An LED-based luminaire for badminton court illumination

2015 ◽  
Vol 49 (3) ◽  
pp. 396-406 ◽  
Author(s):  
X-H Lee ◽  
J-T Yang ◽  
J-H Chang ◽  
W-T Chien ◽  
Y-C Lo ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Power Consumption ◽  
Electric Power ◽  
High Performance ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Volume Scattering ◽  
Light Emitting ◽  
Low Luminance ◽  
Before And After

In this paper, the design of a luminaire for badminton court illumination is demonstrated from concept through computer simulation, construction trials, on-site installation, comparison with simulations and, finally, evaluations of the illuminated environment before and after the installation of the luminaires. The luminaire is composed of two high-performance light-emitting diode lighting modules, volume scattering diffusers with a one-shot transmittance higher than 70% and a reflecting cavity with a reflectivity higher than 85%. The luminaire has three different exit faces forming three Lambertian-like light sources with low luminance so as to reduce glare to the players when looking at the flight of the shuttlecock. Under similar total electric power consumption, compared to the original traditional lighting, the average illuminance on the ground is enhanced by about 300% and the uniformity is obviously improved. A questionnaire was issued to players before and after the installation of the new light-emitting diode luminaires. The new installation gained much more positive responses for brightness, comfort and number of usable courts from the players than the old installation.

Electrically driven single microribbon based near-infrared exciton-polariton light-emitting diode

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mingming Jiang ◽  
Fupeng Zhang ◽  
Kai Tang ◽  
Peng Wan ◽  
Caixia Kan
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Coherent Light ◽  
Light Emitting ◽  
Exciton Polaritons ◽  
Laser Devices

Achieving electrically-driven exciton-polaritons has drawn substantial attention toward developing ultralow-threshold coherent light sources, containing polariton laser devices and high-performance light-emitting diodes (LEDs). In this work, we demonstrate an electrically driven...

Reactivity of bilirubin photoisomers on the measurement of direct bilirubin using vanadic acid method

2017 ◽  
Vol 55 (2) ◽  
pp. 296-298
Author(s):  
Hitoshi Okada ◽  
Susumu Itoh ◽  
Shohei Kawamoto ◽  
Miyo Ozaki ◽  
Takashi Kusaka
Keyword(s):  
High Performance ◽  
Light Emitting Diode ◽  
Direct Bilirubin ◽  
Acid Oxidation ◽  
Albumin Solution ◽  
Light Emitting ◽  
Oxidation Method ◽  
Before And After ◽  
Vanadic Acid ◽  
Human Serum Albumin Solution

Objective Investigation of the reactivity of fractions of bilirubin photoisomers with the vanadic acid oxidation method. Methods Bilirubin photoisomers were prepared by irradiating a bilirubin/human serum albumin solution with blue light emitting diode. Direct bilirubin and bilirubin fractions were measured using the vanadic acid oxidation method and high-performance liquid chromatography in the sample before and after irradiation. Results Direct bilirubin was increased in the solution containing bilirubin photoisomers. ( EE)-/( EZ) -cyclobilirubin-IXα and ( ZE)-/( EZ)-bilirubin-IXα completely disappeared after the addition of vanadic acid. Conclusion Bilirubin photoisomers reacted as direct bilirubin in the vanadic acid oxidation method.

Ultraviolet light-emitting diode-assisted highly sensitive room temperature NO2 gas sensor for low-temperature solution-processed ZnO/TiO2 nanorods decorated with plasmonic Au nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Soon-Hwan Kwon ◽  
Tae-Hyeon Kim ◽  
Sang-Min Kim ◽  
Semi Oh ◽  
Kyoung-Kook Kim
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
No2 Gas Sensor ◽  
Highly Sensitive ◽  
Temperature Solution ◽  
Semiconducting Metal Oxides

Nanostructured semiconducting metal oxides such as SnO2, ZnO, TiO2, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors,...

Reliability of High-Power Light Emitting Diode Attached With Different Thermal Interface Materials

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Temperature Cycling ◽  
Fluorescent Light ◽  
Light Sources ◽  
Light Emitting ◽  
Die Attach ◽  
Nanosilver Paste ◽  
Interconnection Material

As a solid electroluminescent source, white light emitting diode (LED) has entered a practical stage and become an alternative to replace incandescent and fluorescent light sources. However, due to the increasing integration and miniaturization of LED chips, heat flux inside the chip is also increasing, which puts the packaging into the position to meet higher requirements of heat dissipation. In this study, a new interconnection material—nanosilver paste is used for the LED chip packaging to pursue a better optical performance, since high thermal conductivity of this material can help improve the efficiency of heat dissipation for the LED chip. The bonding ability of this new die-attach material is evaluated by their bonding strength. Moreover, high-power LED modules connected with nanosilver paste, Sn3Ag0.5Cu solder, and silver epoxy are aged under hygrothermal aging and temperature cycling tests. The performances of these LED modules are tested at different aging time. The results show that LED modules sintered with nanosilver paste have the best performance and stability.

In-Use Photostability Practice and Regulatory Evaluation for Pharmaceutical Products in an Age of Light-Emitting Diode Light Sources

2019 ◽  
Vol 108 (3) ◽  
pp. 1172-1176 ◽  
Author(s):  
Leonardo R. Allain ◽  
Brittany C. Pierce ◽  
W. Peter Wuelfing ◽  
Allen C. Templeton ◽  
Roy Helmy
Keyword(s):  
Light Emitting Diode ◽  
Pharmaceutical Products ◽  
Light Sources ◽  
Light Emitting ◽  
Regulatory Evaluation

scholarly journals Operando direct observation of spin-states and charge-trappings of blue light-emitting-diode materials in thin-film devices

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fumiya Osawa ◽  
Kazuhiro Marumoto
Keyword(s):  
Blue Light ◽  
High Performance ◽  
Density Functional ◽  
Light Emitting Diode ◽  
Green Light ◽  
Spin States ◽  
Light Emitting ◽  
Full Color ◽  
Color Displays ◽  
Materials Used

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.

Manufacture and Evaluation of Light Emitting Diode Package Substrate Using Flexible Printed Circuit Board

2015 ◽  
Vol 15 (10) ◽  
pp. 7578-7581
Author(s):  
Jung-Kab Park ◽  
Jin-Ha Shin ◽  
Mun-Gi Jung ◽  
Tomabechi Shigehisa ◽  
Hwa-Sun Park ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Light Emitting Diode ◽  
Thermal Conductance ◽  
Polyimide Film ◽  
Luminous Efficiency ◽  
Circuit Board ◽  
Light Sources ◽  
Thermal Shock Test ◽  
Light Emitting ◽  
Au Electrode

Unlike other light sources such as fluorescent lamps and incandescent bulbs, light-emitting diodes (LED) convert 70∼80% of energy into heat. If the heat produced an LED chip is not effectively released, its luminous efficiency and lifespan are reduced. Therefore, as a method effectively release heat, an LED PKG substrate containing a heat-releasing material with excellent thermal conductance was fabricated, and its thermal resistance and luminous efficiency were analyzed. In this experiment, a thin polyimide film with excellent ductility was used to fabricate the LED PKG substrate. A 35-μm-thick Cu foil with excellent thermal conductance was subjected to high temperature and pressure and attached to both sides of the polyimide film. By electroplating Ag or Au, which has excellent thermal conductance, for us as the electrode and heat-releasing material, LED PKG substrate was fabricated with a thickness of approximately 170 μm. (−40 °C → RT → 120 °C). The results revealed that the LED PKG substrate having a Ag electrode with excellent thermal conductance had an excellent thermal resistance of approximately 4.2 °C/W (Au electrode: 5.6 °C/W). The luminous flux after 100 cycles in the thermal shock test was reduced by approximately 0.09% (Au electrode: 2.77%), indicating that the LED PKG substrate had excellent thermal resistance without any mechanical and material defects in a rapid-temperature-changing environment. The advantages and excellent thermal resistance can be exploited in cellular phones and LCD panels, and heat-releasing problems in thin panels be solved.

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