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These grain boundary intermetallic compounds are known as the β phase (Mg17Al12).
Macrostresses represent the forces acting between different macroscopic parts of the specimen, while microstresses reflect the interaction between various microstructural components, e.g. inclusions, distinct phases, neighbouring grains or groups of grains, lattice defects and defect structures (dislocation cells and ladders, slip bands, grain boundaries, etc.).
Experimental method An as-cast bar of HPDC AZ91 alloy of average grain size 4 µm, with dimensions hy = 90 mm, hx =10 mm, hz = 5 mm was used for this analysis.
This guarantees the presence of a large number of grains in the Xray gauge volume (average size is 4 µm) and ensures good averaging across grains of different orientations.

It is known that the microstructural effects of the two mentioned processes can be distinguished because the creep type deterioration can cause cavities along the grain boundaries, while the fatigue process causes voids and cracks through the grains.
Nowadays large number of different investigation techniques can be used for life time estimation [2].
The total lifetime of the sample is defined as the number of cycles at which the length of the cracks reach the so-called "engineering crack size" (0.1 mm).
The applied numbers of thermal shock cycles were 0, 100, 300, 530, 1000, 2000 and 4000.
The increase of the number of thermal shock fatigue cycles seems to decrease the slope of the M(H) curves.

And all samples were dried with a critical point dryer and observed the morphology and the number of the bacterial adherence on the surface of the samples by the S-4800 SEM.
The β grain size of this alloy was 20~60μm.
The composition segregation of grain boundary was not found by investigating its microstructure, and the actual compositions were basically consistent with the design components as shown in Fig.2 (a) and (d).
Because the bacteria are capable of high prolificacy, the number of Actinomyces viscosus has increase with the increase of cultivation time, as shown in Fig.4.
But the number of Actinomyces viscosus on the TiO2 nanotube array film is still few, and that of Actinomyces viscosus on the Ti-alloy undergoes multiple stratification.

The average grain size of the 8 µm foil and the 20 µm foil is 3 and 10 µm, respectively.
The effect of grain size might be important to the fatigue strength.
The number of cycles to failure is Nf=1.4x10 5 in this condition.
Once the relation between the strain and the number of stress cycles is obtained, the fatigue damage can be evaluated by the value of FWHM.
The full width at half maximum, FWHM, was a function of both the applied stress and the number of stress cycles.

Thirdly the construction waste particles whose size was 5~40 mm were broken again by jaw crusher as the second crushing process, and then the construction waste particles with a size of 0~10mm was obtained by screening to serve as recycled aggregate and its grain composition was shown in table 2.
Fig.1 The preparation process of construction waste recycled aggregate Table 2 Grain composition of recycled aggregate Size/mm 5~10 2.36~5 0.6~2.36 ＜0.6 Percentage/% 48.1 11.2 24.3 16.4 Preparation of solid construction waste brick.
There were mainly two points to cause the above phenomenon: (1) In the preparation process of recycled aggregate, there were damage accumulation in crushing and screening, which would result a large number of microcracks in the surface and interior of recycled aggregate.
It made the fluidness and cohesiveness of concrete paste was poor, which led to a lot number of internal defects and voids in samples.
The main reason for this trend was that there were a large number of microcracks in the surface and interior of recycled aggregate.

Furthermore, the annealed graphene samples emerged a deferent number of layers because of morphological surface changes.
The morphology of annealed copper surface includes several characteristics such as grain boundaries, roughness, impurity nanoparticles and defects.
High light transmittance (~85 to 96%) is expected due to the small number of graphene layers found in most samples.
However, the number of layers in graphene samples proportional to the visible spectrum absorption.
Luo, Turning off hydrogen to realize seeded growth of subcentimeter single-crystal graphene grains on copper.

The number density of G.P. zones is defined as the volume fraction of G.P. zones divided by the average volume per one G.P. zone.
On the other hand, the tensile-stress-aged specimen reveals no significant change in the number density with t.
Fig. 1 Effect of free, compressive-stress and tensile-stress aging at 220°C on the number density of disk-shaped G.P. zones.
We selected the grains in which the stress axis was nearly perpendicular or parallel to (001)α or (100)α and (010)α of the Cu matrix, and determined the number density of G.P. zones on {001}α from TEM observations using the electron beam parallel to [110]α or [101]α and [011]α of the grains.
The number density was plotted as a function of the angle θ between the stress axis and the plane normal of the G.P. zones.

These wave numbers are the direct results of metal-oxygen stretching vibrations in the hexagonal lattice [12].
Well-conducting grains detached by thin resistive grain boundaries are known to be ferrites [6].
On the other hand, the resistivity is diminished due to grains in the larger frequency field.
In this way, for the electron transportation between Fe2+ and Fe3+ in the grains, a small energy loss is expected [36].
The action of AC-conductivity may be well defined by the Maxwell-Wagner model and Koop's phenomenological theory, where ferrites are expected to depend on conducting grains detached through strongly resistive grain boundaries of thin layers [36].

Each specimen were reinforced with different number of steel wire mesh layers which are 2 layers, 4 layers and 6 layers.
The effectiveness of those fibers in concrete is measured by its capability to act as a bridge between the grains of the cement mortar matrix.
Percentage of PPF and the number of layers of steel wire mesh used to reinforce the ferrocement will be the controlled parameter in this study.
Results and Discussion The result are analyzed based on two aspects: flexural stress againts percentage of PPF and optimum percentage of PPF for certain number of mesh layers.
However, there is an optimum percentage of PPF can be added depending on the numbers of wire mesh layers.

Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia 4National University of Science and Technology "MISIS, Moscow, Russia 5Institute of Physics of Advanced Materials, Ufa University of Science and Technology, Ufa, Russia a*rybalch@mail.ru, bnataliasmartynenko@gmail.com, crybalchenkogv@lebedev.ru, dntabachkova@gmail.com, eingvvar@gmail.com, fimetran@yandex.ru, ghelenelukyanova@gmail.com, hmisistlp@mail.ru, iagraab@mail.ru, jdobatkin.sergey@gmail.com Keywords: Fe-Mn alloys; equal channel angular pressing; ultrafine-grained structure; twinning; strength; corrosion rate.
ECAP was carried out in a matrix with channels intersecting at an angle of 120° by route Bc at a deformation temperature of 300 °C up to the maximum number of passes.
Results and Discussion The initial structure of the Fe – Mn and Fe – Mn – C alloys after forging and subsequent homogenizing annealing is coarse-grained with an average grain size of 189 ± 17 μm and 226 ± 13 μm, respectively (Fig. 1).
On Fig. 4 a, b an austenitic ultrafine-grained structure with the average size of structural elements about 103 ± 8 nm, calculated from the dark field is shown (Fig. 4b).