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The morphology of the grains is fundamental to identify the type of pollen [2], and different grains differ in the surface texture.
After 24 hours naked in the air, the slide is recycled with pollen grains or other spore fallen on it by gravity, then grains are stained red with safranine.
Pollen grains from different families differ a lot in size and compactness.
In order to use fast Fourier transform (FFT) on the signature, the number of sampling points Ns is chosen as power-of-two integer.
Feature Extraction and Classification Results 1) Statistic of Global Shape Descriptor The average value and standard deviation of GSD are summarized in Table 1, the number of each family are 55 Poaceae, 44 Moraceae and 48 Pinaceae.

A general grain-boundary incremental/iterative algorithm, embedding the flow and hardening rules for crystal plasticity, is developed.
The key feature of the method is the expression of the micro-mechanical problem in terms of inter-granular variables only, resulting in a reduction of the number of DoFs, which may be appealing in multi-scale applications.
In the present work, a novel three-dimensional grain-boundary formulation for small strains crystal plasticity is described.
Formulation The grain boundary formulation for crystal plasticity is here described.
Furthermore, the polycrystalline problem is addressed using a multi-domain approach where each domain, also referred to as grain, is indicated by and its surface, also referred to as grain boundary, by .

The test was conducted using a number of 50 ml acid-washed high-density polyethylene bottles by exposing individual 2.000 g samples of the different treatments to 20 ml of a solution consisting of 0.01 mol/L HNO3.
The potassium-feldspar grains had an irregular and angular particle shape in the early stages of grinding (T0 rock).
The rock particle broke down to finer particles and the potassium-feldspar structure altered gradually and the number of void space was increased.
This showed that activated potassium-feldspar rocks could help in higher dry matter of grain amaranth.
Figure 4 Dry matter accumulation (a) and potassium uptake (b) of grain amaranth with different K supplied.

In these two conditions, pits are nucleated in grains and in grain boundaries, while in condition III (heating up to 1065o C during 1 h and air cooling followed by reheating up to 620o C during 24 h and again air cooling), pits are preferentially nucleated in boundaries of small grains.
In the as-received and treated material it is observed a reduction in the number of pits and increasing trend in the volume fraction of the artifacts, as Figures 2 (a), (b), (c) and (d).
These facts are mainly related with a number of anodic sites and anodic/cathodic area ratio variation during exposure period.
Conditions I and II, pits are nucleated in grains and grain boundaries, while in condition III, pits are preferentially nucleated in boundaries of small grains.
In these two conditions, the pits are nucleated in grains and grain boundaries, while in condition III, pits are preferentially nucleated in boundaries of small grains.

Most of the matrix was found to be composed of fully recrystallized grains with average diameters around 10 microns.
Zones characterized by finer submicron scale grains could also be identified locally as well as grains containing networks of subgrain boundaries.
In their work they consider that the stability of carbides in steels decreases with the increasing element group number.
When measuring grain/particle sizes with EBSD [5] a grain/particle is defined by the minimum number of data points per grain, the threshold boundary misorientation angle and the step size.
Humphreys has shown that a minimum of 8 pixels per grain are required for an accuracy of 5% in determining the grain size [5] The results shown in figure 5 b) indicate that the VC particles are submicron sized with an average particle size of ~400nm.

In the two-step annealed Zr-1Nb-0.12O tubes, dislocation-free recrystallized grains with a larger grain size than regularly annealed Zr-1Nb-0.12O tubes.
Creep life has been suggested to increase with increase of grain size because the contribution of the fast diffusion along grain boundaries decreases.
However, other studies have indicated that the creep rate may increase or decrease with decreasing grain size, or be grain size-insensitive in copper [6].
Both models suggest that the effect of grain size varies with experimental temperature and conditions even in identical materials and the dislocation activity near-grain-boundary regions could increase the creep rate in the small grain size region, supporting the decrease of creep rate with increase of grain size in the present study.
In general, with the increase of temperature, the number and mobility of thermal vacancies increase, causing more vacancies or impurities to diffuse to grain boundaries.

Products differ significantly in terms of grain morphology and the degree of defects in structure.
It allows the synthesis of a number of functional materials with nanometric scale, including perovskites [7, 8] without the excessive grain growth, as well as the presence of sinters.
This technique also generates a large number of defects in the crystal lattice through which the products often exhibit different properties, such as optical, catalytic or electric.
SEM images of Ca0.25Cu0.75TiO3: (a) high-temperature treatment, (b) mechanochemical synthesis High-temperature synthesis method results in grain growth (1.5 - 2.5 μm) and sintering of grains giving uneven distribution of particle size (Fig. 2a).
The milling process provides homogeneity in the distribution of grain size (100 – 500 nm) (Fig. 2b).

Spherical and more uniform tungsten grains distribute in matrix phase in 85W alloys with Ni:Cu ratio of 1:1 than that of 3:7 and 7:3.
Contiguity（CSS） defined as the relative fraction of W-W interfacial area was determined by counting the number of W-W(NSS) and W-M (NSL) intercepts in unit area and calculated by the formula[7] as: CSS = 2NSS / (2NSS + NSL).
The corresponding tungsten grain sizes and CSS values are shown in Table 1.
At lower tungsten content, volume fraction of matrix phase is larger which leads to tungsten atoms fully solving in liquid matrix and then re-precipitation on solid tungsten particles, however, lower tungsten content make total tungsten atom number of solution-re-precipitation reduce.
Table 1 Grain size and CSS of the investigated tungsten heavy alloys 85A 85B 85C 80B 88B Grain size (μm) 27 28 27 23 31 CSS 0.35 0.36 0.36 0.22 0.43 1.2 Ni:Cu ratio effect on microstructure W particles shown in Fig. 1b are more spherical and uniform than those in Fig. 1d and Fig. 1e.

Experimental results have demonstrated that the high shear unit can be used for general melt treatment, physical grain refinement, degassing and preparation of metal matrix composites and semisolid slurries.
The polished surfaces shown in Fig. 3 show that the number of pores and their size were remarkably reduced after intensive melt shearing.
The α-Mg grains are uniformly distributed with a very narrow size range.
For the conventionally cast ingot, the microstructure consists of large dendrites within elongated grains along the solidification direction.
The morphology of the grains changes from dendritic to rather globular.

Application to Welding: In order to model solidification of the weld pool using a granular approach, a number of modifications are required to the components outlined above.
A few columnar grains are also shown in (c) to highlight the difference between two major kinds of grains.
Welding microstructure produced using the improved algorithm: (a) equiaxed grains in the base metal; (b) columnar grains; (c) equiaxed grains at the weld center; (d) assembled image.
It is also assumed that the grain sizes for the equiaxed grains near the base metal, the columnar grains and the equiaxed grains at the center of this weld are 50, 200, and 30 µm.
As each grain contains on average 60 elements, and the simulation consists of 3800 grains, there will be a large number of liquid channels to evaluate.