• Title/Summary/Keyword: A/W

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In-situ Structure Modification of W powder Skeleton and related Cu Infiltration Kinetics in W-Cu (W-Cu 계에서 W 분말골격의 in-situ 구조 변화와 Cu의 용침 kinetics)

  • 이재성
    • Journal of Powder Materials
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    • v.6 no.1
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    • pp.36-41
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    • 1999
  • The present work has attempted to investigate the dependence of Cu infiltration kinetics on in-situ structure modification of W powder skeleton in W-Cu system. In-situ structure modification of W skeleton by addition of 0.3wt%Ni-P eutectic alloy was designed to proceed during heat-up of the W compact for Cu infiltration process. It was found that the Ni-P added W skeleton underwent remarkable stucture change only during heating-up. its structure was composed of large necks of W particles above 0.5 in the ratio of neck to particle size and smooth pore channels. The infiltration experiment showed that the infiltration kinetics for the W-Ni-P followed well the linear relationship of h vs. $t^{1/2}$ the rate constant K of which was in good agreement with the theoretical value. On the other hand, in case of the pure W skeleton a lower K value by 20% than the theoretical one was obatined. Such discrepancy is discussed in terms of skeleton structure induced infiltration mechanics.

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Fermentation Characteristics of Koji inoculated with Cordyceps sp. (동충하초를 이용한 코오지의 발효특성)

  • 권동진
    • Microbiology and Biotechnology Letters
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    • v.30 no.1
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    • pp.46-50
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    • 2002
  • To investigate the quality of Koji produced by Cordyceps sp., a mixed culture of Aspergillus oryzae and the Cordyceps sp. were inoculated in Koji making. Viable cell counts and counts of fungi spore during Koji making for 120 hours were increased rapidly within 24-48 hours, after then their changes were not shown significantly during Koji making. The activities of amylase and protease in Koji inoculated with the mixed culture of A. oryzae and Cordyceps sp. were superior to one with A. oryzae only. The sensory evaluation on the Koji with 0.5% (w/w) A. oryzae and 0.5% (w/w) Cordyceps sp. were evaluated to be superior to ones. The best quality of Koji is prepared from the mixture of Cordyceps sp. and A. oryzae with the ratio of 0.5% and 0.5% (w/w).

A Study for DHRMIS S/W Quantitive Quality Evaluation (국방 인사정보 S/W체계의 정량적 품질평가 연구)

  • Rho, Seung-Dam;Park, Dea-Woo
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.4
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    • pp.273-280
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    • 2008
  • This paper is thing for a quantitive quality evaluation in national Defense Human Resource Management Information S/W system development. Apply a quantitive quality evaluation way to be based on an international standard to admonish at ISO/IEC 9126. Proposed 6 basis of count, and set up sub 27 items detailed functionality, reliability, use anger, efficiency, maintenance anger, a transplant result, and inspection of quality table wrote the Matrix measured S/W quality to a chart. Studied a quantitive evaluation plan of a Defense Human Resource Management Information S/W system to see weight by the priority order that reflected a characteristic of a national defense business to a Purpose of a subject user, and Presented. It is 80% in quantitive quality evaluation application satisfied under 8, Very Satisfied 7(87.5%) Satisfied 1(12.5%) of Defense Human Resource Managers and judgment worked as marked so that satisfaction of reliability and a user regarding functionality was high and there will be contribute to an elevation of defense capabilities as analyze efficient national defense S/W use and effect.

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Characterization of tryptophan residues of human coagulation factor V required for binding to phospholipid membranes (인지질막 결합에 필요한 제5혈액응고인자 트립토판잔기들의 역할규명)

  • Kim, Suhng-Wook
    • Journal of Life Science
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    • v.13 no.4
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    • pp.463-472
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    • 2003
  • Interactions between factor Va (HFVa) and membrane phosphatidylserine (PS) regulate the activity of the prothrombinase complex. I have previously shown that two solvent exposed hydrophobic residues located in the C2-domain, Trp2063 and Trp2064, are required for binding to immobilized PS and for expression of procoagulant activity on membranes containing 5% PS. In order to fully define the functional importance of these two residues I have expressed and isolated recombinant factor Va (rHFVa) W2063A/W2064A double mutant. In contrast to the native protein the two glycoforms resulting from alternative glycosylation of Asn2181 eluted as a single peak with rHFVa1 W2063A/W2064A eluting on the leading edge and rHFVa2 W2063A/W2064A eluting on the trailing edge. The double mutant rHFVa2 W2063A/W2064A expressed little or no procoagulant activity on membranes containing 1-10% mol % PS. In contrast, the procoagulant activity of this mutant was slightly greater than the native protein on membranes containing>18 mol % PS. The binding of rHFVa2 W2063A/W2064A to immobilized phospholipid vesicles was markedly reduced compared to the native protein in a surface plasmon resonance binding assay. I conclude that Trp2063 and Trp2064 are required for high affinity binding of factor Va to PS membranes and that this interaction is necessary for assembly of the prothrombinase complex on membranes containing physiological concentrations of PS.

A Study on Thermal Properties of Rocks from Gyeonggi-do Gangwon-do, Chungchung-do, Korea (경기도, 강원도, 충청도 일대의 암석 열물성 특성 연구)

  • Park, Jeong-Min;Kim, Hyoung-Chan;Lee, Young-Min;Song, Moo-Young
    • Economic and Environmental Geology
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    • v.40 no.6
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    • pp.761-769
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    • 2007
  • We made 712 thermal property measurements on igneous, metamorphic and sedimentary rock samples from Gyeonggi-do, Gangwon-do and Chungchung-do, Korea. The average thermal conductivities of igneous, metamorphic and sedimentary rocks are 3.58W/m-K, 4.16W/m-K and 4.53W/m-K, respectively. Thermal conductivity of granite and gneiss are 2.13-5.87W/m-K and 2.26-6.67W/m-K, with average values of 3.57W/m-K and 3.945W/m-K, respectively. The average of thermal diffusivities are $1.43mm^2/sec\;and\;1.55mm^2/sec$, respectively; the average of specific heat values are 0.914J/gK, 0.912J/gK for granite and gneiss samples, respectively. The thermal conductivity of a rock type generally have a wide range because it depends on various factors such as dominant mineral phase, micro-structure, anisotropy, and so on.

Development of W/O/W Multiple Emulsion Formulation Containing Burkholderia gladioli

  • KIM, HWA-JIN;CHO, YOUNG-HEE;BAE, EUN-KYUNG;SHIN, TAEK-SU;CHOI, SUNG-WON;CHOI, KEE-HYUN;PARK, JI-YONG
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.29-34
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    • 2005
  • W/O/W (water-in-oil-in-water) type multiple emulsion was applied to improve the storage stability of an antagonistic microorganism, Burkholderia gladioli. Encapsulation of microorganism into a W/O/W emulsion was conducted by using a two-step emulsification method. W/O/W emulsion was prepared by the incorporation of B. gladioli into rapeseed oil and the addition of polyglycerin polyriconolate (PGPR) and castor oil polyoxyethylene (COG 25) as the primary and secondary emulsifier, respectively. Microcrystalline cellulose was used as an emulsion stabilizer. To evaluate the usefulness of W/O/W emulsion formulation as a microbial pesticide for controlling the bacterial wilt pathogen (Ralstonia solanacearum), the storage stability and antagonistic activity of emulsion formulation were tested in vitro. The storage stability test revealed that the viability of formulated cells in emulsion was higher than that of unformulated cells in culture broth. At $4^{\circ}C$, the viabilities of formulated cells and unformulated cells at the end of 20 weeks decreased to about 2 and 5 log cycles, respectively. At $37^{\circ}C$, the viability of formulated cells decreased to only 2 log cycles at the end of storage. On the other hand, the viable cells in culture broth were not detected after 13 weeks. In activity test, formulated cells in emulsion were more effective in inhibiting the growth of pathogen than unformulated cells in culture broth. Unformulated cells completely lost their antagonistic activity during storage under similar conditions. The W/O/W multiple emulsion formulation was shown to be useful as the novel liquid formulation for biological control.

An Acoustic Study on the Pronunciation of English [kwJ Sequences by Korean EFL Students

  • Kim, Jung-Eun;Cho, Mi-Hui
    • Speech Sciences
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    • v.9 no.1
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    • pp.193-206
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    • 2002
  • The aim of this study is to find out how the labiovelar onglide /w/ in English kwV sequences that have minimal pairs with kV sequences is pronounced differently among Korean EFL learners based on acoustic evidence. This study tries to identify /w/ sound in English kwV sequences through spectrograms and to examine the duration ratios of each segment in kwV words to compare the patterns of an English native speaker with those of Korean speakers of English. In spectrographic analyses, the complete deletion of /w/ and partial pronunciation of /w/ dubbed [$k^{w}$] were identified as well as the targetappropriate production of /w/. The general production patterns with respect to the duration ratios in English [kw] sequence words showed that the subjects who produced /w/ had similar ratio patterns that the native speaker had in that the vowel duration ratio in kwV sequences was shorter than that in kV sequences. By contrast, the subjects who deleted [w] had a long ratio of the onset [$k^{h}$] while the speaker with a partial pronunciation of /w/ had a long ratio of the following vowel.

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Properties of Bac W42, a Bacteriocin Produced by Bacillus subtilis W42 Isolated from Cheonggukjang

  • Kindoli, Salum;Lee, Hwang A;Kim, Jeong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.22 no.8
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    • pp.1092-1100
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    • 2012
  • Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to $80^{\circ}C$. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.

A short note on the taxonomic identity of Wasabia koreana Nakai (Brassicaceae) (Wasabia koreana Nakai (십자화과)의 분류학적 실체에 대한 고찰)

  • Sin, Hyunchur;Kim, Yeong-Dong
    • Korean Journal of Plant Taxonomy
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    • v.38 no.3
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    • pp.223-231
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    • 2008
  • This study was undertaken to resolve several systematic issues concerning the distribution, nomenclature, and local name of Wasabia koreana. A careful reexamination of the type specimen of W. koreana in TI as well as critical morphological comparison with the related taxa, Cardamine yezoensis and W. japonica, revealed that the W. japonica specimens from Ulleung Island had long been misidentified as W. koreana, resulting in the usage of the same local name for the two distinct taxa. An detailed review for the Cardamine pseudowasabi, a recently proposed name for the misplaced W. koreana, is provided.

A Trial for Preparation of Jam using Sea Mustard Stem (미역줄기를 이용한 잼의 제조조건)

  • AHN Chang-Bum;SHIN Tai-Sun;NAM Taik-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.423-430
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    • 2000
  • Preparation of sea mustard stem jam (SMSJ) with addition of commercial ingredients, sucrose, high methoxyl pectin (HM pectin) or low methoxyl pectin (LM pectin), organic acid (or its salt), and synthetic strawberry flavor to sea mustard stem paste was investigated. The sea mustard stem paste was produced by crushing sea mustard stem and homogenizing it with 2.5 times water of sea mustard stem, then followed by filtering ($30{\~}35 mesh$), The effects of those ingredients on the physical properties and the sensory score of SMSJ were evaluated. The SMSJ prepared with combination of $65{\%}$ (w/w) sugar, $1.0{\%}$ (w/w) pectin, and $0.3{\%}$ (w/w) citric acid or with combination of $65{\%}$ (w/w) sugar, $1.0{\%}$ (w/w) U pectin, and $0.08{\%}$ (w/w) calcium lactate, which finally adjusted to $62{\cdot}Brix$, was similar to commercial strawberry or apple jam in gel strength, Addition of over $0.06{\%}$ (v/w) synthetic strawberry flavor to sea mustard stem paste showed a good effect of masking the undesirable sea mustard flavor.

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