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It is therefore concluded that the control of water-cement ratio, the control of fly ash content, and the sufficient curing with retention of moisture in early stage are all the essential factors to ensure the durability against carbonation for the concrete with fly ash content.
The carbonation speed depends on many factors: Water-cement ratio, admixture (such as fly ash), additives, cement varieties and usage, and construction quality, which affect the carbonation resistance of concrete somehow.
Such concrete with higher water-cement ratio and higher content of active stuff is able to fulfill the engineering requirements for its mechanical properties.
Compared with the case of standard curing 28d, the compressive strength of concrete will decrease by about 40~45%, thus being unable to meet the C30 concrete mechanical property requirements
So it comes to the second conclusion that, the participated control of fly ash content and the sufficient curing with retention of moisture in early stage are both the essential factors to ensure the durability against carbonation and the compressive strength for the concrete with fly ash content.

As a consequence, helium interactions with these materials raise an important issue as for their durability of the mechanical and confinement properties.
The so-obtained complementary data, in term of affected depths and damaged profiles, were of great interest to implement models on helium behaviour (coalescence, diffusion, bubble nucleation and growth) that could eventually induce swelling and material damage. 2- Experimental Samples preparation.
After mechanical one-side polishing, the 1 mm thick samples were submitted to a thermal treatment to reduce the large concentration of cold-rolling and polishing-induced defects.
Since the standard ion-beam techniques (ERDA or RBS) could not be used to analyze helium at large depth corresponding to ion implantation in the MeV range [7], we studied the thermally activated 3He migration using the resonant 3He(d, p)4He nuclear reaction. 3He might be used as an isotopic tracer of 4He diffusion considering an isotopic correction factor.
Application of the Arrhenius law, taking into account the isotopic correction factor of √4/3 between 4He and 3He isotopes diffusion properties, yielded to D0 = 4.9x10-11 cm2.s-1 and Ea = 1.13 eV.

Thailand has been directly affected by climate change, and the volume of water in the main rivers of Thailand is subject to flash flooding; a common phenomenon.
(2) (3) Where f and are the friction factors in the pipe and the specific weight of the water, the friction factor (f) is the main data we wanted to observe.
With a decrease in the friction factor, the flow rate in the pipe increased.
The third theory presented by Sellin R.H. [2] explains that these polymers have an effect on the energy balance between turbulence production and dissipation due to the elastic properties of the macromolecules of the polymer solution which seem as spring to store energy before dissipation into the pipe wall.
Acknowledgments This study was carried out under the support of the Department of Mechanical Engineering, Faculty of Engineering, Naresuan University, And Assistant Professor Dr.

Dept. of Mechanical Engineering, University of Waterloo, 200 University Ave.
It has been shown that the alloy composition affects the strength levels which can be achieved during natural aging and through high temperature aging treatments (i.e. artificial aging) [1-8].
In the case of natural aging, while the change in the Si content does not affect the natural aging kinetics, the increase in Cu content results in an increase in the kinetics of natural aging [9].
The desire to optimize the processing, properties and alloy chemistry for this commercially important class of aluminum alloys has led to the development of the recent analytical and modeling techniques to quantify the microstructural evolution of the alloys during thermal processing [10-14].
These results suggested that Cu addition affected the precipitate nucleation rather than the growth process.

Such a crack is well represented by a special interface element, which has its mechanical properties representing the crack behaviour based on previous experience.
Further crack can appear in the element in dependence on the shear properties of the crack.
Microplane model is a microscopic mechanical model, which describes the material properties on the set of microscopic planes.
Smeared approach is used to model material properties such as cracks or distributed reinforcement.
There can be two reinforcement components with different properties and directions in one material point.

It is closely related to soil physical and chemical properties, and it is regard as an important parameter to evaluate soil resistance to erosion capacity.
Soil Aggregate, Physical and Chemical Properties.
Each physical and chemical soil properties in composite samples for each site of different land-use pattern were averaged at soil depths of 0–20cm to perform statistical analysis.
Land use patterns affected on water stability index and soil organic matter content.
LI, “Effect of soil physical properties to soil erosion in dry and hot valley of Jinshajiang River,” Journal of Water Resources and Water Engineering, vol 19,pp. 38-41,2008

The noise of exhaust muffler is one of the key factors of the noise of the whole car.
The input side is at x = 0 and the output side is at x = L.Cascading property is the method that makes the four-pole formulation so useful.
Thus, clearly we found that the inlet temperature does not affect the transmission loss of muffler.
Sas:Developementof an Active Exhaust Silencer for Internal Combustion Engines, K.U Leuven, Faculty Applied Science, Department Mechanical Engineering, Celstijnenlaan, Belgium, (2004)
Bento Coelho:Journal Brazil Society Mechanical Science& Engineering,Vol.27, No.2 (2005), p. 132-140

Dynamic Characteristic Analysis of the Horizontal Machine Center Li Zhang 1, a, Liangwei Zhong 1, b 1 College of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China a usstcad@126.com, b zlv@usst.edu.cn Keywords: Machine center, modal analysis, harmonic response analysis, resonance vibration Abstract.
This not only affects the accuracy of milling process, but also causes serious damage to the cutter head.
(6) This shows that:  H is the ratio factor of the response  tx to the excitation force  tp .
The amplitude of the forced vibration is only determined by the physical properties (natural frequency), the size of the excitation force and the frequency of the system itself .It has nothing to do with the initial conditions.
The initial conditions only affect the transient vibration of the system.

Many fatigue tests show that the failure of ball screw pair may end with wear or fracture of nuts, which is a significant factor shortening the life of the ball screw pair and affecting its reliability.
Carbide uniformity has significant influence on the mechanical properties and service life of the nut under cyclic impact loads.

Design Optimization and Analysis of NACA 0012 Airfoil using Computational fluid dynamics and Genetic algorithm Ganesh Ram R K1,a, Yashaan Nari Cooper2,b, Vishank Bhatia3,c R.Karthikeyan4,d and C.Periasamy5,e 1,3,4,5 Department of Mechanical Engineering, BITS Pilani, Dubai Campus, UAE 2Department of Electronics and Communication Engineering, BITS Pilani, Dubai Campus, UAE aganeshrk95@gmail.com, byashaancooper@gmail.com, cvishank94@gmail.com drkarthikeyan@dubai.bits-pilani.ac.in, eperisamy@dubai.bits-pilani.ac.in Keywords: Computational Fluid Dynamics, Airfoil, Viscous flow, NACA 0012, ANSYS Fluent, MATLAB, Genetic algorithm, XFoil Abstract.
It is a significant factor in almost any type of vehicle design, including automobiles since air flows around them as well.
It is the cross sectional profile of any aerodynamic structure which is used to analyse the aerodynamic properties.
Since all the important physical mechanism which affect airfoil performance are represented in the overall computational model any airfoil modifications which are found to affect performance can be relied on to have a physical rather than numerical basis.