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BMAP calculator is a simplified software tool to obtain microstructure characteristics and to investigate their isotropic and anisotropic nature using some common broadening methods. The Scherrer and Stokes-Wilson methods as well as the Williamson-Hall plot (microstructure isotropy) and modified Williamson-Hall models (strain anisotropy) are implemented in the calculations. The BMAP input data are the X-ray diffraction peak parameters (the full width at half-maximum or integral breadth and peak position) of a measured line profile and of a reference one. The components of the measured line profile or corrected broadening are based on several approximations (Cauchy, Gauss or Voigt). The linear least-squares fit is used to calculate the size-strain values, and the correlation coefficient for accepting the results. The calculator is applied to an X-ray diffraction experiment of NiO nanoparticles prepared by a sol-gel method for testing. The results of BMAP calculator and the MAUD program, combined with an anisotropic Popa rules approach, are compared. The uniform stress model based on the Cauchy approximation is the most suitable one in cubic nanostructure nickel oxide, with an average crystallite size of 24 nm and anisotropic strains of 1.54 × 10−3, 0.61 × 10−3, 1.77 × 10−3 and 1.49 × 10−3 using the {111}, {200}, {220} and {311} reflections, respectively. Generally, for non-Rietveld users, it is useful to collect different methods into one program to depict the anisotropic nature of materials. [ABSTRACT FROM AUTHOR]

In this paper, using two sets of reference steel blocks (area-amplitude and distance-amplitude) to investigate a modified method to verify the linearity of the system of instruments used in the ultrasonic inspection. The mechanical and physical properties of the material of the blocks before and after heat treatment are measured. The ultrasonic longitudinal and transverse velocities are measured in the blocks and the elastic parameters of the blocks are calculated. The attenuation of the ultrasonic wave at the centers of the blocks as a function of the metal distance in the distance-amplitude and the area amplitude as a function of the hole diameter for steel reference blocks with frequency 10 MHz using the immersion technique at a constant gain has been investigated. According to the experimental results, this study can significantly improve the detection accuracy of reference steel blocks, and will serve as a reference for assessing engineers. [ABSTRACT FROM AUTHOR]

This paper describes a rapid algorithm for effective impedance in multilayered media. The layers are considered losses and have parallel interfaces. Recursive equations are developed and introduced that enable to calculate the effective impedance in compartments composed of any arbitrary number of layers. The calculations are carried out through an iterative process. Several important influence factors, that affect the multilayer acoustic absorber, are discussed. A simple algorithm is proposed, which allows to obtain qualitative knowledge of the behaviour of the frequency band with layer parameters. This technique can be used in different applications of ultrasonic techniques. [ABSTRACT FROM AUTHOR]

Recursive equations were developed and introduced that enable to calculate the transmitted waves through a multiplicity of layers. The calculations are carried out using z-transform technique. The layers are considered lossless and have parallel interface, which are at normal incidence to the field. The multilayered structures are constructed of three aluminum plates connected together with epoxy as the adhesive layers. The method has been successfully used to detect small changes in the thickness of adhesive layers. [ABSTRACT FROM AUTHOR]

Nanoparticles of NiO were prepared by a homogeneous precipitation method with an aqueous solution of nickel nitrate hexahydrate and citric acid. The microstructure and surface morphology of NiO powder were characterized by thermogravimetric (TGA) analysis, differential scanning calorimeter (DSC), X-ray diffraction (XRD), and infrared (IR) spectroscopy. Different thicknesses of nickel oxide (NiO) thin films were deposited onto highly cleaned glass substrates by the electron beam technique. Their structural characteristics were studied by X-ray diffraction (XRD) and scan electron microscope (SEM). The XRD investigation shows that NiO films are polycrystalline with an cubic type structure. The microstructure parameters, e.g., crystallite size and microstrain were calculated. The optical constants (n, k) and film thicknesses of NiO thin films were obtained by fitting the ellipsometric parameters (ψ and Δ) data using three layer model systems in the wavelength range 300-1100 nm. It is found that the refractive index, n increases with the increase of the film thickness. The possible optical transition in these films is found to be allowed direct transitions. The direct energy gaps increase with increasing of the film thickness. [ABSTRACT FROM AUTHOR]