• Journal of Electrochemical Science and Technology
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• 제2권2호
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• pp.68-75
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• 2011

In this review, we have investigated the effect of $TiO_2$-based blocking layers (t-BLs), deposited on a transparent conductive oxide (TCO)-coated glass substrate, on the photovoltaic performance of dye-sensitized solar cells (DSSCs). The t-BL was deposited using spin-coating or sputtering technique, and its thicknesses were varied to study the influence of the thin $TiO_2$ layer in between transparent conducting glass and nanocrystalline $TiO_2$ (nc-$TiO_2$). The DSSC with the t-BL showed the improved adhesion and the suppressed charge recombination at a TCO glass substrate than those without the t-BL, which led to the higher conversion efficiency.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권1호
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• pp.51-56
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• 1999

This paper presents a new transient overvoltage blocking device (TOBD) for info-communication facilities with low power and high frequency bandwidth. Conventional protection devices have some problems such as low frequency bandwidth, low energy capacity and high remnant voltage. In order to improve these limitations, thehybrid type TOBD, which consists of a gas tube, avalanche diodes and junction typefield effect transistors (JFETs), was designed and fabricated. The TOBD differs from the conventional protection devices in configuration, and JFETs were used as an active non-linear element and a high speed switching diode with low capacitance limits high current. Therefore the avalanche dilde with low energy capacity are protected fromthe high current, and the TOBD has a very small input capacitance. From the performance test using combination surge generator, which can produce $1.2/50\mus\;4.2kV_{max}\; 8/20\mus\; 2.1kA_{max}$, it is confirmed that proposed TOBD has an excellent protection performance in tight clamping voltage and limiting current characteristics.

• 한국항공우주학회지
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• 제42권4호
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• pp.291-297
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• 2014

회전익 항공기의 기체 공력특성 측정실험에 실험설계 방법론을 적용하여 풍동실험의 정밀도 향상에 관한 연구를 수행하였다. 블록화와 블록화 되지 않은 경우들에 대한 분산분석결과의 비교를 통해 블록화의 영향을 평가하였다. 2차 반응표면모델의 경우 블록화가 실험결과의 정밀도 향상에 실질적인 영향을 주고 있음을 알 수 있었다. 본 연구를 통해 랜덤화, 블록화 및 반복화와 같은 실험설계원리와 같은 풍동실험 절차의 재배치를 통해 이러한 정밀도 향상이 가능함을 보였다.

• 한국통신학회논문지
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• 제33권5A호
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• pp.517-525
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• 2008

본 논문은 균일한 도심지역에서의 CDMA 시스템의 상향링크에 대하여 송신전력, 간섭전력 및 블로킹 확률 등을 최소화하는데 기지국 배치에 따라 결정되는 셀 모양의 효과를 분석하기 위하여 시스템 수준의 모의실험이 이루어진다. 도심 마이크로 셀에서 기지국에 대한 경로 손실은 단말이 위치한 거리의 방향성에 영향을 받는다. 단말로부터 기준 기지국에 대한 간섭은 2차 Tier까지 고려된다. 간섭 계산의 정확성에 대한 손실 없이 계산 복잡도를 줄이기 위한 방법으로Wrap around method가 사용된다. 모의실험 결과는 송신전력, 간섭전력 및 블로킹 확률 등이 효율적인 기지국 배치에 따른 셀의 모양에 따라 줄어들 수 있음을 보여준다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.219-219
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• 2013

The effect of an electron blocking layer (EBL) on V-I curves in GaN/InGaN multiple quantum well is investigated. For the first time, we found that curves were intersected at 3.012 V and analyzed the reason for intersection. The forward voltage in LEDs with an p-AlGaN EBL is larger than without p-AlGaN EBL at low injection current because the Mg doping efficiency for p-GaN layer was higher than that of p-AlGaN layer. However, the forward voltage in LEDs with an p-AlGaN EBL is smaller than without p-AlGaN EBL at high injection current because the carriers overflow from the active layer when injection current increases in LEDs without p-AlGaN EBL and in case of LED with p-AlGaN EBL, the carriers are blocked by EBL.

• 한국수소및신에너지학회논문집
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• 제20권3호
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• pp.224-231
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• 2009

The improvement of cold start capability is one of the most challenging tasks to be solved for commercialization of fuel cell vehicle. In this study, cold start test and ice blocking test(IBT) of fuel cell stack were carried out under various operating conditions. This fuel cell stack can be thawed from -20$^{\circ}$C within 25s and the voltage change was found to be comprised of 4 steps; the first step is the voltage decrease by overpotential, the second step is the voltage increase by the cell temperature increase, the third step is the voltage decrease by ice blocking, and the last step is the voltage increase by thawing. Bootstrap startup was failed after shutdown at temperature under 40$^{\circ}$C because of much condensed water in the fuel cell. Quantitative estimation of cold start capability have been demonstrated by ice blocking test(IBT). In the results, it was found that cold start capability was improved double every 10$^{\circ}$C from 30$^{\circ}$C to 65$^{\circ}$C and enhanced by 30% at the condition of SR 3/4 compared to SR 1.5/2.0 and enhanced by 20% with dry purge condition compared to with RH 50% purge condition.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10469-10473
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• 2015

Background: Solanum nigrum L. has been used in traditional Chinese medicine because of its diuretic and antipyretic effects. The present research concerned effects of crude polysaccharides isolated from Solanum nigrum L. on erythrocyte membranes of tumor-bearing $S_{180}$ and $H_{22}$ in mice. Materials and Methods: Fluorescence-labeled red blood cell membranes were used with DPH fluorescence spectrophotometry to examine erythrocyte membrane fluidity, and colorimetry to determine degree of erythrocyte surface membrane blocking. Extent of reaction by tumor-bearing mice with the enzyme erythrocyte membrane bubble shadow detection of red cell membrane variation in the degree of closure before and after administration. Results: Solanum nigrum polysaccharide could significantly improve the $S_{180}$ and $H_{22}$ tumor-bearing mice erythrocyte membrane fluidity, compared with the control group, the difference was significant (p<0.01), SNL can significantly improve the red blood cell membrane and then $S_{180}$ tumor-bearing mice sealing ability, compared with the negative control group, the difference was significant(p<0.05, p<0.01). $H_{22}$ tumor-bearing mice can increase red cell membrane and then sealing ability, the difference was significant (p<0.05). Solanum nigrum polysaccharide degree of fluidity and blocking two transplanted tumors in mice restored the ability to raise the red cell membrane has a significant effect. Conclusions: Solanum nigrum L.-type mice transplanted tumor can affect the red blood cell membrane fluidity and re-closed, through the red cell membrane of red blood cells to enhance the immune function of the possibility of erythrocyte immunity against tumor formation garland provide experimental basis.

• 수산해양기술연구
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• 제55권4호
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• pp.310-319
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• 2019

Although mud shrimp (Upogebia Major) provides benefits on the tidal flat ecosystem, it is causing the mass mortality of Manila clam (Tapes philippinarum) and large economic loss to the aquaculture farmer due to spreading in the entire coastal clam farm area of the West Sea of Korea. In this study, a mud shrimp blocking box for cultivating clam was tested to prevent the mud shrimp from invading the habitat of the clam. To determine the effect of the blocking box, the growth characteristics of the clams under various culture conditions were investigated. The shell length, total weight, condition index, the presence of mud shrimp in the box, and the soil decay in the box were examined according to whether the clams were raised in the box or in natural state, whether the box is covered with a net or not and the gap size of the box. As a result, no significant differences in shell length, total weight, and condition index were found between the clam grown in the box and the natural state (P>0.05) without any evidence of invading of mud shrimp to the box. In addition, the soil inside the box was in good condition, not decayed. Therefore, using the mud shrimp blocking box, mud shrimp can be prevented from propagating to the habitat of the clam, thereby contributing to the normal production of the clam and thus to restoring the clam farming.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.75.2-75.2
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• 2013

Atomic layer deposition (ALD), utilizing self-limiting surface reactions, could offer promising perspectives for future efficient energy conversion devices. The capabilities of ALD for surface/interface modification and construction of novel architectures with sub-nanometer precision and exceptional conformality over high aspect ratio make it more valuable than any other deposition methods in nanoscale science and technology. In the context, a variety of researches on fabrication of active materials for energy conversion applications by ALD are emerging. Among those materials, one-dimensional nanotubular titanium dioxide, providing not only high specific surface area but also efficient carrier transport pathway, is a class of the most intensively explored materials for energy conversion systems, such as photovoltaic cells and photo/electrochemical devices. The monodisperse, stoichiometric, anatase, TiO2 nanotubes with smooth surface morphology and controlled wall thickness were fabricated via low-temperature template-directed ALD followed by subsequent annealing. The ALD-grown, anatase, TiO2 nanotubes in alumina template show unusual crystal growth behavior which allows to form remarkably large grains along axial direction over certain wall thickness. We also fabricated dye-sensitized solar cells (DSCs) introducing our anatase TiO2 nanotubes as photoanodes, and studied the effect of blocking layer, TiO2 thin films formed by ALD, on overall device efficiency. The photon convertsion efficiency ~7% were measured for our TiO2 nanotubebased DSCs with blocking layers, which is ~1% higher than ones without blocking layer. We also performed open circuit voltage decay measurement to estimate recombination rate in our cells, which is 3 times longer than conventional nanoparticulate photoanodes. The high efficiency of our ALD-grown, anatase, TiO2 nanotube-based DSCs may be attributed to both enhanced charge transport property of our TiO2 nanotubes photoanode and the suppression of recombination at the interface between transparent conducting electrode and iodine electrolytes by blocking layer.

• 공업화학
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• 제17권4호
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• pp.397-402
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• 2006

TFT-LCD TV용 백라이트 유니트(BLU)의 각 구성성분이 최종 광확산필름의 물리적, 전기적, 열적, 광학적 특성에 미치는 영향에 관하여 고찰하였다. 블로킹 방지층에 있어서는 $6{\mu}m$의 아크릴 비드를 0.5~1.5 wt%로 첨가했을 때 블로킹 방지성이 우수하였고, 4급 암모니움 염을 0.8 wt%로 첨가하였을 경우 Decay-Time 및 수분에 대한 안정성이 가장 우수한 결과를 나타내었다. 광확산층에 있어서는 아크릴 폴리올을 바인더 수지로서 사용하고, 무황변 타입의 HDI계 경화제를 바인더 수지에 대해 30~35 wt%로 첨가하였을 경우가 PET 필름 표면상에의 접착력, 경화속도 및 유연성 측면에서 가장 우수한 결과를 보였다. 또한 $20{\mu}m$의 다분산형 폴리스티렌($20{\mu}m$ PS) 및 폴리메틸메타크릴레이트($20{\mu}m$ PMMA) 비드를 바인더 수지 대비 250 wt%로 첨가하였을 경우에 가장 높은 법선휘도값을 얻을 수 있었으며, PS 입자를 사용했을 경우보다는 PMMA 입자를 사용했을 경우가 투과율 차이로 인해 더 높은 법선휘도값을 나타내었다.