• 제목/요약/키워드: the property (C)

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MnO$_2$가 첨가된 하이드로폰용 PbTiO$_3$계 세라믹스의 구조적 전기적 특성 (Structural and Electrical properties of MnO$_2$ added PbTiO$_3$system ceramics for Hydrophone)

  • 홍재일;유주현;박정흠;이두희;박창엽
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1994년도 추계학술대회 논문집
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    • pp.3-7
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    • 1994
  • In this study, to improve sintering condition, anisotropic Property(k$\_$t//k$\_$p/) of electromechanical coupling coefficients, and hydrostatic piezoelerlric constants d$\_$h/ and g$\_$h/, MnO$_2$impurity was added to the (Pb$\_$0.76/Ca$\_$0.24)[(Co$\_$$\frac{1}{2}$W$\_$$\frac{1}{2}$/)$\_$0.04/Ti$\_$0.96/]O$_3$ System ceramics for hydrophone. And the structural, electrical properties of them were investigated. As a results. tetragonality was decreased with MnO$_2$ additives and density was the highest value of 7.06(g/㎤) at H2-3 specimen. Electromechanical coupling coefficients of H2-3 specimen were k$\_$t/=49 and k$\_$p/ 0, which exibited the hightest hydrostatic piezoelectric constants of d$\_$h/=64.52[10$\^$-1/C/N] and g$\_$h/=35.92[10$\^$-3/ Vm/N].

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Host-Mediated Assay를 이용한 감궁탕의 돌연변이원성 평가 (Evaluation of Mutagenicity with Gamgung-tang Using Host-Mediated Assay)

  • 손윤희;김철호;남경수
    • 생약학회지
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    • 제36권2호통권141호
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    • pp.93-96
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    • 2005
  • Mutagenicity of Gamgung-tang (GGT) was tested using in vitro S-9 mixture in vitro host-mediated assay with Salmonella typhimurium. In the previous reports, GGT was tested for the safety using Ames(-S-9), Bacillus subtilis Rec, and umu gene expression mutagenicity tests. Mutagenic activity in any assays we tested was not found. In this report, we further investigated safety of GGT after metabolic activation in vivo. Ames test with S-9 mixture and host-mediated assay with Salmonella typhimurium TA98 were used to identify metagenic property of GGT. GGT was administered 3 times with i.m. to Balb/c mice did not induced mutagenic effect in Salmonella typhimurium TA98 recovered from the liver after 3.5h with i.p. treatment. Over the entire dose range $(3{\sim}150mg/mouse)$ tested no toxicity was detected to the bacterial cells. These results suggest that there was no DNA damage and mutagenicity by GGT.

인체착용실험에 의한 쾌적성 및 항아토피 성능평가 - 대나무숯 천연염색의류를 중심으로 - (Evaluation of Clothing Comfort and Anti-atopy Properties by Human Wear Test -Focused to Inner Wear Natural Dyed with Bamboo Charcoal-)

  • 김성희;신윤숙
    • 한국의류산업학회지
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    • 제12권1호
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    • pp.122-128
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    • 2010
  • This study examined several dyeing properties, physiological responses and comfort sensation of cotton knit underwear dyed with bamboo charcoal. The cotton knit underwear dyed with bamboo charcoal and treated with chitosan showed 99.9% antibacterial property and improved deodorization, and colorfastness. Eight children with atopic dermatitis worn underwear dyed with bamboo charcoal during 4 months. Their parents reported fewer itches of children. Wearing cotton knit underwear dyed with bamboo charcoal and non-dyed with bamboo charcoal respectively, these eight children rested for 20 minutes, then exercised for 10 minutes, and then rested for 30 minutes in the room maintained $28{\pm}1^{\circ}C$ and $50{\pm}5%R.H.$ Children's rectal temperature, skin temperature and microclimate inside garment of two types of cotton knit underwear were compared. As a result, the rectal temperature and skin temperature were higher when children were wearing underwear dyed with bamboo charcoal than non-dyed underwear. The microclimate temperature and microclimate humidity at the back of children were lower when children with underwear dyed with bamboo charcoal exercised and recovered.

AKD 처리한 홍조류섬유 보강 바이오복합재료의 특성 (Effect of Alkyl Ketene Dimer(AKD) on Red Algae Reinforced Biocomposites)

  • 이민우;박동휘;서영범
    • 펄프종이기술
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    • 제43권2호
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    • pp.66-71
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    • 2011
  • Biocomposites were fabricated with biodegradable polymers and natural fibers. Biocomposites have benefits of low cost, low density, and biodegradability over inorganic fiber composite, and give comparable strength properties. Hydrophobic polymer used for sizing in paper industry, AKD (Akenyl Keten Dimer), was applied to natural fibers, red algae fibers (RAF) in this study, to make fiber surfaces more compatible to hydrophobic nature of matrix polymers. Composites with RAF, kenaf, glass fibers, and carbon fibers have been fabricated by a compression molding method and their thermo-mechanical properties have been studied. Also, the thermal dimensional stability test was done from at 30 to $100^{\circ}C$. The storage moduli and the thermo-mechanical stabilities of polypropylene and poly lactic acid based biocomposites were improved by reinforcing with the RAF and much more with AKD treated fibers. Dimensional stability of biocomposite was also markedly improved by AKD pretrement on RAF.

RF Magnetron Sputtering 방법으로 제조한 In2O3 박막의 미세구조와 전기적 특성 (Microstructure and Electrical Properties of In2O3 Thin Films Fabricated by RF Magnetron Sputtering)

  • 전용수;윤여춘;김성수
    • 한국재료학회지
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    • 제12권4호
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    • pp.290-295
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    • 2002
  • Microstructure and electrical properties of $In_2O_3$ transparent thin films are analyzed on the basis of Structure Zone Model (SZM) proposed by Thornton. Thin films are deposited on glass substrate by RF magnetron sputtering with variation of substrate temperature $(T_s)$ and argon gas pressure $(P_{Ar})$. Microstructure of Zone I of SZM is observed with lowering of substrate temperature or increasing of argon pressure. The higher electrical resistivity of those specimens is due to micro-pores or voids between columnar grains. At the conditions of $T_s=450^{\circ}C$ and $P_{Ar}$=4.2mTorr, the Zone II structure of SZM and the lowest electrical resistivity $(2.1{\times}10^{-2}{\Omega}cm)$ are observed. The dense structure of columnar grains with faceting on growing surface and preferred orientation of (100) plane are observed in those specimens.

Performance Properties of Multi-Functional Finishes on the Enzyme-Pretreated Wool/Cotton Blend Fabrics

  • Ammayappan, L.;Moses, J. Jeyakodi;Senthil, K. Asok;Raja, A.S.M.;Jimmy, Lam K.C.
    • 한국염색가공학회지
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    • 제23권1호
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    • pp.1-10
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    • 2011
  • Research information related to application of enzyme as pretreatment and subsequent functional finishing on wool blended textiles for imparting multi-functional properties is still scanty. Yarn-blended wool/cotton fabric was pretreated with both a cellulase (Bactosol-CA) or a protease (Savinase-16.0LEx) in individual, subsequently finished with Synthappret-BAP and ${\beta}$-cyclodextrin based combination to impart anti-shrink, anti-microbial, softening and anti-crease properties. The performance of the finished fabrics depended on type of finishing combinations applied rather than enzyme pretreatment. Savinase pretreatment followed by Synthappret+Ceraperm-MW combination finishing impart both anti-shrink property as well as softening, while Bactosol pretreatment followed by ${\beta}$-cyclodextrin and sanitize combination finishing impart antimicrobial activity as well as anti-shrink finish to the wool/cotton blend fabric.

콘텐츠 보호를 위한 시스템온칩 상에서 암호 모듈의 구현 (Implementation of Encryption Module for Securing Contents in System-On-Chip)

  • 박진;김영근;김영철;박주현
    • 한국콘텐츠학회논문지
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    • 제6권11호
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    • pp.225-234
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    • 2006
  • 본 논문에서는 콘텐츠 보호의 암호화를 위해 ECC, MD-5, AES를 통합한 보안 프로세서를 SIP (Semiconductor Intellectual Property)로 설계하였다. 각각의 SIP는 VHDL RTL로 모델링하였으며, 논리합성, 시뮬레이션, FPGA 검증을 통해 재사용이 가능하도록 구현하였다. 또한 ARM9과 SIP들이 서로 통신이 가능하도록 AMBA AHB의 스펙에 따라 버스동작모델을 설계, 검증하였다. 플렛폼기반의 통합 보안 SIP는 ECC, AES, MD-5가 내부 코어를 이루고 있으며 각각의 SIP들은 ARM9과 100만 게이트 FPGA가 내장된 디바이스를 사용하여 검증하였으며 최종적으로 매그나칩 $0.25{\mu}m(4.7mm{\times}4.7mm$) CMOS 공정을 사용하여 MPW(Multi-Project Wafer) 칩으로 제작하였다.

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Pd 나노 촉매가 도입된 나피온 막의 기계적 강도 및 고분자 전해질막 연료전지 (PEMFC) 성능 (Mechanical Property of Nafion Membrane Incorporated with Pd Nanocatalyst and the Performance of PEMFC)

  • 이우금;이홍기
    • 한국수소및신에너지학회논문집
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    • 제27권3호
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    • pp.270-275
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    • 2016
  • A simple solid state incorporation method was employed in order to incorporate Pd nanocatalyst into a Nafion film for polymer electrolyte membrane fuel cell (PEMFC) via the reduction of palladium (II) bis (acetylacetonate), $Pd(acac)_2$. It was sublimed, penetrated into Nafion film and then reduced to Pd nanoparticles simultaneously in a glass reactor of N2 atmosphere at $180^{\circ}C$ for 1, 3 and 5 min. This reaction was took place without any reducing agent and any solvent. The morphology of the Pd nanoparticles was observed by transmission electron microscopy (TEM), and Pd distribution was analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). And 23% modification of tensile strength of Pd/Nafion composite film was measured by universal testing machine and I-V curve was estimated by using a unit cell with $5{\times}5cm^2$ active area.

현대 온돌 시스템 적용을 위한 신한옥 바닥난방의 열적특성 비교 (The comparison of thermal characteristics of new Han-ok floor heating for applying modern On-dol system)

  • 이태강;이주엽;송민정;김선우
    • KIEAE Journal
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    • 제13권3호
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    • pp.61-69
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    • 2013
  • The experiment on thermal characteristics of on-dol systems were carried out to apply to New Han-ok's heating system. Change of surface temperature varied with heating times, distribution of surface temperature, radiation property were surveid on four on-dol system in laboratory conditions. Followings are results. 1) "Hwang-to unit" was most favorable condition of the distribution of floor surface temperature. And the results from reaching time to thermal comfort temperature of on-dol system showed that "Hwang-to unit" was the most favorable to continuance of floor temperature. 2) There were a little difference in surface floor radiations of $30^{\circ}C$ for three wet on dol-systems. 3) It was suggested that "Hwang-to unit" is the most appropriate to floor heating system of new han-ok considering eco-friendship and continuance of floor temperature in intermittent heating condition.

Electrical Properties of (Bi,Y)4Ti3O12 Thin Films Grown by RF Sputtering Method

  • Nam, Sung-Pill;Lee, Sung-Gap;Bae, Seon-Gi;Lee, Young-Hie
    • Journal of Electrical Engineering and Technology
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    • 제2권1호
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    • pp.98-101
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    • 2007
  • Yttrium(Y)-substituted bismuth titanate $(Bi_{4-x},Y_x)Ti_3O_{12}$ [x=0, 0.25, 0.5, 0.75, 1](BYT) thin films were deposited using an RF sputtering method on the $Pt/TiO_2/SiO_2/Si$ substrates. The structural properties and electrical properties of yttrium-substituted $(Bi_4-xYx)Ti_3O_{12}$ thin films were analyzed. The remanent polarization of $(Bi_4-xYx)Ti_3O_{12}$ films increased with increasing Y-content. The $(Bi_{3.25}Y_{0.75})Ti_3O_{12}$ films fabricated using a top Au electrode showed saturated polarization-electric field(P-E) switching curves with a remanent polarization(Pr) of $8{\mu}C/cm^2$ and coercive field (Ec) of 53 kV/cm at an applied voltage of 7 V. The $(Bi_{3.25}Y_{0.75})Ti_3O_{12}$ films exhibited fatigue-free behavior up to $4.5{\times}10^{11}$ read/write switching cycles at a frequency of 1MHz.