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The MF technique has been used successfully for the grain refinement in a number of alloys including 7475 aluminum alloy and pure polycrystalline copper etc. [7].
The grains orientation transition still could be found in some grains.
The lack of a homogeneous and clearly defined array of equiaxed grains in many materials after SPD processing makes it difficult to full characterize the ultra-fine grained microstructures in terms of grain size.
While once the cell or the subgrain boundaries have been identified, the grains can simply be defined as the number of points which make up the grain, and the area of a grain in square shape can be calculated by multiplying the number of points making up the grain by EBSD test [10].
The mean grain sizes as a function of strain determined by the EBSD grain reconstruction method is shown in Fig.4.

At room temperature, high angle boundaries (HAB) are observed within some of the initial grains, and not necessarily close to the grain boundaries.
The development of intersecting microshear bands that subdivide the original grains into numerous domains is believed to be the primary grain fragmentation mechanism in MAC.
Barrelling, which tended to worsen with each additional compression, limited the total number of passes and hence the cumulative applied strain.
On the whole, the series of curves suggests that the flow stress reaches saturation after a certain number of passes.
This could indicate the start of the formation of new grains.

The number of cyclic treatment was varied from 0 to 20 cycles.
With increasing the number of heat treatment cycles, the W/W grain boundary area is changed to W/matrix boundaries by the penetration of matrix phase.
Variations of measured impact energy with number of heat treatment cycles.
This anisotropy of plastic deformation in the W grain may be increased with increasing the number of heat treatment cycles.
Residual stresses in W grains measured by XRD were also increased with increasing the number of heat treatment cycles.

Dynamic grain growth, and its related mechanisms, has been the subject of a number of studies [7-13].
The present paper concentrates on the dynamic grain growth behaviour of the SP AA5083 alloy, and particularly on the effect of rapid pre-strain on the grain size, for a given strain, relative to the grain size under constant strain rate conditions.
For each sample, over two thousand grains were analysed.
Shows (a) average grain size, and linear intercept grain sizes in (b) RD (c), TD and (d) ND as a function of time.
In the first stage there would be significant grain elongation with some grain growth, while in the second stage the grains would continue to elongate but would show significant grain growth.

Stereology of Grains in Nano-crystals T.
Grain size homogeneity can be measured and the variation in the grain's elongation.
Grain volume If the investigation of nano-materials is focused on grains rather than grain boundaries, the most natural size parameter is grain volume, V.
The density of grains can be subsequently obtained by dividing the number of counted grains, N, by the studied volume of specimen, Vo: NV = N/Vo
Principles of Saltykov reconstruction Grain size homogeneity, grain shape and grain arrangement Population of grains in polycrystals may differ not only in the mean value of their volume, V , but also in terms of the width of the grain volume distribution function.

Microstructure Evolution in Fine-Grained Microalloyed Steels K.R.
In the present steel, ferrite grain sizes of as low as 2µm have been obtained in this way.
Such process models currently exist for plain carbon and a number of high strength low alloy (HSLA) steels of up to 550MPa minimum yield strength [4].
Similar trends were also observed for the larger austenite grain size of 32 and 53µm.
Similar trends for ferrite refinement were observed for larger austenite grain sizes.

Wheat grain has been irradiated by 200 keV and 305 keV of pulsed electron beams for changing of sowing parameters.
To solve a number of practical problems of the agroindustry, the use of ionizing radiation was widely used.
To determine the total microbial number (TMN), batches of 0.5 g were selected on the surface of wheat seeds.
To determine the germination and germination energy, the number of seeds was 150 pieces for each variant.
The mass of one grain was taken as 0.028 g.

Whether this occurs depends on the misorientation between the grains and the resolved shear stresses in the affected grain.
In general, one might expect multiple dislocation pile-ups along the GB area with varying number of dislocations in each of them, as considered in an earlier publication.
To take into account the effect of the entire pile-up, the following integral has to be performed: F12PU=Nl-l0δα1l-12δα1l-δα12l2F12δα1dδα1 (9) N is the number of dislocations in the pile-up (positive and negative).
The grain diameter was taken equal to 10 mm and the number of dislocations in the pile-up was taken equal to 100, the elastic constants used are the ones for copper and the critical resolved shear stress was put equal to 20 MPa.
Nonetheless, if the Schmidt factor of the second grain is not too low, a much lower number of dislocations could produce the critical punch-out stress locally for certain combinations of misorientation and grain boundary normal.

We want now to adapt it to the grain boundary precipitation.
No deformation of lattice and no disorientation between the two grains are taken into account.
At long time (fig. 2a), one observes approximately the same number of NbC precipitates on the GB and in the bulk.
Figure 3 : Evolution of the size of the precipitate in number of atoms by precipitate during a thermal aging at T=900K and the concentration CC=CNB=0.5%at.
Figure 4 : Evolution of the size of the precipitate in number of atoms by precipitate during a thermal aging at T=900K and the concentration CC=CNB=0.5%at.

Not only cedar pollen in Japan but grass and birch pollens in North Europe [1-4] actinomycetes and fungal spores in US [5, 6] cause allergic symptom, and the number of allergy sufferers increases all over the world.
grains and orbicle substance.
The room has no open window, and therefore the total number of pollen grains is conserved.
In the present study, removal efficiency is fraction of the number of removed pollen grains to all of traced particles that are distributed uniformly in the room.
The bottom numbers indicate the flow rate [m3/min] The alphabet S stands for the smaller device width of 400 mm and L stands for the larger divice width of 450 mm.