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The resulted product had an approximate spherical shape and average grain size of 50 nm in diameter.
From Fig. 3(a), the particles of La2Ti2O7 samples calcined at 600℃ were uniform, and agglomeration was not obvious, with an average grain size of about 50 nm.
According to the literatures, the wave number of 770cm-1 corresponded to the Ti-O stretching vibration, and the wave numbers of 540cm-1 and 460 cm-1corresponded to the La-O stretching vibration.
In addition, comparing Fig. 4 (a) and (b), it could be found that the prepared La2Ti2O7 samples calcined at 600℃ were in the presence of the stretching vibration absorption peaks of water molecules at the wave numbers of about 3450cm-1 and 1500cm-1.

Moreover, uniform grain size of carbothermally derived β-sialon decreases fracture toughness of the resulted ceramics in comparison to reaction-sintered hot-pressed ceramics.
Thus, α/β-sialon composite ceramics produced from carbothermally derived powder could withstand comparison with hot-pressed ceramic if β-sialon forms elongated grains.
In contrary, 15R and 12H phases disappeared after sintering and instead of them α-Al2O3 in the form of large grains were found.
Acknowledgement: This work has been done in the framework of a project supported by the KBN, Poland (Grant number: 4 T08D 018 22 References [1] I.
Cryst. (1974), p. 519 Al2O3 grains primary β-sialon secondary β-sialon YAG 1 µm 2 µm 2 µm

Using the LS method also, the regression equations of the grain size, (63 and 150 micron) as corresponds to the regions of the trunk, gave an optimal fit of R2>0.87 for the selective polynomials based on the grain size of the wood powder, indicating a strong positive relationship.
The results presented in Table 2 show the influence of grain size of the wood powder taken from the pith, bark and pith-bark regions of the trunk on the FWHM and hence on the value of R2.
The strongest diffraction pattern arising from the grain size about 63 micron.
Table 2: Regression Equations According to Age, Grain size and Region of Wood Grain Size Regression Eqn (FWHM vs Age of Tree) R2 Region 63.0 Y = 23.446-25.292x 0.9044 pith 63.0 Y = 23.292-21.385x 0.9875 bark 63.0 Y = 22.924-21.634x 0.9097 Pith-bark 150.0 Y = 23.029-29.195x 0.8759 pith 150.0 Y = 23.194-29.856x 0.9499 bark 150.0 Y = 22.781-28.157x 0.9567 Pith bark Discussion And Conclusion Comparisons of linear polynomials for Acacia mangium at different tree ages had shown that the MFA varies according to age with a small mean and variance.
Using the LS method also, the regression equations of the grain size as corresponds to the regions of the trunk, gave an optimal fit of R2>0.87, indicating a strong positive relationship.

It is therefore essential to minimize grain growth through careful control of consolidation parameters.
The objective of this study is to synthesize and sinter HAp-3YSZ powders with High hardness high toughness, fine grain size and homogeneous constituent distribution.
In the microstructure of the sample sintered at 950 °C, there exist a number of closed pores, entrapped in sample grains.
At the temperature range from 1150 °C to 1200°C, the grain size increases with increasing temperature and many voids appeare due to thermal decomposition and expansion of the HAp.
HAp-20vol. % 3YSZ composites with small grain size, homogeneous microstructure, higher density, hardness and toughness were successfully developed at relatively low temperatures through HFIHS.

A large number of ceramic dielectric materials has been developed and studied.
SEM micrographs from pure TiO2 samples sintered at 1400 °C have shown that the obtained grains are similar in shape and size.
In general, SEM micrographs of fracture surfaces show highly dense microstructures consisting of equiaxed grains.
The grains are similar in shape, with little variation in size.
Minor phases can be found in these micrographs, in particular at the grain boundaries and at the triple point junctions.

The continuous grains in the tests respectively were 5～20mm 、5～31.5mm、 5～40mm.
In order to study the physical and mechanical properties of recycled coarse aggregate, the grain diameter of the three kinds of tested recycled concrete were 5～20mm 、5～31.5mm、 5～40mm.
Then, the directly or indirectly affect of the different grain diameter on recycled concrete strength was measured.
(2)The apparent density increase with the increase of grain diameter.
(2)Instead, the small grain diameter recycled coarse aggregate have higher moisture content.

Sorting of clastic grains by their size and density has happened at the same time.
The deterioration of reservoir properties was observed in a number of wells at the bottom of the formation due to bigger section claying.
In conditions of sea basin regression, the movement of the bar crest follows the retreating sea and the zone of coarse-grained sediments, formed with high hydrodynamic levels, moves towards the open sea, overlapping previously formed fine-grained sediments.
It is represented with medium-grained sandstones, slightly and moderately clayed, well sorted, polymictic.
Siltstones can be found rarely; they are represented by coarse-grained variations: well and medium sorted, moderately clayed, polymictic.

The results show that both alloys exhibit a fully recrystallised grain structure.
Alloy 3H has smaller grain size and less textured.
Also, it is found that with higher Cu content, the grain size is more uniform.
The maximum grain size for 3L is from the minium detectable size by EBSD up to 80μm while for 3H is 63μm.
Si is tied up with Fe and/or Mn in these particles, which appear with a bright white contrast in BSE observation due to the relatively high atomic numbers of Fe and Mn.

Introduction The severe plastic deformation (SPD) of metallic materials has become attractive in resent years because it develops fine grains of typically sub-micrometer level in polycrystalline materials [1~8].
Fine grain structure of 3-pass deformed Al 6063 alloy after recrystallized at 250°C for 30 min is observed by transmission electron microscopy (TEM).
Measured thicknesses and shear angles Sample Numbers Before ECAR (to) [mm] Roll fed (tr) [mm] Inlet Zone (tc) [mm] After ECAR (ts) [mm] Shear Angle (θ) [ ° ] 1 2.25 1.74 2.00 2.32 30 2 2.26 1.75 2.02 2.36 32 3 2.23 1.72 1.97 2.21 30 4 2.27 1.76 2.08 2.39 33 5 2.24 1.73 1.98 2.28 32 Averaged Thickness 2.25±0.01 1.74±0.01 2.01±0.04 2.31±0.07 31.4±1.3 Fig. 5 shows an ultra fine grain structure of Al 6063 alloy sheet deformed by the new ECAR apparatus.
Thus, it is proved that the new ECAR apparatus is useful for grain refining even the shear strain is reduced to 0.61 for 1 pass deformation.
(4) Ultra fine grain structure about 1μm of averaged grain size is obtained in the Al 6063 alloy sheet by 3-pass deformation with the new ECAR apparatus and recrystallized at 250℃ for 30 min.

Since <ε 2> depends on both dislocation density and dislocation interaction, experimental data have been fitted using the relationships determined by Wilkens [12-13] for some simple dislocation distributions, i.e. free dislocations inside the grains (I) and dislocations grouped in tilt boundaries (GB).
R is the distance between dislocations inside the cells, D the distance between the cell boundaries, d the distance between the dislocations in the boundary, ρI the dislocation density inside the grains, ρGB the dislocation density in tilt boundaries and ρT = ρI + ρGB the total density. 4.
Fig. 2 displays the total martensite volume fraction and relative amount of transformed martensite df/(1-f) vs. the number � of shock loads (peak pressure = 27 GPa, pulse duration = 15 µs).
Table 2- Total plastic deformation ε, martensite volume fraction f, mean grain size , dislocation density ρ, stacking fault probability α and ratio between the intensities of {111} and {200} XRD reflections after successive shock loads
For � = 4, in correspondence of the passage from stage I to stage II, the dislocation density is of the order of 1015 m-2, the mean grain size is 11 nm and the stacking fault probability reaches its maximum (α = 0.021) thus the mean distance between faulted {111} planes, d111/α, is ≈10 nm being d111 = 0.208 nm.