• 한국전기전자재료학회논문지
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• 제27권3호
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• pp.141-145
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• 2014

Tubular-shaped ZnO crystals were synthesized by thermal evaporation technique under air atmosphere. Mixture of Zn and Mg powder was used as the source material. The thermal evaporation and oxidation of Zn/Mg mixture were carried out for 1 hr at $1,000^{\circ}C$ and $1,200^{\circ}C$ under in air under atmospheric pressure. When only Zn powder was used as a source material, tetrapod-shaped ZnO crystals were synthesized. This provides that Mg played a key role in the formation of the tubular-shaped crystals. SEM images showed that the tubular-shaped ZnO crystals grew along [0001] direction. XRD spectrum revealed that the ZnO tubes had hexagonal wurtzite structure. Two emission peaks at 380 nm and 510 nm were observed in the room temperature cathodoluminescence spectrum.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.39-42
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• 2004

The $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin film fabricated by using the sputtering method was compared with the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin film fabricated by using the evaporation method. In doing the ultra-low deposition because each element can exist on the substrate surface, both the sputtering method and the evaporation method could easily fabricate single phase of the Bi2212 phase. Also, it is cofirmed that by optimizing the deposition condition, each single phase of the Bi2201 phase and the Bi2212 phase can be fabricated, the sticking coefficient of Bi element is clearly related to the changing of substrate temperature and the formation of the Bi2212 phase.

• 한국전기전자재료학회논문지
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• 제20권6호
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• pp.546-549
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• 2007

As a rule, high temperature superconducting coated conductors have multi-layered buffers consisting of seed, diffusion barrier and cap layers. Multi-buffer layer deposition requires longer fabrication time. This is one of main reasons which increases fabrication cost. Thus, single buffer layer deposition seems to be important for practical coated conductor process. In this study, a single layered buffer deposition of $CeO_2$ for low cost coated conductors has been tried using thermal evaporation technique. 100 nm-thick $CeO_2$ layers deposited by thermal evaporation were found to act as a diffusion layer. $1\;{\mu}m-thick$ SmBCO superconducting layers were deposited by thermal co-evaporation on the $CeO_2$ buffered Ni-5%W substrate. Critical current of 90 A/cm was obtained for the SmBCO coated conductors.

• 대한물리치료과학회지
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• 제9권4호
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• pp.185-192
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• 2002

Ultrasound has been found useful as a therapeutic modality for the reduction of muscular and tendinous spasm. It has also been utilized for pain and other pathologic conditions through the ability of soundwaves to introduce molecules of chemical substances through the skin by a process. Choice of the transmission medium is very important for effective ultrasound treatment in clinical field. The purpose of this study was to analyze the effects of various ultrasound conduction media in regard to ultrasound conductivity and degree of absorption, evaporation and of skin irritation. The media used in this study were Antiphlamine, Sacch lotion, Stereogel, Trastgel, Antiphlamine S lotion, and Mentholatum lotion that have been used in clinical medicine. The study revealed that Antiphlamine was not compatible with a good ultrasound transmitter. Other media excluding Antiphlamine were compatible with a good ultrasound conductor, but they had some drawback with their nature of higher absorption, evaporation and skin irritation. The medium that was prepared by mixing of Antiphlamine with Gel in 1 to 10 ratio was a good ultrasound transmitter and extents of absorption and evaporation and of skin irritation of it were less than the other media.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.743-748
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• 2006

Ren et al. analyzed the performance of the indirect evaporative cooler according to the direction of the flow considering evaporation water flow and wetness. However the effect of NTU of each channel on the performance of the indirect evaporative cooler according to the direction of the flow was not analyzed exactly. In this study the effect of the direction of the flow on the Indirect evaporative cooling performance changing NTU of each channel are investigated theoretically. The cooling process of the indirect evaporative cooler by flow direction is modeled into a set of linear differential equations and solved to obtain the exact solutions to the temperatures of the hot fluid, the moist air, and evaporation water. Based on the exact solution in the case of different NTU of each channel, we study the change of the distribution of the temperature according to each flow direction and at the same time analyze the effect of the flow direction on the cooling performance.

• Current Photovoltaic Research
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• 제7권1호
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• pp.15-20
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• 2019

Most high-efficiency n-type silicon solar cells are based on the high quality surface passivation and ohmic contact between the emitter and the metal. Currently, various metalization methods such as screen printing using metal paste and physical vapor deposition are being used in forming electrodes of n-type silicon solar cell. In this paper, we analyzed the degradation factors induced by the front electrode formation process using e-beam evaporation of double passivation structure of p-type emitter and $Al_2O_3/SiN_x$ for high efficiency solar cell using n-type bulk silicon. In order to confirm the cause of the degradation, the passivation characteristics of each electrode region were determined through a quasi-steady-state photo-conductance (QSSPC).

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1346-1350
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• 2018

An electrode-evaporation technology on both the top and bottom sides of the bare vertical-type single chip separated from the traditional substrate by cooling, was developed for III-nitride vertical-type single chip LEDs with thick GaN epilayer. The post-process of the cooling step was followed by sorting the bare vertical-type single chip LEDs into the holes in a pocket-type shadow mask for deposition of the electrodes at the top and bottom sides of bare vertical-type single chip LEDs without the traditional substrate for electrode evaporation technology for vertical-type single chip LEDs. The variation in size of the hole between the designed shadow mask and the deposited electrodes owing to the use of the designed pocket-type shadow mask is investigated. Furthermore, the electrical and the optical properties of bare vertical-type single chip LEDs deposited with two different shapes of n-type electrodes using the pocket-type shadow mask are investigated to explore the possibility of the e-beam evaporation method.

• Smart Structures and Systems
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• 제30권4호
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• pp.421-432
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• 2022

Regarding the high significance of correct pan evaporation modeling, this study introduces two novel neuro-metaheuristic approaches to improve the accuracy of prediction for this parameter. Vortex search algorithms (VSA), sunflower optimization (SFO), and stochastic fractal search (SFS) are integrated with a multilayer perceptron neural network to create the VSA-MLPNN, SFO-MLPNN, and SFS-MLPNN hybrids. The climate data of Arcata-Eureka station (operated by the US environmental protection agency) belonging to the years 1986-1989 and the year 1990 are used for training and testing the models, respectively. Trying different configurations revealed that the best performance of the VSA, SFO, and SFS is obtained for the population size of 400, 300, and 100, respectively. The results were compared with a conventionally trained MLPNN to examine the effect of the metaheuristic algorithms. Overall, all four models presented a very reliable simulation. However, the SFS-MLPNN (mean absolute error, MAE = 0.0997 and Pearson correlation coefficient, R_P = 0.9957) was the most accurate model, followed by the VSA-MLPNN (MAE = 0.1058 and R_P = 0.9945), conventional MLPNN (MAE = 0.1062 and R_P = 0.9944), and SFO-MLPNN (MAE = 0.1305 and R_P = 0.9914). The findings indicated that employing the VSA and SFS results in improving the accuracy of the neural network in the prediction of pan evaporation. Hence, the suggested models are recommended for future practical applications.

• 한국결정성장학회지
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• 제15권6호
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• pp.217-221
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• 2005

EAF 더스트-점토계 소지에서 혼합비와 열처리 온도에 따른 소지 내의 중금속 총량을 측정하여 높은 증기압을 갖는 Cd, Pb, Zn 등의 중금속 성분의 휘발량을 분석하였으며 TCLP 분석을 통해 소지 내 중금속 성분의 안정화에 대해 평가하였다. 중금속 성분의 휘발은 EAF 더스트-점토의 혼합비와 열처리 온도에 크게 영향을 받으며 점토의 혼합비가 증가할수록 휘발이 효과적으로 억제되었다. 중금속 성분의 용출은 점토의 혼합비와 열처리 온도가 증가할수록 감소하였으며 안정화 효과가 큰 것으로 나타났다. EAF 더스트 20wt%-점토 800 wt%의 혼합비를 갖는 소지의 경우 중금속의 휘발과 용출이 거의 없었으며 XRD 분석 결과에 의하면 점토의 혼합비와 열처리 온도가 증가할수록 EAF 더스트-점토계 소지의 주결정상인 $(Zn{\cdot}Fe)Fe_2O_4$상과 quartz상의 회절강도가 감소하였으며, 이는 중금속의 휘발 억제 및 안정화 기구가 점토의 $SiO_2$ 성분에 의한 유리화 과정에 의한 것임을 나타내는 것으로 보여진다.

• 대한기계학회논문집B
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• 제36권6호
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• pp.579-582
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• 2012

연료전지 시스템에서 잔류 수분의 제거과정은 연료전지의 성능 및 수명 관리를 위해 중요한 과정이다. 효과적인 수분 제거과정의 설계를 위해서는 연료전지내의 수분 제거 특성에 대한 이해가 필수적이다. 이를 위해 본 연구에서는 연료전지의 다공성막인 가스확산층을 통한 수분증발량을 정상상태에서 측정하는 실험 기법을 개발하였다. 이 기법을 이용하여 연료전지의 잔류수분 제거 현상을 모사하는 실험장치를 개발하였다. 그리고 건조가스와 가스확산층의 변수가 수분에 미치는 영향을 실험적으로 측정하였다. 건조가스의 습도가 낮고, 유량이 높을수록 가스확산층을 통해 증발되는 수분량이 높았다. 또한 가스확산층의 두께가 얇을수록 수분 증발량이 높은 특성을 확인하였다.