• 제목/요약/키워드: acid-resistance

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인산형 단위 연료전지의 조업 연구 (Operational Study of the Phosphoric Acid Type Unit Fuel Cell)

  • 이갑수;김화용
    • 한국수소및신에너지학회논문집
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    • 제3권2호
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    • pp.63-69
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    • 1992
  • 2개의 단위전지를 제작하여 각각 산소와 공기를 산화제로 하여 조업하였다. 산소를 사용한 단위전지의 350시간 조업후의 개전압 강하는 30mV였고 내부저항도 증가하였다. 공기를 사용한 단위천지의 250시간 조업후의 개전압강하는 130mV였고 산소를 사용한 경우와는 개전압 차이는 90mV였다. 공기를 이용한 단위전지의 조업 성능을 향상시키기 위하여는 전해질의 공급방법과 전극의 물질전달특성에 관한 연구가 필요하다.

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Chitosan-phthalylsulfathiazole의 합성과 항균성 (Synthesis and Antibacterial Activity of Chitosan-Phthalylsulfathiazole)

  • 최봉종;이기창;황성규;오세영;김판기
    • 한국환경보건학회지
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    • 제23권4호
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    • pp.50-56
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    • 1997
  • Applied for Drug Delivery System, polymer drug was prepared with chitosan and phthalylsulfathiazole. In spite of various application of chitin derivatives, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. In this study, Chitosan were prepared from chitin which were deacetylated under various condition. The synthetic procedures of polymer drug were performed by acid chloride methods. The antibiotic activities of polymer drug exhibited growth-inhibitory activity against Staphylococcus aureus, Staphylococcus epidermidis, E. coli, Salmonella typhimurium, Klebsiella pneumoniae at the concentration of 471-514 $\mu$g/ml in general. Comparatively, Polymer drug exhibited broad antibacterial activity on MICs 897-1280 $\mu$g/ml against Gram-positive and Gram-negative bacteria including Staphylococcus aureus, Staphylococcus epidermidis and E. coli.

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BTCA로 방추가공된 면직물의 미세기공구조 측정 (A Study on the Micropores of BTCA Finished Cotton Fabrics)

  • 최연주;유효선
    • 한국의류학회지
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    • 제26권7호
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    • pp.1078-1084
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    • 2002
  • Cotton fabrics were treated with 1,2,3,4-butanetetracarboxylic acid(BTCA) to impart durable press performance, which is formaldehyde-free DP finishing reagent. The pore structures of BTCA treated cottons were compared using a reverse gel permeation chromatographic technique(reverse GPC). A series consisting 4 kinds of water soluble sugars was used to study the elution characteristics of columns prepared from cotton fibers. From these data, differences in pore size distribution in the control and BTCA treated cottons were distinguished. BTCA crosslinks cellulose molecules provided wrinkle resistance to the treated cotton fabrics through ester linkages. Although crosslinking of cotton with BTCA reduced accessible internal volume across the entire range of pore size, differences in line pores were larger than in small pores. BTCA treated cotton exhibited reductions over 40% in large pore sizes.

효소가공 양모직물의 표면 성질에 관한 연구 (A Study on the Surface Properties of Wool Fabric Treated with Enzyme)

  • 박미라;김환철;박병기
    • 한국염색가공학회지
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    • 제13권4호
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    • pp.227-233
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    • 2001
  • Wool fabrics were pre-treated with corona prior to treating with enzyme for shrinkage resistance. Commercial protease and cellulase were used for degradation of wool and the treatment conditions such as enzyme amount, treating time, and assistant chemicals. Friction coefficient and zeta-potential were measured to certificate an effect of treatment condition on the handle of wool fabric. Corona pretreatment make the wool fabric soft, which result in the decrease of friction coefficient and zeta-potential. Scale removal of wool surface was observed by scanning electron microscope. Amino acid analysis shows the effectiveness of enzyme, and corona pretreatment does not cause severe internal damage.

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무전해 니켈 도금액에서 착화제가 도금피막에 미치는 영향 (The Effect of Complexing Agent on the Deposit Charateristics in the Electroless Nickel Plating Solution)

  • 전준미;구석본;이홍기;박해덕;심수섭
    • 한국표면공학회지
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    • 제37권6호
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    • pp.326-334
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    • 2004
  • Deposit charateristics of Electroless nickel(EN) were investigated with various complexing agents. As expected, the deposition rate of nickel is increased with pH and that of Phosphorous is decreased with pH. The result of SEM investigation shows that the rough surface crystallization is appeared with pH. It is show that the surface resistance of EN deposit is decreased with pH at 85$^{\circ}C$.

Molecular Cloning and Characterization of Soybean Cinnamoyl CoA Reductase Induced by Abiotic Stresses

  • So, Hyun-Ah;Chung, Eun-Sook;Cho, Chang-Woo;Kim, Kee-Young;Lee, Jai-Heon
    • The Plant Pathology Journal
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    • 제26권4호
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    • pp.380-385
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    • 2010
  • Suppression subtractive hybridization was used to isolate wound-induced genes from soybean. One of the wound-induced genes, gmwi143 designated as GmCCR, showed high homology with genes encoding cinnamoyl-CoA reductase (CCR; EC 1.2.1.44). Deduced amino acid sequences encoded by GmCCR showed the highest identity (77%) with those of Acacia CCR. There are 2 CCR genes highly homologous to GmCCR in soybean genome based on Phytozome DB analysis. RNA expression of GmCCR was specifically induced by local and systemic wounding, drought, high salinity or by ultraviolet stress. Our study suggests that GmCCR may be involved in resistance mechanism during abiotic stresses in plants.

고밀도 팽창흑연 성형품의 압축 특성에 관한 연구 (A Study of Mechanical Properties in Compression on High density Graphite Products with Expanded Graphite)

  • 신영우
    • 동력기계공학회지
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    • 제10권1호
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    • pp.52-59
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    • 2006
  • Graphite is well known as a material which has high-temperature thermostable property, chemical resistance against acid and alkaline state also is very easy to environment. Nowadays the need of graphite product is increasing rapidly because of its advantages. In this paper, the mechanical property of newly developed graphite products with high density is investigated with especially in compression test. I introduced the graphite specimens for this study by NGF method with two expandable graphite and compared to the specimens of commercial graphite sheet from expanded graphite which made by the rolling process. I investigated the characteristics of these materials by measuring specific weight, hardness, compressive strength and investigating structures by SEM, It is verified that the graphite products with NGF method has superior properties for using gasket materials than that of commercial graphite sheet.

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Characterization of a New Leuconostoc Species Isolated from Fresh Garlic

  • Lee, Se-Hi;Choi, Jong-Hoon;Kim, Youn-Soon;Kyung, Kyu-Hang
    • Food Science and Biotechnology
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    • 제14권3호
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    • pp.416-419
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    • 2005
  • Unknown bacterium isolated from garlic was characterized using phenotypic methods, phylogenetic analysis, DNA-DNA hybridization, and cultural methods. The strain was identified as typical leuconostoc; Gram-positive, non-sporeforming, heterofermentative, catalase-negative and spherical. Although its 16S rRNA gene sequence showed high homology to Leuconostoc argentinum DSM $8581^T$(99.8%), DNA-DNA hybridization experiments indicated it represents novel genomic species in the genus Leuconostoc. The garlic-specific leuconostoc was more resistant to antimicrobial activity of garlic compared to other common laboratory lactic acid bacteria, and was even stimulated by low concentrations (1-2%) of garlic extract supplemented in trypticase soy broth. Growth stimulation was concentration-dependent when tested with residual aqueous layer after solvent extraction of fresh whole garlic extract.

Ni Plating Technology for PWR Reactor Vessel Cladding Repair

  • Hwang, Seong Sik;Kim, Dong Jin
    • Corrosion Science and Technology
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    • 제18권5호
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    • pp.190-195
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    • 2019
  • SA508 low-alloy steel for a reactor vessel was exposed to primary water in a pressurized water reactor (PWR) plant because the cladding layer of type 309 stainless steel for the RPV was removed, due to an accident in which the detachment of the thermal sleeve occurred. The major advantage of the electrochemical deposition (ECD) Ni plating technique is that the reactor pressure vessel can be repaired without significant thermal effects, and Ni has solid corrosion resistance that can withstand boric acid. The corrosion rate assessment of the damaged part was performed, and its trend was analyzed. Essential variables of the Ni plating for repair of the damaged part were derived. These conditions are applicable variables for the repair plating device, and have been carefully adjusted using the repair plating device. The process for establishing ASME technical standards called Code Case N-840 is described. The process of developing Ni-plating devices, and the electroplating procedure specification (EPS) are described.

Insulin Receptor Substrate 1의 세린731 인산화 억제를 통한 살리실산의 인슐린저항성 개선효과 기전 (Salicylate Enhances Insulin Signaling by Preventing Ser731 Phosphorylation of Insulin Receptor Substrate 1)

  • 이용희
    • 약학회지
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    • 제52권3호
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    • pp.182-187
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    • 2008
  • Salicylate (SA) was shown to alleviate insulin resistance. Here, we showed that SA inhibited Ser731 phosphorylation of insulin receptor substrate 1 (IRS1) and S6 kinase activation, and enhanced tyrosine phosphorylation of IRS1 in response to insulin or amino acid. Experiments using a cJun N-terminal kinase (JNK)-deficient cell and an IRS1 JNK-binding mutant showed that JNK is not required for Ser731 phosphorylation. A two-week treatment of obese mice with SA resulted in decreased Ser731 phosphorylation and enhanced insulin signaling. These results suggest that SA enhances insulin signaling by inhibiting Ser731 phosphorylation of IRS1.