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This reveals that a large number of metal cations exchange between them, may produce multiple complicated spinel compound
After low-temperature (at 950 oC) sintering, the development of crystals are not good enough, inhomogeneity of grain size, only a few large grain sizes and many of small grains some of which are aggregates without definite form.
After 1050 oC, the growth of grain become better and grain sizes are increasing, aggregates of small particles mostly invisible, the profile of crystal is clear.

But the powder diffraction peaks of sintered nano-HA are sharper than not sintered powder diffraction peaks, which shows that the sinter nano-HA powders present a high crystallinity and an increasing size of crystal grain.
Fig.1 XRD pattern of not sintered nano-HA powders Fig.2 XRD pattern of nano-HA powders sintered at 800℃ Grain size was calculated by scherrer's formula, that is, D= Kλ/βcosθ (K=0.9, λ=0.15406nm, β- change width of the diffraction peak, θ- diffraction angle).
The size of grains perpendicular to lattice plane (002) (that is, parallel to axis C) is 24.1nm for the not sintered nano-HA powders.
Using the same calculation method, the size of grains perpendicular to lattice plane (002) (that is, parallel to axis C) is 44.9nm for the sintered nano-HA powders.
Acknowledgements This work was financially supported by Science and Technology Development Plan of Jinan City (Number: 201102056).

The occurrence of the second peak is corresponding to start of hardening deceleration stage, because the barrier on the surface of cement grains reach a certain thickness and diffusion control the hydration process [8].
The acicular AFt on the surface of cement grains slows down the hydration process at earlier ages.
(2) where and are fitting coefficients which meet the requirement of positive number; is porosity, %.
The surface of the fly ash grains is extremely smooth in Fig.4(b).
The tailing grains are covered by some hydration products formed by the reaction between tailing and Ca(OH)2 from cement hydrationin Fig.4(c).

Liapor aggregate has spherical grains and sintered surface.
Grain size of liapor is up to 16 mm.
Grain size of experlite is 0 - 4 mm [4, 11].
In experiment a crushed recycled cork of grain size 0/8 mm from a thermal insulation of buildings was used.
Acknowledgment This work was financially supported by Ministry of Education, support of specific academic research - Student grant competition VŠB - TU Ostrava, the identification number SP2014/161 –Utilization of glassy waste material from biomass combustion.

Close inspection of the product microstructure in the Ag/Zn reaction couple revealed a "duplex" grain morphology of the ε - and γ - phase layers (Fig. 1b, c).
The changes in grain structure are seen to be associated with the presence of the (stable) marker plane(s) inside the reaction products.
The grain structure of the ε -"AgZn3" and γ -"Ag5Zn8" product layers is developing in two ways.
Differently growing grains meet at the Kirkendall plane resulting in the observed "duplex" morphology of the reaction layers.
Analogously, p and q are the number of moles of Zn- and Ag-atoms transported during interaction across unit area of the γ -"Ag5Zn8" (Ag0.394Zn0.606), and r and s are the number of moles of Zn- and Ag-atoms transferred across unit area of the product layer of β -"AgZn" (Ag0.521Zn0.479).

The development of such material is proposed by making a number of consecutive tasks.
The oxide layers are obtained by a number of techniques: chemical oxidation [17-19], electrochemical oxidation [20,21], thermal and hydrothermal oxidation [17,19], PACVD technique from titanium tetrachloride [22].
In first approach the grain were spherical, in the second elongated.
Finally, the open porous structures were obtained with well joined grains, pores between 50 and 250 µm, and porosity approaching 60%.
Three different nanotubes were observed dependent on the base: originating from α grains, β grains and martensitic phase γ` phase.

A polycrystal is a solid that consists of a collection of several tiny crystals that are separated by well defined grain boundaries.
The surface area of the indentation itself divided by the applied force yields the hardness number, which is expressed in kgf/mm2.
The Vickers micro hardness number for the sample is depicted in the fig. as a function of the applied test load.
The Vickers hardness number (Hv) is observed that all the crystals of this work increases with increasing load.
Vickers Hardness number vs Load for LAPC and LAG crystal.

It also can repair the surface of workpiece under the condition that ensure the dimensions and material performances of original workpiece which can recycle the trash. [3-4] Laser cladding has following excellence: 1) Alloy integration can be formed between cladding layer and matrix which can gain interface of high strength. 2) Cladding layer of low dilution ratio can be gained. 3) The heat effect area is small and the heat deformation is low. 4) The process of rapid concreting can get cladding layer whose structure is of imperceptible crystal grain or new phase can't be gained by routine methods.
The powder whose grain size is of 200 meshes is of nickel-based alloy.
Acknowledgments The work described in this paper is supported by Research Bonus Fund for Excellent Yong & Middle-aged Scientists, Shandong Province (Subject number: 2007BSB01502) and research Fund of Shandong University of Technology.
(Subject number: 2005KJM22) References [1] Farish, Mike:Engineering and Technology Vol. 4 (2009), p. 68 [2] Chung Chun-Jen,Wee Hui-Ming: International Journal of Production Economics Vol. 113 (2008), p. 528 [3] Nurminen Janne, Näkki Jonne, Vuoristo Petri: International Journal of Refractory Metals and Hard Materials Vol. 27 (2009), p. 472 [4] Ocelík V., Bosgra J., de Hosson J.Th.M.: Surface and Coatings Technology Vol. 203(2009), p. 3189 [5] Saridemir, Mustafa: Advances in Engineering Software Vol. 40, p. 920

Introduction Scintillating materials require in many applications high density and high atomic numbers of its constituents [1].
Y2O3-2HfO2) present high crystalline densities and high atomic numbers which make them attractive for host lattices activated by rare earths (RE) for applications as scintillating materials [2].
The grain size of Lu2Hf2O7/Tb phosphor is in the range of 20-30 nm, as can be estimated from Fig.2.
The powders prepared using only urea as fuel showed large particle size and severe agglomeration between adjacent grains in our experiment.

Increase of number of metal atoms in the structure changes electrical properties from semiconducting to metallic behavior.
Moreover producing bulk or thin film CdTe single crystal without a Grain Boundary (GB) is not easy task.
The effect of Cu atoms which are located in grain boundary of CdTe crystal will be future interest of our works.
This research has been supported by Scientific and Technological Research Council of Turkey, Türkiye Bilimsel ve Teknolojik Araştırma Kurumu (TÜBİTAK) Project Number: 114F247 References [1] Boer, R. 2001 , ECN Energy in In dustry