• 제목/요약/키워드: Unit cell

검색결과 2,070건 처리시간 0.032초

수자직 복합재료 단위구조의 마크로요소해석 (Unit Cell Analysis of Satin Weave Composites Using Macroelements)

  • 우경식
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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    • pp.35-41
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    • 1997
  • Unit cell analyses were peformed to study the engineering properties of satin weave textile composites. Two 5-harness satin weave layers with fiber tow shifts were modeled by unit cells and repeating boundary conditions were applied at the outer surface of the unit cells. Multi-field macroelements were employed to consider the microstructure details and to effectively reduce computer memory requirements. Preliminary results indicated that the engineering properties of 5-harness satin weave textile composites can vary significantly according to the manner how the adjacent fiber tows were arranged in stacking.

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Visualization of Hepatitis B Virus (HBV) Surface Protein Binding to HepG2 Cells

  • Lee, Dong-Gun;Park, Jung-Hyun;Choi, Eun-A;Han, Mi-Young;Kim, Kil-Lyong;Hahm, Kyung-Soo
    • BMB Reports
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    • 제29권2호
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    • pp.175-179
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    • 1996
  • Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.

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Distribution of Basal Cell Carcinoma and Squamous Cell Carcinoma by Facial Esthetic Unit

  • Choi, Jung Hun;Kim, Young Joon;Kim, Hoon;Nam, Sang Hyun;Choi, Young Woong
    • Archives of Plastic Surgery
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    • 제40권4호
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    • pp.387-391
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    • 2013
  • Background The most common cutaneous malignant masses are basal cell carcinoma (BCC) and squamous cell carcinoma. The predominant site of a malignant mass is the face, which has many opportunities to be exposed to ultraviolet radiation. However the predilection sites of malignant masses have been equivocal due to the use of general regions, rather than anatomical landmarks, in surveys. A facial esthetic unit is an anatomical site classified as an area of similar facial contour characteristics that can be distinguished from other areas. The purpose of this study is to determine widely accepted anatomical landmarks using the esthetic unit. Methods We retrospectively analyzed 118 cases of malignant masses in our clinic from January 2005 to October 2012. We evaluated the patients' age, gender, and predilection site of the malignant mass by esthetic unit through pathology, medical records and patient photographs. We mapped the occurrence site of the malignant mass on schematic drawings of the esthetic units. Results Most of the malignant masses were BCC. The ratio of males to females was 1:1.41. The frequent predilection site of a malignant mass was on the nasal unit (33.1%), followed by the buccal unit (11.0%). Primary closure was the most common method of repairing a surgical defect (38.9%), followed by a local flap (35.5%). Conclusions This review described the relationship between clinical characteristics and esthetic units by proposing objective predilection sites for malignant masses, which can be used commonly as a framework in the study of malignant masses by unifying equivocal occurrence sites.

수치모사를 이용한 CDI Unit Cell 내부의 유로성능 평가 (COMPUTATIONAL STUDY FOR PERFORMANCE EVALUATION OF FLOW CHANNELS INSIDE CDI UNIT CELL)

  • 손덕영;최윤호;박대욱;정충효
    • 한국전산유체공학회지
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    • 제15권1호
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    • pp.31-36
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    • 2010
  • In the present study, computations for flow fields inside the CDI unit cells with electrodes and spacers have been made to evaluate their performance. Three types of unit cells that include a planar type, a serpentine channel type, and a spiral wound type were considered and their flow characteristics were compared. From the computational results, it is found that the serpentine channel type has a large flow resistance and can not guarantee the outflow flux for industrial applications. On the other hand, the planar type can sustain a large enough outflow flux but it's efficiency is low for the electrode-use because of the non-uniform velocity distribution inside the cell and dead zones in every corner. Finally, The spiral wound type has not only a large outflow flux as much as the planar type has, but also a high efficiency for the electrode-use because of uniform velocity distribution. From this comparison, we can expect that the spiral wound type of CDI unit cell would have a high performance deionization capability.

LH 전송선을 이용한 광대역 고역통과 필터 설계 및 제작 (Design and Fabrication of Wideband High Pass Filter Using Left-Handed Transmission Line)

  • 양두영;서수덕;조학래
    • 한국정보통신학회논문지
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    • 제18권2호
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    • pp.260-267
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    • 2014
  • 본 논문에서는 칩커패시터와 마이크로스트립 선로를 이용하여 LH 구조의 단위셀을 고안하고, 제안된 단위셀로부터 등가회로를 추출하여 단위셀의 제반 특성을 분석하였으며, 광대역 고역통과필터를 설계하는데 적용하였다. 이 필터는 고역통과 특성을 갖는 여러 개의 단위셀을 종속 연결하여 마이크로스트립 전송선에 구현하였으며, 그 성능은 0~2.18 GHz의 저지대역에서 62.9dB의 대역제거 특성과 3.0~12.75 GHz의 통과대역에서 1.17dB 이하의 삽입손실을 갖는다.

DSP 칩과 최적분별법을 이용한 새로운 혈구입자 계수기 설계 (A New Design of Blood Cell Counter using DSP chip and Optimal Discrimination Method)

  • 김규학;김종원;김근섭;홍완희;김성환
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1991년도 춘계학술대회
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    • pp.89-93
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    • 1991
  • The purpose of this reserch is to design the blood cell counting instrument which can measure the number of RBC(Red Blood Cell) and WBC(White Blood Cell) including many other blood component. The proposed method uses the electrical impedence method and the new discrimination method wi th DSP chip and software algorithm. The system consist of control unit, blood cell discrimination unit, hemoglobin spectrometer, post detect ion processor unit, and IBM-PC interface unit. In this paper, the discrimination system has been implemented using digital signal processor, which result in the reduction of system hardware and cost. The system is helpful in providing necessary clinical test for screen test and quality control of hematology.

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화학적합성법에 의한 나노 고체 전해질 분말 합성 및 전기화학적 평가 (Electrochemical studies of nano-scale solid electrolyte powder prepared by chemical synthesis process)

  • 김영미;신유철;김호성
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.295-298
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    • 2009
  • Oxygen ionic conductors of CeScSZ electrolyte in SOFC unit cell are applied to anode and cathode as well as electrolyte to have the triple-phase-boundaries of electrochemical reaction, and it is required to decrease the sintering temperature of anode-supported electrolyte by the nanoscale of CeScSZ electrolyte powder. In this report, nanoscale CeScSZ electrolyte powder was synthesized by chemical synthesis method. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under $10{\mu}m$ was fabricated by tape casting using the synthesized CeScSZ electrolyte powder, and ionic conductivity and gas permeability of electrolyte film were evaluated. Finally the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering, in which the active layer, measuring $20{\mu}m$, was introduced in the anode layer to provide a more efficient reaction. Electrochemical evaluations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

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X-대역 응용을 위한 광대역 전파 흡수체 설계 (Design of the Wideband Microwave Absorber for X-band Applications)

  • 홍영택;정구호;최재훈
    • 한국전자파학회논문지
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    • 제28권9호
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    • pp.749-755
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    • 2017
  • 본 논문에서는 X-대역(8~12 GHz) 응용을 위한 광대역 전파 흡수체를 제안하였다. 제안된 흡수체 unit cell 구조는 슬롯과 슬릿을 포함하는 공진기, 뒷면의 도체판, $8.5{\times}8.5{\times}0.5mm^3$의 크기를 갖는 Taconic RF-30(${\varepsilon}_r=3$, $tan{\delta}=0.0014$) 기판으로 이루어져 있다. 제안된 흡수체는 9.83 GHz와 10.37 GHz에서 공진이 발생하는 이중 공진 특성을 갖는다. 제안된 흡수체 구조의 동작 원리를 검증하기 위하여 각각의 공진주파수에서 unit cell 구조의 표면 전류 분포를 분석하였다. 제안된 흡수체의 성능을 확인하기 위하여 $20{\times}20$개의 unit cell 배열 시제품을 제작하였다. 측정 결과, 최대 흡수율을 갖는 지점에서 모두 99 % 이상의 흡수율이 측정되었으며, 측정된 full-width at half-maximum(FWHM) 대역폭은 1.1 GHz(9.51~10.61 GHz)이다.

Prediction of Effective Material Properties for Triaxially Braided Textile Composite

  • Geleta, Tsinuel N.;Woo, Kyeongsik;Lee, Bongho
    • International Journal of Aeronautical and Space Sciences
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    • 제18권2호
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    • pp.222-235
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    • 2017
  • In this study, finite element modeling was used to predict the material properties of tri-axially braided textile composite. The model was made based on an experimental test specimen which was also used to compare the final results. The full interlacing of tows was geometrically modelled, from which repeating parts that make up the whole braid called unit cells were identified based on the geometric and mechanical property periodicity. In order to simulate the repeating nature of the unit cell, periodic boundary conditions were applied. For validation of the method, a reference model was analyzed for which a very good agreement was obtained. Material property calculation was done by simulating uniaxial and pure shear tests on the unit cell. The comparison of these results with that of experimental test results showed an excellent agreement. Finally, parametric study on the effect of number of plies, stacking type (symmetric/anti-symmetric) and stacking phase shift was conducted.