Advanced Materials Research Vol. 549

Abstract: Earthquake response of structure is determined by the vibration properties of earthquake and structure, it is very important for seismic design of storage tanks to accurately grasp the vibration characteristics of tank (frequency and mode shapes). In this paper, finite element model of exposure anchored 2000m3 tanks has been established by software ANSYS, calculating the first 3 order frequencies of liquid (0.247, 0.418, 0.517Hz) and frequencies of beam modes (6.087, 12.748, 21.77Hz), and comparing with the results of standard formula and the literature, both are in permissible error range. Vibration law of tanks has been analyzed, and it is proved that cosθ-type beam modes played a major role in seismic performance of tanks. These can be used as a reference for analysis and design of similar projects.

Abstract: Understanding the heat transfer among particles with uneven temperature distribution is a key to powder processing. In this work, the discrete element method (DEM) is used to optimize the interior structure of a particle mixer with multiple baffles to achieve better heat transfer between two particulate materials. The simulation results show that optimal values exist for the number of baffles and their widths, slope angles and spacing to enhance heat transfer. The results are helpful to the design of a variety of process such as the ultra-fast pyrolysis in “coal topping”.

Abstract: Reissner’s plate bending fracture theory with consideration of transverse shear deformation effects is adopted for the crack problem of functionally graded materials (FGMs) plates. Assume that the crack is perpendicular to the material property gradient. By applying the asymptotic expansion method, the crack-tip higher order asymptotic fields which are similar to Williams’ solutions of homogeneous materials are obtained.

Abstract: The mixing of dry solid particles is extremely important for pharmaceutical and chemical industries. Computer simulation is a convenient way to study the microscopic mixing process. In this paper, a GPU-based DEM software is tested in large-scale simulation of a tote blender by comparing with experiment data from literature and then employed to study the effects of operation conditions on the mixing rate. The results are in good agreement with experiments, confirming that the GPU-based DEM software is an effective and reliable tool for the study of micro-dynamics in particles mixing.

Abstract: This paper focuses on evaluation of the heat exchange process based on cumulative exergy analysis method. The case study chosen is the countercurrent heat exchange process that is widely used in the industrial processes. The optimal design is achieved by minimizing the annual total cumulative exergy consumption of the cold stream. The natural resource-oriented mathematical models are established in details. Obviously, the results from cumulative exergy optimization are imposed by the present state of the technology compared with the ones from thermoeconomics

Abstract: In view of the characteristics of the blasting tunneling roadway, the paper has analyzed the distribution law and the movement rule of dust in roadway. Combined with the practical problems existing in the field, a series of methods were conducted to investigate and analyze the the dust source of tunneling, the authors propose the following optimal comprehensive directional measures: At first, using the wet shotcrete technology as more as possible to improving the shotcrete. Taking use of the corresponding measures of spraying and watering, and the use of water stemming is mandatory. The amount of wind in the exit of the ventilation duct should be controlled and the quality of water should be improved, enhancing the atomization effect. The settled dust on the walls of the tunnel should be moistened with sticking agent and the individual safeguard should be done better. Adopting the above dustproof measures should effectively solve the problems of a large amount of dust and the working environment of high dust concentration in the heading face by blasting. The working environment can be improved by the effective control for the dust concentration in the heading face .The work of dust comprehensive prevention in the heading face is of significance.

Abstract: The gas is one of the most important factors which endanger the security of the mining production. Most of serious accidents are the gas explosion accidents in coal mine. By investigating the damage situations of the gas explosion accidents and the related material, finding out why these incidents happen is an important way to prevent or reduce the gas explosion accidents. Based on the occurred gas explosion accidents, the author use the FLUENT software to simulate the process of gas explosion and get the variation law of various air current parameters is obtained in gas explosion. The explosion causes and development course are discussed. Compared with the explosion parameters collected on scene of accident, it provides comprehensive scientific basis for the accident investigation. The conclusion is helpful to adopt suitable measures to prevent the gas explosion.

Abstract: The coal fly ashes are porous granular waste matters which were produced when the coal burned in power station. Through trial founding that if we modify coal fly ashes by inorganic, organic or physics means, it can increase porosity or surfactant, and enhance the adsorption. In addition, the extract of fly ashes can be synthesized coagulant, such as ploy-silicate alum ferric, when the coagulant apply to industry wastewater, the effect is good, so it is worth popularizing. As porous granular matter, it is a high quality media when used in biological aerated filter. At last we have some conclusions about the problems when using the fly ashes and its development trend in the future.

Abstract: With the continuous improvement of our environmental monitoring system, environmental monitoring laboratory has actually become the typical small pollution sources, which caused very prominent environmental pollutions. However, the pollution problems in the environmental monitoring laboratory are basically in the neglected state and without the standardized management. The paper analyzed the common polluted emissions and characteristics about the process of environmental monitoring in the laboratory. How to reduce laboratory contamination from the sampling, chemical analysis and monitoring processes was discussed. The main pollution problems were caused by the lack of laboratory environmental awareness and the laboratory contamination control at the expense. In conclusion, strengthen the environmental monitoring laboratory management and environmental education, recycling the laboratory waste, separating collection, and treating by different methods are the main ways to solve the pollutions in the Lab. The monitoring departments at all levels must improve its environmental quality in order to reduce the environmental pollutions and make efforts to avoid the pollution of the monitoring laboratory waste.

Abstract: The heavy metal elements analysis had been carried out for the limestone soils collected from Suzhou area, the degree of heavy metals pollution were evaluated by such methods as enrichment factor and geoaccumulation index, and the correlation and principal analysis of the testing results were studied based on SPSS. The results showed that the heavy metals of the samples can be subdivided into tow type: the Pb、Zn and Cr are below the first quality standard level, the Cu and As are between the first and second level of quality standard, the heavy metal element pollution degree were as follows: Cu>As>Cr>Zn>Pb>V. The V and Zr are controlled by the contamination of the detrital; the Pb, Sr and As are controlled by the source rock (limestone); the third factor contain the Zn, Cu and Al, which showed the effect by agriculture.