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To confirm these observations a number of specimens were oxidized in Ar-H2-H2O mixtures.
The tendency to occurrence of spalling did thus not primarily depend on scale thickness but seemed to be nearly exclusively governed by the number and morphology of macroscopic defects (Fig. 3).
Therefore, scale growth in haematite is likely to occur to a large extend via and/or at oxide grain boundaries.
The haematite starts to grow in the form of ridges at the magnetite grain boundaries (Fig. 4a, b).
Mariott, K.Pithan, A Review of the Properties of 9-12%Cr Steels for Use as HP/IP Rotors in Advanced Steam Turbines, Office for Official Publications of the European Communities, Catalogue number: CD-NA-1187-EN-C, 1989 [3] S.

This process is distinctly different from other sand casting processes as the process requires no binders for holding the sand grains together in the mould [24].
It was determined that sand grain shape, size and distribution have a pronounced effect on dimensional accuracy.
The results indicate that the sand grain fineness number and amplitude of vibration were the control factors.
The effect of process parameters, i.e. degree of vacuum, pouring temperature, grain fineness number, amplitude of vibration and time of vibration on the impact strength of Al-7% Si alloy castings in VAEPC process were investigated.

This kind of particle can penetrate a surface and locate itself in the grain boundaries and other defects of materials.
Several types of sites have been found to trap hydrogen, such as grain boundaries, vacancies, voids, dislocations, etc.
Hydrogen frequently leads to the degradation of material characteristics, diffuses through the grain-boundary and locates itself in the lattices.
The hydrogen tries to diffuse into, via grain boundaries, for example, and cause it to fail.
The hydrogen concentration at the trap sites CT is: CT = θTNT (9) where ���� is the occupancy of the trap site and ���� is the number of trap sites per unit volume [32].

With respect to the granulation of the same, an increase in the grain size of the sandstones is observed for the quartzites, due to these recrystallizations, which confers greater resistance to the compressions and the physical wear for the latter.
Historically and among all Brazilian states, that of Minas Gerais is the one with the highest number of applications for quartzites, considering the historical constructions of the 18th and 19th centuries.
With few examples of applications in the South and Northeast regions, the largest number is concentrated in the Southeast and in this case the applications in some historical cities of the state of Rio de Janeiro stand out, especially in its capital, the city of Rio de Janeiro.
The first and most common, was named Phacoidal and is characterized by the presence of porphyritic crystals of feldspar in medium to fine - grained mass.
Sanding, as well as the loss of mass observed in sandstones, quartzites and even in granite rocks, were also considered to be consequences of these detachment of single grains or aggregates of grains.

Therefore, moving the power consumption control mechanism from hardware-level to fine-grained software-level is indispensable and more promising for data centers with virtual machine environments, and has the potential to save more power consumption.
Fine-grained dynamic voltage/frequency scaling is an important tool in managing the balance between power and performance in chip-multiprocessors [20, 21].
Kim et al [22] explored the potential system-wide energy savings offered by implementing both fine-grained and per-core DVS/DFS in a 4-core CMP system.
Therefore, more power reduction can be achieved if fine grained DVS/DFS schemes are used elegantly in virtualization environments.
Due to the high-density of service consolidation and development of new applications and the increasing number of users with heterogeneous requests, providing users with QoS guarantees while executing applications and saving power consumption has become a crucial problem that needs to be addressed.

The average grain size of the alloy is 40 μm.
In addition, the formation of carbides on the grain boundaries occurs during the heat treatment.
Comparing the microstructures of the two specimens, it can be seen that there are some differences in the sizes, morphologies and number densities of the γ′ phases and carbides, which is probably due to the sampling positions from the material.
Generally, with the increase of size and number of sharp angles, the stress concentration induced by carbide and carbonitride inclusions increases, which may encourage crack initiation and growth.
This is common in superalloys because grain boundaries are weak at elevated temperature, and the carbides precipitated on the grain boundaries may also assist the propagation of intergranular cracks.

No or less nitrides were produced under irradiation of very high intensity or less number of shots.
The approach can overcome some problems that occur in the conventional chemical treatments or coating techniques, such as unavoidable heating of the entire workpieces (high energy consumption and possibility of bulk deterioration, e.g., grain coarsening by the heating) and weak film-substrate bonding strength.
Shot number, N, was changed from 1 to 10 for the irradiation, respectively.
N = 1 N = 2 N = 5 N = 10 ○ D2 D2 B2 observed with increased shot number [Fig. 3(b)-(d)].
Secondly, shot number has a crucial influence on formation kinetics of the nitrides and carbontrides.

The interest in packing structures dates back to early times when the grain packings called “heaps” were the first things that were ever measured in ancient civilizations both for trading or taxes collection [1].
For convenience, Eq. (3) is often rearranged in a friction factor-Reynolds number dimensionless correlation.
The penetration efficiency per number of solid spheres is documented in Table 3.
The penetration efficiency per number of solid spheres is also depicted in Fig. 3 in terms of Stokes number expressed by (8) where St is the Stokes number and cc is the Cunningham slip correction factor [7].
According to Fig. 3 we come to the conclusion that the influence of the Stokes number in PN is negligible for 10-5≤St<10-3.

Between 1000 ˚C ~ 1200 ˚C temperature range, reaction speed is improved, at the entrance of coke porosity, CO2 has a large number of consumption, thus weakened the internal reaction.
At this time for the influence of the reaction rate of coke with CO2 mainly comes from chemical reactions. 2)When the temperature increase to 1000˚C ~ 1200 ˚C range, reaction speed is improved, CO2 at the entrance of coke porosity has a large number of consumption.
An image-analysis technique to measure grain-size variation in thin sections of soft clastic sediments sedimentary Geology, 1998(21): 289-298.

The shear deformation is related to the number of twisting, shear strain L nrπ γ 2 = (where r is the radius of wire, L is the length of wire, n is the number of turn).
Zone A includes one or more grains, and it undergoes a smaller shear deformation and a rigid body rotation during torsion.