Theoretical study of Linke's Turbidity at Some Iraqi Sites Based on Solar Radiation

Turbidity was calculated by solar irradiance (Linke's Turbidity) for sixteen Iraqi sites. These sites were distributed among middle, north and south of Iraq. We have updated these results of turbidity by depending on direct solar radiation, diffuse solar radiation, total solar radiation, and solar constant as inputs for mathematical models in computer programs. The latter calculations taking into account the hours of actual sun shine, hours of theoretical sun shine of the sun, the angle of the sun's rays, and the angle of the sun during the months of the year. The results showed that turbidity in the Iraqi sites which considered in this research depends mainly on the months of the year regardless of the fact that this site is located in the north, middle or south of Iraq. The amount of turbidity is at its greatest value during the winter season, specifically the month of December, where the average turbidity varied for those sites. In latter month the turbidity was ranged from (4.85 to 5.73), while in January it ranged from (4.75 to 5.72), then it began to decrease until the value of turbidity in most sites reached its lowest level in September, where the average turbidity of the studied sites varied (except for the site of Najaf) in this month (2.82 - 3.10) While the Najaf site was unique in registering the lowest average amount of turbidity in June by (3.25). The results showed that the turbidity in all sites included in this research ranges between (2.82 - 5.73) during the year.

Elastic Scattering of Electron and Positron by Radium and Radon Atoms

The Differential Cross Sections (DCS's), Total Cross Sections (TCS's) and Momentum Transfer Cross Sections (MTCS's) of electron and positron scattering by radium and radon atoms were calculated in the range of energy (5–500) eV using a total potential consisting of combining the static, exchange and polarization potentials at long distances. In addition, the correlation potential of Perdew–Zunger at short distances for electrons was used, as well as the correlation potential of Jain for positrons. The exchange potential for positrons was neglected. In this study, a good agreement with other experimental values and theoretical values of many investigators was found.

The Structural and Optical Properties of Cobalt dioxide (CoO2 )Thin Films deposited via (SCSP) Technique for photovoltaic applications

The research included the preparation and then studying the structural and optical properties of the cobalt dioxide (CoO2)films. The latter films were prepared using a semi-computerized spray pyrolysis technique (SCSPT),. The X-ray diffraction gave polycrystalline nature with crystal system trigonal (hexagonal axes), and the Energy Dispersive X-ray spectroscopy (EDX) showed that all films contain the elements (Co and O) indicating formation of (CoO2) films with high purity. FTIR measurements showed of chemical bonds of CoO2 clearly. Scanning Electron Microscopy (SEM ) Showed clearly that the formed thin films under the optimum conditions were homogeneous, dense and compact, and Atomic Force Microscopy(AFM) results showed that the topography of the film surface where surface roughness was found to be 7.91 nm, root mean square was 9.69 nm., and the average granularity diameter was 78.00 nm. The optical properties (absorbance, absorption coefficient, extinction coefficient, refractive index, optical Conductivity, the real ε_(1 ) and imaginary ε_2 part of the dielectric constant )were decreased with increasing the wavelength, while the transmittance increases with increasing wavelength. The optical energy gap was (1.98eV) and this is a good optical energy gap values for photovoltaic applications.

Theoretical analysis of short backfire antenna by using Moment of method

The short backfire antenna is one of the important types of antennas due to its high directional and other characteristics. Therefore, this research deals with, a theoretical study to calculate the radiative structures of a short backfire antenna as an axially symmetric body using the moment method. The main goal is to theoretically calculate the radiation fields and compare them with previous practical researches. Where the mathematical analysis with the used software was verified by comparing the results and noting the extent of the match. The other goal is to study the effect of the antenna dimensions on its performance by studying the effect of adding a rim to the edge of the large back reflector, as well as studying the change of the radius of the two reflectors (large and small), where it was confirmed that the best value for the radius of the large reflectors and small (Rm=1λ) (Rs= 0.25 λ) respectively.

A Theoretical Study of H2S Toxic Gas Adsorption on Pristine and Doped Monolayer (AlN)21 Using Density Functional Theory

Been studying the interactions between graphene - like aluminium nitride P(AlN)21 nano ribbons doped and defect (AlN)21Sheet, Molecules and small toxic gas molecules ( H2S), were built for two different adsorption sites on graphene like aluminium nitride P(AlN)21. this was done by employing B3LYP density functional theory (DFT) with 6-31G*(d,p) using Gaussian 09 program, Gaussian viw5.0 package of programs and Nanotube Modeller program 2018. the adsorptions of H2S on P(AlN)21, (C) atoms-doped P(AL-N)20 sheet, D-P(AL-N)20 and D-(C)atoms-doped P(AL-N)19 (on atom) with (Ead) (-0.468eV),(-0.473 eV), (-0.457 eV), (-0.4478 eV) and (-0.454 eV), respectively, (Ead) of H2S on the center ring of the P(AL-N)21, (C) atoms-doped P(AL-N)20 sheet, D-P(AL-N)20 and D-(C,B)atoms-doped P(AL-N)19 sheet are (-0.280 eV),(-0.465 eV), (-0.405 eV), (-0.468 eV) and -0.282 eV), respectively, are weak physisorption . However, the adsorptions of H2S, on the ((AlN)20 -B and D- (AlN)19 -B), (on atom N and center ring the sheet) are a strong chemisorption because of the (Ead) larger than -0.5 eV, due to the strong interaction, the ((AlN)20-B and D-(AlN)19-B), could catalyst or activate, through the results that we obtained, which are the improvement of the sheet P(AlN)21 by doping and per forming a defect in, it that can be used to design sensors. DOI: http://dx.doi.org/10.31257/2018/JKP/2020/120210

An approach to model and optimization of manufacturing of an enhanced swing differential Colpitts oscillator. on influence of miss-match induced stress

In this paper we introduce an approach to increase density of field-effect transistors framework an enhanced swing differential Colpitts oscillator. Framework the approach we consider manufacturing the oscillator in heterostructure with specific configuration. Several required areas of the heterostructure should be doped by diffusion or ion implantation. After that dopant and radiation defects should by annealed framework optimized scheme. We also consider an approach to decrease value of mismatch-induced stress in the considered heterostructure. We introduce an analytical approach to analyze mass and heat transport in heterostructures during manufacturing of integrated circuits with account mismatch-induced stress

Effect of nanoclay (Kaolinite) on mechanical properties of epoxy-fiber composite

An experimental investigation using drag-out tensile test to calculate the interfacial shear strength for different embedded lengths of Kevlar and carbon fibers reinforced epoxy matrix with nanoclay (kaolinite) for different ratio weight, the interfacial shear strength increased by with increasing of embedded length and ratio weight fraction of nanoclay that adding to epoxy matrix.

Effect of molar concentration on the optical and structural properties of ZnO thin films prepared by chemical bath deposition method

This research included the preparation of (ZnO) thin films by CBD technique for the deposition of chemical bath thickness (150 ± 20nm). X-ray diffraction was analyzed and showed that the films crystallize in a polycrystalline hexagonal structure, with a preferred direction along the level (100). Increased volume of calculated crystals for deposited films was found by increasing molar concentration. The surface morphology of films was studied by SEM, and the surface morphology of ZnO films is a heterogeneous distribution. The optical properties of all deposited ZnO films contained a spectral permeability and absorption spectrum in the wavelength range (300-1100nm), and the transmittance decreased with increasing molar concentration, it was found that the value of the light energy gap (Eg) increases with increasing molecular concentration band gap between 3.1 and 3.2 eV.

Using Sun Fits images for calculation of terrestrial aerosol optical depth (AOD) and Ångström turbidity parameters in countryside of Kufa district

Since there are no previous studies conducted for calculating Kufa turbidity parameters considering that the urban pollutions is less than that of the Kufa city. For this The prior location of the Faculty of science telescope was chosen to make such observation using a 60 mm solar telescope Coronado of Hα filter equipped with CCD DSI III pro connected to laptop computer . Sun Fits images were captured under a clear sky as well as dusty conditions. Two types of images were classified, one in the clear sky and the other in dusty weather. Matlab code was used to estimate sun intensities in order to calculate aerosol optical depth and Ångström turbidity parameters from sun images. These values are expressing the normality behavior with nearer places in territorial region.

Reentry of Space Debris from Low Earth Orbit by Pulsed Nd:YAG Laser

This research studies the orbital dynamics of space debris in near earth orbit. The orbital dynamics of space debris is closely examined in near earth orbit whereby (apogee altitude ha=1200 km and perigee altitude hp=200 km). In addition, the lifetime of the space debris is calculated using the influence of the friction force exerted on the atmospheric particles with debris dimensions measuring between (1 and 10 cm). In this study, the Drag Thermospheric Models (DTM78 and DTM94) are used because of their dependence on solar and geomagnetic activities, and pulsed lasers are utilized to interact with Aluminum 2024 particles which are frequently employed in the structure of spacecraft and aerospace designs. A numerical analysis program (NaP1) was built to calculate the lifetime of space debris and its time of return to the atmosphere. It is then integrated with a second numerical analysis program (NaP2) developed using the Lax-Wendroff finite difference method to simulate the laser material interaction model. A high power Nd:YAG laser was applied to produce shock wave pressure in target. The results show that the maximum peak pressure occurs at 50 µm depth then slowly decays, the peak pressure increases with the increase of the laser intensity, and the optimum value of the momentum coupling coefficient (Cm) for the aluminum debris of size range (1and10 cm) is 6.5 dyn.s/j.