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The average grain sizes of BTV ceramic samples are listed in Table 1.
For BTV samples, the peak numbers of Raman mode are larger than that of pure BIT sample at room temperature.
Here n is the number of the carriers, q the charge and μ the mobility.
The number of hole carriers, n, decrease with the increase of V5+ substitution for Ti4+ in BTV ceramics.
Besides, the increase of average grain size would favor better polarization behaviour.

And this is about an interplay between grain boundary (GB) diffusion and grain boundary energy.
Rodin: B or C, because of grain growth.
Having steps or grain boundary dislocations.
Are you strong enough that simulations also provide some number of activation volumes?
Grain boundary segregation and grain boundary diffusion Bokstein: Sergiy, sacramental question: “Does grain boundary segregation decrease grain boundary diffusion?”

In order to ensure this, the microstructural evolution and the deformation mechanisms acting on the mechanical behavior will be identified for a large number of test conditions.
Moreover, the evolution rate was higher for the Ultra Fine Grain microstructure (0.8µm).
Fig. 1 shows the grain size evolution during the annealing tests for the starting microstructure of 3µm.
At 800◦C, Grain Boundary Sliding (GBS) occurred regardless of the strain rate and very significant grain coarsening was observed at the lower strain rate, inducing a strain hardening effect observed in the tensile test.
Therefore, test conditions only inducing grain growth were selected to determine the parameters.

Over the last decades, the number of different reaction-based processing methods for near-net-shaped ceramics has gradually increased.
A vast number of combinations of materials properties can therefore be achieved.
RBAO has an improved mechanical strength since there is limited formation of a glass phase near the grain boundaries and it has a small Al2O3 grain size as is achieved by the controlled oxidation of Al-metal.
The higher strength values of this material are due to fine, Al2O3-grains, free of glassy phases.
The presence of two types of alumina grains, large primary grains from the original Al2O3-powder and small-grained Al2O3 formed during oxidation of the Al-fraction, can be seen from FESEM-pictures, e.g.

The evolution of microstructure is checked against the variation of number density, size and distribution of ductile phase in the glassy matrix.
Grain selection They cannot account for the “grain selection” which occurs a.
During one MC time step, Consider N sites where N is number of sites whose evolution is calculated and is chosen from another N (total number) sites.
If total density of grains which nucleate at a given undercooling is obtained from an average distribution (dc = average (distribution)), the location of these sites is chosen randomly where a1, a2, a3, a4 …… an are distributions of grains 1, 2, 3 to n where n = R (R = Real numbers) 3.
Thus, from equation 16 No = Total number of heterogeneous substrate particles originally available per unit volume N = Number that have already nucleated Io = constant Value of Io can be calculated from equation 15 using another term known as “liquid diffusion coefficient”.

The effect of ultrasonic injection on the microstructure and mechanical properties of A356 alloy Byoung-IL KANG 1,a, Dae-Gyun KO 1,b , Jeong-IL YOUN 1,c, Young-Jig KIM 1,d 1 School of Advanced Materials Science and Engineering, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, 440-746, Korea a subs39th@skku.edu, bkdk121@skku.edu, cyounj1@skku.edu, dyjk1122@skku.edu Keywords: ultrasound, grain refinement, nondendritic structure, A356 alloy.
There have been considerable efforts over the years to minimize casting defects and improving service life of as-cast products by implementing new casting process and application of grain refiners to cast fine grained components which have superior mechanical properties [1, 2].
Since Primary nucleation can be induced by ultrasonic irradiation, it follows that this will allow control over the number of primary nuclei.
Furthermore, controlled indirectly via the number of primary nuclei, the crystal size of the final product is also influenced by ultrasonic injection [9].
The grain size, in this case, is equal to the size of the dendritic arm spacing of the billets solidified under identical conditions but without ultrasonic treatment.

The effect of ultrasonic injection on the microstructure and mechanical properties of A356 alloy Byoung-IL KANG 1,a, Dae-Gyun KO 1,b , Jeong-IL YOUN 1,c, Young-Jig KIM 1,d 1 School of Advanced Materials Science and Engineering, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, 440-746, Korea a subs39th@skku.edu, bkdk121@skku.edu, cyounj1@skku.edu, dyjk1122@skku.edu Keywords: ultrasound, grain refinement, nondendritic structure, A356 alloy.
There have been considerable efforts over the years to minimize casting defects and improving service life of as-cast products by implementing new casting process and application of grain refiners to cast fine grained components which have superior mechanical properties [1, 2].
Since Primary nucleation can be induced by ultrasonic irradiation, it follows that this will allow control over the number of primary nuclei.
Furthermore, controlled indirectly via the number of primary nuclei, the crystal size of the final product is also influenced by ultrasonic injection [9].
The grain size, in this case, is equal to the size of the dendritic arm spacing of the billets solidified under identical conditions but without ultrasonic treatment.

Holding time had great effect on grain size and morphology.
Sinclair et al. demonstrated that CCTO ceramics was electrically heterogeneous and consists of semiconducting grains with insulating grain boundaries and asserted that the giant dielectric phenomenon was attributed to a grain boundary internal barrier layer capacitance (IBLC) rather than an intrinsic property associated with the crystal structure [3, 4].
Sample synthesized at 800 o C exhibited a further increase in particle sizes with a large number of distinct cubic that are clearly visible in a size range of 15-30 µm.
At reaction time reached 8 h, the particles homogeneously transformed to discrete cubic grains and increasingly grew in size at longer reaction times.
Holding time had great effect on grain size and morphology.

The bone grinding was performed by means of an analytical mill in order to obtain a finer grain size.
The grinding of the bones was performed by means of an analytical mill in order to obtain a suitable grain size.
The calcined sample was easier to grind, the non-calcined grains seem to be tougher, including some grains that appear to have a coat of a thin polymeric film.
On the face of the grains where this film was observed, the deposition of a dark staining material was also observed, probably organic residues from the bone itself.
Fig. 2b shows a spectrogram of the calcined sample, which can be seen that is mainly crystalline with the single presence of hydroxyapatite, Ca5(PO4)3(OH), from ICDD PDF number 00-009-0432.

In a number of cases plasma-beam technology allows to get such structure phase states of materials which cannot be realized with traditional methods application [4-6].
Pulse energy constituted ~ 1,5 J/сm2, number of pulses – 4.
PIB irradiation leads to refinement of grain to 0.15 - 0.8 µm (Fig. 2b).
Studies of structure have shown that there are grains of two types: the first type of grain does not have equiaxed structure, whose length is from 0.3 to 1.6 µm, and the width is within the range 0.15 - 0.4 µm; the second type of grain structure is equiaxed size 0.25 – 0.5 µm.
Not equiaxed grains contain dislocations inside.