Papers by Keyword: UV

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Authors: Ching Song Jwo, Chien Chih Chen, Ho Chang, Sih Li Chen, Chi Hsiang Lin
Abstract: This research carries out an inexpensive, rapid and novel exercise, which is applied to perform the photocatalyst decomposition effectiveness of Methanol and Ethanol in gaseous form. The major devices of this applicable measurement developed by this practice are only utilizing ultraviolet-visible spectrophotometer and quartz cuvette, and the experimental procedures are straightforward and speedy. In the conduct experiments, Methanol and Ethanol with a specific concentration is initially injected into an enclosed quartz cuvette. Then the cuvette is put in ultraviolet- visible spectrophotometer to measure the Methanol and Ethanol concentration, so as to obtain an unique UV absorbance spectrum at its particular concentration. In the conduct experiments of measuring photocatalyst decomposition efficiency, the self-made (SANSS) nanocatalyst TiO2 is initially coated in the quartz plate, and put into the quartz. Then a specific concentration of methanol alcohol and ethanol is injected into the quartz cuvette under the UV irradiation exposure, so as to carry out photodecomposition of Methanol and Ethanol experiment. After that, the cuvettes are then put into the ultraviolet-visible spectrophotometer for measuring the absorbance intensity of UV spectrums in order to produce degradation chart. The preliminary results point out that the self-made nanocatalyst TiO2 has exceptionally outstanding decomposition efficiency which further points out the fact that, when UV irradiation for 60minutes, the gaseous Methanol can be reduced to 3.8% of the original sample, and the gaseous Ethanol can be reduced to 6% of the original sample. But when exercising with commercial nanocatalyst TiO2 to undergo the same process exactly under the same circumstances, the residue gaseous concentration can only be reduced to 17% and 16% of the gaseous Methanol and Ethanol original sample.
Authors: Hua Feng Yu, Guang Ming Liu, Hong Huang
Abstract: Neutral red is mainly used to identify and detect the activated state of cells, which accumulates in the lysosomes of uninjured cells. In this paper the influence factors on microalgae of neutral red concentration, staining time, algal cell concentration and pH were studied, which revealed the optimized conditions. The maximum staining ratio occured after 8 min staining with 0.22 g•L-1 of neutral red at pH 7.3. The algal cell concentration had no obvious effect on staining ratio. The UV and UV/O3 process were also investigated for ballast water treatment using heterosigma akashiwo as an indicator. Compared with individual unit processes using UV, the inactivation efficiency of heterosigma akashiwo by the combined UV/O3 process was enhanced. The algae after treatment was unable to re-grow and it revealed that the algal activity assays can reflect the inactivation effect more correctly than cell density, which suggest the neutral red staining method has potential for viability detection of microalgae in ship’s ballast water.
Authors: Supphadate Sujinnapram, Sasimonton Moungsrijun
Abstract: SnO2-ZnO composite films were employed as photocatalytic degradation of organic dye. SnO2 and ZnO were mixed in polyethylene glycol solution with various weight ratios of SnO2. The composite paste was screened onto glass substrate with active area of 1 cm2 and annealed at 400 °C. The photocatalytic activity of composite films for the degradation of Eosin-Y dye was investigated under UV light irradiation. It was found that the normalized absorbance of dye solution decreased after treatment indicated that dye molecules were reduced. The composite films showed better degradation efficiency than conventional ZnO films due to reduced recombination encourage longer reaction time of electron and hole with surrounded environment. The optimized weight ratio of 30% showed the highest degradation rate constant and the lowest half lift.
Authors: Juan Yang, Xiao Yi Li, Fang Zhao, Xin Yu Chen, Ping Shao
Abstract: The solar blind NLOS ultraviolet Ad-hoc network communication bases on atmosphere scatter and absorption. An algorithm of channel sharing for the solar blind NLOS ultraviolet Ad-Hoc network is proposed to avoid conflict. The conflict nodes in the network are colorized based on the hybrid genetic algorithm, and then the network has a higher spatial reuse. The Simulation results show the algorithm of high-speed efficiency, thus having a better engineering practicability.
Authors: Zhe Wang, Wen Yu Zhao, Li Wei Xu, Qi Mu
Abstract: Effluent of aniline wastewater treatment from a company was isolated and fractionated by resin adsorption method into six different fractions. These fractions are operationally categorized as hydrophobic acids (HOA), hydrophobic bases (HOB), hydrophobic neutrals (HON), hydrophilic acids (HIA), hydrophilic bases (HIB) and hydrophilic neutrals (HIN). The dissolved organic carbon (DOC), ultraviolet-visible (UV) and genotoxicity of each fractions were determined. The results showed that hydrophobic matter is the main fractions of DOC and makes the main contributions to the genotoxicity of effluent of aniline wastewater treatment.
Authors: Zhong Liang Deng, Ming Yu Zhao
Abstract: The reasons of using low-pressure mercury lamp as transmitter light source are analyzed. The principle of how the resonant half-bridge switching circuit works is described, and how to use this circuit to achieve 2FSK modulation is discussed. The L6384 chip modulation circuit is briefly introduced. The response performance of low-pressure mercury lamp is tested under the conditions of gradually increasing the transmission rates. The new transmitter has a longer transfer distance but a slower response compared with LED transmitter system.
Authors: Sheng Wu Wang, Xiu Hua Shi, Hui Xu, Zhao Jing Tong
Abstract: Wavelet Analysis extracts the main feature from the fault signal through wavelet transformation, so it is advantageous to withdraw fault characteristic for fault diagnosis. Support Vector Machine (SVM) has shown its good classification performance in fault diagnosis. A new method of fault diagnosis for UV control system based on WAVELET-SVM is raised. The sensor output is sampled in frequency domain and it is preprocessed by wavelet to extract main vectors of the fault features. Fault patterns under various states are classified using multi-class SVM, and fault diagnosis is realized. The simulation results show that WAVELET-SVM is feasible to detect and locate faults quickly and exactly and has high robustness.
Authors: Necar Merah, Aziz Bazoune, Zafar Khan
Abstract: The effects of natural and artificial weathering on mechanical properties of Chlorinated Polyvinyl Chloride (CPVC) pipe material are investigated. Tensile specimens, prepared from locally manufactured CPVC commercial pipes (4-in Schedule 80) were exposed for periods ranging from 2 weeks to 18 months in the harsh weather conditions of Dhahran, Saudi Arabia. The accelerated artificial weathering was carried out in the Q- Sun Xe-3-HS Xenon Test Chambers for periods ranging from 100 to 3000 hours. Standard tensile tests were performed before and after exposure. The tensile test results show that natural and accelerated artificial weathering had limited effects on the tensile and fracture strengths and modulus of elasticity of the material. However, the deterioration of the fracture strain is noticeable for exposure periods as short as 15 days of natural exposure and 100 hours of artificial UV exposure. Visual analysis of exposed specimens revealed that both types of exposures resulted in the discoloration of the specimens.
Authors: Ying Wang, Xiang Xin Xue, Feng Guo Liu
Abstract: In this study, polyhedral oligomeric silsesquioxane (POSS) were blenged with epoxy acrylate (EA) and photoinitiator to prepare nanocomposites through UV-curing process. The vinyl-POSS nanoparticles were added to EA by physically blending at loadings between 0% and 15wt%. Through the FTIR analysis, we found that the POSS nanocomposites didn’t affect the extent of UV curing reactions; the curing reactions were performed to be completed in all POSS containing composites. The XRD analysis convinced the existing of phase separation between EA matrix and vinyl-POSS monomer. The impact resistance and coating adhesion were all enhanced by POSS nanocomposites at low content.
Authors: Young H. Yoon, Sook H. Nam, Jin Chul Joo, Ho Sang Ahn, Tae M. Hwang, Jae Ro Park
Abstract: This study presents the results of removal of Bacillus subtilis sp. and irradiated by UVA(3 μW/cm2) with three types of photo-catalysts (TiO2, ZnO, ZnO/laponite ball) to improve indoor air quality. The results showed that B. subtilis sp. was removed up to over 80% after 2 hours of reaction with all the photo-catalysts used and UVA irradiation. The B. subtilis sp. removal rate increased to more than 30 % when used both UVA and photo-catalysts, compared to that with only UVA control. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilization capacity to TiO2. Further study needs to figure out the optimum intensity of UVA and catalysts dosage to effectively disinfect and destroy the other microorganisms commonly found in indoor air environment.
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