• 한국유체기계학회 논문집
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• 제18권1호
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• pp.5-10
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• 2015

The "Ondong tunnel" is not used now where is one of the tunnels in the Janghang line which is from Cheonan to Iksan. The length of the tunnel is 214 m. The location of the fire source is center of the tunnel and the pool fire with heptane is for the fire source. Tests are carried out for the various fire sizes, the height and obstructed/open condition of the fire source. Temperature on the top of the tunnel is measured. Even if the fire size is same, the maximum temperature on the ceiling of the tunnel for the elevated fire source is very larger than the maximum for the ground fire source. As the fire size is lager the maximum temperature on the ceiling is higher. These test results can be very useful for design and guidelines of fire detectors in tunnels.

• Preventive Nutrition and Food Science
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• 제22권2호
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• pp.131-137
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• 2017

Maximum production of isoquercetin and quercetin simultaneously from rutin by subcritical water hydrolysis (SWH) was optimized using the response surface methodology. Hydrolysis parameters such as temperature, time, and $CO_2$ pressure were selected as independent variables, and isoquercetin and quercetin yields were selected as dependent variables. The regression models of the yield of isoquercetin and quercetin were valid due to the high F-value and low P-value. Furthermore, the high regression coefficient indicated that the polynomial model equation provides a good approximation of experimental results. In maximum production of isoquercetin from rutin, the hydrolysis temperature was the major factor, and the temperature or time can be lower if the $CO_2$ pressure was increased high enough, thereby preventing the degradation of isoquercetin into quercetin. The yield of quercetin was considerably influenced by temperature instead of time and $CO_2$ pressure. The optimal condition for maximum production of isoquercetin and quercetin simultaneously was temperature of $171.4^{\circ}C$, time of 10.0 min, and $CO_2$ pressure of 11.0 MPa, where the predicted maximum yields of isoquercetin and quercetin were 13.7% and 53.3%, respectively. Hydrolysis temperature, time, and $CO_2$ pressure for maximum production of isoquercetin were lower than those of quercetin. Thermal degradation products such as protocatechuic acid and 2,5-dihydroxyacetophenone were observed due to pyrolysis at high temperature. It was concluded that rutin can be easily converted into isoquercetin and quercetin by SWH under $CO_2$ pressure, and this result can be applied for SWH of rutin-rich foodstuffs.

• 한국기후변화학회지
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• 제6권2호
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• pp.87-94
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• 2015

To compare changes in winter temperature over South Korea, 30-year average climate data and climate data of recent 10 years (2014~2014) such as mean temperature, daily maximum temperature and daily minimum temperature were analyzed. Also, we set analysis extreme cold waves frequency related to winter such as freezing days, snow days, days with temperature of below -5, and days with temperature of below -10. This process enabled the comparative analysis of winter temperature changes and extreme cold waves frequency related to winter. This study estimated that winter temperature has gradually increased throughout the last five decades, however, the frequency of extreme weather, such as cold waves has also increased.

• 한국농림기상학회지
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• 제16권4호
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• pp.297-303
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• 2014

기온감률에 의한 고도보정만으로 표현되지 않는 산악지대의 한낮 기온 분포를 추정하기 위해 사면 일사효과모형이 사용되어왔으나 많은 경우 과다추정 경향이 나타났다. 그 원인을 찾고 기존 방법을 개선하기 위한 방안을 모색하기 위해 야외실험을 수행하였다. 경남 하동군 악양집수역의 고밀도 관측망으로부터 2012~2013년의 맑은 날 1500 기온, 1100-1500 적산일사량, 그리고 평균풍속자료를 수집하여 분석한 결과 고도보정 기온추정오차는 풍속과 높은 상관이 확인되었다. 이 결과를 토대로 일사효과모형을 풍속가중치에 의해 보정하는 간단한 방법을 도출하였다. 이 새로운 방법에 의해 2012-2013 기간 중 맑은 날에 대하여 악양집수역 내 10개 검증관측지점의 1500 기온을 추정하여 실측치와 비교하였다. 또한 기존 고도보정 추정치 및 일사효과모형 추정치와도 비교하였다. 그 결과 고도보정에 의한 추정치의 오차특성인 편기성과, 일사효과모형의 과다추정 경향이 새로운 방법에 의해 크게 개선되는 것을 확인할 수 있었다.

• Food Science and Biotechnology
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• 제14권6호
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• pp.836-840
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• 2005

Extraction characteristics of Bonus species of Brassica oleracea var. capita and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 44.07% was obtained at ratio of solvent to sample of 27.94 mL/g, ethanol concentration of 24.35%, and extraction temperature of $55.21^{\circ}C$. At ratio of solvent to sample, ethanol concentration, and extraction temperature of 21.11 mL/g, 58.53%, and $68.83^{\circ}C$, respectively, maximum electron-donating ability was 48.44%. Maximum inhibitory effect on tyrosinase was 68.94% at ratio of solvent to sample, ethanol concentration, and extraction temperature of 24.08 mL/g, 10.49%, and $78.71^{\circ}C$, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 24.78% at ratio of solvent to sample of 22.66 mL/g, ethanol concentration of 45.69%, and extraction temperature of $93.81^{\circ}C$. Based on superimposition of four-dimensional RSM with respect to extraction yield, electron-donating ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were ratio of solvent to sample of 20-30 mL/g, ethanol concentration of 35-65%, and extraction temperature of $50-80^{\circ}C$.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.77-80
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• 2002

Thermal analysis has been performed to evaluate the thermal effect on composite antenna (Ka-band) structure in space environment. The concepts of thermal control are also presented to maintain the antenna components within respective temperature limits. A steady-state algorithm of I-DEAS' thermal analysis software was utilized to predict both maximum and minimum temperature, maximum gradient temperature, and temperature distribution on each antenna component.

• Journal of Ecology and Environment
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• 제33권3호
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• pp.187-193
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• 2010

Seed germination is a biological process that is affected by a variety of genetic and environmental factors. The cardinal temperature and thermal time are required for germination. The principal objective of this study was to identify and characterize variations in the base, optimum, and maximum germination temperatures of Haloxylon aphyllum L. from two seed sources, in order to establish models for use in predicting seeding dates. Mature H. aphyllum seeds were germinated at temperatures between 5 and $35^{\circ}C$. The germination behavior of H. aphyllum seeds to different temperature regimens in light was evaluated over a temperature range of $5-35^{\circ}C$ at intervals of $5^{\circ}C$. The rate of germination increased between base and optimum thermal conditions, and decreased between optimum and maximum thermal conditions; the germination rate varied in a linear fashion at both sub-optimal and supra-optimal temperatures. The linear regression fit the range of germination rates at $5^{\circ}C$ to $25^{\circ}C$ and $25^{\circ}C$ to $30^{\circ}C$, and thus the base temperature, optimum temperature, and maximum temperature for the germination of H. aphyllum were measured to be $0.6^{\circ}C$, $25.69^{\circ}C$, $37.90^{\circ}C$, and $1.76^{\circ}C$, $21.56^{\circ}C$, $37.90^{\circ}C$ for Qom and the Fars dune desert respectively.

• 열처리공학회지
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• 제3권2호
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• pp.20-31
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• 1990

This investigation has been carried out to make clear the effect of deformation temperature, strain rate and grain size on the tensile properties of 304L stainless steel. Tensile properties of the metastable austenitic 304L steel remarkably influenced by deformation temperature. Tensile strength increased with decreasing deformation temperature and the elongation showed maximum value near $40^{\circ}C$. In order to obtain the high elongation, a large amount of deformation is available in austenite before martensitic transformation and the martensite has to be induced gradually. Tensile strength and elongation increased with decreasing grain size. The temperature representing the maximum elongation shifted to low temperature and the peak width of elongation became broaden with decreasing austenite grain size. The volume fraction of strain induced martensite decreased with decreasing austenite grain size. As the strain rate increase, the temperature representing the maximum elongation value shifted to high temperature and volume fraction of strain induced martensite decreased.

• 한국강구조학회 논문집
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• 제28권6호
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• pp.449-458
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• 2016

강박스거더교의 온도하중을 위한 유효온도를 산정하기 위하여, 강박스거더교의 시험체와 실교량에서 온도 데이터가 2년간 측정되었다. 이 실험체와 실교량의 온도 측정결과를 바탕으로 대기온도에 대한 최고 및 최저 유효온도를 2014년, 2015년, 그리고 연속 2년간 산정하였다. 산정된 최고, 최저 유효온도는 EURO code, 그리고 현행 도로교 설계기준과 서로 비교 평가되었다. 2년간(2 year) 측정한 데이터 기준으로 최대 유효온도와 Euro code의 결정계수는 교량 시험체에서 R=0.894, 실교량에서 R=0.927이 산정되며, 최저 유효온도는 교량 시험체에서 R=0.992, 실교량에서 R=0.813이 산정되었다. 또한 연구 결과는 도로교설계기준(한계상태설계법)의 최고온도와 유사하든가 약간 초과하는 것으로 평가되었다.

• 한국식품과학회지
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• 제23권2호
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• pp.157-160
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• 1991

냉동된 닭 가슴살 patty를 계육 가공공장으로부터 얻어서 내부온도가 $0{\pm}1.1^{\circ}C$가 되도록 조절하였다. Potentiometer에 연결된 thermocouple을 patty 중심에 삽입한 뒤 $168.3,\;179.4,\;190.6^{\circ}C$에서 튀겨 내부온도의 범위가 $48.9^{\circ}C$에서 $71.7^{\circ}C$가 되도록 하였다. 일반적으로 patty 내부온도는 튀김 솥(frier)에서 제거한 뒤 튀기는 온도나 내부온도와 관계없이 약 $11.1^{\circ}C$ 증가하였으며, 각각 다른 튀김온도에서 원하는 내부온도와 최종 내부온도는 튀기는 시간을 조절하므로써 얻을 수 있었다. 세 종류의 튀기는 온도에서 튀기는 시간이 독립변수인 3차 회귀다항식으로 시료 내부온도와 최종 내부온도를 예측하였고 최종 내부온도가 독립 변수인 2차 회귀다항식으로 수율을 예측하였다.