• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.5
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• pp.14-21
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• 2002

This paper did the study target for modeling, characteristics analysis and harmonic reduce with the detent torque of a 4 phase and 5 phase hybrid type step motor. For this, it was attempted to derive the mathematical modeling and used the permeance method for flux field analysis. Through this analysis result, this paper acquired the detent torque of this model. To compare the characteristics analysis of phase difference with two motors structure it have obtained to derive the operating detent torque with this model. Here, 5 phase motor has known the harmonic reduce of detail torque compare with 4 phase motor. Also, that has showed to improved the step response. The analysis result has represent the effect that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.

• Membrane Journal
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• v.26 no.5
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• pp.372-380
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• 2016

The present paper reports the effect of precursor alumina particle size on pore structure and single gas permeation properties of tubular ${\alpha}$-alumina supports, prepared by a combined process of slip casting and sintering. Pore diameter of as-prepared ${\alpha}$-alumina support was highly dependent on precursor ${\alpha}$-alumina particle size. Although, increase in the precursor particle size increases the pore diameter, but the porosity of ${\alpha}$-alumina support mainly control by sintering temperature. Sintering studies reveal that as sintering temperature increased porosity of support decreased. Single gas permeance results indicate that permence is proportional to the square of pore diameter and linearly to porosity. These dependencies revealed that gas permeation trough as-prepared ${\alpha}$-alumina support was governed by viscous flow mechanism. The present announces that precursor ${\alpha}$-alumina particle size and sintering temperature are key parameters to control gas permeantion properties of ${\alpha}$-alumina supports.