• Title/Summary/Keyword: A283-C

검색결과 405건 처리시간 0.025초

A Study on the Post-Weld Heat Treatment Effect to Mechanical Properties and Hydrogen Embrittlement for Heating Affected Zone of a RE 36 Steel

  • Moon, Kyung-Man;Lee, Myung-Hoon;Kim, Ki-Joon;Kim, Jin-Gyeong;Kim, Seong-Jong
    • Corrosion Science and Technology
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    • 제2권6호
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    • pp.283-288
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    • 2003
  • The cathodic protection method is being widely used in marine structural steel, however a high tensile steel like RE 36 steel for marine structural steel is easy to get hydrogen embrittlement due to over protection during cathodic protection as well as preferential corrosion of HAZ(Heating Affected Zone) part. In this paper, corrosion resistance and mechanical properties such as elongation and hydrogen embrittlement were investigated with not only in terms of electrochemical view but also SSRT(Slow Strain Rate Test) method with applied constant cathodic potential, analysis of SEM fractography in case of both As-welded and PWHT(Post-Weld Heat Treatment) of $550^{\circ}C$. The best effect for corrosion resistance was apparently indicated at PWHT of $550^{\circ}C$ and elongation was increased with PWHT of $550^{\circ}C$ than that of As-welded condition. On the other hand. Elongation was decreased with applied potential shifting to low potential direction which may be caused by hydrogen embrittlement, however the susceptibility of hydrogen embrittlement was decreased with PWHT of $550^{\circ}C$ than that of As-welded condition and Q.C(quasi cleavage) fracture mode was also observed significantly according to increasing of susceptibility of hydrogen embrittlement. Eventually it is suggested that an optimum cathodic protection potential range not causing hydrogen embrittlernent is from -770 mV(SCE) to -850 mV(SCE) in As-welded condition while is from -770 mV(SCE) to -875 mV(SCE) in PWHT of $550^{\circ}C$.

신조 운항실습선의 여름철 실내 온열환경 실측평가 (A Measurement and Evaluation on the Indoor Thermal Conditions in Summer of a New Training ship)

  • 신동걸;이진욱;이형기;황광일
    • Journal of Advanced Marine Engineering and Technology
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    • 제32권2호
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    • pp.276-283
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    • 2008
  • The purpose of this study is to measure and analyze the ship's indoor thermal conditions and also to integrate experimental database of those which are supplied and controlled by marine HVAC. On this study, temperature, humidity and air volume of 6 different needs' cabin are measured like previous report on a newly-launched training ship during 25th through 27th of July, 2007. Followings are the results of this study. (1)The air supply volumes to each cabins are measured 250CMH(Recreation room), 800CMH(Conference room), 1.000CMH(Bridge), 5,100CMH(Lecture room) respectively. (2)The temperatures are maintained at $21{\sim}27^{\circ}C$ in almost cabins through measuring period, but the temperatures are fluctuated over ${\pm}4^{\circ}C$ at the bridge and conference room. (3)The relative humidities are shown between $40{\sim}60%$ known as comfort conditions, but the conference room is needed to dehumidified because of over 70% humidity. (4)From the student cabins' measurements which have different supply diffuser(s), it is clear that the design is suitable for this case. (5)Because of temperature diversities, only 32% among the measured data are satisfied with the comfort standard range proposed by ASHREA.

합성화합물 $Pt_{34}Sb_7$$Pt_3Sb$에 대한 새로운 자료 (New Data on the Synthetic $Pt_{34}Sb_7$ and $Pt_3Sb$ Phases)

  • 김원사
    • 한국광물학회지
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    • 제1권1호
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    • pp.15-19
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    • 1988
  • In the process of re-checking the phase relations of the Pt-Sb system the previously reported Pt4+Sb phase did not occur. Instead, Pt34Sb7 phase with an average chemical composition (wt%) Pt 89.3, Sb 11.4, total 100.7, has been newly found to exist, and the formula Pt34Sb7 has been tentatively assigned to it, It is pale brownish grey to yellowish grey under refloecting microscope and non-bireflectant, VHN100=225 (206-243). X-ray powder patterns are (d(I/Io)): 2.318(100), 2.293(100), 2.110(30), 1.440(50), 1.390(15), 1.283(5), 1.203(70) and 1.192(40)$\AA$. They are indexable on the basis of tertragonal cell with $\alpha$=3.948(3), c=16.85(1)$\AA$. A question whether the tetragonal Pt34Sb7 is the new phase or a polymorph of the cubic Pt4+Sb phase remains unclear and awaits better X-ray diffraction, electron microprobe analysis and DTA for the Pt4+Sb phase. The Pt3Sb phase reported to be of tetragonal symmetry has been confirmed to exist. It is greyish yellow in air and in oil, very weakly bireflectant, and weakly anisotropic. VHN25=216 (183-240). Its X-ray powder data have been successively indexed on a tetragonal cell with $\alpha$=3.9455(7), c=16.959(5)$\AA$.

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Cloning and Characterization of a Glyoxalase I Gene from the Osmotolerant Yeast Candida magnoliae

  • Park, Eun-Hee;Lee, Dae-Hee;Seo, Jin-Ho;Kim, Myoung-Dong
    • Journal of Microbiology and Biotechnology
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    • 제21권3호
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    • pp.277-283
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    • 2011
  • Glyoxalase I catalyzes the conversion of methylglyoxal to S-D-lactoylglutathione in the presence of glutathione. The structural gene of glyoxalase I (GLO1) was cloned from an osmotolerant yeast, Candida magnoliae, which produces a functional sweetener, erythritol, from sucrose. DNA sequence analysis revealed that the uninterrupted open reading frame (ORF) of C. magnoliae GLO1 (CmGLO1) spans 945 bp, corresponding to 315 amino acid residues, and shares 45.2% amino acid sequence identity to Saccharomyces cerevisiae Glo1. The cloned ORF in a multicopy constitutive expression plasmid complemented the glo1 mutation of S. cerevisiae, confirming that it encodes Glo1 in C. magnoliae. The responses of CmGLO1 to environmental stresses were different from those of S. cerevisiae, which only responds to osmotic stress. An enzyme activity assay and reverse transcription polymerase chain reaction revealed that the expression of CmGLO1 is induced by stress inducers such as methylglyoxal, $H_2O_2$, KCl, and NaCl. The GenBank Accession No. for CmGLO1 is HM000001.

해수에서 분리된 Pelagicola sp. DSW4-44의 초안 유전체 서열분석 (Draft genome sequence of Pelagicola sp. DSW4-44 isolated from seawater)

  • 오지성;노동현
    • 미생물학회지
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    • 제55권3호
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    • pp.283-285
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    • 2019
  • 이 연구에서는 Illumina Hiseq platform을 사용하여 동해 심층 해양수로부터 분리된 Pelagicola sp. DSW4-44 (= KCTC 62762 = KCCM 43261)의 초안 유전체 염기서열 해독을 수행하였다. 그 결과, 유전체는 대략 4.85 Mbp의 길이 및 54.3%의 G + C 함량으로 구성되었고, 전체 4,566개의 단백질 암호 유전자, 3개의 rRNA 유전자, 48개의 tRNA 유전자, 3개의 non-coding RNA 유전자 및 67개의 위유전자(pseudo gene)가 확인되었다. 초안 유전체에서 균주 DSW4-44는 Pelagicola 속의 다른 균주에서 발견되지 않는 이화적 질산염의 암모늄 환원과 탈질화의 질소대사 유전자를 가지고 있었다.

인산가용화 사상균, Penicillium sp. PS-113 균주의 분리 및 배양특성 (Isolation and Cultural Characteristics of a Phosphate-solubilizing Fungus, Penicillium sp. PS-113)

  • 강선철;최명철
    • KSBB Journal
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    • 제13권5호
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    • pp.497-501
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    • 1998
  • A fungus with high phosphate solubilizing activites was isolated from soil using potato dextrose agar-calcium phosphate medium and identified to Penicillium sp. PS-113, based on the morphological characteristics of conidiophore and conidia; flask shape of phialide, simple branching type of conidiophore, and columnar shape of conidial head, in malt extract agar and potato dextrose agar media. The optimum temperature ad initial pH to solubilize rock phosphate in potato dextrose broth-rock phosphate medium were 30$^{\circ}C$ and pH 8.0, respectively. In these conditions phosphate solubilizing activities of Penicillium sp. PS-113 against four types of insoluble phosphate like tricalcium-phosphate, aluminium phosphate, hydroxyapatite and rock phosphate were quantitatively determined. As results, this fungus highly produced free phosphates to the culture broth with the concentrations of 1,283 ppm against tricalcium-phosphate, 585 ppm against rock phosphate, 528 ppm against aluminium phosphate, and 242 ppm against hydroxyapatite, respectively.

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Cloning, Characterization and Antifungal Activity of Defensin Tfgd1 from Trigonella foenum-graecum L.

  • Olli, Sudar;Kirti, P.B.
    • BMB Reports
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    • 제39권3호
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    • pp.278-283
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    • 2006
  • Defensins are small cysteine rich peptides with a molecular mass of 5-10 kDa and some of them exhibit potent antifungal activity. We have cloned the coding region of a cDNA of 225 bp cysteine rich defensin, named as Tfgd1, from the legume Trigonella foenum-graecum. The amino acid sequence deduced from the coding region comprised 74 amino acids, of which the N-terminal 27 amino acids constituted the signal peptide and the mature peptide comprised 47 amino acids. The protein is characterized by the presence of eight cysteine resisdues, conserved in the various plant defensins forming four disulphide bridges, which stabilize the mature peptide. The recombinant protein expressed in E coli exhibited antifungal activity against the broad host range fungus, Rhizoctonia solani and the peanut leaf spot fungus, Phaeoisariopsis personata.

심내막상 결손증의 임상적 고찰7례 보고 (Clinical study of Endocardial Cushion Defect [7 Cases Report])

  • 김승철
    • Journal of Chest Surgery
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    • 제18권2호
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    • pp.283-287
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    • 1985
  • Seven patients had undergone repair of endocardial cushion defect from Jan. 1977 to Dec. 1984 at National Medical Center. Most patients had no associated anomalies except one who had PFO, and mortality case was absent. Five patients had partial ECD and two had complete ECD [Rastelli type A]. In P-ECD patients, the atrial septal defect was closed with patch in all cases and mitral cleft was approximated with 2-3 direct stitches. In two cases of C-ECD, atrial and ventricular septal defect was closed with single patch in one case and atrial septal defect was closed with patch but ventricular septal defect was closed with patch but ventricular septal defect was closed it direct suture in the other case. Atrioventricular cleft was approximated with 2-3 direct sutures. Postop. transient A-V block was noted in 2 cases but returned to regular sinus rhythm after 2 to 6 months.

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긴이형흡충(Heterophyopsis continua)의 새로운 중간숙주인 붕장어(Conger myriaster) (Conger myriaster, a new second intermediate host of Heterophyopsis continua (Digenea: Heterophyidae))

  • 김기홍;최은석;임한종
    • Parasites, Hosts and Diseases
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    • 제34권4호
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    • pp.283-285
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    • 1996
  • 196년 9월 7일 전남 목표항에서 구입한 붕장어의 아가미 새엽에서 6개체의 피낭유충이 검출되었다. 이중 탈낭된 한 개의 형태를 관찰한 바 긴이형흡충의 피낭유충으로 동정되었으며, 붕장어가 긴이형흡층의 제2중간숙주 역활을 한다는 것으로 보고있다.

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Low Temperature Suspension Polymerization of Methyl Methacrylate for the Preparation of High Molecular Weight Poly(methyl methacrylate)/Silver Nanocomposite Microspheres

  • Yeum, Jeong-Hyun;Ghim, Han-Do;Deng, Yulin
    • Fibers and Polymers
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    • 제6권4호
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    • pp.277-283
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    • 2005
  • In order to prepare high molecular weight poly(methyl methacrylate) (PMMA)/silver nanocomposite microspheres, methyl methacrylate was suspension-polymerized in the presence of silver nanoparticles at low temperature with 2,2'-azobis(2,4-dimethylvaleronitrile) as an initiator. The rate of conversion was increased by increasing the initiator concentration. When silver nanoparticles were added, the rate of polymerization decreased slightly. High monomer conversion (about $85\%$) was obtained in spite of low polymerization temperature of $30^{\circ}C$. Under controlled conditions, PMMA/silver microspheres with various number-average degrees of polymerization (6,000-37,000) were prepared. Morphology studies revealed that except for normal suspension microspheres with a smooth surface, a golf ball-like appearance of the microspheres was observed, due to the migration and aggregation of the hydrophilic silver nanoparticles at the sublayer beneath the microsphere's surface.