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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
Thu Dec 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Commercial banks in Iraq had applied in practice different forms of its activities upon surplus funds that deposited from individual, firms and many governments units
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These deposits take many forms like current acc, deposits in order to growth and serve national economy Various in varicose perspectives .

The problem of this paper its concern with un applied the mathematical models that used in profitability analysis of current acc , and deposits in view of risk, profit efficiency and financial leverage for this reason the paper discussion use the cumulate mathematical model to solve these problem, that content three variables that be used to measuring profitability by consequent replacement method by stable base and by moving base for 2007 – 2009 applied the data collect from Iraq middle east bank.           &nbs

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Publication Date
Thu Dec 28 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Microwave Preparation, Spectral Studies and Antimicrobial Activities Evaluation of Mn(II),Ni(II), Hg(II),Co(II) and Cu(II) Complexes with Schiff Base Ligand
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New Schiff base  and their  Mn(II),Co(II),Ni(II), Cu(II) and Hg(II) complexes formed by the condensation of  O-phathaldehyde and ethylene diamine  (2:1)  to give  ligand (L1) in the first step ,then the ligand (L1) with  2- aminophenol (1:2) to give ligand (L2) were prepared by classic addition through microwave method . These compounds (Ligands and complexes) have been diagnosed electronic spectra, FT-IR, 1H-&13C-NMR (only ligand), magnetic susceptibility, elemental microanalysis and molar conductance measurements. Analytical values displayed that all the complexes appeared (metal: ligand) (1:1) ratio with the six chelation. All the compounds appear a high activity versus four types of bacteria suc

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Publication Date
Fri Jul 01 2022
Journal Name
Sustainable Materials And Technologies
Green approach for fabrication of graphene from polyethylene terephthalate (PET) bottle waste as reactive material for dyes removal from aqueous solution: Batch and continuous study
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Publication Date
Sun Dec 06 2009
Journal Name
Baghdad Science Journal
Synthesis and Characterization of (Fe(II),Co(II),Ni(II) and Cu(II)) Complexes with Schiff Base derived from [benzoyl hydrazine] with [benzyl mono oxime]
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The reaction of [Benzoyl hydrazine] with [Diphenyl mono oxime] and Glacial acetic acid was carried out in methanol gave a new tridentate ligand [Benzoic acid (2-hydroxyimino- 1, 2-diphyneylethylidene) - hydrazide]. This ligand was reacted with some metal ions (Fe(II), Co(II), Ni(II), and Cu(II)) in methanol with (1:1) metal : ligand ratio to give a series of new complexes of the general formula [M(L)Cl2.H2O], where M= Fe(11), Co(11), Ni(11) and Cu(11). All compounds were characterized by spectroscopic methods (I.R, UV-Vis), elemental microanalysis (C.H.N), atomic absorption, magnetic susceptibility, and conductivity measurements. From the obtained data the proposed molecular structures were suggested for the complexes of Fe

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Publication Date
Wed Mar 29 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Evaluation of the Relation between Asthma, Obesity and Leptin Level in Iraqi Asthmatic Patients and the Main Risk Factors that are Associated with Leptin Level
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This study tries to clear the correlation and association between asthma, obesity and leptin levels. Also it will work to indicate the main risk factors which play role in the elevation of leptin level within asthmatic patients.  This is a case control study conducted on (38) asthmatic patients and (20) healthy control who were closely similar by age, gender and BMI. The main statistical tests used were student t test, linear regression test and correlation test. Significance was set at P < 0.05. Sampling method used for this study was convenience sampling method.  The main results of this study show a significant association and positive correlation between age (old age  â‰¥ 40 ye

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Publication Date
Thu Apr 17 2025
Journal Name
Journal Of Physical Education
The effect of dynamic lactic training according to the target time fo developing special endurance, lactic acid concentration, and achievement for 800m runners under20 years old
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Publication Date
Fri Mar 28 2014
Journal Name
Advances In Life Science And Technology
Synthesis and Characterization of Novel Schiff Bases, N-Acyl and Diazetines Derived from 3-((5-hydrazinyl-4-phenyl-4H-1,2,4- triazol-3-yl)methyl)-1H-indole
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This work involves synthesis of some new heterocyclic compounds including 1, 3-diazetine. The new Schiff bases [VI] ad derived from 3-((5-hydrazinyl-4-phenyl-4H-1, 2, 4-triazol-3-yl) methyl)-1H-indole [V] which was synthesized by refluxing 5-((1H-indol-3-yl) methyl)-4-phenyl-4H-1, 2, 4-triazole-3-thiol [IV] with hydrazine hydrate in absolute ethanol and this amino compound [V] condensation with different aromatic aldehydes in absolute ethanol to yielded a new Schiff bases [VI] ad. N-acyl compounds [VII] ad were synthesized by addition reaction of acetyl chloride to imine group of Schiff bases in dry benzene. The new diazetine derivatives [VIII] ad synthesized by the reaction of N-acyl compounds [VII] ad with sodium azide in dimethylformamid

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Publication Date
Wed May 31 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of [2-(9-anthryl) -3- (1,3,4- Triazole -1- yl) -2,3- Dihydro -5,6- ene – 1,3- Oxazepine- 4,7-Dione] on Serum AST and ALT Activities
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In this study , the effect of an organic compound prepared as derivative of oxazepine tested on the activities of aspartate amino trasferase (AST) and alanin amino transferase (ALT). The kinetic study of such enzymes is in the presence of oxazepine derivative.  The results revealed that the organic compound is a non competitive inhibitor for both enzymes.  The Km value for AST is 1.3 × 10-3 M and Vmax for the uninhibited is 200 U/mL and for the inhibited is 111.1 U/mL while Km value for ALT is 2.5 × 10-3 M and Vmax are 89.66 U/mL and 56.77 U/mL for the uninhibited and inhibited enzyme respectively.

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Publication Date
Tue Nov 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Adoption of Membership Level for Critical Activities In Knowledge Chain Model Building An Investigation Analytical Study Depending on Fuzzy Logic Architecture for Organizations Pushed by Knowledge
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Abstract

   The aim of this research is to concentrate on the of knowledge management activities, initial activities: (Acquisition, Selection, Generation, Assimilation, Emission) knowledge, and support activities: (Measurement, Control, Coordination, Leadership) that is manipulate and controlling in achieving knowledge management cases in organization, that’s is leads to  knowledge chain model, then determining the level of membership for these activities to knowledge chain model in a sample of Iraqi organization pushed by knowledge (Universities). The research depends on check list for gaining the data required, theses check list designed by apparently  in diagnosing research dimensions and measurem

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Publication Date
Sun Nov 27 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The extent to which the Iraqi environment responds to the requirements of IAS 12 in determining income tax: بحث تطبيقي في الهيئة العامة للضرائب/ قسم الشركات
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The importance of this research comes from the possibility of achieving positive interaction between accounting and tax through the interest in setting accounting standards and adapting them to local tax legislation, as the adoption of the application of the international standard (IAS 12) for income taxes helps to measure and determine the base for income tax and may lead to an increase in the tax outcome. Through the reliance of enterprises on many accounting bases, and that the tax administration in Iraq depends on the element of personal judgment in determining the tax base, which leads to lack of objectivity in determining the tax outcome, as the impact of the accounting standard (IAS 12) on the tax base and tax outcome is one of th

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