• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.2 s.233
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• pp.271-278
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• 2005

In this paper, the performance of Kim-chi refrigerator with three evaporator and one compressor was investigated in employing $55\%$ propane and $45\%$ isobutane (R290/R600a) refrigerant mixture as an alternative refrigerant of R134a. The drop-in test was performed by varying both refrigerant charge and capillary tube length in order to find both the performance and reliability of a small multi-refrigeration system. Results show that the power consumption is decreased by about $15\%$ and COP is increased by about $10\%$, respectively as compared to the baseline system using R-134a. In addition, the propane/isobutane refrigerant mixture system took advantage of the minimization of modification and redesigning of system components because thermodynamic properties such as saturation pressure, temperature, normal boiling point(NBP) characteristics are similar to those of R134a. The reduction of sales cost is caused by the decrease of refrigerant cost per unit mass and refrigerant charge amount necessary for the refrigeration system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.9
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• pp.816-823
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• 2005

This paper deals with the heat exchange performance prediction of a counter flow type double-tube condenser for natural refrigerant mixtures composed of Propane/n-Butane or Propane/i-Butane in a smooth tube and a micro-fin tube. The local characteristics of heat transfer, mass transfer and pressure drop are calculated using a prediction method developed by the authors. The total pressure drop and the overall heat transfer coefficient are also evaluated on various heat exchange conditions. The calculated results of the natural refrigerant mixtures are compared with HCFC22. In conclusion, natural refrigerant mixtures composed of Propane/n-Butane or Propane/i-Butane are appropriate candidates for alternative refrigerant from the viewpoint of heat transfer characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.3 s.234
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• pp.417-423
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• 2005

This paper describes the engine performance of a Homogeneous Charge Compression Ignition(HCCI) engine according to Exhaust Gas Recirculation(EGR), cylinder-to-cylinder, fuel of propane and butane. HCCI engines are being considered as a future alternative for diesel and gasoline engines. HCCI engines have the potential for high efficiency, very low NOx emissions and very low particulate matter(PM). On experimental work, we have done an evaluation of operating conditions in a 4-cylinder compression engine. The engine has been run with propane and butane fuels at a constant speed of 1800rpm. This work is intended to investigate the HCCI operation of the engine in this configuration that has been modified from the base diesel engine. The performance and emissions of the engine are presented. In this paper, the start of combustion(SOC) is defined as the $50{\%}$ point of the peak rate of heat release. SOC is delayed slightly with increasing EGR. As expected, NOx emissions were very low for all EGR range and nbuned HC and CO emission levels were high. CO and HC emissions are lower with using propane than butane as fuels of HCCI engines.

• Membrane Journal
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• v.23 no.5
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• pp.367-374
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• 2013

In the present study, Pebax-2533 plate membranes were prepared by drying precursor solutions which were obtained by dissolving Pebax-2533 polymer in 1-Propanol/n-Butanol mixed solvents. And then the $CO_2$ and $N_2$ permeation behaviors were tested by using a time-lag system. The prepared Pebax-2533 plate membranes showed a considerable $CO_2/N_2$ separation performance : the $CO_2$ permeability was 130 to 288 barr, and the $CO_2/N_2$ permselectivity was 5-8. The $CO_2$ permeation data obtained by varying feed pressure, permeation temperature, and solvent composition announced that not only the $CO_2$ sorption but also the $CO_2$ diffusion is equally important in the overall $CO_2$ permeation.

• Journal of the Korean Vacuum Society
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• v.10 no.3
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• pp.289-297
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• 2001

Highly-porous $SnO_2$thin films were prepared for recognizing and detecting of the inflammable gases, like butane, propane, LPG, carbon monoxide. To obtain sensing films, Sn, Pt/Sn, Au/Sn, and Pt,Au/Sn films were deposited employing a thermal evaporator for Sn film and a sputter for novel metals of Pt or/and Au. These films were annealed for 2 h at $700^{\circ}C$ to form $SnO_2$-based thin films. The films showed the tetragonal structure and also exhibited many defects and porosity, which could give high sensitivity to thin films. The thin films showed high sensitivity and reproductivity to the tested gases(butane, propane, LPG, and carbon monoxide) to even to low gas concentrations in range of workplace environmental standards. Especially, Pt/$SnO_2$film showed the highest sensitivity to butane, LPG, and carbon monoxide. And pure $SnO_2$ film manifested the highest sensitivity to propane. By using the sensing patterns from the films, we could reliably recognize the kinds and the quantities of the tested inflammable gases within the range of the threshold limit values(TLV) and the lower explosion limit(LEL) through the principal component analysis(PCA).

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.753-756
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• 1993

Studies on the molecular interactions of dimethylsulfoxide (DMSO) with water and/or some alkanols were carried out by vapor pressure osmometry at 40$^{\circ}C$. Negative deviation from Raoult's law was observed for the DMSO-water, methanol, ethanol, 1-propanol, 2-propanol, and 2-methyl-1-propanol systems, whereas positive deviation from Raoult's law was observed for the DMSO-1-butanol and 1-pentanol systems. The results were interpreted in terms of molecular interactions between unlike molecules, and of self-association of DMSO molecules, respectively. Measured chemical shift of hydroxyl proton of the solvents also supported the results.

• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.42-49
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• 2007

가스크로마토그래피 불꽃이온화검출기(FID)에서, 천연가스 표준물질만을 사용하여 분석할 때 발생할 수 있는 분석 불확도에 대하여 연구하였다. 일반적으로 $10^5$ 범위 농도까지 직선성이 확보된 것으로 알려진 FID 검출기에 대하여 실제 분석에서 동일한 직선성이 확보되는지를 확인하였다. 본 연구에서 7성분으로 조성된 천연가스용 표준가스를 샘프링 loop의 크기를 1.0mL, 0.50mL, 0.25mL로 변환시키면서 GC/FID를 사용하여 분석한 상대표준불확도 결과는 다음과 같다. 메탄은, 0.458 %, 에탄은 0.20247%, 프로판은 0.1497%, i-부탄은 0.1854 %, n-부탄은 0.2977%, i-펜탄은 0.263%, n-펜탄은 0.383%이었다. 각 경우에서 직선성 상대표준불확도값이 $0.15%{\sim}0.45 %$까지 이른다. 일반적으로 농도가 높은 메탄의 경우에 직선성 불확도값이 큰 값을 보여 주었고 농도범위가 1-5%인 $C2{\sim}C5$의 경우는 작은 직선성 표준불확도를 나타내었다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.316-321
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• 2002

석유화학공업의 발달로 국내에서 생산되는 원유 및 납사 등의 물량이 크게 증가하였으며 이와 함께 석유화학산업의 부산물의 발생량도 크게 증가하였다. 프로판과 부탄 역시 석유화학산업의 부산물로 생성되는 품목들로 이것들에 대한 용도개발과 부가가치를 높이기 위한 연구가 필요하다. 국내에서의 LPG시장도 휘발유가격의 상승 및 환경문제 등으로 기존의 휘발유에서 LPG로의 전환과 함께 사용량이 급격히 증가하고 있다.(중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.99-104
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• 2001

석유화학공업의 발달로 국내에서 사용되는 원유 및 Naptha등의 물량이 증가함에 따라 프로판과 프로필렌, 부탄 등의 석유화학 산업의 부산물 발생량이 크게 증가하였으며 이들의 활용에 따른 문제점들을 보다 체계적인 연구와 기술개발을 함으로써 고부가 창출과 함께 LPG수입 대체에 일익을 담당할 수 있을 것이다.(중략)

• Journal of the Korean Chemical Society
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• v.49 no.5
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• pp.441-448
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• 2005