Effect of Ni on microstructure and wear behaviour of 13Cr-W-Mo-2C white cast iron

The effect of Ni concentration on the microstructure and wear performance of 13Cr-(0.5-7.0)Ni-W-Mo-Mn-2C white cast iron subjected to homogenization heat treatment was examined. Concentration of Ni was altered in the range 0.5-7.0 wt.% to obtain a stable microstructure against for dry sliding wear resistance as long sliding distance. The effect of Ni on the microstructure was analysed by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, elemental mapping and hardness. The wear performances were tested under the loads of 40, 90 and 140 N. Differential thermal analysis of samples with dissimilar Ni values was performed. The increase of Ni concentration decreased the secondary arm spacing of dendrites, refined the dendritic structure and raised the eutectic carbide ratio. The greatest wear performance was obtained for the sample having Ni over 6 wt.%

Rotavirus and adenovirus frequency among patients with acute gastroenteritis and their relationship to clinical parameters: a retrospective study in Turkey

<p>Abstract</p> <p>Background</p> <p>Diarrhea is the third leading cause of death related to infectious diseases all over the world. The diseases related to viral gastroenteritis are gradually increasing, particularly in the developed countries. The purpose of our study was to determine the frequency and to investigate the clinical manifestations of acute rotavirus and adenovirus gatroenteritis and to assess the diagnostic value of the related clinical findings.</p> <p>Methods</p> <p>In 2007-2008 patients with diarrhea and/or vomiting attended to Yeditepe University Hospital and related clinics, Istanbul, were studied. The rotavirus and/or adenovirus antigen in stool of these patients were investigated. Data regarding clinical findings were collected from the electronic records, retrospectively. Age, gender, symptoms, fever, antibiotic use, vomiting, number of vomiting and diarrhaeae, dehydration, abdominal pain, the other pathological physical examination findings were analyzed by the physicians in the study group. To investigate the rotavirus and adenovirus antigen CerTest Rota-Adeno Blister Test (CerTest, Biotec, Spain), a qualitative immunochromotographic assay was used. Statistical analysis wasperformed with SPSS v. 11,5 statistical software. X²test was used for bivariate and logistic regression analysis was used for multivariate analysis.</p> <p>Results</p> <p>Rotavirus positivity was 18,7% (n = 126). Concomitantly, in 596 cases adenovirus antigen test were also performed. Adenovirus positivity was 8,9% (n = 53) and rota-adenovirus co-infection was 4,4% (n = 26). Most of rotavirus positive cases were seen in December, January, February and March (p < 0.001). In clinical parameters, there was a significant difference between rotavirus positive cases and negative cases regarding to vomiting, dehydration and vomiting and diarrhea coexistence (respectively p = 0.010, p < 0.00, p = 0.007).</p> <p>Conclusion</p> <p>Rotavirus can be seen in all age groups, but more frequently in childhood. Although there is no clinical gold standard to distinguish the rotavirus cases from the other gastroenteritis agents, the findings of dehydration and vomiting-diarrhea coexistence, considering months of referral may lead clinician to perform rapid antigen tests and affect approach to the treatment. Prospective studies with representative samples are needed to determine the rotavirus and adenovirus incidence and to develop safe and reliable protective policies in our country.</p

Joint performance of medium carbon steel-austenitic stainless steel double-sided TIG welds

AISI 1040 and AISI 304 steel plates of 10 mm were joined without pretreatment by double-sided TIG arc welding (DSAW). Joints were manufactured by using welding currents of 420, 440, and 460 A. The microstructural variations in the interface of the weld samples were defined by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and microhardness analysis. V-notch impact and tensile tests were done to detect the weld strength of the weld samples. In DSAW welding of different steels, a full penetration joint was achieved without opening the weld edge. The current intensity had a major effect on the symmetrical and hourglass shape in welds. Welding at 460 (A) showed acceptable joint quality. Tensile and impact energy quantities of welded joints had significant ratios. Fractures in the weld metal of the samples were ductile mode. © 2022 Walter de Gruyter GmbH, Berlin/Boston

Collisional damping of giant dipole resonance in Sn-120 and Pb-208

We investigate the collisional damping of giant dipole resonance at finite temperature in the basis of a non-Markovian transport approach. We perform our calculations in Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Gogny force. The results account for about 30% of the observed widths in Sn-120 and Pb-208 at finite temperatures

Effect of FeTi-FeB inoculation on the shape of carbide reinforcements in hypoeutectic high chromium white cast iron

FeTi-FeB was added to molten high chromium white cast iron in amounts of 0.5-2.5 wt% at 50 degrees C above the melting temperature. The samples were produced in four groups. The first group samples were investigated as cast, the second group homogenized at 1000 degrees C for 1 h, and the other two groups were also homogenized at 1000 degrees C but for 3 and 6 h, respectively. To study the effect of FeB and FeTi on the microstructure, the samples were characterized by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and hardness tests. Wear tests were performed using a pin-on disc. A homogeneously dispersed carbide microstructure was produced by the homogenization heat treatment method. The addition of FeTi-FeB inoculants to high Cr white cast iron played an important role in the distribution of hard carbides. The chemical rate and the carbide volume varied on account of the added hard inoculant particles. TiB2, Cr3C2, M7C3, M23C6, and gamma-FeCr phases formed on the surfaces. The hardness and wear resistance were improved considerably due to FeTi-B inoculation.DomexThis work was supported by Domex. The authors are grateful to Domex for their assistance in conducting the experiments

Quantal diffusion approach for multinucleon transfers in Xe plus Pb collisions

Employing a quantal diffusion description based on the stochastic mean-field approach, we analyze the mass distribution of the primary fragments in the collisions of the Xe-136 + Pb-208 system at the bombarding energy E-c.m. = 526 MeV. This quantal approach provides a good description of the primary fragment distribution without any adjustable parameter, including the effects of shell structur