• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 추계학술발표강연 및 논문개요집
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• pp.61-61
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• 1992

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.345-348
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• 2008

Metallic bipolar plate for molten carbonate fuel cell(MCFC) is composed of the shielded slot plate and the center plate. Among these, the center plate plays an important role in gas sealing. Therefore, manufacturing of the center plate is considered one of the key issues in MCFC. The center plate is manufactured by bending process. In bending process, springback and recoiling are two main problems. The aim of this article is to optimize the bending process of the center plate regardless of springback and recoiling. To achieve this goal, we proposed the punch having step to reduce springback and recoiling. Using finite element method and $L_9$ orthogonal array, we determined the main factors in the center plate bending process. And we found the optimal bending process condition for the MCFC center plate.

• 소성∙가공
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• 제21권8호
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• pp.499-505
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• 2012

The fuel cell is a very promising power generation system combining the benefits of extremely low emissions, high efficiency, ease of maintenance and durability. In order to promote the commercialization of fuel cells, a flexible forming process, in which a hyper-elastic rubber is adopted as a medium to transmit forming pressure, is suggested as an efficient and cost effective manufacturing method for fuel cell bipolar plates. In this study, the ability of this flexible forming process to produce the micro channel arrays on metallic bipolar plates was first demonstrated experimentally. Then, a finite element (FE) model was built and validated through comparisons between simulated and experimental results. The effects of key process parameters on the forming performance such as applied load and punch velocity were investigated. As a result, appropriate process parameter values allowing high dimensional accuracy without failure were suggested.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.351-354
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• 2004

This thesis presents Bipolar transistor with SAVEN(Self-Aligned VErtical Nitride) structure as a high-speed device which is essential for high-speed system such as optical storage system or mobile communication system, and proposes 0.8${\mu}m$ BiCMOS Process which integrates LDD nMOS, LDD pMOS and SAVEN bipolar transistor into one-chip. The SPICE parameters of LDD nMOS, LDD pMOS and SAVEN Bipolar transistor are extracted, and comparator operating at 500MHz sampling frequency is designed with them. The small Parasitic capacitances of SAVEN bipolar transistor have a direct effect on decreasing recovery time and regeneration time, which is helpful to improve the speed of the comparator. Therefore the SAVEN bipolar transistor with high cutoff frequency is expected to be used in high-speed system.

• Carbon letters
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• 제14권2호
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• pp.110-116
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• 2013

This study investigated a developed process for producing a composite bipolar plate having excellent conductivity by using coal tar pitch and phenol resin as binders. We used a pressing method to prepare a compact of graphite powder mixed with binders. Resistivity of the impregnated compact was observed as heat treatment temperature was increased. It was observed that pore sizes of the GCTP samples increased as the heat treatment temperature increased. There was not a great difference between the flexural strengths of GCTP-IM and CPR-IM as the heat treatment temperature was increased. The resistivity of GPR700-IM, heat treated at $700^{\circ}C$ using phenolic resin as a binder, was $4829{\mu}{\Omega}{\cdot}cm$ which was best value in this study. In addition, it is expected that with the appropriate selection of carbon powder and further optimization of process we can produce a composite bipolar plate which has excellent properties.

• 멤브레인
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• 제23권5호
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• pp.319-331
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• 2013

바이폴라막을 이용한 전기투석공정은 의약산업, 음식산업 등과 같은 고부가 가치산업에 이용되어 왔으며, 용액으로부터 산 또는 염기를 생산하거나 회수할 수 있는 공정으로 많은 각광을 받아왔다. 전기투석공정은 경제적이며 친환경적인 시스템으로 이온교환공정, 추출공정, 흡착공정과 같은 타 공정과의 복합화가 가능하다. 따라서 본고에서는 이온교환막과 이를 이용한 잠재성을 가진 응용분야에 대하여 조사하였다.

• 한국세라믹학회지
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• 제45권3호
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• pp.161-166
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• 2008

The multi-films of a metallic film and a transparent conducting oxide (TCO, indium-tin oxide, ITO) film were formed on the stainless steel 316 and 304 plates by a sputtering method and an E-beam method and then the external metallic region of the stainless steel bipolar plates was converted into the metal nitride films through an annealing process. The multi-film formed on the stainless steel bipolar plates showed the XRD patterns of the typical indium-tin oxide, the metallic phase and the metal substrate and the external nitride film. The XRD pattern of the thin film on the bipolar plates modified showed two metal nitride phases of CrN and $Cr_2N$ compound. Surface microstructural morphology of the multi-film deposited bipolar plates was observed by AFM and FE-SEM. The metal nitride film formed on the stainless steel bipolar plates represented a microstructural morphology of fine columnar grains with 10 nm diameter and 60nm length in FE-SEM images. The electrical resistivity of the stainless steel bipolar plates modified was evaluated.

• 전기전자학회논문지
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• 제7권1호
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• pp.1-8
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• 2003

본 논문에서는 고내압 및 고속 스위칭 특성을 갖는 고성능 BCD(Bipolar- CMOS-DMOS) 소자 구조를 고안하였다. 공정 및 소자 시뮬레이션을 통하여, 최적화된 공정 규격과 소자 규격을 설계하였으며, 고안된 소자의 전기적 특성을 만족시키기 위하여 이중 매몰층 구조, 트랜치 격리 공정, n-/p- 드리프트 영역 형성기술 및 얕은 접합 깊이 형성기술 등을 채택하였다. 이 스마트 파워 IC는 20V급 Bipolar npn/pnp 소자, 60V급 LDMOS소자, 수 암페어급의 VDMOS, 20V급 CMOS소자 그리고 5V급 논리 CMOS를 내장하고 있다.

• 생물정신의학
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• 제19권3호
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• pp.134-139
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• 2012

Objectives : Proinflammatory process has been implicated as an underlying mechanism of bipolar disorder and schizophrenia. Previous studies have suggested a possible role of lymphotoxin alpha (LTA) gene in the development of schizophrenia and have prompted further investigation in bipolar patients. Association of the LTA +252A/G polymorphism with susceptibility to bipolar I disorder itself as well as with vulnerability among a subset of psychotic bipolar patients were tested. Methods : DNA extraction was done by a standard method and genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 114 Korean patients with bipolar I disorder and 202 healthy controls. SPSS v18.0 was used for statistical analysis. Comparisons of the genotype and allele distributions in LTA +252A/G polymorphism were made using a chi-square test. The genotype and allele associations were also evaluated using odds ratio (OR) and 95% confidence interval (CI). Statistical significance was accepted when p was < 0.05. Results : No significant association was found between the LTA +252A/G polymorphism and bipolar disorder. However, LTA +252G allele was present with significantly higher frequency among bipolar patients with psychotic features compared to those without (${\chi}^2$ = 4.69, p = 0.034, OR = 2.495, 95% CI = 1.069-5.827). Conclusion : The results suggest that the allele LTA +252G of the polymorphism may be associated with the psychotic subset of bipolar disorder but not with bipolar I disorder itself. Adequately powered subsequent studies should be conducted.

• 한국표면공학회지
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• 제44권5호
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• pp.179-184
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• 2011

This work investigated the effect of duty cycle and pulse frequency on the microstructures and properties of titanium nitride thin films deposited by asymmetric bipolar pulsed DC sputtering system. Oscilloscope traces of the I-V waveforms indicate high power and high current density outputs during the asymmetric bipolar pulsed mode. The grain size decreases with decreasing duty cycle. The duty cycle has a strong influence not only on the microstructural properties but also on the mechanical properties of titanium nitride films. Comparing with the continuous DC sputtering, the titanium nitride films prepared by pulsed DC asymmetric bipolar process exhibit better properties.