http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Ariston (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Microstructural Evolution of the Refractory WCuNi Metallic Alloy
Armando C. Souza,Jesualdo L. Rossi,Panos Tsakiropoulos,Flavio Aristone 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11
Science and technology of materials are widely interested in the development of new alloys involving tungsten due to its largeapplicability to the domain of nuclear material transportation. Tungsten is a refractory material and it has many applicationsin the nuclear industry due to its mechanical properties and excellent cross-section for thermal neutrons, being widely usedfor shielding of high-energy radiation. Some of the main elements added to tungsten forming alloys are Nb, Cr, Cu, Fe, Ni,Mo, Co, Sn, Ti, and Ta, which are responsible for modifications of the physical and chemical properties of the resultingalloy, interfering on the attenuation of gamma radiation. The main goal of this paper is to present a refractory alloy based ontungsten with embedded infiltrating elements like copper (Cu) and nickel (Ni) and characterize the microstructural evolutionof different sintering process during its formation. Such a refractory alloy is submitted to the following characterization process:X-rays diffractometry, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electronmicroscopy, and energy dispersive spectroscopy. The diffractometry exhibit typical standard results for the precursor powders:W, Cu, and Ni demonstrating high degrees of purity accordingly to the crystallographic determined parameters. The TGAfor the powder W demonstrated thermal stability until 360 ºC, after an increase of mass due to the process of oxidation. The DSC analyze present two endothermal processes at temperatures 350 °C and 450 °C. The microstructural evolution ofWCuNi samples presents the absence of oxidation, homogeneous morphology and stability of the binary phase α–β (W andCuNi respectively) for different sintering. These results shall be taken into consideration for future works, particularly onthe study of shielding and gamma radiation attenuation.
-
Eliana Guedes Stehling,Tatiana Amabile Campos,Marcelo Brocchi,Vasco Ariston de Carvalho Azevedo,Wanderley Dias da Silveira 대한수의학회 2008 Journal of Veterinary Science Vol.9 No.1
An Escherichia coli strain (SEPT13) isolated from the liver of a hen presenting clinical signs of septicaemia had a LD50 of 4.0 × 105 CFU/ml in one-day-old chickens, expressed Ia, Ib, E1, E3, K and B colicins and aerobactin. The strain was ampicillin and streptomycin resistant, and found to have fimA, csgA and tsh DNA related sequences; it could adhere to and invade HEp-2 and tracheal epithelial cells, expressed fimbriae (observed by electron microscopy), and had five plasmids of 2.7, 4.7, 43, 56, and 88 MDa. Transposon mutagenesis of strain SEPT13, with transposon TnphoA, resulted in a mutant strain named ST16 that had a LD50 of 1.2 × 1012 CFU/ml. All other biological characteristics of strain ST16 were the same as those detected for strain SEPT13 except for the migration of an 88 MDa plasmid to the 93 MDa position indicating the insertion of the transposon into the 88 MDa plasmid. The 93 MDa plasmid of strain ST16 was transferred, by electroporation assay, to non-pathogenic receptor strains (E. coli strains K12 MS101 and HB101), resulting in transformant strains A and B, respectively. These strains exhibited adhesion properties to in vitro cultivated HEp-2 cells but did not have the capacity for invasion. The adherence occurred despite the absence of fimbriae; this finding suggests that the 88 MDa plasmid has afimbrial adhesin genes. An Escherichia coli strain (SEPT13) isolated from the liver of a hen presenting clinical signs of septicaemia had a LD50 of 4.0 × 105 CFU/ml in one-day-old chickens, expressed Ia, Ib, E1, E3, K and B colicins and aerobactin. The strain was ampicillin and streptomycin resistant, and found to have fimA, csgA and tsh DNA related sequences; it could adhere to and invade HEp-2 and tracheal epithelial cells, expressed fimbriae (observed by electron microscopy), and had five plasmids of 2.7, 4.7, 43, 56, and 88 MDa. Transposon mutagenesis of strain SEPT13, with transposon TnphoA, resulted in a mutant strain named ST16 that had a LD50 of 1.2 × 1012 CFU/ml. All other biological characteristics of strain ST16 were the same as those detected for strain SEPT13 except for the migration of an 88 MDa plasmid to the 93 MDa position indicating the insertion of the transposon into the 88 MDa plasmid. The 93 MDa plasmid of strain ST16 was transferred, by electroporation assay, to non-pathogenic receptor strains (E. coli strains K12 MS101 and HB101), resulting in transformant strains A and B, respectively. These strains exhibited adhesion properties to in vitro cultivated HEp-2 cells but did not have the capacity for invasion. The adherence occurred despite the absence of fimbriae; this finding suggests that the 88 MDa plasmid has afimbrial adhesin genes.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
