CENTRAL DRIVE RUNNING PAST THE GARAGE AND TERMINATING AT THE ...

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

CENTRAL DRIVE RUNNING PAST THE GARAGE AND TERMINATING AT THE BARN. The barn’s primary entrance is through the central double doors with chamfered corners on the west façade. The garage was used both as a mechanic shop and to park vehicles. The hipped roof of the pump house can be seen behind the garage. - Kineth Farm, Barn, 19162 STATE ROUTE 20, Coupeville, Island County, WA

Alternative Fuels Data Center: Goss' Garage Provides Tips for Using Ethanol

Science.gov Websites

in Classic Cars Goss' Garage Provides Tips for Using Ethanol in Classic Cars to someone by E -mail Share Alternative Fuels Data Center: Goss' Garage Provides Tips for Using Ethanol in Classic Cars on Facebook Tweet about Alternative Fuels Data Center: Goss' Garage Provides Tips for Using Ethanol

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

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

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

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

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

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

Salt attack in parking garage in block of flats

NASA Astrophysics Data System (ADS)

Beran, Pavel; Frankeová, Dita; Pavlík, Zbyšek

2017-07-01

In recent years many new block of flats with parking garages placed inside the buildings were constructed. This tendency brings beyond question benefits for residents and also for city planning, but it requires new design and structural approaches and advanced material and construction solutions. The analysis of plaster damage on partition wall in parking garage in one of these buildings is presented in the paper. The damage of studied plaster is caused by the salts which are transported together with snow on cars undercarriage into garage area during winter. The snow melts and water with dissolved salts is transported by the capillary suction from concrete floor into the rendered partition wall. Based on the interior temperature, adsorbed water with dissolved chlorides evaporates and from the over saturated pore solution are formed salt crystals that damages the surface plaster layers. This damage would not occur if the partition wall was correctly isolated from the floor finish layer in the parking garage.

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.

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

Field evaluation of ventilation system performance in enclosed parking garages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayari, A.M.; Grot, D.A.; Krarti, M.

2000-07-01

This paper summarizes the results of a field study to determine the ventilation requirements and the contaminant levels in existing enclosed parking garages. The testing was conducted in seven parking garages with different sizes, traffic flow patterns, vehicle types, and locations. In particular, the study compares the actual ventilation rates measured using the tracer gas technique with the ventilation requirements of ANSI/ASHRAE Standard 62-1989. In addition, the field test evaluated the effectiveness of the existing ventilation systems in maintaining acceptable contaminant levels within enclosed parking garages.

Occupational health risk of working in garages: comparative study on blood pressure and hematological parameters between garage workers and Haramaya University community, Harar, eastern Ethiopia.

PubMed

Ataro, Zerihun; Geremew, Abraham; Urgessa, Fekadu

2018-01-01

Occupational exposure to chemicals in garages causes a wide range of biological effects, depending upon the level and duration of exposure. In Ethiopia, there have been few studies conducted to assess the exposure of garage workers to chemicals. Preceding studies have not explored the effect of working in garage on blood pressure and hematological parameters. Therefore, this study aimed to assess differences in blood pressure and hematological parameters among garage workers compared to the Haramaya University community, Harar, eastern Ethiopia. A comparative cross-sectional study was conducted in Harar town, eastern Ethiopia. Thirty garage workers were selected and compared with 30 age- and sex-matched controls comprising of teachers and students. Demographic and occupational data were collected by using a structured questionnaire by a trained data collector. Blood pressure was measured using sphygmomanometry. Hematological parameters were measured with an automated hematology analyzer. Data were analyzed using Stata version 13. The majority of the garage workers did not implement effective preventive or control measures for workplace chemical exposure. Statistically significant increases were found in systolic (128.67±18.14 vs 106.33 ±9.27 mmHg, P <0.0001), diastolic blood pressure (90.33±11.29 vs 75.67 ±5.68 mmHg, P <0.0001), total white blood cells (7.9±1.51 vs 6.72±2.04×10 9 cells/L, P =0.0138), and platelets (323.20±48.82 vs 244.1±47.3×10 9 cells/L, P <0.0001) in garage workers compared to the control group. On the other hand, statistically significant decreases were found in red blood cells (5.13±0.38 vs 5.46±0.36×10 12 cells/L, P =0.0006), hemoglobin (14.89±0.71 vs 15.45±0.87 g/dL, P =0.0062), hematocrit (43.98%±1.99% vs 46.4%3±2.32%, P <0.0001), and mean corpuscular volume (83.19±2.93 vs 85.11±3.87 fL, P =0.0353) among garage workers compared to the control group. There were significant differences in blood pressure and hematological

Occupational health risk of working in garages: comparative study on blood pressure and hematological parameters between garage workers and Haramaya University community, Harar, eastern Ethiopia

PubMed Central

Ataro, Zerihun; Geremew, Abraham; Urgessa, Fekadu

2018-01-01

Background Occupational exposure to chemicals in garages causes a wide range of biological effects, depending upon the level and duration of exposure. In Ethiopia, there have been few studies conducted to assess the exposure of garage workers to chemicals. Preceding studies have not explored the effect of working in garage on blood pressure and hematological parameters. Therefore, this study aimed to assess differences in blood pressure and hematological parameters among garage workers compared to the Haramaya University community, Harar, eastern Ethiopia. Materials and methods A comparative cross-sectional study was conducted in Harar town, eastern Ethiopia. Thirty garage workers were selected and compared with 30 age- and sex-matched controls comprising of teachers and students. Demographic and occupational data were collected by using a structured questionnaire by a trained data collector. Blood pressure was measured using sphygmomanometry. Hematological parameters were measured with an automated hematology analyzer. Data were analyzed using Stata version 13. Results The majority of the garage workers did not implement effective preventive or control measures for workplace chemical exposure. Statistically significant increases were found in systolic (128.67±18.14 vs 106.33 ±9.27 mmHg, P<0.0001), diastolic blood pressure (90.33±11.29 vs 75.67 ±5.68 mmHg, P<0.0001), total white blood cells (7.9±1.51 vs 6.72±2.04×109 cells/L, P=0.0138), and platelets (323.20±48.82 vs 244.1±47.3×109 cells/L, P<0.0001) in garage workers compared to the control group. On the other hand, statistically significant decreases were found in red blood cells (5.13±0.38 vs 5.46±0.36×1012 cells/L, P=0.0006), hemoglobin (14.89±0.71 vs 15.45±0.87 g/dL, P=0.0062), hematocrit (43.98%±1.99% vs 46.4%3±2.32%, P<0.0001), and mean corpuscular volume (83.19±2.93 vs 85.11±3.87 fL, P=0.0353) among garage workers compared to the control group. Conclusion There were significant

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)

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

Interior view of the Descanso Station engine garage, building no. ...

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

Interior view of the Descanso Station engine garage, building no. 2304 facing east. Photograph taken from the elevated position on the west end of the building, detail of the roof structure. - Descanso Ranger Station, Engine Garage, 24321 Viejas Grade Road, Descanso, San Diego County, CA

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

5. ARCHITECTURAL ELEVATIONS AND FLOOR PLANS OF GARAGE, SHEET 1 ...

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

5. ARCHITECTURAL ELEVATIONS AND FLOOR PLANS OF GARAGE, SHEET 1 OF 1, 8' X 10' NEGATIVE AND PRINT MADE FROM COPIES OF ORIGINAL PLANS, MAY 15, 1936, WALLOWA-WHITMAN NATIONAL FOREST SUPERVISOR'S, OFFICE, BAKER CITY, OREGON. - Wallowa Ranger Station, Garage, 602 First Street, Wallowa, Wallowa County, OR

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lansari, A.; Streicher, J.J.; Huber, A.H.

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 indicatedmore » 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.« less

A further study of air pollution in diesel bus garages.

PubMed Central

Waller, R E; Hampton, L; Lawther, P J

1985-01-01

The concentrations of smoke, polycyclic aromatic hydrocarbons (PAHs), and some gaseous air pollutants have been measured in two London Transport diesel bus garages and compared with observations made in the same garages over 20 years earlier. The main feature of the results was a large reduction in the background concentrations of smoke and polycyclic aromatic hydrocarbons from sources such as coal fires, attributable to the implementation of the Clean Air Act. Contributions from the buses to the benzo(a) pyrene content of the air inside the garages were of the same magnitude as before, being small in relation to former coal smoke contributions. PMID:4074654

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

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

Pricing and availability intervention in vending machines at four bus garages.

PubMed

French, Simone A; Hannan, Peter J; Harnack, Lisa J; Mitchell, Nathan R; Toomey, Traci L; Gerlach, Anne

2010-01-01

To evaluate the effects of lowering prices and increasing availability on sales of healthy foods and beverages from 33 vending machines in 4 bus garages as part of a multicomponent worksite obesity prevention intervention. Availability of healthy items was increased to 50% and prices were lowered at least 10% in the vending machines in two metropolitan bus garages for an 18-month period. Two control garages offered vending choices at usual availability and prices. Sales data were collected monthly from each of the vending machines at the four garages. Increases in availability to 50% and price reductions of an average of 31% resulted in 10% to 42% higher sales of the healthy items. Employees were mostly price responsive for snack purchases. Greater availability and lower prices on targeted food and beverage items from vending machines was associated with greater purchases of these items over an 18-month period. Efforts to promote healthful food purchases in worksite settings should incorporate these two strategies.

WELLTON GOVERNMENT CAMP, PERMANENT GARAGE TYPE 1G. PLAN, ELEVATIONS, AND ...

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

WELLTON GOVERNMENT CAMP, PERMANENT GARAGE TYPE 1-G. PLAN, ELEVATIONS, AND SECTIONS. Drawing 50-308-4552, dated October 25, 1949. U.S. Department of the Interior, Bureau of Reclamation, Yuma, Arizona - Wellton-Mohawk Irrigation System, Permanent Garage Type 1-G, 30601 Wellton-Mohawk Drive, Wellton, Yuma County, AZ

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

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-housemore » 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.« less

WELLTON GOVERNMENT CAMP, PERMANENT GARAGE TYPE 2G. PLAN, ELEVATIONS, AND ...

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

WELLTON GOVERNMENT CAMP, PERMANENT GARAGE TYPE 2-G. PLAN, ELEVATIONS, AND SECTIONS. Drawing 50-308-4553, dated October 21, 1949. U.S. Department of the Interior, Bureau of Reclamation, Yuma, Arizona - Wellton-Mohawk Irrigation System, Permanent Garage Type 2-G, 30611 and 30621 Wellton-Mohawk Drive, Wellton, Yuma County, AZ

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Account 394, Tools, shop and garage equipment. 367.3940 Section 367.3940 Conservation of Power and Water Resources FEDERAL... NATURAL GAS ACT Service Company Property Chart of Accounts § 367.3940 Account 394, Tools, shop and garage...

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Account 394, Tools, shop and garage equipment. 367.3940 Section 367.3940 Conservation of Power and Water Resources FEDERAL... NATURAL GAS ACT Service Company Property Chart of Accounts § 367.3940 Account 394, Tools, shop and garage...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Account 394, Tools, shop and garage equipment. 367.3940 Section 367.3940 Conservation of Power and Water Resources FEDERAL... NATURAL GAS ACT Service Company Property Chart of Accounts § 367.3940 Account 394, Tools, shop and garage...

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... NATURAL GAS ACT Service Company Property Chart of Accounts § 367.3940 Account 394, Tools, shop and garage...

Pricing and Availability Intervention in Vending Machines at Four Bus Garages

PubMed Central

Hannan, Peter J; Harnack, Lisa J; Mitchell, Nathan R; Toomey, Traci L; Gerlach, Anne

2009-01-01

Objective To evaluate the effects of lowering prices and increasing availability on sales of healthy foods and beverages from 33 vending machines in four bus garages as part of a multi-component worksite obesity prevention intervention. Methods Availability of healthy items was increased to 50% and prices were lowered at least 10% in the vending machines in two metropolitan bus garages for an 18-month period. Two control garages offered vending choices at usual availability and prices. Sales data were collected monthly from each of the vending machines at the four garages. Results Increases in availability to 50% and price reductions of an average of 31% resulted in 10-42% higher sales of the healthy items. Employees were most price-responsive for snack purchases. Conclusions Greater availability and lower prices on targeted food and beverage items from vending machines was associated with greater purchases of these items over an eighteen-month period. Efforts to promote healthful food purchases in worksite settings should incorporate these two strategies. PMID:20061884

66. FONTHILL GARAGE (1913) AND TERRACE PAVILION (192628), FROM SOUTH. ...

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

66. FONTHILL GARAGE (1913) AND TERRACE PAVILION (1926-28), FROM SOUTH. POURED ATOP AN EARLIER STONE BARN. THE FIRST FLOOR OF THIS STRUCTURE SERVERD AS A GARAGE FOR FONTHILL. IN 1926, MERCER BEGAN CONVERTING THE SECOND FLOOR INTO AND ELABORATELY DECORATED MEETING HOUSE FOR THE DOYLESTOWN NATURE CLUB, CALLED THE TERRACE PAVILION. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinzey, Bruce R.; Myer, Michael; Royer, Michael 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 anmore » 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.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 pressuremore » 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.« less

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

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

[Prediction and influence factors of the ramp's noise of the entrance or exit of garages].

PubMed

Di, Guo-Qing; Zhang, Bang-Jun

2005-09-01

Some typical entrances/exits of the underground garages are chosen in urban residential areas. On the basis of the optimization of the positions of the noise sampling points and the groupings of the synchronous sampling points, by means of the acoustical analysis of the noise samples, the relation of the correlative factors, among the ramps' noise of the entrances or exits of the garages, the structure, grade, shape of the ramps, upgrade and downgrade, is studied. The prediction model of the ramp's noise influence of the entrance or exit of the garage is established through amending the noise influence of the entrance or exit of the even concrete road.

6. AVALON DAM GATE KEEPER'S COMPLEX: GARAGE AND WAREHOUSE ...

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

6. AVALON DAM - GATE KEEPER'S COMPLEX: GARAGE AND WAREHOUSE (LEFT), HOUSE (RIGHT), AND CCC LANDSCAPING (FOREGROUND). VIEW TO NORTH - Carlsbad Irrigation District, Avalon Dam, On Pecos River, 4 miles North of Carlsbad, Carlsbad, Eddy County, NM

Influence of basements, garages, and common hallways on indoor residential volatile organic compound concentrations

NASA Astrophysics Data System (ADS)

Dodson, Robin E.; Levy, Jonathan I.; Spengler, John D.; Shine, James P.; Bennett, Deborah H.

Concentrations of many volatile organic compounds (VOCs) are often higher inside residences than outdoors as a result of sources or activities within the residences. These sources can be located directly in the living space of the home or in areas associated with the home such as an attached garage, basement, or common apartment hallway. To characterize the contributions from these areas to indoor residential concentrations, VOC concentrations were measured inside, outside, and, if present, in the attached garage, basement, or common hallway of an apartment of 55 residences in the Boston area, most over two seasons, as part of the Boston Exposure Assessment in Microenvironments (BEAM) Study. Of the 55 residences in the study, 11 had attached garages and basements, 24 had only basements, 10 other residences had common apartment hallways, and the remaining 10 were treated as single compartment residences. Concentrations in the garage were up to 5-10 times higher at the median than indoor concentrations for mobile source pollutants including benzene, toluene, ethylbenzene, and xylenes. Basement/indoor concentration ratios were significantly >1 for methylene chloride, ethylbenzene, m, p-xylene, and o-xylene, and summer ratios tended to be higher than winter ratios. Approximately, 20-40% of the indoor concentration for compounds associated with gasoline sources, such as methyl t-butyl ether (MTBE), benzene, toluene, ethylbenzene, and xylenes, can be attributed to an attached garage at the residence, with garages laterally attached to the first floor of the home having a larger impact. At the median, basements contributed to approximately 10-20% of the estimated indoor concentrations. For apartments, approximately 5-10% of the estimated indoor concentrations confer with air from the hallway. Contributions of these secondary zones to concentrations in the living area of a home were calculated using concentration and airflow estimates. Our findings illustrate the potential

Garage carbon monoxide levels from sources commonly used in intentional poisoning.

PubMed

Hampson, Neil B; Holm, James R; Courtney, Todd G

2017-01-01

The incidence of intentional carbon monoxide (CO) poisoning is believed to have declined due to strict federal CO emissions standards for motor vehicles and the uniform application of catalytic converters (CC). We sought to compare ambient CO levels produced by automobiles with and without catalytic converters in a residential garage, as well as from other CO sources commonly used for intentional poisoning. CO levels were measured inside a freestanding 73 m3 one-car garage. CO sources included a 1971 automobile without CC, 2003 automobile with CC, charcoal grill, electrical generator, lawn mower and leaf blower. After 20 minutes of operation, the CO level in the garage was 253 PPM for the car without a catalytic converter and 30 PPM for the car equipped withone. CO levels after operating or burning the other sources were: charcoal 200 PPM; generator >999 PPM; lawn mower 198 PPM; and leaf blower 580 PPM. While emissions controls on automobiles have reduced intentional CO poisonings, alternate sources may produce CO at levels of the same magnitude as vehicles manufactured prior to the use of catalytic converters. Those involved in the care of potentially suicidal individuals should be aware of this.

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

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

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

[Risk of chronic carbon monoxide poisoning in automobile garages. Results of a study in the Lausanne region].

PubMed

Köhl, U; Lob, M

1975-01-11

Clinical and physiologic data on chronic carbon monoxide poisoning are reviewed and the results of an investigation involving 7 garages in the Lausanne (Switzerland) area are reported. The aim was a practical approach to the relationships between carbon monoxide level in the air, COHb and clinical picture. The study covered working conditions (especially ventilation) but did not take into account of other factors (stresses) which may effect the parameters investigated. CO was measured by continuous recording with an MSA Carbon Monoxide Alarm and the hourly and daily averages were determined. The garage personnel replied to a questionnaire and underwent a brief clinical examination including taking of digital blood samples for measurement of hematocrit and carboxyhemoglobin level by the method of COMMINS and LAWTHER as modified by BUCHWALD. One of the garages did not meet present health requirements. Statistical analysis revealed a significant correlation between carbon monoxide and carboxyhemoglobin. The incidence of complaints was highest in poorly ventilated garages. On the basis of COHb level in the total group of employees, together with data from individual histories, it is possible to evaluate the risk of carbon monoxide poisoning in a given garage.

Characterization of indoor diesel exhaust emissions from the parking garage of a school.

PubMed

Debia, Maximilien; Trachy-Bourget, Marie-Claude; Beaudry, Charles; Neesham-Grenon, Eve; Perron, Stéphane; Lapointe, Caroline

2017-02-01

Diesel exhaust (DE) emissions from a parking garage located in the basement of a school were characterized during spring and winter using direct reading devices and integrated sampling methods. Concentrations of CO and NO 2 were evaluated using electrochemical sensors and passive colorimetric tubes, respectively. Elemental and total carbon concentrations were measured using the NIOSH 5040 method. Particle number concentrations (PNCs), respirable particulate matter (PM resp ) mass concentrations, and size distributions were evaluated using direct reading devices. Indoor concentrations of elemental carbon, PNC, CO, and NO 2 showed significant seasonal variation; concentrations were much higher during winter (p < 0.01). Concentrations of the PM resp and total carbon did not show significant seasonal variation. Pearson correlation coefficients were 0.9 (p < 0.01) and 0.94 (p < 0.01) between the parking garage and ground floor average daily PNCs, and between the parking garage and first floor average daily PNCs, respectively. Since DE is the main identified source of fine and ultrafine particles in the school, these results suggest that DE emissions migrate from the parking garage into the school. Our results highlight the relevance of direct reading instruments in identifying migration of contaminants and suggest that monitoring PNC is a more specific way of assessing exposure to DE than monitoring the common PM resp fraction.

Aerial view showing US 93, Switchyards, Visitor Center Parking Garage, ...

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

Aerial view showing US 93, Switchyards, Visitor Center Parking Garage, Hoover Dam, and Colorado River Canyon in Nevada - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

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

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

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

3. OBLIQUE VIEW LOOKING NORTHWEST SHOWING GARAGE EXTENSION WITH DOORS. ...

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

3. OBLIQUE VIEW LOOKING NORTHWEST SHOWING GARAGE EXTENSION WITH DOORS. VIEW FROM BUILDING 15. - Chollas Heights Naval Radio Transmitting Facility, Public Works Shop, 6410 Zero Road, San Diego, San Diego County, CA

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

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

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

3. LOCATION OF OPERATORS' COTTAGES AND GARAGE DETAILS, NINE MILE ...

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

3. LOCATION OF OPERATORS' COTTAGES AND GARAGE DETAILS, NINE MILE STATION. Blueprint drawing no. D3252, dated July 21, 1927 - Nine Mile Hydroelectric Development, State Highway 291 along Spokane River, Nine Mile Falls, Spokane County, WA

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

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

PERSPECTIVE VIEW OF THE C. 1930 GREYHOUND BUS GARAGE (CURRENT ...

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

PERSPECTIVE VIEW OF THE C. 1930 GREYHOUND BUS GARAGE (CURRENT USE: RESTAURANT), LOCATED AT 100 NW JACKSON AVENUE, VIEW LOOKING NORTHWEST. - Corvallis Downtown Historic District, Bounded by First & Sixth Streets, Van Buren & Western Avenues, Corvallis, Benton County, OR

Garage Demos: Using Physical Models to Illustrate Dynamic Aspects of Microscopic Biological Processes

PubMed Central

Aguilar-Roca, Nancy

2009-01-01

Colorful PowerPoint presentations with detailed drawings, micrographs, and short animations have become the standard format for illustrating the fundamental features of cell biology in large introductory classes. In this essay, we describe a low-tech tool that can be included in a standard lecture to help students visualize, understand, and remember the dynamic aspects of microscopic cell biological processes. This approach involves use of common objects, including pipe insulation and a garden hose, to illustrate basic processes such as protein folding and cloning, hence the appellation “garage demos.” The demonstrations are short, minimizing displacement of course content, easy to make, and provide an avenue for increasing student–faculty interaction in a large lecture hall. Student feedback over the past 4 years has been overwhelmingly positive. In an anonymous postclass survey in 2007, 90% of the respondents rated garage demos as having been very or somewhat helpful for understanding course concepts. Direct measurements of learning gains on specific concepts illustrated by garage demos are the focus of an ongoing study. PMID:19487500

Modelling of depth stabilization and submerging of tethered underwater garage in conditions of sea oscillating motion

NASA Astrophysics Data System (ADS)

Gayvoronskiy, S. A.; Ezangina, T. A.; Khozhaev, I. V.

2018-03-01

The paper is dedicated to examining dynamics of a submersible underwater garage in conditions of significant sea oscillation. During the considered research, the mathematical model of the electromechanical depth control system, considering interval parametric uncertainty of the system and distribution of tether mass, was developed. An influence of sea oscillation on submerging underwater garages and their depth stabilization processes was analyzed.

9. Interior view of unoccupied space; showing opened exterior garage ...

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

9. Interior view of unoccupied space; showing opened exterior garage door, opened doorway to adjoining rooms, and closed exterior doorway; near southeast corner of building; view to southwest. - Ellsworth Air Force Base, Warehouse, 789 Twining Street, Blackhawk, Meade County, SD

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

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

PERSPECTIVE VIEW OF THE C. 1925 AUTO SALES/GARAGE STRUCTURE LOCATED ...

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

PERSPECTIVE VIEW OF THE C. 1925 AUTO SALES/GARAGE STRUCTURE LOCATED AT 205-209 SECOND STREET NORTHWEST. - Corvallis Downtown Historic District, Bounded by First & Sixth Streets, Van Buren & Western Avenues, Corvallis, Benton County, OR

Learning in the Workplace for Garage Mechanics and Technicians

ERIC Educational Resources Information Center

Jans, Ruben, Bollen, Ria,

2008-01-01

Employees in technical firms, like garages, need more and more formations. Due to the very fast innovation in technology, lifelong learning is a real need for these labour forces. On the other hand, there are the needed formations very specialized and expensive. Another problem employers faced in these economical sectors in Western Europe is the…

Heat dissipation investigation of the internal heat sink geometry of a commercial available LED lamp

NASA Astrophysics Data System (ADS)

Lai, S. L.; Ong, N. R.; Kirtsaeng, S.; Sakuntasathien, S.; Alcain, J. B.; Sauli, Z.; Thangsi, K.; Retnasamy, V.

2017-09-01

Thermal issue is still the bottleneck of the LED to sustain their operational performance. LED lamp is vastly commercialized and has become the next generation of lighting source to substitute the conventional incandescent lamp. Thus, thermal management issue on LED lamp is important to maintain the device reliability. This study focuses on the modification of internal heat sink of the LED lamp which was considered and the thermal performance was investigated. Open source software, Salome and Elmer were used for this study. The result shows that larger surface area of heat sink has better heat dissipation performance.

6. BUILDING 283, WEST SIDE OF THE GARAGE ADDITION (CA.1947) ...

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

6. BUILDING 283, WEST SIDE OF THE GARAGE ADDITION (CA.1947) ON LEFT, NORTH SIDE OF CA.1947-1950 ADDITION ON RIGHT. - Presidio of San Francisco, Warehouse & Auto Shop, Crissy Field North cantonment, San Francisco, San Francisco County, CA

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

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

Lung cancer and exposure to diesel exhaust among bus garage workers.

PubMed

Gustavsson, P; Plato, N; Lidström, E B; Hogstedt, C

1990-10-01

Mortality and cancer incidence was investigated among the 695 bus garage workers employed as mechanics, servicemen, or hostlers for at least six months in five bus garages in Stockholm between 1945 and 1970. The exposure to diesel exhaust and asbestos was estimated by industrial hygienists. A small excess of lung cancer mortality was found in the cohort when occupationally active men in Stockholm were used as the reference group. A case-referent study was performed within the cohort, six referents being selected for each of the 20 lung cancer cases. The lung cancer risk increased with increasing cumulative exposure to diesel exhaust, but not with cumulative asbestos exposure. The relative risk for lung cancer among the highly exposed men was 2.4 (95% CI 1.3-4.5) as compared with those with low exposure. The study indicates that exposure to diesel exhaust increases the risk for lung cancer.

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

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 the...

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 the...

Removal of oil and grease from automobile garage wastewater using electrocoagulation

NASA Astrophysics Data System (ADS)

Manilal, A. M.; Harinarayanan Nampoothiri, M. G.; Soloman, P. A.

2017-06-01

Wastewater from automobile garages and workshops is an important contributor to the water pollution. Oil and grease is one of the major content of wastewater from vehicle garages. Wastewater from a public transport depot at Thrissur district in Kerala, India was collected for the study. A batch reactor has been devised to assess the efficacy of electrocoagulation in removing oil and grease from the wastewater. Aluminium and iron were tested as the anode material with stainless steel as cathode. Experiments were conducted to investigate the effect of various operating parameters such as current density, pH, time and salt concentration on oil and grease removal. The results shown that aluminium is superior to iron in removing the oil and grease from the wastewater. The reactor with aluminium as anode was able to remove 90.8 % of the oil and grease at a current density of 0.6 A/dm2 in 15 minutes. The calculated specific energy consumption is also less for aluminium in comparison with iron.

Occupational lead exposure among automotive garage workers – a case study for Jimma town, Ethiopia

PubMed Central

2012-01-01

Background In Ethiopia, although there are numerous small-scale and medium industries which use lead-based raw materials that may pose health risks to workers, there are no workplace regulations for lead exposure. Moreover, there are no studies carried out on the blood lead levels (BLLs) of workers or on the contribution of common workplace practices to lead poisoning. Method A cross-sectional study on the BLLs of 45 automotive garage workers and 40 non-garage workers was carried out in the town of Jimma, Ethiopia. In addition to BLL analysis, data on some risk factors such as smoking, and chewing ‘khat’ (the leaves of Catha adulis) were gathered through structured questionnaires and interviews and data analysis was performed using SPSS (version 16). The t-test was used to compare mean BLLs of study groups. The analysis of variance (ANOVA), Kruskal-Wallis, Pearson chi-square and odds ratio tests were used to investigate the associations between specific job type, smoking and/or ‘khat’ chewing, service years and occurrence of non-specific symptoms with BLLs. Results The mean BLL of the automotive-garage workers was found to be significantly greater than that of the controls. The BLLs of all the lead-exposed individuals were found to be over 10 μg/dL, and 53% of them had BLLs ranging 12 – 20 μg/dL, with the remaining 47% having over 20 μg/dL. The BLL of the workers increased with the duration of working in an automotive garage. Individuals involved in manual car painting comprise a larger percentage (58%) of those with the highest BLLs (≥ 20 μg/dL). Lead accumulation in individuals who chew ‘khat’ in the work place was found to be faster than in those who are not used to chewing ‘khat’. ‘Khat’ is an evergreen shrub native to tropical East Africa, with dark green opposite leaves which are chewed when fresh for their stimulating effects. Conclusion The findings of the study have clearly demonstrated that the BLLs of automotive-garage

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

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Ladders. (21) Lathes. (22) Machine tools. (23) Motor-driven tools. (24) Motors. (25) Pipe threading and..., shop and garage equipment. 367.3940 Section 367.3940 Conservation of Power and Water Resources FEDERAL... equipment. (a) This account must include the cost of tools, implements, and equipment used in construction...

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.

Analysis of particle and vapour phase PAHs from the personal air samples of bus garage workers exposed to diesel exhaust.

PubMed

Kuusimaki, Leea; Peltonen, Kimmo; Mutanen, Pertti; Savela, Kirsti

2003-07-01

The levels of particle and vapour phase polycyclic aromatic hydrocarbons (PAHs) derived from the diesel exhaust compounds in bus garage work were measured in winter and in summer. Five personal air samples were collected from the breathing zones of 22 garage workers every other day of consecutive weeks. Control samples (n = 22) were collected from office workers in Helsinki. Fifteen PAHs in the air samples were analysed by HPLC using a fluorescence detector. Statistically significant differences were observed between total PAH levels of the exposed workers (2241 and 1245 ng/m(3)) and the control group (254 and 275 ng/m(3)) in both winter (P < 0.001) and summer (P < 0.001). Phenanthrene, pyrene, benzo[ghi]perylene and fluoranthene were the major compounds in the particle phase, and naphthalene, phenanthrene and fluorene in the vapour phase. About 98% of PAHs measured were related to the vapour phase compounds, whereas the high molecular weight PAH compounds were detected only in the particle phase. The PAH levels in the garages were twice as high (P < 0.001) in winter as in summer. Even though the exposure levels were low in the bus garages, the low level does not allow conclusions to be drawn about the possible adverse health effects due to exposure to diesel exhaust.

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.

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

A BLE-Based Pedestrian Navigation System for Car Searching in Indoor Parking Garages

PubMed Central

Wang, Sheng-Shih

2018-01-01

The continuous global increase in the number of cars has led to an increase in parking issues, particularly with respect to the search for available parking spaces and finding cars. In this paper, we propose a navigation system for car owners to find their cars in indoor parking garages. The proposed system comprises a car-searching mobile app and a positioning-assisting subsystem. The app guides car owners to their cars based on a “turn-by-turn” navigation strategy, and has the ability to correct the user’s heading orientation. The subsystem uses beacon technology for indoor positioning, supporting self-guidance of the car-searching mobile app. This study also designed a local coordinate system to support the identification of the locations of parking spaces and beacon devices. We used Android as the platform to implement the proposed car-searching mobile app, and used Bytereal HiBeacon devices to implement the proposed positioning-assisting subsystem. We also deployed the system in a parking lot in our campus for testing. The experimental results verified that the proposed system not only works well, but also provides the car owner with the correct route guidance information. PMID:29734753

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…

Simultaneous measurement of ventilation using tracer gas techniques and VOC concentrations in homes, garages and vehicles.

PubMed

Batterman, Stuart; Jia, Chunrong; Hatzivasilis, Gina; Godwin, Chris

2006-02-01

Air exchange rates and interzonal flows are critical ventilation parameters that affect thermal comfort, air migration, and contaminant exposure in buildings and other environments. This paper presents the development of an updated approach to measure these parameters using perfluorocarbon tracer (PFT) gases, the constant injection rate method, and adsorbent-based sampling of PFT concentrations. The design of miniature PFT sources using hexafluorotoluene and octafluorobenzene tracers, and the development and validation of an analytical GC/MS method for these tracers are described. We show that simultaneous deployment of sources and passive samplers, which is logistically advantageous, will not cause significant errors over multiday measurement periods in building, or over shorter periods in rapidly ventilated spaces like vehicle cabins. Measurement of the tracers over periods of hours to a week may be accomplished using active or passive samplers, and low method detection limits (<0.025 microg m(-3)) and high precisions (<10%) are easily achieved. The method obtains the effective air exchange rate (AER), which is relevant to characterizing long-term exposures, especially when ventilation rates are time-varying. In addition to measuring the PFT tracers, concentrations of other volatile organic compounds (VOCs) are simultaneously determined. Pilot tests in three environments (residence, garage, and vehicle cabin) demonstrate the utility of the method. The 4 day effective AER in the house was 0.20 h(-1), the 4 day AER in the attached garage was 0.80 h(-1), and 16% of the ventilation in the house migrated from the garage. The 5 h AER in a vehicle traveling at 100 km h(-1) under a low-to-medium vent condition was 92 h(-1), and this represents the highest speed test found in the literature. The method is attractive in that it simultaneously determines AERs, interzonal flows, and VOC concentrations over long and representative test periods. These measurements are

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…

Effect of two different commercially available white light LED fixtures on broiler hatchability and chick quality.

PubMed

Archer, G S

2018-06-01

1. The objective of this study was to evaluate the effect of two different spectra of white light on hatchability and chick quality of broiler chickens. 2. A total of 8424 Ross 708 broiler eggs were divided over three light exposure treatments during incubation: No light (DARK), a light emitting diode (LED) light with high levels of blue light (BLUE), or a LED light with high levels of red light (RED). Hatchability, embryo mortality and chick quality were assessed at hatch. 3. DARK had a higher percentage of chicks with unhealed navels (21.1 ± 1.3%) and fewer overall chicks with no defects (77.0 ± 1.2%) compared to both the BLUE (9.9 ± 0.9% and 88.4 ± 1.1%) and RED treatments (7.7 ± 0.8% and 90.2 ± 1.0%). 4. Both the BLUE (80.9 ± 1.0%) and RED treatments (82.9 ± 1.4%) had higher hatchability of fertile eggs than the DARK treatment (76.0 ± 2.2%). 5. These results indicate that either of these LED fixtures could be used to improve hatchability and chick quality in broiler chickens. Utilising these types of lightings in commercial hatcheries will improve the efficiency via increased hatchability and quality of the chicks hatched.

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.

[Organic brain damage in garage workers after long-term exposure to diesel exhaust fumes].

PubMed

Jensen, L K; Klausen, H; Elsnab, C

1989-09-04

Diesel motors are employed to an increasing extent for occupational transport and fumes from diesel driven vehicles constitute an increasing problem as regards atmospheric pollution but, in particular, they constitute a considerable risk to health for the workers exposed to diesel exhaust fumes in their daily work. In the clinic for occupational medicine, The University Hospital, Copenhagen, 14 garage workers were examined. Eleven of these had been exposed to great quantities of diesel exhaust fumes for 2 to 29 years. All 11 presented acute symptoms due to diesel exhaust fumes in the form of headache, vertigo, fatigue, irritation of mucous membranes, nausea, abdominal discomfort or diarrhoea. Seven persons had been employed for more than five years as garage workers. Six complained of failure of memory, difficulty in concentration, irritability, increased sleep requirement, psychological changes or reduced libido. Neuropsychological examination was undertaken in these six persons and in five of them organic brain damage, mainly of slight extent, was demonstrated. Diesel exhaust fumes contain many toxic substances: carbon monoxide, nitrous gases, sulphur oxides, aldehydes and hydrocarbons. It is not possible to indicate a single compound which is responsible for possible brain damage and a combination effect may well be concerned. This is a casuistic material. Only few investigations have previously been available which illustrated a possible connection between the neurotoxic effects and, in particular, brain damage. It is now considered important to emphasize that this may constitute a problem on exposure to diesel exhaust fumes.(ABSTRACT TRUNCATED AT 250 WORDS)

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. Copyright © 2016. Published by Elsevier Ltd.

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.

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.

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

PubMed

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.

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.

Assessment of Material Solutions of Multi-level Garage Structure Within Integrated Life Cycle Design Process

NASA Astrophysics Data System (ADS)

Wałach, Daniel; Sagan, Joanna; Gicala, Magdalena

2017-10-01

The paper presents an environmental and economic analysis of the material solutions of multi-level garage. The construction project approach considered reinforced concrete structure under conditions of use of ordinary concrete and high-performance concrete (HPC). Using of HPC allowed to significant reduction of reinforcement steel, mainly in compression elements (columns) in the construction of the object. The analysis includes elements of the methodology of integrated lice cycle design (ILCD). By making multi-criteria analysis based on established weight of the economic and environmental parameters, three solutions have been evaluated and compared within phase of material production (information modules A1-A3).

A brief history of LED photopolymerization.

PubMed

Jandt, Klaus D; Mills, Robin W

2013-06-01

The majority of modern resin-based oral restorative biomaterials are cured via photopolymerization processes. A variety of light sources are available for this light curing of dental materials, such as composites or fissure sealants. Quartz-tungsten-halogen (QTH) light curing units (LCUs) have dominated light curing of dental materials for decades and are now almost entirely replaced by modern light emitting diode light curing units (LED LCUs). Exactly 50 years ago, visible LEDs were invented. Nevertheless, it was not before the 1990s that LEDs were seriously considered by scientists or manufactures of commercial LCUs as light sources to photopolymerize dental composites and other dental materials. The objective of this review paper is to give an overview of the scientific development and state-of-the-art of LED photopolymerization of oral biomaterials. The materials science of LED LCU devices and dental materials photopolymerized with LED LCU, as well as advantages and limits of LED photopolymerization of oral biomaterials, are discussed. This is mainly based on a review of the most frequently cited scientific papers in international peer reviewed journals. The developments of commercial LED LCUs as well as aspects of their clinical use are considered in this review. The development of LED LCUs has progressed in steps and was made possible by (i) the invention of visible light emitting diodes 50 years ago; (ii) the introduction of high brightness blue light emitting GaN LEDs in 1994; and (iii) the creation of the first blue LED LCUs for the photopolymerization of oral biomaterials. The proof of concept of LED LCUs had to be demonstrated by the satisfactory performance of resin based restorative dental materials photopolymerized by these devices, before LED photopolymerization was generally accepted. Hallmarks of LED LCUs include a unique light emission spectrum, high curing efficiency, long life, low energy consumption and compact device form factor. By

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 tomore » immediate area of the Rust Garage Facility.« less

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.

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

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.

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.

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.

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.

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.

GATEWAY Demonstrations: Exterior LED Lighting Projects at Princeton University

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Robert G.; Evans, WIlliam E.; Murphy, Arthur

This report focuses on four exterior solid-state lighting projects that have been completed at Princeton since 2008, when the University adopted a comprehensive sustainability plan. Through these initial projects – which include a parking garage, a pedestrian path, and two parking lot installations – the school’s facilities engineering staff learned important lessons about SSL technology and gained experience in dealing with the rapidly changing landscape of lighting manufacturers and their suppliers.

Part 3 Specialized aspects of GIS and spatial analysis . Garage band science and dynamic spatial models

NASA Astrophysics Data System (ADS)

Box, Paul W.

GIS and spatial analysis is suited mainly for static pictures of the landscape, but many of the processes that need exploring are dynamic in nature. Dynamic processes can be complex when put in a spatial context; our ability to study such processes will probably come with advances in understanding complex systems in general. Cellular automata and agent-based models are two prime candidates for exploring complex spatial systems, but are difficult to implement. Innovative tools that help build complex simulations will create larger user communities, who will probably find novel solutions for understanding complexity. A significant source for such innovations is likely to be from the collective efforts of hobbyists and part-time programmers, who have been dubbed ``garage-band scientists'' in the popular press.

LEDs for solid state lighting and other emerging applications: status, trends, and challenges

NASA Astrophysics Data System (ADS)

Craford, M. George

2005-09-01

LEDs have been commercially available since the 1960's, but in recent years there have been remarkable improvements in performance. These technology developments have enabled the use of LEDs in a variety of colored and white lighting applications. Colored LEDs have already become the technology of choice for traffic signals, much of interior and exterior vehicle lighting, signage of various types often as a replacement for neon, and other areas. LEDs are expected to become the dominant technology for most colored lighting applications. LEDs are beginning to penetrate white lighting markets such as flashlights and localized task lighting. With further improvement LEDs have the potential to become an important technology for large area general illumination. White LED products already have performance of over 30 lumens/watt which is nearly 3x better than incandescents. White LEDs with outputs of more than 100 lumens are already available commercially, and higher power devices can be expected in the near future. LEDs can be used as point sources, or can be used with light guides of various types to provide distributed illumination. Developments that will need to occur for LEDs to be viable for large area general illumination are discussed.

49 CFR 396.19 - Inspector qualifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... mechanic or inspector in a motor carrier or intermodal equipment maintenance program; (C) Experience as a mechanic or inspector in commercial motor vehicle maintenance at a commercial garage, fleet leasing company...

49 CFR 396.19 - Inspector qualifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... mechanic or inspector in a motor carrier or intermodal equipment maintenance program; (C) Experience as a mechanic or inspector in commercial motor vehicle maintenance at a commercial garage, fleet leasing company...

49 CFR 396.19 - Inspector qualifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... mechanic or inspector in a motor carrier or intermodal equipment maintenance program; (C) Experience as a mechanic or inspector in commercial motor vehicle maintenance at a commercial garage, fleet leasing company...

49 CFR 396.19 - Inspector qualifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... mechanic or inspector in a motor carrier or intermodal equipment maintenance program; (C) Experience as a mechanic or inspector in commercial motor vehicle maintenance at a commercial garage, fleet leasing company...

49 CFR 396.19 - Inspector qualifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... mechanic or inspector in a motor carrier or intermodal equipment maintenance program; (C) Experience as a mechanic or inspector in commercial motor vehicle maintenance at a commercial garage, fleet leasing company...

LED Illuminators for the SNAP Calibration

NASA Astrophysics Data System (ADS)

Misra, Amit; Baptista, B.; Mufson, S.; Mostek, N.

2007-12-01

The Supernova Acceleration Probe, or SNAP, is a proposed satellite mission that will study dark energy to better understand what is driving the universe's accelerated expansion. One of the goals of SNAP is to control systematic color uncertainties to less than 2%. The work described here is directed at the development of a flight calibration illumination system for SNAP that minimizes systematic errors in color. The system is based on LEDs as the illumination lamps. LEDs are compact, long-lived, and low power illuminators, which make them attractive for space missions lasting several years. This poster discusses optical measurements of pulsed, thermally controlled LEDs obtained from commercial vendors. Measurements over short (over the span of one day) and long (over the span of weeks) time scales have shown that the irradiance of the LEDs we tested is constant at the 0.3% level. In these measurements we paid particular attention to the influence of junction heating. Measurements of LED irradiance versus the duty cycle of the pulsed LED show that in general the LED irradiance increases as the junction temperature increases. Additionally, the FWHM of the spectrum also increases as the temperature increases. However, measurements of LED irradiance versus temperature as regulated a by a thermal controller circuit, show that the LED irradiance decreases as the temperature increases. This work has been supported by the National Science Foundation under grant AST-0452975 (REU-Site to Indiana U.).

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.

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

Accelerated Stress Testing of Multi-Source LED Products: Horticulture Lamps and Tunable-White Modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Lynn; Rountree, Kelley; Mills, Karmann

This report discusses the use of accelerated stress testing (AST) to provide insights into the long-term behavior of commercial products utilizing different types of mid-power LEDs (MP-LEDs) integrated into the same LED module. Test results are presented from two commercial lamps intended for use in horticulture applications and one tunable-white LED module intended for use in educational and office lighting applications. Each of these products is designed to provide a custom spectrum for their targeted applications and each achieves this goal in different ways. Consequently, a comparison of the long-term stability of these devices will provide insights regarding approaches thatmore » could be used to possibly lengthen the lifetime of SSL products.« less

49 CFR 396.17 - Periodic inspection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... appendix G of this subchapter. The term commercial motor vehicle includes each vehicle in a combination vehicle. For example, for a tractor semitrailer, full trailer combination, the tractor, semitrailer, and... have a commercial garage, fleet leasing company, truck stop, or other similar commercial business...

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.

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.

Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity: lighten Up randomised controlled trial.

PubMed

Jolly, Kate; Lewis, Amanda; Beach, Jane; Denley, John; Adab, Peymane; Deeks, Jonathan J; Daley, Amanda; Aveyard, Paul

2011-11-03

To assess the effectiveness of a range of weight management programmes in terms of weight loss. Eight arm randomised controlled trial. Primary care trust in Birmingham, England. 740 obese or overweight men and women with a comorbid disorder identified from general practice records. Weight loss programmes of 12 weeks' duration: Weight Watchers; Slimming World; Rosemary Conley; group based, dietetics led programme; general practice one to one counselling; pharmacy led one to one counselling; choice of any of the six programmes. The comparator group was provided with 12 vouchers enabling free entrance to a local leisure (fitness) centre. The primary outcome was weight loss at programme end (12 weeks). Secondary outcomes were weight loss at one year, self reported physical activity, and percentage weight loss at programme end and one year. Follow-up data were available for 658 (88.9%) participants at programme end and 522 (70.5%) at one year. All programmes achieved significant weight loss from baseline to programme end (range 1.37 kg (general practice) to 4.43 kg (Weight Watchers)), and all except general practice and pharmacy provision resulted in significant weight loss at one year. At one year, only the Weight Watchers group had significantly greater weight loss than did the comparator group (2.5 (95% confidence interval 0.8 to 4.2) kg greater loss,). The commercial programmes achieved significantly greater weight loss than did the primary care programmes at programme end (mean difference 2.3 (1.3 to 3.4) kg). The primary care programmes were the most costly to provide. Participants allocated to the choice arm did not have better outcomes than those randomly allocated to a programme. Commercially provided weight management services are more effective and cheaper than primary care based services led by specially trained staff, which are ineffective. Trial registration Current Controlled Trials ISRCTN25072883.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

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 futuremore » 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.« less

76 FR 66692 - Executive-Led Trade Mission to Afghanistan

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... business development trade mission to Kabul, Afghanistan in February 2012. This mission will be led by a..., architecture, transportation and logistics, and infrastructure); mining (including equipment, technology, and.... companies explore long-term business opportunities in Afghanistan and enhance U.S.--Afghan commercial...

Meeting the challenges of developing LED-based projection displays

NASA Astrophysics Data System (ADS)

Geißler, Enrico

2006-04-01

The main challenge in developing a LED-based projection system is to meet the brightness requirements of the market. Therefore a balanced combination of optical, electrical and thermal parameters must be reached to achieve these performance and cost targets. This paper describes the system design methodology for a digital micromirror display (DMD) based optical engine using LEDs as the light source, starting at the basic physical and geometrical parameters of the DMD and other optical elements through characterization of the LEDs to optimizing the system performance by determining optimal driving conditions. LEDs have a luminous flux density which is just at the threshold of acceptance in projection systems and thus only a fully optimized optical system with a matched set of LEDs can be used. This work resulted in two projection engines, one for a compact pocket projector and the other for a rear projection television, both of which are currently in commercialization.

LED-based UV source for monitoring spectroradiometer properties

NASA Astrophysics Data System (ADS)

Sildoja, Meelis-Mait; Nevas, Saulius; Kouremeti, Natalia; Gröbner, Julian; Pape, Sven; Pendsa, Stefan; Sperfeld, Peter; Kemus, Fabian

2018-06-01

A compact and stable UV monitoring source based on state-of-the-art commercially available ultraviolet light emitting diodes (UV-LEDs) has been developed. It is designed to trace the radiometric stability—both responsivity and wavelength scale—of array spectroradiometers measuring direct solar irradiance in the wavelength range between 300 nm and 400 nm. The spectral irradiance stability of the UV-LED-based light source observed in the laboratory after seasoning (burning-in) the individual LEDs was better than 0.3% over a 12 h period of continuous operation. The integral irradiance measurements of the source over a period of several months, where the UV-LED source was not operated continuously between the measurements, showed stability within 0.3%. In-field measurements of the source with an array spectroradiometer indicated the stability of the source to be within the standard uncertainty of the spectroradiometer calibration, which was within 1% to 2%.

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.

Evaluation of an LED Retrofit Project at Princeton University's Carl Icahn Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Robert; Murphy, Arthur; Perrin, Tess

At Princeton University’s Carl Icahn Laboratory, DOE’s Commercial Buildings Integration Program documented the implementation of LED retrofit products for recessed troffers, linear cove lighting, and downlights – as part of Princeton’s first building-wide interior LED project. The conversion to LED enables more extensive use of lighting controls to tailor the lighting to the task and limit the operating hours based on occupancy, and the estimated energy savings including controls is 62% compared to the incumbent system.

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.

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.

Conduction-driven cooling of LED-based automotive LED lighting systems for abating local hot spots

NASA Astrophysics Data System (ADS)

Saati, Ferina; Arik, Mehmet

2018-02-01

Light-emitting diode (LED)-based automotive lighting systems pose unique challenges, such as dual-side packaging (front side for LEDs and back side for driver electronics circuit), size, harsh ambient, and cooling. Packaging for automotive lighting applications combining the advanced printed circuit board (PCB) technology with a multifunctional LED-based board is investigated with a focus on the effect of thermal conduction-based cooling for hot spot abatement. A baseline study with a flame retardant 4 technology, commonly known as FR4 PCB, is first compared with a metal-core PCB technology, both experimentally and computationally. The double-sided advanced PCB that houses both electronics and LEDs is then investigated computationally and experimentally compared with the baseline FR4 PCB. Computational models are first developed with a commercial computational fluid dynamics software and are followed by an advanced PCB technology based on embedded heat pipes, which is computationally and experimentally studied. Then, attention is turned to studying different heat pipe orientations and heat pipe placements on the board. Results show that conventional FR4-based light engines experience local hot spots (ΔT>50°C) while advanced PCB technology based on heat pipes and thermal spreaders eliminates these local hot spots (ΔT<10°C), leading to a higher lumen extraction with improved reliability. Finally, possible design options are presented with embedded heat pipe structures that further improve the PCB performance.

Development and Performance Assessment of White LED Dimmer

NASA Astrophysics Data System (ADS)

Maiti, Pradip Kr.; Roy, Biswanath

2017-10-01

A microcontroller based electronic dimmer is developed using pulse width modulation technique. This dimmer is controllable by infra-red remote within a distance of 4 m and can be electrically connected between LED module and its driver. The performance of a developed LED dimmer is assessed on basis of variation of the photometric parameters of commercially available warm white and cool white LED luminaire used in indoor lighting applications. Four equally spaced dimming levels are considered to measure luminous efficacy, spectral power distribution, CIE 1931 chromaticity coordinates, CIE 1976 CIELUV color difference, correlated color temperature, general color rendering index and one specific color rendering index for saturated red color sample. Variations of above parameters are found out with reference to the values measured at rated voltage without the developed dimmer. Analysis of experimentally measured data shows that the developed LED dimmer is capable to vary light output of the WLED luminaire within a range of 25-100% without appreciable variation of its photometric and color parameters. The only exception is observed for the luminous efficacy parameter where it shows about 17 and 14.7% reduction for warm white and cool white LED luminaire at 25% dimming level.

Using the Sentence Verification Technique to Assess Storage and Retrieval Processes

DTIC Science & Technology

1988-07-01

to the house, Pete peered through the window of the side door which led to the two-car garage . The garage was empty except for three 10-speed bikes...tour stopped for about 20 minutes as they listened to the new Twisted Sister album on the large, shiny stereo in the living room. The dining room, with...stopped for about 20 minutes as they listened to the new Twisted Sister album on the large, shiny stereo in the living room. 68 MEANING CHANGE 14. The two

"Light-box" accelerated growth of poinsettias: LED-only illumination

NASA Astrophysics Data System (ADS)

Weerasuriya, Charitha; Detez, Stewart; Hock Ng, Soon; Hughes, Andrew; Callaway, Michael; Harrison, Iain; Katkus, Tomas; Juodkazis, Saulius

2018-01-01

For the current commercialized agricultural industry which requires a reduced product lead time to customer and supply all year round, an artificial light emitting diodes (LEDs)-based illumination has high potential due to high efficiency of electrical-to-light conversion. The main advantage of the deployed Red Green Blue Amber LED lighting system is colour mixing capability, which means ability to generate all the colours in the spectrum by using three or four primary colours LEDs. The accelerated plant growth was carried out in a "light-box" which was made to generate an artificial day/night cycle by moving the colour mixing ratio along the colour temperature curve of the chromaticity diagram. The control group of plants form the same initial batch was grown on the same shelf in a greenhouse at the same conditions with addition of artificial illumination by incandescent lamps for few hours. Costs and efficiency projections of LED lamps for horticultural applications is discussed together with required capital investment. The total cost of the "light-box" including LED lamps and electronics was 850 AUD.

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.

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.

Adult Competency Education Kit. Basic Skills in Speaking, Math, and Reading for Employment. Part E. ACE Competency Based Job Descriptions: #11--Groundskeeper; #12--Animal Keeper; #15--Tire Repairperson; #16--Muffler Installer; #17--Garage Mechanic.

ERIC Educational Resources Information Center

San Mateo County Office of Education, Redwood City, CA. Career Preparation Centers.

This second of fifteen sets of Adult Competency Education (ACE) Based Job Descriptions in the ACE kit contains job descriptions for Groundskeeper, Animal Keeper, Tire Repairperson, Muffler Installer, and Garage Mechanic. Each begins with a fact sheet that includes this information: occupational title, D.O.T. code, ACE number, career ladder, D.O.T.…

Lens of controllable optical field with thin film metallic glasses for UV-LEDs.

PubMed

Pan, C T; Chen, Y C; Lin, Po-Hung; Hsieh, C C; Hsu, F T; Lin, Po-Hsun; Chang, C M; Hsu, J H; Huang, J C

2014-06-16

In the exposure process of photolithography, a free-form lens is designed and fabricated for UV-LED (Ultraviolet Light-Emitting Diode). Thin film metallic glasses (TFMG) are adopted as UV reflection layers to enhance the irradiance and uniformity. The Polydimethylsiloxane (PDMS) with high transmittance is used as the lens material. The 3-D fast printing is attempted to make the mold of the lens. The results show that the average irradiance can be enhanced by 6.5~6.7%, and high uniformity of 85~86% can be obtained. Exposure on commercial thick photoresist using this UV-LED system shows 3~5% dimensional deviation, lower than the 6~8% deviation for commercial mercury lamp system. This current system shows promising potential to replace the conventional mercury exposure systems.

NDIR gas sensing using high performance AlInSb mid-infrared LEDs as light source

NASA Astrophysics Data System (ADS)

Camargo, E. G.; Goda, Y.; Morohara, O.; Fujita, H.; Geka, H.; Ueno, K.; Shibata, Y.; Kuze, N.

2017-08-01

In this paper, we report the performance of room temperature operated mid-infrared light emitting diode (LED) with an InSb buffer layer and AlInSb active/barrier layers, which showed to be suitable for non-dispersive infrared (NDIR) gas sensing. Characterization of the LED was performed and we found that good carrier confinement and crystalline quality was responsible for its high performance. High efficiency light extraction was obtained by adopting backside emission architecture together with surface roughening treatment and TiO2 anti-reflection coating. The fabricated AlInSb LED showed 75% higher power conversion efficiency when compared with a commercially available device. The developed LED, together with a commercially available infrared (IR) detector equipped with band-pass optical filter (AK9710, manufactured by Asahi Kasei Microdevices) were coupled into a mirror system forming a light path length of 80 mm, which was tested for CO2 gas sensing. For a non-absorbing environment, sensor output of 8 nA was obtained by driving the LED with peak current of 100 mA and, by exposing the system at CO2 concentration of 1000 ppm signal reduction due to absorbance around 12% was obtained.

Liquid cooling applications on automotive exterior LED lighting

NASA Astrophysics Data System (ADS)

Aktaş, Mehmet; Şenyüz, Tunç; Şenyıldız, Teoman; Kılıç, Muhsin

2018-02-01

In this study cooling of a LED unit with heatsink and liquid cooling block which is used in automotive head lamp applications has been investigated numerically and experimentally. Junction temperature of a LED which is cooled with heatsink and liquid cooling block obtained in the experiment. 23°C is used both in the simulation and the experiment phase. Liquid cooling block material is choosed aluminium (Al) and polyamide. All tests and simulation are performed with three different flow rate. Temperature distribution of the designed product is investigated by doing the numerical simulations with a commercially software. In the simulations, fluid flow is assumed to be steady, incompressible and laminar and 3 dimensional (3D) Navier-Stokes equations are used. According to the calculations it is obtained that junction temperature is higher in the heatsink design compared to block cooled one. By changing the block material, it is desired to investigate the variation on the LED junction temperature. It is found that more efficient cooling can be obtained in block cooling by using less volume and weight. With block cooling lifetime of LED can be increased and flux loss can be decreased with the result of decreased junction temperature.

Commerical Transition to LEDs: A Pathway to High-Value Products

NASA Technical Reports Server (NTRS)

Stutte, Gary W.

2015-01-01

The use of light-emitting diodes (LEDs) to support plant growth is a radical departure from use of gas-discharge lamps, which were developed in mid-19th and widely adopted by the industry during the 20th century. Initial investigation by the National Aeronautics and Space Administration (NASA) in the late 1980s on the use of LEDs to grow plant in space is resulting in an industry-wide transition from gas discharge to solid-state lighting systems. This global transformation is given urgency by national policies to reduce energy consumption and being facilitated by ready access to information on LEDs. The combination of research, government policy, and information technology has resulted in an exponential increase in research into the use and application of LED technology in horticulture. Commercial horticulture has identified the opportunities provided by LEDs to optimize light spectra to promote growth, regulate morphology, increase nutrient content, and reduce operating costs. LED-light technology is enabling the development of innovative lighting systems, and is being incorporated into large-scale plant factories for the production of edible, ornamental, and medicinal plants. An overview of prevalence of readily accessible information on LEDs and implications for future adoption in horticulture is discussed.

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).

Single-exposure quantitative phase imaging in color-coded LED microscopy.

PubMed

Lee, Wonchan; Jung, Daeseong; Ryu, Suho; Joo, Chulmin

2017-04-03

We demonstrate single-shot quantitative phase imaging (QPI) in a platform of color-coded LED microscopy (cLEDscope). The light source in a conventional microscope is replaced by a circular LED pattern that is trisected into subregions with equal area, assigned to red, green, and blue colors. Image acquisition with a color image sensor and subsequent computation based on weak object transfer functions allow for the QPI of a transparent specimen. We also provide a correction method for color-leakage, which may be encountered in implementing our method with consumer-grade LEDs and image sensors. Most commercially available LEDs and image sensors do not provide spectrally isolated emissions and pixel responses, generating significant error in phase estimation in our method. We describe the correction scheme for this color-leakage issue, and demonstrate improved phase measurement accuracy. The computational model and single-exposure QPI capability of our method are presented by showing images of calibrated phase samples and cellular specimens.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 unrestrictedmore » future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 themore » 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

Validation of thermal effects of LED package by using Elmer finite element simulation method

NASA Astrophysics Data System (ADS)

Leng, Lai Siang; Retnasamy, Vithyacharan; Mohamad Shahimin, Mukhzeer; Sauli, Zaliman; Taniselass, Steven; Bin Ab Aziz, Muhamad Hafiz; Vairavan, Rajendaran; Kirtsaeng, Supap

2017-02-01

The overall performance of the Light-emitting diode, LED package is critically affected by the heat attribution. In this study, open source software - Elmer FEM has been utilized to study the thermal analysis of the LED package. In order to perform a complete simulation study, both Salome software and ParaView software were introduced as Pre and Postprocessor. The thermal effect of the LED package was evaluated by this software. The result has been validated with commercially licensed software based on previous work. The percentage difference from both simulation results is less than 5% which is tolerable and comparable.

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.

Carrier lifetimes in polar InGaN-based LEDs

NASA Astrophysics Data System (ADS)

Wang, Lai; Jin, Jie; Hao, Zhibiao; Luo, Yi

2018-02-01

Measurement of carrier lifetime is very important to understand the physics in light-emitting diodes (LEDs), as it builds a link between carrier concentration and excitation power or current density. In this paper, we present our study on optical and electrical characterizations on carrier lifetimes in polar InGaN-based LEDs. First, a carrier rate equation model is proposed to explain the non-exponential nature of time-resolved photoluminescence (TRPL) decay curves, wherein exciton recombination is replaced by bimolecular recombination, considering the influence of polarization field on electron-hole pairs. Then, nonradiative recombination and radiative recombination coefficients can be deduced from fitting and used to calculate the radiative recombination efficiency. By comparing with the temperature-dependent photoluminescence (TDPL) and power-dependent photoluminescence (PDPL), it is found these three methods provide the consistent results. Second, differential carrier lifetimes depending on injection current are measured in commercial near-ultraviolet (NUV), blue and green LEDs. It is found that carrier lifetime is longer in green one and shorter in NUV one, which is attributed to the influence of polarization-induced quantum confined Stark effect (QCSE). This result implies the carrier density is higher in green LED while lower NUV LED, even the injection current is the same. By ignoring Auger recombination and fitting the efficiency-current and carrier lifetime-current curves simultaneously, the dependence of injection efficiency on carrier concentration in different LED samples are plotted. The NUV LED, which has the shallowest InGaN quantum well, actually exhibits the most serious efficiency droop versus carrier concentration. Then, the approaches to overcome the efficiency droop are discussed.

Nurse-led versus doctor-led care for bronchiectasis.

PubMed

Lawton, Kathryn; Royals, Karen; Carson-Chahhoud, Kristin V; Campbell, Fiona; Smith, Brian J

2018-06-20

Specialist nursing roles to manage stable disease populations are being used to meet the needs of both patients and health services. With increasing cost pressures on health departments, alternative models such as nurse-led care are gaining momentum as a substitute for traditional doctor-led care. This review evaluates the safety, effectiveness, and health outcomes of nurses practising in autonomous roles while using advanced practice skills, within the context of bronchiectasis management in subacute, ambulatory, and/or community care. To compare the effectiveness of nurse-led care versus doctor-led care in the management of stable bronchiectasis. We searched the Cochrane Airways Group Specialised Register and bibliographies of selected papers in addition to grey literature such as electronic clinical trials registries. Searches were current as of March 2018. Randomised controlled trials were eligible for inclusion in the review. Two reviewers extracted and entered data from included studies. Primary outcomes were numbers of exacerbations requiring treatment with antibiotics, hospital admissions, and emergency department attendances. We included one United Kingdom (UK) study in the review. In this randomised controlled trial, a total of 80 participants, with a mean age of 58 years, were treated for 12 months by a specialist nurse or doctor, then were crossed over to the other clinician for the next 12 months. Two participants died during the study period. Six participants failed to cross over to nurse-led care because of unstable bronchiectasis. Overall, the level of study completion was high.Data show no difference in the numbers of exacerbations requiring treatment with antibiotics (rate ratio 1.09, 95% confidence interval (CI) 0.91 to 1.30, 80 participants, moderate-certainty evidence). Investigators reported more hospital admissions in the nurse-led care group (rate ratio 1.52, 95% CI 1.04 to 2.23, 80 participants, moderate-certainty evidence) and did not

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.

Trauma-Focused Cognitive Behavioral Therapy for Commercially Sexually Exploited Youth.

PubMed

Cohen, Judith A; Mannarino, Anthony P; Kinnish, Kelly

2017-06-01

Commercially sexually exploited children and adolescents ("commercially exploited youth")present numerous clinical challenges that have led some mental health providers to question whether current evidence-based treatments are adequate to address the needs of this population. This paper 1) addresses commonalities between the trauma experiences, responses and treatment challenges of commercially exploited youth and those of youth with complex trauma; 2) highlights the importance of careful assessment to guide case conceptualization and treatment planning for commercially exploited youth; and 3) describes strategies for implementing Trauma-Focused Cognitive Behavioral Therapy for complex trauma specific to these youth.

Rethinking health care commercialization: evidence from Malaysia.

PubMed

Nwagbara, Vitalis Chukwudi; Rasiah, Rajah

2015-11-19

Against the backdrop of systemic inefficiency in the public health care system and the theoretical claims that markets result in performance and efficiency improvement, developing countries' governments have been rapidly commercializing health care delivery. This paper seeks to determine whether commercialization through an expansion in private hospitals has led to performance improvements in public hospitals. Inpatient utilization records of all public hospitals in Peninsular Malaysia over the period 2006-2010 were used in this study. These records were obtained from the Ministry of Health. The study relied on utilization ratios, bed occupancy rates (BOR), bed turnover rates (BTR) and average length of stay (ALOS). The data were analyzed using SPSS 22 Statistical Software and the Pabon Lasso technique. Over 60 % of public hospitals in Malaysia are inefficient and perform sub-optimally. Average BOR among the public hospitals was 56 % in 2006 and 61 % in 2010. There was excessive BTR of 65 and 73 times within the period. Overall, the ALOS was low, falling from 3.4 days in 2006 to 3.1 days in 2010. This study demonstrates that commercialization has not led to performance improvements in the public health care sector in Malaysia. The evidence suggests that efforts to improve performance will require a focus directly on public hospitals.

Effects of pitch and shape for diffraction grating in LED fog lamp

NASA Astrophysics Data System (ADS)

Chen, Hsi-Chao; Lin, Jun-Yu; Wu, Jih-Huah; Ma, Shih-Hsin; Yang, Chi-Hao

2011-10-01

The characteristics of light-emitting diodes (LEDs) that make them energy-efficient and long-lasting light source for general illumination have attracted a great attention from the lighting industry and commercial market. As everyone know LEDs have the advantages of environmental protection, long lifetime, fast response time (μs), low voltage and good mechanical properties. Their high luminance and the wide region of the dominant wavelengths within the entire visible spectrum mean that people have high anticipations for the applications of LEDs. The output lighting from reflector in the traditional fog lamp was required to fit the standard of the ECE R19 F3 regulation. Therefore, this study investigated the effects of pitch and angle for a diffraction grating in LED fog lamp. The light pattern of fog lamp must be satisfied ECE regulations, so a design of diffraction grating to shift down the lighting was required. There are three LEDs (Cree XLamp XPE LEDs) as the light source in the fog lamp for the illumination efficiency. Then, an optimal simulation of diffraction grating was done for the pitch and angle of the diffraction grating at the test distance of 25 meters. The best pitch and angle was 2mm and 60 degree for the grating shape of wedge type.

Time dependence of composite shrinkage using halogen and LED light curing.

PubMed

Uhl, Alexander; Mills, Robin W; Rzanny, Angelika E; Jandt, Klaus D

2005-03-01

The polymerization shrinkage of light cured dental composites presents the major drawback for these aesthetically adaptable restorative materials. LED based light curing technology has recently become commercially available. Therefore, the aim of the present study was to investigate if there was a statistically significant difference in linear and volumetric composite shrinkage strain if a LED LCU is used for the light curing process rather than a conventional halogen LCU. The volumetric shrinkage strain was determined using the Archimedes buoyancy principle after 5, 10, 20, 40 s of light curing and after 120 s following the 40 s light curing time period. The linear shrinkage strain was determined with a dynamic mechanical analyzer for the composites Z100, Spectrum, Solitaire2 and Definite polymerized with the LCUs Trilight (halogen), Freelight I (LED) and LED63 (LED LCU prototype). The changes in irradiance and spectra of the LCUs were measured after 0, 312 and 360 min of duty time. In general there was no considerable difference in shrinkage of the composites Z100, Spectrum or Solitaire2 when the LED63 was used instead of the Trilight. There was, however, a statistically significant difference in shrinkage strain when the composite Definite was polymerized with the LED63 instead of the Trilight. The spectrum of the Trilight changed during the experiment considerably whereas the LED63 showed an almost constant light output. The Freelight I dropped considerably in irradiance and had to be withdrawn from the study because of technical problems. The composites containing only the photoinitiator camphorquinone showed similar shrinkage strain behaviour when a LED or halogen LCU is used for the polymerization. The irradiance of some LED LCUs can also decrease over time and should therefore be checked on a regular basis.

Accelerated optical polymer aging studies for LED luminaire applications

NASA Astrophysics Data System (ADS)

Estupiñán, Edgar; Wendling, Peter; Kostrun, Marijan; Garner, Richard

2013-09-01

There is a need in the lighting industry to design and implement accelerated aging methods that accurately simulate the aging process of LED luminaire components. In response to this need, we have built a flexible and reliable system to study the aging characteristics of optical polymer materials, and we have employed it to study a commercially available LED luminaire diffuser made of PMMA. The experimental system consists of a "Blue LED Emitter" and a working surface. Both the temperatures of the samples and the optical powers of the LEDs are appropriately characterized in the system. Several accelerated aging experiments are carried out at different temperatures and optical powers over a 90 hour period and the measured transmission values are used as inputs to a degradation model derived using plausibility arguments. This model seems capable of predicting the behavior of the material as a function of time, temperature and optical power. The model satisfactorily predicts the measured transmission values of diffusers aged in luminaires at two different times and thus can be used to make application recommendations for this material. Specifically, at 35000 hours (the manufacturer's stated life of the luminaire) and at the typical operational temperature of the diffuser, the model predicts a transmission loss of only a few percent over the original transmission of the material at 450 nm, which renders this material suitable for this application.

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.

Color Maintenance of LEDs in Laboratory and Field Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Royer, Michael P.; Tuttle, Ralph; Rosenfeld, Scott M.

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 littlemore » 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.« less

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…

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.

Miniaturized LEDs for flat-panel displays

NASA Astrophysics Data System (ADS)

Radauscher, Erich J.; Meitl, Matthew; Prevatte, Carl; Bonafede, Salvatore; Rotzoll, Robert; Gomez, David; Moore, Tanya; Raymond, Brook; Cok, Ronald; Fecioru, Alin; Trindade, António Jose; Fisher, Brent; Goodwin, Scott; Hines, Paul; Melnik, George; Barnhill, Sam; Bower, Christopher A.

2017-02-01

Inorganic light emitting diodes (LEDs) serve as bright pixel-level emitters in displays, from indoor/outdoor video walls with pixel sizes ranging from one to thirty millimeters to micro displays with more than one thousand pixels per inch. Pixel sizes that fall between those ranges, roughly 50 to 500 microns, are some of the most commercially significant ones, including flat panel displays used in smart phones, tablets, and televisions. Flat panel displays that use inorganic LEDs as pixel level emitters (μILED displays) can offer levels of brightness, transparency, and functionality that are difficult to achieve with other flat panel technologies. Cost-effective production of μILED displays requires techniques for precisely arranging sparse arrays of extremely miniaturized devices on a panel substrate, such as transfer printing with an elastomer stamp. Here we present lab-scale demonstrations of transfer printed μILED displays and the processes used to make them. Demonstrations include passive matrix μILED displays that use conventional off-the shelf drive ASICs and active matrix μILED displays that use miniaturized pixel-level control circuits from CMOS wafers. We present a discussion of key considerations in the design and fabrication of highly miniaturized emitters for μILED displays.

Visual performance for trip hazard detection when using incandescent and led miner cap lamps.

PubMed

Sammarco, John J; Gallagher, Sean; Reyes, Miguel

2010-04-01

Accident data for 2003-2007 indicate that slip, trip, and falls (STFs) are the second leading accident class (17.8%, n=2,441) of lost-time injuries in underground mining. Proper lighting plays a critical role in enabling miners to detect STF hazards in this environment. Often, the only lighting available to the miner is from a cap lamp worn on the miner's helmet. The focus of this research was to determine if the spectral content of light from light-emitting diode (LED) cap lamps enabled visual performance improvements for the detection of tripping hazards as compared to incandescent cap lamps that are traditionally used in underground mining. A secondary objective was to determine the effects of aging on visual performance. The visual performance of 30 subjects was quantified by measuring each subject's speed and accuracy in detecting objects positioned on the floor both in the near field, at 1.83 meters, and far field, at 3.66 meters. Near field objects were positioned at 0 degrees and +/-20 degrees off axis, while far field objects were positioned at 0 degrees and +/-10 degrees off axis. Three age groups were designated: group A consisted of subjects 18 to 25 years old, group B consisted of subjects 40 to 50 years old, and group C consisted of subjects 51 years and older. Results of the visual performance comparison for a commercially available LED, a prototype LED, and an incandescent cap lamp indicate that the location of objects on the floor, the type of cap lamp used, and subject age all had significant influences on the time required to identify potential trip hazards. The LED-based cap lamps enabled detection times that were an average of 0.96 seconds faster compared to the incandescent cap lamp. Use of the LED cap lamps resulted in average detection times that were about 13.6% faster than those recorded for the incandescent cap lamp. The visual performance differences between the commercially available LED and prototype LED cap lamp were not statistically

16 CFR 1211.14 - Instruction manual.

Code of Federal Regulations, 2010 CFR

2010-01-01

... instruction manual shall give complete instructions for the installation, operation, and user maintenance of... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Instruction manual. 1211.14 Section 1211.14... STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS The Standard § 1211.14 Instruction manual. (a...

Committee Opinion No. 709: Commercial Enterprises in Medical Practice.

PubMed

2017-08-01

Monetary reimbursement of physicians in exchange for medical advice and treatment is well established and accepted in medical practice. However, financial pressures and the pervasiveness of entrepreneurial values have led some physicians to widen the scope of activities for which they seek reimbursement. Some of these commercial activities are ethically problematic in the clinical setting. Obstetrician-gynecologists should strive to ensure that commercial enterprises in medical practice do not compromise the patient-focused mission of clinical care. In this Committee Opinion, the American College of Obstetricians and Gynecologists' Committee on Ethics differentiates between commercial activities judged to be generally ethically appropriate for obstetrician-gynecologists and those that are not.

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. © 2016 John Wiley & Sons Australia, Ltd.

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. Copyright © 2011. Published by Elsevier Ltd.

CALiPER Report 22.1: Photoelectric Performance of LED MR16 Lamps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Royer, Michael P.; Poplawski, Michael E.; Brown, Charles C.

This report is a follow-up to CALiPER Application Summary Report 22, which investigated the photometric performance of LED MR16 lamps. The initial report found that many of the LED MR16 lamps did not perform as required by ENERGY STAR based on their equivalency claims, although they generally did provide substantial efficacy advantages compared to halogen MR16 lamps. All testing was completed using laboratory power supplies, with all but one product tested at 12 V AC. In contrast, this report examined the photoelectric performance of the same set of lamps, using commercially available transformers and dimmers as well as laboratory powermore » supplies providing both AC and DC power.« less

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.

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

USDA-ARS?s Scientific Manuscript database

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...

Polymer dispensing and embossing technology for the lens type LED packaging

NASA Astrophysics Data System (ADS)

Chien, Chien-Lin Chang; Huang, Yu-Che; Hu, Syue-Fong; Chang, Chung-Min; Yip, Ming-Chuen; Fang, Weileun

2013-06-01

This study presents a ring-type micro-structure design on the substrate and its corresponding micro fabrication processes for a lens-type light-emitting diode (LED) package. The dome-type or crater-type silicone lenses are achieved by a dispensing and embossing process rather than a molding process. Silicone with a high viscosity and thixotropy index is used as the encapsulant material. The ring-type micro structure is adopted to confine the dispensed silicone encapsulant so as to form the packaged lens. With the architecture and process described, this LED package technology herein has three merits: (1) the flexibility of lens-type LED package designs is enhanced; (2) a dome-type package design is used to enhance the intensity; (3) a crater-type package design is used to enhance the view angle. Measurement results show the ratio between the lens height and lens radius can vary from 0.4 to 1 by changing the volume of dispensed silicone. The view angles of dome-type and crater-type packages can reach 155° ± 5° and 175° ± 5°, respectively. As compared with the commercial plastic leaded chip carrier-type package, the luminous flux of a monochromatic blue light LED is improved by 15% by the dome-type package (improved by 7% by the crater-type package) and the luminous flux of a white light LED is improved by 25% by the dome-type package (improved by 13% by the crater-type package). The luminous flux of monochromatic blue light LED and white light LED are respectively improved by 8% and 12% by the dome-type package as compare with the crater-type package.

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.

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.

Experimentally comparing the attractiveness of domestic lights to insects: Do LEDs attract fewer insects than conventional light types?

PubMed

Wakefield, Andrew; Broyles, Moth; Stone, Emma L; Jones, Gareth; Harris, Stephen

2016-11-01

LED lighting is predicted to constitute 70% of the outdoor and residential lighting markets by 2020. While the use of LEDs promotes energy and cost savings relative to traditional lighting technologies, little is known about the effects these broad-spectrum "white" lights will have on wildlife, human health, animal welfare, and disease transmission. We conducted field experiments to compare the relative attractiveness of four commercially available "domestic" lights, one traditional (tungsten filament) and three modern (compact fluorescent, "cool-white" LED and "warm-white" LED), to aerial insects, particularly Diptera. We found that LEDs attracted significantly fewer insects than other light sources, but found no significant difference in attraction between the "cool-" and "warm-white" LEDs. Fewer flies were attracted to LEDs than alternate light sources, including fewer Culicoides midges (Diptera: Ceratopogonidae). Use of LEDs has the potential to mitigate disturbances to wildlife and occurrences of insect-borne diseases relative to competing lighting technologies. However, we discuss the risks associated with broad-spectrum lighting and net increases in lighting resulting from reduced costs of LED technology.

Commercial Motor Vehicle, Driver Fatigue And Alertness Study, Technical Summary

DOT National Transportation Integrated Search

1999-05-01

The principal purpose of this study was to provide the Federal Highway Administration with measures to evaluate and assess if the Commercial Driver's License (CDL) program has been effective in (1) addressing problems that led to the enactment of the...

Committee Opinion No. 709 Summary: Commercial Enterprises in Medical Practice.

PubMed

2017-08-01

Monetary reimbursement of physicians in exchange for medical advice and treatment is well established and accepted in medical practice. However, financial pressures and the pervasiveness of entrepreneurial values have led some physicians to widen the scope of activities for which they seek reimbursement. Some of these commercial activities are ethically problematic in the clinical setting. Obstetrician-gynecologists should strive to ensure that commercial enterprises in medical practice do not compromise the patient-focused mission of clinical care. In this Committee Opinion, the American College of Obstetricians and Gynecologists' Committee on Ethics differentiates between commercial activities judged to be generally ethically appropriate for obstetrician-gynecologists and those that are not.

Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

PubMed Central

Stojanovic, Radovan; Karadaglic, Dejan

2013-01-01

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 (SpO2). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2). N-LEDs configuration is proposed for multichannel SpO2 measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption. PMID:23291575

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)

Evaluation of a LED-based flatbed document scanner for radiochromic film dosimetry in transmission mode.

PubMed

Lárraga-Gutiérrez, José Manuel; García-Garduño, Olivia Amanda; Treviño-Palacios, Carlos; Herrera-González, José Alfredo

2018-03-01

Flatbed scanners are the most frequently used reading instrument for radiochromic film dosimetry because its low cost, high spatial resolution, among other advantages. These scanners use a fluorescent lamp and a CCD array as light source and detector, respectively. Recently, manufacturers of flatbed scanners replaced the fluorescent lamp by light emission diodes (LED) as a light source. The goal of this work is to evaluate the performance of a commercial flatbed scanner with LED based source light for radiochromic film dosimetry. Film read out consistency, response uniformity, film-scanner sensitivity, long term stability and total dose uncertainty was evaluated. In overall, the performance of the LED flatbed scanner is comparable to that of a cold cathode fluorescent lamp (CCFL). There are important spectral differences between LED and CCFL lamps that results in a higher sensitivity of the LED scanner in the green channel. Total dose uncertainty, film response reproducibility and long-term stability of LED scanner are slightly better than those of the CCFL. However, the LED based scanner has a strong non-uniform response, up to 9%, that must be adequately corrected for radiotherapy dosimetry QA. The differences in light emission spectra between LED and CCFL lamps and its potential impact on film-scanner sensitivity suggest that the design of a dedicated flat-bed scanner with LEDs may improve sensitivity and dose uncertainty in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

A simple and low-cost biofilm quantification method using LED and CMOS image sensor.

PubMed

Kwak, Yeon Hwa; Lee, Junhee; Lee, Junghoon; Kwak, Soo Hwan; Oh, Sangwoo; Paek, Se-Hwan; Ha, Un-Hwan; Seo, Sungkyu

2014-12-01

A novel biofilm detection platform, which consists of a cost-effective red, green, and blue light-emitting diode (RGB LED) as a light source and a lens-free CMOS image sensor as a detector, is designed. This system can measure the diffraction patterns of cells from their shadow images, and gather light absorbance information according to the concentration of biofilms through a simple image processing procedure. Compared to a bulky and expensive commercial spectrophotometer, this platform can provide accurate and reproducible biofilm concentration detection and is simple, compact, and inexpensive. Biofilms originating from various bacterial strains, including Pseudomonas aeruginosa (P. aeruginosa), were tested to demonstrate the efficacy of this new biofilm detection approach. The results were compared with the results obtained from a commercial spectrophotometer. To utilize a cost-effective light source (i.e., an LED) for biofilm detection, the illumination conditions were optimized. For accurate and reproducible biofilm detection, a simple, custom-coded image processing algorithm was developed and applied to a five-megapixel CMOS image sensor, which is a cost-effective detector. The concentration of biofilms formed by P. aeruginosa was detected and quantified by varying the indole concentration, and the results were compared with the results obtained from a commercial spectrophotometer. The correlation value of the results from those two systems was 0.981 (N = 9, P < 0.01) and the coefficients of variation (CVs) were approximately threefold lower at the CMOS image-sensor platform. Copyright © 2014 Elsevier B.V. All rights reserved.

Giving Kids the Business: The Commercialization of America's Schools.

ERIC Educational Resources Information Center

Molnar, Alex

Corporate involvement in public education is nothing new. This book offers a critique of the growing corporate control and commercialization of public schools. Chapter 1 describes the history of business influence on American education with a focus on the case of Wisconsin, in which the corporate-led restructuring of the American economy has…

High reliable and chromaticity-tunable flip-chip w-LEDs with Ce:YAG glass-ceramics phosphor for long-lifetime automotive headlights applications

NASA Astrophysics Data System (ADS)

Ma, Chaoyang; Cao, Yongge; Shen, Xiaofei; Wen, Zicheng; Ma, Ran; Long, Jiaqi; Yuan, Xuanyi

2017-07-01

Nowadays, major commercial w-LEDs fabricated by the traditionally gold-wire-welding packaging technology have undergone considerable development as indoor/outdoor lighting sources due to its high-energy utilization efficiency, long service life, environmental friendliness, and excellent chromatic stability. While, new generation applications in projections, automotive lighting, street lighting, plaza lighting, and high-end general lighting need further improvements in power handling and light extraction. Herein, transparent Ce:YAG glass-ceramics (GCs) phosphor was prepared by low-temperature co-sintering polycrystalline Ce:YAG phosphor powder and home-made PbO-B2O3-ZnO-SiO2 glass powder. Thereafter, the flip-chip (FC) w-LEDs were fabricated with the GCs phosphor plates and FC blue chips. The GCs-based FC w-LEDs show not only excellent heat- and humidity-resistance characteristics, but also superior optical performances with an LE of 112.8 lm/W, a CRI of 71.2, a CCT of 6103 K as well as a chromaticity coordinate of (0.3202, 0.3298), under a high operation current of 400 mA. The technology route will open a practically commercial feasible approach to achieve excellent performances for advanced high-power FC w-LEDs.

Broadband Radiometric LED Measurements

PubMed Central

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2017-01-01

At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed. PMID:28649167

Broadband radiometric LED measurements

NASA Astrophysics Data System (ADS)

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-09-01

At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

Broadband Radiometric LED Measurements.

PubMed

Eppeldauer, G P; Cooksey, C C; Yoon, H W; Hanssen, L M; Podobedov, V B; Vest, R E; Arp, U; Miller, C C

2016-01-01

At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

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.

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.

Are nurse-led chemotherapy clinics really nurse-led? An ethnographic study.

PubMed

Farrell, Carole; Walshe, Catherine; Molassiotis, Alex

2017-04-01

The number of patients requiring ambulatory chemotherapy is increasing year on year, creating problems with capacity in outpatient clinics and chemotherapy units. Although nurse-led chemotherapy clinics have been set up to address this, there is a lack of evaluation of their effectiveness. Despite a rapid expansion in the development of nursing roles and responsibilities in oncology, there is little understanding of the operational aspects of nurses' roles in nurse-led clinics. To explore nurses' roles within nurse-led chemotherapy clinics. A focused ethnographic study of nurses' roles in nurse-led chemotherapy clinics, including semi-structured interviews with nurses. Four chemotherapy units/cancer centres in the UK PARTICIPANTS: Purposive sampling was used to select four cancer centres/units in different geographical areas within the UK operating nurse-led chemotherapy clinics. Participants were 13 nurses working within nurse-led chemotherapy clinics at the chosen locations. Non-participant observation of nurse-led chemotherapy clinics, semi-structured interviews with nurse participants, review of clinic protocols and associated documentation. 61 nurse-patient consultations were observed with 13 nurses; of these 13, interviews were conducted with 11 nurses. Despite similarities in clinical skills training and prescribing, there were great disparities between clinics run by chemotherapy nurses and those run by advanced nurse practitioners. This included the number of patients seen within each clinic, operational aspects, nurses' autonomy, scope of practice and clinical decision-making abilities. The differences highlighted four different levels of nurse-led chemotherapy clinics, based on nurses' autonomy and scope of clinical practice. However, this was heavily influenced by medical consultants. Several nurses perceived they were undertaking holistic assessments, however they were using medical models/consultation styles, indicating medicalization of nurses' roles

Evaluating the impact of LED bulb development on the economic viability of ultraviolet technology for disinfection.

PubMed

Ibrahim, Mohamed A S; MacAdam, Jitka; Autin, Olivier; Jefferson, Bruce

2014-01-01

Ultraviolet (UV) technologies have been very successful in disinfection applications due to their ability to inactivate microorganisms without producing harmful disinfection by-products. However, there have been a number of concerns associated with the use of conventional UV systems such as hazardous mercury content, high capital investment and reduced electrical efficiency. These concerns have set limitations for the use of UV processes. The study evaluates the development of light emitting diode (LED) technology as an alternative UV source over the last 5 years, analyses the projections provided by the researchers and UV LED manufacturers and presents the information in a cost model with the aim to predict the timeline at which UV LED will compete with traditional UV low pressure high output technology in the commercial market at full-scale residential and industrial disinfection applications.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 radioactivemore » 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.« less

Park Smart

NASA Technical Reports Server (NTRS)

1999-01-01

The Parking Garage Automation System (PGAS) is based on a technology developed by a NASA-sponsored project called Robot sensorSkin(TM). Merritt Systems, Inc., of Orlando, Florida, teamed up with NASA to improve robots working with critical flight hardware at Kennedy Space Center in Florida. The system, containing smart sensor modules and flexible printed circuit board skin, help robots to steer clear of obstacles using a proximity sensing system. Advancements in the sensor designs are being applied to various commercial applications, including the PGAS. The system includes a smartSensor(TM) network installed around and within public parking garages to autonomously guide motorists to open facilities, and once within, to free parking spaces. The sensors use non-invasive reflective-ultrasonic technology for high accuracy, high reliability, and low maintenance. The system is remotely programmable: it can be tuned to site-specific requirements, has variable range capability, and allows remote configuration, monitoring, and diagnostics. The sensors are immune to interference from metallic construction materials, such as rebar and steel beams. Inside the garage, smart routing signs mounted overhead or on poles in front of each row of parking spots guide the motorist precisely to free spaces.

Comparing Smoking Cessation Outcomes in Nurse-Led and Physician-Led Primary Care Visits.

PubMed

Byers, Marcia A; Wright, Patricia; Tilford, John Mick; Nemeth, Lynne S; Matthews, Ellyn; Mitchell, Anita

Smoking is a significant public health concern in the United States, yet 50% of patients do not receive recommended tobacco use screening and counseling. This project compared smoking cessation rates in newly reimbursable nurse-led wellness visits with rates in physician-led visits. Although the findings were not statistically significant, they suggested that smoking cessation is at least equivalent in patients who attend nurse-led visits compared with physician-led visits and may be higher.

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.

LED lamp

DOEpatents

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.

Regenerative Fuel Cell System Testbed Program for Government and Commercial Applications

NASA Technical Reports Server (NTRS)

1996-01-01

NASA Lewis Research Center's Electrochemical Technology Branch has led a multiagency effort to design, fabricate, and operate a regenerative fuel cell (RFC) system testbed. Key objectives of this program are to evaluate, characterize, and demonstrate fully integrated RFC's for space, military, and commercial applications. The Lewis-led team is implementing the program through a unique international coalition that encompasses both Government and industry participants. Construction of the 25-kW RFC testbed at the NASA facility at Edwards Air Force Base was completed in January 1995, and the system has been operational since that time.

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.

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.…

Techno-economic evaluation of a tandem dry batch, garage-style digestion-compost process for remote work camp environments.

PubMed

Hayes, Alexander C; Enongene Ekwe, S; Mervin, Steve; Jenson, Earl

2016-12-01

The extraction of natural resources often involves housing workers in remote work camps far from population centres. These camps are prevalent in northern Alberta where they house approximately 40,000 workers involved in oil sands processing. The central, full-service cafeterias at these camps produce a significant quantity of food and cardboard waste. Due to their remote nature, these camps face high waste disposal costs associated with trucking waste long distances to the landfill. In this study, we investigated the techno-economic feasibility of on-site treatment of food and cardboard waste in a tandem dry batch, garage-style anaerobic digestion-compost process in which the waste material is converted into renewable energy used to heat the camp water supply and a nutrient-rich soil amendment for local land reclamation projects. Dry batch digestion and windrow composting pilot trials were performed on a simulated work camp waste in order to assess technical performance. The quality of the final compost was found to meet regulatory standards. A complete mass balance was then developed for a facility treating 3000 tonnes food waste and 435 tonnes waste cardboard annually. An economic assessment of such a facility was performed and, depending on the level of capital support and recognition of carbon credits for landfill methane mitigation, would require waste disposal costs to be between $115 and $195 CAD per tonne to meet financial criteria for project selection in Alberta's oil and gas industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Wang, Hongtao; Qi, Ying; Mountziaris, T. J.; Salthouse, Christopher D.

2014-05-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hongtao; Salthouse, Christopher D., E-mail: salthouse@ecs.umass.edu; Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003

2014-05-15

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

Temperature analysis during bonding of brackets using LED or halogen light base units.

PubMed

Silva, Paulo César Gomes; De Fátima Zanirato Lizarelli, Rosane; Moriyama, Lílian Tan; De Toledo Porto Neto, Sizenando; Bagnato, Vanderlei Salvador

2005-02-01

The purpose of our investigation is to compare the intrapulpal temperature changes following blue LED system and halogen lamp irradiation at the enamel surface of permanent teeth. The fixation of brackets using composite resin is more comfortable and faster when using a photo-curable composite. Several light sources can be used: halogens, arc plasma, lasers, and recently blue LED systems. An important aspect to be observed during such a procedures is the temperature change. In this study, we have used nine human extracted permanent teeth: three central incisors, three lateral incisors, and three canines. Teeth were exposed to two light sources: blue LED system (preliminary commercial model LEC 470-II) and halogen lamp (conventional photo-cure equipment). The surface of teeth was exposed for 20, 40, and 60 sec at the buccal and lingual enamel surface with an angle of 45 degrees. Temperature values measured by a thermistor placed at pulpar chamber were read in time intervals of 1 sec. We obtained plots showing the temperature evolution as a function of time for each experiment. There is a correlation between heating quantity and exposition time of light source: with increasing exposition time, heating increases into the pulpal chamber. The halogen lamp showed higher heating than the LED system, which showed a shorter time of cooling than halogen lamp. The blue LED system seems like the indicated light source for photo-cure of composite resin during the bonding of brackets. The fixation of brackets using composite resin is more comfortable and faster when using a photo-curable composite. Blue LED equipment did not heat during its use. This could permit a shorter clinical time of operation and better performance.

Attendees' perceptions of commercial influence in noncommercially funded CME programs.

PubMed

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

2012-01-01

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 sources contribute to attendees' perceptions of commercial influence in non-industry-supported CME programs, and how attendees perceive that this influence manifests itself on both speaker and program levels. Evaluation forms were received from 1 544 attendees at 14 live noncommercially supported CME programs in 2006, 2007, and 2010. Attendees rated perceived commercial influence for each lecture and the entire program. Using open-ended and "check all that apply'' questions, participants specified perceived sources and manifestations of commercial influence. Attendees rating individual lectures but not the entire program as commercially influenced accounted for 59.9% of those who identified bias. The most frequently endorsed source of commercial influence was individual speakers' funding, and the most listed manifestations were speakers' mentions of pharmaceuticals and expressions of personal opinions. Rating the entire program commercially influenced correlated with whether attendees considered the funding of referenced research a source of influence. CME attendees consider a broad spectrum of factors when reporting commercial influence. Evaluation forms should include bias questions per lecture as well as items to clarify perceived sources and manifestations of commercial influence. Copyright © 2012 The Alliance for Continuing Education in the Health Professions, the Society for Academic Continuing Medical Education, and the Council on CME, Association for Hospital Medical Education.

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.

Numerical simulation and experimental investigation of GaN-based flip-chip LEDs and top-emitting LEDs.

PubMed

Liu, Xingtong; Zhou, Shengjun; Gao, Yilin; Hu, Hongpo; Liu, Yingce; Gui, Chengqun; Liu, Sheng

2017-12-01

We demonstrate a GaN-based flip-chip LED (FC-LED) with a highly reflective indium-tin oxide (ITO)/distributed Bragg reflector (DBR) ohmic contact. A transparent ITO current spreading layer combined with Ta 2 O 5 /SiO 2 double DBR stacks is used as a reflective p-type ohmic contact in the FC-LED. We develop a strip-shaped SiO 2 current blocking layer, which is well aligned with a p-electrode, to prevent the current from crowding around the p-electrode. Our combined numerical simulation and experimental results revealed that the FC-LED with ITO/DBR has advantages of better current spreading and superior heat dissipation performance compared to top-emitting LEDs (TE-LEDs). As a result, the light output power (LOP) of the FC-LED with ITO/DBR was 7.6% higher than that of the TE-LED at 150 mA, and the light output saturation current was shifted from 130.9  A/cm 2 for the TE-LED to 273.8  A/cm 2 for the FC-LED with ITO/DBR. Owing to the high reflectance of the ITO/DBR ohmic contact, the LOP of the FC-LED with ITO/DBR was 13.0% higher than that of a conventional FC-LED with Ni/Ag at 150 mA. However, because of the better heat dissipation of the Ni/Ag ohmic contact, the conventional FC-LED with Ni/Ag exhibited higher light output saturation current compared to the FC-LED with ITO/DBR.

Effect of Nitrogen Post-Doping on a Commercial Platinum-Ruthenium/Carbon Anode Catalyst

DTIC Science & Technology

2014-02-15

polymer electrolyte membrane fuel cells ( PEMFCs ) closer to commercial viability. However, further improvements in fuel cell durability, particularly...have recently led to significant improvements [3e5]. The genesis of interest in modified carbon support materials for PEMFCs and DMFCs originated in

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

Effect of the combination of white and red LED lighting during incubation on layer, broiler, and Pekin duck hatchability.

PubMed

Archer, G S; Jeffrey, D; Tucker, Z

2017-08-01

Previous research has shown that providing light during incubation can have positive effects on hatchability and chick quality; however, white light alone has been observed to improve these factors only in pigmented broiler eggs and non-pigmented white layer eggs. Monochromatic red light has been shown to improve hatchability in layer eggs. Therefore the objective of this study was to utilize one light fixture that emitted both white and monochromatic red light to determine if this one light source could improve hatchability in both types of chicken eggs and pigmented Pekin duck egg. To determine this, 3 experiments were conducted, the first using White Leghorn eggs (N = 6912), the second using commercial broiler eggs (N = 4608), and the third using commercial Pekin duck eggs (N = 3564) in which eggs were incubated with 12 h of light and 12 h of darkness (LED) or complete darkness (DARK); the light level was 250 lux. Hatchability, embryo mortality, and hatchling quality were measured. In Experiment 1, LED had fewer early dead embryos (P = 0.03), less overall embryo mortality (P = 0.05), fewer chicks with unhealed navels (P < 0.001), fewer chicks with defects (P < 0.001), and a higher percentage of fertile eggs that hatched (P = 0.05) than DARK. In Experiment 2, LED had fewer chicks with unhealed navels (P = 0.003), fewer chicks with defects (P = 0.001), and a higher percentage of fertile eggs that hatched (P = 0.04) than DARK. In Experiment 3, LED had fewer early dead embryos (P = 0.05), lower overall embryo mortality (P = 0.04), and a higher percentage of fertile eggs that hatched (P = 0.05), and had ducklings with lower bodyweights at hatch (P = 0.04) than DARK. These results indicate that providing both white and red light during incubation can improve chick quality across poultry varieties. This type of fixture could be used to improve commercial hatchery efficiency and chick quality. © 2017 Poultry Science Association Inc.

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.

Transformation products formation of ciprofloxacin in UVA/LED and UVA/LED/TiO2 systems: Impact of natural organic matter characteristics.

PubMed

Li, Si; Hu, Jiangyong

2018-04-01

The role of natural organic matter (NOM) in contaminants removal by photolysis and photocatalysis has aroused increasing interest. However, evaluation of the influence of NOM characteristics on the transformation products (TPs) formation and transformation pathways of contaminants has rarely been performed. This study investigated the decomposition kinetics, mineralization, TPs formation and transformation pathways of antibiotic ciprofloxacin (CIP) during photolysis and photocatalysis in the presence of three commercial NOM isolates (Sigma-Aldrich humic acid (SAHA), Suwannee River humic acid (SRHA) and Suwannee River NOM (SRNOM)) by using UVA light emitting diode (UVA/LED) as an alternative light source. NOM isolates insignificantly affected CIP photolysis but strongly inhibited CIP photocatalysis due to competitive radical quenching. The inhibitory effect followed the order of SAHA (49.6%) > SRHA (29.9%) > SRNOM (21.2%), consistent with their •OH quenching abilities, SUVA 254 values and orders of aromaticity. Mineralization rates as revealed by F - release were negatively affected by NOM during CIP photocatalysis. TPs arising from hydroxylation and defluorination were generally suppressed by NOM isolates in UVA/LED and UVA/LED/TiO 2 systems. In contrast, dealkylation and oxidation of piperazine ring were promoted by NOM. The enhancement in the apparent formation kinetics (k app ) of TP245, TP291, TP334a, TP334b and TP362 followed the order of SRNOM > SRHA > SAHA. k app values were positively correlated with O/C ratio, carboxyl content, E2/E3 and fluorescence index (FI) of NOM and negatively related with SUVA 254 values. The observed correlations indicate that NOM properties are important in determining the fate and transformation of organic contaminants during photolysis and photocatalysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Strengthening Children's Advertising Defenses: The Effects of Forewarning of Commercial and Manipulative Intent.

PubMed

Rozendaal, Esther; Buijs, Laura; van Reijmersdal, Eva A

2016-01-01

This study investigated whether a forewarning of advertising's intent can increase children's (N = 159, 8-10 years old) defenses against television commercials to lower their desire for advertised products. Two different forewarnings were tested, one for advertising's commercial intent or warning for the promotional nature, and one for advertising's manipulative intent or warning for the deceptive nature. Results showed that only the warning of manipulative intent prior to advertising exposure was successful in increasing children's advertising defenses. This forewarning activated children's attitudinal advertising literacy (i.e., skepticism toward the commercial), which in turn led to lower advertised product desire. The forewarning of commercial intent was not effective in strengthening children's advertising defenses. These findings have important implications for interventions that aim to lower children's desire for (unhealthy) advertised products by activating their advertising literacy.

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.

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.

Air quality in urban parking garages (PM10, major and trace elements, PAHs): Instrumental measurements vs. active moss biomonitoring

NASA Astrophysics Data System (ADS)

Vuković, Gordana; Aničić Urošević, Mira; Razumenić, Ivana; Kuzmanoski, Maja; Pergal, Miodrag; Škrivanj, Sandra; Popović, Aleksandar

2014-03-01

This study was performed in four parking garages in downtown of Belgrade with the aim to provide multi-pollutant assessment. Concentrations of 16 US EPA priority PAHs and Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were determined in PM10 samples. The carcinogenic health risk of employees' occupational exposure to heavy metals (Cd, Cr, Ni and Pb) and PAHs (B[a]A, Cry, B[b]F, B[k]F, B[a]P and DB[ah]A) was estimated. A possibility of using Sphagnum girgensohnii moss bags for monitoring of trace element air pollution in semi-enclosed spaces was evaluated as well. The results showed that concentrations of PM10, Cd, Ni and B[a]P exceeded the EU Directive target values. Concentration of Zn, Ba and Cu were two orders of magnitude higher than those measured at different urban sites in European cities. Cumulative cancer risk obtained for heavy metals and PAHs was 4.51 × 10-5 and 3.75 × 10-5 in M and PP, respectively; upper limit of the acceptable US EPA range is 10-4. In the moss, higher post-exposure than pre-exposure (background) element concentrations was observed. In comparison with instrumental monitoring data, similar order of abundances of the most elements in PM10 and moss samples was found. However, using of the S. girgensohnii moss bag technique in indoor environments needs further justification.

Nuclear Terrorism: Calibrating Funding for Defensive Programs in Response to the Threat

DTIC Science & Technology

2009-12-01

fertilizer , ceramic tile, and bananas, slow the cargo screening process and in some cases have even led officials to reduce the sensitivity settings...kilograms of HEU or 8 kilograms of plutonium (weights roughly equated to the size of a melon and a plum respectively).234 Terrorists would likely...ed. Schwartz, 214. 69 On February 26, 1993, terrorists detonated 1,400 pounds of fertilizer -based explosives in the underground parking garage of

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.

Theoretical and experimental luminous characteristics of white LEDs composed of multiphosphors and near-UV LED for lighting

NASA Astrophysics Data System (ADS)

Uchida, Yuji; Taguchi, Tsunemasa

2003-07-01

We have performed theoretical studies on the luminous characeristics of white LED light source which composed of multi phosphors and near ultraviolet (UV) LED for general lighting. White LED source for general lighting applications requires the conditions that have high-flux, high luminous efficacy of radiation (> 100 lm/W) in addition to high color rendering index (Ra > 90) and variable color temperatures. Recently, we have proposed a novel type white LED based on multi phosphors and near UV LED system in order to high-Ra (>93). We will describe the excellent luminescence properties of white LED consisting of orange (O), yellow (Y), green (G) and blue (B) phosphor materials, and near UV LED. The color spectral contributions of individual phosphor-coated LED are theoretically analyzed using our multi LED lighting theory calculated the maximum luminous efficacy can be estimated to be approximately 300 lm/W having a high Ra of about 90 taking into account individual radiation spectrum. Illuminance distribution of white LED is in fairly good agreement with the experimental data.

Obstructive sleep apnea among commercial motor vehicle drivers: using evidence-based practice to identify risk factors.

PubMed

Olszewski, Kimberly; Wolf, Debra

2013-11-01

Commercial motor vehicle driving is a hazardous occupation, having the third highest fatality rate among common U.S. jobs. Among the estimated 14 million U.S. commercial motor vehicle drivers, the prevalence of obstructive sleep apnea is reported to be 17% to 28%. Despite the identified increased prevalence of obstructive sleep apnea among commercial motor vehicle drivers, federal law does not require that they be screened for obstructive sleep apnea. This article presents an evidence-based practice change project; the authors developed, implemented, and evaluated a screening program to identify commercial motor vehicle drivers' risk for obstructive sleep apnea during commercial driver medical examinations. The results of this practice change indicated screening for obstructive sleep apnea during the commercial driver medical examination led to improved identification of obstructive sleep apnea risk among commercial motor vehicle drivers and should be a clinical standard in occupational health clinics. Copyright 2013, SLACK Incorporated.

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

Caenorhabditis elegans as a model to study the impact of exposure to light emitting diode (LED) domestic lighting.

PubMed

Abdel-Rahman, Fawzia; Okeremgbo, Bethel; Alhamadah, Fatimah; Jamadar, Sakha; Anthony, Kevin; Saleh, Mahmoud A

2017-04-16

This study aimed to investigate the biological impact of exposure on domestic light emitting diodes (LED) lighting using the free-living nematode Caenorhabditis elegans as a model. Nematodes were separately exposed to white LED light covering the range of 380-750 nm, blue light at 450 nm and black light at 380-420 nm for one life cycle (egg to adult) with dark exposure as the control. Each light range induced stress to the nematode C. elegans such as reducing the number of the hatched eggs and/or delayed the maturation of the hatched eggs to the adult stage. In addition, it lowered or prevented the ability of adults to lay eggs and impaired the locomotion in the exposed worms. The observed type of biological stress was also associated with the production of reactive oxygen species (ROS) as compared to nematodes grown in the dark. It is concluded that the blue light component of white LED light may cause health problems, and further investigation is required to test commercial brands of white LEDs that emit different amounts of blue light.

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…

Estimation of the demand for commercial truck parking on interstate highways in Virginia : final report.

DOT National Transportation Integrated Search

2004-01-01

The steady growth of commercial truck travel has led to an increasing demand for truck parking spaces at public rest areas and private truck stops on interstate highways in Virginia. This study developed a methodology to determine the supply and dema...

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.

Investigating the LED's dark side. Novel LED Model Offers New Insights

DOE PAGES

Chow, Weng Wah

2014-07-01

A revolution in lighting is well on its way. Rewind the clock a year or so and the prices of LED bulbs made many shoppers wince. But now it is possible to get a high-quality 60 W equivalent for well under $10, and that’s allowing sales of LED bulbs incorporating chips from the likes of Cree and Philips Lumileds to take off. Although these solid-state bulbs are much more pricey than incandescents, which have largely disappeared from shelves due to legislation, they more than make up for that additional up-front cost with a substantial trimming of the electricity bill. Itmore » is a more tricky decision, however, whether it makes more sense to buy an LED bulb or a cheaper compact fluorescent (CFL). In terms of durability, adaptability and environmental impact, the solid-state bulb is the clear winner. But both types of light are similar in the efficiency stakes, and thus the running costs.« less

Noise Annoyance Produced by Commercial Vehicles Transit on Rumble Strips

NASA Astrophysics Data System (ADS)

Zaiton, Haron; Khairulzan, Yahya; Nadirah, Darus; Nordiana, Mashros; Azril, Hezmi Muhammad; Samah Rosiah, Abu; Mutalif, Abdul Hameed Abdul; Asyraf, Norudin Wan Mohammad; Habab, Abd Halil Muhammad; Zanariah, Jahya; Hanifi, Othman Mohd

2018-03-01

This paper reports on research examining the extent of noise annoyance affecting residents within the vicinity of installation of two types of transverse rumble strips (TRS), namely Middle Overlapped (MO) and Multilayer Overlapping (MLO). In order to assess the noise annoyance in the area, measurements were taken at 7.5m from centre of road with TRS installation using single vehicle test to determine the extent of changes of sound level indices and sound spectrum. Two light and two medium weight commercial vehicles were used. Indicators LAeq, LAFmax, LAImax, LAIeq, and LASmax were used to determine impulsivity that led to noise annoyance. The results showed that, at 30 km/h, all commercial vehicles considered in this study that transited on MO produced impulsive noise, while only light commercial vehicles caused noise annoyance when they transited on MLO. The research also analysed the extent of low-frequency noise and found a significant low-frequency component, which indicated that noise annoyance might arise from the hitting of MO and MLO by the commercial vehicles. For night-time related annoyance, it was suggested that an additional weighting factor could be added to the average A-weighted value during night-time.

Peer-led versus teacher-led AIDS education for female high-school students in Yazd, Islamic Republic of Iran.

PubMed

Baghianimoghadam, M H; Forghani, H; Zolghadr, R; Rahaei, Z; Khani, P

2012-04-01

Peer-led programmes on AIDS prevention have shown a good level of effectiveness when tested among high-risk populations. This study compared peer-led and teacher-led methods of education about HIV/AIDS among female high-school students in Yazd city, Islamic Republic of Iran. In 2009 students in 3 high schools were trained by their classmates (peer-led), by the research team (teacher-led) or had no education (controls); 180 students completed a specially designed questionnaire based on the health belief model, before and after the intervention. Post-intervention mean knowledge scores increased 2-fold in the peer-led group, and this was significantly higher than the increase in the teacher-led group scores (1.5-fold). Control group scores were unchanged. In the peer-led programme all of the components of the model were significantly improved whereas in the teacher-led programme, only perceived severity and perceived barriers scored significantly higher after the intervention.

Metabolic Engineering for Advanced Biofuels Production and Recent Advances Toward Commercialization

DOE PAGES

Meadows, Corey W.; Kang, Aram; Lee, Taek S.

2017-07-21

Research on renewable biofuels produced by microorganisms has enjoyed considerable advances in academic and industrial settings. As the renewable ethanol market approaches maturity, the demand is rising for the commercialization of more energy-dense fuel targets. Many strategies implemented in recent years have considerably increased the diversity and number of fuel targets that can be produced by microorganisms. Moreover, strain optimization for some of these fuel targets has ultimately led to their production at industrial scale. In this review, we discuss recent metabolic engineering approaches for augmenting biofuel production derived from alcohols, isoprenoids, and fatty acids in several microorganisms. In addition,more » we discuss successful commercialization ventures for each class of biofuel targets.« less

Metabolic Engineering for Advanced Biofuels Production and Recent Advances Toward Commercialization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meadows, Corey W.; Kang, Aram; Lee, Taek S.

Research on renewable biofuels produced by microorganisms has enjoyed considerable advances in academic and industrial settings. As the renewable ethanol market approaches maturity, the demand is rising for the commercialization of more energy-dense fuel targets. Many strategies implemented in recent years have considerably increased the diversity and number of fuel targets that can be produced by microorganisms. Moreover, strain optimization for some of these fuel targets has ultimately led to their production at industrial scale. In this review, we discuss recent metabolic engineering approaches for augmenting biofuel production derived from alcohols, isoprenoids, and fatty acids in several microorganisms. In addition,more » we discuss successful commercialization ventures for each class of biofuel targets.« less

A new approach to preparation of standard LEDs for luminous intensity and flux measurement of LEDs

NASA Astrophysics Data System (ADS)

Park, Seung-Nam; Park, Seongchong; Lee, Dong-Hoon

2006-09-01

This work presents an alternative approach for preparing photometric standard LEDs, which is based on a novel functional seasoning method. The main idea of our seasoning method is simultaneously monitoring the light output and the junction voltage to obtain quantitative information on the temperature dependence and the aging effect of the LED emission. We suggested a general model describing the seasoning process by taking junction temperature variation and aging effect into account and implemented a fully automated seasoning facility, which is capable of seasoning 12 LEDs at the same time. By independent measurements of the temperature dependence, we confirmed the discrepancy of the theoretical model to be less than 0.5 % and evaluate the uncertainty contribution of the functional seasoning to be less than 0.5 % for all the seasoned samples. To demonstrate assigning the reference value to a standard LED, the CIE averaged LED intensity (ALI) of the seasoned LEDs was measured with a spectroradiometer-based instrument and the measurement uncertainty was analyzed. The expanded uncertainty of the standard LED prepared by the new approach amounts to be 4 % ~ 5 % (k=2) depending on color without correction of spectral stray light in the spectroradiometer.

Combined experimental-numerical identification of radiative transfer coefficients in white LED phosphor layers

NASA Astrophysics Data System (ADS)

Akolkar, A.; Petrasch, J.; Finck, S.; Rahmatian, N.

2018-02-01

An inverse analysis of the phosphor layer of a commercially available, conformally coated, white LED is done based on tomographic and spectrometric measurements. The aim is to determine the radiative transfer coefficients of the phosphor layer from the measurements of the finished device, with minimal assumptions regarding the composition of the phosphor layer. These results can be used for subsequent opto-thermal modelling and optimization of the device. For this purpose, multiple integrating sphere and gonioradiometric measurements are done to obtain statistical bounds on spectral radiometric values and angular color distributions for ten LEDs belonging to the same color bin of the product series. Tomographic measurements of the LED package are used to generate a tetrahedral grid of the 3D LED geometry. A radiative transfer model using Monte Carlo Ray Tracing in the tetrahedral grid is developed. Using a two-wavelength model consisting of a blue emission wavelength and a yellow, Stokes-shifted re-emission wavelength, the angular color distribution of the LED is simulated over wide ranges of the absorption and scattering coefficients of the phosphor layer, for the blue and yellow wavelengths. Using a two-step, iterative space search, combinations of the radiative transfer coefficients are obtained for which the simulations are consistent with the integrating sphere and gonioradiometric measurements. The results show an inverse relationship between the scattering and absorption coefficients of the phosphor layer for blue light. Scattering of yellow light acts as a distribution and loss mechanism for yellow light and affects the shape of the angular color distribution significantly, especially at larger viewing angles. The spread of feasible coefficients indicates that measured optical behavior of the LEDs may be reproduced using a range of combinations of radiative coefficients. Given that coefficients predicted by the Mie theory usually must be corrected in order

LED lighting efficacy: Status and directions

DOE PAGES

Morgan Pattison, Paul; Hansen, Monica; Tsao, Jeffrey Y.

2017-12-28

A monumental shift from conventional lighting technologies (incandescent, fluorescent, high intensity discharge) to LED lighting is currently transpiring. The primary driver for this shift has been energy and associated cost savings. LED lighting is now more efficacious than any of the conventional lighting technologies with room to still improve. Near term, phosphor converted LED packages have the potential for efficacy improvement from 160 lm/W to 255 lm/W. Longer term, color-mixed LED packages have the potential for efficacy levels conceivably as high as 330 lm/W, though reaching these performance levels requires breakthroughs in green and amber LED efficiency. LED package efficacymore » sets the upper limit to luminaire efficacy, with the luminaire containing its own efficacy loss channels. In this paper, based on analyses performed through the U.S. Department of Energy Solid State Lighting Program, various LED and luminaire loss channels are elucidated, and critical areas for improvement identified. Beyond massive energy savings, LED technology enables a host of new applications and added value not possible or economical with previous lighting technologies. These include connected lighting, lighting tailored for human physiological responses, horticultural lighting, and ecologically conscious lighting. Finally, none of these new applications would be viable if not for the high efficacies that have been achieved, and are themselves just the beginning of what LED lighting can do.« less

LED lighting efficacy: Status and directions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan Pattison, Paul; Hansen, Monica; Tsao, Jeffrey Y.

A monumental shift from conventional lighting technologies (incandescent, fluorescent, high intensity discharge) to LED lighting is currently transpiring. The primary driver for this shift has been energy and associated cost savings. LED lighting is now more efficacious than any of the conventional lighting technologies with room to still improve. Near term, phosphor converted LED packages have the potential for efficacy improvement from 160 lm/W to 255 lm/W. Longer term, color-mixed LED packages have the potential for efficacy levels conceivably as high as 330 lm/W, though reaching these performance levels requires breakthroughs in green and amber LED efficiency. LED package efficacymore » sets the upper limit to luminaire efficacy, with the luminaire containing its own efficacy loss channels. In this paper, based on analyses performed through the U.S. Department of Energy Solid State Lighting Program, various LED and luminaire loss channels are elucidated, and critical areas for improvement identified. Beyond massive energy savings, LED technology enables a host of new applications and added value not possible or economical with previous lighting technologies. These include connected lighting, lighting tailored for human physiological responses, horticultural lighting, and ecologically conscious lighting. Finally, none of these new applications would be viable if not for the high efficacies that have been achieved, and are themselves just the beginning of what LED lighting can do.« less

Kansas highway LED illumination manual : a guide for the use of LED lighting systems.

DOT National Transportation Integrated Search

2015-12-01

The research project was aimed to assist the Kansas Department of Transportation (KDOT) in the development of a Highway LED Illumination Manual for guiding the upcoming implementation of successful LED roadway lighting systems in Kansas to replace th...

R&D100: LED Pulser

ScienceCinema

Pickett, Lyle; Manin, Julien; Eagle, Ethan

2018-06-12

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.

Strengthening Children’s Advertising Defenses: The Effects of Forewarning of Commercial and Manipulative Intent

PubMed Central

Rozendaal, Esther; Buijs, Laura; van Reijmersdal, Eva A.

2016-01-01

This study investigated whether a forewarning of advertising’s intent can increase children’s (N = 159, 8–10 years old) defenses against television commercials to lower their desire for advertised products. Two different forewarnings were tested, one for advertising’s commercial intent or warning for the promotional nature, and one for advertising’s manipulative intent or warning for the deceptive nature. Results showed that only the warning of manipulative intent prior to advertising exposure was successful in increasing children’s advertising defenses. This forewarning activated children’s attitudinal advertising literacy (i.e., skepticism toward the commercial), which in turn led to lower advertised product desire. The forewarning of commercial intent was not effective in strengthening children’s advertising defenses. These findings have important implications for interventions that aim to lower children’s desire for (unhealthy) advertised products by activating their advertising literacy. PMID:27551271

Miniature LED endoilluminators for vitreoretinal surgery

NASA Astrophysics Data System (ADS)

Hessling, M.; Koelbl, P. S.; Lingenfelder, C.; Koch, F.

2015-07-01

Two innovative approaches for intraocular illumination during vitreoretinal surgery by application of white LEDs are being developed. Both techniques are less harmful to the patient, more convenient for the surgeon and smaller and cheaper compared to conventional illumination by Xenon light sources and optical fibers. These two novel approaches are: I) The miniature LED chandelier endoilluminator consisting of a single white LED with a "light probe" on top of the LED housing that fits in a small incision in the wall of the eye. II) The alternative transscleral LED endoilluminator is integrated into an eye speculum that presses the flat LED top against the eye. The intraocular space is only illuminated by light transmitted through the sclera. In contrast to conventional illumination techniques for vitreoretinal surgery no incision is necessary. Both approaches are evaluated with regard to potential photochemical and thermal risks for the patient's retina and they are tested on porcine eyes.

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

(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.

Perceived Learning Effectiveness of a Course Facebook Page: Teacher-Led versus Student-Led Approach

ERIC Educational Resources Information Center

Tugrul, Tugba Orten

2017-01-01

This research aims to compare the perceived effectiveness of teacher-led and student-led content management approaches embraced in a course Facebook page designed to enhance traditional classroom learning. Eighty-five undergraduate marketing course students voluntarily completed a questionnaire composed of two parts; a depiction of a course…

Standardization of UV LED measurements

NASA Astrophysics Data System (ADS)

Eppeldauer, G. P.; Larason, T. C.; Yoon, H. W.

2015-09-01

Traditionally used source spectral-distribution or detector spectral-response based standards cannot be applied for accurate UV LED measurements. Since the CIE standardized rectangular-shape spectral response function for UV measurements cannot be realized with small spectral mismatch when using filtered detectors, the UV measurement errors can be several times ten percent or larger. The UV LEDs produce broadband radiation and both their peaks or spectral bandwidths can change significantly. The detectors used for the measurement of these LEDs also have different spectral bandwidths. In the discussed example, where LEDs with 365 nm peak are applied for fluorescent crack-recognition using liquid penetrant (non-destructive) inspection, the broadband radiometric LED (signal) measurement procedure is standardized. A UV LED irradiance-source was calibrated against an FEL lamp standard to determine its spectral irradiance. The spectral irradiance responsivity of a reference UV meter was also calibrated. The output signal of the reference UV meter was calculated from the spectral irradiance of the UV source and the spectral irradiance responsivity of the reference UV meter. From the output signal, both the integrated irradiance (in the reference plane of the reference meter) and the integrated responsivity of the reference meter were determined. Test UV meters calibrated for integrated responsivity against the reference UV meter, can be used to determine the integrated irradiance from a field UV source. The obtained 5 % (k=2) measurement uncertainty can be decreased when meters with spectral response close to a constant value are selected.

White LED sources for vehicle forward lighting

NASA Astrophysics Data System (ADS)

Van Derlofske, John F.; McColgan, Michele W.

2002-11-01

Considerations for the use of white light emitting diode (LED) sources to produce illumination for automotive forward lighting is presented. Due to their reliability, small size, lower consumption, and lower heat generation LEDs are a natural choice for automotive lighting systems. Currently, LEDs are being sucessfully employed in most vehicle lighting applications. In these applications the light levels, distributions, and colors needed are achievable by present LED technologies. However, for vehicle white light illumination applications LEDs are now only being considered for low light level applications, such as back-up lamps. This is due to the relatively low lumen output that has been available up to now in white LEDs. With the advent of new higher lumen packages, and with the promise of even higher light output in the near future, the use of white LEDs sources for all vehicle forward lighting applications is beginning to be considered. Through computer modeling and photometric evaluation this paper examines the possibilities of using currently available white LED technology for vehicle headlamps. It is apparent that optimal LED sources for vehicle forward lighting applications will be constructed with hereto undeveloped technology and packaging configurations. However, the intent here in exploring currently available products is to begin the discussion on the design possibilities and significant issues surrounding LEDs in order to aid in the design and development of future LED sources and systems. Considerations such as total light output, physical size, optical control, power consumption, color appearance, and the effects of white LED spectra on glare and peripheral vision are explored. Finally, conclusions of the feasibility of current LED technology being used in these applications and recommendations of technology advancements that may need to occur are made.

Degradation of phosphor-in-glass encapsulants with various phosphor types for high power LEDs

NASA Astrophysics Data System (ADS)

Iqbal, Fauzia; Kim, Sunil; Kim, Hyungsun

2017-10-01

In order to replace conventional silicone-based phosphor light emitting diodes (LEDs), inorganic color converters with high thermal stabilities and transparencies, i.e., phosphors-in-glass (PiGs), have been investigated as encapsulants for high-power LEDs. In this paper, the effect of various types of phosphors, i.e., LuAG (green, Lu3Al5O12:Ce3+), silicate (yellow, Sr2SiO4:Eu2+), CASN (red, CaAlSiN3:Eu2+), and oxynitride (yellow, (Sr,Ba) Si2O2N2:Eu2+), on the reliability/degradation of the remote PiG encapsulants is explored for high power LEDs. For this purpose, a glass composition (SiO2-B2O3-ZnO-Na2O) was separately mixed with each type of phosphor and then sintered at appropriate temperatures to make the corresponding PiG. The reliabilities of the formed PiGs were evaluated by standard accelerated-aging tests (85 °C/85% RH) for 1000 h. Luminosity losses and shifts in the Commission Internationale de l'Eclairage (CIE) coordinates of the PiGs were measured before and after aging. Thermal, and moisture-induced quenching behavior was also analyzed. The surface of PiGs with different phosphors degraded differently, possibly because of structural incompatibilities between the glass matrix and phosphor type. Determining the compatibility of the glass composition with the type of phosphor used is therefore important in order to ensure the long-term stabilities of encapsulants for use in commercial LEDs.

Luminescence properties and energy transfer of site-sensitive Ca(6-x-y)Mg(x-z)(PO(4))(4):Eu(y)(2+),Mn(z)(2+) phosphors and their application to near-UV LED-based white LEDs.

PubMed

Kwon, Ki Hyuk; Im, Won Bin; Jang, Ho Seong; Yoo, Hyoung Sun; Jeon, Duk Young

2009-12-21

On the basis of the structural information that the host material has excellent charge stabilization, blue-emitting Ca(6-x-y)Mg(x)(PO(4))(4):Eu(y)(2+) (CMP:Eu(2+)) phosphors were synthesized and systematically optimized, and their photoluminescence (PL) properties were evaluated. Depending upon the amount of Mg added, the emission efficiency of the phosphors could be enhanced. The substitution of Eu(2+) affected their maximum wavelength (lambda(max)) and thermal stability because the substitution site of Eu(2+) could be varied. To obtain single-phase two-color-emitting phosphors, we incorporated Mn(2+) into CMP:Eu(2+) phosphors. Weak red emission resulting from the forbidden transition of Mn(2+) could be enhanced by the energy transfer from Eu(2+) to Mn(2+) that occurs because of the spectral overlap between the photoluminescence excitation (PLE) spectrum of Mn(2+) and the PL spectrum of Eu(2+). The energy transfer process was confirmed by the luminescence spectra, energy transfer efficiency, and decay curve of the phosphors. Finally, the optimized Ca(6-x-y)Mg(x-z)(PO(4))(4):Eu(y)(2+),Mn(z)(2+) (CMP:Eu(2+),Mn(2+)) phosphors were applied with green emitting Ca(2)MgSi(2)O(7):Eu(2+) (CMS:Eu(2+)) phosphors to ultraviolet (UV) light emitting diode (LED)-pumped white LEDs. The CMS:Eu(2+)-mixed CMP:Eu(2+), Mn(2+)-based white LEDs showed an excellent color rendering index (CRI) of 98 because of the broader emission band and more stable color coordinates than those of commercial Y(3)Al(5)O(12):Ce(3+) (YAG:Ce(3+))-based white LEDs under a forward bias current of 20 mA. The fabricated white LEDs showed very bright natural white light that had the color coordinate of (0.3288, 0.3401), and thus CMP:Eu(2+),Mn(2+) could be regarded as a good candidate for UV LED-based white LEDs.

Automobile proximity and indoor residential concentrations of BTEX and MTBE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corsi, Dr. Richard; Morandi, Dr. Maria; Siegel, Dr. Jeffrey

Attached garages have been identified as important sources of indoor residential air pollution. However, the literature lacks information on how the proximity of cars to the living area affects indoor concentrations of gasoline-related compounds, and the origin of these pollutants. We analyzed data from the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study and evaluated 114 residences with cars in an attached garage, detached garage or carport, or without cars. Results indicate that homes with cars in attached garages were affected the most. Concentrations in homes with cars in detached garages and residences without cars were similar. The contributionmore » from gasoline-related sources to indoor benzene and MTBE concentrations appeared to be dominated by car exhaust, or a combination of tailpipe and gasoline vapor emissions. Residing in a home with an attached garage could lead to benzene exposures ten times higher than exposures from commuting in heavy traffic.« less

Life of LED-Based White Light Sources

NASA Astrophysics Data System (ADS)

Narendran, Nadarajah; Gu, Yimin

2005-09-01

Even though light-emitting diodes (LEDs) may have a very long life, poorly designed LED lighting systems can experience a short life. Because heat at the p-n-junction is one of the main factors that affect the life of the LED, by knowing the relationship between life and heat, LED system manufacturers can design and build long-lasting systems. In this study, several white LEDs from the same manufacturer were subjected to life tests at different ambient temperatures. The exponential decay of light output as a function of time provided a convenient method to rapidly estimate life by data extrapolation. The life of these LEDs decreases in an exponential manner with increasing temperature. In a second experiment,several high-power white LEDs from different manufacturers were life-tested under similar conditions. Results show that the different products have significantly different life values.

LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tuenge, Jason R.

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 ismore » recommended that a product specification and field measurement procedure be developed for implementation in demonstration projects.« less

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

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.

Side-emitting illuminators using LED sources

NASA Astrophysics Data System (ADS)

Zhao, Feng; Van Derlofske, John F.

2003-11-01

This study investigates illuminators composed of light emitting diode (LED) array sources and side-emitting light guides to provide efficient general illumination. Specifically, new geometries are explored to increase the efficiency of current systems while maintaining desired light distribution. LED technology is already successfully applied in many illumination applications, such as traffic signals and liquid crystal display (LCD) backlighting. It provides energy-efficient, small-package, long-life, and color-adjustable illumination. However, the use of LEDs in general illumination is still in its early stages. Current side-emitting systems typically use a light guide with light sources at one end, an end-cap surface at the other end, and light releasing sidewalls. This geometry introduces efficiency loss that can be as high as 40%. The illuminators analyzed in this study use LED array sources along the longitude of a light guide to increase the system efficiency. These new geometries also provide the freedom of elongating the system without sacrificing system efficiency. In addition, alternative geometries can be used to create white light with monochromatic LED sources. As concluded by this study, the side-emitting illuminators using LED sources gives the possibility of an efficient, distribution-controllable linear lighting system.

Cancer nanotechnology: a new commercialization pipeline for diagnostics, imaging agents, and therapies

NASA Astrophysics Data System (ADS)

Ptak, Krzysztof; Farrell, Dorothy; Hinkal, George; Panaro, Nicholas J.; Hook, Sara; Grodzinski, Piotr

2011-06-01

Nanotechnology - the science and engineering of manipulating matter at the molecular scale to create devices with novel chemical, physical and biological properties - has the potential to radically change oncology. Research sponsored by the NCI Alliance for Nanotechnology in Cancer has led to the development of nanomaterials as platforms of increasing complexity and devices of superior sensitivity, speed and multiplexing capability. Input from clinicians has guided researchers in the design of technologies to address specific needs in the areas of cancer therapy and therapeutic monitoring, in vivo imaging, and in vitro diagnostics. The promising output from the Alliance has led to many new companies being founded to commercialize their nanomedical product line. Furthermore, several of these technologies, which are discussed in this paper, have advanced to clinically testing.

[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. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Programmable LED-based integrating sphere light source for wide-field fluorescence microscopy.

PubMed

Rehman, Aziz Ul; Anwer, Ayad G; Goldys, Ewa M

2017-12-01

Wide-field fluorescence microscopy commonly uses a mercury lamp, which has limited spectral capabilities. We designed and built a programmable integrating sphere light (PISL) source which consists of nine LEDs, light-collecting optics, a commercially available integrating sphere and a baffle. The PISL source is tuneable in the range 365-490nm with a uniform spatial profile and a sufficient power at the objective to carry out spectral imaging. We retrofitted a standard fluorescence inverted microscope DM IRB (Leica) with a PISL source by mounting it together with a highly sensitive low- noise CMOS camera. The capabilities of the setup have been demonstrated by carrying out multispectral autofluorescence imaging of live BV2 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

LED-driven backlights for automotive displays

NASA Astrophysics Data System (ADS)

Strauch, Frank

2007-09-01

As a light source the LED has some advantage over the traditionally used fluorescence tube such as longer life or lower space consumption. Consequently customers are asking for the LED lighting design in their products. We introduced in a company owned backlight the white LED technology. This step opens the possibility to have access to the components in the display market. Instead of having a finalized display product which needs to be integrated in the head unit of a car we assemble the backlight, the glass, own electronics and the housing. A major advantage of this concept is the better control of the heat flow generated by the LEDs to the outer side because only a common housing is used for all the components. Also the requirement for slim products can be fulfilled. As always a new technology doesn't come with advantages only. An LED represents a point source compared to the well-known tube thus requiring a mixing zone for the multiple point sources when they enter a light guide. This zone can't be used in displays because of the lack of homogeneity. It's a design goal to minimize this zone which can be helped by the right choice of the LED in terms of slimness. A step ahead is the implementation of RGB LEDs because of their higher color rendering abilities. This allows for the control of the chromaticity point under temperature change but as a drawback needs a larger mixing zone.

Cryogenic characterization of LEDs for space application

NASA Astrophysics Data System (ADS)

Carron, Jérôme; Philippon, Anne; How, Lip Sun; Delbergue, Audrey; Hassanzadeh, Sahar; Cillierre, David; Danto, Pascale; Boutillier, Mathieu

2017-09-01

In the frame of EUCLID project, the Calibration Unit of the VIS (VISible Imager) instrument must provide an accurate and well characterized light source for in-flight instrument calibration without noise when it is switched off. The Calibration Unit consists of a set of LEDs emitting at various wavelengths in the visible towards an integrating sphere. The sphere's output provides a uniform illumination over the entire focal plane. Nine references of LEDs from different manufacturers were selected, screened and qualified under cryogenic conditions. Testing this large quantity of samples led to the implementation of automated testing equipment with complete in-situ monitoring of optoelectronic parameters as well as temperature and vacuum values. All the electrical and optical parameters of the LED have been monitored and recorded at ambient and cryogenic temperatures. These results have been compiled in order to show the total deviation of the LED electrical and electro-optical properties in the whole mission and to select the best suitable LED references for the mission. This qualification has demonstrated the robustness of COTS LEDs to operate at low cryogenic temperatures and in the space environment. Then 6 wavelengths were selected and submitted to an EMC sensitivity test at room and cold temperature by counting the number of photons when LEDs drivers are OFF. Characterizations were conducted in the full frequency spectrum in order to implement solutions at system level to suppress the emission of photons when the LED drivers are OFF. LEDs impedance was also characterized at room temperature and cold temperature.

Sodium monitoring in commercially processed and restaurant foods.

PubMed

Ahuja, Jaspreet K C; Pehrsson, Pamela R; Haytowitz, David B; Wasswa-Kintu, Shirley; Nickle, Melissa; Showell, Bethany; Thomas, Robin; Roseland, Janet; Williams, Juhi; Khan, Mona; Nguyen, Quynhanh; Hoy, Kathy; Martin, Carrie; Rhodes, Donna; Moshfegh, Alanna; Gillespie, Cathleen; Gunn, Janelle; Merritt, Robert; Cogswell, Mary

2015-03-01

Most sodium in the US diet comes from commercially processed and restaurant foods. Sodium reduction in these foods is key to several recent public health efforts. The objective was to provide an overview of a program led by the USDA, in partnership with other government agencies, to monitor sodium contents in commercially processed and restaurant foods in the United States. We also present comparisons of nutrients generated under the program to older data. We track ∼125 commercially processed and restaurant food items ("sentinel foods") annually using information from food manufacturers and periodically by nationwide sampling and laboratory analyses. In addition, we monitor >1100 other commercially processed and restaurant food items, termed "priority-2 foods" (P2Fs) biennially by using information from food manufacturers. These foods serve as indicators for assessing changes in the sodium content of commercially processed and restaurant foods in the United States. We sampled all sentinel foods nationwide and reviewed all P2Fs in 2010-2013 to determine baseline sodium concentrations. We updated sodium values for 73 sentinel foods and 551 P2Fs in the USDA's National Nutrient Database for Standard Reference (releases 23-26). Sodium values changed by at least 10% for 43 of the sentinel foods, which, for 31 foods, including commonly consumed foods such as bread, tomato catsup, and potato chips, the newer sodium values were lower. Changes in the concentrations of related nutrients (total and saturated fat, total sugar, potassium, or dietary fiber) that were recommended by the 2010 Dietary Guidelines for Americans for reduced or increased consumption accompanied sodium reduction. The results of sodium reduction efforts, based on resampling of the sentinel foods or re-review of P2Fs, will become available beginning in 2015. This monitoring program tracks sodium reduction efforts, improves food composition databases, and strengthens national nutrition monitoring. © 2015

Walking Machine Control Programming

DTIC Science & Technology

1983-08-31

configuration is useful for two reasons: first, the machine won’t fit through the garage door unless it is in the tuck position, and second, a principal way...machine out of its garage . ’We call the garage a "laboratory" even though the shorter term is more apt.- We regularly run the machine in the parking...comes down from a high push-up. The natural position for the feet as the machine comes out of the garage is the "tuck" in which each knee is bent in as

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

Nurse-led treatment for occipital neuralgia.

PubMed

Pike, Denise; Amphlett, Alexander; Weatherby, Stuart

Occipital neuralgia is a headache resulting from dysfunction of the occipital nerves. Medically resistant occipital neuralgia is treated by greater occipital nerve injection, which is traditionally performed by neurologists. A nurse-led clinic was developed to try to improve the service. Patient feedback showed that the clinic was positively perceived by patients, with most stating the nurse-led model was more efficient than the previous one, which had been led by consultants.

Effects of color temperatures (Kelvin) of LED bulbs on blood physiological variables of broilers grown to heavy weights.

PubMed

Olanrewaju, H A; Purswell, J L; Collier, S D; Branton, S L

2015-08-01

Light-emitting diode (LED) lighting is being used in the poultry industry to reduce energy usage in broiler production facilities. However, limited data are available comparing efficacy of different spectral distribution of LED bulbs on blood physiological variables of broilers grown to heavy weights (>3 kg). The present study evaluated the effects of color temperature (Kelvin) of LED bulbs on blood physiological variables of heavy broilers in 2 trials with 4 replicates/trial. The study was a randomized complete block design. Four light treatments consisted of 3 LED light bulbs [2,700 K, (Warm-LED); 5,000 K, (Cool-LED-#1); 5,000 K, (Cool-LED-#2)] and incandescent light (ICD, standard) from 1 to 56 d age. A total of 960 1-day-old Ross × Ross 708 chicks (30 males/room 30 females/room) were equally and randomly distributed among 16 environmentally controlled rooms at 50% RH. Each of the 4 treatments was represented by 4 rooms. Feed and water were provided ad libitum. All treatment groups were provided the same diet. Venous blood samples were collected on d 21, 28, 42, and 56 for immediate analysis of selected physiological variables and plasma collection. In comparison with ICD, Cool-LED-#1 had greater (P < 0.05) effects on pH, partial pressure of CO₂(pCO₂), partial pressure of O₂(pO₂), saturated O₂(sO₂), and K⁺. However, all these acid-base changes remained within the normal venous acid-base homeostasis and physiological ranges. In addition, no effect of treatments was observed on HCO(3)(-), hematocrit (Hct), hemoglobin (Hb), Na⁺, Ca²⁺, Cl⁻, mean corpuscular hemoglobin concentration (McHc), osmolality, and anion gap. Moreover, blood glucose concentrations were not affected by treatments. This study shows that the 3 LED light bulbs evaluated in this study may be suitable for replacement of ICD light sources in commercial poultry facilities to reduce energy cost and optimize production efficiency without inducing physiological stress on

Thermoresponsive scattering coating for smart white LEDs.

PubMed

Bauer, Jurica; Verbunt, Paul P C; Lin, Wan-Yu; Han, Yang; Van, My-Phung; Cornelissen, Hugo J; Yu, Joan J H; Bastiaansen, Cees W M; Broer, Dirk J

2014-12-15

White light emitting diode (LED) systems, capable of lowering the color temperature of emitted light on dimming, have been reported in the literature. These systems all use multiple color LEDs and complex control circuitry. Here we present a novel responsive lighting system based on a single white light emitting LED and a thermoresponsive scattering coating. The coated LED automatically emits light of lower correlated color temperature (CCT) when the power is reduced. We also present results on the use of multiple phosphors in the white light LED allowing for the emission of warm white light in the range between 2900 K and 4150 K, and with a chromaticity complying with the ANSI standards (C78.377). This responsive warm white light LED-system with close-to-ideal emission characteristics is highly interesting for the lighting industry.

Kansas highway LED illumination manual : a guide for the use of LED lighting systems : [technical summary].

DOT National Transportation Integrated Search

2015-12-01

The research project was aimed to assist the Kansas Department of Transportation (KDOT) in the development of a Highway LED Illumination Manual for guiding the upcoming implementation of successful LED roadway lighting systems in Kansas to replace th...

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.

Significant growth in. LED use predicted.

PubMed

Simpson, Mike

2012-03-01

Although LED lighting has its critics, a number of whom (see article 'LED--panacea or marketing hype', HEJ--February 2012) are concerned about what they claim are some manufacturers' 'exaggerated claims' about lighting efficiency and lamp lifetime, Philips Lighting believes that, such are the advances being made in this innovative lighting technology, that LED's overall share of the European lighting market will have risen from around 7% in 2008 to 25% by 2020 and that, a decade later, it will account for a remarkable 75% of lighting sales. In the UK, Philips' technical and design director for Lighting, Mike Simpson, told HEJ editor, Jonathan Baillie, healthcare estates and facilities managers are increasingly recognising the potential to save energy, reduce carbon emissions, and cut maintenance costs, using LED.

Peer-led prenatal breast-feeding education: a viable alternative to nurse-led education.

PubMed

Rempel, Lynn A; Moore, Katrina C J

2012-02-01

To evaluate a prenatal breast-feeding class developed and facilitated by peer Breast-feeding Buddies. Non-equivalent control group quasi-experimental study comparing participants of the peer-led class (PLC) to those attending an established hospital-based breast-feeding nurse-led class (NLC). A brief questionnaire was completed immediately prior to the class, and telephone interviews were conducted approximately one week following the class, and one and six months post partum. 54 expectant mothers who registered for the community PLC and 55 expectant mothers who registered for the NLC. Breast-feeding intentions were measured at all time-points. Class evaluations, breast-feeding experiences, and breast-feeding support were measured at all post-class interviews. Both classes were considered worthwhile, but the PLC class was rated as more helpful and participants appreciated learning from the peers' personal experiences. Mothers taught by peers were more likely to access peer breast-feeding support. PLC participants initially decreased their prenatal breast-feeding duration intentions but had significantly stronger intentions to continue breast feeding at six months than did NLC mothers. A peer-led prenatal breast-feeding class is as effective as a traditional model of breast-feeding education and is a valuable tool to promote and support successful breast feeding. RECOMMENDATIONS FOR PRACTICE: Peer-led breast-feeding classes should be provided to enhance the accessibility of breast-feeding education and support for expectant mothers. Copyright © 2010 Elsevier Ltd. All rights reserved.

EC-LEDS Supports the Low-Carbon Transition

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

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.

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.

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.

Evaluating UV-C LED disinfection performance and ...

EPA Pesticide Factsheets

This study evaluated ultraviolet (UV) light emitting diodes (LEDs) emitting at 260 nm, 280 nm, and the combination of 260|280 nm together for their efficacy at inactivating Escherichia. coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores; research included an evaluation of genomic damage. Inactivation by the LEDs was compared with the efficacy of conventional UV sources, the low-pressure (LP) and medium-pressure (MP) mercury vapor lamps. The work also calculated the electrical energy per order of reduction of the microorganisms by the five UV sources.For E. coli, all five UV sources yielded similar inactivation rates. For MS2 coliphage, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was significantly more effective than the LP UV and UVC LED sources. When considering electrical energy per order of reduction, the LP UV lamp was the most efficient for E. coli and MS2, and the MPUV and LPUV were equally efficient for HAdV2 and B. pumilus spores. Among the UVC LEDs, the 280 nm LED unit required the least energy per log reduction of E. coli and HAdV2. The 280 nm and 260|280 nm LED units were equally efficient per log reduction of B. pumilus spores, and the 260 nm LED unit required the lowest energy per order of reduction of MS2 coliphage. The combination of the 260 nm and 280 nm UV LED wavelengths was also evaluated for potential synergistic effects. No dual-wavelength synergy was detected for inactivation of

ZnO-nanorods: A possible white LED phosphor

NASA Astrophysics Data System (ADS)

Sarangi, Sachindra Nath; T., Arun; Ray, Dinseh K.; Sahoo, Pratap Kumar; Nozaki, Shinji; Sugiyama, Noriyuki; Uchida, Kazuo

2017-05-01

The white light-emitting diodes (LEDs) have drawn much attention to replace conventional lighting sources because of low energy consumption, high light efficiency and long lifetime. Although the most common approach to produce white light is to combine a blue LED chip and a yellow phosphor, such a white LED cannot be used for a general lighting application, which requires a broad luminescence spectrum in the visible wavelength range. We have successfully chemically synthesized the ZnO nanorods showing intense broad luminescence in the visible wavelength range and made a white LED using the ZnO nanorods as phosphor excited with a blue LED. Their lengths and diameters were 2 - 10 μm and 200 - 800 nm, respectively. The wurtzite structure was confirmed by the x-ray diffraction measurement. The PL spectrum obtained by exciting the ZnO nanorods with the He-Cd laser has two peaks, one associated with the near band-edge recombination and the other with recombination via defects. The peak intensity of the near band-edge luminescence at 388 nm is much weaker than that of the defect-related luminescence. The latter luminescence peak ranges from 450 to 850 nm and broad enough to be used as a phosphor for a white LED. A white LED has been fabricated using a blue LED with 450 nm emission and ZnO nanorod powders. The LED performances show a white light emission and the electroluminescence measurement shows a stiff increase in white light intensity with increasing blue LED current. The Commission International de1'Eclairage (CIE) chromaticity colour coordinates of 450 nm LED pumped white emission shows a coordinate of (0.31, 0.32) for white LED at 350 mA. These results indicate that ZnO nanorods provides an alternate and effective approach to achieve high-performance white LEDs and also other optoelectronic devices.

Thermal management of LEDs: package to system

NASA Astrophysics Data System (ADS)

Arik, Mehmet; Becker, Charles A.; Weaver, Stanton E.; Petroski, James

2004-01-01

Light emitting diodes, LEDs, historically have been used for indicators and produced low amounts of heat. The introduction of high brightness LEDs with white light and monochromatic colors have led to a movement towards general illumination. The increased electrical currents used to drive the LEDs have focused more attention on the thermal paths in the developments of LED power packaging. The luminous efficiency of LEDs is soon expected to reach over 80 lumens/W, this is approximately 6 times the efficiency of a conventional incandescent tungsten bulb. Thermal management for the solid-state lighting applications is a key design parameter for both package and system level. Package and system level thermal management is discussed in separate sections. Effect of chip packages on junction to board thermal resistance was compared for both SiC and Sapphire chips. The higher thermal conductivity of the SiC chip provided about 2 times better thermal performance than the latter, while the under-filled Sapphire chip package can only catch the SiC chip performance. Later, system level thermal management was studied based on established numerical models for a conceptual solid-state lighting system. A conceptual LED illumination system was chosen and CFD models were created to determine the availability and limitations of passive air-cooling.

Commercial lumber

Treesearch

Kent A. McDonald; David E. Kretschmann

1999-01-01

In a broad sense, commercial lumber is any lumber that is bought or sold in the normal channels of commerce. Commercial lumber may be found in a variety of forms, species, and types, and in various commercial establishments, both wholesale and retail. Most commercial lumber is graded by standardized rules that make purchasing more or less uniform throughout the country...

Patient-led versus physician-led titration of insulin glargine in patients with uncontrolled type 2 diabetes: a randomized multinational ATLAS study.

PubMed

Garg, Satish K; Admane, Karim; Freemantle, Nick; Odawara, Masato; Pan, Chang-Yu; Misra, Anoop; Jarek-Martynowa, Iwona R; Abbas-Raza, Syed; Mirasol, Roberto C; Perfetti, Riccardo

2015-02-01

Self-adjustment of insulin dose is commonly practiced in Western patients with type 2 diabetes but is usually not performed in Asian patients. This multinational, 24-week, randomized study compared patient-led with physician-led titration of once-daily insulin glargine in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering agents. Patient-led (n = 275) or physician-led (n = 277) subjects followed the same dose-titration algorithm guided by self-monitored fasting blood glucose (FBG; target, 110 mg/dL [6.1 mmol/L]). The primary endpoint was change in mean glycated hemoglobin (HbA1c) at week 24 in the patient-led versus physician-led titration groups. Patient-led titration resulted in a significantly higher drop in HbA1c value at 24 weeks when compared with physician-led titration (-1.40% vs. -1.25%; mean difference, -0.15; 95% confidence interval, -0.29 to 0.00; P = .043). Mean decrease in FBG was greatest in the patient-led group (-2.85 mmol/L vs. -2.48 mmol/L; P = .001). The improvements in HbA1c and FBG were consistent across countries, with similar improvements in treatment satisfaction in both groups. Mean daily insulin dose was higher in the patient-led group (28.9 units vs. 22.2 units; P<.001). Target HbA1c of <7.0% without severe hypoglycemia was achieved in 40.0% and 32.9% in the patient-led and physician-led groups, respectively (P = .086). Severe hypoglycemia was not different in the 2 groups (0.7%), with an increase in nocturnal and symptomatic hypoglycemia in the patient-led arm. Patient-led insulin glargine titration achieved near-target blood glucose levels in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering drugs, demonstrating that Asian patients can self-uptitrate insulin dose effectively when guided.

19 CFR 113.67 - Commercial gauger and commercial laboratory bond conditions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Commercial gauger and commercial laboratory bond... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS BONDS Customs Bond Conditions § 113.67 Commercial gauger and commercial laboratory bond conditions. Commercial Gauger Bond Conditions (a) Commercial gauger bond...

A systems approach to the commercialization of space communications technology - The NASA/JPL Mobile Satellite Program

NASA Technical Reports Server (NTRS)

Weber, William J., III; Gray, Valerie W.; Jackson, Byron; Steele, Laura C.

1991-01-01

This paper discusss the systems approach taken by NASA and the Jet Propulsion Laboratory in the commercialization of land-mobile satellite services (LMSS) in the United States. As the lead center for NASA's Mobile Satellite Program, JPL was involved in identifying and addressing many of the key barriers to commercialization of mobile satellite communications, including technical, economic, regulatory and institutional risks, or uncertainties. The systems engineering approach described here was used to mitigate these risks. The result was the development and implementation of the JPL Mobile Satellite Experiment Project. This Project included not only technology development, but also studies to support NASA in the definition of the regulatory, market, and investment environments within which LMSS would evolve and eventually operate, as well as initiatives to mitigate their associated commercialization risks. The end result of these government-led endeavors was the acceleration of the introduction of commercial mobile satellite services, both nationally and internationally.

Medical Applications of White LEDs for Surgical Operation

NASA Astrophysics Data System (ADS)

Shimada, Junichi; Kawakami, Yoichi

Everywhere in the world, the highest quality and quantity of lighting is required during the surgical operations. However, the surgical approach has had many types and various angles, common ceiling surgical halogen lighting system cannot provide an adequate amount of beams because the surgeons' heads hinder the illuminations from reaching the operation field. The evolution of solid-state-lighting is currently going to be developed due to the progress of white light emitting diodes (LEDs). We proposed and developed the new lighting equipment that is a surgical lighting goggle composed of InGaN-YAG (yttrium aluminum garnet):Ce3+-based white LEDs. Here, we newly design surgical lighting system composed of white LEDs equipped on both sides of goggles. In fact, we have succeeded in the first internal shunt operation in the left forearm using the surgical LED lighting system on 11th Sept 2000. Since the white LEDs used were composed of InGaN-blue-emitters and YAG-yellow-phosphors, the color rendering property was not sufficient in the reddish colors. After our first challenge for medical application of white LEDs, we have been trying to improve the luminance power of white LED, the color rendering in red colors and the spectral distribution of white LED to render inherent color of raw flesh such as skin, blood, fat tissue and internal organs. We have produced new concepts for LED lighting sources and new several generations of LED lighting goggles.

Multiple LEDs luminous system in capsule endoscope

NASA Astrophysics Data System (ADS)

Mang, Ou-Yang; Huang, Shih-Wei; Lee, Hsin-Hung; Chen, Yung-Lin; Huang, Ko-Chih; Kuo, Yi-Ting

2007-02-01

Developing the luminous system in a capsule endoscope, it is difficult to obtain an uniform illumination[1] on the observed object because of several reasons: the light pattern of LED is sensitively depend on the driving current, location and projective angles; the optical path of LED light source is not parallel to the optical axis of the nearby imaging lenses; the strong reflection from the inner surface of the dome may saturate the CMOS sensors; the object plane of the observed intestine is not flat. Those reasons induce the over-blooming and deep-dark contrast in a picture and distort the original image strongly. The purpose of the article is to construct a photometric model to analyze the LED projection light pattern, and, furthermore, design a novel multiple LEDs luminous system for obtaining an uniform-brightness image. Several key parameters resulting as illumination uniformity has been taken under the model consideration and proven by experimental results. Those parameters include LED light pattern accuracy, choosing LED position relative to the imaging optical axis, LED numbers, arrangement, and the inner curvature of the dome. The novel structure improves the uniformity from 41% to 71% and reduces the light energy loss under 2%. The progress will help medical professionals to diagnose diseases and give treatment precisely based on the vivid image.

Effect of short LED lamp exposure on wear resistance, residual monomer and degree of conversion for Filtek Z250 and Tetric EvoCeram composites.

PubMed

Kopperud, Hilde M; Johnsen, Gaute F; Lamolle, Sébastien; Kleven, Inger S; Wellendorf, Hanne; Haugen, Håvard J

2013-08-01

The latest LED dental curing devices claim sufficient curing of restorative materials with short curing times. This study evaluates mechanical and chemical properties as a function of curing time of two commercial composite filling materials cured with three different LED lamps. The composites were Filtek Z250 (3M ESPE) and Tetric EvoCeram (Ivoclar Vivadent) and the LED curing devices were bluephase 16i (Ivoclar Vivadent), L.E.Demetron II (Kerr) and Mini L.E.D. (Satelec). Control samples were cured with a QTH-lamp (VCL 400, Kerr). The wear resistance after simulated tooth brushing, degree of conversion, curing depth, and amounts of residual monomers were measured after different curing times. The results of this study show that short curing time with high-intensity LEDs may influence the bulk properties of the materials, resulting in lower curing depth and increased residual monomer content. The measured surface properties of the materials, degree of conversion and wear resistance, were not affected by short curing times to the same extent. This study demonstrates that reduced exposure time with high intensity LEDs can result in composite restorations with inferior curing depth and increased leaching of monomers. Dentists are recommended to use sufficient curing times even with high intensity LEDs to ensure adequate curing and minimize the risk of monomer leaching. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Preliminary Evaluation Of Commercial Supercapacitors For Space Applications

NASA Astrophysics Data System (ADS)

Gineste, Valery; Loup, Didier; Mattesco, Patrick; Neugnot, Nicolas

2011-10-01

Supercapacitors are identified since years as a new technology enabling energy storage together with high power delivery capability to the system. A recent ESA study [1] led by Astrium has demonstrated the interest of these devices for space application, providing that reliability and end of life performances are demonstrated. A realistic commercial on the shelf (COTS) approach (or with limited design modification approved by potential suppliers) has been favoured (as for batteries). This paper presents preliminary test results done by Astrium on COTS supercapacitors: accelerated life tests, calendar life tests, technology analyses. Based on these results, assessment and lessons learnt are drawn in view of future exhaustive supercapacitor validation and future qualification.

8. VIEW OF SWAN FALLS DAM AND VILLAGE FROM LEFT ...

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

8. VIEW OF SWAN FALLS DAM AND VILLAGE FROM LEFT BANK (SOUTH) OF SNAKE RIVER, FACING EAST. VISIBLE VILLAGE STRUCTURES FROM LEFT TO RIGHT ON HILLSIDE ARE: COTTAGE 521, GARAGE 531, COTTAGE 101; VISIBLE AT RIVER LEVEL ARE: COTTAGE 361, COTTAGE 362, COTTAGE 363, BOAT HOUSE 394, CLUB HOUSE 011, GARAGE 393, COTTAGE 191, COTTAGE 181, GARAGE 532. - Swan Falls Village, Snake River, Kuna, Ada County, ID

Sodium monitoring in commercially processed and restaurant foods

PubMed Central

Ahuja, Jaspreet KC; Pehrsson, Pamela R; Haytowitz, David B; Wasswa-Kintu, Shirley; Nickle, Melissa; Showell, Bethany; Thomas, Robin; Roseland, Janet; Williams, Juhi; Khan, Mona; Nguyen, Quynhanh; Hoy, Kathy; Martin, Carrie; Rhodes, Donna; Moshfegh, Alanna; Gillespie, Cathleen; Gunn, Janelle; Merritt, Robert; Cogswell, Mary

2015-01-01

Background Most sodium in the US diet comes from commercially processed and restaurant foods. Sodium reduction in these foods is key to several recent public health efforts. Objective The objective was to provide an overview of a program led by the USDA, in partnership with other government agencies, to monitor sodium contents in commercially processed and restaurant foods in the United States. We also present comparisons of nutrients generated under the program to older data. Design We track ∼125 commercially processed and restaurant food items (“sentinel foods”) annually using information from food manufacturers and periodically by nationwide sampling and laboratory analyses. In addition, we monitor >1100 other commercially processed and restaurant food items, termed “priority-2 foods” (P2Fs) biennially by using information from food manufacturers. These foods serve as indicators for assessing changes in the sodium content of commercially processed and restaurant foods in the United States. We sampled all sentinel foods nationwide and reviewed all P2Fs in 2010–2013 to determine baseline sodium concentrations. Results We updated sodium values for 73 sentinel foods and 551 P2Fs in the USDA’s National Nutrient Database for Standard Reference (releases 23–26). Sodium values changed by at least 10% for 43 of the sentinel foods, which, for 31 foods, including commonly consumed foods such as bread, tomato catsup, and potato chips, the newer sodium values were lower. Changes in the concentrations of related nutrients (total and saturated fat, total sugar, potassium, or dietary fiber) that were recommended by the 2010 Dietary Guidelines for Americans for reduced or increased consumption accompanied sodium reduction. The results of sodium reduction efforts, based on resampling of the sentinel foods or re-review of P2Fs, will become available beginning in 2015. Conclusion This monitoring program tracks sodium reduction efforts, improves food composition

LED-pumped Alexandrite laser oscillator and amplifier

NASA Astrophysics Data System (ADS)

Pichon, Pierre; Blanchot, Jean-Philippe; Balembois, François; Druon, Frédéric; Georges, Patrick

2018-02-01

In this paper, we report the first LED-pumped transition-metal-doped laser oscillator and amplifier based on an alexandrite crystal (Cr3+:BeAl2O4). A Ce:YAG luminescent concentrator illuminated by blue LEDs is used to reach higher pump powers than with LEDs alone. The luminescent 200-mm-long-composit luminescent concentrator involving 2240 LEDs can delivers up to 268 mJ for a peak irradiance of 8.5 kW/cm2. In oscillator configuration, an LED-pumped alexandrite laser delivering an energy of 2.9 mJ at 748 nm in free running operation is demonstrated. In the cavity, we measured a double pass small signal gain of 1.28, in good agreement with numerical simulations. As amplifier, the system demonstrated to boost a CW Ti:sapphire laser by a factor of 4 at 750 nm in 8 passes with a large tuning range from 710 nm to 800 nm.

Commercialization of the Chevron FCC vanadium trap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, J.V.; Kuehler, C.W.; Krishna, A.S.

1995-09-01

Vanadium, present to varying degrees in FCC feed, deposits on the catalyst virtually quantitatively in the cracking process. In resid operations, vanadium levels on catalyst can reach 10,000 ppm at typical catalyst make-up rates. Once on the catalyst, vanadium destroys the zeolite and restricts access to active sites. This reduces catalyst activity. A vanadium trap is a material that when introduced into the catalyst inventory selectively reacts with migrating vanadium, thus protecting the zeolite and other active components of the catalyst. The trap may be incorporated into the catalyst, or introduced as a separate particle. Only a limited amount ofmore » trap can be incorporated into the catalyst without limiting the amount of zeolite that can be included. Gulf began development of a vanadium trap during the early 1980`s. The work produced a variety of promising materials whose use as vanadium traps was subsequently patented. The work ultimately led to a formulation with a phase very active for trapping vanadium while still quite sulfur tolerant. Based on these results, an extensive pilot plant evaluation was undertaken by Chevron after the Chevron-Gulf merger to better simulate commercial operation. The paper describes pilot plant tests as well as 3 commercial tests of this vanadium trap.« less

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

Estimating the supply and demand for commercial heavy truck parking on interstate highways : a case study of I-81 in Virginia.

DOT National Transportation Integrated Search

2002-01-01

The increasing number of trucks traveling on Virginia highways has led to a growing demand for public rest areas and private truck stops. This study developed a methodology to determine the supply and demand for commercial heavy truck parking using I...

New reversing design method for LED uniform illumination.

PubMed

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

2011-07-04

In light-emitting diode (LED) applications, it is becoming a big issue that how to optimize light intensity distribution curve (LIDC) and design corresponding optical component to achieve uniform illumination when distance-height ratio (DHR) is given. A new reversing design method is proposed to solve this problem, including design and optimization of LIDC to achieve high uniform illumination and a new algorithm of freeform lens to generate the required LIDC by LED light source. According to this method, two new LED modules integrated with freeform lenses are successfully designed for slim direct-lit LED backlighting with thickness of 10mm, and uniformities of illuminance increase from 0.446 to 0.915 and from 0.155 to 0.887 when DHRs are 2 and 3 respectively. Moreover, the number of new LED modules dramatically decreases to 1/9 of the traditional LED modules while achieving similar uniform illumination in backlighting. Therefore, this new method provides a practical and simple way for optical design of LED uniform illumination when DHR is much larger than 1.

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

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.

Thermophotonics for ultra-high efficiency visible LEDs

NASA Astrophysics Data System (ADS)

Ram, Rajeev J.

2017-02-01

The wall-plug efficiency of modern light-emitting diodes (LEDs) has far surpassed all other forms of lighting and is expected to improve further as the lifetime cost of a luminaire is today dominated by the cost of energy. The drive towards higher efficiency inevitably opens the question about the limits of future enhancement. Here, we investigate thermoelectric pumping as a means for improving efficiency in wide-bandgap GaN based LEDs. A forward biased diode can work as a heat pump, which pumps lattice heat into the electrons injected into the active region via the Peltier effect. We experimentally demonstrate a thermally enhanced 450 nm GaN LED, in which nearly fourfold light output power is achieved at 615 K (compared to 295 K room temperature operation), with virtually no reduction in the wall-plug efficiency at bias V < ℏω/q. This result suggests the possibility of removing bulky heat sinks in high power LED products. A review of recent high-efficiency GaN LEDs suggests that Peltier thermal pumping plays a more important role in a wide range of modern LED structures that previously thought - opening a path to even higher efficiencies and lower lifetime costs for future lighting.

Investigation of Passive Filter for LED Lamp

NASA Astrophysics Data System (ADS)

Sarwono, Edi; Facta, Mochammad; Handoko, Susatyo

2017-04-01

Light Emitting Diode lamp or LED lamp is one of the energy saving lamps nowadays widely used by consumers. However, LED lamp has contained harmonics caused by the rectifier circuit inside the lamp. Harmonics cause a quality problem in power system. As the harmonics present in current or voltage, the waveforms are distorted. Harmonics can lead to overheating in magnetic core of electrical equipments. In this paper, several tests are carried out to investigate the harmonic content of voltage and currents, and also the level of light intensity of the two brands of LED lamps. Measurements in this study are conducted by using HIOKI Power Quality Analyzer 3197. The test results show that the total harmonic distortion or THD of voltage on various brands of LED lamps did not exceed 5% as in compliance to the limit of IEEE standard 519-1992. The largest harmonic voltage is 2.9%, while maximum harmonic current for tested brands of LED lamp is 170.6%. The use of low pass filter in the form of LC filter was proposed. Based on experimental results, the application of LC filter at input side of LED lamp has successfully reduced THD current in the range of 85%-88%.

Hydroponics or soilless culture

NASA Technical Reports Server (NTRS)

Chapman, H. D.

1963-01-01

Historically, hydroponics is not a new field; plant physiologists have known and used it for some 100 years. Inevitably, some enthusiasts got carried away.Claims were made of enormous potential yields; skyscraper tops were said to be capable of producing enough food for all of their occupants; and closets, basements, garages, etc. were wishfully converted into fields for hydroponic culture. Numerous publications on the subject appeared during this period. Basic requirements for hydropinc techniques are given along with examples of where soilless culture has been used commercially.

Evaluation of a pilot police-led suicide early alert surveillance strategy in the UK.

PubMed

McGeechan, Grant James; Richardson, Catherine; Weir, Kevin; Wilson, Lynn; O'Neill, Gillian; Newbury-Birch, Dorothy

2017-07-19

Those bereaved by suicide are at increased risk of psychological harm, which can be reduced with the provision of timely support. This paper outlines an evaluation of a pilot police-led suicide strategy, in comparison to a coroner-led suicide strategy looking at the number, and length of time it takes for deaths to be recorded for each strategy. Additionally, the police-led strategy offers timely contact from support services for bereaved individuals. We examined what impact this offer of support had on the capacity of support services. A mixed methods evaluation compared how long it took for suspected suicides to be recorded using both strategies. The number of referrals received by support services during the pilot strategy were compared with those from previous years. A feedback focus group, and interviews, were held with key stakeholders. The coroner strategy was more consistent at identifying suspected suicides; however, reports were filed quicker by the police. Bereaved individuals were willing to share contact details with police officers and consent for referral to support services which lead to increased referrals. The focus group and interviews revealed that the pilot police strategy needs better integration into routine police practice. This strategy has the potential to deliver a real benefit to those bereaved by suicide; however, there are still aspects which could be improved. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The Analysis and Development of a Mechanical Breadboard Structure

DTIC Science & Technology

2006-12-01

a George Foreman© grill, a garage door opener, a smoothie blender, and a heavy duty stapler. The customer needs for each product and their...cordless drill, a smoothie blender, a small George Foreman© grill, a garage door opener, and heavy duty stapler. The cordless drill and smoothie ...individually. Table 6: Sample Products and Mechanical Areas Product George Foreman Grill Cordless Drill Garage Door Opener Smoothie Blender

LED structure with enhanced mirror reflectivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergmann, Michael; Donofrio, Matthew; Heikman, Sten

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 andmore » 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.« less

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.

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…

Modular design of the LED vehicle projector headlamp system.

PubMed

Hsieh, Chi-Chang; Li, Yan-Huei; Hung, Chih-Ching

2013-07-20

A well designed headlamp for a vehicle lighting system is very important as it provides drivers with safe and comfortable driving conditions at night or in dark places. With the advances of the semiconductor technology, the LED has become the fourth generation lighting source in the auto industry. In this study, we will propose a LED vehicle projector headlamp system. This headlamp system contains several LED headlamp modules, and every module of it includes four components: focused LEDs, asymmetric metal-based plates, freeform surfaces, and condenser lenses. By optimizing the number of LED headlamp modules, the proposed LED vehicle projector headlamp system has only five LED headlamp modules. It not only provides the low-beam cutoff without a shield, but also meets the requirements of the ECE R112 regulation. Finally, a prototype of the LED vehicle projector headlamp system was assembled and fabricated to create the correct light pattern.

A blue-LED-based device for selective photocoagulation of superficial abrasions: theoretical modeling and in vivo validation

NASA Astrophysics Data System (ADS)

Rossi, Francesca; Pini, Roberto; De Siena, Gaetano; Massi, Daniela; Pavone, Francesco S.; Alfieri, Domenico; Cannarozzo, Giovanni

2010-02-01

The blue light (~400 nm) emitted by high power Light Emitting Diodes (LED) is selectively absorbed by the haemoglobin content of blood and then converted into heat. This is the basic concept in setting up a compact, low-cost, and easy-to-handle photohaemostasis device for the treatment of superficial skin abrasions. Its main application is in reducing bleeding from superficial capillary vessels during laser induced aesthetic treatments, such as skin resurfacing, thus reducing the treatment time and improving aesthetic results (reduction of scar formation). In this work we firstly present the preliminary modeling study: a Finite Element Model (FEM) of the LED induced photothermal process was set up, in order to estimate the optimal wavelength and treatment time, by studying the temperature dynamics in the tissue. Then, a compact, handheld illumination device has been designed: commercially available high power LEDs emitting in the blue region were mounted in a suitable and ergonomic case. The prototype was tested in the treatment of dorsal excoriations in rats. Thermal effects were monitored by an infrared thermocamera, experimentally evidencing the modest and confined heating effects and confirming the modeling predictions. Objective observations and histopathological analysis performed in a follow-up study showed no adverse reactions and no thermal damage in the treated areas and surrounding tissues. The device was then used in human patients, in order to stop bleeding during Erbium laser skin resurfacing procedure. By inducing LED-based photocoagulation, the overall treatment time was shortened and scar formation was reduced, thus enhancing esthetic effect of the laser procedure.

White LEDs as broad spectrum light sources for spectrophotometry: demonstration in the visible spectrum range in a diode-array spectrophotometric detector.

PubMed

Piasecki, Tomasz; Breadmore, Michael C; Macka, Mirek

2010-11-01

Although traditional lamps, such as deuterium lamps, are suitable for bench-top instrumentation, their compatibility with the requirements of modern miniaturized instrumentation is limited. This study investigates the option of utilizing solid-state light source technology, namely white LEDs, as a broad band spectrum source for spectrophotometry. Several white light LEDs of both RGB and white phosphorus have been characterized in terms of their emission spectra and energy output and a white phosphorus Luxeon LED was then chosen for demonstration as a light source for visible-spectrum spectrophotometry conducted in CE. The Luxeon LED was fixed onto the base of a dismounted deuterium (D(2) ) lamp so that the light-emitting spot was geometrically positioned exactly where the light-emitting spot of the original D(2) lamp is placed. In this manner, the detector of a commercial CE instrument equipped with a DAD was not modified in any way. As the detector hardware and electronics remained the same, the change of the deuterium lamp for the Luxeon white LED allowed a direct comparison of their performances. Several anionic dyes as model analytes with absorption maxima between 450 and 600 nm were separated by CE in an electrolyte of 0.01 mol/L sodium tetraborate. The absorbance baseline noise as the key parameter was 5 × lower for the white LED lamp, showing clearly superior performance to the deuterium lamp in the available, i.e. visible part of the spectrum. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multi-Contrast Imaging and Digital Refocusing on a Mobile Microscope with a Domed LED Array.

PubMed

Phillips, Zachary F; D'Ambrosio, Michael V; Tian, Lei; Rulison, Jared J; Patel, Hurshal S; Sadras, Nitin; Gande, Aditya V; Switz, Neil A; Fletcher, Daniel A; Waller, Laura

2015-01-01

We demonstrate the design and application of an add-on device for improving the diagnostic and research capabilities of CellScope--a low-cost, smartphone-based point-of-care microscope. We replace the single LED illumination of the original CellScope with a programmable domed LED array. By leveraging recent advances in computational illumination, this new device enables simultaneous multi-contrast imaging with brightfield, darkfield, and phase imaging modes. Further, we scan through illumination angles to capture lightfield datasets, which can be used to recover 3D intensity and phase images without any hardware changes. This digital refocusing procedure can be used for either 3D imaging or software-only focus correction, reducing the need for precise mechanical focusing during field experiments. All acquisition and processing is performed on the mobile phone and controlled through a smartphone application, making the computational microscope compact and portable. Using multiple samples and different objective magnifications, we demonstrate that the performance of our device is comparable to that of a commercial microscope. This unique device platform extends the field imaging capabilities of CellScope, opening up new clinical and research possibilities.

Multi-Contrast Imaging and Digital Refocusing on a Mobile Microscope with a Domed LED Array

PubMed Central

Phillips, Zachary F.; D'Ambrosio, Michael V.; Tian, Lei; Rulison, Jared J.; Patel, Hurshal S.; Sadras, Nitin; Gande, Aditya V.; Switz, Neil A.; Fletcher, Daniel A.; Waller, Laura

2015-01-01

We demonstrate the design and application of an add-on device for improving the diagnostic and research capabilities of CellScope—a low-cost, smartphone-based point-of-care microscope. We replace the single LED illumination of the original CellScope with a programmable domed LED array. By leveraging recent advances in computational illumination, this new device enables simultaneous multi-contrast imaging with brightfield, darkfield, and phase imaging modes. Further, we scan through illumination angles to capture lightfield datasets, which can be used to recover 3D intensity and phase images without any hardware changes. This digital refocusing procedure can be used for either 3D imaging or software-only focus correction, reducing the need for precise mechanical focusing during field experiments. All acquisition and processing is performed on the mobile phone and controlled through a smartphone application, making the computational microscope compact and portable. Using multiple samples and different objective magnifications, we demonstrate that the performance of our device is comparable to that of a commercial microscope. This unique device platform extends the field imaging capabilities of CellScope, opening up new clinical and research possibilities. PMID:25969980

LED roadway luminaires evaluation.

DOT National Transportation Integrated Search

2012-02-01

This research explores whether LED roadway luminaire technologies are a viable future solution to providing roadway lighting. Roadway lighting : enhances highway safety and traffic flow during limited lighting conditions. The purpose of this evaluati...

Tutorial Guide: Computer Aided Structural Modeling (CASM). Version 1.01, Release Date - February 1990

DTIC Science & Technology

1990-09-01

seats Dining room Parking garage (1 story) Kitchen Required: Prepare a list of live loads for the project. Live load reductions are to be taken for all...Corridor (main) 100 Office: Lobbies 100 Assembly: Mouable seats 100 Dining rooms 100 Garages (passenger cars) 50 Kitchens (non domestic) 150a AI...rooms 100 Garages (passenger cars) 50 Kitchens (non domestic) 150a a. Variable design load. Increase may be necessary. Notes Uniformly distributed live

Modeling the radiation pattern of LEDs.

PubMed

Moreno, Ivan; Sun, Ching-Cherng

2008-02-04

Light-emitting diodes (LEDs) come in many varieties and with a wide range of radiation patterns. We propose a general, simple but accurate analytic representation for the radiation pattern of the light emitted from an LED. To accurately render both the angular intensity distribution and the irradiance spatial pattern, a simple phenomenological model takes into account the emitting surfaces (chip, chip array, or phosphor surface), and the light redirected by both the reflecting cup and the encapsulating lens. Mathematically, the pattern is described as the sum of a maximum of two or three Gaussian or cosine-power functions. The resulting equation is widely applicable for any kind of LED of practical interest. We accurately model a wide variety of radiation patterns from several world-class manufacturers.

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.

Evaluation of LED vehicular and pedestrian modules.

DOT National Transportation Integrated Search

2009-04-01

This study was conducted to verify the compliance of vehicular and pedestrian LED traffic signal modules with the Institute : of Transportation Engineers specifications; and to assess drivers preferences of the LED modules. Four vehicular modules ...

1. EXTERIOR SOUTHWEST CORNER VIEW, FACING NORTHEAST. BUILDING NO. 42 ...

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

1. EXTERIOR SOUTHWEST CORNER VIEW, FACING NORTHEAST. BUILDING NO. 42 GARAGE & TRANSPORTATION MAINTENANCE FACILITY - NASA Industrial Plant, Garage & Transportation Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

2. EXTERIOR SOUTHEAST CORNER VIEW, FACING NORTHWEST. BUILDING NO 42 ...

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

2. EXTERIOR SOUTHEAST CORNER VIEW, FACING NORTHWEST. BUILDING NO 42 GARAGE & TRANSPORTATION MAINTENANCE FACILITY - NASA Industrial Plant, Garage & Transportation Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

4. EXTERIOR NORTHWEST CORNER VIEW, FACING SOUTHEAST. BUILDING NO 42 ...

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

4. EXTERIOR NORTHWEST CORNER VIEW, FACING SOUTHEAST. BUILDING NO 42 GARAGE & TRANSPORTATION MAINTENANCE FACILITY - NASA Industrial Plant, Garage & Transportation Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

3. EXTERIOR NORTHEAST CORNER VIEW, FACING SOUTHWEST. BUILDING NO 42 ...

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

3. EXTERIOR NORTHEAST CORNER VIEW, FACING SOUTHWEST. BUILDING NO 42 GARAGE & TRANSPORTATION MAINTENANCE FACILITY - NASA Industrial Plant, Garage & Transportation Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

Colour differences in Caucasian and Oriental women's faces illuminated by white LED sources.

PubMed

Melgosa, M; Richard, N; Fernández-Maloigne, C; Xiao, K; de Clermont-Gallerande, H; Jost-Boissard, S; Okajima, K

2018-04-10

To provide an approach to facial contrast, analysing CIELAB colour differences (ΔE* ab,10 ) and its components in women's faces from two different ethnic groups, illuminated by modern white light-emitting diodes (LEDs) or traditional illuminants recommended by the International Commission on Illumination (CIE). We performed spectrophotometric measurements of spectral reflectance factors on forehead and cheek of 87 young healthy women (50 Caucasians and 37 Orientals), plus 5 commercial red lipsticks. We considered a set of 10 white LED illuminants, representative of technologies currently available on the market, plus 8 main illuminants currently recommended by the CIE, representative of conventional incandescent, daylight, and fluorescent light sources. Under each of these 18 illuminants we analysed the magnitude and components of ΔE* ab,10 between Caucasian and Oriental women (considering cheek and forehead), as well as for cheek-forehead and cheek-lipsticks in Caucasian and Oriental women. Colour-inconstancy indices for cheek, forehead, and lipsticks were computed, assuming D65 and A as reference illuminants. ΔE* ab,10 between forehead and cheek were quantitatively and qualitatively different in Orientals and Caucasians, but discrepancies with respect to average values for 18 illuminants were small (1.5% and 5.0% for Orientals and Caucasians, respectively). ΔE* ab,10 between Caucasians and Orientals were also quantitatively and qualitatively different both for forehead and cheek, and discrepancies with respect to average values were again small (1.0% and 3.9% for forehead and cheek, respectively). ΔE* ab,10 between lipsticks and cheek were at least 2 times higher than those between forehead and cheek. Regarding ΔE* ab,10 between lipsticks and cheeks, discrepancies with respect to average values were in the range 1.5% - 12.3%, although higher values of up to 54.2% were found for a white RGB LED. This white RGB LED provided the highest average colour

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…

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.

GaN-on-Si blue/white LEDs: epitaxy, chip, and package

NASA Astrophysics Data System (ADS)

Qian, Sun; Wei, Yan; Meixin, Feng; Zengcheng, Li; Bo, Feng; Hanmin, Zhao; Hui, Yang

2016-04-01

The dream of epitaxially integrating III-nitride semiconductors on large diameter silicon is being fulfilled through the joint R&D efforts of academia and industry, which is driven by the great potential of GaN-on-silicon technology in improving the efficiency yet at a much reduced manufacturing cost for solid state lighting and power electronics. It is very challenging to grow high quality GaN on Si substrates because of the huge mismatch in the coefficient of thermal expansion (CTE) and the large mismatch in lattice constant between GaN and silicon, often causing a micro-crack network and a high density of threading dislocations (TDs) in the GaN film. Al-composition graded AlGaN/AlN buffer layers have been utilized to not only build up a compressive strain during the high temperature growth for compensating the tensile stress generated during the cool down, but also filter out the TDs to achieve crack-free high-quality n-GaN film on Si substrates, with an X-ray rocking curve linewidth below 300 arcsec for both (0002) and (101¯2) diffractions. Upon the GaN-on-Si templates, prior to the deposition of p-AlGaN and p-GaN layers, high quality InGaN/GaN multiple quantum wells (MQWs) are overgrown with well-engineered V-defects intentionally incorporated to shield the TDs as non-radiative recombination centers and to enhance the hole injection into the MQWs through the via-like structures. The as-grown GaN-on-Si LED wafers are processed into vertical structure thin film LED chips with a reflective p-electrode and the N-face surface roughened after the removal of the epitaxial Si(111) substrates, to enhance the light extraction efficiency. We have commercialized GaN-on-Si LEDs with an average efficacy of 150-160 lm/W for 1mm2 LED chips at an injection current of 350 mA, which have passed the 10000-h LM80 reliability test. The as-produced GaN-on-Si LEDs featured with a single-side uniform emission and a nearly Lambertian distribution can adopt the wafer-level phosphor

Monomer Release from Resin Based Dental Materials Cured With LED and Halogen Lights

PubMed Central

Ak, Asli Topaloglu; Alpoz, A. Riza; Bayraktar, Oguz; Ertugrul, Fahinur

2010-01-01

Objectives: To measure the release of TEGDMA and BisGMA from two commercially available composite resins; Filtek Z 250 (3M ESPE, Germany), Leaddent (Leaddent, Germany) and two fissure sealants; Helioseal F (3M ESPE, Germany) Enamel Loc (Premiere Rev, USA) over 1, 3 and 7 days after polymerization with standard quartz-tungsten halogen Coltolux II (QHL) (Coltene Switzerland) and a standard blue light emitting diode Elipar Freelight 2 (3M ESPE, Germany). Methods: 9 samples of each material were placed in disc shaped specimens in 1 mm of thickness and 10 mm in diameter (n=36). Each material was polymerized using LED for 20 s (n=12), 40 s (n=12) and halogen for 40 s (n=12), respectively. High Performance Liquid Chromatography (HPLC) was used to measure the amount of monomers released over 1, 3 and 7 days. Data was analyzed using one way ANOVA and Bonferroni test for multiple comparisons with a significance level of .05. Results: LED 20 sec group showed the highest release of monomers at 1, 3 and 7 days in sealant groups. Halogen 40 sec group resulted highest release of monomers for Leaddent at all time intervals (P<.05) Conclusions: Efficiency of the curing unit and applying the recommended curing time of the light activated resin based dental materials is very important to protect the patient from potential hazards of residual monomers. PMID:20046478

Adapting radio technology to LED feedback systems

NASA Astrophysics Data System (ADS)

Salsbury, Marc; Ashdown, Ian

2007-09-01

Superheterodyne techniques were originally developed for radio transmission and reception nearly a century ago. In this paper we explore the adaptation of this technology to the problem of simultaneously monitoring the intensities of multiple LED channels with a single photosensor. The use of superheterodyne techniques obviates the need for multiple photosensors filters and tristimulus color filters to monitor the relative intensities of red, green, and blue LEDs. In addition, they alleviate the problems of electrical and optical noise, as well as the influence of ambient illumination on the photosensors. They can also be used to advantage with phosphor-coated white light LEDs in solid state lighting systems. Taking a broader view, the use of such techniques demonstrates the value of looking outside the realm of conventional LED power and control technologies when designing solid state lighting systems.

Nitride micro-LEDs and beyond--a decade progress review.

PubMed

Jiang, H X; Lin, J Y

2013-05-06

Since their inception, micro-size light emitting diode (µLED) arrays based on III-nitride semiconductors have emerged as a promising technology for a range of applications. This paper provides an overview on a decade progresses on realizing III-nitride µLED based high voltage single-chip AC/DC-LEDs without power converters to address the key compatibility issue between LEDs and AC power grid infrastructure; and high-resolution solid-state self-emissive microdisplays operating in an active driving scheme to address the need of high brightness, efficiency and robustness of microdisplays. These devices utilize the photonic integration approach by integrating µLED arrays on-chip. Other applications of nitride µLED arrays are also discussed.

6. INTERIOR MAIN SPACE DETAIL VIEW, FACING EAST. BUILDING NO ...

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

6. INTERIOR MAIN SPACE DETAIL VIEW, FACING EAST. BUILDING NO 42 GARAGE & TRANSPORTATION MAINTENANCE FACILITY - NASA Industrial Plant, Garage & Transportation Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

5. INTERIOR MAIN SPACE DETAIL VIEW, FACING WEST. BUILDING NO ...

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

5. INTERIOR MAIN SPACE DETAIL VIEW, FACING WEST. BUILDING NO 42 GARAGE & TRANSPORTATION MAINTENANCE FACILITY - NASA Industrial Plant, Garage & Transportation Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

Token-based information security for commercial and federal information networks

NASA Astrophysics Data System (ADS)

Rohland, William S.

1996-03-01

The planning of cryptographic solutions for messaging and electronic commerce applications in the United States during the past few years has been motivated by a high level of interest in the technology on the part of potential users. It has been marked by a high level of controversy over algorithms, patent rights and escrow policy. The diverse needs of the government and commercial sectors have led to mutually exclusive solutions based on different algorithms and policy; this phenomenon is fairly unique to the United States. Because of the strong requirement to preserve the differences that make these solutions unique for the two environments, the near-term evolution of a single standard appears unlikely. Furthermore, the need on the part of some government agencies and some commercial establishments exists to operate in both environments. This paper deals with the technical definition and design approach to a dual-use cryptographic device and the migration paths to the dual-use device from both environments. Such a device is further considered as a component of a secure cryptographic translation facility.

Testing high brightness LEDs relative to application environment

NASA Astrophysics Data System (ADS)

Singer, Jeffrey; Mangum, Scott; Lundberg, John

2006-08-01

Application of light emitting diodes is expanding as the luminous output and efficiencies of these devices improve. At the same time, the number of LED package types is increasing, making it challenging to determine the appropriate device for use in lighting product designs. A range of factors should be considered when selecting a LED for an application including color coordinates, luminous efficacy, cost, lumen maintenance, application life, packaging and manufacturability. Additional complexities can be introduced as LED packages become obsolete and replacement parts must be selected. The replacement LED characteristics must be understood and assessed against the parameters of the original device, in order to determine if the change will be relatively simple or will force other end-product changes. While some characteristics are readily measured and compared, other factors, such as lumen maintenance, are difficult to verify. This paper will discuss the characteristics of a LED that should be considered during the design process as well as methods to validate these characteristics, particularly those which are not typically on data sheets or, are critical to the design and warrant additional validation. Particular attention will be given to LED lumen maintenance. While published manufacturer data typically provides temperature versus performance curves, the data may not be useful depending upon the application's operating environment. Models must be created to estimate the LED's junction temperature and degradation curve at the applied temperature in order to develop a more precise life estimate. This paper presents one approach to a LED device life and performance study designed with application environments in mind.

LED traffic signal lamp characteristics : executive summary.

DOT National Transportation Integrated Search

2002-05-01

LED traffic signal lamps are being used to replace incandescent traffic signal lamps because of the long-term cost saving associated with reduced energy consumption and longer service life. The are reasons to believe that the use of LED traffic signa...

LED traffic signal lamp characteristics : final report.

DOT National Transportation Integrated Search

2002-05-01

LED traffic signal lamps are being used to replace incandescent traffic signal lamps because of : the long-term cost saving associated with reduced energy consumption and longer service life. The are reasons to believe that the use of LED traffic sig...

Surface photonic crystal structures for LED emission modification

NASA Astrophysics Data System (ADS)

Uherek, Frantisek; Škriniarová, Jaroslava; Kuzma, Anton; Šušlik, Łuboš; Lettrichova, Ivana; Wang, Dong; Schaaf, Peter

2017-12-01

Application of photonic crystal structures (PhC) can be attractive for overall and local enhancement of light from patterned areas of the light emitting diode (LED) surface. We used interference and near-field scanning optical microscope lithography for patterning of the surface of GaAs/AlGaAs based LEDs emitted at 840 nm. Also new approach with patterned polydimethylsiloxane (PDMS) membrane applied directly on the surface of red emitting LED was investigated. The overall emission properties of prepared LED with patterned structure show enhanced light extraction efficiency, what was documented from near- and far-field measurements.

A review of passive thermal management of LED module

NASA Astrophysics Data System (ADS)

Huaiyu, Ye; Koh, Sau; van Zeijl, Henk; Gielen, A. W. J.; Guoqi, Zhang

2011-01-01

Recently, the high-brightness LEDs have begun to be designed for illumination application. The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light output, quality, reliability and life time. In this review, only passive thermal solutions used on LED module will be studied. Moreover, new thermal interface materials and passive thermal solutions applied on electronic equipments are discussed which have high potential to enhance the thermal performance of LED Module.

Determination of LEDs degradation with entropy generation rate

NASA Astrophysics Data System (ADS)

Cuadras, Angel; Yao, Jiaqiang; Quilez, Marcos

2017-10-01

We propose a method to assess the degradation and aging of light emitting diodes (LEDs) based on irreversible entropy generation rate. We degraded several LEDs and monitored their entropy generation rate ( S ˙ ) in accelerated tests. We compared the thermoelectrical results with the optical light emission evolution during degradation. We find a good relationship between aging and S ˙ (t), because S ˙ is both related to device parameters and optical performance. We propose a threshold of S ˙ (t) as a reliable damage indicator of LED end-of-life that can avoid the need to perform optical measurements to assess optical aging. The method lays beyond the typical statistical laws for lifetime prediction provided by manufacturers. We tested different LED colors and electrical stresses to validate the electrical LED model and we analyzed the degradation mechanisms of the devices.

The First Large Balloon Launch from Antarctica

DTIC Science & Technology

1988-09-26

On 31 December 1987 the payload and the operations were shifted to Williams Field. The gondola was housed in the garage at Williams Field. Operations...were complete and the system was flight ready. The launch was reconfirmed for 0600 hours 8 January 1988. The gondola was returned to the garage to...0000 hours LST. 13 January. The payload was off-loaded and stored In the garage at Williams Field. At this point the mission was complete except for

Intelligence in the Now: Robust Intelligence in Complex Domains

DTIC Science & Technology

2015-09-26

We have applied our model and the resulting search strategy for a mobile manipulator modeled on a Willow Garage PR2 robot. As shown in Figure 12...with them – the robot tries to move a handle to various target locations and observes the reached location. Figure 13 shows Willow Garage PR2 robot...Massachusetts Institute of Technology, Cambridge, MA 02139 USA barragan@mit.edu, tlp@mit.edu, lpk@mit.edu Fig. 1. Willow Garage PR2 robot manipulating

A comparison of pediatric basic life support self-led and instructor-led training among nurses.

PubMed

Vestergaard, Lone D; Løfgren, Bo; Jessen, Casper L; Petersen, Christina B; Wolff, Anne; Nielsen, Henrik V; Krarup, Niels H V

2017-02-01

Pediatric cardiac arrest carries a poor prognosis. Basic life support improves survival. Studies on pediatric basic life support (PBLS) training are sparse. The aim of our study was to investigate the effect of self-training in PBLS. We conducted a prospective controlled trial enrolling nurses from pediatric and maternity wards (n=29 in each group). Self-training, including a manikin and access to a web-based video on PBLS, was compared with a 2-h instructor-led course. Two weeks after training, all participants were tested in a mock scenario of pediatric cardiac arrest. Fifteen parameters equivalent to the steps in the PBLS algorithm - for example, effective ventilations, effective chest compressions, calling for help, and correct sequence of actions, were evaluated and rated dichotomously (1=approved or 0=not approved). No difference was observed in the baseline demographics between the self-training group and the instructor-led group. The participants in the self-training group accessed the website 2±1.5 times (mean±SD) and spent 41±25 min on the site. There was no significant difference between the two groups in the overall average score (10.5 in the self-training group vs. 10.0 in the instructor-led group, P=0.51) or in any of the 15 parameters. After the study, all participants felt that they had improved their skills and felt capable of performing PBLS. Self-training is not statistically different to instructor-led training in teaching PBLS. Self-evaluated confidence improved, but showed no difference between groups. PBLS may be disseminated through self-training.

Design of a cylindrical LED substrate without radiator

NASA Astrophysics Data System (ADS)

Tang, Fan; Guo, Zhenning

2017-12-01

To reduce the weight and production costs of light-emitting diode (LED) lamps, we applied the principle of the chimney effect to design a cylindrical LED substrate without a radiator. We built a 3D model by using Solidworks software and applied the flow simulation plug-in to conduct model simulation, thereby optimizing the heat source distribution and substrate thickness. The results indicate that the design achieved optimal cooling with a substrate with an upper extension length of 35 mm, a lower extension length of 8 mm, and a thickness of 1 mm. For a substrate of those dimensions, the highest LED chip temperature was 64.78 °C, the weight of the substrate was 35.09 g, and R jb = 7.00 K/W. If the substrate is powered at 8, 10, and 12 W, its temperature meets LED safety requirements. In physical tests, the highest temperature for a physical 8 W cylindrical LED substrate was 66 °C, which differed by only 1.22 °C from the simulation results, verifying the validity of the simulation. The designed cylindrical LED substrate can be used in high-power LED lamps that do not require radiators. This design is not only excellent for heat dissipation, but also for its low weight, low cost, and simplicity of manufacture.

LED Solar Simulator

NASA Image and Video Library

2016-11-18

NASA Glenn's new LED solar simulator was developed by Angstrom Designs and UC Santa Barbara under a Small Business Innovative Research program to test the next generation of high-efficiency space solar cells for future missions. The new simulator contains over 1500 individually adjustable light sources, most of which emit light invisible to the human eye, to cover a 10 x10 foot area.

LED Solar Simulator

NASA Image and Video Library

2016-11-16

NASA Glenn's new LED solar simulator was developed by Angstrom Designs and UC Santa Barbara under a Small Business Innovative Research program to test the next generation of high-efficiency space solar cells for future missions. The new simulator contains over 1500 individually adjustable light sources, most of which emit light invisible to the human eye, to cover a 10 x10 foot area.

Progress in extremely high brightness LED-based light sources

NASA Astrophysics Data System (ADS)

Hoelen, Christoph; Antonis, Piet; de Boer, Dick; Koole, Rolf; Kadijk, Simon; Li, Yun; Vanbroekhoven, Vincent; Van De Voorde, Patrick

2017-09-01

Although the maximum brightness of LEDs has been increasing continuously during the past decade, their luminance is still far from what is required for multiple applications that still rely on the high brightness of discharge lamps. In particular for high brightness applications with limited étendue, e.g. front projection, only very modest luminance values in the beam can be achieved with LEDs compared to systems based on discharge lamps or lasers. With dedicated architectures, phosphor-converted green LEDs for projection may achieve luminance values up to 200-300 Mnit. In this paper we report on the progress made in the development of light engines based on an elongated luminescent concentrator pumped by blue LEDs. This concept has recently been introduced to the market as ColorSpark High Lumen Density LED technology. These sources outperform the maximum brightness of LEDs by multiple factors. In LED front projection, green LEDs are the main limiting factor. With our green modules, we now have achieved peak luminance values of 2 Gnit, enabling LED-based projection systems with over 4000 ANSI lm. Extension of this concept to yellow and red light sources is presented. The light source efficiency has been increased considerably, reaching 45-60 lm/W for green under practical application conditions. The module architecture, beam shaping, and performance characteristics are reviewed, as well as system aspects. The performance increase, spectral range extensions, beam-shaping flexibility, and cost reductions realized with the new module architecture enable a breakthrough in LED-based projection systems and in a wide variety of other high brightness applications.

Commercialization of LARC(TradeMark)-SI Polyimide Technology

NASA Technical Reports Server (NTRS)

Bryant, Robert G.

2008-01-01

LARC(TradeMark)-SI, Langley Research Center-Soluble Imide, was developed in 1992. This new polyimide won a 1995 Research and Development 100 Award, with the first patent issuing in 1997 and subsequent issued patents in 1998 and 2000. Currently, this polymer has been successfully licensed by NASA, and has generated revenues in excess of 1.4 million dollars. This might seem insignificant in comparison to industrially developed technology, where the customer is understood, technologies that use a novel assembly of commercial off the shelf (COTS) components, or software patents and "method based" innovations that do not require any material beyond labor, as examples. However, consider that LARC(TradeMark)-SI competes in areas currently dominated by traditional materials at a cost disadvantage ($350/lb) and that the physical-mechanical properties of LARC(TradeMark)-SI are similar to other high performance polymers. Indeed the success of this particular polymer was due to many factors and many lessons learned to the point that the invention was the most important, but least significant part in the commercialization of this material. This brief paper outlines the significant factors that occurred to make this technology available for the public access and application development that led to the licensing success of this material.

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.

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

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

Design method of high-efficient 
LED headlamp lens.

PubMed

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

2010-09-27

Low optical efficiency of light-emitting diode (LED) based headlamp is one of the most important issues to obstruct applications of LEDs in headlamp. An effective high-efficient LED headlamp freeform lens design method is introduced in this paper. A low-beam lens and a high-beam lens for LED headlamp are designed according to this method. Monte Carlo ray tracing simulation results demonstrate that the LED headlamp with these two lenses can fully comply with the ECE regulation without any other lens or reflector. Moreover, optical efficiencies of both these two lenses are more than 88% in theory.

Influencing of various phosphor parameters on the LED performance

NASA Astrophysics Data System (ADS)

Wu, Yi Ping; Zhang, Shu Qin; Jin, Shang-zhong; Shi, Chang Shou; Li, Liang; Yu, RenYong

2012-10-01

In this paper ,the advantages and disadvantages of the methods to achieve White LED are reviewed, and phosphor-converted white LEDs are discussed in detail. In the case of blue chip exciting YAG phosphor to get white LED, use Mie scattering theory to construct physical model, then analyze how the package, concentration, thickness and particle size of phosphor work on extraction efficiency, spatial Chroma uniformity and color temperature of white LED. The conclusion of this paper advances the application of LED solid-state light source. In the end, the paper puts forward the direction and focus of phosphor research.

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

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.

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

LED street lighting evaluation -- phase II : LED specification and life-cycle cost analysis.

DOT National Transportation Integrated Search

2015-01-01

Phase II of this study focused on developing a draft specification for LED luminaires to be used by IDOT : and a life-cycle cost analysis (LCCA) tool for solid state lighting technologies. The team also researched the : latest developments related to...

Flat-panel video resolution LED display system

NASA Astrophysics Data System (ADS)

Wareberg, P. G.; Kennedy, D. I.

The system consists of a 128 x 128 element X-Y addressable LED array fabricated from green-emitting gallium phosphide. The LED array is interfaced with a 128 x 128 matrix TV camera. Associated electronics provides for seven levels of grey scale above zero with a grey scale ratio of square root of 2. Picture elements are on 0.008 inch centers resulting in a resolution of 125 lines-per-inch and a display area of approximately 1 sq. in. The LED array concept lends itself to modular construction, permitting assembly of a flat panel screen of any desired size from 1 x 1 inch building blocks without loss of resolution. A wide range of prospective aerospace applications exist extending from helmet-mounted systems involving small dedicated arrays to multimode cockpit displays constructed as modular screens. High-resolution LED arrays are already used as CRT replacements in military film-marking reconnaissance applications.

Is light-emitting diode phototherapy (LED-LLLT) really effective?

PubMed Central

Kim, Won-Serk; Calderhead, R Glen

2011-01-01

Background: Low level light therapy (LLLT) has attracted attention in many clinical fields with a new generation of light-emitting diodes (LEDs) which can irradiate large targets. To pain control, the first main application of LLLT, have been added LED-LLLT in the accelerated healing of wounds, both traumatic and iatrogenic, inflammatory acne and the patient-driven application of skin rejuvenation. Rationale and Applications: The rationale behind LED-LLLT is underpinned by the reported efficacy of LED-LLLT at a cellular and subcellular level, particularly for the 633 nm and 830 nm wavelengths, and evidence for this is presented. Improved blood flow and neovascularization are associated with 830 nm. A large variety of cytokines, chemokines and macromolecules can be induced by LED phototherapy. Among the clinical applications, non-healing wounds can be healed through restoring the collagenesis/collagenase imbalance in such examples, and ‘normal’ wounds heal faster and better. Pain, including postoperative pain, postoperative edema and many types of inflammation can be significantly reduced. Experimental and clinical evidence: Some personal examples of evidence are offered by the first author, including controlled animal models demonstrating the systemic effect of 830 nm LED-LLLT on wound healing and on induced inflammation. Human patients are presented to illustrate the efficacy of LED phototherapy on treatment-resistant inflammatory disorders. Conclusions: Provided an LED phototherapy system has the correct wavelength for the target cells, delivers an appropriate power density and an adequate energy density, then it will be at least partly, if not significantly, effective. The use of LED-LLLT as an adjunct to conventional surgical or nonsurgical indications is an even more exciting prospect. LED-LLLT is here to stay. PMID:24155530

A comparison of temperature and humidity effects on phosphor-converted LED packages and the prediction of remaining useful life with state estimation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lall, Pradeep; Zhang, Hao; Davis, Lynn

This paper focuses on the failure mechanisms and color stability of a commercially available high power LED under harsh environmental conditions. 3 groups of the same pc-HB warm white LED were used in the experiment. The first group was subjected to both high temperature and high relative humidity (85°C/85%RH) with a 350mA bias current. The second group was subjected to only temperature stress at 105°C with a 350mA bias current. The last group was subjected to extreme high temperature 175°C and high bias current (500mA). Samples were taken out from the chamber for both photometric and colorimetric analysis at periodicmore » intervals to investigate the change of the optical parameters. The physics of failure due to the material degradation has been correlated with the change in the photometric and colorimetric parameters of the LED packages. At the end of the experiment, 6000 hours of data is projected forward with state estimation methods to compare with projections made with the TM-21 method. Experimental results shows that only optical parts degrades at high temperature conditions. However, at both high temperature and high relative humidity condition, the phosphor layer of the pc-LED can swell and the color stability of LEDs degrades significantly. Also, comparison between TM-21 method and state estimation method shows that state estimation can achieve the same goal with a relatively easy method.« less

Bridgeless SEPIC PFC Converter for Multistring LED Driver

NASA Astrophysics Data System (ADS)

Jha, Aman; Singh, Bhim

2018-05-01

This paper deals with Power Factor Correction (PFC) in Low Voltage High Current (LVHC) multi-string light emitting diode (LED) using a bridgeless (BL) single ended primary inductance converter (SEPIC). This application is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for the lighting control. The BL-SEPIC PFC converter is used as a load emulator for high power factor. The regulated low voltage from flyback converter is a source power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-SEPIC PFC converter inductor design is based on Discontinuous Inductor Current Modes (DICM) which provides good PFC at low cost. Test results are found quite satisfactory for universal input AC (90-265 V). There is significant improvement in the power factor and input current Total Harmonic Distortion (THD) with good margin of harmonic limits for lighting IEC 61000-3-2 Class C.

Parking Structures and the Space Race.

ERIC Educational Resources Information Center

Milshtein, Amy

2000-01-01

Presents some solutions to overcrowded parking on college campuses. Tips on selecting sites for parking garages, making parking decks blend with adjacent communities, and turning parking garages into multi use facilities are addressed. (GR)

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.

Integrated parabolic nanolenses on MicroLED color pixels

NASA Astrophysics Data System (ADS)

Demory, Brandon; Chung, Kunook; Katcher, Adam; Sui, Jingyang; Deng, Hui; Ku, Pei-Cheng

2018-04-01

A parabolic nanolens array coupled to the emission of a nanopillar micro-light emitting diode (LED) color pixel is shown to reduce the far field divergence. For a blue wavelength LED, the total emission is 95% collimated within a 0.5 numerical aperture zone, a 3.5x improvement over the same LED without a lens structure. This corresponds to a half-width at half-maximum (HWHM) line width reduction of 2.85 times. Using a resist reflow and etchback procedure, the nanolens array dimensions and parabolic shape are formed. Experimental measurement of the far field emission shows a HWHM linewidth reduction by a factor of 2x, reducing the divergence over the original LED.

Integrated parabolic nanolenses on MicroLED color pixels.

PubMed

Demory, Brandon; Chung, Kunook; Katcher, Adam; Sui, Jingyang; Deng, Hui; Ku, Pei-Cheng

2018-04-20

A parabolic nanolens array coupled to the emission of a nanopillar micro-light emitting diode (LED) color pixel is shown to reduce the far field divergence. For a blue wavelength LED, the total emission is 95% collimated within a 0.5 numerical aperture zone, a 3.5x improvement over the same LED without a lens structure. This corresponds to a half-width at half-maximum (HWHM) line width reduction of 2.85 times. Using a resist reflow and etchback procedure, the nanolens array dimensions and parabolic shape are formed. Experimental measurement of the far field emission shows a HWHM linewidth reduction by a factor of 2x, reducing the divergence over the original LED.

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.

How a health and safety management training program may improve the working environment in small- and medium-sized companies.

PubMed

Torp, Steffen

2008-03-01

The objective of this controlled intervention study was to investigate the effects of a 2-year training program in health and safety (H&S) management for managers at small- and medium-sized companies. A total of 113 managers of motor vehicle repair garages participated in the training and another 113 garage managers served as a comparison group. The effects were measured using questionnaires sent before and after the intervention to the managers and blue-collar workers at the garages. The intervention group managers reported significantly greater improvement of their H&S management system than the managers in the comparison group. The results also indicate that the management training positively affected how the workers regarded their supportive working environment. H&S management training may positively affect measures at both garage and individual levels.

Effect of commercial mineral-based additives on composting and compost quality.

PubMed

Himanen, M; Hänninen, K

2009-08-01

The effectiveness of two commercial additives meant to improve the composting process was studied in a laboratory-scale experiment. Improver A (sulphates and oxides of iron, magnesium, manganese, and zinc mixed with clay) and B (mixture of calcium hydroxide, peroxide, and oxide) were added to source-separated biowaste:peat mixture (1:1, v/v) in proportions recommended by the producers. The composting process (T, emissions of CO(2), NH(3), and CH(4)) and the quality of the compost (pH, conductivity, C/N ratio, water-soluble NH(4)-N and NO(3)-N, water- and NaOH-soluble low-weight carboxylic acids, nutrients, heavy metals and phytotoxicity to Lepidium sarivum) were monitored during one year. Compared with the control, the addition of improver B increased pH by two units, led to an earlier elimination of water-soluble ammonia, an increase in nitrates, a 10-fold increase in concentrations of acetic acid, and shortened phytotoxicity period by half; as negative aspect it led to volatilization of ammonia. The addition of improver A led to a longer thermophilic stage by one week and lower concentrations of low-weight carboxylic acids (both water- and NaOH-extractable) with formic and acetic of similar amounts, however, most of the aspects claimed by the improver's producer were not confirmed in this trial.

Landsat commercialization

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

1984-04-01

The House of Representatives will soon vote on a bill that outlines steps to commercialize the land remote-sensing system. The bill follows attempts last year to commercialize both the land and meteorological remote sensing satellite systems. Meanwhile, the National Oceanic and Atmospheric Administration (NOAA) has received bids from seven private companies interested in operating Landsat. The bids resulted from a request for proposals issued by the agency earlier this year. Commercialization of the meteorological satellite system was blocked in November.

Progress in LED technology for solid-state lighting

NASA Astrophysics Data System (ADS)

Bhardwaj, Jy; Guth, Greg; Cesaratto, John M.; Shchekin, Oleg B.; Soer, Wouter A.; Götz, Werner; Bonné, Ron; Song, Zhihua F.; den Breejen, Jeroen

2017-02-01

As solid-state lighting adoption moves from bulb socket replacement to lighting system engineering, luminaire manufacturers are beginning to actualize far greater cost savings through luminaire optimization rather than the simplistic process of component cost pareto management. Indeed, there are an increasing number of applications in which we see major shifts in the value chain in terms of increasing the L1 (LED) and L2 (LED array on PCB) value. The L1 value increase stems from a number of factors ranging from simply higher performing LEDs reducing the LED count, to L1 innovation such as high voltage LEDs, optimizing driver efficiency or to the use of high luminance LEDs enabling compact optics, allowing not only more design freedom but also cost reduction through space and weight savings. The L2 value increase is realized predominantly through increasing L2 performance with the use of algorithms that optimize L1 selection and placement and/or through L2 integration of drivers, control electronics, sensors, secondary lens and/or environmental protection, which is also initiating level collapse in the value chain. In this paper we will present the L1 and L2 innovations that are enabling this disruption as well as provide examples of fixture/luminaire level benefits.

Characteristics of white LED transmission through a smoke screen

NASA Astrophysics Data System (ADS)

Zheng, Yunfei; Yang, Aiying; Feng, Lihui; Guo, Peng

2018-01-01

The characteristics of white LED transmission through a smoke screen is critical for visible light communication through a smoke screen. Based on the Mie scattering theory, the Monte Carlo transmission model is established. Based on the probability density function, the white LED sampling model is established according to the measured spectrum of a white LED and the distribution angle of the lambert model. The sampling model of smoke screen particle diameter is also established according to its distribution. We simulate numerically the influence the smoke thickness, the smoke concentration and the angle of irradiance of white LED on transmittance of the white LED. We construct a white LED smoke transmission experiment system. The measured result on the light transmittance and the smoke concentration agreed with the simulated result, and demonstrated the validity of simulation model for visible light transmission channel through a smoke screen.

1. GENERAL VIEW OF ROUTE 209 LOOKING NORTH SHOWING SLEEPING ...

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

1. GENERAL VIEW OF ROUTE 209 LOOKING NORTH SHOWING SLEEPING BEAR INN, SLEEPING BEAR INN GARAGE AND DORMITORY, D.H. DAY STORE, RESTROOM, AND GARAGE - Glen Haven Historic District, Route 209, Glen Arbor, Leelanau County, MI

Prototype Methodology for Designing and Developing Computer-Assisted Instruction

DTIC Science & Technology

1986-08-01

contains essential information and is not set off with commas. For example: The lawn mower that is broken is in the garage. Use "which" whenever the...phrase that follows contains supplementary or incidental information. "Which" clauses are set of by a pair of commas. For example: The lawn mower , which...is broken, is in the garage. If the lawn mower that is broken is in the garage, whereas the lawn mower that is working is in the yard, then the

LED downlights with non-circular spots

NASA Astrophysics Data System (ADS)

Parkyn, William A.; Pelka, David G.

2005-09-01

The ubiquitous downlight inhabits our ceilings by the millions. Hot, inefficient, and electrically wasteful, it is next in line for replacement by the latest high-brightness, high-efficacy white LEDs. The conventional downlight configuration of a large incandescent spotlight in a low-cost, ceiling-recessed metal can, represents the culmination of old technology, fated never to improve significantly. Incandescent downlights add greatly both to direct and indirect electrical consumption, with the lamps requiring relatively frequent replacement. The small size of LED emitters means small optical elements can produce much higher-quality beams than incandescent spotlight-lamps can produce. Herein we introduce compact high-luminosity LED downlights with lenses that deliver uniform illumination to delimited targets such as tables. One version utilizes circular lenses and micro-diffuser films to deliver square outputs. The other uses lenses cut to the target shape. In particular, one of these lenses is the first to offer a semicircular spot suitable for gambling tables.

The NASA LeRC regenerative fuel cell system testbed program for goverment and commercial applications

NASA Astrophysics Data System (ADS)

Maloney, Thomas M.; Prokopius, Paul R.; Voecks, Gerald E.

1995-01-01

The Electrochemical Technology Branch of the NASA Lewis Research Center (LeRC) has initiated a program to develop a renewable energy system testbed to evaluate, characterize, and demonstrate fully integrated regenerative fuel cell (RFC) system for space, military, and commercial applications. A multi-agency management team, led by NASA LeRC, is implementing the program through a unique international coalition which encompasses both government and industry participants. This open-ended teaming strategy optimizes the development for space, military, and commercial RFC system technologies. Program activities to date include system design and analysis, and reactant storage sub-system design, with a major emphasis centered upon testbed fabrication and installation and testing of two key RFC system components, namely, the fuel cells and electrolyzers. Construction of the LeRC 25 kW RFC system testbed at the NASA-Jet Propulsion Labortory (JPL) facility at Edwards Air Force Base (EAFB) is nearly complete and some sub-system components have already been installed. Furthermore, planning for the first commercial RFC system demonstration is underway.

Visual ergonomic evaluations on four different designs of LED traffic signs

NASA Astrophysics Data System (ADS)

Chen, Yi-Chun; Huang, Ting-Yuan; Lee, Tsung-Xian; Sun, Ching-Cherng

2017-08-01

To investigate the legibility and visual comfort of LED traffic signs, an ergonomic experiment is performed on four custom-designed LED traffic signs, including three self-luminous ones as LED lightbox, LED backlight and regional LED backlight, and one non-self-luminous sign with external LED lighting. The four signs are hanged side-by-side and evaluated by observers through questionnaires. The signage dimension is one-sixth of the real freeway traffic signs, and the observation distance is 25 m. The luminance of three self-luminous signs is 216 cd/m2. The illuminance of external LED lighting is 400 lux on the traffic sign. The ambient illuminance is 2.8 and 6.0 lux in two rounds. The results show that self-luminous traffic signs provide superior legibility, visual comfort and user preference than the non-self-luminous one. Among the three self-luminous signs, regional LED backlight is most susceptible to the ambient illumination. LED lightbox has significantly better preference score than LED backlight under darker ambient lighting. Only LED lightbox has significantly better visual comfort than external LED lighting in the brighter environment. Based on the four LED traffic signs evaluated in this study, we suggest LED lightbox as the prior choice. Further investigations on the effect of ambient illumination and other designs of self-luminous traffic signs are in progress.

4. Photocopy of photograph (original in possession of Western Archeological ...

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

4. Photocopy of photograph (original in possession of Western Archeological and Conservation Center (WACC), Tucson, Arizona), photographer unknown, undated NEIL ERICKSON WORKING OUTSIDE OFFICE/GARAGE WHEN IT WAS NEW - Faraway Ranch, Office-Garage, Willcox, Cochise County, AZ

2. D Street facade and rear (east) blank wall of ...

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

2. D Street facade and rear (east) blank wall of parking garage. Farther east is 408 8th Street (National Art And Frame Company). - PMI Parking Garage, 403-407 Ninth Street, Northwest, Washington, District of Columbia, DC

Automated platform for determination of LEDs spatial radiation pattern

NASA Astrophysics Data System (ADS)

Vladescu, Marian; Vuza, Dan Tudor

2015-02-01

Nowadays technologies lead to remarkable properties of the light-emitting diodes (LEDs), making them attractive for more and more applications, such as: interior and exterior lighting, outdoor LED panels, traffic signals, automotive (tail and brake lights, backlighting in dashboard and switches), backlighting of display panels, LCD displays, symbols on switches, keyboards, graphic boards and measuring scales. Usually, LEDs are small light sources consisting of a chip placed into a package, which may bring additional optics to this encapsulated ensemble, resulting in a less or more complex spatial distribution of the light intensity, with particular radiation patterns. This paper presents an automated platform designed to allow a quick and accurate determination of the spatial radiation patterns of LEDs encapsulated in various packages. Keywords: LED, luminous

Evaluating white LEDs for outdoor landscape lighting application

NASA Astrophysics Data System (ADS)

Shakir, Insiya; Narendran, Nadarajah

2002-11-01

A laboratory experiment was conducted to understand the acceptability of different white light emitting diodes (LEDs) for outdoor landscape lighting. The study used a scaled model setup. The scene was designed to replicate the exterior of a typical upscale suburban restaurant including the exterior facade of the building, an approach with steps, and a garden. The lighting was designed to replicate light levels commonly found in nighttime outdoor conditions. The model had a central dividing partition with symmetrical scenes on both sides for side-by-side evaluations of the two scenes with different light sources. While maintaining equal luminance levels and distribution between the two scenes, four types of light sources were evaluated. These include, halogen, phosphor white LED, and two white light systems using RGB LEDs. These light sources were tested by comparing two sources at a time placed side-by-side and by individual assessment of each lighting condition. The results showed that the RGB LEDs performed equal or better than the most widely used halogen light source in this given setting. A majority of the subjects found slightly dimmer ambient lighting to be more typical for restaurants and therefore found RGB LED and halogen light sources to be more inviting. The phosphor white LEDs made the space look brighter, however a majority of the subjects disliked them.

LEDs/ALAN-Working To Be Good Neighbors

NASA Astrophysics Data System (ADS)

Adams, Robert

2015-08-01

ALAN (Artificial Light At Night) and LEDs have recently become major discussion topics in the areas of astronomy, light pollution, endangered species and human health to mention but a few. In years past, MH, LPS and HPS dominated night lighting with LPS and its associated narrow spectrum as the preferred source around observatories and shorelines. LEDs offer the ability to modify the spectrum, realize substantial energy savings and other associated benefits while meeting the requirements of the astronomy community.The primary concern of the different groups relates to blue light content of the LED. For astronomers, the molecular (Raleigh) scattering related to the blue light interferes with certain portions of the spectrum used for deep space studies. The ecologists studying various endangered species find blue and green light can be related to declining leatherback turtle population in certain areas of the world. Other animals ranging from bats to moths and other insects are now being studied to determine the effect of the blue light spectrum on their behavior. The impact of blue light on the human circadian rhythm and vision, especially in the older population, is being extensively studied today.This presentation will discuss the spectral power distribution (SPD) of various light sources, the performance of new LED solutions and how the SPD of these new LED’s can be adapted to address some of the issues raised by various constituencies. A discussion describing why some of the metrics used to describe standard lighting are not adequate for specifying the new LED solutions with the modified spectra will be included.Today, lighting plans and implementation are all too often based on opinions and limited data. The ensuing problems and repercussions make it imperative to collect accurate and thorough information. Data collection is now ongoing using a variety of techniques analyzing the “before” and “after” lighting results from the C of HI LED streetlight

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

LED module with high index lens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.

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.

Clinician-led, peer-led, and internet-delivered dissonance-based eating disorder prevention programs: Acute effectiveness of these delivery modalities.

PubMed

Stice, Eric; Rohde, Paul; Shaw, Heather; Gau, Jeff M

2017-09-01

Because independent trials have provided evidence for the efficacy and effectiveness of the dissonance-based Body Project eating disorder prevention program, the present trial tested whether clinicians produce the largest intervention effects, or whether delivery can be task-shifted to less expensive undergraduate peer educators or to Internet delivery without effect size attenuation, focusing on acute effects. In this study, 680 young women (M age = 22.2 years, SD = 7.1) recruited at colleges in 2 states were randomized to clinician-led Body Project groups, peer-led Body Project groups, the Internet-based eBody Project, or an educational video control condition. Participants in all 3 variants of the Body Project intervention showed significantly greater reductions in eating disorder risk factors and symptoms than did educational video controls. Participants in clinician-led and peer-led Body Project groups showed significantly greater reductions in risk factors than did eBody Project participants, but effects for the 2 types of groups were similar. Eating disorder onset over 7-month follow-up was significantly lower for peer-led Body Project group participants versus eBody Project participants (2.2% vs. 8.4%) but did not differ significantly between other conditions. The evidence that all 3 dissonance-based prevention programs outperformed an educational video condition, that both group-based interventions outperformed the Internet-based intervention in risk factor reductions, and that the peer-led groups showed lower eating disorder onset over follow-up than did the Internet-based intervention is novel. These acute-effects data suggest that both group-based interventions produce superior eating disorder prevention effects than does the Internet-based intervention and that delivery can be task-shifted to peer leaders. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

An analysis of successful commercialization of federally funded R&D energy technologies

NASA Astrophysics Data System (ADS)

Asuquo, Gibson Esang

Several studies indicate that commercialization of federally funded R&D technologies to private sector remains low. In an extension of research demonstrating relative effectiveness of various technology-transfer mechanisms used by the Department of Energy (DOE) in transferring federally funded R&D technologies, this study quantitatively analyzed 52 Industrial Technology Program (ITP) funded R&D technologies, from 1993 through 2006, to understand commercialization success of DOE's funded R&D technologies, based on the correlative significance between independent variables (R&D durations and levels of funding) and dependent variable (technology commercialization output). No statistically significant linear relationship was found between the studied variables. The R2 (the coefficient of multiple determination) value indicates that only three percent (0.03) of the change in the output of commercialized technologies can be explained by the change in the two independent variables. The results of this study have led to an important conclusion that the research, development, and deployment (RD&D) of federally funded energy technologies is complex and a non-linear process. The problem requires a consideration of other factors and a research design that can accommodate the complexity involved. However, as determined by this study, the ITP technology commercialization output (success rate) of 22% is nearly two times as high as the 14% Booz-Allen estimate for the rest of U.S. industry. A quantitative research (such as this study) that attempts to understand the relative significance of correlational relationship between R&D variables appears to offer insufficient explanations as to why the federal government is not getting high technology commercialization output from its dollar investments in R&D. Some qualitative research approaches could move this important research to the next level in the future. Further research in this area should focus on causal effects between R

Commercialism in Schools.

ERIC Educational Resources Information Center

Larson, Kirstin

2001-01-01

This document gives voice to concerns raised by critics and supporters of commercialism in schools and provides brief descriptions of several important resources on this topic. "Commercial Activities in School" (U.S. General Accounting Office) reports on the nature and frequency of commercial activities in public schools, as well as the…

Amenity or necessity? street standards as parking policy [research brief].

DOT National Transportation Integrated Search

2012-06-01

Single family homes, cul de sacs, spacious garages, wide streets, etc. are among the typical features of suburban developments across the United States. Despite the abundant parking spaces available on the premises (inside garages or in driveways), m...

The impact of social and organizational factors on workers' use of personal protective equipment: a multilevel approach.

PubMed

Torp, Steffen; Grøgaard, Jens B; Moen, Bente E; Bråtveit, Magne

2005-08-01

On the basis of the job demands-control-support model by Karasek and Theorell, we investigated how social and organizational factors influence workers' use of personal protective equipment (PPE). A cross-sectional study was performed among 1420 workers in 203 motor vehicle-repair garages. Multilevel modeling was performed to account for the hierarchical structure of the data. Social and management support correlated positively with PPE use at the worker level. Low demands measured at the garage level and having a health and safety management system at the garage also correlated with active use of PPE. An interaction effect between social support and garage-level demands was observed. In addition to health information and provision of PPE, focusing on social and organizational factors seems necessary to get more workers to comply with the instructions on PPE use.

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…

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…

Protection against methanol-induced retinal toxicity by LED photostimulation

NASA Astrophysics Data System (ADS)

Whelan, Harry T.; Wong-Riley, Margaret T. T.; Eells, Janis T.

2002-06-01

We have initiated experiments designed to test the hypothesis that 670-nm Light-Emitting Diode (LED) exposure will attenuate formate-induced retinal dysfunction in a rodent model of methanol toxicity. Methanol intoxication produces toxic injury to the retina. The toxic metabolite formed in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit cytochrome oxidase activity. 670-nm LED light has been hypothesized to act by stimulating cytochrome oxidase activity. To test this hypothesis, one group of animals was intoxicated with methanol, a second group was intoxicated with methanol and LED-treated and a third group was untreated. LED treatment (670 nm for 1 min 45 seconds equals 50 mW/cm2, 4 joules/cm2) was administered at 5, 25, and 50 hours after the initial dose of methanol. At 72 hours of methanol intoxication, retinal function was assessed by measurement of ERG responses and retinas were prepared for histologic analysis. ERG responses recorded in methanol-intoxicated animals revealed profound attenuation of both rod-dominated and UV-cone mediated responses. In contrast, methanol- intoxicated animals exposed to LED treatment exhibited a nearly complete recovery of rod-dominated ERG responses and a slight improvement of UV-cone mediated ERG responses. LED treatment also protected the retina against the histopathologic changes produced by formate in methanol intoxication. These data provide evidence that LED phototherapy protects the retina against the cytotoxic actions of formate and are consistent with the hypothesis that LED photostimulation improves mitochondrial respiratory chain function.

Novel high refractive index, thermally conductive additives for high brightness white LEDs

NASA Astrophysics Data System (ADS)

Hutchison, Richard Stephen

making this decrease in transparency important to note. This decrease in transparency may be partially or wholly why a decrease in light extraction efficiency is observed at the 33.5 wt% zirconia loading fraction used for the LED samples. Preliminary aging studies under full and enhanced power conditions were conducted over 500 and 1000 hours to observe any changes in the spectral output power and phosphor conversion efficiency of the LEDs due to inclusion of the zirconia nanoparticles. It was found that the nanoparticles have no negative effect on the aging properties but also show no enhancement in relative output power over a preliminary aging study. However, their inclusion did result in increased phosphor conversion efficiency over the use of an unfilled silicone. This increase was seen as around a 10% or greater enhancement for the nanocomposite over that for the base Sylgard silicone. These experiments were originally conducted on the commercially available methylated Sylgard 184 silicone and then again on a higher refractive index methyl-phenyl silicone from Momentive. While some of the results from the Momentive silicone were perplexing, it was seen that, even without the inclusion of nanoparticles, the Momentive silicone had a higher refractive index, better aging properties, and a higher phosphor conversion efficiency over 500 hours under enhanced power conditions, warranting further studies into methyl-phenyl silicone nanocomposites.

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.

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.

6. July, 1947 Photocopy of photograph (11/4 x 27/16 inch ...

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

6. July, 1947 Photocopy of photograph (1-1/4 x 2-7/16 inch print, on file, Coronado N. F. Supervisor's Office, Tucson) COLUMBINE R. S. BARN-GARAGE. - Columbine Ranger Station, Garage, Milepost 1343, State Highway 366, Safford, Graham County, AZ

Regression analysis for LED color detection of visual-MIMO system

NASA Astrophysics Data System (ADS)

Banik, Partha Pratim; Saha, Rappy; Kim, Ki-Doo

2018-04-01

Color detection from a light emitting diode (LED) array using a smartphone camera is very difficult in a visual multiple-input multiple-output (visual-MIMO) system. In this paper, we propose a method to determine the LED color using a smartphone camera by applying regression analysis. We employ a multivariate regression model to identify the LED color. After taking a picture of an LED array, we select the LED array region, and detect the LED using an image processing algorithm. We then apply the k-means clustering algorithm to determine the number of potential colors for feature extraction of each LED. Finally, we apply the multivariate regression model to predict the color of the transmitted LEDs. In this paper, we show our results for three types of environmental light condition: room environmental light, low environmental light (560 lux), and strong environmental light (2450 lux). We compare the results of our proposed algorithm from the analysis of training and test R-Square (%) values, percentage of closeness of transmitted and predicted colors, and we also mention about the number of distorted test data points from the analysis of distortion bar graph in CIE1931 color space.

Effective strategies to reduce commercial tobacco use in Indigenous communities globally: A systematic review.

PubMed

Minichiello, Alexa; Lefkowitz, Ayla R F; Firestone, Michelle; Smylie, Janet K; Schwartz, Robert

2016-01-11

All over the world, Indigenous populations have remarkably high rates of commercial tobacco use compared to non-Indigenous groups. The high rates of commercial tobacco use in Indigenous populations have led to a variety of health issues and lower life expectancy than the general population. The objectives of this systematic review were to investigate changes in the initiation, consumption and quit rates of commercial tobacco use as well as changes in knowledge, prevalence, community interest, and smoke-free environments in Indigenous populations. We also aimed to understand which interventions had broad reach, what the common elements that supported positive change were and how Aboriginal self-determination was reflected in program implementation. We undertook a systematic review of peer-reviewed publications and grey literature selected from seven databases and 43 electronic sources. We included studies between 1994 and 2015 if they addressed an intervention (including provision of a health service or program, education or training programs) aimed to reduce the use of commercial tobacco use in Indigenous communities globally. Systematic cross-regional canvassing of informants in Canada and internationally with knowledge of Indigenous health and/or tobacco control provided further leads about commercial tobacco reduction interventions. We extracted data on program characteristics, study design and learnings including successes and challenges. In the process of this review, we investigated 73 commercial tobacco control interventions in Indigenous communities globally. These interventions incorporated a myriad of activities to reduce, cease or protect Indigenous peoples from the harms of commercial tobacco use. Interventions were successful in producing positive changes in initiation, consumption and quit rates. Interventions also facilitated increases in the number of smoke-free environments, greater understandings of the harms of commercial tobacco use and a

48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

48 CFR 227.7202 - Commercial computer software and commercial computer software documentation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... software and commercial computer software documentation. 227.7202 Section 227.7202 Federal Acquisition... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7202 Commercial computer software and commercial computer software documentation. ...

Scalable, Economical Fabrication Processes for Ultra-Compact Warm-White LEDs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowes, Ted

Conventional warm-white LED component fabrication consists of a large number of sequential steps which are required to incorporate electrical, mechanical, and optical functionality into the component. Each of these steps presents cost and yield challenges which multiply throughout the entire process. Although there has been significant progress in LED fabrication over the last decade, significant advances are needed to enable further reductions in cost per lumen while not sacrificing efficacy or color quality. Cree conducted a focused 18-month program to develop a new low-cost, high-efficiency light emitting diode (LED) architecture enabled by novel large-area parallel processing technologies, reduced number ofmore » fabrication steps, and minimized raw materials use. This new scheme is expected to enable ultra-compact LED components exhibiting simultaneously high efficacy and high color quality. By the end of the program, Cree fabricated warm-white LEDs with a room-temperature “instant on” efficacy of >135 lm/W at ~3500K and 90 CRI (when driven at the DOE baseline current density of 35 A/cm2). Cree modified the conventional LED fabrication process flow in a manner that is expected to translate into simultaneously high throughput and yield for ultra-compact packages. Building on its deep expertise in LED wafer fabrication, Cree developed these ultra-compact LEDs to have no compromises in color quality or efficacy compared to their conventional counterparts. Despite their very small size, the LEDs will also be robustly electrically integrated into luminaire systems with the same attach yield as conventional packages. The versatility of the prototype high-efficacy LED architecture will likely benefit solid-state lighting (SSL) luminaire platforms ranging from bulbs to troffers. We anticipate that the prototype LEDs will particularly benefit luminaires with large numbers of distributed compact packages, such as linear and area luminaires (e.g. troffers). The

Integrated Nanoscale Antenna-LED for On-Chip Optical Communication

NASA Astrophysics Data System (ADS)

Fortuna, Seth

Traditional semiconductor light emitting diodes (LEDs) have low modulation speed because of long spontaneous emission lifetime. Spontaneous emission in semiconductors (and indeed most light emitters) is an inherently slow process owing to the size mismatch between the dipole length of the optical dipole oscillators responsible for light emission and the wavelength of the emitted light. More simply stated: semiconductors behave as a poor antenna for its own light emission. By coupling a semiconductor at the nanoscale to an external antenna, the spontaneous emission rate can be dramatically increased alluding to the exciting possibility of an antenna-LED that can be directly modulated faster than the laser. Such an antenna-LED is well-suited as a light source for on-chip optical communication where small size, fast speed, and high efficiency are needed to achieve the promised benefit of reduced power consumption of on-chip optical interconnect links compared with less efficient electrical interconnect links. Despite the promise of the antenna-LED, significant challenges remain to implement an antenna-coupled device in a monolithically integrated manner. Notably, most demonstrations of antenna-enhanced spontaneous emission have relied upon optical pumping of the light emitting material which is useful for fundamental studies; however, an electrical injection scheme is required for practical implementation of an antenna-LED. In this dissertation, demonstration of an electrically-injected III-V antenna-LED is reported: an important milestone toward on-chip optical interconnects. In the first part of this dissertation, the general design principles of enhancing the spontaneous emission rate of a semiconductor with an optical antenna is discussed. The cavity-backed slot antenna is shown to be uniquely suited for an electrically-injected antenna-LED because of large spontaneous emission enhancement, simple fabrication, and directional emission of light. The design

Serological diagnosis of canine leishmaniosis: comparison of three commercially available tests.

PubMed

Wolf, Denis; Failing, Klaus; Taubert, Anja; Pantchev, Nikola

2014-05-01

Quantitative serology is an important tool in canine leishmaniosis diagnostics from clinical and epidemiological points of view. Serologic diagnosis in laboratories is traditionally carried out by immunofluorescent antibody test (IFAT), but enzyme-linked immunosorbent assays (ELISA) are being increasingly employed. Two commercially available ELISAs (LEISHMANIA-ELISA DOG® [LED] and INGEZIM LEISHMANIA® [IL]) for the detection of Leishmania infantum infection in dogs were compared with the classical IFAT technique. Ninety-two canine serum samples covering a broad range of IFAT titers were chosen for evaluation. Titers ranged from negative (<1:50) to high (>1:3,200). Statistical analysis showed high correlation between all three assays for both negative and positive IFAT-tested samples as described by respective Spearman's rank correlation coefficient (r s), but results varied for samples with inconclusive IFAT titers (1:50-1:100) with IL stating samples predominantly negative. The highest accordance was found between LED and IFAT (percentage of identical results = 83.7%; r(s) = 0.90, p < 0.0001). IL showed higher analogy with LED (accordance = 81.5%; r(s )= 0.88, p < 0.0001) than with IFAT (73.9%; r(s) = 0.80, p < 0.0001). The distribution of the different ELISA scores is discussed and grouped according to correspondent IFAT titers to familiarize practitioners with the range of these tests since antibody levels play an important role in clinical management of canine patients with L. infantum infection.

Toward blue emission in ZnO based LED

NASA Astrophysics Data System (ADS)

Viana, Bruno; Pauporté, Thierry; Lupan, Oleg; Le Bahers, Tangui; Ciofini, Ilaria

2012-03-01

The bandgap engineering of ZnO nanowires by doping is of great importance for tunable light emitting diode (LED) applications. We present a combined experimental and computational study of ZnO doping with Cd or Cu atoms in the nanomaterial. Zn1-xTMxO (TM=Cu, Cd) nanowires have been epitaxially grown on magnesium-doped p-GaN by electrochemical deposition. The Zn1-xTMxO/p-GaN heterojunction was integrated in a LED structure. Nanowires act as the light emitters and waveguides. At room temperature, TM-doped ZnO based LEDs exhibit low-threshold emission voltage and electroluminescence emission shifted from ultraviolet to violet-blue spectral region compared to pure ZnO LEDs. The emission wavelength can be tuned by changing the transition metal (TM) content in the ZnO nanomaterial and the shift is discussed, including insights from DFT computational investigations.

Seasat-A and the commercial ocean community

NASA Technical Reports Server (NTRS)

Montgomery, D. R.; Wolff, P.

1977-01-01

The Seasat-A program has been initiated as a 'proof-of-concept' mission to evaluate the effectiveness of remotely sensing oceanology and related meteorological phenomena from a satellite platform in space utilizing sensors developed on previous space and aircraft test programs. The sensors include three active microwave sensors; a radar altimeter, a windfield scatterometer, and a synthetic aperture radar. A passive scanning multifrequency microwave radiometer, visual and infrared radiometer are also included. All weather, day-night measurements of sea surface temperature, surface wind speed/direction and sea state and directional wave spectra will be made. Two key programs are planned for data utilization with users during the mission. Foremost is a program with the commercial ocean community to test the utility of Seasat-A data and to begin the transfer of ocean remote sensing technology to the civil sector. A second program is a solicitation of investigations, led by NOAA, to involve the ocean science community in a series of scientific investigations.

Chip-scale thermal management of high-brightness LED packages

NASA Astrophysics Data System (ADS)

Arik, Mehmet; Weaver, Stanton

2004-10-01

The efficiency and reliability of the solid-state lighting devices strongly depend on successful thermal management. Light emitting diodes, LEDs, are a strong candidate for the next generation, general illumination applications. LEDs are making great strides in terms of lumen performance and reliability, however the barrier to widespread use in general illumination still remains the cost or $/Lumen. LED packaging designers are pushing the LED performance to its limits. This is resulting in increased drive currents, and thus the need for lower thermal resistance packaging designs. As the power density continues to rise, the integrity of the package electrical and thermal interconnect becomes extremely important. Experimental results with high brightness LED packages show that chip attachment defects can cause significant thermal gradients across the LED chips leading to premature failures. A numerical study was also carried out with parametric models to understand the chip active layer temperature profile variation due to the bump defects. Finite element techniques were utilized to evaluate the effects of localized hot spots at the chip active layer. The importance of "zero defects" in one of the more popular interconnect schemes; the "epi down" soldered flip chip configuration is investigated and demonstrated.

A synthetic method of solar spectrum based on LED

NASA Astrophysics Data System (ADS)

Wang, Ji-qiang; Su, Shi; Zhang, Guo-yu; Zhang, Jian

2017-10-01

A synthetic method of solar spectrum which based on the spectral characteristics of the solar spectrum and LED, and the principle of arbitrary spectral synthesis was studied by using 14 kinds of LED with different central wavelengths.The LED and solar spectrum data were selected by Origin Software firstly, then calculated the total number of LED for each center band by the transformation relation between brightness and illumination and Least Squares Curve Fit in Matlab.Finally, the spectrum curve of AM1.5 standard solar spectrum was obtained. The results met the technical indexes of the solar spectrum matching with ±20% and the solar constant with >0.5.

World commercial aircraft accidents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, C.Y.

1993-01-01

This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accidentmore » is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.« less

High-energy radiation and polymers: A review of commercial processes and emerging applications

NASA Astrophysics Data System (ADS)

Clough, R. L.

2001-12-01

Ionizing radiation has been found to be widely applicable in modifying the structure and properties of polymers, and can be used to tailor the performance of either bulk materials or surfaces. Fifty years of research in polymer radiation chemistry has led to numerous applications of commercial and economic importance, and work remains active in the application of radiation to practical uses involving polymeric materials. This paper provides a survey of radiation-processing methods of industrial interest, ranging from technologies already commercially well established, through innovations in the active R&D stage which show exceptional promise for future commercial use. Radiation-processing technologies are discussed under the following categories: cross-linking of plastics and rubbers, curing of coatings and inks, heat-shrink products, fiber-matrix composites, chain-scission for processing control, surface modification, grafting, hydrogels, sterilization, natural product enhancement, plastics recycling, ceramic precursors, electronic property materials, ion-track membranes and lithography for microdevice production. In addition to new technological innovations utilizing conventional gamma and e-beam sources, a number of promising new applications make use of novel radiation types which include ion beams (heavy ions, light ions, highly focused microscopic beams and high-intensity pulses), soft X-rays which are focused, coherent X-rays (from a synchrotron) and e-beams which undergo scattering to generate patterns.

6. Photocopy of Sheet 3 of Building Plan R421, (USDA, ...

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

6. Photocopy of Sheet 3 of Building Plan R4-21, (USDA, Forest Service, Intermountain Region, Ogden. File 7300, 'Buildings') FRAMING PLAN AND GARAGE DOOR DETAIL - Buffalo Guard Station, Garage, U.S. Highway 20/191 at Buffalo River, Island Park, Fremont County, ID

3. Photocopy of architectural blueprint (on file at La Grande ...

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

3. Photocopy of architectural blueprint (on file at La Grande District Office, La Grande, Oregon) USDA Forest Service, 1936 RANGERS RESIDENCE, GARAGE - Union Ranger District Compound, Garage-Rangers Residence, Fronting State Highway 203, at West edge of Union, Union, Union County, OR

7 CFR 1710.106 - Uses of loan funds.

Code of Federal Regulations, 2011 CFR

2011-01-01

... generation facilities to serve RE Act beneficiaries. (3) Warehouse and garage facilities. The purchase, remodeling, or construction of warehouse and garage facilities required for the operation of a borrower's... equipment, including furniture, office, transportation, data processing and other work equipment; and (3...

Highly Efficient Small Form Factor LED Retrofit Lamp

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 powermore » 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.« less

Peer-led small groups: Are we on the right track?

PubMed

Moore, Fraser

2017-10-01

Peer tutor-led small group sessions are a valuable learning strategy but students may lack confidence in the absence of a content expert. This study examined whether faculty reinforcement of peer tutor-led small group content was beneficial. Two peer tutor-led small group sessions were compared with one faculty-led small group session using questionnaires sent to student participants and interviews with the peer tutors. One peer tutor-led session was followed by a lecture with revision of the small group content; after the second, students submitted a group report which was corrected and returned to them with comments. Student participants and peer tutors identified increased discussion and opportunity for personal reflection as major benefits of the peer tutor-led small group sessions, but students did express uncertainty about gaps in their learning following these sessions. Both methods of subsequent faculty reinforcement were perceived as valuable by student participants and peer tutors. Knowing in advance that the group report would be corrected reduced discussion in some groups, potentially negating one of the major benefits of the peer tutor-led sessions. Faculty reinforcement of peer-tutor led small group content benefits students but close attention should be paid to the method of reinforcement.

Bandwidth correction for LED chromaticity based on Levenberg-Marquardt algorithm

NASA Astrophysics Data System (ADS)

Huang, Chan; Jin, Shiqun; Xia, Guo

2017-10-01

Light emitting diode (LED) is widely employed in industrial applications and scientific researches. With a spectrometer, the chromaticity of LED can be measured. However, chromaticity shift will occur due to the broadening effects of the spectrometer. In this paper, an approach is put forward to bandwidth correction for LED chromaticity based on Levenberg-Marquardt algorithm. We compare chromaticity of simulated LED spectra by using the proposed method and differential operator method to bandwidth correction. The experimental results show that the proposed approach achieves an excellent performance in bandwidth correction which proves the effectiveness of the approach. The method has also been tested on true blue LED spectra.

DEVELOPMENT, DESIGN AND CONSUMER TESTING OF MARKETABLE RESIDENTIAL LED LIGHT LUMINAIRES

EPA Science Inventory

Developing marketable LED luminaires poses challenges, even though LEDs are energy-efficient and an ecological alternative to conventionally lighting. Challenges include: perceptions that the color rendition of LEDs is unacceptable to the public; numbers of LEDs must be grou...

LED based opto-wetting platforms for micromixing

NASA Astrophysics Data System (ADS)

Thomas, Tony; Narayanan Unni, Harikrishnan

2018-02-01

The digital microfluidics utilizes the gradient in wettability for droplet transportation. This paper reports a novel technique of LED induced wetting ( Opto-wetting) where a single low power LED (Light emitting diode) emitting light of wavelength 395nm peak with luminous intensity of 300mcd (milli candela) is used to move two droplets of 20μL each on a photo responsive substrate of azobenzene (C12H10N2) coated PDMS (Poly Dimethyl Siloxane) substrate. The PDMS substrate of size 5cmx2cmx0.5cm were modified by thin film coating of Azobenzene dissolved in olive oil solution. The LED was aligned vertically on the top of the substrate. The pulsed operation of LED induces a spatial gradient of surface energy due to the reversible process of photo isomerization of Azobenzene molecules coated on the surface. The Photo-isomerization changes the conformation of the molecules thereby changing its surface energy .The change in surface energy of the substrate induces a change in contact angle of the droplet which initiates its movement. Two water droplets each of 20μL were dispensed on the substrate using micro syringe. Two droplets which were initially at a few cm distance apart were gradually moved towards the focus of light and merged together. The urine droplets (20μL) were moved and mixed with the red dye reagent (20μL) by controlling the light intensity of the LED. This concept provides a cost effective technique of droplet manipulation in the Lab on a chip domain where various multiplexed operations on proteins and DNA droplets can be done for point of care diagnostics.

A comparison of commercial light-emitting diode baited suction traps for surveillance of Culicoides in northern Europe.

PubMed

Hope, Andrew; Gubbins, Simon; Sanders, Christopher; Denison, Eric; Barber, James; Stubbins, Francesca; Baylis, Matthew; Carpenter, Simon

2015-04-22

The response of Culicoides biting midges (Diptera: Ceratopogonidae) to artificial light sources has led to the use of light-suction traps in surveillance programmes. Recent integration of light emitting diodes (LED) in traps improves flexibility in trapping through reduced power requirements and also allows the wavelength of light used for trapping to be customized. This study investigates the responses of Culicoides to LED light-suction traps emitting different wavelengths of light to make recommendations for use in surveillance. The abundance and diversity of Culicoides collected using commercially available traps fitted with Light Emitting Diode (LED) platforms emitting ultraviolet (UV) (390 nm wavelength), blue (430 nm), green (570 nm), yellow (590 nm), red (660 nm) or white light (425 nm - 750 nm with peaks at 450 nm and 580 nm) were compared. A Centre for Disease Control (CDC) UV light-suction trap was also included within the experimental design which was fitted with a 4 watt UV tube (320-420 nm). Generalised linear models with negative binomial error structure and log-link function were used to compare trap abundance according to LED colour, meteorological conditions and seasonality. The experiment was conducted over 49 nights with 42,766 Culicoides caught in 329 collections. Culicoides obsoletus Meigen and Culicoides scoticus Downes and Kettle responded indiscriminately to all wavelengths of LED used with the exception of red which was significantly less attractive. In contrast, Culicoides dewulfi Goetghebuer and Culicoides pulicaris Linnaeus were found in significantly greater numbers in the green LED trap than in the UV LED trap. The LED traps collected significantly fewer Culicoides than the standard CDC UV light-suction trap. Catches of Culicoides were reduced in LED traps when compared to the standard CDC UV trap, however, their reduced power requirement and small size fulfils a requirement for trapping in logistically challenging areas or where many

Nurse-led diabetes management in remote locations.

PubMed

Kirby, Sue; Moore, Malcolm; McCarron, Trish; Perkins, David; Lyle, David

2015-01-01

Nurse-led diabetes management has been shown to be effective in urban and regional general practice. We sought to test the feasibility of providing a nurse-led annual cycle of diabetes care in a remote location and to explore the factors that patients indicated were important in diabetes self-management. We conducted a pilot study in 3 locations: 1 town and 2 small townships in remote Australia. A chronic disease nurse (CDN) visited each patient over the course of a year. We examined patient clinical outcomes and interview data. We estimated the cost per hour of the CDN's time, including travel time, per 1% drop in glycated hemoglobin (HbA1C). A total of 21 patients participated in the pilot study. Clinical findings showed significant reductions in HbA1C levels after the nurse-led intervention. Patients reported that they trusted the nurse and thought her advice was pitched at their level. Patients were motivated through a process that included emotional response, change identity and acceptance. The estimated cost in CDN hours per 1% drop in HbA1C level was A$242.95 (Can$237.60). Nurse-led diabetes care motivated patients to manage their diabetes and resulted in a significant improvement in diabetes management in this remote setting.

Impact of a commercial destocking relief intervention in Moyale district, southern Ethiopia.

PubMed

Abebe, Dawit; Cullis, Adrian; Catley, Andy; Aklilu, Yacob; Mekonnen, Gedlu; Ghebrechirstos, Yodit

2008-06-01

A commercial destocking intervention was piloted in southern Ethiopia during the drought of early 2006. The intervention led to the purchase of an estimated 20,000 cattle valued at USD 1.01 million. On average, destocked households received USD 186 from the sale of cattle--approximately 5,405 households were involved. In terms of aid investment, the approximate cost-benefit ratio was 41:1. During the drought, income from destocking accounted for 54.2 per cent of household income (n = 114 households), and was used to buy food, care for livestock, meet various domestic expenses, support relatives, and either pay off debts or augment savings. Seventy-nine per cent of the income derived from destocking was used to buy local goods or services. Expenditure on livestock care amounted to 36.5 per cent of local spending, and included the private transportation of livestock to better grazing areas. The buoyant livestock export trade was considered to be an important driver of commercial destocking, demonstrating a positive link between livestock and meat exports, and pastoral vulnerability during drought.

Thermal management methods for compact high power LED arrays

NASA Astrophysics Data System (ADS)

Christensen, Adam; Ha, Minseok; Graham, Samuel

2007-09-01

The package and system level temperature distributions of a high power (>1W) light emitting diode (LED) array has been investigated using numerical heat flow models. For this analysis, a thermal resistor network model was combined with a 3D finite element submodel of an LED structure to predict system and die level temperatures. The impact of LED array density, LED power density, and active versus passive cooling methods on device operation were calculated. In order to help understand the role of various thermal resistances in cooling such compact arrays, the thermal resistance network was analyzed in order to estimate the contributions from materials as well as active and passive cooling schemes. An analysis of thermal stresses and residual stresses in the die are also calculated based on power dissipation and convection heat transfer coefficients. Results show that the thermal stress in the GaN layer are compressive which can impact the band gap and performance of the LEDs.

Color adjustable LED driver design based on PWM

NASA Astrophysics Data System (ADS)

Du, Yiying; Yu, Caideng; Que, Longcheng; Zhou, Yun; Lv, Jian

2012-10-01

Light-emitting diode (LED) is a liquid cold source light source that rapidly develops in recent years. The merits of high brightness efficiency, long duration, high credibility and no pollution make it satisfy our demands for consumption and natural life, and gradually replace the traditional lamp-house-incandescent light and fluorescent light. However, because of the high cost and unstable drive circuit, the application range is restricted. To popularize the applications of the LED, we focus on improving the LED driver circuit to change this phenomenon. Basing on the traditional LED drive circuit, we adopt pre-setup constant current model and introduce pulse width modulation (PWM) control method to realize adjustable 256 level-grays display. In this paper, basing on human visual characteristics and the traditional PWM control method, we propose a new PWM control timing clock to alter the duty cycle of PWM signal to realize the simple gamma correction. Consequently, the brightness can accord with our visual characteristics.

Integrated LED-based luminaire for general lighting

DOEpatents

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.

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.

Applying Spatial-Temporal Model and Game Theory to Asymmetric Threat Prediction

DTIC Science & Technology

2007-06-01

Genshe Chen, Denis Garagic, Xiaohuan Tan, Dongxu Li, Dan Shen, Mo Wei, Xu Wang, “Team Dynamics and Tactics for Mission Planning,” Proceedings...Cruz, Jr., Genshe Chen, Dongxu Li, and Denis Garagic, “Target Selection in UAV Cooperative Control Under Uncertain Environment: Genetic Algorithm

Characteristics of GaN-based LEDs using Ga-doped or In-doped ZnO transparent conductive layers grown by atomic layer deposition

NASA Astrophysics Data System (ADS)

Yen, Kuo-Yi; Chiu, Chien-Hua; Hsiao, Chi-Ying; Li, Chun-Wei; Chou, Chien-Hua; Lo, Ko-Ying; Chen, Tzu-Pei; Lin, Chu-Hsien; Lin, Tai-Yuan; Gong, Jyh-Rong

2014-02-01

Ga-doped ZnO (GZO) and In-doped ZnO (IZO) films were prepared by atomic layer deposition (ALD), and the ALD-grown GZO (or IZO) films with (or without) N2 annealing were employed to serve as transparent conducting layers (TCLs) in InGaN/GaN (multiple quantum well) MQW LEDs. Based on θ-to-2θ X-ray diffraction (XRD) analyses, the N2-annealed GZO was found to show almost the same lattice constant c as ZnO does, while the lattice constant c of a N2-annealed IZO was detected to be larger than that of the ZnO. It appears that the implementation of N2-annealed ALD-grown GZO (or IZO) in an InGaN/GaN MQW LED allows to enable light extraction and forward voltage reduction of the LED under certain conditions. At 20 mA operating condition, the 400 °C N2-annealed n-GZO-coated and the 600 °C N2-annealed n-IZO-coated InGaN/GaN MQW LEDs were found to exhibit optimized forward voltages of 3.1 and 3.2 V, respectively, with the specific contact resistances of the n-GZO/p-GaN and n-IZO/p-GaN contacts being 4.1×10-3 and 8.8×10-3 Ω-cm2. By comparing with an InGaN/GaN MQW LED structure having a commercial-grade indium tin oxide (ITO) TCL, the 400 °C N2-annealed n-GZO-coated InGaN/GaN MQW LED shows an increment of light output power of 15% at 20 mA. It is believed that the enhanced light extraction of the n-GZO-coated InGaN/GaN MQW LED is due to a higher refractive index of n-GZO than that of ITO along with a comparable optical transmittance of n-GZO to that of ITO.

Stakeholder Values and Perspectives when Implementing Led Lights on Navy Ships

DTIC Science & Technology

2014-06-01

Additionally, the M1 IntelliTube is a retrofit lamp , 32 which works with line power or any of the legacy ballasts.” ( LED /IntelliTube NAVSEA: LED ...only factor taken into consideration, then break-even point for LED lighting, Navy- wide, is approximately one hour to change the lamp . Of note...Energy Focus. (2013, July 3). Energy Focus: Specifications: IntelliTube LED replacement lamp , 24”, T12 LED lamp . Retrieved from http

Uniformity of LED light illumination in application to direct imaging lithography

NASA Astrophysics Data System (ADS)

Huang, Ting-Ming; Chang, Shenq-Tsong; Tsay, Ho-Lin; Hsu, Ming-Ying; Chen, Fong-Zhi

2016-09-01

Direct imaging has widely applied in lithography for a long time because of its simplicity and easy-maintenance. Although this method has limitation of lithography resolution, it is still adopted in industries. Uniformity of UV irradiance for a designed area is an important requirement. While mercury lamps were used as the light source in the early stage, LEDs have drawn a lot of attention for consideration from several aspects. Although LED has better and better performance, arrays of LEDs are required to obtain desired irradiance because of limitation of brightness for a single LED. Several effects are considered that affect the uniformity of UV irradiance such as alignment of optics, temperature of each LED, performance of each LED due to production uniformity, and pointing of LED module. Effects of these factors are considered to study the uniformity of LED Light Illumination. Numerical analysis is performed by assuming a serious of control factors to have a better understanding of each factor.

A Novel Methodology for Measurements of an LED's Heat Dissipation Factor

NASA Astrophysics Data System (ADS)

Jou, R.-Y.; Haung, J.-H.

2015-12-01

Heat generation is an inevitable byproduct with high-power light-emitting diode (LED) lighting. The increase in junction temperature that accompanies the heat generation sharply degrades the optical output of the LED and has a significant negative influence on the reliability and durability of the LED. For these reasons, the heat dissipation factor, Kh, is an important factor in modeling and thermal design of LED installations. In this study, a methodology is proposed and experiments are conducted to determine LED heat dissipation factors. Experiments are conducted for two different brands of LED. The average heat dissipation factor of the Edixeon LED is 0.69, and is 0.60 for the OSRAM LED. By using the developed test method and comparing the results to the calculated luminous fluxes using theoretical equations, the interdependence of optical, electrical, and thermal powers can be predicted with a reasonable accuracy. The difference between the theoretical and experimental values is less than 9 %.

Skin photorejuvenation effects of light-emitting diodes (LEDs): a comparative study of yellow and red LEDs in vitro and in vivo.

PubMed

Kim, S K; You, H R; Kim, S H; Yun, S J; Lee, S C; Lee, J B

2016-10-01

Red-coloured light-emitting diodes (LEDs) can improve skin photorejuvenation and regeneration by increasing cellular metabolic activity. To evaluate the effectiveness of visible LEDs with specific wavelengths for skin photorejuvenation in vitro and in vivo. Normal human dermal fibroblasts (HDFs) from neonatal foreskin were cultured and irradiated in vitro by LEDs at different wavelengths (410-850 nm) and doses (0-10 J/cm(2) ). In vivo experiments were performed on the skin of hairless mice. Expression of collagen (COL) and matrix metalloproteinases (MMPs) was evaluated by semi-quantitative reverse transcription PCR (semi-qRT-PCR), western blotting and a procollagen type I C-peptide enzyme immunoassay (EIA). Haematoxylin and eosin and Masson trichrome stains were performed to evaluate histological changes. In HDFs, COL I was upregulated and MMP-1 was downregulated in response to LED irradiation at 595 ± 2 and 630 ± 8 nm. In the EIA, a peak result was achieved at a dose of 5 J/cm(2) with LED at 595 ± 2 nm. In vivo, COL I synthesis was upregulated in a dose-dependent manner to both 595 and 630 nm LED irradiation, and this effect was prolonged to 21 days after a single irradiation with a dose of 100 J/cm(2) . These histological changes were consistent with the results of semi-qRT-PCR and western blots. Specific LED treatment with 595 ± 2 and 630 ± 8 nm irradiation was able to modulate COL and MMPs in skin, with the effects persisting for at least 21 days after irradiation. These findings suggest that yellow and red LEDs might be useful tools for skin photorejuvenation. © 2016 British Association of Dermatologists.

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.

Energy-Saving Tunnel Illumination System Based on LED's Intelligent Control

NASA Astrophysics Data System (ADS)

Guo, Shanshan; Gu, Hanting; Wu, Lan; Jiang, Shuixiu

2011-02-01

At present there is a lot of electric energy wastage in tunnel illumination, whose design is based on the maximum brightness outside and the maximum vehicle speed all year round. LED's energy consumption is low, and the control of its brightness is simple and effective. It can be quickly adjusted between 0-100% of its maximum brightness, and will not affect the service life. Therefore, using LED as tunnel's illumination source, we can achieve a good energy saving effect. According to real-time data acquisition of vehicle speed, traffic flow and brightness outside the tunnel, the auto real-time control of tunnel illumination can be achieved. And the system regulated the LED luminance by means of combination of LED power module and intelligent control module. The tunnel information was detected by inspection equipments, which included luminometer, vehicle detector, and received by RTU(Remote Terminal Unit), then synchronously transmitted to PC. After data processing, RTU emitted the dimming signal to the LED driver to adjust the brightness of LED. Despite the relatively high cost of high-power LED lights, the enormous energy-saving effect and the well-behaved controllability is beyond compare to other lighting devices.

Dome diagnostics system of optical parameters and characteristics of LEDs

NASA Astrophysics Data System (ADS)

Peretyagin, Vladimir S.; Pavlenko, Nikita A.

2017-09-01

Scientific and technological progress of recent years in the production of the light emitting diodes (LEDs) has led to the expansion of areas of their application from the simplest systems to high precision lighting devices used in various fields of human activity. However, development and production (especially mass production) of LED lighting devices are impossible without a thorough analysis of its parameters and characteristics. There are many ways and devices for analysis the spatial, energy and colorimetric parameters of LEDs. The most methods are intended for definition only one parameter (for example, luminous flux) or one characteristic (for example, the angular distribution of energy or the spectral characteristics). Besides, devices used these methods are intended for measuring parameters in only one point or plane. This problem can be solved by using a dome diagnostics system of optical parameters and characteristics of LEDs, developed by specialists of the department OEDS chair of ITMO University in Russia. The paper presents the theoretical aspects of the analysis of LED's spatial (angular), energy and color parameters by using mentioned of diagnostics system. The article also presents the results of spatial), energy and color parameters measurements of some LEDs brands.

Sponsored Schools and Commercialized Classrooms: Schoolhouse Commercializing Trends in the 1990's.

ERIC Educational Resources Information Center

Molnar, Alex

This report analyzes commercializing trends in America's schools and classrooms, using data from database searches in seven categories of schoolhouse commercialism in the period 1990-97. The number of citations relating to commercializing activities can provide only a rough approximation of the scope and development of the phenomenon. The number…

Effects of LED or laser phototherapy on bone defects grafted with MTA and irradiated with laser or LED light: a comparative Raman spectroscopic study

NASA Astrophysics Data System (ADS)

Pinheiro, Antonio L. B.; Soares, Luiz G. P.; Barbosa, Artur Felipe S.; Silveira, Landulfo, Jr.

2012-03-01

We studied peaks of calcium hydroxyapatite - CHA on defects grafted with MTA, treated or not with Light Emitting Diode - LED or IR Laser. 54 rats were divided in 6 groups each subdivided into 3 subgroups (15,21,30d). LED (λ850 +/- 10nm) or IR Laser (λ850 nm) was applied over (LED) or in 4 points around the defect at 48 h intervals for 15 days. Raman readings were taken at the surface of the defect. The smaller overall intensity of the peak was found in Group MTA + Laser (1510.2 +/- 274.1) and the highest on Group LED (2322 +/- 715). There were no statistically significant differences between non-irradiated subjects on regards the CHA peaks. On the other hand, there were statistically significant differences between the Group Clot and LED, Clot and Laser, and Clot and MTA + Laser (p =0.01, p = 0.02, p = 0.003). There were no significant differences between Group MTA and MTA + LED (p=0.2) but significant differences were seen between Groups MTA and MTA + Laser (p=0.01). Significant differences were also observed between Groups LED and Laser (p <0.001) and between Groups MTA + LED and MTA + Laser (p=0.009). MTA, due to its characteristics, seemed to be directly affected by the light. However, the use of either phototherapy positively affected bone healing similarly as observed on different studies using other biomaterials. The overall analysis of our results indicated that the use of either light source resulted in a better, more advanced, and of quality bone repair.

The NASA LeRC regenerative fuel cell system testbed program for goverment and commercial applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maloney, T.M.; Prokopius, P.R.; Voecks, G.E.

1995-01-25

The Electrochemical Technology Branch of the NASA Lewis Research Center (LeRC) has initiated a program to develop a renewable energy system testbed to evaluate, characterize, and demonstrate fully integrated regenerative fuel cell (RFC) system for space, military, and commercial applications. A multi-agency management team, led by NASA LeRC, is implementing the program through a unique international coalition which encompasses both government and industry participants. This open-ended teaming strategy optimizes the development for space, military, and commercial RFC system technologies. Program activities to date include system design and analysis, and reactant storage sub-system design, with a major emphasis centered upon testbedmore » fabrication and installation and testing of two key RFC system components, namely, the fuel cells and electrolyzers. Construction of the LeRC 25 kW RFC system testbed at the NASA-Jet Propulsion Labortory (JPL) facility at Edwards Air Force Base (EAFB) is nearly complete and some sub-system components have already been installed. Furthermore, planning for the first commercial RFC system demonstration is underway. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}« less

Commercial Application of In-Space Assembly

NASA Technical Reports Server (NTRS)

Lymer, John; Hanson, Mark; Tadros, Al; Boccio, Joel; Hollenstein, Bruno; Emerick, Ken; Doughtery, Sean; Doggett, Bill; Dorsey, John T.; King, Bruce D.;

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.

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.

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.

38 CFR 1.301 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., including any necessary buildings and structures, garage or parking facility. (e) Parking facilities... whom the Secretary is authorized to furnish medical examination or treatment. (c) Garage means a structure or part of a structure in which vehicles may be parked. (d) Medical facility means any facility or...

38 CFR 1.301 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., including any necessary buildings and structures, garage or parking facility. (e) Parking facilities... whom the Secretary is authorized to furnish medical examination or treatment. (c) Garage means a structure or part of a structure in which vehicles may be parked. (d) Medical facility means any facility or...

38 CFR 1.301 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., including any necessary buildings and structures, garage or parking facility. (e) Parking facilities... whom the Secretary is authorized to furnish medical examination or treatment. (c) Garage means a structure or part of a structure in which vehicles may be parked. (d) Medical facility means any facility or...

38 CFR 1.301 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., including any necessary buildings and structures, garage or parking facility. (e) Parking facilities... whom the Secretary is authorized to furnish medical examination or treatment. (c) Garage means a structure or part of a structure in which vehicles may be parked. (d) Medical facility means any facility or...

38 CFR 1.301 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., including any necessary buildings and structures, garage or parking facility. (e) Parking facilities... whom the Secretary is authorized to furnish medical examination or treatment. (c) Garage means a structure or part of a structure in which vehicles may be parked. (d) Medical facility means any facility or...

26. Photo copy of photograph, (original in Forest Service Office, ...

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

26. Photo copy of photograph, (original in Forest Service Office, Elkins, WV), photographer unknown, ca. 1936. VIEW NORTHWEST, GARAGE (DEMOLISHED), NURSERY MANAGER'S GARAGE AND RESIDENCE, AND PACKING BUILDING, TRANSPLANT SHEDS AND PLOW IN FOREGROUND. - Parsons Nursery, South side of U.S. Route 219, Parsons, Tucker County, WV

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.

Issues and solutions: opportunities for European LED manufacturers

NASA Astrophysics Data System (ADS)

Pearsall, T. P.

2007-09-01

Marketing studies by EPIC show significant revenue opportunities by 2012 for UHB-LEDs in the automotive, LCD backlighting, and architectural lighting sectors. The goal of this workshop on manufacturing issues is to consider five key issues for UHB-LED manufacturing and to propose solutions that will pave the way to full exploitation of the opportunities.

Solution of multi-element LED light sources development automation problem

NASA Astrophysics Data System (ADS)

Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

2014-09-01

The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

Real-time water and wastewater quality monitoring using LED-based fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Bridgeman, John; Zakharova, Yulia

2016-04-01

In recent years there have been a number of attempts to design and introduce into water management tools that are capable of measuring organic and microbial matter in real time and in situ. This is important, as the delivery of safe water to customers, and the discharge of good quality effluent to rivers are primary concerns to water undertakers. A novel, LED-based portable fluorimeter 'Duo Fluor' has been designed and constructed at the University of Birmingham to monitor the quality of (waste)water continuously and in real time, and its performance has been assessed in a range of environments. To be of use across a range of environments, special attention must be paid to two crucially important characteristics of such instruments, i.e. their sensitivity and robustness. Thus, the objectives of this study were: 1. To compare the performance (in terms of their sensitivity and robustness) of the Duo Fluor and two other commercial fluorescence devices in laboratory conditions. 2. To assess the performance of the Duo Fluor in situ, in real time at a 450,000PE WwTW. Initially, the impact of quinine sulphate (QS), a highly fluorescent alkaloid with high quantum fluorescence yield, on peak T fluorescence in environmental waters was examined for the Duo Fluor and two commercially available, chamber-based fluorimeters, (F1) and (F2). The instruments' responses to three scenarios were assessed: 1. Deionised water (DW) spiked with QS (from 0.05 to 0.4 mg/L); 2. Environmental water (pond water, PW) spiked with QS (from 0.05 to 0.4 mg/L); 3. Different water samples from various environmental source. The results show that the facility to amend gain settings and the suitable choice of gain are crucial to obtaining reliable data on both peaks T and C in a wide range of water types. The Duo Fluor offers both of these advantages whilst commercially available instruments currently do not. The Duo Fluor was subsequently fixed at the final effluent (FE) discharge point of a WwTW and FE

Contaminants in commercial preparations of ‘purified’ small leucine-rich proteoglycans may distort mechanistic studies

PubMed Central

Brown, Sharon J.; Fuller, Heidi R.; Jones, Philip; Caterson, Bruce; Shirran, Sally L.; Botting, Catherine H.

2016-01-01

The present study reports the perplexing results that came about because of seriously impure commercially available reagents. Commercial reagents and chemicals are routinely ordered by scientists and expected to have been rigorously assessed for their purity. Unfortunately, we found this assumption to be risky. Extensive work was carried out within our laboratory using commercially sourced preparations of the small leucine-rich proteoglycans (SLRPs), decorin and biglycan, to investigate their influence on nerve cell growth. Unusual results compelled us to analyse the composition and purity of both preparations of these proteoglycans (PGs) using both mass spectrometry (MS) and Western blotting, with and without various enzymatic deglycosylations. Commercial ‘decorin’ and ‘biglycan’ were found to contain a mixture of PGs including not only both decorin and biglycan but also fibromodulin and aggrecan. The unexpected effects of ‘decorin’ and ‘biglycan’ on nerve cell growth could be explained by these impurities. Decorin and biglycan contain either chondroitin or dermatan sulfate glycosaminoglycan (GAG) chains whereas fibromodulin only contains keratan sulfate and the large (>2500 kDa), highly glycosylated aggrecan contains both keratan and chondroitin sulfate. The different structure, molecular weight and composition of these impurities significantly affected our work and any conclusions that could be made. These findings beg the question as to whether scientists need to verify the purity of each commercially obtained reagent used in their experiments. The implications of these findings are vast, since the effects of these impurities may already have led to inaccurate conclusions and reports in the literature with concomitant loss of researchers’ funds and time. PMID:27994047

An LED solar simulator for student labs

NASA Astrophysics Data System (ADS)

González, Manuel I.

2017-05-01

Measuring voltage-current and voltage-power curves of a photovoltaic module is a nice experiment for high school and undergraduate students. In labs where real sunlight is not available this experiment requires a solar simulator. A prototype of a simulator using LED lamps has been manufactured and tested, and a comparison with classical halogen simulators has been performed. It is found that LED light offers lower levels of irradiance, but much better performance in terms of module output for a given irradiance.

Warm white LEDs lighting over Ra=95 and its applications

NASA Astrophysics Data System (ADS)

Kobashi, Katsuya; Taguchi, Tsunemasa

2007-02-01

We have for the first time developed warm white LEDs lighting using a combination of near ultraviolet LED and three-band (red, green and blue) white phosphors. This LED has the average color-rendering index Ra=96. Moreover, special color-rendering index R9 (red) and R15 (face color of Japanese) are estimated to be 95 and 97, respectively. We will describe the results of evaluation on the medical lighting applications such as operation, treatment and endoscope experiments, application to the LED fashions and application to the Japanese antique art (ink painting) lighting.

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.

Commercial Art I and Commercial Art II: An Instructional Guide.

ERIC Educational Resources Information Center

Montgomery County Public Schools, Rockville, MD.

A teacher's guide for two sequential one-year commercial art courses for high school students is presented. Commercial Art I contains three units: visual communication, product design, and environmental design. Students study visual communication by analyzing advertising techniques, practicing fundamental drawing and layout techniques, creating…

Public Good or Commercial Opportunity: Case Studies in Remote Sensing Commercialization

NASA Technical Reports Server (NTRS)

Johnston, Shaida; Cordes, Joseph

2002-01-01

The U.S. Government is once again attempting to commercialize the Landsat program and is asking the private sector to develop a next generation mid-resolution remote sensing system that will provide continuity with the thirty-year data archive of Landsat data. Much of the case for commercializing the Landsat program rests on the apparently successful commercialization of high-resolution remote sensing activities coupled with the belief that conditions have changed since the failed attempt to commercialize Landsat in the 1980s. This paper analyzes the economic, political and technical conditions that prevailed in the 1980s as well as conditions that might account for the apparent success of the emerging high-resolution remote sensing industry today. Lessons are gleaned for the future of the Landsat program.

Smart LED allocation scheme for efficient multiuser visible light communication networks.

PubMed

Sewaiwar, Atul; Tiwari, Samrat Vikramaditya; Chung, Yeon Ho

2015-05-18

In a multiuser bidirectional visible light communication (VLC), a large number of LEDs or an LED array needs to be allocated in an efficient manner to ensure sustainable data rate and link quality. Moreover, in order to support an increasing or decreasing number of users in the network, the LED allocation is required to be performed dynamically. In this paper, a novel smart LED allocation scheme for efficient multiuser VLC networks is presented. The proposed scheme allocates RGB LEDs to multiple users in a dynamic and efficient fashion, while satisfying illumination requirements in an indoor environment. The smart LED array comprised of RGB LEDs is divided into sectors according to the location of the users. The allocated sectors then provide optical power concentration toward the users for efficient and reliable data transmission. An algorithm for the dynamic allocation of the LEDs is also presented. To verify its effective resource allocation feature of the proposed scheme, simulations were performed. It is found that the proposed smart LED allocation scheme provides the effect of optical beamforming toward individual users, thereby increasing the collective power concentration of the optical signals on the desirable users and resulting in significantly increased data rate, while ensuring sufficient illumination in a multiuser VLC environment.

Commercialization and the Commercial Internet Exchange: How the CIX Can Help Further the Commercialization of the Internet.

ERIC Educational Resources Information Center

Estrada, Susan

1992-01-01

To promote successful commercialization of the Internet, the Commercial Internet Exchange Association (CIX) acts on behalf of its members to increase cooperation and an open exchange of ideas regarding networking issues. Of concern are federal regulation, development of standards and pricing agreements, and the development of user friendly…

[Study on the safety of blue light leak of LED].

PubMed

Shen, Chong-Yu; Xu, Zheng; Zhao, Su-Ling; Huang, Qing-Yu

2014-02-01

In this paper, the blue light properties of LED illumination devices have been investigated. Against the status quo of China's LED lighting, we measured the spectrum component of LED lamps and analyzed the photobiological safety under the current domestic and international standards GB/T 20145-2006/CIE S009/E: 2002 and IEC62471: 2006 standards as well as CTL-0744_2009-laser resolution, which provides the reference to the manufacture of LED lighting lamps as well as related safety standards and laws. If the radiance intensity of blue light in LED is lower than 100 W x m(-2) x Sr(-1), there is no harm to human eyes. LEDs will not cause harm to human eyes under normal use, but we should pay attention to the protection of special populations (children), and make sure that they avoid looking at a light source for a long time. The research has found that the blue-rich lamps can affect the human rule of work and rest, and therefore, the LED lamps with color temperature below 4 000 K and color rendering index of 80 are suitable for indoor use. At the same time, the lamps with different parameters should be selected according to the different distances.

Commercialization of Advanced Communications Technology Satellite (ACTS) technology

NASA Astrophysics Data System (ADS)

Plecity, Mark S.; Strickler, Walter M.; Bauer, Robert A.

1996-03-01

In an on-going effort to maintain United States leadership in communication satellite technology, the National Aeronautics and Space Administration (NASA), led the development of the Advanced Communications Technology Satellite (ACTS). NASA's ACTS program provides industry, academia, and government agencies the opportunity to perform both technology and telecommunication service experiments with a leading-edge communication satellite system. Over 80 organizations are using ACTS as a multi server test bed to establish communication technologies and services of the future. ACTS was designed to provide demand assigned multiple access (DAMA) digital communications with a minimum switchable circuit bandwidth of 64 Kbps, and a maximum channel bandwidth of 900 MHZ. It can, therefore, provide service to thin routes as well as connect fiber backbones in supercomputer networks, across oceans, or restore full communications in the event of national or manmade disaster. Service can also be provided to terrestrial and airborne mobile users. Commercial applications of ACTS technologies include: telemedicine; distance education; Department of Defense operations; mobile communications, aeronautical applications, terrestrial applications, and disaster recovery. This paper briefly describes the ACTS system and the enabling technologies employed by ACTS including Ka-band hopping spot beams, on-board routing and switching, and rain fade compensation. When used in conjunction with a time division multiple access (TDMA) architecture, these technologies provide a higher capacity, lower cost satellite system. Furthermore, examples of completed user experiments, future experiments, and plans of organizations to commercialize ACTS technology in their own future offerings will be discussed.

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

Choosing surgical lighting in the LED era.

PubMed

Knulst, Arjan J; Stassen, Laurents P S; Grimbergen, Cornelis A; Dankelman, Jenny

2009-12-01

The aim of this study is to evaluate the illumination characteristics of LED lights objectively to ease the selection of surgical lighting. The illuminance distributions of 5 main and 4 auxiliary lights were measured in 8 clinically relevant scenarios. For each light and scenario, the maximum illuminance E(c) (klux) and the size of the light field d(10) (mm) were computed. The results showed: that large variations for both E(c) (25-160 klux) and d(10) (109-300 mm) existed; that using auxiliary lights reduced both E(c) and d(10) by up to 80% and 30%; that with segmented lights, uneven light distributions occurred; and that with colored LED lights shadow edges on the surgical field became colored. Objective illuminance measurements show a wide variation between lights and a superiority of main over auxiliary lights. Uneven light distributions and colored shadows indicate that LED lights still need to converge to an optimal design.

Bivalent rLP2086 (Trumenba®): Development of a well-characterized vaccine through commercialization.

PubMed

Sunasara, Khurram; Cundy, John; Srinivasan, Sriram; Evans, Brad; Sun, Weiqiang; Cook, Scott; Bortell, Eric; Farley, John; Griffin, Daniel; Bailey Piatchek, Michele; Arch-Douglas, Katherine

2018-05-24

The phrase "Process is the Product" is often applied to biologics, including multicomponent vaccines composed of complex components that evade complete characterization. Vaccine production processes must be defined and locked early in the development cycle to ensure consistent quality of the vaccine throughout scale-up, clinical studies, and commercialization. This approach of front-loading the development work helped facilitate the accelerated approval of the Biologic License Application for the well-characterized vaccine bivalent rLP2086 (Trumenba®, Pfizer Inc) in 2014 under Breakthrough Therapy Designation. Bivalent rLP2086 contains two rLP2086 antigens and is licensed for the prevention of meningococcal meningitis disease caused by Neisseria meningitidis serogroup B in individuals 10-25years of age in the United States. This paper discusses the development of the manufacturing process of the two antigens for the purpose of making it amenable to any manufacturing facility. For the journey to commercialization, the operating model used to manage this highly accelerated program led to a framework that ensured "right the first time" execution, robust process characterization, and proactive process monitoring. This framework enabled quick problem identification and proactive resolutions, resulting in a robust control strategy for the commercial process. Copyright © 2017 Elsevier Ltd. All rights reserved.

LED phototherapy to prevent mucositis: a case report.

PubMed

Lang-Bicudo, Leticia; Eduardo, Fernanda De Paula; Eduardo, Carlos De Paula; Zezell, Denise Maria

2008-12-01

The purpose of this case report was to evaluate the efficacy of phototherapy using light-emitting diodes (LEDs) to prevent oral mucositis in a Hodgkin's disease patient treated with the ABVD (doxorubicin [Adriamycin], bleomycin, vinblastine, and dacarbazine) chemotherapy regimen. Mucositis is a common dose-limiting complication of cancer treatment, and if severe it can lead to alterations in treatment planning or suspension of cancer therapy, with serious consequences for tumor response and survival. Therefore, low-power lasers and more recently LEDs, have been used for oral mucositis prevention and management, with good results. In this study, a 34-year-old man received intraoral irradiation with an infrared LED array (880 nm, 3.6 J/cm2, 74 mW) for five consecutive days, starting on chemotherapy day 1. In each chemotherapy cycle, he received the ABVD protocol on days 1 and 15, and received LED treatment for 5 d during each cycle. To analyze the results, the World Health Organization (WHO) scale was used to grade his mucositis, and a visual analogue scale (VAS) was used for pain evaluation, on days 1, 3, 7, 10, and 13 post-chemotherapy. The results showed that the patient did not develop oral mucositis during the five chemotherapy cycles, and he had no pain symptoms. LED therapy was a safe and effective method for preventing oral mucositis in this case report. However, further randomized studies with more patients are needed to prove the efficacy of this method.

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…

LED Street Lighting Solutions: Flagstaff, Arizona as a Case Study

NASA Astrophysics Data System (ADS)

Hall, Jeffrey C.

2018-01-01

Dark-sky protection in Flagstaff, Arizona extends back to 1958, with the first ordinance in the City banning advertising floodlights. The current ordinance, adopted in 1989, is comprehensive and has played a critical role in maintaining the quality of the night sky for astronomy, tourism, public enjoyment, and other purposes. Flagstaff, like many communities around the world, is now working on a transition from legacy bulb-based technology to LED for its outdoor lighting. The City, Lowell Observatory, the U. S. Naval Observatory, and the Flagstaff Dark Skies Coalition have been working intensively for two years to identify an LED-based street lighting solution that will preserve the City's dark skies while meeting municipal needs. We will soon be installing test fixtures for an innovative solution incorporating narrow-band amber LED and modest amounts of low-CCT white LED. In this talk, I will review the types of LEDs available for outdoor lighting and discuss the plans for Flagstaff's street lighting in the LED era, which we hope will be a model for communities worldwide.

Progress and prospects of GaN-based LEDs using nanostructures

NASA Astrophysics Data System (ADS)

Zhao, Li-Xia; Yu, Zhi-Guo; Sun, Bo; Zhu, Shi-Chao; An, Ping-Bo; Yang, Chao; Liu, Lei; Wang, Jun-Xi; Li, Jin-Min

2015-06-01

Progress with GaN-based light emitting diodes (LEDs) that incorporate nanostructures is reviewed, especially the recent achievements in our research group. Nano-patterned sapphire substrates have been used to grow an AlN template layer for deep-ultraviolet (DUV) LEDs. One efficient surface nano-texturing technology, hemisphere-cones-hybrid nanostructures, was employed to enhance the extraction efficiency of InGaN flip-chip LEDs. Hexagonal nanopyramid GaN-based LEDs have been fabricated and show electrically driven color modification and phosphor-free white light emission because of the linearly increased quantum well width and indium incorporation from the shell to the core. Based on the nanostructures, we have also fabricated surface plasmon-enhanced nanoporous GaN-based green LEDs using AAO membrane as a mask. Benefitting from the strong lateral SP coupling as well as good electrical protection by a passivation layer, the EL intensity of an SP-enhanced nanoporous LED was significantly enhanced by 380%. Furthermore, nanostructures have been used for the growth of GaN LEDs on amorphous substrates, the fabrication of stretchable LEDs, and for increasing the 3-dB modulation bandwidth for visible light communication. Project supported by the National Natural Science Foundation of China (Grant No. 61334009), the National High Technology Research and Development Program of China (Grant Nos. 2015AA03A101 and 2014BAK02B08), China International Science and Technology Cooperation Program (Grant No. 2014DFG62280), the “Import Outstanding Technical Talent Plan” and “Youth Innovation Promotion Association Program” of the Chinese Academy of Sciences.

High-power UV-LED degradation: Continuous and cycled working condition influence

NASA Astrophysics Data System (ADS)

Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

2015-09-01

High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

Student-Led Parent-Teacher Conferences.

ERIC Educational Resources Information Center

Borba, John A.; Olvera, Cherise M.

2001-01-01

Outlines the six-stage process used at Gustine Middle School for student-led parent-teacher conferences. Discusses how this encourages students to participate actively in evaluating their own progress, which motivates them toward personal initiatives to inspire learning, and improves student communication about learning with both parents and…

Compact LED based LCOS optical engine for mobile projection

NASA Astrophysics Data System (ADS)

Zhang, Wenzi; Li, Xiaoyan; Liu, Qinxiao; Yu, Feihong

2009-11-01

With the development of high power LED (light emitting diode) technology and color filter LCOS (liquid crystal on silicon) technology, the research on LED based micro optical engine for mobile projection has been a hot topic recently. In this paper one compact LED powered LCOS optical engine design is presented, which is intended to be embedded in cell phone, digital camera, and so on. Compared to DLP (digital light processor) and traditional color sequential LCOS technology, the color filter based LCOS panel is chosen for the compact optical engine, this is because only white LED is needed. To further decrease the size of the optical engine, only one specifically designed plastic free form lens is applied in the illumination part of the optical engine. This free form lens is designed so that it plays the roles of both condenser and integrator, by which the output light of LED is condensed and redistributed, and light illumination of high efficiency, high uniformity and small incident angle on LCOS is acquired. Besides PBS (polarization beam splitter), LCOS, and projection lens, the compact optical engine contains only this piece of free form plastic lens, which can be produced by plastic injection molding. Finally a white LED powered LCOS optical engine with a compact size of less than 6.6 cc can be acquired. With the ray tracing simulation result, the light efficiency analysis shows that the output flux is over 8.5 ANSI lumens and the ANSI uniformity of over 80%.

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…

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…

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.

Evaluation of an LED (Light-Emitting Diode) high-mounted signal lamp

NASA Astrophysics Data System (ADS)

Olson, P. L.

1987-02-01

Two studies are described evaluating high-mounted stoplights using light-emitting diodes (LEDs) compared with conventional incandescent units. The first of these studies obtained ratings from subjects who drove one car and followed another car that was equipped with the test lamps. The results indicate that the subjects generally preferred the LEDs to the conventional lamp. The second study was a laboratory evaluation of the attention-getting capabilities of LED and incandescent stoplights. Under all conditions tested subjects responded faster to the LED units. The response time advantage for the LED units increased with more difficult viewing conditions, such as high levels of illumination and long viewing distance. The results of these investigations are discussed in terms of the applicability of the LED technology to high mounted stoplights on motor vehicles.

Optical design of a high-power LED-based solar simulator

NASA Astrophysics Data System (ADS)

Toro-Betancur, Veronica; Velásquez-López, Alejandro; Velásquez, David; Acevedo-Gómez, David

2016-04-01

The optical design of a High-Power LED based Solar Simulator was made in order to reach the AM1.5G spectrum standards. An optical model of the light emitted by the LEDs was made and used for spectral intensities calculations and the light intensity uniformity was optimized. A class AAA solar simulator was designed using a hexagonal LED distribution.

LED Lighting Facts® Program Supports Accuracy in SSL Product Information

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Fact sheet that provides a summary of LED Lighting Facts, a program to assure that LED lighting is accurately represented in the marketplace, illustrated by the LED Lighting Facts label to disclose product performance data.

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.

Energy conservation and the residential and commercial sector

NASA Technical Reports Server (NTRS)

1975-01-01

A detailed analysis of energy conservation actions relevant to the residential and commercial sector has led to the conclusion that the potential for savings is great. The task will not be easy, however, since many of the actions require significant life style changes that are difficult to accomplish. Furthermore, many of the conservation actions cited as instant solutions to the energy crisis are those with only mid to long term potential, such as solar energy or heat pumps. Three significant conservation approaches are viable: adjusting price structure, mandating actions, and educating consumers. The first two appear to be the most feasible. But they are not without a price. Higher utility bills adversely affect the poor and the elderly on fixed incomes. Likewise, strict mandatory measures can be quite distasteful. But the effect of alternatives, such as voluntary savings accomplished through education processes, is minimal in a nation without a true conservation ethic.

Analysis of LED arrangement in an array with respect to lens geometry

NASA Astrophysics Data System (ADS)

Ley, Peer-Phillip; Held, Marcel Philipp; Lachmayer, Roland

2018-02-01

Highly adaptive light sources such as LED arrays have been surpassing conventional light sources (halogen, xenon) for automotive applications. Individual LED arrangements within the array, high durability and low energy consumption of the LEDs are some of the reasons. With the introduction of Audi's Matrix beam system, efforts to increase the quantity of pixels were already underway and the stage was practically set for pixel light systems. Current efforts are focused towards the exploration of an optimal LED array density and the use of spatial light modulators. In both cases, one question remains - What arrangement of LEDs is the most suitable in terms of light output efficiency for a given lens geometry? The radiation characteristics of an LED usually shows a Lambertian pattern. Following from the definition of luminous efficacy, this characteristic property of LEDs has a decisive impact on the lens geometry in a given array. Due to the proportional correlation between the lens diameter and the distance of LEDs emission surface to the lens surface. Assuming a constant viewing angle an increase of the distance leads to an increase of the lens diameter. In this paper, two different approaches for an optimized LED array with regards to the LED arrangement will be presented. The introduced designs result from one imaging and one non-imaging optical system, which will be investigated. The paper is concluded with a comparative analysis of the LED array design as a function of the LED pitch and the luminous efficacy.

24 CFR 880.602 - Replacement reserve.

Code of Federal Regulations, 2012 CFR

2012-04-01

... equivalent to .006 of the cost of total structures, including main buildings, accessory buildings, garages... projects, an amount equivalent to at least .006 of the cost of total structures, including main buildings, accessory buildings, garages and other buildings, or any higher rate as required from time to time by: (A...

24 CFR 880.602 - Replacement reserve.

Code of Federal Regulations, 2010 CFR

2010-04-01

... equivalent to .006 of the cost of total structures, including main buildings, accessory buildings, garages... projects, an amount equivalent to at least .006 of the cost of total structures, including main buildings, accessory buildings, garages and other buildings, or any higher rate as required from time to time by: (A...

24 CFR 880.602 - Replacement reserve.

Code of Federal Regulations, 2014 CFR

2014-04-01

... equivalent to .006 of the cost of total structures, including main buildings, accessory buildings, garages... projects, an amount equivalent to at least .006 of the cost of total structures, including main buildings, accessory buildings, garages and other buildings, or any higher rate as required from time to time by: (A...

24 CFR 880.602 - Replacement reserve.

Code of Federal Regulations, 2013 CFR

2013-04-01

... equivalent to .006 of the cost of total structures, including main buildings, accessory buildings, garages... projects, an amount equivalent to at least .006 of the cost of total structures, including main buildings, accessory buildings, garages and other buildings, or any higher rate as required from time to time by: (A...

24 CFR 880.602 - Replacement reserve.

Code of Federal Regulations, 2011 CFR

2011-04-01

... equivalent to .006 of the cost of total structures, including main buildings, accessory buildings, garages... projects, an amount equivalent to at least .006 of the cost of total structures, including main buildings, accessory buildings, garages and other buildings, or any higher rate as required from time to time by: (A...