• 생물환경조절학회지
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• 제28권4호
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• pp.335-341
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• 2019

본 연구는 난방온실의 온도분포 균일화를 위한 기초자료 제공을 목적으로 온수난방 방식의 토마토 재배 온실에서 난방실험을 통하여 난방배관의 표면온도와 실내기온 사이의 상관관계를 분석하고, 난방배관의 열전달특성 분석과 난방배관 배치의 개선을 통하여 난방배관 표면온도의 편차를 줄이고 균일도를 향상시키기 위한 방안을 도출하였다. 서로 다른 두 온실의 온도분포를 분석하여 최대편차와 균일도를 검토한 결과, 온수의 유량이 많고 난방배관의 길이가 짧게 배치된 온실의 온도편차가 작고, 균일도는 높은 것으로 나타났다. 또한 순환팬을 가동한 경우에 온도편차는 작아지고 균일도가 개선되는 것을 확인할 수 있었다. 난방배관의 표면온도와 실내기온 사이의 상관관계를 분석한 결과, 두 온실 모두에서 유의적인(p<0.01) 정적 상관관계가 있는 것으로 나타났다. 온수난방 온실에서 실내기온의 분포는 난방배관 표면온도의 분포에 영향을 받는다는 것을 확인할 수 있었고, 온도편차가 최소화 되도록 난방배관을 배치함으로써 실내기온 분포의 균일도를 개선할 수 있는 것으로 판단되었다. 난방배관의 열전달 특성을 분석한 결과 배관의 길이가 길어지면 온도편차는 커지고, 관내의 유속이 빨라지면 온도편차는 작아지는 것으로 나타났다. 따라서 지선배관의 길이가 짧아지도록 난방배관을 배치하고, 관내의 유속을 제어함으로써 온실의 온도분포와 환경의 균일성을 개선할 수 있을 것으로 판단되었다. 국내 온실에서 가장 많이 사용하고 있는 튜브레일(40A) 방식의 온수난방시스템에서 하나의 지선배관에서의 온도편차를 $3^{\circ}C$ 이내로 조절하기 위해서는 관내의 유속이 0.2, 0.4, 0.6, 0.8, $1.0m{\cdot}s^{-1}$일 때 난방배관의 길이는 각각 40, 80, 120, 160, 200m 이내로 제한해야 하는 것으로 분석되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.817-820
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• 2001

This machine is a high-vacuum exhaust sealing device which makes the inside of PDP element in high vacuum state, blows inactive gases into it and finally seals it. This machine consists of vacuuming parts, heating parts and exhausting parts. Applying the energy saving technology, this machine improves the temperature uniformity of vacuuming and heating parts.

• Elastomers and Composites
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• 제32권5호
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• pp.318-324
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• 1997

Since the rigid and continuous networks of high-purity silica(white carbon) were relatively transparent to microwaves, high purity silica coupled with microwaves using a zirconia susceptor at room temperature and it was then heated to its melting temperature. The low-purity silica, contained small amount of impurities, yielded greater microwave absorption owing to easy motion of the interstitial alkali ions and it was then heated to its melting temperature. X-ray diffraction patterns of the low-purity silica were broader than those of the high-purity silica due to higher concentration of non-bridging bond and more deformed random network structure. In the vulcanization process of whitened or coloured rubber compound which is employing low-purity silica(white carbon) as a reinforcing filler, vulcanizate could be obtained effectively by microwave heating energy.

• 태양에너지
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• 제12권1호
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• pp.88-94
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• 1992

태양광 고온가스가열 장치를 위하여 후레넬렌즈면적 $0.5m^2$을 갖는 소형태양집열 및 추적시스템과 고급의 소형 밀폐형 유동층 태양광 수열기를 개발하였다. 개발된 태양광 수열기는 개방형 유동층의 단점인 SiC입자의 유출과 열사이폰효과를 개선하였다. 공기의 최대 도달온도는 1140K이며, 최대 열효율은 64%얻어졌다. 본 연구에서 개발한 태양광수열기는 기존의 평판이나 관형의 고체표면을 갖는 태양 집열기와 비교할 때 아주 고온에서 효율 좋게 작동된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.70-73
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• 2006

In the present study, the flow-softening behavior occurring during high temperature deformation of AZ31 Mg alloy was investigated. Flow softening of AZ31 Mg alloy was attributed to (1) thermal softening by deformation heating and (2) microstructural softening by dynamic recrystallization. Artificial neural networks method was used to derive the accurate amounts of thermal softening by deformation heating. A series of mechanical tests (High temperature compression and load relaxation tests) was conducted at various temperatures ($250^{\circ}C{\sim}500^{\circ}C$) and strain rates ($10^{-4}/s{\sim}100/s$) to formulate the recrystallization kinetics and grain size relation. The effect of DRX kinetics on microstructure evolution (fraction of recrystallization) was evaluated by the unified SRX/DRX (static recrystallization/dynamic recrystallization) approaches

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1226-1231
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• 2009

This paper presents operating characteristics of internal heat exchanger(IHX) for $CO_2$ geothermal heat pump in the heating mode. Mass flow rate of $CO_2$, inlet temperatures of $CO_2$ at high and low pressure side were selected as main effect factors by using fractional factorial DOE(Design of Experiments). And RSM(Response Surface Method) was used in optimization phase. The results show that heat transfer rate of IHX increases when either inlet temperature of low pressure side decreases or inlet temperature of high pressure side increases. Effectiveness of IHX increases with increasing of inlet temperature of either high pressure side or low pressure side. Finally, performance contour map was provided over the operation ranges of the main design factors.

• Preventive Nutrition and Food Science
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• 제21권4호
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• pp.338-347
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• 2016

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G', G") of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1866-1870
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• 2019

Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, $LiNO_3-ZrO_2$ and $LiCl-ZrO_2$ mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation.

• 미생물학회지
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• 제9권4호
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• pp.155-162
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• 1971

A comparison of dextrinogenic amylase activities in the Asp. niger group was made with their crude and ethanol dialized enzymes before and after heating at high temperature (60-$65^{\circ}C$). The results obtained are as follows ; 1. THe dextrinogenic amylase activity of crude enzymes of Asp. kawachii and Asp. foetidus was strong, but Asp. phoernicis, Asp. carbonarius and Asp.japonicus showed weak activity. The others showed medial grades of activity. 2. The ethanol dialized enzymes of Asp. kawachii, Asp. foetidus and Asp. japonicus was very sesitive to high temperature (60 or $65^{\circ}C$) and their enzymatic activities were diminished greatly. The others did not show diminution of enzymatic activity at 60 or 65.deg.C, but diminished greatly at 70 or $75^{\circ}C$. 3. The ethanol dialized enzymes of the Asp.niger group heated to 65.deg.C was more sensitive at pH 6.0 and 6.5 than at pH 4.5, 5.0 and 5.5. 4. Tested strains in the Asp.niger group were subdivided into 4 subgroups by their dextrinogenic amylase activities before and after heating at 60 or $65^{\circ}C$. The first group showed a medial grade of activity before heating and no diminution of their enzymatic activities after heating. Asp. niger, Asp.pulverulentus, Asp. awamori and Asp. usmii were included in this group. The second group had strong enzymatic activity before heating, but diminished greatly after heating. Asp rawachii and Asp. phoenicis were included in this group. The fourth group showed very weak enzymatic activity before heating, and was inactivated easily by heating. Asp.oryzae of the Asp. flavus group showed a very strong dextrinogenic amylase activity before heating. After the heat treatment, however, its enzymatic activity was diminished greatly.

• 소성∙가공
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• 제20권6호
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• pp.439-449
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• 2011

The temperature distribution and subsequent permanent deformation of SS400 carbon steel plate subjected to an induction-based line heating process were studied by a numerical method involving coupled 3-D electromagnetic-thermal-structural analysis. The numerical study revealed that the amount of permanent deformation is strongly related to the Joule loss caused by such process conditions as input power and moving speed of the heat source. To validate the numerical analysis results, line heating experiments were carried out with a high frequency(HF) induction heating(IH) equipment capable of bending thick plate with the moving accuracy of ${\pm}0.1mm$ in heating coil position. The amount of permanent deformation increased with decreasing moving speed and increasing input power.