Browsing by Author "Chang, KT"

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Effect of adsorbents coated with titanium dioxide on the photocatalytic degradation of propoxur
(1999-02-01)
Lu, MC
;
Chen, JN
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Chang, KT
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環境工程研究所
;
Institute of Environmental Engineering
Photocatalytic oxidation of pesticides in aqueous media irradiated by UV light is a rapidly growing field of research. Therefore, the treatment technology for degradation of propoxur (an insecticide) using titanium dioxide coated on the supports such as activated carbon, zeolite, brick, quartz and glass beads, was performed in this research. Results show that GAC/TiO2 is the best complexing agent for oxidizing propoxur because of its adsorption properities. The others follow the sequence: plain TiO2 > glass beads > zeolite > brick > quartz. The degradation rate of propoxur with plain TiO2 is higher than that with TiO2/GAC complexing agent. But the mineralization rate of propoxur with plain TiO2 is lower than that with TiO2/GAC complexing agent. However, it can be concluded that using GAC as the support can improve the photocatalytic efficiency. (C) 1998 Elsevier Science Ltd. All rights reserved.
Power saving of a dynamic width controller for a monolithic current-mode CMOS DC-DC converter
(2005)
Lee, HC
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Chang, KT
;
Chen, KH
;
Chen, WT
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電控工程研究所
We propose the dynamic power MOS width controlling technique and the adaptive gate driver voltage technique to find out the better approach to power saving in DC-DC converters. It demonstrates that the dynamic power MOS width controlling technique has much improvement in power consumption than that of the adaptive gate driver voltage technique when the load current is heavy or light. After the dynamic power MOS width modification, the simulation results show that the efficiency of current-mode DC-DC buck converter can be improved from 92% to about 98% in heavy load and from 15% to about 16.3% in light load. However, the adaptive gate driver voltage technique has only little improvement of power saving. It means that the dynamic width controller is the better approach to power saving in the DC-DC converter.