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Numerical Simulation of Solar Granulation Dynamics Using Optical Correction Techniques
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High-resolution imaging of celestial bodies, especially the sun, is essential for understanding dynamic phenomena and surface details. However, the Earth's atmospheric turbulence distorts the incoming light wavefront, which poses a challenge for accurate solar imaging. Solar granulation, the formation of granules and intergranular lanes on the sun's surface, is important for studying solar activity. This paper investigates the impact of atmospheric turbulence-induced wavefront distortions on solar granule imaging and evaluates, both visually and statistically, the effectiveness of Zonal Adaptive Optics (AO) systems in correcting these distortions. Utilizing cellular automata for granulation modelling and Zonal AO correction methods, the study aims to understand system behavior under varying atmospheric turbulence conditions and provide recommendations for Zonal AO system enhancement for solar observations. Performance metrics, including Strehl Ratio, Correction Stability, Root Mean Squared Error (RMSE), and Correction Rate, were used to assess system performance under varying turbulence levels. However, challenges arise with increasing turbulence strength, impacting correction precision, stability, and speed. The results showed the weakness of the Zonal AO in treating high distortions in wavefront, as is evident by the decreases in Strehl Ratio values from 0.98 to 0.085 for disturbance strength values from 0.2 to 1, respectively.

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Publication Date
Mon Oct 01 2018
Journal Name
Radioelectronics And Communications Systems
Optical CDMA Coded STBC Based on Chaotic Technique in FSO Communication Systems
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Free-Space Optical (FSO) can provide high-speed communications when the effect of turbulence is not serious. However, Space-Time-Block-Code (STBC) is a good candidate to mitigate this seriousness. This paper proposes a hybrid of an Optical Code Division Multiple Access (OCDMA) and STBC in FSO communication for last mile solutions, where access to remote areas is complicated. The main weakness effecting a FSO link is the atmospheric turbulence. The feasibility of employing STBC in OCDMA is to mitigate these effects. The current work evaluates the Bit-Error-Rate (BER) performance of OCDMA operating under the scintillation effect, where this effect can be described by the gamma-gamma model. The most obvious finding to emerge from the analysis

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Publication Date
Sun Dec 02 2018
Journal Name
Iraqi Journal Of Physics
Optical properties for TiO2 / PMMA nanocomposite thin films prepared by plasma jet
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PMMA/TiO2 homogeneous thin films were deposited by using plasma jet system under normal atmospheric pressure and room temperature. PMMA/TiO2 nanocomposite thin film synthesized by plasma polymerization. Titanium oxide was mixed with Methyl Methacrylate Monomer (MMA) with specific weight ratios (1, 3 and 5 grams of TiO2 per 100 ml of MMA). Optical properties of PMMA/TiO2 nanocomposite thin films were characterized by UV-Visible absorption spectra using a double beam UV-Vis-NIR Spectrophotometer. The thin films surface morphological analysis is carried out by employing SEM. The structure analysis are achieved by X-ray diffraction. UV-Visible absorption spectra shows that the increasing the concentration of titanium oxide added to the polym

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Publication Date
Sat Sep 01 2018
Journal Name
Iraqi Journal Of Science
Polymer optical fiber sensor side-pumped with polymer clad doped lasing compounds
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Publication Date
Tue May 23 2023
Journal Name
Journal Of Engineering
Modeling and Simulation of Copper Removal from the Contaminated Soil by a Combination of Adsorption and Electro-kinetic Remediation
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Electro-kinetic remediation technology is one of the developing technologies that offer great promise for the cleanup of soils contaminated with heavy metals. A numerical model was formulated to simulate copper (Cu) transport under an electric field using one-dimensional diffusion-advection equations describing the contaminant transport driven by chemical and electrical gradients in soil during the electro-kinetic remediation as a function of time and space. This model included complex physicochemical factors affecting the transport phenomena, such as soil pH value, aqueous phase reaction, adsorption, and precipitation. One-dimensional finitedifference computer program successfully predicted meaningful values for soil pH profiles and Cu

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Publication Date
Sat Oct 01 2016
Journal Name
Arpn Journal Of Engineering And Applied Sciences
Numerical and experimental analysis of transient temperature and residual thermal stresses in friction stir welding of aluminum alloy 7020-T53
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Publication Date
Tue Dec 13 2022
Journal Name
Frontiers In Chemistry
Numerical analysis of the energy-storage performance of a PCM-based triplex-tube containment system equipped with arc-shaped fins
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This study numerically intends to evaluate the effects of arc-shaped fins on the melting capability of a triplex-tube confinement system filled with phase-change materials (PCMs). In contrast to situations with no fins, where PCM exhibits relatively poor heat response, in this study, the thermal performance is modified using novel arc-shaped fins with various circular angles and orientations compared with traditional rectangular fins. Several inline and staggered layouts are also assessed to maximize the fin’s efficacy. The effect of the nearby natural convection is further investigated by adding a fin to the bottom of the heat-storage domain. Additionally, the Reynolds number and temperature of the heat-transfer fluid (HTF) are e

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Publication Date
Tue Mar 31 2020
Journal Name
Association Of Arab Universities Journal Of Engineering Sciences
Experimental and Theoretical Analysis of a Mono PV Cell with Five Parameters, Simulation Model Compatible with Iraqi Climate
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The present work included study of the effects of weather conditions such as solar radiation and  ambient temperature on solar panels (monocrystalline 30 Watts) via proposed mathematical model, MATLAB_Simulation was used by scripts file to create a special code to solve the mathematical model , The latter is single –diode model (Five parameter) ,Where the effect of ambient temperature and solar radiation on the output of the solar panel was studied, the Newton Raphson method was used to find the  output current of the solar panel and plot P-V ,I-V curves, the performance of the PV was determined at Standard Test Condition (STC) (1000W/m2)and a comparison between theoretical and experimental results were done .The best efficiency

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Publication Date
Fri Dec 01 2023
Journal Name
Baghdad Science Journal
Numerical Investigation of Physical Parameters in Cardiac Vessels as a New Medical Support Science for Complex Blood Flow Characteristics
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This study proposes a mathematical approach and numerical experiment for a simple solution of cardiac blood flow to the heart's blood vessels. A mathematical model of human blood flow through arterial branches was studied and calculated using the Navier-Stokes partial differential equation with finite element analysis (FEA) approach. Furthermore, FEA is applied to the steady flow of two-dimensional viscous liquids through different geometries. The validity of the computational method is determined by comparing numerical experiments with the results of the analysis of different functions. Numerical analysis showed that the highest blood flow velocity of 1.22 cm/s occurred in the center of the vessel which tends to be laminar and is influe

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Publication Date
Tue Mar 20 2018
Journal Name
Day 2 Wed, March 21, 2018
Numerical Approach for the Prediction of Formation and Hydraulic Fracture Properties Considering Elliptical Flow Regime in Tight Gas Reservoirs
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Abstract<p>As tight gas reservoirs (TGRs) become more significant to the future of the gas industry, investigation into the best methods for the evaluation of field performance is critical. While hydraulic fractured well in TRGs are proven to be most viable options for economic recovery of gas, the interpretation of pressure transient or well test data from hydraulic fractured well in TGRs for the accurate estimation of important reservoirs and fracture properties (e.g. fracture length, fracture conductivity, skin and reservoir permeability) is rather very complex and difficult because of the existence of multiple flow profiles/regimes. The flow regimes are complex in TGRs due to the large hydraulic fractures n</p> ... Show More
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Publication Date
Wed May 01 2024
Journal Name
Journal Of Physics: Conference Series
Study of The Effect of Concentration on The Efficiency of The Sensitive N749-TiO<sub>2</sub> Solar Cell
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Abstract<p>In this research, we studied the effect of concentration carriers on the efficiency of the N749-TiO<sub>2</sub> heterogeneous solar cell based on quantum electron transfer theory using a donor-acceptor scenario. The photoelectric properties of the N749-TiO<sub>2</sub> interfaces in dye sensitized solar cells DSSCs are calculated using the J-V curves. For the (CH3)3COH solvent, the N749-TiO<sub>2</sub> heterogeneous solar cell shows that the concentration carrier together with the strength coupling are the main factors affecting the current density, fill factor and efficiency. The current density and current increase as the concentration increases and the </p> ... Show More
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