• Title/Summary/Keyword: Ghost cell

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Study of the Electrode Formation in the Crystalline Silicon Solar Cells with Various Anti-reflection Layers and Plating

  • Jeong, Myeong-Sang;Choe, Seong-Jin;Gang, Min-Gu;Song, Hui-Eun;Jang, Hyo-Sik
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.472.2-472.2
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    • 2014
  • 현재 결정질 실리콘 태양전지의 전 후면 전극의 형성은 스크린 프린팅 방법이 주를 이루고 있다. 스크린 프린팅 방법은 쉽고 빠르게 인쇄가 가능한 반면 단가가 높고 금속 페이스트에 첨가된 여러 혼합물에 의해서 전극과 기판 사이의 저항이 크다는 단점이 있다. 본 논문에서는 도금을 이용하여 태양전지의 전극을 형성한 후 태양전지의 전기적 특성을 비교하였다. 또한 단일반사방지막($SiN_x$) 증착 후 도금을 이용한 전극 형성 시 반사방지막의 pin-hole에 의해 전극 이외의 표면에 도금이 되는 ghost plating 현상이 발생하게 되는데, 이를 방지하기 위해 thermal oxidation을 이용하여 SiO2/SiNx 이중반사 방지막을 증착함으로써 ghost plating을 최소화 시켰다. Ni을 이용하여 전극과 기판 사이의 저항을 낮추었으며, 주요 전극은 Cu 도금을 사용함으로써 단가를 낮추었으며 마지막으로 Cu전극의 산화를 방지하기 위해 Ag을 이용하여 얇게 도금하였다. 실험에 사용된 Si 웨이퍼 특성은 p-형, $156{\times}156mm2$, $200{\mu}m$, $0.5{\sim}3.0{\Omega}{\cdot}cm$ 이다. 웨이퍼는 표면조직화, p-n접합 형성, 반사방지막 코팅을 하였으며 스크린 프린팅 방법을 이용해 후면 전극을 인쇄하고 열처리 과정을 통해 전극을 형성하였다. 이 후 전면에 레이저를 이용해 전극 패턴을 형성한 후 도금을 실행하여 태양전지를 완성하였다. 완성된 태양전지는 솔라 시뮬레이터, QE 및 TLM패턴을 이용하여 전기적 특성을 분석하였으며, SEM과 linescan, 광학현미경 등을 이용하여 전극을 분석하였다.

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CALCIFYING ODONTOGENIC CYST ASSOCIATED WITH MAXILLARY SINUS - A CASE REPORT - (상악동 전벽을 침범한 석회화 치성 낭종의 치험례)

  • Choi, Bo-Young;Lee, Jun;Kim, Jin-Hwan;Yoon, Dong-Hyun;Lee, Young-Jin;Jo, Byung-Ho;Yoo, Dae-Hyun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.30 no.6
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    • pp.599-603
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    • 2008
  • Calcifying odontogenic cyst(COC) is comparatively rare in occurrence. COC represents about 1% of jaw cysts, and although it may occur in soft tissue, it is most commonly found within bone. Both the intraosseous and extraosseous forms occur with about equal frequency in the maxilla and mandible, mainly in the incisor and canine areas The most notable features of this pathologic entity are histopathological and include a cyst lining demonstrating characteristic "ghost" epithelial cells with a propensity to calcify and the occasional association of this finding with certain odontogenic tumors including the odontoma and the ameloblastoma. In this case, COC was associated with anterior wall of the maxillary sinus which appeared in the anterior maxilla of 64-year-old woman, was reported. We report that the clinical experience of COC with review of literatures.

Development of Viscous Boundary Conditions in an Immersed Cartesian Grid Framework

  • Lee, Jae-Doo
    • Journal of Ship and Ocean Technology
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    • v.10 no.3
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    • pp.1-16
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    • 2006
  • Despite the high cost of memory and CPU time required to resolve the boundary layer, a viscous unstructured grid solver has many advantages over a structured grid solver such as the convenience in automated grid generation and vortex capturing by solution adaption. In present study, an unstructured Cartesian grid solver is developed on the basis of the existing Euler solver, NASCART-GT. Instead of cut-cell approach, immersed boundary approach is applied with ghost cell boundary condition, which can be easily applied to a moving grid solver. The standard $k-{\varepsilon}$ model by Launder and Spalding is employed for the turbulence modeling, and a new wall function approach is devised for the unstructured Cartesian grid solver. Developed approach is validated and the efficiency of the developed boundary condition is tested in 2-D flow field around a flat plate, NACA0012 airfoil, and axisymmetric hemispheroid.

Antibacterial Activity of Powdered Spice against Escherichia coli and Staphylococcus aureus (향신료 분말의 Esdcherichia coli 와 Staphylococcus aureus 에 대한 항균작용)

  • 김미림;최경호;박찬성
    • Food Science and Preservation
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    • v.7 no.1
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    • pp.124-131
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    • 2000
  • Antibacterial activities of powdered spices(garlic , ginger, cinnamon and clove) against pathogenic Escherichia coli )157:H7 and Staphyloccus auresus were investigated. Spice powder was added in was exponetial phase of each bacterial culture . Growth inhibition was determined by the absorbance at 660nm and morphological changes of the cells were observed by transmission electron microscope (TEM). Ginger powder has the highest antibacterial activity, following cinnamon , clove and garlic has the least activity.Growth of Escherichia coli O157:H7 and Staphyloccus aureus were completely inhibited within 5 hours after addition of 1 % of garlic , 0.3% of ginger or cinnamon , 0.5% of clove powder on the exponential phase of the cells. Spice untreated cells of E. coli and S. aureus, the cytoplasm was entirely surrounded by rigid cell wall and cell walls formed a smooth layer well attached to the plasma membrane. In the cells of E. coli and S. aureus treated with spice powder, cell wall and plasma membrane were lysed and severely damaged. E.coli cells growth in the presence of spice powder showed plammolysis, the loss of electron dense material, the formation of extra cellular blebs and cytoplasm burst out from the cell. S .sureus cells grown in the presence of spice powder showed swell of cell wall, the loss of electron dense material , coagulation of cell cytoplasm and formation of extra cellular blebs. Severely damaged cells of S. aureus lost whole cytoplasm and left as ghost of the cell. Spice powder stimulated autolyssi and induced cell death.

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Adsorptive Binding of Plasma Proteins to Red Blood Cell Ghosts (플라즈마 단백질의 고스트 적혈구 흡착 특성)

  • 김동욱;차운오
    • KSBB Journal
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    • v.11 no.6
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    • pp.630-635
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    • 1996
  • Blood plasma proteins dissolved in isotonic phosphate-buffered saline were found to be adsorbed to red blood cell ghosts suspended in the solution. This was evidenced by concentration reduction of the plasma proteins in the bulk solution. For initial concentration of 0.1mg/mL immuno globulin, concentration reduction increased from 14% to 45% as the volume fraction of red blood cell ghosts in the solution increased from 5% to 45%. For initial concentration of 0.075mg/mL albumin, the concentration reduction increased from 12% to 47% as the volume fraction of red blood cell ghosts in the solution increased from 5% to 70%. The concentration reduction of plasma proteins in hardened red blood cell ghosts was higher than that in red blood cell ghosts. The number of adsorbed protein molecules per a red blood cell ghost were reduced as volume fraction of the ghosts in the solution increased.

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Electrode formation using Light induced electroless plating in the crystalline silicon solar cells

  • Jeong, Myeong-Sang;Gang, Min-Gu;Lee, Jeong-In;Kim, Dong-Hwan;Song, Hui-Eun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.347.1-347.1
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    • 2016
  • Screen printing is commonly used to form the electrode for crystalline silicon solar cells. However, it has caused high resistance and low aspect ratio, resulting in decrease of conversion efficiency. Accordingly, Ni/Cu/Ag plating method could be applied for crystalline silicon solar cells to reduce contact resistance. For Ni/Cu/Ag plating, laser ablation process is required to remove anti-reflection layers prior to the plating process, but laser ablation results in surface damage and then decrease of open-circuit voltage and cell efficiency. Another issue with plating process is ghost plating. Ghost plating occurred in the non-metallized region, resulting from pin-hole in anti-reflection layer. In this paper, we investigated the effect of Ni/Cu/Ag plating on the electrical properties, compared to screen printing method. In addition, phosphoric acid layer was spin-coated prior to laser ablation to minimize emitter damage by the laser. Phosphorous elements in phosphoric acid generated selective emitter throughout emitter layer during laser process. Then, KOH treatment was applied to remove surface damage by laser. At this step, amorphous silicon formed by laser ablation was recrystallized during firing process and remaining of amorphous silicon was removed by KOH treatment. As a result, electrical properties as Jsc, FF and efficiency were improved, but Voc was lower than screen printed solar cells because Voc was decreased due to surface damage by laser process. Accordingly, we expect that efficiency of solar cells could be improved by optimization of the process to remove surface damage.

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The Complex Salmonella typhimurium Ghost Cells Play an Additional Role as an Immune Adjuvant (면역보강제로서 부가적인 역할을 가지는 복합 살모넬라 타이피무리움 고스트 세포)

  • Ha, Yeon Jo;Kim, Seung Tae;Kang, Ho Young;Gal, Sang Wan;Kim, Sam Woong
    • Journal of Life Science
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    • v.24 no.2
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    • pp.154-160
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    • 2014
  • Ghost cells have been recognized as eliciting humoral and cell-mediated immune responses and have also been predicted to play a role as an immune adjuvant. In this study, we used the intramuscular (IM) route to inject BALB/c mice with four vaccine groups constructed from Salmonella typhimurium ghost (STG) cells originating from different virulent strains and complex STG groups instead of heat-labile toxin (LT)-B, a type of adjuvant. Although the complex STG groups exhibited a response after a short delay, the groups showed final total IgG levels similar to those of the LT-B group, which encodes LT-B from pMMP300. The IgG1 response to the ${\chi}$3339 group was the highest response at 6 weeks, whereas IgG2a responses to the ${\chi}$3339 and JOL389 groups were higher at 6 and 8 weeks compared to those of the LT-B group. The response of vaginal sIgA to the LT-B group was generally higher than that of the other groups, whereas fecal sIgA to the LT-B group exhibited lower responses. Protection to virulent S. typhimurium in all groups was above 80%, which was similar to the LT-B group. Taken together, we suggest that STG complex groups can be used as an immune adjuvant instead of LT-B.

Effect of AL072, a Novel Anti-Legionella Antibiotic, on Growth and Cell Morphology of Legionella pneumophila

  • Kang, Byeong-Cheol;Park, Jae-Hak;Lee, Yong-Soon;Suh, Jung-Woo;Chang, Jun-Hwan;Lee, Chul-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.9 no.3
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    • pp.371-375
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    • 1999
  • AL072 is a potent anti-Legionella antibiotic produced by Streptomyces strain AL91. The minimum inhibitory concentration (MIC) of AL072 against Legionella pneumophila was 0.2$\mu$g/ml. Bacterial growth was rapidly inhibited at the dose range between the MIC and 20 times of the MIC when the antibiotic was added at the mid-exponential phase. Ultrastructural changes in L. pneumophila were observed upon treatment with AL072. Under electron microscopical observation, the organisms treated with AL072 exhibited characteristic morphological changes in the cellular outer coat. Also irregular morphological changes, such as the formation of filamentous materials in the cytoplasm, an increase in the size and number of cytoplasmic vacuoles, the extruding of cytoplasmic contents, the formation of spheroplast and ghost cells, and blebbings in the cell wall were observed. Furthermore, immunoelectron microscopical observation of the group treated with the MIC showed that the immune complex attached mainly to the cell wall. The results of these experiments indicate that AL072, like the inhibitors of cell wall synthesis, act selectively on the cell wall of L. pneumophila.

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Pilomatricoma (Calcifying Epithelioma of Malherbe) - A case report - (모기질 세포종 - 증례 보고 -)

  • Park, Kyeong-Mee;Shim, Jung-Weon;Ko, Ill-Hyang
    • The Korean Journal of Cytopathology
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    • v.2 no.2
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    • pp.168-171
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    • 1991
  • Pilomatricoma is a well defind and characteristic entity histologically, but this tumor may be encountered during aspiration biopsy of subcutaneous mass, and is, occasionally, confused with other neoplasms, particularly squamous cell carcinoma, basal cell carcinoma, and epidermal inclusion cyst. Recently, we have experienced a case of pilomatricoma diagnosed by aspiration biosy. The smear of the aspirate revealed anucleated "ghost" squamous cells, basaloid or basophilic squamous cells and nucleated squamous cells, which lack nuclear features of malignacy. These findings are consistent with pilomatricoma.

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Antimicrobial Effect of Grapefruit Seed Extract on Vibrio parahaemolyticus Isolated from the Southern Adjacent Sea of Korea (남해안연안에 분포되어 있는 Vibrio Parahaemolyticus의 성상 및 Grapefruit Seed Extract 처리에 의한 향균효과)

  • 조성환;강동훈;전상수;정덕화
    • Journal of Food Hygiene and Safety
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    • v.9 no.3
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    • pp.141-149
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    • 1994
  • To investigate the distribution of Vibrio parahaemopyticus in the southern 4 coastal areas, Vibrio parahaemolyticus was isolated from seawater, shellfish and sediment from May to October in 1991, and antimicrobial effect of grapefruit seed extract (GFSE) on the growth of isolated strains were examined. In the 120 sample from 4 coastal areas, 16 strains of Vibrio parahaemolyticus were isolated and identified. The distribution serotype of isolated strains was 10 types of monovalent k-antiserum. Especially k-5 and k-28 were highly distribyted with 3 and 4 strains. 31.3% of isolated strains showed positive on Kanagawa phenomenon test. All isolated Vibrio parahaemolyticus were sensitive to chloramphenicol and gentamycin, 5 and 6 strains were resistant to streptomycin and colistin, respectively. Isolated strains were compared with geographical, month and sample. The distribution of 16 isolated Vibrio parahamolyticus was high at Hadong with 50%(8 strains), on July with 43.8%(7 strains) and from seawater with 37.5%(6 strains) respectively. Minimal inhibitory level of GFSE to Vibrio parahaemolyticus was 50 ppm. With 100 ppm treatment of GFSE, the destroy of cell membrane function, outflow of cell ingredients and ghost morphology of cell were investigated.

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