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The substitution of Zr for La results in obvious broadening of the major diffraction peaks of the alloys, to be ascribed to the refined grain by thus substitution.
The cycle number dependence of the capacity retaining rates (Rn) of the as-spun alloys is described in Fig. 3.
The benefaction of substituting La with Zr on the cycle stability of the as-spun alloys is basically attribute to the refinement of the grains and the formation of an amorphous phase incurred by such substitution.
The anti-pulverization capability of the alloy basically depends on its grain size.
Fig. 3 Evolution of the capacity retaining rates (Rn) of the as-spun alloys with the cycle number: (a) 5 m/s, (b) 20 m/s Fig. 4 Evolution of the capacity retaining rates (R100) of the as-spun alloys with the Zr content Fig. 5 Evolution of the high rate discharge ability (HRD) of the alloys with the discharge current density: (a) 5 m/s, (b) 20 m/s An amorphous phase improves not only anti-pulverization ability but also anti-corrosion and anti-oxidation abilities of the alloy electrode in a corrosive electrolyte [6].

When cooling they return to their original state (regardless of the number of alternating heating and cooling cycles).When in use such sealants remain in a plastic or viscoelastic state and are mostly used for sealing various types of detachable or undergoing periodic dismantling joints.
Thus, it is possible to formulate the basic requirements for the properties of non-curing sealants: – securing reliable structure impermeability in the entire range of operating temperatures and in various media (air, water, oil, gasoline, etc.); – adhesion to sealing surface (peeling strength is not less than 100 N/m); – workability and ease of processing, i.e. the possibility of applying by any means (brush, spatula, sealant gun, etc.); – satisfactory physical and mechanical properties (conventional tensile strength is not less than 1.0-1.5 MPa, relative tensile elongation is not less than 150%); – low density, available and non-toxic components; – a number of specific properties (dielectric properties, resistance to gasoline, oil, fuel, water, weather, etc.).
The grain- and rhombohedral-structure fillers (calcium carbonate and dolomite) disperse much easier than those having flake and fibrous structure.
The most efficient filler proved to be the grain-fiber or grain-flake filler mixes.

Introduction Composites that are constituted from polymer and ceramics have gained a widespread application in a number of electromechanical transducers such as hydrophones, vibration sensors, pressure and stress sensors, actuators, transducer for medical ultrasonic imaging, transistors MOS, capacitor, Peltier’s element [1].
Properties of composites are known to be determined by the number of phases, the volumetric fraction, properties of individual phases and by the way in which the different phases are interconnected.
Grain size distribution of BiNbO4 powder was established as follows: d0.1=0.20mm; d0.5=1.23mm (median value); d0.9=3.63mm.
In solid materials, a distribution of relaxation times is usually observed and the capacitance is replaced by a CPE, which represents more accurately the behavior of the grain interior, grain boundary and electrode processes [14].

The effective method to decrease hydrogen desorption temperature is by material structural destabilization and therefore a large number of potential destabilization methods exist such as: addition of impurities and/or catalysts, stress and strain introduction by ball milling or ion bombardment etc.
There is an interesting number of theoretical studies considering MgH2 and MgH2- transition metals[5, 6].
It can be seen that the degree of improvement is different, with the amount of Nb2O5, which may be caused by different synthesis methods, technological parameter (such as milling time, rotation velocity or milling atmosphere), specific surface area, grain size and so on.
Hydrogen content/ wt % Time/ s hydrogen content/ wt% Time/ s 0.5 300 7 60 7 90 [20] 250 6 60 6 500 0.2 300 — — 5.2 4800 [23] 200 — — 4.5 4800 0.2 250 — — 4.5 10500 [24] 1 250 5.0 110 — — [25] 300 5.5 110 — — 1 300 4.6 510 5.5 978 [26] 5 5.2 78 6.0 348 The reason why Nb2O5 can present high catalytic activity is relative to grain size and distribution of individual phases[27, 28].
So we can consider preparation methods, structure, technological parameter, specific surface area, grain size and so on, to improve the hydrogen storage properties of MgH2.

After the dwell period has passed, the tool begins the forward traverse along a predetermined path, creating a fine grained recrystallized microstructure behind the tool above the channel.
S-N curves were obtained by measuring the number of cycles to failure that the specimen supported under a sinusoidal waveform as described in Section Material and Methods.
Each point represents an experimental test and the curves were obtained by fitting a linear regression equation (2), assuming as the dependent variable: (2) where is the maximum stress, is the number of cycles to failure and m and K0 are empirical constants, namely the exponent and the coefficient of the S-N curve, respectively.
This interface is a region of stress intensity between very fine and coarse grains that is amplified by channel corner geometry.
All specimens have fractured at the advancing side, in the nugget/TMAZ interface which is an abrupt transition zone of very fine to coarse grain.

The NiCoMo-2 powder alloy was prepared to match the chemical composition of the substrate material which forms lath martensite with a large number of dislocations.
The second reaction is the precipitation of hard carbides and nitrides M(C,N) at austenite grain boundaries.
The directionally oriented cellular-dendrite grains form upon solidification of the melt.
In the grain boundaries, the white pools of reverted austenite are visible (Fig 4a2).
The elastic modulus of 210 GPa and the Poisson number of 0,3 were taken into account in the calculation procedure.

(2) where k is the thermal conductivity, L is a constant Lorenz number of 2.44 x 10-8 WΩK-2 and T is room temperature, 25 °C.
As shown in Fig. 2(a), fracture surface of 0 vol% SiCw/Cu sintered at 800 °C reveals the presence of porosity thus parallel to its low density and it experienced ductile fracture as the failure occurred at the grain boundaries.
However, increasing amount of SiCw suppressed the grain growth, resulting in smaller copper grains which were denoted by wider peaks.
The electrical resistivity of composites is depending on the size and number of microweldments developed between particles during sintering.

Gold-bearing copper oxidized ores often contain a number of valuable components, such as silver, copper, lead, zinc, antimony as well as “non-metallic”, the extraction of which may have economic interest.
Among other features, the ore is characterized by high content of carbonates present in the form of fine-grained clusters of crystals, typically in intergrowths with iron oxides but also in the form of individual crystals.
The ore also contain a large amount of talc in the form of free clusters of fine talc and complex talc grains with oxides of iron and carbonates.
Two samples of ore with a grain size of 50% - 74 µm and 90% - 74 µm need to react with cyanide for 24 h and 12 h respectively to achieve mentioned extraction level.
Acknowledgements Research have been performed at Russian Science Foundation (RSCF) sponsorship (Project number: № 18-19-00186).

The smallest grain sizes are 3-3.5 µm, the crystalline measures of less than 10 µm are frequent and their biggest dimensions are 20-30 µm in the case of unirradiated samples.
In contrast with these observations the pictures, taken on irradiated specimens show a significantly bigger size and density of microcrystals and smaller size and less number of hollows, as compared to the unirradiated ones.
Although the irradiated samples also contain small grains of sizes of 4-6 µm in a little quantity, microcrystals of sizes of 12- 18 µm exist in them in greater amount and the biggest grains reach the dimensions of 30-35 µm, opposite to the unirradiated specimens.
The experiments were performed with the help of a computer-controlled lock-in technique, when each specimens were wound with copper wire with the same number of turns.

Since that period, a large number of modern ballistic ranges have evolved to study many aspects of flight at high speeds, not necessarily related to the weapons of ordnance.
In Eq. 3, is specific internal energy of helium gas, and Nu are thermal conductivity and Nusselt number of helium gas respectively, and are helium gas temperature and wall temperature respectively.
The control equations in powder chamber are as follows: (5) (6) (7) (8) In Eq. 5, and are relative burned thickness and relative burned volume of grains respectively.
and are characteristic quantities of grain form.
In Eq. 6, is average pressure in powder chamber; , and are a half of initial thickness of grains, burn rate coefficient and burn rate exponent respectively.