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The percentage of porosities in the specimen has a direct impact on the mechanical properties and the qualities of the produced RT part, the DOE method (Montgomery, 1997 [1]) was proposed to identify an optimal process parameter setting that can achieve a low porosity percentage of components.
D: µm) are the four controlled factors.
The effects of the SLS variables on the physical and mechanical properties of specimens have been studied by researchers ( Kruth et al., 2004 [2]; Prabhu et al., 2005 [3]; Chao, P.Y. and Hwang, Y.D. (1997) [4]; Evans et al., 2005 [5]; Lin, T. and Chananda, B. (2004) [6]; Yao and Tseng, 2002 [7]).
Table 2 lists the experimental factors and the factor levels for the SLS process.
ANOVA results The Analysis of Variance (ANOVA) is conducted to find significant factors that affect the percentage of porosity in specimens of the SLS process.

The results show that hot pressing temperature, pressing time, pressing pressure, veneer glue spread –four factors affect the bond strength of the structure plywood significantly, but the difference among the three veneer glue spread levels is not significantly.
Compared with ordinary plywood, there are many differences including layers and veneer thickness of plywood, in addition to the physical and mechanical properties of products and production processes.
Pressing pressure is one of the main factors, which impact the plywood’s quality, pressure directly affects the compression rate of plywood and wood utilization.
Conclusions (1) Pressing temperature, pressing time, pressing pressure, veneer glue spread –four factors affect the bond strength of the structure plywood significantly, but the difference among the three veneer glue spread levels is not significantly
Measurement the Phtsical-Mechanical Properties of Poplar Lumber by PF Resin Treatment.

Therefore, it is reasonable factors that the heat input, cooling velocity and temperature gradient to improve the defects of 304 stainless steel serpentine flowing channel industrial condensation board in CO2 laser welding.
However, there have many defects of 304 stainless steel condensation plates during the laser welding process, such as porosity, slag and cracks, which lead to poor joining properties and can not meet the requirements of industrial refrigeration equipment[3,4].
In this paper, we use three different welding technologies to weld 304 (0Cr18Ni9) austenitic stainless steel sheets, and study the microstructure characteristic and mechanical properties of the welding joint.
The welding heat affected zone (HAZ) is very narrow because the source of laser beam is very concentrated.
Therefore, a reasonable welding parameters including the heat input and cooling rate can affect the temperature gradient, which is important factors to improve the welding defects in CO2 laser welding serpentine flow condensation plate.

Introduction Surface morphology is the main control factor of the mechanical properties of rock joints [1, 2].
In order to calculate the parameter statistics for different scales of surface morphology and get the average statistics through model tests, the objective of this article is to provide a technical guarantee for choosing samples, which is based on main influencing factors of sampling representativeness and statistical data of JRC in the tests.
Main influencing factors of sampling representativeness The more JRC approaches to the average statistical value of the whole structural plane, the better sampling representativeness is.
However, the feature of rock joints surface morphology affects the sampling representativeness, such as non-uniformity, anisotropy, anisotropism and scale effect.
When the mechanical properties of rock joints were evaluated by JRC for higher or lower, more errors would be caused; therefore, it is necessary to evaluate the sampling representativeness of rock joints in engineering practice.

The pre-accelerated ageing test carried out showed that mechanical properties were higher 2:1 and 3:1 paper cement mixing ratios.
Durability is defined herein as the retention of mechanical and physical properties after exposure to the ageing process(4).
The following constant factors were observed: Board density (1200kg/m3), additive concentration (3% of cement weight), Pressing pressure (1.23N/mm2), and Board size (350 mm x 350 mm x 7 mm).
The mechanical properties (MOE and MOR) were examined after 21 days of curing; the samples sizes were cut into 195mm x 50mm x7mm.
This is evident as shown in figures 5 and 6, and the fibre property affects the flexural strength which varies with the amount of fibre .The content of cement highly influences the properties of the PCBCB.

In the whole process of making, transportation, storage, construction and working, the properties of Geosynthetics will be affected by many factors.
It makes the geosynthetics discolorate, strength, elongation and other mechanical properties deteriorate gradually.
The factors affecting its aging can be divided into two parts: internal ones—the type of polymer, material composition ratio and additives; external ones—the applicated environment, in which, light, oxygen, heat have great effect to aging.
It is because there were other factors apart from UV decreased the mechanical properties of samples slowly in the underwater environment, such as oxygen dissolved in water, the water and sediment keeping washing out, stress and biological activities etc.
Conclusions (1) The durability of geosynthetics is affected by many factors such as metarial aging, creep, mechanical damage, corrosion by acid or alkali solution and biological activities and its damage usually is the combined result of several factors

Introduction Closed-cell aluminium foams show alluring potential for different engineering application mostly due to significant energy absorption owing to exceptional combination of light weight with new physical and mechanical properties [1, 2].
The superior properties of aluminium foams offer strong motivation regarding the development of different approaches for their fabrication.
As to the melt processing, several factors control energy absorption of aluminium foams by influencing their plateau stress and strain.
Besides structural factors, such as cell morphology and matrix material of the cell walls being essentially affected by parent alloy composition, it is reasonable to suggest that the mechanism of cell collapse plays an essential role in mechanical performance metrics and energy absorbing ability of foams.
Ashby, Cellular Solids: Structure and Properties, Cambridge: Cambridge University Press, 1997

Study on Chemical Mechanical Polishing Removal Mechanism of Monocrystalline Silicon Hongwei Du1, a, Yanni Chen1, b 1 College of Mechanical and Electrical Engineering, Qingdao Agricultural University, China adhwfair@163.com, b609215407@qq.com Keywords: Monocrystalline Silicon; Chemical Mechanical Polishing; Erosion; Scratch; Material removal Abstract.
The polishing pressure is an important factor to obtain ultra-smooth surface without damage.
Monocrystalline ultra-precision machining process often leads to its surface and sub-surface phase transition, cracks and dislocations and other chemical damage and physical properties of materials change and other mechanical damage, which affects the normal use[3-5].
The polishing pressure is an important factor to obtain ultra-smooth surface without damage.
Study on Chemical Mechanical Polishing of Silicon Wafer.

Accordingly, it is clear that the surface properties determined proved favorable to the mechanical properties of the WC/Co coatings.
Most investigations have concentrated on the mechanical properties produced by a HVOF.
The process presents some apparently insoluble problems, such as how to understand the relationship between process, structure and properties and how to simultaneously construct appropriate models to take account of the large amount of factors that affect deposition properties and quality.
RSM provides an ideal approach for a study of the factors affecting the wear resistance of WC-Co coatings.
It is clear that the surface properties studied provide the most favorable mechanical properties in the WC/Co coatings.

Unfortunately, the Egyptian faience objects subject to many deterioration factors, especially humidity.
Unfortunately, most of those faience objects suffer from several decay features related to the deterioration factors that affect the different components of faience.
The mechanical properties of the treated and untreated samples were determined by testing their compressive strength.
Mechanical properties The mechanical properties of the treated and untreated faience samples were determined by testing the compressive strength.
[13] Rehren, T., A review of factors affecting the composition of early Egyptian glasses and faience: alkali and alkali earth oxides, Journal of Archaeological Science, 35, (2008), pp.1345-1354