• Journal of Energy Engineering
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• v.23 no.4
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• pp.247-255
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• 2014

The present study was conducted to elucidate the characteristics of temperature at the inlet and outlet pipes of a refrigerator drain condenser and suggest the method to predict the temperature of the refrigerant at the inlet and outlet pipes of the drain condenser. For this purpose, a built in style refrigerator was installed in a constant temperature chamber to measure temperatures at the inlet and outlet pipes of the drain condenser. From the results of the present analysis, it could be seen that the measured temperatures changed from $37^{\circ}C$ to $46^{\circ}C$ and the actual refrigerant temperatures were higher than the measured temperatures with the difference magnitude of $8^{\circ}C$ to $22^{\circ}C$. The present study suggested that the temperatures of the refrigerator could be calculated with the measured temperatures by introducing curve fitting of the measured temperature. The predicted refrigerant temperatures by the present study had the accuracy within 6% error of the actual refrigerant temperatures.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.45-53
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• 2012

This study was performed to analyze test results on drying shrinkage for concrete specimens mixed with various constituents in concrete mixes. Test variables are coarse aggregate types(Limestone, Sandstone, Granite, Andesite, Gneiss), fine aggregate types(natural sand, crushed sand) and cement amounts(normal strength, high strength). Epoxy coating of(U&V-H(A,B)) was applied onto the specimen surface to simulate diverse volume surface ratios(22.2, 40, 85.7, 150, 200, 300) with different specimen sizes. The experiments had been executed during 1,014 days at a condition of $20^{\circ}C$ and relative humidity of 60% in environmental chambers. Test results showed that shrinkage strain from the specimen equivalent to real pavement decreased to 39% compared to the standard specimen recommended by KS. Test results also showed that shrinkage strain of the specimen mixed with Limestone was 56~76% of that with Sandstone, thus Limestone mix seems to be suitable to the concrete pavement.

• Journal of Conservation Science
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• v.29 no.4
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• pp.421-435
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• 2013

The purpose of this study is to suggest environmental guidelines for the conservation of ceramics excavated from underwater. Accordingly, the conditional change of the soluble salt on surface of the excavated ceramics was examined by changing the relative humidity. Examining the relative ratio [high humidity(RH70%+RH80%)/low humidity(RH20%+ RH40%)] for 24 weeks using accumulated conductivity(${\mu}s/cm$), the result showed that the amount of ion elution increased more in high humidity than in low humidity. In particular, the ion elution increased significantly within the celadon sample. In addition, comparing the accumulated conductivity and physical characteristics of the samples in high humidity, the results indicated that the amount of the ion elution is proportioned to the increased rate of the sample's absorption capacity and porosity. Ceramics excavated from underwater has risks of the secondary physical and chemical attacks from remaining salts. Therefore, it is suggested these ceramics be stored in a storage which maintains proper temperature and low humidity conditions. Also, the collections need to be pre-classified according to the properties of the materials.

• Clean Technology
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• v.19 no.4
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• pp.469-475
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• 2013

In this research, the stabilization characteristics of upgraded coal using palm oil residues were investigated. The Eco coal, which is the Indonesian low-rank coal, was used as a raw material. The low-rank coal was mixed with palm fatty acid distillate (PFAD), and then dried in a nitrogen atmosphere at $107^{\circ}C$. The trend of spontaneous combustion of upgraded coal was studied by measuring of crossing-point temperature (CPT), low temperature oxidation and moisture readsorption. The results of the CPT measuring and low temperature oxidation showed that the propensity of spontaneous combustion of the upgraded coal was improved compared to the dried coal. The moisture readsorption characteristics of the upgraded coal was also improved. The upgraded coal was stabilized through the surface coating with PFAD, and stability of upgraded coal was proportional to the content of PFAD.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.9-15
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• 2018

Radon gas, which is present on the earth, is a primary carcinogen released from rocks, soil, building materials, etc., and exists as a unique gas phase. In order to solve the risk of radon gas, we evaluated the basic performance which can be used as indoor finishing materials in addition to the radon gas reduction properties of the matrix using anthracite. An anthracite used as a conventional filter material was used to produce a matrix, and a test was conducted to replace the gypsum board, which is one of the building materials used in the existing room. As the anthracite replacement ratio increases, flexural failure load strength increases and thermal conductivity tends to decrease. Depending on the thickness of the board, the reduction performance of radon gas shows a slight difference.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1487-1493
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• 2008

In order to investigate the cooling capacity of multi-heat pump applying an inverter compressor, the experiment on the cooling performance characteristics of heat pump with 3 indoor units was performed under the cooling standard and cooling low-temperature conditions. The system data were measured by the psychrometric calorimeter. The operation characteristics and the behavior of the cooling cycle of the heat pump with 3 indoor units were understood from the cooling capacity, COP, and P-h diagram by indoor-unit combination. The operating load and performance of the multi-heat pump depends on the indoor-unit combination. The cooling capacity and COP of the low temperature condition were larger than those of the standard one. Also the cycle was analyzed by using P-h diagram.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3579-3586
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• 2015

In this study, EEG, HRV, and Vibra image were compared and analyzed in the environmental test room due to stimulation of aroma and color temperature. The condition of the environmental test room was in temperature $25[^{\circ}C]$, relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux] with setting up different sensory stimulation condition which are before exposure, single-sensory stimulation of Jasmine scent, single-sensory stimulation of RED color lighting, and multi-sensory stimulation of Jasmine scent and RED color lighting. The result of this study, at multi-sensory stimulation of Jasmine scent and RED color lighting, relative $S{\alpha}$ wave, SEF50, $SMR/{\theta}$ and SDNN were revitalized, and both sides ${\alpha}$ wave asymmetry index, stress index, fatigue degree, and HRT were decreased. Also, Viba image of tension/anxiety and stress were declined. Therefore multi-sensory stimulation of Jasmine scent and RED color lighting effects to increase the Neuro-energy like amenity, productivity of work efficiency, and concentration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4197-4203
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• 2013

In order to investigate the heating performance of multi-heat pump applying an inverter compressor, the experiment on heat pump with 3 indoor units was performed under the heating standard and heating low-temperature conditions. The performance data of heat pump with 3 indoor units were measured by the multi-psychrometric calorimeter. The operation characteristics and the behavior of the refrigerant cycle of the heat pump with 3 indoor units were understood from the heating capacity, heating COP, and P-h diagram by indoor-unit combination. The present experimental results show that the operating load and performance of the multi-heat pump depends on the indoor-unit combination. The heating capacity and heating COP of the low temperature condition were smaller than those of the standard one. Also the refrigerant cycles on indoor-unit combination were analyzed by using P-h diagram.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.418-425
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• 2013

In this study, the three scents effects on subjects due to EEG type, and it researched to find optimal scent to increase their amenity and productivity. EEG and HRV were compared and analyzed in the environmental test room by classifying subjects into two type: A and B. The condition of the environmental test room was in temperature 31[$^{\circ}C$], relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux] with setting up three different scents which are Rosemary, Jasmine and Hazelnut. The result of this study, at Jasmine scent for A and B type, relative ${\alpha}$ wave, SEF50, $\frac{SMR}{\theta}$ and SDNN were revitalized, and ${\alpha}$ wave asymmetry index, HRT, stress index and fatigue degree were decreased. It was found that favorite scent of A and B type is same as Jasmine scent, but A type was more sensitive than B type about scent. Therefore Jasmine scent is very effective to increase amenity, productivity and concentration, and to decrease stress and fatigue degree.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.183.2-183.2
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• 2013

저항이 낮고 투과도가 일정한 투명전도막(TCF)의 내구성을 향상 및 유지 시키는 연구는 상업화에 가장 필요한 연구 분야이다. 그 중 탄소나노튜브(CNT)와 실버나노와이어(AgNW)를 섞어 만든 CNT-AgNW는 우수한 광투과성과 내화학성 및 균일한 전기 전도성을 갖고 있고 그 기반의 투명전도막은 기존의 ITO 및 CNT 박막보다 우수한 유연성을 갖기 때문에 차세대 플렉시블 디스플레이 소재로서 많은 관심을 모으고 있다. 본 연구는 PET를 이용한 CNT-AgNW로 제작된 투명전도막 위에 물성 및 두께 따른 하드오버 코팅을 통한 내구성 개선 및 유지를 연구하였다. 하드오버 코팅 물질로는 실로콘계 하이브리드 투명 하드코팅 소재를 기본으로 하고 용매 및 용질의 합성 온도를 제어하고 코팅막의 두께(Thin, Thick)를 조절을 통해 내구성 개선을 증진시키려 하였다. 연구결과 물성 향상에 가장 많은 영향을 끼치는 것은 CNT-AgNW 코팅층과 하드오버 코팅층과의 젖음성으로, 그 젖음성이 증가할수록 투과도 및 전기전도도가 향상되는 것을 관찰하였다. 분석 결과, 용매의 비점 및 비중, 용질의 합성 온도가 하드오버코팅 젖음성에 가장 많은 영향을 주는 것을 확인하였다. 또한 항온 항습($85^{\circ}C/85%$) 환경에서 240시간 이상 내구성 테스트 결과 하드오버코팅 물질 중 고온합성 및 고비점 용매를 이용하고 thick 조건이 Thin조건보다 투명전도성 평가 지수(${\sigma}DC/{\sigma}OP$)가 향상 되었다. 또한 Thin에서 면저항(${\Omega}/{\square}$) 변화율이 10% 이상을 보인 반면, Thick에서는 10% 이내의 변화율 유지를 확인하였다.