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Thermal Analysis of Mg Hydride by Sievert`s Type Automatic Apparatus
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한정섭 Jeong Seb Han , 박경덕 Kyung Duck Park |
KJMM 48(12) 1123-1129, 2010 |
ABSTRACT
In order to apply the Sievert`s type automatic apparatus to thermal analysis of hydrogen absorbing materials, the dehydrogenation of the Mg-H system was investigated. As the initial wt% of hydrogen was increased to 4.4, the peak temperature of evolution rate shifted to higher temperature. However, with the initial wt% of hydrogen higher than 4.4, peak temperature of evolution rate did not change. The peak temperatures of evolution rate obtained by automatic apparatus were almost the same as those measured by a manual apparatus. As the heating rate was increased, the peak temperatures increased; the peak temperatures for heating rates 1, 2 and 3 K/min were 664, 687 and 702 K, respectively. The activation energy for the decomposition of Mg hydride was 101 kJ/mol. The Sievert`s type automatic apparatus can be successively applied to the thermal analysis of metal hydride.
keyword : Hydrogen absorbing materials, powder processing, decomposition, thermal analysis, magnesium hydride
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Electrical and Mechanical Properties of Cu/Carbon Nano-Particle Hybrids Composites by Cathodic Electrophoresis
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이원오 Woon Oh Lee , 이상복 Sang Bok Lee , 최오영 Oh Young Choi , 이진우 Jin Woo Yi , 변준형 Joon Hyung Byun |
KJMM 48(12) 1130-1135, 2010 |
ABSTRACT
Cu/carbon nano-particle hybrids were fabricated through the cathodic electrophoretic deposition (EPD) process. CNT and CNF nano-particles were modified to give positive charges by polyethyleneimine (PEI) treatment before depositing them on the substrate. Since a Cu plate was used as an anode in the EPD process, Cu particles were also deposited along with the carbon nano-particles. Experimental observation showed the nano-hybrids constructed a novel formicary-like nano-structure which is strong and highly conductive. Utilizing the hybrids, carbon fiber composites were manufactured, and their electrical conductivity and interlaminar shear strength were measured. In addition, the deposition morphology and failure surface were examined by SEM observations. Results demonstrated that the electrical conductivities in the through-the-thickness direction and the interlaminar shear strength significantly increased by 350~2100% and 14%, respectively.
keyword : nanostructured materials, deposition, electrical properties, scanning electron microscopy, SEM, Cu/carbon nano-particle hybrids
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