Advanced Materials Research Vols. 201-203

Abstract: The objective of this work was to evaluate the effect of temperature, alcohol concentration, time, catalyzer dosage and liquor ratio on organic solvent pretreatment of wheat straw. Organic solvent pretreatment is an effective method to remove lignin and make cellulose and hemicellulose degrade. Through experiments and analysis, the parameters of pretreatment were optimized as temperature 185°C, alcohol concentration 55%, reaction time 60min, catalyzer dosage 1.0%, liquor ratio 1:6.

Abstract: MoB/CoCr, a novel material for thermal spraying, with high durability in molten alloys is used to resist erosion by molten Al-Si alloy in solar thermal power generation. The microstructure and phase component of coatings were characterized, and the coatings were also studied on bond strength and thermal shock resistance. The durability of the MoB/CoCr coatings prepared by low pressure plasma spraying (LPPS) has been investigated using a molten-metal immersion tester. The results showed that phase component of powder and coating had little change. The coatings have dense structure and excellent combination with substrate. The main constituents of coatings remain invariant and the coatings have excellent properties of bond strength and thermal shock resistance. The immersion tests revealed that the MoB/CoCr coating has much higher durability without dissolution in the molten Al-12.07wt.%Si alloy.

Abstract: CdS doped lead silicate glasses were prepared with the conventional fusion method. The effects of the ZnO/CdS ratio and the content of CdS on the preparation of CdS doped glasses were both studied. The crystallization process of CdS nanocrystals was investigated by X-ray diffractometry and scanning electron microscopy. Utilizing the Maker fringe method, Second harmonic generation (SHG) was observed from CdS doped glasses without any poling procedures. The SH intensity gets enhanced by increasing the heat-treatment temperature and prolonging the heat-treatment duration.

Abstract: To meet the standard requirements of dust emission for boiler and ensure the safety and normal operation of desulfurization equipment, bag dust filtering technologies have been used widely to deal with flue gas. Because of design defects and different running conditions, abnormal breakage may appear in the key parts of the bags, particularly some issues such as oxidation and acidic corrosion of the bags may happen in short-term application of electrostatic-bag precipitators. This paper elaborates the status of bag filters in coal-fired power plants, discusses some issues of bag filtering technology in design, manufacture and operation, and especially analyses the special problems of composite electrostatic-bag precipitators. Solutions are presented for extending the life of filtering bags.

Abstract: A kind of truss-work used in large-scale tower is introduced in this paper. According to this example, a method of optimization design using the optimum function of ANSYS, which is one of the finite element software, is searched and discussed.

Abstract: Activated alumina granules is a primary sorption media . The intention of this experiment is to get out of the difference between the different regenerate medias, caustic soda and alumina sulfate . Experimental result shows the renewal adsorption capacity of activated alumina using caustic soda regenerate is more than using aluminum sulfate .Under the same experiment condition ,aluminum sulfate can regain 13.27mg/g adsorption capacity while using 0.8 per cent caustic soda to regenerate alumina and 5.36mg/g using 4 per cent aluminum sulfate .The intensity of activated alumina granules reduces when we use caustic soda as regenerate media .The mass wastage of activated alumina granules is between 12% and 14% using caustic soda as regenerate media and between 6% and 8%uing aluminum sulfate .It is needed to neutralized by hydrochloric acid or aluminum sulfate after regenerated by caustic soda .Without neutralized, the concentration of treated water is over 1.0mg/l in the beginning.And neutralized with hydrochloric acid or aluminum sulfate, the efficacious run time can achieve 23 hours and 31hours .

Abstract: With the development of modern industry, silo diameters are bigger and bigger. Lateral pressure of bulk materials in silos is one important parameter for designing silos, which is related to the economy and safety of the structure. However, present calculation methods of the lateral pressure are mostly based on small diameter silos. For now, in the Chinese code the wall pressure computation methods are based on Rankine theory to be calculated. It is shown that the calculated results of Rankine theory may overestimate the pressure. In this paper, the lateral pressure of large diameter silos is studied. A new formula for calculating lateral static pressure on shallow silo wall is derived by static equilibrium method. The formula of this paper is simple of calculation and can be used for large diameter silos with a circular con top pile. The results agree with that of the full-sized silo experiment better than the current code.

Abstract: In this paper, the flow field of the diagonal flow fan is simulated by FLUENT. The flow field of the axial clearance, the guide vanes and the diffuser section are analyzed and evaluated thoroughly. It is confirmed that the main factors influencing the fan performance are the guide vanes, and the diffuser section. The results are useful in guiding the optimal design to improve the flow field of diagonal flow fan.

Abstract: This paper firstly gives a brief description about the principle of resistance-butt welding of nuclear fuel rod, and it points out that the power supply is a key technology for welding process. According to the welding process and the welded material properties, capacitor discharge power supply is devised as welding power supply. The design of charging circuit of single-phase bridge rectifier with SCR and control circuit is finished. The process of power discharge is simulated and the parameters (capacitance C, charging voltage u_c) are optimized with Matlab. By the welding experiments, it shows that the output current curve is suitable for resistance-butt welding of nuclear fuel rods, and the test results of welding samples entirely consistent with process requirements.

Abstract: With social progress and technological development, especially the applications of analysis of structural material ,structural system, and construction scheme ,high-rise buildings are becoming higher, lighter and more flexible.Therefore, the paper aims to make designs in accordance with requested comfort sensation, by providing practical measures.Judging standards adopted in this paper is top maximum acceleration, along with variation trend derived from analysing comfort sensation difference between cross-wind and along-wind acceleration.