Reduction of temperature gradient and carbon contamination in electric current assisted sintering (ECAS/SPS) using a “saw-tooth” heating schedule

2019 ◽  
Vol 45 (17) ◽  
pp. 22987-22990 ◽  
Author(s):  
Vojtěch Nečina ◽  
Willi Pabst
Keyword(s):  
Temperature Gradient ◽  
Electric Current ◽  
Carbon Contamination ◽  
Heating Schedule

scholarly journals Gyrokinetic simulations of electric current generation in ion temperature gradient driven turbulence

2021 ◽  
Vol 28 (11) ◽  
pp. 112303
Author(s):  
Xiang Chen ◽  
Zhixin Lu ◽  
Huishan Cai ◽  
Lei Ye ◽  
Yang Chen ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Electric Current ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Current Generation ◽  
Gyrokinetic Simulations

scholarly journals The Contribution of Phonons to the Thomson Coefficient

1954 ◽  
Vol 7 (3) ◽  
pp. 520 ◽  
Author(s):  
PG Klemens
Keyword(s):  
Temperature Gradient ◽  
Electric Current ◽  
Fermi Energy ◽  
Unit Volume ◽  
Transport Coefficients ◽  
Thomson Coefficient

An electric current of density j flowing in a temperature gradient \1T gives up heat in a reversible way; the amount of heat thus liberated per unit volume and unit time is given by -p.j\1T, (1) p. being the Thomson coefficient, which can be shown to be T d r l(Kl )' p.=-e dT(P Ko -~ 5' (2) where ~ is the Fermi energy, and the K's are the usual transport coefficients as defined by Mott and Jones (1936, p. 306, equation (99)), or more generally by Wilson (1953, p. 305).

scholarly journals Short-Circuit Current in Polymeric Membrane-Based Thermocells: An Experimental Study

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 480
Author(s):  
V. María Barragán
Keyword(s):  
Temperature Gradient ◽  
Electric Current ◽  
Short Circuit ◽  
Electrical Power ◽  
Short Circuit Current ◽  
Membrane System ◽  
Polymeric Membrane ◽  
Experimental Point ◽  
Maximum Output ◽  
Alkali Chloride

Thermocells are non-isothermal electrochemical cells used to convert thermal energy into electricity. In a thermocell, together with the ion flux, heat is also transferred, which can reduce the temperature gradient and thus the delivered electric current. A charged membrane used as a separating barrier in the electrolyte liquid could reduce this problem. Therefore, the use of ion-exchange membranes has been suggested as an alternative in terms of thermoelectricity because of their high Seebeck coefficient. Ion transfer occurs not only at the liquid solution but also at the solid membrane when a temperature gradient is imposed. Thus, the electric current delivered by the thermocell will also be highly dependent on the membrane system properties. In this work, a polymeric membrane-based thermocell with 1:1 alkali chloride electrolytes and reversible Ag|AgCl electrodes at different temperatures is studied. This work focuses on the experimental relation between the short-circuit current density and the temperature difference. Short-circuit current is the maximum electric current supplied by a thermocell and is directly related to the maximum output electrical power. It can therefore provide valuable information on the thermocell efficiency. The effect of the membrane, electrolyte nature and hydrodynamic conditions is analysed from an experimental point of view.

Growth of 4H-SiC in Current-Controlled Liquid Phase Epitaxy

2013 ◽  
Vol 740-742 ◽  
pp. 3-6 ◽  
Author(s):  
Takeshi Mitani ◽  
Masayuki Okamura ◽  
Tetsuo Takahashi ◽  
Naoyoshi Komatsu ◽  
Tomohisa Kato ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Temperature Gradient ◽  
Electric Current ◽  
Joule Heating ◽  
Liquid Phase Epitaxy ◽  
Negative Polarity ◽  
Growth Speed ◽  
Positive Polarity ◽  
Current Leads ◽  
Dc Current

4H-SiC crystallization from Si-C solution in electric current-controlled liquid phase epitaxy was investigated. The dependence of growth speed on a DC current shows that dissolution/growth is controlled by the electric current without altering temperature gradient in the furnace. Application of an electric current leads to reduction of growth speed with negative polarity and enhancement of growth speed with positive polarity. The variation of the growth speed with a DC current density has been explained by the combination of the effects of electromigration of C solute and Joule heating.

Temperature-gradient joining of Ti–6Al–4V alloys by pulsed electric current sintering

2012 ◽  
Vol 535 ◽  
pp. 182-188 ◽  
Author(s):  
Daihua He ◽  
Zhengyi Fu ◽  
Weimin Wang ◽  
Jinyong Zhang ◽  
Zuhair A. Munir ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Electric Current ◽  
Pulsed Electric Current

A critical examination of Benedicks' homogeneous electro-thermal effect

1937 ◽  
Vol 33 (3) ◽  
pp. 385-389 ◽  
Author(s):  
William Band
Keyword(s):  
Temperature Gradient ◽  
Thermal Effect ◽  
Electric Current ◽  
Thermal Equilibrium ◽  
Opposite Sign ◽  
The Other ◽  
Critical Examination ◽  
Temperature Peak ◽  
Small Temperature ◽  
Actual Change

In his work on mercury, Benedicks (1) observed that the small temperature peak in the neighbourhood of the middle of the long tube containing the conductor was displaced in one direction or the other along the tube according to the direction of flow of the electric current by which the conductor was heated. Normally this effect increased with the cube of the current intensity, and was explained as due to Thomson heat. If the temperature was made as uniform as possible by means of controlled heaters at the ends of the tube, the effect became of opposite sign and increased linearly with the current. This was called the “electro-thermal effect” and was explained as due to an actual change of thermal equilibrium by the electric current, or the production of a temperature gradient by a flow of electricity.

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