• Corrosion Science and Technology
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• 제9권6호
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• pp.247-253
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• 2010

The characteristics of selective oxidation prior to hot-dip galvanizing with the annealing atmosphere dew point and chemical composition in dual-phase steels and their effect on the inhibition layer formation relevant to coating adhesion have been studied using a combination of electron microscopic and surface analytical techniques. The annealed and also galvanized samples of 3 kinds of Si/Mn ratios with varied amounts of Si addition were prepared by galvanizing simulator. The dew point was controlled at soaking temperature $800^{\circ}C$ in 15%$H_2$ -85%$N_2$ atmosphere. It was shown that good adhesion factors were mainly uniformity of oxide particle distribution of low number density and low Si/Mn ratio prior to hot-dip galvanizing. Their effect was the greatly reduced coating bare spots and the formation of uniform inhibition layer leading to good adhesion of Zn overlay. The mechanism of good adhesion is suggested by two processes: the formation of inhibition layer on the oxide free surface uncovered with no $SiO_2$-containing particles in particular, and the inhibition layer bridging of oxide particles. The growth of inhibition layer was enhanced markedly by the delayed reaction of Fe and Al with the increase of Si/Mn ratio.

• 한국콘텐츠학회논문지
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• 제11권11호
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• pp.42-48
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• 2011

본 논문에서는 교량구간의 도로 결빙예측 및 감지를 위한 시스템 설계를 제안하였다. 센서 노드의 하드웨어는 마이크로프로세서, 온도 센서, 습도 센서, 그리고 Zigbee 무선 통신으로 구성되었다. 관제센터의 소프트웨어는 관제센터에 수집된 교량 온도, 습도 데이터로 관찰하기 위하여 구현되었다. 교량 노면의 결빙은 노면의 온도가 이슬점 온도 이하이면서 영하일 때 발생한다. 제안된 시스템을 이용하여 도로면의 온도 및 습도 분포를 측정하였다. 측정 데이터는 도로 결빙이 발생하는 시점을 예측하기 위하여 사용되었다. 실제 결빙되는 것보다 최소 30분 이전에 결빙시점을 예측하여 경고가 이루어진다. 이 결과로 결빙으로 인한 교통사고를 방지하기 위하여 사용 할 수 있다.

• 수산해양교육연구
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• 제26권5호
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• pp.1083-1089
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• 2014

The aims of this study are to find out the possibility of the charcoal as a desiccant. The only humidity control under high temperature and high humidity environment can be provided to the thermal comfort at indoor environment. Functionality of charcoal is known to be deodorization, antiseptic effect, filtering effect and humidity control. But research related to humidity control in the country not yet. Thus, the dehumidification capacity of the charcoal experimental results to see the results were as follows : 1) Entering the experimental humidification is 148.02 g/h, 161.05 g/h and 243.2 g/h when air velocity was changed 1.5 m/s, 1.7 m/s and 2.0 m/s. 2) When the basis weight of the charcoal 2.0 m/s air velocity to obtain the largest number of adsorption capacity. 3) Dru bulb temperature and dew point temperature ware measured at front and rear of the charcoal. Absolute humidity is calculated from the measured Dry bulb temperature and dew point temperature. The quantity of dehumidification is calculated from absolute humidity is the largest 129.6 g/h at the air velocity 2.0 m/s.

• 한국도로학회논문집
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• 제14권2호
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• pp.55-61
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• 2012

도로표지는 운전자에게 정보제공의 역할을 하는 도로시설물로서 주행경로에 대한 운전자의 판단을 도와준다. 그러나, 주 야간의 온도, 습도 변화로 인한 도로표지판에 결로발생 시, 정보전달의 결함이 발생하여 교통사고 가능성을 높이는 원인으로 작용한다. 따라서, 도로표지판의 결로발생을 예방하기 위한 기술이 필요하다. 본 연구에서는 도로표지판의 결로발생을 예방하는 대안의 효과를 비교하기 위해 단열소재가 삽입된 시편, 결로방지필름이 부착된 시편을 선정하고 결로방지처리가 되지 않은 일반시편과 비교하였다. 분산분석과 사후검정(Tukey HSD)을 통해 각 시편에 발생한 측정시간에 따른 결로량을 비교 했으며, 결로량과 재귀반사도의 관계를 Pearson의 상관분석으로써 검증하였다. 분석결과, 결로방지필름이 부착된 시편에서 결로량이 적게 나타났으며, 결로발생 90초 후에는 결로방지필름의 부착 시편과 단열소재가 삽입된 시편에서 나타나는 결로량은 결로방지 처리가 되지 않은 시편에서 발생한 결로량과의 통계적인 차이가 존재하였다. 또한, 상관분석결과로써 결로량과 재귀반사도는 반비례하는 것으로 나타났다. 따라서, 도로표지판에 발생된 결로량과 재귀반사 변화율에 대하여, 결로방지필름의 부착과 단열소재의 삽입은 결로방지에 효과가 존재하는 것으로 판단된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.6-9
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• 2008

The efficiency and life time of the proton exchange membrane (PEM) fuel cell system is critically changed with its humidity which should be maintained properly during dynamic operation. Membrane humidifier is required to regulate proper humidity level for the design point of the PEMFC system. In this study, we presented the performance of the cylindrical membrane humidifier which is operated as water-to-gas. Dry air pressure, liquid water flow temperature, and air flow rate were chosen as the operating parameters. Humidity level is expressed with dew point.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.285-290
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• 2009

The main thrust of this paper is to investigate acceptable supply air conditions of a dedicated outdoor air system (DOAS) for highrise apartment buildings. As for a typical $132-m^2$ apartment unit, it was assumed that centralized DOAS-Ceiling Radiant Cooling Panel was installed. Transient behavior and control characteristics of each system were modeled numerically using a commercial equation solver program. The optimized dew point temperature of the DOAS was discussed on the basis of the ASHRAE standard 62.1-2007 and the current Korean ventilation standard for apartments. It was found that the optimized dew point temperature of the DOAS supply air accommodating total latent load of a space is $11-12^{\circ}C$ and the appropriate supply air temperature of the DOAS is $11-12^{\circ}C$ in cooling period and neutral temperature of $18-20^{\circ}C$ in intermediate period.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.916-919
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• 2003

In this paper, we deal with a development of measurement system to apply the leakage rates test of primary containment in nuclear power plant. The measurement test about leakage rates in primary containment is one sort of test to prove safety of nuclear power plant. The parameters which are measured to calculate leakage rates are drybulb temperature, dew point temperature(or relative humidity), absolute pressure and flow. Overall, the measurement system consists of sensor module for data acquisition of the parameters, transfer module for wireless data communication and control module to control system and to calculate leakage rates. Because existing measurement systems are difficult to set in field, we pursued convenience of use, we applied wireless data communication and individual form module using battery. We also changed for the better in confidence. Recently, we are developing a drybulb temperature and a dew point temperature sensor module. We describe about function of developed measurement system, its standard and an plan for verification of measurement system.

• Applied Microscopy
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• 제43권1호
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• pp.40-45
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• 2013

Phase transformation by the Mn-deprivation was observed in the high-Mn twinning-induced plasticity-aided steel. Mn-depletion was induced by the formation of Mn-O oxide during the dew-point control process at temperature above $-20^{\circ}C$, which changed austenitic parent phase to multi-grained ferrite. Mixture of Al-O, Al-Mn-Si-O oxides were observed at the grain boundaries of transformed ferrite.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.111-115
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• 2005

The compact storage of ammunitions in magazine causes serious dew problem on the surface of the shell. Lots of previous studies try to solve this problem by increasing the temperature of air in military magazine. They tried to reduce relative humidity by increasing the temperature of air, but all of them failed. One of the major reasons of these failures is analysed based on the point of view of physics.

• 한국초전도ㆍ저온공학회논문지
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• 제12권1호
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• pp.66-70
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• 2010

The operational temperature range of thermosiphon is generally limited from the critical point to the triple point of the working fluid to maintain two-phase state. Thermosiphon with mixed working fluid has a potential to widen the operational temperature range. In this study, the physical behavior of mixed working fluid during the transient operation of thermosiphon was analyzed with temperature-mole fraction diagram. The condenser and the evaporator temperature variations were explained by the dew line and the bubble line of the mixture. It is encouraging that the thermosiphon operation commences early with larger fraction of high boiling point component, but the temperature gap between the condenser and the evaporator due to the separation of two components has a negative effect on the officient cool down process.