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These features make this material very promising for a number of industrial applications [7].
Regarding the grain size and the phase purity, processing at around 775oC was found to be optimum for the fabrication of good-quality large MgB2 bulk samples.
We found that the number of voids increases with increasing the reaction temperature in the previous study [1].
Here, we see that MgB2 forms stacks of grains about 400 nm in length.
The inset shows an AFM topography image revealing the grain size of about 400 nm.

In this way, thin sheets can be manufactured with a low number of annealing and rolling steps.
In the base material with sheet thickness t = 0.8 mm, an equiaxed microstructure with a mid-range grain size of 6 µm was present after final annealing (Fig. 1).
Furthermore, the number of mechanically formed twins was most likely reduced by the high level of dislocation activity, so that an additional hardening effect (due to grain reorientation or grain refinement) did not occur [15–17].
Acknowledgements The authors wish to acknowledge the financial support of the SMiLE project (“Systemintegrativer Multi-Material-Leichtbau für die Elektromobilität”, project number: 03X3041O) by the Federal Ministry of Education and Research.
Atwell, Influence of grain size on the compressive deformation of wrought Mg-3Al-1Zn, Acta Mater. 52 (2004) 5093–5103

The grain size of the majority of the steel slag that has undergone hot stuffy treatment is smaller than 31.5mm.
The f-CaO in the steel slag has compact structure with large grain and relatively tight crystal lattice and slow in natural slacking[1].
The reason acquired through analysis is that the quantity of the fines with the grain size smaller than 0.3mm is relatively small in the cement stabilized steel slag.
And the degree of the uniformity of the compound is not high, therefore the number of the holes within the test specimen is relatively big, as shown in FIG. 3.
Conclusion The steel slag produced by the converters of Jigang Group co. ltd is scientific in grain composition, excellent in mechanical properties, and can meet the requirement on subbase course materials.

The former has accounted for the vast majority of the number has been known.
In the fractured or coarse grained sediments, the hydrate saturation is relatively high[41], while for fine grained sediments (such as fine sand, clay and shale formation) that is relatively low.
Hydrates generally occur in the sandstone, fine-grained silts or sands layers.
Table 1 Main hydrate exploration programs and their reservoir evaluation results Exploration Programs 1.Reservoir types 2.Occurring modes Reservoir Parameters Ref. porosity saturation “Mallik 2002”program, Canada 1: Sands; 2: Disseminated (Pore-filling) 35% (typical value) approach 80%（from logs） [15, 44] 2007 Mount Elbert Well, Alaska North Slope, U.S 1: Sands; 2: Disseminated (Pore-filling) ～35-40% (from logs, core analysis) 65-75%（from logs） [23, 45, 46] ODP Leg 164, Blake Ridge, U.S. 1: Fine-grained, Fractured fined-grained 2: Disseminated (Pore-filling);nodular, veins, layer, massive (very few) 50～60% (from logs and core analysis) 0-20%（from logs） [47] ODP Leg 204, Hydrate Ridge, U.S. 1: Fine-grained，Fractured fined-grained 2: Disseminated (Pore-filling); nodular, fracture-filling, massive (very few) ～40-80% (density logs) ～10-30% (disseminated, from resistivity logs, Site 1245); 10-92% (in homogeneous, from resistivity logs, Site 1249) [5] 2005 IODP Leg 311, Northern
In a large number of geophysical logging response characteristics, the resistivity and wave velocity are affected greatly by the hydrate occurence.

In Nd2Fe14B magnets, the Hc value is promoted by strong uniaxial magnetocrystalline anisotropy, which makes the nucleation of Bloch domain walls (DW) in grains energetically unfavorable.
Moreover, in sintered magnets, the grains are surrounded by a non-magnetic phase (Nd-rich phase), which smooths the grain boundaries and reduces the number of DW nucleation centers and they remain in a single-domain state [1].
Temperature stability can be improved by strengthening the exchange coupling between grains, by RE elements substitution (for example, by Pr, Tb, or Dy), or by adding Co [21].
As the Co concentration increases, the number of nanoparticle agglomerates and their size increases.
The formation of a FeCo alloy that formed small grains into nanoparticles was detected.

Introduction It has been well known that the Mg and Mg-based alloys with nanocrystalline/amorphous structure possess superior hydrogen storage kinetics in the light of the high surface to volume ratios and the presence of large number of grain boundaries in nanocrystalline alloys which enhance the hydriding/dehydriding rates and capacity [1, 2].
Furthermore, such substitution incurs the visible refinement of the grains of the as-cast alloys.
The superior hydrogen absorption kinetics of the as-spun alloys is undoubtedly ascribed to the refined grains by melt spinning.
Consequently, high densities of crystal defects such as dislocations, stacking faults and grain boundaries are introduced.
The large number of interfaces and grain boundaries available in the nanocrystalline materials provide easy pathways for hydrogen diffusion and accelerate the hydrogen absorbing process [7].

Introduction The mixing process is a particular unit operation which occurs in a great number of practical applications and in every processing industry.
Granular material mixing was defined as a process of dispersing a few components by chaotic, random movement of grains [1].
Moreover, the following dependence was showed: the higher the number of ingredients in the mixture, the higher the percentage share of waste in the product.
Grain material is mixed in various appliances and devices.
Various methods may be applied for the evaluation of grain fodder homogeneity.

The mosaic target is made from holes filled by additional elements which enabling to varied thin films composition through the number and position of holes.
It is well known that the thin film properties strongly depend on the microstructure of the films such as phase, grain, and defect structure, which relate to the deposition parameters.
It can be seen that the small grain and smooth surface were obtained at 300 mA (Fig. 3(a)).
As the sputtering current reached to the highest (700 mA), the grains size on the surface of the as-deposited film become bigger compared to the film deposited at low sputtering current.
When increasing energy distribution of sputtered atoms, the growth and increasing the number of nucleation sites on thin films surface were achieved.

Routinely used in concrete as cement replacement in a number often exceeding 30% by weight [2].
Chemical and physical properties of fly ash Conducted these analyzes and tests ashes: • Assessment of the chemical composition • Assessment of grain • Determination water-intensity according to EN 450-1, Annex B (demand for water) • Determination of the reactivity of fly ash (efficiency index) according to CSN 72 2071 • Evaluation of technological behavior of ash The article will present only the results of the chemical composition of fly ash and fly ash particle size distribution determination.
Graphical evaluation of granularity is shown in Figure 1 Grain size analysis of laser granulometru show that C fly ash has a similar grain tested cements, Czech ash are significantly coarser.
Conclusion The granulometric analysis of fly ashes can be stated that the Czech fly ashes A and B do not reach the subtleties such as of foreign tested fly ash C, the grain size is comparable with the used cement.
Acknowledgements Presented results of which form part of the results of student‘s research number SGS12/170/OHK1/2T/31, Aplication of HVFAC in Czech Republic.

With an increase in , the number of secondary branch on all principal branch further increase and grow rapidly, to form developed side-branches structure.
When the is equal to 0.05, the dendrite arms of the upstream region occur coalescence and the number of secondary branch decrease.
It can be found that, with an increase in (less than 0.05), the SDAAS decreases and the grains refine remarkably.
With introducing thermal noises, the number of secondary branch on all principal branch further increased and they grow rapidly, to form developed side-branches structure.
As noise amplitude increases, the SDAAS on the the upstream of the lateral principal branch decreases and the grains is refined, but the dendrite tip velocity remained about the same.