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Each particle size of abrasive corresponds to a diameter range (dmin~dmax). dmax is diameter of the largest grain for a standard grain size (mm), and dmin is diameter of the smallest grain for a standard grain size (mm).
Table 1 Sizes of dmax, dmin, and dmean Grain size # 36 46 54 60 70 80 90 100 dmax(mm) 0.476 0.354 0.291 0.255 0.211 0.178 0.152 0.142 dmin(mm) 0.354 0.291 0.255 0.211 0.178 0.152 0.142 0.114 dmean(mm) 0.415 0.323 0.273 0.233 0.194 0.165 0.147 0.128 The number of abrasive particles per unit area (grains/mm2) in the belt can be determined as , (2) Where Sg is density of coating grain (%) and rm is the mean radius (mm).
The total number of active grains (i.e. grains contributing to cutting action) within certain time is known, then (20) Then the material removal rate can be given by (21) (a) (b) Fig.4 (a) The relationship between the contact pressure and the indentation depth for the various abrasive grain size; (b) The material removal rate predictions for the various indentation depth (zirconia corundum grits, the belt speed is 10m/s, U71Mn material).
The material removal rate is smaller for larger grain size, since the number of abrasive particles per unit area contributed to cutting action is fewer at greater grain size.
The material removal rate is greater for greater belt velocity, since the number of abrasive particles per unit time contributed to cutting action is more within certain limits.

The aim of this research is to determine the hardness of the Schizolobium amazonicum Wood in directions parallel and normal to the grains.
For each direction in relation to the grain (parallel and normal) were made 6 specimens, according to ABNT NBR 7190: 1997 [10].
(2) Results and Discussions Table 1 shows the average values of hardness parallel and hardness normal to the grain (Xm), standard deviation (SD), variation coefficient (CV) and the number of specimens (x) of Schizolobium amazonicum Wood.
Average values of hardness parallel and hardness normal to the grain of Schizolobium amazonicum Wood [MPa].
Hardness fH0 fH90 x 6 6 Xm 27 15 Sd 6 4 VC [%] 22 25 The average hardness of the Schizolobium amazonicum Wood in the direction parallel to the grain equal to 27 MPa was higher than that determined in the direction perpendicular to grain, this is due to the anatomical composition of wood that ensures greater strengths to wood in the axial direction relative to the grain [14, 15].

Averaging the properties in all directions is based on a large number of grains and random orientations of their crystal lattice.
Otherwise, if the models contain too small number of grains, the obtained properties do not represent the entire system and are representative for the specific grains configuration.
Reduction of dimensionality decreases the number of degrees of freedom in Eq. 11.
This, on the other hand, allows to simulate much higher number of geometrical details of the analysed structures.
First, the number of the modelled grains needs to be sufficiently large, assuring that the results do not depend on the number of grains used.

SEM and FESEM analysis displayed that the microstructure in healing area is should be was mainly ferrite, and ferrite grain growth across the interface of inner crack, and there exists should be exist many polyangular grains of several hundreds nanometer in ferrite of healing area.
The microstructure in healing area mainly is ferrite, and ferrite grain growth across the interface of inner crack.
In the healing area also a certain number of voids left, number of the voids in the grain more than in grain boundaries.
Further reduce of the void size in the grain were achieved by volume diffusion.
A further reduce of the void size in the grain boundaries were achieved by volume diffusion and surface diffusion, therefore, the number of the voids in the grain boundaries is relatively small.

At higher strains the microstructure refines by the break-up of the ribbon grains into lower aspect ratio submicron grains.
This could be simply because of the greater element distortion that results from the higher strain with the 90° die, for the same number of cycles, but may e a result of differences in die friction effects.
Cell bands can also develop HABs in regions near grain boundary surfaces and triple points, in the original grain structure, due to high local orientation gradients resulting from grain-grain interactions [8].
This leads to an increase in grain boundary area simply due to the geometric shape change imposed on a grain [18].
Acknowledgements The authors are grateful to the continued support and insight of Professor John Humphreys over a large number of years and for funding from University of Manchester EPSRC Light Alloys Portfolio Partnership (EP/D029201/1).

The recrystallized grains have no strong preferred orientation about (0001), similar to the grains of growing. 1.
(a) and (c) show number frations, and (b) and (d) show area fractions.
The grain sizes are determined from the grain structure maps based on EBSD measurements.
Fig. 4 (a) and (c) show the number fraction of grains, and Fig. 4 (b) and (d) show the area fraction of grains, respectively.
However, Fig. 4 (c) shows that the number fraction of (0001) oriented grains decreases from 31.9% at annealed state to 27.5% at deformed state.

Introduction Ear differentiation of maize female spike decides the formation of ear number per unit area and grains per panicle, which plays a key role in yield component, especially the ear number per unit area.
Grains per ear and the number of abortive grain of hybrids and inbred lines were both affected under the different shade stress and abortive rate increased while grains per ear decreased with the increase of shade stress.
Grains per ear and the number of abortive grain of the three hybrids all reduced obviously under the shade stress and grains per ear reduced with the increase of shade stress (Table 3).
Grains per ear of Shennong 98A decreased greatly and the early and middle stage abortive grains and total abortive grains increased obviously.
Shade stress could make young female ear short, grains per panicle reduce, the number of abortive grain increase and rates of barren stalk increase, which would aggravate with the increase of shade intensity and the reactions of easy barren stalk varieties were much more obvious, even caused 100% barren stalk led by female ear agenesis.

A number of studies on Inconel 690 have been carried out, of which most of them are focused on the evaluation of corrosion or tensile properties [6, 7], and the precipitation behavior and detailed observation of the intergranular carbides have not been dealt with so far.
The mean grain size was around 29.0µm±0.8µm.
Nucleation and growth of the Cr-rich carbides in the grain boundaries of the Inconel 690 require continuous Cr support through the grain boundaries because grain boundaries provide fast and easy diffusion paths.
There are two adjacent grains across a grain boundary and the two interfaces are facing together.
When we have different point of view on the grain boundary migration, wavy undulating grain boundary could be effective for an improvement of mechanical properties [8] due to increased grain boundary diffusion distance and retarded grain boundary rupture.

The increase in vibration accelerates the grain to fill the empty space between the grains.
In general, the soil grains are distinguished into: gravel, sand, silt and clay, which are commonly found in natural soil deposits in the form of mixed grains.
Amplitude is the maximum displacement, while the frequency is the number of vibrations per second.
During experiment the movement of sand grains recorded.
This was due to the greater frequency of vibration, the faster of grain movement to fill the empty space between the grains so that, the landslide field is wider.

The total mass loss of each group divided by the sample number got the mass loss of each sample in as-welded and heat-treated conditions.
In this manner the formation of a continuous network of chromium-rich phase at the grain boundaries is prevented.
But in the heat-treated sample, the number of fine carbonitride precipitates (<1μm) are in the majority.
However, the number of large particles (>1μm) are not big fluctuation in the two samples.
Table 4 Wear rate of samples Sample Wear rate(10-10g mm-3N-1) As-welded 2.41 Heat-treated 1.32 Conclusions Carbonitride particles in the haidfacing alloy were complex MX precipitate (M= Nb, Ti; X=C and N) distributing on grain boundary and dislocations of the hardfacing alloy with different number and size in as-welded and heat treated conditions.