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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 Jul 01 2019
Journal Name
J. Pharm. Sci. & Res.
Synthesis of coumarin by Pechman reaction - A Review
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Phenol condensed with β-keto esters via Pechmann condensation to form derivatives of Coumarin in various reaction conditions by two ways. Present paper is comparative study of synthesis Coumarin with the yield of product , reaction time and reaction conditions.

Publication Date
Fri Sep 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Treatment of Recurrent Aphthous Ulceration by Mastic Orabase
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Background: Recurrent aphthous ulcer is a chronic inflammatory disease of the oral mucosa. Substance P has activity in the inflammatory response. Transforming growth factor beta (TGF-β) as immune-modulators regulates the immune response and has anti-inflammatory, pro-inflammatory effects. Pistacia lentiscus (mastic) of Anacardiaceae family have pharmacological activities like anti-inflammatory, antioxidant, and used in treatment of wound and repair. The aim of this study is to find the safety and efficacy of a new product mastic orabase; experimentally and clinically. Methods: This research studied two parts: first; experimentally for assessment of mastic orabase effects on rabbit dermal irritation, efficacy of mastic orabase on the indu

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Publication Date
Fri Dec 01 2023
Journal Name
Iraqi Journal Of Physics
Characterization of Magnetized-Plasma System Induced by Laser
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  This study investigated the effect of applying an external magnetic field on the characteristics of laser-induced plasma, such as its parameters plasma, magnetization properties, emission line intensities, and plasma coefficients, for plasma induced from zinc oxide: aluminum composite (ZO:AL) at an atomic ratio of 0.3 %. Plasma properties include magnetization and emission line intensities. The excitation was done by a pulsed laser of Nd:YAG with 400 mJ energy at atmospheric pressure. Both the electron temperature and number density were determined with the help of the Stark effect principle and the Boltzmann-Plot method. There was a rise in the amount of (ne) and (Te) that was produced

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Publication Date
Mon Jan 01 2018
Journal Name
Asian Journal Of Ournal Of Chemistry
Extraction of Ocimum basillicum Oil by Solvents Methods
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The extraction of Basil oil from Iraqi Ocimum basillicum leaves using n-hexane and petroleum ether as organic solvents were studied and compared. The concentration of oil has been determined in a variety of extraction temperatures and agitation speed. The solvent to solid ratio effect has been studied in order to evaluate the concentration of Ocimum basillicum oil. The optimum experimental conditions for the oil extraction were established as follows: n-hexane as organic solvent, 60 °C extraction temperature, 300 rpm agitation speed and 40:1mL:g amount of solvent to solid ratio.

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Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Removal of Emulsified Kerosene from Water by Flotation
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Publication Date
Tue Sep 01 2020
Journal Name
Baghdad Science Journal
Modified Mathematical Model of Tumor Treatment by Radiotherapy
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In this research, a mathematical model of tumor treatment by radiotherapy is studied and a new modification for the model is proposed as well as introducing the check for the suggested modification. Also the stability of the modified model is analyzed in the last section.

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Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Multidisciplinary Engineering Science Studies
Investigation of p-Ps Produced by Electrochemical Etching
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The nanocrystalline porous silicon (PS) films are prepared by electrochemical etching ECE of p -type silicon wafer with current density (10mA/cm ) and etching times on the formation nano -sized pore array with a dimension of around different etching time (10 and 20) min. The films were characterized by the measurement of XRD, atomic force microscopy properties (AFM). We have estimated crystallites size from X -Ray diffraction about nanoscale for PS and AFM confirms the nanometric size Chemical fictionalization during the electrochemical etching show on the surface chemical composition of PS. The atomic force microscopy investigation shows the rough silicon surface, with increasing etching process (current density and etching time) porous st

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Publication Date
Wed Mar 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Treatment of Used lubricant Oil by Solvent Extraction
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This study investigates the treatment of used lubricating oils from AL-Mussaib Gas Power Station Company-Iraq, which was treated with different extractive solvents (heptane and 2-propanol). The performance activity of these solvents in the extraction process was examined and evaluated experimentally. Operating parameters were solvent to oil ratios of (1:2, 1:4, 1:6, and 1:8), mixing time (20, 35, 50, and 65 min), temperatures (30, 40, 50, and 60 ºC), and mixing speed (500 rpm). These parameters were studied and analyzed. The quality is determined by the measuring and assessment of important characteristics specially viscosity, viscosity index, specific gravity, pour point, flash point, and ash content. The results confirm that the solve

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Publication Date
Fri Jan 04 2019
Journal Name
Drinking Water Engineering And Science Discussions
Bio-purification of drinking water by froth flotation
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Abstract. The main technique for removing bacteria from water for various applications is chemical disinfection. However, this method has many disadvantages such as producing disinfectant by-products (DBPs), biofilm formation and either rendering the water unpotable (at high residual disinfection) or leaving a potential for lethal diseases such as Cholera (if the residual disinfection is too low). Recently, a process was developed for continuous removal of bacteria from water using the principle of froth flotation through compressed air only without any chemicals (Hassan, 2015). This work examines the extent to which chemical free froth flotation can purify drinking water. The experiments were carried out using two flotation columns

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
REMOVAL OF COPPER ION FROM WASTEWATER BY FLOTATION
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Several industrial wastewater streams may contain heavy metal ions, which must be effectively removal
before the discharge or reuse of treated waters could take place. In this paper, the removal of copper( II)
by foam flotation from dilute aqueous solutions was investigated at laboratory scale. The effects of
various parameters such as pH, collector and frother concentrations, initial copper concentration, air flow
rate, hole diameter of the gas distributor, and NaCl addition were tested in a bubble column of 6 cm inside
diameter and 120 cm height. Sodium dodecylsulfate (SDS) and Hexadecyl trimethyl ammonium bromide
(HTAB) were used as anionic and cationic surfactant, respectively. Ethanol was used as frothers and the

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