Preferred Language
Articles
/
joe-600
Compensation of the Nonlinear Power Amplifier by Using SCPWL Predistorter with Genetic Algorithm in OFDM technique
...Show More Authors

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.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Jan 01 2018
Journal Name
Journal Of Physics Conference Series
Enhanced phot-respons of porous silicon photo- detectors by embedding Titanium -dioxide nano-particles
...Show More Authors

: Porous silicon (n-PS) films can be prepared by photoelectochemical etching (PECE) Silicon chips n - types with 15 (mA /cm2), in15 minutes etching time on the fabrication nano-sized pore arrangement. By using X-ray diffraction measurement and atomic power microscopy characteristics (AFM), PS was investigated. It was also evaluated the crystallites size from (XRD) for the PS nanoscale. The atomic force microscopy confirmed the nano-metric size chemical fictionalization through the electrochemical etching that was shown on the PS surface chemical composition. The atomic power microscopy checks showed the roughness of the silicon surface. It is also notified (TiO2) preparation nano-particles that were prepared by pulse laser eradication in e

... Show More
Publication Date
Wed Aug 26 2020
Journal Name
Iraqi Journal Of Agricultural Sciences
STIMULATION GROWTH AND YIELD OF POTATO BY BUTTONWOOD PRUNNING RESIDUES AND SPRAYING SEVERAL MICRONUTRIENTS
...Show More Authors

This study was aimed to estimate the influence of Conocarpus erectus L. residues, and some micronutrients on growth and production of potato. This research was conducted at one of the fields of the College of Agricultural Engineering Sciences - University of Baghdad. The experiment was implemented using factorial arrangement (4X3X3) within randomized complete block design with three replicates. Conocarpus fertilizer was represented the first factor with three levels (7.5, 15, 30 ton.ha-1), which symbolized (C2, C3, C4). Mineral fertilizer as recommended dose as a control, which symbolized (C1). The second factor was foliar spraying with three levels of iron (0, 100, 200 mg.L-1), which symbolized (F0, F1, F2). The third factor is fol

... Show More
Scopus (6)
Crossref (1)
Scopus Crossref
Publication Date
Tue Jan 01 2013
Journal Name
Iraqi Journal Of Cancer And Medical Genetics
Cytotoxicity of purified methionine γ- lyase produced by Pseudomonas putida on several cell lines
...Show More Authors

The cytotoxicity of different concentrations of purified methionine γ- lyase from Pseudomonas putida on cancer cell lines (RD, AMN3 and AMGM) at 96 hr was studied. The bacterial enzyme with concentration 1000µg/ml was revealed highly cytotoxicity against cancer cell lines in comparison with other concentrations whereas slight cytotoxicity was observed on normal cell (REF).

Publication Date
Tue Apr 05 2022
Journal Name
Nano Hybrids And Composites
Structural and Optical Properties of ZnO Nanostructures Synthesized by Hydrothermal Method at Different Conditions
...Show More Authors

Zinc oxide (ZnO) nanoparticles were synthesized using a modified hydrothermal approach at different reaction temperatures and growth times. Moreover, a thorough morphological, structural and optical investigation was demonstrated using scanning electron microscopy (SEM), x-ray diffraction (XRD), ultra-violate visible light spectroscopy (UV-Vis.), and photoluminescence (PL) techniques. Notably, SEM analysis revealed the occurrence of nanorods-shaped surface morphology with a wide range of length and diameter. Meanwhile, a hexagonal crystal structure of the ZnO nanoparticles was perceived using XRD analysis and crystallite size ranging from 14.7 to 23.8 nm at 7 and 8 ℎ𝑟𝑠., respectively. The prepared ZnO samples showed good abso

... Show More
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Structural and Optical Properties of SnS2:Cu Thin films prepared by chemical Spbay Pyrolysis
...Show More Authors

Thin filis have been prepared from the tin disulphide (SnS2 ), the pure and the doped with copper (SnS2:Cu) with a percentages (1,2,3,4)% by using ahemical spray pyrolysis techniqee on substrate of glass heated up to(603K)and sith thicknesses (0.7±0.02)?m ,after that the films were treated thermally with a low pressure (10-3mb) and at a temperature of (473K) for one hour. The influence of both doping with copper and the thermal treatment on some of the physical characteristics of the prepared films(structural and optical) was studied. The X-ray analysis showed that the prepared films were polycrystalline Hexagonal type. The optical study that included the absorptance and transmitance spectra in the weavelength range (300-900)nm

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Materials Today: Proceedings Journal
Improving torsional – Flexural resistance of concrete beams reinforced by hooked and straight steel fibers
...Show More Authors

Scopus (10)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Wed Aug 31 2022
Journal Name
Al-kindy College Medical Journal
A comparison of cross sections for Selenium -73 radioisotopes produced by accelerators and reactors
...Show More Authors

Background: Selenium-73 with half- life of 7.15 hour emits β+ in nature and has six stable isotopes which are ( 74Se,76Se,77Se,78Se,80Se and 82Se ). Selenium-73 has many applications in technology and radioselenium compounds of metallic have found various applications in medicine. Objective:  To make a comparison between different reactions that produced cross sections of Se-73 radioisotopes. Subjects and methods: The feasibility of the production of Selenium -73 via various nuclear reactions was investigated. Excitation functions of 73Se production by the reactions of 75As (p,3n), 169Tm( d,x), 74Se, natSe, natBr (p,x) , 75As (d,4n), natGe (3He,x), 70Ge (α, n), and 72Ge (α, 3n) and neutron capture were calculated using the avail

... Show More
Crossref
Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Evaluation Study of Glass Fiber Reinforced Polyester and Kevlar Reinforced Polyester by Taguchi Method
...Show More Authors

     In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at

... Show More
View Publication Preview PDF
Publication Date
Wed Jan 01 2025
Journal Name
Journal Of Applied Spectroscopy
Evaluation of Stability Constant for Vitamin B1 Depending on Stoichiometric Curves by Visible Spectroscopy
...Show More Authors

View Publication
Scopus Clarivate Crossref
Publication Date
Mon Dec 01 2014
Journal Name
Photonic Sensors
Crystalline Structure and Surface Morphology of Tin Oxide Films Grown by DC Reactive Sputtering
...Show More Authors

Abstract: Tin oxide thin films were deposited by direct current (DC) reactive sputtering at gas pressures of 0.015 mbar – 0.15 mbar. The crystalline structure and surface morphology of the prepared SnO2 films were introduced by X-ray diffraction (XRD) and atomic force microscopy (AFM). These films showed preferred orientation in the (110) plane. Due to AFM micrographs, the grain size increased non-uniformly as the working gas pressure increased.

Preview PDF