• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4375-4380
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• 2015

This study was performed to evaluate a newly proposed heating process of blank, which was used for Crank throw in the diesel engine, and provide design guidelines of heating processes. Non-linear numerical analyses were done using ANSYS program to investigate temperature and thermal stress distributions of blank during heating processes. The heating process consists of two stages; one is a heating stage with 20 hours, and the other is a holding stage with 12 hours, totaling 32-hour heating time. Based on analysis results, it was found that the temperature difference between the center and the surface of blank increased linearly during the heating stage but decreased gradually during the holding stage of heating processes, while max. equivalent stress, $12.5kg/mm^2$, was found at the center of blank after 10-hour heating time. As the guideline of blank heating process, it was recommended to keep the temperature difference between the center and the surface of blank to be within $150^{\circ}C$ when the environment temperature in furnace reaches $650^{\circ}C$ during a heating stage.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04a
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• pp.44-44
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• 1999

전적으로 해외기술에 의존하고 있는 소프트 닙 캘린더 피복의 국산화를 위해 시험 제작 된 소프트 닙 캘린더용 연질롤의 캘린더링 효과를 구명하기 위해서 공정 변수에 따른 신문 용지의 물성변화를 평가하였다. 연질 롤로는 (주)광성고무롤에서 시험제작된 경도 90 Shore D의 것을 사용하였으며, 캘린 더링 시의 압력, 가열 롤의 표면온도, 닙 체류 시간, 유입지의 함수율 변화에 따른 신문용지 의 별크, 평활도, 광택도, 인장강도, 인열강도, 불투명도 변화를 조사하였다. 별크는 캘린더링 시 압력, 가열 롤의 표면온도, 닙 체류시간의 증가에 따라 감소하였다. 가열 롤의 표면온도가 높을수록 별크가 크게 감소되었으며, 닙 체류시간이 짧은 경우에는 1 120 226;C 이하에서 캘린더링을 실시하는 것이 별크 유지에 효과적이었다. 평활도는 가열 롤의 표연 온도, 닙 체류시간이 증가함에 따라 개선되었으며, 선압과 함 수율 증가에 의해서도 상승되는 경향을 보였. 인장강도는 유입지의 함수율, 닙 체류시간, 가열 롤의 표면온도가 모두 상승할 경우 증 가하는 결과를 나타내었다. 이는 함수율 증가에 의해 섬유의 유연성이 향상된 상태에서는 칼렌더링 온도와 닙체류 시간 증가에 의한 섬유의 기계적 변형과 열전달에 의한 섬유의 열 변형이 효과적으로 발생하여 섬유간 결합면적이 증가된 결과로 생각되었다. 인열강도는 소프트닙 캘린더링 후 전반적으로 감소하였으나 캘린더링 온도와 닙체류시 간은 인열강도에 미치는 영향은 적은 것으로 나타났다. 소프트 닙 캘린더링 시 발생하는 인 열강도의 저하를 막기 위해서는 닙 체류시간을 짧게 적용하고 섬유의 열변형이 종이의 표변 에서만 일어날 수 있도록 유입지 함수율과 가열롤의 표면온도를 적절히 조절하는 것이 필요 하리라 판단되었다.광택도는 온도와 압력이 증가할수록 증가하였으나, 닙 체류시간에 따라서는 큰 변화를 나타내지 않았으며 120도씨에서는 닙 체류시간의 증가에 따라 광택도가 오히려 감소하기도 하였다. 불투명도는 벌크와 마찬가지로 압력이 높고 가열롤의 표면온도가 높은 경우 낮게 나타 났다 특히 닙 체류시간의 증가에 따라 감소하는 경향을 보였다.보였다.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.89-99
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• 2014

This study aims to make stock using cod bones with the hot water extraction method. Moisture content, chromaticity, pH, salinity, sugar content, mineral contents, quantitative analysis, and overall acceptance were studied to determine the standard formula. The results are as follows. The moisture content decreased (p < 0.001) and color value increased as heating time increased. The pH was highest in CS5 which was heated for 30 minutes and lowest in CS1. The salinity and sugar content significantly increased with more heating time (p < 0.001). In terms of mineral contents, sodium was highest in 138.87~154.17 mg, magnesium and iron showed proportion difference with increased heating time. The mineral analysis test result revealed that sodium, magnesium and iron showed proportional difference with increased heating time, while potassium and calcium did not change. The result of quantitative analysis test showed transparency, fishy smell, delicate flavor, savory flavor, salt taste and umami taste became stronger as high-pressure heating time increased. From these result, CS4 was evaluated to be the best in appearance, flavor, taste, aftertest and overall acceptance. Also, 60 minute high-pressure heating time is the most desirable to produce stock using cod bones as a main ingredient.

• Culinary science and hospitality research
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• v.19 no.3
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• pp.209-217
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• 2013

This study aims to develop mussel stock, which is the base of sauce, soup, etc., using various nourishing elements in mussels. In mussel stock with different heating times, the moisture content was significantly different according to heating times(p < 0.05). For the color value of mussel stock, L value was highest in MS1(35.48), a value in MS1(-2.39), and b value in MS5(-9.49). pH was lowest as 6.56 in MS5, and with increased heating time, pH decreased significantly (p < 0.001). With increased heating time, the sugar content was highest as $4.03^{\circ}Brix$ in MS3 and lowest as $3.37^{\circ}Brix$ in MS1. The salinity content was lowest as 0.71% in MS1, and with increased heating time, the salinity content increased significantly (p < 0.001). The test for characteristic differences of mussel stock showed that its color intensity, transparency, fish flavor, fish taste, and salty taste increased with increased heating time. Savory taste of mussel stock was highest in MS4 with 4.33% According to the results of acceptance test, taste, and overall acceptance test, MS3 showed the best results. In conclusion, mussel stock showed great preference with increased heating time, and the preference has increased when it was heated for 15 min.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.9-13
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• 2015

This study was conducted to investigate the effect of heating temperature and time on the quality of baked egg. Eggs were baked at various temperatures (80, 90, 100, 105 and $110^{\circ}C$) for different times (5, 6, 7 and 8 h) using a commercial heater. Our results revealed that heating loss in the $110^{\circ}C$ treatment was significantly (p<0.05) higher than those of other remaining treatments. The pH value of egg white in the 5 h treatment was significantly (p<0.05) higher compared to those of other treatments. While, no significant differences in pH values of egg yolks occurred among the treatments. Regarding the texture, hardness and cohesiveness values were not significantly different among the treatments. Regarding color, the $110^{\circ}C$ treatment samples had lower lightness value whereas had higher redness and yellowness values compared to the $105^{\circ}C$ treatments (p<0.05). Moisture content of baked eggs showed an decreased tendency as increasing the heating temperature and time. These results suggested that the proper conditions were 8 hours for total baking time including more than 5 h at $105^{\circ}C$ or 2 h at $110^{\circ}C$.

• Korean journal of food and cookery science
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• v.18 no.1
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• pp.51-56
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• 2002

This study was carried out to develop a traditional functional beverage by using hot-water extraction of dried peels of Korean tangerine. The pH of the hot-water extracts of dried tangerine peels decreased as the extraction time increased. The acidity and viscosity of the extracts increased as the extraction time increased. The antioxidative activity of the extracts during the extraction was monitored by measuring the electron donating ability. The electron donating abilities of the extracts were in the range of 80.93-83.27%. Extraction time did not affect the antioxidative activity of the extracts. The fibrinolytic activity of the extracts increased as the extraction time increased. The pH of the beverage made with the peel extract was not affected by the extraction time and the kind of sweetener added. The viscosity of the beverage increased as the extraction time increased. In sensory evaluation the highest score was obtained in the beverage samples made with the ones extracted for 180 min and added with sugar. The aboveresults indicate that the dried peel of Korean tangerine can be used as a functional material in beverage industry.

• Food Science and Preservation
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• v.14 no.2
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• pp.142-147
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• 2007

We optimized braising time to improve the storage quality of braised kidney beans. The beans were prepared with different heating times between 25 and 50 min. and then stored at $10^{\circ}C$ for 20 day. Physical, chemical, microbiological, and organoleptic quality indices were monitored throughout storage. Longer braising times yielded products with lower concentrated brine coverage. Bis resulted in higher soluble contents and slightly lower water activities. Excessive heating time exposed the kidney beans to air and caused rapid microbial growth on the surfaces of the beans, which negatively affected product quality. The longest heating time of 50 min. also resulted in a large increase in product hardness. A braising time of 30 min. was best for preservation, as good sensory quality was mainatained.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.242-245
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• 2004

다양한 가열온도와 가열시간에 따른 겔의 특성을 조사한 결과, 돈육을 이용한 수리미유사물 제조시 $75^{\circ}C$에서 25분간 가열하는 것이 겔 강도와 경도, 색깔을 고려해 볼 때 가장 적절한 것으로 사료된다.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.112-118
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• 1978

Four domestic frying oils (soybean, corn, rapeseed and rice bran oil) were studied on their changing properties according to thermal oxidation by means of chemical analysis of their compositions and measurements of various physical and chemical properties. The content of linoleic acid which is an essential unsaturated fatty acid and the total amount of unsaturated fatty acids were highest in soybean oil (53.2% and 80.3% respectively) among the unheated frying oils and the degree of its thermal degradation was lowest during the continuous heating period for 48 hours at $180^{\circ}C$. However in general, the contents of unsaturated fatty acids were sharply decreased by thermal oxidation whereas the saturated fatty acid contents ranging 10-17% were not changed considerably, which largely agreed with the results of iodine value measurements. The free acid and peroxide values were also lowest in soybean oil (0.09 and 5.6 respectively) among the unheated oils whereas an anomalously high free acid value was observed in rapeseed oil (54.8) which was packed in unleveled glass bottles. Such a high value is probably ascribed to the photo-catalyzed oxidation during storage. The viscosity measurements have shown similar values before heating, but after thermal oxidation for 32 hours the rapeseed and rice bran oils became too thick to measure viscosity by capillary flow method with heavy darkening in color.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.746-749
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• 2019

자유 단조는 고온에 가열한 강괴에 높은 압력을 가하여 원하는 형상의 제품을 만드는 공정으로 에너지 소모가 매우 크다. 여러 개의 강괴를 가열로에 장입하여 고온에 가열한 후 소재를 하나씩 꺼내어 프레스 공정을 수행한다. 가열로에 함께 장입되는 소재들의 조합에 따라 가열 시 소요 시간 및 에너지 사용량이 달라진다. 소재 조합에 따른 가열 비용 예측을 통해 최적의 소재 조합을 결정하여 에너지 효율을 높일 수 있다. 비용 예측 모형을 학습하기 위해서는 가열 소요 시간 및 에너지 사용량 데이터가 필요하다. 따라서 본 논문에서는 가열로의 온도 및 가스 사용량 데이터를 이용하여 가열로의 가동 상태 변경 지점을 감지하는 방안을 제안한다. 가열로의 온도 및 가스 사용량은 IoT 인프라를 기반으로 손 쉽게 획득할 수 있다. 가열로의 상태 별로 온도 및 가스 사용량에 나타나는 패턴을 이용하여 상태 변경 지점을 감지한다. 이를 통해 가열 공정 데이터를 획득할 수 있을 뿐만 아니라 가열로의 상태를 실시간에 모니터링이 가능함으로써 불필요하게 가열하는 것을 예방하여 에너지 효율을 높일 수 있다.