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joe-1752
Performance of STBC Based MIMO-OFDM Using Pilot-aided Channel Estimation
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Many studies have been published to address the growing issues in wireless communication systems. Space-Time Block Coding (STBC) is an effective and practical MIMO-OFDM application that can address such issues. It is a powerful tool for increasing wireless performance by coding data symbols and transmitting diversity using several antennas. The most significant challenge is to recover the transmitted signal through a time-varying multipath fading channel and obtain a precise channel estimation to recover the transmitted information symbols. This work considers different pilot patterns for channel estimation and equalization in MIMO-OFDM systems. The pilot patterns fall under two general types: comb and block types, with a proper arrangement suitable to the multiple transmit antennas. The two main channel estimation methods, LS and MMSE, are compared by evaluating performance in terms of Bit Error Rate (BER) to analyze the performance of pilot-aided channel estimation for 2x2 and 4x4 MIMO arrangements utilizing LTE parameters and the effects of modifying different numbers of OFDM subcarriers under different channel models It has been discussed, a 4x4 system performs better than a 2x2 system in terms of BER with an acceptable amount of additional complexity.

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Publication Date
Wed Jan 01 2014
Journal Name
Journal Of The College Of Languages (jcl)
Las formas no personales del verbo en español y su traducción al árabe Non-personal forms of the verb in Spanish and their translations into Arabic
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Las formas verbales: el infinitivo, el gerundio y el participio, son derivados verbales que se comportan como sustantivos, adverbios o adjetivos, respectivamente; aunque, dado su carácter verbal pueden también funcionar como verbos y, por tanto, como núcleos del predicado.

 El presente trabajo presenta una visión general sobre las formas no personales del verbo en español. Se debe recordar que las formas no personales del verbo tiene funciones y valores dentro de la oración.

  Este trabajo lo dividimos  en dos partes: la primera presenta  un breve marco teórico en que se explica las formas no personales del verbo y como se forman además de sus funciones.

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Publication Date
Sun Nov 25 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and study the Structural and electrical and mechanical properties of High Temperature Superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ Substituted with nickel oxide for n=3
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   on this research is to study the effect of nickel oxide substitution on the pure phases superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ (n=3) where x=(0,0.2,0.4,0.6,0.8.and 1.0). The specimens in this work were prepared with used  procedure of solid state reaction with sintering temperature 8500C for 24 h .we used technical (4-prob)to calculated and the critical temperature Tc . The results of the XRD diffraction analysis showed that the structure for pure and doped phases was tetragonal with phases high-Tc phase (1223),(1212) and low-Tc phase (1202)  and add

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Publication Date
Sun Dec 31 2023
Journal Name
College Of Islamic Sciences
The book Al-Durr Al-Manzoum in the dropping of prayer and fasting by Issa Al-Safti Al-Hanafi, who died in the year (1143 AH)
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At the conclusion of my research for this readiness, I am ready to show the most important results I have reached, of which I can mention the most important:
Sheikh Al-Safti was a memorizer and jurist, and all the scientific strokes that he left behind for subsequent generations were in the disciplines of Hanafi jurisprudence, and this does not obscure the opinions of the jurists of other schools of thought. But among them: that these lines continue on a group of fatwas for the later in the gold of Abu Hanifa, may God have mercy on him, and then the books of fatwas usually refer to what is below the evidence.

He has no shock other than the knowledge of jurisprudence; And for this reason, it is due to the fact that the s

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Roleof Time Management in Stages Claims Settlement of Insurance from Fire: Research Exploratory in General Iraqi Insurance Company and Private Al hamra Company for Insurance
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The insurance activity in the various countries of the world are important indicators of the strength of the country's economy, he came to study the stages compensation insurance settlement against fire and the importance of investing time risk in achieving the payment of compensation speed, and the implications for the continuation of the insured to carry out insurance with the insurance company, whether working within the public sector or the private sector. Hence the research problem in how quickly insurance companies to pay compensation as soon as possible and the return of the insured to carry out its work and make up for what he died from loss. Intentional sample was selected from branches and divisions and Their assistants manager

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Publication Date
Sun Apr 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of Some O-[2-{''2Substituted Aryl (''1,''3,''4 thia diazolyl) ['3,'4-b]-'1,'2,'4- Triazolyl]-Ethyl]-p- chlorobenzald oxime Derivatives.
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In this study new derivatives of O-[2-{''2-Substituted Aryl (''1,''3,''4 thia diazolyl) ['3,'4b]-'1,'2,'4- Triazolyl]-Ethyl]-p- chlorobenzald oxime (6-11) have been synthesized from the starting material p-chloro – E- benzaldoxime 1. Compound 2 was synthesized by the reaction of p-chloro – E- benzaldoxime with ethyl acrylate in basic medium. Refluxing compound 2 with hydrazine hydrate in ethanol absolute afforded 3. Derivative 4 was prepared by the reaction of 3 with carbon disulphide, treated of compound 4 with hydrazine hydrate gave 5. The derivatives (6-11) were prepared by the reaction of 5 with different substitutes of aromatic acids. The structures of these compounds were characterized from their melting points, infra

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Publication Date
Sun May 30 2021
Journal Name
Indian Journal Of Forensic Medicine & Toxicology,
Effect of Diabetes and Hypertension on Right Carotid Artery Intima Media Thickness and Variable Spectral Waveform Indices And Parameters in Relation To Age for Iraqi Patients
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Background: Arterial stiffness is related with atherosclerosis and cardiovascular disease events. Patients with atherosclerotic disease show to have larger diameters, reduced arterial compliance and lower flow velocities. Aim of study : To compare between patients of two age groups with concomitant diseases diabetes and hypertension in regard to intima media thickness and blood flow characteristics in order to estimate the blood perfusion to the brain via the common and internal carotid arteries. Subject and Methods : 40 patients with (diabetic and hypertension) diseases were enrolled , they were classified according to age. Color Doppler and B mode ultrasound was used to determine lumen Diameter (D), Intima – media thickness (IMT)

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Publication Date
Mon Oct 30 2023
Journal Name
Iraqi Journal Of Science
Silver nanoparticles synthesized by three species of genus Streptococcus and evaluate their synergistic effects with the oil extracted from Syzygium Aromaticum on some clinical bacterial isolates
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Silver nanoparticles synthesized by different species

Publication Date
Thu Mar 30 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Synthesis, Characterization and Antibacterial Activities of Ligand Type N2O4 Schiff base and its Novel Complexes with Co(II), Ni(II), Cu(II) and Zn(II) ions.
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The reaction of 2-amino benzoic acid with 1,2-dichloroethane under reflux in methanol and KOH as a base to gave the precursor [H4L]. The precursor under reflux and drops of CH3COOH which reacted with (2mole) from salicycaldehyde in methanol to gave a new type N2O4 ligand [H2L], this ligand was reacted with (MCl2) Where [M= Co (II), Ni(II), Cu(II) and Zn(II)] in (1:1) ratio at reflux in methanol using KOH as a base, to give complexes of the general formula [M(L)]. All compounds have been characterized by spectroscopic methods [1H NMR ( just to the ligand), FTIR, uv-vis, atomic absorption], melting point, conductivity, chloride content, as well as m

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Publication Date
Mon Dec 25 2017
Journal Name
Biomedical And Pharmacology Journal
Evaluation of Crestal Bone Loss and Alkaline Phosphatase Level in Saliva According To Different Flap Designs in Single-Tooth Dental Implant Surgery (A Clinical Comparative Study)
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Publication Date
Wed Feb 01 2023
Journal Name
Health Science Reports
Diagnostic potential of salivary interleukin‐17, RANKL, and OPG to differentiate between periodontal health and disease and discriminate stable and unstable periodontitis: A case‐control study
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Abstract<sec><title>Background and Aims

Limitations of the conventional diagnostic techniques urged researchers to seek novel methods to predict, diagnose, and monitor periodontal disease. Use of the biomarkers available in oral fluids could be a revolutionary surrogate for the manual probing/diagnostic radiograph. Several salivary biomarkers have the potential to accurately discriminate periodontal health and disease. This study aimed to determine the diagnostic sensitivity and specificity of salivary interleukin (IL)‐17, receptor activator of nuclear factor‐κB ligand (RANKL), osteoprotegerin (OPG), RANKL/OPG for differentiating (1) periodontal health from disease and (2) stable a

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