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The grain sizes and crystalline phases increased with rising annealing temperature.
For reaching high reflectivity, it is necessary to increase the difference of refraction index and number pairs of DBR.
The SiO2/HfO2 DBR with different numbers of pairs are shown in Fig. 3(a).
Fig. 4 shows reflection spectra and reflectance of the different numbers of SiO2/HfO2 DBR pair.
The reflectance can be increased with the number of DBR pair increase, and the reflectance saturated at 8-pair SiO2/HfO2 DBR.

As the ingots continue to leaving the mold, grain growth direction is along the heat flow in the opposite direction to obtain columnar grain structure.
The grain growth speed along the z direction is greater than the grain growth along the x direction.
The entire plate forms columnar grains in the z direction.
There are some small grains on the columnar grains.
The melt nucleates on the mold wall, forming a large number of equiaxed grains.

The grain morphology shows granular accumulation and the grain size is less than 1μm.
A large number of isolated and spherical mesopores are formed between grains.
The number of mesopores is reduced, but the pore diameter has no significantly effect.
Meanwhile, the pore diameter and the grain size are also increased.
A large number of isolated and spherical mesopores were uniform distribution.

Fig. 2 shows the influence of wt% Al2O3 on morphology and grain size of Al2O3/ CCTO composite.
The grain distributes well in all microstructure.
This number shows that addition of Al2O3 effect on εr of CCTO.
This is agree with FESEM micrograph in Fig. 2 that with addition wt% of Al2O3, CCTO grain size become bigger and Al2O3 grain size remained the same and this is why εr decreased.
Wang, Grain boundary effect on the dielectric properties of CaCu3Ti4O12 ceramics, J.

Annealing resulted in recrystallization and grain growth starting from the deformed zone.
Misorientations between the single crystal matrix and the grown grains were gathered and were studied in order to investigate the possibility for selective growth based on a specific misorientation.
A selective growth mechanism is based on increased grain boundary mobility for a specific crystallographic misorientation between two neighbouring grains.
On the annealed samples the crystallographic orientation was measured of 77 large grains, which had grown out of the scratch affected zone into the single crystal area.
The ratio of the fraction of experimental RF-vectors to the fraction of random RF-vectors confined to a certain range of tolerance around the reference <110>26.5 RF-vectors can be considered as the number intensity of these reference vectors, expressed in times random units.

Thus, the number of convenient sites for the formation of new nuclei (pearlite) is much higher than in the original material.
The reason for this is not clear for the authors; however, it may be attributed to recrystalization and grain growth phenomena.
Therefore, at such a high temperature range when low cooling rates are used, recrystalization and grain growth may occur.
Thus, martensite transformation is retarded as a result of small size of austenite grains which were deformed heavily prior to the transformation.
As a result, plastic deformation of austenite hinders the growth of martensite, giving rise to lessening in the transformed fraction although the heterogeneous nucleation rate is increased in correspondence with the larger number of grains and defect density [10, 16].

The grain size was measured by the linear intercept method counting 100 grains.
TEM images at different magnifications were recorded both by a CCD camera and on film for measuring of particle number density, average needle lengths, average cross section areas, and width of the precipitate free zone (PFZ) at grain boundaries.
Microstructure: All 6 tempers analyzed in this work refer to fully recrystallized grain structures.
The results from the linear intercept measurements counting 100 grains were close to 150 µm for all alloys.
Hence, the grain structure is expected to have the same influence on the overall mechanical properties of all the samples analyzed.

Such parameters are: square root deviation of profile s; number of maximum m and number of zeroes (crossings with middle line) n(0).
When embedding the grain under angle towards edge a bead roll (see Fig. 3) is formed in front of it (grain) that can be transformed into shavings under certain conditions.
Proof of relation of real radius of grain rounding rI from modes of treatment is considered in work [7].
Interaction of model of single grain with processed surface.
When embedding of abrasive grains within spherical part of model of abrasive grain taking into consideration rolling yG (by data of work [11]) the depth is detected by equitation: yG=KYyE+rI∙2AE–sinψoAE–AoctgφGS+ctgφE at yЕ £ yD , where yЕ – depth of penetration of abrasive grains.

The introduction of biodegradable materials minimizes the number of invasive procedures required, patient’s morbidity and overall cost [1, 2].
Zhou et al. reported that MgZnCa alloys synthesized by a twin-roll rapid solidification technique produced a large number of precipitates, which contributed to precipitation hardening [10].
Additionally, these phases serve as grain refining agents and contribute to grain boundary strengthening.
Average grain size of Mg MMCs.
Nevertheless, a large variation in lattice parameters can lead to grain boundary segregation and grain growth restriction.

A considerable number of investigations on the properties of HSLA steels and their welding have been carried out in the past 30 years [6, 7].
Table.1 Welding Parameters Used in ASME SFA 5.5-96 Weld metal Coupons Heat input (KJ/mm) Welding speed (mm/s) Electric Tension (V) Intensit y (A) Interpass temperatur e (° C) Number of passes Number of layers Welding position 2.73 1.46 30 133 100 11 5 Flat 4.3 0.64 25 110 100 7 3 Upward Vertical Mechanical Testing.
Whereas the growth direction of welding grains is parallel to the path of a created notch and crack in the microstructure of upward vertical welding position (fig.3) and the grains act as readily available path for easy crack propagation in this condition.
Because created crack in impact test crosses more grain boundary and the micro crack will be stopped by an effective barrier (the grain boundary) more often the finer the grain size.
As a result, the crack is forced to reinitiate repeatedly and considerable energy is expended as it alters direction in search of the most likely propagation plane in the contiguous grain.