10 research outputs found
Effect of chemical composition on the microstructure, hardness and electrical conductivity profiles of the Bi-Ge-In alloys
In this study, the microstructure, hardness, and electrical properties of selected ternary Bi-Ge-In alloys were investigated. Isothermal sections of the Bi-Ge-In system at 25, 200, and 300 ° C were extrapolated using optimized thermodynamic parameters from the literature. The used experimental techniques include optical microscopy, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS), Brinell hardness, and electrical conductivity measurements. The results of EDS phase composition analysis were compared with the calculated isothermal sections and a good overall agreement was reached. The results of the XRD were also in line with the predicted phase balance. By using ANOVA analysis and experimental results of Brinell hardness and electrical conductivity, a mathematical model was suggested for the calculation of these properties along with all composition ranges. The appropriated mathematical model was subsequently used for the prediction of hardness and electrical conductivity throughout the whole composition range
Mechanical and electrical properties of the Bi-Ge-Sn alloys
Mechanical and electrical properties of the ternary Bi-Ge-Sn alloys were investigated in this study. Calculation of isothermal section at 200, 300, and 25 ºC was carried out by using optimized thermodynamic parameters for the constitutive binary systems. Microstructures of alloys were observed by using optical microscopy and scanning electron microscopy (SEM). Phases in microstructures have been detected by X-ray diffraction (XRD) analysis and compositions of the phase by energy dispersive spectrometry (EDS). EDS results were compared with the predicted isothermal section at 200 and 300 ºC, and good agreement has been reached between them. The Brinell hardness and electrical conductivity of selected alloys were measured. Through ANOVA analysis and application of the obtained results, an appropriate mathematical model is proposed for every composition of alloys. By using the appropriated mathematical model for Brinell hardness and electrical conductivity, isolines for those properties were presented
Experimental Evaluation of 300 degrees C section of Cu-In-Ni Phase Diagram, Hardness and Electrical Conductivity of Selected Alloy
The paper reports comparative experimental and thermodynamic calculation of a Cu-In-Ni ternary system. An isothermal section of the Cu-In-Ni system at 300 degrees C was extrapolated using optimized thermodynamic parameters for the constitutive binary systems from literature. Microstructural and phase composition analysis were carried out using scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS) and X-ray powder diffraction (XRD) technique. Brinell hardness and electrical conductivity of a selected number of alloy samples with compositions along three vertical sections (Cu-In0.5Ni0.5, In-Cu0.8Ni0.2, and x(In) = 0.4) of the studied Cu-In-Ni system were experimentally determined. Based on the obtained experimental results and by using appropriate mathematical models values of hardness and electrical conductivity for the whole ternary system were predicted. A close agreement between calculations and experimental results was obtained both in case of thermodynamic, electrical conductivity and hardness predictions
Closure to “Supercritical flow in circular conduit bends”
A complex flow pattern occurring in a circular conduit bend with supercritical flow has been studied. The main objective was to obtain reliable criteria for prediction of the onset of helical and choking flow, in order to facilitate the design of bottom outlets, tunnel spillways and drainage collectors with bends. A series of scale model experiments provided data for developing empirical relationships describing the effects of the bend curvature, bend deflection angle and approach flow conditions (relative flow depth and Froude number) on the inception of helical and choking flow. Expressions for the energy bend loss coefficient were also proposed. The bend curvature and approach flow conditions proved to have a major influence on the onset of helical flow, while the deflection angle becomes an important parameter for angles less than 45 degrees. Bend curvature and deflection angle have commensurable influence on the onset of choking flow
Effect of chemical composition on the microstructure, hardness and electrical conductivity profiles of the Bi-Ge-In alloys
© 2020, Association of Metallurgical Engineers of Serbia. All rights reserved. In this study, the microstructure, hardness, and electrical properties of selected ternary Bi-Ge-In alloys were investigated. Isothermal sections of the Bi-Ge-In system at 25, 200, and 300 °C were extrapolated using optimized thermodynamic parameters from the literature. The used experimental techniques include optical microscopy, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS), Brinell hardness, and electrical conductivity measurements. The results of EDS phase composition analysis were compared with the calculated isothermal sections and a good overall agreement was reached. The results of the XRD were also in line with the predicted phase balance. By using ANOVA analysis and experimental results of Brinell hardness and electrical conductivity, a mathematical model was suggested for the calculation of these properties along with all composition ranges. The appropriated mathematical model was subsequently used for the prediction of hardness and electrical conductivity throughout the whole composition range
Effect of chemical composition on the microstructure, hardness and electrical conductivity profiles of the Ag-Bi-Ge Alloys
© 2019 Universidade Federal de Sao Carlos. All rights reserved. Microstructure, hardness and electrical properties of the selected ternary Ag-Bi-Ge alloys were investigated in this study. Isothermal sections of the Ag-Bi-Ge system at 25, 100 and 500 °C have been extrapolated using optimized thermodynamic parameters from literature and experimentally investigated. Performed experiments were optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), X-ray powder diffraction (XRD), hardness measurements by Brinell method and electrical conductivity measurements. EDS results were compared with predicted phase equilibria and good overall agreement between experimental and calculated values was obtained. XRD results were also in agreement with predicted phase equilibria. Hardness and electrical conductivity of selected alloys were measured and by using appropriated mathematical model these properties were predicted in the whole composition range
Description of the Liquidus Surface and Characterization of Alloys of the Ternary Bi-Cu-In System
Lead-free solders with copper are considered as a possible substitution for standard lead-tin solders. Ternary Bi-Cu-In system is a potential soldering material based on copper. For a more complete characterization of the ternary Bi-Cu-In system, alloys from the three vertical sections were investigated using microstructural analysis as well as by electrical conductivity and Brinell hardness measurements. The microstructures of the alloys were investigated at room temperature by application of scanning electron microscopy combined with energy dispersive spectrometry and optical microscopy. Isolines of electrical conductivity and hardness for the entire Bi-Cu-In system were calculated using regression models. In addition, a thermodynamic assessment of the system has been carried out by calculation of the isothermal section at 25 A degrees C and description of the liquidus surface using the CALPHAD method. Experimental and analytical results were found to be in a good agreement
Electrical properties of ternary Bi-Ge-Sb and Al-Cu-Sb alloys
Copyright: © 2017 CSIC. Electrical properties of ternary Bi-Ge-Sb and Al-Cu-Sb alloys. This paper presents review of electrical properties of two ternary systems based on Sb, ternary Bi-Ge-Sb and Al-Cu-Sb system. Beside electrical properties in paper are presented microstructures of both systems observed with light optical microscopy. On four samples microstructural analysis was carried out by scanning electron microscopy combined with energy dispersive spectrometry and X-ray powder diffraction technique. Moreover, micro hardness of selected alloys from the ternary Bi-Ge-Sb system was determined using Vickers hardness tests
Evaluation of single-cell gel electrophoresis data: Combination of variance analysis with sum of ranking differences
Specimens of the mussel Mytilus galloprovincialis were collected from
five sites in the Boka Kotorska Bay (Adriatic Sea, Montenegro) during
the period summer 2011-autumn 2012. Three types of tissue, haemolymph,
digestive gland were used for assessment of DNA damage. Images of
randomly selected cells were analyzed with a fluorescence microscope and
image analysis by the Comet Assay IV Image-analysis system. Three
parameters, viz, tail length, tail intensity and Olive tail moment were
analyzed on 4200 nuclei per cell type. We observed variations in the
level of DNA damage in mussels collected at different sites, as well as
seasonal variations in response. Sum of ranking differences (SRD) was
implemented to compare use of different types of cell and different
measure of comet tail per nucleus. Numerical scales were transferred
into ranks, range scaling between 0 and 1; standardization and
normalization were carried out.
SRD selected the best (and worst) combinations: tail moment is the best
for all data treatment and for all organs; second best is tail length,
and intensity ranks third (except for digestive gland). The differences
were significant at the 5\% level. Whereas gills and haemolymph cells do
not differ significantly, cells of the digestive gland are much more
suitable to estimate genotoxicity. Variance analysis decomposed the
effect of different factors on the SRD values. This unique combination
has provided not only the relative importance of factors, but also an
overall evaluation: the best evaluation method, the best data
pre-treatment, etc., were chosen even for partially contradictory data.
The rank transformation is superior to any other way of scaling, which
is proven by ordering the SRD values by SRD again, and by cross
validation. (C) 2014 Elsevier B.V. All rights reserved.Ministry of Science of Montenegro; OTKA (Hungarian Scientific - Research
Foundation) {[}K112547]This is the peer reviewed version of the following article: Héberger K, Kolarević S, Kračun-Kolarević M, Sunjog K, Gačić Z, Kljajić Z, Mitrić M, Vuković-Gačić B. Evaluation of single-cell gel electrophoresis data: Combination of variance analysis with sum of ranking differences. Mutat Res Toxicol Environ Mutagen. 2014;771:15–22. [https://doi.org/10.1016/j.mrgentox.2014.04.028