• 제목/요약/키워드: TETRA

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Development and Analysis on Noise Characteristics of Low Noise Cooling Fan for an Alternator by Using Numerical Method (수치적 방법을 이용한 저소음 얼터네이터 냉각팬의 개발 및 소음 특성 분석)

  • Kim, Wook;Jeon, Wan-Ho;Hyun, Jae-Jin;Lim, Chul-Koo;Lee, Sung-Ha
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.608-609
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    • 2008
  • An alternator which converts mechanical rotating energy into electric energy is an important component of a vehicle. It operates in broad range from 3000 RPM to 18000 RPM. So, sufficient flow rate and low noise are needed in such broad operating range for a cooling fan of this alternator. In current study, the cooling fan of an alternator is developed through DFSS process and numerical analysis. In order to calculate flow rate and noise level, SC/Tetra and FlowNoise S/W are used respectively, for a new developed fan, compared with original model, numerical result shows 3 dBA reduction and measured value shows 4 dBA reduction.

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시베리아 자판기 시장'무주공산'

  • Korea Vending Machine Manufacturers Association
    • Vending industry
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    • v.6 no.1 s.16
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    • pp.38-39
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    • 2006
  • 자판기 생산업체가 없어 전량을 수입에 의존하고 있는 러시아 모스크바를 중심으로 자판기 설치가 대중화되고 있어, 향후 최고의 비즈니스 아이템으로 부상하고 있다. 러시아에서 다수를 차지하는 자판기 정류로는 커피자판기와 캔자판기로 95% 이상이 모스크바에 집중돼 있는 것으로 나타났는데, 모스크바의 경우 자판기 설치대수는 유럽의 5%에 불과하며, 자판기 1대가 약 1,600명꼴로 보급이 되어 있는 반면, 유럽은 1대당 평균 134명 꼴로 보급되어 있는 것으로 나타나 향후 전망이 매우 밝은 것으로 예상된다. 전문가들에 의견에 따르면 러시아 자판기 시장 잠재력은 매우 커 향후 5년간 자판기 판매 금액만 연간 1억 4000만달러, 자판기를 통한 음료수 판매액은 연간 10억달러에 달할 것으로 전망하고 있다. 한편 러시아에 수입괴고 있는 자판기 대수에 대한 정확한 수치는 나와 있지 않지만, 수입통계 및 전문가들의 의견을 고려해 볼 때 모스크바에만 약 5000대의 자판기가 설치돼 있는 것으로 추정된다. 그러나 이들 자판기중 30%는 코카콜라가 제공하고, 10%는 네슬레사, 그리고 펩시콜라, TetraPak사 등이 공급한 것으로 나타나 일반적인 자판기 시장의 확대 여지는 큰 것으로 분석되고 있다.

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What Can Caenorhabditis elegans Tell Us About Nematiocides and Parasites\ulcorner

  • Dent, Joseph A.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.4
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    • pp.252-263
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    • 2001
  • Nematode infections compromise human health and reduce agricultural productivtiy. Experiments that exploit the powerful molecular genetics of the free-living nematode Caenorhabdl - elegans have contributed to our understanding of how the major classes of anthelmintic nema-tocides kill worms and how worms might evolve resistance to these drugs In C. elegans, as in parasites, benzimidixoles interfere with microtubule polyumerization the imidazothiazoles/tetra-hydropyrimidines activate nicotinic acetylcholine receptors, and the macrocyclic la ctones activate qlutamate-gate chloride chanels. Mutant alleles of genes that encode drug targes often confer resistance in C. elegans. Preliminary evidence suggests that alleles of homologous genes in parasites will, in many cases, also play a role in resistance. Thus information acquired from C. elegans can be usefully applied to understand the mechanisms of drug sensitivity and the genetics of resis-tance in parasites.

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Retro-synthesis of Analogues of Ginsenosides (역합성법에 의한 진세노사이드 유사체의 합성)

  • Chang, Eun-Ha;Je, Nam-Gyung;Im, Kwang-Sik
    • YAKHAK HOEJI
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    • v.40 no.2
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    • pp.163-169
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    • 1996
  • Glycosidation of 20(S)-protopanaxadiol obtained by the alkaline hydrolysis of total ginsenosides with 2,3,4,6-tetra-O-acetyl-${\alpha$-D-glucopyranosyl bromide in the presence of $CdCO_3$ in benzene-dioxane gave a mixture of acetylated monoglucosides and diglucosides in a total yield of 68%. Under the same condenstion condition, 20-dehydroxyglucosides were formed by dehydration of 12-O-glucosides. The structures of produced glycosides were elucidated as 3-O-${\beta$-D-glucopyranosyl-20(S)-protopanaxadiol, 12-O-${\beta$-D-glucopyranosyl-dammar-20(22), 24-dien-$3{\beta},12{\beta}$-diol, 3,12-di-O-${\beta}$-D-glucopyranosyl-dammar-20(22), 24-dien-$3{\beta},\;12{\beta}$-diol, respectively.

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Flexible Protocol Reconfiguration for Emergency Communication Systems

  • Zhang, Ji;Li, Hai;Hou, Shujuan
    • ETRI Journal
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    • v.33 no.1
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    • pp.18-26
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    • 2011
  • The necessity for services of emergency communication systems to be uninterrupted and reliable has brought forward strict requirements for express software upgrades of base stations. Based on reconfigurability technology, this paper presents a protocol reconfiguration scheme for emergency communication base stations. By introducing the concept of 'local safe state,' the proposed scheme could make the updating and replacement of the protocol software flexible and maintain interactions during the updating procedure to achieve seamless system upgrades. Further, taking TETRA protocol stack and VxWorks operating system as an example, specific processes and realization methods of reconfiguration are proposed in this paper, along with the measurements of the factors impacting on the system performance. Simulation results show that, compared with traditional technology, the method proposed significantly improves the system efficiency and does not interrupt system services.

Decreased Effectiveness on Cytotoxicity of Metal-Metal and Metal-Chelator Combinations (중금속 상호간의 작용 및 착화제에 의한 세포독성의 억제효과)

  • Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.1
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    • pp.115-118
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    • 1996
  • The study on the cytotoxicities of heavy metals, metal-metal and metal-chelator combinations was carried out to evaluate the cytotoxic effect of those on mouse L929 fibroblasts. The colorimetric assays (NR and MTT) were conveniently carried out in 96-well microtiter plates. The rank order was Cd > Zn Ni > Cr(III) for the heavy metals tested. Examination of the effect of metal-metal interaction on cytotoxicity showed a moderate reduction of cadmium toxicity by zinc. The colorimetric assays were also effectively used to investigate the effect of the chelators, ethylenediamine tetra acetic acid (EDTA) and chitosan. Reduction of heavy metal toxixity by chelator was efficient.

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Design of Thermoelectric Films for Micro Generators (마이크로 발전기의 열전박막 설계)

  • Kim, Hyun-Se;Lee, Yang-Lae;Lee, Kong-Hoon
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1455-1458
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    • 2007
  • In this research, a polycrystalline silicon (poly-Si) film layer for micro thermoelectric generator (TEG) was fabricated. The fabrication process of the thermoelectric poly-Si film layer is explained. The P-type and N-type poly-Si films were fabricated on a tetra ethoxy silane (TEOS) layer with a supporting Si wafer. Seebeck coefficient and electrical conductivity were measured, including the transport properties such as the hall coefficient, hall mobility and carrier concentration. The design parameters for a rapid thermal process (RTP) were decided based on the experimental results. The measured power factors of the P-type and N-type were $21.2\;{\mu}Wm^{-1}K^{-2}$ and $26.7\;{\mu}Wm^{-1}K^{-2}$, respectively.

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Thermo-Mechanica1 Stress Analyses of Part with Coated Layer under Contact Load Using Partial Model (부분 모델을 이용한 접촉하중을 받는 코팅층이 있는 부재의 열적/기계적 응력해석)

  • 권영두;김석삼;신세현;추상우
    • Tribology and Lubricants
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    • v.18 no.3
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    • pp.228-234
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    • 2002
  • Generally, space structures are subjected to severe situations, such as, sublimation, strong evaporation of lubricants, thermal stresses, high temperature gradients, irradiation, impacts by microscopic meteorites, and other factors. Recent]y, various kinds of coatings are applied to the parts under heavy contact stresses, in order to insure long wear-free lives and/or reduce friction coefficients. In space structures, molybdenum disulfide is using frequently. Moreover TiN, Al$_2$O$_3$, PTFE(Poly Tetra Fluor Ethylene) are introduced recently for space structure. In this part we are going to apply the partial model method, developed in reference[11] to analyze part with coated layer. In referencer[l1], we compute the reasonable size of partial model and aspect ratio. Using these data, we analyze the structures coated with TiN, Al$_2$O$_3$, PTFE under contact load, temperature and crack model . Beside, we consider the stress analysis under time dependent load and transient thermal effect.

Synthesis and Photoluminescence of Biphenol Derivatives with Fluorescent Chromophore (형광 발색단을 가진 biphenol유도체의 합성과 PL)

  • Lee, Mun-Hag;Yang, Jong-Heon;Chung, Su-Tae;Son, Se-Mo;Kim, Sung-Bin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1010-1012
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    • 2002
  • 3,3'-di-benzothiazole-4,4-biphenol(DBTB), 3,3',5,5'-tetra-benzothiazole-4,4'- biphenol(TBTB), 5,5'-methy lene-bis(2-(2'-hydroxyphenyl) benzothiazole derivatives were synthesized by multistep. PL of DBTB and TBTB were dramatically shift 47nm and 75nm respectively longer wavelength than the emission of 2-(2'-hydroxyphenyl)-benzothiazole(HBT) because of intramolecular extened $\pi$-conjugate system but methylene-bis-benzothiazole derivatives do not occur at Wavelength-shift.

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