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Compensation of the Nonlinear Power Amplifier by Using SCPWL Predistorter with Genetic Algorithm in OFDM technique
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The High Power Amplifiers (HPAs), which are used in wireless communication, are distinctly characterized by nonlinear properties. The linearity of the HPA can be accomplished by retreating an HPA to put it in a linear region on account of power performance loss. Meanwhile the Orthogonal Frequency Division Multiplex signal is very rough. Therefore, it will be required a large undo to the linear action area that leads to a vital loss in power efficiency. Thereby, back-off is not a positive solution. A Simplicial Canonical Piecewise-Linear (SCPWL) model based digital predistorters are widely employed to compensating the nonlinear distortion that introduced by a HPA component in OFDM technology. In this paper, the genetic algorithm has been used to optimized the SCPWL coefficients by using Matlab 2015b, and then the Bit Error Rate (BER) performance has been evaluated for OFDM signal with 16-QAM and 64-QAM modulations in three cases, with nonlinear effects, without nonlinear effects (ideal case), with SCPWL and with nonlinear effects (compensated case)). The simulation results showed that the predistorter that adjusted by the genetic algorithm accomplishes huge execution change by successfully compensating the nonlinearity and reducing the input and output back-off (IBO, OBO) of the HPA.

 

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Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Evaluated the level density for proton induced nuclear resonances in (P+48Ti) reaction using different models
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The experimental proton resonance data for the reaction P+48Ti have been used to calculate and evaluate the level density by employed the Gaussian Orthogonal Ensemble, GOE version of RMT, Constant Temperature, CT and Back Shifted Fermi Gas, BSFG models at certain spin-parity and at different proton energies. The results of GOE model are found in agreement with other, while the level density calculated using the BSFG Model showed less values with spin dependence more than parity, due the limitation in the parameters (level density parameter, a, Energy shift parameter, E1and spin cut off parameter, σc). Also, in the CT Model the level density results depend mainly on two parameters (T and ground state back shift energy, E0), which are app

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Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
The commercial dealing means in the Albidaya Walnihaya book by Iben Katheer Al Dimashqi (701-774 A.H./1301-1372 A.D.)
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Iben Katheer Al Dimashqi is considered among the eminent scholars in the eighth Hijri century / fourteenth Gregorian century. He acquired eminent academic and social standing. His book Albidaya Walnihaya is considered among the important historical sources. This book's study of the subject of commercial dealing methods clarifies that the commercial dealing methods dealt by the people throughout the successive historical eras were multiple, most prominent of which was money (whether Dirhams, Dinars, measures (mikyals), weights (like Sa') in addition to other means like usury. But here we notice that Iben Katheer stressed that usury must be prohibited because it is religiously forbidden and cited many Quranic verses and Prophetic sayings w

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Publication Date
Tue Jan 01 2008
Journal Name
Journal Of Alfateh
Study of the current of the MHD generator with modified Bohm diffusion
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generator the metal conductor is replaced by conducting gas plasma.

Publication Date
Wed Jul 01 2020
Journal Name
Journal Of Engineering
Improvement the Mechanical Characteristics of Alloy Steel DIN 41Cr4 by Shot Peening
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The effects of shot peening treatment (SPT) were studied at (10,20, and 30) minutes on the rotating bending fatigue behavior and the behavior of the alloy steel DIN 41Cr4 vibrations. The hardness test, tensile test, constant amplitude fatigue tests, and the vibration measurements were performed on samples with and without cracks at room temperature (RT), also, the fracture surface was examined and analyzed by a Scanning Electron Microscope (SEM). The results of the investigations, for example, Stress to Number of cycles to failure (S-N) curves, fatigue strength improvement factor of 5% to 10%, the decreasing percentage of maximum Fast Fourier Transform (FFT) acceleration of the shot-peened condition were compared to untr

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Publication Date
Sun Dec 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The Production of Ethanol from Sugar Beet Waste by Immobilized Saccharomyces Cerevisiae
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Saccharomyces Cerevisiae cells were immobilized in calcium alginate beads and activated charcoal for use in the
production of ethanol from batch fermentation of sugar beet waste. Treatment of the waste with NaOH to increase the
ability of lignocellulose material to hydrolysis by acid (2N H2SO4) to monosaccharide and disaccharide (mainly glucos).
The high reducing sugar concentration obtained was equal to 9.2gm/100ml (10Brix) after treatment. Fermentation
parameters, are (pH, glucose concentration (2.5-25 gm/100ml), immobilized agent concentration (2.5-25 gm/100ml)
were studied to find the optimum physiological condition. And the highest ethanol concentration obtained from the
fermentation in the presence of 20%(wt/v) ca

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Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Improving the Activity of NiO-NiFe2 Catalyst by Na2O for Phenol Synthesis
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Publication Date
Sat Oct 01 2011
Journal Name
Iraqi Journal Of Physics
The Structure and Electrical Properties of Porous Silicon Prepared by Electrochemical Etching
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Porous silicon was prepared by using electrochemical etching process. The structure, electrical, and photoelectrical properties had been performed. Scanning Electron Microscope (SEM) observations of porous silicon layers were obtained before and after rapid thermal oxidation process. The rapid thermal oxidation process did not modify the morphology of porous layers. The unique observation was the pore size decreased after oxidation; pore number and shape were conserved. The wall size which separated between pore was increased after oxidation and that effected on charge transport mechanism of PS

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Publication Date
Wed Jan 01 2020
Journal Name
Methods And Objects Of Chemical Analysis
Predicting The Composition Of Qurna Crude Oil Fraction By Ternary Composition Diagram
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With a goal to identify, and ultimately removing from the oil fraction, the carcinogenic components, an oil fraction oil has been analyzed into a main three hydrocarbon groups, paraffins, aromatics, and polycyclic saturates. A multi-stage adsorption apparatus has been used. Four units of 300 g alumina each seems to be sufficient for removing the polynuclear aromatics from 75 g of an oil fraction boiling between 365-375 °C from Qurna crude oil. The usefulness of the ternary diagram for analyzing the oil fraction to the three hydrocarbons groups has been studied and verified. An experimentally based linear relationship of density and refractive index was established to enable of identifying the composition of an oil fraction using th

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Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
The antibacterial activity of indium oxide thin film prepared by thermal deposition
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Indium oxide In2O3 thin films fabricated using thermal evaporation of indium metal in vacuum on a glass substrate at 25oC using array mask, after deposition the indium films have been subjected to thermal oxidation at temperature 400 °C for 1h. The results of prepared Indium oxide reveal the oxidation method as a strong effect on the morphology and optical properties of the samples as fabricated. The band gap (Eg) of In2O3 films at 400 °C is 2.7 eV. Then, SEM and XRD measurements are also used to investigate the morphology and structure of the indium oxide In2O3 thin films. The antimicrobial activity of indium oxide In2O3 thin films was assessed against gram-negative bacterium using inhibition zone of bacteria which improved higher ina

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Publication Date
Mon Dec 11 2006
Journal Name
Iraqi Journal Of Laser
The Inhibition of Streptococcus mutans by He- Ne Laser via TBO Photosensitizer
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This work aims to investigate the inhibition of vitality of Streptococcus mutans, which is the causative agent of caries. A 632.8 nm He-Ne laser with the output power of 4.5mW was used in combination with toluidine blue O (TBO) at the concentration of 50μg/ml as a photosensitizer. Streptococcus mutans was isolated from 35 patients if carious teeth. Three isolates were chosen and exposed to different energy densities of He – Ne laser light 3.8, 11.7, 34.5 and 104.1 J/cm². After irradiation, substantial reduction was observed in the number of colony forming units (CFU)/ ml. The reduction in the number of CFU was increasing as the dose increased.

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