• 대한전기학회논문지
• /
• 제45권2호
• /
• pp.224-229
• /
• 1996

Performance characteristics of single cell in phosphoric acid fuel cell were studied for various electrode fabrication parameters such as teflon content, electrode structure, thickness of electrocatalyst layer, platinum content and electrode area. The performance of single cell was decided from the measured voltage-current through a load change. The electrode of 40wt.% teflon exhibited high initial performance of single cell, but in the long term operation, the cell performance of 45 wt.% teflon was better. Also the single cell appeared good performance in case of electrodes with duplicate structure, thin electrocatalyst in thickness, more platinum content, and small area. These results of cell performance were discussed as related to the electrolyte flooding, formation of 3 phase boundary area, internal resistance of electrode, and microstructure of electrode.

• 센서학회지
• /
• 제23권1호
• /
• pp.19-23
• /
• 2014

A new hydraulic tube structure for WIM sensor of a new generation is presented in this paper. The double-tube structure has been developed in order to improve the performance of the hydraulic load cell. The double-tube structure hydraulic element could be reduced by 46% in pressure changes according to temperature compared to a single-tube structure. In addition to the nonlinearity can be reduced by 67.19% at the same load condition. The hydraulic load cell shows an excellent linearity and measurement accuracy as the result of the static load test.

• The Korean Journal of Physiology and Pharmacology
• /
• 제8권5호
• /
• pp.253-257
• /
• 2004

Schwann cells play an important role in peripheral nerve regeneration. Upon neuronal injury, activated Schwann cells clean up the myelin debris by phagocytosis, and promote neuronal survival and axon outgrowth by secreting various neurotrophic factors. However, it is unclear how the nerve injury induces Schwann cell activation. Recently, it was reported that certain cytoplasmic molecules, which are secreted by cells undergoing necrotic cell death, induce immune cell activation via the toll-like receptors (TLRs). This suggests that the TLRs expressed on Schwann cells may recognize nerve damage by binding to the endogenous ligands secreted by the damaged nerve, thereby inducing Schwann cell activation. Accordingly, this study was undertaken to examine the expression and the function of the TLRs on primary Schwann cells and iSC, a rat Schwann cell line. The transcripts of TLR2, 3, 4, and 9 were detected on the primary Schwann cells as well as on iSC. The stimulation of iSC with poly (I : C), a synthetic ligand for the TLR3, induced the expression of $TNF-{\alpha}$ and RANTES. In addition, poly (I : C) stimulation induced the iNOS expression and nitric oxide secretion in iSC. These results suggest that the TLRs may be involved in the inflammatory activation of Schwann cells, which is observed during Wallerian degeneration after a peripheral nerve injury.

• Applied Microscopy
• /
• 제29권4호
• /
• pp.417-426
• /
• 1999

농어의 피부는 크게 상피층과 진피층으로 구분된다. 상피층은 지지세포와 단세포선들로 구성된다. 지지세포는 표면세포, 중간세포 및 기저세포로 구분된다. 선세포는 점액분비세포와 곤봉상세포로 구분되는데, 이들의 분포밀도는 곤봉상세포가 더 높다. 표면세포는 편평형 또는 입방형이며 세포질에는 조면소포체가 잘 발달되어 있으며, microridge가 뚜렷하다. 표면세포들은 membrane interdigitation구조와 부착반에 의해서 다른 세포들과 연결되어 있다. 중간세포는 난형이며, 전자밀도는 다른 지지세포 보다 높다. 기저세포는 입방형이며, 세포소기관의 가운데 미토콘드리아의 발달이 현저하며, membrane interdigitation 구조들이 발달되어 있다. 점액분비세포는 막으로 싸인 다수의 분비과립들을 함유한다. 곤봉상세포의 세포질은 수질부와 피질부로 구분되는데, 수질부에서는 핵, 세포소기관, 중심공포가 관찰되며, 피질부에서는 발달된 장미세섬유들이 관찰된다. 곤봉상세포들은 잘 발달된 membrane interdigitation구조와 부착반에 의해서 다른 세포들과 연계되어 있다.

• 한국자기공명학회논문지
• /
• 제15권1호
• /
• pp.1-13
• /
• 2011

9Pbw2 is a 9-mer analog of protaetiamycine derived from the larvae of the beetle Protaetia brevitarsis. Previously, we designed four 9-mer peptide analogues to optimize the balance between the hydrophobicity and cationicity of the peptides and to increase bacterial cell selectivity. Among them, 9Pbw2 has high antibacterial activity without cytotoxicity. The results obtained in previous study suggest that the bactericidal action of 9Pbw2 may be attributed to the inhibition of the functions of intracellular components after penetration of the bacterial cell membrane. In order to understand structure-activity relationships, we determined the three-dimensional structure of 9Pbw2 in 200 mM DPC micelle by NMR spectroscopy. 9Pbw2 has one hydrophobic turn helix from $Trp^3$ to $Arg^8$ and positively charged residues at the N- and C-terminus. This result suggested that positively charged residues from position at the C-terminus in 9Pbw2 may be important for the primary binding to the negatively charged phospholipid head groups in bacterial cell membranes and hydrophobic residues in the middle portion face toward the acyl chains of the hydrophobic lipid in the bacterial cell membrane.

• 한국추진공학회지
• /
• 제10권2호
• /
• pp.1-14
• /
• 2006

본 논문은 약한 불안정 데토네이션 영역부터 강한 불안정 데토네이션 영역까지 여러 영역에 걸친 데토네이션 파 셀 구조 모사에 대한 수치적 문제점들을 살펴보았다. 비열 비 값이 변하는 점성 유체 역학 방정식 및 1단계 Arrhenius 반응 모델 해석을 위하여 MUSCL-type TVD 기법을 이용한 공간 차분과 4차 정확도의 Runge-Kutta 시간 적분을 이용하였다. 일련의 수치해석 연구는 여러 반응 상수 및 격자 해상도에 따른 데토네이션 셀 구조를 해석하기 위하여 요구되는 계산 조건을 구하기 위하여 다양한 데토네이션 현상 영역에서 수행되었다. 다른 영역의 데토네이션 현상에서 셀 구조를 포착하기 위한 계산 영역의 크기와 최소 격자 해상도를 찾아내기 위하여 정상 1차원 ZND 해석 결과와 전산 해석 결과를 비교 검토하였다.

• Current Photovoltaic Research
• /
• 제8권3호
• /
• pp.94-101
• /
• 2020

This study was trying to focus on achieving high efficiency of multi junction solar cell with thin film silicon solar cells. The proposed thin film Si-Ge/c-Si tandem junction solar cell concept with a combination of low-cost thin-film silicon solar cell technology and high-efficiency c-Si cells in a monolithically stacked configuration. The tandem junction solar cells using amorphous silicon germanium (a-SiGe:H) as an absorption layer of upper sub-cell were simulated through ASA (Advanced Semiconductor Analysis) simulator for acquiring the optimum structure. Graded Ge composition - effect of E_g profiling and inserted buffer layer between absorption layer and doped layer showed the improved current density (J_sc) and conversion efficiency (η). 13.11% conversion efficiency of the tandem junction solar cell was observed, which is a result of showing the possibility of thin film Si-Ge/c-Si tandem junction solar cell.

• 대한의생명과학회지
• /
• 제7권3호
• /
• pp.127-131
• /
• 2001

This study was undertaken to examine the effect of amino acids on anoxia-induced cell injury in rabbit renal cortical slices. In order to induce anoxic cell injury, slices were exposed to a 100% $N_2$ atmosphere and control slices were exposed to 100% $O^2$. Irreversible cell injury was estimated by measuring lactate dehydrogenase (LDH) release and alterations in renal cell function were examined by measuring p-aminohippurate (PAH) uptake. Anoxia caused the increase in LDH release in a time-dependent manner. Glycine and glutathione almost completely prevented anoxia-induced LDH release. Of amino acids tested, glycine and alanine exerted the protective effect against anoxia-induced cell injury. However, asparagine with amide side chain, leucine and valine with hydrocarbon side chain, and basic amino acids (lysine, histidine, and arginine) were not effective. Anoxia-induced inhibition of PAM uptake was prevented by glycine. ATP content was decreased by anoxia, which was not affected by glycine. Anoxia-induced depletion of glutathione was significantly prevented by glycine. These results suggest that neutral amino acids with simple structure exert the Protective effect against anoxia-induced cell injury the involvement of specific interaction of amino acids and cell structure.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.305-308
• /
• 2007

The field of dye-sensitized solar cell (DSC) is being researched actively at present. Because DSC has several advantages to pass the limits of Si solar cells such as a low manufacturing expense, a simple manufacturing process and its transparency. A lot of researches are underway about materials and processes in the field of dye-sensitized solar cell but its structure has been fixed up as the sandwich structure that both edges are used as positive and negative terminals. But the structure as of present is a factor of decreasing efficiency because the more electrons are recombined the further distance from terminal, considering about the characteristic of dye-sensitized solar cell that electrons generated inside cell are moved by diffusion. In this study, we made experiment on expanding the terminal to shorten internal moving distance of electron and compared the results according to the variation of active area to find out the effect of this trial. As a result, we achieved about 15.5% improvement of maximum power and 0.5% improvement of efficiency from terminal-expanded dye-sensitized solar cell of $2cm^{2}$ active area and concluded that the increasing rate of efficiency is raised as the active area becomes wider.

• 전기전자학회논문지
• /
• 제7권2호
• /
• pp.218-222
• /
• 2003

전자파 방사 및 측정 시험설비로 표준 시험장인 야외시험장을 사용하고 있으나 시험장 구축의 어려움으로 이를 대체할 수 있는 대용시험장을 사용하여 측정시험을 할 수 있도록 하고 있다. 본 논문에서는 최적화된 측정시스템을 구성하기 위한 대용시험시설인 GTEM CELL(Gigahertz Transverse Electro Magnetic Cell)의 구조분석 및 설계를 하기 위하여 내부도체(Septum)의 넓이 및 두께 변화에 따른 내부도체의 특성임피던스 변화를 살펴보았다.