Does Light Color Temperature Influence Aspects of Oviposition by the Black Soldier Fly (Diptera: Stratiomyidae)?

2020 ◽  
Vol 113 (5) ◽  
pp. 2549-2552
Author(s):  
Patrick Klüber ◽  
Daniel Bakonyi ◽  
Holger Zorn ◽  
Martin Rühl

Abstract In recent years, black soldier fly, Hermetia illucens (L.), larvae have attracted increasing attention because of their high capacity for bioconversion of diverse organic material into high-quality protein and lipids. Although previous studies have focused on optimization of breeding conditions, such as the acceptance of substrates, and temperatures and moisture contents, little is known about light-dependent adult development. Artificial light sources are important to commercial H. illucens breeding, especially at latitudes with short days in autumn and winter months. We examined how 3,000, 4,000, and 6,500 K color temperatures affect aspects of oviposition. Mating occurred under all of the broad spectrum light-emitting diode panels, resulting in fertilized egg clusters. Oviposition lasted up to 15 d, while the shortest oviposition period, in the 3,000 K light treatment, was 2 d. Total oviposition performance and oviposition period were not affected by the light treatments. Oviposition peaked 1–7 d after eggs were first deposited. The time until oviposition peaked was positively correlated with increasing color temperature.

Author(s):  
John D. Bullough ◽  
Yi-wei Liu

Airfield lighting for runways and taxiways is currently undergoing a transition from filament-based incandescent sources to light emitting diodes (LEDs). Although models to assess the relative brightness, discomfort glare, and peripheral detectability of signal lights such as those used for aviation exist, their applicability to white LED airfield lighting has not been verified independently. A series of three experiments was conducted to compare white LED sources, having correlated color temperatures of 2,700 K and 5,900 K, in terms of their relative brightness, discomfort glare, and peripheral detectability. The perceived brightness and discomfort glare from the light sources closely matched predictions from the published models, demonstrating the usefulness of these models at characterizing these responses in airfield lighting. In the case of peripheral detectability, there was little to no difference in how quickly the two LEDs were perceived at low light levels, suggesting that there is no need to consider spectral differences between light source spectra for this response when the intensities are similar to those used in the present study.


2020 ◽  
Vol 11 (1) ◽  
pp. 74
Author(s):  
Jeungmo Kang ◽  
Yoonhee Cho ◽  
Woojin Jang

Organic light-emitting diode is one of the future-proof solid-state-based lighting sources. OLED shows great aesthetic advantages and good color quality without glare. Moreover OLED is a kind of surface light sources naturally. There are some studies on the long-term reliability characteristics of OLED light source. However, these studies focused on the light output degradation of OLED light sources mainly. In this paper, we have investigated the long-term reliability characteristics of OLED panel and luminaires in terms of lumen maintenance, correlated color temperature, color rendering index, and operating voltage. Total twelve OLED panels with four different kinds and six OLED luminaires with two different kinds were analyzed up to six thousand hours and analyzed for the general lighting applications.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Mingming Jiang ◽  
Fupeng Zhang ◽  
Kai Tang ◽  
Peng Wan ◽  
Caixia Kan

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...


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 209
Author(s):  
Gopi Chandra Adhikari ◽  
Saroj Thapa ◽  
Yang Yue ◽  
Hongyang Zhu ◽  
Peifen Zhu

All-inorganic lead halide perovskite (CsPbX3) nanocrystals (NCs) have emerged as a highly promising new generation of light emitters due to their extraordinary photophysical properties. However, the performance of these semiconducting NCs is undermined due to the inherent toxicity of lead and long-term environmental stability. Here, we report the addition of B-site cation and X-site anion (pseudo-halide) concurrently using Ba(SCN)2 (≤50%) in CsPbX3 NCs to reduce the lead and improve the photophysical properties and stability. The as-grown particles demonstrated an analogous structure with an almost identical lattice constant and a fluctuation of particle size without altering the morphology of particles. Photoluminescence quantum yield is enhanced up to near unity (~98%) by taking advantage of concomitant doping at the B- and X-site of the structure. Benefitted from the defect reductions and stronger bonding interaction between Pb2+ and SCN− ions, Ba(SCN)2-based NCs exhibit improved stability towards air and moisture compared to the host NCs. The doped NCs retain higher PLQY (as high as seven times) compared to the host NCs) when stored in an ambient atmosphere for more than 176 days. A novel 3D-printed multiplex color conversion layer was used to fabricate a white light-emitting diode (LED). The obtained white light shows a correlated color temperature of 6764 K, a color rendering index of 87, and luminous efficacy of radiation of 333 lm/W. In summary, this work proposes a facile route to treat sensitive lead halide perovskite NCs and to fabricate LEDs by using a low-cost large-scale 3-D printing method, which would serve as a foundation for fabricating high-quality optoelectronic devices for near future lighting technologies.


2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu

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.


2019 ◽  
Vol 108 (3) ◽  
pp. 1172-1176 ◽  
Author(s):  
Leonardo R. Allain ◽  
Brittany C. Pierce ◽  
W. Peter Wuelfing ◽  
Allen C. Templeton ◽  
Roy Helmy

2015 ◽  
Vol 15 (10) ◽  
pp. 7578-7581
Author(s):  
Jung-Kab Park ◽  
Jin-Ha Shin ◽  
Mun-Gi Jung ◽  
Tomabechi Shigehisa ◽  
Hwa-Sun Park ◽  
...  

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.


2010 ◽  
Vol 30 (8) ◽  
pp. 2412-2416 ◽  
Author(s):  
董伟 Dong Wei ◽  
原遵东 Yuan Zundong ◽  
卢小丰 Lu Xiaofeng

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