Browsing by Author "Li, KC"

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Correlation between dewatering index and dewatering performance of three mechanical dewatering devices
(2003-05-01)
Pan, JRS
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Huang, CP
;
Cherng, MY
;
Li, KC
;
Lin, CF
Efficient sludge conditioning can improve sludge dewatering characteristics and promote the separation of flocs from the liquid phase to achieve a high solid content. To optimize this process, a reliable dewatering index must be established. Although numerous researches investigated sludge conditioning, few are devoted to the correlation between the conditioning index and the dewatering efficiency. In this study, sludges were conditioned with both synthetic and natural polymers, and their dewatering characteristics after three different mechanical dewatering devices, the filter press, belt press, and the centrifuge, were compared. The result shows that the traditionally used dewatering index may not reflect sludge conditioning properly. Correlation between sludge conditioning indices and dewaterability depends upon both the type of sludge and the means of sludge conditioning and dewatering. It is therefore concluded that dewatering index must be properly chosen for optimum sludge conditioning. (C) 2002 Elsevier Science Ltd. All rights reserved.
Fuzzy GIS assisted landfill siting analysis
(1996)
Lin, HY
;
Kao, JJ
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Li, KC
;
Hwang, HY
;
交大名義發表
This paper presents a prototypical fuzzy geographical information system (GIS) developed to facilitate landfill siting analysis. Landfill siting requires extensive effort to process massive spatial information, to evaluate various factors, and to review numerous criteria and regulations. A computerized GIS, although capable of effectively manipulating spatial information, generally lacks the ability to evaluate the suitability levers of candidate sites based on factors/criteria with some degree of imprecision and/or uncertainty. Because of their imprecision/uncertainty, many siting factors/criteria are not appropriate to be evaluated with a binary assessment, e.g., yes/no. Fuzzy set algorithms are therefore applied to overcome this difficulty. With proper membership functions assigned to imprecise/uncertain factors/criteria, the suitability score of a candidate site can be determined by a series of fuzzy calculations. The algorithms are incorporated into a previously developed landfill siting GIS to assist an engineer in improving siting decisions. This article, in addition to the description of the prototype, presents a case study to demonstrate the effectiveness of the developed Fuzzy GIS.
Microstructural study of the effect of chloride ion on electroplating of copper in cupric sulfate-sulfuric acid bath
(2005)
Kao, YL
;
Li, KC
;
Tu, GC
;
Huang, CA
;
材料科學與工程學系
The purpose of this work is to study the electrocrystallization behavior of the copper deposit on pure titanium substrate. The electroplating was conducted at 0.7 A/cm(2), 65 degrees C in cupric sulfate-sulfuric acid bath with various chloride additions (45-350 ppm). Initial growth morphology and microstructure of the deposit were examined with a field-emission scanning electron microscope (FESEM) and a high-resolution transmission electron microscope integrated with an energy-dispersive X-ray spectrometer. Results of cathodic polarization and galvanostatic plating experiments show that the increasing concentration of chloride ions in the plating bath would significantly increase the cathodic potential. This cathodic potential increase was found to be induced by the presence of CuCl precipitates on the cathodic surface as well as on the copper cluster formed during the electrocrystallization process. At the initial plating stage, both copper and hexagonal-shaped CuCl precipitates were produced simultaneously. Eventually, the pyramid-shaped CuCl precipitates were observed, which consisted of many parallel hexagonal planes stemming from a screw dislocation. The polarization effect of CuCl precipitate on the Ti substrate was further confirmed and clarified. Through measurement of the electrode response and investigation of the deposit using FESEM, it was observed that under identical electroplating conditions, much less CuCl forms on a copper substrate in the initial stages than on a titanium substrate, leading to lower polarization. (c) 2005 The Electrochemical Society.
Synthesis and characterization of alternating fluorene-based copolymers containing diaryl- and non-substituted bithiophene units
(2005-11-14)
Lin, HC
;
Sung, HH
;
Tsai, CM
;
Li, KC
;
材料科學與工程學系
A series of soluble alternating fluorene-based copolymers containing diaryl- and non-substituted bithiophene units are synthesized by palladium-catalyzed Suzuki coupling reaction. All polymers demonstrate green colors of photoluminescence (PL) in chloroform, good thermal stability (with, decomposition temperatures above 436 degrees C), and high glass transition temperatures (in the range of 120-144 degrees C). Owing to the large steric hindrance of diaryl substituents on bithiophenes in the polymers (P2-P4), the aggregation of solids is reduced as well as the solubility is improved, so the performance of their PLED devices are superior to that of the non-substituted polymer (PI). Compared with P1, the introduction of substitutents at 3,3'-position of bithiophene in P2-P4 has significant effects on the photophysical properties of resulting polymers in solution and solid states. Though the PL quantum yield of P1 is much higher than those of diaryl-substituted polymers (P2-P4), the PLED device of P1 has the worst electroluminescence (EL) properties due to the poor solubility of P1. Consequently, among these polymers, the device made of P3 as an emitter has the highest luminance of 2590 cd/m(2) at 9.5 V. For optimum device performance, a device of P3 blended with PVK can be further enhanced to a brighter luminance of 4284 cd/m(2) at 18 V. (c) 2005 Elsevier Ltd. All rights reserved.
The electrochemical behavior of tin-doped indium oxide during reduction in 0.3 M hydrochloric acid
(2003-10-30)
Huang, CA
;
Li, KC
;
Tu, GC
;
Wang, WS
;
材料科學與工程學系
The electrochemical behavior of tin-doped indium oxide (ITO) on SiO2 in 0.3 M HCl was studied using voltammetric scanning method. The result showed that an obvious reduction current peak occurred during the first cathodic potential scanning. The reduction reaction became less active after annealing ITO at 500 C for 1 h. The result was attributed to the replenishment of oxygen-deficient site, which acts as current carrier, by the annealing treatment. Many spherical In-Sn particles with sizes about 100-500 nm were formed on the ITO surface adjacent to the grain boundary when the reduction current took place. The In-Sn particles initiated preferentially on the ITO surface near grain boundaries attending the dissolution of ITO grain boundary. In the scanning period, after completion of the reduction current peak, reduction of hydrogen ions occurred in more negative potential region. A schematic illustration for the formation mechanism of the In-Sn reduction particle was postulated based on the metallographical and electrochemical results in this work. (C) 2003 Elsevier Ltd. All rights reserved.