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The Nyquist plot shows the dominant grain effect in the electrical conduction.
Among of them, lutetium niobate (Lu3NbO7) would be expected to an ideal host material for microlens and scintillators for its high refractive index and high density with Lu’s high Z number (71).
In polycrystalline ceramics, the semicircles attributed to relaxation phenomena with different time constants due to the contribution of grain, grain boundary and electrode.
The R-CPE in high frequency region represented grains with capacitance of 10-9F, while the other in low frequency region represented electrode-ceramic interface with capacitance of 10-3-10-5 F [15].
The dominant grain effect has been observed from the Nyquist plot and Lu3NbO7 transparent ceramic exhibits ion-conducting behavior, with an activation energy of 1.30 eV.

The accelerating austenite-martensitic transformation would be promoted significantly by the increased number of dislocations and shear band intersections at the high strain rates deformation stage.
The firet type of retained austenite grain transformation had been influenced by the high local stress at the grain boundaries.[25] The high local stress was generated due to the increased number of shear band intersections and dislocations at the grain boundaries during high stain rate deformation.
The higher the local stress, these retained austenite grains transformed faster [26].
Besides, the proportion of such these retained austenites grains were relatively large.
Raabe, On the effffect of manganese on grain size stability and hardenability in ultrafifine-grained ferrite/martensite dual-phase steels, Metall.

The theory is formulated when heat transfer is limited by the scattering of phonons from defects, grain boundaries, charge carriers, and phonons.
In the weak interaction case, it has been calculated to the lowest order of the various interactions and is defined elsewhere [8] ( The electronic thermal conductivity of a metal for the low-temperature behavior for electron-impurity contribution is [kele = L0T/r0], L0 being the Lorenz number and ρ0 is residual resistivity mainly due to impurity scattering.
It is found that the κph increases exponentially due the grain boundaries scattering as the temperature increases in the absence of the other scattering mechanism.
An estimate of electronic thermal conductivity (κele) can be obtained from the Wiedemann-Franz law with L = 2.45 x 10-8 W Ω K-2, the Lorenz number and is plotted in the inset of Fig. 1.

The results from this study was that route C and B are recommended, in order to achieve a small metallographic grain size quicker.
Submicrometric or even nanometric grain size material can be obtained by using ECAE process and an appropriate thermal treatment.
First of all, some parts are needed, after processing each part different number of passages through the ECAE die, the parts are manufacturing as specimens for tensile testing.
To reduce the total number of generated elements, the mesh was made coarser in the interior of the body.
Prangnell, Ronald Priestner, Fine-grained alloys by thermomechanical processing, 2001,Vol. 5, p. 15-21

Some commercial ZnO varistors contain Sb, which increases the varistor voltage by reducing the ZnO grain size.
The addition of Y to a Bi-based Sb-added ZnO varistor reduces the average ZnO grain size enabling the varistor voltage to be doubled, but it also increases the leakage current [4,5].
The reduction in the resistance to electrical degradation on adding Y to Bi–Mn–Co–Sb–Si–Cr–Ni-added ZnO varistors (the same composition as one of commercial varistors) is caused by an increase in the number of willemite (Zn2SiO4) particles or a reduction in the number of spinel (Zn2.33Sb0.67O4) particles; the resistance to electrical degradation was improved by adding Zr [6,7].
Moreover, the reduction in the average ZnO grain size on adding Y was a major factor in increasing the varistor voltage and ZnO grain growth was suppressed by the formation of an unknown compound on adding Y.
Y and Zr have been reported to coexist as segregated particles at grain boundaries and triple points in samples to which 0–2 mol% Y and 0.45 mol% Zr had been added [7].

Minor change in peaks of sintered samples was due to removal of grain boundary defects after sintering.
By controlling the number and movement of charge carriers, the electrical conductivity can be increased.
At higher frequency, the number of successful hopping increases and hence conductivity increases.
This happens due to the influence of grain boundaries.
The contribution of grain boundaries decreases as the frequency increases and hence impedance decreases.

Depending on a number of factors, the oxide material formed in the process of oxidation of contact surfaces are more or less likely to display donor-acceptor characteristics.
It determines the sequence and rate of oxidation of carbide grains and cobalt interlayers.
Free carbon, as a rule, is located in the surface area of carbide grains.
If a number of strong acid sites are localized in the area of the strong main site, the total concentration and strength of the main active sites decreases.
This takes place when a certain number of strong base sites are located nearby a strong acid site of the oxide surface.

Numbers of samples were deformed before aging with deformation degree of 40%.
Numbers of samples were not defomed.
Numbers of samples were cold rolled 30%, and other numbers were cold rolled 40% before aging.
In Figure 3b, the microstructure observation by optical microscope shows that grains have been rearranged and twins appeared.
The diameter of γ grain is approximatly 100nm.

So few grains breaked away from the surface of sample 2#.
The dissolution of sample 3# and 4# acted gradually from grain boundaries to the interior of grains.
Shapes of grains were island and loose owning to the dissolution priority of grain boundaries.
The grains fell off in the dissolution process.
As we know, the number of active sites and dissolution zones grow with Fe content at the initial dissolution stage.

The numbers nv and nh of intersections of dislocations with the vertical (Lv) and horizontal (Lh) grid lines were counted [14].
The martensite lath width can be determined by counting the number of intersections of lath boundaries with straight lines vertical to elongated direction of lath grains.
Dislocations cannot be observed in some grains for all three specimens.
It indicates that the plastic deformation of polycrystalline metals in grain scale is not uniform because of different grain crystallographic orientations [15].
Prat, et al., Effect of Processing Parameters on the Evolution of Dislocation Density and Sub-grain Size of a 12%Cr Heat Resistant Steel During Creep at 650 ºC, Mater.