scholarly journals VISCOSITY OF CuPb, CuPbSn, CuPbSnGa AND CuPbSnGaBi MELTS OF EQUIATOMIC COMPOSITIONS

2021 ◽  
Vol 25 (1) ◽  
pp. 33-40
Author(s):  
Olga Chikova ◽  
Vladimir Tsepelev ◽  
Kseniya Shmakova
Keyword(s):  
Optical Microscopy ◽  
Structural Changes ◽  
Ternary Eutectic ◽  
Equiatomic Composition ◽  
Structural Components ◽  
Melt Structure ◽  
High Entropy ◽  
Heating And Cooling ◽  
Temperature Dependences ◽  
Specific Temperature

We investigated the viscosity of CuPb, CuPbSn, CuPbSnGa and CuPbSnGaBi melts of equiatomic compositions by the method of damped torsion vibrations of a crucible. We saw the melts of equiatomic composition as the melts high-entropy. All the investigated melts demonstrated the different temperature dependences of viscosity for heating and cooling. There is an anomalous reduction in viscosity resulted when the melt is heated to a specific temperature. The anomalous behaviour for viscosity we interpreted in terms of melt structure. This structural changes in the melt resulted when the melt is heated to a specific temperature. The microstructure of CuPbSnGaBi ingot of equiatomic composition we investigated using optical microscopy and measurement of microhardness. Collations data of the microstructures with of the microhardness gave three structural components: CuGa2 dendrites, (Sn) + (Bi) + Bi3Pb7 ternary eutectic and rounded Pb inclusions having dimensions of 5 m.

scholarly journals Viscosity of CuPb, CuPbSn, CuPbSnGa and CuPbSnGaBi melts of equiatomic compositions

2019 ◽  
Vol 25 (1) ◽  
pp. 33
Author(s):  
Olga Chikova ◽  
Vladimir Tsepelev ◽  
Kseniya Shmakova
Keyword(s):  
Optical Microscopy ◽  
Structural Changes ◽  
Ternary Eutectic ◽  
Equiatomic Composition ◽  
Structural Components ◽  
Melt Structure ◽  
High Entropy ◽  
Heating And Cooling ◽  
Temperature Dependences ◽  
Specific Temperature

<p class="AMSmaintext">We investigated the viscosity of CuPb, CuPbSn, CuPbSnGa and CuPbSnGaBi melts of equiatomic compositions by the method of damped torsion vibrations of a crucible. We see the melts of equiatomic composition as the melts high-entropy. All the investigated melts demonstrated the different temperature dependences of viscosity for heating and cooling. There is an anomalous reduction in viscosity resulted when the melt is heated to a specific temperature. The anomalous behaviour for viscosity we interpreted in terms of melt structure. This structural changes in the melt resulted when the melt is heated to a specific temperature.  The microstructure of CuPbSnGaBi ingot of equiatomic composition we investigated using optical microscopy and measurement of microhardness. Collations data of the microstructures with of the microhardness gave three structural components: CuGa<sub>2</sub> dendrites, (Sn) + (Bi) + Bi<sub>3</sub>Pb<sub>7</sub> ternary eutectic and rounded Pb inclusions having dimensions of  »5 mm.</p>

Phases and Structure Characteristics of the Near Eutectic Al-Sl-Cu Alloy Using Derivative Thermo Analysis

2010 ◽  
Vol 638-642 ◽  
pp. 475-480 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Mariusz Krupinski ◽  
Krzysztof Labisz ◽  
Beata Krupinska ◽  
Adam Grajcar
Keyword(s):  
Structural Changes ◽  
Cast Alloy ◽  
Ternary Eutectic ◽  
Heating And Cooling ◽  
Cu Alloy ◽  
Electron Scanning Microscopy ◽  
Cooling Speed ◽  
Alloy Microstructure ◽  
Liquid Metal Processing ◽  
Iron And Manganese

For determining of the micro-structural changes taking place in a near eutectic Al-Si-Cu aluminium cast alloy during heating and cooling process the UMSA device (Universal Metallurgical Simulator and Analyzer) was used. In this work the dependence between the regulated cooling speed and structure on the basis of the thermo-analysis was carried out. The thermal analysis was performed at a cooling rate in a range of 0,2 °C to 1,25 °C. The changes were examined and evaluated qualitatively by optical and electron scanning microscopy methods and the EDS microanalysis. During the investigation the formation of aluminium reach (α-Al) dendrites was revealed and also the occurrence of the α+β eutectic, the ternary eutectic α+Al2Cu+β, as well a iron and manganese containing phase was confirmed. The performed investigation are discussed for the reason of an possible improvement of thermal and structural properties of the alloy. The achieved results can be used for liquid metal processing in science and industry – for example foundry for developing and obtaining of a required alloy microstructure and properties influenced by a proper production conditions.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

scholarly journals A design concept of active cooling for tailored forming workpieces during induction heating

2021 ◽  
Vol 15 (2) ◽  
pp. 177-186
Author(s):  
Caner-Veli Ince ◽  
Anna Chugreeva ◽  
Christoph Böhm ◽  
Fadi Aldakheel ◽  
Johanna Uhe ◽  
...  
Keyword(s):  
Dissimilar Materials ◽  
Heating Process ◽  
Algorithmic Approach ◽  
Cooling Strategy ◽  
Heating And Cooling ◽  
Temperature Constraint ◽  
Inhomogeneous Temperature ◽  
Specific Temperature ◽  
Tailored Forming

AbstractThe demand for lightweight construction is constantly increasing. One approach to meet this challenge is the development of hybrid components made of dissimilar materials. The use of the hybrid construction method for bulk components has a high potential for weight reduction and increased functionality. However, forming workpieces consisting of dissimilar materials requires specific temperature profiles for achieving sufficient formability. This paper deals with the development of a specific heating and cooling strategy to generate an inhomogeneous temperature distribution in hybrid workpieces. Firstly, the heating process boundaries with regard to temperature parameters required for a successful forming are experimentally defined. Secondly, a design based on the obtained cooling strategy is developed. Next a modelling embedded within an electro-thermal framework provides the basis for a numerical determination of admissible cooling rates to fulfil the temperature constraint. Here, the authors illustrate an algorithmic approach for the optimisation of cooling parameters towards an effective minimum, required for applicable forming processes of tailored forming.

The Study of Structural Changes in Homogenized High-Entropy Alloys

2021 ◽  
Vol 24 (6) ◽  
pp. 663-673
Author(s):  
G. R. Aripov ◽  
V. V. Cheverikin ◽  
A. I. Bazlov ◽  
H. Mao ◽  
D. V. Louzguine-Luzgin ◽  
...  
Keyword(s):  
Structural Changes ◽  
High Entropy Alloys ◽  
High Entropy

Die deutsche Krankenhauspolitik: Eine Geschichte verpasster Strukturreformen?

2018 ◽  
Vol 67 (1) ◽  
pp. 1-28
Author(s):  
Heidi Dittmann
Keyword(s):  
Structural Changes ◽  
Regulatory Framework ◽  
Operating Costs ◽  
German Hospital ◽  
Structural Components ◽  
Drg System ◽  
Hospital Reform ◽  
Hospital Structure Act ◽  
Hospital Finance

Abstract: The introduction of the DRG system in 2003/04 can be considered the last real hospital reform. Although the latest reform was called Hospital Structure Act due to its insufficient structural components it is sometimes referred to as missed reform. Essential aspects of the institutional background remained unchanged. However, a closer look reveals even the introduction of the DRG system was only a change in the reimbursement of operating costs. Further structural changes were neither discussed nor induced. The same applies to all subsequent reforms. The key parameters of the regulatory framework are for the greater part the same as those established by the German Hospital Finance Act in 1972. Against this backdrop, the presented paper discusses the institutional background and potential reasons for its continuance. The focus is on the question, whether missed reforms are based on its optimality or which alternative explanations seem to be convincing.

scholarly journals THE COMPARATIVE MORPHOLOGICAL ANALYSIS OF THE NEPHROTOXICITY OF DOXORUBICIN AND NANOSTRUCTURED DOXORUBICIN IN CONDITIONS OF TRANSPLANTABLE CARCINOGENESIS

2018 ◽  
Vol 26 (2) ◽  
pp. 45-48
Author(s):  
I. N. Chairkin ◽  
N. V. Chairkina ◽  
O. N. Deryabina ◽  
V. Y. Medvezhonkov ◽  
O. V. Kalmin
Keyword(s):  
Morphological Analysis ◽  
Structural Changes ◽  
Morphological Changes ◽  
Control Group ◽  
Structural Components ◽  
Laboratory Rats ◽  
Chemotherapy Drugs ◽  
Morphological Evaluation ◽  
Comparative Morphological Analysis ◽  
Convoluted Tubules

The study was carried out on 120 mongrel white laboratory rats, to whom were transplanted the ascitiс Zaidel's hepatoma and which were divided into three equal groups. Of these, the first group of animals was a control group without treatment. In the second group, to animals doxorubicin was injected, in the third group, nanostructured doxorubicin was injected to the animals for 21 days. The aim of the study was to assess the degree of morphological changes in the tubules and glomeruli of the kidneys under the influence of nanostructured doxorubicin and doxorubicin in the condition of transplantable carcinogenesis. Given the nephrotoxicity of the chemotherapy drugs studied, the dynamics of structural changes in the tubules and glomeruli of the kidneys was studied. Conducted a comparative morphological evaluation of the changes occurring in the kidneys. The results of a morphological study of the structural components of the kidneys prove that doxorubicin and nanostructured doxorubicin have different effects on both the tubular apparatus and the glomeruli of the kidneys in the condition of transient carcinogenesis. The use of doxorubicin is accompanied by a relatively pronounced nephrotoxic effect, which is indicated by dystrophic and necrobiotic changes in the epithelium of convoluted tubules and the glomerular apparatus of the kidneys. The use of nanostructured doxorubicin is limited to moderately expressed dystrophic changes in the epithelium of the tubular apparatus of the kidneys, the glomerular apparatus remains intact at the same time. Thus, the use of the preparation of nanostructured doxorubicin for the treatment of the ascitic hepatoma of Zaidel in experimental animals has a less pronounced toxic and damaging effect on the renal parenchyma.

Structural Changes of Soymilk Proteins during Heating and Cooling, and Freeze-Gelation of Soymilk

2003 ◽  
pp. 290-299
Author(s):  
Makoto Shimoyamada ◽  
Kayoko Tômatsu ◽  
Satomi Oku ◽  
Wataru Koseki ◽  
Kenji Watanabe
Keyword(s):  
Structural Changes ◽  
Heating And Cooling

scholarly journals Study of Phase Formation Processes in Li2ZrO3 Ceramics Obtained by Mechanochemical Synthesis

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Maxim V. Zdorovets ◽  
Artem L. Kozlovskiy ◽  
Baurzhan Abyshev ◽  
Talgat A. Yensepbayev ◽  
Rizahan U. Uzbekgaliyev ◽  
...  
Keyword(s):  
Phase Formation ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Image Data ◽  
Formation Processes ◽  
Ceramic Structure ◽  
Current Voltage ◽  
Average Grain Size ◽  
Temperature Dependences

The article is dedicated to the study of the phase formation processes in Li2ZrO3 ceramics obtained by the method of solid phase synthesis. Interest in these types of ceramics is due to their great potential for use as blanket materials in thermonuclear reactors, as well as being one of the candidates for tritium breeder materials. Analysis of the morphological features of the synthesized ceramics depending on the annealing temperature showed that the average grain size is 90–110 nm; meanwhile the degree of homogeneity is more than 90% according to electronic image data processing results. The temperature dependences of changes in the structural and conducting characteristics, as well as the phase transformation dynamics, have been established. It has been determined that a change in the phase composition by displacing the impurity LiO and ZrO2 phases results in the compaction of ceramics, as well as a decrease in their porosity. These structural changes are due to the displacement of LiO and ZrO2 impurity phases from the ceramic structure and their transformation into the Li2ZrO3 phase. During research, the following phase transformations that directly depend on the annealing temperature were established: LiO/ZrO2/Li2ZrO3 → LiO/Li2ZrO3 → Li2ZrO3. During analysis of the obtained current-voltage characteristics, depending on the annealing temperature, it was discovered that the formation of the Li2ZrO3 ordered phase in the structure results in a rise in resistance by three orders of magnitude, which indicates the dielectric nature of the ceramics.

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