National Library of Energy BETA

Sample records for high brightness led

  1. Concepts for Phosphorescent Organic LEDs at High Brightness ...

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

    Concepts for Phosphorescent Organic LEDs at High Brightness May 24, 2010 at 3pm36-428 Sebastian Reineke Institut fr Angewandte Photophysik, Dresden reineke001 abstract: Organic...

  2. Low Cost Lithography Tool for High Brightness LED Manufacturing

    SciTech Connect (OSTI)

    Andrew Hawryluk; Emily True

    2012-06-30

    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

    tolerance to humidity, low power consumption and minimal heat generation. Light-emitting diodes (LEDsOptical Wireless based on High Brightness Visible LEDs Grantham Pang, Thomas Kwan, Hugh Liu, Chi use of lighting or signaling devices constructed by light-emitting diodes (LEDs). The idea

  5. Ultra Bright LED Light Injection Calibration System for MINOS

    E-Print Network [OSTI]

    B. Anderson; A. Anjomshoaa; P. Dervan; J. A. Lauber; J. Thomas

    1998-10-26

    We describe here a proposal for a light injection calibration system for the MINOS detectors based on ultra bright blue LEDs as the light source. We have shown that these LEDs are bright enough to span over two orders of magnitude in light intensity, commensurate with that expected in a single scintillator strip in the MINOS neutrino detectors.

  6. 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.

  7. Multicolor, High Efficiency, Nanotextured LEDs

    SciTech Connect (OSTI)

    Jung Han; Arto Nurmikko

    2011-09-30

    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.

  8. A Probabilistic Approach of Designing Driving Circuits for Strings of High-Brightness Light

    E-Print Network [OSTI]

    Lehman, Brad

    Email : abhattac@ece.neu.edu Abstract-Often, High Brightness LEDs (HB-LED) are connected in series to create strings. According to their data sheets, the HB-LEDs have a variation in their forward voltage in parallel. This paper proposes a probabilistic approach for modeling the forward voltage drop across the HB-LEDs

  9. High Power UV LED Industrial Curing Systems

    SciTech Connect (OSTI)

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

    2012-05-14

    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. 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)

    2002-01-01

    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.

  11. White LED with High Package Extraction Efficiency

    SciTech Connect (OSTI)

    Yi Zheng; Matthew Stough

    2008-09-30

    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.

  12. 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.

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

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

    Minuscule crystals that glow different colors may be the missing ingredient for white LED lighting that illuminates homes and offices as effectively as natural sunlight....

  14. 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...

  15. High Performance Green LEDs by Homoepitaxial

    SciTech Connect (OSTI)

    Wetzel, Christian; Schubert, E Fred

    2009-11-22

    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.

  16. A high-brightness source of polarization-entangled photons

    E-Print Network [OSTI]

    Weinfurter, Harald

    A high-brightness source of polarization-entangled photons optimized for applications in free space for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Ontario N2L 3G1, Canada 3, 1090 Wien, Austria 7 Department of Electrical and Electronic Engineering, University of Bristol

  17. 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.

  18. Inverse Free Electron Laser Interactions with Sub-Picosecond High Brightness Electron Beams

    E-Print Network [OSTI]

    Moody, Joshua Timothy

    2014-01-01

    Accelerated Electron Beam Spectrum . . . . . . . . . . . .2 High Brightness Electron Beams Produced in thetion of Uniformly Filled Ellipsoidal Electron Beam: Method-

  19. High Efficacy Green LEDs by Polarization Controlled MOVPE

    SciTech Connect (OSTI)

    Wetzel, Christian

    2013-03-31

    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

  20. Bright x-ray sources from laser irradiation of foams with high...

    Office of Scientific and Technical Information (OSTI)

    Bright x-ray sources from laser irradiation of foams with high concentration of Ti Citation Details In-Document Search Title: Bright x-ray sources from laser irradiation of foams...

  1. Robust difference imaging of high surface brightness targets

    E-Print Network [OSTI]

    Kerins, E; Duke, J P; Gould, A; Han, C; Newsam, A; Park, B -G; Street, R

    2010-01-01

    Over the last two decades the Andromeda Galaxy (M31) has been something of a test-bed for methods aimed at obtaining accurate time-domain relative photometry within highly crowded fields. Difference imaging methods, originally pioneered towards M31, have evolved into sophisticated methods, such as the Optimal Image Subtraction (OIS) method of Alard & Lupton (1998), that today are most widely used to survey variable stars, transients and microlensing events in our own Galaxy. We show that modern difference image (DIA) algorithms such as OIS, whilst spectacularly successful towards the Milky Way bulge, may perform badly towards high surface brightness targets such as the M31 bulge. Poor results typically occur in the presence of common data systematics that scale with image flux such as internal reflections, scattered light, flat field errors or fringing. Using data from the Angstrom Project microlensing survey of the M31 bulge, we show that very good results are usually obtainable by first performing caref...

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

    Energy Savers [EERE]

    the Yuma (Arizona) Sector Border Patrol Area. Six LED luminaires - installed on three poles as part of a trial installation detailed in a prior GATEWAY report - continue to be...

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

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

    Scalable Light Module for Low-Cost, High Efficiency LED Luminaires Scalable Light Module for Low-Cost, High Efficiency LED Luminaires Lead Performer: Cree, Inc. - Durham, NC DOE...

  4. Aalborg Universitet Two phase interleaved buck converter for driving high power LEDs

    E-Print Network [OSTI]

    Munk-Nielsen, Stig

    Aalborg Universitet Two phase interleaved buck converter for driving high power LEDs Beczkowski. (2011). Two phase interleaved buck converter for driving high power LEDs. In Proceedings of the 14th #12;Two phase interleaved buck converter for driving high power LEDs Szymon Bczkowski, Stig Munk

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

    E-Print Network [OSTI]

    Gilchrist, James F.

    -emitting diode (LED) is the most popular technique due to its advantages of small volume, long lifetime, high reliability, low power consumption, and nonpollution. The progress in solid-state lighting has been driven to the progress in visible InGaN-based light-emitting diodes (LEDs) based on III-nitride based semiconductor

  6. Measured Properties of the DUVFEL High Brightness, Ultrashort Electron Beam

    SciTech Connect (OSTI)

    Emma, Paul J

    2002-08-20

    The DUVFEL electron linac is designed to produce sub-picosecond, high brightness electron bunches to drive an ultraviolet FEL. The accelerator consists of a 1.6 cell S-band photoinjector, variable pulse length Ti:Sapp laser, 4 SLAC-type S-band accelerating sections, and 4-dipole chicane bunch compressor. In preparation for FEL operation, the compressed electron beam has been fully characterized. Measurement of the beam parameters and simulation of the beam are presented. The properties of the laser and photoinjector are summarized in Table 1. In typical running, 10 mJ of IR light is produced by the Spectraphyics Tsunami Ti:Sapphire oscillator and TSA50 amplifier, which is frequency tripled to produce 450 uJ of UV light. After spatial filtering and aperturing of the gaussian mode to produce a nearly uniform laser spot, about 200-300 uJ is delivered to the cathode. This produces 300 pC of charge at the accelerating phase of 30 degrees. The RF cavity is a Gun IV [1] with copper cathode that has been modified for better performance [2]. In principle, the laser pulse length may be adjusted from 100 fs to 10 ps, however there are practical limitations on the range of adjustment due to dispersion characteristics and efficiency of the BBO crystals. The thickness of the harmonic crystals is optimized for pulse lengths from 1-5 ps. Within this range of pulse lengths there is evidence [3] of variations in the time profile of the UV light that are sensitive to the phase-matching angle of the crystal.

  7. South African night sky brightness during high aerosol epochs

    E-Print Network [OSTI]

    Winkler, Hartmut; Marang, Fred

    2014-01-01

    Sky conditions in the remote, dry north-western interior of South Africa are now the subject of considerable interest in view of the imminent construction of numerous solar power plants in this area. Furthermore, the part of this region in which the core of the SKA is to be located (which includes SALT) has been declared an Astronomical Advantage Zone, for which sky brightness monitoring will now be mandatory. In this project we seek to characterise the sky brightness profile under a variety of atmospheric conditions. Key factors are of course the lunar phase and altitude, but in addition the sky brightness is also significantly affected by the atmospheric aerosol loading, as that influences light beam scattering. In this paper we chose to investigate the sky characteristics soon after the Mount Pinatubo volcanic eruption in 1991, which resulted in huge ash masses reaching the stratosphere (where they affected solar irradiance for several years). We re-reduced photometric sky measurements from the South Afric...

  8. Development & Industrialization of InGaN/GaN LEDs on Patterned...

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

    low-cost LED products. Target MarketAudience: Commercial products are targeted for the high- brightness illumination markets. 3 Purpose and Objectives Problem Statement: * In...

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

    E-Print Network [OSTI]

    O'Shea, Finn Henry

    2012-01-01

    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

  10. High Efficiency LED Lamp for Solid-State Lighting

    SciTech Connect (OSTI)

    James Ibbetson

    2006-12-31

    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.

  11. 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...

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

    SciTech Connect (OSTI)

    David, Aurelien

    2012-10-15

    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.

  13. High brightness symmetric emittance rf photoinjector preliminary design report

    SciTech Connect (OSTI)

    Colby, E.R.; Ostiguy, J.F. [Fermi National Accelerator Lab., Batavia, IL (United States); Rosenzweig, J.B. [California Univ., Los Angeles, CA (United States). Dept. of Physics

    1994-08-01

    A preliminary design for a high bunch charge (8 nC), low emittance (< 20 mm-mr) radiofrequency electron photoinjector matched to the requirements of the Tesla Test Facility is presented. A 1.5 cell iris coupled {pi}mode structure with high average accelerating gradient is chosen for its high shunt impedance, simplicity, and ability to accommodate an externally mounted solenoid for simultaneous beam divergence control and emittance compensation. Beam optics are optimized for an overall injector consisting of the electron gun followed by one linac capture section, a dipole chicane for magnetic bunch compression to achieve a bunch length corresponding to {sigma}{sub z} = 1 mm. Electrical and beam dynamical aspects of the photoinjector design are presented. A description of the proposed experimental program is included.

  14. DEVELOPMENT OF A HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN NATIONAL LABORATORY*

    E-Print Network [OSTI]

    McDonald, Kirk

    954 DEVELOPMENT OF A HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN, New York 11973 and K. McDonald Princeton [Jniversity Abstract An electron gun utilizing a radio). Here we report on the de;$n of the electron gun which will provide r.f. bunches of up to 10 electrons

  15. Energy-Efficient, High-Color-Rendering LED Lamps Using Oxyfluoride and Fluoride Phosphors

    SciTech Connect (OSTI)

    Setlur, A.; Radkov, E; Henderson, C; Her, J; Srivastava, A; Karkada, N; Kishore, M; Kumar, N; Aesram, D; et al.

    2010-01-01

    LED lamps using phosphor downconversion can be designed to replace incandescent or halogen sources with a 'warm-white' correlated color temperature (CCT) of 2700-3200 K and a color rendering index (CRI) greater than 90. However, these lamps have efficacies of {approx}70% of standard 'cool-white' LED packages (CCT = 4500-6000 K; CRI = 75-80). In this report, we describe structural and luminescence properties of fluoride and oxyfluoride phosphors, specifically a (Sr,Ca){sub 3}(Al,Si)O{sub 4}(F,O):Ce{sup 3+} yellow-green phosphor and a K{sub 2}TiF{sub 6}:Mn{sup 4+} red phosphor, that can reduce this gap and therefore meet the spectral and efficiency requirements for high-efficacy LED lighting. LED lamps with a warm-white color temperature (3088 K), high CRI (90), and an efficacy of {approx}82 lm/W are demonstrated using these phosphors. This efficacy is {approx}85% of comparable cool-white lamps using typical Y{sub 3}Al{sub 5}O{sub 12}:Ce{sup 3+}-based phosphors, significantly reducing the efficacy gap between warm-white and cool-white LED lamps that use phosphor downconversion.

  16. 90.6% efficient 11MHz 22W LED driver using GaN FETs and burst-mode controller with 0.96 power factor

    E-Print Network [OSTI]

    Chandrakasan, Anantha P.

    With the advent of reliable, high brightness and high efficacy LEDs, the lighting industry is expected to see a significant growth in the near future. However, for LEDs to completely replace the traditional incandescent ...

  17. 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)

    2014-12-15

    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.

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

    SciTech Connect (OSTI)

    Ratner, Daniel; /Stanford U. /SLAC

    2012-05-25

    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.

  19. Magnification 3x -1,000,000x Electron Gun High brightness Schottky

    E-Print Network [OSTI]

    Damm, Werner

    SEM Column Magnification 3x - 1,000,000x Electron Gun High brightness Schottky Emitter Resolution Current 1 pA to 40 nA Accelerating Voltage 1 kV to 5 kV, 10kV to 30 kV Gun Vacuum Magnification 150x to 1,000,000x Resolution (SE) Gun Ga liquid metal ion source Chamber

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

    DOE Patents [OSTI]

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

    2014-02-18

    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.

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

    SciTech Connect (OSTI)

    Paul Fini

    2010-11-30

    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.

  2. High-Voltage LED Light Engine with Integrated Driver | 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 on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancingR Walls - Building America Topa High BindingVoltage LED

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

    SciTech Connect (OSTI)

    Soer, Wouter

    2013-09-19

    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.

  4. 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 on Delicious Rank EERE:Financing Tool Fits the Bill Financing ToolSustainableSecurityHighDepartment ofLight-Emitting Diode

  5. 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)

    2009-10-27

    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.

  6. 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 ...

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

    SciTech Connect (OSTI)

    Dupuis, Russell

    2012-02-29

    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.

  8. 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).

  9. REX, a 5-MV pulsed-power source for driving high-brightness electron beam diodes

    SciTech Connect (OSTI)

    Carlson, R.L.; Kauppila, T.J.; Ridlon, R.N.

    1991-01-01

    The Relativistic Electron-beam Experiment, or REX accelerator, is a pulsed-power source capable of driving a 100-ohm load at 5 MV, 50 kA, 45 ns (FWHM) with less than a 10-ns rise and 15-ns fall time. This paper describes the pulsed-power modifications, modelling, and extensive measurements on REX to allow it to drive high impedance (100s of ohms) diode loads with a shaped voltage pulse. A major component of REX is the 1.83-m-diam {times} 25.4-cm-thick Lucite insulator with embedded grading rings that separates the output oil transmission line from the vacuum vessel that contains the re-entrant anode and cathode assemblies. A radially tailored, liquid-based resistor provides a stiff voltage source that is insensitive to small variations of the diode current and, in addition, optimizes the electric field stress across the vacuum side of the insulator. The high-current operation of REX employs both multichannel peaking and point-plane diverter switches. This mode reduces the prepulse to less than 2 kV and the postpulse to less than 5% of the energy delivered to the load. Pulse shaping for the present diode load is done through two L-C transmission line filters and a tapered, glycol-based line adjacent to the water PFL and output switch. This has allowed REX to drive a diode producing a 4-MV, 4.5-kA, 55-ns flat-top electron beam with a normalized Lapostolle emittance of 0.96 mm-rad corresponding to a beam brightness in excess of 4.4 {times} 10{sup 8} A/m{sup 2} {minus}rad{sup 2}. 6 refs., 13 figs.

  10. 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

    2014-09-15

    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.

  11. Production of high brightness H- beam by charge exchange of hydrogen atom beam in sodium jet

    SciTech Connect (OSTI)

    Davydenko, V.; Zelenski, A.; Ivanov, A.; Kolmogorov, A.

    2010-11-16

    Production of H{sup -} beam for accelerators applications by charge exchange of high brightness hydrogen neutral beam in a sodium jet cell is experimentally studied in joint BNL-BINP experiment. In the experiment, a hydrogen-neutral beam with 3-6 keV energy, equivalent current up to 5 A and 200 microsecond pulse duration is used. The atomic beam is produced by charge exchange of a proton beam in a pulsed hydrogen target. Formation of the proton beam is performed in an ion source by four-electrode multiaperture ion-optical system. To achieve small beam emittance, the apertures in the ion-optical system have small enough size, and the extraction of ions is carried out from the surface of plasma emitter with a low transverse ion temperature of {approx}0.2 eV formed as a result of plasma jet expansion from the arc plasma generator. Developed for the BNL optically pumped polarized ion source, the sodium jet target with recirculation and aperture diameter of 2 cm is used in the experiment. At the first stage of the experiment H{sup -} beam with 36 mA current, 5 keV energy and {approx}0.15 cm {center_dot} mrad normalized emittance was obtained. To increase H{sup -} beam current ballistically focused hydrogen neutral beam will be applied. The effects of H{sup -} beam space-charge and sodium-jet stability will be studied to determine the basic limitations of this approach.

  12. High-intensity, high-brightness polarized and unpolarized beam production in charge-exchange collisions

    SciTech Connect (OSTI)

    Zelenski, A.; Ritter, J.; Zubets, V.; Steski, D.; Atoian, G.; Davydenko, V.; Ivanov, A.; Kolmogorov, A.

    2011-03-28

    Basic limitations on the high-intensity H{sup -} ion beam production were experimentally studied in charge-exchange collisions of the neutral atomic hydrogen beam in the Na-vapour jet ionizer cell. These studies are the part of the polarized source upgrade (to 10 mA peak current and 85% polarization) project for RHIC. In the source the atomic hydrogen beam of a 5-10 keV energy and total (equivalent) current up to 5 A is produced by neutralization of proton beam in pulsed hydrogen gas target. Formation of the proton beam (from the surface of the plasma emitter with a low transverse ion temperature {approx}0.2 eV) is produced by four-electrode spherical multi-aperture ion-optical system with geometrical focusing. The hydrogen atomic beam intensity up to 1.0 A/cm{sup 2} (equivalent) was obtained in the Na-jet ionizer aperture of a 2.0 cm diameter. At the first stage of the experiment H-beam with 36 mA current, 5 keV energy and {approx}1.0 cm {center_dot} mrad normalized emittance was obtained using the flat grids and magnetic focusing.

  13. 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

  14. 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.

    2014-11-07

    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.

  15. 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

    1996-05-06

    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.

  16. LED Update

    SciTech Connect (OSTI)

    Johnson, Mark L.; Gordon, Kelly L.

    2006-09-01

    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.

  17. LED lamp

    DOE Patents [OSTI]

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12

    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.

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

    E-Print Network [OSTI]

    Choi, Jae Ik

    2014-01-01

    for Near-UV LED Solid State Lighting” ECS Journal of Solidfor Near-UV LED Solid State Lighting”, ECS J. Solid Statefor near-UV LED solid state lighting,” ECS J. Solid State

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

    E-Print Network [OSTI]

    Choi, Jae Ik

    2014-01-01

    for near-UV LED solid state lighting,” Solid State Sci.for near-UV LED solid state lighting,” ECS J. Solid Statefor Near-UV LED Solid State Lighting” ECS Journal of Solid

  20. LED Lighting Retrofit 

    E-Print Network [OSTI]

    Shaw-Meadow, N.

    2011-01-01

    kWh is the one that never gets used? ?Dedicated to making environmentally responsible products? Ringdale Introduction LED Roadway Lighting Better Light, Fewer Watts. Period. Nathan Shaw-Meadow LED Lighting Specialist Ringdale ActiveLED ESL.../exponential efficiency growth often deters investment today 7 Challenges to Implementation ESL-KT-11-11-57 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ? Municipal Street Light Case Study 8 ? Replaced 400W High Pressure Sodium fixtures with 52W Active...

  1. 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

    2008-01-01

    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...

  2. EUV light source with high brightness at 13.5 nm

    SciTech Connect (OSTI)

    Borisov, V M; Prokof'ev, A V; Khristoforov, O B [State Research Center of Russian Federation 'Troitsk Institute for Innovation and Fusion Research', Troitsk, Moscow Region (Russian Federation); Koshelev, K N [Institute of Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow (Russian Federation); Khadzhiyskiy, F Yu [EUV Labs, Ltd., Troitsk, Moscow (Russian Federation)

    2014-11-30

    The results of the studies on the development of a highbrightness radiation source in the extreme ultraviolet (EUV) range are presented. The source is intended for using in projection EUV lithography, EUV mask inspection, for the EUV metrology, etc. Novel approaches to creating a light source on the basis of Z-pinch in xenon allowed the maximal brightness [130 W(mm{sup 2} sr){sup -1}] to be achieved in the vicinity of plasma for this type of radiation sources within the 2% spectral band centred at the wavelength of 13.5 nm that corresponds to the maximal reflection of multilayer Mo/Si mirrors. In this spectral band the radiation power achieves 190 W in the solid angle of 2? at a pulse repetition rate of 1.9 kHz and an electric power of 20 kW, injected into the discharge. (laser applications and other topics in quantum electronics)

  3. 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

    2008-01-12

    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.

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

    Energy Savers [EERE]

    and the common household light bulb have in common? If your answer is that light emitting diode (LED) technology can power all these things, then you're pretty bright. LEDs...

  5. 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...

  6. Bright Ideas

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransen Plasma Asher An O2 RFand1120019 Bright Ideas

  7. LED ProspectsLED Prospects photometric units

    E-Print Network [OSTI]

    Pulfrey, David L.

    -life incandescent with LED. · 10 light fixtures/home, lights on for 6h/day, 333 days/yr. · Electricity 0.12 $/kWh. W 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

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

    E-Print Network [OSTI]

    - This paper introduces a digital architecture suitable for driving a large number of High Brightness LightDigital Architecture for Driving Large LED Arrays with Dynamic Bus Voltage Regulation and Phase distinct performance advantage over conventional lighting technology. Higher optical efficiency, long

  9. High efficiency and brightness fluorescent organic light emitting diode by triplet-triplet fusion

    DOE Patents [OSTI]

    Forrest, Stephen; Zhang, Yifan

    2015-02-10

    A first device is provided. The first device further comprises an organic light emitting device. The organic light emitting device further comprises an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer may include an organic host compound and at least one organic emitting compound capable of fluorescent emission at room temperature. Various configurations are described for providing a range of current densities in which T-T fusion dominates over S-T annihilation, leading to very high efficiency fluorescent OLEDs.

  10. LOW-COST LED LUMINAIRE FOR GENERAL ILLUMINATION

    SciTech Connect (OSTI)

    Lowes, Ted

    2014-07-31

    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.

  11. Impulsive and Long Duration High-Energy Gamma-ray Emission From the Very Bright 2012 March 7 Solar Flares

    E-Print Network [OSTI]

    ,

    2013-01-01

    The Fermi Large Area Telescope (LAT) observed two bright X-class solar flares on 2012 March 7, and detected gamma-rays up to 4 GeV. We detected gamma-rays both during the impulsive and temporally-extended emission phases, with emission above 100 MeV lasting for approximately 20 hours. Accurate localization of the gamma-ray production site(s) coincide with the solar active region from which X-ray emissions associated with these flares originated. Our analysis of the >100 MeV gamma-ray emission shows a relatively rapid monotonic decrease in flux during the first hour of the impulsive phase, and a much slower, almost monotonic decrease in flux for the next 20 hours. The spectra can be adequately described by a power law with a high energy exponential cutoff, or as resulting from the decay of neutral pions produced by accelerated protons and ions with an isotropic power-law energy distribution. The required proton spectrum has a number index ~3, with minor variations during the impulsive phase, while during the t...

  12. High brightness microwave lamp

    DOE Patents [OSTI]

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

    2003-09-09

    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.

  13. LEDs / Solid state lighting 1. J. Bruckbauer, P.R. Edwards, T.Wang and R.W. Martin `High resolution

    E-Print Network [OSTI]

    Greenaway, Alan

    Energy LEDs / Solid state lighting 1. J. Bruckbauer, P.R. Edwards, T.Wang and R.W. Martin `High-processed OLED devices Source: ORGANIC ELECTRONICS Volume: 11 Issue: 9 Pages: 1561-1568 2010 3. Author(s): Lai(III) Complexes: Synthesis and Light-Emitting Properties Source: MACROMOLECULES Volume: 43 Issue: 17 Pages: 6986

  14. LEDs_3LEDs_3 current efficiency

    E-Print Network [OSTI]

    Pulfrey, David L.

    1 LEDs_3LEDs_3 LECTURE 12 · current efficiency · extraction efficiency · wall-plug efficiency efficiencySec. 8.4 How much power gets out for GaAs? Adapted from Schubert, loc. cit. #12;5 Design to improve extraction efficiencyDesign to improve extraction efficiencySec. 8.4 What are the features of this LED from

  15. High-power InAs/InAsSbP heterostructure leds for methane spectroscopy ({lambda} {approx} 3.3 {mu}m)

    SciTech Connect (OSTI)

    Astakhova, A. P.; Golovin, A. S.; Il'inskaya, N. D.; Kalinina, K. V.; Kizhayev, S. S., E-mail: serguie@mail.ru; Serebrennikova, O. Yu.; Stoyanov, N. D. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Horvath, Zs. J. [Hungarian Academy of Sciences, Research Institute for Technical Physics and Materials Science (Hungary); Yakovlev, Yu. P. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

    2010-02-15

    Two designs of light-emitting diodes (LEDs) based on InAsSbP/InAs/InAsSbP double hetero-structures grown by metal-organic vapor phase epitaxy on p- and n-InAs substrates have been studied. The current-voltage and electroluminescence characteristics of the LEDs are analyzed. It is shown that the LED design with a light-emitting crystal (chip) mounted with the epitaxial layer down on the LED case and emission extracted through the n-InAs substrate provides better heat removal. As a result, the spectral characteristics remain stable at increased injection currents and the quantum efficiency of radiative recombination is higher. The internal quantum efficiency of light-em itting structures with an emission wavelength {lambda} = 3.3-3.4 {mu}m is as high as 22.3%. The optical emission power of the LEDs is 140 {mu}W at a current of 1 A in the quasi-continuous mode and reaches a value of 5.5 mW at a current of 9 A in the pulsed mode.

  16. LED Market Intelligence Report

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

    around dimming capabilities. 16 LED Market Intelligence Report Home Depot Walmart Cree Philips TCP GE LSG Osram Feit Costco Lowe's Retail, Regulations, and LEDs Like...

  17. 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

  18. Energy Efficiency of LEDs

    Broader source: Energy.gov [DOE]

    This fact sheet discusses the current state of the LED market and discusses package efficacy, luminaire efficacy, and application efficacy.

  19. White lighting LEDs are fast replacing conventional lighting because not only are they energy efficient light sources but also can be modulated at frequencies up to 20MHz for high-speed wireless communication, especially for indoor applications.

    E-Print Network [OSTI]

    Sekercioglu, Y. Ahmet

    Background White lighting LEDs are fast replacing conventional lighting because not only by using ceiling mounted white lighting LEDs Jiun Bin Choong Supervisor : Prof. Jean Armstrong A B F 1 2 1 are they energy efficient light sources but also can be modulated at frequencies up to 20MHz for high

  20. LED Market Adoption

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDFLEDLED MR16LED

  1. General Service LED Lamps

    Broader source: Energy.gov [DOE]

    A U.S. DOE SSL technology fact sheet that compares general service LED light bulbs with incandescent and CFL bulbs.

  2. LED Frequently Asked Questions

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

    term for semiconductors used to convert electricity into light. LED - light-emitting diode. CCT - correlated color temperature; a measure of the color appearance of a white...

  3. 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.

  4. Production, formation, and transport of high-brightness atomic hydrogen beam studies for the relativistic heavy ion collider polarized source upgrade

    SciTech Connect (OSTI)

    Kolmogorov, A. Stupishin, N.; Atoian, G.; Ritter, J.; Zelenski, A.; Davydenko, V.; Ivanov, A.; Novosibirsk State University, Novosibirsk

    2014-02-15

    The RHIC polarized H{sup ?} ion source had been successfully upgraded to higher intensity and polarization by using a very high brightness fast atomic beam source developed at BINP, Novosibirsk. In this source the proton beam is extracted by a four-grid multi-aperture ion optical system and neutralized in the H{sub 2} gas cell downstream from the grids. The proton beam is extracted from plasma emitter with a low transverse ion temperature of ?0.2 eV which is formed by plasma jet expansion from the arc plasma generator. The multi-hole grids are spherically shaped to produce “geometrical” beam focusing. Proton beam formation and transport of atomic beam were experimentally studied at test bench.

  5. 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)

    2013-09-11

    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.

  6. High-brightness picosecond ion beam source based on BNL Terawatt CO2 laser: Proof-of-principle experiments

    SciTech Connect (OSTI)

    Shkolnikov, Peter

    2012-10-04

    Under the continuing DOE support, we have: o assembled the basic experiment setup and then continued expanding it to include diverse diagnostics and to accommodate gas jet targets in addition to metal foils; o conducted an extensive study of our novel laser, significantly enhanced laser beam diagnostics, and improved relevant laser parameters; o turned our experiments into a truly international endeavor with active collaboration of close to 20 researchers in US, UK, and Germany; o conducted the first ever experiments with proton and ion acceleration by lasers interacting with overcritical plasma of gas jets; o for the first time directly observed radiation pressure acceleration of protons, including quasi-monoenergetic spectra promising for future applications; o for the first time directly observed quasi-stable, bubble-like plasma structures that likely evolved from relativistic laser-plasma solitons (post-solitons). Thus, we have confirmed a strong potential of a picosecond TW CO2 laser as a research tool in laser-plasma science and as a promising vehicle for future applications of laser ion acceleration. This has led to apparent increase of the interest in mid-IR laser ion acceleration. In particular, another major research group began extensive proton acceleration experiments with their own CO2 laser at UCLA. As a result, the mechanisms responsible for laser proton acceleration in gas jets have become somewhat clearer. It is also important to note that modest DOE funding played the role of a seed support ensuring the formation of a multinational research team, whose members contributed its time and equipment with value well in excess of that seed amount.

  7. Cavity Light-Emitting Diode for Durable, High-Brightness and High-Efficiency Lighting Applications: First Budget Period Technical Report

    SciTech Connect (OSTI)

    Yijian Shi

    2009-09-30

    A COLED device consists of a top electrode (anode) and a bottom electrode (cathode) separated by a thin dielectric layer. In this metal/dielectric stack, numerous small wells, or cavities, are etched through the top electrode and the dielectric layer. These cavities are subsequently filled with LEP molecules. When a voltage is applied between the top and bottom electrodes, holes (from the top electrode) and electrons (from the bottom electrode) are injected into the polymer. Light emission is generated upon recombination of holes and electrons within the polymer along the perimeters of cavities. Figure 1 compares the structures of the COLED and the traditional OLED. The existing COLED fabrication process flow is illustrated in Figure 2. A COLED can potentially be 5 times more efficient and can operate at as much as 100 times higher current density with much longer lifetime than an OLED. To fully realize these potential advantages, the COLED technology must overcome the following technical barriers, which were the technical focused points for Years 1 and 2 (Phase I) of this project: (1) Construct optimum thickness dielectric layer: In the traditional OLED structure, the optimal thickness of the LEP film is approximately 80-100 nm. In a COLED device, the effective LEP thickness roughly equals the thickness of the dielectric layer. Therefore, the optimal dielectric thickness for a COLED should also be roughly equal to 80-100 nm. Generally speaking, it is technically challenging to produce a defect-free dielectric layer at this thickness with high uniformity, especially over a large area. (2) Develop low-work-function cathode: A desired cathode should have a low work function that matches the lowest unoccupied molecular orbital (LUMO) level of the LEP molecules. This is usually achieved by using a low-work-function metal such as calcium, barium, lithium, or magnesium as the cathode. However, these metals are very vulnerable to oxygen and water. Since the cathode of the COLED will be exposed to air and processing chemicals during the COLED fabrication process, these low-work-function metals cannot be used directly in the COLED structure. Thus, new materials with low work function and better chemical stability are needed for the COLED cathode. (3) Increase active device area: Since photons are only generated from perimeters of the cavities, the actual active area in a COLED device is smaller than the device surface area. The cavity diameter and cavity spacing of the COLED devices previously produced at SRI by conventional photolithography processing are typically in the range of 3 to 7 {mu}m with an estimated active area of 2-3%. To achieve the same brightness of a traditional OLED at the same applied voltage, the active device area of a COLED should be at least 20% (1/5) of the device surface area, provided the COLED has 5 times higher EQE. This requires reducing the cavity diameter and cavity spacing to the sub-micrometer region, which can be achieved by electron-beam lithography or nanoimprint lithography. (4) Improve metal/polymer interfaces: The polymer/metal interfaces are critical issues to improve and optimize since they directly affect the effectiveness and balance of hole and electron injection, and consequently the device performance. Conventional approaches for improving a metal/polymer interface include deposition of a special interfacial material on the selected electrode surface or applying a proper surface treatment prior to deposition of the LEP. Since these approaches are generally nonselective to the cathode and anode, they cannot be directly adopted for COLED devices. Generally, the interface integration in current OLED technology still needs a better chemical approach. Hence, advanced methodology developed for the COLED technology as promoted in this project may be also suitable for other OLED devices.

  8. LED Outdoor Area Lighting Fact Sheet

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

    Outdoor Area Lighting LED technology is rapidly becoming competitive with high-intensity discharge light sources for outdoor area lighting. This document reviews the major design...

  9. Optical Safety of LEDs

    SciTech Connect (OSTI)

    none,

    2013-06-01

    Solid-state lighting program technology fact sheet that clarifies the issue of LED lighting safety for the human eye and takes a look at current standards for photobiological safety.

  10. LED Directional Lamps

    SciTech Connect (OSTI)

    2012-11-01

    Solid-state lighting program technology fact sheet that provides an overview of the current performance of LED PAR-, BR-, R-, and AR-shaped lamps, which were all investigated by CALiPER in 2012.

  11. 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

    2011-01-01

    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 ...

  12. 100 LPW 800 Lm Warm White LED

    SciTech Connect (OSTI)

    Decai Sun

    2010-10-31

    An illumination grade warm white (WW) LED, having correlated color temperature (CCT) between 2800 K and 3500K and capable of producing 800 lm output at 100 lm/W, has been developed in this program. The high power WW LED is an ideal source for use as replacement for incandescent, and Halogen reflector and general purpose lamps of similar lumen value. Over the two year period, we have made following accomplishments: developed a high power warm white LED product and made over 50% improvements in light output and efficacy. The new high power WW LED product is a die on ceramic surface mountable LED package. It has four 1x1 mm{sup 2} InGaN pump dice flip chip attached to a ceramic submount in 2x2 array, covered by warm white phosphor ceramic platelets called Lumiramicâ?¢ and an overmolded silicone lens encapsulating the LED array. The performance goal was achieved through breakthroughs in following key areas: (1) High efficiency pump LED development through pump LED active region design and epi growth quality improvement (funded by internal programs). (2) Increase in injection efficiency (IE) represented by reduction in forward voltage (V{sub f}) through the improvement of the silver-based p-contact and a reduction in spreading resistance. The injection efficiency was increased from 80% at the start of the program to 96% at the end of the program at 700 mA/mm{sup 2}. (3) Improvement in thermal design as represented by reduction in thermal resistance from junction to case, through improvement of the die to submount connection in the thin film flip chip (TFFC) LED and choosing the submount material of high thermal conductivity. A thermal resistance of 1.72 K/W was demonstrated for the high power LED package. (4) Improvement in extraction efficiency from the LED package through improvement of InGaN die level and package level optical extraction efficiency improvement. (5) Improvement in phosphor system efficiency by improving the lumen equivalent (LE) and phosphor package efficiency (PPE) through improvement in phosphor-package interactions. Another achievement in the development of the phosphor integration technology is the demonstration of tight color control. The high power WW LED product developed has been proven to have good reliability. The manufacturing of the product will be done in Philips Lumiledsâ?? LUXEON Rebel production line which has produced billions of high power LEDs. The first high power WW LED product will be released to the market in 2011.

  13. 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.

  14. 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

  15. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResource and JobLCLS Operating3 DocumentReview1ImageLED

  16. Design, construction and analysis of an LED strobe controller

    E-Print Network [OSTI]

    Villalva, Nicholas E

    2012-01-01

    In this thesis, I describe an LED strobe controller that I designed and built. With the advent of much brighter LEDs, it is possible to create stroboscopes with both high intensity output and high maximum flash rates. ...

  17. European Particle Accelerator Conference -Rome, Italy -June 7-12, 1988 DEVELOPMENT OFA HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT

    E-Print Network [OSTI]

    McDonald, Kirk

    BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN NATIONAL LABORATORY* K. Batchelor, HDonald Princeton University At innBNL--41767 DE89 002179 Abstract An electron gun utilizing aradio frequency on the design of (he electron gun which will provide r.f. bunches of upto 101 electrons synchronized

  18. 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

  19. A merged two-stage converter for LED lighting applications

    E-Print Network [OSTI]

    Ranson, John (John David)

    2012-01-01

    Light Emitting Diodes (LEDs) are a very promising technology for developing more efficient lighting. For high-efficiency applications, a switching current regulator is necessary to control the power drawn by an LED string. ...

  20. MOF Coating a Promising Path to White LEDs

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

    MOF Coating a Promising Path to White LEDs MOF Coating a Promising Path to White LEDs Print Friday, 27 February 2015 17:11 Hu et al. designed a new yellow phosphor with high...

  1. The Distribution of Star Formation and Metals in the Low Surface Brightness Galaxy UGC 628

    E-Print Network [OSTI]

    Young, J E; Wang, Sharon X

    2015-01-01

    We introduce the MUSCEL Program (MUltiwavelength observations of the Structure, Chemistry and Evolution of LSB galaxies), a project aimed at determining the star-formation histories of low surface brightness galaxies. MUSCEL utilizes ground-based optical spectra and space-based UV and IR photometry to fully constrain the star-formation histories of our targets with the aim of shedding light on the processes that led low surface brightness galaxies down a different evolutionary path from that followed by high surface brightness galaxies, such as our Milky Way. Here we present the spatially-resolved optical spectra of UGC 628, observed with the VIRUS-P IFU at the 2.7-m Harlen J. Smith Telescope at the McDonald Observatory, and utilize emission-line diagnostics to determine the rate and distribution of star formation as well as the gas-phase metallicity and metallicity gradient. We find highly clustered star formation throughout UGC 628, excluding the core regions, and a log(O/H) metallicity around -4.2, with mo...

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

    E-Print Network [OSTI]

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

    2014-08-03

    temperature and high vacuum processes, rendering them uneconomical for use in large area displays. Here, we report high brightness light-emitting diodes based on solution-processed organometal halide perovskites. We demonstrate electroluminescence in the near...

  3. A brightness exceeding simulated Langmuir limit

    SciTech Connect (OSTI)

    Nakasuji, Mamoru

    2013-08-15

    When an excitation of the first lens determines a beam is parallel beam, a brightness that is 100 times higher than Langmuir limit is measured experimentally, where Langmuir limits are estimated using a simulated axial cathode current density which is simulated based on a measured emission current. The measured brightness is comparable to Langmuir limit, when the lens excitation is such that an image position is slightly shorter than a lens position. Previously measured values of brightness for cathode apical radii of curvature 20, 60, 120, 240, and 480 ?m were 8.7, 5.3, 3.3, 2.4, and 3.9 times higher than their corresponding Langmuir limits, respectively, in this experiment, the lens excitation was such that the lens and the image positions were 180 mm and 400 mm, respectively. From these measured brightness for three different lens excitation conditions, it is concluded that the brightness depends on the first lens excitation. For the electron gun operated in a space charge limited condition, some of the electrons emitted from the cathode are returned to the cathode without having crossed a virtual cathode. Therefore, method that assumes a Langmuir limit defining method using a Maxwellian distribution of electron velocities may need to be revised. For the condition in which the values of the exceeding the Langmuir limit are measured, the simulated trajectories of electrons that are emitted from the cathode do not cross the optical axis at the crossover, thus the law of sines may not be valid for high brightness electron beam systems.

  4. GATEWAY Demonstrations: LED Street Lighting

    SciTech Connect (OSTI)

    Cook, Tyson; Shackelford, Jordan; Pang, Terrance Pang

    2008-12-01

    This report summarizes an assessment project conducted to study the performance of light emitting diode (LED) luminaires in a street lighting application in San Francisco, CA.

  5. Metacapacitors for LED Lighting: Metacapacitors

    SciTech Connect (OSTI)

    None

    2010-09-02

    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. Recessed LED Downlights | Department of Energy

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

    Recessed LED Downlights Recessed LED Downlights A Dept of Energy Solid-State Lighting Program technology fact sheet on recessed LED downlights. recesseddownlight.pdf More...

  7. LED Frequently Asked Questions | Department of Energy

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

    Frequently Asked Questions LED Frequently Asked Questions EERE Solid-State Lighting LED Factsheet ledbasics.pdf More Documents & Publications LED Frequently Asked Questions SSL...

  8. Demonstration Assessment of LED Roadway Lighting: Philadelphia...

    Office of Scientific and Technical Information (OSTI)

    LED Roadway Lighting: Philadelphia, PA Royer, Michael P.; Tuenge, Jason R.; Poplawski, Michael E. Roadway Lighting; Solid-state lighting; LED lighting; SSL; LED; GATEWAY Roadway...

  9. 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...

  10. LED Lighting | Department of Energy

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

    focusing light in ways that are useful in homes and commercial settings. The light-emitting diode (LED) is one of today's most energy-efficient and rapidly-developing lighting...

  11. LED Lighting | Department of Energy

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

    are directional, focusing light in ways that are useful in homes and commercial settings. The light-emitting diode (LED) is one of today's most energy-efficient and...

  12. Bright Lights, Black Leather 

    E-Print Network [OSTI]

    LaSalle, R.

    1995-01-01

    My research is a qualitative study about the Asian American experience. Studies have shown that Asian Americans obtain high levels of educational attainment and household income, but these figures are misleading. Asian ...

  13. LED lamp color control system and method

    DOE Patents [OSTI]

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

    2013-02-05

    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 lamp power management system and method

    DOE Patents [OSTI]

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

    2013-03-19

    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.

  15. White LED with High Package Extraction Efficiency

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking WithTelecentricNCubicthe FOIA? The FOIA,Department of

  16. Generation of Bright, Spatially Coherent Soft X-Ray High Harmonics in a Hollow Waveguide Using Two-Color Synthesized Laser Pulses

    E-Print Network [OSTI]

    Jin, Cheng

    We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser ...

  17. LED structure with enhanced mirror reflectivity

    DOE Patents [OSTI]

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

    2014-04-01

    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.

  18. INTRODUCTION TO ARDUINO AND LEDS

    E-Print Network [OSTI]

    7/16/13 1 INTRODUCTION TO ARDUINO AND LEDS Activity one: Make sure everybody is up and running Arduino #12;7/16/13 2 Arduino USB Interface External Power ATmega328 Analog Inputs Digital I Arduino Programming Load Examples - Basics - Blink Arduino SW system Two required functions void setup

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

    E-Print Network [OSTI]

    Tracy, Jennifer

    2010-01-01

    LED-Based Flashlights Available in the Kenyan Off-Grid LightingLED technology holds promise to provide affordable, high quality lightingLED technology has the potential to provide high quality lighting

  20. Philadelphia International Airport Apron Lighting: LED System...

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

    Philadelphia International Airport Apron Lighting: LED System Performance in a Trial Installation Philadelphia International Airport Apron Lighting: LED System Performance in a...

  1. Testimonials - Partnerships in LED Lighting - Philips Lumileds...

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

    LED Lighting - Philips Lumileds Lighting, LLC Testimonials - Partnerships in LED Lighting - Philips Lumileds Lighting, LLC Addthis An error occurred. Try watching this video on...

  2. Raman beam combining for laser brightness enhancement

    DOE Patents [OSTI]

    Dawson, Jay W; Allen, Grahan S; Pax, Paul H; Heebner, John E; Sridharan, Arun K; Rubenchik, Alexander M; Barty, Christopher B.J

    2015-11-05

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  3. Raman beam combining for laser brightness enhancement

    DOE Patents [OSTI]

    Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.

    2015-10-27

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  4. 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

  5. Low-Cost Illumination-Grade LEDs

    SciTech Connect (OSTI)

    Epler, John

    2013-08-31

    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.

  6. Two-Stage Power Conversion Architecture for an LED Driver Circuit

    E-Print Network [OSTI]

    Perreault, Dave

    Two-Stage Power Conversion Architecture for an LED Driver Circuit Seungbum Lim, John Ranson, David with 0.93 power factor at 8.4 W average power. I. INTRODUCTION LED lighting promises unprecedented efficiency, and high-power-factor LED drivers [1]. A survey of commercial LED drivers illustrates this

  7. LEDS | OpenEI Community

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EAInvervar HydroElectric Cooperative(Redirected fromUni LandLEDS Home

  8. Demonstration of LED Street Lighting

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street Lighting Host Site: City of Kansas City,

  9. Advanced 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin: Energy Resources JumpAdelan UK LtdWisconsin:Missouri:LLCLeadLeds

  10. Lighting the Great Outdoors: LEDs in Exterior Applications

    SciTech Connect (OSTI)

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

    2008-08-17

    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.

  11. LED Chips and Packaging for 120 LPW SSL Component

    SciTech Connect (OSTI)

    James Ibbetson

    2009-09-30

    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.

  12. 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...

  13. 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

    2012-07-30

    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.

  14. 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.

    2013-03-05

    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.

  15. 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.

    2008-11-10

    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.

  16. 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)

    2009-10-19

    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.

  17. LEDs for Street Lighting—Here Today

    SciTech Connect (OSTI)

    2013-11-29

    Fact sheet that provides a brief overview of the viability of LED street lighting in municipalities and highlights case studies of two cities—Los Angeles and Seattle—that have invested in LED street lighting.

  18. UNDERSTANDING LED COLOR-TUNABLE PRODUCTS

    Broader source: Energy.gov [DOE]

    LED luminaires with the ability to deliver varying light color have been on the architectural lighting market since the early days of LED lighting, but improved efficacy, colors, controls, and...

  19. LED Solutions for the Dark Hours

    Energy Savers [EERE]

    technologies 5 LEDs for Street and Roadway Lighting Portland, OR Philadelphia, PA New York, NY Kansas City, MO 6 Boston Las Vegas Seattle Number of LED Replacements to Date (4...

  20. DOE ZERH Webinar: LED Lighting Efficiency

    Broader source: Energy.gov [DOE]

    Description: LED lighting offers efficiency and performance benefits we've never seen in traditional lighting technologies. Commercial buildings have seen rapid growth in LED deployment, and in the...

  1. Smart Lighting: LED Implementation and Ambient Communication Applications

    E-Print Network [OSTI]

    Agogino, Alice M.

    Smart Lighting: LED Implementation and Ambient Communication Applications by Nicholas Adrian Galano............................................................................................................................................1 LED Implementation..........................................................................................................................2 LED Energy Usage

  2. 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

  3. An Brief Overview Of Using LEDs In Lab

    E-Print Network [OSTI]

    Baas, Bevan

    (~zero current) ­ Forward biased (high current flow) Regular (Non-Light-Emitting) Diode Operation 0 V 5 V Current ~0 high (too high); typically ~2-3V 5 V 0 V I anode cathode #12;3 Light-Emitting Diodes · A Light-Emitting Diode (LED) is a special type of diode that emits photons (light) when current flows through the diode

  4. 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.

  5. Dual LED/incandescent security fixture

    DOE Patents [OSTI]

    Gauna, Kevin Wayne

    2005-06-21

    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.

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

    SciTech Connect (OSTI)

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

    2009-03-31

    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.

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

    DOE Patents [OSTI]

    Zolotorev, Max (Oakland, CA)

    2010-07-13

    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.

  8. System Reliability for LED-Based Products

    SciTech Connect (OSTI)

    Davis, J Lynn; Mills, Karmann; Lamvik, Michael; Yaga, Robert; Shepherd, Sarah D; Bittle, James; Baldasaro, Nick; Solano, Eric; Bobashev, Georgiy; Johnson, Cortina; Evans, Amy

    2014-04-07

    Results from accelerated life tests (ALT) on mass-produced commercially available 6” downlights are reported along with results from commercial LEDs. The luminaires capture many of the design features found in modern luminaires. In general, a systems perspective is required to understand the reliability of these devices since LED failure is rare. In contrast, components such as drivers, lenses, and reflector are more likely to impact luminaire reliability than LEDs.

  9. 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,...

  10. A Practical Primer to LED Technology

    Energy Savers [EERE]

    ssl.energy.gov 2011 LED Transformations, LLC 60 Acknowledgements Support for the development and presentation of this educational seminar was provided by the US Department of...

  11. 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.

  12. Solid State Lighting LED Manufacturing Roundtable Summary

    SciTech Connect (OSTI)

    None

    2010-03-31

    Summary of a meeting of LED experts to develop proposed priority tasks for the Manufacturing R&D initiative, including task descriptions, discussion points, recommendations, and presentation highlights.

  13. 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...

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

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

    Boston, MA Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Boston, MA This page provides links to the presentations given at the DOE Municipal...

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

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

    Dallas, TX Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Dallas, TX This page provides links to the presentations given at the DOE Municipal...

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

    Open Energy Info (EERE)

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

  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 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).

  19. Bright Star Astrometry with URAT

    E-Print Network [OSTI]

    Zacharias, Norbert

    2015-01-01

    The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) is observing the northern sky since April 2012 for an astrometric survey. Multiple overlaps per year are performed in a single bandpass (680$-$750 nm) using the "redlens" 20 cm aperture astrograph and a mosaic of large CCDs. Besides the regular, deep survey to magnitude 18.5, short exposures with an objective grating are taken to access stars as bright as 3rd magnitude. A brief overview of the program, observing and reductions is given. Positions on the 8 to 20 mas level are obtained of 66,202 Hipparcos stars at current epochs. These are compared to the Hipparcos Catalog to investigate its accuracy. About 20\\% of the observed Hipparcos stars are found to have inconsitent positions with the Hipparcos Catalog prediction on the 3 sigma level or over (about 75 mas or more discrepant position offsets). Some stars are now seen at an arcsec (or 25 sigma) off their Hipparcos Catalog predicted position.

  20. Today LED Holiday Lights, Tomorrow the World?

    SciTech Connect (OSTI)

    Gordon, Kelly L.

    2004-12-20

    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.

  1. Joint Visible Light Communication and Navigation via LEDs

    E-Print Network [OSTI]

    Zheng, Dongfang

    2014-01-01

    modulated automobile LED lightings to estimate the vehiclemodulates the automobile LED lighting - either taillights orpositioning using lighting led and image sensor. In Computer

  2. Getting Ready for LEDs: LED Lighting Video Series Explains the Basics

    Broader source: Energy.gov [DOE]

    A new video series from ElectricTV.net explains the changes and opportunities offered by LED lighting.

  3. Updated Spitzer emission spectroscopy of bright transiting hot...

    Office of Scientific and Technical Information (OSTI)

    Updated Spitzer emission spectroscopy of bright transiting hot Jupiter HD 189733b Citation Details In-Document Search Title: Updated Spitzer emission spectroscopy of bright...

  4. 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...

  5. Demonstration Assessment of LED Freezer Case Lighting

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

    Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case Lighting Host Site: Albertsons Grocery, Eugene, Oregon Final Report prepared in support of the U.S. DOE Solid...

  6. 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....

  7. 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...

  8. All inorganic colloidal quantum dot LEDs

    E-Print Network [OSTI]

    Wood, Vanessa Claire

    2007-01-01

    This thesis presents the first colloidal quantum dot light emitting devices (QD-LEDs) with metal oxide charge transport layers. Colloidally synthesized quantum dots (QDs) have shown promise as the active material in ...

  9. SPECIFYING LED COLOR-TUNABLE PRODUCTS

    Broader source: Energy.gov [DOE]

    Specifying LED color-tunable luminaires is dependent on being able to make accurate comparisons between products. Yet reporting performance values for color-tunable products is much more...

  10. DOE Hosts LED Industry Standards Workshop

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy hosted an LED Industry Standards Workshop on March 1, 2006 in Washington, D.C. The Workshop provided a forum to encourage greater cooperation and coordination among...

  11. LED ADOPTION REPORT | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDF icon Report:

  12. LED MR16 Lamps | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDFLED

  13. LED MR16 Lamps | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDFLEDLED MR16

  14. LED Market Adoption: Status and Trends

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDFLEDLED

  15. LED PAR38 Lamps | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT

  16. LED Roundtable Reports | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORTLEDLED Roundtable

  17. It's 2015: Should All Your Sockets be Filled with LEDs?

    Energy Savers [EERE]

    - mid-power LEDs on PCb used in 2x4 troffers 4 LED Modules and Light Engines GE Infusion Philips Fortimo Osram PrevaLED 5 LEDs: A New Light Source for Everything * Outdoor...

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

    SciTech Connect (OSTI)

    Not Available

    2014-03-01

    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.

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

    Office of Energy Efficiency and Renewable Energy (EERE)

    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.

  20. Pittsburgh LED Street Lighting Research Project Performance Criteria

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  1. 130 LPW 1000 Lm Warm White LED for Illumination

    SciTech Connect (OSTI)

    Soer, Wouter

    2012-06-14

    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.

  2. A Single-phase Rectifier With Ripple-power Decoupling and Application to LED Lighting 

    E-Print Network [OSTI]

    Tian, Bo

    2015-05-12

    In recent years, Light-Emitting-Diode (LED) is widely used in lighting applications for its high efficacy and high reliability. However, the rectifier, which is required by the LEDs to convert the AC power from the grid into DC power, suffers from...

  3. Massive Disks in Low Surface Brightness Galaxies

    E-Print Network [OSTI]

    B. Fuchs

    2002-09-09

    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.

  4. Fusion Energy An Industry-Led Initiative

    E-Print Network [OSTI]

    business not big science InternationalCompetitivenessissue - $26T/yr energy market with $300B/yr futureFusion Energy An Industry-Led Initiative September 10,1993 ATeam Effort TRW General Dynamics;Energy Supply and Needs Global per capita energy usage Global Per Capita energy usage will increase even

  5. LED Lighting in a Performing Arts Building

    SciTech Connect (OSTI)

    Miller, N. J.; Kaye, S. M.; Coleman, P. M.; Wilkerson, A. M.; Perrin, T. E.; Sullivan, G. P.

    2014-07-31

    At the University of Florida in Gainesville, the DOE Solid-State Lighting GATEWAY program evaluated LED architectural and theatrical lighting in four academic/performance-related spaces within the Nadine McGuire Theatre + Dance Pavilion. Due to a wise choice of products and luminaire light distributions, the change brought significant quality improvements including improved controllability and color.

  6. 12RESEARCHERS Western-led creation of

    E-Print Network [OSTI]

    Denham, Graham

    delegation to Brazil, accompanied by Governor General David Johnston, in April 2012 alternative energy Next-generation renewable energy sources from wind, sun and biofuels for a greener world BRAZIL Impact / Reputation globalbrazil #12;BRAZIL Investment 12RESEARCHERS Western-led creation of Canada Visiting Chair

  7. 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.

  8. Bright and dark sides of computational intelligence

    E-Print Network [OSTI]

    Wilamowski, Bogdan Maciej

    Bright and dark sides of computational intelligence Bogdan M. Wilamowski Auburn University positive and negative values and the resulted neuron excitation net is calculated as a sum of products of incoming signals multiplied by weights: xw=net ii n =1i (1) k net out netk-+1 1 =f(net)=out exp Fig. 2

  9. Sustainable LED Fluorescent Light Replacement Technology

    SciTech Connect (OSTI)

    2011-06-30

    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.

  10. Measured Off-Grid LED Lighting System Performance

    E-Print Network [OSTI]

    Granderson, Jessica

    2009-01-01

    4 Measured Off-Grid LED Lighting System Performance Jessicapeople, the quality of LED lighting products remains acomponents of off-grid LED lighting systems (e.g. light

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

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

    To Bridge LEDs' Green Gap, Scientists Think Small To Bridge LEDs' Green Gap, Scientists Think Small Nanostructures Half a DNA Strand-Wide Show Promise for Efficient LEDs April 4,...

  12. LED Performance Specification Series: T8 Replacement Lamps

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

    the better fixture efficiency measured with LED T8s compared to fluorescent. Note that luminous efficacy for the LED T8 is not specified. This is because LED T8 watt- age...

  13. LED Roadway Lighting | 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 on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIALU.S. DepartmentJeanKeyLANL SustainableRoadway Lighting LED

  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

    lights with LEDs is a reduction in power consumption [7]. In addition, incandescent traffic signals burn1 DUAL USE OF LEDS: SIGNALING AND COMMUNICATIONS IN ITS Grantham Pang, Chi-ho Chan, Hugh Liu of light-emitting diodes (LEDs) over incandescent lights is well-supported. This is due to their high

  15. 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.

    1996-03-01

    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.

  16. Which LED Lighting Products Would You Consider Trying?

    Broader source: Energy.gov [DOE]

    Which LED lighting products would you consider trying? Or, if you're already using LEDs, what do you think of them?

  17. (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...

  18. Demonstration of LED Street Lighting in Kansas City, MO Kinzey...

    Office of Scientific and Technical Information (OSTI)

    Street Lighting in Kansas City, MO Kinzey, Bruce R.; Royer, Michael P.; Hadjian, M.; Kauffman, Rick LED streetlighting; field illuminance measurement LED streetlighting; field...

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

    Energy Savers [EERE]

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

  20. 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...

  1. Technical Feasibility Assessment of LED Roadway Lighting on the...

    Office of Scientific and Technical Information (OSTI)

    Technical Feasibility Assessment of LED Roadway Lighting on the Golden Gate Bridge Tuenge, Jason R. LED; induction; ceramic metal halide; plasma; roadway lighting; Golden Gate...

  2. Application Summary Report 22: LED MR16 Lamps

    SciTech Connect (OSTI)

    Royer, Michael P.

    2014-07-23

    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.

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

    SciTech Connect (OSTI)

    2008-09-14

    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. EC-LEDS Transport | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, Alabama (UtilityInstrumentsAreafor GeothermalNorthWorldwideMitigation | OpenEC-LEDS

  5. Category:LEDS Toolkit | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar Energy LLCLtd Jump to: navigation, searchsource History ViewEnFederalLEDS

  6. LED Green Power 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EAInvervar HydroElectric Cooperative(Redirected fromUni Land JV JumpLED

  7. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS Report UrlNM-bRenewableSMUDSectional Modelof the| OpenSemiLEDs Jump

  8. LedEngin 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History ViewInformationWinds Jump to:Laredo RidgeLaymanJersey:LedEngin Inc

  9. Flexible LEDs bring light to fingertips Oct 19, 2010

    E-Print Network [OSTI]

    Rogers, John A.

    Flexible LEDs bring light to fingertips Oct 19, 2010 Glowing gloves Light-emitting diodes ­ or LEDs counterparts, known as holes, are driven into the well where they combine to emit light. LEDs are normally made that is populated with red LEDs. Stitches incorporating these tiny light emitters have been inserted

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

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

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

    epitaxial growth of indium gallium nitride (InGaN) layers capable of producing high-efficiency LEDs when combined with chip-on-board packaging techniques. The proposed...

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

    E-Print Network [OSTI]

    Thompson, Maria do Rosário

    2007-01-01

    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, ...

  13. High Efficiency Driving Electronics for General Illumination LED Luminaires

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article) |different|(Journal(Conference) |

  14. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D. Title: Professor - Research PXHickFrontiers

  15. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-DoseOptionsthroughput spectrometer forInnovationand

  16. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OFAMERICA'SHeavy Electricals Ltd BHEL Jump to:Bottomline EnergyBrightSource

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

    SciTech Connect (OSTI)

    Ted Lowes

    2012-04-08

    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?¥ 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.

  18. 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.

    2013-04-09

    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.

  19. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Part 3: LED Environmental Testing

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street LightingFrom theHighI _s - s iLessonsBUILDING

  20. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, Part 2: LED Manufacturing and Performance

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street LightingFrom theHighI _s - s

  1. 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

    2004-05-16

    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.

  2. Center for Energy Nanoscience at USC

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

    LED Nanowire LEDs GaN based light emitting diodes (LEDs) are a key technology for high brightness LEDs. Although already successful commercially, fundamental physical and device...

  3. 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

  4. Abundance gradients in low surface brightness spirals: clues on the origin of common gradients in galactic discs

    E-Print Network [OSTI]

    Bresolin, Fabio

    2015-01-01

    We acquired spectra of 141 HII regions in ten late-type low surface brightness galaxies (LSBGs). The analysis of the chemical abundances obtained from the nebular emission lines shows that metallicity gradients are a common feature of LSBGs, contrary to previous claims concerning the absence of such gradients in this class of galaxies. The average slope, when expressed in units of the isophotal radius, is found to be significantly shallower in comparison to galaxies of high surface brightness. This result can be attributed to the reduced surface brightness range measured across their discs, when combined with a universal surface mass density-metallicity relation. With a similar argument we explain the common abundance gradient observed in high surface brightness galaxy (HSBG) discs and its approximate dispersion. This conclusion is reinforced by our result that LSBGs share the same common abundance gradient with HSBGs, when the slope is expressed in terms of the exponential disc scale length.

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

    SciTech Connect (OSTI)

    Yu, Tong-Pu Hu, Li-Xiang; Yin, Yan; Shao, Fu-Qiu; Zhuo, Hong-Bin; Ma, Yan-Yun; Yang, Xiao-Hu; Luo, Wen; Pukhov, Alexander

    2014-09-15

    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.

  6. The Search for Cosmological Black Holes: A Surface Brightness Variability Test

    E-Print Network [OSTI]

    Geraint F. Lewis; Rodrigo A. Ibata

    2000-04-04

    Recently it has been suggested that the majority of dark matter in the universe resides in the form of Jupiter mass black holes distributed cosmologically. This population makes itself apparent by microlensing high redshift quasars and introducing pronounced variability into their observed light curves. While several arguments dismissing this hypothesis have been presented, a conclusive observational test is, alas, sadly lacking. In this paper we investigate the effect of a cosmologically distributed population of microlensing masses on galaxies at low to intermediate redshift. The magnification of bright stars in these galaxies leads to small, but observable, fluctuations in their surface brightness. The variability time scale for Jupiter-mass lensing objects is of the order of a few months and this population may be detected through a future space-based monitoring campaign of a field containing $z \\sim 0.5$ galaxies. The monitoring of galactic surface brightness will provide an effective test of the nature of dark matter on cosmological scales.

  7. Regenerative braking on bicycles to power LED safety flashers

    E-Print Network [OSTI]

    Collier, Ian M

    2005-01-01

    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, ...

  8. Model Specification for LED Roadway Luminaires, V2.0

    Office of Energy Efficiency and Renewable Energy (EERE)

    Version 2.0 of the Model Specification for LED Roadway Luminaires is now available. Changes are substantial and include streamlined structure and formatting, new diagrams, updated references, and leveraging of LED Lighting Facts® program guidance.

  9. DOE Publishes GATEWAY Report on LED Lighting in a Performing...

    Energy Savers [EERE]

    LED Lighting in a Performing Arts Setting DOE Publishes GATEWAY Report on LED Lighting in a Performing Arts Setting August 6, 2014 - 2:46pm Addthis The U.S. Department of Energy...

  10. New DOE Report Estimates LED Savings in Common Lighting Applications...

    Energy Savers [EERE]

    New DOE Report Estimates LED Savings in Common Lighting Applications New DOE Report Estimates LED Savings in Common Lighting Applications July 24, 2015 - 11:00am Addthis The U.S....

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

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

    LED Light Pilot Project Illuminates the Way in Alabama This is one of the 100 decorative solar-powered LED lights that replaced natural gas-powered streetlights in the city of...

  12. Seeing the Light: LED Under-Cabinet and Recessed Downlights ...

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

    operating at their optimum energy efficiency. I'm definitely drawn to the light-emitting diode (LED) under-cabinet and recessed downlights-just two of the many LED products....

  13. 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...

  14. Reducing LED Costs Through Innovation | Department of Energy

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

    Reducing LED Costs Through Innovation Reducing LED Costs Through Innovation November 19, 2013 - 3:49pm Addthis A combination solid-state laser turret cutter and stamping machine...

  15. Demonstration Assessment of Light-Emitting Diode (LED) Roadway...

    Office of Scientific and Technical Information (OSTI)

    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....

  16. 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...

  17. 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.

  18. LED Parking Lot Lighting Working Group Fact Sheet

    SciTech Connect (OSTI)

    2008-10-01

    This fact sheet describes the Retailer Energy Alliance LED Parking Lot Lighting Working Group and its Technology Procurement Project.

  19. 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.

  20. 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.

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  2. Demonstration of Light-Emitting Diode (LED) Retrofit Lamps

    SciTech Connect (OSTI)

    Miller, N.

    2011-09-01

    GATEWAY program report on a demonstration of LED retrofit lamps at the Jordan Schnitzer Museum of art in Eugene, OR

  3. Semiconductors 4-bit I2C LED dimmer

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    LEDs to 25 mA · Edge rate control on outputs · No glitch on power-up · Supports hot insertion · LowPhilips Semiconductors PCA9533 4-bit I2C LED dimmer Product data sheet Supersedes data of 2003 Sep 19 2004 Oct 01 INTEGRATED CIRCUITS #12;Philips Semiconductors Product data sheet PCA95334-bit I2C LED

  4. Breakthrough Makes LED Lights More Versatile Author: Andrea Thompson

    E-Print Network [OSTI]

    Rogers, John A.

    Breakthrough Makes LED Lights More Versatile Author: Andrea Thompson Source: http these limitations by combining the best of two worlds of LEDs to make ultrathin, ultrasmall and flexible light-sized inorganic LEDs after a request from Ford Motor Co. to create a third brake light for cars that would

  5. Aalborg Universitet Current-voltage model of LED light sources

    E-Print Network [OSTI]

    Munk-Nielsen, Stig

    Aalborg Universitet Current-voltage model of LED light sources Beczkowski, Szymon; Munk version (APA): Beczkowski, S., & Munk-Nielsen, S. (2012). Current-voltage model of LED light sources from vbn.aau.dk on: juli 06, 2015 #12;Current-voltage model of LED light sources Szymon Bczkowski, Stig

  6. CALiPER Snapshot Report: Indoor LED Luminaires

    SciTech Connect (OSTI)

    2014-04-01

    Snapshot reports use data from DOE's LED Lighting Facts product list to compare the LED performance to standard technologies, and are designed to help lighting retailers, distributors, designers, utilities, energy efficiency program sponsors, and other stakeholders understand the current state of the LED market and its trajectory.

  7. DOE Publishes Report on Color Stability of LED Lighting Products

    Broader source: Energy.gov [DOE]

    DOE has published a new GATEWAY report on color maintenance of LEDs in laboratory and field applications, summarizing color shift data of LED lamps used in real-world applications as well as LED products monitored by the CALiPER program in a lab

  8. Are Low Surface Brightness Discs Young?

    E-Print Network [OSTI]

    Paolo Padoan; Raul Jimenez; Vincenzo Antonuccio-Delogu

    1996-09-12

    We reconsider the problem of the age of the stellar discs of late-type Low Surface Brightness (LSB) galaxies by making use of a new IMF recently derived from numerical fluid dynamical simulations (Padoan, Nordlund and Jones, 1997). While a Miller-Scalo IMF cannot adequately describe the photometric properties of LSBs, when we apply the new Padoan et al. (1997) IMF to a simple exponential disc model with parameters appropriate to LSBs, we get excellent fits of the colors and color gradients. We then conclude that: a) The star formation history of LSB disc galaxies can be described by an initial burst of a few times $10^7$ yr followed by a quiescent period with only sporadic star formation; b) LSBs' discs are not young. The age of the LSB disc galaxies for which colors have been measured are all larger than about 10 Gyr$.

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

    SciTech Connect (OSTI)

    Cerio, Frank

    2013-09-14

    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.

  10. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01

    111 Transverse electron beamfemtosecond relativistic electron beams . . Organization offields of a relativistic electron beam. Phys. Rev. Lett. ,

  11. High Average Brightness Photocathode Development for FEL Applications...

    Office of Scientific and Technical Information (OSTI)

    Laser Conference, FEL 2013; Manhattan, NY; 20130826 through 20130830 Research Org: Brookhaven National Laboratory (BNL) Sponsoring Org: USDOE SC OFFICE OF SCIENCE (SC) Country of...

  12. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01

    Hastings, F. M. Rudakov, D. H. Dowell, J. F. Schmerge, J. D.F. -J. Decker, Y. Ding, D. Dowell, P. Emma, J. Frisch, Z.Brachmann, F. -J. Decker, D. Dowell, P. Emma, J. Frisch, S.

  13. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01

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

  14. Phosphorescent organic light emitting diodes with high efficiency and brightness

    DOE Patents [OSTI]

    Forrest, Stephen R; Zhang, Yifan

    2015-11-12

    An organic light emitting device including a) an anode; b) a cathode; and c) an emissive layer disposed between the anode and the cathode, the emissive layer comprising an organic host compound and a phosphorescent compound exhibiting a Stokes Shift overlap greater than 0.3 eV. The organic light emitting device may further include a hole transport layer disposed between the emissive layer and the anode; and an electron transport layer disposed between the emissive layer and the cathode. In some embodiments, the phosphorescent compound exhibits a phosphorescent lifetime of less than 10 .mu.s. In some embodiments, the concentration of the phosphorescent compound ranges from 0.5 wt. % to 10 wt. %.

  15. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01

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

  16. High Average Brightness Photocathode Development for FEL Applications

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article) |different|(Journal

  17. High Average Brightness Photocathode Development for FEL Applications

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article) |different|(Journal(Conference) | SciTech

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

    SciTech Connect (OSTI)

    Tracy, Jenny; Jacobson, Arne; Mills, Evan

    2009-09-14

    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).

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

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDF iconLED

  20. Semiconductor nanowires: from LEDs to Solar Cells | MIT-Harvard...

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

    Semiconductor nanowires: from LEDs to Solar Cells May 4, 2010 at 3pm36-428 Silvija Gradeak Laboratory for Nanophotonics and Electronics, Massachusetts Institute of Technology...

  1. Demonstration Assessment of Light-Emitting Diode (LED) Street...

    Office of Scientific and Technical Information (OSTI)

    Street Lighting Host Site: Lija Loop, Portland, Oregon Citation Details In-Document Search Title: Demonstration Assessment of Light-Emitting Diode (LED) Street Lighting Host Site:...

  2. 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...

  3. Color Maintenance of LEDs in Laboratory and Field Applications...

    Office of Scientific and Technical Information (OSTI)

    Royer, Michael P.; Tuttle, Ralph; Rosenfeld, Scott M.; Miller, Naomi J. Light-emitting diode (LED), color shift, color stability, color maintenance, warranty Light-emitting...

  4. Application Assessment of Bi-Level LED Parking Lot Lighting

    SciTech Connect (OSTI)

    None

    2009-02-01

    This report summarizes an assessment project conducted to evaluate light-emitting diode (LED) luminaires with bi-level operation in an outdoor parking lot application.

  5. 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...

  6. REA Refrigerated Display Case LED Lighting Performance Specification...

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

    Retailer Energy Alliances (REA) Project rearefrigdisplayspec.pdf More Documents & Publications CBEA LED Site Lighting Specification - Version 1.3, Released 2152012 Model...

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

    Office of Energy Efficiency and Renewable Energy (EERE)

    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.

  8. Purchasing Energy-Efficient Commercial and Industrial LED Luminaires

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for commercial and industrial light emitting diode (LED) luminaires, a product category covered by FEMP efficiency...

  9. Lighting for Health: LEDs in the New Age of Illumination

    SciTech Connect (OSTI)

    2014-05-01

    DOE Solid-State Lighting program technology fact sheet that provides background on current science and considerations related to LED light and health.

  10. 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)

    2014-02-20

    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.

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

    SciTech Connect (OSTI)

    Tuenge, Jason R.

    2011-12-01

    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.

  12. CALiPER Report 21.3. Cost Effectiveness of Linear (T8) LED Lamps

    SciTech Connect (OSTI)

    2014-05-01

    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.

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

    SciTech Connect (OSTI)

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

    2014-05-27

    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.

  14. 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

    2000-11-20

    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.

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

    E-Print Network [OSTI]

    B. Fuchs

    2002-04-23

    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.

  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. ECE 466: LED Lighting Systems -Incandescent lightings rise and

    E-Print Network [OSTI]

    Connors, Daniel A.

    ECE 466: LED Lighting Systems - Incandescent lightings rise and demise via government policy - Alternative Fluorescent light sources and compact fluorescent lights (CFL) to incandescents - Alternative LED light sources - Color index as well as Watts to Lumens efficiency available from all three light sources

  18. Appraisers Project Plan: Wireless Controls and Retrofit LED Lighting Demonstration

    Broader source: Energy.gov [DOE]

    Appraisers Project Plan: Wireless Controls and Retrofit LED Lighting Demonstration Measurement and Verification Report This report details the measurement and verification tools and methods used to evaluate the effectiveness of wireless lighting controls and LED lighting at the Appraisers Building, a federal office building in San Francisco, CA.

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

    SciTech Connect (OSTI)

    Ian Ferguson; Chris Summers

    2009-12-31

    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.

  20. The Effect of Acute Bright Light Exposure on Social Affiliation

    E-Print Network [OSTI]

    Botanov, Yevgeny

    2014-08-31

    In recent decades, bright light has emerged as a useful tool in numerous clinical and non-clinical applications, with the potential to influence circadian rhythms, sleep, mood, and several other functional domains. However, ...

  1. Induction effects for heterochromatic brightness matching, heterochromatic flicker photometry,

    E-Print Network [OSTI]

    Dobkins, Karen R.

    Induction effects for heterochromatic brightness matching, heterochromatic flicker photometry flicker photometry (HFP), and minimally distinct border (MDB). For HBM, subjects varied the relative compared with those obtained on two other tasks: hetero- chromatic flicker photometry (HFP) and minimally

  2. Infrared Brightness Temperature of Mars, 1983-2103

    E-Print Network [OSTI]

    E. L. Wright

    2007-03-25

    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.

  3. Bright Transients from Black Hole - Neutron Star Mergers

    E-Print Network [OSTI]

    D'Orazio, Daniel J; Murray, Norman W; Price, Larry

    2016-01-01

    Direct detection of black hole-neutron star (BHNS) pairs is anticipated with the advent of aLIGO. Electromagnetic counterparts may be crucial for a confident gravitational-wave detection as well as for extraction of astronomical information. Yet BHNS star pairs are notoriously dark and so inaccessible to telescopes. Contrary to this expectation, a bright electromagnetic transient can occur in the final moments before merger as long as the neutron star is highly magnetized. The orbital motion of the neutron star magnet creates a Faraday flux and corresponding power available for luminosity. A spectrum of curvature radiation ramps up until the rapid injection of energy ignites a fireball, which would appear as an energetic blackbody peaking in the X-ray to gamma-rays for neutron star field strengths ranging from $10^{12}$G to $10^{16}$G respectively and a $10M_{\\odot}$ black hole. The fireball event may last from a few milliseconds to a few seconds depending on the NS magnetic field strength, and may be observa...

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

    E-Print Network [OSTI]

    Tracy, Jenny

    2010-01-01

    2008. "Measured Off? Grid LED Lighting System Performance."early manifestation of LED lighting in the developing worldfor off-grid lighting products based on LED technology (

  5. University of Nevada Las Vegas LED Display Engineering

    SciTech Connect (OSTI)

    None

    2010-08-31

    The primary objective of this part of the project is to develop and implement a method that compensates for the inefficiency of the green LED. The proposed engineering solution which will be the backbone of this project will be to use RGBW combination in every pixel to save energy. Two different RGBW geometrical pixel configurations will be implemented and compared against traditional LED configurations. These configurations will be analyzed for energy efficiency while keeping the quality of the display the same. Cost of the addition of white LEDs to displays along with energy cost savings will be presented and analyzed.

  6. National Consortium Supports Cities in Evaluating LED Streetlights

    SciTech Connect (OSTI)

    2013-09-30

    Fact sheet that introduces Municipal Solid-State Street Lighting Consortium, a group of municipalities, utilities, and energy efficiency organizations who are interested in making investments in LED street and area lighting.

  7. LED Watch: Unlocking the Full Potential of Indoor Systems | Department...

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

    Systems june2015ledwatch.pdf More Documents & Publications 2015 ARTICLES What's Next for Solid-State Lighting - February 2015 LED Watch: NGL Tells Us the State of Solid-State...

  8. Demonstration Assessment of Light-Emitting Diode (LED) Accent...

    Office of Scientific and Technical Information (OSTI)

    Accent Lighting at the Field Museum in Chicago, IL Citation Details In-Document Search Title: Demonstration Assessment of Light-Emitting Diode (LED) Accent Lighting at the Field...

  9. Demonstration Assessment of Light-Emitting Diode (LED) Parking...

    Office of Scientific and Technical Information (OSTI)

    Search Title: Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting at T.J.Maxx in Manchester, NH Phase I A report describing the process and results of...

  10. Laboratory Evaluation of LED T8 Replacement Lamp Products

    SciTech Connect (OSTI)

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

    2011-05-23

    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.

  11. Implementing and Sustaining Operator Led Energy Efficiency Improvements 

    E-Print Network [OSTI]

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

    2011-01-01

    , 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...

  12. Department of Defense led Institutes for Manufacturing Innovation

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

    within 5-7 years 5 DoE and DoD-led Institutes * Established Institutes: - America Makes (Additive Manufacturing)-Established Aug 2012 DoD - Next Gen. Power Electronics Manuf....

  13. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting

    SciTech Connect (OSTI)

    None

    2009-11-01

    A U.S. Department of Energy Solid-State Lighting Gateway Report on a Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting in Lija Loop, Portland, Oregon.

  14. Energy - LEDs to light UT arena | ornl.gov

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

    to 85 percent more efficient than conventional arena metal halide lights. The light-emitting diode fixtures developed by Oak Ridge-based LED North America incorporate an Oak...

  15. 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...

  16. Better than CFL? Dimmable LED Downlights in Hospitality Facilities Webinar

    Broader source: Energy.gov [DOE]

    LEDs represent less than 1% of the installed base of U.S. downlights, which in 2012 numbered about 700 million. In hospitality facilities, past efforts to reduce lighting energy use have mainly...

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

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

    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...

  18. 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...

  19. Measured Off-Grid LED Lighting System Performance

    E-Print Network [OSTI]

    Granderson, Jessica

    2009-01-01

    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

  20. LED LUMINAIRE LIFETIME: Recommendations for Testing and Reporting |

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDF

  1. LED Lights for All Occasions | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDFLED Lights for

  2. LED Luminaire Lifetime: Recommendations for Testing and Reporting

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORT PDFLED Lights

  3. LED Performance Under Tough Conditions | Department of Energy

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORTLED Performance

  4. Millimeter Wavelength Brightness Fluctuations of the Atmosphere Above the South Pole

    E-Print Network [OSTI]

    Bussmann, R S; Kuo, C L

    2004-01-01

    We report measurements of the millimeter wavelength brightness fluctuations produced by the atmosphere above the South Pole made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The data span the 2002 Austral winter during which ACBAR was mounted on the Viper telescope at the South Pole. We recover the atmospheric signal in the presence of instrument noise by calculating the correlation between signals from distinct elements of the ACBAR bolometer array. With this method, it is possible to measure atmospheric brightness fluctuations with high SNR even under the most stable atmospheric conditions. The observed atmospheric signal is characterized by the parameters of the Komolgorov-Taylor (KT) model, which are the amplitude and power law exponent describing the atmospheric power spectrum, and the two components of the wind angular velocity at the time of the observation. The KT model is typically a good description of the observed fluctuations, and fits to the data produce values of the Komolgorov...

  5. Bright, Coherent, Ultrafast Soft X-Ray Harmonics Spanning the Water Window from a Tabletop Light Source

    E-Print Network [OSTI]

    M. C. Chen; P. Arpin; T. Popmintchev; M. Gerrity; B. Zhang; M. Seaberg; M. M. Murnane; H. C. Kapteyn

    2010-06-20

    We demonstrate fully phase matched high-order harmonic generation with emission spanning the water window spectral region important for bio- and nano-imaging and a breadth of materials and molecular dynamics studies. We also generate the broadest bright coherent bandwidth (~300eV) to date obtained from any light source, small or large. The harmonic photon flux at 0.5 keV is 10^3 higher than demonstrated previously, making it possible for the first time to demonstrate spatial coherence in the water window. The continuum emission is consistent with a single attosecond burst, that extends bright attosecond pulses into the soft x-ray region.

  6. Generation of Dark and Bright Spin Wave Envelope Soliton Trains through Self-Modulational Instability in Magnetic Films

    E-Print Network [OSTI]

    Patton, Carl

    Generation of Dark and Bright Spin Wave Envelope Soliton Trains through Self-Modulational spin wave envelope soliton trains from a continuous wave input signal due to spontaneous modulational instability has been observed for the first time. The dark soliton trains were formed from high dispersion

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

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

    Diode Testing Lead Performer: KLA-Tencor Corporation - Milpitas, CA Partners: Ocean Optics - Dunedin, FL DOE Total Funding: 3,994,729 Cost Share: 4,626,422 Project Term: 815...

  8. Origin of the bright prompt optical emission in the naked eye burst

    SciTech Connect (OSTI)

    Hascoeet, R.; Daigne, F.; Mochkovitch, R.

    2010-10-15

    The huge optical brightness of GRB 080319B (the 'Naked Eye Burst') makes this event really challenging for models of the prompt GRB emission. In the framework of the internal shock model, we investigate a scenario where the dominant radiative process is synchrotron emission and the high optical flux is due to the dynamical properties of the relativistic outflow : if the initial Lorentz factor distribution in the jet is highly variable, many internal shocks will form within the outflow at various radii. The most violent shocks will produce the main gamma-ray component while the less violent ones will contribute at lower energy, including the optical range.

  9. LED Lighting: Applying Lessons Learned from the CFL Experience

    SciTech Connect (OSTI)

    McCullough, Jeffrey J.; Gilbride, Theresa L.; Gordon, Kelly L.; Ledbetter, Marc R.; Sandahl, Linda J.; Ton, My K.

    2008-08-20

    Light emitting diode (LED) technology has emerged as an exciting new lighting alternative with the potential for significant energy savings. There is concern, however, that white light LEDs for general illumination could take a long, bumpy course similar to another energy-efficient lighting technology – compact fluorescent lights (CFLs). Recognizing the significant potential energy-efficient lighting has to reduce U.S. energy consumption, Congress mandated in the Energy Policy Act of 2005 that the U.S. Department of Energy (DOE) develop Solid State Lighting (SSL) through a Next Generation Lighting Initiative. DOE’s first step was to analyze the market introduction of compact fluorescent lighting to determine what lessons could be learned to smooth the introduction of SSL in the United States (Sandahl et al. 2006). This paper summarizes applicable lessons learned from the market introduction of CFLs and describe how DOE and others are applying those lessons to speed the development and market introduction of energy-efficient LED lighting for general illumination applications. A description of the current state of LED technology and compares LEDs to incandescent, fluorescent, and halogen lights is also provided.

  10. Night-sky brightness monitoring in Hong Kong - a city-wide light pollution assessment

    E-Print Network [OSTI]

    Pun, Chun Shing Jason

    2011-01-01

    Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe - the urban night-skies (sky brightness at 15.0 mag per arcsec square) are on average ~100 times brighter than at the darkest rural sites (20.1 mag per arcsec square), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag per arcsec square can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by hu...

  11. New bright optical spectrophotometric standards: A-type stars from the STIS Next Generation Spectral Library

    E-Print Network [OSTI]

    Prieto, Carlos Allende

    2015-01-01

    Exoplanets have sparked interest in extremely high signal-to-noise ratio spectroscopic observations of very bright stars, in a regime where flux calibrators, in particular DA white dwarfs, are not available. We argue that A-type stars offer a useful alternative and reliable space-based spectrophotometry is now available for a number of bright ones in the range 3model fluxes, we identify 18 new very-bright trustworthy A-type flux standards for the optical range (400-800 nm), and provide scaled model fluxes for them. Our tests suggest that the absolute fluxes for these stars in the optical are reliable to within 3%. We limit the spectral range to 400-800 nm, since our models have difficulties to reproduce the observed fluxes in the near-infrared and, especially, in the near-UV, where the discrepancies rise up to ~ 10%. Based on our model fits, we derive angular diameters with an estimated accuracy of about 1%.

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

    SciTech Connect (OSTI)

    McKittrick, Joanna

    2013-09-30

    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.

  13. Tests gauge LED sensors for fuel-dye measurements

    SciTech Connect (OSTI)

    Ozanich, Richard M.; Lucke, Richard B.; Melville, Angela M.; Wright, Bob W.

    2009-10-19

    The goal of this work was to develop a low cost, robust sensor to allow direct measurement of Solvent Red 164 dye concentration in off-road fuel at refineries and fuel terminals. Optical absorption sensors based on light emitting diodes (LEDs) are rugged, low-cost, have low power consumption, and can be designed to be intrinsically safe.LED-based systems have been used in a variety of chemical detection applications including heavy metals, pH, CO2, and O2. The approach for this work was to develop a sensor that could be mounted on a pipeline sight glass, precluding the need for direct contact of the sensor with the fuel. Below is described the design and testing of three different LED/photodiode sensors utilizing reflectance spectrometry for the measurement of dye concentration.

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

    SciTech Connect (OSTI)

    Sandra Schujman; Leo Schowalter

    2010-10-15

    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.

  15. A Bright Year for Tidal Disruptions?

    E-Print Network [OSTI]

    Metzger, Brian D

    2015-01-01

    When a star is tidally disrupted by a supermassive black hole (BH), roughly half of its mass falls back to the BH at super-Eddington rates. Being tenuously gravitationally bound and unable to cool radiatively, only a small fraction f_in few 1e4 K, converting the emission to optical/near-UV wavelengths where photons more readily escape due to the lower opacity. This can explain the unexpectedly low and temporally constant effective temperatures of optically-discovered TDE flares. For BHs with relatively high masses M_BH > 1e7 M_sun the ejecta can become ionized at an earlier stage, or for a wider range of viewing angles, producing a TDE flare which is instead dominated by thermal X-ray emission. We predict total radiated energies consistent with those of observed TDE flares, and ejecta velocities that agree with the measured emission line widths. The peak optical luminosity for M_BH wind, possibly contributing to the unexpected dearth of o...

  16. 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

    2011-01-01

    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.

  17. The Future Looks Bright for Teraflop Computing

    SciTech Connect (OSTI)

    Farber, Rob

    2007-11-01

    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.

  18. ASPE -Instructor Led Class Vendor Item ID Class Cost

    E-Print Network [OSTI]

    Dennis, Robert G.

    ASPE - Instructor Led Class Vendor Item ID Class Cost 26500 Data Modeling - Onsite Session for up Day Course 1,871.00$ #12;ASPE - Virtual Class Vendor Item ID Class Cost 26500V Data Modeling - Onsite Session for up to 20 Students 9,500.00$ 26500PV Data Modeling - Public Course (price per student) 1

  19. Nanoscale LEDs DOI: 10.1002/smll.200600628

    E-Print Network [OSTI]

    Odom, Teri W.

    of macroscale organic light-emitting diodes (OLEDs) for full-color dis- plays have created interestNanoscale LEDs DOI: 10.1002/smll.200600628 Addressable, Large-Area Nanoscale Organic Light in generating OLEDs at the nanoscale.[1,2] Reducing the size of an OLED can produce higher device densities per

  20. 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.

    2014-09-30

    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.

  1. Prognostication of LED Remaining Useful Life and Color Stability in the Presence of Contamination

    SciTech Connect (OSTI)

    Lall, Pradeep; Zang, Hao; Davis, J Lynn

    2015-06-22

    The reliability of LED products may be affected by both luminous flux drop and color shift. Previous research on the topic focuses on either luminous maintenance or color shift. However, luminous flux degradation usually takes very long time to observe in LEDs under normal operating conditions. In this paper, the impact of a VOC (volatile organic compound) contaminated luminous flux and color stability are examined. As a result, both luminous degradation and color shift had been recorded in a short time. Test samples are white, phosphorconverted, high-power LED packages. Absolute radiant flux is measured with integrating sphere system to calculate the luminous flux. Luminous flux degradation and color shift distance were plotted versus aging time to show the degradation pattern. A prognostic health management (PHM) method based on the state variables and state estimator have been proposed in this paper. In this PHM framework, unscented kalman filter (UKF) was deployed as the carrier of all states. During the estimation process, third order dynamic transfer function was used to implement the PHM framework. Both of the luminous flux and color shift distance have been used as the state variable with the same PHM framework to exam the robustness of the method. Predicted remaining useful life is calculated at every measurement point to compare with the tested remaining useful life. The result shows that state estimator can be used as the method for the PHM of LED degradation with respect to both luminous flux and color shift distance. The prediction of remaining useful life of LED package, made by the states estimator and data driven approach, falls in the acceptable errorbounds (20%) after a short training of the estimator.

  2. 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

  3. 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)

    2013-09-15

    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.

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

    E-Print Network [OSTI]

    Johnstone, Peter

    2009-01-01

    of fuel-based and LED lighting technology for business useSelf-reported Impacts of LED Lighting Technology Compared tocost-of- ownership of LED lighting products are an important

  5. 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.

  6. LEDS Collaboration in Action Workshop Participant Pack | Open Energy

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: EnergyKulpsville, Pennsylvania: Energy Resources JumpInformation LEDS

  7. SPECIFYING LED COLOR-TUNABLE PRODUCTS | 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 on Delicious RankADVANCED MANUFACTURINGEnergy BillsNo. 195 -Rob Robertseere.energy.govFreedom of InformationSPECIFYING LED

  8. Model Specification for LED Roadway Luminaires | 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 on Delicious RankADVANCED MANUFACTURING OFFICESpecialAPPENDIX F Wetlandsof Energy Model Repair SpecificationsLED

  9. 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 Data Center Home Page on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIALU.S. DepartmentJeanKeyLANL Sustainable Designlightbulbs -LED

  10. Current crowding in GaInN / GaN LEDs grown on insulating substrates X. Guo, E. F. Schubert and J. Jahns

    E-Print Network [OSTI]

    Jahns, Jürgen

    Current crowding in GaInN / GaN LEDs grown on insulating substrates X. Guo, E. F. Schubert and J. Jahns Current crowding in mesa-structure GaInN/GaN light-emitting diodes (LEDs) grown on insulating and a saturation of the optical output power at high injection currents. It is shown that the optical power

  11. Bright Skies Ahead for Moapa | 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 on Delicious Rank EERE:FinancingPetroleum Based Fuels ResearchofDerivative Classifiers Should KnowLandfillBright Skies

  12. Characterising and Testing Deep UV LEDs for Use in Space Applications

    E-Print Network [OSTI]

    Hollington, D; Sumner, T J; Wass, P J

    2015-01-01

    Deep ultraviolet (DUV) light sources are used to neutralise isolated test masses in highly sensitive space-based gravitational experiments. An example is the LISA Pathfinder charge management system, which uses low-pressure mercury lamps. A future gravitational-wave observatory such as eLISA will use UV light-emitting diodes (UV LEDs), which offer numerous advantages over traditional discharge lamps. Such devices have limited space heritage but are are now available from a number of commercial suppliers. Here we report on a test campaign that was carried out to quantify the general properties of three types of commercially available UV LEDs and demonstrate their suitability for use in space. Testing included general electrical and UV output measurements, spectral stability, pulsed performance, temperature dependence as well as thermal vacuum, radiation and vibration survivability.

  13. Use of Occupancy Sensors in LED Parking Lot and Garage Applications...

    Office of Scientific and Technical Information (OSTI)

    Experiences Kinzey, Bruce R.; Myer, Michael; Royer, Michael P.; Sullivan, Greg P. LED lighting; parking lot lighting; occupancy sensors LED lighting; parking lot lighting;...

  14. LED Watch: NGL Tells Us the State of Solid-State | Department...

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

    & Publications LED Watch: A Specifier's Guide to Color-Tunable Lighting LED Watch: The Outlook for OLEDs May 2015 Postings Advanced Manufacturing Home Key Activities Research &...

  15. 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...

  16. 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)

    2014-05-15

    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.

  17. vol. 181, no. 5 the american naturalist may 2013 Warning Signal Brightness Variation: Sexual Selection

    E-Print Network [OSTI]

    Cummings, Molly E.

    and females are exceptionally bright, this population is also sexually dimorphic in terms of aposemvol. 181, no. 5 the american naturalist may 2013 E-Note Warning Signal Brightness Variation: Sexual) and conspecifics but not to the presumed major predator (birds). This study thus suggests that signal brightness

  18. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Part 3: LED Environmental Testing

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTIONto Commercialization |BUILDING TECHNOLOGIES

  19. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, Part 2: LED Manufacturing and Performance

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTIONto Commercialization |BUILDING

  20. 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

    2012-02-14

    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.

  1. A bright on-demand source of indistinguishable single photons at telecom wavelengths

    E-Print Network [OSTI]

    Kim, Je-Hyung; Richardson, Christopher J K; Leavitt, Richard P; Waks, Edo

    2015-01-01

    Long-distance quantum communication relies on the ability to efficiently generate and prepare single photons at telecom wavelengths. In many applications these photons must also be indistinguishable such that they exhibit interference on a beamsplitter, which implements effective photon-photon interactions. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem. We demonstrate a telecom wavelength source of indistinguishable single photons using an InAs/InP quantum dot in a nanophotonic cavity. The cavity enhances the quantum dot emission, resulting in a nearly Gaussian transverse mode profile with high out-coupling efficiency exceeding 46%, leading to detected photon count rates that would exceed 1.5 million counts per second. We also observe Purcell enhanced spontaneous emission rate as large as 4. Using this source, we generate linearly polarized, high purity single photons at telecom-wavelength and demonstrate the indistinguishable nature o...

  2. A SOUTHERN SKY AND GALACTIC PLANE SURVEY FOR BRIGHT KUIPER BELT OBJECTS

    SciTech Connect (OSTI)

    Sheppard, Scott S.; Udalski, Andrzej; Kubiak, Marcin; Pietrzynski, Grzegorz; Poleski, Radoslaw; Soszynski, Igor; Szymanski, Michal K.; Ulaczyk, Krzysztof; Trujillo, Chadwick

    2011-10-15

    About 2500 deg{sup 2} of sky south of declination -25{sup 0} and/or near the Galactic Plane were surveyed for bright outer solar system objects. This survey is one of the first large-scale southern sky and Galactic Plane surveys to detect dwarf planets and other bright Kuiper Belt Objects in the trans-Neptunian region. The survey was able to obtain a limiting R-band magnitude of 21.6. In all, 18 outer solar system objects were detected, including Pluto which was detected near the Galactic center using optimal image subtraction techniques to remove the high stellar density background. Fourteen of the detections were previously unknown trans-Neptunian objects, demonstrating that the southern sky had not been well searched to date for bright outer solar system objects. Assuming moderate albedos, several of the new discoveries from this survey could be in hydrostatic equilibrium and thus could be considered dwarf planets. Combining this survey with previous surveys from the northern hemisphere suggests that the Kuiper Belt is nearly complete to around 21st magnitude in the R band. All the main dynamical classes in the Kuiper Belt are occupied by at least one dwarf-planet-sized object. The 3:2 Neptune resonance, which is the innermost well-populated Neptune resonance, has several large objects while the main outer Neptune resonances such as the 5:3, 7:4, 2:1, and 5:2 do not appear to have any large objects. This indicates that the outer resonances are either significantly depleted in objects relative to the 3:2 resonance or have a significantly different assortment of objects than the 3:2 resonance. For the largest objects (H < 4.5 mag), the scattered disk population appears to have a few times more objects than the main Kuiper Belt (MKB) population, while the Sedna population could be several times more than that of the MKB.

  3. LEDS Collaboration in Action Workshop Agenda | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: EnergyKulpsville, Pennsylvania: Energy Resources Jump to:Kyle,LACLED Exit SignsLEDS

  4. LEDSGP/about/Asia LEDS Partnership | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: EnergyKulpsville, Pennsylvania:LEDSGP/about < LEDSGP(RedirectedAsia LEDS

  5. List of LED Exit Signs Incentives | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas:Montezuma, Arizona:Oregon: Energy ResourcesGrove, Iowa:Lisle, Illinois:List of LED

  6. Costa Rica-LEDS Tier I Activities | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar EnergyLawler,CoalConcordiaConsumerLEDS Tier I Activities Jump to: navigation,

  7. Kenya-LEDS Tier I Activities | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EAInvervar Hydro JumpHuariKeewatin PublicInformationLEDS Tier I

  8. Category:LEDS Global Partnership Tools | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank,CammackFLIR Jump to: navigation,Ground Gravity SurveyIsotopic Analysis-LEDS

  9. DOE Publishes GATEWAY Report on Portland's LED Streetlight Conversion |

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i pStateDOE FederalThe Department ofFederalLED LuminairesDepartment

  10. DOE Publishes GATEWAY Report on Successful LED Wall Washer Retrofit |

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i pStateDOE FederalThe Department ofFederalLED

  11. 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 Data Center Home Page on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIALU.S. DepartmentJeanKeyLANL SustainableRoadway LightingLEDs: The

  12. EECBG Success Story: LEDs Ready for Takeoff at Louisiana Airport |

    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 on Delicious Rank EERE:FinancingPetroleum Based|Department of EnergyDepartment ofDepartment of Energy LEDs Ready

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

    DOE Patents [OSTI]

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

    2013-09-24

    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.

  14. 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

  15. PPPL: Great story, Bright Future | Princeton Plasma Physics Lab

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access| Department ofStephen P riceawards |PPPL: Great story, Bright

  16. The Future is bright for Y-12 Â… and diverse

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab) 2016TheTheFuture is bright for Y-12

  17. 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.

    2004-01-01

    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...

  18. IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 53, NO. 3, MARCH 2006 427 White LED Based on Polyfluorene Co-Polymers

    E-Print Network [OSTI]

    Kanicki, Jerzy

    -layer organic LEDs (OLEDs) can be used as a plane light source for current large-area liquid-crystal display to generate the white light [5]. In 1999, Deshpande et al. also demonstrated a white light emitting OLED Member, IEEE Abstract--We report on high-performance, white light emission from polyfluorene co

  19. Overview of Recent Progres on High Repetition Rate, High Brightness Electron Guns

    E-Print Network [OSTI]

    Sannibale, F.

    2014-01-01

    Ceramic DC Electron Gun for the Jefferson Laboratory FEL.ALICE (ERLP) DC Photoinjector Gun Commissioning, Proc. ofa 500-kV Photo- cathode DC Gun for the ERL Light Sources in

  20. Statistical Properties of Bright Galaxies in the SDSS Photometric System

    E-Print Network [OSTI]

    Shimasaku, K; Doi, M; Hamabe, M; Ichikawa, T; Okamura, S; Sekiguchi, M; Yasuda, N

    2001-01-01

    We investigate the photometric properties of 456 bright galaxies using imaging data recorded during the commissioning phase of the Sloan Digital Sky Survey (SDSS). Morphological classification is carried out by correlating results of several human classifiers. Our purpose is to examine the statistical properties of color indices, scale lengths, and concentration indices as functions of morphology for the SDSS photometric system. We find that $u'-g'$, $g'-r'$, and $r'-i'$ colors of SDSS galaxies match well with those expected from the synthetic calculation of spectroscopic energy distribution of template galaxies and with those transformed from $UBVR_CI_C$ color data of nearby galaxies. The agreement is somewhat poor, however, for $i'-z'$ color band with a discrepancy of $0.1-0.2$ mag. With the aid of the relation between surface brightness and radius obtained by Kent (1985), we estimate the averages of the effective radius of early type galaxies and the scale length of exponential disks both to be 2.6 kpc for...

  1. An Insurance-Led Response to Climate Change

    E-Print Network [OSTI]

    Webster, Anthony J

    2015-01-01

    Climate change is widely expected to increase weather related damage and the insurance claims that result from it. This has the undesirable consequence of increasing insurance costs, in a way that is independent of a customer's contribution to the causes of climate change. This is unfortunate because insurance provides a financial mechanism that mitigates some of the consequences of climate change, allowing damage from increasingly frequent events to be repaired. We observe that the insurance industry could reclaim any increase in claims due to climate change, by increasing the insurance premiums on energy producers for example, without needing government intervention or a new tax. We argue that this insurance-led levy must acknowledge both present carbon emissions and a modern industry's carbon inheritance, that is, to recognise that fossil-fuel driven industrial growth has provided the innovations and conditions needed for modern civilisation to exist and develop. The increases in premiums would initially b...

  2. 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)

    2014-02-15

    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.

  3. 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

    2011-01-01

    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

  4. Suppression of fiber modal noise induced radial velocity errors for bright emission-line calibration sources

    SciTech Connect (OSTI)

    Mahadevan, Suvrath; Halverson, Samuel; Ramsey, Lawrence; Venditti, Nick

    2014-05-01

    Modal noise in optical fibers imposes limits on the signal-to-noise ratio (S/N) and velocity precision achievable with the next generation of astronomical spectrographs. This is an increasingly pressing problem for precision radial velocity spectrographs in the near-infrared (NIR) and optical that require both high stability of the observed line profiles and high S/N. Many of these spectrographs plan to use highly coherent emission-line calibration sources like laser frequency combs and Fabry-Perot etalons to achieve precision sufficient to detect terrestrial-mass planets. These high-precision calibration sources often use single-mode fibers or highly coherent sources. Coupling light from single-mode fibers to multi-mode fibers leads to only a very low number of modes being excited, thereby exacerbating the modal noise measured by the spectrograph. We present a commercial off-the-shelf solution that significantly mitigates modal noise at all optical and NIR wavelengths, and which can be applied to spectrograph calibration systems. Our solution uses an integrating sphere in conjunction with a diffuser that is moved rapidly using electrostrictive polymers, and is generally superior to most tested forms of mechanical fiber agitation. We demonstrate a high level of modal noise reduction with a narrow bandwidth 1550 nm laser. Our relatively inexpensive solution immediately enables spectrographs to take advantage of the innate precision of bright state-of-the art calibration sources by removing a major source of systematic noise.

  5. Hacking commercial quantum cryptography systems by tailored bright illumination

    E-Print Network [OSTI]

    Lydersen, Lars; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Makarov, Vadim; 10.1038/NPHOTON.2010.214

    2010-01-01

    The peculiar properties of quantum mechanics allow two remote parties to grow a private, secret key, even if the eavesdropper can do anything permitted by the laws of nature. In quantum key distribution (QKD) the parties exchange non-orthogonal or entangled quantum states to generate quantum correlated classical data. Consequently, QKD implementations always rely on detectors to measure the relevant quantum property of the signal states. However, practical detectors are not only sensitive to quantum states. Here we show how an eavesdropper can exploit such deviations from the ideal behaviour: We demonstrate experimentally how the detectors in two commercially available QKD systems can be fully remote controlled using specially tailored bright illumination. This makes it possible to acquire the full secret key without leaving any trace; we propose an eavesdropping apparatus built of off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photo diodes (APDs) to detect ...

  6. Hacking commercial quantum cryptography systems by tailored bright illumination

    E-Print Network [OSTI]

    Lars Lydersen; Carlos Wiechers; Christoffer Wittmann; Dominique Elser; Johannes Skaar; Vadim Makarov

    2011-03-04

    The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built of off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.

  7. Prediction of Lumen Output and Chromaticity Shift in LEDs Using Kalman Filter and Extended Kalman Filter Based Models

    SciTech Connect (OSTI)

    Lall, Pradeep; Wei, Junchao; Davis, J Lynn

    2014-06-24

    Abstract— Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. Life prediction of L70 life for the LEDs used in SSL luminaires from KF and EKF based models have been compared with the TM-21 model predictions and experimental data.

  8. Statistical Properties of Bright Galaxies in the SDSS Photometric System

    E-Print Network [OSTI]

    K. Shimasaku; M. Fukugita; M. Doi; M. Hamabe; T. Ichikawa; S. Okamura; M. Sekiguchi; N. Yasuda

    2001-05-23

    We investigate the photometric properties of 456 bright galaxies using imaging data recorded during the commissioning phase of the Sloan Digital Sky Survey (SDSS). Morphological classification is carried out by correlating results of several human classifiers. Our purpose is to examine the statistical properties of color indices, scale lengths, and concentration indices as functions of morphology for the SDSS photometric system. We find that $u'-g'$, $g'-r'$, and $r'-i'$ colors of SDSS galaxies match well with those expected from the synthetic calculation of spectroscopic energy distribution of template galaxies and with those transformed from $UBVR_CI_C$ color data of nearby galaxies. The agreement is somewhat poor, however, for $i'-z'$ color band with a discrepancy of $0.1-0.2$ mag. With the aid of the relation between surface brightness and radius obtained by Kent (1985), we estimate the averages of the effective radius of early type galaxies and the scale length of exponential disks both to be 2.6 kpc for $L^*$ galaxies. We find that the half light radius of galaxies depends slightly on the color bands, consistent with the expected distribution of star-forming regions for late type galaxies and with the known color gradient for early type galaxies. We also show that the (inverse) concentration index, defined by the ratio of the half light Petrosian radius to the 90% light Petrosian radius, correlates tightly with the morphological type; this index allows us to classify galaxies into early (E/S0) and late (spiral and irregular) types, allowing for a 15-20% contamination from the opposite class compared with eye-classified morphology.

  9. 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)

    2015-01-01

    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.

  10. 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.

    2014-07-01

    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.

  11. A design for an RGB LED driver with independent PWM control and fast settling time

    E-Print Network [OSTI]

    Ashiabor, Awo Dede O

    2007-01-01

    A small sized and efficient method to power RGB LEDs for use as backlights in flat panel displays is explored in this thesis. The proposed method is to drive a parallel switched connection of LEDs with a single Average ...

  12. Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Phase III Continuation

    SciTech Connect (OSTI)

    None

    2008-11-01

    This report summarizes the third phase of an LED street lighting assessment project in Oakland, California, conducted to study the applicability of LED luminaires in a street lighting application.

  13. 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

  14. 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...

  15. Hydrogen Storage Lab PI Workshop: HyMARC and NREL-Led Characterization...

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

    Lab PI Workshop: HyMARC and NREL-Led Characterization Effort Hydrogen Storage Lab PI Workshop: HyMARC and NREL-Led Characterization Effort The National Renewable Energy Laboratory...

  16. Los Alamos-led consortium works to enhance fuel cell technology

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

    Los Alamos-led consortium works to enhance fuel cell technology Los Alamos-led consortium works to enhance fuel cell technology Los Alamos National Laboratory is leading a...

  17. Comparison of Test Procedures and Energy Efficiency Criteria in Selected International Standards & Labeling Programs for Copy Machines, External Power Supplies, LED Displays, Residential Gas Cooktops and Televisions

    E-Print Network [OSTI]

    Zheng, Nina

    2013-01-01

    Machines, External Power Supplies, LED Displays, Residentialmachines, external power supply, LED displays, residentialPower Supplies .. 6 LED

  18. Assessment of LED Technology in Ornamental Post-Top Luminaires. Sacramento, CA

    SciTech Connect (OSTI)

    Tuenge, J. R.; Bryan, M. M.; Bisbee, D. A.

    2011-12-01

    GATEWAY program report on a demonstration of LED ornamental post-top luminaires in a residential part of Sacramento, CA.

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  20. CALiPER Benchmark Report: Performance of Halogen Incandescent MR16 Lamps and LED Replacement

    SciTech Connect (OSTI)

    None

    2008-11-01

    This benchmark report addresses the halogen MR16 lamp and its commercially available light-emitting diode (LED) replacements.

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  2. Demonstration of LED Retrofit Lamps at the Smithsonian Art Museum, Washington, DC

    SciTech Connect (OSTI)

    Miller, N. J.; Rosenfeld, S. M.

    2012-06-01

    GATEWAY program report on a demonstration of LED retrofit lamps at the Smithsonian American Art Museum in Washington, DC.

  3. Crystal coat warms up LED light 16:46 01 February 2008

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    in the home. Now researchers have used nanocrystals to create LEDs that give off a warm white light. FineCrystal coat warms up LED light 16:46 01 February 2008 NewScientist.com news service Mason Inman Topping LEDs with a coating of carefully tuned nanocrystals makes their light warmer and less clinical

  4. Aalborg Universitet Led spectral and power characteristics under hybrid PWM/AM dimming strategy

    E-Print Network [OSTI]

    Munk-Nielsen, Stig

    Aalborg Universitet Led spectral and power characteristics under hybrid PWM/AM dimming strategy Citation for published version (APA): Beczkowski, S., & Munk-Nielsen, S. (2010). Led spectral and power #12;LED SPECTRALAND POWER CHARACTERISTICS UNDER HYBRID PWM/AM DIMMING STRATEGY Szymon Bczkowski* Stig

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

    E-Print Network [OSTI]

    Mills, Evan

    2007-01-01

    lamp. Off-grid lighting products using the poorer LEDs wouldLED products encountered in the market by firms designing and assembling complete lightingLED) light sources have recently attained levels of efficiency and cost that allow them to compete with fluorescent lighting

  6. 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

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

    Energy Savers [EERE]

    cbealedsitelightingspec.pdf More Documents & Publications CBEA High-Efficiency Parking Structure Lighting Specification FEMP Outdoor Solid-State Lighting Intiative:...

  8. Secretary Chu Announces Funding for 71 University-Led Nuclear...

    Energy Savers [EERE]

    Development and Validation for High Temperature Gas Cooled Reactor Cavity Cooling System (RCCS) Applications Texas A&M University Study of Air ingress across the duct during...

  9. Analysis Led Intake Port Development | Department of Energy

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

    Premixed Combustion in a Heavy-Duty Diesel Engine Vehicle Technologies Office Merit Review 2013: Accelerating Predictive Simulation of IC Engines with High Performance Computing...

  10. CALiPER Retail Lamps Study 3.2: Lumen and Chromaticity Maintenance of LED A Lamps Operated in Steady-State Conditions

    SciTech Connect (OSTI)

    none,

    2014-12-31

    This CALiPER report examines lumen depreciation and color shift of 17 different A lamps in steady-state conditions (15 LED, 1 CFL, 1 halogen). The goal of this investigation was to examine the long-term performance of complete LED lamps relative to benchmark halogen and CFL lamps—in this case, A lamps emitting approximately 800 lumens operated continuously at a relatively high ambient temperature of 45°C.

  11. Low emittance pion beams generation from bright photons and relativistic protons

    E-Print Network [OSTI]

    Serafini, L; Petrillo, V

    2015-01-01

    Present availability of high brilliance photon beams as those produced by X-ray Free Electron Lasers in combination with intense TeV proton beams typical of the Large Hadron Collider makes it possible to conceive the generation of pion beams via photo-production in a highly relativistic Lorentz boosted frame: the main advantage is the low emittance attainable and a TeV-class energy for the generated pions, that may be an interesting option for the production of low emittance muon and neutrino beams. We will describe the kinematics of the two classes of dominant events, i.e. the pion photo-production and the electron/positron pair production, neglecting other small cross-section possible events like Compton and muon pair production. Based on the phase space distributions of the pion and muon beams we will analyze the pion beam brightness achievable in three examples, based on advanced high efficiency high repetition rate FELs coupled to LHC or Future Circular Collider (FCC) proton beams, together with the stud...

  12. Millimeter Wavelength Brightness Fluctuations of the Atmosphere Above the South Pole

    E-Print Network [OSTI]

    R. S. Bussmann; W. L. Holzapfel; C. L. Kuo

    2004-12-02

    We report measurements of the millimeter wavelength brightness fluctuations produced by the atmosphere above the South Pole made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The data span the 2002 Austral winter during which ACBAR was mounted on the Viper telescope at the South Pole. We recover the atmospheric signal in the presence of instrument noise by calculating the correlation between signals from distinct elements of the ACBAR bolometer array. With this method, it is possible to measure atmospheric brightness fluctuations with high SNR even under the most stable atmospheric conditions. The observed atmospheric signal is characterized by the parameters of the Komolgorov-Taylor (KT) model, which are the amplitude and power law exponent describing the atmospheric power spectrum, and the two components of the wind angular velocity at the time of the observation. The KT model is typically a good description of the observed fluctuations, and fits to the data produce values of the Komolgorov exponent that are consistent with theoretical expectations. By combining the wind angular velocity results with measurements of the wind linear velocity, we find that the altitude of the observed atmospheric fluctuations is consistent with the distribution of water vapor determined from radiosonde data. For data corresponding to frequency passbands centered on 150, 219, and 274 GHz, we obtain median fluctuation power amplitudes of [10, 38, 74] mK^{2} rad^{-5/3} in Rayleigh-Jeans temperature units. Comparing with previous work, we find that these median amplitudes are approximately an order of magnitude smaller than those found at the South Pole during the Austral summer and at least 30 times lower than found at the ALMA site in the Atacama desert.

  13. Bright and dark excitons in semiconductor carbon nanotubes: insights from electronic structure calculations

    E-Print Network [OSTI]

    Tretiak, Sergei

    Bright and dark excitons in semiconductor carbon nanotubes: insights from electronic structure Article on the web 23rd March 2009 DOI: 10.1039/b818473a We review electronic structure calculations (bright) and optically forbidden (dark) states from the lowest excitonic band of the nanotubes

  14. Magnitude-range brightness variations of overactive K giants

    E-Print Network [OSTI]

    Oláh, K; K?vári, Zs; Granzer, T; Strassmeier, K G; Kriskovics, L; Vida, K

    2014-01-01

    We study three representative, overactive spotted K giants (IL Hya, XX Tri, and DM UMa) known to exhibit V-band light variations between 0.65-1.05 mags. Our aim is to find the origin of their large brightness variation. We employ long-term phase-resolved multicolor photometry, mostly from automatic telescopes, covering 42 yr for IL Hya, 28 yr for XX Tri, and 34 yr for DM UMa. For one target, IL Hya, we present a new Doppler image from NSO data taken in late 1996. Effective temperatures for our targets are determined from all well-sampled observing epochs and are based on a V-I_C color-index calibration. The effective temperature change between the extrema of the rotational modulation for IL Hya and XX Tri is in the range 50-200 K. The bolometric flux during maximum of the rotational modulation, i.e., the least spotted states, varied by up to 39% in IL Hya and up to 54% in XX Tri over the course of our observations. We emphasize that for IL Hya this is just about half of the total luminosity variation that can...

  15. Stellar Populations and Surface Brightness Fluctuations: New Observations and Models

    E-Print Network [OSTI]

    John P. Blakeslee; Alexandre Vazdekis; Edward A. Ajhar

    2000-08-15

    We examine the use of surface brightness fluctuations (SBF) for both stellar population and distance studies. New V-band SBF data are reported for five Fornax cluster galaxies and combined with literature data to define a new V-band SBF distance indicator. We use new stellar population models, based on the latest Padua isochrones transformed empirically to the observational plane, to predict SBF magnitudes and integrated colours for a wide range of population ages and metallicities. We examine the sensitivity of the predictions to changes in the isochrones, transformations, and IMF. The new models reproduce the SBF data for globular clusters fairly well, especially if higher metallicity globulars are younger. The models also give a good match to the "fluctuation colors" of elliptical galaxies. In order to obtain theoretical calibrations of the SBF distance indicators, we combine our single-burst models into composite population models. These models reproduce the observed behavior of the SBF magnitudes as a function of stellar population parameters, including the steep colour dependence found for HST/WFPC2 F814W SBF data. Because the theoretical SBF calibrations are fairly sensitive to uncertain details of stellar evolution, the empirical calibrations are more secure. However, the sensitivity of SBF to these finer details potentially makes it a powerful constraint for stellar evolution and population synthesis. [abbridged

  16. The dearth of nuclear star clusters in bright galaxies

    E-Print Network [OSTI]

    Arca-Sedda, Manuel; Spera, Mario

    2015-01-01

    We investigate the interaction of a massive globular cluster (GC) with a super massive black hole (SMBH), located at the centre of its host galaxy, by means of direct $N$-body simulations. The results show that tidal distortions induced by the stellar background and the SMBH act on a time shorter than that of dynamical friction decay for a $10^6$ M$_\\odot$ GC whenever the SMBH mass exceeds $\\sim 10^8$ M$_\\odot$. This implies an almost complete dissolution of the infalling GC before it reaches the inner region ($\\lesssim 5$ pc) of the parent galaxy. The generalization of this result to a larger sample of infalling GCs shows that such destructive process may prevent the formation and growth of a bright galactic nucleus. Another interesting, serendipitous, result we obtained is that the close interaction between the SMBH and the GC produces a ``wave'' of stars that escape from the cluster and, in a fraction, even from the whole galaxy.

  17. The effect of the fifth-order nonlinearity on the existence of bright solitons below the modulation instability threshold

    E-Print Network [OSTI]

    Gandzha, I S

    2015-01-01

    We analyze three different high-order nonlinear Schr\\"{o}dinger equation (HONLSE) models that have been used in the literature to describe the evolution of slowly modulated gravity waves on the surface of ideal finite-depth fluid. We demonstrate that the inclusion of the fifth-order nonlinear term to the HONLSE model introduces only a small correction to the amplitude of the bright HONLSE soliton solutions obtained without this term. Such soliton slutions behave as quasi-solitons in this more general case.

  18. A bright on-demand source of indistinguishable single photons at telecom wavelengths

    E-Print Network [OSTI]

    Je-Hyung Kim; Tao Cai; Christopher J. K. Richardson; Richard P. Leavitt; Edo Waks

    2015-11-17

    Long-distance quantum communication relies on the ability to efficiently generate and prepare single photons at telecom wavelengths. In many applications these photons must also be indistinguishable such that they exhibit interference on a beamsplitter, which implements effective photon-photon interactions. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem. We demonstrate a telecom wavelength source of indistinguishable single photons using an InAs/InP quantum dot in a nanophotonic cavity. The cavity enhances the quantum dot emission, resulting in a nearly Gaussian transverse mode profile with high out-coupling efficiency exceeding 46%, leading to detected photon count rates that would exceed 1.5 million counts per second. We also observe Purcell enhanced spontaneous emission rate as large as 4. Using this source, we generate linearly polarized, high purity single photons at telecom-wavelength and demonstrate the indistinguishable nature of the emission using a two-photon interference measurement. Our results provide a promising approach to generate on-demand indistinguishable single photons at telecom wavelength for applications in quantum networking and quantum communication.

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

    Energy Savers [EERE]

    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...

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

    E-Print Network [OSTI]

    Mahmood Zuhdi, Ahmad Wafi; Zuhdi, Ahmad

    2015-06-29

    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 ...

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

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics And StatisticsProgramof Energy ConsentCertify DOEDOE Names OakApril 8,| DepartmentLamps

  2. 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 Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy BillsNo. 195 -RobSSL INDepartment ofJune 28, 2011and MoneySavingSaw

  3. Materials and Designs for High-Efficacy LED Light Engines | Department of

    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 on Delicious RankADVANCED MANUFACTURING OFFICESpecial Report ManagementMarineLaboratory: FocusGo/No-Go2

  4. 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 Data Center Home Page on Delicious Rank EERE:Financing Tool FitsProjectData Dashboard RutlandSTEAB's1-E Wholesale Powerand beEnergy

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

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuilding energy codesPhiladelhia Gas Works (PGW) Doe FurnaceDepartment

  6. NOVEL TECHNOLOGIES DEVELOPED BY CREE LOWER THE COST OF HIGH-PERFORMANCE LED

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties -Department of EnergyNEW1for AcquisitionNORTHEAST HOMENOTICE:

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

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties -DepartmentAvailable for Public Comment (MarchNew Fundingof

  8. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogoFeet) DeliveriesSubstrates

  9. Research Support in Hungary Machine scheduling LED public lighting Microsimulation in public transportation Finally Optimization and Operation Research methods for

    E-Print Network [OSTI]

    Balázs, Bánhelyi

    Research Support in Hungary Machine scheduling LED public lighting Microsimulation in public Innovation Problems #12;Research Support in Hungary Machine scheduling LED public lighting Microsimulation in Hungary Machine scheduling LED public lighting Microsimulation in public transportation Finally The word

  10. Use Patterns of LED Flashlights in Kenya and a One-Year Cost Analysis of Flashlight Ownership

    E-Print Network [OSTI]

    Tracy, Jennifer

    2010-01-01

    for off-grid lighting products based on LED technology (LED technology has quickly emerged as the dominant source of portable lightingLEDs have achieved price levels that make them cost competitive with conventional lighting

  11. I2C 2005-1 Demonstration Board LED Dimmers and Blinkers

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    the programmed blinking or dimming schemes Each LED driver can be programmed to be: Fully OFF (default power up.6 % LED DIMMERS Hex value 2.3 V to 5.5 V power supply with 5 V tolerant I/O's Device portfolio: 8 16 PCA power over the cables SW 8 turns on 9V battery power Push Buttons control micro and LEDs Reprogram micro

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

    Broader source: Energy.gov [DOE]

    Despite being cool, ultra-efficient and long lasting, the light-emitting diode (LED) faces a problem called “efficiency droop.” New findings from simulations carried out at the National Energy Research Scientific Computer Center (NERSC) have unearthed droop’s elusive cause, researchers say, paving the way for wider LED use. An illustration of nitride-based LEDs.| Courtesy of the National Energy Research Scientific Computing Center.

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

    Energy Savers [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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTION REPORT LED ADOPTION REPORTLED PerformanceLED

  14. Bright X-ray source from a laser-driven micro-plasma-waveguide

    E-Print Network [OSTI]

    Yi, Longqing; Thanh, Phuc Luu; Shen, Baifei

    2015-01-01

    Bright tunable x-ray sources have a number of applications in basic science, medicine and industry. The most powerful sources are synchrotrons, where relativistic electrons are circling in giant storage rings. In parallel, compact laser-plasma x-ray sources are being developed. Owing to the rapid progress in laser technology, very high-contrast femtosecond laser pulses of relativistic intensities become available. These pulses allow for interaction with micro-structured solid-density plasma without destroying the structure by parasitic pre-pulses. The high-contrast laser pulses as well as the manufacturing of materials at micro- and nano-scales open a new realm of possibilities for laser interaction with photonic materials at the relativistic intensities. Here we demonstrate, via numerical simulations, that when coupling with a readily available 1.8 Joule laser, a micro-plasma-waveguide (MPW) may serve as a novel compact x-ray source. Electrons are extracted from the walls by the laser field and form a dense ...

  15. Development of an LED reference light source for calibration of radiographic imaging detectors

    E-Print Network [OSTI]

    M. Weierganz; D. Bar; B. Bromberger; V. Dangendorf; G. Feldman; M. B. Goldberg; M. Lindemann; I. Mor; K. Tittelmeier; D. Vartsky

    2010-02-08

    A stable reference light source based on an LED (Light Emission Diode) is presented for stabilizing the conversion gain of the opto-electronic system of a gamma- and fast-neutron radiographic and tomographic imaging device. A constant fraction of the LED light is transported to the image plane of the camera and provides a stable reference exposure. This is used to normalize the images during off-line image processing. We have investigated parameters influencing the stability of LEDs and developed procedures and criteria to prepare and select LEDs suitable for delivering stable light outputs for several 100 h of operation.

  16. 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:

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

    ScienceCinema (OSTI)

    Beeson, Tracy; Miller, Naomi

    2014-06-23

    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.

  18. Sandia Energy - Sandia-Developed LED Pulser Delivers Laser-Like...

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

    Sandia-Developed LED Pulser Delivers Laser-Like Performance at Fraction of the Cost Home Energy CRF Facilities Capabilities News News & Events Research & Capabilities Systems...

  19. CALiPER Benchmark Report: Performance of Incandescent A Type and Decorative Lamps and LED Replacements

    SciTech Connect (OSTI)

    None

    2008-11-01

    This benchmark report addresses common omnidirectional incandescent lamps - A-type and small decorative, candelabra-type lamps - and their commercially available light-emitting diode (LED) replacements.

  20. Demonstration Assessment of Light-Emitting Diode (LED) Area Lights for a Commercial Garage

    SciTech Connect (OSTI)

    None

    2008-11-01

    This U.S. Department of Energy GATEWAY Demonstration project studied the applicability of light-emitting diode (LED) luminaires for commercial parking garage applications.

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

    SciTech Connect (OSTI)

    Beeson, Tracy; Miller, Naomi

    2014-06-17

    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.

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

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

    Office of Energy Efficiency and Renewable Energy (EERE)

    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.

  4. Demonstration Assessment of LED Roadway Lighting: NE Cully Blvd., Portland, OR

    SciTech Connect (OSTI)

    Royer, M. P.; Poplawski, M. E.; Tuenge, J. R.

    2012-08-01

    GATEWAY program report on a demonstration of LED roadway lighting on NE Cully Boulevard in Portland, OR, a residential collector road.

  5. National Aeronautics and Space Administration organizations around the nation, and is led

    E-Print Network [OSTI]

    Rathbun, Julie A.

    National Aeronautics and Space Administration NASAfacts organizations around the nation, and is led;National Aeronautics and Space Administration George C. Marshall Space Flight Center Huntsville, AL 35812

  6. 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.

  7. 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.

  8. Federally Led Accident Investigation Reports | 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 on Delicious Rank EERE:FinancingPetroleum12, 2015Executive Order14,Energy 9, 2013Federal TaxMAY 3-4,Into High Gear

  9. Measured Off-Grid LED Lighting System Performance

    SciTech Connect (OSTI)

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

    2008-12-18

    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.

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

    E-Print Network [OSTI]

    T. J. Davidge

    1998-03-24

    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.

  11. 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

  12. 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 ...

  13. Tuning the correlated color temperature of white LED with a guest-host liquid crystal

    E-Print Network [OSTI]

    Wu, Shin-Tson

    Tuning the correlated color temperature of white LED with a guest-host liquid crystal Haiwei Chen the molecular reorientation of dichroic dyes, the power ratio of the transmitted blue and red lights. P. Schuurmans, and M. D. Pashley, "Red, green, and blue LEDs for white light illumination," IEEE J

  14. Monday, 18 October 2010 The LEDs can be twisted into a 720-degree

    E-Print Network [OSTI]

    Rogers, John A.

    Monday, 18 October 2010 The LEDs can be twisted into a 720-degree helix (Source: University ) , Science Online, 26 Apr 2010 Scientists develop bendable LEDs (/science/articles/2009/08/21/2662953.htm ) , Science Online, 21 Aug 2009 Piezoelectrics harness hamster power (/science/articles/2009/03/10/2511998.htm

  15. 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.

    2014-10-14

    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.

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

    Office of Energy Efficiency and Renewable Energy (EERE)

    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.

  18. January 12, 2006Washington University Teaching Center Peer-Led Team Learning

    E-Print Network [OSTI]

    January 12, 2006Washington University Teaching Center Peer-Led Team Learning K. DeAngelis, S Center #12;January 12, 2006Washington University Teaching Center Outline Frey Peer-led team-learning (PLTL) model Peer leaders at Washington University Hockings General Chemistry I and II Woods General

  19. Long-Run Growth in Open Economies: Export-Led Cumulative Causation or

    E-Print Network [OSTI]

    Carlini, David

    Long-Run Growth in Open Economies: Export-Led Cumulative Causation or a Balance. On the one hand, models of export-led cumulative causation (ELCC) stress the possibility that some countries competitiveness, rising exports, and rapid output growth (although, in this view, other countries may be doomed

  20. 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

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

    SciTech Connect (OSTI)

    Royer, Michael P.

    2014-08-30

    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.

  2. An Electrolytic-Free Offline LED Driver with a Ceramic-Capacitor-Based Compact SSC Energy

    E-Print Network [OSTI]

    Perreault, Dave

    An Electrolytic-Free Offline LED Driver with a Ceramic-Capacitor-Based Compact SSC Energy Buffer of a compact ceramic-capacitor-based stacked switched capacitor (SSC) energy buffer for a single-stage offline precharge circuit. The prototype LED driver presented here uses a ceramic-capacitor-based SSC energy buffer

  3. Magical Mystery Devices or Not: How do LED Lamps and Luminaires Really Measure-Up?

    SciTech Connect (OSTI)

    Paget, Maria L.; McCullough, Jeffrey J.; Steward, Heidi E.

    2008-08-15

    Solid-state lighting products for general lighting applications are now gaining a market presence, and more and more people are asking, “Which of these are ‘good’ products? Do they perform as claimed? How do they compare? Light Emitting Diodes (LEDs) differ from other light sources enough to require new procedures for measuring their performance and comparing to other lighting options, so both manufacturers and buyers are facing a learning curve. The energy-efficiency community has traditionally compared light sources based on system efficacy: rated lamp lumens divided by power into the system. This doesn’t work for LEDs because there are no standard LED “lamp” packages and no lamp ratings, and because LED performance depends heavily on thermal, electrical, and optical design of complete lighting unit or ‘luminaire’. Luminaire efficacy is the preferred metric for LEDs because it measures the net light output from the luminaire divided by power into the system.

  4. KIC 4768731: a bright long-period roAp star in the Kepler Field

    E-Print Network [OSTI]

    Smalley, B; Murphy, S J; Lehmann, H; Kurtz, D W; Holdsworth, D L; Cunha, M S; Balona, L A; Briquet, M; Bruntt, H; de Cat, P; Lampens, P; Thygesen, A O; Uytterhoeven, K

    2015-01-01

    We report the identification of 61.45 d^-1 (711.2 mu Hz) oscillations, with amplitudes of 62.6-mu mag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V=9.17) chemically peculiar star with spectral type A5 Vp SrCr(Eu) has previously been found to exhibit rotational modulation with a period of 5.21 d. Fourier analysis reveals a simple dipole pulsator with an amplitude that has remained stable over a 4-yr time span, but with a frequency that is variable. Analysis of high-resolution spectra yields stellar parameters of T_eff = 8100 +/- 200 K, log g = 4.0 +/- 0.2, [Fe/H] = +0.31 +/- 0.24 and v sin i = 14.8 +/- 1.6 km/s. Line profile variations caused by rotation are also evident. Lines of Sr, Cr, Eu, Mg and Si are strongest when the star is brightest, while Y and Ba vary in anti-phase with the other elements. The abundances of rare earth elements are only modestly enhanced compared to other roAp stars of similar T_eff and log g. Radial velocities in the literature suggest a significant...

  5. 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)

    2001-01-01

    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.

  6. 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.

    2003-01-01

    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...

  7. Investigation of intergranular bright points from the New Vacuum Solar Telescope

    E-Print Network [OSTI]

    Ji, Kai-Fan; Xiang, Yong-yuan; Feng, Song; Deng, Hui; Wang, Feng; Yang, Yun-Fei

    2015-01-01

    Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope (NVST) are used to investigate the properties of intergranular bright points (igBPs). We detect the igBPs using a Laplacian and morphological dilation algorithm (LMD) and track them using a three-dimensional segmentation algorithm automatically, and then investigate the morphologic, photometric and dynamic properties of igBPs, in terms of equivalent diameter, the intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm the previous studies based on G-band or TiO-band igBPs from the other telescopes. It illustrates that the TiO data from the NVST have a stable and reliable quality, which are suitable for studying the igBPs. In addition, our method is feasible to detect and track the igBPs in the TiO data from the NVST. With the aid of the vector magnetograms obtained from the Solar Dynamics Observatory /Helioseismic and Magnetic Imager, the properties of igBP...

  8. New OLED Lighting Systems Shine Bright, Save Energy

    Office of Energy Efficiency and Renewable Energy (EERE)

    Case study that describes how Universal Display Corporation received SBIR funding to adapt its PHOLED lighting technology for high-end commercial and institutional building applications.

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

    SciTech Connect (OSTI)

    Tracy, Jennifer; Jacobson, Arne; Mills, Evan

    2010-03-02

    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.

  10. 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 as the light source, which is composed of blue LED die and yellow phosphor. By optimizing the illumination

  11. 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)

    2012-04-10

    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.

  12. KELT-7b: A hot Jupiter transiting a bright V=8.54 rapidly rotating F-star

    E-Print Network [OSTI]

    Bieryla, Allyson; Beatty, Thomas G; Eastman, Jason; Siverd, Robert J; Pepper, Joshua; Gaudi, B Scott; Stassun, Keivan G; Canas, Caleb; Latham, David W; Buchhave, Lars A; Sanchis-Ojeda, Roberto; Winn, Joshua N; Jensen, Eric L N; Kielkopf, John F; McLeod, Kim K; Gregorio, Joao; Colon, Knicole D; Street, Rachel; Ross, Rachel; Penny, Matthew; Mellon, Samuel N; Oberst, Thomas E; Fulton, Benjamin J; Wang, Ji; Berlind, Perry; Calkins, Michael L; Esquerdo, Gilbert A; DePoy, Darren L; Gould, Andrew; Marshall, Jennifer; Pogge, Richard; Trueblood, Mark; Trueblood, Patricia

    2015-01-01

    We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of $1.28 \\pm 0.18$ MJ, radius of $1.53_{-0.047}^{+0.046}$ RJ, and an orbital period of $2.7347749 \\pm 0.0000039$ days. The bright host star (HD33643; KELT-7) is an F-star with $V=8.54$, Teff $=6789_{-49}^{+50}$ K, [Fe/H] $=0.139_{-0.081}^{+0.075}$, and $\\log{g}=4.149 \\pm 0.019$. It has a mass of $1.535_{-0.054}^{+0.066}$ Msun, a radius of $1.732_{-0.045}^{+0.043}$ Rsun, and is the fifth most massive, fifth hottest, and the ninth brightest star known to host a transiting planet. It is also the brightest star around which KELT has discovered a transiting planet. Thus, KELT-7b is an ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, and bright host star. The rapid rotation of the star ($73 \\pm 0.5$ km/s) results in a Rossiter-McLaughlin effect with an unusually large amplitude of several hundred m/s. We find that the orbit normal of the planet is likely to be well-aligned with ...

  13. Applications of Robust, Radiation Hard AlGaN Optoelectronic Devices in Space Exploration and High Energy Density Physics

    SciTech Connect (OSTI)

    Sun, K.

    2011-05-04

    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.

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

    SciTech Connect (OSTI)

    Miller, N. J.; Poplawski, M. E.

    2013-10-01

    DOE GATEWAY program report reviewing how phase-cut dimmers work, how LEDs differ from the incandescent lamps these dimmers were originally designed to control, and how those differences can lead to complications when attempting to dim LEDs. Providing 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—the report aims to reduce the chance of experiencing compatibility-related problems and, if possible, ensure good dimming performance.

  15. Sparkling extreme-ultraviolet bright dots observed with Hi-C

    SciTech Connect (OSTI)

    Régnier, S.; Alexander, C. E.; Walsh, R. W.; Winebarger, A. R.; Cirtain, J.; Golub, L.; Korreck, K. E.; Weber, M.; Mitchell, N.; Platt, S.; De Pontieu, B.; Title, A.; Kobayashi, K.; Kuzin, S.; DeForest, C. E.

    2014-04-01

    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 Å. 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.

  16. Inverse Free Electron Laser Interactions with Sub-Picosecond High Brightness Electron Beams

    E-Print Network [OSTI]

    Moody, Joshua Timothy

    2014-01-01

    the OAP chamber, goes through a periscope that preserves itsthe OAP chamber, goes through a periscope that preserves itsPolarization Preserving Periscope Periscope with Window 500

  17. Digital Sliding Mode Pulsed Current Averaging IC Drivers for High Brightness Light Emitting Diodes

    E-Print Network [OSTI]

    Lehman, Brad

    to the load. A variable frequency boost converter in Discontinuous Conduction Mode (DCM) has been used algorithm of the inductor current variations for a digitally controlled DC-DC boost converter operating in Continuous Conduction Mode. [10] describes a microcontroller based digital boost converter for a RGB

  18. Bright x-ray sources from laser irradiation of foams with high...

    Office of Scientific and Technical Information (OSTI)

    efficiency with foam targets is due to novel fabrication techniques based on atomic-layer-deposition of Ti atoms on an aerogel scaffold. A Ti concentration of 33 at. % was...

  19. Generation, transport and focusing of high-brightness heavy ion beams

    E-Print Network [OSTI]

    Henestroza, Enrique

    2006-01-01

    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 ...

  20. Bright x-ray sources from laser irradiation of foams with high

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing Bacteria (Technical Report) |

  1. Bright x-ray sources from laser irradiation of foams with high

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing Bacteria (Technical Report) |concentration of Ti (Journal Article) | SciTech

  2. Bright x-ray sources from laser irradiation of foams with high

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing Bacteria (Technical Report) |concentration of Ti (Journal Article) |

  3. High-Ti-concentration aerogels for bright x-ray sources (Technical Report)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article)SciTech ConnectMicrofabricated| SciTech

  4. High-Ti-concentration aerogels for bright x-ray sources (Technical Report)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article)SciTech ConnectMicrofabricated| SciTech|

  5. High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article)SciTech ConnectMicrofabricated|Targets

  6. High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article)SciTech

  7. 2 Gb/s ?LED-APD Based Visible Light Communications Using Feed-forward Pre-equalization and PAM-4 Modulation

    E-Print Network [OSTI]

    Li, X.; Bamiedakis, N.; Guo, X.; McKendry, J. J. D.; Xie, E.; Ferreira, R.; Gu, E.; Dawson, M. D.; Penty, R. V.; White, I. H.

    2015-10-01

    ) , E. Gu (2) , M. D. Dawson (2) , R. V. Penty (2) , I. H. White (2) ((1) Electrical Engineering Division, Engineering Department, University of Cambridge, Cambridge CB3 0FA, UK; Email address: xl336@cam.ac.uk (2) Institute of Photonics, SUPA... as light-emitting diodes (LEDs) can provide high-speed data transmission as well as illumination. Such LED- based optical wireless systems are a potential solution to the spectrum crunch in radio frequency systems as they can make use of hundreds...

  8. 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)

    2002-01-15

    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.

  9. 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)

    2003-06-17

    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.

  10. 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.

    2014-05-20

    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.

  11. Two-stage power conversion architecture for an LED driver circuit

    E-Print Network [OSTI]

    Lim, Seungbum

    This paper presents a merged-two-stage circuit topology suitable for efficient LED drivers operating from either wide-range dc input voltage or ac line voltage. This two-stage topology is based on a soft-charged ...

  12. 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...

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

    Office of Energy Efficiency and Renewable Energy (EERE)

     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...

  14. 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.

  15. University of Washington | Office of Global Affairs Faculty-led Program Grant Application

    E-Print Network [OSTI]

    Fukuda, Munehiro

    University of Washington | Office of Global Affairs Page 1 Faculty-led Program Grant Application Systems _____ College: University of Washington Bothell_____________ Email: mfukuda@u.washington_________________________________________________________ Email: stiber@u.washington.edu________________ Phone Number: 425-352-5280________________________ Campus

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

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

    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...

  17. 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...

  18. 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...

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

    E-Print Network [OSTI]

    Tracy, Jenny

    2010-01-01

    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

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

    E-Print Network [OSTI]

    Kim, LeeAnn

    2006-01-01

    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 ...

  1. 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...

  2. 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...

  3. Demonstration Assessment of Light-Emitting Diode (LED) Post-Top...

    Office of Scientific and Technical Information (OSTI)

    Central Park in New York City A review of five post-top light-emitting diode (LED) pedestrian luminaires installed in New York City's Central Park for possible replacement to the...

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

    SciTech Connect (OSTI)

    Miller, Naomi J.; Poplawski, Michael E.

    2013-10-01

    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.

  5. 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.

  6. 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

    2010-11-06

    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.

  7. 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.

    2008-11-11

    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.

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

    E-Print Network [OSTI]

    are being developed including biomass, geothermal, hydropower, ocean thermal energy conversion, solar in technology development. The high capital costs typical of sustainable technologies coupled with the cyclic Time: 3:00 PM Location: A265 Bourns Hall Abstract: Low cost energy is critical to our lifestyles

  9. SOLAR POLAR X-RAY JETS AND MULTIPLE BRIGHT POINTS: EVIDENCE FOR SYMPATHETIC ACTIVITY

    SciTech Connect (OSTI)

    Pucci, Stefano; Romoli, Marco; Poletto, Giannina; Sterling, Alphonse C.

    2012-02-15

    We present an analysis of X-ray bright points (BPs) and X-ray jets observed by Hinode/X-Ray Telescope on 2007 November 2-4, within the solar northern polar coronal hole. After selecting small subregions that include several BPs, we followed their brightness evolution over a time interval of a few hours, when several jets were observed. We find that most of the jets occurred in close temporal association with brightness maxima in multiple BPs: more precisely, most jets are closely correlated with the brightening of at least two BPs. We suggest that the jets result from magnetic connectivity changes that also induce the BP variability. We surmise that the jets and implied magnetic connectivity we describe are small-scale versions of the active-region-scale phenomenon, whereby flares and eruptions are triggered by interacting bipoles.

  10. A Characterization of the Brightness Oscillations During Thermonuclear Bursts From 4U 1636-536

    E-Print Network [OSTI]

    M. Coleman Miller

    1999-04-08

    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.

  11. Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's

    SciTech Connect (OSTI)

    Royer, Michael P.

    2013-09-17

    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.

  12. 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

  13. LEDS Global Partnership in Action: Advancing Climate-Resilient Low Emission Development Around the World (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-11-01

    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.

  14. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting, I-35W Bridge, Minneapolis, Minnesota, Phase II Report

    SciTech Connect (OSTI)

    Kinzey, B. R.; Davis, R. G.

    2014-09-30

    On the I-35W Bridge in Minneapolis, Minnesota, the GATEWAY program conducted a two-phase demonstration of LED roadway lighting on the main span, which is one of the country's oldest continuously operated exterior LED lighting installations. The Phase II report documents longer-term performance of the LED lighting system that was installed in 2008, and is the first report on the longer-term performance of LED lighting in the field.

  15. 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

  16. Technical Evaluation Report "ND2 Attenuation of the COS Bright Object Aperture"

    E-Print Network [OSTI]

    Colorado at Boulder, University of

    Technical Evaluation Report "ND2 Attenuation of the COS Bright Object Aperture" Date: 30 June 2000 Document Number: COS-11-0019 Revision: Initial Release Contract No.: NAS5-98043 CDRL No.: N/A Prepared By: J. Morse, COS Project Scientist, CU/CASA Date Reviewed By: J. Green, COS Principal Investigator, CU

  17. 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

  18. 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

  19. Observational difference between gamma and X-ray properties of optically dark and bright GRBs

    SciTech Connect (OSTI)

    Balazs, L. G. [Konkoly Observatory, Budapest (Hungary); Horvath, I. [Bolyai Military University, Budapest (Hungary); Bagoly, Zs.; Veres, P. [Eoetvoes University, Budapest (Hungary); Meszaros, A. [Charles University, Prague (Czech Republic)

    2008-05-22

    Using the discriminant analysis of the multivariate statistical analysis we compared the distribution of the physical quantities of the optically dark and bright GRBs, detected by the BAT and XRT on board of the Swift Satellite. We found that the GRBs having detected optical transients (OT) have systematically higher peak fluxes and lower HI column densities than those without OT.

  20. METHANE AND ETHANE ON THE BRIGHT KUIPER BELT OBJECT 2005 FY9 M. E. Brown,1

    E-Print Network [OSTI]

    Brown, Michael E.

    METHANE AND ETHANE ON THE BRIGHT KUIPER BELT OBJECT 2005 FY9 M. E. Brown,1 K. M. Barkume,1 G. A indicates the clear presence of ethane, an expected product of UV photolysis of methane. No evidence for N2 of 2005 FY9 that leads to large methane grains, abundant sites for ethane formation through UV photolysis