nanocrystalline hydroxyapatite was precipitated from calcium hydroxide and phosphoric acid. effects of precipitation temperature and different calcium to phosphate ratios (ca/p) on the obtained powders were investigated. characteriza-tion of the powders was performed using xrd and ftir spectra, scanning electron microscopy, and transmission electron microscopy. increase in precipitation tempera...

In this paper, glass fiber-reinforced polypropylene (GF50-PP) composite composed of long fibers was prepared by the thermo-compression process for very first time. This presents high mechanical strength and is used in infrastructures, which demand resistance against severe conditions. Mechanical multi-scale damage analysis GF50-PP at ambient cryogenic temperatures have been investigated study u...

In this study at first, in laboratory, three types of vanadium oxide were produced by using porous graphene and amine framework in hydrothermal method nanostructures such as: vanadium oxide - octadecyl amine - graphene, vanadium oxide - dodecyl amine - graphene and vanadium oxide – aniline - graphene (V-ODA-G، V-DDA-G، V-A-G). Then their structures and functions in propane dehydrogenation react...

The discharge of lead containing effluents into the environment and water bodies is harmful for the human, animals, aquatic flora and fauna. Herein, a novel surface engineered magnetic nanoparticle for removing Pb2+  ions was studied. After surface modification of the magnetite by 3-amino-propyltriethoxysilane (APTES) magnetic nanoparticles with covalently linked porphyrins were synthesize...

The high-pressure behaviour of PbS was investigated by angular dispersive X-ray powder diffraction up to pressures of 6.8 GPa. Experiments were accompanied by first principles calculations at the density functional theory level. By combining both methods reliable data for the elastic properties of rock-salt type αand high-pressure β-PbS could be obtained. β-PbS could be determined to crystallis...

Reconstituted nanostructured powders were plasma sprayed using various processing conditions to produce nanostructured alumina–titania coatings. Properties of the nanostructured coatings were related to processing conditions through a critical plasma spray parameter (CPSP) that in turn, can be related to the amount of unmelted powder incorporated into the final coating. Those coatings that reta...

The Knoevenagel condensation of aromatic aldehydes with barbituric acid, dimedone and malononitrile occurred in the presence of BF3/nano-γ-Al2O3 at room temperature in ethanol. This catalyst is characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and energy-disper...

abstract background: the radiographic image accuracy depends on the x-ray film information visibility. good visibility is found by good contrast. radiation exposure parameters (kvp, mas) and film processing conditions have impact on contrast. in dentistry radiography machines, exposure time and processing procedure are set by radiographer. no optimized exposure time and processing conditions ma...

When using heteropolycompounds in the selective oxidation of isobutane to methacrolein and methacrylic acid, both the keeping of the primary structure (Keggin units) and the presence of acidic sites are necessary to obtain the desired products. The structural evolution of supported (NH4)3HPMo11VO40 (APMV) catalysts under preliminary thermal oxidizing and reducing treatments was investigated. Va...

We review an atomic resolution imaging method based on the analysis of the fine structure in X-ray absorption anisotropy, which results from incident beam diffraction. For a polychromatic X-ray beam, due to the suppression of higher order diffraction fringes, X-ray absorption anisotropy patterns can be interpreted as distorted real-space projections of the atomic structure around absorbing atom...