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A number of fabrication methods involve severe plastic deformation, SPD, and involve refinement of the coarse-grained structures to grain sizes on a nanometre scale.
Among other factors, the effect of grain refinement down to nanometres has been examined in a number of metals and alloys [1-5].
A number of them involve severe plastic deformation, SPD, and consist in transformation of the coarse grained structures to grain sizes in a nanometre range via the accumulation, rearrangement/annihilation of the crystal lattice defects, primarily dislocations, and formation of new grain boundaries with misorientations increasing with applied strain [8].
It can be easily demonstrated that vastly different grain structures may have the same average grain size.
Figure 3 shows yield strengths of 7475 aluminium alloy strengthened by (a) precipitates (grain size of 70µm); (b) grain boundaries (grain size of 70 nm) and (c) by their combined effect (grain size of 70nm + precipitates).

A very fine meshing scheme was adopted, i.e., meshing seed number used was 0.005 (i.e., total number of elements ≈ 200,000).
When the meshing seed number was changed to 0.05 from 0.005, the simulations took less time to complete and the results were only 5% on higher side of the values (to be show afterwards).
When a meshing seed number of 0.001 was adopted, a comprehensive increase in time of simulations was observed with a change in values of results less than 1% from the values shown in the article.
Deflection at the inner most point of grain (Δ)
Garrison, Grain Stress Analysis Study, AD Report No.

Impedance spectroscopy characterization indicated that the conductivity decreases as Cr concentration increases, probably due to Cr segregation at grain boundaries, which reduces grain size, increasing the number of resistive boundaries.
Table 2 presents the relative density and mean grain size of systems after sintering.
Increase in Cr concentration also leads to reduction of SnO2 mean grain size.
This decrease in mean grain size could be associated to segregation in the grain boundaries.
The Cr segregates at the grain boundary and appears to control sintering and grain growth rates.

Commercial varistors are generally made of sintered ZnO powder mixed with a number of other oxides such as Bi2O3, Sb2O3, V2O5, Pr6O11 etc.
The breakdown voltage of a varistor is inversely proportional to the grain size [2] which means that a higher breakdown voltage can be achieved simply by reducing the grain size [3].
Considering at least ten digitally acquired SEM images, the average grain size (d) of ZnO has been determined by linear intercept method using the formula [7]: d = 1.56 L / M x N (1) where, L is the random line length on the micrograph, M is the magnification of the micrograph, and N is the number of the grain boundaries intercepted by a line.
Secondary phases appear primarily at the grain boundaries and nodal points; however, occasional presence within the grains has been observed for 2 mol.% Er2O3 added specimen (Fig. 1(c)).
The microstructure of sintered pellet consists of ZnO grain and intergranular (V, Mn and Er-rich) secondary phases that exist primarily along the grain boundaries and triple points.

Stability of the results with respect to numerical parameters The influence of the number of grains and number of FEs per grain have been extensively studied using the simplest microstructure (Fig. 2 a).
The mean grain stress and plastic strain distributions depend only slightly on the number of grains provided they are higher than a few hundred (bulk grain or surface grain distributions).
In the following, the predicted curves or distributions computed by different approaches (mean-field versus full-field computations, microstructures of increasing complexity) are always compared for the same number of grains, FEs par grains if required and remote plastic strain.
Prediction of the distributions of the numbers of cycles to microcrack initiation The number of cycles to microcrack initiation, Ni, is computed for each grain.
Fig. 7 Computed distributions of mean grain number of cycles to microcrack initiation (see the criterion used in [11,18]).

With water-saving irrigation, the yield under N3 is more than that under N2, this is mainly contributed by the increase of the grain number per panicle and the thousand seed weight.
A significant increasing was found on grain number and seed setting rate in four nitrogen levels except the N4 treatment.
Under saving irrigation or traditional condition, effective panicles, grain number and seed setting rate was firstly increased and then decreased with the increase of N fertilizer (Table 1).
Water-saving irrigation was increased the average of grain number of primary rachis branches in less nitrogen (N0, N1, N2), but no significant different in treatment N3 and N4.The average of grain number of second rachis branches was reduced in treatment N1and N4 under water-saving irrigation, which indicated that less and more nitrogen both had impact on grain number of second rachis branches addition.
Zhai et al. showed that water-saving irrigation conditions could increase grain number, tillers, seed setting rate and thousand seed weight under the appropriate fertilizer.

The number of the SPPs of each alloy was more than 15 for EDS analysis.
In comparison with the tubes final annealed at 480 ℃, the number of dislocations in the grains annealed at 510 ℃ was reduced, and the grains began to transform from the fiber structure during rolling to the equiaxed recrystallized structure, but since the recrystallization was not sufficient, elongated grains along the rolling direction were remained.
With the increase of the final annealing temperature, the number of low-angle grain boundaries decreased.
(c) (b) (a) Fig. 2 Grain boundary diagram of SZA-6 alloy cladding tubes (a) Final annealed at 480℃, (b) Final annealed at 510℃, (c) Final annealed at 560℃ (b) TEM analysis showed that after final annealing at 480℃, the SZA-6 alloy cladding tube contained a large number of dislocation lines, dislocation cells, sub-grains, and deformed grains, showing the appearance of unstressed state of grain morphology (Fig. 3a).
With the increase of corrosion weight gain, the number of holes or “steps” existing between the columnar crystals increased.

As this process can be repeated, the total shear can be accumulated to give an ultra-fine grained structure having a large proportion of high angle grain boundaries.
For the fabrication of ultra-fine grained wires or fibres the original form of ECAP may not be appropriate.
This also means that the number of tortuous channels leading through the discs is strongly reduced by reducing the disc grade.
Effective grain refinement associated with the new microstructure formed by dynamic recrystallization was observed as the processing temperature was apparently too low to induce further grain growth.
Under the conditions chosen for this preliminary work, significant grain refinement was achieved.

Acid Hydrolysis and Utilization of Distillers' Grains Yan Chen1, 2, a, Rongrong Su1, 2, b, Xiaoyan Lin1, 2, c 1School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, China 2Engineering Research Center for Biomass Materials, Ministry of Education, China a copte@163.com, b supaipai@126.com, c lxy20100205@163.com Keywords: distillers' grains, hydrolysis, reducing sugar, sulfuric acid Abstract.
Distillers' grains (DG) has high cellulose contents and is suitable for conversion to reducing sugar under dilute acid conditions.
Among the many renewable energies, biomass which distillers' grains (DG) is one kind of, is the only one which could transform directly into liquid fuel, and this kind of resource is more and more important.
The FT-IR spectrum of DG powders before and after hydrolysis display a number of absorption peaks (Fig. 6).

Fig.1 Original grain for hot rolling sheet Fig.2 Grain in air cooling after heated to 900˚C Fig.3 Grain after imposed pulsating in austenite region Fig.4 Grain after imposed pulsating in ferrite region Seen from Fig.1, the initial fine grain size of hot rolled coil is about 12μm (10 grades).
The grain grow bigger after being heated.
Its growth of grain strip is more obviously compared to Fig.2.
The austenitic grain tends to uniform and large-angle grain boundaries after being imposed pulsating micro-magnetic radiation (100mT). 2.
In the tensile test, the mechanical property is in accordance with the grain size, it decreased obviously when the grain become larger.