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In addition, the occurrence of bone fractures has increase due to an increased number of traffic accidents and the increase in life expectancy from age 35 to 70.
For instance, Niespodziana et al. had described in a very recent paper about production of metallic titanium-HA nanocomposites with different HA contents, but the grain size of Ti is given as <45 micron.
It is clearly seen that similar microstructures were observed in composites sintered at 1000°C (Fig.3a,c) and typical densification behaviour and grain growth were observed at composites sintered 1300°C (Fig.3b,d).

Thereby, grain refinement, microstructure homogenization, degassing, and purification would be induced [6].
Thereby the nucleation rate of Co-bearing phases would be increased, and then the grain refined.
Secondly, a large number of Co-bearing atomic clusters with long range disorder but short range order would be heated quickly and melt under the action of local high temperature induced by ultrasonic cavitation.

In recent years, Chinese researchers have conducted a series of field researches in irrigated farmland ecosystems, the characteristics of energy balance and available energy redistribution under different climate conditions, such as humid climate, semi-humid climate and desert climate [7-14] are studied, the results indicate that in farmland ecosystem, energy exchange has obvious pattern of diurnal variation as well as seasonal variation, energy exchange is influenced by crop leaf area index, soil water content and meteorological factors; however, there is only a small number of field researches conducted in dry farmland located in semi-arid and arid regions, that study the characteristics of energy and material exchange in the soil-atmosphere interface [15-16].
In monoculture cropping systems of spring maize dry-land, during the whole growth period, at noon hours as well as in the day-time period, there is no obvious peak in the seasonal variation of net radiation flux; the precipitation in August (142.3 mm) accounted for 40% of the accumulated precipitation during the whole growth period (357.3mm); during exuberant crop growth (maize heading and initial grain filling stage) from early to mid August, the energy consumption through evapotranspiration reached peak level, the average latent heat flux at noon hours (12:00 - 14:00) was 300 W/m2, accompanied by significant decrease of the sensible heat flux and soil heat flux, the H and G flux at noon hours (12:00 - 14:00) were 110 W/m2 and 90W/m2, respectively; during the sowing to seedling period (prior to maize heading), the latent heat flux showed a slowly increasing trend, due to precipitation, the latent heat flux significantly increased .
From maize sowing to grain filling stage, the sensible heat flux showed a slowly decreasing trend, at maize maturation stage, the sensible heat flux increased slightly; from June to early July, the soil heat flux reached peak level, the average value of soil heat flux at noon hours (12:00 - 14:00) was around 185W / m2 (Figure 4).

The bottom-up coarse-grained clastic materials of lithology have a significantly increase, showing an overall anti-cycle.
The bottom-up coarse-grained clastic materials of lithology increase highly, showing an overall anti-cycle.
Sand bodies show very complex connectivity laterally, and the number of sand body layers decreases from east to west in the research area, with declining thickness, while western sand body is characterized by thinness, small-scale of development, and poor lateral connectivity, displaying significant oil and water distribution control, which contributes to the formation of concealed lithologic oil and gas reservoirs free from the structural control.

The molecular dynamics (MD) simulation was performed using the NPT (constant number of atoms, constant pressure, and constant temperature) ensemble.
The scale of shear transition region about amorphous alloys is smaller than the size of crystalline metal grains[15].
Since there is no grain dislocations and other defects, no cutting force increased for metallic glasses for the late stage.

The fine, equiaxed grain structure is evident in Figure 10 (b), the grain size ranges from approximately 6 to 25 µm. 500 mm (a) (b) Figure 10.
Powder Manipulation Technology A number of size reduction methods have been trialled at CSIRO with TiRO™ powder including the CSIRO Powder manipulation technology (PMT).

In a successive paper [5] Akeret specified that a good joint must realize a gap between the streams in the order of the interatomic distance during bonding thus providing an electrons mobility across the weld similar to any other grain boundaries (Fig. 1 left).
Again, the Ccr value was indicated as the critical number to be found by means of specific tests.
Some considerations can be driven from these tests: i) a small amount of oxidation was always present inside the weld even with the careful experimental procedure adopted; ii) the ratio between welding pressure and flow stress was always very low with respect to the ordinary extrusion process (pressure ranged between 15 and 100MPa, thus providing p/σ ratios below 1.2); iii) in industrial extrusion a subsequent deformation occurs after welding (at the die exit), thus promoting shear and grain distortions on he welding surface; this effect is not present in this experiment.

A combination of MA and hot extrusion has produced the microstructures that contain nano-sized particles, uniformly dispersed in a work hardened, fine grained Al matrix [5].
After producing nano-composite powders by the MA, MM or RM processes, a number of consolidation processes have been applied to fabricate to bulk materials, e. g. a combination of cold pressing and hot extrusion, hot pressing and hot isostatic pressing.
Therefore, coarsening of fine grains and nano-sized dispersed particles in MAed powders can be avoided, and superior mechanical properties can be achieved compared to those obtained for materials produced by general PM routes [9-12].

Introduction Powder Metallurgy, PM, is an evolving production technology to manufacture, frequently netshape, a growing number of components of increasingly complex shapes from an expanding range of alloys.
Metallographic examination revealed grain/particle carbide films, thicker and continuous in the specimens sintered at 1310C, responsible for brittleness.
The microstructure of the material sintered at 1310C comprised Widmandstatten ferrite, propagating from the prior austenite grain boundaries, with tiny sub-micron carbides (i.e. ferrite + carbide) plus tempered martensite.

Markou et al. [10] studied the effect of many factors such as grain sizes, water to cement, superplasticizer, on effectiveness of cement grouting and compression strength and permeability coefficient.
Table 4 Collected datum of strain at different load Number 1 2 3 4 5 6 7 8 9 10 Load/KN 0 7.2 8.5 20.6 30 42.6 60 68 79 87 Strain/mm 0 0 0.75 3.46 6.22 9.31 11.4 12.64 13.96 15.71 It can be seen in Table 4 that at the first stage, the stress increased to 7.2 kN while the strain remained unchanged.
Pull-out strength of axially loaded steel rods bonded in glulam perpendicular to the grain [J].