Searched for: subject:"Degradation"
(1 - 10 of 10)
document
Yazdan Mehr, M. (author), Bahrami, A. (author), van Driel, W.D. (author), Fan, X.J. (author), Davis, J.L. (author), Zhang, G.Q. (author)
In this paper, degradation mechanisms of optical materials, used in the light emitting diode (LED)-based products, are reviewed. The LED lighting is one of the fastest technology shifts in human history. Lighting accounts for almost 20% of the global electrical energy use, inferring that replacement of traditional lighting sources with LEDs...
journal article 2020
document
Guo, Y. (author), Markine, V.L. (author), Zhang, X. (author), Qiang, Weile (author), Jing, Guoquig (author)
The performance and deformation of ballast bed are significantly influenced by the particle morphology (size and shape), the rheology (translation and rotation), and the degradation (breakage and abrasion). Regarding the ballast particle morphology, the ballast particle size is generally measured by sieving and described with the Particle Size...
review 2019
document
Chen, Wei (author), Fan, J. (author), Qian, Cheng (author), Pu, Bin (author), Fan, Xuejun (author), Zhang, G.Q. (author)
The inherent luminous characteristics and stability of LED packages during the operation period are highly dependent on their junction temperatures and driving currents. In this paper, the luminous flux of LED packages operated under a wide range of driving currents and junction temperatures are investigated to develop a luminous flux...
journal article 2019
document
Cai, Miao (author), Liang, Yonghu (author), Yun, Minghui (author), Chen, Xuan-You (author), Yan, Haidong (author), Yu, Zhaozhe (author), Yang, Daoguo (author), Zhang, G.Q. (author)
A novel silicone rubber elastic key (SREK) is proposed in this paper for surface mounting technology (SMT) applications. Effects of thermal reflowing stress on the mechanical properties of SMT-SREKs are investigated. The manufactured SMT-SREKs, which underwent various reflowing conditions in advance, are subjected to pressing force and...
journal article 2019
document
Guo, Y. (author), Markine, V.L. (author), Qiang, Weile (author), Zhang, Hui (author), Jing, Guoqing (author)
Higher speed, more freight and frequent maintenance increase ballast degradation and reduce the ballast lifespan. To reduce ballast degradation, crumb rubber used as buffering aggregates in ballast bed is relatively unexplored and needs more studies, because using it has the advantage of reusing the waster rubber and absorbing the noises. The...
journal article 2019
document
Jiang, X. (author), Luo, Chengwei (author), Qiang, X. (author), Zhang, Qilin (author), Kolstein, M.H. (author), Bijlaard, F.S.K. (author)
To investigate the mechanical degradation of the shear properties of glass fiber-reinforced polymer (GFRP) laminates in bridge decks under hygrothermal aging effects, short-beam shear tests were performed following the ASTM test standard (ASTM D790-10A). Based on the coupled hygro-mechanical finite element (FE) analysis method, an inverse...
journal article 2018
document
Yazdan Mehr, M. (author), van Driel, W.D. (author), De Buyl, Francois (author), Zhang, G.Q. (author)
Degradation mechanisms of silicone plates under harsh environment conditions are studied in this investigation. Environmental degradation of silicone free form, used as secondary optics in Light Emitting Diode LED lighting lamps and luminaires or any other applications requiring high quality optics being used, has negative implications for the...
journal article 2018
document
Sun, B. (author), Fan, Xuejun (author), Ye, H. (author), Fan, Jiajie (author), Qian, Cheng (author), van Driel, W.D. (author), Zhang, G.Q. (author)
In this paper, an integrated LED lamp with an electrolytic capacitor-free driver is considered to study the coupling effects of both LED and driver's degradations on lamp's lifetime. An electrolytic capacitor-less buck-boost driver is used. The physics of failure (PoF) based electronic thermal simulation is carried out to simulate the lamp's...
journal article 2017
document
Cai, Miao (author), Yang, Daoguo (author), Huang, J. (author), Zhang, Maofen (author), Chen, Xianping (author), Liang, Caihang (author), Koh, S.W. (author), Zhang, G.Q. (author)
The color coordinate shift of light-emitting diode (LED) lamps is investigated by running three stress-loaded testing methods, namely step-up stress accelerated degradation testing, step-down stress accelerated degradation testing, and constant stress accelerated degradation testing. A power model is proposed as the statistical model of the...
journal article 2017
document
Yazdan Mehr, M. (author), van Driel, W.D. (author), Zhang, G.Q. (author)
In this paper, progresses of color maintenance, also known as color shift, in solid-state lighting (SSL) systems are thoroughly reviewed. First, color shift is introduced and a few examples are given from different real-life industrial conditions. Different degradation mechanisms in different parts of the system are also explained. Different...
review 2015
Searched for: subject:"Degradation"
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