• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.1-3
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• 2009

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.131-134
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• 1990

Many papers have been published on drying shrinkage of hardened cement paste and cement mortar. The causes of drying shrinkage in cement mortar may be attributed to its mechanical properties, temperature, curing time and the evaporation of water from cement mortar. This paper deals only with drying shrinkage in cement mortar. In particular, the relationships between water evaporation and drying shrinkage are discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.719-725
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• 2000

In order to save the energy and to protest environmental conservation, a evaporation type of PTC heater was developed as a Part of replacement in automobile industry. The honeycomb type of PTC heater made by Texas Instrument draw a much attention for this purpose. Especially this paper will describe the general and characterize the typical electrical properties of PTC heater for the application of automobile in detail.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
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• pp.30-30
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• 2005

• Carbon letters
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• 제3권3호
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• pp.142-145
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• 2002

Multiwall carbon nanotubes (MWNT) were produced using the arc-discharge graphite evaporation technique. Composite films were developed using MWNT dispersed in polystirol polymer. In the present work, various properties of the polymeric thin film containing carbon nanotubes were investigated by optical absorption, electrical resistivity and the same have been discussed.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3208-3212
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• 2012

Controlled drug delivery systems employing microparticles offer lots of advantages over conventional drug dosage formulations. Microencapsulation technique have been conducted with biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA) and poly(lactic acid) (PLA) for its adjustable biodegradability and biocompatibility. In this study, we evaluated two techniques, oil-in-water (o/w) emulsion solvent evaporation and spray drying, for preparation of polymeric microparticles encapsulating a newly synthesized drug, SS-AG20, for the long-term drug delivery of this low-molecular-weight drug with a very short half-life. Drug-loaded microparticles prepared by the solvent evaporation method showed a smoother morphology; however, relatively poor encapsulation efficiency and drastic initial burst were discovered as drawbacks. Spray-dried drug-loaded microparticles had an imperfect surface with pores and distorted portions so that its initial burst was critical (70.05-87.16%) when the preparation was carried out with a 5% polymeric solution. By increasing the concentration of the polymer, the morphology was refined and undesirable initial burst was circumvented (burst was reduced to 35.93-74.85%) while retaining high encapsulation efficiency. Moreover, by encapsulating the drug with various biodegradable polymers using the spray drying method, gradual and sustained drug release, for up to 2 weeks, was achieved.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.67-73
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• 2009

Recently, Europe decided to start the regulation of diesel engine nanoparticles because of its well known adverse health effects. The diesel nanoparticles can be classified as solid carbon particles and volatile particles. The volatile particles generates during dilution process by condensation of gas phase volatile compounds such as hydrocarbon. The new nanoparticle regulation considers only solid particles because of difficulty of measurement of volatile particles. The aim of this study is to suggest a proper dilution method that prevent the volatile particle generation. As a result, it is found that the $1^{st}$ dilution air temperature should be above $120^{\circ}C$ in order to prevent volatile particle generation effectively. It is also found that the volatile particles can be removed effectively in the evaporation tube by the increase of evaporation tube temperature. But when exhaust gas is hot enough (>$190^{\circ}C$, in this study) and it is diluted in the first diluter with high temperature air (>$120^{\circ}C$), removal phenomenon of volatile particles by increasing of evaporation tube temperature can not be seen. It means that there are no volatile particles in the diluted exhaust gas. Additionally, dilution ratio is not an important factor for volatile particle generation compared with dilution air temperature or evaporation tube temperature.

• 한국식품과학회지
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• 제22권4호
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• pp.479-485
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• 1990

증발 농축공정중 각종 운전 조건의 제어 및 데이터 수집을 자동으로 하기 위하여 제어 및 데이터 수집 부위에 각종 조절기와 센서를 부착하여 컴퓨터 프로그램에 의하여 공정이 진행되도록 하였다. 증발 농축 장치는 원심식 박막증발기인 Centri-Therm$(CT-1B,\;{\alpha}-Laval\;Co.,\;Sweden)$이 이용되었으며 제어 변수로는 증발기의 압력, 급액 속도, 증기의 온도 및 냉각수의 유량 등을 택했다. 그리고 데이타 수집 부위로는 급액 및 농축액의 온도와 농도, 냉각수의 입구 및 출구 온도, 증기의 온도, 증발 온도, 원료 및 농축액의 중량 변화, 응축수의 양 등을 택했다. 운전 프로그램은 PASCAL language를 이용해 작성하였으며 전 공정은 균일하게 콘트롤되었다. 냉각수는 밸브 콘트롤러에 의해 시간당 125kg의 유속으로 흐르도록 하였으며 급액 속도 125/h에서 최대 증발 속도는 41.7kg/h였다.

• 한국해양공학회지
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• 제28권6호
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• pp.517-526
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• 2014

The leakage of cryogenic LNG through cracks in the insulation membrane of an LNG carrier causes the hull structure to experience a cold spot as a result of the heat transfer from the LNG. The hull structure will become brittle at this cold spot and the evaporated natural gas may potentially lead to a hazard because of its flammability. This paper presents a computational model for the LNG flow and heat diffusion in an LNG insulation panel subject to leakage. The temperature distribution in the insulation panel and the speed of gas diffusion through it are simulated to assess the safety level of an LNG carrier subject that experiences a leak. The behavior of the leaked LNG is modeled using a multiphase flow that considers the mixture of liquid and gas. The simulation model considers the phase change of the LNG, gas-liquid multiphase interactions in the porous media, and accompanying rates of heat transfer. It is assumed that the NO96-GW membrane storage is composed of glass wool and plywood for the numerical simulation. In the numerical simulation, the seepage, heat diffusion, and evaporation of the LNG are investigated. It is found that the diffusion speed of the leakage is very high to accelerate the evaporation of the LNG.

• 대한기계학회논문집B
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• 제38권1호
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• pp.41-48
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• 2014

Urea-SCR 시스템은 주로 열해리와 증발시간의 부족으로 인해 발생하는 암모니아 슬립 현상과 관련된 몇 가지 문제점들을 가지고 있으며, 이러한 문제점들은 분사된 요소수용액의 불균일한 분포를 초래한다. 따라서 본 연구에서는, 배기가스와 요소수용액 사이의 증발 및 혼합특성을 강화시키기 위해 인젝터 장착 각도 그리고 믹서의 장착 및 설치 각도와 같은 다양한 매개변수들을 바꾸며 전산해석 연구를 수행하였다. 그 결과, 이와 같은 매개변수들이 배기가스와 요소수용액의 증발 및 혼합특성에 상당한 영향을 미친다는 것을 알 수 있었으며, 이 매개변수들의 최적화가 요구된다. 또한, 본 논문은 Urea-SCR 분사 시스템의 DeNOx 성능을 증가시키고 암모니아 슬립을 감소시키기 위한 최적 설계 시 유용한 기준을 제안할 것이다.