The FSO technique depends on the compatibility of the optical path between the transmitter and the receiver (line-of-sight) to transmit data between two points. FSO system uses the light to provide optical Contact to send and receive various data. This study shows the design of a new optical system for the transmission of voice through free space at wavelengths (650,532,405) nm within point-point technology for specified distances. What distinguishes this work is the quality of the reflection-based modulation based on the Doppler phenomenon. Also, it is interested in studying the different attenuation conditions of the atmosphere at the wavelengths used, in addition to the attenuation caused by the

       Thin films of pure yttrium oxide (Y₂O₃) and doped with cerium oxide (CeO₂) were prepared by the chemical spray pyrolysis(CSP)method. The structural, optical and electrical properties of the prepared films were investigated. The analysis of X-ray diffraction (XRD) thin films revealed that the undoped and doped Y₂O₃  were amorphous with a broad hump around 27^o and narrow humps around 48^o and 62^o for all samples. Except for the Y₂O₃:6wt.%CeO₂ thin film, all had signal preferential orientation along the (100) plane at 2θ=12.71^o which belongs to CeO₂, Field emission scanning electron mic

Spray pyrolysis technique (SPT) is employed to synthesize cadmium oxide nanostructure with 3% and 5% Cobalt concentrations. Films are deposited on a glass substrate at 350 ᵒC with 150 nm thickness. The XRD analysis revealed a polycrystalline nature with cubic structure and (111) preferred orientation. Structural parameters represent lattice spacing, crystallite size, lattice parameter and dislocation density. Homogeneous surfaces and regular distribution of atoms were showed by atomic force microscope (AFM) with 1.03 nm average roughness and 1.22 nm root mean square roughness. Optical properties illustrated a high transmittance more than 85% in the range of visible spectrum and decreased with Co concentration increasing. The absorption

This research explores the preparation of polypyrrole (PPy) using chemical oxidation and its enhancement with graphene oxide (GO) for optical sensor applications. PPy was synthesized by polymerizing pyrrole monomers with ferric chloride (Fe2Cl3) as the oxidant. The resulting PPy was then combined with GO to form a composite material, aiming to improve its electrical and optical properties. Polypyrrole nanofibers were obtained and after adding graphene oxide, the sensitivity increased. Characterization techniques including UV-Vis spectroscopy, DC conductivity measurements, Field Emission Scanning Electron Microscopy (FESEM) and response of photocurrent analysis were employed. The incorporation of GO into PPy resulted in a significant reducti

    Change in structure of land surface can affect atmospheric boundary layer and formation of internal boundary layer. This will change shear stresses and turbulent boundary layer. Change in low level wind shear and turbulent can affect air craft performance and has potentially adverse effects on flight safety during landing and taking-off stages. In this study, change in land area around Baghdad Airport and its effects on structure of boundary layer and radix layer through summer season (July from years 1985 and 2014) is examined. The examination is done through atmospheric data of radiosonde (at altitude more than 1500 m) and remote sensing by Landsat 5 and 8 images (circular region around airport has radius 3.250 km and the airpor

The Detour distance is one of the most common distance types used in chemistry and computer networks today. Therefore, in this paper, the detour polynomials and detour indices of vertices identified of n-graphs which are connected to themselves and separated from each other with respect to the vertices for n≥3 will be obtained. Also, polynomials detour and detour indices will be found for another graphs which have important applications in Chemistry.

An evaluation of pollution level has been done for drinking water which is used in Kirkuk city by heavy metals ( As,Cd,Cu,Fe,Mn,Ni,Zn,Cr,Pb) samples were collected during wet and dry of 2016-2017 from Kirkuk unified water supplied project (WTP) which is supply the city with drinking water, as well as from water of tanks type (GST2), and also from (tap water) (Zone3). The results showed the concentration of the (As,Cd,Cu,Fe,Mn,Ni,Zn,Cr,Pb)inppbfor (WTP)are (0.5,0.6,6.45,38,4.6,2.5,6537,0.58,1.4) (0.6,0.8,6.76,46,5.5,3.5,6675,1,2.4) for (GST) (0.5,0.63,6.46,52.3,4.4,3.6,6550,0.6,2.5) (0.60,0.7,6.78,63.7,6.7,3.7,6680,1.1,2.6) and for tap water are (0.53,0.65,7.00,60.2,4.4,3.65,7200,0.8,2.7) (0.60, 0.71, 7.10, 67.6, 6.8,3.75,7320,0.9,2.75) f

Abstract: Stars whose initial masses are between (0.89 - 8.0) M☉ go through an Asymptotic Giant Branch (AGB) phase at the end of their life. Which have been evolved from the main sequence phase through Asymptotic Giant Branch (AGB). The calculations were done by adopted Synthetic Model showed the following results: 1- Mass loss on the AGB phase consists of two phases for period (P <500) days and for (P>500) days; 2- the mass loss rate exponentially increases with the pulsation periods; 3- The expansion velocity VAGB for our stars are calculated according to the three assumptions; 4- the terminal velocity depends on several factors likes metallicity and luminosity. The calculations indicated that a super wind phase (S.W) developed on the A

This study focuses on studying the effect of reinforced steel in detail, and steel reinforcement (tensile ratio, compression ratio, size, and joint angle shape) on the strength of reinforced concrete (compressive strength) Fc' and searching for the most accurate details of concrete divisions, their behavior, and corner resistance of reinforced concrete joint. The comparison of this paper with previous studies, especially in the studied properties. The conclusions of the chapter are summarized that these effects had a clear effect and a specific effect on the behavior and resistance of the reinforced concrete corner joints under the negative moments and under their influence and the resulting stress conditions. The types of defects that can