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In this study, Al-Mg alloy plates with three kinds of crystal grain sizes were used.
In the case of large grain size, 3000μm, the strain concentration occur at a certain specific crystal grain in early stage of plastic deformation shown in Fig4(b).
But, the grain size become large, the order of the strength turns over as shown in Fig.5(c).
That of grain size d=42μm also shows the similar tendency.
The crystal grain boundary shape was approximated by Voronoi multi-divisional model.

For the non heat treated samples, glassy regions were revealed, by centered dark field images, using diffuse scattered electrons, to be located at three and four point grain junctions.
Stress exponents near unity, related to grain boundary accommodation processes were obtained for low temperatures and for heat treated samples.
The deformation processes in these cases were correlated to stress concentrations at grain boundary and triple point junctions, caused by grains rotation and sliding, accommodated by cavitation.
For a series of materials in the Si-Mg-O-N systems it has been deducted that creep can occur by a number of mechanisms, including (6,19,20) diffusional creep, cavitational creep, grain boundary sliding accommodated by the elastic deformation of constrained grains and hardening due to compositional change induced by oxidation.
Clarke: Techinical Report, AFOSR Contract Number F49620-77- C-0072, (1978)

The strength of Cu-Ag alloys is determined by a number of strengthening mechanisms, which to a certain extend influence each other.
Work hardening originates from the cold work, that is applied in order to prepare the wire in its final dimension, and thus takes into account both, the increasing number of dislocations and the decreasing grain size.
Perpendicular to the drawing direction, i.e. the shorter length scale of the grains, a mean grain size in the order of 100 nm is estimated by TEM analyses.
From Fig. 5b primary recrystallised grains can be seen, which have a mean grain size right below 100 nm.
However even coarsened grains are observed after annealing the sample at this temperature.

In order to fabricate billets with a fine-grained spherical microstructure in the semi-solid state, a number of fabrication methods have been proposed including cooling slope process [3,4], magnetohydrodynamic stirring [5], strain-induced melt activation (SIMA) route [6] and recrystallisation and partial melting (RAP) route [7].
As the temperature was 1250�C, carbides dissolved into the austenite grains and resulted in the one-phase austenite structure with grain size of 200µm as shown in Fig. 2b.
G: grain boundary; C: carbide; LF: liquid film; QL: grains from quenched liquid.
During the austenite growth stage, the combination of austenite grains swallowed some grain boundaries and entrapped and concentrated the alloying elements which once located on those grain boundaries.
Even clusters of small grains existed.

In case of a two-phase ceramic composite [1–13] the number of unknown material and interfacial constants, that have to be calibrated experimentally, increases rapidly [14, 15].
The only material parameters in this model are two Lame constants for each phase and two damage constants, both for the bulk grain and the grain boundary.
Lowering the limit strain for the grain boundary (force between two points that belong to different grains) mimics a weak GB and privileges intergranular fracture.
Further damage propagates mainly through grain boundaries.
Acknowledgement This work was financially supported by Ministry of Science and Higher Education within the statutory research number S/20/2015.

The number of cycles to cause complete failure was taken as fatigue life ( fN ).
The alloy after solution heat treatment has an average equiaxed grain size of 110 mµ .
Small discrete carbide particles probably being of the MC types are found to be present in both the interior of the grains and at the grain and twin boundaries.
A TEM observation of the carbide particles in both the interior of grains and at the grain boundaries are typically shown in Fig.3.
TEM observations exhibited that at low strains ( %2.0grains, while at high strains ( %2.0>apε ) large number of slip bands with more than one slip system were seen within the grains.

In addition to the differences on protein content, there are also differences on wheat grain shape, grain color, grain weight and many other characteristics between these materials.
Assume that the number of samples M and the number of wavelengths K make up a near-infrared spectrum of absorption matrix XM×K, denoted by xk(0) and N(Nnumber of wavelengths we need to extract.
The number of input layer node is 8 and export layer node is 1.
Input is 8 sensitive wave points and export is the corresponding grain protein content.
Maximum number of training steps is 10000.

The higher vibration frequency is, the more the globular grains are and the finer the globular grains is.
The microstructure takes on fine globular grains for lower pouring temperature, whereas many clubbed grains appear when the pouring temperature is higher.
The results show that lower temperature is avail to the formation of fine globular grains.
The increase of the chilling rate can help to obtain more fine globular grains.
Acknowledgements This work is sponsored by the National Natural Science Foundation of China under the grant number of 50471065.

Through the mechanical analysis about the sand grain in the downstream of the pipe, the critical condition about of scour start is derived.
Through the mechanical analysis about the sand grain in the scour hole, the maximal scour hole depth is got.
And they point out that the KC number is the major parameter to control the scour hole depth in regular wave.
The sediment grain can be assumed as sphere, so ,d is the medial grain diameter.
So the seepage force can be written as: (4) The submerged weight of the sediment grain, W is (5) Where, s is the specific gravity of sand grains (), is the specific weight of sand grains, is the specific weight of water[19].

The numbers and locations of the thermocouples are also shown in Fig. 1.
The structure of the specimen in the as cast condition exhibits coarse equiaxed grains in the center and finer grains in the chill zone close to the die wall.
By increasing vibrations’ intensity up to 20g and reducing the grain size, a higher number of ceramic particles is detected at grain boundaries rather than in the interdendritic channels (Fig. 10b).
At the highest vibrations’ conditions, with a grain size about 100 µm, the reinforcement exclusively segregates at grain boundaries (Fig. 10c).
While the SiC particles are preferably entrapped in the interdendritic regions in the castings solidified without vibrations, by increasing vibrations’ intensity and reducing the grain size, a higher number of ceramic particles is detected at grain boundaries rather than in the interdendritic channels