Browsing by Author "Chang, SM"

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Concentration and fate of persistent organochlorine pesticides in estuarine sediments using headspace solid-phase microextraction
(2006-03-01)
Chang, SM
;
Doong, RA
;
環境工程研究所
;
Institute of Environmental Engineering
The concentration and fate of persistent organochlorine pesticides (OCPs) in estuarine surface sediments in Erh-jen and Lan-yang rivers, Taiwan were investigated using headspace solid-phase microextraction (HSSPME) method to evaluate the possible pollution potential and guideline for OCP concentrations in Taiwan. The HSSPME method exhibits a good analytical performance with low detection limits for OCP determination in sediment. In addition, results obtained using the developed HSSPME method were in good agreement with those obtained using Soxhlet extraction in a certified sample. The developed analytical method was further applied to the determination of concentrations of OCP residues in surface sediments from the estuaries of the selected rivers in Taiwan. A total of 20 surface sediments from each river was collected from 10 sampling stations. The total OCP concentrations in sediments from Erh-jen River ranged from 0.17 to 5.04 ng/g-dw with the mean values of 0.25-1.24 ng/g-dw for HCHs, 0.10-0.89 ng/g-dw for cyclodienes and 0.16-0.64 ng/g-dw for DDTs. The concentrations of OCPs in sediments from Lan-yang River were in the range 0.37-0.9 ng/g-dw with an average of lower than 0.5 ng/g-dw. HCHs and DDTs were abundant in the estuarine sediments from the selected rivers. Results obtained in this study show that the origin of OCPs in the surface sediments from Erh-jen River is a combination of erosion of the weathered soils and long-range atmospheric transport, while the OCP concentrations found in Lan-yang River could be regarded as the background levels of OCPs in Taiwan. (c) 2005 Elsevier Ltd. All rights reserved.
Efficient white light emission in conjugated polymer homojunctions
(2004-11-15)
Ho, GK
;
Meng, HF
;
Lin, SC
;
Horng, SF
;
Hsu, CS
We study polymer light-emitting diodes with a homojunction, i.e., junction between two layers with the same host material. One layer is poly (9,9-dioctylfluorene-2,7-diyl) (PFO) host blended with a small amount of poly (2-methoxy-5 (2'-ethyl-hexyloxy)-1,4-phenylene vinylene), another layer is either pure PFO or PFO host blended with green-emitting polyfluorene copolymers. Such homojunction devices are solution processed and show efficient white light emission. The peak luminance 3000 cd/m(2) is reached at 10 V with Internationale de L'Eclairage (CIE) coordinate (0.34, 0.34). (C) 2004 American Institute of Physics.
Exposure assessment of organic solvents for aircraft paint stripping and spraying workers
(2006-03-01)
Uang, SN
;
Shih, TS
;
Chang, CH
;
Chang, SM
;
Tsai, CJ
The main objective of this study is to investigate the personal or area exposure of organic solvents during paint stripping and paint spraying. Three aircraft paint stripping/spraying workplaces in Taiwan were selected, and the Council of Labor Affairs and NIOSH recommended sampling/analytical methods used in this study. Activated charcoal tubes were used to investigate the personal and area exposure concentration of organic solvents in paint stripping and paint spraying operations. During aircraft paint stripping, experiment results show that methylene chloride personal exposure concentration at the ground area, 42.01 +/- 31.86 ppm, is higher than that at the working platform 4 M high above the ground, 20.41 +/- 11.43 ppm. Exposure concentration of methylene chloride in the initial paint stripping operation stage of every workplace is over the PEL (50 ppm) set by the Taiwan Council of Labor Affairs. Corrective actions are needed. During paint spraying, concentrations of all organic solvents were found to be below the PEL of OSHA. (c) 2005 Elsevier B.V. All rights reserved.
Mismatch analysis of TAB-on-Glass connection with ACF
(2000)
Hou, WF
;
Kam, TY
;
Hsieh, A
;
Chen, JC
;
Chang, SM
Mismatch between outer lead bonds (OLBs) of a tape automated bonding (TAB) and a glass panel during fabrication is studied using the finite element method. A two-dimensional finite element model for the TAB-on Glass (TOG) connector is presented for determining the deformation of the connector. The deformation of the TOG connector induced by residual thermal stresses are determined via a two-stage approach. At the first stage, the TOG connector is under heat and pressure. The anisotropic conductive film (ACF) in-between the TAB and glass panel is assumed to be in a melting condition so that both TAB and glass panel can expand freely. At the second stage, the connector is cooled down to room temperature and the ACF becomes solidified. The deformations of the connector at the two stages are determined in the finite element analysis in which the temperature dependence of material properties is considered. Effects of particular parameters on the mismatch between the OLBs are studied by means of a number of numerical examples. A method for compensation design of the lead locations of the OLBs is proposed. It has been shown that the compensation design can produce results that will avoid the occurrence of unwanted mismatch.
One-polymer active pixel
(2004-01-26)
Tzeng, KL
;
Meng, HF
;
Tzeng, MF
;
Chen, YS
;
Liu, CH
A metal-oxide field-effect transistor (MOSFET) based on an electroluminescent conjugated polymer is fabricated on a glass substrate. It is found that the mobility horizontal to the substrate is two to three orders of magnitude larger than the mobility vertical to the substrate. The high horizontal mobility is attributed to the in-plane chain alignment in amorphous spin-coated films. We demonstrate an active pixel in which the light-emitting diode and the driving MOSFET share the same active polymer. (C) 2004 American Institute of Physics.
Robust control design of front-wheel-steering system by LMI approach
(2004)
Wu, BF
;
Chang, SM
;
Perng, JW
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents an application of H-infinity robust control theory to a Front-Wheel-Steering (FWS) mechanical model (complex model) substituted for the linearized dynamics model. The input signal of the structure can be determined by a given steering angle, and then a Linear Matrix Inequality (LMI) based on H, method is proposed to solve the uncertainty problem under the conditions of the mass and velocity. Finally the simulation results show that the remainder velocities and masses are located inside the assignment boundary.
Strong red emission in heterojunctions of conjugated polymer blends
(2004-06-14)
Li, ZL
;
Meng, HF
;
Horng, SF
;
Hsu, CS
;
Chen, LC
We demonstrate strong red electroluminescence in bilayer polymer light-emitting diodes with poly(3-hexylthiophene) and polyfluorene copolymers. The emission spectrum of the diode, peaked at 612 nm, is different from either of the two polymer layers, and is attributed to the exciplex state existing only at the heterojunction. The efficiency of this junction emission is very high for red polymer light-emitting diodes. Peak luminance of 3500 cd/m(2) with yield 1.3 cd/A is achieved. The emission color can be made more saturated by blending red-emitting polymers into the polyfluorene to eliminate the small residual green emission. (C) 2004 American Institute of Physics.