• Korean journal of food and cookery science
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• v.17 no.6
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• pp.589-597
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• 2001

This study was conducted to develop a standardized Korean cold noodle stock recipe which can be used in food service establishments. The qualities of three kinds of stock made of beef rib only(B group), beef rib added with chicken(BC group), and beef rib added with chicken and vegetable(BCV group) were investigated by using sensory evaluation and instrumental analyses for free amino acids and nucleotides during heating (2, 3, 4, and 6 hr) at 90$\pm$ 5$\^{C}$ The highest amino acid contained in B, BCV, and BCV groups was arginine followed by alanine, glycine, and glutamic acid. B and BC groups was extracted to the best contents of amino acids by heating for 4 hours but BCV group for 3 hours. Nucleotides were extracted from B and BC group between 3 and 4 hours of heating but in BCV group between 2 and 3 hours. In sensory evaluation, BCV group obtained the highest score for overall preference. In the measurement of color difference, BCV group was the lowest in L value(lightness) but the highest in b value(yellowness).

• Journal of Biomedical Engineering Research
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• v.11 no.2
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• pp.295-304
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• 1990

In order to use for artificial dental tooth (dental crowens) , new glass-ceramics material has been studied. Its basic composition and the condition of heat treatment for crystalization, mechanical and chemical properties were investigated. Adding of the LAS system composition in the basic glass, time and temperature for crystalization were shortened. Fracture toughness (kic)of samples heat treated at 90$0^{\circ}C$ for 2 hours is 2.5-2.6MN/m3/2, the optimum condition of heat treatment for artificial tooth is A and B samples heating to 75$0^{\circ}C$ for 2 hours, raising to 90$0^{\circ}C$ and maintaining at 90$0^{\circ}C$ for 2 hours and C sample heating to 75$0^{\circ}C$ maintaining at 75$0^{\circ}C$ for 2 hours. In acid and'alkali solution, chemical durability is excellent.

• Journal of Nutrition and Health
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• v.10 no.3
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• pp.1-6
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• 1977

Flow properties of heated edible oils, such as soybean, rapeseed, rice bran, corn and perilla oils, were measured with Maron-Belner type capillary viscometer. These oils were heated at $180{\pm}5^{\circ}C$ (general cooking temperature) for $5{\sim}20$ hours except soybean oils ($5{\sim}40$ hours). Fluidities of these heated oils except rice bran oil were decreased according to heating time and decreasing ratio of fluidity was outstanding after 15 hour heating in corn oil and 20 hours heating in soybean and perilla oils. All the oils examined in this experiments except rice bran oil showed non-Newtonian motion after 15 hour hinting at high shear stress and Newtonian motion at less than 10 hour heating. In the soybean oil non-Newtonian flow property was outstanding after 30 hour heating at $180{\pm}5^{\circ}C$. Rice bran oil exhibit characteristic flow property, that is, non heated rice bran oil has lowest fluidity but heated one has highest fluidity compared to other oils examined in this experiment. Change of fluidity with extension of heating time was not detected and non heated rice bran oil showed non-Newtonian motion.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.1
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• pp.114-122
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• 1994

A cold temperature control system for the BAF(batch annealing furnace) has been established in order to reduce energy consumption to imrpove productivity and stabilize the properties of products. Therefore we confirmed a relation between annealing cycle time and atmospheric gas, changing annealing cycle time according to BAF temperature with time during heating and actual temperature measurements cold spot during soaking. The results of the temperature variation effect on the batch annealing are as follows. 1) Cooling rate is increasing gradually with increasing atmospheric gas flow, but heating rate is hardly increasing without atmospheric gas component. Heating time is reduced to one half with increasing atmospheric gas flow rate and changing of atmospheric gas component from HNx to Ax gas and annealing cycle time is reduce to 2.7 times. 2) With enlarging the difference between furnace temperature and soaking temperature at the HNx BAF, heating time becomes short, but cooling time is indifferent. 3) If temperature difference of 300.deg. C in the temperature change of cold spot according to the annealing cycle control temperature, Hi-CON/H2BAF is interchanging at each other at 26hours, but HNxBAF at 50 hours. 4) Soaking time at batch annealing cycle determination is made a decision by the input coil width, and soaking time for quality homogenization of 1219 mm width coil must be 2.5 hours longer then that of 914mm width coil for the same coil weight at Hi-CON/H2BAF. But, it is necessary to make 2 hours longer at HNxBAF.

• Journal of Korea Foundry Society
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• v.15 no.3
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• pp.252-261
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• 1995

The purposes of this study were to investigate the microstructural changes in alloy ribbons of Al-Fe-Mo-Si quarternary system at $450{\sim}500^{\circ}C$, and to study the coarsening mechanism of fine precipitates. Using the hot stage in TEM, in situ microstructural changes in Al-4Fe-0.5Mo-1.5Si alloy ribbon and Al-8Fe-2Mo-1.5Si alloy ribbon have been examined successively up to 60 hours at $450^{\circ}C$ and $500^{\circ}C$. Cell structure in zone B of Al-4Fe-0.5Mo-1.5Si alloy ribbon was observed to collapse even in 10 minutes by in-situ heating at $450^{\circ}C$ and the size of precipitates in zone B increased twice in 60 hours. The precipitates in zone A of Al-4Fe-0.5Mo-1.5Si alloy ribbon showed slower coarsening rate than those in zone B by in-situ heating at $450^{\circ}C$. The precipitates in zone A of Al-8Fe-2Mo-1.5Si alloy ribbon increased 50% by in-situ heating at $500^{\circ}C$ in 50 hours compared to the initial precipitates while any microstructual change in zone B was not observed by in-situ heating at $500^{\circ}C$ up to 50 hours. Only the precipitates in zone A of Al-4Fe-0.5Mo-1.5Si alloy ribbon satisfied $r^3{\propto}t$ relationship of coarsening mechanism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.17-25
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• 1981

The purpose of this study was to determine effects of thermal oxidation according to heating time and temperature, using sunflower oil from seed grown in Korea. To investigate these effects, the lipid components, fatty acid compositions, and chemical characteristics of crude oil from sunflower seed were determined. The content of nonpolar and polar in total lipids was 94.1% and 5.9%, respectively. The fatty acid compositions in the total lipids showed 6.21% palmitic, 4.50% stearic, 59.84% oleci and 29.48% linoleic acid. The concent of linoleic acid decreased during heating. However, the concent of oleic, palmitic and stearic acid increased during heating. The components of neutral lipid were found 6 fractions, including triglyceride, diglyceride and free fatty acid. The content of triglyceride decreased but diglyceride and monoglyceride increased during heating. The content of free fatty acid increased during the continuous heating period for 32 hours at $100^{\circ}C$, whereas decreased in 16 hours at $180^{\circ}C$. Iodine value decreased during heating, and peroxide value increased during the continuous heating period for 32 hours at $100^{\circ}C$, whereas decreased in 16 hours at $180^{\circ}C$.

• Journal of Powder Materials
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• v.5 no.3
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• pp.178-183
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• 1998

Ultrafine WC-10wt.%Co cemented carbides powders were synthesized by direct carburization. W-Co composite powders and carbon black powders were mixed by wet ball milling and dried. The mixed powders were heated to 800 $^{\circ}C$ with heating rate of 8.2$^{\circ}C$/min and held for various times in flowing $H_2$. For carbon addition of 140%, the carburization was completed by heating at 80$0^{\circ}C$ for 4 hours. The carburization time decreased with increasing amount of carbon and carburization was completed by heating at 800 $^{\circ}C$ for 2 hours with carbon addition of 150%. WC-10 wt%Co cemented carbides powders fabricated by direct carburization have nanoscale WC($\/leqq$100 nm) size.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.3_4
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• pp.97-102
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• 2007

A Korean seasoned meat product, seasoned bulgogi was developed in processing and packaging for improved convenience and extended shelf life. The optimal process conditions were found to consist of aging for $20{\sim}30$ hours at $5^{\circ}C$ and air heating for 20 minutes at $210^{\circ}C$ Aging of 24 hours could attain soft texture with little change in pH, color and total aerobic bacterial count. Appropriate drip level could be achieved at air heating of 20 minutes at $210^{\circ}C$, while the air heating at $180^{\circ}C$ could not give suitable level of texture. Modified atmosphere packaging of 60% $CO_2$ and 40% $N_2$ could preserve the product significantly better compared to control of air package and vacuumed package.

• Journal of the Korean Ceramic Society
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• v.18 no.3
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• pp.182-186
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• 1981

The extraction of $Al_2O_3$ from the backed mixture of grinded aluminium silicates with $H_2SO_4$ and required heating energy for the baking process has been investigated. The extraction ration of $Al_2O_3$ from baked kaolin and alunite being mixed with 70-80% $H_2SO_4$ at 12$0^{\circ}C$ for 3 hours was more than 90%, the yield was based on alumina component in the ore by extracted with water. The required heating energy was 1782 cal/300gr (Alunite), that is, when alunite ore treated with equivalent amount of 80% $H_2SO_4$, also left it for 75 minites at 12$0^{\circ}C$, The required heating energy was 22, 553 cal/200gr(Alunite) when the above sample was heated again at 15$0^{\circ}C$ for 2 hours.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.170.1-170.1
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• 2010

Performance of water-to-air heat pump using raw water has been analyzed under part load heating operation in March, 2010. The water source heat pump of 30 RT was installed for 24 hours cooling and heating ventilation, and the gravity inflow water from Daechung dam is used as the heat source. The daily averaged water and air temperatures are $5.7^{\circ}C$ and $9.9^{\circ}C$ respectively, and the heat pump is operated under part load condition for 7.5 hours in 24 hours. The daily averaged heat pump COP calculated with heat transferred from the brine water is 2.49 and the monthly averaged COP is 2.25 in March. Based on the database of the California Energy Commission, the monthly averaged COPs of air source heat pumps installed in U.S.A. are 1.97 in March and 2.03 in April. Therefore it is confirmed again that the performance of the heat pump using raw water is better than that of air source heat pumps.