Measurement of electrical conductivity of magnesium oxide single crystal at high temperature using a solar furnace

Afzal, Faizan; Giutronich, J.E.

doi:10.1016/0038-092x(73)90122-9

Cited by 9 publications

(1 citation statement)

References 5 publications

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“…No errors due to any of the above causes were apparent. Further, to check for the effect of the presence of high furnace currents (up to 1000 A, 50 Hz) the electrical conductivity measurements were repeated using a solar furnace (Afzal and Giutronich 1973). There was no significant difference in the results obtained.…”

Section: Electrical Conductivitymentioning

confidence: 99%

Stimulated Brillouin scattering in an acoustic resonator

Morozov¹,

Chernyshev²

1980

Sov. J. Quantum Electron.

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A graphite tube electric furnace has been designed to facilitate measurement of electrical properties of small refractory samples at high temperatures. Conductivity data are obtained with the sample at a uniform temperature in the central zone of the furnace. Thermal EMF data are obtained with the sample in a controlled and measurable temperature gradient at either end of the zone. The furnace tube is mounted axially in a water-cooled cylindrical chamber filled with argon or nitrogen at atmospheric pressure. A novel feature is that, with no thermal insulation other than an annular space round the furnace tube, fast rates of heating/cooling are possible, and thermal equilibrium can be achieved rapidly (in 3 min) at any desired sample temperature up to 3000°C. An Arrhenius-type plot of conductivity-reciprocal temperature data for MgO crystals containing 116 ppm impurity shows three regions joined by knees at approximately 1800 and 2100°C. The knees shift to higher temperatures with increase of impurity content; these effects and the nature of the associated conduction processes are discussed. Preliminary data for the Seebeck coefficient of MgO indicate n-type conduction.

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Section: Electrical Conductivitymentioning

confidence: 99%

Stimulated Brillouin scattering in an acoustic resonator

Morozov¹,

Chernyshev²

1980

Sov. J. Quantum Electron.

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Entropy analysis of MHD flow in hybrid nanofluid over a rotating disk with variable viscosity and nonlinear thermal radiation

Mandal,

Mukherjee,

Shit

et al. 2024

Z Angew Math Mech

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In this study, we aim to investigate the entropy production in the magnetohydrodynamic (MHD) flow of hybrid nanofluids over permeable rotating disks. We will analyze the entropy production within a three‐dimensional MHD flow of Ag‐MgO nanofluid over a rotating porous disk with variable fluid properties. Our analysis will incorporate time‐dependent radial stretching and slip effects on velocities and temperature. Moreover, the study will take into account exponentially temperature‐dependent viscosity and nonlinear thermal radiation. The study uses self‐similar transformations to convert the coupled nonlinear partial differential equations into a set of nonlinear ordinary differential equations. Numerically solving these equations involves using a shooting technique and relies on the 4th‐order Runge–Kutta–Fehlberg method. The rotation of the disk introduces a parameter that accelerates fluid motion. The study explores heat transfer rate, skin friction, and entropy production quantified by the Bejan number. Various factors, including magnetic field intensity, disk rotation, thermal radiation, and variable viscosity, influence this quantification. The outcomes of the study can enhance system efficiency through suitable parameter choices, deepening our understanding of entropy generation and system performance under varying factors. This research is important for improving heat transfer processes, reducing energy waste, and improving the design and operation of advanced fluid systems in engineering applications. The results could lead to innovations in thermal management, energy conservation, and sustainable engineering practices.

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