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Taipei, Taiwan

Chen C.-Y.,Hsing Wu College
Water, Air, and Soil Pollution | Year: 2010

The oxidation of di-(2-ethylhexyl) phthalate (DEHP) in solution using UV/H2O2 and direct UV photolysis are analyzed in this study. It was found that DEHP was 100% removal in the solution by 180-min UV/H2O2 treatment and 73.5% removal by 180-min direct UV photolysis. The effect of different factors, such as DEHP concentration, H 2O2 concentration, and UV light intensity, on photochemical degradation was investigated. The degradation mechanism of DEHP and the acute toxicity of intermediates were also studied. The photochemical degradation process was found to follow pseudo-first-order kinetics. The results of our study suggested that the concentration with 40 mg/L H2O 2 and 5 μg/mL DEHP in the solution at pH 7 with 10.0 × 10-6 Einstein l-1 s-1 UV was the optimal condition for the photochemical degradation of DEHP. The photochemical degradation with UV/H2O2 can be an efficient method to remove DEHP in wastewater. © 2009 Springer Science+Business Media B.V.

Chen C.-Y.,Hsing Wu College | Wu L.-C.,China University of Science and Technology | Chen H.-Y.,China University of Science and Technology | Chung Y.-C.,China University of Science and Technology
Water, Air, and Soil Pollution | Year: 2010

Photocatalytic activity in titanium dioxide (TiO2) has been extensively studied because of its potential use in sterilization, sanitation, and remediation applications. The aim of the study reported here was to assess the feasibility of "fixed" TiO2 as the photocatalyst for inactivating pathogenic bacteria selected, Staphylococcus aureus and Escherichia coli, from a water stream. The investigation was undergone in a properly designed laboratory-scale evaluation. Using the system reported here, we obtained an effective bactericidal capability for E. coli and S. aureus with 90.0% and 98.0% after 30 and 10 min ultraviolet-A light irradiation with fixed TiO2, respectively. Parameters such as the various initial bacteria concentration, TiO2 concentrations, interruption of illumination, turbidity, and coexisted organic matters were examined to identify the removal efficiency in the photocatalytic reaction. Results indicated the negative effect by high bacteria concentration, coexisted organic matters, and turbidity on inactivation of bacteria, and positive effect on disinfection was associated with higher TiO2 concentration. Furthermore, our results indicated that under the same experimental conditions, the removal efficiency of the system in synthetic water was performed better than that of crude water. This inferior removal capability in crude water is mainly caused by the negative effect from the unknown coexisted factors. © 2010 Springer Science+Business Media B.V.

Sung Y.-T.,National Taiwan Normal University | Chang K.-E.,National Taiwan Normal University | Chang T.-H.,Taipei Municipal Jin Hua Junior High School | Yu W.-C.,Hsing Wu College
Journal of Adolescence | Year: 2010

Self- and peer assessments are becoming more popular in classrooms, but there are few data on the reliability and validity of such assessments performed by school children. Because these factors are greatly affected by the number of raters, we conducted two studies to determine the rating behaviours of teenagers in self- and peer assessments, and how the number of raters influences the reliability and validity of self- and peer assessments. The first study involved 116 seventh graders (the first grade of middle school), where students individually playing musical recorders were subject to self- and peer assessments. The second study involved 110 eighth graders, with Web pages constructed by students being subject to self- and peer assessments. Generalizability theory and criterion-related validity were used to obtain the reliability and validity coefficients of the self- and peer ratings. Analyses of variance were used to compare differences in self- and peer ratings between low- and high-achieving students. The coefficients of reliability and validity increased with the number of raters in both studies, reaching the acceptable levels of 0.80 and 0.70, respectively, with 3 or 4 raters in the first study (involving assessments of individual performance) and with 14-17 raters in the second study (involving assessments of group work). Furthermore, low- and high-achieving students tended to over- and underestimate the quality of their work in self-assessment, respectively. The discrepancy between the ratings of students and experts was higher in group-work assessments then in individual-work assessments. The results have both theoretical and practical implications for researchers and teachers. © 2009 The Association for Professionals in Services for Adolescents.

Huang W.-B.,National Dong Hwa University | Chen C.-Y.,Hsing Wu College
Water, Air, and Soil Pollution | Year: 2010

The degradation of diethyl phthalate (DEP) in aqueous solution by titanium dioxide (TiO2) photocatalysis has been investigated in our research. DEP was completely removed in the solution by 50-min irradiation. Results show that DEP degradation rate was affected by initial DEP concentration, photocatalyst amount, light intensity, and pH. Photocatalytic degradation intermediates were identified by gas chromatography-mass spectrometry intermediates were identified by gas chromatography-mass spectrometry. The major intermediates are methyl benzoate, ethyl benzoate, and carboxylic derivatives. The photocatalytic degradation process was found to obey first-order reaction. Consequently, the result of photocatalytic degradation could be an efficient method of DEP removal from wastewater. © 2009 Springer Science+Business Media B.V.

Yin M.-S.,Hsing Wu College | Tang H.W.V.,Ming Chuan University
Mathematical and Computer Modelling | Year: 2013

Motivated by the high probability of inconsistent and insufficient information from official statistics in China, this research paper conducted an out-of-sample forecasting competition between grey prediction and straightforward extrapolation for quantity and quality of laborers in China under the assumption that the performance of grey prediction is superior in dealing with uncertain and insufficient data inputs. In line with previous comparative studies on time-series forecasting techniques, the purpose of this study was to verify that the GM(1,1), GM(1,1) rolling and FGM(1,1) models derived from grey system theory would provide forecasts that are at least as accurate as the straightforward extrapolation approach for China's labor variables. The findings revealed that the forecasting efficiency of GM(1,1) and GM(1,1) rolling models were superior to straightforward extrapolation and FGM(1,1). The results can offer valuable insights and provide a basis for further research in model building for short-term estimation under the circumstances of data incompleteness or information inconsistency. © 2012 Elsevier Ltd.

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