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In order to meet the requirements of high voltage vacuum circuit breakers, a large number of investigations have been made on the insulation designs of vacuum interrupters [1,2] and double-break vacuum circuit breakers [3-5].
It is reported that the breakdown strength can be enhanced significantly by microstructural refinement of the contact materials along with the decrease in the grain size of the breakdown weak phase.
Therefore, the intermediate layer is mainly consisted of Cr grains.

This gas mixture produces diamond films where the grain size is around 3-5 nm, and they have little or no graphitic impurities at the grain boundaries.
The numbering (a-c) refers to different magnifications.

Most industrial materials are polycrystalline aggregate having fine grains.
X-ray stress measurement theory for use of two-dimensinal detector If incident X-rays are inclined from a sample normal and the Debye ring is measured, the independent strain εL33 (referred to as εα below) of sufficient large number for stress calculation will be obtained from the whole Debye ring.
This shows that the specimen surface may have fine and random oriented crystal grains.

Iron (Fe) 61.36 Balance Aluminum (Al) 0.72 No have Cesium (Cs) 0.43 No have Chlorine (Cl) 0.29 No have The carbon, nitrogen and oxygen elements were not detected in the results of EDX steel studied, because of the limitations of this technique is the identification and quantification of low atomic number elements with low percentage values.
Aluminium structures of steel acts as deoxidizer, degassing, grain refiner and especially to soothe low carbon steels by controlling the grain size of the austenite [13].

When the carbon content is too high, the excess carbon will attach to the boundaries of two grain boundaries, so that the density of the sintered silicon carbide ceramics is reduced.
The excess carbon will attach to the silicon carbide grain boundaries, thereby affecting the sintering density, and the mechanical properties of silicon carbide ceramics are reduced.
It can be seen from the figures that a and b contains a large number of pores showing a poor compactnes, while b contains less pores than a.

Introduction Superabrasive grinding wheels commonly are consisted of metal bond, resin bond or vitrified bond wheels with grains of diamond or Cubic Boron Nitride (CBN).
Summary The dressing operation of superabrasive wheel is one of most important process for protruding the grains of wheel to improving the efficiency of grinding process.
Characterization of dressing processes by determination of the collision number of the abrasive grits.

However, problems of thixoforming are higher feedstock material price and limited number of suppliers.
Therefore, the pressing-out of the liquid phase from the thick zone of piston into the thin contributes to the generation of grain-boundary slit porosity, which is not healed at the stage of forming, even at the extremely high values ​​of the force of the hydraulic press used.
This is due to the fact that it’s intrinsically weak grain boundary strength; casting defects (i.e. gas porosity, shrinkage porosity, and microporosity) has not been completely eliminated by heat treatment.

Diffraction peaks become shaper and stronger with the increase of heat-treatment temperature, which indicate ZrO2 grains grow gradually and crystal phase tend to be complete.
ZrO2 sol grains grow gradually and crystal phase tend to be complete when the heat-treatment temperature is about 700 oC.
Acknowledgements This work has been supported by the Hebei Province Science and Technology Support Program (Grant No. 12211103), National Students' Innovative Entrepreneurship Training Program (Item Number 201210081002) and Hebei United University 2012 Innovation Experiment Program for University Students (No.

When grinding Al2O3 wheel, the value of ε ranges from 60 to 90% [15]; when grinding CBN wheel, this value is about 84% [16]; α is the thermal diffusivity of the part material, α can be found in [17]; M is the mesh number used in the grading sieve of the grinding wheel; n is a positive coefficient, ranging from 0.8 to 1 [18]; k is the thermal conductivity of the material, k can be found in [19]; f is the ratio of the volume of the grinding grain cut to the surface of the part, f = 0.5 [20]; r is the chip width to thickness ratio, r ranges from 10-20 [21]; t is the depth of cut; vg is the speed of the grinding wheel; vw is the workpiece speed; dg is the diameter of the grinding wheel; dw is the workpiece diameter, when surface grinding, dw=∞, so it can be considered dg.dw/(dg+dw)= dg; s is the percentage of the volume of the grinding grain compared to the total volume of the grinding wheel, s value ranges from 12.5% to 37.5% [22].

Table 1 Physical and mechanical characteristics of the original soils Name of the characteristic Type of soil Sandy loam easy Sandy loam Natural humidity, Wnat, % 19,8 9,55 Moisture at the yield point, WL, % 34,7 18,8 Humidity at the rolling edge, Wp, % 25,6 12,84 Number of ductility, IL 9,1 5,96 Maximum density, ρмах, g / cm 3 1,39 2,03 Optimal humidity, Wopt, % 20,0 8,2 Table 2 The particle size distribution Sieve size, mm 2 1 0,5 0,25 0,1 <0,01 Sandy loam easy (loamy soil) Private residues, % 0,00 0,05 0,38 3,22 8,46 84,99 Full residues, % 2,90 2,95 3,33 6,55 15,01 100,00 Full passage through a sieve, % 97,10 97,05 96,67 93,45 84,99 0,00 Sandy loam Private residues, % 4,21 12,62 64,38 10,31 4,77 5,02 Full residues, % 2,90 15,52 79,90 90,21 94,98 100,00 Full passage through a sieve, % 97,10 84,48 20,10 9,79 5,02 0,00 To stabilize the soils used stabilizing additives of the trade mark «Chimston» («Chimston-1» and «Chimston-2») produced by the Limited Liability Company Scientific-Production
The method of laboratory determination of granulometric (grain) and micro aggregate composition ".
Ultimately, the introduction of the Chimston-1 additive results in an improvement in the mobility of the soil particles relative to each other in the presence of a thinner and uniform film of water around them, which improves the packing of the grains during compaction and high density is achieved with less water.