• 제목/요약/키워드: iSC

검색결과 392건 처리시간 0.029초

태양전지용 ${\mu}c$-Si:H 박막의 저온증착 및 특성분석 (Low Temperature Deposition of ${\mu}c$-Si:H Thin-films for Solar Cell Application)

  • 정연식;이정철;김석기;윤경훈;송진수;박이준;권성원;임광수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 C
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    • pp.1592-1594
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    • 2003
  • This paper presents the deposition and characterization of microcrystalline silicon(${\mu}c$-Si:H) films by HWCVD(Hot-wire Chemical Vapor Deposition) method at low substrate($300^{\circ}C$). The filament temperature, pressure and $SiH_4$ concentration were determined to be a critical parameter for the deposition of poly-Si films. Series A was deposited under the conditions of $1380^{\circ}C$(Tf), 100 mTorr and $2{\sim}10%\{SC:SiH_4/(SiH_4+H_2)\}$ for 60 min. Series B was deposited under the conditions of $1400{\sim}1450^{\circ}(T_f)$, 30 mTorr and $2{\sim}12%$(SC) for 60 min. The physical characteristics were measured by Raman and FTIR spectroscopy, dark and photoconductivity measurements under AM1.5 illumination.

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Immune-Enhancing Effects of Lactobacillus plantarum 200655 Isolated from Korean Kimchi in a Cyclophosphamide-Induced Immunocompromised Mouse Model

  • Kim, Kyeong Jin;Paik, Hyun-Dong;Kim, Ji Yeon
    • Journal of Microbiology and Biotechnology
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    • 제31권5호
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    • pp.726-732
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    • 2021
  • In this study, we evaluated the immune-enhancing activity of kimchi-derived Lactobacillus plantarum 200655 on immune suppression by cyclophosphamide (CP) in ICR mice. Animals were fed distilled water or 1×109 colony-forming unit/kg B.W. 200655 or Lactobacillus rhamnosus GG as a positive control for 14 days. An in vivo model of immunosuppression was induced using CP 150 and 100 mg/kg B.W. at 7 and 10 days, respectively. Body weight, spleen index, spleen weight, and gene expression were measured to estimate the immune-enhancing effects. The dead 200655 (D-200655) group showed an increased spleen weight compared to the sham control (SC) group. Similarly, the spleen index was significantly higher than that in the CP-treated group. The live 200655 (L-200655) group showed an increased mRNA expression of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in splenocytes. Also, the iNOS and COX-2 mRNA expression was upregulated in the L-200655 group compared to the CP-only (SC) group. The phosphorylation of ERK and MAPK was also upmodulated in the L-200655 group. These results indicate that L. plantarum 200655 ameliorated CP-induced immune suppression, suggesting that L. plantarum 200655 may have the potential to enhance the immune system.

Effects of soil-structure interaction and variability of soil properties on seismic performance of reinforced concrete structures

  • Mekki, Mohammed;Hemsas, Miloud;Zoutat, Meriem;Elachachi, Sidi M.
    • Earthquakes and Structures
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    • 제22권3호
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    • pp.219-230
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    • 2022
  • Knowing that the variability of soil properties is an important source of uncertainty in geotechnical analyses, we will study in this paper the effect of this variability on the seismic response of a structure within the framework of Soil Structure Interaction (SSI). We use the proposed and developed model (N2-ISS, Mekki et al., 2014). This approach is based on an extension of the N2 method by determining the capacity curve of the fixed base system oscillating mainly in the first mode, then modified to obtain the capacity curve of the system on a flexible basis using the concept of the equivalent nonlinear oscillator. The properties of the soil that we are interested in this paper will be the shear wave velocity and the soil damping. These parameters will be modeled at first, as independent random fields, then, the two parameters will be correlated. The results obtained showed the importance of the use of random field in the study of SSI systems. The variability of soil damping and shear wave velocity introduces significant uncertainty not only in the evaluation of the damping of the soil-structure system but also in the estimation of the displacement of the structure and the base-shear force.

소프트웨어의 품질을 고려한 비용 평가 모델의 제안과 평가 (Proposal and Evaluation of a Cost Estimation Model Considering Software Quality)

  • 이용근;양해술
    • 한국정보처리학회논문지
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    • 제1권2호
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    • pp.194-201
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    • 1994
  • 최근 소프트웨어 적용분야가 확대됨에 따라 소프트웨어가 차지하는 비중이 점차 높아지고 개발 비용에 대한 중요성이 증대되고 있다. 그러나 종래의 개발비용 평가 모델은 주로 소프트웨어의 기능면에서 평가한것이 대부분 이었다. 본 논문에서는 소 프트웨어의 가치를 기능면 뿐만 아니라 품질면에서도 평가할 수 있는 소프트웨어 개 발비용 평가모델 COSMOS-Q(COSt MOdel for Subcontract-Quality)를 제안한다. 제안 모델의 목적은 소프트웨어 발주자가 발주 명세 정보만을 기본으로 정확한 소프트웨어 의 비용을 견적으로 할 수 있도록 하는 것이다. 특히, 본 연구에서는 ISO/SC7의 소프 트웨어 품질특성에 관한 검토 결과를 참고로 비용에 변동을 부여한 품질특성 요인의 추출 및 발주조건으로 지정가능한 각 요인의 평가척도를 설정하여 품질을 고려한 비 용 평가 모델을 제안하고 그 타당성을 평가하였다.

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벼 재배에서 imazosulfuron+fentrazamide 합제의 제형 및 처리시기에 따른 제초활성 (Herbicidal efficacy of various formulations and application timings of imazosulfuron+fentrazamide mixtures in rice)

  • 강광식;원옥재;박수혁;엄민용;황기선;서수정;변종영;박기웅
    • 농업과학연구
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    • 제41권1호
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    • pp.17-22
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    • 2014
  • This study was conducted to evaluate the efficacy of formulations and application timings of imazosulfuron+fentrazamide in rice field. Weeding efficacy of imazosulfuron+fentrazamide SC (75+300 g a.i./ha) was more than 95% except Bidens tripartita. The efficacy of this formulation was not related to its formulations but was highly related to application timing. Herbicide application before 5 days after transplanting was best timing to get a maximum weed control. Systemic application before and after transplanting was much higher than single application for weed control. Second leaf stage of Echinochloa spp. and sulfonylurea resistant Monochoria vaginalis was controled over 90% in the imazosulfuron+fentrazamide SC (75+300 g a.i./ha). Based on these data, imazosulfuron+fentrazamide can be applied to provide effective weed control especially in the field infested with herbicide resistant M. vaginalis.

고효율 HIT Solar Cell 제작을 위한 AFORS HET 시뮬레이션 실험 (AFORS HET Simulation for Optimization of High Efficiency HIT Solar Cell)

  • 조수현;허종규;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.450-451
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    • 2008
  • 비정질 실리콘 태양전지는 n-i-p형 구조가 일반적이며, 각 층의 두께와 도핑농도가 태양전지의 효율을 결정하는 중요한 요인이다. 최대의 효율을 얻을 수 있는 태양전지 설계를 위해 AFORS HET 시뮬레이션을 통하여 n층의 두께와 도핑농도, 그리고 p층의 도핑농도롤 변화시켰다. 최적화 결과, a-Si:H(n) 층의 두께 1nm, a-Si:H(n)층의 도핑농도 $2\times10^{20}cm^{-3}$, a-Si:H(p+)층의 도핑농도 $1\times10^{19}cm^{-3}$에서 $V_{oc}$=679.5mV, $J_{sc}$=39.02mA/$cm^2$, FF=83.71%, Efficiency=22.21%의 고효율을 얻을 수 있다. 본 연구를 통하여 실제의 높은 효율을 갖는 태양전지 설계와 제조 시에 이용할 수 있을 것이다.

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PC1D를 이용한 결정질 실리콘 태양전지 최적화 (Optimization of High Efficiency Single Crystalline Silicon Solar Cell by Using PC1D)

  • 이용우;이영석;한규민;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.195-196
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    • 2008
  • 결정질 실리콘 웨이퍼의 도핑농도와 도핑깊이, 비저항은 태양전지의 효율을 결정하는데 매우 중요한 요소이다. 높은 효율을 갖는 태양전지의 설계를 위해 PC1D를 이용해 태양전지의 에미터 도핑농도와 깊이, 베이스 비저항을 조절하였다. 최적화 결과 emitter peak doping $1\times10^{19}cm^{-3}$와 depth factor $1{\mu}m$, base $\rho$ $ 0.1\Omega$-cm, 즉 sheet resistance $69.15\Omega$/square와 $X_j$ $1.603{\mu}m$일 때 $I_{sc}$ = 5.478(A), $V_{oc}$ = 0.7013(V), $P_{max}$ = 2.828(W), FF = 73.61(%), Efficiency = 19.03(%)의 고효율을 얻을 수 있다.

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Homogeneous 에미터와 Selective 에미터 결정질 실리콘 태양전지의 온도에 따른 전류-전압 특성 변화 측정 및 분석 (Measurement and Analysis of Temperature Dependence for Current-Voltage Characteristics of Homogeneous Emitter and Selective Emitter Crystalline Silicon Solar Cells)

  • 남윤정;박효민;이지은;김수민;김영도;박성은;강윤묵;이해석;김동환
    • 한국재료학회지
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    • 제24권7호
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    • pp.375-380
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    • 2014
  • Solar cells exhibit different power outputs in different climates. In this study, the temperature dependence of open-circuit voltage(V-oc), short-circuit current(I-sc), fill factor(FF) and the efficiency of screen-printed single-crystal silicon solar cells were studied. One group was fabricated with homogeneously-doped emitters and another group was fabricated with selectively-doped emitters. While varying the temperature (25, 40, 60 and $80^{\circ}C$), the current-voltage characteristics of the cells were measured and the leakage currents extracted from the current-voltage curve. As the temperature increased, both the homogeneously-doped and selectively-doped emitters showed a slight increase in I-sc and a rapid degradation of V-oc. The FF and efficiency also decreased as temperature increased in both groups. The temperature coefficient for each factor was calculated. From the current-voltage curve, we found that the main cause of V-oc degradation was an increase in the intrinsic carrier concentration. The temperature coefficients of the two groups were compared, leading to the idea that structural effects could also affect the temperature dependence of current-voltage characteristics.

Extracellular ATP Stimulates $Na^+\;and\;Cl^-$ Transport through the Activation of Multiple Purinergic Receptors on the Apical and Basolateral Membranes in M-1 Mouse Cortical Collecting Duct Cells

  • Jung, Jin-Sup;Hwang, Sook-Mi;Lee, Ryang-Hwa;Kang, Soo-Kyung;Woo, Jae-Suk;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • 제5권3호
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    • pp.231-241
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    • 2001
  • The mammalian cortical collecting duct (CCD) plays a major role in regulating renal NaCl reabsorption, which is important in $Na^+$ and $Cl^-$ homeostasis. The M-1 cell line, derived from the mouse cortical collecting duct, has been used as a mammalian model of the study on the electrolytes transport in CCD. M-1 cells were grown on collagen-coated permeable support and short circuit current $(I_{sc})$ was measured. M-1 cells developed amiloride-sensitive current $5{\sim}7$ days after seeding. Apical and basolateral addition of ATP induced increase in $I_{sc}$ in M-1 cells, which was partly retained in $Na^+-free$ or $Cl^--free$ solution, indicating that ATP increased $Na^+$ absorption and $Cl^-$ secretion in M-1 cells. $Cl^-$ secretion was mediated by the activation of apical cystic fibrosis transmembrane regulator (CFTR) chloride channels and $Ca^{2+}-activated$ chloride channels, but $Na^+$ absorption was not mediated by activation of epithelal sodium channel (ENaC). ATP increased cAMP content in M-1 cells. The RT-PCR analysis demonstrated that M-1 cells express $P2Y_2,\;P2X_3\;and\;P2Y_4$ receptors. These results showed that ATP regulates $Na^+$ and $Cl^-$ transports via multiple P2 purinoceptors on the apical and basolateral membranes in M-1 cells.

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Identification of Putative Regulatory Alterations Leading to Changes in Gene Expression in Chronic Obstructive Pulmonary Disease

  • Kim, Dong-Yeop;Kim, Woo Jin;Kim, Jung-Hyun;Hong, Seok-Ho;Choi, Sun Shim
    • Molecules and Cells
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    • 제42권4호
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    • pp.333-344
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    • 2019
  • Various genetic and environmental factors are known to be associated with chronic obstructive pulmonary disease (COPD). We identified COPD-related differentially expressed genes (DEGs) using 189 samples accompanying either adenocarcinoma (AC) or squamous cell carcinoma (SC), comprising 91 normal and 98 COPD samples. DEGs were obtained from the intersection of two DEG sets separately identified for AC and SC to exclude the influence of different cancer backgrounds co-occurring with COPD. We also measured patient samples named group 'I', which were unable to be determined as normal or COPD based on alterations in gene expression. The Gene Ontology (GO) analysis revealed significant alterations in the expression of genes categorized with the 'cell adhesion', 'inflammatory response', and 'mitochondrial functions', i.e., well-known functions related to COPD, in samples from patients with COPD. Multi-omics data were subsequently integrated to decipher the upstream regulatory changes linked to the gene expression alterations in COPD. COPD-associated expression quantitative trait loci (eQTLs) were located at the upstream regulatory regions of 96 DEGs. Additionally, 45 previously identified COPD-related miRNAs were predicted to target 66 of the DEGs. The eQTLs and miRNAs might affect the expression of 'respiratory electron transport chain' genes and 'cell proliferation' genes, respectively, while both eQTLs and miRNAs might affect the expression of 'apoptosis' genes. We think that our present study will contribute to our understanding of the molecular etiology of COPD accompanying lung cancer.