Advanced Materials Research Vols. 538-541

Abstract: By Using Two Different Kinds of the Graphite Particles 80 Mesh and 325 Mesh on the Whole Water-blown Rigid Polyurethane Foam, its Properties Will Be Modified and Improved. the Result Shows that both of them Can Improve the Compressive Strength of Matrix when the Graphite Content Is Low. the 80 Mesh Graphite Destroys the Pore Structure of the Matrix, Resulting in the Increase of the Thermal Conductivity. in Addition, the Tensile Properties Are Reduced. in Contrast, the 325 Mesh Graphite Reduces the Thermal Conductivity of the Matrix, and the Tensile Properties Get Improved. Meanwhile, the Thermal Stability Enhancement of 325 Mesh Graphite Is Better than 80 Mesh Graphite.

Abstract: One of the major current challenges to the chemical industry is the efficient use of renewable lignocellulosic biomass for the production of performance materials, platform chemicals, and biofuels. Dissolution of natural polymers including cellulose in ionic liquids has attracted much more attention around all over the world. However, the time for complete dissolution of cellulose in ionic liquids was too long for processing and derivatization to produce industrial materials. Herein, ethanol pretreatment was introduced to improve cellulose dissolution in ionic liquids. The pretreated cellulose was easily wetted and penetrated for dissolution in ionic liquids, which efficiently avoided the formation of the agglomerates of cellulose mixed with air wrapped with viscous ionic liquids. The dissolution time of pretreated cellulose could decrease to 75 min under the given conditions. FT-IR and CP/MAS 13C-NMR analyses indicated that ethanol pretreatment and dissolution in ionic liquid did not lead to any functionalization of cellulose. It was also found that the crystalline structure of native cellulose was destroyed and the regenerated cellulose was mainly composed of amorphous structure. The thermal stability of cellulose decreased and the pyrolysis residues increased after dissolution and regeneration.

Abstract: In the presence of glucose oxidase, glucose in samples was oxygenated to hydrogen peroxide, the solution turned from colourless to yellow upon the reaction of potassium titanyl oxalate to the generated hydrogen peroxide. Using ultraviolet spectrophotometry, a new optical method for detecting glucose in amylofermentation liquid has been established. Results demonstrated that glucose concentrations were proportional to absorbance at the maximum absorption wavelength of 380 nm. A favorable linearity was presented in the range of 1 mmol/L to 60 mmol/L. The linear coeffciency was 0.993. This method was simple, reliable, and could be used for determing glucose in samples.

Abstract: Zinc acetate and Zn-oxo complex of Zn4O(CH3COO)6 containing in the spent catalyst of vinyl synthesis were investigated by means of the first principles of density functional (DFT) methods. The geometries, energies, charge populations and local electron density distributions of the two compounds and their formate analogues were analyzed. Based on the pyrolysis characteristics of the spent catalyst, the thermodynamic properties of ΔG, ΔH and ΔS for possible decomposition reactions of zinc acetate and Zn4O(CH3COO)6 were calculated as functions of temperature. The results provide a theoretical evidence that Zn4O(CH3COO)6 is more stable than zinc acetate due to the regular Zn4O and ZnO4 tetrahedral coordination between Zn atoms and two kinds of O atoms. The preparation of Zn4O(CH3COO)6 via the hydrolysis of zinc acetate is thermodynamically feasible. Zn4O(CH3COO)6 is further decomposed into ZnO via a decarboxylation reaction rather than a hydrolysis reaction.

Abstract: The influence of equiaxed crystal movements in a superheated environment on the melt kinetics of the equiaxed crystals was experimentally investigated by observation of the settling and melting behaviors of NH4Cl equiaxed crystals in its aqueous solution. The experimental set-up composed of the settling tubes, water bath and video capture device, where NH4Cl equiaxed crystals were acquired in a cooling zone and then introduced into the superheated settling tubes filling with NH4Cl-H2O model alloy, and the morphologies of the equiaxed crystals were video captured for further analysis. Two kinds of morphology evolution have been observed, and the difference was related with typical spinning movements of the equiaxed crystals during their sedimentation. Changes of the length of six primary dendrite arms have been measured; the results were compared with the calculated melting rate for equiaxed crystals without any convection. It has been shown that the convection induced by the sedimentation imposes a strong influence on the melting kinetics of the equiaxed crystals.

Abstract: The oxidization of hydrolyzates of manganese sulfate had been investigated in ammoniacal solution. The results show that hydrolyzates of manganese sulfate are oxidized slowly by air, furthermore, their oxidization rate less depends on temperature and acidity in the ranges of their respective certain values, but the oxidization rate for hydrolyzates of manganese sulfate can be increased significantly by adding some additives, activatiing hydrolyzates or changing molecular structure of hydrolyzates.

Abstract: The liquefaction properties of silt soil which were drilled and sampled from engineering site of Tangshan area in China, were studied and analyzed by DDS-70 computer-controlled Dynamic Triaxial apparatus in this paper. And by recording the curves of dynamic stress and vibration numbers, the resisted liquefaction intensity of saturated silts were analyzed. And the enumerated experimental results of several kinds of soils can apply and guide the engineering practice in Tangshan Area.

Abstract: This paper discusses combustion and emissions of internal combustion engine when oxygen-enriched combustion air and nitrogen-enriched combustion air are used. Nitrogen-enriched combustion can reduce the formation of NOx by inhibiting the combustion temperature in cylinder. Engine combustion is mainly subject to components of oxygen and nitrogen in the intake, the former combustion and the latter flame retardant. So we can control the two components during combustion process to re-engineering their component in the intake to the implementation control the combustion and emissions.

Abstract: Throughout the world, there are numerous of studies on quartz crystal microbalance (QCM). Today, we come up with a new way to reduce both the size of QCM structure and the crystal impedance without lowering the sensitivity. Beyond the conventional design of QCM originally developed in recent years, a new disk shape with multi-groove structures is proposed and investigated thoroughly to realize the miniaturized QCM. Along the miniaturization stage, there are two main approaches to remain the efficiency of vibration. One is to improve the piezoelectric effect which can be further increased by reducing the distance of electric field and the other is to improve the effective area of electric potential flow between the electrodes. Several proposed design with grooves in the disk has been proposed to make effective area larger, crystal impedance lower ,and Q value higher. We will investigate between different groove structures on QCM under the same bias voltage. In this study, we propose and verify the innovative design of QCM and a thorough investigation of the electric and mechanical response were performed with evidence marvelous efficiency. Consequently, the three groove structure gives the best piezoelectric performance than the other.

Abstract: According to extensive literature research, we introduce and summarize both physical, chemical properties, main hazards of phenol and the recent phenol water pollutions. We get the problem that it’s hardly to meet the standard and ensure the safety of water supply because of the low removal ratio in the process of water treatment when the water source is polluted by sporadic phenol pollution. After we analyze and compare the removal technology in polluted water and potable water respectively, we know the removal ratio of polymeric aluminum chloride-powdered activated carbon and permanganate potassium- activated carbon is significantly higher than activated carbon only, but the output water couldn’t reach the standard when facing high concentration phenol pollution (500μg/L). The biological technologies and membrane methods used in waste water treatment are introducing into the potable water treatment.