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Sample records for led commercial garage

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

    SciTech Connect

    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

  2. Use of Occupancy Sensors in LED Parking Lot and Garage Applications: Early Experiences

    SciTech Connect

    Kinzey, Bruce R.; Myer, Michael; Royer, Michael P.; Sullivan, Greg P.

    2012-11-07

    Occupancy sensor systems are gaining traction as an effective technological approach to reducing energy use in exterior commercial lighting applications. Done correctly, occupancy sensors can substantially enhance the savings from an already efficient lighting system. However, this technology is confronted by several potential challenges and pitfalls that can leave a significant amount of the prospective savings on the table. This report describes anecdotal experiences from field installations of occupancy sensor controlled light-emitting diode (LED) lighting at two parking structures and two parking lots. The relative levels of success at these installations reflect a marked range of potential outcomes: from an additional 76% in energy savings to virtually no additional savings. Several issues that influenced savings were encountered in these early stage installations and are detailed in the report. Ultimately, care must be taken in the design, selection, and commissioning of a sensor-controlled lighting installation, else the only guaranteed result may be its cost.

  3. 4. TENSTALL GARAGE. GARAGE DOOR DETAIL. VIEW TO WEST. ...

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

    4. TEN-STALL GARAGE. GARAGE DOOR DETAIL. VIEW TO WEST. - Rainbow Hydroelectric Facility, Ten Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  4. SCHOOL BUS GARAGES, 1966 REVISION.

    ERIC Educational Resources Information Center

    JOHNSON, HERBERT F.

    STANDARDS AND RECOMMENDATIONS ARE GIVEN FOR THE DESIGN AND CONSTRUCTION OF SCHOOL BUS GARAGES INCLUDING BRIEF DISCUSSIONS OF--(1) SITE DEVELOPMENT, (2) DESIGN AND CONSTRUCTION, AND (3) MECHANICAL (HEATING, PLUMBING, AND VENTILATION) AND ELECTRICAL FACTORS. (JT)

  5. Garage Band or GarageBand[R]? Remixing Musical Futures

    ERIC Educational Resources Information Center

    Vakeva, Lauri

    2010-01-01

    In this paper, I suggest that it is perhaps time to consider the pedagogy of popular music in more extensive terms than conventional rock band practices have to offer. One direction in which this might lead is the expansion of the informal pedagogy based on a "garage band" model to encompass various modes of digital artistry wherever this artistry…

  6. On the design of GaN vertical MESFETs on commercial LED sapphire wafers

    NASA Astrophysics Data System (ADS)

    Atalla, Mahmoud R. M.; Noor Elahi, Asim M.; Mo, Chen; Jiang, Zhenyu; Liu, Jie; Ashok, S.; Xu, Jian

    2016-12-01

    Design of GaN-based vertical metal-semiconductor field-effect transistors (MESFETs) on commercial light-emitting-diode (LED) epi-wafers has been proposed and proof of principle devices have been fabricated. In order to better understand the IV curves, these devices have been simulated using the charge transport model. It was found that shrinking the drain pillar size would significantly help in reaching cut-off at much lower gate bias even at high carrier concentration of unintentionally doped GaN and considerable leakage current caused by the Schottky barrier lowering. The realization of these vertical MESFETs on LED wafers would allow their chip-level integration. This would open a way to many intelligent lighting applications like on-chip current regulator and signal regulation/communication in display technology.

  7. An efficient luminescence conversion LED for white light emission, fabricated using a commercial InGaN LED and a 1,8-naphthalimide derivative

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Jeong; Jin, Ji-Young; Lee, Youn-Sik; Lee, Sang-Hee; Hong, Chang-Hee

    2006-11-01

    A highly efficient luminescence conversion light emitting diode (LUCO LED) was fabricated, using a commercial InGaN LED (460 nm) and 4- N, N-diphenyl-9-(4- tert-butylphenyl)-1,8-naphthalimide (DBN), dispersed in epoxy as the primary light source and LUCO material, respectively. The emission of very bright white light was observed at 20 mA, with CIE chromaticity coordinates of (0.32, 0.33) and conversion efficiency of 82%. The luminescent output of the LUCO LED decreased rapidly, but when the LUCO LED was prepared using DNB dispersed in poly(methyl methacrylate), it only decreased to about 67% of the initial value after 19 days of continual operation at 200 mA.

  8. 1. Photocopy of photograph of Garage at Hornet Ranger Station. ...

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

    1. Photocopy of photograph of Garage at Hornet Ranger Station. Original on file with the Payette National Forest, Supervisor's Office, McCall, Idaho. GARAGE, CA. 1935. - Hornet Ranger Station, Garage, Forest Service Road No. 50002, Council, Adams County, ID

  9. Cooling of High-Power LED Lamp Using a Commercial Paraffin Wax

    NASA Astrophysics Data System (ADS)

    Zmywaczyk, J.; Zbińkowski, P.; Smogór, H.; Olejnik, A.; Koniorczyk, P.

    2017-03-01

    Commercial paraffin wax used by Bolsius Nederland B.V. for manufacturing various kinds of candles was applied as a phase-change material (PCM) for cooling a 28 W high-power light emitting diode (LED) panel during its operation. The main problem arising during operation of an LED is thermal management. According to the manufacturer's datasheet specifications (BioSolution Ltd. www.biosolution.pl, the operating temperature range for the LED street lamp UL28W is (-30 {°}C) to (+40 {°}C). The object of the present study was an LED panel containing 28 pieces of high-power 1W LEDs connected in series (4 LEDs in each of the 7 rows) mounted on an aluminum plate of dimensions 80 mm by 135 mm. The tested aluminum plate was placed in a block made of aluminum with a hollow compartment containing Bolsius paraffin wax of density 914 kg\\cdot m^{-3} at room temperature. Temperatures were recorded using K-type thermocouples at selected locations of the tested LED panel for several values of the power supplied to it, while utilizing PCM and without it. As the manufacturer of Bolsius wax candles does not provide any data on the thermal properties of the material used, it was necessary to carry out micro-calorimetric research. Thermophysical properties of the paraffin wax such as the apparent specific heat, enthalpy of phase transition and temperature of phase change transition during heating and cooling were determined using the Netzsch DSC 214 Polyma. The Netzsch TG 209F3 Tarsus was used for TG/DTG measurements. DSC investigations revealed the following thermal transitions taking place during the first heating: solid-solid transition (onset 30.4 {°}C, peak at 40.9 {°}C), solid-liquid transition (onset 47.7 {°}C, peak at 54.9 {°}C, end at 58.3 {°}C), latent heat of energy storage 201 J\\cdot g^{-1}, apparent specific heat corresponding to peak at 41.5 {°}C (5.498 J\\cdot g^{-1}\\cdot K^{-1}). DTG investigations revealed that the decomposition of paraffin wax is a two

  10. Interior view of garage facing back wall (east) Presidio ...

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

    Interior view of garage facing back wall (east) - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  11. 1. CONTEXT VIEW OF GARAGE COMPLEX AT SOUTHEAST END OF ...

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

    1. CONTEXT VIEW OF GARAGE COMPLEX AT SOUTHEAST END OF OPERATOR'S CAMP SHOWING MECHANIC'S GARAGE AT RIGHT, 4-CAR GARAGE AT CENTER, AND 3-CAR GARAGE AT LEFT. VIEW TO SOUTHEAST. - Holter Hydroelectric Facility, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  12. 3. CONTEXT VIEW OF GARAGE COMPLEX AT SOUTHEAST END OF ...

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

    3. CONTEXT VIEW OF GARAGE COMPLEX AT SOUTHEAST END OF OPERATOR' CAMP SHOWING MECHANIC'S GARAGE NO. 48 AT LEFT, 4-CAR GARAGE AT CENTER, AND 3-CAR GARAGE AT RIGHT. VIEW TO NORTH-NORTHWEST - Holter Hydroelectric Facility, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  13. 2. CONTEXT VIEW OF GARAGE COMPLEX AT SOUTHEAST END OF ...

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

    2. CONTEXT VIEW OF GARAGE COMPLEX AT SOUTHEAST END OF OPERATOR'S CAMP SHOWING MECHANIC'S GARAGE AT RIGHT, 4-CAR GARAGE AT CENTER, AND 3-CAR GARAGE AT LEFT. VIEW TO SOUTHWEST. - Holter Hydroelectric Facility, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  14. Good-bye Garage, Hello CCD

    ERIC Educational Resources Information Center

    Augur, Eleanor

    1977-01-01

    The idea of having a religious education center in a four car garage may sound ridiculous to some but to the parishioners of Saint George's Church in Guilford, Connecticut, it was heaven-sent. (Author/RK)

  15. Automated parking garage system model

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1975-01-01

    A one-twenty-fifth scale model of the key components of an automated parking garage system is described. The design of the model required transferring a vehicle from an entry level, vertically (+Z, -Z), to a storage location at any one of four storage positions (+X, -X, +Y, +Y, -Y) on the storage levels. There are three primary subsystems: (1) a screw jack to provide the vertical motion of the elevator, (2) a cam-driven track-switching device to provide X to Y motion, and (3) a transfer cart to provide horizontal travel and a small amount to vertical motion for transfer to the storage location. Motive power is provided by dc permanent magnet gear motors, one each for the elevator and track switching device and two for the transfer cart drive system (one driving the cart horizontally and the other providing the vertical transfer). The control system, through the use of a microprocessor, provides complete automation through a feedback system which utilizes sensing devices.

  16. Macroscopic car condensation in a parking garage.

    PubMed

    Ha, Meesoon; Den Nijs, Marcel

    2002-09-01

    An asymmetric exclusion process type process, where cars move forward along a closed road that starts and terminates at a parking garage, displays dynamic phase transitions into two types of condensate phases where the garage becomes macroscopically occupied. The total car density rho(o) and the exit probability alpha from the garage are the two control parameters. At the transition, the number of parked cars N(p) diverges in both cases, with the length of the road N(s), as N(p) approximately N(y(p))(s) with y(p)=1/2. Towards the transition, the number of parked cars vanishes as N(p) approximately epsilon(beta) with beta=1, epsilon=/alpha-alpha(*)/ or epsilon=|rho(*)(o)-rho(o)/ being the distance from the transition. The transition into the normal phase represents also the onset of transmission of information through the garage. This gives rise to unusual parked car autocorrelations and car density profiles near the garage, which depend strongly on the group velocity of the fluctuations along the road.

  17. 3. TENSTALL GARAGE. NORTH AND WEST SIDES. VIEW TO SOUTHEAST. ...

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

    3. TEN-STALL GARAGE. NORTH AND WEST SIDES. VIEW TO SOUTHEAST. - Rainbow Hydroelectric Facility, Ten Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  18. 1. TWOSTALL GARAGE. FRONT (SOUTHWEST) SIDE. VIEW TO NORTHEAST. ...

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

    1. TWO-STALL GARAGE. FRONT (SOUTHWEST) SIDE. VIEW TO NORTHEAST. - Rainbow Hydroelectric Facility, Two Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  19. 3. TWOSTALL GARAGE SOUTHEAST AND NORTHEAST SIDES. VIEW TO WEST. ...

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

    3. TWO-STALL GARAGE SOUTHEAST AND NORTHEAST SIDES. VIEW TO WEST. - Rainbow Hydroelectric Facility, Two Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  20. 2. THREESTALL GARAGE. NORTHEAST SIDE. VIEW TO SOUTHWEST. Rainbow ...

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

    2. THREE-STALL GARAGE. NORTHEAST SIDE. VIEW TO SOUTHWEST. - Rainbow Hydroelectric Facility, Three Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  1. 1. THREESTALL GARAGE. SOUTHEAST AND NORTHEAST SIDES. VIEW TO WEST. ...

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

    1. THREE-STALL GARAGE. SOUTHEAST AND NORTHEAST SIDES. VIEW TO WEST. - Rainbow Hydroelectric Facility, Three Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  2. 3. THREESTALL GARAGE. NORTHWEST AND SOUTHWEST SIDES. VIEW TO EAST. ...

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

    3. THREE-STALL GARAGE. NORTHWEST AND SOUTHWEST SIDES. VIEW TO EAST. - Rainbow Hydroelectric Facility, Three Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  3. 4. MECHANIC'S GARAGE. SOUTHWEST CORNER, AND WEST AND SOUTH SIDES ...

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

    4. MECHANIC'S GARAGE. SOUTHWEST CORNER, AND WEST AND SOUTH SIDES OF ADDITION. VIEW TO NORTHEAST. - Holter Hydroelectric Facility, Mechanic's Garage, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  4. 2. View looking south, showing house, service wing, garage, connection ...

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

    2. View looking south, showing house, service wing, garage, connection to blacksmith shop/garage, setting - Lamprey House, South side of Dover Road, 0.05 mile east of Goboro Road, Epsom, Merrimack County, NH

  5. View of back of garage, windows of bays 13, facing ...

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

    View of back of garage, windows of bays 1-3, facing southwest. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  6. View of front and side of garage, bays 67, facing ...

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

    View of front and side of garage, bays 6-7, facing northeast. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  7. Interior view of garage showing roof, post and beam, and ...

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

    Interior view of garage showing roof, post and beam, and stored materials. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  8. View of front of garage, detail of building number over ...

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

    View of front of garage, detail of building number over bay 4. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  9. View of front of garage, bays 37, facing south ...

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

    View of front of garage, bays 3-7, facing south - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  10. View of front and side of garage, bay 7, facing ...

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

    View of front and side of garage, bay 7, facing east. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  11. View of front of garage, bays 14, facing northeast ...

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

    View of front of garage, bays 1-4, facing northeast - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  12. View of front of garage bays 57, facing northeast. ...

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

    View of front of garage bays 5-7, facing northeast. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  13. View of garage interior from northern bay looking south. ...

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

    View of garage interior from northern bay looking south. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  14. 1. VIEW OF LARGE GARAGE (FEATURE 13), FACING NORTHEAST. STORAGE ...

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

    1. VIEW OF LARGE GARAGE (FEATURE 13), FACING NORTHEAST. STORAGE BUILDING (FEATURE 24) IS VISIBLE ON THE HILL IN THE BACKGROUND. - Copper Canyon Camp of the International Smelting & Refining Company, Large Garage, Copper Canyon, Battle Mountain, Lander County, NV

  15. VIEW OF TANK (BLDG. 1929) AND GARAGE (BLDG. 1930). Looking ...

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

    VIEW OF TANK (BLDG. 1929) AND GARAGE (BLDG. 1930). Looking northwest - Edwards Air Force Base, X-15 Engine Test Complex, Tank & Garage, Rogers Dry Lake, east of Runway between North Base & South Base, Boron, Kern County, CA

  16. Bexar County Parking Garage Photovoltaic Panels

    SciTech Connect

    Weir, Golda

    2012-01-23

    The main objective of the Bexar County Parking Garage Photovoltaic (PV) Panel project is to install a PV System that will promote the use of renewable energy. This project will also help sustain Bexar County ongoing greenhouse gas emissions reduction and energy efficiency goals. The scope of this project includes the installation of a 100-kW system on the top level of a new 236,285 square feet parking garage. The PV system consists of 420 solar panels that covers 7,200 square feet and is tied into the electric-grid. It provides electricity to the office area located within the garage. The estimated annual electricity production of the PV system is 147,000 kWh per year.

  17. 4. Relationship of claim house, residence, and garage to each ...

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

    4. Relationship of claim house, residence, and garage to each other and immediate surroundings, looking northeast - George Spangerberger Farmstead, 2012 West Illinois Avenue, South Hutchinson, Reno County, KS

  18. GARAGE, SOUTH (REAR) AND EAST SIDE, LOOKING NORTHWEST Irvine ...

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

    GARAGE, SOUTH (REAR) AND EAST SIDE, LOOKING NORTHWEST - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  19. GARDEN (FOREGROUND), GARAGE (CENTER), AND PUMPHOUSE, LOOKING NORTHWEST Irvine ...

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

    GARDEN (FOREGROUND), GARAGE (CENTER), AND PUMPHOUSE, LOOKING NORTHWEST - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  20. Exhaust ventilation in attached garages improves residential indoor air quality.

    PubMed

    Mallach, G; St-Jean, M; MacNeill, M; Aubin, D; Wallace, L; Shin, T; Van Ryswyk, K; Kulka, R; You, H; Fugler, D; Lavigne, E; Wheeler, A J

    2017-03-01

    Previous research has shown that indoor benzene levels in homes with attached garages are higher than homes without attached garages. Exhaust ventilation in attached garages is one possible intervention to reduce these concentrations. To evaluate the effectiveness of this intervention, a randomized crossover study was conducted in 33 Ottawa homes in winter 2014. VOCs including benzene, toluene, ethylbenzene, and xylenes, nitrogen dioxide, carbon monoxide, and air exchange rates were measured over four 48-hour periods when a garage exhaust fan was turned on or off. A blower door test conducted in each garage was used to determine the required exhaust fan flow rate to provide a depressurization of 5 Pa in each garage relative to the home. When corrected for ambient concentrations, the fan decreased geometric mean indoor benzene concentrations from 1.04 to 0.40 μg/m(3) , or by 62% (P<.05). The garage exhaust fan also significantly reduced outdoor-corrected geometric mean indoor concentrations of other pollutants, including toluene (53%), ethylbenzene (47%), m,p-xylene (45%), o-xylene (43%), and carbon monoxide (23%) (P<.05) while having no impact on the home air exchange rate. This study provides evidence that mechanical exhaust ventilation in attached garages can reduce indoor concentrations of pollutants originating from within attached garages.

  1. GARAGE EXTERIOR EAST SIDE AND REAR SHOWING PIER SUPPORTS UNDER ...

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

    GARAGE EXTERIOR EAST SIDE AND REAR SHOWING PIER SUPPORTS UNDER SHED-ROOFED REAR STORAGE COMPARTMENT, ASBESTOS SIDING OVER ORIGINAL WOOD SIDING, AND SINGLE CASEMENT WINDOW OVER REAR STORAGE COMPARTMENT. VIEW TO NORTHWEST - Big Creek Hydroelectric System, Big Creek Town, Operator House Garage, Orchard Avenue south of Huntington Lake Road, Big Creek, Fresno County, CA

  2. 1. TENSTALL GARAGE. FRONT (EAST) AND SOUTH SIDES. VIEW TO ...

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

    1. TEN-STALL GARAGE. FRONT (EAST) AND SOUTH SIDES. VIEW TO NORTHWEST. - Rainbow Hydroelectric Facility, Ten Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  3. 2. TWOSTALL GARAGE. FRONT (SOUTHWEST) AND NORTHWEST SIDES. VIEW TO ...

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

    2. TWO-STALL GARAGE. FRONT (SOUTHWEST) AND NORTHWEST SIDES. VIEW TO EAST. - Rainbow Hydroelectric Facility, Two Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  4. 2. TENSTALL GARAGE. FRONT (EAST) AND PARTIAL NORTH SIDES. VIEW ...

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

    2. TEN-STALL GARAGE. FRONT (EAST) AND PARTIAL NORTH SIDES. VIEW TO SOUTHWEST. - Rainbow Hydroelectric Facility, Ten Stall Garage, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  5. Air Leakage and Air Transfer Between Garage and Living Space

    SciTech Connect

    Rudd, Armin

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed.

  6. 2. GARAGE. VIEW LOOKING NORTHWEST. THE ORIGINAL DOOR IN THE ...

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

    2. GARAGE. VIEW LOOKING NORTHWEST. THE ORIGINAL DOOR IN THE SOUTHEND HAS BEEN INFILLED. THE DARK RECTANGLE (AT RIGHT OF WINDOW) IS A PIECE OF PLYWOOD WITH AN ELECTRICAL RECEPTACLE ITS PURPOSE WAS NOT DETERMINED. - Tonto Ranger Station, Garage, Forest Service Road 65 at Tonto Wash, Skull Valley, Yavapai County, AZ

  7. 56. View of street level entrance to parking garage elevators ...

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

    56. View of street level entrance to parking garage elevators and detail of aluminum and glass connection to brick from east side of 1946/1948 store for homes and parking garage. - Rich's Downtown Department Store, 45 Broad Street, Atlanta, Fulton County, GA

  8. 3. DETAIL VIEW OF STATION GARAGE SHOWING SOUTHEAST FACADE WITH ...

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

    3. DETAIL VIEW OF STATION GARAGE SHOWING SOUTHEAST FACADE WITH WATER SOFTENER BUILDING (BUILDING NO. 42) TO LEFT AND ANIMAL HOUSE (BUILDING NO. 26) TO REAR. VIEW TO WEST. - VA Medical Center, Aspinwall Division, Station Garage, 5103 Delafield Avenue, Aspinwall, Allegheny County, PA

  9. VIEW OF TANK (BLDG. 1929) AND GARAGE (BLDG. 1930). SHOP ...

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

    VIEW OF TANK (BLDG. 1929) AND GARAGE (BLDG. 1930). SHOP (BUILDING 1928) IS THE LARGER STRUCTURE IN THE BACKGROUND. Looking southeast - Edwards Air Force Base, X-15 Engine Test Complex, Tank & Garage, Rogers Dry Lake, east of Runway between North Base & South Base, Boron, Kern County, CA

  10. Air Leakage and Air Transfer Between Garage and Living Space

    SciTech Connect

    Rudd, A.

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the Baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  11. Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, WEST (REAR), ...

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

    Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, WEST (REAR), LOOKING NORTHEAST - Irvine Ranch Agricultural Headquarters, Boyd Tenant House, Southeast of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  12. GARAGE (L) IN RELATION TO TENANT HOUSE (R), LOOKING SOUTHWEST ...

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

    GARAGE (L) IN RELATION TO TENANT HOUSE (R), LOOKING SOUTHWEST - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  13. Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, EAST (FRONT) ...

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

    Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, EAST (FRONT) AND WEST SIDE, LOOKING SOUTHEAST - Irvine Ranch Agricultural Headquarters, Boyd Tenant House, Southeast of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  14. Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, EAST (FRONT), ...

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

    Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, EAST (FRONT), LOOKING WEST - Irvine Ranch Agricultural Headquarters, Boyd Tenant House, Southeast of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  15. Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, SOUTH SIDE ...

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

    Everett Weinreb, Photographer, April 1989 GARAGE BEHIND HOUSE, SOUTH SIDE AND WEST (REAR) FACADES, LOOKING NORTHEAST - Irvine Ranch Agricultural Headquarters, Boyd Tenant House, Southeast of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  16. 2. FIRST FLOOR, FIRE ENGINE GARAGE, VIEW SHOWING STAIRWAY AND ...

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

    2. FIRST FLOOR, FIRE ENGINE GARAGE, VIEW SHOWING STAIRWAY AND FIRE POLE (NOTE THE STAMPWORK ON WALL AND CEILING) - Hoboken Fire Engine Company Number Two, 1313 Washington Street, Hoboken, Hudson County, NJ

  17. 8. INTERIOR, FIRE ALARM CONTROL ROOM (NORTH OF MAIN GARAGE), ...

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

    8. INTERIOR, FIRE ALARM CONTROL ROOM (NORTH OF MAIN GARAGE), FROM ENTRYWAY, LOOKING NORTH, SHOWING ADDITIONAL 'GAMEWELL' FIRE ALARM SYSTEMS. - Oakland Naval Supply Center, Firehouse, East of Fourth Street, between A & B Streets, Oakland, Alameda County, CA

  18. 9. LOOKING NORTHWEST TOWARD SOUTHERN SIDES OF BUILDING 1. GARAGE ...

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

    9. LOOKING NORTHWEST TOWARD SOUTHERN SIDES OF BUILDING 1. GARAGE ADDITION AT RIGHT. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

  19. 19. WINDOW DETAIL, NORTH WALL OF GARAGE ADDITION. VIEW SHOWS ...

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

    19. WINDOW DETAIL, NORTH WALL OF GARAGE ADDITION. VIEW SHOWS CONCRETE BLOCK CONSTRUCTION OF ADDITION. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

  20. 6. VIEW SOUTH TOWARD SOUTHERN PORTION OF BUILDING 1. GARAGE ...

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

    6. VIEW SOUTH TOWARD SOUTHERN PORTION OF BUILDING 1. GARAGE ADDITION AT LEFT. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

  1. 8. VIEW EAST, CIVILIAN CONSERVATION CORPS CAMP PARSONS GARAGE, MODERN ...

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

    8. VIEW EAST, CIVILIAN CONSERVATION CORPS CAMP PARSONS GARAGE, MODERN SHED, CIVILIAN CONSERVATION CORPS CAMP PARSONS BLACKSMITH SHOP, AND MODERN SHED. - Parsons Nursery, South side of U.S. Route 219, Parsons, Tucker County, WV

  2. Section A, view of cooling water pipes and parking garage ...

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

    Section A, view of cooling water pipes and parking garage entrance/exit on west slurry wall, looking west. (BH) - World Trade Center Site, Bounded by Vesey, Church, Liberty Streets, & Route 9A, New York County, NY

  3. 3. View of garages east of headgate operator's house, looking ...

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

    3. View of garages east of headgate operator's house, looking northeast. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, Headgate Operator's House, 600 North River Avenue, Dieringer, Pierce County, WA

  4. 5. GENERAL VIEW OF GARAGE AREA FROM WEST; STEPS TO ...

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

    5. GENERAL VIEW OF GARAGE AREA FROM WEST; STEPS TO WEST FRONT ENTRANCE VISABLE TO THE RIGHT - Isaac N. Hagan House, Kentuck Knob, U.S. Route 40 vicinity (Stewart Township), Chalkhill, Fayette County, PA

  5. 1. View looking south, showing blacksmith house/garage connecting to residential ...

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

    1. View looking south, showing blacksmith house/garage connecting to residential garage and setting - Lamprey Blacksmith Shop, South side of Dover Road, 0.05 miles east of Goboro Road, Epsom, Merrimack County, NH

  6. Oblique view of garage, looking southwest OvertheHorizon Backscatter Radar ...

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

    Oblique view of garage, looking southwest - Over-the-Horizon Backscatter Radar Network, Tulelake Radar Site Receive Sector Four Garage, Unnamed road west of Double Head Road, Tulelake, Siskiyou County, CA

  7. 2. View of stable looking south with garage/stable to the ...

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

    2. View of stable looking south with garage/stable to the right and paddock fence to the left - Richmond Hill Plantation, Stable/Garage, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  8. 1. VIEW OF CHICKEN COOP (FEATURE C7), FACING NORTHWEST. GARAGE ...

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

    1. VIEW OF CHICKEN COOP (FEATURE C-7), FACING NORTHWEST. GARAGE (FEATURE C-8) IS VISIBLE IN THE BACKGROUND. - Bell Family Residence, Chicken Coop & Garage, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  9. 4. 4CAR GARAGE. WEST SIDE (RIGHT) SHOWING JUNCTURE WITH SOUTH ...

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

    4. 4-CAR GARAGE. WEST SIDE (RIGHT) SHOWING JUNCTURE WITH SOUTH WALL (LEFT) OF MECHANIC'S GARAGE (MT-94-F). VIEW TO NORTHEAST. - Holter Hydroelectric Facility, Four-Car Garage, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  10. High-Tech Garage to Showcase Strategies for Reducing Energy (Fact Sheet)

    SciTech Connect

    Not Available

    2011-08-01

    NREL's new parking garage structure is proving that large garages can be designed and built sustainably at no extra cost. This fact sheet describes the garage's energy and water-saving measures, renewable energy technologies, sustainable and durable building materials, another campus improvements.

  11. 3. FOREMAN'S HOUSE, TENSTALL GARAGE, AND STEPS TO SWIMMING POOL. ...

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

    3. FOREMAN'S HOUSE, TEN-STALL GARAGE, AND STEPS TO SWIMMING POOL. VIEW TO SOUTH-SOUTHWEST. - Rainbow Hydroelectric Facility, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  12. 4. ROOF OF TWOSTALL GARAGE, SURGE TANK, HOUSE No. 16, ...

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

    4. ROOF OF TWO-STALL GARAGE, SURGE TANK, HOUSE No. 16, RELIEF TANK IN BACKGROUND. VIEW TO SOUTH. - Rainbow Hydroelectric Facility, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  13. 38. Photocopy of photograph (Pentran file), photographer unknown. Bus garage ...

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

    38. Photocopy of photograph (Pentran file), photographer unknown. Bus garage to left now demolished. Trolley car drivers, maintenance personnel and management staff in 1915. VIEW SOUTH - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  14. OBLIQUE VIEW OF POWERHOUSE OFFICE AND CORRUGATED METALCLAD VEHICLE GARAGE ...

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

    OBLIQUE VIEW OF POWERHOUSE OFFICE AND CORRUGATED METAL-CLAD VEHICLE GARAGE AND FUEL PUMP. MAINTENANCE BUILDING IS AT RIGHT CENTER. 90mm lens - Tule River Hydroelectric Complex, CA Highway 190 at North Fork of Middle Fork of Tule River, Springville, Tulare County, CA

  15. 1. Postandbeam garage (far left), oneroom log cabin (left of ...

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

    1. Post-and-beam garage (far left), one-room log cabin (left of center), house (right of center), garden shed and outhouse (far right). View to west-southwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  16. 7. INTERIOR, MAIN GARAGE, SOUTHERN WALL, FROM CLOSE TO WALL, ...

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

    7. INTERIOR, MAIN GARAGE, SOUTHERN WALL, FROM CLOSE TO WALL, LOOKING SOUTH, SHOWING 'GAMEWELL' FIRE ALARM TAPE CONTROL SYSTEM (TECHNOLOGY CIRCA 1910) AT CENTER, AND ENTRY TO OFFICE AT FAR RIGHT. - Oakland Naval Supply Center, Firehouse, East of Fourth Street, between A & B Streets, Oakland, Alameda County, CA

  17. General view, looking northeast. Retrofitted into a garage during the ...

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

    General view, looking northeast. Retrofitted into a garage during the twentieth century, this building dates from very early in the Lazaretto's history and is believed to have once functioned as a summer kitchen or bake house. - Lazaretto Quarantine Station, Kitchen/Bake House, Wanamaker Avenue and East Second Street, Essington, Delaware County, PA

  18. View of McKenzieRichey garage showing east side and north back. ...

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

    View of McKenzie-Richey garage showing east side and north back. Note log construction, house in the background and fence in the foreground, facing southwest - McKenzie Property, Garage, North Bank of Sailor Gulch, 750 feet northwest of intersection of U.S.F.S. Roads 651 & 349, Placerville, Boise County, ID

  19. View of McKenzieRichey garage showing front opening, the false front, ...

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

    View of McKenzie-Richey garage showing front opening, the false front, metal roofing and horizontal plank siding, facing northeast - McKenzie Property, Garage, North Bank of Sailor Gulch, 750 feet northwest of intersection of U.S.F.S. Roads 651 & 349, Placerville, Boise County, ID

  20. Technology Solutions Case Study: Air Leakage and Air Transfer Between Garage and Living Space, Waldorf, Maryland

    SciTech Connect

    2014-11-01

    In this project, Building Science Corporation worked with production homebuilder K. Hovnanian to evaluate air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multipoint fan pressurization tests and additional zone pressure diagnostic testing measured the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  1. 2. View looking east, showing west elevation of blacksmith shop/garage ...

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

    2. View looking east, showing west elevation of blacksmith shop/garage and change in slope - Lamprey Blacksmith Shop, South side of Dover Road, 0.05 miles east of Goboro Road, Epsom, Merrimack County, NH

  2. Pumphouse/garage and shed, looking southwest Thomas Murphy Homestead, North ...

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

    Pumphouse/garage and shed, looking southwest - Thomas Murphy Homestead, North of John Moulton Homestead, approximately 1,000 feet west of Mormon Row Road, and .25 mile north of Antelope Flats Road, Kelly, Teton County, WY

  3. 2. Oblique view of caretaker's house with garage/stable to the ...

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

    2. Oblique view of caretaker's house with garage/stable to the left looking south - Richmond Hill Plantation, Caretaker's House, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  4. 4. Oblique view of caretaker's house with garage/stable to the ...

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

    4. Oblique view of caretaker's house with garage/stable to the right looking north - Richmond Hill Plantation, Caretaker's House, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  5. 6. Southeast side of the caretaker's house with garage/stable to ...

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

    6. Southeast side of the caretaker's house with garage/stable to the left in background - Richmond Hill Plantation, Caretaker's House, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  6. 26. GARAGE AND RETAINING WALLS NEAR SAR3. NOTE SEVEN OAKS ...

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

    26. GARAGE AND RETAINING WALLS NEAR SAR-3. NOTE SEVEN OAKS DAM ROAD CONSTRUCTION SCAR ON MOUNTAINSIDE IN DISTANCE. VIEW TO NORTHWEST. - Santa Ana River Hydroelectric System, Redlands, San Bernardino County, CA

  7. 3. FROM LEFT TO RIGHT: RESIDENCE/SCHOOLHOUSE (FEATURE 14), LARGE GARAGE ...

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

    3. FROM LEFT TO RIGHT: RESIDENCE/SCHOOLHOUSE (FEATURE 14), LARGE GARAGE (FEATURE 13), AND RESIDENCE (FEATURE 12). FACING NORTH. - Copper Canyon Camp of the International Smelting & Refining Company, Residence, Copper Canyon, Battle Mountain, Lander County, NV

  8. 1. Overview of Hailey Administrative Site looking west. Garage/Equipment building ...

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

    1. Overview of Hailey Administrative Site looking west. Garage/Equipment building left foreground, Office rear center, Gas and Oil House on the right. - Hailey Administrative Site, 309 South Main Street, Hailey, Blaine County, ID

  9. Preliminary investigation of uncombusted auto fuel vapor dispersion within a residential garage microenvironment

    SciTech Connect

    Lansari, A.; Streicher, J.J.; Huber, A.H.; Crescenti, G.H.; Zweidinger, R.B.

    1993-01-01

    Evaporative emissions from vehicles in an attached garage may represent a significant source of indoor pollution and human exposure. A pilot field study was undertaken to investigate potential in-house dispersion of evaporative emissions of uncombusted fuels from a vehicle parked inside an attached garage. In a set of experiments using sulfur hexafluoride tracer gas, the multizonal mass balance model, CONTAM88, was used to predict interzonal air flow rates and SF6 concentration distributions within the garage and house. Several experiments were included to evaluate the effect of meteorology and mechanical mixing mechanisms on the dispersion of automobile fuel vapor. Measurements indicated that approximately three percent of the garage maximum concentration was measured in a room adjacent to the garage. The model successfully predicted garage concentrations under well mixed conditions, but underpredicted the measured concentrations within various rooms of the house, in which mixing was incomplete. Multizonal mass balance models such as CONTAM88 may be useful in approximating contaminant concentrations at various locations within the house.

  10. LED Update

    SciTech Connect

    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.

  11. LED lamp

    SciTech Connect

    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.

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

    SciTech Connect

    2011-01-01

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

  13. A One-Piece Lunar Regolith Bag Garage Prototype

    NASA Technical Reports Server (NTRS)

    Smithers, G. A.; Nehls, M. K.; Hovater, M. A.; Evans, S. W.; Miller, J. S.; Broughton, R. M., Jr.; Beale, D.; Kilinc-Balci, F.

    2007-01-01

    Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. This Technical Memorandum details the design and construction of a prototype for a one-piece regolith bag unpressurized garage concept and a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. The conceptualization was that a lightweight fabric form be launched from Earth and landed on the lunar surface to be robotically filled with raw lunar regolith. Regolith bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and also performed under cold and elevated temperatures. In some cases, Johnson Space Center lunar simulant (JSC-1) was used in conjunction with testing. A series of preliminary structures was constructed during final prototype design based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite. The structure is free-standing, but has not yet been load tested. Future plans would be to construct higher fidelity prototypes and to conduct appropriate tests of the structure.

  14. Light Emitting Diodes (LEDs)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique, called Photodynamic Therapy, requires the surgeon to use tiny, pinhead-size Light Emitting Diodes (LEDs) (a source that releases long wavelengths of light ) to activate light-sensitive, tumor-treating drugs. 'A young woman operated on in May 1999 has fully recovered with no complications and no evidence of the tumor coming back,' said Dr. Harry Whelan, a pediatric neurologist at the Medical Hospital of Wisconsin in Milwaukee. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can be used for hours at a time while still remaining cool to the touch. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The LEDs, developed and managed by NASA's Marshall Space Flight Center, have been used on seven Space Shuttle flights inside the Microgravity Astroculture Facility. This technology has also been successfully used to further commercial research in crop growth.

  15. Respiratory symptoms and lung function in garage workers and taxi drivers.

    PubMed

    Bener, A; Galadari, I; al-Mutawa, J K; al-Maskari, F; Das, M; Abuzeid, M S

    1998-12-01

    The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p < 0.007); dyspneoa (p < 0.001); and sinusitis (p < 0.03). A higher prevalence of all acute symptoms was recorded in garage workers than in taxi drivers, although the differences were significant only for throat (p < 0.02), hearing problems (p < 0.002); nose (dryness, bleeding and secretion) (p < 0.008); and low back pain (p < 0.05). Almost all forced spirometric tests in the exposed garage workers were lower than in taxi drivers. The results of stepwise multiple regression analysis showed that only phlegm, sinusitis, hearing problems, nasal catarrh, throat, low back pain, smoking and FEF25-75, variables were statistically significant predictors as risk factors. In conclusion, the present study suggests that a high prevalence of respiratory symptoms is associated with exposure to motor vehicle exhaust emission in garage working places. Long-term working as garage workers in the United Arab Emirates (UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.

  16. A One-Piece Lunar Regolith-Bag Garage Prototype

    NASA Technical Reports Server (NTRS)

    Smithers, Gweneth A.; Nehls, Mary K.; Hovater, Mary A.; Evans, Steven W.; Miller, J. Scott; Broughton, Roy M.; Beale, David; Killing-Balci, Fatma

    2007-01-01

    Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. We designed and constructed a prototype for a one-piece regolith-bag unpressurized garage concept, and, in parallel, we conducted a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. In our concept, a lightweight fabric form is launched from Earth to be landed on the lunar surface and robotically filled with raw lunar regolith. In the materials testing program, regolith-bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and, within our current means, we also performed these tests under cold and elevated temperatures. In some cases, lunar simulant (JSC-1) was used in conjunction with testing. Our ambition is to continuously refine our testing to reach lunar environmental conditions to the extent possible. A series of preliminary structures were constructed during design of the final prototype. Design is based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite (fairly close to the weight of lunar regolith on the moon). The structure is free-standing, but has not yet been load tested. Our plan for the future would be to construct higher fidelity mockups with each iteration, and to conduct appropriate tests of the structure.

  17. A One-Piece Lunar Regolith-Bag Garage Prototype

    NASA Technical Reports Server (NTRS)

    Smithers, Gweneth A.; Nehls, Mary K.; Hovater, Mary A.; Evans, Steven W.; Miller, J. Scott; Broughton, Roy M., Jr.; Beale, David; Killinc-Balci, Fatma

    2006-01-01

    Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. We designed and constructed a prototype for a one-piece regolith-bag unpressurized garage concept, and, in parallel, we conducted a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. In our concept, a lightweight fabric form is launched from Earth to be landed on the lunar surface and robotically filled with raw lunar regolith. In the materials testing program, regolith-bag fabric candidates included: VectranTM, NextelTM, Gore PTFE FabricTM, ZylonTM TwaronTM and NomexTM. Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and, within our current means, we also performed these tests under cold and elevated temperatures. In some cases, lunar simulant (JSC-1) was used in conjunction with testing. Our ambition is to continuously refine our testing to reach lunar environmental conditions to the extent possible. A series of preliminary structures were constructed during design of the final prototype. Design is based on the principles of the classic masonry arch. The prototype was constructed of KevlarTM and filled with vermiculite (fairly close to the weight of lunar regolith on the moon). The structure is free-standing, but has not yet been load tested. Our plan for the future would be to construct higher fidelty mockups with each iteration, and to conduct appropriate tests of the structure.

  18. Building America Case Study: Air Leakage and Air Transfer Between Garage and Living Space, Waldorf, Maryland (Fact Sheet)

    SciTech Connect

    Not Available

    2014-11-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the Baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  19. Light Emitting Diode (LED)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique called photodynamic therapy, requires the surgeon to use tiny pinhead-size Light Emitting Diodes (LEDs) (a source releasing long wavelengths of light) to activate light-sensitive, tumor-treating drugs. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can also be used for hours at a time while still remaining cool to the touch. The LED probe consists of 144 tiny pinhead-size diodes, is 9-inches long, and about one-half-inch in diameter. The small balloon aids in even distribution of the light source. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The probe was developed for photodynamic cancer therapy by the Marshall Space Flight Center under a NASA Small Business Innovative Research program grant.

  20. 18 CFR 367.3940 - Account 394, Tools, shop and garage equipment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Account 394, Tools, shop and garage equipment. 367.3940 Section 367.3940 Conservation of Power and Water Resources FEDERAL.... (17) Gasoline pumps, oil pumps and storage tanks. (18) Greasing tools and equipment. (19) Hoists....

  1. 17 CFR 256.309 - Automobiles, other vehicles, and related garage equipment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Automobiles, other vehicles... § 256.309 Automobiles, other vehicles, and related garage equipment. This account shall include the delivered cost of all service company owned automobiles, vans, trucks, and other vehicles used by...

  2. 17 CFR 256.309 - Automobiles, other vehicles, and related garage equipment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Automobiles, other vehicles... § 256.309 Automobiles, other vehicles, and related garage equipment. This account shall include the delivered cost of all service company owned automobiles, vans, trucks, and other vehicles used by...

  3. Effects of garage employment and tobacco smoking on breathing-zone concentrations of carbonyl compounds.

    PubMed

    Zhang, Lin; Chung, Fung-Lung; Boccia, Laura; Colosimo, Steven; Liu, Weili; Zhang, Junfeng

    2003-01-01

    Exposure to carbonyl compounds may cause adverse health effects. The present study examined whether working in a garage and smoking can significantly affect personal "daily" exposure to a number of important carbonyl compounds. The study was carried out on 37 subjects including 22 garage workers (9 smokers and 13 nonsmokers) and 15 nongarage workers or so-called controls (4 smokers and 11 nonsmokers). Daily exposure was estimated using 48-hour integrated measurement of breathing-zone concentrations. The measurement involved the use of a passive carbonyl sampler and high performance liquid chromatography/fluorescence analysis technique. Each subject was measured for up to three measurement sessions. A wide range of breathing-zone concentrations (unit: microgram per cubic meter) was observed for each of the following carbonyls: formaldehyde (14.1-80.1); acetaldehyde (8.41-80.3); acetone (0.65-1096); acrolein (<0.14-3.71); propionaldehyde (1.08-14.6); crotonaldehyde (<0.13-2.80); benzaldehyde (1.79-9.91); and hexaldehyde (0.122-22.4). Statistical significance of smoking effects and working in a garage effects were assessed using SAS mixed models. The results show that the garage workers had significantly higher levels of formaldehyde and acetaldehyde than the controls, and that the smokers had significantly higher levels of acetaldehyde, propionaldehyde, and hexaldehyde, than the nonsmokers (P<.10). Garage employment and smoking appeared to increase breathing-zone concentrations of crotonaldehyde. In general, within-subject variations were smaller than between-subject variations on 48-hour averaged breathing-zone concentrations of carbonyl compounds.

  4. EPA Proposes Additional Water Line Connections for Groundwater Contamination at Tinkham Garage Superfund Site in Londonderry, NH

    EPA Pesticide Factsheets

    The U.S. EPA in consultation with NHDES, is proposing additional connections to an existing water line for residents whose wells have been found to have contamination and whom live northeast section of the Tinkham Garage Superfund Site (Site).

  5. Concentrations of vehicle-related air pollutants in an urban parking garage.

    PubMed

    Kim, Sung R; Dominici, Francesca; Buckley, Timothy J

    2007-11-01

    There is growing evidence that traffic-related air pollution poses a public health threat, yet the dynamics of human exposure are not well understood. The urban parking garage is a microenvironment that is of concern but has not been characterized. Using time-resolved measurement methods, we evaluated air toxics levels within an urban parking garage and assessed the influence of vehicle activity and type on their levels. Carbon monoxide (CO) and particle-bound polycyclic aromatic hydrocarbons (pPAH) were measured with direct-reading instruments. Volatile organic compounds (VOCs) were measured in 30 min intervals using a sorbent tube loaded sequential sampler. Vehicle volume and type were evaluated by video recording. Sampling was conducted from June 24 to July 17, 2002. We observed garage traffic median volumes of 71 counts/h on weekdays and 6 counts/h on weekends. The 12-fold reduction in traffic volume from weekday to weekend corresponded with a decrease in median air pollution that varied from a minimum 2- (CO) to a maximum 7 (pPAH)-fold. The actual 30-min median weekday and weekend values were: CO--2.6/1.2 ppm; pPAH--19/2.6 ng/m(3); 1,3-butadiene-0.5/0.2 microg/m(3), MTBE-7.4/0.4 microg/m(3); and benzene-2.7/0.3 microg/m(3). The influence of traffic was quantified using longitudinal models. The pollutant coefficients provide an indication of the average air pollution vehicle source contribution and ranged from 0.31 (CO) to 1.08 (pPAH) percent increase/vehicle count. For some pollutants, a slightly higher (0.5-0.6%) coefficient was observed for light-trucks relative to cars. This study has public health relevance in providing a unique assessment of air pollution levels and source contribution for the urban parking garage.

  6. System Reliability for LED-Based Products

    SciTech Connect

    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.

  7. LEDs for Efficient Energy

    ERIC Educational Resources Information Center

    Guerin, David A.

    1978-01-01

    Light-emitting diodes (LEDs) are described and three classroom experiments are given, one to prove the, low power requirements and efficiency of LEDs, an LED on-off detector circuit, and the third an LED photoelectric smoke detector. (BB)

  8. Superfund record of decision (EPA Region 1): Town Garage Radio Beacon, Londonderry, NH. (First remedial action), September 1992. Final report

    SciTech Connect

    Not Available

    1992-09-30

    The Town Garage Radio Beacon, NH, site includes the Holton Circle residential development of 23 homes, a town garage area, and an undeveloped hillslope and wetlands area in Londonderry, New Hampshire. From 1940 to 1968, the area was owned by the Department of Defense (DOD), who reportedly used it as a radio beacon facility from 1940 to 1947. The ROD provides a final remedy for the contaminated onsite ground water. No further remedial actions are anticipated for the site. The primary contaminants affecting the ground water are VOCs; and metals, including chromium.

  9. Arbitrary object localization and tracking via multiple-camera surveillance system embedded in a parking garage

    NASA Astrophysics Data System (ADS)

    Ibisch, André; Houben, Sebastian; Michael, Matthias; Kesten, Robert; Schuller, Florian

    2015-03-01

    We illustrate a multiple-camera surveillance system installed in a parking garage to detect arbitrary moving objects. Our system is real-time capable and computes precise and reliable object positions. These objects are tracked to warn of collisions, e.g. between vehicles, pedestrians or other vehicles. The proposed system is based on multiple grayscale cameras connected by a local area network. Each camera shares its field of view with other cameras to handle occlusions and to enable multi-view vision. We aim at using already installed hardware found in many modern public parking garages. The system's pipeline starts with the synchronized image capturing process separately for each camera. In the next step, moving objects are selected by a foreground segmentation approach. Subsequently, the foreground objects from a single camera are transformed into view rays in a common world coordinate system and are joined to receive plausible object hypotheses. This transformation requires a one-time initial intrinsic and extrinsic calibration beforehand. Afterwards, these view rays are filtered temporally to arrive at continuous object tracks. In our experiments we used a precise LIDAR-based reference system to evaluate and quantify the proposed system's precision with a mean localization accuracy of 0.24m for different scenarios.

  10. Can We Afford These Affordances? GarageBand and the Double-Edged Sword of the Digital Audio Workstation

    ERIC Educational Resources Information Center

    Bell, Adam Patrick

    2015-01-01

    The proliferation of computers, tablets, and smartphones has resulted in digital audio workstations (DAWs) such as GarageBand in being some of the most widely distributed musical instruments. Positing that software designers are dictating the music education of DAW-dependent music-makers, I examine the fallacy that music-making applications such…

  11. A Case Study Exploring the Use of GarageBand[TM] and an Electronic Bulletin Board in Preservice Music Education

    ERIC Educational Resources Information Center

    Vratulis, Vetta; Morton, Charlene

    2011-01-01

    This qualitative research study is an exploration of the merit and shortcomings of using a combination of the music software GarageBand[TM] and an electronic bulletin board to facilitate musical and peer learning in a 3-month elementary music methods curriculum and instruction course. A pedagogical objective of this assignment was to increase the…

  12. LED Color Characteristics

    SciTech Connect

    2012-01-01

    Color quality is an important consideration when evaluating LED-based products for general illumination. This fact sheet reviews the basics regarding light and color and summarizes the most important color issues related to white-light LED systems.

  13. Industrial scale garage-type dry fermentation of municipal solid waste to biogas.

    PubMed

    Qian, M Y; Li, R H; Li, J; Wedwitschka, H; Nelles, M; Stinner, W; Zhou, H J

    2016-10-01

    The objectives of this study was to through monitoring the 1st industrial scale garage-type dry fermentation (GTDF) MSW biogas plant in Bin County, Harbin City, Heilongjiang Province, China, to investigate its anaerobic digestion (AD) performance and the stability of process. After a monitoring period of 180days, the results showed that the volumetric biogas production of the digesters and percolate tank was 0.72 and 2.22m(3) (m(3)d)(-1), respectively, and the specific biogas yield of the feedstock was about 270m(3)CH4tVS(-1), which indicated that the GTDF is appropriate for the Chinese MSW. This paper also raised some problems aimed at improving the process stability and AD efficiency.

  14. Pulmonary function abnormalities associated with exposure to automobile exhaust in a diesel bus garage and roads.

    PubMed

    Chattopadhyay, B P; Alam, J; Roychowdhury, A

    2003-01-01

    In Kolkata city the road transports are maintained by private and Government organization. A major work force belonged to the State Transport Corporation (KSTC), Government of West-Bengal. The pollution caused by these vehicles affects the workers health and caused different types of respiratory problems. This study was undertaken to assess the pulmonary function status of these workers. City KSTC garage workers were investigated and categorically divided into two group: garage mechanics and the (2) those transporting the passengers (drivers and conductors). Vital capacity (VC), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were recorded by Spirovit-SP-10 (Schiller Ltd, Switzerland) and Wright's Peak Flow Meter (UK) on 236 workers. The different flow volumes, FEV(1), FEV(1%), and flow rates, FEF(02-121), FEF(25-75%), etc. were calculated. The administrative people had higher PFT than the other categories. Drivers and conductors have almost equal mean PFT values but mechanical workers had slightly higher. PFT values according to different age ranges and duration of exposure showed gradual decrement as age and duration of exposure increased. Non-smokers had higher lung volumes compared to smokers and ex-smokers. Restrictive, obstructive and combined types of impairments were noticed in 28.4%, 1.7% and 2.9%, respectively, workers. The restrictive impairment was found to be 30.4% in conductors; 28.9% in drivers, 27.9% in mechanics and 21.7% in administration people. Obstructive type of impairment was found to be 2.9% in both drivers and conductors. The effect of pollution by dust and fumes may be responsible for these pulmonary function impairments, restrictive impairments being greater.

  15. Refrigerated display case lighting with LEDs

    NASA Astrophysics Data System (ADS)

    Raghavan, Ramesh; Narendran, Nadarajah

    2002-11-01

    The rapid development of high brightness light emitting diodes (LEDs) has triggered many applications, especially in the area of display lighting. This paper focuses on the application of white LEDs in refrigerated display cases. The fluorescent lighting presently used in commercial refrigerators is inefficient in the application and also it provides poor lighting for merchandising. A laboratory human factors experiment was conducted to assess the preference for the different lighting systems, namely, fluorescent and LED. Two refrigerated display cases, one with the traditional fluorescent lighting system and the other with a prototype LED lighting system, were placed side-by-side in a laboratory setting. Illuminance measurements made within the two display cases showed that the lighting was more uniform with the LED system compared to the traditional fluorescent system. Sixteen human subjects participated in this study and rated their preference for the two lighting systems. The results show that human subjects strongly preferred the display case with the LED lighting. The authors of this manuscript believe a field study would be greatly beneficial to further confirm these results and to understand the relationship between preference and sales. Considering the luminous efficacy of white LEDs presently available in the marketplace, it is possible to develop a LED based lighting system for commercial refrigerators that is competitive with fluorescent lighting system in terms of energy use. The LED based lighting would provide better lighting than traditional fluorescent lighting.

  16. LED champing: statistically blessed?

    PubMed

    Wang, Zhuo

    2015-06-10

    LED champing (smart mixing of individual LEDs to match the desired color and lumens) and color mixing strategies have been widely used to maintain the color consistency of light engines. Light engines with champed LEDs can easily achieve the color consistency of a couple MacAdam steps with widely distributed LEDs to begin with. From a statistical point of view, the distributions for the color coordinates and the flux after champing are studied. The related statistical parameters are derived, which facilitate process improvements such as Six Sigma and are instrumental to statistical quality control for mass productions.

  17. Diodes stabilize LED output

    NASA Technical Reports Server (NTRS)

    Deters, R. A.

    1977-01-01

    Small-signal diodes are placed in series with light-emitting diodes (LED's) to stabilize LED output against temperature fluctuations. Simple inexpensive method compensates for thermal fluctuations over a broad temperature range. Requiring few components, technique is particularly useful where circuit-board space is limited.

  18. Large area LED package

    NASA Astrophysics Data System (ADS)

    Goullon, L.; Jordan, R.; Braun, T.; Bauer, J.; Becker, F.; Hutter, M.; Schneider-Ramelow, M.; Lang, K.-D.

    2015-03-01

    Solid state lighting using LED-dies is a rapidly growing market. LED-dies with the needed increasing luminous flux per chip area produce a lot of heat. Therefore an appropriate thermal management is required for general lighting with LEDdies. One way to avoid overheating and shorter lifetime is the use of many small LED-dies on a large area heat sink (down to 70 μm edge length), so that heat can spread into a large area while at the same time light also appears on a larger area. The handling with such small LED-dies is very difficult because they are too small to be picked with common equipment. Therefore a new concept called collective transfer bonding using a temporary carrier chip was developed. A further benefit of this new technology is the high precision assembly as well as the plane parallel assembly of the LED-dies which is necessary for wire bonding. It has been shown that hundred functional LED-dies were transferred and soldered at the same time. After the assembly a cost effective established PCB-technology was applied to produce a large-area light source consisting of many small LED-dies and electrically connected on a PCB-substrate. The top contacts of the LED-dies were realized by laminating an adhesive copper sheet followed by LDI structuring as known from PCB-via-technology. This assembly can be completed by adding converting and light forming optical elements. In summary two technologies based on standard SMD and PCB technology have been developed for panel level LED packaging up to 610x 457 mm2 area size.

  19. LEDs Are Diodes.

    ERIC Educational Resources Information Center

    Lisensky, George C.; Condren, S. Michael; Widstrand, Cynthia G.; Breitzer, Jonathan; Ellis, Arthur B.

    2001-01-01

    Describes an activity comparing incandescent bulbs and LEDs powered by dc and ac voltage sources to illustrate properties of matter and the interactions of energy and matter. Includes both instructor information and student activity sheet. (Author/YDS)

  20. Energy Efficiency of LEDs

    SciTech Connect

    2013-03-01

    Solid-state lighting program technology fact sheet on energy efficiency of LEDs, characterizing the current state of the market and discussing package efficacy, luminaire efficacy, and application efficacy.

  1. White LED performance

    NASA Astrophysics Data System (ADS)

    Gu, Yimin; Narendran, Nadarajah; Freyssinier, Jean Paul

    2004-10-01

    Two life tests were conducted to compare the effects of drive current and ambient temperature on the degradation rate of 5 mm and high-flux white LEDs. Tests of 5 mm white LED arrays showed that junction temperature increases produced by drive current had a greater effect on the rate of light output degradation than junction temperature increases from ambient heat. A preliminary test of high-flux white LEDs showed the opposite effect, with junction temperature increases from ambient heat leading to a faster depreciation. However, a second life test is necessary to verify this finding. The dissimilarity in temperature effect among 5 mm and high-flux LEDs is likely caused by packaging differences between the two device types.

  2. Deep UV LEDs

    NASA Astrophysics Data System (ADS)

    Han, Jung; Amano, Hiroshi; Schowalter, Leo

    2014-06-01

    Deep ultraviolet (DUV) photons interact strongly with a broad range of chemical and biological molecules; compact DUV light sources could enable a wide range of applications in chemi/bio-sensing, sterilization, agriculture, and industrial curing. The much shorter wavelength also results in useful characteristics related to optical diffraction (for lithography) and scattering (non-line-of-sight communication). The family of III-N (AlGaInN) compound semiconductors offers a tunable energy gap from infrared to DUV. While InGaN-based blue light emitters have been the primary focus for the obvious application of solid state lighting, there is a growing interest in the development of efficient UV and DUV light-emitting devices. In the past few years we have witnessed an increasing investment from both government and industry sectors to further the state of DUV light-emitting devices. The contributions in Semiconductor Science and Technology 's special issue on DUV devices provide an up-to-date snapshot covering many relevant topics in this field. Given the expected importance of bulk AlN substrate in DUV technology, we are pleased to include a review article by Hartmann et al on the growth of AlN bulk crystal by physical vapour transport. The issue of polarization field within the deep ultraviolet LEDs is examined in the article by Braut et al. Several commercial companies provide useful updates in their development of DUV emitters, including Nichia (Fujioka et al ), Nitride Semiconductors (Muramoto et al ) and Sensor Electronic Technology (Shatalov et al ). We believe these articles will provide an excellent overview of the state of technology. The growth of AlGaN heterostructures by molecular beam epitaxy, in contrast to the common organo-metallic vapour phase epitaxy, is discussed by Ivanov et al. Since hexagonal boron nitride (BN) has received much attention as both a UV and a two-dimensional electronic material, we believe it serves readers well to include the

  3. Geohydrology and contamination at the Michigan Department of Transportation maintenance garage area, Kalamazoo County, Michigan

    USGS Publications Warehouse

    Lynch, E.A.; Huffman, G.C.

    1996-01-01

    A leaking underground storage tank was removed from the Michigan Department of Transportation maintenance garage area in Kalamazoo County., Mich., in 1985. The tank had been leaking unleaded gasoline. Although a remediation system was operational at the site for several years after the tank was removed, ground-water samples collected from monitoring wells in the area consistently showed high concentrations of benzene, toluene. ethylbenzene, and xylenes--indicators of the presence of gasoline. The U.S. Geological Survey did a study in cooperation with the Michigan Department of Transportation, to define the geology, hydrology, and occurrence of gasoline contamination in the maintenance garage area. The aquifer affected by gasoline contamination is an unconfined glaci'a.l sand and gravel aquifer. The average depth to water in the study area is about 74.7 feet. Water-level fluctuations are small; maximum fluctuation was slightly more than 1 foot during August 1993-August 1994. Hydraulic conductivities based on aquifer-test data collected for the study and estimated by use of the Cooper-Jacob method of solution ranged from 130 to 144 feet per day. Ground water is moving in an east-southeasterly direction at a rate of about I foot per day. Leakage from perforated pipes leading from the underground storage tanks to the pump station was identified as a second source of gasoline contamination to saturated and unsaturated zones. The existence of this previously unknown second source is part of the reason that previous remediation efforts were ineffective. Residual contaminants in the unsaturated zone are expected to continue to move to the water table with recharge, except in a small area covered by asphalt at the land surface. The gasoline plume from the perforated pipe source has merged with that from the leaking underground storage tank, and the combined plume in the saturated zone is estimated to cover an area of 30,000 square feet. The combined plume is in the upper 20

  4. [LED lights in dermatology].

    PubMed

    Noé, C; Pelletier-Aouizerate, M; Cartier, H

    2017-04-01

    The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology.

  5. Increased Efficiency LED

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O. (Inventor); Rogowski, Robert S. (Inventor)

    1998-01-01

    In an LED a large portion of the light produced is lost due to total internal reflection at the air-semiconductor interface. A reverse taper of the semiconductor is used to change the angle at which light strikes the interface so that a greater portion of the light is transmitted.

  6. High Power UV LED Industrial Curing Systems

    SciTech Connect

    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.

  7. Large Stereoscopic LED Display by Use of a Parallax Barrier

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hirotsugu; Hayasaki, Yoshio; Nishida, Nobuo

    Since the development of high-brightness blue and green LEDs, the use of outdoor commercial LED displays has been increasing. Because of their high-brightness, good visibility, and long-term durability, LED displays are a preferred technology for outdoor installations such as stadiums, street advertising, and billboards. This chapter deals with a large stereoscopic full-color LED display using a parallax barrier. We discuss optimization of viewing areas, which depend on LED arrangements. Enlarged viewing areas have been demonstrated by using a three-in-one chip LED panel that has wider black regions than ordinary LED lamp cluster panels. We have developed a real-time system to measure a viewer's position and investigated the movements of viewers who watch different designs of stereoscopic LED displays, including conventional designs and designs to eliminate pseudoscopic viewing areas. The design of parallax barrier for plural viewers was utilized for a 140-inch stereoscopic LED display.

  8. Epidemiological-environmental study of diesel bus garage workers: chronic effects of diesel exhaust on the respiratory system

    SciTech Connect

    Gamble, J.; Jones, W.; Minshall, S.

    1987-10-01

    Two hundred and eighty-three (283) male diesel bus garage workers from four garages in two cities were examined to determine if there was excess chronic respiratory morbidity related to diesel exposure. The dependent variables were respiratory symptoms, radiographic interpretation for pneumoconiosis, and pulmonary function (FVC, FEV1, and flow rates). Independent variables included race, age, smoking, drinking, height, and tenure (as surrogate measure of exposure). Exposure-effect relationships within the study population showed no detectable associations of symptoms with tenure. There was an apparent association of pulmonary function and tenure. Seven workers (2.5%) had category 1 pneumoconiosis (three rounded opacities, two irregular opacities, and one with both rounded and irregular). The study population was also compared to a nonexposed blue-collar population. After indirect adjustment for age, race, and smoking, the study population had elevated prevalences of cough, phlegm, and wheezing, but there was no association with tenure. Dyspnea showed a dose-response trend but no apparent increase in prevalence. Mean percent predicted pulmonary function of the study population was greater than 100%, i.e., elevated above the comparison population. These data show there is an apparent effect of diesel exhaust on pulmonary function but not chest radiographs. Respiratory symptoms are high compared to blue-collar workers, but there is no relationship with tenure.

  9. Comparative assessment of blood lead levels of automobile technicians in organised and roadside garages in Lagos, Nigeria.

    PubMed

    Saliu, Abdulsalam; Adebayo, Onajole; Kofoworola, Odeyemi; Babatunde, Ogunowo; Ismail, Abdussalam

    2015-01-01

    Occupational exposure to lead is common among automobile technicians and constitutes 0.9% of total global health burden with a majority of cases in developing countries. The aim of this study was to determine and compare the blood lead levels of automobile technicians in roadside and organised garages in Lagos State, Nigeria. This was a comparative cross-sectional study. Data were collected using interviewer-administered questionnaires. Physical examinations were conducted and blood was analysed for lead using atomic spectrophotometery. Statistical analyses were performed to compare the median blood lead levels of each group using the independent sample (Mann-Whitney U) test. Seventy-three (40.3%) of the organised compared to 59 (34.3%) of the roadside groups had high blood lead levels. The organised group had statistically significant higher median blood lead levels of, 66.0 µg/dL than the roadside 43.5 µg/dL (P < 0.05). There was also statistically significant association between high blood lead levels and abnormal discolouration of the mucosa of the mouth in the organised group. Automobile technicians in organised garages in Lagos have higher prevalence of elevated blood lead levels and higher median levels than the roadside group. Preventive strategies against lead exposures should be instituted by the employers and further actions should be taken to minimize exposures, improve work practices, implement engineering controls (e.g., proper ventilation), and ensure the use of personal protective equipment.

  10. Comparative Assessment of Blood Lead Levels of Automobile Technicians in Organised and Roadside Garages in Lagos, Nigeria

    PubMed Central

    Saliu, Abdulsalam; Adebayo, Onajole; Kofoworola, Odeyemi; Babatunde, Ogunowo; Ismail, Abdussalam

    2015-01-01

    Occupational exposure to lead is common among automobile technicians and constitutes 0.9% of total global health burden with a majority of cases in developing countries. The aim of this study was to determine and compare the blood lead levels of automobile technicians in roadside and organised garages in Lagos State, Nigeria. This was a comparative cross-sectional study. Data were collected using interviewer-administered questionnaires. Physical examinations were conducted and blood was analysed for lead using atomic spectrophotometery. Statistical analyses were performed to compare the median blood lead levels of each group using the independent sample (Mann-Whitney U) test. Seventy-three (40.3%) of the organised compared to 59 (34.3%) of the roadside groups had high blood lead levels. The organised group had statistically significant higher median blood lead levels of, 66.0 µg/dL than the roadside 43.5 µg/dL (P < 0.05). There was also statistically significant association between high blood lead levels and abnormal discolouration of the mucosa of the mouth in the organised group. Automobile technicians in organised garages in Lagos have higher prevalence of elevated blood lead levels and higher median levels than the roadside group. Preventive strategies against lead exposures should be instituted by the employers and further actions should be taken to minimize exposures, improve work practices, implement engineering controls (e.g., proper ventilation), and ensure the use of personal protective equipment. PMID:25759723

  11. Germanium-on-InP heterojunction-structure LED

    NASA Technical Reports Server (NTRS)

    Hawrylo, F. Z.

    1980-01-01

    Ge-on-InP heterojunction structure LED has been developed where in Ge film is evaporated onto commercially available InP substrate. Forward bias of device is approximately 1 volt, and it emits light in 9.800 angstrom region. Technique permits easy and inexpensive fabrication of LED for application at this wavelength.

  12. White LED with High Package Extraction Efficiency

    SciTech Connect

    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

  13. High-luminance LEDs replace incandescent lamps in new applications

    NASA Astrophysics Data System (ADS)

    Evans, David L.

    1997-04-01

    The advent of high luminance AlInGaP and InGaN LED technologies has prompted the use of LED devices in new applications formally illuminated by incandescent lamps. The luminous efficiencies of these new LED technologies equals or exceeds that attainable with incandescent sources, with reliability factors that far exceed those of incandescent sources. The need for a highly efficient, dependable, and cost effective replacement for incandescent lamps is being fulfilled with high luminance LED lamps. This paper briefly described some of the new applications incorporating high luminance LED lamps, traffic signals and roadway signs for traffic management, automotive exterior lighting, active matrix and full color displays for commercial advertising, and commercial aircraft panel lighting and military aircraft NVG compatible lighting.

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

    SciTech Connect

    Lingard, R. D.; Myer, M. A.; Paget, M. L.

    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.

  15. LED Device Illuminates New Path to Healing

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Among NASA s research goals is increased understanding of factors affecting plant growth, including the effects of microgravity. Impeding such studies, traditional light sources used to grow plants on Earth are difficult to adapt to space flight, as they require considerable amounts of power and produce relatively large amounts of heat. As such, an optimized experimental system requires much less energy and reduces temperature variance without negatively affecting plant growth results. Ronald W. Ignatius, founder and chairman of the board at Quantum Devices Inc. (QDI), of Barneveld, Wisconsin, proposed using light-emitting diodes (LEDs) as the photon source for plant growth experiments in space. This proposition was made at a meeting held by the Wisconsin Center for Space Automation and Robotics, a NASA-sponsored research center that facilitates the commercialization of robotics, automation, and other advanced technologies. The Wisconsin group teamed with QDI to determine whether an LED system could provide the necessary wavelengths and intensities for photosynthesis, and the resultant system proved successful. The center then produced the Astroculture3, a plant growth chamber that successfully incorporated this LED light source, which has now flown on several space shuttle missions. NASA subsequently identified another need that could be addressed with the use of LEDs: astronaut health. A central concern in astronaut health is maintaining healthy growth of cells, including preventing bone and muscle loss and boosting the body s ability to heal wounds all adversely affected by prolonged weightlessness. Thus, having determined that LEDs can be used to grow plants in space, NASA decided to investigate whether LEDs might be used for photobiomodulation therapy (PBMT).

  16. High-power LEDs for plant cultivation

    NASA Astrophysics Data System (ADS)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  17. Electrical efficiency and droop in MQW LEDs

    NASA Astrophysics Data System (ADS)

    Malyutenko, V. K.

    2014-02-01

    It is believed that low power conversion efficiency in commercial MQW LEDs occurs as a result of efficiency droop, current-induced dynamic degradation of the internal quantum efficiency, injection efficiency, and extraction efficiency. Broadly speaking, all these "quenching" mechanisms could be referred to as the optical losses. The vast advances of high-power InGaN and AlGaInP MQW LEDs have been achieved by addressing these losses. In contrast to these studies, in this paper we consider an alternative approach to make high-power LEDs more efficient. We identify current-induced electrical efficiency degradation (EED) as a strong limiting factor of power conversion efficiency. We found that EED is caused by current crowding followed by an increase in current-induced series resistance of a device. By decreasing the current spreading length, EED also causes the optical efficiency to degrade and stands for an important aspect of LED performance. This paper gives scientists the opportunity to look for different attributes of EED.

  18. Nobel Prize for blue LEDs

    NASA Astrophysics Data System (ADS)

    Kraftmakher, Yaakov

    2015-05-01

    A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent light bulbs caused by the Planck distribution and properties of the human eye are illustrated. The efficiency and luminous efficacy of thermal radiation are calculated for various temperatures; the results clearly show the limitations for thermal radiators. The only way to overcome these limitations is using non-thermal radiators, such as fluorescent lamps and light-emitting diodes (LEDs). Unique advantages of LEDs undoubtedly made a revolution in this field. A crucial element of this progress is the blue LEDs (Nobel Prize 2014). Some experiments with a blue and a green LED are described: (i) the luminescence triggered in a green-yellow phosphor inside a white LED by the blue LED; (ii) radiant spectra and ‘efficiency droop’ in the LEDs; (iii) modulation of the blue LED up to 4 MHz; and (iv) the h/e ratio from the turn-on voltage of the green LED. The experiments are suitable for undergraduate laboratories and usable as classroom demonstrations.

  19. Is the "Motor" or the "Garage" More Important to the "Car"? The Difference between Semantic Associations in Single Word and Sentence Production

    ERIC Educational Resources Information Center

    Muehlhaus, Juliane; Heim, Stefan; Sachs, Olga; Schneider, Frank; Habel, Ute; Sass, Katharina

    2013-01-01

    The aim of the present study was to investigate the impact of part-whole (e.g., "car-motor") and functional associations (e.g., "car-garage") on single word (Experiment 1) and sentence production (Experiment 2). In Experiment 1, a classical picture-word task was used. In Experiment 2, the same stimuli and distractors were embedded into a sentence.…

  20. LEDs Illuminate Bulbs for Better Sleep, Wake Cycles

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Life on the International Space Station (ISS) wreaks havoc on an astronaut’s biological rhythms, and one way NASA mitigates the problem is through the use of LED lighting to alternately stimulate energy and focus and induce relaxation. Satellite Beach, Florida-based Lighting Science partnered with Kennedy Space Center to commercialize an LED system designed for the ISS, resulting in its DefinityDigital product line of light bulbs now used in numerous homes, hotel chains, and resorts.

  1. Light pipes for LED measurements

    NASA Technical Reports Server (NTRS)

    Floyd, S. R.; Thomas, E. F., Jr.

    1976-01-01

    Light pipe directly couples LED optical output to single detector. Small area detector measures total optical output of diode. Technique eliminates thermal measurement problems and channels optical output to remote detector.

  2. LED minilidar for Mars rover

    NASA Astrophysics Data System (ADS)

    Shiina, Tatsuo; Yamada, Sonoko; Senshu, Hiroki; Otobe, Naohito; Hashimoto, George; Kawabata, Yasuhiro

    2016-10-01

    A mini-lidar to observe the activity of Martian atmosphere is developed. The 10cm-cube LED mini-lidar was designed to be onboard a Mars rover. The light source of the mini-lidar is a high powered LED of 385nm. LED was adopted as light source because of its toughness against circumference change and physical shock for launch. The pulsed power and the pulse repetition frequency of LED beam were designed as 0.75W (=7.5nJ/10ns) and 500kHz, respectively. Lidar echoes were caught by the specially designed Cassegrain telescope, which has the shorter telescope tube than the usual to meet the 10cm-cube size limit. The high-speed photon counter was developed to pursue to the pulse repetition frequency of the LED light. The measurement range is no shorter than 30m depending back-ground condition. Its spatial resolution was improved as 0.15m (=1ns) by this photon counter. The demonstrative experiment was conducted at large wind tunnel facility of Japan Meteorological Agency. The measurement target was smoke of glycerin particles. The smoke was flowed in the wind tunnel with wind speed of 0 - 5m. Smoke diffusion and its propagation due to the wind flow were observed by the LED mini-lidar. This result suggests that the developed lidar can pursue the structure and the motion of dust devil of >2m.

  3. Commercial Crew

    NASA Video Gallery

    Phil McAlister delivers a presentation by the Commercial Crew (CC) study team on May 25, 2010, at the NASA Exploration Enterprise Workshop held in Galveston, TX. The purpose of this workshop was to...

  4. A garage sale bargain: A leaking 2.2 GBq {sup 226}Ra source, Phase 1 - the incident

    SciTech Connect

    Freeman, B.; Andrews, M.; Hogan, A.

    1996-06-01

    In March 1995, a private citizen living in Bristol, Tennessee, went to a local garage sale and purchased a box containing old medical equipment and paraphernalia for $10.00. The man put the box in the trunk of his car where it remained for several weeks. He then took the box into his home where he examined all of the items, including a small wooden box with a metal sleeve. After significant effort, he managed to remove the inner box which bore the word {open_quotes}radium.{close_quotes} Unsure of what this meant, he called his son-in-law who understood that radium was a radioactive material and called the Tennessee Division of Radiological Health (TDRH). The TDRH investigation quickly located and isolated the source and determined that the contamination was spread throughout the man`s home and yard. Exposure rate readings as high as 160 mR h{sup -1} were found along with removable contamination as high as 3,000,000 dpm/100 cm{sup 2}. Over the next several days, the TDRH organized a voluntary effort for the medical evaluation of the man and his wife, the removal of the source, and the decontamination of the home, yard, car, etc. The two following papers will describe these aspects of this incident. On 26 May 1995, the remediation was completed, ending this unusual, but not unique, radiation incident.

  5. Observations of working postures in garages using the Ovako Working posture Analysing System (OWAS) and consequent workload reduction recommendations.

    PubMed

    Kant, I; Notermans, J H; Borm, P J

    1990-02-01

    The working postures of mechanics (n = 84) in 42 garages were observed using the Ovako Working posture Analysis System (OWAS). During observation, both working postures and work activities were recorded. A computer program was developed for the data analyses. Using this program it is possible to calculate the working posture load for each work activity and the contribution of a specific activity to the total working posture load. This is a substantial extension of the original OWAS method. Five out of 19 observed postures of the body members were classified as Action Category 2, which suggests they were slightly harmful to the musculoskeletal system and likely to cause discomfort. Of the so-called typical working postures, 31.9% was classified in Action Category 2, suggesting that during a substantial part of the working day typical working postures occur which are at least slightly harmful to the musculoskeletal system. Moreover, those work activities principally causing the workload to fall in OWAS' higher Action Categories were identified. For each of these three work activities an alternative work method was observed. The data show that in all three work activities the use of a vehicle lift reduces the number of poor working postures thereby reducing the load on the musculoskeletal system.

  6. Space Commercialization

    NASA Technical Reports Server (NTRS)

    Martin, Gary L.

    2011-01-01

    A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

  7. Enhancing the luminance of converted green LEDs in LED projectors

    NASA Astrophysics Data System (ADS)

    Schulz, Benjamin; Neumann, Cornelius

    2017-02-01

    High-power light-emitting diodes have successfully found their way into projection applications. Owing to their long lifetime, small size, and easy electrical drive, they are getting more and more attractive for use in various kinds of projectors. The challenge to achieve higher brightness levels lies in the étendue limitation, which is determined mainly by the size of the microdisplay inside the projection system. In this paper, a new approach is presented to increase the output flux of LED-based projectors by enhancing the luminance of converted green LEDs.

  8. Low-Cost Illumination-Grade LEDs

    SciTech Connect

    Epler, John

    2013-08-31

    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.

  9. Effects of Cryogenic Temperatures on LEDs and Optical Fiber

    NASA Technical Reports Server (NTRS)

    Pantel, Erica R.

    2005-01-01

    Light Emitting Diodes (LEDs) may provide a simple, low powered light source for future space missions. However, the effects of cryogenic temperatures on LEDs and optical fibers are largely unknown. Tests were performed on a selection of commercially-available LEDs, with wavelengths varying from 468 nm to 950 nm, as well as "white" LEDs. Dry ice and liquid nitrogen (LN2) were used to bring the LEDs to the desired temperatures. The optical fibers were tested using a specially-machined brass cylinder that would allow the fibers to be cooled slowly and evenly in an LN2 dewer. An optical fiber coupled to a spectrometer was used to acquired spectra of a calibration light source (wavelength range 253-922 nm) at various temperatures. Examination of the LED spectra has shown several different effects, depending on the LED in question. Those with wavelengths above 590 nm tend to show a "blue shift" in their peak wavelength and an increase in intensity. Other LEDs developed secondary or tertiary peaks, or showed no peak shift at all, although all LEDs did show an increase in observed intensity. The optical fiber showed a slight non-uniform decrease in transmission as the temperature cooled to -195 C.

  10. Peer-Led Team Learning.

    ERIC Educational Resources Information Center

    Cracolice, Mark S.; Deming, John C.

    2001-01-01

    Introduces the Peer-Led Team Learning (PLTL) model as an alternative to traditional cooperative learning. Discusses the difficulties of PLTL based curriculum which include finding the peer leaders, selecting the right materials for implementation, and training techniques for peer leaders. (YDS)

  11. Multicolor, High Efficiency, Nanotextured LEDs

    SciTech Connect

    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.

  12. Student-Led Portfolio Conferences.

    ERIC Educational Resources Information Center

    Paulson, F. Leon; Paulson, Pearl R.

    In at least one Oregon school system, student-led conferences have begun to replace traditional report cards. When conferences are well done, parents believe they have learned more about their child's learning and progress than they would through a traditional report card. There is an important additional benefit in that students can rise to the…

  13. Commercial Fishing.

    ERIC Educational Resources Information Center

    Florida State Dept. of Education, Tallahassee. Div. of Vocational Education.

    This document is a curriculum framework for a program in commercial fishing to be taught in Florida secondary and postsecondary institutions. This outline covers the major concepts/content of the program, which is designed to prepare students for employment in occupations with titles such as net fishers, pot fishers, line fishers, shrimp boat…

  14. Optimal colour quality of LED clusters based on memory colours.

    PubMed

    Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

    2011-03-28

    The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant.

  15. Large LED screen 3D television system without eyewear

    NASA Astrophysics Data System (ADS)

    Nishida, Nobuo; Yamamoto, Hirotsugu; Hayasaki, Yoshio

    2004-10-01

    Since the development of high-brightness blue and green LEDs, the use of outdoor commercial LED displays has been increasing. Because of their high brightness, good visibility, and long-term durability to the weather, LED displays are a preferred technology for outdoor installations such as stadiums, street advertising, and billboards. This paper deals with a large stereoscopic full-color LED display by use of a parallax barrier. We discuss optimization of the viewing area, which depends on LED arrangements. An enlarged viewing area has been demonstrated by using a 3-in-1 chip LED panel that has wider black regions than ordinary LED lamp cluster panels. We have developed a real-time measurement system of a viewer's position and utilized the measurement system for evaluation of performance of the different designs of stereoscopic LED displays, including conventional designs to provide multiple perspective images and designs to eliminate pseudoscopic viewing areas. In order to show real-world images, it is necessary to capture stereo-images, to process them, and to show in real-time. We have developed an active binocular camera and demonstrated the real-time display of stereoscopic movies and real-time control of convergence.

  16. An Inexpensive LED Light Sensor

    ERIC Educational Resources Information Center

    Kutzner, Mickey; Wright, Richard; Kutzner, Emily

    2010-01-01

    Light irradiance measurements are important for students grappling with abstract optical phenomena such as the inverse square law, polarization, diffraction, interference, and spectroscopy. A variety of commercial light sensors are available from scientific vendors such as the CI-6504A from PASCO scientific and the LS-BTA from Vernier Software and…

  17. Curing efficiency of modern LED units.

    PubMed

    Rencz, Adam; Hickel, Reinhard; Ilie, Nicoleta

    2012-02-01

    Recent reports claim that modern light-emitting diode (LED) curing units improve curing efficiency by increasing the units' irradiance. In this context also, short polymerisation times up to 5 s are proposed. The aim of this study was to examine whether there are differences in the curing efficiency of modern LED curing units by assessing their effect on two different composite materials and by varying the irradiation time. A nano- and a micro-hybrid resin-based composite (RBC) were polymerised for 5, 10 and 20 s with three commercial and a Prototype LED unit (Elipar™ S10). Cylindrical specimens (6 mm in depth, 4 mm in diameter) were prepared in three increments, each 2-mm thick, and were consecutively cured. Degree of cure was measured for 20 min in real time at the bottom of the samples, starting with the photoinitiation. The micro-mechanical properties (modulus of elasticity, E and Vickers hardness, HV) were measured as a function of depth, in 100-μm steps, on the above described samples stored in distilled water for 24 h at 37°C. Data were analysed with multivariate ANOVA followed by Tukey's test, t test and partial eta-squared statistics. In descending order of the strength of their effect, the type of RBC, depth, polymerisation time and curing unit were significant factors affecting the micro-mechanical parameters (p < 0.05). The degree of cure at 6-mm depth was less but significantly influenced by the curing unit and curing time and was independent from the type of RBC. A 5-s irradiation time is not recommended for these units. Whereas a 5-s irradiation is acceptable at the sample's surface, a minimum of 20 s of irradiation is necessary for an adequate polymerisation 2 mm beyond the surface.

  18. LED lamp color control system and method

    DOEpatents

    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.

  19. LED lamp power management system and method

    DOEpatents

    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.

  20. LED Chips and Packaging for 120 LPW SSL Component

    SciTech Connect

    Ibbetson, James

    2009-12-28

    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) 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.

  1. Carbon monoxide poisoning from use of gasoline-fueled power washers in an underground parking garage--District of Columbia, 1994.

    PubMed

    1995-05-12

    On June 17, 1994, five workers in the District of Columbia were treated in an emergency department for carbon monoxide (CO) poisoning following exposure to the exhaust from two gasoline-fueled power washers (i.e., pressure washers), which they had used in an empty underground parking garage. These cases were identified by The George Washington University (GWU) Division of Occupational and Environmental Medicine (DOEM) through ongoing surveillance for work-related injuries among construction workers treated in the GWU emergency department (1). This report summarizes the results of an investigation by DOEM of this incident.

  2. LED instrument approach instruction display

    NASA Technical Reports Server (NTRS)

    Meredith, B. D.; Kelly, W. L., IV; Crouch, R. K.

    1979-01-01

    A display employing light emitting diodes (LED's) was developed to demonstrate the feasibility of such displays for presenting landing and navigation information to reduce the workload of general aviation pilots during IFR flight. The display consists of a paper tape reader, digital memory, control electronics, digital latches, and LED alphanumeric displays. A presentable digital countdown clock-timer is included as part of the system to provide a convenient means of monitoring time intervals for precise flight navigation. The system is a limited capability prototype assembled to test pilot reaction to such a device under simulated IFR operation. Pilot opinion indicates that the display is helpful in reducing the IFR pilots workload when used with a runway approach plate. However, the development of a compact, low power second generation display was recommended which could present several instructions simultaneously and provide information update capability. A microprocessor-based display could fulfill these requirements.

  3. Colorimetric characterization of LED luminaires

    NASA Astrophysics Data System (ADS)

    Costa, C. L. M.; Vieira, R. R.; Pereira, R. C.; Silva, P. V. M.; Oliveira, I. A. A.; Sardinha, A. S.; Viana, D. D.; Barbosa, A. H.; Souza, L. P.; Alvarenga, A. D.

    2015-01-01

    The Optical Metrology Division of Inmetro - National Institute of Metrology, Quality and Technology has recently started the colorimetric characterization of lamps by implementing Correlated Color Temperature (CCT) and Color Rendering Index (CRI) measurements of incandescent lamps, followed by the CFL, and LED lamps and luminaires. Here we present the results for the verification of the color characterization of samples of SSL luminaires for public as well as indoor illumination that are sold in Brazil.

  4. Site-specific standard request for Underground Storage Tanks 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility Buildings 9754-1 and 9720-15

    SciTech Connect

    Not Available

    1994-08-01

    This document is a site-specific standard request for underground storage tanks located at the Rust Garage Facility. These standards are justified based on conclusion derived from the exposure assessment that indicates there is no current or forseeable future human health risk associated with petroleum contaminants on the site, that current and future ecological risks would be generally limited to subsurface species and plant life with roots extending into the area, and that most of the impacted area at the site is covered by asphalt or concrete. The vertical and horizontal extent of soil and ground water contamination are limited to immediate area of the Rust Garage Facility.

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

    SciTech Connect

    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.

  6. Current State of the Art in High Brightness LEDs

    NASA Astrophysics Data System (ADS)

    Craford, George

    2007-03-01

    LED's have been commercially available since the 1960's. For many years they were used primarily for indicator applications. The remarkable increase in materials technology and efficiency that has been achieved since the early 1990's for AlInGaP red and amber LEDs, and InGaN green and blue LEDs, has enabled the penetration of markets such as outdoor display, signaling, and automotive brake light and turn signal applications. White LEDs, which are either blue LEDs combined with a phosphor, or a combination of red, green, and blue LEDs, are being used in emerging applications such as cell phone flash, television backlights, projection, and automotive headlights. In addition, to efficiency improvements these applications have required the development of higher power packages and, in some of these applications which are etendue limited, higher luminance devices. High power devices are commercially available which are capable of 140 lumens output and have an efficacy of around 70 lm/W for white emission. New package and chip technologies have been demonstrated which have a luminance of 38 mega nits (Mcd/m^2), approximately 50% more luminance than that of an automotive headlamp halogen bulb (˜25 mega nits). The recent progress in materials technology, packaging, and chip technology makes it clear that LED's will become important for general illumination applications. The rate of LED penetration of this market will depend upon continued increases in performance and lower costs as well as better control of the white spectral emission. Efficiency, current density, and costs are closely linked because the cost in dollars/lumen is inversely proportional to how many lumens can be realized from each unit of device area for a given device type. Performance as high as 138 lm/W, and over 40% wall plug efficiency, has been reported for low power research devices and over 90 lm/W for high power research devices. It is clear that high power commercial products with performance in

  7. Spectral design flexibility of LED brings better life

    NASA Astrophysics Data System (ADS)

    Ou, Haiyan; Corell, Dennis; Ou, Yiyu; Poulsen, Peter B.; Dam-Hansen, Carsten; Petersen, Paul-Michael

    2012-03-01

    Light-emitting diodes (LEDs) are penetrating into the huge market of general lighting because they are energy saving and environmentally friendly. The big advantage of LED light sources, compared to traditional incandescent lamps and fluorescent light tubes, is the flexible spectral design to make white light using different color mixing schemes. The spectral design flexibility of white LED light sources will promote them for novel applications to improve the life quality of human beings. As an initial exploration to make use of the spectral design flexibility, we present an example: 'no blue' white LED light source for sufferers of disease Porphyria. An LED light source prototype, made of high brightness commercial LEDs applying an optical filter, was tested by a patient suffering from Porphyria. Preliminary results have shown that the sufferer could withstand the light source for much longer time than the standard light source. At last future perspectives on spectral design flexibility of LED light sources improving human being's life will be discussed, with focus on the light and health. The good health is ensured by the spectrum optimized so that vital hormones (melatonin and serotonin) are produced during times when they support human daily rhythm.

  8. Epidemiological-environmental study of diesel bus garage workers: acute effects of NO/sub 2/ and respirable particulate on the respiratory system

    SciTech Connect

    Gamble, J.; Jones, W.; Minshall, S.

    1987-02-01

    Personal samples of nitrogen dioxide (NO/sub 2/) and respirable particulate (RP) were collected over the shift on 232 workers in four diesel bus garages. Response was assessed by an acute respiratory questionnaire and before and after shift spirometry. Measures of exposure to NO/sub 2/ and RP were associated with work-related symptoms of cough; itching, burning, or watering eyes; difficult or labored breathing; chest tightness; and wheeze. The prevalence of burning eyes, headaches, difficult or labored breathing, nausea, and wheeze experienced at work were higher in the diesel bus garage workers than in a comparison population of battery workers, while the prevalence of headaches was reduced. Mean reductions in forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), peak flow, and flows at 50 and 75% of FVC were not obviously different from zero. There was no detectable association of exposure to NO/sub 2/ or respirable particulate and acute reductions in pulmonary function. Workers who often had respiratory work-related symptoms generally had a slightly greater mean acute reduction in FEV1 and FEF50 than did those who did not have these symptoms, but these differences were not statistically significant.

  9. Commercial Capaciflector

    NASA Astrophysics Data System (ADS)

    Vranish, John M.

    1991-12-01

    A capacitive proximity/tactile sensor with unique performance capabilities ('capaciflector' or capacitive reflector) is being developed by NASA/Goddard Space Flight Center (GSFC) for use on robots and payloads in space in the interests of safety, efficiency, and ease of operation. Specifically, this sensor will permit robots and their attached payloads to avoid collisions in space with humans and other objects and to dock these payloads in a cluttered environment. The sensor is simple, robust, and inexpensive to manufacture with obvious and recognized commercial possibilities. Accordingly, NASA/GSFC, in conjunction with industry, is embarking on an effort to 'spin' this technology off into the private sector. This effort includes prototypes aimed at commercial applications. The principles of operation of these prototypes are described along with hardware, software, modelling, and test results. The hardware description includes both the physical sensor in terms of a flexible printed circuit board and the electronic circuitry. The software description will include filtering and detection techniques. The modelling will involve finite element electric field analysis and will underline techniques used for design optimization.

  10. Commercial Capaciflector

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1991-01-01

    A capacitive proximity/tactile sensor with unique performance capabilities ('capaciflector' or capacitive reflector) is being developed by NASA/Goddard Space Flight Center (GSFC) for use on robots and payloads in space in the interests of safety, efficiency, and ease of operation. Specifically, this sensor will permit robots and their attached payloads to avoid collisions in space with humans and other objects and to dock these payloads in a cluttered environment. The sensor is simple, robust, and inexpensive to manufacture with obvious and recognized commercial possibilities. Accordingly, NASA/GSFC, in conjunction with industry, is embarking on an effort to 'spin' this technology off into the private sector. This effort includes prototypes aimed at commercial applications. The principles of operation of these prototypes are described along with hardware, software, modelling, and test results. The hardware description includes both the physical sensor in terms of a flexible printed circuit board and the electronic circuitry. The software description will include filtering and detection techniques. The modelling will involve finite element electric field analysis and will underline techniques used for design optimization.

  11. Developing Successful International Faculty Led Program

    ERIC Educational Resources Information Center

    Fabregas Janeiro, Maria G.; Fabre, Ricardo Lopez; Rosete, Rodrigo Tello

    2012-01-01

    Faculty Led Programs are study abroad experiences led by university professors. Faculty Led Programs are considered as an opportunity for college students, especially in the United States to attend a short-term international experience (Mills, 2010). Faculty Led Program is an international experience which is different from the traditional…

  12. Successful commercialization of nanophotonic technology

    NASA Astrophysics Data System (ADS)

    Jaiswal, Supriya L.; Clarke, Roger B. M.; Hyde, Sam C. W.

    2006-08-01

    The exploitation of nanotechnology from proof of principle to realizable commercial applications encounters considerable challenges in regards to high volume, large scale, low cost manufacturability and social ethics. This has led to concerns over converting powerful intellectual property into realizable, industry attractive technologies. At The Technology Partnership we specifically address the issue of successful integration of nanophotonics into industry in markets such as biomedical, ophthalmic, energy, telecommunications, and packaging. In this paper we draw on a few examples where we have either developed industrial scale nanophotonic technology or engineering platforms which may be used to fortify nano/microphotonic technologies and enhance their commercial viability.

  13. A thermosyphon heat pipe cooler for high power LEDs cooling

    NASA Astrophysics Data System (ADS)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  14. A Multipurpose LED Light Source for Optics Experiments

    NASA Astrophysics Data System (ADS)

    Mak, Se-yuen

    2004-12-01

    The traditional light source for studying lenses and mirrors is either a bare white light bulb, or one encased inside a lamphouse.2, 3 A simple pattern like an arrow, mounted on an optical bench or printed on the window of a lamphouse, serves as the object. Ironically, the image captured on a translucent screen is often the shadow of the pattern with no light falling on it. Although LEDs have been used in commercial display boards for decades, the advantage of using LEDs as a multipurpose light source in the physics laboratory has been overlooked by many physics teachers. In this paper, we remind readers of a few examples of how LEDs can be used to replace the incandescent lamp for geometrical optics, physical optics, and fiber optics experiments.

  15. Commercial applications

    NASA Astrophysics Data System (ADS)

    The near term (one to five year) needs of domestic and foreign commercial suppliers of radiochemicals and radiopharmaceuticals for electromagnetically separated stable isotopes are assessed. Only isotopes purchased to make products for sale and profit are considered. Radiopharmaceuticals produced from enriched stable isotopes supplied by the Calutron facility at ORNL are used in about 600,000 medical procedures each year in the United States. A temporary or permanent disruption of the supply of stable isotopes to the domestic radiopharmaceutical industry could curtail, if not eliminate, the use of such diagnostic procedures as the thallium heart scan, the gallium cancer scan, the gallium abscess scan, and the low radiation dose thyroid scan. An alternative source of enriched stable isotopes exist in the USSR. Alternative starting materials could, in theory, eventually be developed for both the thallium and gallium scans. The development of a new technology for these purposes, however, would take at least five years and would be expensive. Hence, any disruption of the supply of enriched isotopes from ORNL and the resulting unavailability of critical nuclear medicine procedures would have a dramatic negative effect on the level of health care in the United States.

  16. Gurus in the garage.

    PubMed

    Leonard, D; Swap, W

    2000-01-01

    Before the days of the Internet, it was primarily venture capitalists who coached young entrepreneurs in Silicon Valley. Today, because of the phenomenal number of new companies, venture capitalists are just too busy. The largest firms still take on a few carefully selected, highly promising zero-stage start-ups, but they simply can't spend the time on ones that aren't going to grow huge quickly. To fill the void, a new breed of adviser has stepped in to coach entrepreneurs. Called mentor capitalists, they help entrepreneurs with everything from recruiting top talent to attracting their first million in seed money. The mentor capitalists in Silicon Valley are cashed-out, highly successful business architects who no longer want to start businesses but who love the thrill of the entrepreneurial game. They spend hours and hours with first-time entrepreneurs, guiding them as they create and refine a business model, test their ideas in the marketplace, build business processes, raise money, and find talent. The authors of this article found through dozens of extensive interviews with entrepreneurs and their coaches that mentor capitalists play many roles: sculptor, psychologist, diplomat, kingmaker, talent magnet, process engineer, and rainmaker. In exchange for small equity stakes, the mentor capitalists wear these different hats, doling out expertise just in time, as situations arise, and in doses appropriate to the situation. Mentor capitalists seed Silicon Valley with expertise and knowledge, augmenting or even substituting for classes in entrepreneurship at local universities. But, as the authors note, the role of the mentor capitalist is essential to any start-up, anywhere.

  17. Remaining Sites Verification Package for the 100-B-20, 1716-B Maintenance Garage Underground Tank, Waste Site Reclassification Form 2006-019

    SciTech Connect

    L. M. Dittmer

    2006-09-27

    The 100-B-20 waste site, located in the 100-BC-1 Operable Unit of the Hanford Site, consisted of an underground oil tank that once serviced the 1716-B Maintenance Garage. The selected action for the 100-B-20 waste site involved removal of the oil tanks and their contents and demonstrating through confirmatory sampling that all cleanup goals have been met. In accordance with this evaluation, a reclassification status of interim closed out has been determined. The results demonstrate that the site will support future unrestricted land uses that can be represented by a rural-residential scenario. These results also show that residual concentrations support unrestricted future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River.

  18. Attendees' Perceptions of Commercial Influence in Noncommercially Funded CME Programs

    ERIC Educational Resources Information Center

    Goldfarb, Elizabeth; Baer, Lee; Fromson, John A.; Gorrindo, Tristan; Iodice, Kristin E.; Birnbaum, Robert J.

    2012-01-01

    Introduction: The controversy surrounding commercial support for continuing medical education (CME) programs has led to policy changes, but data show no significant difference in perceived bias between commercial and noncommercial CME. Indeed, what attendees perceive as commercial influence is not fully understood. We sought to clarify what…

  19. Color Maintenance of LEDs in Laboratory and Field Applications

    SciTech Connect

    Royer, Michael P.; Tuttle, Ralph; Rosenfeld, Scott M.; Miller, Naomi J.

    2013-09-30

    Synopsis: To date, consideration for parametric failure of LED products has largely been focused on lumen maintenance. However, color shift is a cause of early failure for some products, and is especially important to consider in certain applications, like museums, where visual appearance is critical. Example data collected by the GATEWAY program for LED lamps installed in museums shows that many have changed color beyond a reasonable tolerance well before their rated lifetime was reached, necessitating replacement. Similar data collected by the CALiPER program between 2008 and 2010 reveals that many early products shifted beyond acceptable tolerances in as little as a few thousand hours. In contrast, data from the L Prize program illustrates that commercially available LED products can have exemplary color stability that is unmatched by traditional light sources. Beyond presenting data from the aforementioned DOE programs, this report discusses the metrics used for communicating color shift—namely MacAdam ellipses and Δu'v'—as well as providing guidance for end users on how to monitor color shift and what to look for in manufacturer warranties. Also included are descriptions of the physical changes that have been documented as leading to color shift in some example types of LED packages. As with complete products, the data presented herein for LED packages shows that a wide variety of products are available; in order for specifiers and consumers to make educated choices, more detailed and standardized information should be made available.

  20. LEDs for Street Lighting—Here Today

    SciTech Connect

    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.

  1. Shipboard LED Lighting: A Business Case Analysis

    DTIC Science & Technology

    2009-12-01

    components are placed under an epoxy dome to form an LED “package.” Groups of packages are clustered together in a housing, forming an LED lamp ...Unlike traditional screw-in bulbs, LED lamps must be integrated into specially designed fixtures or “luminaires.” Proper luminaire design, in...replacement LED fixtures due to lamp mortality. 2. Cost of maintenance—includes labor to replace burned out lamps or defective components and material

  2. Dual LED/incandescent security fixture

    DOEpatents

    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.

  3. Generation of solar spectrum by using LEDs

    NASA Astrophysics Data System (ADS)

    Lu, Pengzhi; Yang, Hua; Pei, Yanrong; Li, Jing; Xue, Bin; Wang, Junxi; Li, Jinmin

    2016-09-01

    Light emitting diode (LED) has been recognized as an applicable light source for indoor and outdoor lighting, city beautifying, landscape facilities, and municipal engineering etc. Conventional LED has superior characteristics such as long life time, low power consumption, high contrast, and wide viewing angle. Recently, LED with high color-rendering index and special spectral characteristics has received more and more attention. This paper is intended to report a solar spectrum simulated by multichip LED light source. The typical solar spectrum of 5500k released by CIE was simulated as a reference. Four types of LEDs with different spectral power distributions would be used in the LED light source, which included a 430nm LED, a 480nm LED, a 500nm LED and a white LED. In order to obtain better simulation results, the white LED was achieved by a 450nm LED chip with the mixture of phosphor. The phosphor combination was prepared by mixing green phosphor, yellow phosphor and red phosphor in a certain proportion. The multichip LED light source could provide a high fidelity spectral match with the typical solar spectrum of 5500k by adjusting injection current to each device. The luminous flux, CIE chromaticity coordinate x, y, CCT, and Ra were 104.7 lm, 0.3337, 0.3681, 5460K, and 88.6, respectively. Because of high color-rendering index and highly match to the solar spectrum, the multichip LED light source is a competitive candidate for applications where special spectral is required, such as colorimetric measurements, visual inspection, gemstone identification and agriculture.

  4. White LED visible light communication technology research

    NASA Astrophysics Data System (ADS)

    Yang, Chao

    2017-03-01

    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  5. The stability of spectrum reproduction by LEDs

    NASA Astrophysics Data System (ADS)

    Yang, Hua; Li, Jing; Yao, Ran; Lu, Pengzhi; Pei, Yanrong

    2015-09-01

    Spectral power distribution together with color consistency and constancy of natural light is studied and simulated before the white-light LED systems are fabricated to reproduce the natural light. The model with 3, 4, 6 and more primary LEDs based on the real measured spectrum and theoretical spectrum are analyzed. The spectral power sensitivity relation between the LEDs with different wavelength and color characteristic is analyzed. This research simplifies the approach of visible spectrum reconstruction which is an efficient way to use in the design and realization of LED-based luminaire.

  6. Liquid explosive detection using near infrared LED

    NASA Astrophysics Data System (ADS)

    Itozaki, Hideo; Ito, Shiori; Sato-Akaba, Hideo; Miyato, Yuji

    2015-10-01

    A bottle scanner to detect liquid explosive has been developed using technologies of near infrared. Its detection rate of liquid explosive is quite high and its false alarm rate of safe liquids quite low. It uses a light source with wide spectrum such as a halogen lamp. Recently a variety of LEDs have been developed and some of them have near infrared spectrum. Here a near infrared LED is tested as a light source of the liquid explosive detector. Three infrared LEDs that have a main peak of spectrum at 901nm, 936nm, and 1028 nm have been used as a light source to scan liquids. Spectrum widths of these LEDs are quite narrow typically less than 100 nm. Ten typical liquids have been evaluated by these LEDs and the correlation coefficients of a spectrum by an LED and a tungsten lamp were more than 0.98. This experiment shows that the infrared LED can be used as a light source for the liquid scanner. An LED has some merits, such as long life of more than some ten thousand hours and small consumption electric power of less than 0.2 W. When the LED is used as a light source for the liquid scanner, it is also more compact and handy.

  7. Blue LEDs feasibility for tissue fluorescence analysis

    NASA Astrophysics Data System (ADS)

    Dets, Sergiy M.; Denisov, Nikolay A.

    2000-04-01

    We considered the limited number of light-induced fluorescence applications for marketed ultra-bright blue LEDs where they can compete with versatile laser sources. Satisfactory optical output and miniature size as well as low power consumption of blue LEDs emitting at 470 nm allow to consider them as a promising alternatives to metal vapor or gas lasers used in many expires LIF applications. Available to authors LEDs form Hewlett-Packard, Micro Electronics Corp., Nichia Chemical Industries Ltd. and Toyoda Gosei Co. were tested to comply with demands to a tissue excitation source for portable spectroscopes. The optical performance of LEDs has shown that selected group of InGaN LEDs could be successfully used for that. The miniature illuminator that includes LED, focusing condenser, filter set and distal fiberoptic light concentrator was designed and tested in conjunction with portable CCD- equipped spectroscope. Operating in dark condition the proposed LED illuminator provides the level of fluorescence signal sufficient to detect spectral abnormalities in human Caucasian skin and excised gastrointestinal samples. All tissue autofluorescence data taken under LED illumination were compared with readings under He-Cd laser excitation and showed a good match. A new diagnostic designs based on LEDs were considered for clinical use.

  8. Solid State Lighting LED Manufacturing Roundtable Summary

    SciTech Connect

    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.

  9. Projecting LED product life based on application

    NASA Astrophysics Data System (ADS)

    Narendran, Nadarajah; Liu, Yi-wei; Mou, Xi; Thotagamuwa, Dinusha R.; Eshwarage, Oshadhi V. Madihe

    2016-09-01

    LED products have started to displace traditional light sources in many lighting applications. One of the commonly claimed benefits for LED lighting products is their long useful lifetime in applications. Today there are many replacement lamp products using LEDs in the marketplace. Typically, lifetime claims of these replacement lamps are in the 25,000-hour range. According to current industry practice, the time for the LED light output to reach the 70% value is estimated according to IESNA LM-80 and TM-21 procedures and the resulting value is reported as the whole system life. LED products generally experience different thermal environments and switching (on-off cycling) patterns when used in applications. Current industry test methods often do not produce accurate lifetime estimates for LED systems because only one component of the system, namely the LED, is tested under a continuous-on burning condition without switching on and off, and because they estimate for only one failure type, lumen depreciation. The objective of the study presented in this manuscript was to develop a test method that could help predict LED system life in any application by testing the whole LED system, including on-off power cycling with sufficient dwell time, and considering both failure types, catastrophic and parametric. The study results showed for the LED A-lamps tested in this study, both failure types, catastrophic and parametric, exist. The on-off cycling encourages catastrophic failure, and maximum operating temperature influences the lumen depreciation rate and parametric failure time. It was also clear that LED system life is negatively affected by on-off switching, contrary to commonly held belief. In addition, the study results showed that most of the LED systems failed catastrophically much ahead of the LED light output reaching the 70% value. This emphasizes the fact that life testing of LED systems must consider catastrophic failure in addition to lumen depreciation, and

  10. Corrective Action Plan for underground storage tanks 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility, Buildings 9720-15 and 9754-1

    SciTech Connect

    Bohrman, D.E.; Ingram, E.M. )

    1992-04-01

    This document represents the Corrective Action Plan for underground storage tanks 1219-U, 1222-U, and 2068-U, all previously located at the Buildings 9720-15/ 9754-1 site (Facility Identification {number sign}0-010117), Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. This site is commonly referred to as the Rust Garage Facility'' and will be so referenced in this document hereafter. This document presents a comprehensive summary of all environmental assessment investigations conducted at the Rust Garage Facility and the corrective action measures that are proposed for remediation of subsurface petroleum contamination identified at the facility. This document is written in accordance with the regulatory requirements of the Tennessee Department of Environment and Conservation (TDEC) Rule 1200-1-15-.06(7). The Corrective Action Plan for the Rust Garage Facility incorporates all elements of both the Corrective Action Plan Format and the Environmental Assessment Report/Corrective Action Plan guidelines that are applicable to the facility. However, in cases where the latter guideline elements offered the more precise and clear presentation of applicable information, they were used in place of elements detailed in the Corrective Action Plan Format.

  11. Today LED Holiday Lights, Tomorrow the World?

    SciTech Connect

    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.

  12. Investigation of radiation influence on LED

    NASA Astrophysics Data System (ADS)

    Rabinovich, O. I.; Legotin, S. A.; Didenko, S. I.; Krasnov, A. A.; Kovalev, A. N.; Podgornaya, S. V.

    2017-01-01

    In this paper the investigation goal was to study the radiation effect (irradiation by fast electrons) on detectors, LEDs electro-physical parameters as they are widely used in space shuttles, satellites and airplanes on which space radiation influence. It was detected the critical value of irradiation for the irreversible changes in LED. The way for reducing characteristics degradation is suggested.

  13. 130 LPW 1000 Lm Warm White LED for Illumination

    SciTech Connect

    Soer, Wouter

    2012-12-21

    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

  14. 100 LPW 800 Lm Warm White LED

    SciTech Connect

    Sun, Decai

    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 Lumiramica 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

  15. Advances in LEDs for automotive applications

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

    2016-03-01

    High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

  16. High Performance Green LEDs by Homoepitaxial

    SciTech Connect

    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.

  17. Accurate colorimetric feedback for RGB LED clusters

    NASA Astrophysics Data System (ADS)

    Man, Kwong; Ashdown, Ian

    2006-08-01

    We present an empirical model of LED emission spectra that is applicable to both InGaN and AlInGaP high-flux LEDs, and which accurately predicts their relative spectral power distributions over a wide range of LED junction temperatures. We further demonstrate with laboratory measurements that changes in LED spectral power distribution with temperature can be accurately predicted with first- or second-order equations. This provides the basis for a real-time colorimetric feedback system for RGB LED clusters that can maintain the chromaticity of white light at constant intensity to within +/-0.003 Δuv over a range of 45 degrees Celsius, and to within 0.01 Δuv when dimmed over an intensity range of 10:1.

  18. White LEDs with limit luminous efficacy

    SciTech Connect

    Lisitsyn, V. M.; Stepanov, S. A. Yangyang, Ju; Lukash, V. S.

    2016-01-15

    In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated.

  19. Using LEDs to reduce energy consumption

    NASA Astrophysics Data System (ADS)

    Eweni, Chukwuebuka E.

    The most popularly used light bulb in homes is the incandescent. It is also the least energy efficient. The filament in the bulb is so thin that it causes resistance in the electricity, which in turn causes the electricity's energy to form heat. This causes the incandescent to waste a lot of energy forming heat rather than forming the light. It uses 15 lumens per watt of input power. A recorded MATLAB demonstration showcased LED versatility and how it can be used by an Arduino UNO board. The objective of this thesis is to showcase how LEDs can reduce energy consumption through the use of an Arduino UNO board and MATLAB and to discuss the applications of LED. LED will be the future of lighting homes and will eventually completely incandescent bulbs when companies begin to make the necessary improvements to the LED.

  20. Nonspherical LED packaging lens for uniformity improvement

    NASA Astrophysics Data System (ADS)

    Chang, Yu-Cheng; Ou, Chung-Jen; Tsai, Yu-Sheng; Juang, Fuh-Shyang

    2009-05-01

    Light emitting diode (LED) has more advantages compared with a traditional incandescent light bulb and a fluorescent lamp, such as small size, low quantity of heat, long life, low power consumption, fast response, plain packaging and ease of develop ment of a frivolous short product. A methodology is proposed to improve the uniformity of the LED illumination system. As a light source in a backlight unit (BLU), the requirement for optical characteristics of a LED is different from highly directional conventional ones. New diffused-type LEDs need to be developed to fulfill the requirement of the BLU industry. A non-spherical lens is designed to optimize uniformity, and a great improvement in uniformity from 28.4 to 64% is demonstrated. In the future, it may used in an LED display to improve the unevenness of illumination.

  1. High-power LED package requirements

    NASA Astrophysics Data System (ADS)

    Wall, Frank; Martin, Paul S.; Harbers, Gerard

    2004-01-01

    Power LEDs have evolved from simple indicators into illumination devices. For general lighting applications, where the objective is to light up an area, white LED arrays have been utilized to serve that function. Cost constraints will soon drive the industry to provide a discrete lighting solution. Early on, that will mean increasing the power densities while quantum efficiencies are addressed. For applications such as automotive headlamps & projection, where light needs to be tightly collimated, or controlled, arrays of die or LEDs will not be able to satisfy the requirements & limitations defined by etendue. Ultimately, whether a luminaire requires a small source with high luminance, or light spread over a general area, economics will force the evolution of the illumination LED into a compact discrete high power package. How the customer interfaces with this new package should be an important element considered early on in the design cycle. If an LED footprint of adequate size is not provided, it may prove impossible for the customer, or end user, to get rid of the heat in a manner sufficient to prevent premature LED light output degradation. Therefore it is critical, for maintaining expected LED lifetime & light output, that thermal performance parameters be defined, by design, at the system level, which includes heat sinking methods & interface materials or methdology.

  2. Remote monitoring of LED lighting system performance

    NASA Astrophysics Data System (ADS)

    Thotagamuwa, Dinusha R.; Perera, Indika U.; Narendran, Nadarajah

    2016-09-01

    The concept of connected lighting systems using LED lighting for the creation of intelligent buildings is becoming attractive to building owners and managers. In this application, the two most important parameters include power demand and the remaining useful life of the LED fixtures. The first enables energy-efficient buildings and the second helps building managers schedule maintenance services. The failure of an LED lighting system can be parametric (such as lumen depreciation) or catastrophic (such as complete cessation of light). Catastrophic failures in LED lighting systems can create serious consequences in safety critical and emergency applications. Therefore, both failure mechanisms must be considered and the shorter of the two must be used as the failure time. Furthermore, because of significant variation between the useful lives of similar products, it is difficult to accurately predict the life of LED systems. Real-time data gathering and analysis of key operating parameters of LED systems can enable the accurate estimation of the useful life of a lighting system. This paper demonstrates the use of a data-driven method (Euclidean distance) to monitor the performance of an LED lighting system and predict its time to failure.

  3. Is the motor or the garage more important to the car? The difference between semantic associations in single word and sentence production.

    PubMed

    Muehlhaus, Juliane; Heim, Stefan; Sachs, Olga; Schneider, Frank; Habel, Ute; Sass, Katharina

    2013-02-01

    The aim of the present study was to investigate the impact of part-whole (e.g., car-motor) and functional associations (e.g., car-garage) on single word (Experiment 1) and sentence production (Experiment 2). In Experiment 1, a classical picture-word task was used. In Experiment 2, the same stimuli and distractors were embedded into a sentence. The relation between target and distractor was either part-whole, functional or unrelated. At single word level, part-whole and functional relations facilitate naming. Additionally, the facilitation effect was stronger for part-whole in comparison to functional associations. During sentence production, facilitation shifted to interference. The difference between both relations disappeared. The findings of the different effects between functional and part-whole associations depend on the length of utterances and highlight the divergent impact of associations. The differences between part-whole and functional associations in single word production might reflect a differential organization of associative links at the conceptual level. In contrast, during sentence production the syntactic processing at the lexical level seem to be more important than types of semantic associations at the conceptual level.

  4. R&D100: LED Pulser

    SciTech Connect

    Pickett, Lyle; Manin, Julien; Eagle, Ethan

    2015-11-19

    A Sandia National Laboratories' light emitting diode (LED) driver is generating light pulses with shorter duration higher repetition frequency and higher brightness than anything on the market. The Sandia LED Pulser uses custom electronic circuitry to drive high-power LEDs to generate short, bright, high frequency light pulses. A single device can emit up to four different colors - each with independent pulse timing - crucial for light-beam forming in many optical applications and is more economical than current light sources such as lasers.

  5. R&D100: LED Pulser

    ScienceCinema

    Pickett, Lyle; Manin, Julien; Eagle, Ethan

    2016-10-19

    A Sandia National Laboratories' light emitting diode (LED) driver is generating light pulses with shorter duration higher repetition frequency and higher brightness than anything on the market. The Sandia LED Pulser uses custom electronic circuitry to drive high-power LEDs to generate short, bright, high frequency light pulses. A single device can emit up to four different colors - each with independent pulse timing - crucial for light-beam forming in many optical applications and is more economical than current light sources such as lasers.

  6. Addressing the variables in LED product design to ensure product reliability

    NASA Astrophysics Data System (ADS)

    Keebler, Philip F.; Sharp, Frank D.

    2011-10-01

    Continuing developments in LED lighting are leading to more lighting products for illumination in LED fixtures for the residential, commercial, and industrial facilities. Most of the research in the past ten years has been aimed at developing LEDs with higher brightness, higher efficacies, good color performance and longer life. Many efforts have been accomplished to develop LED driver circuits to drive LED arrays, even drivers that are dimmable. Manufacturers are increasing their level of concern with the performance and life of the whole LED product with a renewed emphasis on reliability. Reliability for LED products not only involves thermal management, fixture design, and driver loading but also how products respond to electrical disturbances that occur in the building electrical environments where the products must function. EPRI research has demonstrated that the immunity of LED lighting systems to common everyday electrical disturbances is critical to establishing the reliability needed to ensure expected performance and for their survival during product life. Test results showing the application of voltage surges, transients, and sags among other disturbances will be presented. This paper will discuss the application of the results of EPRI research in this area, the test protocol associated with EPRI system compatibility concept, examples of how applying the concept has identified reliability problems in LED products, and how the reliability of these LED systems can be easily improved.

  7. Integrating sphere design for characterization of LED efficacy

    NASA Astrophysics Data System (ADS)

    Mujahid, Muhammad Abdul Aziz Al; Panatarani, C.; Maulana, Dwindra W.; Wibawa, Bambang Mukti; Joni, I. Made

    2016-02-01

    The integrating sphere (IS) is one of the most important device in characterization of illuminance of a light source, such as CFL, LED etc. to obtain their efficacy. IS is a hollowed sphere with its interior covered with a diffuse white reflective coating where its accuracy of the measurement is highly affected by reflectance of its interior coating. This paper report the preparation of inner surface coating of the IS with inner diameter of 25 cm attempt to create a durable and highly reflective interior coating by combining BaSO4 with a binding material (either Polyethylene Glycol (PEG) or white paint). The various inner surface coating mixture vary in weight % ratio of BaSO4:PEG or BaSO4:white paint were investigated. The results show that the inner surface coating mixture of BaSO4:PEG (99.8:0.2) has highest reflectance compared to others mixture. The IS with best mixture was calibrated with white LED and resulted an average sphere multiplier (M) was 8.7, and average reflectance (ρ) was 0.90. The result of the relative error of luminescence measurement using calibrated M and ρ is 6.7 %. It is concluded that the developed IS produced lower allowed error compared to the commercially available IS. However at lower wavelength shows lower intensity compare to the available datasheet of the LED under investigation.

  8. A metasynthesis of midwife-led care.

    PubMed

    Walsh, Denis; Devane, Declan

    2012-07-01

    The purpose of this metasynthesis is to describe and interpret qualitative research relating to midwife-led care to see if it sheds light on why low-risk women experience fewer birth interventions within this model of care. Eleven articles were included in the review. Three themes emerged: (a) relationally mediated benefits for women that resulted in increased agency and empathic care; (b) the problematic interface of midwife-led units with host maternity units, stemming from a clash of models and culture; and (c) greater agency for midwives within midwife-led models of care though bounded by the relationship with the host maternity unit. This metasynthesis suggests that lower rates of interventions could be linked to the greater agency experienced by women and midwives within midwife-led models, and that these effects are mediated, in part, by the smallness of scale in these settings.

  9. LED Outdoor Area Lighting Fact Sheet

    SciTech Connect

    2008-06-01

    This fact sheet reviews the major design and specification concerns for outdoor area lighting, and discusses the potential for LED luminaires to save energy while providing high quality lighting for outdoor areas.

  10. Commercial Buildings Characteristics, 1992

    SciTech Connect

    Not Available

    1994-04-29

    Commercial Buildings Characteristics 1992 presents statistics about the number, type, and size of commercial buildings in the United States as well as their energy-related characteristics. These data are collected in the Commercial Buildings Energy Consumption Survey (CBECS), a national survey of buildings in the commercial sector. The 1992 CBECS is the fifth in a series conducted since 1979 by the Energy Information Administration. Approximately 6,600 commercial buildings were surveyed, representing the characteristics and energy consumption of 4.8 million commercial buildings and 67.9 billion square feet of commercial floorspace nationwide. Overall, the amount of commercial floorspace in the United States increased an average of 2.4 percent annually between 1989 and 1992, while the number of commercial buildings increased an average of 2.0 percent annually.

  11. Tunable fiber confocal sensor with LED

    NASA Astrophysics Data System (ADS)

    Weng, Chun-Jen; Lan, Tzu-Hsien; Hwang, Chi-Hung; Chu, Nien-Nan; Huang, Chien-Yao; Cheng, Pi-Ying

    2015-07-01

    A novel concept of confocal sensor based on focal lens is proposed to measure the displacement. The light source is a stabilized fiber coupled LED. A 1x2 graded-index multimode fiber optic coupler is used in this sensor. One port is a LED input port via SMA connector, another port is a LED output port connected to a reflective collimator and the other port is a reflective sensor port connected to a photo detector. The focusing sensor head is the cascade of a focal lens and a 20X objective lens. In this confocal displacement sensor, LED passes through a focal lens and an objective lens so that the LED beam focuses at a fixed focal point. A test target is placed after the objective lens. The displacement between the sensor head and a target can be measured quickly by detecting the reflective power according to the confocal principle. The long-term stability of LED is under 0.5%. The effective back focal length is varied from 5.67mm to 6.57mm by 0-290mA current driving so that the measuring range is about 0.9mm. The FWHM resolution of displacement is about 50μm. This sensor has the features of low cost, high stability, high precision and compact.

  12. Temperature measurements of high power LEDs

    NASA Astrophysics Data System (ADS)

    Badalan (Draghici), Niculina; Svasta, Paul; Drumea, Andrei

    2016-12-01

    Measurement of a LED junction temperature is very important in designing a LED lighting system. Depending on the junction temperature we will be able to determine the type of cooling system and the size of the lighting system. There are several indirect methods for junction temperature measurement. The method used in this paper is based on the thermal resistance model. The aim of this study is to identify the best device that would allow measuring the solder point temperature and the temperature on the lens of power LEDs. For this purpose four devices for measuring temperature on a high-power LED are presented and compared according to the acquired measurements: an infrared thermal camera from FLIR Systems, a multimeter with K type thermocouple (Velleman DVM4200), an infrared-spot based noncontact thermometer (Raynger ST) and a measurement system based on a digital temperature sensor (DS1821 type) connected to a PC. The measurements were conducted on an 18W COB (chip-on-board) LED. The measurement points are the supply terminals and the lens of the LED.

  13. LED luminaire longevity strategy models comparison

    NASA Astrophysics Data System (ADS)

    Lemieux, Hugo; Thibault, Simon; Martel, Alain A.

    2010-08-01

    As energy efficiency becomes more and more important, light-emitting diodes (LEDs) are a promising alternative to traditional lighting. Indeed, the energy efficiency of LEDs is still improving as their luminosity is modulated by current. Moreover, for applications such as exterior lamp posts, their small size, directionality, colors and high frequency response allow to combine them and provide design possibilities which are impossible with any other light source. However, as any lamp, LEDs have a lumen depreciation which is a function of both current and temperature. Thus, to take advantage of the full characteristics of LEDs, LED luminaire longevity strategies must be carefully studied and planned, especially since the IES and CIE guidelines state clearly that the luminaire must maintain the rated recommended light level until the end of the system's operating life. The recommended approach for LED luminaire specification is therefore to use the end-of-life light level when evaluating the luminaire. Different power supply strategies have been simulated to determine which one maximizes energy saving and lifetime. With these results, it appears that active control can save at least 25% in energy, but the best strategy cannot be determined because of uncertainties in luminosity degradation models.

  14. Thermal Analysis of LED Phosphor Layer

    NASA Astrophysics Data System (ADS)

    Perera, Ukwatte Lokuliyanage Indika Upendra

    Solid-state lighting technology has progressed to a level where light-emitting diode (LED) products are either on par or better than their traditional lighting technology counterparts with respect to efficacy and lifetime. At present, the most common method to create "white" light from LEDs for illumination applications is by using the LED primary radiation and wavelength-converting materials. In this method, the re-emission from the wavelength-converting materials excited by the LED primary radiation is combined with the LED primary radiation to create the "white" light. During this conversion process, heat is generated as a result of conversion inefficiencies and other loss mechanisms in the LED and the wavelength-converting materials. This generated heat, if not properly dissipated, increases the operating temperature, thereby increasing the light output degradation of the system over both the short and long term. The heat generation of the LED and thermal management of the LED have been studied extensively. Methods to effectively dissipate heat from the LEDs and maintain lower LED operating temperature are well understood. However, investigation of factors driving heat generation, the resulting temperature distribution in the phosphor layer, and the influence of the phosphor layer temperature on LED performance and reliability have not received the same focus. The goal of this dissertation was to understand the main factors driving heat and light generation and the transport of light and heat in the wavelength-converting layer of an LED system. Another goal was to understand the interaction between heat and light in the system and to develop and analyze a solution to reduce the wavelength-converting layer operating temperature, thereby improving light output and reliability. Even though past studies have explored generation and transfer separately for light and heat, to the best of the author's knowledge, this is the first study that has analyzed both factors

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

    SciTech Connect

    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.

  16. NASA commercial programs

    NASA Technical Reports Server (NTRS)

    1988-01-01

    An expanded role for the U.S. private sector in America's space future has emerged as a key national objective, and NASA's Office of Commercial Programs is providing a focus for action. The Office supports new high technology commercial space ventures, the commercial application of existing aeronautics and space technology, and expanded commercial access to available NASA capabilities and services. The progress NASA has made in carrying out its new assignment is highlighted.

  17. Industry Research and Recommendations for New Commercial Buildings

    SciTech Connect

    Hendron, B.; Leach, M.; Gregory, N.; Pless, S.; Selkowitz, S.; Matthew, P.

    2014-05-01

    Researchers evaluated industry needs and developed logic models to support possible future commercial new construction research and deployment efforts that could be led or supported by DOE's Commercial Building Integration program or other national initiatives. The authors believe that these recommendations support a proposed course of action from the current state of commercial building energy efficiency to a possible long-term goal of achieving significant market penetration of cost-effective NZE buildings in all building sectors and climates by 2030.

  18. Affordable underwater wireless optical communication using LEDs

    NASA Astrophysics Data System (ADS)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  19. Commercial Banking Industry Survey.

    ERIC Educational Resources Information Center

    Bright Horizons Children's Centers, Cambridge, MA.

    Work and family programs are becoming increasingly important in the commercial banking industry. The objective of this survey was to collect information and prepare a commercial banking industry profile on work and family programs. Fifty-nine top American commercial banks from the Fortune 500 list were invited to participate. Twenty-two…

  20. Commercialization of Nanotechnology

    DTIC Science & Technology

    2007-03-01

    NATO LECTURES M. Meyyappan Commercialization of Nanotechnology Abstract Nanotechnology is an enabling technology and as such, will have an...years), medium term (10 years) and long term (> 15 years) prospects. In addition, the challenges currently being faced to commercialize nanotechnology...will be discussed in detail. A summary outlining efforts across the world in terms of commercialization , startup activities, participation of major

  1. Commercial Radio as Communication.

    ERIC Educational Resources Information Center

    Rothenbuhler, Eric W.

    1996-01-01

    Compares the day-to-day work routines of commercial radio with the principles of a theoretical communication model. Illuminates peculiarities of the conduct of communication by commercial radio. Discusses the application of theoretical models to the evaluation of practicing institutions. Offers assessments of commercial radio deriving from…

  2. COMMERCIAL FOODS, MATHEMATICS - I.

    ERIC Educational Resources Information Center

    DORNFIELD, BLANCHE E.

    THE UNDERSTANDING AND MASTERY OF FUNDAMENTAL MATHEMATICS IS A NECESSARY PART OF COMMERCIAL FOODS WORK. THIS STUDENT HANDBOOK WAS DESIGNED TO ACCOMPANY A COMMERCIAL FOODS COURSE AT THE HIGH SCHOOL LEVEL FOR STUDENTS WITH APPROPRIATE APTITUDES AND COMMERCIAL FOOD SERVICE GOALS. THE MATERIAL, TESTED IN VARIOUS INTERESTED CLASSROOMS, WAS PREPARED BY…

  3. LED illuminator for a microdisplay projector

    NASA Astrophysics Data System (ADS)

    Magarill, Simon

    2012-10-01

    An illumination system for a microdisplay projector with a two-step imaging system is described here. In the first step, an imaging condenser creates an image of the LED at the color combiner entrance window. In the second step, we relay the image of the integrator exit window onto the micro-display. The illuminator demonstrates high collection efficiency, small footprint, and efficient mixing of light from RGB LEDs that provides required uniformity. A variety of approaches to collecting light emitted from LEDs of various types are compared, leading to the two-step design. A design example using a 0.55" diagonal DLP-based optical engine is presented with the following characteristics: Footprint: 3.9"x3.3"x2.0" (25.7 cubic inches) Light output: 338 white lumens Efficiency: 4.7 lm/watt

  4. LED-based NDIR natural gas analyzer

    NASA Astrophysics Data System (ADS)

    Fanchenko, Sergey; Baranov, Alexander; Savkin, Alexey; Sleptsov, Vladimir

    2016-03-01

    A new generation of the light-emitting diodes (LEDs) and photodiodes (PDs) was used recently to develop an open path non-dispersive infrared (NDIR) methane analyzer. The first open path detector prototype was constructed using LEDs for measurement and reference channels, accordingly, and first measurements for methane gas have been performed using optical paths of the order of several meters [3]. The natural gas consists of several first alkanes, mainly methane, and it is important to have a possibility of measuring all of them. In the present work we report the results of NDIR measurements for propane-butane mixture and new measurements of methane using LEDs for measurement and reference channels at 2300 and 1700 nm wavelengths, accordingly. The necessity of the double beam scheme is demonstrated and obtained results for methane and propane-butane mixture are compared.

  5. Optical communications. V - Light emitting diodes /LED/

    NASA Astrophysics Data System (ADS)

    Best, S. W.

    1980-10-01

    The process of assembling diode chips is discussed, along with their application in optical communications. Metal plating is performed with an evaporation technique using primarily AuGe on the back side and Al or AuZn on the front side. The assembling of LED-chips with metal casings is illustrated. The chip is mounted on a flat bottom plate and electrical contact is established by means of an alloying or adhesion procedure. A glass fiber can be attached to the diode and then fitted with a casing, or the diode can be assembled with a metal cap and a lense, or with an open cap that is sealed with a clear synthetic resin plastic. The typical emission spectra of an LED and a semiconductor laser are compared. Limitations in the operation of an LED in a photoconductor are examined, taking into account spectral line width and radiated power criteria.

  6. Laser and LED external teeth-bleaching

    NASA Astrophysics Data System (ADS)

    Zanin, Fatima A.; Brugnera, Aldo, Jr.; Marchesan, Melissa A.; Pecora, Jesus D.

    2004-09-01

    Teeth-bleaching is an initial phase in the reproduction of an aesthetic smile; thus, it is very important that the dentist knows how to diagnose the causes of color changes and indicate whitening before proposing dental treatment. Technological advances in teeth-whitening lead to the development of new techniques, improving comfort, security and decreasing time of execution: argon laser, diode Laser, LED whitening, xenon light whitening. The clearing agent used in all techniques, including home whitening, is hydrogen peroxide (H2O2) in different concentrations. In this study, the authors describe mechanisms of gel activation, the use of Laser and LED"s for teeth-bleaching, the importance of diagnosis and the comfort of the patient in in-office teeth-bleaching techniques.

  7. LED module with high index lens

    SciTech Connect

    Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.; Sun, Decai; Wei, Yajun

    2016-07-05

    An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.

  8. Embedded systems for controlling LED matrix displays

    NASA Astrophysics Data System (ADS)

    Marghescu, Cristina; Drumea, Andrei

    2016-12-01

    LED matrix displays are a common presence in everyday life - they can be found in trains, buses, tramways, office information tables or outdoor media. The structure of the display unit is similar for all these devices, a matrix of light emitting diodes coupled between row and column lines, but there are many options for the display controller that switches these lines. Present paper analyzes different types of embedded systems that can control the LED matrix, based on single board computers, on microcontrollers with different peripheral devices or with programmable logic devices like field programmable gate arrays with implemented soft processor cores. Scalability, easiness of implementation and costs are analyzed for all proposed solutions.

  9. Nonintrusive Measurement Of Temperature Of LED Junction

    NASA Technical Reports Server (NTRS)

    Leidecker, Henning; Powers, Charles

    1991-01-01

    Temperature inferred from spectrum of emitted light. Method of determining temperature of junction based on two relevant characteristics of LED. Gap between valence and conduction electron-energy bands in LED material decreases with increasing temperature, causing wavelength of emitted photon to increase with temperature. Other, as temperature increases, non-radiative processes dissipate more of input electrical energy as heat and less as photons in band-gap wavelenth region; optical and quantum efficiencies decrease with increasing temperature. In principal, either characteristic alone used to determine temperature. However, desirable to use both to obtain indication of uncertainty.

  10. Design of an oximeter based on LED-LED configuration and FPGA technology.

    PubMed

    Stojanovic, Radovan; Karadaglic, Dejan

    2013-01-04

    A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (S(p)O(2)). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (S(p)O(2)). N-LEDs configuration is proposed for multichannel S(p)O(2) measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

  11. High performance, LED powered, waveguide based total internal reflection microscopy

    PubMed Central

    Ramachandran, Srinivasan; Cohen, Daniel A.; Quist, Arjan P.; Lal, Ratnesh

    2013-01-01

    Total internal reflection fluorescence (TIRF) microscopy is a rapidly expanding optical technique with excellent surface sensitivity and limited background fluorescence. Commercially available TIRF systems are either objective based that employ expensive special high numerical aperture (NA) objectives or prism based that restrict integrating other modalities of investigation for structure-function analysis. Both techniques result in uneven illumination of the field of view and require training and experience in optics. Here we describe a novel, inexpensive, LED powered, waveguide based TIRF system that could be used as an add-on module to any standard fluorescence microscope even with low NA objectives. This system requires no alignment, illuminates the entire field evenly, and allows switching between epifluorescence/TIRF/bright field modes without adjustments or objective replacements. The simple design allows integration with other imaging systems, including atomic force microscopy (AFM), for probing complex biological systems at their native nanoscale regimes. PMID:23823601

  12. Comparison of instructor-led versus peer-led debriefing in nursing students.

    PubMed

    Roh, Young Sook; Kelly, Michelle; Ha, Eun Ho

    2016-06-01

    Despite its widespread support, the most effective simulation-based debriefing method has little evidence to support its efficacy. In this study, we compared the effect of peer-led and instructor-led debriefing among nursing students. The study was conducted with a non-equivalent control group using a pretest-post-test design. A convenience sample of third-year nursing students was used for the study, where 65 students enrolled in a 2-week clinical placement rotation were randomly assigned to the instructor-led group or peer-led group. The quality of cardiopulmonary resuscitation skills, satisfaction with simulation, and quality of debriefing in the peer-led group were compared to those in the instructor-led group. Group differences at each testing interval were analyzed using independent t-test. Nursing students in the instructor-led debriefing group showed better subsequent cardiopulmonary resuscitation performance, more satisfaction with simulation experience, and higher debriefing scores compared to the peer-led group. From our study, instructor-led debriefing is an effective method in improving skills performance, inducing favorable satisfaction, and providing better quality of debriefing among nursing students.

  13. Child-Led Enquiry in Primary Science

    ERIC Educational Resources Information Center

    Dunlop, Lynda; Compton, Kirsty; Clarke, Linda; McKelvey-Martin, Valerie

    2015-01-01

    This research describes and evaluates the application of a child-led approach to scientific enquiry (the Community of Scientific Enquiry, CoSE) to children aged 8-11 (Key Stage 2) in Northern Ireland. Primary teachers were introduced to CoSE at a workshop and asked to evaluate its implementation with their class. Results from children (n = 364)…

  14. Peer Led Focus Groups and Young People

    ERIC Educational Resources Information Center

    Murray, Cathy

    2006-01-01

    Peer led focus groups, a qualitative social science research method, and their use with young people are examined. The paper outlines three developments that have contributed to their emergence, namely: traditional focus groups, peer education and participatory research. Drawing on a study in progress, the advantages and challenges associated with…

  15. LED structure with enhanced mirror reflectivity

    DOEpatents

    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.

  16. LED Lighting in a Performing Arts Building

    SciTech Connect

    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.

  17. Portrait of a Teacher-Led School

    ERIC Educational Resources Information Center

    Nazareno, Lori

    2013-01-01

    Imagine a school with no principal and with a leadership structure that holds teachers accountable for the learning of all students. About 50 such teacher-led schools currently operate across the United States, and this article tells the story of one of them. The Mathematics and Science Leadership Academy (MSLA) in Denver, Colorado, serves about…

  18. Photomatrix LED therapy of extensive cutaneous pathology

    NASA Astrophysics Data System (ADS)

    Zharov, Vladimir P.; Menyaev, Yulian A.; Zharova, I. Z.; Leviev, Dmitry O.; Tsarev, V. N.; Sarantsev, V. P.; Krusic, Joze

    2000-05-01

    Standard sources of radiation have not sufficient efficiency at treating spatially extended pathology, especially when pathologic areas involve opposite sides of the human being's body or when they are uneven in shape. The typical examples of such pathology are extensive burns, oedema, inflammatory processes, infectious wounds, actinic keratosis, psoriasis, arthritis and neurological diseases. Superbright LEDs gathered in a matrix and grasping the area of irradiation are the most suitable sources of radiation. This article presents the result of investigation of the effectiveness of various types of the blue-to-infrared spectrum range LED array that allow irradiating a surface with an area from several cm2 to several thousand cm2 including the whole human being's body with the intensity varying from 1 to 100 mW/cm2. Besides the matrixes, composed of separate light diodes, modular systems with separate monolithic hybrid chips with a high density of positioning the sources of radiation are considered. The peculiarities and results of applying such systems to treat oedema, cancer, weight regulation, neurological diseases, different infections diseases in combination with PDT, stomatitis and paradontosis are analyzed. The parameters of the photomatrix LED for different spectral regions and different geometry from flat shape to semispherical and cylindrical are presented. The perspective combination photomatrix LED with another therapeutical devices including photovacuum and photomagnetic therapy are considered.

  19. NASA Ames UV-LED Poster Overview

    NASA Technical Reports Server (NTRS)

    Jaroux, Belgacem Amar

    2015-01-01

    UV-LED is a small satellite technology demonstration payload being flown on the Saudisat-4 spacecraft that is demonstrating non-contacting charge control of an isolated or floating mass using new solid-state ultra-violet light emitting diodes (UV-LEDs). Integrated to the rest of the spacecraft and launched on a Dnepr in June 19, 2014, the project is a collaboration between the NASA Ames Research Center (ARC), Stanford University, and King Abdulaziz City for Science and Technology (KACST). Beginning with its commissioning in December, 2015, the data collected by UV-LED have validated a novel method of charge control that will improve the performance of drag-free spacecraft allowing for concurrent science collection during charge management operations as well as reduce the mass, power and volume required while increasing lifetime and reliability of a charge management subsystem. UV-LED continues to operate, exploring new concepts in non-contacting charge control and collecting data crucial to understanding the lifetime of ultra-violet light emitting diodes in space. These improvements are crucial to the success of ground breaking missions such as LISA and BBO, and demonstrates the ability of low cost small satellite missions to provide technological advances that far exceed mission costs.

  20. Determination of radiative current in LED's

    NASA Technical Reports Server (NTRS)

    Thomas, E. F.

    1976-01-01

    Directly measureable quantity of radiative output in LED's is total forward current. When applied forward voltage is below 1.05 V the forward current is primarily nonradiative and varies with forward voltage as exp(qV/2kT), when q is the charge, V is applied voltage, K is Boltzmann's constant, and T is operating temperature.

  1. Student-Led Conferencing as Democratic Practice

    ERIC Educational Resources Information Center

    Tholander, Michael

    2011-01-01

    School conferences, in which teachers meet with parents and students, have long been criticised for being an undemocratic practice. Traditionally, such conferences have been organised and governed by the teacher. However, in recent years, student-led conferences have become more common in Swedish schools. The present article focuses on eight such…

  2. LED solution for E14 candle lamp

    NASA Astrophysics Data System (ADS)

    Li, Yun; Liu, Ye; Boonekamp, Erik P.; Shi, Lei; Mei, Yi; Jiang, Tan; Guo, Qing; Wu, Huarong

    2009-08-01

    On a short to medium term, energy efficient retrofit LED products can offer an attractive solution for traditional lamps replacement in existing fixtures. To comply with user expectations, LED retrofit lamps should not only have the same mechanical interface to fit (socket and shape), but also have the similar light effect as the lamps they replace. The decorative lighting segment shows the best conditions to meet these requirements on short term. In 2008, Philips Lighting Shanghai started with the development of an LED candle lamp for the replacement of a 15W Candle shape (B35 E14) incandescent bulb, which is used in e.g. chandeliers. In this decorative application the main objective is not to generate as much light as possible, but the application requires the lamp to have a comparable look and, primarily, the same light effect as the incandescent candle lamp. This effect can be described as sparkling light, and it has to be directed sufficiently downwards (i.e., in the direction of the base of the lamp). These requirements leave very limited room for optics, electronics, mechanics and thermal design to play with in the small outline of this lamp. The main voltage AC LED concept is chosen to save the space for driver electronics. However the size of the AC LED is relatively big, which makes the optical design challenging. Several optical solutions to achieve the required light effect, to improve the optical efficiency, and to simplify the system are discussed. A novel prismatic lens has been developed which is capable of transforming the Lambertian light emission from typical high power LEDs into a butter-fly intensity distribution with the desired sparkling light effect. Thanks to this lens no reflecting chamber is needed, which improves the optical efficiency up to 70%, while maintaining the compact feature of the original optics. Together with advanced driver solution and thermal solution, the resulting LED candle lamp operates at 230V, consumes 1.8W, and

  3. Diamond LED substrate and novel quantum dots.

    PubMed

    Sung, James C; Sung, Michael

    2009-02-01

    Nitride LED (e.g., GaN) has become the mainstream of blue light source. The blue light can be converted to white light by exciting a phosphor (e.g., Nichia's YAG or Osram's TAG) with the complementary yellow emission. However, GaN is typically deposited on sapphire (Al2O3) substrates formed by crystal pulling or hexagonal (e.g., 4 H or 6 H) SiC wafers condensed from SiC vapor. In either case, the nitride lattice is ridden (e.g., 10(9)/cm2) with dislocations. The high dislocation density with sapphire is due to the large (>13%) lattice mismatch; and with hexagonal SiC, because of intrinsic defects. Cubic (beta) SiC may be deposited epitaxially using a CVD reactor onto silicon wafer by diffusing the interface and by chemical gradation. A reactive echant (e.g., hydrogen or fluorine) can be introduced periodically to gasify mis-aligned atoms. In this case, large single crystal wafers would be available for the manufacture of high bright LED with superb electro-optical efficiency. The SiC wafer may be coated with diamond film that can eliminate heat in real time. As a result of lower temperature, the nitride LED can be brighter and it will last longer. The blue light of GaN LED formed on SiC on Diamond (SiCON) LED may also be scattered by using novel quantum dots (e.g., 33 atom pairs of CdSe) to form a broad yellow light that blend in with the original blue light to form sunlight-like white light. This would be the ideal source for general illumination (e.g., for indoor) or backlighting (e.g., for LCD).

  4. LED mini-lidar as minimum setup

    NASA Astrophysics Data System (ADS)

    Shiina, Tatsuo

    2014-10-01

    The LED mini-lidar has been designed and demonstrated as the near range atmosphere monitoring, dust and gas detections. The LED lamp is used as a lidar light source. It is not a special one, and just used as a small status indicator or a spot luminaire. For the atmospheric monitoring in the near range of a few hundreds meters, the energy of 1nJ (=100mW/10ns) is enough for lidar observation in the nighttime. The LED lamp is excited at the high repetition frequency of < 1MHz. The signal-to-noise ratio can be increased by this high frequency even if the receiving photons are a little at each pulse. It is adequate because the spatiotemporal scale of the low-altitude atmosphere is small of a ten seconds and a few tens meters. To pursue such quick motion of the atmosphere and dust, the high-speed photon counter has been developed. It can act with BIN width of 4ns (Spatial resolution 0.6m) at the repetition frequency of <500kHz. The LED mini-lidar has been demonstrated to monitor the actual atmosphere of the observation range of <500m in the nighttime and <100m in the daytime with the receiving lens of 200mmφ. The interest approach is tired to distinguish the dust characteristics by using the counting rate of dust echoes. It is effective in the case that the dust material is given. And for trial, the LED mini-Raman-lidar is developed to monitor certain gas detection in near distance, too.

  5. Enhancement of astaxanthin production using Haematococcus pluvialis with novel LED wavelength shift strategy.

    PubMed

    Xi, Tianqi; Kim, Dae Geun; Roh, Seong Woon; Choi, Jong-Soon; Choi, Yoon-E

    2016-07-01

    Haematococcus pluvialis is a green microalga of particular interest, since it is considered the best potential natural source of astaxanthin, which is widely used as an additive for natural pigmentation. In addition, astaxanthin has recently garnered commercial interest as a nutraceutical, cosmetic, and pharmaceutical. However, producing astaxanthin from H. pluvialis necessitates separation with distinctive culture conditions, dividing between the microalgae growth and the astaxanthin production stages. Light-emitting diodes (LEDs) have emerged as a replacement for traditional light sources, and LED applications are now rapidly expanding to multiple areas in fields such as biotechnology. However, further detail application into microalgae biotechnology remains limited. In this study, we have attempted to establish new protocols based on the specific wavelength of LEDs for the cultivation and production of astaxanthin using H. pluvialis. Specifically, we applied red LEDs for microalgae cell growth and then switched to blue LEDs to induce astaxanthin biosynthesis. The result showed that astaxanthin productions based on a wavelength shift from red to blue were significantly increased, compared to those with continuous illumination using red LEDs. Furthermore, additional increase of astaxanthin production was achieved with simultaneous application of exogenous carbon with blue LED illumination. Our approach based on the proper manipulation of LED wavelengths upon H. pluvialis cell stages will enable the improvement of biomass and enhance astaxanthin production using H. pluvialis.

  6. Evaluation Capacity Building in the Schools: Administrator-Led and Teacher-Led Perspectives

    ERIC Educational Resources Information Center

    Lawrenz, Frances; Thomas, Kelli; Huffman, Douglas; Clarkson, Lesa Covington

    2008-01-01

    The purpose of this article is to describe evaluation capacity building using an immersion approach in two schools: one with an administrator-led process and one with a teacher-led process. The descriptions delineate conceptual, developmental, and sustainability aspects of capacity building through the perspectives of the teachers, principals, and…

  7. Sustainable LED Fluorescent Light Replacement Technology

    SciTech Connect

    None, None

    2011-09-30

    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

  8. Lunar Commercialization Workshop

    NASA Technical Reports Server (NTRS)

    Martin, Gary L.

    2008-01-01

    This slide presentation describes the goals and rules of the workshop on Lunar Commercialization. The goal of the workshop is to explore the viability of using public-private partnerships to open the new space frontier. The bulk of the workshop was a team competition to create a innovative business plan for the commercialization of the moon. The public private partnership concept is reviewed, and the open architecture as an infrastructure for potential external cooperation. Some possible lunar commercialization elements are reviewed.

  9. Regulating Commercial Telephone Solicitations,

    DTIC Science & Technology

    1978-03-01

    also proposed that telephone subscribers be given the right to indicate if they do not want to receive commercial advertising calls , whether from...federal government should prohibit all commercial advertising calls. Advertisers have rights to free speech , and some consumers, I am told , don ’t...of the same arguments against giving subscribers the right to refuse commercial advertising calls that they made in 1965. They have stated that placing

  10. Fluorescent protein integrated white LEDs for displays

    NASA Astrophysics Data System (ADS)

    Press, Daniel Aaron; Melikov, Rustamzhon; Conkar, Deniz; Nur Firat-Karalar, Elif; Nizamoglu, Sedat

    2016-11-01

    The usage time of displays (e.g., TVs, mobile phones, etc) is in general shorter than their functional life time, which worsens the electronic waste (e-waste) problem around the world. The integration of biomaterials into electronics can help to reduce the e-waste problem. In this study, we demonstrate fluorescent protein integrated white LEDs to use as a backlight source for liquid crystal (LC) displays for the first time. We express and purify enhanced green fluorescent protein (eGFP) and monomeric Cherry protein (mCherry), and afterward we integrate these proteins as a wavelength-converter on a blue LED chip. The protein-integrated backlight exhibits a high luminous efficacy of 248 lm/Wopt and the area of the gamut covers 80% of the NTSC color gamut. The resultant colors and objects in the image on the display can be well observed and distinguished. Therefore, fluorescent proteins show promise for display applications.

  11. Lifetime Estimation of High Power White LEDs

    NASA Astrophysics Data System (ADS)

    Ishizaki, Shinya; Kimura, Hideyoshi; Sugimoto, Masaru

    We have developed a high power and long lifetime white LED module which can be used in general lighting applications. Since the materials in the package are very robust at high temperatures, the device can be operated at junction temperatures (Tj) over 250°C. Moreover, the thermal resistance of the package is less than 20°C/W. Therefore the device can be operated at input power as high as 2.4 W, making it possible to shorten the duration of accelerated lifetime tests. An acceleration ratio greater than 100 has been achieved. Assuming a thermally activated degradation process and applying the Arrhenius model, the LED chip lifetime (defined as a 50% reduction in luminous flux) is determined to be 40,000 hours for a Tj of 130°C. The activation energy of the degradation process was determined to be 1.55 eV.

  12. LED based full color stereoscopic projection system

    NASA Astrophysics Data System (ADS)

    Bogaert, Lawrence; Meuret, Youri; Van Giel, Bart; Thienpont, Hugo

    2007-02-01

    We present a compact light emitting diode (LED) based projection system with potential for stereoscopic viewing. The optical core consists of four polarizing beam splitters (PBS), positioned in a cross configuration, with wavelength selective half wave plates placed between them. Four liquid crystal on silicon (LCoS) panels are located at the exterior facets of two PBSs in opposite corners of the cuboid. The illumination system combines individual LED sources and ensures telecentric illumination through the optical core. This architecture gives rise to two light paths that independently generate two linear polarized images with orthogonal polarization direction. When the observer wears polarization sensitive eyeglasses and a polarization maintaining screen is used, each eye will see a different projected image such that three-dimensional (3-D) viewing can be perceived. On the other hand, 2-D vision is possible by projecting two identical images.

  13. Laser and LED external teeth-bleaching

    NASA Astrophysics Data System (ADS)

    Zanin, Fatima; Brugnera, Aldo, Jr.; Marchesan, Melissa A.; Pecora, Jesus D.

    2004-05-01

    Teeth-bleaching is an initial phase in the reproduction of an aesthetic smile; thus, it is very important that the dentist knows how to diagnose the causes of color changes and indicate whitening before proposing dental treatment. Technological advances in teeth-whitening lead to the development of new techniques, improving comfort, security and decreasing time of execution: argon laser, diode laser, LED whitening, xenon light whitening. The clearing agent used in all techniques, including home whitening, is hydrogen peroxide (H2O2) in different concentrations. In this study, the authors describe mechanisms of gel activation, the use of Laser and LED's for teeth-bleaching, the importance of diagnosis and the comfort of the patient in in-office teeth-bleaching techniques.

  14. LED color mixing with diffractive structures

    NASA Astrophysics Data System (ADS)

    Bonenberger, Theresa; Baumgart, Jörg; Wendel, Simon; Neumann, Cornelius

    2013-03-01

    Lighting solutions with colored LEDs provide many opportunities for illumination. One of these opportunities is to create a color tunable light source. In this way different kinds of white light (color temperature) as well as discrete colors may be realized. This opens the field for applications as mood lighting. But there is always a spatial separation of the distinct LEDs that might get converted into an angular separation by any collimating optics. This angular separation causes such problems like color fringes and colored shadows that cannot be accepted in most applications. Conventional methods to solve these problems include e.g. mixing rods or dichroic filters. A new approach is the use of the dispersive effect of a diffractive structure to compensate the angular separation of the different colors. In this contribution the potential and limitations of diffractive structures in LED color mixing applications are discussed. Ray tracing simulations were performed to analyze such important parameters like efficiency, color performance and the cross section of the color mixing optics. New means for the estimation of color mixing performance were developed. A software tool makes it possible to detect the color distribution within ray trace data and it provides a quality factor to estimate the color mixing performance. It can be shown that the spectral band width has a large influence on the mixing process. Ray tracing simulations are compared with results of an experimental setup such that both measured as well as simulated data is presented.

  15. Phosphor-converted LEDs with low circadian action for outdoor lighting.

    PubMed

    Zabiliūtė, Akvilė; Vaicekauskas, Rimantas; Vitta, Pranciškus; Zukauskas, Artūras

    2014-02-01

    Dichromatic phosphor-converted (pc) light-emitting diodes (LEDs) with low circadian action are proposed for low-luminance photobiologically safe outdoor illumination. The LEDs feature the partial conversion of blue radiation in an orange phosphor with the resulting correlated color temperature in the "firelight" range of 1700-2500 K. The circadian action factor, which is the ratio of the biological efficacy of radiation due to the excitation of intrinsically photosensitive retinal ganglion cells to the mesopic luminous efficacy of radiation, is considerably lower than that of commercial white pc LEDs. The equivalent general color-rendering index estimated with regard to the reduced color-discrimination ability of human vision at low luminances has appropriate values in between those of common white pc LEDs and high-pressure sodium lamp.

  16. Tobacco prevention advertising: lessons from the commercial world.

    PubMed

    Rust, L

    1999-01-01

    This paper presents observations on how commercial TV advertising usually works with young people, discusses the special circumstances using advertising as a smoking prevention tool, and suggests research to guide future efforts. It is important for prevention efforts to recognize that in everyday life many young people are not systematic decision-makers; their intentions are extremely volatile and context-dependent, and they are highly spontaneous. So trying to change their smoking risk status with a TV ad that affects their conscious intentions toward smoking may not impact how they react when someone offers to share a cigarette with them behind the garage--even if it affects how they answer a "Do you think you'll ever take up smoking?" question right after seeing the ad. Advertising is good at getting consumers to focus on products--either in creating new brands, or in keeping familiar brands foremost in mind. Advertising is also good at providing models of concrete behaviors for people to imitate. Prevention efforts need to use advertising for what it is good at, and by and large this means being very concrete. Ultimately, for research to contribute to better prevention advertising, it needs to give the people who actually create that advertising a set of vivid, compelling images of who it is they are trying to reach and what it is that moves them. Some research methods which, when done properly, can serve this function are focus groups, anthropological studies, psychographic segmentations, moment-by-moment observational measurement, improved copy-testing methodology, and grounded-theory development.

  17. Lunar Commercialization Workshop

    NASA Technical Reports Server (NTRS)

    Martin, Gary L.

    2009-01-01

    This slide presentation outlines a competition that has as its goal to explores the viability of using public-private partnerships to open space frontier for commercial uses. The teams have the objective of designing a business plan to open the space frontier to commercial interests.

  18. Commercial Crew Launch America

    NASA Technical Reports Server (NTRS)

    Thon, Jeffrey S.

    2016-01-01

    This presentation is intended to discuss NASA's long term human exploration goals of our solar system. The emphasis will be on how our CCP (Commercial Crew Program) supports our space bound human exploration goals by encouraging commercial entities to perform missions to LEO (Low Earth Orbit), thus allowing NASA to focus on beyond LEO human exploration missions.

  19. Technology Transfer and Commercialization

    NASA Technical Reports Server (NTRS)

    Martin, Katherine; Chapman, Diane; Giffith, Melanie; Molnar, Darwin

    2001-01-01

    During concurrent sessions for Materials and Structures for High Performance and Emissions Reduction, the UEET Intellectual Property Officer and the Technology Commercialization Specialist will discuss the UEET Technology Transfer and Commercialization goals and efforts. This will include a review of the Technology Commercialization Plan for UEET and what UEET personnel are asked to do to further the goals of the Plan. The major goal of the Plan is to define methods for how UEET assets can best be infused into industry. The National Technology Transfer Center will conduct a summary of its efforts in assessing UEET technologies in the areas of materials and emissions reduction for commercial potential. NTTC is assisting us in completing an inventory and prioritization by commercialization potential. This will result in increased exposure of UEET capabilities to the private sector. The session will include audience solicitation of additional commercializable technologies.

  20. BiliLED low cost neonatal phototherapy, from prototype to industry

    NASA Astrophysics Data System (ADS)

    Geido, Daniel; Failache, Horacio; Simini, Franco

    2007-11-01

    BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14×14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described.

  1. Investigation of phosphor-LED lamp for real-time half-duplex wireless VLC system

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Chow, Chi-Wai; Chen, Hsing-Yu; Liu, Yen-Liang; Hsu, Dar-Zu

    2016-06-01

    In this investigation, a 71.3 to 148.4 Mbit s-1 white phosphor-LED visible light communication (VLC) system is proposed and demonstrated under the practical transmission length of 140 to 210 cm. Here, a commercial white-light LED lamp with five cascaded phosphor-LED chips is utilized for illumination and communication simultaneously. In the measurement, we utilize the optical orthogonal frequency division multiplexing quadrature amplitude modulation (OFDM-QAM) with bit-loading algorithm and propose an optimal bias-tee circuit design to improve the modulation bandwidth from 1 MHz to 27 MHz. Moreover, a blue optical filter is not used on the client side. Finally, to realize and demonstrate the real-time transmission performance in the proposed LED VLC system, a commercial OFDM-based digital signal processor (DSP) chip is utilized on the LED lighting side and client side, respectively. Hence, the proposed real-time half-duplex VLC transmission could achieve the 70 Mbit s-1 downstream and upstream data throughputs, under a practical transmission length of 200 cm.

  2. Wheat Under LED's (Light Emitting Diodes)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Astroculture is a suite of technologies used to produce and maintain a closed controlled environment for plant growth. The two most recent missions supported growth of potato, dwarf wheat, and mustard plants, and provided scientists with the first opportunity to conduct true plant research in space. Light emitting diodes have particular usefulness for plant growth lighting because they emit a much smaller amount of radiant heat than do conventional lighting sources and because they have potential of directing a higher percentage of the emitted light onto plants surfaces. Furthermore, the high output LED's have emissions in the 600-700 nm waveband, which is of highest efficiency for photosynthesis by plants.

  3. Characterization of angled tapered superluminescent LEDs.

    PubMed

    Causa, Federica; Sarma, Jayanta; Yunus, Sharina

    2002-08-20

    We present a detailed analysis of the output beam of high-power edge-emitting angled tapered superluminescent LEDs (A-TSLEDs). A device model, including spontaneous and stimulated emission processes as well as the typical nonuniform carrier-density distribution due to current spreading and carrier diffusion, has been developed and used to interpret the experimentally obtained characteristics of inhouse-fabricated A-TSLEDs. The good match between measured and theoretical results indicates that the model reproduces the A-TSLED operation very satisfactorily and clearly explains the role of the collecting lens on the pronounced asymmetry of some of the measured optical intensity profiles.

  4. Child-led enquiry in primary science

    PubMed Central

    Dunlop, Lynda; Compton, Kirsty; Clarke, Linda; McKelvey-Martin, Valerie

    2015-01-01

    This research describes and evaluates the application of a child-led approach to scientific enquiry (the Community of Scientific Enquiry, CoSE) to children aged 8–11 (Key Stage 2) in Northern Ireland. Primary teachers were introduced to CoSE at a workshop and asked to evaluate its implementation with their class. Results from children (n = 364) and teachers (n = 19) found that CoSE engaged children with their science learning, and also developed confidence and oracy. However, teachers require more experience developing facilitation skills and in fitting science into a thematic teaching unit. PMID:27152060

  5. LED Context Lighting System in Residential Areas

    PubMed Central

    Im, Kyoung-Mi

    2014-01-01

    As issues of environment and energy draw keen interest around the globe due to such problems as global warming and the energy crisis, LED with high optical efficiency is brought to the fore as the next generation lighting. In addition, as the national income level gets higher and life expectancy is extended, interest in the enhancement of life quality is increasing. Accordingly, the trend of lightings is changing from mere adjustment of light intensity to system lighting in order to enhance the quality of one's life as well as reduce energy consumption. Thus, this study aims to design LED context lighting system that automatically recognizes the location and acts of a user in residential areas and creates an appropriate lighting environment. The proposed system designed in this study includes three types of processing: first, the creation of a lighting environment index suitable for the user's surroundings and lighting control scenarios and second, it measures and analyzes the optical characteristics that change depending on the dimming control of lighting and applies them to the index. Lastly, it adopts PIR, piezoelectric, and power sensor to grasp the location and acts of the user and create a lighting environment suitable for the current context. PMID:25101325

  6. Studying Light Color using White LED Lighting

    NASA Astrophysics Data System (ADS)

    Yamagishi, Misako; Yamaba, Kazuo; Nagata, Manori; Kubo, Chiho; Nokura, Kunihiro

    Recently, white Light Emitting Diodes (LEDs) are receiving attention worldwide as new lighting devices. This study examined effects of a lighting application on performance using white LEDs. The light color—the correlated color temperature (CCT) —was assessed. It affected to psychological states and physiological conditions. Three CCT conditions were respectively set for the experiment: 2500 K, 5000 K, and 8200 K. In all, 20 younger subjects (20-30 years old), 15 middle-aged to elderly subjects (45-60 years old) and 12 elderly subjects (over 65 years-old) participated. They were presented a Numerical Verification (NV) task for performance measurement. The psychological states on performance were evaluated using the lighting assessment questionnaire. The physiological conditions were recorded using an electrocardiograph. Results show that the effects of CCT differ among age groups. Especially, the performance of younger subjects might differ from CCT conditions; elderly subjects are affected by CCT condition because of their visual acuity or response to contrast of objects.

  7. LED context lighting system in residential areas.

    PubMed

    Kwon, Sook-Youn; Im, Kyoung-Mi; Lim, Jae-Hyun

    2014-01-01

    As issues of environment and energy draw keen interest around the globe due to such problems as global warming and the energy crisis, LED with high optical efficiency is brought to the fore as the next generation lighting. In addition, as the national income level gets higher and life expectancy is extended, interest in the enhancement of life quality is increasing. Accordingly, the trend of lightings is changing from mere adjustment of light intensity to system lighting in order to enhance the quality of one's life as well as reduce energy consumption. Thus, this study aims to design LED context lighting system that automatically recognizes the location and acts of a user in residential areas and creates an appropriate lighting environment. The proposed system designed in this study includes three types of processing: first, the creation of a lighting environment index suitable for the user's surroundings and lighting control scenarios and second, it measures and analyzes the optical characteristics that change depending on the dimming control of lighting and applies them to the index. Lastly, it adopts PIR, piezoelectric, and power sensor to grasp the location and acts of the user and create a lighting environment suitable for the current context.

  8. Freeform LED lens for rectangularly prescribed illumination

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Liu, Sheng; Chen, Fei; Qin, Zong; Liu, Zongyuan; Luo, Xiaobing

    2009-10-01

    Freeform lenses are playing a more and more important role in LED secondary optics design. In this study, based on the new light energy mapping relationship, edge ray principle, Snell's law and error control of surface construction, a modified discontinuous freeform lens design method was presented for rectangularly prescribed illumination, with the advantages of a flexible energy mapping relationship, accurate light irradiation control and easier to manufacture. A polymethyl methacrylate (PMMA) discontinuous freeform lens was designed as an example for LED tunnel illumination according to this method. The numerical simulation results demonstrated that the light pattern of the lens was in good agreement with the expected illumination performance when using a point source. Tolerance analyses were also conducted. An extended light source had little effect on the light output efficiency (LOE) of the lens but significantly decreased the effective illumination area. Installation errors had more effect on the uniformity and shape of the light pattern than the LOE of the lens. The tolerances of vertical, horizontal and rotational deviation of this lens were 0.4 mm, 0.4 mm and 2°, respectively.

  9. Commercial Biomedical Experiments Payload

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Experiments to seek solutions for a range of biomedical issues are at the heart of several investigations that will be hosted by the Commercial Instrumentation Technology Associates (ITA), Inc. The biomedical experiments CIBX-2 payload is unique, encompassing more than 20 separate experiments including cancer research, commercial experiments, and student hands-on experiments from 10 schools as part of ITA's ongoing University Among the stars program. Here, Astronaut Story Musgrave activates the CMIX-5 (Commercial MDA ITA experiment) payload in the Space Shuttle mid deck during the STS-80 mission in 1996 which is similar to CIBX-2. The experiments are sponsored by NASA's Space Product Development Program (SPD).

  10. Commercial considerations for immunoproteomics.

    PubMed

    Ferguson, Scott M

    2013-01-01

    The underlying drivers of scientific processes have been rapidly evolving, but the ever-present need for research funding is typically foremost amongst these. Successful laboratories are embracing this reality by making certain that their projects have commercial value right from the beginning of the project conception. Which factors to be considered for commercial success need to be well thought out and incorporated into a project plan with similar levels of detail as would be the technical elements. Specific examples of commercial outcomes in the field of Immunoproteomics are exemplified in this discussion.

  11. NASA commercial programs

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Highlights of NASA-sponsored and assisted commercial space activities of 1989 are presented. Industrial R and D in space, centers for the commercial development of space, and new cooperative agreements are addressed in the U.S. private sector in space section. In the building U.S. competitiveness through technology section, the following topics are presented: (1) technology utilization as a national priority; (2) an exploration of benefits; and (3) honoring Apollo-Era spinoffs. International and domestic R and D trends, and the space sector are discussed in the section on selected economic indicators. Other subjects included in this report are: (1) small business innovation; (2) budget highlights and trends; (3) commercial programs management; and (4) the commercial programs advisory committee.

  12. Comparing Commercial WWW Browsers.

    ERIC Educational Resources Information Center

    Notess, Greg R.

    1995-01-01

    Four commercial World Wide Web browsers are evaluated for features such as handling of WWW protocols and different URLs: FTP, Telnet, Gopher and WAIS, and e-mail and news; bookmark capabilities; navigation features; file management; and security support. (JKP)

  13. EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

    NASA Astrophysics Data System (ADS)

    Grandjean, N.

    2010-09-01

    Generating white light from electricity with maximum efficacy has been a long quest since the first incandescent lamp was invented by Edison at the end of the 19th century. Nowadays, semiconductors are making reality the holy grail of converting electrons into photons with 100% efficiency and with colours that can be mixed for white light illumination. The revolution in solid-state lighting (SSL) dates to 1994 when Nakamura reported the first high-brightness blue LED based on GaN semiconductors. Then, white light was produced by simply combining a blue dye with a yellow phosphor. After more than a decade of intensive research the performance of white LEDs is quite impressive, beating by far the luminous efficacy of compact fluorescent lamps. We are likely close to replacing our current lighting devices by SSL lamps. However, there are still technological and fabrication cost issues that could delay large market penetration of white LEDs. Interestingly, SSL may create novel ways of using light that could potentially limit electricity saving. Whatever the impact of SSL, it will be significant on our daily life. The purpose of this special cluster issue is to produce a snapshot of the current situation of SSL from different viewing angles. In an introductory paper, Tsao and co-workers from Sandia National Laboratories, present an energy-economics perspective of SSL considering societal changes and SSL technology evolution. In a second article, Narukawa et al working at Nichia Corporation—the pioneer and still the leading company in SSL—describe the state of the art of current research products. They demonstrate record performance with white LEDs exhibiting luminous efficacy of 183 lm W-1 at high-current injection. Then, a series of topical papers discuss in detail various aspects of the physics and technology of white LEDs Carrier localization in InGaN quantum wells has been considered the key to white LEDs' success despite the huge density of defects. A

  14. Technology Commercialization Program 1991

    SciTech Connect

    Not Available

    1991-11-01

    This reference compilation describes the Technology Commercialization Program of the Department of Energy, Defense Programs. The compilation consists of two sections. Section 1, Plans and Procedures, describes the plans and procedures of the Defense Programs Technology Commercialization Program. The second section, Legislation and Policy, identifies legislation and policy related to the Program. The procedures for implementing statutory and regulatory requirements are evolving with time. This document will be periodically updated to reflect changes and new material.

  15. Characterising and testing deep UV LEDs for use in space applications

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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 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 power measurements, spectral stability, pulsed performance and temperature dependence, as well as thermal vacuum, radiation and vibration survivability.

  16. Switched-capacitor isolated LED driver

    SciTech Connect

    Sanders, Seth R.; Kline, Mitchell

    2016-03-22

    A switched-capacitor voltage converter which is particularly well-suited for receiving a line voltage from which to drive current through a series of light emitting diodes (LEDs). Input voltage is rectified in a multi-level rectifier network having switched capacitors in an ascending-bank configuration for passing voltages in uniform steps between zero volts up to full received voltage V.sub.DC. A regulator section, operating on V.sub.DC, comprises switched-capacitor stages of H-bridge switching and flying capacitors. A current controlled oscillator drives the states of the switched-capacitor stages and changes its frequency to maintain a constant current to the load. Embodiments are described for isolating the load from the mains, utilizing an LC tank circuit or a multi-primary-winding transformer.

  17. LED--panacea or marketing hype?

    PubMed

    Baillie, Jonathan

    2012-02-01

    With energy efficiency and carbon reduction, and the importance of a relaxing, therapeutic patient environment, ever more in the spotlight, LED lighting's proponents claim the technology offers healthcare estates personnel many of the answers on both fronts. However some observers believe its benefits are being over-sold, often to the detriment of other high-performing types of more 'conventional lighting', and to a sometimes uninitiated audience too easily swayed by slick sales patter. HEJ editor Jonathan Baillie spoke to one highly experienced lighting professional, Nicholas Bukorović, a former employee of Thorn, Cooper, and Thorlux Lighting, and the principal author of the last CIBSE/Society of Light and Lighting (SLL) Guide LG2 on healthcare lighting, to seek some expert illumination.

  18. Scandium oxide antireflection coatings for superluminescent LEDs

    NASA Technical Reports Server (NTRS)

    Ladany, I.; Zanzucchi, P. J.; Andrews, J. T.; Kane, J.; Depiano, E.

    1986-01-01

    For an employment of laser diodes as superluminescent LEDs (SLDs) or amplifiers, the facets of the diodes must be coated with antireflection films. In the work reported, scandium oxide was evaporated from an e-beam source onto Supersil II fused silica substrates. The obtained samples were used for measurements of absorption and reflectivity. Results of index measurements on e-beam evaporated films are presented. It is shown that excellent coatings with reflectivities of 0.00025 can be obtained using these films. Attention is given to the refractive indices for scandium oxide films as a function of wavelength, the power output vs current for laser before coating and after coating with Sc2O3.

  19. RGB color sensor implemented with LEDs

    NASA Astrophysics Data System (ADS)

    Filoteo-Razo, J. D.; Estudillo-Ayala, J. M.; Hernández-Garcia, J. C.; Trejo-Durán, M.; Muñoz-Lopez, A.; Jauregui-Vázquez, D.; Rojas-Laguna, R.

    2015-09-01

    This paper presents the design and implementation of an optical sensor to detect color changes in fruit by means of white light reflection to measure fruit ripeness in industrial and agricultural applications. The system consists of a LED RGB array including photodetectors, a power source and plastic optic fiber (POF). By means of Labview ® graphic interface we can control the power emission of the diodes digitally mixing the colors at different intensities until we achieve white light to be used as a source for the color sensor. We used an ATmega2560 microcontroller as a data collection device to monitor the colors obtained and to show them as color models using Matlab ®. We show results from tests conducted using two guava samples, observing the evolution of the color change on the fruit skin until they became overripe.

  20. ERC commercialization activities

    SciTech Connect

    1995-08-01

    The ERC family of companies is anticipating market entry of their first commercial product, a 2.8-MW power plant, in the second quarter of 1999. The present Cooperative Agreement provides for: (1) Commercialization planning and organizational development, (2) Completion of the pre-commercial DFC technology development, (3) Systems and plant design, (4) Manufacturing processes` scale-up to full-sized stack components and assemblies, (5) Upgrades to ERC`s test facility for full-sized stack testing, (6) Sub-scale testing of a DFC Stack and BOP fueled with landfill gas. This paper discusses the first item, that of preparing for commercialization. ERC`s formal commercialization program began in 1990 with the selection of the 2-MW Direct Fuel Cell power plant by the American Public Power Association (APPA) for promotion to the over 2000 municipal utilities comprising APPA`s segment of the utility sector. Since that beginning, the APPA core group expanded to become the Fuel Cell Commercialization Group (FCCG) which includes representation from all markets - utilities and other power generation equipment buyers.

  1. ERC commercialization activities

    SciTech Connect

    Maru, H.C.

    1995-12-01

    The ERC family of companies is anticipating market entry of their first commercial product, a 2.8-MR power plant, in the second quarter of 1999. The present Cooperative Agreement provides for: (1) Commercialization planning and organizational development, (2) Completion of the pre-commercial DFC technology development, (3) Systems and plant design, (4) Manufacturing processes` scale-up to full- sized stack components and assemblies, (5) Upgrades to ERC`s test facility for full-sized stack testing, and (6) Sub-scale testing of a DFC Stack and BOP fueled with landfill gas. This paper discusses the first item, that of preparing for commercialization. ERC`s formal commercialization program began in 1990 with the selection of the 2-MR Direct Fuel Cell power plant by the American Public Power Association (APPA) for promotion to the over 2000 municipal utilities comprising APPA`s segment of the utility sector. Since that beginning, the APPA core group expanded to become the Fuel Cell Commercialization Group (FCCG) which includes representation from all markets - utilities and other power generation equipment buyers.

  2. Measurement of g Using a Flashing LED

    NASA Astrophysics Data System (ADS)

    Terzella, T.; Sundermier, J.; Sinacore, J.; Owen, C.; Takai, H.

    2008-10-01

    In one of the classic free-fall experiments, a small mass is attached to a strip of paper tape and both are allowed to fall through a spark timer, where sparks are generated at regular time intervals. Students analyze marks (dots) left on the tape by the timer, thereby generating distance-versus-time data, which they analyze to extract the acceleration due to gravity g with good results. The apparatus, however, is cumbersome and often frustrating for students. High-tech versions of this experiment are done with an object dropped and followed by a motion sensor connected to a computer. The sensor relies on ultrasonic ranging to record distance and time data, which may then be displayed graphically. Students inspect the graphs to determine the value of g. Although the results are excellent, the emphasis on the computer's ability to collect and analyze data leaves little analysis for the students to perform.2 Furthermore, neither technique gives an intuitive display of what is happening. The motivation for our work was to overcome these issues by developing an innovative method for measuring g. In our version of the experiment, students drop a flashing LED at a known frequency and record its trajectory using long exposure photography with a digital camera. Proper choice of flashing LED timing parameters produces an image that allows for an accurate measurement of g and at the same time helps to explain what happens during free fall. The experiment remains high-tech in the sense that students learn to use updated equipment to record data and to carry out the analysis.

  3. Parking garage threats and countermeasures.

    PubMed

    Clark, Sam

    2004-01-01

    Preventing and dealing with crime in hospital parking facilities poses a serious challenge to administration and security. Multiple methods to effectively combat the threats are described by the author, but their implementation depends on how seriously a healthcare organization views its responsibility to provide a safe and secure environment for its staff, patients and visitors.

  4. Influence of the quantum well models on the numerical simulation of planar InGaN/GaN LED results

    NASA Astrophysics Data System (ADS)

    Podgórski, J.; Woźny, J.; Lisik, Z.

    2016-04-01

    Within this paper, we present electric model of a light emitting diode (LED) made of gallium nitride (GaN) followed by examples of simulation results obtained by means of Sentaurus software, which is the part of the TCAD package. The aim of this work is to answer the question of whether physical models of quantum wells used in commercial software are suitable for a correct analysis of the lateral LEDs made of GaN.

  5. Revisiting of LED pumped bulk laser: first demonstration of Nd:YVO₄ LED pumped laser.

    PubMed

    Barbet, Adrien; Balembois, François; Paul, Amandine; Blanchot, Jean-Philippe; Viotti, Anne-Lise; Sabater, Jacques; Druon, Frédéric; Georges, Patrick

    2014-12-01

    We describe here what is, to the best of our knowledge, the first LED pumped Nd:YVO₄ laser. Near-IR LED arrays with a wavelength centered close to 850 nm were used to pump transversely the crystal. By pulsing LEDs, with a duration of the order of the laser transition lifetime, we obtained sufficient pump intensities to reach the laser threshold. At a frequency of 250 Hz, we obtained an output energy of 40 μJ at 1064 nm for an input pump energy of 7.4 mJ, which corresponds to an optical efficiency of 0.5%. Experimental results of small signal gain are compared with theoretical analysis.

  6. Open LED Illuminator: A Simple and Inexpensive LED Illuminator for Fast Multicolor Particle Tracking in Neurons

    PubMed Central

    Bosse, Jens B.; Tanneti, Nikhila S.; Hogue, Ian B.; Enquist, Lynn W.

    2015-01-01

    Dual-color live cell fluorescence microscopy of fast intracellular trafficking processes, such as axonal transport, requires rapid switching of illumination channels. Typical broad-spectrum sources necessitate the use of mechanical filter switching, which introduces delays between acquisition of different fluorescence channels, impeding the interpretation and quantification of highly dynamic processes. Light Emitting Diodes (LEDs), however, allow modulation of excitation light in microseconds. Here we provide a step-by-step protocol to enable any scientist to build a research-grade LED illuminator for live cell microscopy, even without prior experience with electronics or optics. We quantify and compare components, discuss our design considerations, and demonstrate the performance of our LED illuminator by imaging axonal transport of herpes virus particles with high temporal resolution. PMID:26600461

  7. Compact lens with circular spot profile for square die LEDs in multi-LED projectors

    NASA Astrophysics Data System (ADS)

    Kari, Thøger; Gadegaard, Jesper; Thykjaer Jørgensen, Dennis; Søndergaard, Thomas; Pedersen, Thomas Garm; Pedersen, Kjeld

    2011-08-01

    In the stage illumination industry, LED technology is promising both in terms of energy use and novel features, but it also has inherent issues. This paper presents a solution to the poor color homogeneity arising when multiple rectangular images formed from LED dies are combined into a circular spot profile. Using ray tracing, a nonrotationally symmetric collimating lens was optimized to round off such die images. The result is a high-output lens with an almost perfectly circular spot. In a simulated red green blue color mixing projector with seven LEDs, the lens reduced measurable color inhomogeneity by ≈24.1%, with a 5.3% luminous gain, compared to the best rotationally symmetric benchmark lens.

  8. Light-emitting diodes (LED) for domestic lighting: any risks for the eye?

    PubMed

    Behar-Cohen, F; Martinsons, C; Viénot, F; Zissis, G; Barlier-Salsi, A; Cesarini, J P; Enouf, O; Garcia, M; Picaud, S; Attia, D

    2011-07-01

    Light-emitting diodes (LEDs) are taking an increasing place in the market of domestic lighting because they produce light with low energy consumption. In the EU, by 2016, no traditional incandescent light sources will be available and LEDs may become the major domestic light sources. Due to specific spectral and energetic characteristics of white LEDs as compared to other domestic light sources, some concerns have been raised regarding their safety for human health and particularly potential harmful risks for the eye. To conduct a health risk assessment on systems using LEDs, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), a public body reporting to the French Ministers for ecology, for health and for employment, has organized a task group. This group consisted physicists, lighting and metrology specialists, retinal biologist and ophthalmologist who have worked together for a year. Part of this work has comprised the evaluation of group risks of different white LEDs commercialized on the French market, according to the standards and found that some of these lights belonged to the group risk 1 or 2. This paper gives a comprehensive analysis of the potential risks of white LEDs, taking into account pre-clinical knowledge as well as epidemiologic studies and reports the French Agency's recommendations to avoid potential retinal hazards.

  9. Development of a new water sterilization device with a 365 nm UV-LED.

    PubMed

    Mori, Mirei; Hamamoto, Akiko; Takahashi, Akira; Nakano, Masayuki; Wakikawa, Noriko; Tachibana, Satoko; Ikehara, Toshitaka; Nakaya, Yutaka; Akutagawa, Masatake; Kinouchi, Yohsuke

    2007-12-01

    Ultraviolet (UV) irradiation is an effective disinfection method. In sterilization equipment, a low-pressure mercury lamp emitting an effective germicidal UVC (254 nm) is used as the light source. However, the lamp, which contains mercury, must be disposed of at the end of its lifetime or following damage due to physical shock or vibration. We investigated the suitability of an ultraviolet light-emitting diode at an output wavelength of 365 nm (UVA-LED) as a sterilization device, comparing with the other wavelength irradiation such as 254 nm (a low-pressure mercury lam) and 405 nm (LED). We used a commercially available UVA-LED that emitted light at the shortest wavelength and at the highest output energy. The new sterilization system using the UVA-LED was able to inactivate bacteria, such as Escherichia coli DH5 alpha, Enteropathogenic E. coli, Vibrio parahaemolyticus, Staphylococcus aureus, and Salmonella enterica serovar Enteritidis. The inactivations of the bacteria were dependent on the accumulation of UVA irradiation. Taking advantage of the safety and compact size of LED devices, we expect that the UVA-LED sterilization device can be developed as a new type of water sterilization device.

  10. POF data link employing a display-type green LED fabricated from GaN material

    NASA Astrophysics Data System (ADS)

    Kato, Satoru; Kagami, Manabu; Ito, Hiroshi

    2003-07-01

    Data links incorporating a green light source at 520nm are required for use with polymethyl methacrylate (PMMA) plastic optical fiber (POF) systems because they have a lower attenuation coefficient compared with conventional red light sources at 650nm. Recently, green LEDs have been developed based on Gallium Nitride (GaN) materials, and high optical output power GaN green LED lamps are now commercially available for general use in display applications. In this paper, we describe in detail the fundamental characteristics of these GaN green LEDs that are due to be employed in POF data links. We evaluate the temperature coefficients of the optical output power and the center wavelength shift and also demonstrate a green LED POF data link that complies with IEEE 1394 S100 operation. GaN green LEDs seem to be promising candidates as light sources for the next generation of POF data links for automotive applications or for long distance In-house multimedia networks. This is because, as we will show, they can operate both at high temperatures and with reduced temperature sensitivity compared with red LEDs fabricated from AlGaInP materials.

  11. LED dynamic electro-optical responses and light-fidelity-application optimization.

    PubMed

    Bialic, Emilie; Nguyen, Dinh Chuong; Vaufrey, David

    2014-11-01

    Commercial light-emitting diodes (LEDs) from different manufacturers were studied by means of impedance measurements in the frequency range between 75 kHz and 10 MHz. Electrical characteristics of these LEDs, such as impedance and resistance, were proven to be strongly influenced by the applied frequencies, the bias values, and the alternating-signal amplitudes. Through these measurements, a specific bias value, which later could be of great importance, was pointed out. Coupled with the optical signal-to-noise ratio measurements, this frequency-, bias-, and alternating-signal-amplitude-dependent impedance shows a close correlation between optical and electrical responses of LEDs, which turns out to be useful for visible light communication. Hence, a new and simple method of light-fidelity optimization through impedance measurements is proposed in this article.

  12. Optimization of LED light spectrum to enhance colorfulness of illuminated objects with white light constraints.

    PubMed

    Wu, Haining; Dong, Jianfei; Qi, Gaojin; Zhang, Guoqi

    2015-07-01

    Enhancing the colorfulness of illuminated objects is a promising application of LED lighting for commercial, exhibiting, and scientific purposes. This paper proposes a method to enhance the color of illuminated objects for a given polychromatic lamp. Meanwhile, the light color is restricted to white. We further relax the white light constraints by introducing soft margins. Based on the spectral and electrical characteristics of LEDs and object surface properties, we determine the optimal mixing of the LED light spectrum by solving a numerical optimization problem, which is a quadratic fractional programming problem by formulation. Simulation studies show that the trade-off between the white light constraint and the level of the color enhancement can be adjusted by tuning an upper limit value of the soft margin. Furthermore, visual evaluation experiments are performed to evaluate human perception of the color enhancement. The experiments have verified the effectiveness of the proposed method.

  13. Television Commercials' Effects on Children.

    ERIC Educational Resources Information Center

    Quisenberry, James D.

    1982-01-01

    Discusses research focused on characteristics of children's TV commercials, the relationship between commercials and children's learning and reasoning, and effects of commercials on children's language, attitudes, and beliefs. (Author/RH)

  14. New paradigm of multi-chip white LEDs: combination of an InGaN blue LED and full down-converted phosphor-converted LEDs.

    PubMed

    Oh, Ji Hye; Oh, Jeong Rok; Park, Hoo Keun; Sung, Yeon-Goog; Do, Young Rag

    2011-05-09

    This study introduces innovative multi-chip white LED systems that combine an InGaN blue LED and green/red or green/amber/red full down-converted, phosphor-conversion LEDs (pc-LEDs). Efficient green, amber, and red full down-converted pc-LEDs were fabricated by simply capping a long-wave pass filter (LWPF) on top of LED packing associated with each corresponding powder phosphor. The principal advantage of this type of color-mixing approach in newly developed multi-chip white LEDs based on colored pc-LEDs is thought to be dynamic control of the chromaticity and better light quality. In addition, the color-mixing approach improves the low efficacy of green/amber LEDs in the "green gap" wavelength; reduces the wide color/efficacy variations of each primary LED with at different temperatures and currents; and improves the low color rendering indexes of the traditional color-mixing approach in red, green, and blue (RGB) multi-chip white LEDs.

  15. Blue LED irradiation to hydration of skin

    NASA Astrophysics Data System (ADS)

    Menezes, Priscila F. C.; Requena, Michelle B.; Lizarelli, Rosane F., Z.; Bagnato, Vanderlei S.

    2015-06-01

    Blue LED system irradiation shows many important properties on skin as: bacterial decontamination, degradation of endogenous skin chromophores and biostimulation. In this clinical study we prove that the blue light improves the skin hydration. In the literature none authors reports this biological property on skin. Then this study aims to discuss the role of blue light in the skin hydration. Twenty patients were selected to this study with age between 25-35 years old and phototype I, II and III. A defined area from forearm was pre determined (A = 4.0 cm2). The study was randomized in two treatment groups using one blue light device (power of 5.3mW and irradiance of 10.8mW/cm2). The first treatment group was irradiated with 3J/cm2 (277seconds) and the second with 6J/cm2 (555 seconds). The skin hydration evaluations were done using a corneometer. The measurements were collected in 7, 14, 21 and 30 days, during the treatment. Statistical test of ANOVA, Tukey and T-Student were applied considering 5% of significance. In conclusion, both doses were able to improve the skin hydration; however, 6J/cm2 has kept this hydration for 30 days.

  16. Novel aplanatic designs for LED concentration

    NASA Astrophysics Data System (ADS)

    Ricketts, Melissa; Winston, Roland; Jiang, Lun

    2014-09-01

    Aplanats make great concentrators because of their near perfect imaging. Aplanatic conditions can be satisfied using two surface curves (generally mirrored surfaces) in two dimensions (see Figure 1) which are constructed by successive approximation to create a highly efficient concentrator for both concentration and illumination. For concentration purposes, having a two mirror system would be impossible because the front mirror would block incoming light (see figure 2) so the idea is to replace the front mirror with a "one-way" mirror. Light from a lower index can be transmitted, so if the aplanat surface is a higher index light is allowed to enter, and be trapped. In the Jellyfish design, TIR takes place except for light striking the surface within the range of critical angles. To combat that, a small area of reflective coating is applied to the central top part of the Jellyfish, where TIR fails (In the middle) to keep the light there from directly escaping (see figure 3). The design works in both forwards and reverse. Light entering can be focused to a collecter, or the collecter can be replaced with a light source to concentrate light out. In this case, LEDs are used for their highly efficienct properties.

  17. Factors that led to the Walkerton tragedy.

    PubMed

    Salvadori, Marina I; Sontrop, Jessica M; Garg, Amit X; Moist, Louise M; Suri, Rita S; Clark, William F

    2009-02-01

    In May 2000, bacterial contamination of municipal water in Walkerton, Ontario, resulted in the worst public health disaster involving municipal water in Canadian history. At least seven people died and 2300 became ill. A public inquiry led by judge Dennis O'Connor examined the events and delineated the causes of the outbreak, including physical causes, the role of the public utilities operators, the public utilities commissioners, the Ministry of the Environment (MOE), and the provincial government. Improper practices and systemic fraudulence by the public utility operators, the recent privatization of municipal water testing, the absence of criteria governing quality of testing, and the lack of provisions made for notification of results to multiple authorities all contributed to the crisis. The MOE noted significant concerns 2 years before the outbreak; however, no changes resulted because voluntary guidelines as opposed to legally binding regulations governed water safety. The inquiry concluded that budgetary restrictions introduced by the provincial government 4 years before the outbreak were enacted with no assessment of risk to human health. The ministers and the cabinet had received warnings about serious risks. Budgetary cuts destroyed the checks and balances that were necessary to ensure municipal water safety.

  18. Effects of color temperatures (Kelvin) of LED bulbs on growth performance, carcass characteristics, and ocular welfare indices of broilers grown to heavy weights

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited data are available for comparing light-emitting diode (LED) bulbs that are currently available in commercial broiler production facilities. We evaluated the effects of color temperatures (Kelvin) of LED bulbs on growth performance, carcass characteristics, and ocular welfare indices of broil...

  19. Commercial space services

    NASA Technical Reports Server (NTRS)

    Christensen, D. L.

    1984-01-01

    An overview of space service opportunities as identified by a Wyle Laboratories' research team is given. Through the use of a baseline space scenario, a variety of space hardware, services, and commercial activities are identified and related on a time-phased basis. A model is presented to relate the potential functions of government and the private sector in a commercialized space environment during the period 1984 to 2004. Barriers, incentives and key issues are likewise identified and addressed to aid in the implementation of private sector activities for spacerelated programs. Broader awareness, legislative actions, incentive development and benefit analyses are considered in the presentation. The time-phased plan provides a useful planning and management tool, allows broader communication, and supports overall space commercialization program assessment.

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

    SciTech Connect

    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

  1. Warm white LED light by frequency down-conversion of mixed yellow and red Lumogen

    NASA Astrophysics Data System (ADS)

    Mosca, Mauro; Caruso, Fulvio; Zambito, Leandro; Seminara, Biagio; Macaluso, Roberto; Calı, Claudio; Feltin, Eric

    2013-05-01

    This work reports on the benefits and promising opportunities offered by white LED hybrid technology, based on a mixing perylene-based dyes in order to obtain a warm white light for frequency-down conversion. In a standard Ce:YAG-based white LED, the white light appears cold due to the weakness of red wavelength components in the emission spectrum. In order to obtain a warmer white, one possible solution is to add a red phosphor to the yellow one to move the chromatic coordinates properly, though the luminous efficiency drastically decreases due to the increased light absorption of the coating layer. It is generally believed that the low efficiency of warm white LEDs is the main issue today for LED-based lighting. Using photoluminescence of Lumogen® F Yellow 083, a perylene-based polymer dye commercialized by BASF, and adding a small quantity of another perylene-based dye, Lumogen® F Red 305 (BASF), we obtained high-efficiency warm white LEDs by yellow and red conversion from a standard 450 nm GaN/InGaN royal blue LED. Different weight proportions of dyes were dissolved in solutions with equal amounts of poly-methyl-methacrylate (PMMA) in ethyl acetate, then the LEDs were dip-coated in each solution and optically characterized. Record values of 8.03 lm of luminous flux and 116.11 lm/W of optical efficiency were achieved. Finally, the effects of both driving current, and pump wavelength on LED performances - such as chromatic coordinates, correlated color temperature, color rendering index (CRI), and optical efficiency - were investigated.

  2. Commercial Biomedical Experiments

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Experiments to seek solutions for a range of biomedical issues are at the heart of several investigations that will be hosted by the Commercial Instrumentation Technology Associates (ITA), Inc. Biomedical Experiments (CIBX-2) payload. CIBX-2 is unique, encompassing more than 20 separate experiments including cancer research, commercial experiments, and student hands-on experiments from 10 schools as part of ITA's ongoing University Among the Stars program. Valerie Cassanto of ITA checks the Canadian Protein Crystallization Experiment (CAPE) carried by STS-86 to Mir in 1997. The experiments are sponsored by NASA's Space Product Development Program (SPD).

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

    SciTech Connect

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

    2011-05-06

    This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a commercial parking lot lighting application, under the U.S. Department of Energy (DOE) Solid-State Lighting Technology GATEWAY Demonstration Program. The parking lot is for customers and employees of a Walmart Supercenter in Leavenworth, Kansas and this installation represents the first use of the LED Parking Lot Performance Specification developed by the DOE’s Commercial Building Energy Alliance. The application is a parking lot covering more than a half million square feet, lighted primarily by light-emitting diodes (LEDs). Metal halide wall packs were installed along the building facade. This site is new construction, so the installed baseline(s) were hypothetical designs. It was acknowledged early on that deviating from Walmart’s typical design would reduce the illuminance on the site. Walmart primarily uses 1000W pulse-start metal halide (PMH) lamps. In order to provide a comparison between both typical design and a design using conventional luminaires providing a lower illuminance, a 400W PMH design was also considered. As mentioned already, the illuminance would be reduced by shifting from the PMH system to the LED system. The Illuminating Engineering Society of North America (IES) provides recommended minimum illuminance values for parking lots. All designs exceeded the recommended illuminance values in IES RP-20, some by a wider margin than others. Energy savings from installing the LED system compared to the different PMH systems varied. Compared to the 1000W PMH system, the LED system would save 63 percent of the energy. However, this corresponds to a 68 percent reduction in illuminance as well. In comparison to the 400W PMH system, the LED system would save 44 percent of the energy and provide similar minimum illuminance values at the time of relamping. The LED system cost more than either of the PMH systems when comparing initial costs

  4. Validating Community-Led Forest Biomass Assessments

    PubMed Central

    Venter, Michelle; Venter, Oscar; Edwards, Will; Bird, Michael I.

    2015-01-01

    The lack of capacity to monitor forest carbon stocks in developing countries is undermining global efforts to reduce carbon emissions. Involving local people in monitoring forest carbon stocks could potentially address this capacity gap. This study conducts a complete expert remeasurement of community-led biomass inventories in remote tropical forests of Papua New Guinea. By fully remeasuring and isolating the effects of 4,481 field measurements, we demonstrate that programmes employing local people (non-experts) can produce forest monitoring data as reliable as those produced by scientists (experts). Overall, non-experts reported lower biomass estimates by an average of 9.1%, equivalent to 55.2 fewer tonnes of biomass ha-1, which could have important financial implications for communities. However, there were no significant differences between forest biomass estimates of expert and non-expert, nor were there significant differences in some of the components used to calculate these estimates, such as tree diameter at breast height (DBH), tree counts and plot surface area, but were significant differences between tree heights. At the landscape level, the greatest biomass discrepancies resulted from height measurements (41%) and, unexpectedly, a few large missing trees contributing to a third of the overall discrepancies. We show that 85% of the biomass discrepancies at the tree level were caused by measurement taken on large trees (DBH ≥50cm), even though they consisted of only 14% of the stems. We demonstrate that programmes that engage local people can provide high-quality forest carbon data that could help overcome barriers to reducing forest carbon emissions in developing countries. Nonetheless, community-based monitoring programmes should prioritise reducing errors in the field that lead to the most important discrepancies, notably; overcoming challenges to accurately measure large trees. PMID:26126186

  5. Commercializing Biological Control

    ERIC Educational Resources Information Center

    LeLeu, K. L.; Young, M. A.

    1973-01-01

    Describes the only commercial establishment involved in biological control in Australia. The wasp Aphitis melinus, which parasitizes the insect Red Scale, is bred in large numbers and released in the citrus groves where Red Scale is causing damage to the fruit. (JR)

  6. Kids vs. commercials.

    PubMed

    Lewis, M A; Lewis, C E

    1975-11-01

    A game show with fifth and sixth graders effectively demonstrated their ability to critically evaluate television commercials about health-related products. While the family physician is in a unique position to affect future drug utilization patterns of children by counseling parents, a more active role, such as this exercise in the evaluation of TV messages, may be even more effective.

  7. Commercial Baking. Final Report.

    ERIC Educational Resources Information Center

    Booth, Nancy

    A project filmed three commercial baking videotapes for use by secondary and adult students in food service programs. The three topics were basic dinner rolls, bread making, and hard breads and rolls. Quick-rise dough recipes were developed, written down, and explained for use with the videotapes. A pretest, posttest, and student guide were…

  8. The Commercial Speech Doctrine.

    ERIC Educational Resources Information Center

    Luebke, Barbara F.

    In its 1942 ruling in the "Valentine vs. Christensen" case, the Supreme Court established the doctrine that commercial speech is not protected by the First Amendment. In 1975, in the "Bigelow vs. Virginia" case, the Supreme Court took a decisive step toward abrogating that doctrine, by ruling that advertising is not stripped of…

  9. Estolides - Ready for commercialization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estolides have shown great promise as a bio-based lubricant and are ready for commercialization. Estolides are nontoxic and biodegradable. Testing has shown estolides have increased oxidative stability over vegetable oil based lubricants and have a relatively low pour point, allowing them to be use...

  10. Commercial applications of telemedicine

    NASA Technical Reports Server (NTRS)

    Natiello, Thomas A.

    1991-01-01

    Telemedicine Systems Corporation was established in 1976 and is a private commercial supplier of telemedicine systems. These systems are various combinations of communications and diagnostic technology, designed to allow the delivery of health care services to remote facilities. The technology and the health care services are paid for by the remote facilities, such as prisons.

  11. Commercial Crew Medical Ops

    NASA Technical Reports Server (NTRS)

    Heinbaugh, Randall; Cole, Richard

    2016-01-01

    Provide commercial partners with: center insight into NASA spaceflight medical experience center; information relative to both nominal and emergency care of the astronaut crew at landing site center; a basis for developing and sharing expertise in space medical factors associated with returning crew.

  12. Commercial Earth Observation

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Through the Earth Observation Commercial Applications Program (EOCAP) at Stennis Space Center, Applied Analysis, Inc. developed a new tool for analyzing remotely sensed data. The Applied Analysis Spectral Analytical Process (AASAP) detects or classifies objects smaller than a pixel and removes the background. This significantly enhances the discrimination among surface features in imagery. ERDAS, Inc. offers the system as a modular addition to its ERDAS IMAGINE software package for remote sensing applications. EOCAP is a government/industry cooperative program designed to encourage commercial applications of remote sensing. Projects can run three years or more and funding is shared by NASA and the private sector participant. Through the Earth Observation Commercial Applications Program (EOCAP), Ocean and Coastal Environmental Sensing (OCENS) developed SeaStation for marine users. SeaStation is a low-cost, portable, shipboard satellite groundstation integrated with vessel catch and product monitoring software. Linked to the Global Positioning System, SeaStation provides real time relationships between vessel position and data such as sea surface temperature, weather conditions and ice edge location. This allows the user to increase fishing productivity and improve vessel safety. EOCAP is a government/industry cooperative program designed to encourage commercial applications of remote sensing. Projects can run three years or more and funding is shared by NASA and the private sector participant.

  13. Commercial and Industrial Wiring.

    ERIC Educational Resources Information Center

    Kaltwasser, Stan; Flowers, Gary

    This module is the third in a series of three wiring publications, includes additional technical knowledge and applications required for job entry in the commercial and industrial wiring trade. The module contains 15 instructional units that cover the following topics: blueprint reading and load calculations; tools and equipment; service;…

  14. Commercial Carpentry: Instructional Units.

    ERIC Educational Resources Information Center

    Diehl, Donald W.; Penner, Wayman R.

    This manual contains instructional materials which measure student performance on commercial carpentry behavioral objectives; criterion-referenced evaluation instruments are also included. Each of the manual's eleven sections consists of one or more units of instruction. Each instructional unit includes behavioral objectives, suggested activities…

  15. Lunar Commercial Mining Logistics

    NASA Astrophysics Data System (ADS)

    Kistler, Walter P.; Citron, Bob; Taylor, Thomas C.

    2008-01-01

    Innovative commercial logistics is required for supporting lunar resource recovery operations and assisting larger consortiums in lunar mining, base operations, camp consumables and the future commercial sales of propellant over the next 50 years. To assist in lowering overall development costs, ``reuse'' innovation is suggested in reusing modified LTS in-space hardware for use on the moon's surface, developing product lines for recovered gases, regolith construction materials, surface logistics services, and other services as they evolve, (Kistler, Citron and Taylor, 2005) Surface logistics architecture is designed to have sustainable growth over 50 years, financed by private sector partners and capable of cargo transportation in both directions in support of lunar development and resource recovery development. The author's perspective on the importance of logistics is based on five years experience at remote sites on Earth, where remote base supply chain logistics didn't always work, (Taylor, 1975a). The planning and control of the flow of goods and materials to and from the moon's surface may be the most complicated logistics challenges yet to be attempted. Affordability is tied to the innovation and ingenuity used to keep the transportation and surface operations costs as low as practical. Eleven innovations are proposed and discussed by an entrepreneurial commercial space startup team that has had success in introducing commercial space innovation and reducing the cost of space operations in the past. This logistics architecture offers NASA and other exploring nations a commercial alternative for non-essential cargo. Five transportation technologies and eleven surface innovations create the logistics transportation system discussed.

  16. Teaching CAD at the University: Specifically Written or Commercial Software?

    ERIC Educational Resources Information Center

    Garcia, Ramon Rubio; Quiros, Javier Suarez; Santos, Ramon Gallego; Penin, Pedro I. Alvarez

    2007-01-01

    At most universities throughout the world Computer Aided Design is taught using commercial programs more suitable for business and industry than for teaching. This led us to write our own design program (GIcad) starting from the best-known standards on the market, but always avoiding unnecessary commands in the first steps of the learning process.…

  17. Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

    NASA Astrophysics Data System (ADS)

    Kong, H. J.; Park, J. W.; Kim, Y. M.

    2013-01-01

    We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m-2, the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system.

  18. Optical properties and electronic requirements for low-temperature operation of yellow semiconductor LEDs

    NASA Astrophysics Data System (ADS)

    Lee, Susanne M.; Mueller, Eduard K.; Van de Workeen, Brian C.; Mueller, Otward M.

    2001-05-01

    In such LED applications as lighting, it is desirable to have the highest light output for the lowest power consumption. This paper investigates the optical properties and electronic requirements of a commercially available yellow LED as a function of temperature from ambient to liquid nitrogen temperatures. It was found that the illuminance increased by almost an order of magnitude, producing much higher light output at the same diode current. However, the operating voltage increased, increasing the overall power consumption slightly. The efficiency (light-watt output to electrical watts consumed) of the LED, though, improved by a factor of more than three. This, combined with the enhanced light output, compensates for the small increase in power consumption and added cooling costs. These improvements further translate into a comparable increase in the lifetime of the LEDs. In general, each ten-degree reduction in temperature corresponds to a doubling of the lifetime of semiconductor devices. It was also found that the maximum operating current increased significantly at liquid nitrogen temperatures over that at ambient temperatures. Lastly, the emitted wavelength range shifted to shorter values in addition to the significant increase in brightness. Thus, a yellow- colored LED at room temperature gave off a much brighter yellow-green-white color at liquid nitrogen temperatures.

  19. Improved wound healing in blue LED treated superficial abrasions

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Bacci, Stefano; De Siena, Gaetano; Cicchi, Riccardo; Pavone, Francesco; Alfieri, Domenico

    2013-06-01

    A blue-LED photocoagulator device was designed in order to induce a selective photocoagulation effect in superficial bleeding. An in vivo study in rat back skin evidenced an improved healing process in the LED treated abrasions.

  20. Photorealistic rendering application to the design of LED flash lens

    NASA Astrophysics Data System (ADS)

    Chern, Jyh-Long

    2012-10-01

    LED flash module becomes popular in current mobile communication devices, such as for the smart phones and tablet. As a lighting apparatus for image taking, photo rendering performance is crucial. We explore the LED flash lens design with a stress of photorealistic rendering application toward a high-performance LED flash illumination.

  1. Mapping Student-Led Peer Learning in the UK

    ERIC Educational Resources Information Center

    Keenan, Chris

    2014-01-01

    Peer-led academic learning has increased in importance, but there is little sense of how many institutions support it, how they understand its purposes or what peer-led learning best practice is. This report examines the provision of peer-led learning in the UK. It identifies challenges and opportunities, including international perspectives and…

  2. EC-LEDS Supports the Low-Carbon Transition

    SciTech Connect

    2016-09-01

    EC-LEDS is a flagship U.S. government-led effort that assists countries to create and implement low emission development strategies, or LEDS -- development frameworks that promote sustainable social and economic development while reducing greenhouse gas emissions over the medium to long term.

  3. CALiPER Snapshot Report: Indoor LED Luminaires

    SciTech Connect

    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.

  4. LEDs: DOE Programs Add Credibility to a Developing Technology

    ERIC Educational Resources Information Center

    Conbere, Susan

    2009-01-01

    LED (light-emitting diode) technology is moving fast, and with justification, some facility managers have viewed it with a wary eye. Some LEDs on the market do not perform as promised, and the technology is changing rapidly. But new developments from the U.S. Department of Energy (DOE) now make it easier for facility managers to find LEDs that…

  5. Computer-Based Experiment for Determining Planck's Constant Using LEDs

    ERIC Educational Resources Information Center

    Zhou, Feng; Cloninger, Todd

    2008-01-01

    Visible light emitting diodes (LEDs) have been widely used as power indicators. However, after the power is switched off, it takes a while for the LED to go off. Many students were fascinated by this simple demonstration. In this paper, by making use of computer-based data acquisition and modeling, we show the voltage across the LED undergoing an…

  6. High Efficiency Driving Electronics for General Illumination LED Luminaires

    SciTech Connect

    Upadhyay, Anand

    2012-10-31

    New generation of standalone LED driver platforms developed, which are more efficient These LED Drivers are more efficient (≥90%), smaller in size ( 0.15 in3/watt), lower in cost ( 12 cents/watt in high volumes in millions of units). And these products are very reliable having an operating life of over 50,000 hours. This technology will enable growth of LED light sources in the use. This will also help in energy saving and reducing total life cycle cost of LED units. Two topologies selected for next generation of LED drivers: 1) Value engineered single stage Flyback topology. This is suitable for low powered LED drivers up to 50W power. 2) Two stage boost power factor correction (PFC) plus LLC half bridge platform for higher powers. This topology is suitable for 40W to 300W LED drivers. Three new product platforms were developed to cover a wide range of LED drivers: 1) 120V 40W LED driver, 2) Intellivolt 75W LED driver, & 3) Intellivolt 150W LED driver. These are standalone LED drivers for rugged outdoor lighting applications. Based on these platforms number of products are developed and successfully introduced in the market place meeting key performance, size and cost goals.

  7. Design and construction evaluation of a photovoltaic DC LED lighting system

    NASA Astrophysics Data System (ADS)

    Bhamidipati, Jyotsna

    2008-08-01

    The market demand for commercialization of Photovoltaic (PV) systems depends a lot on the reliability, efficiency and performance of various components within the system. PV panels produce DC power when exposed to sunlight, and an inverter converts this to AC power in a typical solar powered building. Though, PV lighting has existed for a long time it hasn't been very effective, as incandescent light sources were commonly used which are inefficient. Today fluorescent fixtures are mostly used with PV's due to its high efficacy. Light-emitting diodes present a new vision to energy efficiency in lighting design with their low energy consumption. Current research predicts improved efficiencies of LED light fixtures and their commercial use is a few years away. LEDs which operate on DC voltages when coupled with photovoltaics can be a simple PV lighting application and a sustainable solution with potential for payback. This research evaluates the design and construction of a photovoltaic DC LED lighting system for a solar house at Pennsylvania State University. A detailed cost and payback analysis of a PV DC LED lighting system is presented in this research. PV output simulations for the solar house are presented. Results presented in this research indicate that the Solid state lighting market is evolving rapidly and that LED's are a choice in stand-alone photovoltaic DC lighting systems. The efficiency and the cost-effectiveness of such systems would however improve in the coming years with research and development now focused on PV systems and on Solid state lighting technologies.

  8. Commercial jet transport crashworthiness

    NASA Technical Reports Server (NTRS)

    Widmayer, E.; Brende, O. B.

    1982-01-01

    The results of a study to identify areas of research and approaches that may result in improved occupant survivability and crashworthiness of transport aircraft are given. The study defines areas of structural crashworthiness for transport aircraft which might form the basis for a research program. A 10-year research and development program to improve the structural impact resistance of general aviation and commercial jet transport aircraft is planned. As part of this program parallel studies were conducted to review the accident experience of commercial transport aircraft, assess the accident performance of structural components and the status of impact resistance technology, and recommend areas of research and development for that 10-year plan. The results of that study are also given.

  9. Hyperspectral fluorescence imaging with multi wavelength LED excitation

    NASA Astrophysics Data System (ADS)

    Luthman, A. Siri; Dumitru, Sebastian; Quirós-Gonzalez, Isabel; Bohndiek, Sarah E.

    2016-04-01

    Hyperspectral imaging (HSI) can combine morphological and molecular information, yielding potential for real-time and high throughput multiplexed fluorescent contrast agent imaging. Multiplexed readout from targets, such as cell surface receptors overexpressed in cancer cells, could improve both sensitivity and specificity of tumor identification. There remains, however, a need for compact and cost effective implementations of the technology. We have implemented a low-cost wide-field multiplexed fluorescence imaging system, which combines LED excitation at 590, 655 and 740 nm with a compact commercial solid state HSI system operating in the range 600 - 1000 nm. A key challenge for using reflectance-based HSI is the separation of contrast agent fluorescence from the reflectance of the excitation light. Here, we illustrate how it is possible to address this challenge in software, using two offline reflectance removal methods, prior to least-squares spectral unmixing. We made a quantitative comparison of the methods using data acquired from dilutions of contrast agents prepared in well-plates. We then established the capability of our HSI system for non-invasive in vivo fluorescence imaging in small animals using the optimal reflectance removal method. The HSI presented here enables quantitative unmixing of at least four fluorescent contrast agents (Alexa Fluor 610, 647, 700 and 750) simultaneously in living mice. A successful unmixing of the four fluorescent contrast agents was possible both using the pure contrast agents and with mixtures. The system could in principle also be applied to imaging of ex vivo tissue or intraoperative imaging in a clinical setting. These data suggest a promising approach for developing clinical applications of HSI based on multiplexed fluorescence contrast agent imaging.

  10. European commercial aeronautics

    NASA Technical Reports Server (NTRS)

    Van Zandt, J Parker

    1925-01-01

    During the months of June to September, 1924, I personally visited the principal airports of Europe and traveled as a passenger some 6500 air miles on English, French, Romanian, Polish, German and Dutch air lines in order to investigate the development of commercial aviation abroad. The results of the investigation are embodied in a series of reports, of which a summary of the general findings is given below.

  11. Commercial Parts Radiation Testing

    DTIC Science & Technology

    2015-01-13

    AFRL /RVIL Kirtland AFB, NM 87117-5776 2 cys Official Record Copy AFRL /RVSE/Keith Avery 1 cy ... AFRL -RV-PS- AFRL -RV-PS- TR-2014-0172 TR-2014-0172 COMMERCIAL PARTS RADIATION TESTING Craig J. Kief COSMIAC at UNM 2350 Alamo Avenue SE Suite 300...Vehicles Directorate 3550 Aberdeen Ave SE AIR FORCE MATERIEL COMMAND KIRTLAND AIR FORCE BASE, NM 87117-5776 DTIC COPY NOTICE AND SIGNATURE

  12. Commercialization of nanotechnology.

    PubMed

    Hobson, David W

    2009-01-01

    The emerging and potential commercial applications of nanotechnologies clearly have great potential to significantly advance and even potentially revolutionize various aspects of medical practice and medical product development. Nanotechnology is already touching upon many aspects of medicine, including drug delivery, diagnostic imaging, clinical diagnostics, nanomedicines, and the use of nanomaterials in medical devices. This technology is already having an impact; many products are on the market and a growing number is in the pipeline. Momentum is steadily building for the successful development of additional nanotech products to diagnose and treat disease; the most active areas of product development are drug delivery and in vivo imaging. Nanotechnology is also addressing many unmet needs in the pharmaceutical industry, including the reformulation of drugs to improve their bioavailability or toxicity profiles. The advancement of medical nanotechnology is expected to advance over at least three different generations or phases, beginning with the introduction of simple nanoparticulate and nanostructural improvements to current product and process types, then eventually moving on to nanoproducts and nanodevices that are limited only by the imagination and limits of the technology itself. This review looks at some recent developments in the commercialization of nanotechnology for various medical applications as well as general trends in the industry, and explores the nanotechnology industry that is involved in developing medical products and procedures with a view toward technology commercialization.

  13. EVALUATING COMMERCIALLY AVAILABLE DERMAL ...

    EPA Pesticide Factsheets

    As the Human Exposure Program focuses on the exposure of children to pesticides, there are concerns about the effect, or perceived effect, of components of the sampling procedure on the health and well-being of the infant and the ability to collect pesticide residues. One concern involves the materials in wipes used to collect pesticide residues or other contact materials on the skin. In recent studies (e.g., National Human Exposure Assessment Survey; NHEXAS), isopropyl alcohol has been used as a solvent in conjunction with a cloth wipe to obtain samples from the hands of adults and children. Although isopropyl alcohol is generally considered innocuous, the use of commercially available products could eliminate concerns about exposure to alcohol. A few studies have evaluated the potential of commercially available baby wipes to collect personal exposure samples for metals research, but not for the area of pesticide research (Millson et al., 1994; Campbell et al., 1993; Lichtenwalner et al., 1993). Therefore, there is a need to evaluate the potential for using commercially available baby wipes for collecting pesticide samples from skin and other surfaces. Another concern involves establishing a convenient and safe method for assessing overall dermal exposure for children, especially for those in crawling stage. One route that the U .S. Environmental Protection Agency (EPA) would like to investigate is the use of cotton body suits (infant sleepers) as an indicator

  14. Optimizing Structure of LED Light Bulb for Heat Transfer

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Itami, D.; Hashimoto, R.; Takashina, T.; Kanematsu, H.; Mizuta, K.; Utsumi, Y.

    2013-04-01

    In this paper, in order to optimize the heat transfer structure of LED light bulb, the effects of various parameters on the temperature of the LED device were systematically analyzed, and a design guideline was shown. Although LED device has become popular due to its high-efficiency and long life, the design issues on the heat transfer structure of LED light bulbs has still remained. Because the original efficiency and life of the LED device can not be obtained due to the local temperature rise of LED element and the surrounding polymer molding material. Therefore, heat transfer analysis by finite element method was conducted systematically by changing parameters such as the shape, number and thickness of the radiating fin of the LED. As a result, advantage of open type structure was shown, and the proper design guidance for the structure of the fin shape was obtained.

  15. [Study of achieving white organic LED by fluorescence dye].

    PubMed

    Wang, Jin; Wang, Jing; Zheng, Rong-er; Meng, Ji-wu

    2005-08-01

    Some hybrid organic LEDs are made by using fluorescence dye and InGaN blue-light chip and the possibility of achieving white organic LED is investigated according to light conversion theory. Firstly, the LEDs made by normal method and double-dotting glue method are studied. It is found that the double-dotting glue method is too complex and the LEDs made by this way is low-luminance, so it isn't fit to make LED. Secondly the different weight ratio of 1/1/100, 1/1/200, 2/1.5/100 ax-17/zq-13/AB LEDs are manufactured. The 2/1.5/100 LED's color coordinate is (0.32, 0.30), approaching to white point and the correlative color temperature is 6290K which is close to sunlight. So it is a relatively ideal white lamp-house.

  16. LED power reduction trade-offs for ambulatory pulse oximetry.

    PubMed

    Peláez, Eduardo Aguilar; Villegas, Esther Rodríguez

    2007-01-01

    The development of ambulatory arterial pulse oximetry is key to longer term monitoring and treatment of cardiovascular and respiratory conditions. The investigation presented in this paper will assist the designer of an ambulatory pulse oximetry monitor in minimizing the overall LED power consumption (P LED,TOT) levels by analyzing the lowest achievable limit as constrained by the optical components, circuitry implementation and final SpO2 reading accuracy required. LED duty cycle (D LED) reduction and light power (P LED,ON) minimization are proposed as methods to reduce P LED,TOT. Bandwidth and signal quality calculations are carried out in order to determine the required P LED,TOT as a function of the different noise sources.

  17. Increased lumens per etendue by combining pulsed LEDs

    NASA Astrophysics Data System (ADS)

    Murat, Hueseyin; De Smet, Herbert; Cuypers, Dieter; Meuret, Youri; Thienpont, Hugo; Vervaeke, Michael; Desmet, Lieven

    2005-04-01

    Led based projectors have numerous advantages compared to traditional projectors, such as: compact, larger color gamut, longer lifetime, lower supply voltage, etc. As LED's can switch rapidly, there is the possibility to pulse. However, there is also an important disadvantage. The optical power per unit of etendue of a LED is significantly lower than e.g. an UHP-lamp (approximately 50 times). This problem can be remedied partly by pulsing of the LED"s. If one drives a LED with a pulsed current source, the peak luminance can be higher, albeit that the average luminance will not increase. By pulsing X LED's alternately, their increased flux can be added up in time and will generate a higher average flux within the same etendue. This can be carried out in a number of different configurations. The first configuration uses moving components where a number of LED's (e.g. 8) are mounted on a carrousel and consecutively the pulsed LED is brought in the light path of the projector to fill up the time with its peak flux. An alternative without moving components can be reached with 2 LED's which are combined with a PBS. By alternately pulsing the LED's with 50% duty cycle and changing the polarisation of one LED with a switchable retarder, one can combine the flux of both LED's in the same etendue. Because of its fast switching time ferro-electric retarders are used here. This can be extended further to 4,8,16... LED's, at the price of a larger and more complicated optical architecture.

  18. Straightforward fabrication of stable white LEDs by embedding of inorganic UV-LEDs into bulk polymerized polymethyl-methacrylate doped with organic dyes.

    PubMed

    Di Martino, Daniela; Beverina, Luca; Sassi, Mauro; Brovelli, Sergio; Tubino, Riccardo; Meinardi, Francesco

    2014-03-18

    Stable white-emitting down-converted LEDs are straightforwardly prepared by bulk polymerization of an organic dye doped polymethyl-methacrylate (PMMA) shell directly on top of a highly efficient commercial blue-emitting InGaN LED. Our optimized polymerization procedure allows for extending the form factor of achievable luminescence converter (LUCO) material beyond the conventional thin film form and to directly produce devices with light bulb design. The selected organic dyes, the blue-emitting Coumarin 30 and a red-emitting diketopyrrolopyrrole derivative, exhibit high compatibility with the free radical polymerization reaction of the PMMA matrix and ensure high stability of the final hybrid device. The control of both the thickness of the PMMA shell and the concentration of the dopant dyes allow for fine tuning of the emission color of the LUCO LED and to obtain white light with CIE chromatic coordinates x = 0.32 and y = 0.33, with rendering index as high as 80. This simple and versatile procedure is not dye-exclusive and is therefore extendable to other molecular systems for color-tunable efficient solid-state lighting sources.

  19. Straightforward fabrication of stable white LEDs by embedding of inorganic UV-LEDs into bulk polymerized polymethyl-methacrylate doped with organic dyes

    NASA Astrophysics Data System (ADS)

    di Martino, Daniela; Beverina, Luca; Sassi, Mauro; Brovelli, Sergio; Tubino, Riccardo; Meinardi, Francesco

    2014-03-01

    Stable white-emitting down-converted LEDs are straightforwardly prepared by bulk polymerization of an organic dye doped polymethyl-methacrylate (PMMA) shell directly on top of a highly efficient commercial blue-emitting InGaN LED. Our optimized polymerization procedure allows for extending the form factor of achievable luminescence converter (LUCO) material beyond the conventional thin film form and to directly produce devices with light bulb design. The selected organic dyes, the blue-emitting Coumarin 30 and a red-emitting diketopyrrolopyrrole derivative, exhibit high compatibility with the free radical polymerization reaction of the PMMA matrix and ensure high stability of the final hybrid device. The control of both the thickness of the PMMA shell and the concentration of the dopant dyes allow for fine tuning of the emission color of the LUCO LED and to obtain white light with CIE chromatic coordinates x = 0.32 and y = 0.33, with rendering index as high as 80. This simple and versatile procedure is not dye-exclusive and is therefore extendable to other molecular systems for color-tunable efficient solid-state lighting sources.

  20. Introduction: Commercialization of Academic Science and a New Agenda for Science Education

    ERIC Educational Resources Information Center

    Irzik, Gürol

    2013-01-01

    Certain segments of science are becoming increasingly commercialized. This article discusses the commercialization of academic science and its impact on various aspects of science. It also aims to provide an introduction to the articles in this special issue. I briefly describe the major factors that led to this phenomenon, situate it in the…

  1. DOE acceptance of commercial mixed waste -- Studies are under way

    SciTech Connect

    Plummer, T.L.; Owens, C.M.

    1993-03-01

    The topic of the Department of Energy acceptance of commercial mixed waste at DOE facilities has been proposed by host States and compact regions that are developing low-level radioactive waste disposal facilities. States support the idea of DOE accepting commercial mixed waste because (a) very little commercial mixed waste is generated compared to generation by DOE facilities (Department of Energy--26,300 cubic meters annually vs. commercial--3400 cubic meters annually); (b) estimated costs for commercial disposal are estimated to be $15,000 to $40,000 per cubic foot; (c) once treatment capability becomes available, 70% of the current levels of commercial mixed waste will be eliminated, (d) some State laws prohibit the development of mixed waste disposal facilities in their States; (e) DOE is developing a nationwide strategy that will include treatment and disposal capacity for its own mixed waste and the incremental burden on the DOE facilities would be minuscule, and (6) no States are developing mixed waste disposal facilities. DOE senior management has repeatedly expressed willingness to consider investigating the feasibility of DOE accepting commercial mixed waste. In January 1991, Leo Duffy of the Department of energy met with members of the Low-Level Radioactive Waste Forum, which led to an agreement to explore such an arrangement. He stated that this seems like a cost-effective way to solve commercial mixed waste management problems.

  2. Site-specific standard request for underground storage tanks 1219-U, 1222-U, 2082-U, and 2068-U at the rust garage facility buildings 9754-1 and 9720-15: Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Facility ID No. 0-010117

    SciTech Connect

    1994-12-01

    This document represents a Site-specific Standard Request for underground storage tanks (USTs) 1219-U,1222-U and 2082-U previously located at former Building 9754-1, and tank 2086-U previously located at Building 9720-15, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. The tanks previously contained petroleum products. For the purposes of this report, the two building sites will be regarded as a single UST site and will be referred to as the Rust Garage Facility. The current land use associated with the Y-12 Plant is light industrial and the operational period of the plant is projected to be at least 30 years. Thus, potential future residential exposures are not expected to occur for at least 30 years. Based on the degradation coefficient for benzene (the only carcinogenic petroleum constituent detected in soils or groundwater at the Rust Garage Facility), it is expected that the benzene and other contaminants at the site will likely be reduced prior to expiration of the 30-year plant operational period. As the original sources of petroleum contamination have been removed, and the area of petroleum contamination is limited, a site-specific standard is therefore being requested for the Rust Garage Facility.

  3. Corrective Action Plan for underground storage tanks 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility, Buildings 9720-15 and 9754-1. Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Facility ID No. 0-010117

    SciTech Connect

    Bohrman, D.E.; Ingram, E.M.

    1992-04-01

    This document represents the Corrective Action Plan for underground storage tanks 1219-U, 1222-U, and 2068-U, all previously located at the Buildings 9720-15/ 9754-1 site (Facility Identification {number_sign}0-010117), Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. This site is commonly referred to as the ``Rust Garage Facility`` and will be so referenced in this document hereafter. This document presents a comprehensive summary of all environmental assessment investigations conducted at the Rust Garage Facility and the corrective action measures that are proposed for remediation of subsurface petroleum contamination identified at the facility. This document is written in accordance with the regulatory requirements of the Tennessee Department of Environment and Conservation (TDEC) Rule 1200-1-15-.06(7). The Corrective Action Plan for the Rust Garage Facility incorporates all elements of both the Corrective Action Plan Format and the Environmental Assessment Report/Corrective Action Plan guidelines that are applicable to the facility. However, in cases where the latter guideline elements offered the more precise and clear presentation of applicable information, they were used in place of elements detailed in the Corrective Action Plan Format.

  4. Options for commercial tokamaks

    SciTech Connect

    Dabiri, A.E.; Keeton, D.C.; Thomson, S.L.

    1986-07-01

    Systems studies have been performed at the Fusion Engineering Design Center (FEDC) to assess commercial tokamak options. One study investigates the economics of high-beta operation and determines an optimum operating range of 10 to 20% beta, with a corresponding neutron wall loading of 6 to 8 MW/m/sup 2/. A second study determines conditions under which small, low-power tokamaks can be economically combined into a 1200-MW(electric) multiplex power plant. The results of these studies have directed future efforts at the FEDC toward a high-beta, tokamak design using a modular maintenance configuration.

  5. Accelerating Commercial Remote Sensing

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Through the Visiting Investigator Program (VIP) at Stennis Space Center, Community Coffee was able to use satellites to forecast coffee crops in Guatemala. Using satellite imagery, the company can produce detailed maps that separate coffee cropland from wild vegetation and show information on the health of specific crops. The data can control coffee prices and eventually may be used to optimize application of fertilizers, pesticides and irrigation. This would result in maximal crop yields, minimal pollution and lower production costs. VIP is a mechanism involving NASA funding designed to accelerate the growth of commercial remote sensing by promoting general awareness and basic training in the technology.

  6. Optical design of LED-based automotive headlamps

    NASA Astrophysics Data System (ADS)

    Zhu, Xiangbing; Zhu, Qian; Wu, Han; Chen, Chun

    2013-02-01

    In order to solve the problem of high cost and low optical efficiency of current LED-based headlamps, we introduced a new optical design approach for LED-based automotive headlamps. In this configuration, 48 pieces of LEDs are used to build a LED array and the measuring screen is divided into multiple blocks to allow each LED to illuminate a block. A kind of secondary optical lens for a single LED is used so that the lights radiated from a single LED can form a rectangular beam region, whose optical efficiency is above 85% in theory. Lighting up different LEDs can illuminate different blocks, so as to realize low-beam and high-beam lighting. Ray tracing simulation results fulfill the low-beam and high-beam optical demands of the regulation. Since low-power LEDs need no additional reflectors, cost lower and obtain higher efficiency than high-power LEDs, this configuration achieves high reliability installation and can partially realize the functions of Adaptive Front-Lighting System (AFS).

  7. LED light engine concept with ultra-high scalable luminance

    NASA Astrophysics Data System (ADS)

    Hoelen, Christoph; de Boer, Dick; Bruls, Dominique; van der Eyden, Joost; Koole, Rolf; Li, Yun; Mirsadeghi, Mo; Vanbroekhoven, Vincent; Van den Bergh, John-John; Van de Voorde, Patrick

    2016-03-01

    Although LEDs have been introduced successfully in many general lighting applications during the past decade, high brightness light source applications are still suffering from the limited luminance of LEDs. High power LEDs are generally limited in luminance to ca 100 Mnit (108 lm/m2sr) or less, while dedicated devices for projection may achieve luminance values up to ca 300 Mnit with phosphor converted green. In particular for high luminous flux applications with limited étendue, like in front projection systems, only very modest luminous flux values in the beam can be achieved with LEDs compared to systems based on discharge lamps. In this paper we introduce a light engine concept based on a light converter rod pumped with blue LEDs that breaks through the étendue and brightness limits of LEDs, enabling LED light source luminance values that are more than 4 times higher than what can be achieved with LEDs so far. In LED front projection systems, green LEDs are the main limiting factor. With our green light emitting modules, peak luminance values well above 1.2 Gnit have been achieved, enabling doubling of the screen brightness of LED based DLP projection systems, and even more when this technology is applied to other colors as well. This light source concept, introduced as the ColorSpark High Lumen Density (HLD) LED technology, enables a breakthrough in the performance of LED-based light engines not only for projection, where >2700 ANSI lm was demonstrated, but for a wide variety of high brightness applications.

  8. History of commercializing sexed semen for cattle.

    PubMed

    Garner, D L; Seidel, G E

    2008-04-15

    Although the basic principles controlling the sex of mammalian offspring have been known for a relatively long time, recent application of certain modern cellular methodologies has led to development of a flow cytometric system capable of differentiating and separating living X- and Y-chromosome-bearing sperm in amounts suitable for AI and therefore, commercialization of this sexing technology. After a very long history of unsuccessful attempts to differentiate between mammalian sperm that produce males from those that produce females, a breakthrough came in 1981 when it was demonstrated that precise DNA content could be measured. Although these initial measurements of DNA content killed the sperm in the process, they led to the ultimate development of a sperm sorting system that was capable, not only of differentiating between live X- and Y-sperm, but of sorting them into relatively pure X- and Y-sperm populations without obvious cellular damage. Initial efforts to predetermine the sex of mammalian offspring in 1989 required surgical insemination, but later enhancements provided sex-sorted sperm in quantities suitable for use with IVF. Subsequent advances in flow sorting provided minimal numbers of sperm sufficient for use in AI. It was not until the flow cytometric sorting system was improved greatly and successful cryopreservation of sex-sorted bull sperm was developed that efficacious approaches to commercialization of sexed semen could be implemented worldwide in cattle. A number of companies now offer sex-sorted bovine sperm. Innovative approaches by a diverse group of scientists along with advances in computer science, biophysics, cell biology, instrumentation, and applied reproductive physiology provided the basis for commercializing sexed semen in cattle.

  9. Accelerating advanced-materials commercialization

    NASA Astrophysics Data System (ADS)

    Maine, Elicia; Seegopaul, Purnesh

    2016-05-01

    Long commercialization times, high capital costs and sustained uncertainty deter investment in innovation for advanced materials. With appropriate strategies, technology and market uncertainties can be reduced, and the commercialization of advanced materials accelerated.

  10. Overview of Commercial Buildings, 2003

    EIA Publications

    2008-01-01

    The Energy Information Administration conducts the Commercial Buildings Energy Consumption Survey (CBECS) to collect information on energy-related building characteristics and types and amounts of energy consumed in commercial buildings in the United States.

  11. MPRS (URBOT) commercialization

    NASA Astrophysics Data System (ADS)

    Ciccimaro, Donny; Baker, William; Hamilton, Ian; Heikkila, Leif; Renick, Joel

    2003-09-01

    The Man Portable Robotic System (MPRS) project objective was to build and deliver hardened robotic systems to the U.S. Army"s 10 Mountain Division in Fort Drum, New York. The system, specifically designed for tunnel and sewer reconnaissance, was equipped with visual and audio sensors that allowed the Army engineers to detect trip wires and booby traps before personnel entered a potentially hostile environment. The MPRS system has shown to be useful in government and military supported field exercises, but the system has yet to reach the hands of civilian users. Potential users in Law Enforcement and Border Patrol have shown a strong interest in the system, but robotic costs were thought to be prohibitive for law enforcement budgets. Through the Center for Commercialization of Advanced Technology (CCAT) program, an attempt will be made to commercialize the MPRS. This included a detailed market analysis performed to verify the market viability of the technologies. Hence, the first step in this phase is to fully define the marketability of proposed technologies in terms of actual market size, pricing and cost factors, competitive risks and/or advantages, and other key factors used to develop marketing and business plans.

  12. Commercial nuclear power 1990

    SciTech Connect

    Not Available

    1990-09-28

    This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The nuclear capacity projections are discussed in terms of two projection periods: the intermediate term through 2010 and the long term through 2030. A No New Orders case is presented for each of the projection periods, as well as Lower Reference and Upper Reference cases. 5 figs., 30 tabs.

  13. Aerocapacitor commercialization plan

    SciTech Connect

    1995-09-12

    The purpose of the Power-One Aerocapacitor Commercialization Plan is to communicate to members of management and to all employees the overall objectives of the corporation. Power-One, Inc., has participated in a US Federal Government Technology Reinvestment Project (TRP), entitled {open_quotes}Advanced Power Conversion based on the Aerocapacitor{close_quotes}: the project is a group effort, with Lawrence Livermore National Labs, GenCorp/Aerojet, PolyStor Corp. (a start-up company), and Power-One forming the consortium. The expected resulting technology is the {open_quotes}Aerocapacitor{close_quotes}, which possesses much higher performance levels than the usual capacitors on the market today. Power-One hopes to incorporate the Aerocapacitor into some of its products, hence enhancing their performance, as well as market privately-labeled aerocapacitors through its distribution channels. This document describes the details of Power-One`s plan to bring to market and commercialize the Aerocapacitor and Aerocapacitor-based products. This plan was formulated while Power-One was part of the Oerocap project. It has since pulled out of this project. What is presented in this plan is the work which was developed prior to the business decision to terminate this work.

  14. Multiplexed coded illumination for Fourier Ptychography with an LED array microscope

    PubMed Central

    Tian, Lei; Li, Xiao; Ramchandran, Kannan; Waller, Laura

    2014-01-01

    Fourier Ptychography is a new computational microscopy technique that achieves gigapixel images with both wide field of view and high resolution in both phase and amplitude. The hardware setup involves a simple replacement of the microscope’s illumination unit with a programmable LED array, allowing one to flexibly pattern illumination angles without any moving parts. In previous work, a series of low-resolution images was taken by sequentially turning on each single LED in the array, and the data were then combined to recover a bandwidth much higher than the one allowed by the original imaging system. Here, we demonstrate a multiplexed illumination strategy in which multiple randomly selected LEDs are turned on for each image. Since each LED corresponds to a different area of Fourier space, the total number of images can be significantly reduced, without sacrificing image quality. We demonstrate this method experimentally in a modified commercial microscope. Compared to sequential scanning, our multiplexed strategy achieves similar results with approximately an order of magnitude reduction in both acquisition time and data capture requirements. PMID:25071971

  15. A multispectral LED array for the reduction of background autofluorescence in brain tissue☆

    PubMed Central

    Duong, Haison; Han, Martin

    2013-01-01

    The presence of fixative-induced and cellular-derived artifactual autofluorescences (AAFs) presents a challenge in histological analysis involving immunofluorescence. We have established a simple and highly effective method for the reduction of AAFs that are ubiquitous in fixed mammalian brain and other tissues. A compact AAF-quenching photo-irradiation device was constructed using a commercially available light emitting diode (LED) array, cooling unit, and supporting components. The LED panel is comprised of an array of multispectral high intensity LEDs which serve as the illumination source for the photo-irradiation process. Rabbit and cat brain specimens of 5 μm- and 40 μm-thicknesses, respectively, were photo-irradiated for various durations. The AAFs were reduced to near tissue background levels after 24 h of treatment for both deparaffinized and paraffinized rabbit brain specimens, and for the free-floating cat brain specimens. Subsequent immunofluorescence staining using primary antibodies against GFAP, NeuN, Iba-1, and MAP-2, and the corresponding Qdot® and Alexafluor® fluoroconjugates confirmed that the LED photo-irradiation treatment did not compromise the efficiency of the immunofluorescence labeling. The use of the device is not labor intensive, and only requires minimal tissue processing and experimental set-up time, with very low maintenance and operating costs. Finally, multiple specimens, in both slide and well-plate format, can be simultaneously photo-irradiated, thus, allowing for scalable batch processing. PMID:23994358

  16. Development and Tests of the LED Calibration System for the Daya Bay Reactor Neutrino Experiment

    NASA Astrophysics Data System (ADS)

    Morang, Melinda

    2007-10-01

    The Daya Bay reactor neutrino experiment must measure the neutrino rate and spectrum with very precision. Thus, the detector modules must be carefully calibrated in order to produce reliable data. This study consists of hardware research and development for the LED portion of the detector calibration system, for which a fast timing resolution is key. We used a photomultiplier tube and CAMAC DAQ to test possible components, including pulsing circuits, LEDs, coaxial cable, and an electrical slip ring. We produced a 4ns light pulse using a DEI PCO-7110 Laser Diode Driver Module and an Industrial Fiber Optics, Inc. IF-E92A 430nm LED in parallel with a 0.12μH inductor. We determined that the Moog, Inc. electrical slip ring does not significantly distort or widen the light pulse, and the Cooner Wire CW2040-3650F coaxial cable causes only a very small amount of pulse widening. Because these quick pulses are fast enough for use in the calibration system and because the slip ring and coaxial cable are satisfactory, these components are viable options for Daya Bay. Because these components are all commercially available, they would be simpler to use and possibly more reliable than custom-made components. Thus, we have demonstrated that these components are a good option, and we recommend them as the baseline of the LED calibration system for Daya Bay.

  17. An overview of LED applications for general illumination

    NASA Astrophysics Data System (ADS)

    Pelka, David G.; Patel, Kavita

    2003-11-01

    This paper begins by reviewing the current state of development of LEDs, their existing markets as well as their potential for energy conservation and their potential for gaining market share in the general illumination market. It discusses LED metrics such as chip size, lumens per watt, thermal resistance, and the recommended maximum current rating. The paper then goes on to consider the importance of non-imaging optics for both optically efficient and extremely compact LED lighting systems. Finally, microstructures useful for controlling the fields-of-view of LED lighting systems are considered and described in some detail. An extremely efficient and cost effective microstructure, called kinoform diffusers, is shown to have very unique properties that make this technology almost ideal for shaping the output beams of LED lighting systems. It concludes by illustrating some general illumination LED lighting systems

  18. TV Commercials Can Teach Nutrition

    ERIC Educational Resources Information Center

    Brent, Catherine

    1974-01-01

    In California non-commercial "commercials" short spots of pantomime and bilingual messages fitted into and around television's entertainment programs, are used as a means of providing nutrition education to urban and rural low-income people. As revealed by audience requests for nutritional information offered, the commercials are popular…

  19. Rapid fabrication of microfluidic chips based on the simplest LED lithography

    NASA Astrophysics Data System (ADS)

    Li, Yue; Wu, Ping; Luo, Zhaofeng; Ren, Yuxuan; Liao, Meixiang; Feng, Lili; Li, Yuting; He, Liqun

    2015-05-01

    Microfluidic chips are generally fabricated by a soft lithography method employing commercial lithography equipment. These heavy machines require a critical room environment and high lamp power, and the cost remains too high for most normal laboratories. Here we present a novel microfluidics fabrication method utilizing a portable ultraviolet (UV) LED as an alternative UV source for photolithography. With this approach, we can repeat several common microchannels as do these conventional commercial exposure machines, and both the verticality of the channel sidewall and lithography resolution are proved to be acceptable. Further microfluidics applications such as mixing, blood typing and microdroplet generation are implemented to validate the practicability of the chips. This simple but innovative method decreases the cost and requirement of chip fabrication dramatically and may be more popular with ordinary laboratories.

  20. LED Arrays as Cost Effective and Efficient Light Sources for Widefield Microscopy

    PubMed Central

    Sato, Tomokazu F.; Meister, Markus; Murthy, Venkatesh N.

    2008-01-01

    New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission filters and shutters for fluorescence imaging. These components can be expensive, difficult to maintain and preclude stable illumination. Here, we describe methods to construct inexpensive and easy-to-use light sources for optical microscopy using light-emitting diodes (LEDs). We also provide examples of its applicability to biological fluorescence imaging. PMID:18478056

  1. Interior LED Lighting Technology. Navy Energy Technology Validation (Techval) Program

    DTIC Science & Technology

    2015-09-01

    lamps. What is the Technology? An LED is a semiconductor- diode that emits light when power is applied. A driver is used, much as a ballast, to...Approved for public release: distribution unlimited TDS-NAVFAC EXWC-PW-1601 Sep 2015 Interior LED Lighting Technology Navy Energy...NAVFAC EXWC) to determine the potential energy savings for Interior LED lighting technology in office environments. NAVAFAC EXWC concluded that

  2. Effect of LED lamping on the chlorophylls of leaf mustard

    NASA Astrophysics Data System (ADS)

    Wu, Shiqiang; Zhu, Liang; Zhao, Fuli; Yang, Bowen; Chen, Zuxin; Cai, Ruhai; Chen, Jiansheng

    The absorption coefficients of chloroplast of leaf mustard were measured by a spectrophotometer. The leaves were collected from seven treatments with different lighting. The chlorophyll content was calculated following Arnon equation. LEDs for filling the light source can increase the conduction of plants. Compared with other treatments, Chlorophyll in the leaves got an higher concentration under the lamping of red LEDS to blue LEDS for 7:1 .

  3. High-Modulation-Speed LEDs Based on III-Nitride

    NASA Astrophysics Data System (ADS)

    Chen, Hong

    III-nitride InGaN light-emitting diodes (LEDs) enable wide range of applications in solid-state lighting, full-color displays, and high-speed visible-light communication. Conventional InGaN quantum well LEDs grown on polar c-plane substrate suffer from quantum confined Stark effect due to the large internal polarization-related fields, leading to a reduced radiative recombination rate and device efficiency, which limits the performance of InGaN LEDs in high-speed communication applications. To circumvent these negative effects, non-trivial-cavity designs such as flip-chip LEDs, metallic grating coated LEDs are proposed. This oral defense will show the works on the high-modulation-speed LEDs from basic ideas to applications. Fundamental principles such as rate equations for LEDs/laser diodes (LDs), plasmonic effects, Purcell effects will be briefly introduced. For applications, the modal properties of flip-chip LEDs are solved by implementing finite difference method in order to study the modulation response. The emission properties of highly polarized InGaN LEDs coated by metallic gratings are also investigated by finite difference time domain method.

  4. Excellent color rendering indexes of multi-package white LEDs.

    PubMed

    Oh, Ji Hye; Yang, Su Ji; Sung, Yeon-Goog; Do, Y R

    2012-08-27

    This study introduces multi-package white light-emitting diodes (LEDs) system with the ability to realize high luminous efficacy and an excellent color rendering index (CRI, R a) using the R B,M A B,M G B,M C B (R B,M A B,M G B,M denoted as a long-pass dichroic filter (LPDF)-capped, monochromatic red, amber and green phosphor converted-LED (pc-LED) pumped by a blue LED chip, and C B denoted as a cyan and blue mixed pc-LED pumped by a blue LED) system. The luminous efficacy and color rendering index (CRI) of multi-package white LED systems are compared while changing the concentration of the cyan phosphor used in the paste of a cyan-blue LED package and the driving current of individual LEDs in multi-package white LEDs at correlated color temperatures (CCTs) ranging from 6,500 K (cold white) to 2,700 K (warm white) using a set of eight CCTs as specified by the American National Standards Institute (ANSI) standard number C78.377-2008. A R B,M A B,M G B,M C B white LED system provides high luminous efficacy (≥ 96 lm/W) and a color rendering index (≥ 91) encompassing the complete CCT range. We also compare the optical properties of the R B,M A B,M G B,M C B system with those of the R B,M A B,M G B,M B and RAGB (red, amber, green, and blue semiconductor-type narrow-spectrum-band LEDs) systems. It can be expected that the cyan color added to a blue LED in multi-package white LEDs based on LPDF-capped, phosphor-converted monochromatic LEDs will meet the needs of the high-quality, highly efficient, full-color white LED lighting market in the near future.

  5. The commercialization of migration.

    PubMed

    Abrera-mangahas, M A

    1989-01-01

    International migration is not new to the Philippines. In the recent outflow of contract workers to the Middle East, there is a shift from individual and family initiated migrations to the more organized, highly commercial variety. While profit-taking intermediaries have played some role in the past, the increase in the number and influence of these intermediaries has altered the story of migration decision-making. In 1975, the signing of the bilateral labor agreement between the governments of Iran and the Philippines signalled the rising demand for Filipino contract workers. From 1970 to 1975, the number of Asian migrant workers in the Gulf countries rose from about 120,000 to 370,000. These figures rose dramatically to 3.3 million in 1985. The growing share of organized and commercialized migration has altered migration decision making. Primarily, intermediaries are able to broaden access to foreign job and high wage opportunities. Commercialization effectively raises the transaction costs for contract migration. Studies on recruitment costs and fees show that self-solicited foreign employment costs less than employment obtained through recruitment agents and intermediaries. The difference in the 2 prices is due, not only to overhead costs of intermediation, but more importantly to the rent exacted by agents from having job information and placement rights. In the Philippines in October 1987 the average placement fee was P8000, greatly exceeding the mandated maximum fee level of P5000. This average is understated because the computation includes the 17% who do not pay any fees. The widespread and popular view of recruitment intermediaries is negative, dominated by images of abuses and victims. Private intermediaries and the government bureaucracy need each other. Intermediaries need government; their consistent demand for incentives and protection is indicative. On the other hand, government expands its supervision of control of overseas employment via the

  6. Commercializing solar hydrogen production

    SciTech Connect

    Holmes, J.T.; Prairie, M.R.

    1991-01-01

    This paper discusses the need for a government-supported program to commercialize hydrogen production methods which use solar energy as the main source of energy. Current methods use hydrocarbons and generate large amounts of carbon dioxide. The paper describes results from a literature survey performed to identify technologies using direct solar energy that were likely to succeed on an industrial scale in the near term. Critical parameters included calculated efficiencies, measured efficiencies, and development status. The cost of solar collectors is cited as the reason most promising solar hydrogen research is not taken to the pilot plant stage. The author recommends use of existing DOE facilities already in operation for pilot plant testing. 14 refs. (CK)

  7. Commercial aircraft noise

    NASA Astrophysics Data System (ADS)

    Smith, M. J.

    The history of aircraft noise control development is traced with an eye to forecasting the future. Noise control became imperative with the advent of the first generation of commercial jet aircraft, which were extremely loud. The steady increases in the size of turbofans have nearly matched the progress in noise reduction capabilities in recent years. Only 5 dB of reduction in fleet noise has been achieved since early standards were met. Current engine design is concentrated on increasing fuel efficiency rather than lowering noise emissions. Further difficulties exist because of continued flights with older aircraft. Gains in noise reduction have been made mainly by decreasing exhaust velocities from 600-700 m/sec to 300-400 m/sec. New techniques being explored comprise mixing the core and bypass flows, interaction tone control, reduction of broadband sources, development of acoustic liner technology and alterations in the number of fan blades and stage spacing.

  8. Endotoxins in commercial vaccines.

    PubMed Central

    Geier, M R; Stanbro, H; Merril, C R

    1978-01-01

    Twenty samples of commercial vaccines intended for administration to humans were assayed for the presence of bacterial endotoxins by using the Limulus amebocyte lysate test. Sixteen of the vaccines contained more than 0.1 ng of endotoxin per ml (which corresponds to 103 bacterial cell wall equivalents per ml in the undiluted vaccines). These results suggest that at some stage of preparation, the vaccines have contained varying amounts of gram-negative bacteria and may indicate the presence of other bacterial products as well. It might be useful to list the level of endotoxins, phage, and other contaminants on each vaccine lot to facilitate studies on any side effects of these contaminants. Selection of vaccine lots with the least endotoxin might reduce some of the adverse effects of vaccinations. PMID:727776

  9. Horizontally assembled green InGaN nanorod LEDs: scalable polarized surface emitting LEDs using electric-field assisted assembly

    PubMed Central

    Park, Hoo Keun; Yoon, Seong Woong; Eo, Yun Jae; Chung, Won Woo; Yoo, Gang Yeol; Oh, Ji Hye; Lee, Keyong Nam; Kim, Woong; Do, Young Rag

    2016-01-01

    In this study, we report the concerted fabrication process, which is easy to transform the size of active emitting area and produce polarized surface light, using the electric-field-assisted assembly for horizontally assembled many tiny nanorod LEDs between two metal electrodes. We fabricate the millions of individually separated 1D nanorod LEDs from 2D nanorod arrays using nanosphere lithography, etching and cutting process of InGaN/GaN LED structure on a flat sapphire substrate. The horizontally assembled InGaN-based nanorods LED device shows bright (~2,130 cd/m2) and uniform polarized (polarization ratio, ρ = ~0.61) green emissions from large area (0.7 cm × 0.6 cm) planar surface. The realization of a horizontally assembled nanorod LED device can prove the concept of an innovative idea to fabricate formable and scalable polarized surface LED lighting. PMID:27324568

  10. Horizontally assembled green InGaN nanorod LEDs: scalable polarized surface emitting LEDs using electric-field assisted assembly

    NASA Astrophysics Data System (ADS)

    Park, Hoo Keun; Yoon, Seong Woong; Eo, Yun Jae; Chung, Won Woo; Yoo, Gang Yeol; Oh, Ji Hye; Lee, Keyong Nam; Kim, Woong; Do, Young Rag

    2016-06-01

    In this study, we report the concerted fabrication process, which is easy to transform the size of active emitting area and produce polarized surface light, using the electric-field-assisted assembly for horizontally assembled many tiny nanorod LEDs between two metal electrodes. We fabricate the millions of individually separated 1D nanorod LEDs from 2D nanorod arrays using nanosphere lithography, etching and cutting process of InGaN/GaN LED structure on a flat sapphire substrate. The horizontally assembled InGaN-based nanorods LED device shows bright (~2,130 cd/m2) and uniform polarized (polarization ratio, ρ = ~0.61) green emissions from large area (0.7 cm × 0.6 cm) planar surface. The realization of a horizontally assembled nanorod LED device can prove the concept of an innovative idea to fabricate formable and scalable polarized surface LED lighting.

  11. Whither Commercial Nanobiosensors?

    SciTech Connect

    Achyuthan, Komandoor

    2011-01-01

    The excitement surrounding the marriage of biosensors and nanotechnology is palpable even from a cursory examination of the scientific literature. Indeed, the word “nano” might be in danger of being overused and reduced to a cliché, although probably essential for publishing papers or securing research funding. The biosensor literature is littered with clever or catchy acronyms, birds being apparently favored (“CANARY”, “SPARROW”), quite apart from “electronic tongue,” “electronic nose,” and so on. Although biosensors have been around since glucose monitors were commercialized in the 1970s, the transition of laboratory research and innumerable research papers on biosensors into the world of commerce has lagged. There are several reasons for this phenomenon including the infamous “valley of death” afflicting entrepreneurs emerging from academic environment into the industrial world, where the rules for success can be radically different. In this context, musings on biosensors and especially nanobiosensors in an open access journal such as Journal of Biosensors and Bioelectronics is topical and appropriate especially since market surveys of biosensors are prohibitively expensive, sometimes running into thousands of dollars for a single copy. The contents and predictions of market share for biosensors in these reports also keep changing every time a report is published. Not only that, the market share projections for biosensors differs considerably amongst various reports. An editorial provides the opportunity to offer personal opinions and perhaps stimulate debate on a particular topic. In this sense, editorials are a departure from the rigor of a research paper. This editorial is no exception. With this preamble, it is worthwhile to stop and ponder the status of commercial biosensors and nanobiosensors.

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

    SciTech Connect

    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

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

    SciTech Connect

    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

  14. Student-Led Parent Conferences: A Model for Teaching Responsibility.

    ERIC Educational Resources Information Center

    Guyton, Jane M.; Fielstein, Lynda L.

    1989-01-01

    Describes program in which elementary school students lead parent-teacher conferences, shares authors' experiences with the student-led conferences, and discusses how the process has fostered student responsibility. Describes results of informal study that support the student-led conference. (NB)

  15. Low Cost Lithography Tool for High Brightness LED Manufacturing

    SciTech Connect

    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.

  16. Evaluation of LED-based Instrumentation for JLab Detectors

    NASA Astrophysics Data System (ADS)

    Durham, Stephanie; Parvatam, Ruhi

    2014-09-01

    Light-Emitting Diodes have a multitude of uses due to their increasing efficiency, reliability, durability, and practical size. The wavelength-intensity properties of LEDs are important in the characterization of aerogel optical properties and thus the uniformity and performance of the Hall C threshold aerogel Cherenkov detectors at Jefferson Laboratory. LEDs are also practical for the PWO-based calorimeters at JLab for monitoring and recovering these crystals during and after exposure to radiation. This project is aimed at the construction and evaluation of LED-based instrumentation to characterize the optical properties of aerogel used in the JLab aerogel detectors and its application to future detectors. LEDs emit light at a nominal wavelength, but their spectrum covers a broad range. It is thus important to understand the LED spectrum. A spectrometer was constructed including a collimator, diffraction grating, and high-speed photodiode to measure the voltage, which was then converted into luminous intensity. This presentation will convey the results from measurements with LED-based instrumentation and discuss the application of LEDs covering wavelengths from the ultraviolet to near-infrared regions in future PWO-based detectors. Light-Emitting Diodes have a multitude of uses due to their increasing efficiency, reliability, durability, and practical size. The wavelength-intensity properties of LEDs are important in the characterization of aerogel optical properties and thus the uniformity and performance of the Hall C threshold aerogel Cherenkov detectors at Jefferson Laboratory. LEDs are also practical for the PWO-based calorimeters at JLab for monitoring and recovering these crystals during and after exposure to radiation. This project is aimed at the construction and evaluation of LED-based instrumentation to characterize the optical properties of aerogel used in the JLab aerogel detectors and its application to future detectors. LEDs emit light at a nominal

  17. Wide color gamut LCD module using white light LED

    NASA Astrophysics Data System (ADS)

    He, Chang-Feng; Qian, Ke-Yuan; Wang, Han-Feng

    2016-01-01

    LED is a kind of reliable source of LCD backlight. The characteristics of LED determine the color gamut and brightness of LCD TV. At present, the mainstream of white LED mainly uses blue chip coated with YAG phosphor to get white light, which can only guarantee the color gamut to 72%NTSC. Based on the color characteristics of backlight module, the method of calculating the color gamut of backlight module are introduced in detail. Coating blue chip by different kind of phosphors, a new LED backlight for LCD TV is developed. The color gamut is improved to more than 80%NTSC or more. At the same time, through the optimization of combination of blue chip with selected green phosphor and red phosphor excitation peak, this white LED solution can get the different color gamut and the highest color gamut, which will be 88%NTSC at most. This technique has been applied to a LCD TV.

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

    SciTech Connect

    Cabot Corporation

    2007-09-30

    are used. This spherical morphology will result in better light extraction and so an improvement of efficiency in the overall device. Cabot is a 2.5 billion dollar company that makes specialized materials using propriety spray based technologies. It is a core competency of Cabot's to exploit the spray based technology and resulting material/morphology advantages. Once a business opportunity is clearly identified, Cabot is positioned to increase the scale of the production to meet opportunity's need. Cabot has demonstrated the capability to make spherical morphology micron-sized phosphor powders by spray based routes for PDP and CRT applications, but the value proposition is still unproven for LED applications. Cabot believes that the improvements in phosphor powders yielded by their process will result in a commercial advantage over existing technologies. Through the SSL project, Cabot has produced a number of different compositions in a spherical morphology that may be useful for solid state lights, as well as demonstrated processes that are able to produce particles from 10 nanometers to 3 micrometers. Towards the end of the project we demonstrated that our process produces YAG:Ce powder that has both higher internal quantum efficiency (0.6 compared to 0.45) and external quantum efficiency (0.85 compared to 0.6) than the commercial standard (see section 3.4.4.3). We, however, only produced these highly bright materials in research and development quantities, and were never able to produce high quantum efficiency materials in a reproducible manner at a commercial scale.

  19. GaN-based LEDs for light communication

    NASA Astrophysics Data System (ADS)

    Zhao, LiXia; Zhu, ShiChao; Wu, ChunHui; Yang, Chao; Yu, ZhiGuo; Yang, Hua; Liu, Lei

    2016-10-01

    Rapid improvement in the efficiency of GaN-based LEDs not only speed up its applications for general illumination, but offer the possibilities for data transmission. This review is to provide an overview of current progresses of GaN-based LEDs for light communications. The modulation bandwidth of GaN-based LEDs has been first improved by optimizing the LED epilayer structures and the modulation bandwidth of 73 MHz was achieved at the driving current density of 40 A/cm2 by changing the multi-quantum well structures. After that, in order to increase the current density tolerance, different parallel flip-chip micro-LED arrays were fabricated. With a high injected current density of ˜7900 A/cm2, a maximum modulation bandwidth of ˜227 MHz was obtained with optical power greater than 30 mW. Besides the increase of carrier concentrations, the radiative recombination coefficient B was also enhanced by modifying the photon surrounding environment based on some novel nanostructures such as resonant cavity, surface plasmon, and photonic crystals. The optical 3 dB modulation bandwidth of GaN-based nanostructure LEDs with Ag nanoparticles was enhanced by 2 times compared with GaN-based nanostructure LEDs without Ag nanoparticles. Our results demonstrate that using the QW-SP coupling can effectively help to enhance the carrier spontaneous emission rate and also increase the modulation bandwidth for LEDs, especially for LEDs with high intrinsic IQE. In addition, we discuss the progress of the faster color conversion stimulated by GaN-based LEDs.

  20. Designing low cost LED display for the billboard

    NASA Astrophysics Data System (ADS)

    Hong, Yi-Jian; Uang, Chii-Maw; Wang, Ping-Chieh; Ho, Zu-Sheng

    2011-10-01

    With quickly advance of the computer, microelectronics and photonics technologies, LED display panel becomes a new electronic advertising media. It can be used to show any information whatever characters or graphics. Most LED display panels are built of many Light-Emitting Diodes arranged in a matrix form. The display has many advantages such as low power, low cost, long life and high definition. Because the display panel is asked to show rich color, the LED display panel's driving system becomes very complex. The design methodology of LED display panel's driver becomes more and more important to meet the market requirements. Cost is always the most important issue in public market domain. In this paper, we report a design methodology of LED display panel's driver based on the microprocessor control unit (MCU) system and LED display controller IC, HT1632C, to control three colors, RGB, color LED display panel and the modular panel size is 24*16 in matrix form. The HT1632C is a memory mapping LED display controller, it can be used on many applications, such as digital clock, thermometer, counter, voltmeter or other instrumentation readouts. Three pieces of HT1632C are used to drive a 24*16 RGB LED display panel, in our design case. Each HT163C chip is used to control one of the R, G and B color. As the drive mode is driven in DC mode, the RGB display panel can create and totally of seven colors under the control of MCU. The MCU generates the control signal to drive HT1632C. In this study, the software design methodology is adopted with dynamic display principle. When the scan frequency is 60Hz, LED display panel will get the clear picture and be able to display seven colors.

  1. Commercializing medical technology.

    PubMed

    Scanlon, Kevin J; Lieberman, Mark A

    2007-04-01

    As medicine moves into the 21st century, life saving therapies will move from inception into medical products faster if there is a better synergy between science and business. Medicine appears to have 50-year innovative cycles of education and scientific discoveries. In the 1880's, the chemical industry in Germany was faced with the dilemma of modernization to exploit the new scientific discoveries. The solution was the spawning of novel technical colleges for training in these new chemical industries. The impact of those new employees and their groundbreaking compounds had a profound influence on medicine and medical education in Germany between 1880 and 1930. Germany dominated international science during this period and was a training center for scientists worldwide. This model of synergy between education and business was envied and admired in Europe, Asia and America. British science soon after evolved to dominate the field of science during the prewar and post World War (1930's-1970's) because the German scientists fled Hitler's government. These expatriated scientists had a profound influence on the teaching and training of British scientists, which lead to advances in medicine such as antibiotics. After the Second World War, the US government wisely funded the development of the medical infrastructure that we see today. British and German scientists in medicine moved to America because of this bountiful funding for their research. These expatriated scientists helped drive these medical advances into commercialized products by the 1980's. America has been the center of medical education and advances of biotechnology but will it continue? International scientists trained in America have started to return to Europe and Asia. These American-trained scientists and their governments are very aware of the commercial potential of biotechnology. Those governments are now more prepared to play an active role this new science. Germany, Ireland, Britain, Singapore

  2. Commercializing medical technology

    PubMed Central

    Lieberman, Mark A.

    2007-01-01

    As medicine moves into the 21st century, life saving therapies will move from inception into medical products faster if there is a better synergy between science and business. Medicine appears to have 50-year innovative cycles of education and scientific discoveries. In the 1880’s, the chemical industry in Germany was faced with the dilemma of modernization to exploit the new scientific discoveries. The solution was the spawning of novel technical colleges for training in these new chemical industries. The impact of those new employees and their groundbreaking compounds had a profound influence on medicine and medical education in Germany between 1880 and 1930. Germany dominated international science during this period and was a training center for scientists worldwide. This model of synergy between education and business was envied and admired in Europe, Asia and America. British science soon after evolved to dominate the field of science during the prewar and post World War (1930’s–1970’s) because the German scientists fled Hitler’s government. These expatriated scientists had a profound influence on the teaching and training of British scientists, which lead to advances in medicine such as antibiotics. After the Second World War, the US government wisely funded the development of the medical infrastructure that we see today. British and German scientists in medicine moved to America because of this bountiful funding for their research. These expatriated scientists helped drive these medical advances into commercialized products by the 1980’s. America has been the center of medical education and advances of biotechnology but will it continue? International scientists trained in America have started to return to Europe and Asia. These American-trained scientists and their governments are very aware of the commercial potential of biotechnology. Those governments are now more prepared to play an active role this new science. Germany, Ireland, Britain

  3. Advanced commercial tokamak study

    SciTech Connect

    Thomson, S.L.; Dabiri, A.E.; Keeton, D.C.; Brown, T.G.; Bussell, G.T.

    1985-12-01

    Advanced commercial tokamak studies were performed by the Fusion Engineering Design Center (FEDC) as a participant in the Tokamak Power Systems Studies (TPSS) project coordinated by the Office of Fusion Energy. The FEDC studies addressed the issues of tokamak reactor cost, size, and complexity. A scoping study model was developed to determine the effect of beta on tokamak economics, and it was found that a competitive cost of electricity could be achieved at a beta of 10 to 15%. The implications of operating at a beta of up to 25% were also addressed. It was found that the economics of fusion, like those of fission, improve as unit size increases. However, small units were found to be competitive as elements of a multiplex plant, provided that unit cost and maintenance time reductions are realized for the small units. The modular tokamak configuration combined several new approaches to develop a less complex and lower cost reactor. The modular design combines the toroidal field coil with the reactor structure, locates the primary vacuum boundary at the reactor cell wall, and uses a vertical assembly and maintenance approach. 12 refs., 19 figs.

  4. Commercial users panel

    NASA Technical Reports Server (NTRS)

    Byrd, Joseph S.; Flatau, Carl; Hodge, David C.; Hollis, Ralph; Leach, Eugene F.; Gilbert, Ray; Cleland, John; Leifer, Larry; Naser, Joseph; Schmuter, Samson D.

    1987-01-01

    The discussions of motives and requirements for telerobotics application demonstrated that, in many cases, lack of progress was a result not of limited opportunities but of inadequate mechanisms and resources for promoting opportunities. Support for this conclusion came from Telerobotics, Inc., one of the few companies devoted primarily to telerobot systems. They have produced units for such diverse applications as nuclear fusion research, particle accelerators, cryogenics, firefighting, marine biology/undersea systems and nuclear mobile robotics. Mr. Flatau offered evidence that telerobotics research is only rarely supported by the private sector and that it often presents a difficult market. Questions on the mechanisms contained within the NASA technology transfer process for promoting commercial opportunities were fielded by Ray Gilbert and Tom Walters. A few points deserve emphasis: (1) NASA/industry technology transfer occurs in both directions and NASA recognizes the opportunity to learn a great deal from industry in the fields of automation and robotics; (2) promotion of technology transfer projects takes a demand side approach, with requests to industry for specific problem identification. NASA then proposes possible solutions; and (3) comittment ofmotivated and technically qualified people on each end of a technology transfer is essential.

  5. Parent, Student, and Teacher Perceptions of Student-Led Conferences and Strategies to Host Effective Student-Led Conferences

    ERIC Educational Resources Information Center

    Jackson, Sharon M.

    2012-01-01

    This is a mixed-methods case study designed to examine the perceptions parents, students and teachers have about student-led conferences with the purpose of informing practices at the researcher's school as well as sharing strategies used to host effective student-led conferences. Parents and students were interviewed and surveyed. Teachers were…

  6. Peer-led and professional-led group interventions for people with co-occurring disorders: a qualitative study.

    PubMed

    Pallaveshi, Luljeta; Balachandra, Krishna; Subramanian, Priya; Rudnick, Abraham

    2014-05-01

    This pilot study evaluated the experience of people with co-occurring disorders (mental illness and addiction) in relation to peer-led and professional-led group interventions. The study used a qualitative (phenomenological) approach to evaluate the experience of a convenience sample of 6 individuals with co-occurring disorders who participated in up to 8 sessions each of both peer-led and professional-led group interventions (with a similar rate of attendance in both groups). The semi-structured interview data were coded and thematically analyzed. We found 5 themes within and across the 2 interventions. In both groups, participants experienced a positive environment and personal growth, and learned, albeit different things. They were more comfortable in the peer-led group and acquired more knowledge and skills in the professional-led group. Offering both peer-led and professional-led group interventions to people with co-occurring disorders may be better than offering either alone.

  7. A high efficiency LED driver based on optical feedback

    NASA Astrophysics Data System (ADS)

    Marti-Arbona, Edgar; Copani, Tino; Bakkaloglu, Bertan; Kiaei, Sayfe

    2014-09-01

    Light emitting diodes (LEDs) offer durability, long life, and high efficiency that make them an excellent alternative for illumination applications. The efficiency of conventional drivers suffers from losses due to the current sensing method that they employ. In this paper, the LED array itself is used as an optical sensor by periodically measuring neighboring cells' light intensity, instead of employing the commonly used series current-sense resistor. The results of this approach show that it provides accurate compensation of the LED characteristics, with less than one lumen variation in illumination, stability in color (color shift over time as low as ΔE = 0.76), and efficiency of up to 98.66%. The proposed sensor compensates for actual optical performance of the LED array and reduces aging effects compared to the approaches based in current measurement and control. The optical current-sensing method is a closed-loop feedback alternative, which improves the power efficiency of the LED driver by 3%. It maintains constant output illumination of the LED over time, and it utilizes a reduced number of components, thus extending the effective lifetime of LED-based devices.

  8. Vision communications based on LED array and imaging sensor

    NASA Astrophysics Data System (ADS)

    Yoo, Jong-Ho; Jung, Sung-Yoon

    2012-11-01

    In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

  9. LOW-COST LED LUMINAIRE FOR GENERAL ILLUMINATION

    SciTech Connect

    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.

  10. LED projection architectures for stereoscopic and multiview 3D displays

    NASA Astrophysics Data System (ADS)

    Meuret, Youri; Bogaert, Lawrence; Roelandt, Stijn; Vanderheijden, Jana; Avci, Aykut; De Smet, Herbert; Thienpont, Hugo

    2010-04-01

    LED-based projection systems have several interesting features: extended color-gamut, long lifetime, robustness and a fast turn-on time. However, the possibility to develop compact projectors remains the most important driving force to investigate LED projection. This is related to the limited light output of LED projectors that is a consequence of the relative low luminance of LEDs, compared to high intensity discharge lamps. We have investigated several LED projection architectures for the development of new 3D visualization displays. Polarization-based stereoscopic projection displays are often implemented using two identical projectors with passive polarizers at the output of their projection lens. We have designed and built a prototype of a stereoscopic projection system that incorporates the functionality of both projectors. The system uses high-resolution liquidcrystal- on-silicon light valves and an illumination system with LEDs. The possibility to add an extra LED illumination channel was also investigated for this optical configuration. Multiview projection displays allow the visualization of 3D images for multiple viewers without the need to wear special eyeglasses. Systems with large number of viewing zones have already been demonstrated. Such systems often use multiple projection engines. We have investigated a projection architecture that uses only one digital micromirror device and a LED-based illumination system to create multiple viewing zones. The system is based on the time-sequential modulation of the different images for each viewing zone and a special projection screen with micro-optical features. We analyzed the limitations of a LED-based illumination for the investigated stereoscopic and multiview projection systems and discuss the potential of a laser-based illumination.

  11. Essentials for Successful and Widespread LED Lighting Adoption

    NASA Astrophysics Data System (ADS)

    Khan, Nisa

    2011-03-01

    Solid-state lighting (SSL), with light-emitting diodes (LEDs) as the light source, is a growing and essential field, particularly in regard to the heightened need for global energy efficiency. In recent years, SSL has experienced remarkable advances in efficiency, light output magnitude and quality. Thus such diverse applications as signage, message centers, displays, and special lighting are now adopting LEDs, taking 2010's market to 9.1 billion - 68% growth from the previous year! While this is promising, future growth in both display and lighting applications will rely upon unveiling deeper understanding and key innovations in LED lighting science and technologies. In this presentation, some LED lighting fundamentals, engineering challenges and novel solutions will be discussed to address reduction in efficiency (a.k.a. droop) at high currents, and to obtain uniform light distribution for overcoming LEDs' directional nature. The droop phenomenon has been a subject of much controversy in the industry and despite several studies and claims, a widely-accepted explanation still lacks because of counter arguments and experiments. Recently several research studies have identified that the droop behavior in nitride-based LEDs beyond certain current density ranges can only be comprehensively explained if the current leaking beyond the LED active region is included. Although such studies have identified a few useful current leakage mechanisms outside the active region, no one has included current leakage, due to non-ideal, 3-D device structures that create undesirable current distribution inside and outside the active region. This talk will address achieving desirable current distributions from optimized 3-D device structures that should reduce current leakage and hence the droop behavior. In addition to novel LED design solutions for droop reduction and uniform light distribution, the talk will address cost and yield concerns as they pertain to core material scarcity

  12. Monolithic LED arrays, next generation smart lighting sources

    NASA Astrophysics Data System (ADS)

    Lagrange, Alexandre; Bono, Hubert; Templier, François

    2016-03-01

    LED have become the main light sources of the future as they open the path for intelligent use of light in time, intensity and color. In many usages, strong energy economy is done by adjusting these properties. The smart lighting has three dimensions, energy efficiency brought by GaN blue emitting LEDs, integration of electronics, sensors, microprocessors in the lighting system and development of new functionalities and services provided by the light. Monolithic LED arrays allow two major innovations, the spatial control of light emission and the adjustment of the electrical properties of the source.

  13. University of Nevada Las Vegas LED Display Engineering

    SciTech Connect

    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.

  14. Energy efficient LED layout optimization for near-uniform illumination

    NASA Astrophysics Data System (ADS)

    Ali, Ramy E.; Elgala, Hany

    2016-09-01

    In this paper, we consider the problem of designing energy efficient light emitting diodes (LEDs) layout while satisfying the illumination constraints. Towards this objective, we present a simple approach to the illumination design problem based on the concept of the virtual LED. We formulate a constrained optimization problem for minimizing the power consumption while maintaining a near-uniform illumination throughout the room. By solving the resulting constrained linear program, we obtain the number of required LEDs and the optimal output luminous intensities that achieve the desired illumination constraints.

  15. Optimized Phosphors for Warm White LED Light Engines

    SciTech Connect

    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.

  16. Study on underwater wireless communication system using LED

    NASA Astrophysics Data System (ADS)

    Son, Hyun-Joong; Choi, Hyeung-Sik; Tran, Ngoc-Huy; Ha, Ji-Hoon; Ji, Dae-Hyeung; Kim, Joon-Young

    2015-03-01

    In this paper, a new variable-focus LED light device is developed for underwater communication. Usually used as an underwater lighting fixture, the LED light device in this study is utilized as an underwater communication device (UCD) by controlling the distance between light source and lens when communication is needed. A transmission and a receiving part of LED light for communication using photoelectric sensor and Fresnel lens are also developed. The communication system was tested in fresh water and sea water to verify its communication performance; results of which are presented in this study.

  17. The possible ocular hazards of LED dental illumination applications.

    PubMed

    Stamatacos, Catherine; Harrison, Janet L

    2013-01-01

    The use of high-intensity illumination via Light-Emitting Diode (LED) headlamps is gaining in popularity with dentists and student dentists. Practitioners are using LED headlamps together with magnifying loupes, overhead LED illumination and fiber-optic dental handpieces for long periods of time. Although most manufacturers of these LED illuminators advertise that their devices emit "white" light, these still consist of two spectral bands--the blue spectral band, with its peak at 445 nm, and the green with its peak at 555 nm. While manufacturers suggest that their devices emit "white" light, spectral components of LED lights from different companies are significantly different. Dental headlamp manufacturers strive to create a white LED, and they advertise that this type of light emitted from their product offers bright white-light illumination. However, the manufacturing of a white LED light is done through selection of a white LED-type based on the peak blue strength in combination with the green peak strength and thus creating a beam-forming optic, which determines the beam quality. Some LED illuminators have a strong blue-light component versus the green-light component. Blue-light is highly energized and is close in the color spectrum to ultraviolet-light. The hazards of retinal damage with the use of high-intensity blue-lights has been well-documented. There is limited research regarding the possible ocular hazards of usage of high-intensity illuminating LED devices. Furthermore, the authors have found little research, standards, or guidelines examining the possible safety issues regarding the unique dental practice setting consisting of the combined use of LED illumination systems. Another unexamined component is the effect of high-intensity light reflective glare and magnification back to the practitioner's eyes due to the use of water during dental procedures. Based on the result of Dr. Janet Harrison's observations of beginning dental students in a

  18. Integrated slanted microneedle-LED array for optogenetics.

    PubMed

    Kwon, Ki Yong; Khomenko, Anton; Haq, Mahmoodul; Li, Wen

    2013-01-01

    This paper presents a three-dimensional (3-D) flexible micro light emitting diode (μ-LED) array for selective optical stimulation of cortical neurons. The array integrated individually addressable μ-LED chips with slanted polymer-based microneedle waveguides to allow precise light delivery to multiple cortical layers simultaneously. A droplet backside exposure method was developed to monolithically fabricate slanted microneedles on a single polymer platform. A wafer-level assembly technique was demonstrated, which permits large-scale, high-density system integration. The electrical, optical, thermal, and mechanical properties of the 3-D slanted microneedle-LED array were characterized experimentally.

  19. Surviving Nuclear Winter Towards a Service-Led Business

    NASA Astrophysics Data System (ADS)

    Rocha, Michael; Chou, Timothy

    During the tech-led recession in 2001 a little known transformation occurred at the world's largest business software company. This transformation was led by a realization that existing customers of mature software need service of the products they purchased more than just purchasing new products. Organizing around the installed base of customers both defined new organizations, as well as new technology to power the specialists. This paper both gives a glimpse of the Oracle transformation as well as lays out some fundamental tenants of anyone interested in a service-led business.

  20. The possible ocular hazards of LED dental illumination applications.

    PubMed

    Stamatacos, Catherine; Harrison, Janet L

    2014-04-01

    The use of high-intensity illumination via Light-Emitting Diode (LED) headlamps is gaining in popularity with dentists and student dentists. Practitioners are using LED headlamps together with magnifying loupes, overhead LED illumination and fiber-optic dental handpieces for long periods of time. Although most manufacturers of these LED illuminators advertise that their devices emit "white" light, these still consist of two spectral bands - the blue spectral band, with its peak at 445 nm, and the green with its peak at 555 nm. While manufacturers suggest that their devices emit "white" light, spectral components of LED lights from different companies are significantly different. Dental headlamp manufacturers strive to create a white LED, and they advertise that this type of light emitted from their product offers bright white-light illumination. However, the manufacturing of a white LED light is done through selection of a white LED-type based on the peak blue strength in combination with the green peak strength and thus creating a beam-forming optic, which determines the beam quality. Some LED illuminators have a strong blue-light component versus the green-light component. Blue-light is highly energized and is close in the color spectrum to ultraviolet-light. The hazards of retinal damage with the use of high-intensity blue-lights has been well-documented. There is limited research regarding the possible ocular hazards of usage of high-intensity illuminating LED devices. Furthermore, the authors have found little research, standards, or guidelines examining the possible safety issues regarding the unique dental practice setting consisting of the combined use of LED illumination systems. Another unexamined component is the effect of high-intensity light reflective glare and magnification back to the practitioner's eyes due to the use of water during dental procedures. Based on the result of Dr. Janet Harrison's observations of beginning dental students in a

  1. Fundamentals of Commercial Art. Module 1. Commercial Art. Instructor's Guide.

    ERIC Educational Resources Information Center

    Davis, Diane; Tadrick, Christine

    This module is the first of five in the Commercial Art series. The curriculum guide is designed for competency-based teaching and testing. Within this module on fundamentals of commercial art are six instructional units. A cross-reference table reveals how the instructional components of the module relate to Missouri competencies. Each unit…

  2. A portable inspection system to estimate direct glare of various LED modules

    NASA Astrophysics Data System (ADS)

    Chen, Po-Li; Liao, Chun-Hsiang; Li, Hung-Chung; Jou, Shyh-Jye; Chen, Han-Ting; Lin, Yu-Hsin; Tang, Yu-Hsiang; Peng, Wei-Jei; Kuo, Hui-Jean; Sun, Pei-Li; Lee, Tsung-Xian

    2015-07-01

    Glare is caused by both direct and indirect light sources and discomfort glare produces visual discomfort, annoyance, or loss in visual performance and visibility. Direct glare is caused by light sources in the field of view whereas reflected glare is caused by bright reflections from polished or glossy surfaces that are reflected toward an individual. To improve visual comfort of our living environment, a portable inspection system to estimate direct glare of various commercial LED modules with the range of color temperature from 3100 K to 5300 K was developed in this study. The system utilized HDR images to obtain the illumination distribution of LED modules and was first calibrated for brightness and chromaticity and corrected with flat field, dark-corner and curvature by the installed algorithm. The index of direct glare was then automatically estimated after image capturing, and the operator can recognize the performance of LED modules and the possible effects on human being once the index was out of expecting range. In the future, we expect that the quick-response smart inspection system can be applied in several new fields and market, such as home energy diagnostics, environmental lighting and UGR monitoring and popularize it in several new fields.

  3. A high efficiency LED portable desk lamp based on V-groove cells LGP

    NASA Astrophysics Data System (ADS)

    Chen, Chi-Feng; Kuo, Shin-Hong

    2014-11-01

    The research studies a new LED portable desk lamp with V-groove cells light guide plate (LGP). Such LGP enables light of edge LED to be transmitted from the LGP with high efficiency and uniformity to enter a lighting area. Here, the so called V-groove cell is a unit composed of multiple V-grooves we provided, which may regulate light effectively with appropriate design to implement the design goal of lighting. We analyze the impact of V-grooves parameters on LGP, and further, use portable DL as an example to search for suitable V-groove units, and acquire successfully a set of LGP with high efficiency, high illuminance uniformity, and low direct glare. Compared to the commercially available DL, the efficiency is increased by 1.4 times, and the illuminance distribution of target area is similar. Obviously, such microstructure unit composed of multiple V-groove microstructure (VGM) cells can implement design goal of LED portable DL with high efficiency.

  4. High-speed phosphor-LED wireless communication system utilizing no blue filter

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Chow, C. W.; Chen, H. Y.; Chen, J.; Liu, Y. L.; Wu, Y. F.

    2014-09-01

    In this paper, we propose and investigate an adaptively 84.44 to 190 Mb/s phosphor-LED visible light communication (VLC) system at a practical transmission distance. Here, we utilize the orthogonal-frequency-division-multiplexing quadrature-amplitude-modulation (OFDM-QAM) modulation with power/bit-loading algorithm in proposed VLC system. In the experiment, the optimal analogy pre-equalization design is also performed at LED-Tx side and no blue filter is used at the Rx side for extending the modulation bandwidth from 1 MHz to 30 MHz. In addition, the corresponding free space transmission lengths are between 75 cm and 2 m under various data rates of proposed VLC. And the measured bit error rates (BERs) of < 3.8×10-3 [forward error correction (FEC) limit] at different transmission lengths and measured data rates can be also obtained. Finally, we believe that our proposed scheme could be another alternative VLC implementation in practical distance, supporting < 100 Mb/s, using commercially available LED and PD (without optical blue filtering) and compact size.

  5. Comparison between peer-led and teacher-led education in tuberculosis prevention in rural middle schools in Chongqing, China.

    PubMed

    Liu, Qin; Liu, Liping; Vu, Huyen; Liu, Xiaoxue; Tang, Shenglan; Wang, Hong

    2015-03-01

    The aim of this study was to investigate the efficacy of tuberculosis (TB) education through a comparison of peer-led and teacher-led methods of education about TB prevention among middle school students in rural Chongqing, China. A preintervention and postintervention questionnaire survey was conducted in 2 different middle school student groups to measure changes in knowledge, attitude, and practice (KAP) status of those students before and after each TB education program. Of 1265 students participating in the preintervention survey, 1176 completed the postintervention survey. KAP scores of both peer-led and teacher-led groups after intervention improved by as much as 2 times compared with before the intervention and those of the control group (P < .01). KAP scores of immediate evaluation were higher than those of long-term evaluation in the teacher-led education group (P < .01). The teacher-led group had a larger improvement than the peer-led group in practice scores (P < .01) in immediate effect evaluation.

  6. Inverse design of LED arrangement for visible light communication systems

    NASA Astrophysics Data System (ADS)

    Zheng, Huanhuan; Chen, Jian; Yu, Changyuan; Gurusamy, Mohan

    2017-01-01

    In this paper, an optimal LED arrangement for indoor visible light communications (VLC) is proposed and numerically investigated. By using the concept of inverse design, the LED distribution can be formulated as a convex optimization problem and resolved accordingly. We show that sufficient brightness and uniform signal to noise ratio (SNR) can be achieved within the indoor coverage by using the proposed optimal LED arrangement, thus enabling the terminal mobility for indoor VLC. In addition, the analysis of delay spread distribution over the receiving plane shows that the design exhibits enhanced tolerance of inter-symbol interference (ISI). With the consideration of cabling cost for practical implementation, the suboptimal LED arrangement design is also investigated. Numerical results indicate that the suboptimal design can reduce the power consumption of the system with acceptable performance degradation.

  7. LED lamp incorporating remote phosphor with heat dissipation features

    DOEpatents

    Tong, Tao; Letoquin, Ronan; Keller, Bernd; Tarsa, Eric

    2016-11-22

    An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and a remote planar phosphor carrier having at least one conversion material. The phosphor carrier can be remote to the light sources and mounted to the heat sink so that heat from the phosphor carrier spreads into the heat sink. The phosphor carrier can comprise a thermally conductive transparent material and a phosphor layer, with an LED based light source mounted to the heat sink such that light from the light source passes through the phosphor carrier. At least some of the LED light is converted by the phosphor carrier, with some lamp embodiments emitting a white light combination of LED and phosphor light. The phosphor arranged according to the present invention can operate at lower temperature to thereby operate at greater phosphor conversion efficiency and with reduced heat related damage to the phosphor.

  8. On the spectral quality of scanner illumination with LEDs

    NASA Astrophysics Data System (ADS)

    Cui, Chengwu

    2013-01-01

    Document scanner illumination has evolved along with general illumination technologies. LEDs have become more and more popular as the illumination sources for document scanning. LED technologies provide a wide range of choices both in terms of structural design and spectral compositions. In this report, we examine some popular LED technologies used for document scanner. We evaluate the color rendering performance of scanner models with different illumination technologies by examining their rendering of the Macbeth ColorChecker™ in sRGB. We found that more phosphors in phosphor conversion types of white LEDs may not be necessarily advantageous in terms of scanner color rendering performance. Also CIS type of scanner may be sensitive to the peak wavelength shift and can be particularly problematic when the peaks are out of certain range.

  9. National Consortium Supports Cities in Evaluating LED Streetlights

    SciTech Connect

    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.

  10. Adaptive filtering for white-light LED visible light communication

    NASA Astrophysics Data System (ADS)

    Hsu, Chin-Wei; Chen, Guan-Hong; Wei, Liang-Yu; Chow, Chi-Wai; Lu, I.-Cheng; Liu, Yen-Liang; Chen, Hsing-Yu; Yeh, Chien-Hung; Liu, Yang

    2017-01-01

    White-light phosphor-based light-emitting diode (LED) can be used to provide lighting and visible light communication (VLC) simultaneously. However, the long relaxation time of phosphor can reduce the modulation bandwidth and limit the VLC data rate. Recent VLC works focus on improving the LED modulation bandwidths. Here, we propose and demonstrate the use of adaptive Volterra filtering (AVF) to increase the data rate of a white-light LED VLC system. The detailed algorithm and implementation of the AVF for the VLC system have been discussed. Using our proposed electrical frontend circuit and the proposed AVF, a significant data rate enhancement to 700.68 Mbit/s is achieved after 1-m free-space transmission using a single white-light phosphor-based LED.

  11. Design and performance of nitride-based ultraviolet (UV) LEDs

    SciTech Connect

    CRAWFORD,MARY H.; HAN,JUNG

    2000-04-24

    The authors overview several of the challenges in achieving high efficiency nitride-based UV (< 400 nm) LEDs. The issue of optical efficiency is presented through temperature-dependent photoluminescence studies of various UV active regions. These studies demonstrate enhanced optical efficiencies for active regions with In-containing alloys (InGaN, AlInGaN). The authors compare the performance of two distinct UV LED structures. GaN/AlGaN quantum well LEDs with {lambda} < 360 nm emission have demonstrated output powers > 0.1 mW, but present designs suffer from internal absorption effects. InGaN/AlInGaN quantum well LEDs with 370 nm < {lambda} < 390 nm emission and > 1 mW output power are also presented.

  12. Influence of the LED heterostructure on the degradation behavior of (InAlGa)N-based UV-B LEDs

    NASA Astrophysics Data System (ADS)

    Glaab, Johannes; Lobo Ploch, Neysha; Rass, Jens; Kolbe, Tim; Wernicke, Tim; Mehnke, Frank; Kuhn, Christian; Enslin, Johannes; Stölmacker, Christoph; Kueller, Viola; Knauer, Arne; Einfeldt, Sven; Weyers, Markus; Kneissl, Michael

    2016-02-01

    In this paper we report on the influence of the heterostructure design of (InAlGa)N-based UV-B LEDs grown by metalorganic vapor phase epitaxy on sapphire substrates on the degradation behavior of the device. Two types of LEDs with different heterostructure design, resulting in peak-wavelengths of about 290 nm and 310 nm, respectively, were stressed at a constant operation current of 100 mA and a heat sink temperature of 20°C. Electro-optical characterization of the LEDs over 1.000 h of operation shows two different degradation modes with respect to the change of the emission spectrum and leakage current. The first mode during the initial hours (290 nm LED: 0 h - 500 h, 310 nm LED: 0 h - 100 h) of operation is represented by a fast reduction of the quantum well (QW) luminescence, a constant or increasing parasitic luminescence between 310 nm and 450 nm and a fast increase of the reverse- and forward-bias leakage current. These changes are more pronounced (higher degradation rate) in the 290 nm LEDs and can therefore be attributed to the different heterostructure design. In contrast, the second degradation mode at longer operation times (290 nm LED: >500 h, 310 nm LED: >100 h) is marked by a slow reduction of both the QW and the parasitic luminescence, as well as a slow increase of the leakage current which are similar for both types of LEDs. Furthermore, the second mode is marked by a square-root time dependence of the QW luminescence intensity, indicating a diffusion process to be involved.

  13. LED Unit of Compact, High Power and Long Lifetime

    NASA Astrophysics Data System (ADS)

    Sugimoto, Masaru; Urano, Yoji; Kuzuhara, Ikko; Hayashi, Takao; Masui, Mikiko; Tanaka, Ken-Ichi

    The encapsulation optical component shaped in an elliptical dome over the LED chip and the mixing of multiple types of fluorescent materials in an appropriate ratio improves colour rendering properties and distribution controllability while suppressing colour variation. The developed technologies can be applied to produce an LED luminaire that resembles a compact ceiling-light but can be used as a downlight with the light intensity equivalent to a 60W incandescent lamp and light quality comparable to a fluorescent lamp.

  14. Integrated LED-based luminaire for general lighting

    SciTech Connect

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

    2016-08-30

    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. Integrated LED-based luminare for general lighting

    DOEpatents

    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.

  16. Biological Research in Canisters (BRIC) - Light Emitting Diode (LED)

    NASA Technical Reports Server (NTRS)

    Levine, Howard G.; Caron, Allison

    2016-01-01

    The Biological Research in Canisters - LED (BRIC-LED) is a biological research system that is being designed to complement the capabilities of the existing BRIC-Petri Dish Fixation Unit (PDFU) for the Space Life and Physical Sciences (SLPS) Program. A diverse range of organisms can be supported, including plant seedlings, callus cultures, Caenorhabditis elegans, microbes, and others. In the event of a launch scrub, the entire assembly can be replaced with an identical back-up unit containing freshly loaded specimens.

  17. (abstract) Space Science with Commercial Funding

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The world-wide recession, and other factors, have led to reduced or flat budgets in real terms for space agencies around the world. Consequently space science projects and proposals have been under pressure and seemingly will continue to be pressured for some years into the future. A new concept for space science funding is underway at JPL. A partnership has been arranged with a commercial, for-profit, company that proposes to implement a (bandwidth-on-demand) information and telephone system through a network of low earth orbiting satellites (LEO). This network will consist of almost 1000 satellites operating in polar orbit at Ka-band. JPL has negotiated an agreement with this company that each satellite will also carry one or more science instruments for astrophysics, astronomy, and for earth observations. This paper discussed the details of the arrangement and the financial arrangements. It describes the technical parameters, such as the 60 GHz wideband inter-satellite links and the frequency, time, and position control, on which the science is based, and it also discusses the complementarity of this commercially funded space science with conventional space science.

  18. COMMERCIAL SURROGACY: WHAT ROLE FOR LAW IN AUSTRALIA?

    PubMed

    Sifris, Ronli; Ludlow, Karinne; Sifris, Adiva

    2015-12-01

    This editorial begins by illuminating current conversations regarding the regulation of commercial surrogacy in Australia. It defines "commercial surrogacy" and explains the interaction between changes in social attitudes and changes to the law before setting out the current Australian law and practice in this area. An examination of current domestic law and practice reveals that surrogacy legislation in Australia is mired in inconsistencies and a lack of uniformity but that the one key common element is the prohibition of commercial surrogacy. The inability of couples to access commercial surrogacy within Australia has led to offshore reproductive tourism and unpredictable, contradictory decision-making as the Family Court attempts to apply legislation which was never intended to apply in this context. The editorial then turns to consider the international arena, discussing the approach of the Hague Conference on Private International Law before delving into a human rights analysis of commercial surrogacy arrangements. The adoption of a rights-based approach requires an analysis of this vexed issue from the perspective of the child, surrogate and intending parents. While questions surrounding the human rights implications of legalising commercial surrogacy continue to be the subject of passionate debate, the authors believe that the human rights of all parties are best protected through appropriate regulation rather than absolute prohibition.

  19. 150 Passenger Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Bucovsky, Adrian; Romli, Fairuz I.; Rupp, Jessica

    2002-01-01

    It has been projected that the need for a short-range mid-sized, aircraft is increasing. The future strategy to decrease long-haul flights will increase the demand for short-haul flights. Since passengers prefer to meet their destinations quickly, airlines will increase the frequency of flights, which will reduce the passenger load on the aircraft. If a point-to-point flight is not possible, passengers will prefer only a one-stop short connecting flight to their final destination. A 150-passenger aircraft is an ideal vehicle for these situations. It is mid-sized aircraft and has a range of 3000 nautical miles. This type of aircraft would market U.S. domestic flights or inter-European flight routes. The objective of the design of the 150-passenger aircraft is to minimize fuel consumption. The configuration of the aircraft must be optimized. This aircraft must meet CO2 and NOx emissions standards with minimal acquisition price and operating costs. This report contains all the work that has been performed for the completion of the design of a 150 passenger commercial aircraft. The methodology used is the Technology Identification, Evaluation, and Selection (TIES) developed at Georgia Tech Aerospace Systems Design laboratory (ASDL). This is an eight-step conceptual design process to evaluate the probability of meeting the design constraints. This methodology also allows for the evaluation of new technologies to be implemented into the design. The TIES process begins with defining the problem with a need established and a market targeted. With the customer requirements set and the target values established, a baseline concept is created. Next, the design space is explored to determine the feasibility and viability of the baseline aircraft configuration. If the design is neither feasible nor viable, new technologies can be implemented to open up the feasible design space and allow for a plausible solution. After the new technologies are identified, they must be evaluated

  20. Commercial researcher perspective

    NASA Technical Reports Server (NTRS)

    Delucas, Larry

    1992-01-01

    Protein crystallography--a research tool used to study the structure of the complex building blocks of living systems--has a lot to gain from space-based research. In order to know how a protein works in the human body, researchers must understand its molecular structure. Researchers have identified 150,000 different proteins in the body, but they now know the structure of less than a third of them. The only viable technique for analyzing the structure of these proteins is x-ray diffraction of the proteins in their crystal form. The better the quality of a protein crystal, the more useful it is to researchers who are trying to delineate its structure. The microgravity environment of space allows protein crystals to grow nearly undisturbed by convection and other gravity-driven forces that cause flaws to form in them on the ground. In space, lack of convection enables protein crystals to grow more slowly than they do on Earth, and the slower a protein crystal grows, the fewer flaws it will have. Protein crystal growth experiments have already flown on 14 Space Shuttle missions. This year's USML-1 Spacelab mission included protein crystal growth experiments conducted for commercial researchers. The results of protein crystal experiments flown thus far have been larger crystals with more uniform morphologies. The Center for Macromolecular Crystallography (A NASA-cosponsored CCDS) currently builds flight hardware to meet researchers' needs and handles sample loading and retrieval for flight experiments. Protein crystallography enables 'rational drug design': the development of drugs that bind only with the target protein and, hence, do not cause side effects. For example, pharmaceutical companies presently are interested in developing drugs that can inhibit purine nucleoside phosphorylase (PNP), a protein that plays a role in auto-immune diseases. To continue these kinds of investigations, researchers need a constant supply of protein crystals that are as free of flaws

  1. Commercial researcher perspective

    NASA Astrophysics Data System (ADS)

    Delucas, Larry

    Protein crystallography--a research tool used to study the structure of the complex building blocks of living systems--has a lot to gain from space-based research. In order to know how a protein works in the human body, researchers must understand its molecular structure. Researchers have identified 150,000 different proteins in the body, but they now know the structure of less than a third of them. The only viable technique for analyzing the structure of these proteins is x-ray diffraction of the proteins in their crystal form. The better the quality of a protein crystal, the more useful it is to researchers who are trying to delineate its structure. The microgravity environment of space allows protein crystals to grow nearly undisturbed by convection and other gravity-driven forces that cause flaws to form in them on the ground. In space, lack of convection enables protein crystals to grow more slowly than they do on Earth, and the slower a protein crystal grows, the fewer flaws it will have. Protein crystal growth experiments have already flown on 14 Space Shuttle missions. This year's USML-1 Spacelab mission included protein crystal growth experiments conducted for commercial researchers. The results of protein crystal experiments flown thus far have been larger crystals with more uniform morphologies. The Center for Macromolecular Crystallography (A NASA-cosponsored CCDS) currently builds flight hardware to meet researchers' needs and handles sample loading and retrieval for flight experiments. Protein crystallography enables 'rational drug design': the development of drugs that bind only with the target protein and, hence, do not cause side effects. For example, pharmaceutical companies presently are interested in developing drugs that can inhibit purine nucleoside phosphorylase (PNP), a protein that plays a role in auto-immune diseases. To continue these kinds of investigations, researchers need a constant supply of protein crystals that are as free of flaws

  2. Teaching Commercial German Through Advertisements.

    ERIC Educational Resources Information Center

    Heyer, Elfriede A.

    Advertisements can be used in many ways to facilitate the teaching of a commercial language. If reproduced as slides or other visual aids, they serve as a visual warm-up exercise for each class period, either reinforcing previously discussed topics or introducing new ones. Catchy headlines in commercials promote rapid expansion of vocabulary and…

  3. Space Station commercial user development

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The commercial utilization of the space station is investigated. The interest of nonaerospace firms in the use of the space station is determined. The user requirements are compared to the space station's capabilities and a feasibility analysis of a commercial firm acting as an intermediary between NASA and the private sector to reduce costs is presented.

  4. In vitro antimicrobial activity of LED irradiation on Pseudomonas aeruginosa.

    PubMed

    Petrini, Morena; Trentini, Paolo; Tripodi, Domenico; Spoto, Giuseppe; D'Ercole, Simonetta

    2017-03-01

    Pseudomonas aeruginosa is an opportunistic pathogen responsible of many deaths due to nosocomial pneumonia each year. It is particularly resistant to many different classes of antibiotics and disinfectants. For all these reasons, there is the necessity to find novel approaches of treatment. The aim of this study was to evaluate the effect of 880nm light emitting diodes (LED) irradiation on P. aeruginosa, in vitro. Different LED irradiation parameters (time, energy output and the addition of methylene blue and chlorhexidine) have been tested in order to evaluate the effects on this bacterium. After treatment, the colony forming units per milliliter (CFU mL-1) were recorded and the data were submitted to ANOVA and Bonferroni post hoc tests at a level of significance of 5%. A statistical significant reduction of bacterial count has been registered after 5min of LED irradiation. The antibacterial effect was directly proportional to irradiation time and the output energy. The pre-treatment with methylene blue, seems to be not effective against P. aeruginosa, independently from irradiation parameters. On the contrary, the contemporary action of LED and chlorhexidine has shown a great reduction of bacterial count that was statistical significant respect chlorhexidine and LED alone. The effect of LED irradiation was visible also after 24h, when a lower bacterial count characterized all irradiated samples respect controls.

  5. Infrared imaging of LED lighting tubes and fluorescent tubes

    NASA Astrophysics Data System (ADS)

    Siikanen, Sami; Kivi, Sini; Kauppinen, Timo; Juuti, Mikko

    2011-05-01

    The low energy efficiency of conventional light sources is mainly caused by generation of waste heat. We used infrared (IR) imaging in order to monitor the heating of both LED tube luminaires and ordinary T8 fluorescent tubes. The IR images showed clearly how the surface temperatures of the fluorescent tube ends quickly rose up to about +50...+70°C, whereas the highest surface temperatures seen on the LED tubes were only about +30...+40°C. The IR images demonstrated how the heat produced by the individual LED chips can be efficiently guided to the supporting structure in order to keep the LED emitters cool and hence maintain efficient operation. The consumed electrical power and produced illuminance were also recorded during 24 hour measurements. In order to assess the total luminous efficacy of the luminaires, separate luminous flux measurements were made in a large integrating sphere. The currently available LED tubes showed efficacies of up to 88 lm/W, whereas a standard "cool white" T8 fluorescent tube produced ca. 75 lm/W. Both lamp types gave ca. 110 - 130 lx right below the ceiling-mounted luminaire, but the LED tubes consume only 40 - 55% of the electric power compared to fluorescent tubes.

  6. Intensity estimation method of LED array for visible light communication

    NASA Astrophysics Data System (ADS)

    Ito, Takanori; Yendo, Tomohiro; Arai, Shintaro; Yamazato, Takaya; Okada, Hiraku; Fujii, Toshiaki

    2013-03-01

    This paper focuses on a road-to-vehicle visible light communication (VLC) system using LED traffic light as the transmitter and camera as the receiver. The traffic light is composed of a hundred of LEDs on two dimensional plain. In this system, data is sent as two dimensional brightness patterns by controlling each LED of the traffic light individually, and they are received as images by the camera. Here, there are problems that neighboring LEDs on the received image are merged due to less number of pixels in case that the receiver is distant from the transmitter, and/or due to blurring by defocus of the camera. Because of that, bit error rate (BER) increases due to recognition error of intensity of LEDs To solve the problem, we propose a method that estimates the intensity of LEDs by solving the inverse problem of communication channel characteristic from the transmitter to the receiver. The proposed method is evaluated by BER characteristics which are obtained by computer simulation and experiments. In the result, the proposed method can estimate with better accuracy than the conventional methods, especially in case that the received image is blurred a lot, and the number of pixels is small.

  7. From suborbital space tourism to commercial personal spaceflight

    NASA Astrophysics Data System (ADS)

    Peeters, Walter

    2010-06-01

    Excellent essays have been recently published on the profitability and the future of space tourism. This paper is intended to supplement the considerations in this field and emphasizes the further potential evolution of commercial personal spaceflights. Indeed, based upon work done at the International Space University (ISU) the oligopolistic character of suborbital space tourism has been linked to marketing and product life cycle (PLC) considerations and has led to the thesis that space tourism as a profitable sector will require a follow-on strategy. Orbital space tourism, on one hand, could become an extension of the PLC but, on the other hand, it is assumed that point-to-point (P2P) commercial space transport will become the long term sustainable market. Without ignoring technical challenges, this paper will mainly concentrate on marketing and commercial aspects of personal spaceflight.

  8. Commercial Optics for Space Surveillance and Astronomy

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Kopit, E.; McGraw, J.; Zimmer, P.

    Since the first days of the space program, there have been both amateur and government satellite watchers. Large, expensive government systems with custom optics are still the most capable, but with modern sensors and high speed computers, amateur trackers are easily pushing the limits of what government systems achieved only a decade ago. A very recent trend in the space world is the emergence of commercial space operations centers. Once the exclusive purview of governments, corporations are now providing orbital environment awareness services to the operators of commercial satellites. The requirement for synoptic satellite observations has led to corporations developing world-wide observing networks. A problem facing both amateur and corporate observers is the limited availability of suitable optical systems. Most observing efforts rely on long focus (f/8 or greater) optical systems with focal reducers, and a somewhat limited field of view. Often, the cameras in use are not ideally matched to the optical system. While there are a few exceptions, the choices are not many. Celestron recently introduced the C-11 RASA optical system, with an 11-inch aperture and an f/2.2 focal ratio. This optical system is designed for dedicated imaging and is ideally suited for both wide-field astronomy and the detection and tracking of satellites. The larger C-14 RASA, to be introduced later this year, was specifically designed for wide-field imaging with large commercial CCDs. It offers greater sensitivity and a wider field of view than the smaller C-11 RASA and should prove to be the instrument of choice for both amateur and corporate satellite observers. We present data from satellite observations with a production model C-11 RASA and estimated performance for the new C-14 RASA.

  9. Measuring the cost-effectiveness of midwife-led versus physician-led intrapartum teams in developing countries.

    PubMed

    Friedman, Howard S; Liang, Mengjia; Banks, Jamie L

    2015-07-01

    International agencies have advocated scaling-up of midwifery resources as an important method for improving maternal health and reducing maternal mortality rates (MMR). The cost-effectiveness of midwife-led versus physician-led intrapartum care is an important consideration in the human resource planning required to reduce MMR. Studies suggest that midwife-led teams can achieve comparable effectiveness and outcomes using less medically intensive care compared with physician-led teams. In the absence of adequate medical cost data, decision makers should consider the substantially lower average costs for three main drivers: salaries, benefits and incentives (≥two-times lower); preservice training (three-times lower) and attrition (two-times lower) necessary to deliver intrapartum care at the level of midwife competencies. This suggests that scale-up of midwifery resources is a less expensive and more cost-effective way to reduce MMRs and could potentially increase access to skilled intrapartum care.

  10. In vitro inactivation of Enterococcus faecalis with a led device.

    PubMed

    D'Ercole, S; Spoto, G; Trentini, P; Tripodi, D; Petrini, M

    2016-07-01

    Non-coherent light-emitting diodes (LEDs) are effective in a large variety of clinical indications; however, the bactericidal activity of LEDs is unclear, although the effectiveness of such lights is well known. Currently, no studies have examined the effects of NIR-LED on bacteria. The aims of this study were to verify the antibacterial activity of 880-nm LED irradiation on a bacterial suspension of Enterococcus faecalis and to compare it with the actions of sodium hypochlorite (NaOCl) and the concurrent use of both treatments. Before we proceeded with the main experiment, we first performed preliminary tests to evaluate the influence of such parameters as the distance of irradiation, the energy density, the irradiation time and the presence of photosensitizers on the antimicrobial effects of LEDs. After treatment, the colony forming units per milliliter (CFU/mL) was recorded and the data were submitted to ANOVA and Bonferroni post hoc tests at a level of significance of 5%. The results showed that LED irradiation, at the parameters used, is able to significantly decrease E. faecalis viability in vitro. The total inhibition of E. faecalis was obtained throughout concurrent treatment of LED and NaOCl (1%) for 5min. The same antimicrobial activity was confirmed in all of the experiments (p<0.05), but no statistically significant differences were found by varying such parameters as the distance of irradiation (from 0.5mm to 10mm), energy density (from 2.37 to 8.15mJ/s), irradiation time (from 5min to 20min) or by adding toluidine blue O (TBO).

  11. The value, solutions, and costs of patterning LED's

    NASA Astrophysics Data System (ADS)

    Watts, Michael P. C.; Zoorob, M.; Lee, T.; McKenzie, J.

    2007-02-01

    The literature on high brightness LED's shows that patterning the top surface of LED's with photonic crystals is being used to create the most intense LED light sources. The best example is that you can now buy projection displays that are illuminated by LED's with Photonic Crystals. The experimental and model data, reviewed in this article, shows that patterning delivers value through improved beam shaping and light extraction using carefully optimized photonic crystals. The data also suggests that in the future, patterning in combination with sub micron device layers and strategically placed mirrors can produce extraction efficiencies of greater than 80%. In addition, patterning can improve current spreading and reduce epitaxy defects. The long term goal is to develop a LED that can be used with minimal additional packaging to focus the light or extract heat. The solution to low cost patterning for Photonic Crystals 100 nm features is to use imprint. The imprint patterning process is implemented in a module that consists of a clean and coat tool, an imprint tool and an etch tool. Cleaning is essential because imprint is a contact technology and particles will lead to process defects and mold damage. There are 2 companies that are developing production tools for LED applications; Molecular Imprints (MII) and Obducat. There are 2 companies that are supporting research tools, and expect to develop production systems in response to customer order, EV Group and Nanonex. The principal difference between imprint suppliers are the different strategies used to conform the mold to the substrate, and the state of system development. To date MII has published the most complete process performance data on an automated production tool. The cost of patterning is less than 0.5 cent per device. First the value of increased LED output will be described, followed by a discussion of the different patterning solutions for improving output, then the different solutions for creating

  12. Progress toward achieving high power and high efficiency semipolar LEDs and their characterization

    NASA Astrophysics Data System (ADS)

    Zhong, Hong

    Performance of current commercially available wurtzite nitride based light-emitting diodes (LEDs), grown along the polar (0001) c-plane orientation, is limited by the presence of polarization-related electric fields inside multi-quantum wells (MQWs). The discontinuities in both spontaneous and piezoelectric polarization at the heterointerfaces result in internal electric fields in the quantum wells. These electric fields cause carrier separation [quantum confined Stark effect (QCSE)] and reduce the radiative recombination rate within the quantum wells. One approach to reduce and possibly eliminate the polarization-related effects is to grow III-nitride devices on crystal planes that are inclined with respect to the c-axis, i.e., on semipolar planes. In this dissertation, metalorganic chemical vapor deposition (MOCVD) has been employed for the homoepitaxial growth of GaN based LEDs on semipolar orientations. As a consequence of growing on high-quality bulk GaN substrates, the LEDs have significantly reduced threading dislocation and stacking fault densities, resulting in remarkable improvements in EQE and output power. High efficiency semipolar (1011) violet-blue and blue LEDs have been demonstrated without any intentional effort to enhance the light extraction from those devices. Optimizations of epitaxial structures have led to increased output power and external quantum efficiency. A silicone encapsulated single quantum well blue LED with peak wavelength of 444 nm with output power of 24.3 mW, external quantum efficiency of 43% and luminous efficacy of 75 lm/W (with phosphorescent coating) at 20 mA has been demonstrated. Polarization fields in strained (1011) and (112¯2) InGaN quantum wells have been experimentally determined through bias-dependent optical studies. Our results show that the polarization field flips its direction in semipolar InGaN quantum wells with large inclination angles (i.e. around 60°). This suggests that there exists a polarization

  13. Campylobacter jejuni in commercial eggs

    PubMed Central

    Fonseca, Belchiolina Beatriz; Beletti, Marcelo Emílio; de Melo, Roberta Torres; Mendonça, Eliane Pereira; Coelho, Letícia Ríspoli; Nalevaiko, Priscila Christen; Rossi, Daise Aparecida

    2014-01-01

    This study evaluated the ability of Campylobacter jejuni to penetrate through the pores of the shells of commercial eggs and colonize the interior of these eggs, which may become a risk factor for human infection. Furthermore, this study assessed the survival and viability of the bacteria in commercial eggs. The eggs were placed in contact with wood shavings infected with C. jejuni to check the passage of the bacteria. In parallel, the bacteria were inoculated directly into the air chamber to assess the viability in the egg yolk. To determine whether the albumen and egg fertility interferes with the entry and survival of bacteria, we used varying concentrations of albumen and SPF and commercial eggs. C. jejuni was recovered in SPF eggs (fertile) after three hours in contact with contaminated wood shavings but not in infertile commercial eggs. The colonies isolated in the SPF eggs were identified by multiplex PCR and the similarity between strains verified by RAPD-PCR. The bacteria grew in different concentrations of albumen in commercial and SPF eggs. We did not find C. jejuni in commercial eggs inoculated directly into the air chamber, but the bacteria were viable during all periods tested in the wood shavings. This study shows that consumption of commercial eggs infected with C. jejuni does not represent a potential risk to human health. PMID:24948916

  14. Demonstration of 575-Mb/s downlink and 225-Mb/s uplink bi-directional SCM-WDM visible light communication using RGB LED and phosphor-based LED.

    PubMed

    Wang, Yuanquan; Wang, Yiguang; Chi, Nan; Yu, Jianjun; Shang, Huiliang

    2013-01-14

    We propose and experimentally demonstrate a novel full-duplex bi-directional subcarrier multiplexing (SCM)-wavelength division multiplexing (WDM) visible light communication (VLC) system based on commercially available red-green-blue (RGB) light emitting diode (LED) and phosphor-based LED (P-LED) with 575-Mb/s downstream and 225-Mb/s upstream transmission, employing various modulation orders of quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM). For the downlink, red and green colors/wavelengths are assigned to carry useful information, while blue chip is just kept lighting to maintain the white color illumination, and for the uplink, the low-cost P-LED is implemented. In this demonstration, pre-equalization and post-equalization are also adopted to compensate the severe frequency response of LEDs. Using this scheme, 4-user downlink and 1-user uplink transmission can be achieved. Furthermore, it can support more users by adjusting the bandwidth of each sub-channel. Bit error rates (BERs) of all links are below pre-forward-error-correction (pre-FEC) threshold of 3.8x 10(-3) after 66-cm free-space delivery. The results show that this scheme has great potential in the practical VLC system.

  15. LED-based endoscopic light source for spectral imaging

    NASA Astrophysics Data System (ADS)

    Browning, Craig M.; Mayes, Samuel; Favreau, Peter; Rich, Thomas C.; Leavesley, Silas J.

    2016-03-01

    Colorectal cancer is the United States 3rd leading cancer in death rates.1 The current screening for colorectal cancer is an endoscopic procedure using white light endoscopy (WLE). There are multiple new methods testing to replace WLE, for example narrow band imaging and autofluorescence imaging.2 However, these methods do not meet the need for a higher specificity or sensitivity. The goal for this project is to modify the presently used endoscope light source to house 16 narrow wavelength LEDs for spectral imaging in real time while increasing sensitivity and specificity. The process to do such was to take an Olympus CLK-4 light source, replace the light and electronics with 16 LEDs and new circuitry. This allows control of the power and intensity of the LEDs. This required a larger enclosure to house a bracket system for the solid light guide (lightpipe), three new circuit boards, a power source and National Instruments hardware/software for computer control. The results were a successfully designed retrofit with all the new features. The LED testing resulted in the ability to control each wavelength's intensity. The measured intensity over the voltage range will provide the information needed to couple the camera for imaging. Overall the project was successful; the modifications to the light source added the controllable LEDs. This brings the research one step closer to the main goal of spectral imaging for early detection of colorectal cancer. Future goals will be to connect the camera and test the imaging process.

  16. Thermal simulation of flexible LED package enhanced with copper pillars

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Leung, Stanley Y. Y.; Wong, Cell K. Y.; Yuan, Cadmus A.; Guoqi, Zhang; Fenglian, Sun

    2015-06-01

    Chip on flexible substrate (COF) is a new packaging technology for light emitting diodes (LED). This paper investigated the effect of Cu-pillar in the polyimide (PI) layer on the thermal properties of COF LED packages by finite element analysis. The thermal distribution and thermal resistance were studied in both COF LED packages with and without Cu-pillar. The PI layer showed the highest thermal resistance in the typical package and led to a high chip temperature. With the addition of Cu-pillars, however, the thermal resistance of the PI layer significantly decreased due to the improvement of vertical thermal dissipation under LED chips. Based on the results of simulation and calculation, the relationship between the amount of Cu-pillar and thermal resistance of the COF package has been built. For the packages studied in this research, an 8 × 8 Cu-pillars array was adequate to improve the thermal performance of COF packages. Project supported by the Research and Scientific Foundation of Heilongjiang Education Department (No. 12541112).

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

    SciTech Connect

    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.

  18. LED Monitoring System of the Phenix Muon Piston Calorimeter

    NASA Astrophysics Data System (ADS)

    Motschwiller, Steven

    2010-11-01

    The Muon Piston Calorimeter in the PHENIX experiment at RHIC has a monitoring system consisting of LEDs and PIN diodes to calibrate out the time dependent changes to the detector. The LEDs track the temperature and radiation-damage changes to the response of the MPC, while the absolute calibration can be done using 0̂ decays. To execute this, LEDs flash light through the PbWO4 crystal to the Avalanche Photo Diodes The MPC is made up of 416 independent electromagnetic calorimeter towers. By using the LEDs we can correct for changes in the gains of each tower in the MPC, on a run by run basis. Because the LED value only gives a relative measurement of the gain over time, this method of calibration can only be used in conjunction with absolute calibrations provided by 0̂ decays or by minimum ionizing peaks . This work will be used to make a final measurement on Transverse energy at √sNN = 200 GV in Au+Au collisions.

  19. Highly Efficient Small Form Factor LED Retrofit Lamp

    SciTech Connect

    Steven Allen; Fred Palmer; Ming Li

    2011-09-11

    This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.

  20. Recent results and latest views on microcavity LEDs

    NASA Astrophysics Data System (ADS)

    Weisbuch, Claude; David, Aurelien; Fujii, Tetsuo; Schwach, C.; DenBaars, Steven P.; Nakamura, Shuji; Rattier, M.; Benisty, Henri; Houdré, Romuald; Stanley, R.; Carlin, Jean-Francois; Krauss, Thomas F.; Smith, Christopher J. M.

    2004-06-01

    We are progressively approaching the physical limits of microcavity LEDs (MC-LEDs) for high brightness, high efficiency LEDs. They are promising high efficiency devices and they offer the very attractive prospect of full planar fabrication process. However, to compete with other high efficiency LED schemes, they need to approach or surpass the 50 % efficiency mark. We first explore the limits of planar MC-LEDs in both the GaAlInAsP and GaInAlN materials systems, and show that the single-step extraction limit is in the 40 % range at best, depending on the materials system used, with the largest part of the non-extracted light being emitted into guided modes. The waveguided light can itself be extracted by photon recycling, when the internal quantum efficiency is high. Otherwise, another extraction scheme for that light is provided by various photonic-crystal-assisted extraction schemes. Simple photonic crystals (PCs) appear to lack the omnidirectional extraction properties required. However, more rotation-invariant PCs like Archimedean tilings allow to obtain such extraction with added efficiencies already in the 10% range. We discuss the further improvements to such structures.

  1. Novel LED array used for photodynamic therapy (PDT)

    NASA Astrophysics Data System (ADS)

    Daly, Steven R.; Zheng, Frank; Krouse, Mike; Guo, Zihong; Mahoney, Paula; McIlroy, Brian W.

    2003-07-01

    Light Sciences Corporation has developed a novel LED array that was designed and manufactured to treat large bulky tumors. We describe our LED design process, culminating in the manufacture of a flexible silicone catheter currently under investigation in a Phase 1 clinical trial. The performance characteristics of the wire-bonded die to a flexible polyimide substrate forming a linear array are discussed. The LED array consists of 100 die arranged asymmetrically on the substrate with 50 LED's on either side producing up to 60mW total optical power at 38°C (500mA) over a spectral bandwidth 645-670nm FWHM. The LED's are encapsulated within biocompatible silicon for interstitial placement within the treatment tissue. The effect of time, temperature and humidity on the device performance was investigated. Optical power ranged from -2.5% to +0.5% of the normalized original power over 50 hours in 100% RH within the control group. Over a temperature range of 35°C to 50°C the optical power decreased at a rate of 0.56% per °C. Preliminary non-clinical experiments carried out in normal swine muscle demonstrate a significant treatment zone and are consistent with threshold models for photodynamic effect.

  2. Aerial LED signage by use of crossed-mirror array

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hirotsugu; Kujime, Ryousuke; Bando, Hiroki; Suyama, Shiro

    2013-03-01

    3D representation of digital signage improves its significance and rapid notification of important points. Real 3D display techniques such as volumetric 3D displays are effective for use of 3D for public signs because it provides not only binocular disparity but also motion parallax and other cues, which will give 3D impression even people with abnormal binocular vision. Our goal is to realize aerial 3D LED signs. We have specially designed and fabricated a reflective optical device to form an aerial image of LEDs with a wide field angle. The developed reflective optical device composed of crossed-mirror array (CMA). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. The depth between LED lamps is represented in the same depth in the floating 3D image. Floating image of LEDs was formed in wide range of incident angle with a peak reflectance at 35 deg. The image size of focused beam (point spread function) agreed to the apparent aperture size.

  3. Blue laser diode (LD) and light emitting diode (LED) applications

    NASA Astrophysics Data System (ADS)

    Bergh, Arpad A.

    2004-09-01

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography.As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc.Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity.Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care.

  4. Pilot production & commercialization of LAPPD™

    NASA Astrophysics Data System (ADS)

    Minot, Michael J.; Bennis, Daniel C.; Bond, Justin L.; Craven, Christopher A.; O`Mahony, Aileen; Renaud, Joseph M.; Stochaj, Michael E.; Elam, Jeffrey W.; Mane, Anil U.; Demarteau, Marcellinus W.; Wagner, Robert G.; McPhate, Jason B.; Helmut Siegmund, Oswald; Elagin, Andrey; Frisch, Henry J.; Northrop, Richard; Wetstein, Matthew J.

    2015-07-01

    We present a progress update on plans to establish pilot production and commercialization of Large Area (400 cm2) Picosecond Photodetector (LAPPD™). Steps being taken to commercialize this MCP and LAPPD™ technology and begin tile pilot production are presented including (1) the manufacture of 203 mm×203 mm borosilicate glass capillary arrays (GCAs), (2) optimization of MCP performance and creation of an ALD coating facility to manufacture MCPs and (3) design, construction and commissioning of UHV tile integration and sealing facility to produce LAPPDs. Taken together these plans provide a "pathway toward commercialization".

  5. Evaluation of OLED and edge-lit LED lighting panels

    NASA Astrophysics Data System (ADS)

    Mou, Xi; Narendran, Nadarajah; Zhu, Yiting; Freyssinier, Jean Paul

    2016-09-01

    Solid-state lighting (SSL) offers a new technology platform for lighting designers and end-users to illuminate spaces with low energy demand. Two types of SSL sources include organic light-emitting diodes (OLEDs) and light-emitting diodes (LEDs). OLED is an area light source, and its primary competing technology is the edge-lit LED panel. Generally, both of these technologies are considered similar in shape and appearance, but there is little understanding of how people perceive discomfort glare from large area light sources. The objective of this study was to evaluate discomfort glare for the two lighting technologies under similar operating conditions by gathering observers' reactions. The human factors study results showed no statistically significant difference in human response to discomfort glare between OLED and edge-lit LED panels when the two light sources produced the same lighting stimulus. This means both technologies appeared equally glary beyond a certain luminance.

  6. Inorganic phosphors in lead-silicate glass for white LEDs

    NASA Astrophysics Data System (ADS)

    Nikonorov, N. V.; Kolobkova, E. V.; Aseev, V. A.; Bibik, A. Yu.; Nekrasova, Ya. A.; Tuzova, Yu. V.; Novogran, A. I.

    2016-09-01

    Luminescent composites of the "phosphor-in-glass" type, based on a highly reflective lead-silicate matrix and fine-grained powders of YAG:Ce3+ and SiAlON:Eu2+ crystals, are developed and synthesized. Phosphor and glass powders are sintered at a temperature of 550°C to obtain phosphor samples for white LEDs. The composites are analyzed by X-ray diffraction and luminescence spectroscopy. The dependence of the light quantum yield on the SiAlON:Eu2+ content in the samples is investigated. A breadboard of a white LED is designed using a phosphor-in-glass composite based on lead-silicate glass with a low glasstransition temperature. The total emission spectra of a blue LED and glass-based composites are measured. The possibility of generating warm white light by choosing an appropriate composition is demonstrated.

  7. LED-based digital hologram reconstruction by compressive sensing

    NASA Astrophysics Data System (ADS)

    Weng, Jiawen; Yang, Chuping; Qin, Yi; Li, Hai

    2015-10-01

    LED-based digital hologram, considered as low-coherence digital hologram, is confined to in-line holography because the interference fringes could be observed only when the angle between the object and reference wave is small enough. So, phase-shifting technique is usually employed. But it is not fit for dynamic analysis for demanding more than one hologram. A numerical reconstruction method based on compressive sensing theory for single LED-based digital hologram is proposed to achieve dynamic analysis. By this method, the out-of-focus twin image and the coherent noise can be inhibited to some extent. The theory is presented in detail, and experimental result on LED-based digital holography with USAF pattern as test target, is performed to demonstrate the feasibility and validity of the method.

  8. Dynamic analysis of sea wave data measured by LED lidar

    NASA Astrophysics Data System (ADS)

    Mori, Yasukuni; Shimada, Shohei; Shiina, Tatsuo; Baji, Hiroyuki; Takemoto, Sae

    2016-10-01

    Form of sea wave is greatly affected by not just flow and depth of sea water, but also wind blowing on the sea surface. Therefore, measurement and analysis of sea wave motion is of assistance for control and operational safety of boats and ships. Generally, oceanic information is gauged by acoustic and electric wave. But these methods have not provided enough spatial and temporal resolution, and are completely out of touch with the on-site needs. Thus, the LED liar for sea wave measurement has been developed. The dynamic analysis of sea wave image measured by the LED lidar was conducted and the relationship with wind speed was evaluated. In this report, we first present the specifications and measurement methodologies of the LED lidar. Then we describe the actual measurements of sea wave with shallow angle by using this lidar and the results of their analysis.

  9. Novel chip coating approaches to improve white LED technology

    NASA Astrophysics Data System (ADS)

    Hartmann, Paul; Schweighart, Marko; Sommer, Christian; Wenzl, Franz-P.; Zinterl, Ernst; Hoschopf, Hans; Pachler, Peter; Tasch, Stefan

    2008-02-01

    Key market requirements for white LEDs, especially in the general lighting and automotive headlamp segments call for improved concepts and performance of white LEDs based on phosphor conversion. Major challenges are small emission areas, highest possible intensities, long-term color stability, and spatial homogeneity of color coordinates. On the other hand, the increasingly high radiation power of the blue LEDs poses problems for all involved materials. Various thick film coating technologies are widely used for applying the color conversion layer to the semiconductor chip. We present novel concepts based on Silicate phosphors with high performance in terms of spatial homogeneity of the emission and variability of the color temperature. Numerical calculation of the optical properties with the help of state-of-the-art simulation tools was used as a basis for the practical optimization of the layer geometries.

  10. LEDs as light source: examining quality of acquired images

    NASA Astrophysics Data System (ADS)

    Bachnak, Rafic; Funtanilla, Jeng; Hernandez, Jose

    2004-05-01

    Recent advances in technology have made light emitting diodes (LEDs) viable in a number of applications, including vehicle stoplights, traffic lights, machine-vision-inspection, illumination, and street signs. This paper presents the results of comparing images taken by a videoscope using two different light sources. One of the sources is the internal metal halide lamp and the other is a LED placed at the tip of the insertion tube. Images acquired using these two light sources were quantitatively compared using their histogram, intensity profile along a line segment, and edge detection. Also, images were qualitatively compared using image registration and transformation. The gray-level histogram, edge detection, image profile and image registration do not offer conclusive results. The LED light source, however, produces good images for visual inspection by an operator. The paper will present the results and discuss the usefulness and shortcomings of various comparison methods.

  11. Self-aligning LED-based optical link

    NASA Astrophysics Data System (ADS)

    Shen, Thomas C.; Drost, Robert J.; Rzasa, John R.; Sadler, Brian M.; Davis, Christopher C.

    2016-09-01

    The steady advances in light-emitting diode (LED) technology have motivated the use of LEDs in optical wireless communication (OWC) applications such as indoor local area networks (LANs) and communication between mobile platforms (e.g., robots, vehicles). In contrast to traditional radio frequency (RF) wireless communication, OWC utilizes electromagnetic spectrum that is largely unregulated and unrestricted. OWC communication may be especially useful in RF-denied environments, in which RF communication may be prohibited or undesirable. However, OWC does present some challenges, including the need to maintain alignment between potentially moving nodes. We describe a novel system for link alignment that is composed of a hyperboloidal mirror, camera, and gimbal. The experimental system is able to use the mirror and camera to detect an LED beacon of a neighboring node and estimate its bearing (azimuth and elevation), point the gimbal towards the beacon, and establish an optical link.

  12. A projective LED low-beam headlamp of motorbikes

    NASA Astrophysics Data System (ADS)

    Ge, Peng; Wang, Xiang; Li, Yang; Wang, Hong

    2014-11-01

    In this paper we propose a projective LED low-beam headlamp of motorbikes. An ellipsoidal reflector is used to collect light emitting from the LED source. A baffle plate is located in the focal point of the ellipsoidal reflector to form the cut-off line.Then the light is redistributed by an optical lens. We set the measuring screen as an semi-circular zone and divide it into many small lattices, divide the spatial angle of the LED source into many parts and make relationships between them. According to the conservation of energy and Snell law, the lens is generated by freeform optics design method. Then the optical system is simulated by Monte Carlo method using ASAP software. Light pattern of simulation could meet the national standard. The low-beam headlamp is finally fabricated and assembled into a physical object. Experiment results can fully comply with regulations GB5948-1998.

  13. A novel solution for LED wall lamp design and simulation

    NASA Astrophysics Data System (ADS)

    Ge, Rui; Hong, Weibin; Li, Kuangqi; Liang, Pengxiang; Zhao, Fuli

    2014-11-01

    The model of the wall washer lamp and the practical illumination application have been established with a new design of the lens to meet the uniform illumination demand for wall washer lamp based on the Lambertian light sources. Our secondary optical design of freeform surface lens to LED wall washer lamp based on the conservation law of energy and Snell's law can improve the lighting effects as a uniform illumination. With the relationship between the surface of the lens and the surface of the target, a great number of discrete points of the freeform profile curve were obtained through the iterative method. After importing the data into our modeling program, the optical entity was obtained. Finally, to verify the feasibility of the algorithm, the model was simulated by specialized software, with both the LED Lambertian point source and LED panel source model.

  14. Philips' 2nd generation Novallure LED candle lamp

    NASA Astrophysics Data System (ADS)

    Li, Yun; Pei, Zhigang; Yuan, Chuan; Jiang, Tan; Lu, Zhengsong; Wang, Yuqian; Duan, Xiaoqing; Xiong, Yan; Zhong, Hong; Liu, Ye

    2010-08-01

    Finding an energy efficient replacement of incandescent candle lamp has been a technical challenge. Compact fluorescent lamps, for example, can be miniaturized to fit the form factor of a candle lamp but they fail to reproduce its "sparkle" effect. Empowered by solid state lighting technology along with original optical design, Philips has successfully developed LED-powered candle lamps "Novallure" with great energy savings (2W power consumption with lumen output of 55 lumen) and the "butterfly" radiation pattern that mimics the sparkle effect from an incandescent candle lamp. With new high performance LED packages, novel under-cut prismatic optics and state-of-the-art electronic driver solution and thermal solution, we have developed a 2nd generation Novallure with breakthrough performance: a dimmable 2700K 136 lumen LED candle lamp with CRI 90.

  15. Developing a nurse-led clinic using transformational leadership.

    PubMed

    Gousy, Mamood; Green, Kim

    2015-03-25

    Nurses are at the forefront of implementing and managing change, given constantly changing healthcare services and the increase in demand for health care. Therefore, it is important to identify the best style of leadership to engage nurses in implementing service-led improvements. This article explores the effects of transformational leadership in bringing about service-led improvements in health care, using the example of setting up a nurse-led acupuncture clinic to optimise the care of patients with chronic pain. Transformational leadership was used throughout the project - from the initial local planning, training and development, through to liaising with the appropriate staff and deciding on an evaluation strategy. Transformational leadership proved to be an effective way to engage and empower nurses and other members of the chronic pain team to enable them to achieve the project aims.

  16. Semiconductor lasers vs LEDs in diagnostic and therapeutic medicine

    NASA Astrophysics Data System (ADS)

    Gryko, Lukasz; Zajac, Andrzej; Szymanska, Justyna; Blaszczak, Urszula; Palkowska, Anna; Kulesza, Ewa

    2016-12-01

    Semiconductor emitters are used in many areas of medicine, allowing for new methods of diagnosis, treatment and effective prevention of many diseases. The article presents selected areas of application of semiconductor sources in UVVIS- NIR range, where in recent years competition in semiconductor lasers and LEDs applications has been observed. Examples of applications of analyzed sources are indicated for LLLT, PDT and optical diagnostics using the procedure of color contrast. Selected results of LLLT research of the authors are presented that were obtained by means of the developed optoelectronic system for objectified irradiation and studies on the impact of low-energy laser and LED on lines of endothelial cells of umbilical vein. Usefulness of the spectrally tunable LED lighting system for diagnostic purposes is also demonstrated, also as an illuminator for surface applications - in procedure of variable color contrast of the illuminated object.

  17. Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles

    PubMed Central

    Cool, Simon; Pieters, Jan G.; Mertens, Koen C.; Mora, Sergio; Cointault, Frédéric; Dubois, Julien; van de Gucht, Tim; Vangeyte, Jürgen

    2015-01-01

    Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m2 with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications. PMID:26569261

  18. Thermal and optical design analyses, optimizations, and experimental verification for a novel glare-free LED lamp for household applications.

    PubMed

    Khan, M Nisa

    2015-07-20

    Light-emitting diode (LED) technologies are undergoing very fast developments to enable household lamp products with improved energy efficiency and lighting properties at lower cost. Although many LED replacement lamps are claimed to provide similar or better lighting quality at lower electrical wattage compared with general-purpose incumbent lamps, certain lighting characteristics important to human vision are neglected in this comparison, which include glare-free illumination and omnidirectional or sufficiently broad light distribution with adequate homogeneity. In this paper, we comprehensively investigate the thermal and lighting performance and trade-offs for several commercial LED replacement lamps for the most popular Edison incandescent bulb. We present simulations and analyses for thermal and optical performance trade-offs for various LED lamps at the chip and module granularity levels. In addition, we present a novel, glare-free, and production-friendly LED lamp design optimized to produce very desirable light distribution properties as demonstrated by our simulation results, some of which are verified by experiments.

  19. Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles.

    PubMed

    Cool, Simon; Pieters, Jan G; Mertens, Koen C; Mora, Sergio; Cointault, Frédéric; Dubois, Julien; van de Gucht, Tim; Vangeyte, Jürgen

    2015-11-12

    Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m² with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications.

  20. The puzzle of graphene commercialization

    NASA Astrophysics Data System (ADS)

    Park, Seongjun

    2016-11-01

    The commercialization of graphene-based products is challenging, because many engineering and economical aspects have to be taken into consideration. A stronger collaboration between academia and industry would be beneficial for accelerating the process.

  1. Commercial and Institutional Case Studies

    EPA Pesticide Factsheets

    Throughout the country, commercial and institutional (CI) building owners and facility managers are taking actions to reduce their water use, implementing many of the operations and maintenance, retrofit, and replacement projects.

  2. Commercialization in NASA Space Operations

    NASA Technical Reports Server (NTRS)

    Gilbert, Charlene E.

    1998-01-01

    Various issues associated with commercialization in NASA space operations are presented in viewgraph form. Specific topics include: 1) NASA's financial outlook; 2) Space operations; 3) Space operations technology; and 4) Strategies associated with these operations.

  3. Commercialization of parabolic dish systems

    NASA Technical Reports Server (NTRS)

    Washom, B.

    1982-01-01

    The impact of recent federal tax and regulatory legislation on the commercialization of parabolic solar reflector technology is assessed. Specific areas in need of technical or economic improvement are noted.

  4. Commercial Crew Planning Status Forum

    NASA Video Gallery

    NASA presents an overview of common themes captured from industry responses provided to NASA's Commercial Crew Initiative Request for Information (RFI) published on May 21, 2010. The forum includes...

  5. An LED-based flasher system for VERITAS

    NASA Astrophysics Data System (ADS)

    Hanna, D.; McCann, A.; McCutcheon, M.; Nikkinen, L.

    2010-01-01

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

  6. LED and Semiconductor Photo-effects on Living Things

    NASA Astrophysics Data System (ADS)

    Fujiyasu, Hiroshi; Ishigaki, Takemitsu; Fujiyasu, Kentarou; Ujihara, Shirou; Watanabe, Naoharu; Sunayama, Shunji; Ikoma, Shuuji

    We have studied LED irradiation effects on plants and animals in the visible to UV region of light from GaN LEDs. The results are as follows. Blue light considers to be effective for pearl cultivation or for attraction of small fishes living in near the surface of sea such as Pompano or Sardine, white light radiation is effective for cultivation of botanical plankton for shells. Other experiments of UV light irradiation attracting effect on baby sea turtle and the germination UV effect of mushroom, green light weight enhance effect on baby pigs, light vernalization effect of vegitable and Ge far infrared therapic effect on human body are also given.

  7. Peer-Led Team Learning Helps Minority Students Succeed

    PubMed Central

    Snyder, Julia J.; Sloane, Jeremy D.; Dunk, Ryan D. P.; Wiles, Jason R.

    2016-01-01

    Active learning methods have been shown to be superior to traditional lecture in terms of student achievement, and our findings on the use of Peer-Led Team Learning (PLTL) concur. Students in our introductory biology course performed significantly better if they engaged in PLTL. There was also a drastic reduction in the failure rate for underrepresented minority (URM) students with PLTL, which further resulted in closing the achievement gap between URM and non-URM students. With such compelling findings, we strongly encourage the adoption of Peer-Led Team Learning in undergraduate Science, Technology, Engineering, and Mathematics (STEM) courses. PMID:26959826

  8. CMOS-compatible plenoptic detector for LED lighting applications.

    PubMed

    Neumann, Alexander; Ghasemi, Javad; Nezhadbadeh, Shima; Nie, Xiangyu; Zarkesh-Ha, Payman; Brueck, S R J

    2015-09-07

    LED lighting systems with large color gamuts, with multiple LEDs spanning the visible spectrum, offer the potential of increased lighting efficiency, improved human health and productivity, and visible light communications addressing the explosive growth in wireless communications. The control of this "smart lighting system" requires a silicon-integrated-circuit-compatible, visible, plenoptic (angle and wavelength) detector. A detector element, based on an offset-grating-coupled dielectric waveguide structure and a silicon photodetector, is demonstrated with an angular resolution of less than 1° and a wavelength resolution of less than 5 nm.

  9. Modulation selection for visible light communications using lighting LEDs

    NASA Astrophysics Data System (ADS)

    Siuzdak, Jerzy

    2015-09-01

    The paper analyzes suitability of various spectrally efficient modulations (PAM, CAP, OFDM/DMT) in a VLC system using lighting LEDs as a transmitter. Although under ideal conditions all modulation have similar efficiency i.e. they produce similar throughputs with a given BER, their practical performances are different. For example, the level of nonlinear distortions generated by each modulation is the least for PAM and by far the greatest for OFDM/DMT locating CAP in the middle. The suitability of various OFDM/DMT variants in a VLC LED link was also analyzed proving that the asymmetrically clipped (ACO) OFDM has a worse performance as compared with DC biased (DCO) OFDM.

  10. Peer-Led Team Learning Helps Minority Students Succeed.

    PubMed

    Snyder, Julia J; Sloane, Jeremy D; Dunk, Ryan D P; Wiles, Jason R

    2016-03-01

    Active learning methods have been shown to be superior to traditional lecture in terms of student achievement, and our findings on the use of Peer-Led Team Learning (PLTL) concur. Students in our introductory biology course performed significantly better if they engaged in PLTL. There was also a drastic reduction in the failure rate for underrepresented minority (URM) students with PLTL, which further resulted in closing the achievement gap between URM and non-URM students. With such compelling findings, we strongly encourage the adoption of Peer-Led Team Learning in undergraduate Science, Technology, Engineering, and Mathematics (STEM) courses.

  11. Flip Chip Bonding of 68 x 68 MWIR LED Arrays

    DTIC Science & Technology

    2009-01-01

    256 solar - blind focal plane arrays based on AlxGa1-xN,” Appl. Phys. Lett., vol. 86, pp. 11117-1–11117-3, 2005. [10] S. J. Chang, W. S. Chen, Y. C. Lin...Terms—CMOS drivers, contact resistance, flip chip bonding, led array. I. INTRODUCTION P ASSIVE IR imaging and IR detector arrays for seekersplay a very...scene generation applications, the LED devices are required to simulate very high temperature targets on the order of 3000 K apparent black body

  12. Review of recent technological advances in high power LED packaging

    NASA Astrophysics Data System (ADS)

    Panahi, Allen S.

    2012-06-01

    High Power LED is poised to replace traditional lighting sources such as Fluorescent, HID, Halogen and conventional incandescent bulbs in many applications. Due to the solid state compact nature of the light source it is inherently rugged and reliable and has been the favored lighting source for most indoor and outdoor applications including many hazardous locations that impact, and safety environments including mining, bridge, Aerospace, Automotive . In order to accelerate this transition many enhancements and advances are taking place to improve on the reliability, and thermal performance of these devices. This paper explores the various improvements and advances made in the packaging of LEDs to enhance their performance

  13. The development of student-led interprofessional education and collaboration.

    PubMed

    VanderWielen, Lynn M; Enurah, Alexander S; Osburn, Ian F; LaCoe, Kristen N; Vanderbilt, Allison A

    2013-09-01

    Prominent healthcare organizations have called upon the academic and health communities to utilize interprofessional education (IPE) and collaboration to meet the changing needs of patients worldwide. Two student-led initiatives have overcome the various barriers that have historically impeded IPE and have embraced the call to improve the health of local and international underserved patients. This short report describes these two organizations, the International Health Service Collaborative at the University of South Florida and the Inter Health Professionals Alliance at Virginia Commonwealth University, and aims to encourage emerging health professional students and educators to embrace student-led IPE.

  14. High-Voltage LED Light Engine with Integrated Driver

    SciTech Connect

    Soer, Wouter

    2016-02-29

    LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm2), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm2 and 4 mm2) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux

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

    SciTech Connect

    Tuenge, Jason R.; Hollomon, Brad; Dillon, Heather E.; Snowden-Swan, Lesley J.

    2013-03-01

    This report covers the third part of a larger U.S. Department of Energy (DOE) project to assess the life-cycle environmental and resource impacts in the manufacturing, transport, use, and disposal of light-emitting diode (LED) lighting products in relation to incumbent lighting technologies. All three reports are available on the DOE website (www.ssl.energy.gov/tech_reports.html). • Part 1: Review of the Life-Cycle Energy Consumption of Incandescent, Compact Fluorescent and LED Lamps; • Part 2: LED Manufacturing and Performance; • Part 3: LED Environmental Testing. Parts 1 and 2 were published in February and June 2012, respectively. The Part 1 report included a summary of the life-cycle assessment (LCA) process and methodology, provided a literature review of more than 25 existing LCA studies of various lamp types, and performed a meta-analysis comparing LED lamps with incandescent and compact fluorescent lamps (CFLs). Drawing from the Part 1 findings, Part 2 performed a more detailed assessment of the LED manufacturing process and used these findings to provide a comparative LCA taking into consideration a wider range of environmental impacts. Both reports concluded that the life-cycle environmental impact of a given lamp is dominated by the energy used during lamp operation—the upstream generation of electricity drives the total environmental footprint of the product. However, a more detailed understanding of end-of-life disposal considerations for LED products has become increasingly important as their installation base has grown. The Part 3 study (reported herein) was undertaken to augment the LCA findings with chemical analysis of a variety of LED, CFL, and incandescent lamps using standard testing procedures. A total of 22 samples, representing 11 different models, were tested to determine whether any of 17 elements were present at levels exceeding California or Federal regulatory thresholds for hazardous waste. Key findings include: • The selected

  16. Industry's Commercial Initiatives on ISS

    NASA Astrophysics Data System (ADS)

    Shields, C. E.; Kessler, C.; Lavitola, M. S.

    2002-01-01

    For more than ten years, private industry has worked to develop a commercial human space market and to create a sustainable ISS commercial utilization customer base. Before ISS assembly was underway - and long before NASA and the international space agencies began to craft ISS commercial business terms and conditions - industry planted and nurtured the seeds of interest in exploiting human space utilization for commerce. These early initiatives have yielded the impetus and framework for industry approaches to ISS commercial utilization today and for NASA's and the International Partners' planned accommodation of private sector interests and desires on the ISS. This paper chronicles major industry initiatives for commercial ISS utilization, emphasizing successful marketing and business approaches and why these approaches have a higher likelihood of success than others. It provides an overview of individual companies' initiatives, as well as collaborative efforts that cross company lines and country borders; and it assesses the relative success of each. Rather than emphasize negative issues and barriers, this paper characterizes and prioritizes actionable success factors for industry and government to make ISS commercial utilization a sustainable reality.

  17. LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project

    SciTech Connect

    Tuenge, Jason R.

    2011-01-17

    Tungsten-halogen (halogen) lamps have traditionally been used to light surgical tasks in hospitals, even though they are in many respects ill-suited to the application due to the large percentage of radiant energy outside the visible spectrum and issues with color rendering/quality. Light-emitting diode (LED) technology offers potential for adjustable color and improved color rendition/quality, while simultaneously reducing side-effects from non-visible radiant energy. It also has the potential for significant energy savings, although this is a fairly narrow application in the larger commercial building energy use sector. Based on analysis of available products and Hospital Energy Alliance member interest, it is recommended that a product specification and field measurement procedure be developed for implementation in demonstration projects.

  18. Trace analysis of oil-in-water by using visible LED and metal waveguide capillary.

    PubMed

    Bai, Min; Huang, Hui; Yu, Yan; Hao, Jian; Zhang, Ji; Fan, Jianchao; Yan, Jun

    2016-06-27

    Trace analysis of oil-in-water (O/W) has wide applications in life science, industry and environmental monitoring (such as oil spilling). In this paper, with the aid of surfactant, diesel was dispersed in water as O/W emulsion, which can be detected by using visible LED and metal-waveguide-capillary (MWC). Due to the enhancement of optical-path and related light-droplet interaction in MWC, detecting diesel of a concentration as low as 2.14 ng/ml was realized with a 7cm long MWC. The detection limit was improved 125 fold compared with that of commercial spectrophotometer with 1 cm-cuvette. The detecting system features compact, low cost and high sensitivity.

  19. Effects of LED lighting during incubation on layer and broiler hatchability, chick quality, stress susceptibility and post-hatch growth.

    PubMed

    Huth, Jesse C; Archer, Gregory S

    2015-12-01

    Providing light during incubation has been shown to affect hatchability, but the use of LED lights has not been evaluated. This experiment evaluated the effects of LED lighting during embryogenesis on White Leghorn and commercial broiler eggs. To determine this, two experiments were conducted, the first using White Leghorn eggs (N=3456) and the second using commercial broiler eggs (N=3456) where eggs were incubated 12 h of light and 12 h of darkness (LED) or complete darkness (DARK); the light level was 250 lux. Hatchability, embryo mortality, and chick quality were measured in both studies, and a subset of one of the broiler egg trials were grown out to investigate fear and stress parameters. There was no effect (P>0.05) on hatchability of layer eggs; however, there was a difference (P=0.02) observed in chick quality, with the LED group having more chicks (75.34%) with no defects than the DARK group (56.53%). Broiler eggs exposed to LED light showed an increase in hatchability (90.12%, P=0.03) and an increase in no-defect chick percentage (86.12%, P=0.04) at hatch compared to the DARK chicks (85.76% and 69.43%, respectively). Differences were observed between treatments during the 14 d grow-out. The LED birds had lower (P<0.05) physical asymmetry (0.90±0.05 mm) and heterophil/lymphocyte ratios (0.279±0.021), indicating that they were less susceptible to stress than the DARK birds (1.16±0.07 mm and 0.347±0.021, respectively). There was no difference (P>0.05) observed between treatments in growth, FCR, or fear measures at 14 d. These results indicate that providing LED light during incubation can improve chick quality in both white layer and broiler eggs; however, it only appears to improve hatchability in broilers, which could be related to shell pigmentation. It was also demonstrated that providing LED light during incubation can reduce the stress susceptibility of broilers post-hatch. Utilizing light during incubation may be useful tool for the poultry

  20. Commercializing fuel cells: managing risks

    NASA Astrophysics Data System (ADS)

    Bos, Peter B.

    Commercialization of fuel cells, like any other product, entails both financial and technical risks. Most of the fuel cell literature has focussed upon technical risks, however, the most significant risks during commercialization may well be associated with the financial funding requirements of this process. Successful commercialization requires an integrated management of these risks. Like any developing technology, fuel cells face the typical 'Catch-22' of commercialization: "to enter the market, the production costs must come down, however, to lower these costs, the cumulative production must be greatly increased, i.e. significant market penetration must occur". Unless explicit steps are taken to address this dilemma, fuel cell commercialization will remain slow and require large subsidies for market entry. To successfully address this commercialization dilemma, it is necessary to follow a market-driven commercialization strategy that identifies high-value entry markets while minimizing the financial and technical risks of market entry. The financial and technical risks of fuel cell commercialization are minimized, both for vendors and end-users, with the initial market entry of small-scale systems into high-value stationary applications. Small-scale systems, in the order of 1-40 kW, benefit from economies of production — as opposed to economies to scale — to attain rapid cost reductions from production learning and continuous technological innovation. These capital costs reductions will accelerate their commercialization through market pull as the fuel cell systems become progressively more viable, starting with various high-value stationary and, eventually, for high-volume mobile applications. To facilitate market penetration via market pull, fuel cell systems must meet market-derived economic and technical specifications and be compatible with existing market and fuels infrastructures. Compatibility with the fuels infrastructure is facilitated by a

  1. Small Area Array-Based LED Luminaire Design

    SciTech Connect

    Thomas Yuan

    2008-01-09

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

  2. EC-LEDS Mexico: Advancing Clean Energy Goals

    SciTech Connect

    2016-07-01

    EC-LEDS works with the government of Mexico to help meet its goals of reducing greenhouse gas emissions from the energy sector. The program targets specific, highly technical areas where Mexico has indicated the program can add value and make an impact.

  3. The LED outdoor lighting revolution : Opportunities, threats and mitigation

    NASA Astrophysics Data System (ADS)

    Aube, Martin

    2017-01-01

    The presence of artificial light at night (ALAN) in environment is now known to have non negligible consequences on the night sky, the fauna, the flora and the human health. A real revolution is undergoing in the outdoor lighting industry threatens the night integrity. This revolution is driven by the advent of the cost-effective Light-Emitting Diode (LED) technology into the outdoor lighting industry. The LEDs provides many opportunities: they are long lasting, easily controlled, and generally allow a more efficient photometric design which, in term, may result in energy savings.After explaining the complex and non-linear behaviour of the propagation of the ALAN into the nocturnal environment, we will outline the potential impact of the ALAN on the human health and on the night sky, and we will introduce some dedicated indicators for its evaluation. We will focus on the role of the blue content of the ALAN in the evaluation of its impact. More specifically we will show how white LED technology, that often shows increased blue light content, compares to the traditional High Pressure Sodium technology. Finally, we will identify the possible mitigations to restrict the adverse impacts of the white LEDs in the urban and rural environment.

  4. Professors as Academic Leaders: The Perspectives of "the Led"

    ERIC Educational Resources Information Center

    Evans, Linda; Homer, Matthew; Rayner, Stephen

    2013-01-01

    Most research and scholarship in the field of educational leadership and management seems focused on leaders and managers and their perspectives, while the perspective of an entire constituency--"the led"--is generally overlooked and neglected. This article contributes towards redressing this imbalance. Located within the context of the…

  5. Teacher-Led Design of an Adaptive Learning Environment

    ERIC Educational Resources Information Center

    Mavroudi, Anna; Hadzilacos, Thanasis; Kalles, Dimitris; Gregoriades, Andreas

    2016-01-01

    This paper discusses a requirements engineering process that exemplifies teacher-led design in the case of an envisioned system for adaptive learning. Such a design poses various challenges and still remains an open research issue in the field of adaptive learning. Starting from a scenario-based elicitation method, the whole process was highly…

  6. Doing Reflective Practice: A Data-Led Way Forward

    ERIC Educational Resources Information Center

    Walsh, Steve; Mann, Steve

    2015-01-01

    This article makes the case for an approach to reflective practice (RP) that is both evidence-based and data-led. We argue that, while RP within the field of TESOL enjoys a relatively high level of acceptance and status (perhaps even an orthodoxy), it has little corresponding knowledge base that demonstrates how RP "gets done". We…

  7. 11. Short subways led to the lower deck of the ...

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

    11. Short subways led to the lower deck of the Detroit-Superior Bridge. Street cars entered the subways through open wells located in the center of the roadways. This undated photograph shows the Superior Avenue entrance. The view is looking west. Photograph courtesy Office of the Cuyahoga County Engineer in Cleveland, Ohio. - Detroit Superior High Level Bridge, Cleveland, Cuyahoga County, OH

  8. Ghana Fiasco Shows Risks of Faculty-Led Study Trips

    ERIC Educational Resources Information Center

    Fischer, Karin

    2007-01-01

    This article illustrates the importance of preparation for professors who take students overseas. A University of Washington study-abroad program in Ghana that was cut short last summer after the medical evacuation of half of its participants highlights the potential hazards associated with programs led by individual faculty members who may lack…

  9. Numerical simulation of high power LED heat-dissipating system

    NASA Astrophysics Data System (ADS)

    Wu, Shih-Jeh; Hsu, Hsiang-Chen; Fu, Shen-Li; Yeh, Jiam-Nan

    2014-03-01

    In this paper, thermal analysis of the heat dissipation under different heat sink for high-power white Light Emitting Diode (LED) is presented. Junction temperature of LED is elevated as the power of LED increases, which brings up deterioration of light efficiency and other side effects. Heat dissipation is another design concern other than material and illumination efficiency. The purpose of this paper is to investigate the cooling of high-power LED chips and modules for design of heat sinks. Three types of heat sinks are designed for a tandem 12-chip module and an extensive numerical investigation of the heat sink design performance is conducted by Computational Fluid Dynamics software Fluent. The effects of heat sink geometry and adhesive material are also investigated. Design variables are the thickness of sink base, number, thickness and length of fins. The total wetted area is the dominant factor to the junction temperature. The objective of design regarding the junction temperatures around 50°C is easily achieved. However, its effect is limited at high values of these parameters, furthermore an excessive number of fins incurs reverse consequence due to problem of ventilation also waste of material.

  10. Compact fluorescent lamps, LED lamps and harmonic distortion

    NASA Astrophysics Data System (ADS)

    Franco, A. M. R.; Debatin, R. M.; Cotia, F. C. G.; Silva, M. V. M.; Ribeiro, R. S.; Zampilis, R. R. N.

    2015-01-01

    The aim of this paper is to evaluate the harmonic distortion in the current waveform of Compact Fluorescent Lamps (CFL) and Lamps Lighting Emitting Diode (LED). For this, we analysed the power factor, voltage waveform, current waveform, total harmonic distortion (THD) and active power consumed.

  11. 76 FR 14904 - Executive-Led Trade Mission to Afghanistan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... International Trade Administration Executive-Led Trade Mission to Afghanistan AGENCY: International Trade... Commerce's International Trade Administration is organizing a business development trade mission to Kabul... to port cities such as Karachi. After 30 years of war reconstruction and development efforts...

  12. Color digital lensless holographic microscopy: laser versus LED illumination.

    PubMed

    Garcia-Sucerquia, Jorge

    2016-08-20

    A comparison of the performance of color digital lensless holographic microscopy (CDLHM) as utilized for illumination of RGB lasers or a super-bright white-light LED with a set of spectral filters is presented. As the use of lasers in CDLHM conceals the possibility of having a compact, lightweight, portable, and low cost microscope, and additionally the limited available laser radiation wavelengths limit a real multispectral imaging microscope, here we present the use of super-bright white-light LED and spectral filters for illuminating the sample. The performance of RGB laser-CDLHM and LED-CDLHM is evaluated on imaging a section of the head of a Drosophila melanogaster fly. This comparison shows that there is trade-off between the spatial resolution of the microscope and the light sources utilized, which can be understood with regard to the coherence properties of the illuminating light. Despite the smaller spatial coherence features of LED-CDLHM in comparison with laser-CDLHM, the former shows promise as a portable RGB digital lensless holographic microscope that could be extended to other wavelengths by the use of different spectral filters.

  13. Biologically inspired LED lens from cuticular nanostructures of firefly lantern

    PubMed Central

    Kim, Jae-Jun; Lee, Youngseop; Kim, Ha Gon; Choi, Ki-Ju; Kweon, Hee-Seok; Park, Seongchong; Jeong, Ki-Hun

    2012-01-01

    Cuticular nanostructures found in insects effectively manage light for light polarization, structural color, or optical index matching within an ultrathin natural scale. These nanostructures are mainly dedicated to manage incoming light and recently inspired many imaging and display applications. A bioluminescent organ, such as a firefly lantern, helps to out-couple light from the body in a highly efficient fashion for delivering strong optical signals in sexual communication. However, the cuticular nanostructures, except the light-producing reactions, have not been well investigated for physical principles and engineering biomimetics. Here we report a unique observation of high-transmission nanostructures on a firefly lantern and its biological inspiration for highly efficient LED illumination. Both numerical and experimental results clearly reveal high transmission through the nanostructures inspired from the lantern cuticle. The nanostructures on an LED lens surface were fabricated by using a large-area nanotemplating and reconfigurable nanomolding with heat-induced shear thinning. The biologically inspired LED lens, distinct from a smooth surface lens, substantially increases light transmission over visible ranges, comparable to conventional antireflection coating. This biological inspiration can offer new opportunities for increasing the light extraction efficiency of high-power LED packages. PMID:23112185

  14. LED's in Physics Demos: A Handful of Examples.

    ERIC Educational Resources Information Center

    Lottis, Dan; Jaeger, Herbert

    1996-01-01

    Describes the use of light-emitting diodes (LED) instead of incandescent bulbs in experiments that generally use battery and bulbs to enable students to explore and understand fundamental electrical phenomena. Presents the following examples: Faraday's Law demonstration, conductors and insulators, and rectifying action of a diode. (JRH)

  15. Youth-Led Decision Making in Community Development Grants

    ERIC Educational Resources Information Center

    Blanchet-Cohen, Natasha; Manolson, Sarah; Shaw, Katie

    2014-01-01

    This study examines youth-led decision making (YLDM) among groups of youth who are providers or recipients of community development grants. Focus groups, interviews, and participant observation with 14- to 20-year-olds and supporting adults showed youth have a preference for consensus-based decisions. Youth used due process to reach decisions…

  16. Double Blind: Supervising Women as Creative Practice-Led Researchers

    ERIC Educational Resources Information Center

    Pedersen, Courtney; Haynes, Rachael

    2015-01-01

    Many women creative practice-led researchers appear inhibited by a number of factors directly connected to their gender. This article discusses these factors, including the culture of visual arts professional practice, the circumstances surrounding women postgraduate students and unproductive self-theories about intelligence and creativity. A…

  17. A driving scheme to reduce AC LED flicker

    NASA Astrophysics Data System (ADS)

    Tan, Jianchuan; Narendran, Nadarajah

    2013-09-01

    Light flicker is a common but unwelcome phenomenon in conventional lighting applications. In solid-state lighting, driving or dimming methods also give rise to light flicker. AC LED products in today's marketplace suffer from flicker, which stems from the arrangement of the micro-LEDs and the driving method. Research has shown that light flicker can be a health hazard to humans. Several solutions have been proposed to reduce light flicker in solid-state lighting applications; however, most have drawbacks in terms of power and other performance. This paper proposes a circuit design to reduce light flicker from AC LEDs while maintaining a normal power factor and high power efficiency. The circuit is composed of one resistive branch and one capacitive branch, and each branch drives a load which is made up of high-voltage LEDs. Percent flicker, power factor, and power efficiency were selected as three metrics, and their benchmarks were set to evaluate the performance of this circuit. Phase shift between the two branches was selected as a factor that could determine the circuit performance. The variations of percent flicker, power factor, and power efficiency as a function of phase shift were identified by theoretical analysis and were verified by experiments. The experimental results show that an optimal solution can be achieved for this circuit design at proper phase shift, where the benchmarks of the three metrics are reached.

  18. Some quantitative aspects of temporary blinding from high brightness LEDs

    NASA Astrophysics Data System (ADS)

    Reidenbach, Hans-Dieter

    2007-02-01

    According to the new European Directive on Artificial Optical Radiation (2006/25/EC) the employer has to determine the exposure and the assessment of risks, i.e. workers shall not be exposed above the exposure limit values, which are based on various ICNIRP guidelines. In addition, the employer shall give particular attention, when carrying out the risk assessment, to any indirect effects amongst others such as temporary blinding. Since up to now no quantitative values exist in order to rank or classify artificial optical sources and its associated capability of temporary blinding, we have investigated some aspects of glare and dazzling from a high-brightness LED (HB-LED). With such a single device and an array consisting of 80 HB-LEDs we have found in a previous investigation that the frequency of the blink reflex exceeds the one achieved with laser belonging to class 2 according to the international standard IEC 60825-1, however is less than about 50 %. The size of an after-image as a function of time and the visual acuity after an exposure from a white high-brightness LED has been investigated in detail with 3 test persons. The results have shown that the size of an after-image on the human retina remains nearly constant with a slight decrease over a time duration of about 12 minutes, whereas the initial visual acuity is recovered within 30 up to 60 seconds. Linear and exponential regression descriptions are given for both characteristics.

  19. Heterostructures for Increased Quantum Efficiency in Nitride LEDs

    SciTech Connect

    Davis, Robert F.

    2010-09-30

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

  20. Student-Led Campus Climate Change Initiatives in Canada

    ERIC Educational Resources Information Center

    Helferty, Anjali; Clarke, Amelia

    2009-01-01

    Purpose: The purpose of this paper is to provide a comprehensive list of student-led, campus-based climate change initiatives, and offers details on many specific cases. The paper also documents the roles students have played and considers the larger youth engagement implications. Many of these initiatives can be replicated elsewhere, thereby…