Abstract: A mixture of TiO2 and HZSM-5 zeolite was used for photocatalytic degradation of an azo dye, C.I. Reactive Red 2(RR2). The adsorption of RR2 on TiO2 and the effect of TiO2 concentration were studied. HZSM-5 addition was also investigated to ascertain the function of the zeolite on RR2 decoloration. The results show that, the azo dye is quite stable under exposure of UV-C light. Less than 1.7% of the dye was adsorbed on TiO2 surface and 20 min was needed to reach dye adsorption equilibrium. The optimum TiO2 concentration was 320 mg/l. RR2 adsorption rate increased to more than 40% when HZSM-5 addition amount increased to 0.6 g in the solution. The total decoloration rate increased with the addition of HZSM-5 although zeolite addition could not enhance photocatalytic activity of TiO2.
Abstract: Mechanical vibration was introduced into the solidification in order to overcome the defects of coarse microstructure and low mechanical properties of the AZ91D magnesium alloy via lost foam casting（LFC）. The microstructure with fine uniform dendrite grains were achieved with mechanical vibration, which was mainly attributed to the cavitation and the melts flow induced by the mechanical vibration. The mechanical vibration has strong influence on the mechanical properties of AZ91D alloy. With application of mechanical vibration, the ultimate tensile strength and elongation of the AZ91D alloy increase 23% and 26%, resepectively.
Abstract: For dynamic process planning under reconfigurable manufacturing system (RMS), the method of process planning based on similarity theory was presented. Part feature description was built as well as case index structure. Procedure combination principia suited for reconfigurable machine tool (RMT) and sort rule based on relation among features were given. Similarity process information was created by comparability judgment of part feature multiple-tree, procedure was combined by the agglomerative hierarchical clustering method, and every working-step was sorted in procedure group. Moreover, the process planning system was developed with Visual C++ and verified through example test.
Abstract: Porous TiO2 films and smooth TiO2 films were fabricated by sol-gel dip-coating technique using titanium plate as support substrate. Photoelectrocatalytic (PEC) degradation of methyl orange was investigated in aqueous NaCl solution using the TiO2 films. PEC degradation efficiencies showed strong dependence on the concentrations of aqueous NaCl solutions and applied potentials. Photoelectrocatalytic activity of the porous TiO2 film was higher than that of the smooth TiO2 film at lower applied potential. 95.2% decolorization of the dye could be achieved in 50 minutes at applied potential of 0.6 V in 0.05 M NaCl solution on porous TiO2 films, while the efficiency was only 79.9% on smooth TiO2 films. Electrodegradation (ED) of these two film electrodes almost had no effect on methyl orange. Photocatalytic oxidation (PCO) degradation was 36.4% for the porous TiO2 thin film after 80 min, and 32.6% for the smooth TiO2 thin film during the same condition.
Abstract: A composite of TiO2 and HZSM-5 zeolite was used for photocatalytic degradation of C.I. Reactive Red 2(RR2). With TiO2 concentration of 320 mg/l, the optimum composite was composed of TiO2 and HZSM-5 by the weight ratio of 1:10. The composite showed higher activity than the P25 powder in calcination temperature range from 400 to 600 oC and 450 oC can be the optimum calcination temperature. When irradiation time was 40 min, the composite degraded 96.8% of the initial RR2. 94.9% of the dye was degraded in 70 min using pure TiO2. The RR2 degradation rate increased constantly with increasing composite photocatalyst concentration up to 320 mg/l. The activity of the composite grinded without ethanol was less than that of the composite photocatalyst grinded with ethanol.
Abstract: The purpose of this research is to study the manufacturing of biocompatible implant component by using rapid prototyping technology, in particular of 3D printing process. The biocompatible material consist of 80% cobalt-chromium-HAP were prepared by mechanically blended with 10% maltodextrin and 10% polyvinyl alcohol as binding mechanism for 3D printing process. Test specimens were fabricated using experimental 3D printing machine followed by sintering process. The characteristic of the composites were studied using various techniques including Scanning Electron Microscope (SEM and EDS), hardness test, flexural test, porosity and density measurement. The results show that the biocompatible cobalt implant composite can be fabricated successfully using 3D printing process. Further investigation can be carried out on the samples to study the toxicity, chemical reaction and cell reaction for implant application.
Abstract: Based on the experiments, the effect of waste gypsum on the formation of paste structure, the early strength and the stability of lime-fly ash is discussed in the article. As is shown by the results, the early strength of paste was improved by adding waste gypsum into lime-fly ash. The stability of lime-fly ash paste modified by waste gypsum could meet technical requirements when waste gypsum admixture was less than 40%. With the increase of hydration age, the number of ettringite (AFt) and C-S-H gel in paste would increase.
Abstract: This study evaluated the performance of a photoreactor packed with TiO2/Quartz and ZrO2/Quartz, ZnO/Quartz, initiated by UV irradiation. The experimental results showed that the concentration of VOCs increased and the degration efficiency decreased at the same residence time. Additionally, as the residence time increased, degration efficiency increased. According to the Langmuir-Hinshelwood Model’s predicted results, the reaction rate constant (kc) was 50.1, 7.2, and 3.0 ppm min-1 for TiO2/Quartz, ZrO2/Quartz and ZnO/Quartz, respectively. In contrast, the adsorption equilibrium constant (K) was 10.0, 21.9, and 2.4 ppm-1 with the previous catalyst, individually.
Abstract: A new method of Differential Mobility Analyzer (DMA) operation using a Fast Scanning Differential Mobility Analyzer (FDMA) nanometer particle sizer has been implemented. By optimizing the flow and voltage ramps, improvements can be made in the FDMA's measurement size range, counting statistics and resolution. In this study, an electrostatic classifier was used to generate mono-dispersed particles of different sizes to calibrate the delay time of the FDMA. The aerosol from incense combustion could be measured directly by FDMA although the particulate concentration was as high as 1,011 particles cm-3. The resolution of the FDMA was 3 nm and better than the SMPS (10nm).