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Only one or two slip systems seem to be active in almost each grain.
No special affects of the grain, sub grain or twin boundaries can be observed.
Most of the grains contain only bands with one particular orientation but in some grains, bands with two different orientations can be observed.
The width of these bands is larger than the width of those observed after experiments and their number is probably underestimated.
These bands are too large and their number is underestimated.

Northern Shaanxi is one of the pilot zones for implementating of Grain for Green Project.
Meanwhile, the carbon (C) stock benefits of Grain for Green Project were analyzed through the different land cover types and slope gradients.
The results in this study indicated that the Grain for Green project resulted in good C stock benefits.
Introduction Northern Shaanxi, a typical epitome with all features of the Loess Plateau, is one of the first pilot regions of implementation Grain for Green project in China.
The estimate formula is represented as: (2) Where i is the number of monitored years (1-8); Slope explain that trend changes of the NPP in this pixel from years 1 to 8.

Diffusion bonding of Ti-6Al-4V titanium alloy in the coarse grained and ultrafine grained state was performed.
Since grain boundaries play a major role in diffusion, it can be assumed that reducing the grain size and increasing the surface area of grain boundaries should improve diffusion.
UFG and CG couples of samples, with average roughness Ra=50 nm, bonded at temperature of 725°C have approximately the same number of pores of similar shape (Fig. 4a and Fig. 4b).
Zhu, Grain boundary diffusion and creep of UFG Ti and Ti-6Al-4V alloy processed by severe plastic deformation, Proc. of Ultrafine Grained Materials III. (2004) 621-628
Valiev, Grain boundaries in ultrafine grained materials processed by severe plastic deformation and related phenomena, Materials Science and Engineering A. 540 (2012) 1– 12

Both XRD and TEM showed that a small difference in grain sizes remains even after 5 revolutions of HPT with smaller grain sizes at the peripheral region of the sample.
The increase in microhardness was attributed to further grain refinement, the formation of a larger fraction of high-angle grain boundaries and grain boundaries being closer to equilibrium after recovery.
Fig. 1 indicates that the local microstrain undergoes marked oscillations as a function of the number of rotations of HPT.
In the HPT state, the grain size was about 500nm, and the adjacent grains showed similar contrast, a characteristic of low-angle GBs; while in the recovered sample, many grains having sizes of about 200nm or less were observed.
Conclusions The local level of microstrain showed dynamical oscillations as a function of the numbers of rotations of HPT as a result of evolution of crystalline defects during the HPT procedure.

Investigation of the microstructure showed the primary alpha grains to align with the direction of torsion for the forward test and return to an equiaxed shape on strain reversal, though a significant numbers of deformation twins are formed and retained after the full strain reversal.
Misorientation analysis of the αP grains shows misorientation accumulations of up to 20˚ in individual grains, indicating that a significant amount of the applied macroscopic strain was accommodated by the αP grains.
This change in strain path has also returned elongated αP grains back to an equiaxed structure.
This observation may explain the significant drop in σss on strain reversal as grains of favourable orientation have reduced their dislocation density, reducing the effective number of barriers to further dislocation movement.
Upon reversal there is significant reduction in the accumulated misorientation within the αP grains

Grain Boundary properties.
The total system energy at a given time (MonteCarlo time) is given by E = 1 2 γ(Si,Sj) 1−δSi S j( )+ F Sj( ) { } i n ∑j N ∑ (1) Where, E is the system energy, the first summation is over the total number of orientations, grains, in the microstructure, the second summation is over nearest neighbors, 26 in this case, γ(Si, Sj) is the interaction energy between different orientations (grain boundary energy) and F(Sj) is used to introduce stored energy as function of grain orientation in the system.
× exp −∆E kT       ∆E > 0        (2) Where, µ(Si,Sj) is the mobility of the grain boundary between grain i and grain j and γmax and µmax are the maximum grain boundary energy and mobility respectively.
As the value of T/Tc increases the level of anisotropy, in high angle grain boundaries as a function of grain boundary misorientation, decreases.
Acknowledgements The authors would like to acknowledge project support under contract number DE-FC07- 01ID14194 from the Office of Industrial Technology of the US Department of Energy (DOE) and from the MRSEC at Carnegie Mellon University under NSF grant number is DMR-0520425 for providing access to experimental facilities.

Since it’s impractical to obtain the austenite grain size distribution in the beam blank during industrial hot rolling, the calculated rolling loads are compared with the mills loads instead of grain size comparison between the predicted average value and the real ones. 1.
A number of mathematic models [1-3] have been developed in the past few decades.
Results and Discussion Fig.3 describes the temperature distribution in the hot blank after a 30s inter-pass interval, the temperature varies form 1087℃ to 1236℃ in the whole blank.Fig.4 describes the distribution of austenite grain size in a hot blank after a numerical simulation of an 11-pass hot rolling process, and it shows that the smallest grain size 34μm was achieved in the web of the blank.Fig.5 describes the evolution of austenite grain size in different parts of the hot blank during an 11-pass hot rolling process.
Fig.4 Distribution of austenite grain size in the hot blank Fig.3 Temperature distribution in the hot blank after 30s inter-pass interval Fig.5 Evolution of grain size in the hot blank during multi-pass rolling Fig.6 Comparison of rolling force between measured and computed values 5.
Spreadsheet Modeling of Grain Size Evolution during Rod Rolling [J], ISIJ International, 1996, 36 (6): 720-728

The hybrid material model developed by the strain gradient theory in which the dislocation cell structure, cell densities (interior and wall) engaged to define the polycrystalline aggregate and calculated the dislocations in a grain (grain interior and grain wall).
In the thick sheet, it easy to analyze the effect of a large number of grains in the thickness direction but for the thin sheet, no mechanism has been developed yet.
The grains located at the free surface of material have less hardening effect than the inner grains, so the strengthening effect in surface layer can be neglected [22].
Grain size effect of thickness/average grain size on mechanical behaviour, fracture mechanism and constitutive model for phosphor bronze foil.
"Size effect on the tensile strength of fine-grained copper."

The solute diffusion in the liquid and solid phases was also considered in developing a grain growth model.
Dilthey and Pavlik [9] used a modified cellular automaton model to simulate grain morphology.
Simulated dendrite grain growth of Al-7wt%Si alloy.
This is related to the fact that an increase in cooling rate will lead to an increase in undercooling and the number of nuclei activated in one certain domain, which causes the grains to refine.
The program code developed can predict not only the grain structure of the castings but also the textures inside the grains, such as branching, dendrite morphology and eutectic microstructure.

A number of special techniques of plastic working has been successfully utilised for processing the ultrafine grained metallic materials [5].
The grain/subgrain sizes were measured perpendicular to the rolling axis by a linear intercept method.
Appearance of individual equiaxed annealed grains takes place upon heating to temperatures of T ³ 500°C.
At 400°C, no changes in the hardness and the transverse grain/subgrain size take place in the both steels during annealing.
Such a uniform mixture of grains of different phases impedes effectively any discontinuous grain growth during annealing.