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Yan Lai Nicolás Cordero Frank Barthel Frank Tebbe Jörg Kuhn Robert Apfelbeck Dagmar Würtenberger 《Applied Thermal Engineering》2009,29(5-6):1239-1244
With the advances in the technology of materials based on GaN, high brightness white light emitting diodes (LEDs) have flourished over the past few years and have shown to be very promising in many new illumination applications such as outdoor illumination, task and decorative lighting as well as aircraft and automobile illuminations. The objective of this paper is to investigate an active liquid cooling solution of such LEDs in an automotive headlights application. The thermal design from device to board to system level has been carried out in this research. Air cooling and passive liquid cooling methods were investigated and excluded as unsuitable, and therefore an active liquid cooling solution was selected. Several configurations of the active liquid cooling system were studied and optimisation work was carried out to find an optimum thermal performance. 相似文献
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Schoder D Winter P Kareem A Baumgartner W Wagner M 《The Journal of dairy research》2003,70(4):395-401
We describe a case of listerial mastitis in a flock of 130 sheep. The animals were housed at a farm where the bulk raw ewe milk was processed to produce raw milk soft cheese. List. monocytogenes was shed from the right mammary complex. Shedding was observed over a period of 99 d. A mean level of 4-56 x 10(4) cfu (colony forming units) Listeria monocytogenes/ml was recovered from the raw milk originating from the infected udder. The numbers ranged from 9 x10(1) to 2.95 x 10(5). The bulk milk was contaminated by approx. 5.7 x 10(3) cfu/ml. In the cheese product, 2.0 x 10(2) cfu List. monocytogenes/g were constantly detectable for a period of 7 d post manufacture. The starter culture used for coagulation had a pivotal influence on the behaviour of List. monocytogenes during cheesemaking. Using the same mesophilic buttermilk culture as used by the farmer allowed numbers of Listeria to increase 60-fold within 12 h owing to a delayed acidification of the bulk milk. Addition of a thermophilic yogurt culture reduced the numbers of Listeria within 8 h of incubation. 相似文献
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Sameepa Poongavalappil Petr Svoboda Rajesh Theravalappil Dagmar Svobodova Michal Danek Martin Zatloukal 《应用聚合物科学杂志》2013,128(5):3026-3033
Ethylene‐octene copolymer (EOC) was irradiated using electron beam irradiation at different dosages (30, 60, 90, and 120 kGy). Effect of irradiation dosage on thermal and mechanical properties was studied. When compared to low density polyethylene, EOC exhibited higher degree of crosslinking reflected in increased gel content, higher elastic modulus (G′), and lower tan δ obtained by rheology measurement at 150°C. Crosslinking caused improvement in high‐temperature creep and room temperature and also elevated temperature elastic properties. Differential scanning calorimetry revealed that e‐beam irradiation has caused a gradual reduction in crystallinity and a presence of a fraction with higher melting temperature. In the case of EOC, as the extent of crosslinking increased, stress at break showed an increasing trend whereas irradiation dosage had an inverse effect on elongation at break. Radiation dosage has positive effect on thermal stability estimated by thermogravimetric analysis. After 30 min of thermal degradation at 220°C, slightly higher C?O peak for crosslinked sample was found by Fourier transform infrared spectroscopy while for room temperature samples no C?O peak was detected. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Horňáková Natália Jurík Lukáš Hrablik Chovanová Henrieta Cagáňová Dagmar Babčanová Dagmar 《Wireless Networks》2021,27(3):1683-1691
Wireless Networks - The paper deals with handling equipment that can be used to transport/handle the final products in a selected industrial enterprise. The suitable handling equipment listed in... 相似文献
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Mobile Networks and Applications - New solutions are more and more needed due to the fact that new trends in technology, communication, global knowledge, new managerial approaches, building new... 相似文献
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Firas J. Hmood Janka Wilbig Dagmar Nicolaides Andrea Zocca Jens Günster 《Ceramics International》2021,47(14):20045-20050
This study suggests a tool for a better control on the sintering/crystallization of 3D-printed bioactive glass-ceramics bodies. A small cantilever in form of a bar with square cross section attached to a base and inclined 34° with the horizon, was used to monitor the viscous flow and sintering/crystallization headway of a glass-ceramic systems. 3D printing and sintering of bioactive glass-ceramics is of great interest for medical care applications. Viscous flow ensures sufficient densification of the typically low density printed green bodies, while crystallization prevents the structure from collapsing under the gravitational load. As a model system, a bioactive glass called BP1 (48.4 SiO2, 1 B2O3, 2 P2O5, 36.6 CaO, 6.6 K2O, 5.6 Na2O (mol%)), which has a chemical composition based on that of ICIE16, was employed in this work. In addition, ICIE16 was used as a reference glass. The results show that the suggested design is a very promising tool to track the real-time deformation of 3D printed glass-ceramic specimens and gives a good indication for the onset of crystallization as well. 相似文献