• Journal of the Korean Wood Science and Technology
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• v.43 no.2
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• pp.168-176
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• 2015

This study was performed to investigate the effects of heat treatment the on mechanical properties of two species of wood under different heating conditions including at $180^{\circ}C$ for 12 h and 24 h, and at $210^{\circ}C$ for 3 h and 6 h. Two species of wood, Pinus densiflora and Larix kaempferi, were exposed to different heat treatments to assess the effects on the volume change, bending properties in static and dynamic mode and compressive strength. The results showed heat treatment caused significant changes in mechanical properties such as the static and dynamic moduli of elasticity ($MOE_d$ and $MOE_s$), and the modulus of rupture (MOR). The volume of the wood after heat treatment decreased as the heating temperature and time were increased. The bending strength performance of the wood after heat treatment decreased as the heating temperature and time were increased. The effect of heat treatment at a high temperature on the bending MOR was greater in both species than that for a long time. However, the compressive strengths of all the heat-treated samples were higher than the control sample. Furthermore, highly significant correlations between $MOE_d$ and MOR, and $MOE_s$ and MOR were found for all heating conditions.

• New & Renewable Energy
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• v.5 no.4
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• pp.60-65
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• 2009

The present study was conducted for a comparative evaluation of wet and dry floor heating systems using geothermal heat pump. We circulated hot water from geothermal heat pump which is $10{\sim}15^{\circ}C$ lower than that from boiler. In order to access indoor temperature ($25^{\circ}C$) it took 74 minutes for dry type and 247 minutes for wet type. Average floor temperature was $23.9^{\circ}C$ for wet type and $32.7^{\circ}C$ for dry type. Energy saving rate gradually increased by 66% after 138 minutes. As a result, in case of floor heating system using low temperature circulation water, dry type was more practicable for stable floor heating than wet type in terms of floor temperature and access time to indoor set temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.25-28
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• 2005

The experimental results on the mechanical behavior of high-strength concretes subjected to high temperature were presented. Main variables were heating temperature, heating continuance time, and cooling condition. The compressive strength properties of high strength concrete(HSC) varied differently with temperature than those of normal strength concrete(NSC). HSC had higher rates of strength loss than NSC in the temperature range of between $20^{circ}C$ and $400^{circ}C$. Especially, HSC exploded in $400^{circ}C$ of high temperature.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.160-161
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• 2022

This study is to investigate the temperature history over time of the cement mortar to confirm the bubble sheet insulation effect using the heat generat sheet. As a result of the experiment, it was confirmed that the heating effect was 6℃ higher on average than other types of sheets when the heating sheet is attached on the bottom of the double layered bubble sheet. For future research, it is planned to verify the heating performance by using the heating sheet under the same environmental conditions as the heating performance will be verified.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.738-742
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• 2006

In this study we developed the electrical heating mold core by applying three different heating methods. In order to find out the optimal heating method, we observed the temperature profiles with time. We also injection-molded the parts by the heating methods and investigated the shrinkage ratio, density, surface roughness and weld-lines. The temperature rise time and cycle time showed the promising results for commercial applications(the rise time is $130^{\circ}C$/14sec, the cycle time is 55sec). By comparing with the conventional and gas flame heating method, the parts by this method were proven to have good qualities. The shrinkage ratio reduced by 5.1%, the density increase by 2.66%, the smoothness increased about 3 times, and the weld-line did not observed by naked eyes.

• Journal of Soil and Groundwater Environment
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• v.17 no.1
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• pp.8-12
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• 2012

This study is maintains the condition of high temperature (above $600^{\circ}C$) within a short time using on microwave and high temperature heating elements. And removal characteristics according to changes in soil moisture, microwave power and temperature through the decomposition of the contaminated soil by oil. The difficulty resolvability material was sort of lubricating oil having long carbocyclic (C18-C50) and TPH removal rate reached 85.2% at 6 kW and $700^{\circ}C$ and thus the contaminant was removed 1,788 mg/kg within a process time of 40 minutes. In the case of light oil, gasoline contaminated soil, the removal amount showed 567 mg/kg and the treatment rate reached 98.4% at 6 kW, $500^{\circ}C$ and 20 minute. In the case of non-resolvability reached TPH concentrations on 2,000 mg/kg of worrisome level of soil contamination in the 3 zones at 6 kW, $700^{\circ}C$ and 30 minute. At the time, showed up processing costs 8,173 won per ton.

• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.961-967
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• 2009

In order to examine the availability of heat treatment for color developing in persimmon dyeing, the rayon fabrics dyed with persimmon extract from unripe persimmon which was used after stock and fermentation. Dyed fabrics were heated at various temperature and time by contacting press heat and drying heat. Color developing results were influenced by the difference of heating method. Press heating method is more available than drying heat method. Effect of temperature and time on ${\Delta}Ea^*b^*$ and color values of dyed rayon fabrics was considerable. Considering the practical aspect, The temperature around $140{\sim}160^{\circ}C$ and the time no longer 40 minutes can be reach the region of the full color developing by press heating process. It was very shortened than any other method(drying air heat, xenon radiation, sunlight). The dyed rayon fabrics with heat treatment have darker and deeper red-yellow color than which by sunlight and xenon radiation.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.575-581
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• 1990

The existence of the equivalent point for a thermal processing system was demonstrated using arbitrarily chosen ideal direct heating curves. i.e. isothermal heating curves at $120^{\circ}C$ for 10min and at $135^{\circ}C$ for 10sec. Under these conditions, G-values and F-values were calculated at various values of Ea- and z-values by applying the Arrhenius and the Bigelow models respectively. The equivalent time and equivalent temperature were determined by both line intersection and linear regression methods. The equivalent points estimated by both the line intersection and the linear regression methods were consistent and their values were the same as the heating time and temperature of the ideal direct heating curves.

• Food Science of Animal Resources
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• v.18 no.3
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• pp.269-275
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• 1998

The purpose of this study was to determine the thermal inactivation of Salmonella enteritidis, Salmonella typhimurium and E. coli O111 in liquid cultures treated with microwave energy. Furthermore, this study was to introduce new methodologies for studying nonthermal microwave effects on microorganisms, using controlled microwave energy and specially designed apparatuses. For the automatic temperature control during microwave heating, the real time data acquisition and computation system is designed with BASIC routine. The automatic temperature control system used in the experiments perform relatively stable control at the experiment temperature of 45, 50, 55 60$^{\circ}C$ and 65$^{\circ}C$ for 30 minutes. The effects of microwave heating on liquid cultures was compared with that of conventional heating, still reduces effectively the number of pathogenic bacteria in liquid cultures. While no particular differences between microwave heating and conventional heating was observed in the activation of E. coli at 45$^{\circ}C$ test, the activation of Sal. enteritidis and Sal. typhimurium was slightly reduced during the microwave treatments.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.2
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• pp.162-168
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• 1997

Digital variable structure controller(DVSC) is implemented to control the temperature for the hot water heating circulating pump control system. For the DVSC, a control algorithm is suggested, which using a nonlinear sliding surface and a PID sliding surface outside and inside of steady state error boundary layer, respectively. Smith predictor algorithm is used for the compensation of long dead time. The DVSC of the suggested algorithm yields improved control performance compared with the one of existing algorithm. The system responses with the suggested DVSC shows good responses without overshoot and steady state error inspite of heating load change. By decreasing sampling time, dead time and rise time are increasing, and system output noise by flow dynamics is amplified.