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Determination of the electrical and thermal properties of Al-Sn-Zn alloys
No full textIn the present work, the electrical resistivity, thermal conductivity and microstructure of the70 at. % Al-15 at. % Sn-15 at. % Zn alloy have been investigated. The electrical resistivity ofthe alloy was obtained by four-point probe (DC 4PPT) method. Electrical resistivitymeasurements are used in conjunction with Wiedeman-Franz (W-F) law and Smith-Palmer(S-P) equations to obtain the thermal conductivity of the alloy. The microstructure parametersof the Al-Sn-Zn ternary alloy were obtained by XRD. The surface and phases of alloy wereshowed by SEM, and the composition of each phase was determined by EDX
Change of Thermoelectric, Magnetic, and Mechanical Properties of Al-Ni-Co Ternary Alloy Depending on Grain Size
No full textHerein, we investigated Al-[9 - x] at % Ni-x at % Co (x = 2 and 5) ternary alloy, which has a wide range of applications in terms of tribological properties and magnetic properties. The impact of grain size on the electrical, thermal, magnetic and mechanical properties of these alloys was investigated. Results demonstrated that a decrease in the average grain size of these alloys increases their electrical resistance and decreases their thermal conductivity. Moreover, mechanical properties such as strength, durability and hardness improved depending on grain size. The alloy composition that exhibits optimum properties is the Al-4 at % Ni-5 at % Co alloy. The magnetic properties, such as magnetic transition temperature and magnetisation curves were determined for both alloy compositions
Study on Electrical, Thermal, Magnetic Properties and Microstructure for ?- Al, ?-Al2Cu, ?-Al7Cu2Fe Phases in Al-32.5 wt. % Cu-1 wt. % Fe Ternary Alloy
No full textThe electrical properties of the Al-32.5 wt. % Cu-1 wt. % Fe ternary alloy were examined, it was observed that the electrical resistivity increased depending on the temperature and it was found as 6.8546x10-8 ?m - 5.7780x10-7?m in the temperature range of 298-810K. The thermal conductivity was calculated using electrical measurement results and it was observed that it decreased depending on the temperature. The ternary alloy (cubic ?-Al, Fm-3m, 225 a = 4.0480 Å, ?-tetragonal Al2Cu, I4mcm, 140, a=6.0654 Å c=4.8732 Å, ?-tetragonal Al7Cu2Fe, P4 /mnc, 128, a = 6.3360 Å, m and c = 14.87 Å) phases were obtained. In this ternary alloy, phases were clearly seen in XRD studies and EDAX analyzes at room temperature. Magnetic properties such as magnetic transition temperature and magnetization curves of the alloy were determined
The solid-liquid interfacial energy for solid Zn solution at the eutectic Zn-Sn-Mg ternary alloy
No full textThe Gibbs-Thomson coefficient, Gamma, the effective entropy change, Delta S-f, the solid-liquid interfacial energy, sigma(SL), and the grain boundary energy, sigma(GB), for solid Zn solution at the eutectic Zn-Sn-Mg ternary alloy have been calculated using the grain boundary groove method with Bridgman-type directional solidification apparatus. (C) 2014 Elsevier B.V. All rights reserved
Improvement of thermoelectric, hardness, and strength properties with Cu exchange in Zn-based ternary alloy
No full textThe electrical properties, hardness, and strength of the Zn-based ternary alloys were determined based on their microstructural properties. Formation and microstructural analyses were performed on Cu5Zn8, Al4Cu9, and Cu3Al intermetallic phases. When the electrical properties of the alloy were examined, it was seen that the electrical resistivity increased according to the amount of Cu. Electrical resistivity values were obtained in the range of 9.7216 x 10-8 -6.5881 x 10-7 omega m by DC four-point probe method (FPPM). The results obtained with the FPPM showed good electrical resistance, which can be applied to electronics as a lead-free soldering material. For each composition of Zn-Al-Cu alloys, the hardness value was measured within the range of 82.70-94.03 Hv0.1, the ultimate tensile strength (UTS) was measured within the range of 133.48-202.56 MPa. In addition, yield strength (YS0.2) was measured within the range of 128.22-174.67 MPa. The results of our study are compatible with the expectation that the highest strength, yield strength, hardness etc. properties will be obtained in eutectic alloy systems.Cumhuriyet UniversityThe authors declare the following fi nancial interests/personal re- lationships which may be considered as potential competing interests: Canan Alper Billur reports a relationship with Cumhuriyet University that includes: employment
Experimental determination of interfacial energy for solid Al in the Al-Sn-Mg eutectic system with Bridgman-type apparatus
No full textThe equilibrated grain boundary groove shape of solid Al in equilibrium with Al-Sn-Mg eutectic liquid was observed by using a Bridgman type directional solidification apparatus. The ratio of the thermal conductivity of the equilibrated liquid to the thermal conductivity of solid Al has been obtained as 0.91. In addition, the average Gibbs-Thomson coefficient, (Gamma) over bar = (4.20 +/- 0.35) x 10(-8) Km, the solid-liquid interfacial energy, sigma(SL) = 180.68 +/- 23.48 mJ/m(2) and the grain boundary energy, sigma(GB) = 309.30 +/- 29.47 ml/m(2), in the Al/Al-Sn-Mg system have been calculated from the measured grain boundary shapes. (C) 2019 Elsevier B.V. All rights reserved.Sivas Cumhuriyet University Research Fund [SMYO-018]; Erciyes University Research Fund [FBD-10-3263]The results of this paper are in the frame of project SMYO-018 financed by the Sivas Cumhuriyet University Research Fund and FBD-10-3263 financed by the Erciyes University Research Fund
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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