• 한국전기전자재료학회논문지
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• 제17권11호
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• pp.1246-1251
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• 2004

This paper is investigated about the effect of carrier gas type and the humidity for generating hydrogen gas. The vibration of the water surface is more powerful with increasing applied voltage. In this experimental reactor which is made of multi-needle and plate, the maximum acquired hydrogen production rate is about 3500 ppm. In the experimental result of generating hydrogen gas by non-thermal plasma reactor, the rate of generating hydrogen gas is different with what kind of carrier gas is. We used two types of carrier gas, such as $N_2$ and He. $N_2$ as carrier gas is more efficient to generate hydrogen gas than He because $N_2$ is reacted with $O_2$, which is made from water dissociation. In comparison with water droplet by humidifier and without water droplet by humidifier, the generation of hydrogen gas is decreased in case of water droplet by humidifier. That is the result that the energy for water dissociation is reduced on water surface because a part of plasma energy is absorbed at the small water molecular produced from humidifier.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.215-219
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• 2004

This paper is investigated about the effect of carrier gas and humidity for generating hydrogen gas. In the experimental result of generating hydrogen gas by non-thermal plasma reactor, the rate of generating hydrogen gas is different with what kind of carrier gas is. We used two types of carrier gas, such as $N_2$ and He. $N_2$ as carrier gas is more efficient to generate hydrogen gas than He because $N_2$ is reacted with $O_2$, which is made from water dissociation. In comparison with no humidity and humidity 45[%], the generation of hydrogen gas is decreased with increasing the humidity. That is the result that the energy for water dissociation is reduced on water surface because a part of plasma energy is absorbed at the small particle produced from humidifier.

• Animal cells and systems
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• 제5권1호
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• pp.77-83
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• 2001

The present study was conducted to elucidate whether the expression level of poly(ADP-ribose) polymerase (PARP) is related to the ultraviolet radiation (UV)-induced apoptosis. After treatment of the mammalian cell lines HeLa S3 and Chinese hamster ovary (CHO) with 50 J/m2 UV, induction of apoptosis was determined by several means during 24 h post-incubation. Incidence of apoptosis was much lower in CHO than HeLa S3 cells based on the percentage of apoptotic cells in terms of morphological changes in nucleus or direct counting of viable cells and qualitative or quantitative DNA fragmentation. Interestingly, when the expression level of PARP was measured by western blotting, the amounts of PARP that was retained at each time point inversely correlated with the incidences of apoptosis in these cells. Concomitant with generation of the 85 kDa fragment, 116 kDa PARP disappeared in HeLa S3 within 6 h after UV treatment, whereas a fair amounts of 116 kDa band was still retained in CHO cells at 36 h post-incubation. This inverse relationship was also observed in the adaptive response system, in which cells weve treated with a high dose of UV after pretreatment with a low dose. As expected, typical adaptive responses appeared in CHO cells but not in HeLa cells, showing greater cell viability and lesser DNA fragmentation. During the adaptive response in CHO cells, PARP was expressed at much higher level compared to the single, high dose-treated cells. Interestingly, even though PARP was induced at 6 h post-incubation In both cell types, its expression was more prominent in CHO cells. Thus, our data indicate that the retained level of intact PARP against UV damage inversely correlates with incidence of apoptosis in mammalian cells, and also suggest that a machinery to protect the PARP degradation against UV damage exists in CHO but not in HeLa S3 cells.

• BMB Reports
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• 제42권6호
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• pp.331-337
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• 2009

We investigate the correlation between the glycosylation modified prion proteins and apoptosis. The wild-type PRNP gene and four PRNP gene glycosylated mutants were transiently expressed in HeLa cells. The effect of apoptosis induced by PrP mutants was confirmed by MTT assay, Hochest staining, Annexin-V staining and PI staining. ROS test detected ROS generation within the cells. The mitochondrial membrane potential was analyzed by the flow cytometry. The expression levels of Bcl-xL, Bax, cleaved Caspase-9 proteins were analyzed by Western Blot. The results indicated that the expressed non-glycosylated PrP in HeLa cells obviously induced apoptosis, inhibited the growth of cells and reduced the mitochondrial membrane potential, and more ROS generation and low levels of the apoptosis-related proteins Bcl-xL, the activated the cleaved Caspase-9 proteins were found. The apoptosis induced by non-glycosylated PrP demonstrates that its underlying mechanism correlates with the mitochondria-mediated signal transduction pathway.

• 한국콘텐츠학회논문지
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• 제22권6호
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• pp.160-174
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• 2022

본 연구는 매그넘 포토스 소속으로 한국전쟁 기간에 종군한 사진가 베르너 비숍의 종군활동과 주요 사진을 분석하였다. 베르너 비숍은 1951년과 1952년 두 번 한국에 입국해 종군했다. 그가 남긴 한국전쟁 사진과 에세이, 각종 편지, 사진집 등의 자료를 통해서 그의 종군활동과 종군 배경을 밝히고, 1·2차 종군에서 촬영한 대표 사진을 중심으로 주요 메시지와 특징을 분석했다. 비숍은 한국에서 '인간' 중심의 작품을 촬영했다. 특히 '전쟁지역에서 민간인은 어떻게 되는가?'에 대한 주제의식을 가졌다. 비숍은 1차 종군에서 전쟁에 휘말린 민간인의 고통과 전쟁의 참상을 알리고자 산양리 주민을 카메라에 담았다. 2차 종군에서는 최초 재정적 이유로 인해 마지못해 종군하였으나 포로수용소에서 이뤄지는 이념재교육의 실상과 포로들의 생활상을 인본주의적 관점에서 비판적으로 담아냈다. 흑백의 뚜렷한 대비, 인물 중심의 이미지 배열, 뛰어난 시선 처리 등의 특징을 보였다. 그의 종군은 한국전쟁 중 일어나는 민간인의 피해와 인본주의적 탐색에 배경을 두고 있었으며, 이러한 주제의식은 당시 종군한 여느 종군기자들과는 결이 다른 것으로 시대를 관통하는 특징을 갖는다.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1188-1195
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• 2014

This paper presents an analytical technique for reliability evaluation of electrical distribution network (EDN) containing distributed generation (DG). Based on hierarchical levels of circuit breaker controlling zones and feeder sections, a directed-relation-graph (DRG) for an END is formed to describe the hierarchical structure of the EDN. The reliability indices of EDN and load points can be evaluated directly using the formed DRG, and the reliability evaluation of an EDN containing DGs can also be done without re-forming the DRG. The proposed technique incorporates multi-state models of photovoltaic and diesel generations, as well as weather factors. The IEEE-RBTS Bus 6 EDN is used to validate the proposed technique; and a practical campus EDN containing DG was also analyzed using the proposed technique.

• 한국콘텐츠학회논문지
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• 제18권12호
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• pp.108-117
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• 2018

샤오취안은 정체되어 있던 중국의 다큐멘터리적 초상사진의 새로운 극복으로 평가되고 있다. 획일화되어 있던 집단적 접근 방식을 벗어나 사진가의 독창성에 기반한 개별적 접근방식의 형태를 제시했다. 특히, 샤오취안은 <우리들 세대>를 통해 중국의 개혁개방 이후 1980-90년대 문화, 예술 발전에 큰 역할을 한 인물들이 살아온 시대에 대한 자신의 감정과 해석을 일정한 사진적 형식을 통해 표현하고자 했다. 샤오취안은 촬영 대상과의 소통을 기반으로 인물의 진정한 내면적 모습을 파악하고 이에 영향을 끼친 시대적 배경 및 사상을 구현했다. 그는 촬영 대상의 복장과 생활환경을 활용해 그 시대의 문화, 예술적 흐름을 반영하고자 했다. 구도적으로도 화면 구조의 변화를 활용해 촬영 대상과 배경의 상징적 결합을 시도했다. 또한 인물의 표정을 통해 표현되는 감정을 시각적으로 구현해 사회상을 표현했다. 본 연구는 중국 초상사진의 다큐멘터리적 표현방식을 제시할 뿐만 아니라 역사적 기록으로써의 초상사진의 가치를 제고하는 기회를 제공한다.

• 한국진공학회지
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• 제11권2호
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• pp.127-134
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• 2002

본 논문은 AC PDP에서 사용하는 가스의 혼합비, 압력, 페닝 효과를 고려한 가스 조합의 최적화를 통해 낮은 방전전압으로 휘도의 증가를 얻을 수 있는 고휘도, 고효율 PDP 페닝 기체 혼합비를 찾고자 하였다. He(70%)-Ne(27%)-Xe(3%)의 3원 혼합기체와 Ne(96%)Xe(4%)의 2원 혼합기체에 페닝 효과를 극대화하기 위한 소량의 Ar, Kr을 첨가하여 각각의 첨가비에 따른 방전 개시전압, 방전 유지전압, 휘도, 발광효율 등을 측정하였다. 또한 페닝효과에 의한 방전 공간상의 전자수 증가를 확인하기 위해 셀 내의 전극 위에 쌓이는 벽전하 양을 측정하였다. 소량의 Ar(0.01%-0.03%) 또는 Kr(0.01%-0.03%)을 HE-Ne-Xe과 Ne-Xe 혼합가스에 첨가했을 때 페닝효과에 기인하여 휘도 및 발광효율이 각각 최고 10%-20% 증가하였다. 또한 페닝효과를 확인하기 위한 벽전하의 양은 10%-25% 증가를 보였다. 방전개시전압 및 최소방전유지전압은 대략 2V-3V정도 감소하였다.

• 천문학회보
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• 제46권1호
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• pp.41.2-41.2
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• 2021

In this study, we generate He I 1083 nm images from Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images using a novel deep learning method (pix2pixHD) based on conditional Generative Adversarial Networks (cGAN). He I 1083 nm images from National Solar Observatory (NSO)/Synoptic Optical Long-term Investigations of the Sun (SOLIS) are used as target data. We make three models: single input SDO/AIA 19.3 nm image for Model I, single input 30.4 nm image for Model II, and double input (19.3 and 30.4 nm) images for Model III. We use data from 2010 October to 2015 July except for June and December for training and the remaining one for test. Major results of our study are as follows. First, the models successfully generate He I 1083 nm images with high correlations. Second, the model with two input images shows better results than those with one input image in terms of metrics such as correlation coefficient (CC) and root mean squared error (RMSE). CC and RMSE between real and AI-generated ones for the model III with 4 by 4 binnings are 0.84 and 11.80, respectively. Third, AI-generated images show well observational features such as active regions, filaments, and coronal holes. This work is meaningful in that our model can produce He I 1083 nm images with higher cadence without data gaps, which would be useful for studying the time evolution of chromosphere and coronal holes.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2534-2546
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• 2023

Gas-cooled space reactor, which adopts He-Xe gas mixture as working fluid, is a better choice for megawatt power generation. In this paper, thermal-hydraulic characteristics of He-Xe gas mixture in 2×2 rod bundle wrapped with helical wires is numerically investigated. The velocity, pressure and temperature distribution of the coolant are obtained and analyzed. The results show that the existence of helical wires forms the vortexes and changes the velocity and temperature distribution. Hot spots are found at the contact corners between helical wires and fuel rods. The highest temperature of the hot spots reach 1600K, while the mainstream temperature is less than 400K. The helical wire structure increases the friction pressure drop by 20%-50%. The effect extent varies with the pitch and the number of helical wires. The helical wire structure leads to the reduction of Nusselt number. Comparing thermal-hydraulic performance ratios (THPR) of different structures, the THPR values are all less than 1. It means that gas-cooled space reactor adopting helical wires could not strengthen the core heat removal performance. This work provides the thermal-hydraulic design basis for He-Xe gas cooled space nuclear reactor.