• International Journal of Air-Conditioning and Refrigeration
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• 제12권4호
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• pp.206-213
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• 2004

Cycle test for developed phase change material (PCM) is necessary in order to assess the variation of latent heat, which decreases with time by deterioration. T-history method and measurement using heat-flux meter are appropriate for the cycle test in a tube filled with PCM because they do not need an extraction of sample in measuring heat of fusion. In the present study, these methods were applied to a PCM having a melting point below a room temperature, different to the past studies for PCMs melting above a room temperature. As a result of experiment using pure water as specimen, we can obtained rea-sonable values for heat of fusion.

• 한국기계가공학회지
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• 제20권7호
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• pp.1-7
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• 2021

Restrictions on the emissions of nitrogen oxides, sulfur oxides, carbon dioxide, and particulate matter from marine engines are being tightened. Each of these emissions requires different reduction technologies, which are costly and require many pieces of equipment to meet the requirements. Liquefied natural gas (LNG) fuel has a great advantage in reducing harmful emissions emitted from ships. Therefore, the marine engine application of LNG fuel is significantly increasing in new ship buildings. Accordingly, this study analyzed the internal support structure, insulation type, and fuel supply piping system of a 35 m3 International Maritime Organization C type pressurized storage tank of an LNG-fueled ship. Analysis of the heat transfer characteristics revealed that A304L stainless steel has a lower heat flux than A553 nickel steel, but the effect is not significant. The heat flux of pearlite insulation is much lower than that of vacuum insulation. Moreover, the analysis results of the constraint method of the support ring showed no significant difference. A553 steel containing 9% nickel has a higher strength and lower coefficient of thermal expansion than A304L, making it a suitable material for cryogenic containers.

• 콘크리트학회논문집
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• 제25권3호
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• pp.331-338
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• 2013

최근 국가적 차원의 녹색성장이라는 패러다임 아래 건설분야에서도 자원과 에너지 절감을 위한 다양한 노력이 시도되고 있다. 이러한 방안의 하나로 단열성능이 향상된 콘크리트의 개발을 목적으로 높은 열저장 용량의 장점이 있는 PCM(phase change material)을 다공성의 경량골재에 함침 및 코팅 처리하여 경량골재 콘크리트를 개발하였으며 이를 평가하였다. 그 결과 흡수율이 높은 경량골재는 PCM 함침 및 코팅에 의해 흡수율이 저하되어 높은 흡수율에 따른 경량골재 콘크리트의 품질 저하를 방지하는 효과가 있음을 확인하였다. 또한 함침하지 않은 경량골재를 사용한 경량골재 콘크리트의 열전도율은 보통골재 콘크리트보다 약 33%의 단열성능 향상을 보였으며 함침된 골재의 경우 보통골재 콘크리트에 비해 40~43%의 단열성능 향상이 있는 것을 확인하였다. 또한 함침된 골재의 경우 비함침 골재에 비해 열전도율이 12~14% 정도 낮아지는 것을 확인 할 수 있었다.

• 한국산업융합학회 논문집
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• 제14권3호
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• pp.87-93
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• 2011

When applying back panel(this material is aluminum complex panel coated with fire resistance substances) for curtain wall, solar radiation and heat storage of indoor air occurs to result in thermal warpage for back panel. The purpose of this analysis is to find out the cause of thermal warpage and come up with a solution to prevent changes of back panel and reduce elements that bring negative visual elements. Also to solve this problem analyse that case to reduce heat transfer by inserting additional material and cases to increase air space distance.

• 한국산업융합학회 논문집
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• 제12권3호
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• pp.163-169
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• 2009

A preheating module for domestic heating facility will increase a energy efficiency. That collects the wasted heat of exhaust gas and saves the energy. So a heating load is decreased because of a preheating that has a heating energy. Using of a preheating module, a boiler can reduce frequent operation of a burner. So it is increased persistence, decreased discharging noxious gases. Therefore we will intend to develop a heating facility that is a convenient system for the saving energy.

• 설비공학논문집
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• 제13권12호
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• pp.1223-1229
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• 2001

Though conventional calorimetry methods such as differential scanning calorimetry (DSC) and differential thermal analysis (DTA) are used generally in measuring heat of fusion, T-history method has the advantages of a simple experimental apparatus and no requirements of sampling process, which is particularly useful for measuring thermal properties of inhomogeneous phase change materials (PCMs) in sealed tubes. However, random criteria (a degree of supercooling) used in selecting the range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion. In the present study, it was shown that a 40% discrepancy exists between the original T-history and the present methods when analyzing the same experimental data. As a result, a reasonable modification to the original T-history method is proposed.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권1호
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• pp.32-39
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• 2003

Though conventional calorimetry methods such as differential scanning calorimetry and differential thermal analysis are used generally in measuring heat of fusion, T-history method has advantages of a simple experimental apparatus and no requirements of sampling process, which is particularly useful for measuring thermophyical properties of in-homogeneous phase change materials in sealed tubes. However, the degree of supercooling used in selecting a range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion. In the present study, it was shown that a 40% discrepancy exists between the original T-history and the present methods when analyzing the same experimental data. As a result, a reasonable modification to the original T-history method is proposed.

• 한국식품조리과학회지
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• 제32권3호
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• pp.316-324
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• 2016

Purpose: This study chose Vaccinium oldhamii as a material to complement the redness of Sansuyu, which is unstable to heat, to Sansuyu pudding. Methods: The level of browning and hunter color of Corni fructus juice supernatant (CFS) and Vaccinium oldhamii extract (VOE) were examined and dependent on heating time and storage period. Results: A value (redness) of VOE was high, browning was moderate during the storage period, and though the storage period was extended, the value stayed stable, meaning overall redness was maintained. With the increase in the amount of added VOD, the color preference of Sansuyu pudding, and D (VOE 10.0%) was marked the highest at 5.80. As for the preference of texture, B (VOE not added) was the highest at 5.35, but C (VOE 5.0%) was marked the highest at 5.10 for overall preference. The DPPH radical scavenging ability of Sansuyu pudding was 15.86-21.39% at a concentration of 1,000 ppm, and the total polyphenol content was 136.76-139.62 mg/100 g. Since the redness of Sansuyu is unstable to heat and then is heated, its degree of browning and b value (degree of yellowness) increases. Conclusion: So if a material with a red color that is stable to heat is added to Sansuyu, the preference of Sansuyu products will improve.

• 한국축산식품학회지
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• 제21권3호
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• pp.235-245
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• 2001

This study was conducted to evaluate the usefulness of Second-Heat-Seal film(SHS) as an alternative material to PVDC/EVA shrink film(VSP) being currently used by domestic meat packer for vacuum-packaging of fresh meat. The samples from pork loin and beef striploin and round were stored at 2$^{circ}C$ for 5 weeks and measured for the changes of microbial counts, color, pH, volatile basic nitrogen(VBN), purge loss and sensory parameters. The pork loins packed with SHS showed higher spermine contents during the whole storage period at 2$^{circ}C$, and lower counts in total microbes and lactic acid bacteria after 28 days storage at 2$^{circ}C$ than those packed with SHS tended to be lower than those packed with VSP over the storage time. Nevertheless, no significant differences were observed between two packaging treatments in the other quality parameters evaluated. It is therefore concluded that SHS film might have a possibility to substitute for VSP film for vacuum-packaging of fresh meat at least from a materials point of view.

• 한국태양에너지학회 논문집
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• 제35권1호
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• pp.97-106
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• 2015

Gypsum board is easy to manufacture of a variety of forms and has stable mechanical properties and thermal properties. And gypsum boards are widely used to the walls and ceiling of the building as the interior building materials. The studies about technology of applying the various features in the gypsum board with additives are being actively investigated. Development methods for enhancing performance of the gypsum board using additives are largely divided into two categories. The first case is functional gypsum board that is to improve the moisture absorption and moisture-proof properties. Also studies of adsorption and decomposition of indoor air pollutants of the gypsum board using porous materials as an additive are being actively investigated. Another case is applying thermal storage materials which gives the heat storage performance to gypsum board. In this paper, we would like to introduce the various cases of gypsum board applied various additives.