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It has been reviewed that a number of proteins played important roles in mediating the proliferation/differentiation of the osteoblasts and their content changed with the proliferation/differentiation process [3].
(a) (b) Fig. 1 Typical FESEM pictures of the nanostructured HA coatings at their surfaces showing nanosized grains of ~50-100nm, (a) spherical shaped grains, (b) rod-like grains.
The coating with more rod-like grains showed higher MTT value, hence the more proliferated cells (the ratio of absorbance is proportional to the cell number).
The results might indicate that, compared to the spherical grains, the rod-like nanosized grains would be more capable of promoting attachment and proliferation of the cells.
Furthermore, it was found that the rod-like nanosized grains triggered attachment/proliferation of more cells than the spherical nanosized grains.

The general problem in comparing single crystal and polycrystal is that the slip pattern of individual grains in a polycrystal is affected by grain boundary.
However, since multiple slip is required to be activated within individual grains for inducing coherency of grains across their grain boundaries in polycrystal, comprehensive research on the orientation rotation behavior inside individual grains is also very significant.
The single crystal was taken from a pure alumimun plate with an approximat grain size of 5 cm.
As strain increases, the color of each grain is observed to be changed from single color to similar or dissimilar colors, indicating that a grain with single orientation is divided into several subgrains by applying deformation.
References <001> <111> <101> B A C [112] C Journal Title and Volume Number (to be inserted by the publisher) [1] J.F.W.

Such problems have been known to occur due to the precipitation of γ2 phase and the formation of larger grain size in the process[3,4].
Ternary based alloy, in Fig. 1(a), shows large average grain size of 620 �, but it decreases to 60 � by addition of alloying elements.
It suggests that misch metal as a alloying element has a role of inhibition of grain growth due to the dispersion at grain boundary or within grain.
It is seen that, for both alloys, grain size increase slightly with the treatment for 24h and at 100� whereas phase transformations do not occur.
Differences of transformation temperature among the curves with change of number of thermal cycling are due to the easy transformation of β1' and γ1' to α or γ2 phase after the third thermal cycling.

At 980°C,when theα2 phase grain size changed from large to small then large and the cavitations in the fracture surface were larger and deeper with decreasing strain rate, the alloy showed the larger elongation and the lower flow stress.
3.3×10 -2 s-1 to 5.5×10 -3 s-1 , the kinetic energy of the atom is further increased, the difference in strength between the soft phase and the hard one is decreased, grains insert each other, and the number of grains participating deformation is also increased.
When the specimen is deformed at the optimal strain rate , the recrystal α2 phase particles are still equiaxed (Fig.4(c)), but they have already grown up,it is related to the merge and the growth of the recrystal α2 phase grains due to accumulative recrystallization.With decreasing strain rate, the grains are coarsening at directions that is disadvantage for deformation, so the formed dimples are relatively larger and deeper, and the fluctuation of the fracture surface is also relatively larger (Fig. 7(a)).
Grain boundary sliding is the main mechanism of superplastic deformation in intermetallics[18,19].
At 980°C, when theα2 phase grain size is from large to small then large and the cavitations in the fracture surface are larger and deeper with decreasing strain rate ,the alloy shows the larger elongation and the lower flow stress. when the specimen is deformed with the strain rate of 3.3×10 -4 s-1, the recrystal α2 phase particles are still equiaxed, but they have already grown up.It is related to the merge and the growth of the recrystal α2 phase grains due to the accumulative recrystallization.

The material removal results from a large number of cutting edges with different material removal characteristics.
By investigating the single grain engagement with adequate approaches, it is possible to draw conclusions about the mechanisms and interrelations of multi-grain collectives [3].
The cuts of the single grains along the contact length can be seen clearly.
At the entry section a small single grain chip thickness is present.
At the exit section of the contact zone the single grain chip thickness is at its maximum value and the grains face the highest load.

In addition, oxygen coordination number, CN around Nb5+ ions was 6, while CNs around Zr4+ and Y3+ ions were 8.
There are a number of observable bulk crystals in Fig. 3(a), which is the micrograph for Pure YSZ pellet (i.e. no dopant).
The grain size and boundaries become visible at 5000 x magnification.
The increasing in grain size stops at 1.5% Nb, where it can be seen that the number of grains is significantly more than all other samples, however with smaller grains (1-4µm) Fig. 4 SEM Micrographs of Yttria-Stabilised Zirconia at 5,000 magnification with (a) no dopant, (b) 0.5% Nb, (c) 1.0% Nb, (d) 1.5% Nb.
Generally, the impedance of an ionic conductive material consists of the grain-interior impedance, grain-boundary impedance, and electrode-electrolyte interface polarisation.

This is possible with optimized number of cutting edges, which is a measure of the grain spacing and the grain protrusions which depends on the other hand on the micro and macro topography of the grinding wheel.
The scratches on the workpiece surface indicate grain breakouts.
Higher concentrations mean generally higher number of static cutting edges and lower spaces between the grits.
As already known, higher grain concentration leads to harder grinding wheel behaviour.
This project is promoted by german Bundesministerium für Wirtschaft und Technologie (BMWi) under the program Zentrales Innovationsprogramm Mittelstand (ZIM), grand number KF 2518713PK.

Besides a large number of different chemical modifications, topographic changes were frequently applied and a reaction of the bio-system was observed.
Deep grain boundaries have been excavated by the etchant as well as a surface structure on top of the grains.
Many grains exhibit a lamellar surface structure with a characteristic correlation length, which varies between different grains.
Characteristic distances between two summits of the lamellae were found between 400 and 800 nm for different grains, but the measured values only slightly varies for an individual grain.
Interestingly, a large number of filopodia ends on the lamellae summits (Figure 4, 30000 x magnification / 200 nm bar and 60000 x magnification / 100 nm bar).

Grain size (GS) was measured with colour micrographs and the intercept method.
Longer holding times merely lead to coarsening of the globules and a reduction in the number of small globules due to ripening.
Apparently, heating promotes grain growth, but as there is not enough time for the liquid to penetrate the dendrite branches, causing them to detach and form new grains, only limited growth is observed.
In the case of the samples that were heat treated for 30 s or more, even without any previous deformation or recrystallization, the grains are smaller and comparable to the as-cast grains because of the grain multiplication phenomena, were small branches wetted by the liquid, detaches, leading to the formation of new grains as described in [10].
Note that a grain can contain several globules that are in fact interconnected.

Among them, it can be mentioned: the grain size, second phases and segregation of impurities at the grain boundaries, etc.
Grain boundary sliding means a parallel motion to the grain boundary and it is responsible for 70-80% of the deformation in superplasticity of fine grained ceramics [12-14] as shown by measurement of the grain aspect ratio, by SEM and by atomic force microscopy and displayed recently by Duclos [11] in YTZP.
The extensive potential applications, together with the control of powder processing, have been the synergy for the appearance and fast development of a large number of ceramic systems with superplastic capabilities.
Their technique exploits the fact that grain boundary migration and grain boundary diffusion exhibits different kinetics.
At this second temperature, grain growth is negligible since grain boundary migration is inhibited, but grain boundary migration is still a significant driving force to allow pores to shrink by capillarity forces.