Advanced Materials Research Vol. 629

Abstract: For improving contact strength of the thick-walled cellular solid with irregular pores structures, which is used in high temperature self-compensating lubricating environment, a concept of relative porosity ratio αi was proposed to describe the proportion of the porosity φi of the each shape pores in the materials to the total porosity φ of the materials. The results show that the characteristic value of αi, the distribute radius and regularity as well as the orientation of pores affected the contact strength strongly. The cracks phenomenon of the materials was also observed by experiments.

Abstract: In this work some theoretical aspects of constitutive equations for thixotropic fluids and restrictions on their functional forms are formally discussed. In the current study a formal emphasis has been given to the structural nature of this substances. The behavior of thixotropic fluids is analyzed in terms of simple isothermal laminar shear flow.

Abstract: Bianchi type I bulk viscous fluid tilted cosmological model filled with disordered radiation and heat conduction is investigated. We assume that (constant), where is the coefficient of bulk viscosity and  is the expansion in the model. Here, we assume a linear relation between shear and expansion i.e. =constant, which leads to A=BC, where A, B, C are metric potentials. The physical and geometrical aspects of the model in the presence and absence of bulk viscosity are also discussed.

Abstract: We consider a second order two scale (SOTS) approximate solution to the 3-D small periodic configuration composite plate. Classical two scale approximation yields a O( ) error in whole domain. We construct here a second-order mixed boundary layers corrections for the rectangle composite plate. Based on the boundary layers correctors, we prove that the optimal convergence order of the approximate solution to composite plate is O( ) in H1-norm. The numerical results for predicting the elastic parameters and the displacement and strains to composite plate made of 3-D 4-direction braided materials are demonstrated. Those show that the two scale approximation solution can capture the macroscopic phenomena caused from 3-D microcosmic configuration well.

Abstract: An improved wide-band analysis which combines the hybrid method of moments-physical optics (MoM-PO) formula with impedance matrix interpolation technique for antennas around large platforms is presented. The algorithm proposed in this paper interpolated the mutual impedance matrix between MoM and PO regions rather than the MoM self-matrix. This practice can result in more accurate frequency response than the conventional approach. Sample numerical results demonstrate the capability of the algorithm.

Abstract: Three main obstacles in modeling electrostatic torsional micromirror are hard to calculate – damping coefficient, mechanical spring constant and electrostatic torsion accurately. Because that parameter variations and model uncertainty of the torsional micromirror resulting from fabrication imperfections are inevitable, it is another problem to seek a control scheme for achieving accurate positioning and trajectory tracking of an electrostatic torsional micromirror. In this paper, aimed at a real prototype of circular electrostatic torsional micromirrorr, both static and dynamic behaviors are modeled and studied. A novel nonlinear Proportional, Integral and Derivative (PID) control are proposed in succession. Simulation results show that the system model derived is more accurate to the micromirror and the nonlinear PID can eliminate the static deviation.

Abstract: Animal facilities produce large amounts of harmful gases, and many of them have a pungent odor such as ammonia, hydrogen sulfide and other malodorous gases. The malodorous gases generated by animal house not only affect the health of people and livestock but also pollute the air. The detection of the malodorous gases can effectively improve efficiency of livestock production and reduce environmental pollution. More and more gas detection method is applied to the detection of the malodorous gases generated by animal house. This paper summarizes contact sensors for monitoring of malodorous gases in animal house recently, including semiconductor sensors electrochemical sensors and electronic nose. The basic principle and the characteristics of these methods were illustrated and the applications on the detection of malodorous gases in animal house were described. Meanwhile, the researches of malodorous gases monitoring for livestock production applied contact sensors were listed. The status quo and future development of the contact sensors for malodorous gases generated by animal house were summarized.

Abstract: This article analyzes the methods for project supervision in the geological prospecting industry at present, and proposes an embedded supervisal system of geological prospecting designed with the mobile terminals as an assistant supervisal measure, to increase the efficiency of project supervision. Supervisal indicators are categorized and studied, and an indicator system for the geological prospecting is introduced. The method for implementing AMF protocol based system is presented to solve huge data filling in the field.

Abstract: In this article, Using the latest Visual studio.net 2005 supplied C # serial class implements PC and single-chip microcomputer of serial communication. Summarizes the card the integrated function of the integrated management system, and probes into how to use C# serial kind of design for serial communication program, through the C# serial class in one card the specific application of integrated management system, and analyzes the application of C# serial kind characteristics, proved the C# serial class can make serial communication program design flexibility, can improve the reliability of the data in the serial port transmission. The actual operation shows that this kind of programming method is stable, reliable and practical.

Abstract: An ultrasonic power for rotary machining is introduced based on ARM. Its frequency tracking principle is analyzed. The improved accurate frequency tracking method using a phase lock loops (PLL) is presented. The control circuit based on ARM is designed and the presentation of system program flow chart is given. The experimental result proved that the ultrasonic power system can realize quick and accurate frequency tracking. Ihe power can work well with constant amplitude control.