• 한국염색가공학회지
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• 제15권6호
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• pp.33-38
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• 2003

This study surveys the effects of POY physical properties and processing conditions of belt texturing machine to the textured yarns. The various textured yarns are made with the variations of 1st heater temperature, draw ratio, velocity ratio, and the physical properties of these specimens such as yam linear density, tenacity, breaking strain, and wet and dry thermal shrinkages are measured and analysed with the various processing conditions of texturing machine. Especially, the thermal characteristics of the textured yarns, which are affected at the fabric hands and the determination of the processing conditions in the dyeing and finishing processes, are investigated through the thermal stress analyser and DSC experiments.

• 설비공학논문집
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• 제28권7호
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• pp.283-287
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• 2016

One of the most important factors for determining the thermal performance of an evaporative cooling system is the wettability of the evaporative heat exchanger surface. Evaporation of a widely spread water film on the heat exchanger surface promotes heat transfer between the "dry" air and "wet" air passages. Hydrophilic coating is generally applied on the heat exchanger surfaces to increase the wettability of the heat exchanger surface and the COP of the evaporative cooling system. In this paper, a simple lamellar patterned structure is suggested to maximize the spreading of a water film on the vertically oriented walls. The capillary height of the lamellar structured grooves is analyzed through a theoretical model, and the results are compared with the numerical analysis through a finite element analysis tool, SE-FIT. A good agreement between the theoretical model and the numerical analysis can be observed as long as the channel depth is comparable to or larger than the channel width of the lamellar structure.

• 한국강구조학회 논문집
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• 제28권2호
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• pp.97-108
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• 2016

금속용사 또는 도장은 강구조물의 방식에 널리 사용되고 있다. 금속용사와 도장의 복합피복방식법은 혹독한 부식환경하에 놓인 강구물의 새로운 일반적 피복방식법으로 선택되고 있다. 본 연구에서는 아연, 아연-15%알루미늄 합금, 알루미늄, 알루미늄-5%마그네슘 합금의 4종류 금속용사 후 실링 처리한 시편, 4종류 금속용사 후 중방식 도장한 시편과 도장한 시편에 대해 175일간의 NORSOK M-501 부식촉진실험, 250일간의 해수 Wet/dry 반복 부식실험, 3년간의 해양환경 옥외노출실험을 실시하였다. 그 결과, 외관관찰에 근거하여 각 방식법의 내후성능을 비교, 검토하였다.

• 한국생활과학회지
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• 제7권2호
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• pp.113-119
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• 1998

The purpose of this study was to investigate the effect of geometrical structure on the heat transfer of insulating nonwovens. Commercially available single and double layered polyester nonwovens have used. Thermal conductivity, k and thermal conductance, h were measured by using a constant temperature sandwich type device at dry and wet state. The results obtained were as follows: 1. Double layered nonwovens showed slightly lower thermal conductance and higher warmability than single layered nonwovens. 2. As moisture regain increased, double layered nonwovens showed higher increasing rate of thermal conductivity than single layered nonwovens.

• 콘크리트학회지
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• 제9권1호
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• pp.143-151
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• 1997

전기로 집진 분진상의 중금속(Pb, $Cr^{6+}$, Cu, Cd, Zn)을 함침시킨 규조토를 열처리방법($750^{\circ}C$-30분)으로 활성화하였다. 활성규조토로 일반시멘트 모르터의 시멘트양을 중량비로 0%, 2.5%, 5.0%, 10%, 20%까지 대체하고 압축강도와 화학저항성을 조사하였다. 화학저항성 조사에는 습윤건조반복실험(Wetting /Drying Cycle)과 화학침식저항성($H_2SO_4,\; CaCl_2,\; MgSO_4$)이 포함되었다. 결과에 의하면 일반시멘트 모르터에 활성규조토를 시멘트에 10%까지 치환하여 갈수록 압축강도(28일)는 증가하였다. 최고의 압축강도는 활성규조토가 10%까지 치환하였을 때 $496kgf/cm^2$이었으며, 활성규조토가 전혀 혼합되지 아니한 시멘트 모르터의 압축강도($391kgf/cm^2$)보다 약 275까지 증가되었다. 이때 중금속들은 99% 이상의 고정율을 보였으며 Wet/Dry cycle 및 화학침식저항성에서도 활성규조토가 혼합된 시멘트 모르터가 일반 시멘트 모르터보다 훨씬 높은 저항성을 보였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.436-439
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• 2008

It has been known that the value of soil resistance drops when a high impulse curennt is injected into a grounding electrode. In this paper, impulse generator is used to investigate the dry soil and wet soil characteristics in cylinderical test cell. The impulse resistances and breakdown characteristics were discussed based on its voltage and current traces. As a result, sand resistances are decreased with increasing the applied currents. It was thought that a decrease in resistance of dry sand with increasing current is due to both thermal and ionization processes. On the other hand, in case there is no water presence in the soil, the reduction in resistance as the currents are of dry sand increased is mainly due to the ionization process.

• 한국의류학회지
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• 제32권1호
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• pp.157-165
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• 2008

Transient thermal response of five types of underwear(cotton jersey, wool jersey, nylon jersey, cotton mesh and polyester mesh) for a protective coverall is evaluated using a sweating thermal manikin. Experimental protocol for transient thermal response of the sweating thermal manikin was also proposed. As results, it was found that steady state thermal response from sweating thermal manikin was not sensitive enough to evaluate thermal comfort of the experimental garments. However, when half time is used as an index of the heat flux change in transient thermal response, difference was found among underwear materials. Half time of cotton was the shortest and heat transfer of cotton was the fastest followed by polyester mesh, cotton jersey, nylon jersey and wool jersey. Dynamic thermal response of wool underwear was quite different from that of cotton underwear. Wool shows quite less heat flow at the initial stage, however, moisture permeability of wool was higher than cotton at the later stage. It was difficult to distinguish surface temperature difference visually using thermogram taken right before the completion of dry and wet test in steady state thermal response.

• 한국전산유체공학회지
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• 제21권2호
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• pp.54-61
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• 2016

When spent fuel assemblies from the reactor of nuclear power plants(NPPs) are transported, the assemblies are exposed to short-term operations that can affect the peak cladding temperature of spent fuel assemblies. Therefore, it needs to perform the analysis of heat transfer on spent fuel dry cask during the operation. For 3 dimensional computational fluid dynamnics(CFD) simulation, it is proposed that the short-term operation is divided into three processes: Wet, dry, and vacuum drying condition. The three processes have different heat transfer mode and medium. Metal transportation cask, which is Korea Radioactive Waste Agency(KORAD)'s developing cask, is evaluated by the methods proposed in this work. During working hours, the boiling at wet process does not occur in the cask and the peak cladding temperatures of all processes remain below $400^{\circ}C$. The maximum peak cladding temperature is $173.8^{\circ}C$ at vacuum drying process and the temperature rise of dry, and vacuum drying process occurs steeply.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.415-417
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• 2005

In order to retrieve the latent and sensible heat fluxes, high-resolution airborne imageries with visible, near infrared, and thermal infrared bands and ground-base meteorology measurements are utilized in this paper. The retrieval scheme is based on the balance of surface energy budget and momentum equations. There are three basic surface parameters including surface albedo $(\alpha)$, normalized difference vegetation index (NOVI) and surface kinetic temperature (TO). Lowtran 7 code is used to correct the atmosphere effect. The imageries were taken on 28 April and 5 May 2003. From the scattering plot of data set, we observed the extreme dry and wet pixels to derive the fitting of dry and wet controlled lines, respectively. Then the sensible heat and latent heat fluxes are derived from through a partitioning factor A. The retrieved latent and sensible heat fluxes are compared with in situ measurements, including eddy correlation and porometer measurements. It is shown that the retrieved fluxes from our scheme match with the measurements better than those derived from the S-SEBI model.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.56-59
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• 2000

In this paper, we have made a comparison between secondary ion mass spectroscopy(SIMS) data by the 5kcV-15keV boron implantation and computer simulation results. In order to make electrical activation of implanted carriers, thermal annealing are carried out by RTP method for 30s at 1000$^{\circ}C$ Two dimensional doping concentration distribution from different mask dimensions under inert gas annealing, dry-, and wet-oxidation condition were calculated and simulated with microtec simulator.