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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
Thu Jun 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
CFD Simulation of Air Flow Patterns in a Spray Dryer Fitted With a Rotary Disk
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The air flow pattern in a co-current pilot plant spray dryer fitted with a rotary disk atomizer was determined experimentally and modelled numerically using Computational Fluid Dynamics (CFD) (ANSYS Fluent ) software. The CFD simulation used a three dimensions system, Reynolds-Average Navier-Stokes equations (RANS), closed via the RNG k −ε turbulence model. Measurements were carried out at a rotation of the atomizer (3000 rpm) and when there is no rotation using a drying air at 25 oC and  air velocity at the inlet of  5 m/s without swirl. The air flow pattern was predicted experimentally using cotton tufts and digital anemometer. The CFD simulation predicted a downward central flowing air core surrounded by a slow

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Publication Date
Mon Aug 18 2025
Journal Name
Journal Of Baghdad College Of Dentistry
An Assessment of Oral Health in Hypertensive Patients Treated with HMG-CoA Reductase Inhibitors (Statins)
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Background: Hypertension is a chronic medical condition in which the blood pressure in the arteries is elevated, it's classified as either primary (essential) hypertension or secondary hypertension, and it increases the risk of ischemic heart disease, peripheral vascular disease and other cardiovascular diseases. Several classes of medications collectively referred to as antihypertensive drugs like beta blockers, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers, renin inhibitors and statins (HMG-CoA) reductase inhibitor. Statin medication may have some beneficial effects when subjects have dental plaque or signs of periodontitis as gingival bleeding. The purpose of this study were to as

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Publication Date
Tue Dec 17 2013
Journal Name
Al-kindy College Medical Journal
Levels of Some Proinflammatory Cytokines in Obese Women with Polycystic Ovary Syndrome after Metformin Therapy
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Publication Date
Fri Jan 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Evaluation of Osteocalcin and Some Biochemical Marker in Diabetes Mellitus Iraqi Women's patients with Osteoporosis
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Diabetes mellitus is a set of metabolic diseases, the most prevalent of which is chronic hyperglycemia. The culprits include insulin synthesis, insulin action, or both. Osteoporosis is a progressive systemic skeletal disorder defined by decreased bone mass and micro architectural degeneration of bone tissue, resulting in increased bone fragility and fracture risk, according to the World Health Organization (WHO). The degree of Nervosa damage determines how much a diabetic patient's body has been compromised. The current study's goal is an estimation: Age, BMI, FBS, HbA1C, D3, ALP, Ca, P, and Osteocalcin in Iraqi T2DM Women's patients with and without Osteoporosis. Three vitamins are required for Osteocalcin biosynthesis: vitamin K for Gla f

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Publication Date
Mon Mar 31 2014
Journal Name
Al-khwarizmi Engineering Journal
Corrosion Behavior of V2AlC and Cr2AlC Compared with SS 316L in NaOH at Four Temperatures
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Abstract

      This work involves the manufacturing of MAX phase materials include V2AlC and Cr2AlC using powder metallurgy as a new class of materials which characterized by regular crystals in lattice. Corrosion behavior of these materials was investigated by Potentiostat to estimate corrosion resistance and compared with the most resistant material represented by SS 316L. The experiments were carried out in 0.01N of NaOH solution at four temperatures in the range of 30–60oC. Polarization resistance values which calculated by Stern-Geary equation indicated that the MAX phase materials more resistant than SS 316L. Also cyclic polarization tests confirme

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Publication Date
Fri Mar 15 2019
Journal Name
Journal Of Baghdad College Of Dentistry
Assessment of caries experience, enamel defects and selected salivary biomarkers in children with nutritional rickets
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Background: Nutritional Rickets is a condition produced by an absence of Vitamin D, calcium or phosphate. It clues to relaxing and fading of the bones. Dental expression of children with rickets contains enamel hypoplasia and delayed tooth eruption. This study was conducted in order to assess caries experience (dmfs) and enamel defects among study and control groups, and to evaluate and compare the levels of selected salivary biomarkers between children with nutritional rickets and apparently healthy children. Material and methods: Assessment of caries according to WHO in 1987, and assessment of enamel defects according to enamel defect index EDI of WHO in 1997. In addition a stimulated saliva samples were collected according to Palone e

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Publication Date
Sun Feb 03 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Use Dividend Discount Model , DDM in Stocks Valuation With Framework of Inflation: An Applied Study
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The theme of this Study presents analysis and discuss to the "Share the framework for assessing inflation," a practical study in a sample of joint stock companies listed on the Iraq Stock Exchange for the years (2009-2013). To determine the extent of the disparity between the nominal value of shares (Nominal Value) before deducting inflation and the real value (Real Value) per share, after deducting inflation in the case of zero growth. The study relied on annual reports of the companies of the research sample of the Iraq Stock Exchange, as well as the Iraqi Securities Commission. Besides the annual reports issued by the Ministry of Planning, as well as annual reports and statistical bulletin issued by the Central Bank of Iraq. It is fra

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Publication Date
Mon Oct 05 2015
Journal Name
Journal Of Natural Sciences Research
Immunomodulatory of Cordia myxa (L.) aqueous extract fruit in immunized mice with hydatid cyst fluid
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Human cystic echinococcosis caused by Echinococcus granulosus is one of most important and widespreadparasitic zoonoses in the world. The present study was aimed to identify the immunomodulatory activity ofaqueous extract of Cordia myxa fruit since this plant considers one of medically important plants, which is widely used for treatment of numerous diseases, that correlate with the effectiveness of immunized by hydatid cyst fluid antigen HCFAg. Forty Balb/c mice were divided into equal groups, first group was immunized with HCFAg, the second group was treated with aqueous extract of C. muxa fruit, the third group was immunized and treated, the fourth group was as a control. Delayed type hypersensitivity (DTH), Mitotic index (MI) and histop

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Publication Date
Thu Dec 01 2022
Journal Name
Baghdad Science Journal
Molecular Characterization of Potential Crop Pathogens Associated with Weeds as Endophytes in Uniilorin Plantations, Nigeria
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Crop diseases are usually caused by inoculum of pathogens which might exist on alternate hosts or weeds as endophytes. These endophytes, cum pathogens, usually confer some beneficial attributes to these weeds or alternate hosts from protection against herbivores, disease resistance, stress tolerance to secondary metabolites production. This study was therefore carried out to isolate potential crop pathogens which exist as endophytes on weed species in the University of Ilorin plantations. Green asymptomatic leaves were collected from 10 weed species across the plantations, and processed for their endophytic fungi isolation. Isolates were purified into pure cultures and used for molecular identification using the internal transcribed spac

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Publication Date
Sun Jun 30 2013
Journal Name
Al-kindy College Medical Journal
Levels of Some Proinflammatory Cytokines in Obese Women with Polycystic Ovary Syndrome after Metformin Therapy
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Background: Polycystic ovary syndrome is a heterogeneous disorder and its etiology appears to be complex and multifactorial; characterized by hyperandrogenism, chronic anovulation and infertility. It’s associated with evidence of low-grade chronic inflammation, as indicated by the presence of elevated levels of high sensitive C- reactive protein levels, interleukin-6 and tumor necrosis factor-α. The source of excess circulating tumor necrosis factor-α in obese Polycystic ovary syndrome patient is likely to be the adipose tissues while in lean women increased visceral adiposity has been proposed as a source of excess tumor necrosis factor-α.Objectives: to evaluate the levels of high sensitive C- reactive protein, tumor necrosis facto

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