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During grain coarsening the average grain size increases.
The grain boundaries have an excess energy to the grain interior.
If the grain coarsening is described phenomenological it could be seen, that in the grain relations the small grains become smaller, and the big grains become bigger.
The difference came from the stochastic nature of the automaton and the finite number of the cells.
This happens due to the finite number of cells in the universe.

Grain growth kinetics of accumulative roll bonded AZ61 alloy H.
Based on the experimental results of grain growth during annealing treatments, the grain growth exponent and the activation energy for grain growth were determined.
However, with limited number of slip systems and hexagonal close packed structure, magnesium alloys exhibit limited formability at ambient temperatures.
It shows ultrafine grains consisting mainly of α-Mg phase with an average grain size of 0.5 µm.
Wang, Grain growth kinetics of a fine-grained AZ31 magnesium alloy produced by hot rolling, J Alloys Compounds. 493 (2010) 87 – 90

XRD, FESEM and EDS results showed that with increasing TiB2 content, the matrix of TiC-TiB2 composite ceramics transformed a number of fine TiB2 platelets from the TiC spherical grains, and fine-grained even ultrafine-grained microstructures were achieved in solidified TiC-50mol% TiB2 due to eutectic growth under rapid solidification of the ceramic.
In contrast, for TiC-60mol%, 66.7mol% and 80mol% TiB2, the matrix of TiC-TiB2 ceramics transformed the one consisting of a number of TiB2 platelets, and some coarsened TiB2 platelets were observed while a few of irregular TiC grains were distributed in between TiB2 platelets, as shown in Fig. 1 (d), Fig, 1 (e) and Fig. 1 (f), respectively.
However, for TiC-50mol% TiB2, the refined microstructure that a number of fine TiB2 platelets were embedded irregularly in TiC matrix, was achieved by comparing to the other material of different compositions, as shown in Fig. 1 (c).
Meanwhile, the highest hardness obtained in TiC-50mol% TiB2 also is attributed to the achievement of fine-grained or ultrafine-grained microstructure in the near-full-density solidified ceramic.
In contrast, For TiB2 platelets of high elastic modulus, because they directly grow from liquid ceramic, their grain boundaries become poor interfaces in the ceramic due to a number of defects at their grain boundaries, so intercrystalline fracture in the ceramic is inclined to takes place at the boundaries of TiB2 platelets.

However their poor ductility due to a small number of slip systems in the basal plane and a difficulty in dislocation activities in the non-basal plane limits further applications.
The SPD processed materials show not only the unique physical and mechanical properties inherent in various UFG materials but also a number of advantages over nanostructured materials manufactured by other methods through powder processing.
With increasing the ECAP processing temperature, the number of cracks decreased, because the activity of non-basal slip systems [4], hence the ductility of Mg, increases with increasing temperature.
The initial grain is equiaxed and larger than 1 mm, showing a recrystallized state with some twinning in the grain interior.
In addition, Mg alloys with fine grains of less than 10 µm (this is similar to our small grain size!)

This dissolution resulted in grain separation at the surfaces and finally in fracture.
And the dissolution was concentrated on those grains adjacent to pores rather than those in the dense region.
And the hydroxyapatite showed characteristic absorption bands with maxima at the wave numbers of 1095, 2043 and 568cm -1 which should be ascribed to the asymmetric stretching vibrations of P-O groups in the PO4 tetrahedron.
It was probably due to the absence of grain boundary secondary phase.
TEM results showed the secondary phase around the grain boundaries was significantly decreased.

The traditional temperature and humidity monitoring system of grain depot used to realize in wired network which needs to deploy a large number of cables.
We present a solution of monitoring temperature and humidity of grain depot based on wireless sensor network(WSN).
WSN is composed of a large number of sensor nodes distributed in the monitoring range, in which all nodes consist of a distributed wireless network in Ad hoc[3,4].
Once the temperature and humidity of a grain depot exceeds the warning limit, the system will alarm in sound and light.
It automatically calculates the maximum, minimum and average values of temperature and humidity of grain depots.

Using atomistic simulation technique to modeling the PMMA-b-PVP melts at meso-scale is still difficult nowadays because of the huge number degrees of freedom in the system.
A possible solution to this problem is to reduce the number of degrees of freedom through the mapping of an atomistic model onto coarse grained structures.
Fig. 1 Illustration of the coarse graining mapping schemes for (1) PMMA and (2) PVP.
Coarse-Grained Simulations 3.1.
The coarse-grained dynamic simulations are faster than atomistic ones.

Their reliability is however critical as they control an increasing number of on-board applications.
Pulses are 120 Amp; components are kept at 25°C. ton: pulse duration; Nf: number of cycles at failure (see text); 1fN : number of cycles at which the first component (out of the batch of 10) failed.
It should be emphasized that the number of fatigue cycles is not a pertinent parameter: indeed it is observed that the evolution of RDSon is not directly connected to the number of fatigue cycles (Fig. 2b).
stressed components for which RDSon is still in the specification limit and consequently the delamination at the power die/heat sink interface is low) the mean grain size increases with the number of fatigue cycles, which suggests that grain growth in the source metallization may be a good marker for quantifying the ageing of these components.
However in failed components (RDSon out of the specification limit), the grain growth is much faster than in operational ones, even if the number of fatigue cycles is lower.

Grain growth and mechanical properties of nanograined bulk Fe-25Ni alloy Hongbin Wang 1,2, Xiaoyu Wang 1, J.H.
Grain growth.
A number of more recent theoretical treatments came to the same conclusion that normal grain growth should ideally occur in a parabolic manner [10]: ktDD =− 2 0 2
According to the results of the phase transformation during heating mentioned above, the grain growth occurred in the single austenite (fcc) phase region and the possible reasons of this inhibition of grain growth (n is much low than 0.5) are anisotropic grain boundary energy, the solute drag effect and pinning forces due to obstacles to the grain boundary migration such as porosity and second phase particles [11].
At a grain size of 140nm, the hardness of the annealed sample is 684.7MPa.

Every limestone grain model is built respectively and the space among the grains is hot air.
In this figure, the circle is the limestone grains, the space among the grains is hot air, X is the distance between the centre of the adjacent grains, r is the radius of the grain, A/B/C are the grains at different position.
Nu=hl/λ=CRem (2) Where, Nu is Nusselt number; l is the diameter of the tube; λ is the thermal conductivity of the fluid; Re is the Reynolds number of the fluid; C and m is defined in the calculation parameters table of the air cross-flow tube bundles.
(2).Defining the material number of the hot air as 1# and the limestone as 2#.
So it can be said that change the structure of the preheater properly to increase the number of the limestone grain in the high temperature area to improve the heat efficiency.