• 제목/요약/키워드: Cell expansion

검색결과 522건 처리시간 0.026초

a-Si 박막형 태양전지의 잔류응력 해석에 관한 연구 (A Study on the Residual Stress Analysis of a-Si Thin Film Solar Cell)

  • 허장욱;김동욱;최성대
    • 한국기계가공학회지
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    • 제12권2호
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    • pp.14-19
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    • 2013
  • The size and distribution of residual stresses and the effect of the minimum mesh size were investigated by the a-Si thin film solar cell. Attributed to the difference in coefficient of thermal expansion of the a-Si and Ag concentrated residual stresses at the joint interface of dissimilar materials. The ${\sigma}y$ and ${\tau}xy$ didn't appear in the central part, but ${\sigma}x$ existed. However, ${\sigma}x$, ${\sigma}y$ and ${\tau}xy$ appeared in the edge part and concentrated residual stresses at the interface between a-Si and Ag. Minimum mesh size gets smaller, the concentration of ${\sigma}y$ was significantly and existence area was reduced. As a result, the failure of thin film solar cells during the cutting process can be explained by the residual stresses.

열전달 및 열하중을 고려한 자동차 연료전지(PEMFC) 분리판의 두께 최적설계 (Optimization of Automotive PEMFC Bipolar Plates considering Heat Transfer and Thermal Loads)

  • 김영성;김철
    • 한국자동차공학회논문집
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    • 제23권1호
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    • pp.34-40
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    • 2015
  • A stack in the proton exchange membrane fuel cell (PEMFC) consists of bipolar plates, a membrane electrode assembly, a gas diffusion layer, a collector and end plates. High current density is usually obtainable partially from uniform temperature distribution in the fuel cell. A size optimization method considering the thermal expansion effect of stacked plates was developed on the basis of finite element analyses. The thermal stresses in end, bipolar, and cooling plates were calculated based on temperature distribution obtained from thermal analyses. Finally, the optimization method was applied and optimum thicknesses of the three plates were calculated considering both fastening bolt tension and thermal expansion of each unit cell (72 cells, 5kW). The optimum design considering both thermal and mechanical loads increases the thickness of an end plate by 0.64-0.83% the case considering only mechanical load. The effect can be enlarged if the number of stack increases as in an automotive application to 200-300 stacks.

Mining Proteins Associated with Oral Squamous Cell Carcinoma in Complex Networks

  • Liu, Ying;Liu, Chuan-Xia;Wu, Zhong-Ting;Ge, Lin;Zhou, Hong-Mei
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권8호
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    • pp.4621-4625
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    • 2013
  • The purpose of this study was to construct a protein-protein interaction (PPI) network related to oral squamous cell carcinoma (OSCC). Each protein was ranked and those most associated with OSCC were mined within the network. First, OSCC-related genes were retrieved from the Online Mendelian Inheritance in Man (OMIM) database. Then they were mapped to their protein identifiers and a seed set of proteins was built. The seed proteins were expanded using the nearest neighbor expansion method to construct a PPI network through the Online Predicated Human Interaction Database (OPHID). The network was verified to be statistically significant, the score of each protein was evaluated by algorithm, then the OSCC-related proteins were ranked. 38 OSCC related seed proteins were expanded to 750 protein pairs. A protein-protein interaction nerwork was then constructed and the 30 top-ranked proteins listed. The four highest-scoring seed proteins were SMAD4, CTNNB1, HRAS, NOTCH1, and four non-seed proteins P53, EP300, SMAD3, SRC were mined using the nearest neighbor expansion method. The methods shown here may facilitate the discovery of important OSCC proteins and guide medical researchers in further pertinent studies.

공간 차원에 관한 시각적 패턴 연구 - 황금비, 피보나치 수열, 프랙털 이론을 중심으로 - (Study on Visual Patterns about Spatial Dimensions - Centered on the Golden Ratio, Fibonacci Sequence, and Fractal Theory -)

  • 김민석;김개천
    • 한국실내디자인학회논문집
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    • 제23권1호
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    • pp.88-95
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    • 2014
  • This study intended arousal of other viewpoints that deal with and understand spaces and shapes, by describing the concept of 'dimensions' into visual patterns. Above all, the core concept of spatial dimensions was defined as 'expandability'. Then, first, the 'golden ratio', 'Fibonacci sequence', and 'fractal theory' were defined as elements of each dimension by stage. Second, a 'unit cell' of one dimension as 'minimum unit particles' was set. Next, Fibonacci sequence was set as an extended concept into two dimensions. Expansion into three dimensions was applied to the concept of 'self-similarity repetition' of 'Fractal'. In 'fractal dimension', the concept of 'regularity of irregularity' was set as a core attribute. Plus, Platonic solids were applied as a background concept of the setting of the 'unit cell' from the viewpoint of 'minimum unit particles'. Third, while 'characteristic patterns' which are shown in the courses of 'expansion' of each dimension were embodied for the visual expression forms of dimensions, expansion forms of dimensions are based on the premise of volume, directional nature, and concept of axes. Expressed shapes of each dimension are shown into visually diverse patterns and unexpected formative aspects, along with the expression of relative blank spaces originated from dualism. On the basis of these results, the 'unit cell' that is set as a concept of theoretical factor can be defined as a minimum factor of a basic algorism caused by other purpose. In here, by applying diverse pattern types, the fact that meaning spaces, shapes, and dimensions can be extracted was suggested.

소형셀 네트워크 전송용량 향상을 위한 분산 파일저장 및 커버리지 확장 기법 (Distributed File Placement and Coverage Expansion Techniques for Network Throughput Enhancement in Small-cell Network)

  • 홍준표
    • 한국정보통신학회논문지
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    • 제22권1호
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    • pp.183-189
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    • 2018
  • 본 논문은 제한된 백홀 용량으로 발생하는 소형셀 네트워크에서의 트래픽 병목현상을 완화하기 위한 분산 파일저장 기술과 커버리지 확장 기술을 제안하였다. 제안 기법은 한정된 메모리 용량으로 백홀 망의 부하를 최소화하기 위해 파일의 인기도와 기지국의 메모리 용량에 따라 기지국의 커버리지와 파일 저장방법을 결정한다. 즉, 메모리 공간이 작거나 이용자들로부터 요청되는 파일이 다양할 경우 개별 기지국에 저장된 파일로 이용자를 서비스할 수 있는 확률이 낮아지므로 커버리지를 확장하고 기지국 사이 저장 파일의 중복을 줄여 커버리지 중첩지역에 있는 이용자가 다수의 기지국에 저장된 다양한 파일로 서비스 받을 수 있게 한다. 시뮬레이션을 통한 기존 배타적인 커버리지를 갖는 소형셀 네트워크에서의 파일저장 기법과의 전송용량 비교를 통해 제안 기법이 메모리 공간이 작거나 이용자들로 부터 요청되는 파일이 다양한 상황에서 높은 성능 이득을 가짐을 보였다.

인공 항원제시세포의 표면 분자의 특성 및 상호작용이 T 세포 활성화에 미치는 영향 (The effects of properties and interactions of surface molecules in antigen presenting cells on T cell activation)

  • 민영실;강윤중
    • 융합정보논문지
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    • 제10권6호
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    • pp.164-176
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    • 2020
  • 인체 적응 면역 반응을 일으키는데 중요한 항원 특이적 T 세포를 활용한 면역 세포 치료에서 T 세포를 체외에서 배양하고 클론 확장시키는 과정은 매우 섬세하고 복잡하여 조절하기가 쉽지 않아 T 세포의 활성화와 클론 확장을 유도하면서도 조절 및 취급이 용이한 인공 항원제시세포 개발의 필요성이 대두되고 있다. 인공 항원제시세포는 인체의 항원제시세포의 세포 표면 분자와 작용을 모방하게 되는데, 기본적인 신호 분자인 MHC-항원 복합체, 공동 자극 분자, 그리고 용해성 면역 조절 분자를 필수적으로 발현하여야 한다. 또한 T 세포가 항원과 접촉할 때, 이들 분자들이 잘 조직화되어 작용하는 것이 효과적인 T 세포 활성화에 중요하다. 본 논문에서는 여러 인공 항원제시세포 제작 방법과 세포 표면 분자들의 결합 방법과 물리적인 특성이 T 세포와의 상호작용에 중요함을 고찰하였으며, 효과적인 T 세포 활성화를 유도하며 면역세포치료에 적용 가능한 인공항원제세세포의 제작 방법을 살펴보았다.

eICIC 가 적용된 이종 셀룰러 망을 위한 부하 분산 기법 (Load Balancing Scheme for Heterogeneous Cellular Networks Using e-ICIC)

  • 홍명훈;박승영
    • 한국통신학회논문지
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    • 제39A권5호
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    • pp.280-292
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    • 2014
  • 기존의 매크로 셀룰러 망 환경은 공간 재사용의 한계로 인해 최근 급증하는 데이터 트래픽을 제대로 지원할 수 없게 되었다. 이 문제를 극복하기 위해 매크로 셀룰러 망위에 스몰 셀이 설치되어 적극적인 공간 재사용이 가능한 이종 셀룰러 망이 등장하게 되었다. 하지만, 매크로 셀과 스몰 셀 사이의 전송전력 차이로 인해 매크로 셀에 집중된 부하를 스몰 셀로 충분히 분산 시킬 수 없었다. 따라서, 프레임의 일정구간에서 매크로 셀의 전송전력을 차단하는 almost blank subframe (ABS) 와 스몰 셀 커버리지를 확장하여 사용자 부하를 스몰 셀로 강제 분산시키는 cell range expansion을 결합한 enhanced inter-cell interference coordination (eICIC) 기법이 제안되었다. 그러나, 이러한 eICIC 기법만으로는 효과적인 부하 분산을 달성하기 어렵다. 본 논문에서는 eICIC 기법이 적용된 이종 셀룰러 망 환경에서 비례공정을 향상시키는 부하 분산 기법을 제안한다. 구체적으로 제안된 기법은 탐욕 알고리즘 기반의 사용자의 소속 기지국 전환과 ABS 구간비율 갱신을 재귀적으로 결합하여 부하 분산을 실행한다.

Th17 Cell and Inflammatory Infiltrate Interactions in Cutaneous Leishmaniasis: Unraveling Immunopathogenic Mechanisms

  • Abraham U. Morales-Primo;Ingeborg Becker;Claudia Patricia Pedraza-Zamora;Jaime Zamora-Chimal
    • IMMUNE NETWORK
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    • 제24권2호
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    • pp.14.1-14.26
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    • 2024
  • The inflammatory response during cutaneous leishmaniasis (CL) involves immune and non-immune cell cooperation to contain and eliminate Leishmania parasites. The orchestration of these responses is coordinated primarily by CD4+ T cells; however, the disease outcome depends on the Th cell predominant phenotype. Although Th1 and Th2 phenotypes are the most addressed as steers for the resolution or perpetuation of the disease, Th17 cell activities, especially IL-17 release, are recognized to be vital during CL development. Th17 cells perform vital functions during both acute and chronic phases of CL. Overall, Th17 cells induce the migration of phagocytes (neutrophils, macrophages) to the infection site and CD8+ T cells and NK cell activation. They also provoke granzyme and perforin secretion from CD8+ T cells, macrophage differentiation towards an M2 phenotype, and expansion of B and Treg cells. Likewise, immune cells from the inflammatory infiltrate have modulatory activities over Th17 cells involving their differentiation from naive CD4+ T cells and further expansion by generating a microenvironment rich in optimal cytokines such as IL-1β, TGF-β, IL-6, and IL-21. Th17 cell activities and synergies are crucial for the resistance of the infection during the early and acute stages; however, if unchecked, Th17 cells might lead to a chronic stage. This review discusses the synergies between Th17 cells and the inflammatory infiltrate and how these interactions might destine the course of CL.

리본 두께에 따른 태양전지 Bowing현상 연구 (A Study on Bow of Silicon Solar Cell by Soldering Different Thickness of Ribbon)

  • 윤나리;정태희;신준오;강기환;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.68-68
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    • 2010
  • To reduce PV manufacturing costs, the thickness of solar cell is getting thinner. Bow is shown after cooling down the temperature of solder cell. It happens because of different thermal expansion coefficients of different metals. Bowed cell can make micro crack while module processing and it can drop off efficiency of PV module. As thinner solar cell is produced, the thickness of ribbon should be concerned to prevent extra bow. In this paper we investigate the contrast of deflection when we solder different thickness of ribbons on same solar cell. This approach would help to find out the optical thickness of ribbon for particular thickness of solar cell later on.

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Widdrol Blocks 3T3-L1 Preadipocytes Growth and Differentiation Due to Inhibition of Mitotic Clonal Expansion

  • Yun, Hee-Jung;Kim, Jeong-Hwan;Jeong, Hyun-Young;Ji, Hyang-Hwa;Nam, Soo-Wan;Lee, Eun-Woo;Kim, Byung-Woo;Kwon, Hyun-Ju
    • Journal of Microbiology and Biotechnology
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    • 제22권6호
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    • pp.806-813
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    • 2012
  • Adipocyte differentiation is strongly associated with obesity, which causes metabolic disorders. In this study, we investigated the inhibitory effects of widdrol on 3T3-L1 preadipocyte growth and differentiation. Widdrol decreased lipid droplet accumulation and down-regulated adipogenic transcription factors such as C/$EBP{\alpha}$, C/$EBP{\beta}$, and $PPAR{\gamma}$. Widdrol blocked preadipocyte proliferation and differentiation through the inhibition of mitotic clonal expansion, which was accompanied by the failure of degradation of p21, a cyclin-dependent kinase inhibitor. Cell-cycle analysis clearly indicated that widdrol actively induces cell-cycle arrest at the G1-S phage transition, causing cells to remain in the preadipocyte state. Moreover, widdrol increased p21 expression and inhibited Rb phosphorylation in preadipocyte incubated in a hormone medium. Therefore, these findings clearly suggest that widdrol blocks preadipocyte growth and differentiation through the inhibition of mitotic clonal expansion by p21-and Rb-dependent G1 arrest and can be developed as a potent anti-adipogenic agent for reducing obesity.