• Transactions of the Korean hydrogen and new energy society
• /
• v.8 no.2
• /
• pp.57-65
• /
• 1997

Thermal analysis has been performed to design a high-performance $LH_2$ vessel with about 1% per day evaporation loss. Analysis includes the combined insulations of MLI(Multi-Layer Insulation) and VCS (Vapor-Cooled Shield) under high vacuum. Combined insulation of MLI and VCS shows the existence of optimal location of VCS to minimize evaporation loss. Comparison of parallel-type DVCS (Double Vapor-Cooled Shield) and serial-type DVCS is also made to show the effectiveness of the system. The results indicate that the serial-type DVCS vessel is better than the parallel-type DVCS vessel with respect to overall evaporation loss. The combined insulation of SVCS (Single Vapor-Cooled Shield) with a partial MLI can give a similar performance characteristics compared to that with MLI and DVCS.

• Journal of the Korean Ceramic Society
• /
• v.41 no.2
• /
• pp.102-105
• /
• 2004

ZnO-In$_2$O$_3$ films were fabricated on Corning 1737 glass substrate by an electron beam evaporation technique and their characteristics were investigated. The composition of ZnO-In$_2$O$_3$ films had a marked effect on the electrical properties of the films. The ZnO-In$_2$O$_3$ films showed superior transparent-conducting characteristics with increase of Zn content. The resistivity and carrier concentration of the film having Zn content of 45 at% are 4.45${\times}$10$^{-3}$ cm and 3.1${\times}$10$^{19}$ cm$^{-3}$ , respectively. Also, the transmittance was higher than 80% throughout the visible range. The average roughness of the film was 14.6 $\AA$ in terms of root mean square.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.865-868
• /
• 2004

열 진공 증착법(thermal vacuum evaporation)에 의해 p-형 열전박막을 $3{\times}10^{-4}{\sim}3{\times}10^{-6}$ Torr의 범위에서 유리 기판 위에 제조하였다. 제조된 박막의 전기저항은 고진공일수록 저항이 증가하였으며, $Bi_2Te_3$와 $Sb_2Te_3$상을 가지고 있었다. 박막의 조성은 기판의 위치에 따라 변화하였고, 원자 번호가 작을수록 위치의 영향이 크고, 반대로 원자번호가 큰 원소는 그 영향이 작았다. 또한 고진공에서 제조된 박막일수록 상대적으로 저진공에 비해 조성의 변화가 적게 나타났다.

• ETRI Journal
• /
• v.31 no.4
• /
• pp.351-356
• /
• 2009

We present a simple semiconductor process to fabricate nanogap arrays for application in molecular electronics and nano-bio electronics using a combination of freestanding silicon nanowires and angle evaporation. The gap distance is modulated using the height of the silicon dioxide, the width of the Si nanowires, and the evaporation angle. In addition, we fabricate and apply the nanogap arrays in single-electron transistors using DNA-linked Au nanoparticles for the detection of DNA hybridization.

• Journal of Mechanical Science and Technology
• /
• v.16 no.2
• /
• pp.270-278
• /
• 2002

In order to reduce the exhaust emissions of a spark ignition engine, it is important not only to improve the catalyst conversion efficiency, but also to directly reduce the engine-out exhaust emissions during a cold starting of the engine and warm up periods. The purpose of this study is to evaluate feasibility of a glow plug for an early fuel evaporator. In order to promote atomization, gasoline is injected on the glow plug with room temperature(20$\^{C}$) and high temperature(250$\^{C}$). To analyze the spray behavior characteristics, a PMAS is used to measure the SMD and the dropsize distribution of an impinging spray and a free spray. Results show that the evaporation rate of the impinging spray on the high temperature surface of the glow plug was higher than that of the free spray on the room temperature surface.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.362-365
• /
• 1997

In the field of Micro-Mechanics, it has been known diffcult to integrate the micro-machine with sensor and source line for the conventional copper line cnanot be used in compact and small size. We developed a system to make thethin copper film as a connect line on the poyurethane pipe (2mm in diameter) by the evaporation technique. This system consists of an evaporation chamber two long branches, substrate hoider and a Linear-Rotary motion feed feedthrough. The results showed that thin copper film coated polyurethanc pipe could be applied th the small medical devices such as the micro active endoscope.

• Journal of Power System Engineering
• /
• v.15 no.2
• /
• pp.25-30
• /
• 2011

A fresh water generation system is designed for converting brackish water or seawater into fresh water. In this paper fresh water generation by distillation process that evaporates feed water and subsequently condenses vapor as evaporation product to get fresh water was studied and city water was employed as feed water. The system uses the ejector to create a vacuum, under which liquid can be evaporated at lower temperature than it at normal or atmospheric condition, hence less energy consumption. The effect of various operating conditions i.e. temperature of feed water and different orifice diameters were studied experimentally to investigate the characteristic of the system. It was found that these parameters have significant effect in the performance of fresh water generation system with low pressure evaporation.

• Journal of ILASS-Korea
• /
• v.19 no.1
• /
• pp.15-18
• /
• 2014

In the present study, experiment on the evaporation of pure water droplet on heated surface was conducted, and the evaporative heat transfer coefficients were calculated from experimental results. The pure water droplet of about $10{\mu}l$ was applied onto the heat transfer surface, then the shape of the droplet was analyzed during the evaporation. In addition, the effect of surface roughness on the evaporative heat transfer was also investigated. Experimental results showed that the evaporative heat transfer coefficients increased rapidly along with the increase of surface temperature and the heat transfer coefficients increased with the increase of surface roughness.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.25 no.1
• /
• pp.61-70
• /
• 2001

As important factors determining human sensorial comfort, liquid moisture management and surface properties of heat resistant workwear materials were examined. To figure out liquid moisture management properties of the test materials, absorption capacity, rate of absorption, and evaporation properties were assessed. A modified GATS(Gravimetric Absorbency Testing System) was used to measure the liquid moisture accumulation associated with the wicking of liquid moisture from sweating skin. The GATS procedure measures demand wettability of materials to take up liquid in a direction perpendicular to the fabric surface and it was modified to incorporate a special test cell and cover to assess absorption behavior in the presence of evaporation. Fabric stiffness, smoothness, number and the length of surface fibers, and an estimate of the contact area between the skin and fabric surface were measured to characterize the mechanical and surface properties of the test materials. Also an estimate of the force with which a fabric clings to moist skin was made using as wet-cling index.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.8
• /
• pp.864-869
• /
• 2013

As the size of mechanical components decreases, capillary forces and surface tension become increasingly significant. A major problem in maintaining high reliability of these small components is that of large frictional forces due to capillary action and surface tension. Unlike the situation with macro-scale systems, liquid lubrication cannot be used to reduce friction of micro-scale components because of the excessive capillary and drag forces. In this work, the feasibility of using evaporation to coat a thin film of organic lubricant on a solid surface was investigated with the aim of reducing friction. Petroleum and silicone oils were used as lubricants to coat a silicon substrate. It was found that friction could be significantly reduced and, furthermore, that the effectiveness of this method was strongly dependent on the coating conditions.