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The results indicated that the doped Pr6O11 basically existed at the boundary of ZnO grains in the varistor ceramics, and SnO2 might enter into the lattice of ZnO grains or precipitate in reaction with Pr6O11 into Pr2Sn2O7 at the gain boundaries particularly where there were three or more ZnO grains.
The analysis of scanning electron microscopy further revealed that Pr6O11 doping would inhibit the growth of ZnO grains, resulting in decreasing ZnO grain size with increasing doping level of Pr6O11.
The calculated average ZnO grain size is summarized in Table 1.
The reason for this phenomenon may be that the radius of Pr3+ (0.113 nm) is much larger than Zn2+ (0.074nm), so most of the doped Pr6O11 are segregated at grain boundary, thus hindering the ZnO grain growth.
The varistor voltage increase may be caused by the increase in the number of grain boundaries owing to the decrease of ZnO grain size.

From activation energy values, they deduced that the creep mechanism is governed by grain boundary sliding.
In comparison to the drawn copper ( Fig.1a), this heat treatment regenerates new grains in material by primary recrystallization reaction ( Fig.1b).
The numbers of cavities and cracks decrease from the surface to the centre even at fracture, suggesting that cavities nucleate preferentially at small oxide particles created by oxygen ingress along grain boundaries during creep exosure.
In addition, the low ductility of unheated deformed material can be explained by the high number of voids in comparison to the heat treated material.
Adjepong: “Grain boundary creep in copper” Journal of Materials Science Letters, 12, (1993) 1008-1010

Grain coarsening decreases the number of intersections of grain boundaries on the surface which in turn decreases the number of oxide crystallites formed and so the possibillities of oxygen diffusion channeling between the oxide grains.
Grains and grain boundaries are difficult to distinguish because of the characteristic lancette structures of these phases.
On the other hand the sample sheet exhibits ferritic structure which grain boundaries decorated with plate likes Zr-Ge precipitations.
This is caused by the effect of grain coarsening on the top most of the sample sheet due to high temperature during hot rolling.
This effect decreased the number of oxide layer crystals during the testing because of decreasing the amount of oxygen diffusion channels.

In addition, it has been proved that fine grain size in MIM Ti-6Al-4V produces a more tolerant material with respect to fatigue load [8].
The maximum number of cycles was established at 107 cycles for presenting the fatigue life.
Lamellar colony structure is formed inside the primary β-grains at every oxygen content.
However, there is a slight reduction of fatigue strength at lower number of cycles.
At lower numbers of load cycles (106), the fatigue strength even increases from 705 to 765 MPa.

Near infrared spectroscopy can be according to the difference of absorption and reflection of near-infrared light of various pests identification of insect pests.China's grain and oil storage> specified, insect food grade standard of pest density is in proportion to the number of live worms to the division, only need to count and classification of live insects.
The detector by near infrared spectroscopy and automatic grain conveyor.
Grain conveyor to a single grain to the testing room, near infrared spectrometer scanning for wheat by near-infrared spectroscopy.
In the figure 2，4 dark spots near the image boundary are characteristic markers, the rest of the object are stored grain insects.
Rapid machine vision method for the detection of insects and other particulate biocontaminants of bulk grain in transit[J].

The reductions of carriers in grains create the depletion region in both sides of each grain.
The depletion region and grain boundary are called composite grain boundary in a joint name.
The polysilicon consist of grain and composite grain boundary.
The grain boundary is not stable.
This trapping and detrapping will change the total number of conduction carriers, which cause large nonlinearity.

Structure consists of coarse dendritic grains with carbides at grain bondaries and shrinkinge pores up to 0.5 mm in diameter - see [7,8] for comparison.
The hysteresis loops for selected numbers of cycles were recorded.
Fatigue life curves in the representation of stress amplitude σa at half life vs the number of cycles to fracture Nf are shown in Fig. 3.
Just several PSMs occurred in few grains.
Arrows show cracks along grain boundaries.

For example, the effects caused by metal grains become dominant when forming size is close to grain size, so the yield strength changes depending on the thickness or grain size [4].
Smaller parts contain fewer numbers of grains inside, and this causes the lack of formability [3].
This deformation can cause very large strain with low stress, and a number of studies has been investigated his deformation property [5,6].
After the etching, the grains were observed with optical microscope.
This probably reflects the reduction of grain boundary because superplastic deformation is caused by the grain boundary sliding.

Regions adjacent to the triple junction are rotated by more that 40 o from the parent grains, which show little orientation spread in the grain interiors [41].
Finally, we should emphasises that the number of recrystallization nuclei is very small, typically of the order of 1 per old grain, and that these are most unlikely to be detected by 2-d EBSD measurements.
This type of SIBM occurs most readily into Soriented grains adjacent to the cube bands.
Despite the importance of SIBM there are a number of unresolved issues which require attention.
Conf. on Recrystallization and Grain Growth.

These observations also proved that the zirconia phase is mainly localized at the grain boundaries of Al2O3.
The higher number of microcracks was detected in the sample containing 25 vol.% ZrO2(3Y) in comparison with samples with less zirconia due to the large amount of phase transformation of t-ZrO2 to m-ZrO2 during cooling down after sintering.
However, the addition of larger amount of ZrO2(3Y) from 15 vol.% up to 25 vol.% resulted in enhancement of sintered composite strength owing to the formation of large number of microcracks as a result of phase transformation from t-ZrO2 to m-ZrO2.
The lowest strength of sample sintered at 1650oC could be explained by the excessive Al2O3 grain growth at high temperature.
The crack path between large grains is less tortuous than that between small grains resulting in high crack growth rate and lower strength.