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where D is the mean grain size, λ is the X-ray wavelength (for Cu kα radiation, λ=1.5406Å), β is the FWHM of diffraction peak and θ is the diffraction angle.
Based on the full width at half maximum of there flection planes(111, 220 and 311) in zinc-blend structure, the mean grain sizes of the undoped ZnS and Mn2+-doped ZnS particles as calculated by using Eq. (1) from the most intense peak were around 3.8 and 4.5nm, respectively.
Thus, the existence of Mn2+ pairs is important for the occurrence of the concentration quenching process; the excitation energy is transferred from one Mn2+ ion to its nearest Mn2+ ion by nonradiative transition and via a number of transfer steps, finally to a quenching site (such as defect state).

Measurements were taken with a Pundit instrument (C.N.S Farnel electronics), using conical transducers, that were placed indirectly and parallel to the grain since "direct" measurements were impossible to be taken due to poor signal propagation owed to the heavily decayed surface of sample.
Four drills perpendicular to the grain were made per sample, at the same spots where ultrasound testing was deployed.
For samples S3 and S4, graded both as "severely attacked", the x-ray result showed a different preservation condition, where S4 appeared to be more solid than S3 and enclosed a high number of knots.

As a result of this process, the crystal lattice is distorted, the number of defects in it and the free energy of the system grows, forming an anisotropy of properties in the metal [7, 8].
In this case, due to the interaction between grains separated by a distortion boundary and a decrease in grain size, deformation resistance increases.

Polymer-matrix Nanocomposites are increasingly been applied as structural materials in the aerospace, automotive and chemical industries, in a number of tribological applications including such components as bearings, gears, cams, seals, vacuum pumps particularly in areas where traditional fluid lubricants cannot be used. [4].
The crystallite size of TiO2 nanoparticles can be obtained based on Scherer equation as shown below:- D= 0.9λ / β cos θ (2) where: - D is the grain size, the λ diffraction wavelength equal (0.1541 nm), β is the Full With at Half Maximum must be in rad and θ is the diffraction angle.
The crystallite size is determined at FWHM (0.17) at 27.4˚ peaks based on Scherer equation, the grain size is 47.23 nm in diameter [14].

Al-Cr solid solution of AC specimen are in less development state, ρ-Al2O3 powder Decreased activity of ρ-Al2O3 powder increase the sintering barrier, block up Al-Cr solid solution grain growing up further, eventually forming a thin layer of Al-Cr solid solution attached to the particles.
There exist a large number of defects such as crack and pore in Al-Cr solid solution (Figure E).
Solid grain of C4 specimens adding double peak（D50=1.4μm） distribution alumina powder grew adequately, and developed well.

Considering thermodynamics factor, Thompson[13] had proposed that both surface and strain energy minimizations govern the grain growth in thin films.
Under a low-temperature and low ion energy growth condition, the competitive growth for grains with all orientations should play a dominant role in textural evolution, wherein the fast-growing surface arriving at the substrate is (111), corresponding to a low diffusivity surface[14].
At low Ei, with increasing Ei the number of displaced atoms (defect) increases, thereby giving rise to an increase of compressive stress.

For an AZ31 magnesium alloy circular tube, the combination process both ECAE and extrusion were also conducted to obtain fine grain microstructure which lead to good superplastic characteristic[15].
Summary This work was supported by JSPS KAKENHI Grant-in-Aid for Scientific Research (B) Grant Numbers 24360310.
Manabe, Grain Refinement by Combined ECAE/Extrusion and Dieless Drawing Processes for AZ31 Magnesium Alloy Tubes, Mater.

Recent advancements involve engineering grain boundaries to enhance fracture strain and superelastic properties, particularly in Cu-Al-Ni SMAs [12].
Alloy Types Sample Number σMs (MPa) σMf (MPa) σAs (MPa) σAf (MPa) εl (%) εr (%) Uh (MJ/m3) 1 Ni-Ti SMA S1 539 627 523 383 3.1 -- 31.13 S2 596 720 601 469 2.9 -- 32.04 2 Cu-based SMA S1 440 566 -- -- 0.3 3.4 21.17 S2 445 585 -- -- 1.1 2.6 22.31 3 Fe-based SMA S1 772 850 -- -- 0.8 2.3 62.42 S2 785 862 -- -- 1.3 2.1 63.37 Fig. 3 illustrates the stress-strain hysteresis loops for the three SMA types, depicting failed samples after cyclic tension-compression tests.
Xie: Enhanced mechanical properties of polycrystalline Cu-Al-Ni alloy through grain boundary orientation and composition control, Materials Science and Engineering: A 650(2016), 218-224

Static recrystallization occurs after recovery is complete; in which a new set of strain-free and equiaxed grains having low dislocation densities form, by nucleation and growth [7].
When recrystallization is complete, the newly formed strain-free grains will coarsen (as distinct from “growing”, the latter being part of the recrystallization process) provided that the sample is left at elevated temperatures.
The cold spray equipment used for this study was funded by CFI project number 8246, McGill University (Montreal, Canada) with the support of Cold Gas Technology GmbH and Tecnar Automation Ltd.

A number of semiconductor materials have been investigated to meet the requirement if the PEC.
In the case of longer W sputtering times above 3 minute, the W nuclei grow become larger nanocrystallites exceeding the optimum amount will form does not enter into lattice of TiO2 but it follow the Frank and van der Merwe by forming a continuous monolayer deposit to attain independent identity, the transfer of electrons and holes is hindered by the thick W layer and their grain boundaries.
Samples loading longer than 3 min, photocurrent was in the range of (1.5-1.7 mA) indicating that further loading of WO3 do not affect/improve photoinduced charge separation in the TiO2 due to these exceeding optimized W particles act like an independent system with electron transport limited by grain boundaries.