Chung Yuan Christian University

About: Chung Yuan Christian University is a education organization based out in Taoyuan City, Taiwan. It is known for research contribution in the topics: Membrane & Fuzzy logic. The organization has 9819 authors who have published 11623 publications receiving 213139 citations. The organization is also known as: Tiong-gôan-tāi-ha̍k & CYCU.

Flame-retardant epoxy resins from o-cresol novolac epoxy cured with a phosphorus-containing aralkyl novolac

Abstract: A novel phosphorus-containing aralkyl novolac (Ar-DOPO-N) was prepared from the reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) first with terephthaldicarboxaldehyde and subsequently with phenol. The chemical structures of the synthesized compounds were characterized with Fourier transform infrared, 1H and 31P NMR, and elemental analysis. Ar-DOPO-N blended with phenol formaldehyde novolac was used as a curing agent for o-cresol formaldehyde novolac epoxy, resulting in cured epoxy resins with various phosphorus contents. The epoxy resins exhibited high glass-transition temperatures (159–177 °C), good thermal stability (>320 °C), and retardation on thermal degradation rates. High char yields and high limited oxygen indices (26–32.5) were observed, indicating the resins' good flame retardance. Using a melamine-modified phenol formaldehyde novolac to replace phenol formaldehyde novolac in the curing composition further enhanced the cured epoxy resins' glass-transition temperatures (160–186 °C) and limited oxygen index values (28–33.5). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2329–2339, 2002

Insight into the adsorption mechanism of cationic dye onto biosorbents derived from agricultural wastes

Abstract: This study investigated the phenomenon and mechanism of adsorption of methylene green 5 (MG5) on three pristine biosorbents: golden shower pod (GS), coconut shell (CC), and orange peel (OP). The results showed that the biosorbents possessed low specific surface areas, but abundant functional groups. Adsorption was strongly affected by the solution’s pH and ionic strength. As revealed in the kinetic study, equilibrium was rapidly established, requiring low activation energies; a removal rate of 30%–87% was achieved within 1 min. The maximum Langmuir adsorption capacities at 30°C exhibited the following order: GS (106 mg/g) > OP (92 mg/g) > CC (59 mg/g). Thermodynamic experiments suggested that the adsorption occurred spontaneously (−ΔG°) and exothermically (−ΔH°). The primary adsorption mechanisms involved electrostatic attraction, hydrogen bonding formations, and n-π interaction. Thermogravimetric analysis (TGA) revealed that three biopolymer components (i.e., hemicellulose, cellulose, and lignin)...

Optimal planning of large passive-harmonic-filters set at high voltage level

Abstract: This paper proposes the optimal planning of large passive-harmonic-filters set at high voltage level based on multi-type and multi-set of filters, from which the types, set numbers, capacities and the important parameters of filters are well determined to satisfy the requirements of harmonic filtering and power factor. Four types of filters, namely single-tuned filter, second-order, third-order and C-type damped filters are selected for the planning. Firstly, the characteristics of filters are analyzed. The cost function and the constraints of filters and system are constructed for formulating the optimization problem of the planning of filters. Secondly, the simulated-annealing (SA) algorithm for searching the optimal solution of planning of filters is developed. Finally, three cases of filter planning are presented to show that the superiority and availability of the SA algorithm and proposed planning results of filters.

Wavelet-based off-line handwritten signature verification

Abstract: In this paper, a wavelet-based off-line handwritten signature verification system is proposed The proposed system can automatically identify useful and common features which consistently exist within different signatures of the same person and, based on these features, verify whether a signature is a forgery or not The system starts with a closed-contour tracing algorithm The curvature data of the traced closed contours are decomposed into multiresolutional signals using wavelet transforms Then the zero-crossings corresponding to the curvature data are extracted as features for matching Moreover, a statistical measurement is devised to decide systematically which closed contours and their associated frequency data of a writer are most stable and discriminating Based on these data, the optimal threshold value which controls the accuracy of the feature extraction process is calculated The proposed approach can be applied to both on-line and off-line signature verification systems Experimental results show that the average success rates for English signatures and Chinese signatures are 9257% and 9368%, respectively