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The surface atomic number, and specific surface area can increase with the decrease of the particle size, which makes the materials have good optical properties, magnetic, catalytic, etc., in the light absorption, medicine, magnetic medium and catalyst has a wide range of applications [5-6].
Table 1 Average grain sizes and lattice distortion of α-Fe2O3 nanocrystals (a) (b) (c) (d) 2θ(104 crystal face) 33.35 33.23 33.27 33.17 d222(nm) 0.269 0.270 0.269 0.270 average diameter (nm) 34 42 38 36 ε×103 4.68 4.79 4.70 4.70 Fig.3 shows UV-vis spectrum of α-Fe2O3 nanocrystals.

When the size of the prepared particles is less i.e. improvement in the number of grains increases the surface area of the nanoparticles, which can be very much applicable for the field of gas sensors. 100 nm 20 nm (a) 100 nm 20 nm (c) 100 nm 20 nm (d) 100 nm 20 nm (b) Fig. 3.

The input variables are as follows: - design loads of the connection: Fd1 = 43kN; Fd2 = 28kN, - width of the middle timber part: t2=140mm, - material of the middle timber part: Glued laminated timber, class GL24h, - apparent density: ρk=380 kg/m3, - angle between the load directions and the grain of the middle timber part: α = 90°, - characteristic tensile strenght of the bolt: fuk = 800MPa, - iameter of the bolts: d = 16mm, - tensile bolt area: As = 157mm2, - thickness of the outer steel plates: tplate = 8mm, - modification factor: kmod = 0,8, - partial factor for timber: γM = 1,3, - partial factor for bolts: γM2 = 1,25.
We would have to increase the number of the bolts in the girder.

Increasing the hydrogen dilution ratio, the film will be converted to microcrystalline silicon, and a large number of studies show that the stability of the microcrystalline silicon is greatly improved.[4-5] Due to the increase of the operating frequency, VHF-PECVD technology helped to increase the concentration of electrons in the plasma and lower the temperature, which are conducive to the stability of the film's high-speed growth.[6] Thus microcrystalline silicon thin films were prepared by VHF-PECVD under different ratios of hydrogen dilution, and structural characteristics, deposition rate and photosensitivity were analyzed under different hydrogen dilution ratios in this paper.
The most important is the passivation of the grain boundaries in the growth process, which greatly reduced density of defect states.[8] Thus it is can be found that with the improvement of the hydrogen dilution ratio, the film of amorphous components gradually reduced, while the crystal components gradually increased, crystallization rate had been improved.[9] Figure 1.

In recent years, as nanocrystalline powders with ultra-fine grain size promised potentials for changing and improving the mechanical properties of metal and its alloy [8], so a synthesis of the Ti-Ni alloy nanopowders have been received a great attention from the viewpoint of both the scientific research and technological applications.
The value of specific surface area of the Ti-Ni alloy nanopowders was markedly high, which was about 54.8 m 2/g based on a BET method. 20 25 30 0 5 10 15 20 Number of Particles Particle Size (nm) Fig. 3.

If the mechanical energy is used to drive machinery, such as for grinding grain or pumping water, the device is called a windmill or wind pump.
The higher of Turbulence kinetic energy value is good because it can produce large number of blade rotation to generate more electricity.

Therefore significantly reduces the possibility of the grain growth.
As the number of points of computational mesh of this axis is fixed at this step leads to the change and the need to consider the calculation grid deformations in equations (2) - (5).

The main mechanical properties of high-chromium cast iron are; the tensile resistance is about 490Mpa, and Brinell hardness number ranges between 290-340, and it has a good resistance to shocks.
Through the study of the microstructure of the alloy it’s observed the regular distribution of the graines as a result of heat treatments and the presence of homogeneity in the grain size. 4.

Using an optical microscopy, Fig. 1 illustrates the microstructure of these three materials in which several twins and carbide were observed in the grain.
of cycles Inconel 600 (Plain Fatigue) Inconel 600 (Fretting Fatigue) Inconel 690 (Plain Fatigue) Inconel 690 (Fretting Fatigue) Incoloy 800 (Plain Fatigue) Incoloy 800 (Fretting Fatigue) 100 101 102 103 10 4 10 5 10 6 107 108 200 400 600 800 1000 1200 1400 1600 1800 2000 Friction force (N) Number of cycles INCONEL 600 (101MPa) INCONEL 600 (177MPa) INCONEL 600 (205MPa) INCONEL 690 (182MPa) INCONEL 690 (202MPa) INCONEL 690 (231MPa) INCOLOY 800 (150MPa) INCOLOY 800 (200MPa) INCOLOY 800 (230MPa) 10 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 0 5 10 15 20 25 30 35 40 45 50 Local relative slip amplitude (µm) Number of cycles INCONEL 600 (101MPa) INCONEL 600 (177MPa) INCONEL 600 (205MPa) INCONEL 690 (182MPa) INCONEL 690 (202MPa) INCONEL 690 (231MPa) INCOLOY 800 (150MPa) INCOLOY 800 (200MPa) INCOLOY 800 (230MPa) INCOLOY 800 used as steam generator tubes registered very low levels.
Fig. 4 illustrates changes in friction force according to the number of repetition cycles after applying a fretting fatigue test with 50MPa of constant contact force at the contact region between the specimen and the contact pad.
Fig. 5 shows the local relative slip amplitude according to the number of repetition cycles after apply a fretting fatigue test.
As shown in Fig. 8 (d), a large number of dimples were observed in the final fracture region.

They found that the high entropy alloys have simple microstructure, the number of phases is few, and cubic solution is the main phase.
According to the Gibbs phase rule, F=C−P+1 (F: degree of freedom, C: number of components, and P: number of phase), the maximum number of equilibrium phases in the C components system at constant pressure is P=C+1.
Crystal grains were finer when the cooling speed was faster, so the strengths and plasticity might be increased slightly by effect of fine-crystal.
And the total number of phases is much smaller than the maximum equilibrium number allowed by the Gibbs phase rule