [OSTI]

    Lehman, Brad

    LED Lighting Flicker and Potential Health Concerns: IEEE Standard PAR1789 Update Arnold Wilkins for mitigating health risks to viewers" has been formed to advise the lighting industry, ANSI/NEMA, IEC, EnergyStar and other standards groups about the emerging concern of flicker in LED lighting. This paper introduces

  17. Proposal -Interactive City Lighting LED based lighting systems have enabled radically new

    E-Print Network [OSTI]

    Proposal - Interactive City Lighting Abstract LED based lighting systems have also be integrated with sensors and smart environments. This has opened up a new world. The use of the LED as a potential means for providing interactive city lighting for social

  18. Largest-area Photonic Crystal LED Fabricated Demonstrates Uniform Light Emission

    Broader source: Energy.gov [DOE]

    Lumileds Lighting, the University of New Mexico, and Sandia National Laboratories teamed to demonstrate uniform light emission from the largest-area III-Nitride photonic crystal LED (1 x 1 mm2) ever fabricated. Most previous photonic crystal LED research has relied on small-area patterns written by slow, serial-writing electron-beam lithography.

  19. Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

    SciTech Connect (OSTI)

    Calciati, Marco; Vallone, Marco; Zhou, Xiangyu; Ghione, Giovanni [Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino (Italy); Goano, Michele, E-mail: michele.goano@polito.it; Bertazzi, Francesco [Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino (Italy); IEIIT-CNR, Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino (Italy); Meneghini, Matteo; Meneghesso, Gaudenzio; Zanoni, Enrico [Dipartimento di Ingegneria dell'Informazione, Universitŕ di Padova, Via Gradenigo 6/B, 35131 Padova (Italy); Bellotti, Enrico [Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary's Street, 02215 Boston, MA (United States); Verzellesi, Giovanni [Dipartimento di Scienze e Metodi dell'Ingegneria, Universitŕ di Modena e Reggio Emilia, 42122 Reggio Emilia (Italy); Zhu, Dandan; Humphreys, Colin [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

    2014-06-15T23:59:59.000Z

    Electroluminescence (EL) characterization of InGaN/GaN light-emitting diodes (LEDs), coupled with numerical device models of different sophistication, is routinely adopted not only to establish correlations between device efficiency and structural features, but also to make inferences about the loss mechanisms responsible for LED efficiency droop at high driving currents. The limits of this investigative approach are discussed here in a case study based on a comprehensive set of current- and temperature-dependent EL data from blue LEDs with low and high densities of threading dislocations (TDs). First, the effects limiting the applicability of simpler (closed-form and/or one-dimensional) classes of models are addressed, like lateral current crowding, vertical carrier distribution nonuniformity, and interband transition broadening. Then, the major sources of uncertainty affecting state-of-the-art numerical device simulation are reviewed and discussed, including (i) the approximations in the transport description through the multi-quantum-well active region, (ii) the alternative valence band parametrizations proposed to calculate the spontaneous emission rate, (iii) the difficulties in defining the Auger coefficients due to inadequacies in the microscopic quantum well description and the possible presence of extra, non-Auger high-current-density recombination mechanisms and/or Auger-induced leakage. In the case of the present LED structures, the application of three-dimensional numerical-simulation-based analysis to the EL data leads to an explanation of efficiency droop in terms of TD-related and Auger-like nonradiative losses, with a C coefficient in the 10{sup ?30} cm{sup 6}/s range at room temperature, close to the larger theoretical calculations reported so far. However, a study of the combined effects of structural and model uncertainties suggests that the C values thus determined could be overestimated by about an order of magnitude. This preliminary attempt at uncertainty quantification confirms, beyond the present case, the need for an improved description of carrier transport and microscopic radiative and nonradiative recombination mechanisms in device-level LED numerical models.

  20. The Sloan Bright Arcs Survey : Discovery of Seven New Strongly Lensed Galaxies from $\\rm{z}=0.66-2.94$

    SciTech Connect (OSTI)

    Kubo, Jeffrey M.; Allam, Sahar S.; Annis, James; Buckley-Geer, Elizabeth J.; Diehl, H.Thomas; Drabek, Emily; Frieman, Joshua A.; Hao, Jiangang; Kubik, Donna; Lin, Huan; Soares-Santos, Marcelle

    2010-10-01T23:59:59.000Z

    We report the discovery of seven new, very bright gravitational lens systems from our ongoing gravitational lens search, the Sloan Bright Arcs Survey (SBAS). Two of the systems are confirmed to have high source redshifts z = 2.19 and z = 2.94. Three other systems lie at intermediate redshift with z = 1.33, 1.82, 1.93 and two systems are at low redshift z = 0.66, 0.86. The lensed source galaxies in all of these systems are bright, with i-band magnitudes ranging from 19.73-22.06. We present the spectrum of each of the source galaxies in these systems along with estimates of the Einstein radius for each system. The foreground lens in most systems is identified by a red sequence based cluster finder as a galaxy group; one system is identified as a moderately rich cluster. In total the SBAS has now discovered nineteen strong lens systems in the SDSS imaging data, eight of which are among the highest surface brightness z {approx_equal} 2-3 galaxies known.

  1. Assessing the Performance of LED-Based Flashlights Available in the Kenyan Off-Grid Lighting Market

    SciTech Connect (OSTI)

    Tracy, Jennifer; Jacobson, Arne; Mills, Evan

    2010-03-02T23:59:59.000Z

    Low cost rechargeable flashlights that use LED technology are increasingly available in African markets. While LED technology holds promise to provide affordable, high quality lighting services, the widespread dissemination of low quality products may make it difficult to realize this potential. This study includes performance results for three brands of commonly available LED flashlights that were purchased in Kenya in 2009. The performance of the flashlights was evaluated by testing five units for each of the three brands. The tests included measurements of battery capacity, time required to charge the battery, maximum illuminance at one meter, operation time and lux-hours from a fully charged battery, light distribution, and color rendering. All flashlights tested performed well below the manufacturers? rated specifications; the measured battery capacity was 30-50percent lower than the rated capacity and the time required to fully charge the battery was 6-25percent greater than the rated time requirement. Our analysis further shows that within each brand there is considerable variability in each performance indicator. The five samples within a single brand varied from each other by as much as 22percent for battery capacity measurements, 3.6percent for the number of hours required for a full charge, 23percent for maximum initial lux, 38percent for run time, 11percent for light distribution and by as much as 200percent for color rendering. Results obtained are useful for creating a framework for quality assurance of off-grid LED products and will be valuable for informing consumers, distributors and product manufacturers about product performance.

  2. 78.1: Ultra Compact Polarization Recycling System for White Light LED based Pico-Projection System

    E-Print Network [OSTI]

    78.1: Ultra Compact Polarization Recycling System for White Light LED based Pico-Projection System polarization recycling system, for white light LED based projectors, is proposed. White light LED is applied. In this paper, we propose an ultra compact polarization recycling system for white light LED based projection

  3. VERITAS OBSERVATIONS OF SIX BRIGHT, HARD-SPECTRUM FERMI-LAT BLAZARS

    SciTech Connect (OSTI)

    Aliu, E.; Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Aune, T.; Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Boettcher, M. [Astrophysical Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Cui, W. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Duke, C. [Department of Physics, Grinnell College, Grinnell, IA 50112-1690 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Falcone, A., E-mail: afurniss@ucsc.edu, E-mail: pafortin@cfa.harvard.edu, E-mail: deirdre@llr.in2p3.fr [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Collaboration: VERITAS Collaboration; and others

    2012-11-10T23:59:59.000Z

    We report on VERITAS very high energy (VHE; E {>=} 100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band, taking gamma-ray absorption by the extragalactic background light into account. This allowed the selection of six bright, hard-spectrum blazars that were good candidate TeV emitters. Spectroscopic redshift measurements were attempted with the Keck Telescope for the targets without Sloan Digital Sky Survey spectroscopic data. No VHE emission is detected during the observations of the six sources described here. Corresponding TeV upper limits are presented, along with contemporaneous Fermi observations and non-concurrent Swift UVOT and X-Ray Telescope data. The blazar broadband spectral energy distributions (SEDs) are assembled and modeled with a single-zone synchrotron self-Compton model. The SED built for each of the six blazars shows a synchrotron peak bordering between the intermediate- and high-spectrum-peak classifications, with four of the six resulting in particle-dominated emission regions.

  4. Vapochromic LED

    DOE Patents [OSTI]

    Kunugi, Yoshihito (Hiroshima, JP); Mann, Kent R. (North Oaks, MN); Miller, Larry L. (Minnetonka, MN); Exstrom, Christopher L. (Kearney, NE)

    2003-06-17T23:59:59.000Z

    A sandwich device was prepared by electrodeposition of an insoluble layer of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin oxide coated glass, spin coating the stacked platinum compound, tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene onto the oligomer layer, and then coating the platinum complex with aluminum by vapor deposition. This device showed rectification of current and gave electroluminescence. The electroluminescence spectrum (.lambda..sub.max =545 nm) corresponded to the photoluminescence spectrum of the platinum complex. Exposure of the device to acetone vapor caused the electroemission to shift to 575 nm. Exposure to toluene vapor caused a return to the original spectrum. These results demonstrate a new type of sensor that reports the arrival of organic vapors with an electroluminescent signal. The sensor comprises (a) a first electrode; (b) a hole transport layer formed on the first electrode; (c) a sensing/emitting layer formed on the hole transport layer, the sensing/emitting layer comprising a material that changes color upon exposure to the analyte vapors; (d) an electron conductor layer formed on the sensing layer; and (e) a second electrode formed on the electron conductor layer. The hole transport layer emits light at a shorter wavelength than the sensing/emitting layer and at least the first electrode comprises an optically transparent material.

  5. Vapochromic LED

    DOE Patents [OSTI]

    Kunugi, Yoshihito (Hiroshima, JP); Mann, Kent R. (North Oaks, MN); Miller, Larry L. (Minnetonka, MN); Exstrom, Christopher L. (Kearney, NE)

    2002-01-15T23:59:59.000Z

    A sandwich device was prepared by electrodeposition of an insoluble layer of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin oxide coated glass, spin coating the stacked platinum compound, tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene onto the oligomer layer, and then coating the platinum complex with aluminum by vapor deposition. This device showed rectification of current and gave electroluminescence. The electroluminescence spectrum (.mu..sub.max =545 nm) corresponded to the photoluminescence spectrum of the platinum complex. Exposure of the device to acetone vapor caused the electroemission to shift to 575 nm. Exposure to toluene vapor caused a return to the original spectrum. These results demonstrate a new type of sensor that reports the arrival of organic vapors with an electroluminescent signal. The sensor comprises (a) a first electrode; (b) a hole transport layer formed on the first electrode; (c) a sensing/emitting layer formed on the hole transport layer, the sensing/emitting layer comprising a material that changes color upon exposure to the analyte vapors; (d) an electron conductor layer formed on the sensing layer; and (e) a second electrode formed on the electron conductor layer. The hole transport layer emits light at a shorter wavelength than the sensing/emitting layer and at least the first electrode comprises an optically transparent material.

  6. LED Provides Effective and Efficient Parking Area Lighting at the NAVFAC Engineering Service Center

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

    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 on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PM toLED Lighting Facts LED LightingOutdoorLED

  7. The Near-Infrared Photometric Properties of Bright Giants in the Central Regions of the Galactic Bulge

    E-Print Network [OSTI]

    T. J. Davidge

    1998-03-24T23:59:59.000Z

    Images recorded through broad (J, H, K), and narrow (CO, and 2.2micron continuum) band filters are used to investigate the photometric properties of bright (K < 13.5) stars in a 6 x 6 arcmin field centered on the SgrA complex. The giant branch ridgelines in the (K, J-K) and (K, H-K) color-magnitude diagrams are well matched by the Baade's Window (BW) M giant sequence if the mean extinction is A_K ~ 2.8 mag. Extinction measurements for individual stars are estimated using the M_K versus infrared color relations defined by M giants in BW, and the majority of stars have A_K between 2.0 and 3.5 mag. The extinction is locally high in the SgrA complex, where A_K ~ 3.1 mag. Reddening-corrected CO indices, CO_o, are derived for over 1300 stars with J, H, and K brightnesses, and over 5300 stars with H and K brightnesses. The distribution of CO_o values for stars with K_o between 11.25 and 7.25 can be reproduced using the M_K versus CO_o relation defined by M giants in BW. The data thus suggest that the most metal-rich giants in the central regions of the bulge and in BW have similar photometric properties and 2.3micron CO strengths. Hence, it appears that the central region of the bulge does not contain a population of stars that are significantly more metal-rich than what is seen in BW.

  8. A Chandra Snapshot Survey of IR-bright LINERs: A Possible Link Between Star Formation, AGN Fueling, and Mass Accretion

    E-Print Network [OSTI]

    R. P. Dudik; S. Satyapal; M. Gliozzi; R. M. Sambruna

    2004-10-13T23:59:59.000Z

    We present results from a high resolution X-ray imaging study of nearby LINERs observed by Chandra. This study complements and extends previous X-ray studies of LINERs, focusing on the under-explored population of nearby dust-enshrouded infrared-bright LINERs. The sample consists of 15 IR-bright LINERs (L_FIR/L_B > 3), with distances that range from 11 to 26 Mpc. Combining our sample with previous Chandra studies we find that ~ 51% (28/55) of the LINERs display compact hard X-ray cores. The nuclear 2-10 keV luminosities of the galaxies in this expanded sample range from ~ 2 X 10^38 ergs s^-1 to ~ 2 X 10^44 ergs s^-1. We find an intriguing trend in the Eddington ratio vs. L_FIR and L_FIR/L_B for the AGN-LINERs in the expanded sample that extends over seven orders of magnitude in L/L_Edd. This correlation may imply a link between black hole growth, as measured by the Eddington ratio, and the star formation rate (SFR), as measured by the far-IR luminosity and IR-brightness ratio. If the far-IR luminosity is an indicator of the molecular gas content in our sample of LINERs, our results may further indicate that the mass accretion rate scales with the host galaxy's fuel supply. We discuss the potential implications of our results in the framework of black hole growth and AGN fueling in low luminosity AGN. (Abridged)

  9. THE STABILITY OF LOW SURFACE BRIGHTNESS DISKS BASED ON MULTI-WAVELENGTH MODELING

    E-Print Network [OSTI]

    MacLachlan, J. M.

    To investigate the structure and composition of the dusty interstellar medium (ISM) of low surface brightness (LSB) disk galaxies, we have used multi-wavelength photometry to construct spectral energy distributions for ...

  10. Visualizing individual microtubules by bright field microscopy Braulio Gutirrez-Medinaa

    E-Print Network [OSTI]

    Block, Steven

    a microscope with conventional bright field optics in conjunction with a webcam-type camera and a light-emitting diode illuminator. The light scattered by microtubules is image-processed to remove the background

  11. Progress in bright ion beams for industry, medicine and fusion at LBNL

    E-Print Network [OSTI]

    Kwan, Joe W.

    2002-01-01T23:59:59.000Z

    HI FAN 1160 LBNL-50492 Progress in Bright Ion BeamsMedicine and Fusion at LBNL Joe W. Kwan Lawrence BerkeleyAbstract Recent progresses at LBNL in developing ion beams

  12. Member Case Studies: LED Street Lighting Programs in Algona (IA), Asheville (NC), and Boston (MA)

    Broader source: Energy.gov [DOE]

    This May 8, 2013 webcast featured presentations from DOE Municipal Solid-State Street Lighting Consortium member cities about their experiences with LED street lighting. Presenters John Bilsten of...

  13. LED Linear Lamps and Troffer Lighting: CALiPER Report Series 21

    Broader source: Energy.gov [DOE]

    View the video about CALiPER Report Series 21 on LED Linear Lamps and Troffer Lighting, featuring interviews with Tracy Beeson and Naomi Miller of Pacific Northwest National Laboratory.

  14. Transcranial LED therapy for cognitive dysfunction in chronic, mild traumatic brain injury: Two case reports

    E-Print Network [OSTI]

    Hamblin, Michael R.

    Two chronic, traumatic brain injury (TBI) cases are presented, where cognitive function improved following treatment with transcranial light emitting diodes (LEDs). At age 59, P1 had closed-head injury from a motor vehicle ...

  15. Deposition of colloidal quantum dots by microcontact printing for LED display technology

    E-Print Network [OSTI]

    Kim, LeeAnn

    2006-01-01T23:59:59.000Z

    This thesis demonstrates a new deposition method of colloidal quantum dots within a quantum dot organic light-emitting diode (QD-LED). A monolayer of quantum dots is microcontact printed as small as 20 ,Lm lines as well ...

  16. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products

    Broader source: Energy.gov [DOE]

    This March 28, 2013 webcast reviewed DOE's recently completed three-part study of the life-cycle energy and environmental impacts of LED lighting products relative to incandescent and CFL...

  17. Quality and Performance of LED Flashlights in Kenya: Common End User Preferences and Complaints

    E-Print Network [OSTI]

    Tracy, Jenny

    2010-01-01T23:59:59.000Z

    at ensure the success of the off-grid lighting market. Theand E. Mills. 2008. "Measured Off? Grid LED Lighting Systemtechnology into the broader off-grid lighting market. The

  18. adjustable red-green-blue led: Topics by E-print Network

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

    or by combining green and red phosphors on a background consisting of a blue-light emitting diode (LED) or by employing nanocrystals (NCs) of the three primary colors (red,...

  19. Text-Alternative Version: CALiPER Report Series 20 on LED PAR38 Lamps

    Broader source: Energy.gov [DOE]

    Michael Royer, Lighting Engineer, Pacific Northwest National Laboratory: The CALiPER program looks at typical LED lamp performance attributes. As we've gone through the progression of reports, we...

  20. DOE Publishes CALiPER Snapshot Report on LED MR16 Lamps

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy's CALiPER program has released a Snapshot Report on MR16 lamps, which utilizes the LED Lighting Facts® program's extensive product database to help industry...

  1. Dimming LEDs with Phase-Cut Dimmers: The Specifier's Process for Maximizing Success

    SciTech Connect (OSTI)

    Miller, Naomi J.; Poplawski, Michael E.

    2013-10-01T23:59:59.000Z

    This report reviews how phase-cut dimmers work, how LEDs differ from the incandescent lamps that the dimmers were historically designed to control, and how these differences can lead to complications when trying to dim LEDs. Compatibility between a specific LED source and a specific phase-cut dimmer is often unknown and difficult to assess, and ensuring compatibility adds complexity to the design, specification, bidding, and construction observation phases for new buildings and major remodel projects. To maximize project success, this report provides both general guidance and step-by-step procedures for designing phase-controlled LED dimming on both new and existing projects, as well as real-world examples of how to use those procedures.

  2. DOE Publishes CALiPER Report on LED T8 Lamps

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy's CALiPER program has released an Application Summary Report that focuses on the bare-lamp performance of 31 linear LED lamps intended as an alternative to T8...

  3. Collective Experience: A Database-Fuelled, Inter-Disciplinary Team-Led Learning System

    E-Print Network [OSTI]

    Celi, Leo Anthony G.

    We describe the framework of a data-fuelled, interdisciplinary team-led learning system. The idea is to build models using patients from one's own institution whose features are similar to an index patient as regards an ...

  4. Applied Materials Develops an Advanced Epitaxial Growth System to Bring Down LED Costs

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, Applied Materials has developed an advanced epitaxial growth system for gallium nitride (GaN) LED devices that decreases operating costs, increases internal quantum efficiency, and improves binning yields.

  5. Quality and Performance of LED Flashlights in Kenya: Common End User Preferences and Complaints

    E-Print Network [OSTI]

    Tracy, Jenny

    2010-01-01T23:59:59.000Z

    grid lighting market. The lead acid batteries embedded inrechargeable sealed lead-acid batteries are the most popularlead-acid (SLA) battery, LED flashlights powered by dry cell batteries,

  6. LED Replacement Lamps: Current Performance and the Latest on ENERGY STAR®

    Broader source: Energy.gov [DOE]

    This May 19, 2009 webcast summarized CALiPER's recent benchmark testing of common omnidirectional incandescent lamps (e.g., A-lamps), and provided an update on ENERGY STAR criteria for LED integral...

  7. Text-Alternative Version: LED Lighting in a Performing Arts Building Webinar

    Broader source: Energy.gov [DOE]

     Welcome ladies and gentlemen. I'm Bob Davis with the Pacific Northwest National Laboratory, and I'd like to welcome you to today's webcast titled, LEDs, Can They Perform in a Performing Arts...

  8. EECBG Success Story: Shining Energy-Saving LEDs on Utah Starry...

    Energy Savers [EERE]

    LEDs across 14 rural communities. About 2,500 streetlights will be replaced and could save the town 20% to 50% on electricity bills. Learn more. Addthis Related Articles A...

  9. Successful Selection of LED Streetlight Luminaires: Optimizing Illumination and Economic Performance

    Broader source: Energy.gov [DOE]

    This March 6, 2013 webcast reviewed the factors involved in successful selection of LED streetlight luminaires. Presenters Eric Haugaard of Cree Lighting and Chad Stalker of Philips Lumileds guided...

  10. Two PPPL-led teams win increased supercomputing time to study...

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

    Two PPPL-led teams win increased supercomputing time to study conditions inside fusion plasmas By John Greenwald January 9, 2014 Tweet Widget Google Plus One Share on Facebook...

  11. Demonstration Assessment of Light Emitting Diode (LED) Commercial Garage Lights In the Providence Portland Medical Center, Portland, Oregon

    SciTech Connect (OSTI)

    Ton, My K.; Richman, Eric E.; Gilbride, Theresa L.

    2008-11-11T23:59:59.000Z

    This U.S. Department of Energy GATEWAY Demonstration project studied the applicability of light-emitting diode (LED) luminaires for commercial parking garage applications. High-pressure sodium (HPS) area luminaires were replaced with new LED area luminaires. The project was supported under the U.S. Department of Energy (DOE) Solid State Lighting Program. Other participants in the demonstration project included Providence Portland Medical Center in Portland, Oregon, the Energy Trust of Oregon, and Lighting Sciences Group (LSG) Inc. Pacific Northwest National Laboratory (PNNL) conducted the measurements and analysis of the results. PNNL manages GATEWAY demonstrations for DOE and represents their perspective in the conduct of the work. Quantitative and qualitative measurements of light and electrical power were taken at the site for both HPS and LED light sources. Economic costs were estimated and garage users’ responses to the new light sources were gauged with a survey. Six LED luminaires were installed in the below-ground parking level A, replacing six existing 150W HPS lamps spread out over two rows of parking spaces. Illuminance measurements were taken at floor level approximately every 4 ft on a 60-ft x 40-ft grid to measure light output of these LED luminaires which were termed the “Version 1” luminaires. PNNL conducted power measurements of the circuit in the garage to which the 6 luminaires were connected and determined that they drew an average of 82 W per lamp. An improved LED luminaire, Version 2, was installed in Level B of the parking garage. Illuminance measurements were not made of this second luminaire on site due to higher traffic conditions, but photometric measurements of this lamp and Version 1 were made in an independent testing laboratory and power usage for Version 2 was also measured. Version 1 was found to produce 3600 lumens and Version 2 was found to produce 4700 lumens of light and to consume 78 Watts. Maximum and minimum light levels were measured for the HPS and LED Version 1 luminaires and projected for the Version 2 luminaires. Maximum light levels were 23.51 foot candles, 20.54 fc, and 26.7 fc respectively and minimum light levels were 1.49 fc, 1.45 fc, and 1.88 fc. These results indicate very similar or even slightly higher light levels produced by the LED lamps, despite the higher lumen output of the HPS lamp. The LED lamps provide higher luminaire efficacy because all of the light is directed down and out. None of it is “lost” in the fixture. Also the HPS luminaire had poorly designed optics and a plastic covering that tended to get dirty and cracked, further decreasing the realized light output.[is this an accurate way to say this?] Consumer perceptions of the Version 2 LED were collected via a written survey form given to maintenance and security personnel. More than half felt the LED luminaires provided more light than the HPS lamps and a majority expressed a preference for the new lamps when viewing the relamped area through a security camera. Respondents commented that the LED luminaires were less glary, created less shadows, had a positive impact on visibility, and improved the overall appearance of the area. PNNL conducted an economic analysis and found that the Version 1 lamp produced annual energy savings of 955 kWh and energy cost savings of $76.39 per lamp at electricity rates of 6.5 cents per kWh and $105.03 at 11 cents per kWh. PNNL found that the Version 2 lamp produced annual energy savings of 991 kWh and energy cost savings of $79.26 per lamp at electricity rates of 6.5 cents per kWh and $108.98 at 11 cents per kWh. PNNL also calculated simple payback and found that Version 1 showed paybacks of 5.4 yrs at 6.5c/kWh and 4.1 yrs at 11c/kWh while Version 2 showed paybacks of 5.2 yrs at 6.5c/kWh and 3.9 yrs at 11c/kWh.

  12. DOE CALiPER Program, Report 21.2: Linear (T8) LED Lamp Performance in Five Types of Recessed Troffers

    SciTech Connect (OSTI)

    Miller, Naomi J.; Perrin, Tess E.; Royer, Michael P.; Wilkerson, Andrea M.; Beeson, Tracy A.

    2014-05-20T23:59:59.000Z

    Although lensed troffers are numerous, there are many other types of optical systems as well. This report looked at the performance of three linear (T8) LED lamps chosen primarily based on their luminous intensity distributions (narrow, medium, and wide beam angles) as well as a benchmark fluorescent lamp in five different troffer types. Also included are the results of a subjective evaluation. Results show that linear (T8) LED lamps can improve luminaire efficiency in K12-lensed and parabolic-louvered troffers, effect little change in volumetric and high-performance diffuse-lensed type luminaires, but reduce efficiency in recessed indirect troffers. These changes can be accompanied by visual appearance and visual comfort consequences, especially when LED lamps with clear lenses and narrow distributions are installed. Linear (T8) LED lamps with diffuse apertures exhibited wider beam angles, performed more similarly to fluorescent lamps, and received better ratings from observers. Guidance is provided on which luminaires are the best candidates for retrofitting with linear (T8) LED lamps.

  13. Illuminating the Pecking Order in Off-Grid Lighting: A Demonstration of LED Lighting for Saving Energy in the Poultry Sector

    SciTech Connect (OSTI)

    Tracy, Jennifer; Mills, Evan

    2010-11-06T23:59:59.000Z

    The Lumina Project and Lighting Africa conducted a full-scale field test involving a switch from kerosene to solar-LED lighting for commercial broiler chicken production at an off-grid farm in Kenya. The test achieved lower operating costs, produced substantially more light, improved the working environment, and had no adverse effect on yields. A strategy using conventional solar-fluorescent lighting also achieved comparable yields, but entailed a six-fold higher capital cost and significantly higher recurring battery replacement costs. Thanks to higher energy and optical efficiencies, the LED system provided approximately twice the illumination to the chicken-production area and yet drew less than half the power.At the study farm, 3000 chickens were grown in each of three identical houses under kerosene, fluorescent, and LED lighting configurations. Under baseline conditions, a yearly expenditure of 1,200 USD is required to illuminate the three houses with kerosene. The LED system eliminates this fuel use and expense with a corresponding simple payback time of 1.5 years, while the solar-fluorescent system has a payback time of 9.3 years. The corresponding reduction in fuel expenditure in both cases represents a 15percent increase in after-tax net income (revenues minus expenses) across the entire business operation. The differential cost-effectiveness between the LED and fluorescent systems would be substantially greater if the fluorescent system were upsized to provide the same light as the LED system. Providing light with the fluorescent or LED systems is also far more economical than connecting to the grid in this case. The estimated grid-connection cost at this facility is 1.7 million Kenya Schillings (approximately 21,250 USD), which is nearly six-times the cost of the fluorescent system and 35-times the cost of the LED system.The LED system also confers various non-energy benefits. The relative uniformity of LED lighting, compared to the fluorescent or kerosene lighting, reduced crowding which in turn created a less stressful environment for the chickens. The far higher levels of illumination also created a better environment for the workers, while eliminating the time required for obtaining fuel and maintaining kerosene lanterns. An additional advantage of the LED system relative to the solar fluorescent system was that the former does not require a skilled technician to carry out the installation. The portable LED system lighting layout is also more easily adjusted than that of the hardwired fluorescent systems. Furthermore, switching to the LED system avoids over one metric ton of carbon dioxide emissions per house on an annual basis compared to kerosene. There is high potential for replication of this particular LED lighting strategy in the developing world. In order to estimate the scale of kerosene use and the potential for savings, more information is needed on the numbers of chickens produced off-grid, as well as lighting uses for other categories of poultry production (egg layers, indigenous broilers ). Our discovery that weight gain did not slow in the solar-fluorescent house after it experienced extended lighting outages beginning on day 14 of the 35-day study suggests that conventional farming practices in Kenyan broiler operations may call for more hours of lighting than is needed to achieve least-cost production.

  14. Bright Lyman Break Galaxies in the Sloan Digital Sky Survey First Data Release

    E-Print Network [OSTI]

    Bentz, M C; Weinberg, D H; Bentz, Misty C.; Osmer, Patrick S.; Weinberg, David H.

    2003-01-01T23:59:59.000Z

    We report the discovery of six compact, starburst galaxies with redshifts 2.3 < z < 2.8 and r-band magnitudes 19.8-20.5 in the Quasar Catalog of the Sloan Digital Sky Survey First Data Release (SDSS DR1). The SDSS spectra of these objects resemble the composite spectrum of Lyman Break Galaxies (LBGs) at z \\approx 3, but the galaxies are 4-5 magnitudes brighter than an ``L*'' LBG and 2-3 magnitudes brighter than the most luminous objects in typical LBG spectroscopic surveys. Star formation rates inferred from the UV continuum luminosities are about 300-1000 M_sun yr^-1 with no correction for dust extinction. Such rates are similar to those inferred for ultraluminous infrared galaxies, but in these UV-bright objects the star formation is evidently not obscured by high dust column densities. The SDSS images show no evidence of multiple imaging or foreground lensing structures, but amplification by gravitational lensing (as in the case of MS 1512-cB58) cannot be ruled out with the present data. Assuming tha...

  15. Preparation of brightness stabilization agent for lignin containing pulp from biomass pyrolysis oils

    DOE Patents [OSTI]

    Agblevor, Foster A. (Blacksburg, VA); Besler-Guran, Serpil (Flemington, NJ)

    2001-01-01T23:59:59.000Z

    A process for producing a brightness stabilization mixture of water-soluble organic compounds from biomass pyrolysis oils comprising: a) size-reducing biomass material and pyrolyzing the size-reduced biomass material in a fluidized bed reactor; b) separating a char/ash component while maintaining char-pot temperatures to avoid condensation of pyrolysis vapors; c) condensing pyrolysis gases and vapors, and recovering pyrolysis oils by mixing the oils with acetone to obtain an oil-acetone mixture; d) evaporating acetone and recovering pyrolysis oils; e) extracting the pyrolysis oils with water to obtain a water extract; f) slurrying the water extract with carbon while stirring, and filtering the slurry to obtain a colorless filtrate; g) cooling the solution and stabilizing the solution against thermally-induced gelling and solidification by extraction with ethyl acetate to form an aqueous phase lower layer and an organic phase upper layer; h) discarding the upper organic layer and extracting the aqueous layer with ethyl acetate, and discarding the ethyl acetate fraction to obtain a brown-colored solution not susceptible to gelling or solidification upon heating; i) heating the solution to distill off water and other light components and concentrating a bottoms fraction comprising hydroxyacetaldehyde and other non-volatile components having high boiling points; and j) decolorizing the stabilized brown solution with activated carbon to obtain a colorless solution.

  16. Sub-GeV flashes in $?-$ray burst afterglows as probes of underlying bright UV flares

    E-Print Network [OSTI]

    Yizhong Fan; Tsvi Piran

    2006-04-17T23:59:59.000Z

    Bright optical and X-ray flares have been observed in many Gamma-ray Burst (GRB) afterglows. These flares have been attributed to late activity of the central engine. In most cases the peak energy is not known and it is possible and even likely that there is a significant far-ultraviolet component. These far-ultraviolet photons escape our detection because they are absorbed by the neutral hydrogen before reaching Earth. However, these photons cross the blast wave produced by the ejecta that have powered the initial GRB. They can be inverse Compton upscattered by hot electrons within this blast wave. This process will produce a strong sub-GeV flare that follows the high energy (soft X-ray) tail of the far-UV flare but lasts much longer and can be detected by the upcoming {\\em Gamma-Ray Large Area Telescope} (GLAST) satellite. This signature can be used to probe the spectrum of the underlying far-ultraviolet flare. The extra cooling produced by this inverse Compton process can lower the X-ray emissivity of the forward shock and explain the unexpected low early X-ray flux seen in many GRBs.

  17. Formation of multi-solitons and vortex bright solitons in Bose-condensed alkali-metal atoms

    E-Print Network [OSTI]

    Luca Salasnich

    2003-09-02T23:59:59.000Z

    Formation of multi-solitons and vortex bright solitons in Bose-condensed alkali-metal atoms is analyzed by using the nonpolynomial Schordinger equation. A train of bright solitons is obtained from an axially homogeneous Bose-Einstein condensate by a sudden change of the scattering length from repulsive to attractive. We derive an analytical expression for the number of bright solitons generated by using this mechanism. The formula generalizes a previous formula obtained with the 1D Gross-Pitaevskii equation. In the second part we consider vortex bright solitons, namely cigar-shaped bright solitons with a nonzero angular quantum number $k$ along the axial direction. By using a variational approach we determine the shape of vortex bright solitons, showing that the critical number of atoms for the collapse of the vortex soliton increases with a larger $k$. Finally we calculate monopole and quadrupole collective oscillations of these vortex bright solitons.

  18. A COMPLETE SAMPLE OF BRIGHT SWIFT LONG GAMMA-RAY BURSTS. I. SAMPLE PRESENTATION, LUMINOSITY FUNCTION AND EVOLUTION

    SciTech Connect (OSTI)

    Salvaterra, R. [INAF, IASF Milano, via E. Bassini 15, I-20133 Milano (Italy); Campana, S.; Vergani, S. D.; Covino, S.; D'Avanzo, P.; Fugazza, D.; Ghirlanda, G.; Ghisellini, G.; Melandri, A.; Sbarufatti, B.; Tagliaferri, G. [INAF, Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate (Saint Lucia) (Italy); Nava, L. [SISSA, via Bonomea 265, I-34136 Trieste (Italy); Flores, H. [Laboratoire GEPI, Observatoire de Paris, CNRS-UMR8111, Univ. Paris-Diderot 5 place Jules Janssen, 92195 Meudon (France); Piranomonte, S., E-mail: ruben@lambrate.inaf.it [INAF, Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monte Porzio Catone, Rome (Italy)

    2012-04-10T23:59:59.000Z

    We present a carefully selected sub-sample of Swift long gamma-ray bursts (GRBs) that is complete in redshift. The sample is constructed by considering only bursts with favorable observing conditions for ground-based follow-up searches, which are bright in the 15-150 keV Swift/BAT band, i.e., with 1-s peak photon fluxes in excess to 2.6 photons s{sup -1} cm{sup -2}. The sample is composed of 58 bursts, 52 of them with redshift for a completeness level of 90%, while another two have a redshift constraint, reaching a completeness level of 95%. For only three bursts we have no constraint on the redshift. The high level of redshift completeness allows us for the first time to constrain the GRB luminosity function and its evolution with cosmic times in an unbiased way. We find that strong evolution in luminosity ({delta}{sub l} = 2.3 {+-} 0.6) or in density ({delta}{sub d} = 1.7 {+-} 0.5) is required in order to account for the observations. The derived redshift distributions in the two scenarios are consistent with each other, in spite of their different intrinsic redshift distributions. This calls for other indicators to distinguish among different evolution models. Complete samples are at the base of any population studies. In future works we will use this unique sample of Swift bright GRBs to study the properties of the population of long GRBs.

  19. BRIGHT POINTS AND JETS IN POLAR CORONAL HOLES OBSERVED BY THE EXTREME-ULTRAVIOLET IMAGING SPECTROMETER ON HINODE

    SciTech Connect (OSTI)

    Doschek, G. A.; Landi, E.; Warren, H. P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Harra, L. K., E-mail: george.doschek@nrl.navy.mi [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom)

    2010-02-20T23:59:59.000Z

    We present observations of polar coronal hole bright points (BPs) made with the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. The data consist of raster images of BPs in multiple spectral lines from mostly coronal ions, e.g., Fe X-Fe XV. The BPs are observed for short intervals and thus the data are snapshots of the BPs obtained during their evolution. The images reveal a complex unresolved temperature structure (EIS resolution is about 2''), with the highest temperature being about 2 x 10{sup 6} K. Some BPs appear as small loops with temperatures that are highest near the top. But others are more point-like with surrounding structures. However, the thermal time evolution of the BPs is an important factor in their appearance. A BP may appear quite different at different times. We discuss one BP with an associated jet that is bright enough to allow statistically meaningful measurements. The jet Doppler speed along the line of sight is about 15-20 km s{sup -1}. Electron densities of the BPs and the jet are typically near 10{sup 9} cm{sup -3}, which implies path lengths along the line of sight on the order of a few arcsec. We also construct differential emission measure curves for two of the best observed BPs. High spatial resolution (significantly better than 1'') is required to fully resolve the BP structures.

  20. Applications of Robust, Radiation Hard AlGaN Optoelectronic Devices in Space Exploration and High Energy Density Physics

    SciTech Connect (OSTI)

    Sun, K.

    2011-05-04T23:59:59.000Z

    This slide show presents: space exploration applications; high energy density physics applications; UV LED and photodiode radiation hardness; UV LED and photodiode space qualification; UV LED AC charge management; and UV LED satellite payload instruments. A UV LED satellite will be launched 2nd half 2012.

  1. Light Wars: The Bright Future of Laser Weapons

    E-Print Network [OSTI]

    Mistry, Hemma

    2009-01-01T23:59:59.000Z

    currently the highest power solid-state laser in the world,funding the Joint High Power Solid-State Laser (JHPSSL)Solid-state lasers and chemical lasers have certain limitations on the power

  2. GLOBAL PROPERTIES OF M31'S STELLAR HALO FROM THE SPLASH SURVEY. I. SURFACE BRIGHTNESS PROFILE

    SciTech Connect (OSTI)

    Gilbert, Karoline M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Guhathakurta, Puragra [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Beaton, Rachael L.; Majewski, Steven R.; Ostheimer, James C.; Patterson, Richard J. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Bullock, James; Tollerud, Erik J. [Center for Cosmology, Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697 (United States); Geha, Marla C. [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Kalirai, Jason S. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Kirby, Evan N. [California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Tanaka, Mikito; Chiba, Masashi, E-mail: kgilbert@astro.washington.edu [Astronomical Institute, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan)

    2012-11-20T23:59:59.000Z

    We present the surface brightness profile of M31's stellar halo out to a projected radius of 175 kpc. The surface brightness estimates are based on confirmed samples of M31 red giant branch stars derived from Keck/DEIMOS spectroscopic observations. A set of empirical spectroscopic and photometric M31 membership diagnostics is used to identify and reject foreground and background contaminants. This enables us to trace the stellar halo of M31 to larger projected distances and fainter surface brightnesses than previous photometric studies. The surface brightness profile of M31's halo follows a power law with index -2.2 {+-} 0.2 and extends to a projected distance of at least {approx}175 kpc ({approx}2/3 of M31's virial radius), with no evidence of a downward break at large radii. The best-fit elliptical isophotes have b/a = 0.94 with the major axis of the halo aligned along the minor axis of M31's disk, consistent with a prolate halo, although the data are also consistent with M31's halo having spherical symmetry. The fact that tidal debris features are kinematically cold is used to identify substructure in the spectroscopic fields out to projected radii of 90 kpc and investigate the effect of this substructure on the surface brightness profile. The scatter in the surface brightness profile is reduced when kinematically identified tidal debris features in M31 are statistically subtracted; the remaining profile indicates that a comparatively diffuse stellar component to M31's stellar halo exists to large distances. Beyond 90 kpc, kinematically cold tidal debris features cannot be identified due to small number statistics; nevertheless, the significant field-to-field variation in surface brightness beyond 90 kpc suggests that the outermost region of M31's halo is also comprised to a significant degree of stars stripped from accreted objects.

  3. Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's

    SciTech Connect (OSTI)

    Royer, Michael P.

    2013-09-17T23:59:59.000Z

    Synopsis: Light loss factors are used to help lighting systems meet quantitative design criteria throughout the life of the installation, but they also influence energy use. As the light sources currently being specified continue to evolve, it is necessary to reevaluate the methods used in calculating light loss factors, as well as carefully consider the consequences of different product performance attributes. Because of the unique operating characteristics of LEDs and lack of a comprehensive lifetime rating—as well as the problematic relationship between lifetime and lumen maintenance—determining an appropriate lamp lumen depreciation (LLD) factor for LED products is difficult. As a result, a unique solution has been advocated: when quantity of light is an important design consideration, the IES recommends using an LLD of not greater than 0.70. This method deviates from the typical practice for conventional sources of using the ratio of mean to initial lumen output, and can misrepresent actual performance, increase energy use, and inhibit comparisons between products. This paper discusses the complications related to LLD and LEDs, compares the performance of conventional and LED products, and examines alternatives to a maximum LLD of 0.70 for LEDs.

  4. THE WAVE PROPERTIES OF CORONAL BRIGHT FRONTS OBSERVED USING SDO/AIA

    SciTech Connect (OSTI)

    Long, David M.; DeLuca, Edward E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gallagher, Peter T., E-mail: longda@tcd.ie [Astrophysics Research Group, School of Physics, Trinity College Dublin, Dublin 2 (Ireland)

    2011-11-15T23:59:59.000Z

    Coronal bright fronts (CBFs) are large-scale wavefronts that propagate through the solar corona at hundreds of kilometers per second. While their kinematics have been studied in detail, many questions remain regarding the temporal evolution of their amplitude and pulse width. Here, contemporaneous high cadence, multi-thermal observations of the solar corona from the Solar Dynamic Observatory (SDO) and Solar TErrestrial RElations Observatory (STEREO) spacecraft are used to determine the kinematics and expansion rate of a CBF wavefront observed on 2010 August 14. The CBF was found to have a lower initial velocity with weaker deceleration in STEREO observations compared to SDO observations ({approx}340 km s{sup -1} and -72 m s{sup -2} as opposed to {approx}410 km s{sup -1} and -279 m s{sup -2}). The CBF kinematics from SDO were found to be highly passband-dependent, with an initial velocity ranging from 379 {+-} 12 km s{sup -1} to 460 {+-} 28 km s{sup -1} and acceleration ranging from -128 {+-} 28 m s{sup -2} to -431 {+-} 86 m s{sup -2} in the 335 A and 304 A passbands, respectively. These kinematics were used to estimate a quiet coronal magnetic field strength range of {approx}1-2 G. Significant pulse broadening was also observed, with expansion rates of {approx}130 km s{sup -1} (STEREO) and {approx}220 km s{sup -1} (SDO). By treating the CBF as a linear superposition of sinusoidal waves within a Gaussian envelope, the resulting dispersion rate of the pulse was found to be {approx}8-13 Mm{sup 2} s{sup -1}. These results are indicative of a fast-mode magnetoacoustic wave pulse propagating through an inhomogeneous medium.

  5. Sparkling extreme-ultraviolet bright dots observed with Hi-C

    SciTech Connect (OSTI)

    Régnier, S.; Alexander, C. E.; Walsh, R. W. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston, Lancashire, PR1 2HE (United Kingdom); Winebarger, A. R.; Cirtain, J. [NASA Marshall Space Flight Center, VP 62, Huntsville, AL 35812 (United States); Golub, L.; Korreck, K. E.; Weber, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Mitchell, N.; Platt, S. [School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston, Lancashire, PR1 2HE (United Kingdom); De Pontieu, B.; Title, A. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Kobayashi, K. [Center for Space Plasma and Aeronomic Research, 320 Sparkman Dr, Huntsville, AL 35805 (United States); Kuzin, S. [Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, Moscow, 119991 (Russian Federation); DeForest, C. E. [Southwest Research Institute, 1050 Walnut Street Suite 300, Boulder, CO 80302 (United States)

    2014-04-01T23:59:59.000Z

    Observing the Sun at high time and spatial scales is a step toward understanding the finest and fundamental scales of heating events in the solar corona. The high-resolution coronal (Hi-C) instrument has provided the highest spatial and temporal resolution images of the solar corona in the EUV wavelength range to date. Hi-C observed an active region on 2012 July 11 that exhibits several interesting features in the EUV line at 193 Ĺ. One of them is the existence of short, small brightenings 'sparkling' at the edge of the active region; we call these EUV bright dots (EBDs). Individual EBDs have a characteristic duration of 25 s with a characteristic length of 680 km. These brightenings are not fully resolved by the SDO/AIA instrument at the same wavelength; however, they can be identified with respect to the Hi-C location of the EBDs. In addition, EBDs are seen in other chromospheric/coronal channels of SDO/AIA, which suggests a temperature between 0.5 and 1.5 MK. Based on their frequency in the Hi-C time series, we define four different categories of EBDs: single peak, double peak, long duration, and bursty. Based on a potential field extrapolation from an SDO/HMI magnetogram, the EBDs appear at the footpoints of large-scale, trans-equatorial coronal loops. The Hi-C observations provide the first evidence of small-scale EUV heating events at the base of these coronal loops, which have a free magnetic energy of the order of 10{sup 26} erg.

  6. LEDS Global Partnership in Action: Advancing Climate-Resilient Low Emission Development Around the World (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-11-01T23:59:59.000Z

    Many countries around the globe are designing and implementing low emission development strategies (LEDS). These LEDS seek to achieve social, economic, and environmental development goals while reducing long-term greenhouse gas (GHG) emissions and increasing resiliency to climate change impacts. The LEDS Global Partnership (LEDS GP) harnesses the collective knowledge and resources of more than 120 countries and international donor and technical organizations to strengthen climate-resilient low emission development efforts around the world.

  7. LED Light Fixture Project FC1 Director's Conference Room: Life Cycle Cost and Break-even Analysis

    E-Print Network [OSTI]

    Johnston, Daniel

    . A light-emitting diode (LED) is a solid-state lighting source that switches on instantly, is readily

  8. Use Patterns of LED Flashlights in Kenya and a One-Year Cost Analysis of Flashlight Ownership

    E-Print Network [OSTI]

    Tracy, Jennifer

    2010-01-01T23:59:59.000Z

    rechargeable sealed-lead acid (SLA) batteries are alsolead-acid (SLA) battery, LED flashlights powered by dry cell batteries,

  9. Towards an Understanding of the Mid-Infrared Surface Brightness of Normal Galaxies

    E-Print Network [OSTI]

    Daniel A. Dale; George Helou; Nancy A. Silbermann; Alessandra Contursi; Sangeeta Malhotra; Robert H. Rubin

    1999-08-09T23:59:59.000Z

    We report a mid-infrared color and surface brightness analysis of IC 10, NGC 1313, and NGC 6946, three of the nearby galaxies studied under the Infrared Space Observatory Key Project on Normal Galaxies. Images with < 9 arcsecond (170 pc) resolution of these nearly face-on, late-type galaxies were obtained using the LW2 (6.75 mu) and LW3 (15 mu) ISOCAM filters. Though their global I_nu(6.75 mu)/I_nu(15 mu) flux ratios are similar and typical of normal galaxies, they show distinct trends of this color ratio with mid-infrared surface brightness. We find that I_nu(6.75 mu)/I_nu(15 mu) ~< 1 only occurs for regions of intense heating activity where the continuum rises at 15 micron and where PAH destruction can play an important role. The shape of the color-surface brightness trend also appears to depend, to the second-order, on the hardness of the ionizing radiation. We discuss these findings in the context of a two-component model for the phases of the interstellar medium and suggest that star formation intensity is largely responsible for the mid-infrared surface brightness and colors within normal galaxies, whereas differences in dust column density are the primary drivers of variations in the mid-infrared surface brightness between the disks of normal galaxies.

  10. Characterization of failure modes in deep UV and deep green LEDs utilizing advanced semiconductor localization techniques.

    SciTech Connect (OSTI)

    Tangyunyong, Paiboon; Miller, Mary A.; Cole, Edward Isaac, Jr.

    2012-03-01T23:59:59.000Z

    We present the results of a two-year early career LDRD that focused on defect localization in deep green and deep ultraviolet (UV) light-emitting diodes (LEDs). We describe the laser-based techniques (TIVA/LIVA) used to localize the defects and interpret data acquired. We also describe a defect screening method based on a quick electrical measurement to determine whether defects should be present in the LEDs. We then describe the stress conditions that caused the devices to fail and how the TIVA/LIVA techniques were used to monitor the defect signals as the devices degraded and failed. We also describe the correlation between the initial defects and final degraded or failed state of the devices. Finally we show characterization results of the devices in the failed conditions and present preliminary theories as to why the devices failed for both the InGaN (green) and AlGaN (UV) LEDs.

  11. Development of Advanced Manufacturing Methods for Warm White LEDs for General Lighting

    SciTech Connect (OSTI)

    Deshpande, Anirudha; Kolodin, Boris; Jacob, Cherian; Chowdhury, Ashfaqul; Kuenzler, Glenn; Sater, Karen; Aesram, Danny; Glaettli, Steven; Gallagher, Brian; Langer, Paul; Setlur, Anant; Beers, Bill

    2012-03-31T23:59:59.000Z

    GE Lighting Solutions will develop precise and efficient manufacturing techniques for the “remote phosphor” platform of warm-white LED products. In volume, this will be demonstrated to drive significant materials, labor and capital productivity to achieve a maximum possible 53% reduction in overall cost. In addition, the typical total color variation for these white LEDs in production will be well within the ANSI bins and as low as a 4-step MacAdam ellipse centered on the black body curve. Achievement of both of these objectives will be demonstrated while meeting a performance target of > 75 lm/W for a warm-white LED and a reliability target of <30% lumen drop / <2-step MacAdam ellipse shift, estimated over 50,000 hrs.

  12. LED-Induced Fluorescence System for Tea Classification and Quality Assessment

    E-Print Network [OSTI]

    Dong, Yongjiang; Mei, Liang; Feng, Chao; Yan, Chunsheng; He, Sailing

    2013-01-01T23:59:59.000Z

    A fluorescence system is developed by using several light emitting diodes (LEDs) with different wavelengths as excitation light sources. The fluorescence detection head consists of multi LED light sources and a multimode fiber for fluorescence collection, where the LEDs and the corresponding filters can be easily chosen to get appropriate excitation wavelengths for different applications. By analyzing fluorescence spectra with the principal component analysis method, the system is utilized in the classification of four types of green tea beverages and two types of black tea beverages. Qualities of the Xihu Longjing tea leaves of different grades, as well as the corresponding liquid tea samples, are studied to further investigate the ability and application of the system in the evaluation of classification/quality of tea and other foods.

  13. Lattice-mismatched GaInP LED devices and methods of fabricating same

    DOE Patents [OSTI]

    Mascarenhas, Angelo; Steiner, Myles A; Bhusal, Lekhnath; Zhang, Yong

    2014-10-21T23:59:59.000Z

    A method (100) of fabricating an LED or the active regions of an LED and an LED (200). The method includes growing, depositing or otherwise providing a bottom cladding layer (208) of a selected semiconductor alloy with an adjusted bandgap provided by intentionally disordering the structure of the cladding layer (208). A first active layer (202) may be grown above the bottom cladding layer (208) wherein the first active layer (202) is fabricated of the same semiconductor alloy, with however, a partially ordered structure. The first active layer (202) will also be fabricated to include a selected n or p type doping. The method further includes growing a second active layer (204) above the first active layer (202) where the second active layer (204) Is fabricated from the same semiconductor alloy.

  14. High-brightness single photon source from a quantum dot in a directional-emission nanocavity

    E-Print Network [OSTI]

    Mitsuru Toishi; Dirk Englund; Andrei Faraon; Jelena Vuckovic

    2009-04-08T23:59:59.000Z

    We analyze a single photon source consisting of an InAs quantum dot coupled to a directional-emission photonic crystal (PC) cavity implemented in GaAs. On resonance, the dot's lifetime is reduced by more than 10 times, to 45ps. Compared to the standard three-hole defect cavity, the perturbed PC cavity design improves the collection efficiency into an objective lens (NA=0.75) by factor 6, and improves the coupling efficiency of the collected light into a single mode fiber by factor 1.9. The emission frequency is determined by the cavity mode, which is antibunched to g(2)=0.05. The cavity design also enables efficient coupling to a higher-order cavity mode for local optical excitation of cavity-coupled quantum dots.

  15. Compact radiation sources for increased access to high brightness x-rays

    E-Print Network [OSTI]

    O'Shea, Finn Henry

    2012-01-01T23:59:59.000Z

    Chao, Handbook of Accelerator Physics and Engineering. WorldWiedemann, Particle Accelerator Physics I: Basic PrinciplesDynamics. Particle Accelerator Physics, Springer, 1999. [33

  16. Critical issues for high-brightness heavy-ion beams -- prioritized

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    W. Molvik, L. Prost, P. K. Roy, P. A. Seidl, G. Westenskow,A. Seidl, M. Leitner, P. K. Roy, W. Sharp, W. L. Waldron, “Haber, M. L. Leitner, P. K. Roy, W. L. Waldron, J-L. Vay, “

  17. High-brightness single photon source from a quantum dot in a directional-emission

    E-Print Network [OSTI]

    Vuckovic, Jelena

    , Stanford University, Stanford CA 94305 2 Sony Corporation, Shinagawa-ku, Tokyo, Japan, 141-0001 3, Stanford University, Stanford CA 94305 a mitsuru.toishi@jp.sony.com, b englund@fas.harvard.edu, c jela

  18. Development of a High-Brightness VHF Electron Source at LBNL

    E-Print Network [OSTI]

    Lidia, Steven M.; Sannibale, Fernando; Staples, John W.; Virostek, Steve P.; Wells, Russell P.

    2008-01-01T23:59:59.000Z

    VHF ELECTRON SOURCE AT LBNL* S. Lidia # , F. Sannibale, J.S. Virostek, R. Wells, LBNL, Berkeley, CA, USA Abstract

  19. Compact radiation sources for increased access to high brightness x-rays

    E-Print Network [OSTI]

    O'Shea, Finn Henry

    2012-01-01T23:59:59.000Z

    are considering radiation, the electric fields detected areof synchrotron radiation from the General Electric syn-by the null in the electric dipole radiation pattern in the

  20. Generation, transport and focusing of high-brightness heavy ion beams

    E-Print Network [OSTI]

    Henestroza, Enrique

    2006-01-01T23:59:59.000Z

    The Neutralized Transport Experiment (NTX) has been built at the Heavy Ion Fusion Virtual National Laboratory. NTX is the first successful integrated beam system experiment that explores various physical phenomena, and ...

  1. Use Patterns of LED Flashlights in Kenya and a One-Year Cost Analysis of Flashlight Ownership

    SciTech Connect (OSTI)

    Tracy, Jennifer; Jacobson, Arne; Mills, Evan

    2010-02-16T23:59:59.000Z

    Flashlight usage is widespread across much of sub-Saharan Africa.1 In Kenya in particular, over half of all households report owning a flashlight (Kamfor, 2002). Aside from household use, flashlights are also widely used to perform income-earning jobs in Kenya. Lumina Research Note No.4, the first report in this series documenting flashlight use in Kenya, highlights flashlight use patterns of night watchmen and bicycle taxi drivers. Both of these are occupations that rely on the use of flashlights on a nightly basis (Tracy et al., 2009). Also highlighted by Research Note No.4, flashlight users in Kenya have reported being highly dissatisfied with the quality of the low-cost LED flashlights that are available, and they identify several reoccurring problems they have faced as flashlight end-users (Tracy et al., 2009). The fact that there exists a substantial dependency upon flashlights in Kenya and that users are disgruntled with the available products suggests reasons for concern about flashlight quality. This concern is present despite two recent technological transitions in the flashlight market. First, LED technology has quickly emerged as the dominant source of portable lighting in Kenya, outpacing incandescent flashlights (Johnstone et al., 2009). LED technology has the potential to provide efficiency and performance benefits relative to incandescent bulbs, and low-cost LEDs have achieved price levels that make them cost competitive with conventional lighting sources for a number of applications (Mills, 2005). Second, rechargeable sealed-lead acid (SLA) batteries are also becoming more prevalent alternatives to disposable dry cell batteries. Flashlights using rechargeable SLA batteries tend to have a lower total cost of ownership over a two-year period than a flashlight using dry cell batteries (Radecsky, 2009); however, as this current report highlights, this may vary depending on the intensity of use patterns. To avoid a potential market spoiling effect for off-grid lighting products based on LED technology (Mills and Jacobson, 2008; Lighting Africa, 2007) a better understanding of flashlight use-patterns is crucial (Tracy et al., 2009). In addition, the economic implications faced by rural flashlight end-users provide further incentive for a move toward higher quality low-cost flashlights. In this report, our team uses interviews with 46 end users of flashlights to collect information about their use patterns and costs associated with owning and operating flashlight products. While flashlights used in their portable mode typically do not represent a substitute for kerosene or other forms of fuel-based lighting, at times they are used in stationary applications in place of a fuel-based lamp. In either case, these products often represent end users first exposure to LED technology and rechargeable dry cell batteries, and thus stand to either provide a positive or negative impression of these technologies for a diversity of lighting applications.

  2. Demonstration of LED Retrofit Lamps at the Smithsonian American Art Museum, Washington, DC

    SciTech Connect (OSTI)

    Miller, Naomi J.; Rosenfeld, Scott M.

    2012-06-22T23:59:59.000Z

    This report documents observations and results obtained from a lighting demonstration project conducted under the U.S. Department of Energy GATEWAY Solid-State Lighting (SSL) Technology Demonstration Program at the Smithsonain American Art Museum in Washington, DC. LED Lamp samples were tested in the museum workshop, temporarily installed in a gallery for feedback, and ultimately replaced all traditional incandescent lamps in one gallery of modernist art at the American Art Museum and partially replacing lamps in two galleries at the Musesum's Renwick Gallery. This report describes the selection and testing process, technology challenges, perceptions, economics, energy use, and mixed results of usign LED replacement lamps in art galleries housing national treasures.

  3. LEDS-An overview of the state of the art in technology and application

    SciTech Connect (OSTI)

    Johnson, Stephen

    2002-03-01T23:59:59.000Z

    Solid state lighting in the form of Light Emitting Diodes (LEDs) is bringing new sources with different operating characteristics to the market. With the control in dimension, optics, intensity and color, these sources have the potential to transform the way we use light. This paper will review the recent improvements in performance that have been achieved by these devices, focusing on those product attributes identified as being critical to end users. The paper will conclude with a consideration of applications capitalizing on the LEDs' unique operating and physical properties.

  4. The artificial night sky brightness mapped from DMSP Operational Linescan System measurements

    E-Print Network [OSTI]

    P. Cinzano; F. Falchi; C. D. Elvidge; K. E. Baugh

    2000-03-28T23:59:59.000Z

    We present a method to map the artificial sky brightness across large territories in astronomical photometric bands with a resolution of approximately 1 km. This is useful to quantify the situation of night sky pollution, to recognize potential astronomical sites and to allow future monitoring of trends. The artificial sky brightness present in the chosen direction at a given position on the Earth's surface is obtained by the integration of the contributions produced by every surface area in the surrounding. Each contribution is computed based on detailed models for the propagation in the atmosphere of the upward light flux emitted by the area. The light flux is measured with top of atmosphere radiometric observations made by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System. We applied the described method to Europe obtaining the maps of artificial sky brightness in V and B bands.

  5. A Characterization of the Brightness Oscillations During Thermonuclear Bursts From 4U 1636-536

    E-Print Network [OSTI]

    M. Coleman Miller

    1999-04-08T23:59:59.000Z

    The discovery of nearly coherent brightness oscillations during thermonuclear X-ray bursts from six neutron-star low-mass X-ray binaries has opened up a new way to study the propagation of thermonuclear burning, and may ultimately lead to greater understanding of thermonuclear propagation in other astrophysical contexts, such as in Type Ia supernovae. Here we report detailed analyses of the ~580 Hz brightness oscillations during bursts from 4U 1636-536. We investigate the bursts as a whole and, in more detail, the initial portions of the bursts. We analyze the ~580 Hz oscillations in the initial 0.75 seconds of the five bursts that were used in a previous search for a brightness oscillation at the expected ~290 Hz spin frequency, and find that if the same frequency model describes all five bursts there is insufficient data to require more than a constant frequency or, possibly, a frequency plus a frequency derivative. Therefore, although it is appropriate to use an arbitrarily complicated model of the ~580 Hz oscillations to generate a candidate waveform for the ~290 Hz oscillations, models with more than two parameters are not required by the data. For the bursts as a whole we show that the characteristics of the brightness oscillations vary greatly from burst to burst. We find, however, that in at least one of the bursts, and possibly in three of the four that have strong brightness oscillations throughout the burst, the oscillation frequency reaches a maximum several seconds into the burst and then decreases. This behavior has not been reported previously for burst brightness oscillations, and it poses a challenge to the standard burning layer expansion explanation for the frequency changes.

  6. Chip-Scale Power Conversion for LED Lighting: Integrated Power Chip Converter for Solid-State Lighting

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    ADEPT Project: Teledyne is developing cost-effective power drivers for energy-efficient LED lights that fit on a compact chip. These power drivers are important because they transmit power throughout the LED device. Traditional LED driver components waste energy and don't last as long as the LED itself. They are also large and bulky, so they must be assembled onto a circuit board separately which increases the overall manufacturing cost of the LED light. Teledyne is shrinking the size and improving the efficiency of its LED driver components by using thin layers of an iron magnetic alloy and new gallium nitride on silicon devices. Smaller, more efficient components will enable the drivers to be integrated on a single chip, reducing costs. The new semiconductors in Teledyne's drivers can also handle higher levels of power and last longer without sacrificing efficiency. Initial applications for Teledyne's LED power drivers include refrigerated grocery display cases and retail lighting.

  7. Asia-Pacific Trade Economists' Conference Trade-Led Growth in Times of Crisis

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Asia-Pacific Trade Economists' Conference Trade-Led Growth in Times of Crisis The World Trade session 2: The Crisis: A Catalyst for More Coherent Trade Policies and Inclusive Growth? Author: Patrick A or carrying the endorsement of the United Nations. #12;1 Policy Brief October 26, 2009 The World Trade Regime

  8. 1 Introduction The development of wind energy use has led to

    E-Print Network [OSTI]

    Heinemann, Detlev

    1 Introduction The development of wind energy use has led to a noticeable contribution in of electricity by wind energy acts as a negative load leading to an increase in fluctuations of net load patterns conventional reserves have to be kept ready to replace the wind energy share in case of decreasing wind speeds

  9. 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

  10. Coupled optical and electronic simulations of electrically pumped photonic-crystal-based LEDs

    E-Print Network [OSTI]

    Dutton, Robert W.

    to investigate design tradeoffs in electrically pumped photonic crystal light emitting diodes. A finite. Keywords: Photonic crystal light emitting diode, electrically pumped device 1. INTRODUCTION Recently optoelectronic devices, such as light emitting diodes (LEDs) and lasers. It has been suggested that a thin slab

  11. Ruofan Wu, Hieu Pham Trung Nguyen and Zetian Mi INTRODUCTION TO LEDs

    E-Print Network [OSTI]

    Barthelat, Francois

    -in-a-Wire Light Emitting Diodes and Prevention Method Nano-electronic Devices and Materials, Electrical Computer., Efficiency droop in nitride-based light-emitting diodes. Physica Status Solidi a-Applications and Materials history. Nature Photonics 2007, 1 (4), 189-192. [4] Holonyak, N., Is the light emitting diode (LED

  12. DOE Publishes CALiPER Report on Linear (T8) LED Lamps in Recessed Troffers

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy's CALiPER program has released Report 21.2, which is part of a series of investigations on linear LED lamps. Report 21.2 focuses on the performance of three linear (T8...

  13. DOE Publishes CALiPER Report on Cost-Effectiveness of Linear (T8) LED Lamps

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy's CALiPER program has released Report 21.3, which is part of a series of investigations on linear LED lamps. Report 21.3 details a set of life-cycle cost simulations...

  14. What led to the pervasiveness of hybrids between Cx. pipiens and Cx. molestus in

    E-Print Network [OSTI]

    What led to the pervasiveness of hybrids between Cx. pipiens and Cx. molestus in North America populations with a few hybrid individuals, as well as populations with pure Cx. pipiens signatures and populations with a mix of pure Cx. pipiens and pure Cx. molestus signatures (Fig. 2). Indeed, previous

  15. forestry.gov.uk/carboncode The Woodland Carbon Code is an initiative led by the

    E-Print Network [OSTI]

    carbon from these projects brings many benefits in addition to carbon sequestration. is effectivelyforestry.gov.uk/carboncode ® The Woodland Carbon Code is an initiative led by the Forestry Commission and supported by a Carbon Advisory Group of UK forest industry and carbon market experts. A buyers

  16. Office of International Programs Education Abroad CSU Faculty-Led Programs Support

    E-Print Network [OSTI]

    Office of International Programs ­ Education Abroad 12/2012 CSU Faculty-Led Programs Support Below describes the levels of support and ways that the Office of International Programs ­ Education Abroad unit in the field of international education Application and Maintain website and online application system

  17. General practitioner-led commissioning in the NHS: progress, prospects and pitfalls

    E-Print Network [OSTI]

    Birmingham, University of

    General practitioner-led commissioning in the NHS: progress, prospects and pitfalls Russell Mannion of general practitioner (GP) consortia. These organisations will have responsibility for commissioning on impact of the previous models of GP commissioning that have been introduced in the NHS with the aim

  18. Calibration of Cangaroo II Telescope Using a Fast Blue LED Light Flasher

    E-Print Network [OSTI]

    Enomoto, Ryoji

    , as well as test the data acquisition electronics. Our technique is an independent variation of the laser , and a risetime of #24; 1 ns. The LED has a double emitter giving a non-uniform light pool. By drilling a small

  19. Philips' LED Luminaires Brighten the Rensselaer Engineering Fabrication & Prototyping Facility (also known as the Machine Shop)

    E-Print Network [OSTI]

    Linhardt, Robert J.

    . #12;To help bridge its research efforts with currently available solid state lighting technology outreach to increase campus and community awareness as to the benefits of solid state lighting. About Royal a donation of LED fixtures from Philips Lighting. The Smart Lighting Sustainability Club, comprised

  20. December 2014 CCE-Led One-Time Service Projects Transportation Provided

    E-Print Network [OSTI]

    Collins, Gary S.

    December 2014 CCE-Led One-Time Service Projects Transportation Provided Check In Times Listed Place Senior Center Manicures 6 PM ­ 8 PM 4 Colton Pen Friends 8:15 AM ­ 11:30 AM Recycling Outreach Friends 8:15 AM ­ 11:30 AM Recycling Outreach Campus to Community 10 AM ­ 1 PM Whitman Senior Living

  1. Mercury Releases to Air and Rivers Contaminate Ocean Fish: Dartmouth-Led Effort Publishes Major Findings

    E-Print Network [OSTI]

    Myers, Lawrence C.

    Mercury Releases to Air and Rivers Contaminate Ocean Fish: Dartmouth-Led Effort Publishes Major and in Sources to Seafood: Mercury Pollution in the Marine Environment-- a companion report by the Dartmouth released into the air and then deposited into oceans, contaminates seafood commonly eaten by people

  2. Crystal coat warms up LED light 16:46 01 February 2008

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    in the commercial market. Illuminating buildings accounts for about a quarter of the electricity used in the US in the home. Now researchers have used nanocrystals to create LEDs that give off a warm white light. Fine Articles 'Smart' lamp offers true mood lighting http://technology.newscientist.com/article/mg19626276

  3. Schmidt modes in the angular spectrum of bright squeezed vacuum

    E-Print Network [OSTI]

    Polina R. Sharapova; Angela M. Perez; Olga V. Tikhonova; Maria V. Chekhova

    2014-10-24T23:59:59.000Z

    We study the spatial properties of high-gain parametric down-conversion (PDC). From the Hamiltonian we find the Schmidt modes, apply the Bloch-Messiah reduction, and calculate analytically the measurable quantities, such as the angular distributions of photon numbers and photon-number correlations. Our approach shows that the Schmidt modes of PDC radiation can be considered the same as for the low-gain (biphoton) case while the Schmidt eigenvalues strongly depend on the parametric gain. Its validity is confirmed by comparison with several experimental results, obtained by us and by other groups.

  4. Demonstration Assessment of LED Roadway Lighting: NE Cully Boulevard Portland, OR

    SciTech Connect (OSTI)

    Royer, Michael P.; Poplawski, Michael E.; Tuenge, Jason R.

    2012-06-29T23:59:59.000Z

    A new roadway lighting demonstration project was initiated in late 2010, which was planned in conjunction with other upgrades to NE Cully Boulevard, a residential collector road in the northeast area of Portland, OR. With the NE Cully Boulevard project, the Portland Bureau of Transportation hoped to demonstrate different light source technologies and different luminaires side-by-side. This report documents the initial performance of six different newly installed luminaires, including three LED products, one induction product, one ceramic metal halide product, and one high-pressure sodium (HPS) product that represented the baseline solution. It includes reported, calculated, and measured performance; evaluates the economic feasibility of each of the alternative luminaires; and documents user feedback collected from a group of local Illuminating Engineering Society (IES) members that toured the site. This report does not contain any long-term performance evaluations or laboratory measurements of luminaire performance. Although not all of the installed products performed equally, the alternative luminaires generally offered higher efficacy, more appropriate luminous intensity distributions, and favorable color quality when compared to the baseline HPS luminaire. However, some products did not provide sufficient illumination to all areas—vehicular drive lanes, bicycle lanes, and sidewalks—or would likely fail to meet design criteria over the life of the installation due to expected depreciation in lumen output. While the overall performance of the alternative luminaires was generally better than the baseline HPS luminaire, cost remains a significant barrier to widespread adoption. Based on the cost of the small quantity of luminaires purchased for this demonstration, the shortest calculated payback period for one of the alternative luminaire types was 17.3 years. The luminaire prices were notably higher than typical prices for currently available luminaires purchased in larger quantities. At prices that are more typical, the payback would be less than 10 years. In addition to the demonstration luminaires, a networked control system was installed for additional evaluation and demonstration purposes. The capability of control system to measure luminaire input power was explored in this study. A more exhaustive demonstration and evaluation of the control system will be the subject of future GATEWAY report(s).

  5. The Elusive “Life” of LEDs: How TM-21 Contributes to the Solution

    SciTech Connect (OSTI)

    Richman, Eric E.

    2011-11-18T23:59:59.000Z

    This magazine article discusses the issue of LED 'lifetime' and explains where TM-21 plays as part of the solution to this issue. In August 2011, the Illuminating Engineering Society (IES) published the TM-21 document entitled 'Lumen degradation lifetime estimation method for LED light sources.' TM-21 is the IES-recommended method for projecting lumen degradation of an LED package, array or module based on data collected according to LM-80. The lighting community expects TM-21 to become the standard method for projecting useful LED lighting product life at realistic operating temperature. This article presents the development process behind TM-21, and clarifies how and when to apply the lifetime extrapolation method to arrive at reasonable and useful estimations. Why TM-21 and why now? We are all familiar with the very real but sometimes exaggerated long-life attributes of LED technology. Not the least of these is the potential for very long life that helps make it an attractive design choice. The trick has been and continues to be how to measure or estimate this longevity to provide assurance to users of this technology's reliability (life) compared to other options. We also understand that the overall reliability of a complete LED lighting fixture can be affected by the reliability of individual product components (driver, lens, etc.) and should be accounted for in lifetime estimations. The useful life of standard lighting technologies is defined as the time to filament or cathode failure. For most of these lamps, the time period prior to failure exhibits acceptable levels of light output, as shown with the solid lines in Fig. 1. This makes it easy to determine when to replace the lamp. However, LEDs do not have filament burn-out that conveniently announces the end of life (dashed line in Fig. 1). Further, the rapid development of the technology and the desire to bring products to market in a timely manner does not allow for actual testing verification of the long lives claimed (100,000 or even 35,000 hours). As a result, the industry has come to accept a definition of the end of the useful life of an LED as the point when it no longer provides a specified level of light output. And finally, the life and performance of LED lighting products depends greatly on excess heat retained at the diode. This is why LEDs require testing at multiple temperatures such that when a source is installed in a luminaire, its actual operating temperature can be measured and lumen depreciation of the product can be derived. Therefore, to serve the solid-state lighting industry, the Technical Procedures Committee (TPC) of the IES proceeded to develop appropriate tests for use in rating LED product longevity. The initial need was a measure of the basic lumen degradation of LED source components identified by a module, package, or array of diodes and this came in the form of LM-80. Importantly, LM-80 only specifies how to measure lumen depreciation to a minimum of 6000 hours (but recommends testing to 10,000 hours or longer). LM-80 stops short of using that data to estimate any depreciation after that, which is where TM-21 comes in. The TM-21 working group (WG) as part of the IES TPC was formed to develop the lumen depreciation projection method and spent over three years exploring many options. The WG evaluated various projection options starting with an analysis of various mathematical, engineering-based models to provide effective depreciation fit and a useful projection method. Next, the WG analyzed LED lumen maintenance behavior using over 40 sets of LM-80-08 test data (20 sets with 10,000 hours or more) collected from four major LED manufacturers. The working group also examined the accuracy of proposed projections using various proposed models and LM-80 data that extended up to 15,000 hours.

  6. BRIGHT BROADBAND AFTERGLOWS OF GRAVITATIONAL WAVE BURSTS FROM MERGERS OF BINARY NEUTRON STARS

    SciTech Connect (OSTI)

    Gao He; Ding Xuan; Wu Xuefeng [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhang Bing [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States); Dai Zigao, E-mail: xfwu@pmo.ac.cn, E-mail: zhang@physics.unlv.edu, E-mail: dzg@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2013-07-10T23:59:59.000Z

    If double neutron star mergers leave behind a massive magnetar rather than a black hole, then a bright early afterglow can follow the gravitational wave burst (GWB) even if there is no short gamma-ray burst (SGRB)-GWB association or if there is an association but the SGRB does not beam toward Earth. Besides directly dissipating the proto-magnetar wind, as suggested by Zhang, here we suggest that the magnetar wind could push the ejecta launched during the merger process and, under certain conditions, would reach a relativistic speed. Such a magnetar-powered ejecta, when interacting with the ambient medium, would develop a bright broadband afterglow due to synchrotron radiation. We study this physical scenario in detail and present the predicted X-ray, optical, and radio light curves for a range of magnetar and ejecta parameters. We show that the X-ray and optical light curves usually peak around the magnetar spin-down timescale ({approx}10{sup 3}-10{sup 5} s), reaching brightnesses readily detectable by wide-field X-ray and optical telescopes, and remain detectable for an extended period. The radio afterglow peaks later, but is much brighter than the case without a magnetar energy injection. Therefore, such bright broadband afterglows, if detected and combined with GWBs in the future, would be a probe of massive millisecond magnetars and stiff equations of state for nuclear matter.

  7. Cell Cycle Regulation of Cyclin-Dependent Kinases in Tobacco Cultivar Bright Yellow-2 Cells1

    E-Print Network [OSTI]

    Murray, J.A.H.

    Cell Cycle Regulation of Cyclin-Dependent Kinases in Tobacco Cultivar Bright Yellow-2 Cells1 David different regulation during the cell cycle. CdkA mRNA and protein accumulate during G1 in cells re, although CdkA mRNA and protein levels are not significantly regulated. In contrast, CdkB1 transcripts

  8. KEEPING THE FUTURE BRIGHT 2004 Canadian Electricity Human Resource Sector Study

    E-Print Network [OSTI]

    supply 8 Electricity consumption 9 Supply and demand projections 9 Electricity exports and importsKEEPING THE FUTURE BRIGHT 2004 Canadian Electricity Human Resource Sector Study #12;This project Electricity Association The Canadian Electricity Association (CEA), founded in 1891, is the national forum

  9. Special Sensor Microwave Imager and Sounder (SSMIS) Antenna Brightness Temperature Data Record (TDR)

    E-Print Network [OSTI]

    Special Sensor Microwave Imager and Sounder (SSMIS) Antenna Brightness Temperature Data Record (TDR/NESDIS/Center for Satellite Applications and Research Contributors from: Banghua Yan (Lead), QSS/JCSDA Ninghai Sun, IMSG, Metoffice, UK Yong Han, STAR/JCSDA Mark Liu, QSS/JCSDA Distribution to: Ralph Ferrrao, STAR Tom Schott, OSD

  10. Improving the photostability of bright monomeric orange and red fluorescent proteins

    E-Print Network [OSTI]

    Tsien, Roger Y.

    Improving the photostability of bright monomeric orange and red fluorescent proteins Nathan C illumination. Although fluorescent proteins typically bleach at a substantially slower rate than many small-molecule dyes, in many cases the lack of sufficient photostability remains an important limiting factor

  11. The Threat to the Planet* Dark & Bright Sides of Global Warming

    E-Print Network [OSTI]

    Hansen, James E.

    The Threat to the Planet* Dark & Bright Sides of Global Warming Jim Hansen 3 October 2007 presented provides most important information on global warming. Recorded human history occurs within the Holocene for these large climate change is perturbations of Earth's orbit. #12;Continental Drift Fig. 1 "Global Warming

  12. 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

  13. A BRIGHT IMPULSIVE SOLAR BURST DETECTED AT 30 THz

    SciTech Connect (OSTI)

    Kaufmann, P.; Fernandes, L. O. T.; Kudaka, A. S.; De Souza, R. V.; Valio, A.; Raulin, J.-P. [Center of Radio Astronomy and Astrophysics, Engineering School, Mackenzie Presbyterian University, Sao Paulo, SP (Brazil); White, S. M. [Air Force Research Laboratories, Space Vehicles Directorate, Albuquerque, NM 87117 (United States); Freeland, S. L. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States); Marcon, R. [''Gleb Wataghin'' Physics Institute, State University of Campinas, Campinas, SP (Brazil); Aballay, J. L.; Fernandez, G.; Godoy, R.; Marun, A.; Gimenez de Castro, C. G. [El Leoncito Astronomical Complex, CONICET, San Juan (Argentina)

    2013-05-10T23:59:59.000Z

    Ground- and space-based observations of solar flares from radio wavelengths to gamma-rays have produced considerable insights but raised several unsolved controversies. The last unexplored wavelength frontier for solar flares is in the range of submillimeter and infrared wavelengths. Here we report the detection of an intense impulsive burst at 30 THz using a new imaging system. The 30 THz emission exhibited remarkable time coincidence with peaks observed at microwave, mm/submm, visible, EUV, and hard X-ray wavelengths. The emission location coincides with a very weak white-light feature, and is consistent with heating below the temperature minimum in the atmosphere. However, there are problems in attributing the heating to accelerated electrons. The peak 30 THz flux is several times larger than the usual microwave peak near 9 GHz, attributed to non-thermal electrons in the corona. The 30 THz emission could be consistent with an optically thick spectrum increasing from low to high frequencies. It might be part of the same spectral component found at sub-THz frequencies whose nature remains mysterious. Further observations at these wavelengths will provide a new window for flare studies.

  14. Bright Water- hydrosols, water conservation and climate change

    E-Print Network [OSTI]

    Seitz, Russell

    2010-01-01T23:59:59.000Z

    Since air-water and water-air interfaces are equally refractive, cloud droplets and microbubbles dispersed in bodies of water reflect sunlight in much the same way. The lifetime of sunlight-reflecting microbubbles, and hence the scale on which they may be applied, depends on Stokes Law and the influence of ambient or added surfactants. Small bubbles backscatter light more efficiently than large ones, opening the possibility of using highly dilute micron-radius hydrosols to substantially brighten surface waters. Such microbubbles can noticeably increase water surface reflectivity, even at volume fractions of parts per million and such loadings can be created at an energy cost as low as J m-2 to initiate and milliwatts m-2 to sustain. Increasing water albedo in this way can reduce solar energy absorption by as much as 100 W m-2, potentially reducing equilibrium temperatures of standing water bodies by several Kelvins. While aerosols injected into the stratosphere tend to alter climate globally, hydrosols can be...

  15. Summary of sessions B and F: High intensity linacs and frontend & proton drivers

    SciTech Connect (OSTI)

    Ferdinand, R.; /Saclay; Chou, W.; /Fermilab; Galambos, J.; /Oak Ridge

    2005-01-01T23:59:59.000Z

    This paper summarizes the sessions B&F of the 33rd ICFA Advanced Beam Dynamics Workshop on High Intensity & High Brightness Hadron Beams held in Bensheim, Germany. It covers high intensity linacs, front ends and proton driver topics.

  16. GRB 090926A AND BRIGHT LATE-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS

    SciTech Connect (OSTI)

    Swenson, C. A.; Roming, P. W. A.; Vetere, L.; Kennea, J. A. [Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Maxham, A.; Zhang, B. B.; Zhang, B. [University of Nevada, Las Vegas, Box 454002, 4505 Maryland Parkway, Las Vegas, NV 89154 (United States); Schady, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Holland, S. T. [Universities Space Research Association, 10227 Wincopin Circle, Suite 500, Columbia, MD 21044 (United States); Kuin, N. P. M.; Oates, S. R.; De Pasquale, M. [The UCL Mullard Space Science Laboratory, Holmbury St Mary, Surrey, RH5 6NT (United Kingdom); Page, K. L., E-mail: cswenson@astro.psu.ed [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2010-07-20T23:59:59.000Z

    GRB 090926A was detected by both the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. Swift follow-up observations began {approx}13 hr after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long-lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10{sup 5} s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 gamma-ray bursts; nine of these bursts, including GRB 090926A, also have been observed by Swift. Of the nine Swift-observed LAT bursts, six were detected by UVOT, with five of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for five years and has detected nearly 500 bursts, but has only seen {approx}30% of bursts with optical afterglows that live longer than 10{sup 5} s. We have calculated the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate that the LAT bursts are more energetic than 88% of all Swift bursts and also have brighter than average X-ray and optical afterglows.

  17. HAT-P-7b: An Extremely Hot Massive Planet Transiting a Bright Star in the Kepler Field

    E-Print Network [OSTI]

    A. Pal; G. A. Bakos; G. Torres; R. W. Noyes; D. W. Latham; Geza Kovacs; G. W. Marcy; D. A. Fischer; R. P. Butler; D. D. Sasselov; B. Sipocz; G. A. Esquerdo; Gabor Kovacs; R. Stefanik; J. Lazar; I. Papp; P. Sari

    2008-03-05T23:59:59.000Z

    We report on the latest discovery of the HATNet project; a very hot giant planet orbiting a bright (V = 10.5) star with a small semi-major axis of a = 0.0377 +/- 0.0005 AU. Ephemeris for the system is P = 2.2047299 +/- 0.0000040 days, mid-transit time E = 2,453,790.2593 +/- 0.0010 (BJD). Based on the available spectroscopic data on the host star and photometry of the system, the planet has a mass of Mp = 1.78+/-^{0.08}_{0.05} MJup and radius of Rp = 1.36+/-^{0.20}_{0.09} RJup. The parent star is a slightly evolved F6 star with M = 1.47+/-^{0.08}_{-0.05} Msun,R = 1.84+/-^{0.23}_{0.11} Rsun, Teff = 6350 +/- 80 K, and metallicity [Fe/H] = +0.26 +/- 0.08. The relatively hot and large host star, combined with the close orbit of the planet, yield a very high planetary irradiance of (4.71+/-^{1.44}_{0.05}) 10^9 erg cm^{-2}s^{-1}, which places the planet near the top of the pM class of irradiated planets as defined by Fortney et al. (2007). If as predicted by Fortney et al. (2007) the planet re-radiates its absorbed energy before distributing it to the night side, the day-side temperature should be about (2730+/-^{150}_{100}) K. Because the host star is quite bright, measurement of the secondary eclipse should be feasible for ground-based telescopes, providing a good opportunity to compare the predictions of current hot Jupiter atmospheric models with the observations. Moreover, the host star falls in the field of the upcoming Kepler mission; hence extensive space-borne follow-up, including not only primary transit and secondary eclipse observations but also asteroseismology, will be possible.

  18. The SDSS view of the Palomar-Green bright quasar survey

    SciTech Connect (OSTI)

    Jester, Sebastian; Schneider, Donald P.; Richards, Gordon T.; Green, Richard F.; Schmidt, Maarten; Hall, Patrick B.; Strauss, Michael A.; Vanden Berk, Daniel E.; Stoughton, Chris; Gunn, James E.; Brinkmann, Jon; Kent, Stephen M.; Smith, J.Allyn; Tucker, Douglas, L.; Yanny, Brian; /Fermilab /Penn State U., Astron. Astrophys. /Princeton U.

    2005-02-01T23:59:59.000Z

    The author investigates the extent to which the Palomar-Green (PG) Bright Quasar Survey (BQS) is complete and representative of the general quasar population by comparing with imaging and spectroscopy from the Sloan Digital Sky Survey. A comparison of SDSS and PG photometry of both stars and quasars reveals the need to apply a color and magnitude recalibration to the PG data. Using the SDSS photometric catalog, they define the PG's parent sample of objects that are not main-sequence stars and simulate the selection of objects from this parent sample using the PG photometric criteria and errors. This simulation shows that the effective U-B cut in the PG survey is U-B < -0.71, implying a color-related incompleteness. As the color distribution of bright quasars peaks near U-B = -0.7 and the 2-{sigma} error in U-B is comparable to the full width of the color distribution of quasars, the color incompleteness of the BQS is approximately 50% and essentially random with respect to U-B color for z < 0.5. There is however, a bias against bright quasars at 0.5 < z < 1, which is induced by the color-redshift relation of quasars (although quasars at z > 0.5 are inherently rare in bright surveys in any case). They find no evidence for any other systematic incompleteness when comparing the distributions in color, redshift, and FIRST radio properties of the BQS and a BQS-like subsample of the SDSS quasar sample. However, the application of a bright magnitude limit biases the BQS toward the inclusion of objects which are blue in g-i, in particular compared to the full range of g-i colors found among the i-band limited SDSS quasars, and even at i-band magnitudes comparable to those of the BQS objects.

  19. AN INFRARED SPACE OBSERVATORY ATLAS OF BRIGHT SPIRAL GALAXIES1 George J. Bendo,2,3,4

    E-Print Network [OSTI]

    Joseph, Robert D.

    AN INFRARED SPACE OBSERVATORY ATLAS OF BRIGHT SPIRAL GALAXIES1 George J. Bendo,2,3,4 Robert D in a series we present an atlas of infrared images and photometry from 1.2 to 180 lm for a sample of bright galaxies. Using the Infrared Space Observatory (ISO), we have obtained 12 lm images and photometry at 60

  20. SWIFT PANCHROMATIC OBSERVATIONS OF THE BRIGHT GAMMA-RAY BURST GRB 050525a A. J. Blustin,1

    E-Print Network [OSTI]

    Zhang, Bing

    SWIFT PANCHROMATIC OBSERVATIONS OF THE BRIGHT GAMMA-RAY BURST GRB 050525a A. J. Blustin,1 D. Band,2 ABSTRACT The bright gamma-ray burst GRB 050525a has been detected with the Swift observatory, providing. This jet break time combined with the total gamma-ray energy of the burst constrains the opening angle

  1. LED lamp or bulb with remote phosphor and diffuser configuration with enhanced scattering properties

    DOE Patents [OSTI]

    Tong, Tao; Le Toquin, Ronan; Keller, Bernd; Tarsa, Eric; Youmans, Mark; Lowes, Theodore; Medendorp, Jr., Nicholas W; Van De Ven, Antony; Negley, Gerald

    2014-11-11T23:59:59.000Z

    An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and an optical cavity. The optical cavity comprises a phosphor carrier having a conversions material and arranged over an opening to the cavity. The phosphor carrier comprises a thermally conductive transparent material and is thermally coupled to the heat sink structure. An LED based light source is mounted in the optical cavity remote to the phosphor carrier with light from the light source passing through the phosphor carrier. A diffuser dome is included that is mounted over the optical cavity, with light from the optical cavity passing through the diffuser dome. The properties of the diffuser, such as geometry, scattering properties of the scattering layer, surface roughness or smoothness, and spatial distribution of the scattering layer properties may be used to control various lamp properties such as color uniformity and light intensity distribution as a function of viewing angle.

  2. Lumen and Chromaticity Maintenance of LED PAR38 Lamps Operated in Steady-State Conditions

    SciTech Connect (OSTI)

    Royer, Michael P.

    2014-12-01T23:59:59.000Z

    The lumen depreciation and color shift of 38 different lamps (32 LED, 2 CFL, 1 ceramic metal halide [CMH], 3 halogen) were monitored in a specially developed automated long-term test apparatus (ALTA2) for nearly 14,000 hours. Five samples of each lamp model were tested, with measurements recorded on a weekly basis. The lamps were operated continuously at a target ambient temperature between 44°C and 45°C.

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

    SciTech Connect (OSTI)

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

    2009-03-21T23:59:59.000Z

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

  4. CALiPER Report 20.3: Robustness of LED PAR38 Lamps

    SciTech Connect (OSTI)

    Poplawski, Michael E.; Royer, Michael P.; Brown, Charles C.

    2014-12-31T23:59:59.000Z

    Three samples of 40 of the Series 20 PAR38 lamps underwent multi-stress testing, whereby samples were subjected to increasing levels of simultaneous thermal, humidity, electrical, and vibrational stress. The results do not explicitly predict expected lifetime or reliability, but they can be compared with one another, as well as with benchmark conventional products, to assess the relative robustness of the product designs. On average, the 32 LED lamp models tested were substantially more robust than the conventional benchmark lamps. As with other performance attributes, however, there was great variability in the robustness and design maturity of the LED lamps. Several LED lamp samples failed within the first one or two levels of the ten-level stress plan, while all three samples of some lamp models completed all ten levels. One potential area of improvement is design maturity, given that more than 25% of the lamp models demonstrated a difference in failure level for the three samples that was greater than or equal to the maximum for the benchmarks. At the same time, the fact that nearly 75% of the lamp models exhibited better design maturity than the benchmarks is noteworthy, given the relative stage of development for the technology.

  5. Self-reported Impacts of LED Lighting Technology Compared to Fuel-based Lighting on Night Market Business Prosperity in Kenya

    E-Print Network [OSTI]

    Johnstone, Peter

    2009-01-01T23:59:59.000Z

    s kiosk illuminated by her LED lamp [1/2009] “A.N. ” Market:charge at a shop) “The [LED] lamp is very important and mylamp, hurricane lamp, and LED lamp illuminate night market

  6. LED Lamp Project Lights the Way to Flicker-Free Replacement Jade Sky Technologies and UC Davis's California Lighting Technology Center demonstrate the

    E-Print Network [OSTI]

    California at Davis, University of

    LED Lamp Project Lights the Way to Flicker-Free Replacement Jade Sky the flicker and dimming requirements set by the Voluntary California Quality LED Lamp for incentivized LED replacement lamps. These criteria go beyond energy efficiency

  7. Text-Alternative Version: LED Site Lighting in the Commercial Building Sector: Opportunities, Challenges, and the CBEA Performance Specification

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the LED Site Lighting in the Commercial Building Sector: Opportunities, Challenges, and the CBEA Performance Specification webcast.

  8. On the Frequency Evolution of X-ray Brightness Oscillations During Thermonuclear X-ray Bursts: Evidence for Coherent Oscillations

    E-Print Network [OSTI]

    Tod E. Strohmayer; Craig B. Markwardt

    1999-03-03T23:59:59.000Z

    We investigate the time dependence of the frequency of X-ray brightness oscillations during thermonuclear bursts from several neutron star low mass X-ray binaries. We find that the oscillation frequencies in the cooling tails of X-ray bursts from 4U 1702-429 and 4U 1728-34 are well described by an exponential "chirp" model. With this model we demonstrate that the pulse trains in the cooling tails of many bursts are highly phase coherent, having oscillation quality factors as high as Q ~ 4000. We use this model of the frequency evolution to search sensitively for significant power at the harmonics and first sub-harmonic of the 330 and 363 Hz signals in bursts from 4U 1702-429 and 4U 1728-34, respectively, but find not evidence for significant power at any harmonic or the sub-harmonic. We argue that the high coherence favors stellar rotation as the source of the oscillations. We briefly discuss the frequency evolution in terms of rotational motion of an angular momentum conserving thermonuclear shell. we discuss how the limits on harmonic content can be used to infer properties of the neutron star.

  9. Bright Blue

    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 for4,645U.S. DOE Office511041clothAdvanced Materials Advanced Materials FindAdvanced MaterialsDepartment FOR IMMEDIATE

  10. Modeling Bright Gamma-ray and Radio Emission at Fast Cloud Shocks

    E-Print Network [OSTI]

    Lee, Shiu-Hang; Raymond, John C; Nagataki, Shigehiro; Slane, Patrick O; Ellison, Donald C

    2015-01-01T23:59:59.000Z

    Recent observations by the Large Area Telescope (LAT) onboard the Fermi satellite have revealed bright gamma-ray emission from middle-aged supernova remnants (SNRs) inside our Galaxy. These remnants, which also possess bright non-thermal radio shells, are often found to be interacting directly with surrounding gas clouds. We explore the non-thermal emission mechanism at these dynamically evolved SNRs by constructing a hydrodynamical model. Two scenarios of particle acceleration, either a re-acceleration of Galactic cosmic rays (CRs) or an efficient nonlinear diffusive shock acceleration (NLDSA) of particles injected from downstream, are considered. Using parameters inferred from observations, our models are contrasted with the observed spectra of SNR W44. For the re-acceleration case, we predict a significant enhancement of radio and GeV emission as the SNR undergoes a transition into the radiative phase. If sufficiently strong magnetic turbulence is present in the molecular cloud, the re-acceleration scenari...

  11. Quantum efficiency enhancement in nanocrystals using nonradiative energy transfer with optimized donor-acceptor ratio for hybrid LEDs

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Quantum efficiency enhancement in nanocrystals using nonradiative energy transfer with optimized donor-acceptor ratio for hybrid LEDs Sedat Nizamoglu, Onur Akin, and Hilmi Volkan Demira Department emitting diodes LEDs . For this purpose, we investigate energy gradient mixture of nanocrystal solids

  12. Philips Light Sources & Electronics is Developing an Efficient, Smaller, Cost-Effective Family of LED Drivers

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, Philips Light Sources & Electronics is developing a new family of LED drivers that are more efficient and cost-effective as well as smaller in size than currently available drivers. The new drivers are switch-mode power supplies that are similar to today's drivers, but with an improved design. In addition, they have a different topology—boost plus LLC—for wattages of 40W and above, but they retain the commonly used flyback topology at lower wattages.

  13. Solar LED Light Pilot Project Illuminates the Way in Alabama | Department

    Office of Environmental Management (EM)

    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 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmart Metersof Energy LED Light Pilot

  14. Zimbabwe-Terms of Reference for Future LEDS | 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-fTriWildcat 1 Wind Projectsource History ViewZAP JumpZenergyZeppiniLEDS

  15. Intel Led OpenMP Training Session at NERSC This Wednesday March 25

    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 for4,645U.S. DOE Office of Science (SC)Integrated Codes | National Nuclear Security AdministrationIntegratingIntel IntelLed

  16. Unique PPPL-led workshop assesses research crucial to the success of ITER |

    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 SpinPrinceton Plasma Physics Lab Unique PPPL-led workshop assesses

  17. Kenya-EC-LEDS in the Agriculture Sector | 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: navigation, searchOf Kilauea Volcano, Hawaii |Island,Kas Farmssource HistoryKenworthLEDS in

  18. Enhancing Capacity for Low Emission Development Strategies (EC-LEDS) | Open

    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 JumpConceptual Model,DOEHazel Crest,EnergySerranopolis JumpESLEnergy Information LEDS)

  19. $?$--PhotoZ: Photometric Redshifts by Inverting the Tolman Surface Brightness Test

    E-Print Network [OSTI]

    Michael J. Kurtz; Margaret J. Geller; Daniel G. Fabricant; William F. Wyatt; Ian P. Dell'Antonio

    2007-07-03T23:59:59.000Z

    Surface brightness is a fundamental observational parameter of galaxies. We show, for the first time in detail, how it can be used to obtain photometric redshifts for galaxies, the $\\mu$-PhotoZ method. We demonstrate that the Tolman surface brightness relation, $\\mu \\propto (1+z)^{-4}$, is a powerful tool for determining galaxy redshifts from photometric data. We develop a model using $\\mu$ and a color percentile (ranking) measure to demonstrate the $\\mu$-PhotoZ method. We apply our method to a set of galaxies from the SHELS survey, and demonstrate that the photometric redshift accuracy achieved using the surface brightness method alone is comparable with the best color-based methods. We show that the $\\mu$-PhotoZ method is very effective in determining the redshift for red galaxies using only two photometric bands. We discuss the properties of the small, skewed, non-gaussian component of the error distribution. We calibrate $\\mu_r, (r-i)$ from the SDSS to redshift, and tabulate the result, providing a simple, but accurate look up table to estimate the redshift of distant red galaxies.

  20. Cloning Hubble Deep Fields II: Models for Evolution by Bright Galaxy Image Transformation

    E-Print Network [OSTI]

    Rychard J. Bouwens; Tom Broadhurst; Joseph Silk

    1998-10-29T23:59:59.000Z

    In a companion paper we outlined a methodology for generating parameter-free, model-independent ``no-evolution'' fields of faint galaxy images, demonstrating the need for significant evolution in the HDF at faint magnitudes. Here we incorporate evolution into our procedure, by transforming the input bright galaxy images with redshift, for comparison with the HDF at faint magnitudes. Pure luminosity evolution is explored assuming that galaxy surface brightness evolves uniformly, at a rate chosen to reproduce the I-band counts. This form of evolution exacerbates the size discrepancy identified by our no-evolution simulations, by increasing the area of a galaxy visible to a fixed isophote. Reasonable dwarf-augmented models are unable to generate the count excess invoking moderate rates of stellar evolution. A plausible fit to the counts and sizes is provided by `mass-conserving' density-evolution, consistent with small-scale hierarchical growth, where the product of disk area and space density is conserved with redshift. Here the increased surface brightness generated by stellar evolution is accomodated by the reduced average galaxy size, for a wide range of geometries. These models are useful for assessing the limitations of the HDF images, by calculating their rates of incompleteness and the degree of over-counting. Finally we demonstrate the potential for improvement in quantifying evolution at fainter magnitudes using the HST Advanced Camera, with its superior UV and optical performance.

  1. DOE Announces Selections for SSL Core Technology and Product...

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

    LED Applications Summary: The project seeks to develop high-brightness light-emitting diode encapsulants that exceed commercially available systems in refractive index and...

  2. Demonstration Assessment of Light Emitting Diode (LED) Walkway Lighting at the Federal Aviation Administration William J. Hughes Technical Center, in Atlantic City, New Jersey

    SciTech Connect (OSTI)

    Kinzey, Bruce R.; Myer, Michael

    2008-03-18T23:59:59.000Z

    This report documents the results of a collaborative project to demonstrate a solid state lighting (SSL) general illumination product in an outdoor area walkway application. In the project, six light-emitting diode (LED) luminaires were installed to replace six existing high pressure sodium (HPS) luminaires mounted on 14-foot poles on a set of exterior walkways and stairs at the Federal Aviation Administration (FAA) William J. Hughes Technical Center in Atlantic City, New Jersey, during December, 2007. The effort was a U.S. Department of Energy (DOE) SSL Technology Gateway Demonstration that involved a collaborative teaming agreement between DOE, FAA and Ruud Lighting (and their wholly owned division, Beta LED). Pre- and post-installation power and illumination measurements were taken and used in calculations of energy savings and related economic payback, while personnel impacted by the new lights were provided questionnaires to gauge their perceptions and feedback. The SSL product demonstrated energy savings of over 25% while maintaining illuminance levels and improving illuminance uniformity. PNNL's economic analysis yielded a variety of potential payback results depending on the assumptions used. In the best case, replacing HPS with the LED luminaire can yield a payback as low as 3 years. The new lamps were quite popular with the affected personnel, who gave the lighting an average score of 4.46 out of 5 for improvement.

  3. Demonstration of LED Retrofit Lamps at the Jordan Schnitzer Museum of Art

    SciTech Connect (OSTI)

    Miller, Naomi J.

    2011-09-01T23:59:59.000Z

    The Jordan Schnitzer Museum of Art in Eugene, Oregon, houses a remarkable permanent collection of Asian art and antiquities, modern art, and sculpture, and also hosts traveling exhibitions. In the winter and spring of 2011, a series of digital photographs by artist Chris Jordan, titled "Running the Numbers," was exhibited in the Coeta and Donald Barker Special Exhibitions Gallery. These works graphically illustrate waste (energy, money, health, consumer objects, etc.) in contemporary culture. The Bonneville Power Administration and the Eugene Water and Electricity Board provided a set of Cree 12W light-emitting diode (LED) PAR38 replacement lamps (Cree LRP38) for the museum to test for accent lighting in lieu of their standard Sylvania 90W PAR38 130V Narrow Flood lamps (which draw 78.9W at 120V). At the same time, the museum tested LED replacement lamps from three other manufacturers, and chose the Cree lamp as the most versatile and most appropriate color product for this exhibit. The lamps were installed for the opening of the show in January 2011. This report describes the process for the demonstration, the energy and economic results, and results of a survey of the museum staff and gallery visitors on four similar clusters of art lighted separately by four PAR38 lamps.

  4. Careers Bachelor if Sciences in The future is bright for those pursuing an education in geology or a geoscience

    E-Print Network [OSTI]

    Walker, Lawrence R.

    Careers ­ Bachelor if Sciences in Geology The future is bright for those pursuing an education in geology or a geoscience related field as demand and gas industry (median $125,350). Forbes recently ranked Geology #7 in its "15

  5. Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps.

    SciTech Connect (OSTI)

    Royer, Michael P.; Poplawski, Michael E.; Brown, Charles C.

    2014-12-14T23:59:59.000Z

    To date, all three reports in the retail lamps series have focused on basic performance parameters, such as lumen output, efficacy, and color quality. This report goes a step further, examining the photoelectric characteristics (i.e., dimming and flicker) of a subset of lamps from CALiPER Retails Lamps Study 3. Specifically, this report focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers. The results demonstrate notable variation across the various lamps, but little variation between the four dimmers. Overall, the LED lamps: ~tended to have higher relative light output compared to the incandescent and halogen benchmark at the same dimmer output signal (RMS voltage). The lamps’ dimming curves (i.e., the relationship between control signal and relative light output) ranged from linear to very similar to the square-law curve typical of an incandescent lamp. ~generally exhibited symmetrical behavior—the same dimming curve—when measured proceeding from maximum to minimum or minimum to maximum control signal. ~mostly dimmed below 10% of full light output, with some exceptions for specific lamp and dimmer combinations ~exhibited a range of flicker characteristics, with many comparing favorably to the level typical of a magnetically-ballasted fluorescent lamp through at least a majority of the dimming range. ~ always exceeded the relative (normalized) efficacy over the dimming range of the benchmark lamps, which rapidly decline in efficacy when they are dimmed. This report generally does not attempt to rank the performance of one product compared to another, but instead focuses on the collective performance of the group versus conventional incandescent or halogen lamps, the performance of which is likely to be the baseline for a majority of consumers. Undoubtedly, some LED lamps perform better—or more similar to conventional lamps—than others. Some perform desirably for one characteristic, but not others. Consumers (and specifiers) may have a hard time distinguishing better-performing lamps from one another; at this time, physical experimentation is likely the best evaluation tool.

  6. CALiPER Retail Lamps Study RRL3.2 Lumen and Chromaticity Maintenance of LED A lamps Operated in Steady-State Conditions

    SciTech Connect (OSTI)

    Royer, Michael P.; McCullough, Jeffrey J.; Tucker, Joseph C.

    2014-12-01T23:59:59.000Z

    The lumen depreciation and color shift of 17 different A lamps (15 LED, 1 CFL, 1 halogen) was monitored in the automated long-term test apparatus (ALTA) for more than 7,500 hours. Ten samples of each lamp model were tested, with measurements recorded on a weekly basis. The lamps were operated continuously at an ambient temperature of 45°C (-1°C). Importantly, the steady-state test conditions were not optimized for inducing catastrophic failure for any of the lamp technologies—to which thermal cycling is a strong contributor— and are not typical of normal use patterns—which usually include off periods where the lamp cools down. Further, the test conditions differ from those used in standardized long-term test methods (i.e., IES LM-80, IES LM-84), so the results should not be directly compared. On the other hand, the test conditions are similar to those used by ENERGY STAR (when elevated temperature testing is called for). Likewise, the conditions and assumptions used by manufacturers to generated lifetime claims may vary; the CALiPER long-term data is informative, but cannot necessarily be used to discredit manufacturer claims. The test method used for this investigation should be interpreted as one more focused on the long-term effects of elevated temperature operation, at an ambient temperature that is not uncommon in luminaires. On average, the lumen maintenance of the LED lamps monitored in the ALTA was better than benchmark lamps, but there was considerable variation from lamp model to lamp model. While three lamp models had average lumen maintenance above 99% at the end of the study period, two products had average lumen maintenance below 65%, constituting a parametric failure. These two products, along with a third, also exhibited substantial color shift, another form of parametric failure. While none of the LED lamps exhibited catastrophic failure—and all of the benchmarks did—the early degradation of performance is concerning, especially with a new technology trying to build a reputation with consumers. Beyond the observed parametric failures nearly half of the products failed to meet early-life thresholds for lumen maintenance, which were borrowed from ENERGY STAR specifications. That is, the lumen maintenance was sufficiently low at 6,000 hours that seven of the products are unlikely to have lumen maintenance above 70% at their rated lifetime (which was usually 25,000 hours). Given the methods used for this investigation—most notably continuous operation—the results should not be interpreted as indicative of a lamp’s performance in a typical environment. Likewise, these results are not directly relatable to manufacturer lifetime claims. This report is best used to understand the variation in LED product performance, compare the robustness of LED lamps and benchmark conventional lamps, and understand the characteristics of lumen and chromaticity change. A key takeaway is that the long-term performance of LED lamps can vary greatly from model to model (i.e., the technology is not homogenous), although the lamp-to-lamp consistency within a given model is relatively good. Further, operation of LED lamps in an enclosed luminaire (or otherwise in high ambient temperatures), can induce parametric failure of LEDs much earlier than their rated lifetime; manufacturer warnings about such conditions should be followed if performance degradation is unacceptable.

  7. Demonstration of LED Retrofit Lamps at an Exhibit of 19th Century Photography at the Getty Museum

    SciTech Connect (OSTI)

    Miller, Naomi J.; Druzik, Jim

    2012-03-02T23:59:59.000Z

    This document is a report of observations and results obtained from a lighting demonstration project conducted under the U.S. Department of Energy (DOE) GATEWAY Demonstration Program. The program supports demonstrations of high-performance solid-state lighting (SSL) products in order to develop empirical data and experience with in-the-field applications of this advanced lighting technology. The DOE GATEWAY Demonstration Program focuses on providing a source of independent, third-party data for use in decision-making by lighting users and professionals; this data should be considered in combination with other information relevant to the particular site and application under examination. Each GATEWAY Demonstration compares SSL products against the incumbent technologies used in that location. Depending on available information and circumstances, the SSL product may also be compared to alternate lighting technologies. Though products demonstrated in the GATEWAY program may have been prescreened for performance, DOE does not endorse any commercial product or in any way guarantee that users will achieve the same results through use of these products. This report reviews the installation and use of LED PAR38 lamps to light a collection of toned albument photographic prints at the J. Paul Getty Museum in Malibu, California. Research results provided by the Getty Conservation Institute are incorporated and discussed.

  8. LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project

    SciTech Connect (OSTI)

    Tuenge, Jason R.

    2011-01-17T23:59:59.000Z

    Tungsten-halogen (halogen) lamps have traditionally been used to light surgical tasks in hospitals, even though they are in many respects ill-suited to the application due to the large percentage of radiant energy outside the visible spectrum and issues with color rendering/quality. Light-emitting diode (LED) technology offers potential for adjustable color and improved color rendition/quality, while simultaneously reducing side-effects from non-visible radiant energy. It also has the potential for significant energy savings, although this is a fairly narrow application in the larger commercial building energy use sector. Based on analysis of available products and Hospital Energy Alliance member interest, it is recommended that a product specification and field measurement procedure be developed for implementation in demonstration projects.

  9. Bright X-ray flares in XRF 050406 and GRB 050502B provide evidence for extended central engine activity

    E-Print Network [OSTI]

    Burrows, D N; Falcone, A; Kobayashi, S; Zhang, B; Moretti, A; O'Brien, P T; Goad, M R; Campana, S; Page, K L; Angelini, L; Barthelmy, S D; Beardmore, A P; Capalbi, M; Chincarini, G; Cummings, J; Cusumano, G; Fox, D; Giommi, P; Hill, J E; Kennea, J A; Krimm, H; Mangano, V; Marshall, F; Mészáros, P; Morris, D C; Nousek, J A; Osborne, J P; Pagani, C; Perri, M; Tagliaferri, G; Wells, A A; Woosley, S; Gehrels, N

    2005-01-01T23:59:59.000Z

    Gamma-ray bursts (GRBs) are the most powerful explosions since the Big Bang, with typical energies around 10**51 ergs. Long GRBs (duration > 2 s) are thought to signal the creation of black holes, most likely by collapse of massive stars. The detected signals from the resulting highly relativistic fireball consist of prompt gamma-ray emission (from internal shocks in the fireball) lasting for several seconds to minutes, followed by afterglow emission (from external shocks as the fireball encounters surrounding material) covering a broad range of frequencies from radio through X-rays. Because of the time needed to determine the GRB position, most afterglow measurements have been made hours after the burst, and little is known about the characteristics of afterglows in the minutes following a burst, when the afterglow emission is actively responding to inhomogeneities in both the fireball and the circumburst environment. Here we report our discovery of two bright X-ray flares peaking a few minutes after the bur...

  10. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting on Residential and Commercial Streets in Palo Alto, CA

    SciTech Connect (OSTI)

    Myer, Michael; Kinzey, Bruce R.; Tam, Christine

    2010-06-24T23:59:59.000Z

    This report is part of a GATEWAY demonstration that replaced existing HPS streetlights with two different types of LED products and one induction product. Energy savings ranged from 6% to 44%.

  11. 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.

  12. CALiPER Report 20.1: Quality of Beam, Shadow, and Color in LED PAR38 Lamps

    Broader source: Energy.gov [DOE]

    View the video about CALiPER Report 20.1 which focuses on human-evaluated characteristics, including beam quality, shadow quality, and color quality in LED PAR38 lamps.

  13. Assessing the Performance of LED-Based Flashlights Available in the Kenyan Off-Grid Lighting Market

    E-Print Network [OSTI]

    Tracy, Jennifer

    2010-01-01T23:59:59.000Z

    testing of emerging off-grid White-LED illumination systems,the economics behind off-grid lighting products for smallAvailable in the Kenyan Off-Grid Lighting Market Jennifer

  14. DOE Publishes CALiPER Report on Linear (T8) LED Lamps in a 2x4...

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

    than those with a wide distribution (i.e., with a diffuse optic), and all of the linear LED lamps resulted in a higher luminaire efficiency than the fluorescent benchmark. The...

  15. Correlation analysis of mean global radiation values with mean brightness values for one year 

    E-Print Network [OSTI]

    Kolczynski, Edward Franklin

    1971-01-01T23:59:59.000Z

    quantities of global radiation, = kb. sin h i oi where i denotes the number of the month (1 to 12), Q. is the individual monthly quantity of global radiation, h . is the solar altitude relat- oi ed to noon of the middle day of the month, and k is the coei... which now exists in the data bank of this field. B. ~Db' t' The objective of the proposed research is to investigate a pos- sible relationship between global radiation, as measured from ground- based instruments, and mean brightness values...

  16. The Bright Lights in New York Could Be Solar | Department of Energy

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

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartmentTest for Pumping System EfficiencyRole(EAP)EnergyThe Bright

  17. SN1994D in NGC4526: a normally bright type Ia supernova

    E-Print Network [OSTI]

    Georg Drenkhahn; Tom Richtler

    1999-09-07T23:59:59.000Z

    SN1994D of type Ia has been suspected not to fit into the relation between decline rate, colour, and brightness. However, an individual distance of its host galaxy, NGC4526, other than that of the Virgo cluster, has not yet been published. We determined the distance by the method of globular cluster luminosity functions on the basis of HST archive data. A maximum-likelihood fit returns apparent turn-over magnitudes of 23.16+-0.16mag in V and 21.96+-0.09mag in I. The corresponding distance modulus is 30.4+-0.3mag, where the error reflects our estimation of the absolute distance scale. The absolute magnitudes (not corrected for decline rate and colour) are -18.67+-0.30mag, -18.62+-0.30mag, and -18.40+-0.30mag for B, V, and I, respectively. The corrected magnitudes are -18.69+-0.31mag, -18.69+-0.31mag, and -18.44+-0.31mag. Compared with other supernovae with reliably determined distances, SN1994D fits within the errors. It is therefore not a counter-example against a uniform decline-rate-colour-brightness relation.

  18. 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 ...

  19. Table Set-up with Modern Engineering Tools Target Aud ience: Parents of elementary school students (grades 3-6) and Middle and High School Students

    E-Print Network [OSTI]

    Linhardt, Robert J.

    of a 40 lumen equivalent LED bulb (cluster of single LEDs) attached , the Lamp specifications spreadsheet (grades 3-6) and Middle and High School Students Objectives: 1. Introduce LED technology and design by using the USB Microscope. 2. Introduce the LED and bulb as an efficient alternative to conventional

  20. Color stable phosphors for LED lamps and methods for preparing them

    DOE Patents [OSTI]

    Murphy, James Edward; Setlur, Anant Achyut; Camardello, Samuel Joseph

    2013-11-26T23:59:59.000Z

    An LED lamp includes a light source configured to emit radiation with a peak intensity at a wavelength between about 250 nm and about 550 nm; and a phosphor composition configured to be radiationally coupled to the light source. The phosphor composition includes particles of a phosphor of formula I, said particles having a coating composition disposed on surfaces thereof; ((Sr.sub.1-zM.sub.z).sub.1-(x+w)A.sub.wCe.sub.x).sub.3(Al.sub.1-ySi.sub.y-)O.sub.4+y+3(x-w)F.sub.1-y-3(x-w) I wherein the coating composition comprises a material selected from aluminum oxide, magnesium oxide, calcium oxide, barium oxide, strontium oxide, zinc oxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, strontium hydroxide, zinc hydroxide, aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, strontium phosphate, and combinations thereof; and A is Li, NA, K, or Rb, or a combination thereof; M is Ca, Ba, Mg, Zn, or a combination thereof; and 0