• Journal of Nutrition and Health
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• v.11 no.1
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• pp.33-37
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• 1978

The effect of heating time (0 to 30 hours at $180{\pm}5^{\circ}C$) on the change of flow properties, fatty acid compositions and some other characteristics such as acid value, iodine value, peroxide value and density of purified edible rice bran oil were observed. flow properties were measured with Maron-Belner type capillary viscometer. Newtonian motion was observed in non-heated oil and the oil heated for 5 hours but non-Newtonian motion was observed in the oil heated for more than 10 hours and at high shear stress. The fatty acid compositions were analyzed by gas liquid chromatography and all the components of fatty acids were reduced in amounts with extention of heating time. The acid value, peroxide value and density were increased but iodine value were decreased with extension of heating time.

• Journal of the Korean Wood Science and Technology
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• v.14 no.2
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• pp.36-42
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• 1986

Both the control and heated specimen of oak, hornbean, alder, poplar, red pine and pitch pine among domestic commercial species and taun imported were used for radial and tangential shrinkage and movement that occurred on changing the relative humidity of the atmosphere from 90 percent to 60 percent at $25^{\circ}C$. The results of this study were as follows. 1. The radial and tangential shrinkage of the control and heated hornbean and oak wood, except alder, of high specific gravity showed greater than species with low specific gravity. The ratio of tangential to radial shrinkage was 1.46 for taun to 2.70 for alder. Green volume specific gravity of the heated and soaked specimen of all species except poplar decreased 1.5 to 3.1 percent. Shrinkage of the heated specimen increased more than that of the control specimen, and antishrink efficiency of all timbers except alder had negative value. Shrinkage from green to air dry of treated specimens increased more than case of total shrinkage, and radial shrinkage of those specimen increased greater than tangential shrinkage. 3. The movement of the heating specimen for 120 hours decreased than those of the control and the heating specimen for 240 hours. The movement of heating oak, poplar, red pine and pitch pine (or 240 hours increased rather than those of the control specimen.

• Korean journal of food and cookery science
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• v.6 no.2
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• pp.67-76
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• 1990

To observe the propability as the frying oil and oxidative stability of red pepper seed oil, some physico-chemical tests of the oil were examined during 21 days storage period at 5$^{\circ}C$, 15$^{\circ}C$ and 30$^{\circ}C$, and AOM value determined and after heating the oil at 180${\pm}$5$^{\circ}C$ for 40 hours with or without antioxidants. The analysis storage stability of red pepper seed oil showed that the quality of storage group at 5$^{\circ}C$ was almost as good as fresh oil, and the storage group at 30$^{\circ}C$ showed certain degree of rancidity. Change of physico-chemical characteristic during storage were so small so that storage stability of red pepper seed oil was found to be good. AOM stability of red pepper seed oil was 7 hours which is lower than other vegetable oil, but the degree of stability grew greatly after adding phenolic antioxidants, such on TBHQ or PG. As for the chemical change after heating continuously for 40 hours, acid value, peroxide value and refractive index increased, but iodine value decreased as the heating processed. The fatty acid composition also showed the remarkable reduction of linoleic acid. The addition of antioxidants resulted in the delay of oxidation, the degree of which was greater in TBHQ than in PG.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.173-181
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• 1994

A Cold spot temperature control system for the batch annealing furnace has been estabilished in order to reduce energy consumption to improve productivity and stabilize the propertics of products. Therefore we confirmed a relation between annealing cycle time and atmospheric gas, variation of coil cold spot temperature with time during heating and actual temperature measurements at mid-width of each coil during heating and actual temperature measurements at mid-width of each coil during soaking. The results of the tempaeature variation effect on the batch annealing are as follows. 1) 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 reduced to 2.7 times. 2) In case of short time healing, the slowest heating part is the center of B coil, in case of long time heating, the low temperature point moves from the center of coil to inside coil. And the temperature in this part is higher than other parts when cooling. When finished heating, the cold spot is located 1/3 of coil inside in case of HNx atmospheric gas. But center of coil in case of Ax atmospheric gas. 3) The outside of top coil is the highest temperature point when heating, which becomes the lowest temperature point when cooling. So, this point becomes high temperature zone at heating and low temperature zone at cooling, It has relation according to atmospheric gas component and flow rate. 4) Soaking time at batch annealing cycle determination is made a decision by the input coil width, and soaking time for quality homogenization of 1214mm width coil must be 2.5 hours longer than that of 914mm width coil for the same ciol weight. 5) Annealing cycle time with Ax atmospheric gas is extended 1 hour in of slow cooling during 5 hours in order to avoid rapid cooling.

• Journal of Families and Better Life
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• v.3 no.1
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• pp.15-22
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• 1985

This study was designed to examine leisure time and leisure activities of homemakers and to predict future leisure time and future leisure time orientation. Present leisure time and future leisure time orientation were studied in relation to sociodemographic and physical environmental variables, time use variables and attitude variables. The major findings were the average daily housework time of homemakers was 6.5 hours on weekends. Housework time of employed homemakers was 3.5 hours and full-time homemakers was 8.0 hours. Daily leisure time of homemakers was 4.0 hours on weekdays and 4.8 hours o weekends. Most homemakers leisure activities on weekdays and weekends were reading, watching TV or listening to the radio and resting. In the future, they want to go hiking, hunting, traveling or fishing, attending concerts, drama or movies and playing sports games. The homemakers who felt their amount of present leisure time was sufficient were 35.4% and insufficient were 37.9%. Regarding the present leisure activities, 43.1% of homemakers expressed dissatisfaction, though 21.9% of them satisfied. Factors affecting the homemakers weekday leisure time were homemakers' occupation, family type, type of heating form house and cooking, weekday and weekend housework time of homemakers. Weekend leisure time interacted with family life cycle, number of children, income, education and occupation of homemakers, size of house, type of heating for house and cooking, weekday housework time of homemakers. housework time of employed housekeeper, husbands' weekend housework time, weekday leisure time of homemakers.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.57-60
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• 2005

This study discusses spalling and fire enduring performance of high performance concrete (HPC) RC column subjected to loading under heating for 3 hours. According to the test, both the plain concrete and the concrete attached with fire enduring PC panel exceed allowable temperature after 60 minutes due to the exposure of steel bar and falling off of concrete resulting from severe spalling failure. It leads to buckling of main bar and at the same time, occurrence of collapse of plain HPC column member is observed after 2 hours and 1 hour 40 minutes's exposure to fire, respectively. On the other hand, HPC applying both PP fiber of 0.1$\%$ by mass of concrete and PP fiber+lateral confinement by metal lath maintains their original cross section, which is satisfied with the 3 hours fire endurance criteria, by discharging internal vapour pressure and enhanced lateral confinement force.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.1068-1074
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• 2012

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside of food when electrical current is flown into. In other study, we researched about soybean protein's characteristic changes by ohmic heating. Nevertheless treated same temperature, denaturation of soybean protein were accelerated by ohmic heating than conventional heating. In this time, we studied thermal property change of potato starch by ohmic heating besides conventional heating. For this purpose, potato starch was heated at same subgelatinization temperature by ohmic and conventional heating. And thermal properties were tested using DSC. Annealing of starch is heat treatment method that heated at 3~4% below the gelatinization point. DSC analysis results of this study, the $T_o$, $T_p$, $T_c$ of potato starch levels were increased, whereas $T_c{\sim}T_o$ was narrowed. This thermal property changes appear similar to annealing's result. It is thought the results shown in this study, because the heating from below the gelatinization point. 6, 12, 24, 72, and 120 hours heating at $55^{\circ}C$ for potato starch, $T_o$, $T_p$, $T_c$ values continue to increased with heating time increase. The gelatinization temperature of raw potato starch was $65.9^{\circ}C$ and the treated starch by conventional heating at $55^{\circ}C$ for 120 hr was $72^{\circ}C$, ohmic was $76^{\circ}C$. The gelatinization range of conventional (72 hr) was $10^{\circ}C$, ohmic was $8^{\circ}C$. In case of 24 hours heating at 45, 50, 55, 60, $65^{\circ}C$ for potato starch, the result was similar to before. $T_o$, $T_p$, $T_c$ values continue to increased and gelatinization range narrowed with heating temperature increase. In case of conventional heating at $60^{\circ}C$, the results of gelatinization temperature and range were $70.1^{\circ}C$ and $9.1^{\circ}C$. And ohmic were $74.4^{\circ}C$ and $7.5^{\circ}C$. When viewed through the results of the above, the internal structure of starch heated by ohmic heating was found that the shift to a more stable form and to increase the homology of the starch internal structure.

• Advances in concrete construction
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• v.5 no.5
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• pp.513-537
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• 2017

In this study, the fracture toughness $K_{IC}$ of high performance concrete (HPC) was investigated by conducting three-point bending tests on a total of 240 notched beams of $500mm{\times}100mm{\times}100mm$ subjected to heating temperatures up to $450^{\circ}C$ with exposure times up to 16 hours and various heating and cooling rates. For a heating rate of $3^{\circ}C/min$, $K_{IC}$ for the hot concrete sustained a monotonic decrease trend with the increasing heating temperature and exposure time, from $1.389MN/m^{1.5}$ at room temperature to $0.942MN/m^{1.5}$ at $450^{\circ}C$ for 4-hour exposure time, $0.906MN/m^{1.5}$ for 8-hour exposure time and $0.866MN/m^{1.5}$ for 16-hour exposure time. For the cold concrete, $K_{IC}$ sustained a two-stage decrease trend, dropping slowly with the heating temperature up to $150^{\circ}C$ and then rapidly down to $0.869MN/m^{1.5}$ at $450^{\circ}C$ for 4-hour exposure time, $0.812MN/m^{1.5}$ for 8-hour exposure time and $0.771MN/m^{1.5}$ for 16-hour exposure time. In general, the $K_{IC}$ values for the hot concrete up to $200^{\circ}C$ were larger than those for the cold concrete, and an inverse trend was observed thereafter. The increase in heating rate slightly decreased $K_{IC}$, and at $450^{\circ}C$ $K_{IC}$ decreased from $0.893MN/m^{1.5}$ for $1^{\circ}C/min$ to $0.839MN/m^{1.5}$ for $10^{\circ}C/min$ for the hot concrete and from $0.792MN/m^{1.5}$ for $1^{\circ}C/min$ to $0.743MN/m^{1.5}$ for $10^{\circ}C/min$ for the cold concrete after an exposure time of 16 hours. The increase in cooling rate also slightly decreased $K_{IC}$, and at $450^{\circ}C$ $K_{IC}$ decreased from $0.771MN/m^{1.5}$ for slow cooling to $0.739MN/m^{1.5}$ for fast cooling after an exposure time of 16 hours. The fracture energy-based fracture toughness $K_{IC}$' was also assessed, and similar decrease trends with the heating temperature and exposure time existed for both hot and cold concretes. The relationships of two fracture toughness parameters with the weight loss and the modulus of rapture were also evaluated.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.245-250
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• 2004

To investigate the effect of early-morning heating periods on growth and yield of cucumber and heating load in a greenhouse cultivation, three additional heating periods (0, 1 and 2 hours) were compared to rise temperature from $12^{\circ}C\;to\;16^{\circ}C$ in the early-morning. Leaf temperature just before opening the thermal screen was $3.3^{\circ}C\;and\;4.1^{\circ}C$ higher in the 1 and 2 hour heating compared to that in the control (0 hour heating), respectively. Photosynthetic rate, conductance to $H_2O$ and transpiration rate of cucumber leaves were the highest in the 2 hour heating, and the lowest in the control. However. the difference between the 1 hour and 2 hour heating was not significant. Inorganic element content in cucumber leaves was not significant among the treatments of duration. Initial growth after planting of cucumber was greater in the 1 and 2 hour heating than that in the control. Yield increased by $11\%\;and\;15\%$ in the 1 hour and 2 hour heating compared to that in the control. respectively. Fuel consumption for heating increased by $12\%\;and\;22\%$ in the 1 hour and 2 hour heating compared to that in the control, respectively. Considering in the yield and fuel consumption for heating. 1 or 2 hours of early morning heating could be effective in temperature management for cucumber in a greenhouse cultivation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.19-22
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• 2003

The purpose of this study is to analyze the curing effect of planar surface heater for concreting in cold weather. Some experiments were conducted to evaluate the temperature history of concrete structures cured with heating sheets. Results are as follows ; (1) The temperature of concrete showed continuously rising trend with the heating by planar surface heater under the cold environmental condition of 3~-12$^{\circ}C$. And after about 24 hours the maximum temperature of concrete was reached at 25~3$0^{\circ}C$. (2) The temperature of slab concrete heated by planar surface heater of 130W/$m^2$ was at least $25^{\circ}C$ higher than that of an exterior air, and the curing performance was much more effective than heating by hot wind machine. (3) Through the curing by planar surface heater for 48 hours, the concrete maturity of about 1.5 times to heating by hot wind machine was acquired.