• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.2
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• pp.36-47
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• 2012

Time-series variation of groundwater temperature in Mongolia shows that maximum temperature is occured from end of October to the first of February(winter time) and minimum temperature is observed from end of April to the first of May(summer time). Therefore ground temperature is s a good source for space heating in winter and cooling in summer. Groundwater temperatures monitored from 3 alluvial wells in Ulaabaatar at depth between 20 and 24 m are $(4.43{\pm}0.8)^{\circ}C$ with average of $4.21^{\circ}C$ but mean annual ground temperature(MAGT) at the depth of 100 m in Ulaanbaatar was about $3.5{\sim}6.0^{\circ}C$. Bore hole length required to extract 1 RT's heat energy from ground in heating time and to reject 1 RT's heat energy to ground in summer time are estimated about 130 m and 98 m respectively. But in case that thermally enhanced backfill and U tube pipe placement along the wall are used, the length can be reduced about 25%. Due to low MAGT of Ulaabaatar such as $6^{\circ}C$, the required length of GHX in summer cooling time is less than the one of winter heating time. Mongolia has enough available property, therefore the most cost effective option for supplying a heating energy in winter will be horizontal GHX which absorbs solar energy during summer time. It can supply 1 RT's ground heat energy by 570 m long horizontally installed GHX.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.407-411
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• 1997

Effects of heating time and storage temperature on the oxidative stability of heated palm oil were studied. Palm oil was heated at $150^{\circ}C$ for 0, 1, 10 or 20 min and stored at 4, 20 or $65^{\circ}C$. The oxidative stability of the sample was evaluated by determining peroxide value of the oil and measuring the volatiles in the headspace of the sample. Significant difference in the peroxide or volatile formation was observed (p<0.05) in heated palm oils between samples stored at 4 or $20^{\circ}C$ and those stored at $65^{\circ}C$. Pentane, hexanal, heptane and total volatiles increased with heating time, while storage temperature did not significantly affect their formation, indicating that heating time played more important role in volatile formation in the heated palm oil than storage temperature. However, adverse results were observed for the formation of peroxide. The interaction effect of heating time and storage temperature on the oxidative stability of heated palm oil was also observed.

• Macromolecular Research
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• v.8 no.2
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• pp.73-79
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• 2000

The influence of mastication of natural rubber (NR) on properties of carbon black-filled NR compounds was studied. Variations of viscosities of the masticated NR and the carbon black-filled NR compound by heating were also investigated. The viscosities of the compounds decreased by increasing the mastication time of the raw rubber. The viscosities of the masticated NR and the compounds increased by increasing the heating time. This was explained by the combination reaction between functional groups in the rubber. The viscosity increment of the masticated rubber and the compounds by heating became larger with increased mastication time. Cure rate of the compound became faster by increasing the mastication time. Modulus of the vulcanizate made of the rubber masticated for a long time was higher than that of the vulcanizate made of the rubber masticated for a short time while elongation at break of the former was shorter than that of the latter. This was explained by the content of bound rubber and chain length of the rubber molecules.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.430-437
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• 2004

This paper is intended as an investigation of study on the thermal and electrical characteristics of the carbon heating element. In this experimentation, the electric material used is the crystalline graphite a kind of natural graphite. The bentonite is used to solidify the heating element and the vacuum furnace is used for sintering it. It is noted that the natural drying time should be at least 58 hours. The plating of the electric pole with the electroless nickel showed the lowest contact resistance among others. The resistance shows linear variation with regard to length. For the insulation and resolution, the glaze coating is best with 80% of water content. The temperature rising characteristic of the heating element is better than sheath heater saving 43% of rising time. The correlation equation for temperature was obtained with the electric power.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.4
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• pp.528-536
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• 1999

This work studies the effects of transient reflectance on the thermal responses of a metal(gold) thin-film during ultrashort laser heating. The heating process is calculated using the conventional conduction model (parabolic one-step: POS), parabolic two-step model (PTS) with and without variable properties, hyperbolic two-step model (HTS). Results from the HTS model are very similar to those from the PTS model, since the laser heating time in this study is greater than the electron relaxation time. PTS model with variable properties, however, results in totally different temperature profiles compared to those from POS models or calculation with constant properties. Transient reflectances are estimated from electron temperature distributions and based on the linear relationship between the electron temperature and complex dielectric constants. Reflectance of the front surface can be changed with respect to dielectric constants, while those of the rear surface remain unchanged.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.973-978
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• 2009

In this study, the thermal environment characteristics of On-Off control and thermal difference proportional control method in floor radiant heating system were researched by computer simulation. For the analysis of unsteady heat transfer phenomena in household, the method of using electrical equivalent R-C circuit is applied, and radiation heat transfer between panel, ceiling and walls in household is calculated by enclosure analysis method. The parametric study on two control methods, conventional on-off control and temperature error based time control(T.E.B.T.C.) method, are performed to compare thermal heating control performances, respectively.

• Journal of Mechanical Science and Technology
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• v.19 no.10
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• pp.1950-1956
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• 2005

An analysis has been carried out to investigate the effect of the reflectivity on the temperature distribution of a glass panel by infrared radiant heating. Halogen lamps are used to heat the panel, located near the top and bottom of the rectangular chamber. The thermal energy is transferred from the lamps to the panel only by radiation and it is considered by using view factor. The conductive transfer is limited inside the panel. The results show that the uniformity of the temperature distribution of the panel is improved and, at the same time, the time for heating increases as the wall reflectivity increases. The temperature difference between the center and the corner reaches a maximum in the early stage of the heating process and then decreases until it reaches a uniform steady-state value.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.284-291
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• 1997

Microwave vacuum heating method (2450 MHz) was used for a low intensity of heat treatments. High vacuum under the microwave heating could bring low temperature condition. Inactivation of ${\alpha}-amylase,\;{\beta}-amylase$, glucoamylase and peroxidase by microwave vacuum heating were investigated at 60-$80^{\circ}C$. It was compared with conventional heating. The heating condition of microwave vacuum heating was confirmed by the destruction of ascorbic acid. When thermal inactivations of the enzymes by microwave vacuum heating were determined, it was less effective than that of conventional method at the initial stage of heating. It was due to a lag time of microwave heating. However, the heating time for complete inactivation of the enzymes by microwave vacuum heating could be reduced comparing with that of conventional heating. Optimum conditions for inactivation of the enzymes could be obtained by microwave vacuum heating.

• Investigative Magnetic Resonance Imaging
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• v.24 no.2
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• pp.67-75
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• 2020

When a patient takes an MRI scan, the patient has a risk of unexpected injuries due to the intensive electromagnetic (EM) field. Among the injuries, the tissue heating by the time-varying EM field is one of the main issues. Since an implanted artificial structure with a conductive material aggravates the heating effect, lots of studies have been conducted to investigate the effect around the implants. In this review article, a mechanism of RF heating around the implants and related studies are comprehensively investigated.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.2
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• pp.163-171
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• 2019

Recently, rural housing in urban areas has been increasing due to the improvement of income level. With the increase of the construction of the power house, the installation of the heating system using the harmonious fuel for the purpose of heating and the beauty of the room is increasing rapidly. In addition to the increasing use of firewood heating equipment, the incidence of fire is also increasing. Analysis of the National Fire Data System of the Fire Department The result of the analysis of the National Fire Data System Many parts of the fire are incinerated by the accumulation of tar due to the incompleteness of periodic cleaning inside the cylinder. The distance between the fire extinguisher and the combustible materials such as ceiling, Resulting in fire. In addition, it was found that much of the fire of the firewood heating system in the time zone occurs during the sleeping and resting time and there is not enough time for the residents to cope. This, in turn, causes serious harm to the lives and property of the users of the pyrotechnic heating system. Therefore, in this study, domestic and foreign standards and laws related to fuel oil heating facilities were analyzed and 12 cases of fire accidents were analyzed. Through the revision of the fire prevention and firefighting facilities installation and maintenance law, the installation standards of the alarm and fire extinguishing facilities were presented.