Abstract: The power and the size of the final spot of the laser beam reaching the target are very important requirements in most of the laser applications and fields such as medical, military, and scientific, so studying laser propagation in the atmosphere is a very important topic. The propagation of the laser beam through the atmosphere is subject to several attenuation processes that deplete the power and expand the beam. Through the simulation results of the free electron laser within the visible region of the electromagnetic spectrum (400-700nm), it was found that the attenuation increases with decreasing wavelength. Laser propagation in the presence of rain and snow leads to a very large l

The purpose of this paper is to gain a good understanding about wake region behind the car body due to the aerodynamic effect when the air flows over the road vehicle during its movement. The main goal of this study is to discuss the effect of the geometry on the wake region and the aerodynamic drag coefficient. Results will be achieved by using two different shapes, which are the fastback and the notchback. The study will be implemented by the Computational Fluid Dynamic (CFD) by using STAR-CCM+^® software for the simulation. This study investigates the steady turbulent flow using k-epsilon turbulence model. The results obtained from the simulation show that the region of the air separation behind the vehicle

    The electronic properties (such as energy gap HOMO levels. LUMO levels, density of state and density of bonds in addition to spectroscopic properties like IR spectra, Raman spectra, force constant and reduced masses as a function of frequency) of coronene C24 and reduced graphene oxide C24OX , where x=1-5, were studied.. The  methodology employed was  Density Functional Theory (DFT) with Hybrid function B3LYP and 6-311G** basis sets. The energy gap was calculated for C24 to be 3.5 eV and for C24Ox was from 0.89 to 1.6862 eV  for x=1-5 ,respectively.   These energy gaps values are comparable to the measured gap of Graphene (1-2.2 eV). The spectroscopic properties were  compared with experimental measurements, specificall

Research in Iraq has expanded in the field of material technology involving the properties of the lightweight concrete using natural aggregate. The use of the porcelinate aggregate in the production of structural light concrete has a wide objective
and requires a lot of research to become suitable for practical application. In this work metakaolin was used to improve compressive strength of lightweight porcelinate concrete which usually have a low compressive strength about 17 MPa . The effect of metakaolin on compressive, splitting tensile, flexure strengths and modulus of elasticity of lightweight porcelinate concrete have been investigated. Many experiments were carried out by replacing cement with different percentages of
met

This study investigates the ionic conduction dependence on the size of alkaline cations in gel polymer electrolytes based on double iodide can enhance by incorporating a salt having a bulky cation.

This study was conducted according to contract with the North Refineries Company-Baiji and deals with the hydrodesulphurization of vacuum gas oil of Kirkuk crude oil, boiling range 611-833 K. A trickle bed reactor packed with a commercial cobalt-molybdenum on alumina catalyst was used. The operating conditions were: temperature range 583-643 K, liquid hourly space velocity range 1.50-3.75 1/h, hydrogen to oil ratio about 250 l/l and pressure kept constant at 3.5MPa.
The results showed that the aromatic content decreased and sulfur removal increased with increasing temperature and decreasing space velocity. The properties (viscosity, density, flash point and carbon residue) of the products decrease with temperature increasing, but the

To assess the effects of dietary oil sources on productive and reproductive traits, sunflower oil, flax oil, corn oil, or fish oil were induced in quail diets. One hundred and sixty-eight 7-week-old Japanese quail were randomly assigned to 4 groups (12 males and 30 females each) with 3 replicates per group containing 4 males and 10 females each and fed for 13 weeks (including one week as an adaptation period) on a commercial diet supplemented with 3% of sunflower oil (T1), flax oil (T2), corn oil (T3), or fish oil (T4). The birds received water and were fed ad libitum during the study. The results of the experiment revealed that dietary supplementation with different sources of oil had no significant effect on male body weight, female body

This research has studied the effect of addition glass fibers (woven and chopped)
and Zirconium oxide Nano-particles (ZrO2) with different weight percent to the
conventional poly (methyl methacrylate) (PMMA). The prepared Nano-crystalline
ZrO2 powder with particle size of about 95nm was syntheses directly by sol-gel
method. The gel dried at 100oC for 1 hour and annelid at 400oC for 3 hours.
The conventional acrylic resin prepared with 2:1 powder to liquid ratio to prepare
pure sample, composite samples prepared by reinforcing PMMA with woven or
chopped glass fiber (8, 12) wt.%, and reinforcing by (1,2,3) wt.% of prepared ZrO2
Nano-powder.
The structural tests include: (XRD, AFM, and FTIR). The crystallized phas

Abstract: This paper presents the results of the structural and optical analysis of CdS thin films prepared by Spray of Pyrolysis (SP) technique. The deposited CdS films were characterized using spectrophotometer and the effect of Sulfide on the structural properties of the films was investigated through the analysis of X-ray diffraction pattern (XRD). The growth of crystal became stronger and more oriented as seen in the X-ray diffraction pattern. The studying of X-ray diffraction showed that; all the films have the hexagonal structure with lattice constants a=b=4.1358 and c=6.7156A°, the crystallite size of the CdS thin films increases and strain (ε) as well as the dislocation density (δ) decreases. Also, the optical properties of the