• Journal of the Korean institute of surface engineering
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• v.27 no.1
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• pp.19-28
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• 1994

A study on adhesion property of evaporated Al-Cr films was conducted on steel sheet by using two-source evaporator. Adhesion of Al-Cr coated steel was evaluated by tape test after $180^{\circ}$bending. Adhesion was decreased with increasing the Cr content in Al-Cr films. It was thought that the decrease in adhesion with increasing Cr content be related to insufficient wetting and diffusion of Cr atoms in the film. Best adhesion was achieved in the case of pure aluminum film..

• Korean Journal of Materials Research
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• v.14 no.2
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• pp.133-140
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• 2004

We carried out anodic aluminum oxide (AAO) on a Si and a sapphire substrate. For anodic oxidation of Al two types of specimens prepared were Al(0.5 $\mu\textrm{m}$)!Si and Al(0.5 $\mu\textrm{m}$)/Ti(0.1 $\mu\textrm{m}$)$SiO_2$(0.1 $\mu\textrm{m}$)/GaN(2 $\mu\textrm{m}$)/Sapphire. Surface morphology of Al film was analyzed depending on the deposition methods such as sputtering, thermal evaporation, and electron beam evaporation. Without conventional electron lithography, we obtained ordered nano-pattern of porous alumina by in- situ process. Electropolishing of Al layer was carried out to improve the surface morphology and evaluated. Two step anodizing was adopted for ordered regular array of AAO formation. The applied electric voltage was 40 V and oxalic acid was used as an electrolyte. The reference electrode was graphite. Through the optimization of process parameters such as electrolyte concentration, temperature, and process time, a regular array of AAO was formed on Si and sapphire substrate. In case of Si substrate the diameter of pore and distance between pores was 50 and 100 nm, respectively. In case of sapphire substrate, the diameter of pore and distance between pores was 40 and 80 nm, respectively

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.552-559
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• 2005

The evaporation pressure drop of $CO_2$ (R-744) in a horizontal tube was investigated experimentally. The experiments were conducted without oil in a closed refrigerant loop which was driven by a magnetic gear pump. The main components of the refrigerant loop are a receiver, a variable-speed pump. a mass flow meter, a pre-heater and evaporator (test section). The test section consists of a smooth. horizontal stainless steel tube of 7.75 mm inner diameter. The experiments were conducted at mass flux of 200 to $500\;kg/m^{2}s$, saturation temperature of $-5^{\circ}C\;to\;5^{\circ}C$. and heat flux of 10 to $40\;kW/m^2$. The test results showed the evaporation pressure drop of $CO_2$ are highly dependent on the vapor qualify, heat flux and saturation temperature. The evaporation pressure drop of $CO_2$ is very lower than that of R-22. In comparison with test results and existing correlations. the best fit of the present experimental data is obtained with the correlation of Choi et al. But existing correlations failed to predict the evaporation pressure drop of $CO_2$. Therefore, it is necessary to develop reliable and accurate predictions determining the evaporation pressure drop of $CO_2$ in a horizontal tube.

• Clean Technology
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• v.15 no.4
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• pp.253-257
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• 2009

The waste solution discharged form the LCD(Liquid Crystal Display) manufacturing process contains phosphoric acid, nitric acid, acetic acid and metal ions such Al and other impurities. In this study, vacuum evaporation and diffusion dialysis was developed to commercialize an efficient system for recovering the high-purity phosphoric acid and manufacturing monoammonium phosphate. By vacuum evaporation, almost 99% of nitric and acetic acid was removed. Also, by diffusion dialysis, about 97.5% of Al was removed. Monoammonium phosphate was manufactured from purified phosphoric acid and ammonium hydroxide. In order to get the optimum manufacturing condition, the molar ratio of ammonium hydroxide and phosphoric acid, pH and temperature was controlled. Using this optimum condition, we obtained the recovery rate of monoammonium phosphate of about 90%.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.399-399
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• 2009

CIS계 화합물 태양전지는 높은 광흡수계수와 열적 안정성 및 Ga 조성 조절을 통한 밴드갭 조절이 용이해 고효율 박막 태양전지로 각광 받고 있다. CIS 태양전지의 광 흡수층 제조 방법으로는 여러 가지 방법이 있지만 본 연구에서는 가장 높은 에너지 변환 효율을 달성한 Co-Evaporation 방법을 사용하기로 하였다. 미국의 NREL의 경우 Co-Evaporation 방법을 사용해 20%의 에너지 변환 효율을 달성한 바가 있다. 하지만 이러한 효율의 태양전지는 실험실에서 연구용으로 제작한 아주 작은 면적으로 태양전지 양산화에 그대로 적용하기는 힘들다. 따라서 CIGS 태양전지의 양산화 적용을 위해 대면적화가 필수적이다. 본 연구에서는 기존의 3 stage 방식을 이용해 광흡수층을 증착하여 최적화 조건을 연구하였다. 또한 기판의 면적 증가에 따라 효율과 Voc, Jsc, F.F가 얼마나 감소하는지 실험하여 보았다. 기판은 soda lime glass를 사용 하였으며 후면 전극으로 약$1{\mu}m$ 두께의 Mo를 DC Supptering 방법을 이용해 증착하였다. 다음으로 약 $2{\mu}m$이상의 광흡수층을 Co-Evaporation 방법을 이용하여 증착 하였으며 buffer층으로는 약 50nm의 CdS층을 CBD방법을 이용하여 제조 하였다. TCO층으로 약 50nm의 i-ZnO와 약 450nm의 Al-ZnO를 RF Sputtering 방법을 이용하여 증착 하였다. 마지막으로 앞면 전극으로 약 $3{\mu}m$의 Al을 Thermal Evaporation 방법으로 증착하였다. 태양전지 소자의 면적은 $0.49cm^2$, $25cm^2$, $100cm^2$로 각각 면적을 달리하며 효율을 비교 분석하였다.

• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.29-33
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• 2003

The objective of the present work is to examine evaporation cooling of droplet due to surface roughness on a heated surface. The surface temperatures varied from 80-$160^{\circ}C$ on aluminum alloy (AL 2024) md surface roughness was 0.l8$\mu\textrm{m}$ 1.36$\mu\textrm{m}$. The results are as follows; Regardless of surface roughness, as droplet diameter is bigger, the in-depth temperature of solid decreases and evaporation time increases. In the case of same initial temperature on the heated surface, as droplet diameter is smaller and small surface roughness is bigger, evaporation time decreases and time averaged heat flux increases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.956-960
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• 2009

The characteristics of organic films can be affected by the temperature of evaporation source because the temperature of evaporation source has an effect on substrate temperature during OLED fabrication process using the thermal evaporation. To investigate the characteristics of OLED devices fabricated by using thermally damaged organic films, I-V-L and half life-time in OLED devices fabricated with various substrate temperatures were measured. During emission layer(EML) evaporation, OLED devices with a structure of ITO(100 nm)/ELM200(50 nm)/NPB(30 nm)/$Alq_3$(55 nm)/LiF(0.7 nm)/Al(100 nm) were fabricated at various substrate temperatures(room temperature, $30^{\circ}C$, $40^{\circ}C$, and $50^{\circ}C$). The characteristics of current density and luminance versus applied voltage in OLED devices fabricated shows that many electrical currents flowed and high brightness appeared at low voltage, but that the lifetime of OLED devices dropped suddenly. This phenomenon explained that the crystallization of $Alq_3$ thin film appeared owing to the substrate heating during evaporation.

• Journal of Korea Water Resources Association
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• v.53 no.7
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• pp.557-567
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• 2020

The six current models for estimating pan coefficient were applied to test the applicability of models in Seoul, South Korea. The models are Cuenca's model, Snyder's model, Pereira et al.'s model, Allen et al.'s model, Orang's model, and Raghuwanshi and Wallender's model. The estimated pan coefficients were compared with measured one. The measured pan coefficient was obtained by using measured pan evaporation and FAO Penman-Monteith reference evapotranspiration. Estimated evaporation by using estimated pan coefficients was compared with measured one. Furthermore, model for estimating pan coefficient in Seoul was developed. When applying 6 current models for 10 m, 15 m and 20 m fetch distances, pan coefficient estimates from Snyder's model were most similar to measured pan coefficients for all fetch distances. On the other hand, pan coefficient estimates from Pereira et al.'s model were most different from measured one. Therefore, model for estimating pan coefficient in Seoul was developed by modifying Snyder's model. When applying developed model, estimated monthly average evaporation was 92.1 mm for 10 m, 15 m and 20 m fetch distances and measured one was 91.9 mm, indicating that evaporation estimate from developed model is closest to measured one, compared with those of current models.

• Atmosphere
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• v.26 no.4
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• pp.553-563
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• 2016

Land evaporation contribution to precipitation over East Asia is studied to understand terrestrial moisture source of continental precipitation. Moisture recycling of precipitation relying on terrestrial evaporation is estimated based on the analysis method of Van der Ent et al. (2010). We utilize HadGEM2-AO simulations for the period of 1970~1999 and 2070~2099 from RCP8.5. Globally, 46% of terrestrial precipitation is depending from continental evaporation. 58% of terrestrial evaporation returns as continental precipitation. Over East Asia, precipitation has been affected by local evaporation and transported moisture. The advection of upwind continental evaporation results from the prevailing westerlies from the midwestern of Eurasian continent. For the present-day period, about 66% of the precipitation over the land of East Asia originates from land evaporation. Regionally, the ratios change and the ratios of precipitation terrestrial origin over the Northern inland and Southern coast of East Asia are 82% and 48%, respectively. Seasonally, the continental moisture recycling ratio is larger during summer (JJA) than winter (DJF). According to RCP8.5, moisture recycling ratio is expected to change. At the end of the 21st century, the impact of continental moisture sources for precipitation over East Asia is projected to be reduced by about 5% compared to at the end of 20th century. To understand the future changes, moisture residence time change is investigated using depletion and replenishment time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1462-1465
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• 2004

A new method to fabricate metal electrodes on side wall of the microchannel is presented. Coulter counter allows to count the number of cell passing through the microchannel by detecting impedance variation between two electrodes. The relative position of two electrodes is important for sensitivity of impedance measurement. 100nm thick Al electrodes are deposited on the channel side wall by means of shadow evaporation.