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A minimum number of five specimens were tested for each experimental condition.
Moreover, it is found that SiC particles are mainly located at the grain boundaries and surround ZrC or ZrB2 grains (as shown in Fig.2(c)).
The average grain size decreases from 4 µm for ZS to 2.8 µm for ZS20B.
The grain sizes are similar between 4µm and 3.8µm.
This refinement feature of the grains further presents in the case of sample sintered with higher content of 20vol.% ZrB2, as shown in Fig.3(d), and the grain size appears to be 2.8 µm.

Noticeable refining of austenite grain is observed, and grain boundaries become thinner.
Highly disperse oxicarbonitride inclusions are distributed inside an austenite grain (refer with: Fig. 2).
The actual grain size and topography are determined by statistic calculations with the use of Gaussian curves.
If Νs is an actual number of particles in the intersected surface, and Ν΄s is an actual number of particles in the replica, then: α · Νs= Ν΄s
The summary data on particle size and topography obtained by studying a large number of replica images are given in Table 2.

The contradiction between two measurements was studied by microhardness of AlSi7 grain and eutectic mass materials.
The microhardness increase revealed on grain measurement for AlSi7 alloy samples, explain the changes of HV5 hardness.
Other explanation of HV5 changes could be the growth of grain of α phase and refining of silica lamellae present on the eutectic mass.
The high number of measurements allowed us to avoid the data errors interpretation.
World, Vol. 7, No.2, p. 69-71, 1999 Fig. 6, Grain HV0.01 microhardness for AlSi7 alloy A, B and C samples Fig. 7, Eutectic HV0.01 microhardness for AlSi7 alloy A, B and C samples

A large number of pores existed in oxide layers which leading to a poor oxidation resistance.
For Ti3SiC2 matrix composites, rutile grains in oxidation layers were refined due to the introduction of the second phase.
For Ti3SiC2 matrix composites, rutile grains in oxidation layers were refined due to the introduction of the second phase.
The other dark region was SiO2 which combined with rutile grains to form a compact protective layer (C region).
A large number of pores were existed in oxide layers which leading to a poor oxidation resistance. 2) For Ti3SiC2 matrix composites, rutile grains in oxidation layers were refined due to the introduction of the second phase.

This procedure is repeated until the desired number of grains is obtained.
The deformation in each grain is taken to be identical to the macroscopic deformation of the aggregate.
Taking the volume fraction of each grain to be identical, the macroscopic stress, σσσσ , is obtained from averaging the Cauchy stress σσσσ in each grain over the total number of grains.
In these analyses, texture models with 1600 grains were used.
The 1000 grain texture models shown in Fig. 1 were used.

The research objective is a laboratory research on the selection of acid compositions for bottomhole formation zone treatment for a number of low-permeability reservoirs in Western Siberia.
The paper presents laboratory research on the selection of acid compositions for bottomhole formation zone treatment of a number of low-permeability reservoirs in Western Siberia.
Table 1 Lithological features and PPP of reservoir units of a number of fields in Western Siberia.
Core sampling interval [m] Lithological-petrographic description of rocks Porosity [%] Perme-ability [n‧10-3 μm2] Carbon-ate content [%] Barsukovskoye PK19-20 3224 1703.0-1711.0 Intercalation of sandstones, siltstones and mudstones; fine-grained sandstone 27.6 137 6.8 Komsomolskoye PK18 6122 1527.0-1534.0 Medium fine-grained sandstone with sparse deposits of carbonaceous micaceous material 25.5 44 2.9 AP5 6122 1862.4-1867.0 Sandstone with frequent deposits and interbeds of carbonaceous clay material 25.9 168 0.9 BP63 6122 2331.5-2337.5 Siltstone homogeneous fine-grained sandstone 18.6 15 0.4 Peschanoye YUK2-3 623 R 2293.0-2293.5 Fine-grained sandstone with interbeds to medium fine-grained sandstone 17.4 12.5 2.4 2293.0-2293.5 Fine-grained sandstone with deposits of carbon detritus with an admixture of siderite 17.4 10.2 0.7 2293.0-2295.0 Fine-grained sandstone with deposits of carbon detritus 21.4 18.2 45.5 YUK4 623 R 2330.0-2330.5 Fine-grained sandstone with frequent debris of mudstone
The solubility of asphalt, resin, and paraffin deposits (ARPD) in compositions of organic solvents has been researched for a number of design objects.

Further deformation, up to 8% of plastic strain at 10-3 s-1, leads to an increase of the number of prismatic dislocations (Fig. 2-a).
Grain boundaries are shown with dotted lines.
Anyway, the increase of internal stresses with plastic deformation has often been related to strain incompatibilities between grains because of the anisotropic behavior of Zircaloy-4 and limited number of slip systems [4,5].
Strain incompatibilities between grains can therefore account for pseudo-cleavage activation on strain-hardened Zircaloy-4, because of dislocation number increase.
Moreover, in grains primarily well oriented for prismatic slip, further deformation becomes harder due to strain-hardening induced dislocation number increase, which is about to limit plastic accommodation for fluting, and enhance cleavage-like cracking.

A large number of researches have been conducted to optimize corrosion resistance of magnesium alloys, and it have been confirmed that the poor corrosion resistance of magnesium alloys is mainly attributed to the following two reasons.
There are a large number of second phase particles (50- 300 nm) in diffuse distribution, and most of them are Mg2Sn phase which precipitated out during hot extrusion.
In HI-EX alloy grains are refined (~3.5 μm), and coarse broken particles (2-6 μm) and fine precipitated particles (0.5-1.8 μm) are located in extrusion direction (Fig. 1b).
A further analyze on the grain size and phase composition of the RS-EX alloy is carried out by TEM with EDS, as shown in Fig. 2.
Summary Rapid solidification and hot extrusion causes fine grains (~250 nm)and uniform second phase particles (50-300 nm) for TAE542 alloy, while conventional hot extrusion lead to relatively coarse grains (3.5 μm) and particles (0.5-6 μm).

Thus, Ndα-SiAlON forms elongated grains most readily, while Yb-α-SiAlON does not form elongated grains under normal heating conditions.
It can be achieved by reducing the number of nucleation sites, lowering the driving force, or slowing the nucleation kinetics.
Therefore, they are highly effective in producing elongated grains.
Figure 10: The measured number of large grains (experimental) and estimated number seeds revealed on a section.
Grain width in (b) is half that of (a) but same area fraction of elongated grains is maintained in both microstructures.

There is still not one single machine which can deal with all kinds of material grain.
There are some gaps, cracks and tiny holes on the grain surface.
These defects make the stress highly concentrate and urge the grains' break.
As the velocity of the grain is so fast, mainly kinds of the grain can be conferred as absolute elastomer.
the kinetic energy of the grain is ΔE＝ (4) whereΔE is the kinetic energy of the grain, m is mass of the grain, U is the velocity of the grain.