Applied Mechanics and Materials Vols. 423-426

Abstract: Based on the hydrodynamic model and wind field data, a multi-module coupled oil spill model is constructed for simulating the trajectory of oil movement. A case study is researched in Bohai Bay. The model works well and the numerical simulation results show the model is suitable for oil spill trajectory simulation. Two cases are considered with and without wind to show its important influence for the oil spill.

Abstract: Research on rural-urban construction land expansion is on the macro perspective at home and abroad. However there is less research on detail characteristics and internal mutation of rural-urban construction land expansion, so that the accurate spatial distribution of rural-urban construction land may not be realized. In this paper, Tonglu County of Zhejiang Province is selected as study area. The spatial characteristic in micro level of rural-urban construction land is analyzed based on the spatial residual distribution of geographically weighted regression model. Residual of the model is used to describe the difference between actuality value and simulation value. Original residual of the model is standardized, which describes the hot spots and cold spots for development of rural-urban construction land. This research will support the micro decision-making of rural-urban construction land both in technology and decision, and guarantee the healthy development of rural-urban construction land with rational distribution.

Abstract: Conventional process-based rainfall-runoff models are difficult to catch the non-linear factors and to take full advantages of previous information of rainfall and runoff. However, these factors are closely related to the initial watershed average saturation deficit at each time step. Therefore, in order to address the issue, this study selected the parameter about initial underground flow in TOPMODEL (TOPOgraphic driven Model) as the breakthrough point. Then we used the previous two-day observed runoff and rainfall data as the inputs of an artificial neural network (ANN) and initial subsurface flow of present day as an output, then integrated ANN into runoff generation module in TOPMODEL and finally applied the integrated model for daily runoff modeling in Yingluoxia watershed with 10009km², China. In addition, this work also utilized particle swarm optimization technique (PSO) to avoid the local optimization, especially for the integration of black-box and physical models. The result shows that during the validation period the Nash-Sutcliffe efficiency coefficient (NE) and root mean square error (RMSE) of TOPMODEL are 0.45 and 3.88×10^-4m respectively while the NE of 0.70 and RMSE of 2.85×10^-4m for the integrated model. Significantly, the integrated model performs much better than the traditional model. Hence, this new method of integrating ANN with the runoff generation module of TOPMODEL is promising and easily extended to other process-based rainfall-runoff models as well.

Abstract: A fractal model simulate the internal structure of the sludge, and on the model deduce that fractal dimension is D and the corresponding pore is r, the porosity is P. Determine the rate in the air-blast and microwave drying and calculate its different fractal dimension under different ages. The results showed that: the fractal dimension and its rate of water loss has a good correlation. Fractal dimension can describe a certain amount of sludge pore channels and internal cell rupture can cause that which would accelerate the evaporation of bound water. Microwave and the excessive energy of air-blast can be caused by temperature changes in the structure of the sludge that could change the structure of sludge.

Abstract: Sodium calcium borate glass derived hydroxyapatite (G-HAP) scaffolds were prepared by dipping with polymer foam. The effects of adsorption time and G-HAP scaffolds dosage on adsorption performance were studied. The results showed that G-HAP scaffolds could remove fluorine ions in solution effectively. The mechanism of G-HAP scaffolds in removing fluorine ions from aqueous solutions was investigated by the X-ray diffraction, Infrared Spectra and Scanning electron microscopy-Energy Dispersive Spectrometer.

Abstract: This study aims at discussing the applicability of modified TOPMODEL in different areas with various climate conditions in China, choosing the Youshuijie catchment (the humid zone) and the Yingluoxia catchment (the arid zone) . Hydro-meteorological data and 90-m-resolution DEMs are used for driving the models. From the Nash-Sutcliffe efficiency coefficient (NE), we can see that TOPMODEL performed much better in the Youshujie catchment than in the Yingluoxia catchment, which suggests that modified TOPMODEL is much more suitable in the humid zone.

Abstract: Chemical speciation of brine and groundwater is examined to assess the distribution of chemical stability and behaviors of their solutions. Brine and groundwater are randomly collected from Ban Muang and Wanon Niwat District, Sakon Nakhon province. Hydrochemical parameters and also chemical compositions of their major ions are examined to evaluate the hydrochemical facies. Brine is generally indicated the Na-Cl type. For major cations, groundwater expresses mainly the sodium and calcium ions. However, brine presents dominantly sodium and potassium ions. Major anions of groundwater display principally the bicarbonate and chloride, but brine shows primarily the chloride and sulphate. The salinity zone of sodium chloride is confined only in the small area. The influence of rock salts in some areas is concerned. Relationship of Na+ and Cl-proves the stoichiometric balance of them. Chemical phases from the saturation indices consist of anhydrite, calcite, dolomite and gypsum, which found most in every sample. Generally, saturation condition of groundwater indicates the under saturation. Besides, saturation indices (SI) of brine state the super saturation for anhydrite. The anhydrite saturation index is obviously presented the supersaturated condition when the total dissolved solids (TDS) are greater than 250,000 mg/L.

Abstract: Establish the mechanical model of wire knot which was formed by the automatic bundling machine, and the model is simulated by ANSYS. The method can simulate testing and evaluation the strapping characteristics, thus can provide the support to design and use bundling machine properly as well as improve the strapping quality of automatic bundling machine.

Abstract: This paper carried out temperature analysis in the working state of the electron gun structure, the thermal deformation under high temperature and thermal stress analysis. Firstly, from the steady state temperature cloud chart of the electron gun we can see the cathode temperature is 985 °C, shadow grid temperature is same as cathode temperature, and the controlled-grid temperature is as high as 540 °C. Secondly, on the basis of thermal analysis, the coupled thermo-mechanical simulation technology is broken through; further thermal stress and thermal deformation at high temperature are analyzed. Thermal stress analysis results show that the maximum stress point is at contact area of cathode and its supporting tube. And the thermal deformation result shows that at high temperature under the action of thermal deformation, the axial distance of cathode-grid distance reduced 0.078 mm. Based on thermal deformation, the development personnel of microwave tube can use simulator to analysis the influence of thermal deformation to the electron gun design parameters, which can provide theoretical basis for tube design.

Abstract: Tapered interference fits, which can transfer large torques, are widely used in the connection design for propeller hubs and shafts of large vessels. In this paper, a model was developed to study the influences of torques, rotational speeds and tapers on the tapered interference fit between a propeller hub and a shaft. Using the classic elastic plane stress theory, the exact solutions of the radial stresses, tangential stresses and radial displacements of the propeller hub and shaft are derived. Then the calculation method of the magnitude of the tapered interference fit was presented. Finally taking a screw propeller system as an example, the above solutions were calculated using the numerical method. The results show that improving the stress distribution of the propeller hub is an effective approach to increase the connection strength and torque transmission capacity. If the rotation speed has to be considered, the stress and displacement would be increased significantly due to the centrifugal force. The present analytical solutions are expected to be useful in the structure design of tapered interference fits for propeller hubs and shafts.