The Walfisch model predicts the average path loss from a conceptualised model of the propagation environment in which propagation is assumed to take place over rows of buildings of equal height and spacing. The propagation loss is then separated into that resulting from free space wavefront spreading, multiple forward-diffraction past the rows of buildings and diffraction over the final rooftop...

in this paper, a new propagation model based on utd for multiple diffraction paths in cellular mobile radio communications in urban environments is proposed. moreover, the most rigorous novel utd-based expressions for multiple diffractions by buildings and excess path losses are d - rived and analyzed. for this purpose, building rows are supposed to have rectangular cross-sections with the same...

In this study, the impact of finite ground plane edge diffractions on the amplitude patterns of aperture antennas is examined. The Uniform Theory of Diffraction (UTD) and the Geometrical Optics (GO) methods are utilized to calculate the amplitude patterns of a conical horn, and rectangular and circular waveguide apertures mounted on square and circular finite ground planes. The electric field d...

This paper presented a theoretical and numerical investigation of the Compact Antenna Test Range (CATR) equipped with Super Hybrid Modulated Segmented Exponential Serrations (SHMSES). The investigation was based on diffraction theory and, more specifically, the Fresnel diffraction formulation. The CATR provides uniform illumination within the Fresnel region to test antenna. Application of serra...

Optical diffraction patterns from electron micrographs of both longitudinal and cross sections of normal and anomalous canine cardiac Z bands have been compared. The data indicate that anomalous cardiac Z bands resembling nemaline rods are structurally related to Z bands in showing a repeating lattice common to both. In thin sections transverse to the myofibril axis, both electron micrographs a...

we report the growth by ion exchange synthesis of zns nanoparticles in mcm-41 matrices using zn (ch3coo)2 and na2s starting sources. the final product (zns/mcm-41) was characterized by x-ray diffraction (xrd) pattern, transmission electron microscopy (tem), scanning electron microscopy (sem), infrared spectrometry (ir) and uv-vis spectroscopy. its crystalline structure and morphology was studie...

The multiwavelength anomalous diffraction (MAD) method for phase evaluation is now widely used in macromolecular crystallography. Successful MAD structure determinations have been carried out at the K or L absorption edges of a variety of elements. In this study, we investigate the anomalous scattering properties of uranium at its M(IV) (3.326 A) and M(V) (3.490 A) edge. Fluorescence spectra sh...

Oxide nanoparticles can exhibit unique physical and chemical properties due to their limited size and a high density of corner or edge surface sites. In this study, MgO nanoparticle was synthesized using Mg(CH3COO)2 and hexamethylenetetramine as starting materials. The structure and optical properties of these particles are investigated by using X-ray diffraction (XRD), sc...

The expressions derived for the calculation of multiple diffraction patterns for a perfect crystal in the framework of the kinematical theory are compared with the relevant result of the kinematical power-transfer equation deduced for a mosaic crystal. It is shown that the results of the two concepts differ appreciably.