• 제목/요약/키워드: ODF2

검색결과 20건 처리시간 0.024초

통신안테나 설비의 2자유도 체상 위상 추적 제어 시스템의 설계 (A Design of Optimal Satellite-Tracking Control System with Two-Degree-of Freedom for Communication Antenna Equipments)

  • 황창선;황현준;김동완;김문수;정호성
    • 한국조명전기설비학회지:조명전기설비
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    • 제11권3호
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    • pp.97-105
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    • 1997
  • 위성통신설비를 위한 인공위성 추적 안테나 제어 시스템은 바람에 의한 외란과 베어링 공기역학적 마찰로 인한 전달함수의 파라메타 변동이 존재하므로, 이러한 시스템의 불확실성에도 불구하고 만족스러운 명령추종성을 가지는 강인한 제어 시스템의 설계가 요구된다. 본 연구에서는 $\mu$-설계법을 사용하여 피드백 \ulcorner 포워드 제어기를 각각 독립적으로 설계할 수 있는 강인한 성능을 가지는 2자유도계의 설계법을 제시한다. 또한, 제시된 설계법을 위성추적 안테나 제어 시스템에 제어 시스템에 적용되고 컴퓨터 시뮬레이션을 통하여 1자유도계와 성능을 비교 고찰하여 그 유용성을 확인한다.

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0.1% Sc이 첨가된 7X1X Al-합금의 압연과 T-6열처리에 따른 집합조직의 발달 (Texture Development of Cold Rolled and T-6 Treated 7X1X Al-alloy with 0.1% Sc)

  • 제창웅;진승준;정동석;임성택;박노진
    • 열처리공학회지
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    • 제17권2호
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    • pp.101-105
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    • 2004
  • After extrusion, cold rolling and T-6 treatment, texture development of 7x1x Al-alloy with 0.1% Sc is studied. During extrusion the very strong <111>+weak <100> fiber texture is developed, which is Influenced on the formation of rolling texture. The texture after 80% cold rolling can be described by strong{112}<111>(Cu)+{123}<634>(S) component in the cross section of the extruded rod, the strong -fiber+weak{110}<001>(Goss) components in the longitudinal section, and the strong {110}<112>(Bs)+weak{001}<100>(Cube) components in the transverse section. The components of rolling texture are remained after T-6 treatment, but the maximum density of ODF is higher. The calculated mean r-values and the planar anisotropy are relatively high, which are dependent on the texture. After T-6 treatment, recrystallized equiaxed grains with average grain size of $1{\sim}2{\mu}m$ are obtained.

이온빔 합성법에 의해 증착된 다이아몬드성 카본 필름의 구조 및 특성 (Structure and properties of ion beam deposited diamond-like carbon films)

  • 김성화;이광렬;은광용
    • 한국진공학회지
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    • 제8권3B호
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    • pp.346-352
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    • 1999
  • Diamond-like carbon (DLC) lims were deposited by using end hall type ion gun. Benzene gas was used for the generation of carbon ions. In order to systematically control the ion energy, we applied to the substrate DC, pulsed DC or 250 kHz medium frequency bias voltage, DLC films of superior mechanical properties of hardness 39$\pm$4 GPa and elastic mudulus 290$\pm$50GPa (2 to 6 times better than those of the films deposited by plasma assisted CVD method) could be obtained. Deposition rate was much higher than when using Kaufman type ion source, which results from higher ion beam current of end hall type ion gun. The mechanical properties and atomic bond structure were independent of the bias voltage type ion gun. The mechanical properties and atomic bond structure were independent of the bias voltage type but intimately related with the magnitude of the bias voltage. With increasing the negative bias voltage, the structure of the films changed to graphitic one resulting in decreased content of three dimensional inter-links. Degradation of the mechanical properties with increasing bias voltage could be thus understood in terms of the content odf three dimensional inter-links.

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차세대 선재 기판용 Ag 테이프의 제조공정에서 가공 열처리가 집합조직에 미치는 영향 (Effect of thermo-mechanical treatment on fabrication of Ag tapes for YBCO coated conductor)

  • 이남진;오상수;박찬;송규정;하동우;권영길;류강식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 초전도 자성체
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    • pp.46-49
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    • 2002
  • The aim of this paper is to investigate the influence of various deformation ratio on texture of Ag tapes that can be used as a RE-$Ba_2Cu_3O_{7-{\delta}}$ coated conductor tapes without any buffer layer. We fabricated as-rolled Ag substrate with various deformation ratio per step. Thickness and total deformation ratio of Ag tapes were $100{\mu}m$ and >98%, respectively. And as-rolled Ag substrate was annealed at $750^{\circ}C$ for 30min. The as-rolled and recrystallization textures were measured using x-ray pole figures and orientation distribution function (ODF) analysis. With the increase of rolling ratio from 5 to 20%, deformation texture are changed from {1l0}<311> to {1l0}<112>, {032}<100>, {051}<211>. After recrystallization by annealing, main texture was observed to {013}<100> under present condition.

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Lactobacillus acidophilus and Lactobacillus crispatus Culture Supernatants Downregulate Expression of Cancer-testis Genes in the MDA-MB-231 Cell Line

  • Azam, Rosa;Ghafouri-Fard, Soudeh;Tabrizi, Mina;Modarressi, Mohammad-Hossein;Ebrahimzadeh-Vesal, Reza;Daneshvar, Maryam;Mobasheri, Maryam Beigom;Motevaseli, Elahe
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권10호
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    • pp.4255-4259
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    • 2014
  • Lactobacilli are probiotics shown to have antitumor activities. In addition, they can regulate gene expression through epigenetic mechanisms. In this study, we aimed to assess anti tumor activities of Lactobacillus acidophilus and Lactobacillus crispatus on the MDA-MB-231 breast cancer cell line. The effects of culture supernatants were determined by MTT [3-(4,5-dimethylthiazol-2-y-2,5-diphenyltetrazolium bromide] assay. Changes in expression of 5 cancer-testis antigens (CTAs), namely AKAP4, ODF4, PIWIL2, RHOXF2 and TSGA10, were analyzed by quantitative real time RT-PCR. The culture supernatants of the 2 lactobacilli inhibited MDA-MB-231 cell proliferation. In addition, transcriptional activity of all mentioned CTAs except AKAP4 was significantly decreased after 24 hour treatment with culture supernatants. This study shows that Lactobacillus acidophilus and Lactobacillus crispatus have antiproliferative activity against MDA-MB-231 cells. In addition, these lactobacilli could decrease transcriptional activity of 4 CTAs. Previous studies have shown that expression of CTAs is epigenetically regulated, so it is possible that lactobacilli cause this expression downregulation through epigenetic mechanisms. As expression of CTAs in cancers is usually associated with higher grades and poor prognosis, downregulation of their expression by lactobacilli may have clinical implications.

Adverse effects of pesticide/metabolites on boar spermatozoa

  • Wijesooriya Mudhiyanselage Nadeema Dissanayake;Jung Min Heo;Young-Joo Yi
    • 농업과학연구
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    • 제50권4호
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    • pp.941-952
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    • 2023
  • The metabolites of agrichemicals, such as organophosphorus pesticides, are known to be more hazardous than their parent pesticides. 3,5,6-trichloro-2-pyridinol (TCP) is a major degradation product of chlorpyrifos, one of the organophosphate insecticides widely used in agriculture. In vivo or in vitro exposure to chlorpyrifos has been known to interfere with male reproductive functions, leading to reduced fertility in mammals. Therefore, this study was performed to examine the changes in the fertilization competence of boar spermatozoa exposed to TCP. Sperm samples were subjected to varying concentrations of TCP (10, 50, 100, 200 µM) and different periods of incubation. Sperm motility, motion kinematics, viability, acrosome integrity, intracellular reactive oxygen species (ROS) production, and gene expression levels (ODf2, ZPBP2, AKAP3 and AKAP4) were evaluated after exposure of the sperm to TCP. A significant dose-dependent reduction in motility was observed in sperm samples incubated with TCP compared to the controls after both incubation periods. Sperm viability was significantly decreased in samples incubated with 50, 100, and 200 µM TCP in both incubation periods. A significantly lower percentage of normal acrosomes and gene expression levels were observed in sperm samples exposed to 50, 100, and 200 µM TCP after both incubation periods, compared to the controls. There was a significant increase in the ROS production in spermatozoa incubated with 100 - 200 µM TCP after both incubation periods. Consequently, the direct exposure of boar spermatozoa to TCP interferes with sperm functions and leads to decreased fertilization. In order to identify and address the various causes of reproductive decline, the impact of chemical metabolites needs to be discussed in depth.

양축 정렬된 Ni 기판의 특성에 미치는 W 첨가의 효과 (The Influence of W Addition on Cube Textured Ni Substrates for YBCO Coated Conductor)

  • 김규태;임준형;김정호;장석헌;김호진;주진호;김찬중;송규정;신형섭
    • Progress in Superconductivity
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    • 제6권1호
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    • pp.64-68
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    • 2004
  • We fabricated cube-textured Ni and Ni-W alloy substrates for coated conductors and characterized the effects of W addition on microstructure, mechanical strength, and magnetic properties of the substrate. Pure Ni and Ni-(2, 3, 5at.%)W alloys were prepared by plasma arc melting, heavily cold rolled and then annealed at various temperatures of $600-1300^{\circ}C$. The texture was evaluated by pole-figure and orientation distribution function (ODF) analysis. Mechanical properties were investigated by micro Vickers hardness and tension test. Ferromagnetism of the substrate was measured by physical property measurement system (PPMS). It was observed that Ni-W substrates had sharp cube texture, and the full-width at half-maximums (FWHMs) of in-plane texture was $^{\circ}$-5.57$4.42^{\circ}$, which is better than that of pure Ni substrate. In addition cube texture of Ni-W substrates was retained at higher temperature up to $1300^{\circ}C$. Microstructural observation showed that the Ni-W substrates had fine grain size and higher mechanical properties than the pure Ni substrate. These improvements are probably due to strengthening mechanisms such as solid solution hardening and/or grain size strengthening. PPMS analysis showed that addition of W effectively reduced saturation magnetization in applied magnetic field and Curie temperature.

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무전해 도금법을 이용한 cube 집합조직을 가지는 Au/Ni template 제조 (Fabrication of cube textured Au/Ni template using electoless-plating)

  • 임준형;김정호;장석헌;김규태;이진성;윤경민;주진호;김찬중;하홍수;박찬
    • Progress in Superconductivity
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    • 제6권2호
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    • pp.133-137
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    • 2005
  • We fabricated the Au/Ni template for YBCO coated conductors and evaluated texture formation and the microstructural evolution. The cube textured Ni substrate was fabricated by rolling and recrystallization annealing, and subsequently Au layer formed on the substrate by electroless-plating method. The texture was evaluated by pole-figure with x-ray goniometer with orientation distribution function (ODF) analysis. The surface roughness and grain boundary morphology of template were characterized by atomic force microscopy (AFM) We observed that Au layer deposited epitaxially on Ni substrate and formed a strong cube texture when plating time was optimized. The full-width at half-maximum (FWHM) was $8.4^{\circ}$ for out-of-plane and $9.98^{\circ}$ for in-plane texture for plating time of 30 min. Microstructural observation showed that the Au layer was homogeneous and dense without formation of crack/microcrack. In addition, we observed that root-mean-square (RMS) and depth of grain boundary were 14.6 nm and 160 $\AA$ for the Au layer, respectively, while those were 27.0 nm and 800 $\AA$ for the Ni substrate, indicating that the electoless-plated Au layer had relatively smooth surface and effectively mollified grain groove.

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수열합성법에 의한(Ni, Zn)-Ferrites의 초미세분말 합성공정 및 $CO_2$분해 특성 연구 (Study on The Synthesis of The Ultra-Fine (Ni, Zn)-ferrite by The Hydrothermal Method and its $CO_2$ Decomposition)

  • 김정식;안정률;류호진
    • 한국재료학회지
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    • 제10권3호
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    • pp.223-226
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    • 2000
  • 산소 결핍 페라이트 (oxygen deficient ferrites, ODF) $MeFe_2O_{4-\delta}$는 약 $300^{\circ}C$의 낮은 온도에서 $CO_2$를 C와 $O_2$로 분해한다. 본 연구에서는 $(Ni_x,\;Zn_{1-x}Fe_2_4$ 초미세 페라이트 분말을 수열합성법으로 제조하여 $CO_2$ 분해특성을 살펴보았다. 제조된 페라이트는 XRD 분석 결과, 페라이트의 전형적인 스피넬 구조를 보여주고 있으며, ICP-AES, EDS 정량분석에 의하여 초기 혼합 조성비와 거의 동일한 조성비로 합성되었음을 알 수 있었다. 제조된 (Ni, Zn)-ferrites 분말의 BET 비표면적은 약 $110\textrm{mg}^2$/g$ 이상의 큰 값으로 나타났으며, 입자크기는 약 5~10nm로 매우 작았다. 산소결핍 페라이트 $(Ni_x,\;Zn_{1-x})Fe_2O_{4-{$\delta}}$$CO_2$ 분해 효율은 조성에 따라 큰 차이를 보이지 않았으며 3원계 (Ni, Zn)-ferrite가 Ni-ferrite보다 더 높았다.

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Macrophage Colony-Stimulating Factor와 Osteoclast Differentiation Factor로 분화 유도된 생쥐 파골세포에서 Vitamin D 및 수종의 싸이토카인 수용체의 발현 (Expression of receptors of Vitamin D and cytokines in osteoclasts differentiated by M-CSF and ODF)

  • 성수미;엄흥식;고성희;우경미;장범석
    • Journal of Periodontal and Implant Science
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    • 제32권4호
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    • pp.865-873
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    • 2002
  • The primary cause of tooth loss after 30 years of age is periodontal disease. Destruction of alveolar bone by periodontal disease is done by bone resorbing activity of osteoclasts. Understanding differentiation and activation mechanism of osteoclasts is essential for controling periodontal disease. The purpose of this study is to identify the possible effects of Vitamin D and cytokines affecting osteoclasts and its precursor cells. Four to six week-old mice were killed and humerus, radius, tibia and femur were removed aseptically and washed two times with Hank's solution containing penicillin-streptomycin and then soft tissue were removed. Bone marrow cells were collected by 22 gauge needle. Cells were cultured in Hank's solution containing 1 mg/ml type II collagenase, 0.05% trypsin, 41mM EDTA. Supernatant solution was removed 5 times after 15 minutes of digestion with above mentioned enzyme solution, and remained bone particles were maintained in alpha-MEM for 15 minutes and $4^{\circ}C$ temperature. Bone particles were agitated for 1 minute and supernatant solution containing osteoclast precursor cells were filtrated with cell stainer. These separated osteoclast precursor cells were dispensed with 100-mm culture dish by $1{\times}10^7$ cells unit and cultured in ${\alpha}$- MEM containing 20 ng/ml recombinant human M-CSF, 30 ng/ml recombinant human soluble osteoclast differentiation factor and 10% fetal calf serum for 2 and 7 days. Total RNA of osteoclast precursor cells were extracted using RNeasy kit. One ${\mu}g$ of total RNA was reverse transcribed in $42^{\circ}C$ for 30 minutes using SuperScriptII reverse transcriptase. Expression of transcribed receptors of each hormone and cytokine were traced with 1 ${\mu}l$ of cDNA solution by PCR amplification. Vitamin D receptor WAS found in cells cultured for 7 days. TNF-${\alpha}$ receptor was found in cells cultured for 2 days and amount of receptors were increased by 7 days. IL-1 type I receptor was not found in cells cultured 2 and 7 days. But, IL-1 receptor type II was found in cells cultured for 2 days. TGF-${\alpha},{\beta}$type I receptor was found in cells cultured 2 and 7 days, and amount of receptors were increased by 7 days of culture. These results implies Vitamin D and cytokines can affect osteoclasts directly, and affecting period in differentiation cycle of osteoclasts is different by Vitamin D and cytokines.