• 한국가시화정보학회지
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• 제8권4호
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• pp.38-42
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• 2010

Ion concentration polarization is an electrokinetic phenomenon which occurs in membrane systems, such as in an electrodialysis and fuel-cell system. But the phenomenon is not fully understood because hydrodynamics, electrokinetics and electrochemistry are coupled with each other. Here, we report that there occurs a change of pH value of buffer solution in concentration polarization phenomenon. To visualize the change of pH, the litmus solution which is one of the pH indicators was used. It is conjectured that the pH of solution changes because hydrogen ions were concentrated in cathodic side and hydroxide ions were concentrated in anodic side. We anticipate that this work may contribute to the fundamental understanding on the ion concentration polarization phenomenon.

• 한국해양학회지:바다
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• 제9권3호
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• pp.106-109
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• 2004

2004년 6월 초순 부산연안역, 진해만, 남해도∼통영해역에 이르는 남해 동부연안에서 Cochlodinium polykrikoides 의 분포와 양을 조사하였다. 표층해수 11를 10$\mu\textrm{m}$의 망으로 농축하여 현장에서 바로 C. polykrikoides를 현미경 관찰한 후 촬영하였다. 그 결과 C. polykrikoides 세포는 진해만에서 60∼660 cells/1로 가장 높게 나타났으며, 부산연안역은 45∼330cells/1였으나, 남해도∼통영 해역에서는 발견되지 않았다. 발견된 C. polykrikoides는 세포내 빨간 원형물질을 함유하였고, 세포 분열이 되어 체인을 형성할수록 세포내 빨간 물질의 크기가 감소하였다.

• 한국태양에너지학회 논문집
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• 제21권2호
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• pp.1-8
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• 2001

The most effective methods for utilizing solar energy are to use the sunlight and solar thermal energy such as hybrid panel simultaneously and to use concentrator. From such a view point systems using various kinds of photovoltaic panels are constructed in the world. However, there has not been a hybrid panel with a concentrator. If the sunlight is concentrated on solar cell, cell conversion efficiency increases and the temperature of the solar cell s increases. As the temperature of the solar cells increases, the cell conversion efficiency gradually decreases. For maintaining the cell conversion efficiency constant, it is necessary to keep solar cell at low temperature. In this paper, after designing a concentration rate for concentrating, we propose a model for cooling the cell and for using wasted heat. And, we compare it with conventional panels after calculating the electrical and thermal efficiency, using the energy balance equation.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.85-92
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• 2005

One of the most effective methods for utilizing solar energy is to combine thermal solar and optical energy simultaneously using a hybrid panel. Many systems using various kinds of photovoltaic panels have already been constructed. But utilizing solar energy by means of a hybrid panel with concentrator has not been to be attempted yet. Normally if sunlight is directed on the solar cell, and there is no increase in temperature, the absorption energy of each cell will increase per unit area. In a silicon solar cell. however, cell conversion efficiency decreases according to the increasing temperature. Therefore, to maintain cell conversion efficiency under normal condition, it is necessary to keep the cell at operating temperature. we design and make new hybrid panel with cooling system to prevent increasing of temperature on cell, collect effectively thermal energy. We compared performance of new hybrid panel with PV module and thermal panel. We also evaluated conversion efficiency, electric power and thermal capacity and confirmed cooling effect from thermal absorption efficiency.

• Current Photovoltaic Research
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• 제2권4호
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• pp.168-172
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• 2014

Under concentrated illuminations, the solar cells show higher efficiencies mainly due to an increase of the open circuit voltage. In this study, InGaP/InGaAs/Ge triple-junction solar cells have been grown by a low pressure metalorganic chemical vapor deposition. Photovoltaic characteristics of the fabricated solar cells are investigated with a class A solar simulator under concentrated illuminations from 1 to 100 suns. Ideally, the open circuit voltage should increase with the current level when maintained at the same temperature. However, the fabricated solar cells show degraded open circuit voltages under high concentrations around 100 suns. This means that the heat sink design is not optimized to keep the cell temperature at $25^{\circ}C$. To demonstrate the thermal degradation, changes of the device performance are investigated with different bonding conditions and heat sink materials.

• Parasites, Hosts and Diseases
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• 제39권1호
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• pp.13-21
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• 2001

Pneumocystis carinii causes serious pulmonary infection in immuno-suppressed patients. This study was undertaken to observe the cytoskeletal proteins of P. carinii by immune-electron microscopy. P. carinii infection was experimentally induced by immunosuppression of Sprague-Dawley rats for seven weeks, and their lungs were used for the observations of this study. The gold particles localized actin, tropomyosin, and tubulin. The actin was irregularly scattered in the cytoplasm of the trophic forms but was much more concentrated in the inner space of the cell wall of the cystic forms called the inner electron-lucent layer No significant amount of tropomyosin was observed in either trophic forms or cystic forms. The tubulin was distributed along the peripheral cytoplasm and filopodia of both the trophic and cystic forms rather than in the inner side of the cytoplasm. Particularly, in the cystic forms, the amount of tubulin was increased and located mainly in the inner electron-lucent layer of the cell wall where the actin was concentrated as well. The results of this study showed that the cell wall of P carinii cystic forms is a structure whose inner side is rich in actin and tubulin. The location of the actin and tubulin in P. carinii suggests that the main role of these proteins is an involvement in the protection of cystic forms from the outside environment by maintaining rigidity of the cystic forms.

• 한국환경농학회지
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• 제16권4호
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• pp.311-319
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• 1997

광산폐수, 산업폐수등으로 부터 Cd, Pb, Zn 및 Cu등의 중금속에 강한 내성을 지니고 있을 뿐만 아니라 균체내 중금속 축적능력이 우수한 중금속 내성 미생물 균주 Pseudomonas putida(Cd), Pseudomonas aeruginosa(Pb), Pseudomonas chlororaphis(Zn) 및 Pseudomonas stutzeri(Cu)를 각각 분리하여, 여러가지 물리화학적인 방법으로 세포를 전처리하여 세포구성성분을 인위적으로 조절한 후 세포내 중금속이온의 흡수 거동 및 조단백질 함량과 중금속 축적관계를 조사한 결과는 다음과 같다. 세포를 알카리로 전처리하였을 경우 세포내 중금속 축적은 매우 감소되었으며, 메탄올과 클로포름으로 전처리하였을 경우에는 중금속 축적에 큰 영향을 미치지 않았으나, 메탄올과 클로로포름으로 전처리한 후 다시 알카리로 재차 처리하였을 경우에는 중금속 축적이 매우 감소되었다. 전처리된 세포내 중금속 축적은 용출되지 않고 남아있는 조단백질 함량이 감소됨에 따라 더 얼마나 크게 감소되었으므로 세포 구성물질중 단백질이 중금속 축적에 중요한 역할을 하는 물질인 것으로 판단되었다.

• 공업화학
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• 제30권4호
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• pp.504-508
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• 2019

GaInP/AlGaInP 이종접합 구조를 제안하고 집광 조건에서 가장 높은 효율을 달성한 III-V 화합물 반도체 다중접합 태양전지의 맨 위 subcell에 주로 사용되는 GaInP 동종접합 구조를 대체해 이종접합 구조가 응용될 가능성에 대하여 조사하였다. $2^{\circ}$ off 된 웨이퍼와 $10^{\circ}$ off 된 서로 다른 off-cut 방향을 갖는 두 종류의 GaAs 기판 위에 성장된 태양전지의 특성을 집광 조건에서 측정하고 비교하였다. $10^{\circ}$ off 된 태양전지에서 더 높은 단락전류와 변환효율을 얻었다. 1 sun 조건에서 $10^{\circ}$ off 된 기판 위에 제작된 $2{\times}2mm^2$ 면적의 태양전지에서 $9.21mA/cm^2$의 단락전류밀도와 1.38 V의 개방 전압이 측정되었다. $10^{\circ}$ off 기판 위에 제작된 $5{\times}5mm^2$ 태양전지에서 집광도 증가에 따라 곡선인자(fiill factor)가 감소하여 변환효율은 6.03% (1 sun)에서 5.28% (20 sun)로 측정되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.463-466
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• 2001

The most effective methods of utilizing solar energy are to use the sunlight and solar thermal energy such as hybrid panel simultaneously and to use concentrator. From such a view point, systems using various kinds of photovoltaic panels were constructed in the world. However there have not been a type of panel using concentrator and hybrid simultaneously. If the sunlight are concentrated on the solar cell, cell conversion efficiency increase and the temperature of the solar cells increases. As the temperature of the solar cells increases, so cell conversion efficiency decreases. Therefore, for maintaining cell conversion efficiency at these conditions, it is necessary to keep the cell at low temperature. In this paper, after designing a concentrate rate for concentrating, we proposed model for cooling cell and using waste heat, and we compared with conventional panels after calculating the electrical and thermal efficiency using energy balance equation.

• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.251-256
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• 2006

To design the effective usage of electric double layer capacitors (EDLCs) used for a storage device of dye sensitized solar cell (DSC) energy, we first investigated the accumulation state of electrical charges and the charge behavior in the EDLCs. Based on the results, the voltage characteristics of EDLCs connected to DSC energy were evaluated. The results showed that the charge accumulation region concentrated on the central part of the carbonaceous electrode in EDLCs and the required times for charging and discharging were almost the same.