• 제목/요약/키워드: heat-stable

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PCB회로 보드장치내의 안정적 방열설계를 위한 연구 (The stable design of radiant heat inside PCB circuit board device)

  • 원종운;이종휘
    • 대한안전경영과학회지
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    • 제15권2호
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    • pp.129-134
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    • 2013
  • In this study, the heat flow analysis compatible commercial code CFX 11 was used to develop the structure inside PCB circuit board devices, which could stable radiant heat as well as the cooling device within it. In case of modifying the arrangement of electronic parts on the PCB inside the multi channel temperature measurement board devices, radiant heat effects did not show a rising tendency, whereas the overall temperature went down in case of installing the vents in the outer case of PCB circuit board devices. In terms of installation location, it was the most appropriate to install it on the electronic parts with no heat. Besides, in case of mounting the fan as a cooling device by considering various user environments for multi channel temperature measurement board devices, the radiant heat effects were shown higher than in case of installing the vents, and the middle sections were the most appropriate to its installation location. In case of changing the wind quantity of the fan from its selected installation location, the best radiant heat effects were shown at high speed as expected.

적층형 디지털송수신모듈의 방열특성 분석 (Analysis on Heat Dissipation Characteristics of a Tile-Type Digital Transmitter/Receiver Module)

  • 윤기철;김상운;허재훈;곽노진;김찬홍
    • 한국군사과학기술학회지
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    • 제22권2호
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    • pp.249-254
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    • 2019
  • A Digital Transmitter/Receiver Module(DTRM), which is an essential part in active phased-array radar systems, generates a high heat density, and needs to be properly cooled for stable operation. A tile-type DTRM that is a stacking structure of multi-layer components was modeled with simplification and heat dissipation characteristics of the DTRM model were studied using computational fluid dynamics(CFD) simulations. Most of the heat was dissipated by the heat conduction through the cold plate, but the heat transfer by the forced convection on top of the DTRM also was found to play an important role in the thermal management. Under the given conjugated heat transfer environment, the DTRM was confirmed to secure a stable operating temperature range.

Heat Stable Antifungal Component of Burkholderia cepacia CH-67

  • Lee, Kwang-Youll;Heo, Kwang-Ryool;Choi, Ki-Hyuck;Kong, Hyun-Gi;Kim, Dae-Wook;Lee, Seon-Woo;Moon, Byung-Ju
    • 한국생명과학회:학술대회논문집
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    • 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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    • pp.104.2-104.2
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    • 2007
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HEMAGGLUTINATION AND COLONY HYBRIDIZATION FOR THE IDENTIFICATION OF ENTEROTOXIGENIC Escherichia coli ISOLATED FROM HEALTHY PIG

  • Choi, S.H.;Oh, M.J.;Sung, C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권6호
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    • pp.671-677
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    • 1996
  • Erythrocytes from three different animal species were used to determine mannose-sensitive hemagglutination (MSHA) and mannose-resistant hemagglutination (MRHA) of 755 isolates obtained from rectal swabs of healthy pig. In addition, colony hybridization using digoxigenin-dUTP labeled polynucleotide probes was performed for the detection of heat-stable and heat-labile enterotoxin genes carried by MRHA positive isolates. Of 755 strains, 9, 4 and 28 strains gave a positive MRHA with bovine, equine and pig erythrocytes, respectively. Of these isolates, 28 (3.7%) were characterized for positive MRHA by at least one blood. Seven isolates gave a positive MRHA with two kinds of blood. Three gave a positive MRHA with three kinds of blood. Twenty-eight strains, while positive in MRHA, yielded negative signals in the colony hybridization assay for the detection of heat-stable (STaI and STaII) and heat-labile (LT) enterotoxin genes in E. coli.

저NOx형 하니컴 촉매버너의 개발 (Development of a low NOx burner with honeycomb catalyst)

  • 서용석;박병식;강성규
    • 대한기계학회논문집B
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    • 제21권6호
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    • pp.822-829
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    • 1997
  • A catalytic burner was studied which can be used as a heater operated in medium temperature. Noble metal catalysts (Pd/NiO) were used, which were supported on alumina wash coated honeycomb. The maximum heat-resisting temperature of the catalyst is about 900.deg. C. Combustion efficiency of the catalytic burner reached more than 99.5 % at the excess air ratio above 1.25.NOx emissions were lower than 1.0 ppm at all operation conditions. The operation condition for a stable catalytic combustion was obtained. It was dependent on the catalyst thickness. The 30 mm thick catalyst showed the widest stable catalytic combustion region. Stable catalytic combustion region of 30 mm thick catalyst was the operation condition of excess air ratio 1.25 - 1.75 and heat flux 7 - 14 kcal/h center dot cm$^{2}$.

Purification and Characterization of Peptidyl Prolyl cis-trans Isomerase (PPlase) from Bacillus stearothermophilus SIC1

  • KIM Dong-Ju
    • 한국수산과학회지
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    • 제28권6호
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    • pp.728-735
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    • 1995
  • The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

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메탄 과농-희박 예혼합화염의 안정화 메커니즘 (Stabilizing Mechanism for Methane Rich-Lean Flame)

  • 이원남;서동규
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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    • pp.19-24
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    • 2002
  • Recent studies of a triple flame suggested that the presence of triple point (triple line in this planar configuration) could explain the mechanisms of stable fuel-lean premixed flames with equivalence ratio lower than the flammability limit. In the present study, for better understanding of the stability mechanisms of fuel rich-lean premixed flames, the fuel-rich flames were replaced with hot coils that will provide heat flux into the fuel-lean flames. It is found that the fuel-lean premixed flames could be stabilized without any triple point (triple line): however, the equivalence ratio limit for stable fuel-lean flame in this case is higher than that of the present work with the presence of fuel-rich flames. These results demonstrate that heat flux coming from fuel-rich flames should be considered in order to properly understand the roll of a triple flame for stable fuel rich-lean flames.

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이어도 종합해양과학기지에서 관측된 난류 플럭스의 계절적 특성 (Seasonal Characteristics of Turbulent Fluxes Observed at leodo Ocean Research Station)

  • 오현미;하경자;심재설;현유경;윤경숙
    • 대기
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    • 제17권4호
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    • pp.421-433
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    • 2007
  • We have investigated the seasonal characteristics of surface turbulent fluxes observed at Ieodo Ocean Research Station from 2005 to 2006. Both 10Hz and 30 minutes flux data are quality controled, and tilt correction is performed in 10Hz data before quality control. The turbulent fluxes of open sea shows clear seasonal variations, though diurnal variations are barely shown. The seasonal ratio of stable and unstable conditions are closely related to the temperature difference between sea surface and air. In stable and semi-stable condition, latent and sensible heat fluxes have very small values without any relationship with wind speed. Though friction velocity shows slightly increasing trend with wind speed, it has many outliers. In unstable condition, turbulent fluxes increased with wind speed. Especially, latent heat flux increased rapidly during DJF. The latent heat flux at high wind speeds is more scatter.

A Highly Sensitive Indirect Enzyme-Linked Immunosorbent Assay (ELISA) Based on a Monoclonal Antibody Specific to Thermal Stable-Soluble Protein in Pork Fat for the Rapid Detection of Pork Fat Adulterated in Heat-Processed Beef Meatballs

  • Sol-A Kim;Jeong-Eun Lee;Dong-Hyun Kim;Song-min Lee;Hee-Kyeong Yang;Won-Bo Shim
    • 한국축산식품학회지
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    • 제43권6호
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    • pp.989-1001
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    • 2023
  • Processed foods containing pork fat tissue to improve flavor and gain economic benefit may cause severe issues for Muslims, Jews, and vegetarians. This study aimed to develop an indirect enzyme-linked immunosorbent assay (iELISA) based on a monoclonal antibody specific to thermal stable-soluble protein in pork fat tissue and apply it to detect pork fat tissue in heat-processed (autoclave, steam, roast, and fry) beef meatballs. To develop a sensitive iELISA, the optimal sample pre-cooking time, coating conditions, primary and secondary dilution time, and various buffer systems were tested. The change in the iELISA sensitivity with different 96-well microtiter microplates was confirmed. The detection limit of iELISA performed with an appropriate microplate was 0.015% (w/w) pork fat in raw and heat-treated beef. No cross-reactions to other meats or fats were shown. These results mean that the iELISA can be used as an analytical method to detect trace amounts of pork fat mixed in beef.

수용성비타민과 지용성비타민의 가열에 대한 안정성 (The Stability of Water-soluble and Fat-soluble vitamin in milk by Heat treatments)

  • 허정윤;황인경
    • 한국식품조리과학회지
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    • 제18권5호
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    • pp.487-494
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    • 2002
  • This study was conducted to investigate the thermal stability of water-soluble and fat-soluble vitamins dissolved in water and milk by various heat treatments. Vitamin samples were prepared by dissolving them in water and milk at various concentrations, and were heat treated for 30 min at 65$\^{C}$, 15 sec at 85$\^{C}$, 5 sec at 100$\^{C}$, 121$\^{C}$ at 15 min, the levels of residual vitamin were measured by using HPLC. Milk samples were fortified with vitamins before and after UHT treatment. As heating over 100$\^{C}$, riboflavin in water were destructed more than 92% but fortified in milk showed less than 20% destruction, suggesting that riboflavin was protected by milk components. Also retinol heated ever 100$\^{C}$ was more stable in milk than in water. L-Ascorbic acid and cholecalciferol(D$_3$) showed a similar destruction rate in water and in fortified milk. L-ascorbic acid was easily destructed by UHT treatment. Destruction of thiamin and tocopherol was increased in fortified milk. Among tour capsulated water-soluble vitamins, L-ascorbic acid was much more stable compared with powder form. Nicotinic acid and folic acid either in capsule or powder form showed a slight destruction by heat treatment. The results suggested that the fortification of unstable vitamins such as L-ascorbic acid, thiamin, tocopherol and cholecalciferol(D$_3$) should be made in milk after heat treatment.