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...

A method of measuring biaxial stress-strain curves for sheet metal samples subjected to large plastic strains is described for one example aluminum alloy (AA 5754-O). The method uses a portable X-ray diffraction (XRD) system to measure in situ stresses during tensile deformations. Calibration of X-ray elastic constants and the effects of texture and intergranular stresses are discussed. Uniaxia...

Structures of carbon supported Pt-Ru catalyst in a polymer-electrolyte-fuel-cell (PEFC) were analyzed by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAFS). XRD analysis identified a face-centered-cubic (fcc) alloy structure for Pt-Ru. XAFS analysis revealed that Pt and Ru atoms were, however, not randomly distributed in the Pt-Ru fcc lattice. A Pt atom was more likely surrounded ...

Molecular beam epitaxy grown InAs/GaSb superlattices, containing InSb-like interfacial layers, were analyzed by a combination of x-ray diffraction XRD and structural refinement. The superlattice refinement from x rays SUPREX method determines with high accuracy the average thicknesses and d spacings of the individual InAs and GaSb layers in addition to standard structural parameters usually obt...

High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased error...

X-ray diffraction is a commonly used experimental technique for identifying the structure of crystalline materials[3]. A crystalline material has its atoms arranged in periodic lattices with long-range symmetry. As a result, it scatters a beam of X-rays in well-defined patterns. Analysis of an X-ray diffraction pattern produced by a material yields extensive information about the structure of t...

calcium fluoride nanoparticles with special amount of cerium ion (%1) were synthesized by coprecipitation. fourier transforms infrared spectroscopy (ftir), x-ray diffraction (xrd), absorption and photoluminescence (pl) from caf2ce nanoparticles has been investigated. ftir spectra reveal that there are some amounts of oh, no3 and other organic functional groups on the particle surfaces before th...

X-Ray Diffraction (XRD) has long been used to determine the atomic-scale structure of materials. This technique is based on the fact that the wavelength of X-rays is comparable to the distances between atoms in condensed matter. When a material exhibiting a long-range (i.e. at least micrometers), periodic atomic order, such as a crystal, is irradiated with X-rays it acts as an extended, well-de...

This work presents the results for identification of chemical phases obtained by several laboratories as a part of an international nuclear forensic round-robin exercise. In this work powder X-ray diffraction (p-XRD) is regarded as the reference technique. Neutron diffraction produced a superior high-angle diffraction pattern relative to p-XRD. Requiring only small amounts of sample, µ-Raman sp...

This paper studies the properties of thermally evaporated 1 μm of aluminium (Al) thin films on polyimide (PI) and polyethylene terephthalate (PET) substrates at room temperature with thermal evaporation in a vacuum of about 3 x 10 -5 Torr for use as window materials for solar cells. Effects of substrate types on the structural and electrical characteristics of the films were studied. Sets of ex...