• 한국식생활문화학회지
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• 제23권1호
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• pp.26-32
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• 2008

: In this experiment, three samples of oils were used. These oils were hydrated soybean oil, pure soybean oil and regular soybean oil. Oil was used after heating at $235-240^{\circ}C$ every four hours term and total heating hours was 16 hours. The physio-chemical analysis and sensory evaluation were performed on these oils. The hydrated soybean oil showed lower acid, peroxide and carbonyl value than the other two oils (p<0.05 or p<0.001). The other two oils were more affected in rancidity than the hydrated soybean oil. In color test, whereas L value lowed during the heating time, a and b value increased during the heating time. The tendency of high L value and low b value in a long-time heating was more apparant on the pure soybean oil and the regular soybean oil than on the hydrated soybean oil (p<0.05). In sensory evaluation, color and rancidity order increased during the heating time. The hydrated soybean oil showed color and rancidity order than the other two oils. In overall quality test, the pure and regular soybean oil that had been used for 12 and 16 hour were not preferable. The hydrated soybean oil that had been used for 16 hour were not preferable. In sensory evaluation, the hydrated soybean oil, the pure and regular soybean oil did not show a apparent difference, although the hydrated soybean oil had a little better scores on the overall quality.

• Journal of Nutrition and Health
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• 제11권3호
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• pp.25-30
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• 1978

A study was planned to evaluate the influence of continual heating at $150{\pm}5^{\circ}C$ and $170{\pm}5^{\circ}C$ respectively upon edible oils for frying the several food. Two kinds of domestic edible oils (Sample A and B) were collected by random sampling from market and in order to estimate deterioration degrees at both temperatures previously mentioned, thiobarbituric acid (TBA) value, acid value (AV), peroxide value (POV) and carbonyl value (CV) were measured at intervals due to its optical density. Those values were examined and compared according to the temperatures and times, and it was concluded as follows: 1) TBA value was rapidly increased until 24 hours in both temperatures and after 1 day its value have shown a slower increase as compared with initial rapid reaction. 2) Acid value and peroxide value of both oils (A & B) used for frying were increased continuously during heating and the changes in these values were dependent on the thermal oxidation, and moreover at low temperature $(150{\pm}5^{\circ}C)$ these values were found to be increased more readily than at high temperature $(170{\pm}5^{\circ}C)$. 3) Carbonyl value of both sample A and B show almost the same increasing rate at either $150{\pm}5^{\circ}C$ or $170{\pm}5^{\circ}C$ in proportion to the heating time. 4) It was found that there were differences between the chemical changes caused by heating sample A and B at high and low temperature.

• 한국산학기술학회논문지
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• 제11권1호
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• pp.234-241
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• 2010

사업장 가연성폐기물은 그 자체의 높은 발열량(3,000kcal/kg 이상)으로 인해 고형연료 원료로 매우 유용하게 사용할 수 있다. 현재 국내 대부분의 고형연료 제조업체는 제조가 쉽고 발열량이 높은 필름류 플라스틱을 주로 사용하고 있기 때문에 본 연구에서는 보다 다양한 폐기물을 이용하여 고형연료 제조 가능성을 알아보았다. 실험에 사용된 폐기물 중에서 폐합성수지, 폐타이어로 제조된 고형연료는 발열량이 6,000kcal/kg 이상을 나타내었으며 폐지, 폐목재가 혼합될 경우 발열량은 감소하였다.

• 한국태양에너지학회 논문집
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• 제30권4호
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• pp.49-54
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• 2010

Most energy using in building part is mainly consumed for heating and cooling to meet occupancy's comfort temperature. Generally, heating energy consumption show high value than cooling energy in Korea because of high temperature difference in winter season as compared with summer in apartment building. The efforts to develope mechanical performance have been studied to reduce energy consumption in building energy field until now. However, the energy consumption in building is impacted by not only system performance but also PMV particularly at temperature and Clo value. This means that energy consumption can be changed by occupancy's comfort setting temperature in apartment building. This study investigated the passibility of overheating in apartment building by occupant' slow Clo and its setting temperature from preceding research and then the heating energy consumption by setting temperature was calculated with ESP-r. The effects of heating energy and $CO_2$ reduction are also evaluated quantitatively with Clo value. The results showed that keeping ISO-7730 standards can reduce heating energy up to 21% in compared with option 2; also, wearing underclothes with ISO-7730 standard can considerably reduce heating energy consumption up to 50%. As compared with option 2, the reduction of $CO_2$ emission for option 3 showed 0.63TCO2 of kerosene, 0.49TCO2 of LNG and 1.09TCO2 of electricity. The option 4 can be reduced by 1.48TCO2 of kerosene, 1.16TCO2 of LNG and 2.57TCO2 of electricity respectively.

• Journal of Ginseng Research
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• 제22권3호
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• pp.193-199
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• 1998

The purpose of this study was to Investigate characteristics of the water soluble browning reaction products (WS-BRPs) from Korean red ginseng by heat treatment. Absorbance of WS- BRPs was increased with increases of heating temperature and time, but pH value were decreased In Muter color value L and b value were decreased, while a value was increased. and absorbance at 280 nm in spectrum of the WS-BRPs was increased according to the increase of heating temperature. When the WS-BRPs were applied on Bio-Gel P-30 column after heating and pH treatment, two majors browning products increased according to the progress on time. And pH 3.0 increased in quantity of high molecular fractions and pH 8.0 increased in quantity of low molecular fractions.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.106-111
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• 2001

This paper is a study on the heat generation characteristics of the carbon heating source with high temperature. The main variables of this study are the input current and the amount of carbon heating source. As the results of the experiment in the waste rate of carbon heating source. The case of carbon heating source 300g was large than 500g. As the input current and the temperature are increased, the resistance values of carbon heating source were large. The Joule heat was represented the large value as the amount of heating source decrease with the input current. Finally, the heating source was represented the electrical steady state as the input current is increase.

• 공업화학
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• 제20권4호
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• pp.411-415
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• 2009

고점도인 최저급 폐유를 난방유로 대체하기 위하여 폐유에 희석용제로 경유,벙커C유를 이용하여 일정비율로 혼합한 후 연료 특성을 분석하였다. 혼합조건은 교반속도 3400~3600 rpm에서, 반응 시간을 30 s~30 min으로 조절하였고 반응온도는 $75{\pm}5^{\circ}C$로 유지하였다. 벙커C유, 경유를 이용하여 폐유의 점도를 낮춘 결과 최소 81%, 최대 96% 정도 감소되었다. 난방연료로서 폐유 : 벙커C유 : 경유의 최적 혼합 비율은 1 : 1 : 1이었으며 이 경우 인화점 $78^{\circ}C$, 동점도 $20.02mm^{2}/s$, 발열량 9158 kcal/L을 가짐을 확인하였다.

• Advances in concrete construction
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• 제4권1호
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• pp.1-14
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• 2016

In this study, high performance concrete beams and prisms with high content of PFA were heated to various temperatures up to $450^{\circ}C$ at heating rates of $1^{\circ}C/min$, $3^{\circ}C/min$ and $10^{\circ}C/min$. The thermal gradient was found to increase first with the heating time until a peak value was reached and then decrease until the thermal equilibrium was reached, measured as $115^{\circ}C$, $240^{\circ}C$ and $268^{\circ}C$ for the three heating rates. Spalling occurred on some specimens when the heating temperature was over $400^{\circ}C$ for heating rates of $3^{\circ}C/min$ and $10^{\circ}C/min$. The hygric gradient was found to reach its maximum when the thermal gradient reached its peak. This study indicates that spalling of HPC could happen when the heating temperature was high enough, and both thermal and hygric gradients reached their maxima.

• 한국농공학회논문집
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• 제53권2호
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• pp.61-65
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• 2011

Biomass is considered to be a major potential fuel and renewable resource for the future. In fact, there is high potential to produce the large amount of energy from biomass around the world. In this study, to obtain basic data for practical application of agricultural and forest by-products as fuel of heating system in agriculture, agricultural and forest biomass resources were surveyed, the pelletizer with capacity of $50\;kg{\cdot}h^{-1}$ was designed and manufactured and pellets were made by the pelletizer. High heating value, ash content, etc. of pellets made of agricultural and forest by-products were estimated. Straw of rice was the largest agricultural biomass in 2009 and the total amount of rice straw converted into energy of $299{\times}10^3$ TOE. And in 2009, amount of forest by-product converted into energy of $9,579{\times}10^3$ TOE. High heating values of pellets made of stem and seed of rape, stem of oat, rice straw and rice husk were 16,034, 16,026, 16,089, 15,650, $15,044\;kJ{\cdot}kg^{-1}$ respectively. High heating values of pellets made of agricultural by-products were average 83.6% compared to that of wood pellet. Average bulk density of pellets made of stem and seed of rape, stem of oat, rice straw and rice husk was $1,400\;kg{\cdot}m^{-3}$ ($1.4\;g{\cdot}cm^{-3}$). Ash contents of the pellets were 6.6, 7, 6.2, 5.5, 33% respectively. Rice husk pellet produced the largest ash content compared to other kinds of pellets.

• 한국환경과학회지
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• 제19권1호
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• pp.9-16
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• 2010

This pilot study evaluated fueling feasibility of sewage sludge, which contains a large amount of water content, by applying melting of thermoplastic polyethylene (PE). This study has identified a simultaneous achievement of drying and heating value improvement of the sewage sludge. The sewage sludge collected from a sewage sludge treatment plant during a winter period had a water content of 83.7 wt%, a combustible volatile content of 12.5 wt%, and an ash content of 3.8 wt%. The higher heating value (HHV) of the dried sewage sludge, before impregnation or coating of PE, was 4,600 kcal/kg. The collected sewage sludge was immersed into the melted PE solution, which had a HHV of 11,070 kcal/kg, and kept immersing with increasing reaction time. As the reaction (immersing or coating or impregnation) time increased, the water content of the sludge decreased. However, the HHV of the sludge increased with increasing the reaction time. The HHVs of the sewage sludge immersed or dipped into the melted PE solution for 15 min ranged from 6,780 to 8,170 kcal/kg with water content less than 7 wt%. This result indicates the melted PE solution can be utilized as an improvement technology for dryness and heating value of the sewage sludge with high water content. The sewage sludge impregnated or coated with melted PE can be utilized as potential fuel or energy resources.