Abstract: Adsorption performance of aminated lignin (AmL) for nitrobenzene (NB) removal was investigated through batch experiments. The results showed that AmL possessed strong adsorption ability for NB with hydrogen bond interaction. The equilibrium adsorption data were well represented by the Freundlich isotherm model and the saturated adsorption capacity could reach 24.2mg/g. The adsorption process was found to follow pseudo-second-order kinetics. The maximum adsorption of NB on AmL occurred around the neutral pH.
Abstract: Trace organic micropollutants have adverse effects on human health and ecosystem at low concentrations. In this study, feasibility of new catalysts for oxidation of organic micropollutants was investigated. Iron tetrasulfophthalocyanine (FeTsPc) has been immobilized on the surface of functionalized MCF (mesocellular silica form)-NH2 and MCM-41 mesoporous silicas by means of chemical bonding to ammosilane groups. MCF, prepared by precipitation from a micellar solution, consisted of unit cells which had internal void (~20 nm) and pores (~11 nm). NH2-functional groups were added to the surface of MCF and MCM-41 using (3-aminopropyl)triethoxysilane (APTES). 1-ethyl-3-(3’dimethylaminopropyl)carbodiimide (WSC) was used as a coupling agent. N-hydroxysuccinimide (NHS) was added during the reaction to improve the efficiency of amination. The prepared materials, FeTsPc/NH2-MCF and FeTsPc/NH2-MCM-41, were characterized by UV-DRS (diffuse reflectance UV-vis spectroscopy) and FT-IR. Bisphenol-A (BPA) was chosen as a model micropollutant. The catalytic activities of the supported Fe-TsPc were examined by the oxidation of BPA in the presence of hydroperoxide. The amount of immobilized FeTsPc and the specific reactivity were also analyzed to provide quantitative evaluation of the catalysts. The results indicated that the FeTsPc/NH2-MCM-41 showed higher activity and durability in the liquid-phase oxidation of BPA under mild condition compared with the FeTsPc/NH2-MCF and unsupported catalyst.
Abstract: With respect to metal doping into TiO2, the doping limits for V, Cr, Zr, Nb, Mo, and W are predicted to be higher than other transition metals according to the binding energy calculations in a unit cell model of anatase TiO2, which suggests that Cr and W can be doped into anatase structure more easily than Ag or Pt, for example. Our investigation has twofold research objectives. One is to prepare metal-doped TiO2 nano-powders from these transition metals, and the other is to test photocatalytic activity of each resulting powder. For the former, sonochemical process has been used to produce Cr-doped, W-doped, Ag-doped, and Pt-doped TiO2 nanoparticles. For the latter, we have performed photocatalytic oxidation of methylene blue. The combined results of the morphology and photocatalytic activites have enabled characterization of the physicochemical properties of these transition metal-doped nanoparticles.
Abstract: In this work, ferric stearate, ferrocene and nickel N,N-dibuty dithiocarbamate (NiDBC) were utilized as photocatalyst for the decolorization of methylene blue (MB) aqueous solutions under sunlight irradiation. Pure MB solution was used as reference. Absorption intensities and surface morphology of these photocatalyst were investigated by Diffuse Reflectance Spectroscopy (DRS) and Scanning Electron Microscopy (SEM).The study indicated that ferric stearate had minimal promotion to the decolorization of MB aqueous solutions; and ferrocene exhibited better photocatalysis ability after had been irradiated 60 hours. In this study, NiDBC showed the best photocatalysis ability from the beginning. Furthermore, NiDBC enhanced the decolorization of MB after been irradiated for 31 hours. And after being irradiated 270 hours, the MB aqueous was completely decolorized by NiDBC.
Abstract: Full dense and highly pure TiAl/Ti2AlC in situ composites were successfully synthesized by reactive synthesis from the powder mixtures of Ti, Al and carbon black by hot-press-assisted reaction process. The reaction process, microstructure and bending strength of the TiAl/Ti2AlC in situ composites were investigated in detail. The results show that the as fabricated composites posses three phases, namely, TiAl, Ti3Al and Ti2AlC. The matrix phases are mainly equiaxed TiAl with a minor lamellar Ti3Al phase. Ti2AlC particles with size less than 1 μm are distributed uniformly in matrix grains as a reinforcing phase. When C content is 0.44 wt %, the flexural strength reaches 426.21 MPa, which is increased by 35 %.
Abstract: Relationship of the adsorption behaviors of phosphorus with several natural materials and artificial HAS-clay with various chemical compositions was investigated. The amounts of phosphorus adsorbed by them were closely related with the contents of aluminum in the material. It was found that the higher the aluminum contents of material, larger the amount of phosphorus were adsorbed.
Abstract: The separation of cobalt from zinc sulfate solutions by oxidation-precipitation process using peroxy-monosulfuric acid as oxidant has been presented according to the technological conditions of removal of cobalt from zinc electrolyte. After investigating the important parameters governing the separation of cobalt and their effect on the separation process, the optimal parameters of oxidation precipitation of cobalt were determined, the oxidation precipitation percent of cobalt was up to 90% under the conditions. The XRD analysis results of precipitates demonstrated that the precipitate was cobalt hydroxide oxide (CoOOH) in pure cobalt system while the precipitates were cobaltosic oxide (Co3O4) and basic zinc sulfate (ZnSO4(OH)6.H2O) in zinc-cobalt system.
Abstract: The purpose of present study was to increase productivity and to promote the quality of the part in the forming system for hinge strap in automobile. So the roller-bending simulation was carried out to develop the forming system for the hinge strap. A square tube used in the roller-bending for the hinge strap was fabricated using process of the sheet forming and the welding. So study on the mechanical properties of the original metal sheet (SPCC 1.6t) and weld-line (including a HAZ) were performed before the roller-bending simulation. And the body forces of the roller (rigid body) in the roller-bending process simulation were calculated to make an accurate estimate the capacity of the oil pressure cylinder for a pressure device. Then the roller-bending process was divided into 5 steps for the simulation for validating the effect of the bending velocity on the springback. At the end, the shape after springback was estimated. The result was adopted in the design for the bending die.
Abstract: In order to investigate the texture development in cold rolled and annealed tantalum (Ta), the present study was carried out. For this work, cold rolling was performed up to ~ 96% reduction in thickness, and annealing was performed at elevated temperature up to ~ 1200 °C for 60 min under the high vacuum to prevent the surface oxidation. As a result, increase in the reduction ratio of the cold rolled Ta was effective to develop the a fibre texture, with its texture components such as (001)<110> and (112)<110>. Also, resulting grain size was more refined by increase in reduction ratio, consequently, 96% cold rolled and annealed material showed the best refined grain size. However, in case of annealed material, g fibre texture with its texture component, such as (111)<121> and (111)<112>, was developed by increase in annealing temperature. In this study, we systematically discussed the texture development due to the increase in reduction ratio.
Abstract: Choosing the basis of 6-311++G (d. p) with chitosan as its model, we use the density functional B3LYP method to optimize the structure and calculate the energy for the chitosan and sulfate. We study the adsorption for the sulfate from different adsorption point (amidogen, hydroxide and carbon-ring) with or without the protonation of chitosan amidogen. Through a comparative analysis of the bond-lengths, bond-angles, charges and binding energies before and after the interaction of chitosan and sulfate, we find that the adsorption of chitosan for sulfate is mainly the adsorption of amidogen after protonation. The adsorption mode is the combination of sulfate with two amidogens after protonation.