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It was shown that the surface engineering and modification of surface chemical properties by various surface passivation treatments, deposition of hydrophobic coatings and lubrication with low surface energy self-assembled monolayers are effective methods for enhancing the fabrication and tribological performance of MEMS, but it was not concern with the effect of electrostatic tangential force in the MEMS devices.
Because of the surface falling charge, any surface can produce charge and then produce the electrostatic field and form a resistance to prevent the move between two parallel and charged flat mechanical elements.
These bumps would affect electrostatic field between two parallel plates, and lead to the capacitance and electrostatic resistance to change.
The factors of the applied voltage, the rate of all micro bumps projective area to the moving plate area, and the relative surface roughness are primarily considered to examine the electrostatic resistance between two charged moving elements.
Hou: Chinese Journal of Mechanical Engineering Vol. 21(5) (2008), p. 55-58

The Applied Research of Numerical Simulation Techniques in the Forming of Covered Parts of Automobile Hui Yong Yu1, a,Hui Lin Zhou1, b, Jun Hua Hu2,c 1Department of Materials Engineering, Henan Mechanical and Electrical Engineering College, Xinxiang, 453002, China 2 College of Materials Science and Engineering, Zhengzhou University, HeNan, Zhengzhou, 450002,China ayuhuiyong_123@163.com, b zhl801209@163.com, c26866355@qq.com Keywords: Numerical simulation, DYNAFORM, Car beams Abstract.
Introduction The automobile has a large outline and a complicated structure , which was affected in the process of forming by many factors, such as material properties, blank and mould shape, draw bead form and layout, press direction and speed, friction lubrication conditions, the size of the blank-holder force and so on, involving geometry nonlinear, physical nonlinear and boundary nonlinear problems.
Among them, the mandrelling process is the foundation and the key to other processes and the forming quality of drawing parts will directly affect the progress of the subsequent process[4].
This suggests that increasing blank-holder force can't affect well[5].

Thermal resistivity properties of LED packages with thermal via Hyo Soo Lee1,a, Hyeong Won Shin1,b, and Seung Boo Jung2,c 1 Advanced Material Division, Korea institute of Industrial Technology, 7-47 Songdo-dong, Yeonsu-gu, Incheon 406-840, Korea 2 Dept. of Adv.
In fact, the heat from an LED package with 1~3W LED chip shows a nearly 60~150℃, which affects thermal damage related to performance, joint failure, crack, etc.
The strucure of thermal via was drawn also as Fig. 1, which was the same as a pin-through hole in printed circuit board formed by mechanical drill process.
Chracterization of thermal properties of the LED were carried out by a 2 type of experiments.
And it was observed that the copper volume of inner layer in thermal via was dominant factor on the heat dissipation, which was also exactly correlated with thermal resistivity of each specimen.

In this study, sintered iron was machined and the influences of resin impregnation on its thermal properties, coefficient of friction, and flow stress (deformation resistance) were investigated.
Since the machinability of impregnated compacts is determined by various factors in a complex way, in addition to conducting drilling and 2D cutting experiments, various tests were performed to individually investigate possible causes.
To this end a ring compression test was conducted to valuate the coefficient of friction, the thermal properties were measured to investigate the cutting temperature, and a compression test with grooved dies was performed to determine the embrittlement and flow stress (deformation resistance) of the material.
The thermophysical properties that affect the cutting temperature of wrought material are the thermal diffusivity K and the product λρc (where λ is the thermal conductivity, ρ is the density and c is the specific heat).
(2) The increase in machinability caused by resin impregnation is not caused by a reduction in the coefficient of friction or by a modification of the thermophysical properties.

In the mechanical system, the similar conditions should design the energy-saving system. 
These seriously affect the accuracy of press operation and service life. 
It is not only affecting the efficiency of the forging press but also leading the vibration of the forging press.
Fig.2 20MN fast forging hydraulic system forging motion curve 3.2Analysis of the accumulator absorption process during hydraulic shock The effect of hydraulic shock absorption of the accumulator in system associates with many factors, such as the quality of oil in the accumulator and pipelines, structure parameters and state parameter of accumulator, pipeline characteristics, the characteristics of loop components and flow pulsation frequency etc.
Meanwhile, the accumulator directly connected in chips, which need no pipeline connection, and has less influence factors of the system performance.

The influences of phenolic resin content, forming pressure, sintering temperature of samples on the performance of green body, mechanical microstructure and properties of RBSC were studied.
As well as we known, the existence of residual silicon in RBSC would restrain the working temperature and reduce the mechanical properties of RBSC[11], which is unavoidable due to the RBSC process of infiltrating molten silicon into carbonaceous green body under capillary action.
Therefore, the characteristics (such as mass ratio of raw materials, density, porosity, pore-size, etc.,) of green body decided by green body preparing is one of the most important factor to affect the residual silicon content and the properties of RBSC.
The effects of green body forming process parameters on microstructure and properties of RBSC had been investigated.
Heinrich, Processing-microstructure-properties relationships of MoSi2-SiC composites, J.

Indeed, due to their intrinsic characteristics, laminate composites are characterised by poor mechanical properties in the out-of-plane direction [3].
The mechanical properties of the reference material are presented in Table 1, while in Table 2 nanoparticles’ properties are listed.
Table 1: RTM6 - Tenax HTS 12k mechanical properties.
E1 [MPa] E2 [MPa] G12 [MPa] G12 [MPa] ν12 ν12 t [mm] 135000 8500 4200 4200 0.35 0.35 0.190 Table 2: Nanoparticles’ properties.
Modeling of the mechanical properties of nanoparticle/polymer composites. (2005) Polymer, 46 (2), pp. 553-562

Xie et al.[25] successfully prepared Ag/ZnO samples with properties up to the relevant standards by mechanical mixing method.
Comparing the effects on properties of Ag/ZnO(10.8) contacts prepared by mechanical mixing, spry co-deposition and mechanical alloying, P.B.
Nanotechnology modification can promote the super-refinement of grain and the homogenization of microstructure and improve the mechanical and electrical properties of Ag/ZnO material.
While preparing Ag/ZnO by powder metallurgy or pre-oxidation, the sintering process of powder particles will affect the density of the material, and then affect the processability and electrical properties.
Failure of Ag/ZnO Electrical Contact Material The reliability of electrical contacts aimed at making current is one of the important factors restricting the efficient and long-term use of electrical contact materials.

In the following, the improved ESAD device which uses optimized opto-mechanical components is presented.
Schematical view of the opto-mechanical set-up of the ESAD device.
ESAD shearing deflectometry thus incorporates three central metrological advantages: (1) ESAD is based on the propagation of light as the primary straightness standard. (2) ESAD ensures optimal measurand (angle and length) traceability to the SI units. (3) ESAD benefits from the error-eliminating properties of the shearing (difference) method.
Figure 2 shows the opto-mechanical set-up of PTB's ESAD device [3-6].
A comprehensive analysis of different error influences affecting ESAD measurements and detailed uncertainty budgets were published [3,4,6].

In addition via the reverse co-precipitation method, the pH which is an important factor in synthesis of magnetite was controlled at high values easily.
The experimental results reveal that addition of surfactants affected on the size and morphology of the nanoparticles based on the X-ray diffraction (XRD) and scanning electron microscope (SEM) characterizations.
Introduction In recent years, various nanomaterials have been extensively pursued for their catalytic, optical, electrical, mechanical, and magnetic properties, which are quite different from those of their bulk counterparts [1].
In spite of the method of synthesis, the preparation conditions (e.g., surfactants, concentrations, PH, reaction temperature, stirring rate, etc.) strongly influence the chemical composition, particle size, size distribution, particle morphology, crystal structure and consequently the properties and applications of the products [18,19].
In the second case, the mixed metal solution was directly dropped into an alkaline solution; consequently, the pH which is a critical factor in synthesis of magnetite could be controlled at high values easily