Enhanced spectral power density and reduced linewidth at 1.3 μm in an InGaAsP quantum well resonant‐cavity light‐emitting diode

1992 ◽  
Vol 61 (19) ◽  
pp. 2287-2289 ◽  
Author(s):  
N. E. J. Hunt ◽  
E. F. Schubert ◽  
R. A. Logan ◽  
G. J. Zydzik
2002 ◽  
Vol 80 (12) ◽  
pp. 2198-2200 ◽  
Author(s):  
F. B. Naranjo ◽  
S. Fernández ◽  
M. A. Sánchez-Garcı́a ◽  
F. Calle ◽  
E. Calleja

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4215
Author(s):  
Radosław Wróbel ◽  
Lech Sitnik ◽  
Monika Andrych-Zalewska ◽  
Łukasz Łoza ◽  
Radostin Dimitrov ◽  
...  

The article presents the results of research on the vibroacoustic response of internal combustion engines mounted in a vehicle. The vehicles studied belong to popular models, which became available in successive versions. Each group included vehicles of the same model of an older generation (equipped with a naturally aspirated engine) and of a newer generation, including downsized (and turbocharged) engines. Tests in each group were carried out under repeatable conditions on a chassis-load dynamometer. The vibrations were measured using single-axis accelerometers mounted on the steering wheel, engine, and driver’s head restraint mounting. The primary purpose of the study was to verify whether the new generations of vehicles equipped with additional high-speed elements (compressors) generate additional harmonics (especially those within the range potentially affecting travel comfort and human health) and whether there are significant changes in the distribution of spectral power density in the new generations. As the study showed, new generations of vehicles are characterized by a different vibroacoustic response, and the trend of change is the same in each of the families studied.


2021 ◽  
Vol 13 (9) ◽  
pp. 4852
Author(s):  
Jack Ngarambe ◽  
Inhan Kim ◽  
Geun Young Yun

Spectral power distribution (SPD) is an essential element that has considerable implications on circadian energy and the perception of lit environments. The present study assessed the potential influences of SPD on energy consumption (i.e., considering circadian energy), visual comfort, work performance and mood. Two lighting conditions based on light-emitting diode (LED) and organic light-emitting diode (OLED) were used as proxies for SPDs of different spectral content: dominant peak wavelength of 455 nm (LED) and 618 nm (OLED). Using measured photometric values, the circadian light (CL), melatonin suppression (MS), and circadian efficacy (CE) of the two lighting sources were estimated via a circadian-phototransduction model and compared. Additionally, twenty-six participants were asked to evaluate the said lit environments subjectively in terms of visual comfort and self-reported work performance. Regarding circadian lighting and the associated energy implications, the LED light source induced higher biological actions with relatively less energy than the OLED light source. For visual comfort, OLED lighting-based conditions were preferred to LED lighting-based conditions, while the opposite was true when considering work performance and mood. The current study adds to the on-going debate regarding human-centric lighting, particularly considering the role of SPD in energy-efficient and circadian lighting practices.


2007 ◽  
Vol 17 (01) ◽  
pp. 81-84
Author(s):  
J. Senawiratne ◽  
M. Zhu ◽  
W. Zhao ◽  
Y. Xia ◽  
Y. Li ◽  
...  

Optical properties of green emission Ga 0.80 In 0.20 N/GaN multi-quantum well and light emitting diode have been investigated by using photoluminescence, cathodoluminescence, electroluminescence, and photoconductivity. The temperature dependent photoluminescence and cathodoluminescence studies show three emission bands including GaInN/GaN quantum well emission centered at 2.38 eV (~ 520 nm). The activation energy of the non-radiative recombination centers was found to be ~ 60 meV. The comparison of photoconductivity with luminescence spectroscopy revealed that optical properties of quantum well layers are strongly affected by the quantum-confined Stark effect.


2013 ◽  
Vol 38 (17) ◽  
pp. 3370 ◽  
Author(s):  
Horng-Shyang Chen ◽  
Yu-Feng Yao ◽  
Che-Hao Liao ◽  
Charng-Gan Tu ◽  
Chia-Ying Su ◽  
...  

2000 ◽  
Vol 180 (1) ◽  
pp. 33-35 ◽  
Author(s):  
Y.-K. Song ◽  
M. Diagne ◽  
H. Zhou ◽  
A.V. Nurmikko ◽  
R.P. Schneider

2020 ◽  
Vol 22 (4) ◽  
pp. 651-657
Author(s):  
Javier Castilla-Gutiérrez ◽  
Juan Carlos Fortes ◽  
Jose Miguel Davila

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