• Journal of the Korean Society of Combustion
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• v.12 no.3
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• pp.24-32
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• 2007

A theoretical model was developed for rotary kiln and computational study was conducted to find the effect of feeding characteristics. One dimensional model with the variations of heating distribution, length of heating zone, excess air ratio and revolution was considered. The comparison of parallel-flow rotary kiln with that of counter-flow was conducted. For parallel-flow type, it is found that the variation of temperature of solid is not great for the zone that is following flame-heating zone. This zone is good to take the special treatment because thermal deviation is small and contacting time is enough for another treatment. Increase of excess air ratio have the effect of decreasing solid temperature. But this effect of decreasing solid temperature goes small for the great excess air ratio. The heating is efficient for the flame which has the maximum heating at the central region of the full length.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.99-106
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• 2012

This study presents estimation method of temperature-dependent thermal conductivity by using solution of inverse heat conduction problem. Time and depth temperature distribution data from full-scale fire test were used for estimating temperature-dependent thermal conductivity on hybrid-fiber reinforced shield tunnel lining. At short heating time, estimated thermal conductivity sharply decreased within $100^{\circ}C$. On the other hand, it reflected thermal properties of concrete and effect of steel fiber at heating time of measured maximum heating temperature. Thus arbitrary time should be determined to estimate temperature-dependent thermal conductivity in time zone of measured maximum heating temperature. Estimated temperature-dependent thermal conductivity is similar to results of other study.

• Korean Journal of Metals and Materials
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• v.48 no.2
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• pp.141-147
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• 2010

An Ni-Al intermetallic coating has been produced by induction heating on mild steel. The effect of the induction heating conditions on the microstructure of the coating has been investigated. The reaction synthesis of the intermetallic compounds was promoted while increasing the heating rate and the holding time at reaction temperature. Especially, an NiAl phase corresponding to the initial composition of mixed powder was predominantly formed. However, the synthesis at low reaction temperatures occurred by solid state diffusion during the holding time and an Fe-Al reaction layer was formed at the interface with the substrate, regardless of the heating rate. The combustion synthesis of the intermetallic compound occurred at a temperature higher than 1023 K and resulted in an almost single phase NiAl structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.22-22
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• 2009

The silver thick film has been used in many industries such as display, chip, solar cell, automobile, and decoration with conventional heating. The silver thick film is fired with optimal time and temperature. However, decreasing the fabrication time is required due to high production power. Furthermore, there is a problem that silver in electrode is diffused throughout any substrates. For inhibiting the Ag diffusion and long fabrication time we considered a microwave heating. We investigated firing of silver thick film with conventional and microwave heating. The temperature of substrate was measured by thermal paper and the temperature of substrate was under $100\;^{\circ}C$ The shrinkage of electrode was measured with optical microscopy and optical profilometry. The shrinkage of electrode heat treated with microwave for 5min was similar to the that fired by the conventional heating for several hours. After firing by two types of heating, the diffusion of silver was determined using a optical microscope. The microstructure of sintered silver thick film was observed by SEM. Based on our results, the microwave heating should be a candidate heating source for the fabrication electronic devices in terms of saving the tact time and preventing the contamination of substrate.

• Food Science of Animal Resources
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• v.39 no.2
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• pp.296-308
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• 2019

Although the yellow mealworm (Tenebrio molitor L.) is a promising alternative protein source, the effects of processing conditions on functional properties are unclear. In this study, a protein extract of yellow mealworm larvae (PEYM) was subjected to different heat temperature ($55^{\circ}C$, $75^{\circ}C$, and $95^{\circ}C$) with different time (20, 40, and 60 min) to evaluate the functional properties and protein oxidation. Different heat temperature treatment significantly affected the exposure of surface hydrophobicity of the proteins and protein molecule aggregation, which reached maximum levels at $95^{\circ}C$ for 60 min. Protein oxidation was inversely proportional to the temperature. Both the highest carbonyl value (1.49 nmol/mg protein) and lowest thiol value (22.94 nmol/mg protein) were observed at $95^{\circ}C$ for 60 min. The heating time-temperature interaction affected several functional properties, including solubility, emulsifying potential, and gel strength (GS). Solubility decreased near the isoelectric point (pH 5 to 6). As the temperature and heating time increased, emulsifying properties decreased and GS increased. The oil absorption capacity and foaming properties decreased and the water absorption capacity increased. These results confirmed that PEYM is a suitable source of proteins for processing and applications in the food industry.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.3
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• pp.241-245
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• 2008

The characteristics of temperature profile around human body with heating life vest at sea were investigated in this paper. Especially, the temperature profile of human body was numerically calculated by finite difference method with Mathcad. The main parameters were seasonal mean sea water temperature, heating amount and heating duration time of heating life vest. In this paper, the boundary layer was composed by the difference matters, and the thermal conductivity was calculated with an adjacent cells using thermal resistance method. It was clarified that the body temperature was kept highly and the risk of death from hypothermia was reduced by wearing heating life vest.

• Journal of Applied Biological Chemistry
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• v.54 no.3
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• pp.147-152
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• 2011

The physical properties of puffed snack by pellet with sweet potato flour, brown rice flour and wheat flour were evaluated at different moisture content, puffing temperature, and puffing time. The sweet potato pellets were tempered to 14, 16, and 18% moisture content and were puffed at 233, 238, and $243^{\circ}C$ for 4, 5 and 6 s. The whitness ($L^*$) value decreased as the heating temperature and time increased. The redness ($a^*$) and yellowness ($b^*$) values increased with increasing heating temperature and time. The specific volume of sweet potato puffed snacks showed an increasing trend with higher puffing conditions. The hardness of sweet potato puffed snacks increased as heating time and heating temperature increased. The sweet potato puffed snacks prepared with increasing moisture content (18%), heating times (6 s), and heating temperatures ($243^{\circ}C$) were awarded the highest scores for most of the sensory attributes and hence declared as best sweet potato puffed snacks.

• Journal of Acupuncture Research
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• v.19 no.2
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• pp.114-127
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• 2002

Objective : The purpose of this study is to investigate the mechanism and effect of moxibustion objectively and to be used as the quantitative data for developing the new thermal stimulating treatment by observing the combustion time and temperature of commercial moxaes. Methods : We have selected two types(large-size moxa A(LMA), large-size moxa B (LMB)) among large moxaes used widely in the clinic. We examined combustion times, temperatures in each period during a combustion of moxa. Results : 1. The combustion time in the preheating period was about 30sec in both moxaes on the non-contact heated surface. 2. The combustion time in the heating period was about 345sec in LMA and about 1391 sec in LMB, about 4 times longer in LMB on the non-contact surface. 3. The maximum temperature in the heating period was $44.5^{\circ}C$ in LMA and $45.4^{\circ}C$ in LMB respectively, higher by $0.9^{\circ}C$ in LMB. The average temperature in the heating period was $35.5{\sim}37.6^{\circ}C$ in LMA and $36.0{\sim}39.8^{\circ}C$ in LMB, a little higher in LMB. 4. The combustion time in the retaining period in LMA was 45.4sec and 13% of that in the heating period, and in LMB 594.7sec and 43% of that in the heating period on the non-contact surface. 5. On the point(PH) measured maximum temperature, the average temperature during the retaining period was $44.0^{\circ}C$, $42.9^{\circ}C$ respectively and the temperature at an end of the retaining period was $43.0^{\circ}C$, $40.2^{\circ}C$ respectively. 6. The time at a beginning of the cooling period was about 418 sec from ignition in LMA and 2021sec in LMB, and the temperature at that time was $36.9{\sim}39.1^{\circ}C$ on the non-contact surface. Conclusion : It was thought that not only the figure of moxicombustion device, but also the form and size of moxa had influence on the combustion characteristics deciding the performance of stimulus seriously.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.717-723
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• 2009

Thermal degradation characteristics of sucrose was investigated. A 20% sucrose solution was heated to temperatures of $110-150^{\circ}C$ for 1-5 hr. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugars, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) of the heated sucrose solutions were evaluated. With increasing temperatures and times, the L-, a-, and b-values decreased; however, total color difference (${\Delta}E_{ab}$) increased. The pH and sucrose contents decreased, and fructose and glucose contents increased with increasing heating temperature and time. Organic acids, such as formic acid, lactic acid, and levulinic acid, and HMF contents increased with increasing heating temperatures and times. EDA (%) and the AEAC of the heated sucrose solutions increased with increasing heating temperature and time. The heated sucrose solution was more effective than unheated sucrose solution, having higher EDA (90 fold), and AEAC (13 fold).

• Journal of Welding and Joining
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• v.8 no.1
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• pp.43-53
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• 1990

The transient temperature distribution in the continuous friction welding 304 stainless steel bars is investigated by experimental and analytical methods. It is calculated by F.D.M. (finite difference method). The heating pressure, the rotational speed and friction coefficient obtained from experiment are used to determine the heat input at the contacting surface. Thermal properties of the workpiece are the function of temperature. The calculated temperature is well coincided with the measured value. The grain size at weld interface is extremely small due to the severe plastic deformation at high temperature, and result of this refined zone reveals higher hardness value. Because the HAZ is very narror about 2-3 mm, welding defects do not occure.