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· Volmer-Weber (island growth): large number of surface nuclei are formed, and each deposited atom attaches to an island (or incipient particle); islands grow appreciably before joining up to cover the substrate completely
Fig. 1a shows few amounts of Al grains formed on the surface of SS substrate and yet not covering the whole surface of the specimen.
These grains have formed by nucleation and island growth.
It can be shown from Fig. 1a that the nano-sized grains, which formed at the early stages, connect to each other by a neck.
The columns are generally not single grains, but are composed of smaller more equiaxed grains, or can be completely amorphous [16].

However, the causes of EMS in the mechanism of grain refinement have not yet clarified.
The distribution of the secondary arm spacing from the ingot surface to center is measured, and grain boundary is marked off by hand according to the primary dendrite arm for the measurement of grain size distribution.
(6) where is the magnetic flux density at the ingot surface, is the magnetic permeability of vacuum, ,,ω is the magnetic field frequency, σ is electrical conductivity, k is the wave number of linear traveling magnetic field, x is the distance between the liquidus front and the ingot center(the distance between CET position and the ingot center in Table.2), x0 is half of the ingot thickness.
Distributions of secondary arm spacing, cooling rate and grain size with respect to distance from surface to center of the ingot for these three steels are shown in Fig. 2 to 5，respectively.
The grain size is refined by EMS.

At some places the inclusions are decorating the grain boundaries in RSW (Fig. 2 e-f).
In GTA welded plate, the grain boundaries of the coarse grained HAZ was also found to be decorated by ferrite (Fig. 2 - b).
An enrichment of aluminium was observed in the fusion boundaries of welded TRIP steel where a zone of allotriomorphic ferrite grains was found.
Thus soft ferritic zones are formed close to the fusion lines and columnar grain boundaries.
Acknowledgements This research was carried out under the project number MC8.04188 in the framework of the Research Program of the Materials innovation institute M2i (www.m2i.nl), the former Netherlands Institute for Metals Research.

In most cases, this is due to a difference in grain size.
According to the theoretical model of Becher et al. [21], a maximum toughness in air sintered Ce-TZP should be achieved with a grain size of 5 µm, whereas a toughness of 6 MPa m1/2 is expected for a submicrometer grain size.
Because of the difference in mean atomic number, the Al2O3 phase is dark whereas the ZrO2 is bright on the backscattered electron micrographs.
The detailed backscattered electron micrographs however also reveal the presence of a third phase with intermediate contrast and a grain shape with a certain aspect ratio.
Three phases can be distinguished: tetragonal Ce-TZP (white), Al2O3 (black) and a solid solution of Ce and La in Al2O3 (grey elongated grains).

This basic requirement limits the number of possible candidates to three metals, magnesium, zinc and iron [1].
The as-cast Mg-3Gd and Mg-3Gd-1Y alloys show very similar microstructures (Fig. 1a, b) consisting of large grains of more than 1 mm in size.
Zirconium present in this alloy act as a very powerful grain refiner.
Unlike in the previous alloys, individual dendrites are not observed in the Mg-3Nd-4Y alloy due to the small grain size.
Moreover, the dynamic recrystallization occurring during hot extrusion also significantly refines α-Mg grains to 5 µm.

Atomic structure at grain boundary is different from atomic structure in the grain which leads to larger free carrier concentration and presence of potential barriers at boundaries.
Numpud et al. found that with highest concentration, the surface roughness mean squre (rms) and average grain size of the coated films increased [37].
Numpud et.al. report that the grain size and surface roughness mean square (rms) depend on the withdrawal speed [37].
Both grain size and surface roughness mean square (rms) increased with the increasing in withdrawal speed.
The change in withdrawal speed effects on the transmittance of the coating films because there was difference in the grain size of ZnO thin films on each substrate.

A coarse-grained copolymer model examined by using Molecular Dynamic simulation is employed.
Simulation Model and Method We use a coarse-grained model for the system consisting of two apposing walls coated with diblock copolymer chains.
The total number of counterions is NC=NB×CN, where CN=81 is the number of diblock copolymer chains.
With the A-block length increase, the number of counterions is decrease.
Therefore, the change of ρg is very small at large number of counterions.

The compression strength perpendicular to the grain and the contact area between the logs govern the resistance of the log structures to vertical load.
Current building codes only consider that the compression perpendicular to the grain and shear stress at intersections between walls are responsible for the seismic resistance.
Aim and Scope of the Project In order to obtain the European Technical Approval (ETA) for the entry of the log house under study into the commercial market, a number of experimental and numerical studies have to be performed to make a detailed characterization of the construction system.
A number of mechanical fasteners in the form of screws have been provided at necessary locations in the house - around the openings, near the joints of the cross walls, between the floor beams and walls, at the ridge and at the top and bottom of the rafters.
The following damages were observed during the test- fracture along the length of the log due to out-of-plane flexure, slippage of logs due to shear, fracture along the grain at connections between orthogonal walls due to shear, internal cracks in the log section and fracture at the top and bottom notches of the logs.

The first deformation zone is located in the front of diamond abrasive grains and neighboring zone.
The second deformation zone is located under the diamond abrasive grain.
Strong plastic deformation is only a few microns thick, contact area of granite and diamond abrasive grains under the action of high temperature and high pressure will produce local plastic deformation.
The third deformation zone is located in the rear of diamond abrasive grain. some small particles of rock composition similar to the tail is formed in diamond brasive particles adjacent region.
Fig.6 Stress nephogram of element 3343 during sawing process The front number for 38243 unit body, middle number for 39395 of the unit body and the back end element 40530 is intercepted in the whole process from Figure 7.

The heat partition ratio, η, can be determined according to the analysis of burn prediction [9]: ( ) ( ) 1 0 5.0 )( 06.11 −                 += a hwp sgp GAf VCk VCk ξ ρ ρ η (4) where )()exp(1 2 )( 2 5.0 ξξ ξ π ξ erf f − = (5) 5.0 02       = scg VA Lγπα ξ (6) qo y L z qcs B qcs qcs x qct Vh χ ζ H Lc ψ In the above equations, subscripts g and w denote wheel-grain and workpiece, respectively; γ is an abrasive shape factor and is taken to be unit since grains used in making the grinding wheels are approximately equiaxed [10].
Ao is the average single grain-workpiece contact area; and Ga is the number of active grains per unit area of the wheel surface.
In dry grinding, the heat transfer coefficient, ha is estimated following the empirical relation for a square section with a characteristic length B subjected to a cross flow of air [6, 11]. 31675.0 102.0 PrRe kBh )u a a == (14) where )u, Pr and Re are the Nusselt, Prandtl and Reynolds numbers, respectively, i.e., ( ) νν BVBVV Re s hs ≈ ± = (15) where ν is the viscosity of air.