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A Partial CSI Estimation Approach for Downlink FDD massive-MIMO System with Different Base Transceiver Station Topologies
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Massive multiple-input multiple-output (massive-MIMO) is a promising technology for next generation wireless communications systems due to its capability to increase the data rate and meet the enormous ongoing data traffic explosion. However, in non-reciprocal channels, such as those encountered in frequency division duplex (FDD) systems, channel state information (CSI) estimation using downlink (DL) training sequence is to date very challenging issue, especially when the channel exhibits a shorter coherence time. In particular, the availability of sufficiently accurate CSI at the base transceiver station (BTS) allows an efficient precoding design in the DL transmission to be achieved, and thus, reliable communication systems can be obtained. In order to achieve the aforementioned objectives, this paper presents a feasible DL training sequence design based on a partial CSI estimation approach for an FDD massive-MIMO system with a shorter coherence time. To this end, a threshold-based approach is proposed for a suitable DL pilot selection by exploring the statistical information of the channel covariance matrix. The mean square error of the proposed design is derived, and the achievable sum rate and bit-error-rate for maximum ratio transmitter and regularized zero forcing precoding is investigated over different BTS topologies with uniform linear array and uniform rectangular array. The results show that a feasible performance in the DL FDD massive-MIMO systems can be achieved even when a large number of antenna elements are deployed by the BTS and a shorter coherence time is considered.

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Publication Date
Thu Jan 21 2021
Journal Name
Iop Conf. Series: Materials Science And Engineering
Synthesis, spectroscopic study, biological activity and dyeing application of curcumin - Schiff base with various metal ions complexes
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A tetradentate (N2O2) Schiff base (H2Ldfm) was successfully synthesized via condensation of curcumin / diferuloylmethane (dfm) and L-leucine amino acid (HL). There were three different methods that used for synthesizing H2Ldfm; (refluxing, grading, and fusion). Ten different metal complexes were also successfully synthesized by combination of the Schiff base (H2Ldfm) and 1,10-phenanthroline (phen) ligand to form a hexadentate (N4O2) mixed ligands (Ldfm , phen) with ten different metal salts (M) where{ M= Al(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Ag(I), Cd(II), Hg(II), and Pb(II)}. The molar ratio of reactants was (1:1:1) (M: H2Ldfm : phen). The new Schiff base and its new complexes were characterized by different physicochemical tec

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Publication Date
Wed Apr 13 2016
Journal Name
The Pharma Innovation Journal
Preparation, spectroscopic study of Schiff base ligand complexes with some metal ions and Evaluation of antibacterial activity
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The new bidentate Schiff base ligand namely [(E)-N1-(4-methoxy benzylidene) benzene-1, 2-diamine] was prepared from condensation of 4-Methoxy benzaldehyde with O-Phenylene diamine at 1:1 molar ratio in ethanol as a solvent in presence of drops of 48% HBr. The structure of ligand (L) was characterized by, FT-IR, U.V-Vis., 1H-, 13C- NMR spectrophotometer, melting point and elemental microanalysis C.H.N. Metal complexes of the ligand (L) in general molecular formula [M(L)3], where M= Mn(II), Co(II), Ni(II),Cu(II) and Hg(II); L=(C14H14N2O) in ratio (1:3)(Metal:Ligand) were synthesized and characterized by Atomic absorption, FT- IR, U.V-Vis. spectra, molar conductivity, chloride content, melting point and magnetic susceptibility from the above d

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Publication Date
Fri Jan 01 2016
Journal Name
The Pharma Innovation
Preparation, spectroscopic study of Schiff base ligand complexes with some metal ions and Evaluation of antibacterial activity
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Publication Date
Mon Feb 20 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of Transition Metals Ions Complexes with 2-Thioxoimidazolidin-4-One Schiff Base as Ligand
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Mn(II), Co(II), Ni(II), Cu(II), and Cr(III) metal complexes with the ligand (L) [3-(2nitro benzylidene) amino-2-thioxoimidazolidin-4-one] have been prepared and characterized in their solid state using the elemental micro analysis (C.H.N.S), flame atomic absorption, UV-Vis spectroscopy, FT-IR, magnetic susceptibility measurements, and electrical molar conductivity. The ratio of metal to ligand [M:L] was got for all complexes in the ethanol by using the molar ratio method, which produced comparable results with those results obtained for the solid complexes. From the data of all techniques, octahedral geometry was proposed for Cr(III), Mn(II), and Co(II) complexes, while tetrahedral structure was proposed for Ni(II), Cu(II) complexes.

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Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Natural Gas Science And Engineering
Experimental determination of hydrate phase equilibrium for different gas mixtures containing methane, carbon dioxide and nitrogen with motor current measurements
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Hydrate dissociation equilibrium conditions for carbon dioxide + methane with water, nitrogen + methane with water and carbon dioxide + nitrogen with water were measured using cryogenic sapphire cell. Measurements were performed in the temperature range of 275.75 K–293.95 K and for pressures ranging from 5 MPa to 25 MPa. The resulting data indicate that as the carbon dioxide concentration is increased in the gas mixture, the gas hydrate equilibrium temperature increases. In contrast, by increasing the nitrogen concentration in the gas mixtures containing methane or carbon dioxide decreased the gas hydrate equilibrium temperatures. Furthermore, the cage occupancies for the carbon dioxide + methane system were evaluated using the Van der Wa

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Publication Date
Tue Dec 06 2022
Journal Name
Iraqi National Journal Of Nursing Specialties
Assessment of Reasons for Partial Compliance and Non-compliance to the Routine Childhood Vaccination Schedule in Al-Karkh District
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Abstract

      Objective (s): To evaluate reasons for partial compliance and non-compliance to the

                              routine childhood vaccination schedule in Al-Karkh district 

Methodology: Descriptive study , using the evaluation approach, is carried throughout the present study to determine the reasons for the Routine Childhood Vaccination at  health care sectors and primary health care centers at  Al-Karkh District in Baghdad City, Convenient, non-probability, sample of (90) mother who are recruited from health care sectors at Al-Karkh District in Baghdad City. All mothers, who ha

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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
A realistic vision of the ration card system in Iraq for the duration (1997-2003) and (2017-2003)
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Abstract:

The researcher shed light on a diet in Iraq before 2003 became in this period. And how the ration card has a variety of vocabulary and cover the need of the population of commodities and have a key role in saving Iraq from a real crisis in the period of economic siege, especially in light of the State's direction to support the agricultural sector, which in that period able to fill half of the market needs of food the basic. As well as providing strategic storage at the Ministry of Commerce enough for six months But after the events of 2003 and the crises that hit the country and the unstable security situation began to rise voices calling for reform of the ration card system as a system that is a burden on the

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Publication Date
Fri Jan 01 2021
Journal Name
Microchemical Journal
A flow analysis system integrating an optoelectronic detector for the quantitative determination of active ingredients in pharmaceutical formulations
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Publication Date
Sun Nov 07 2021
Journal Name
Review Of International Geographical Education Online
Requirements of Formulating a National Strategy for Developing the Cybersecurity System in Iraq According to GCI.v4(2019) Index
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The present study aims to present a proposed realistic and comprehensive cyber strategy for the Communications Directorate for the next five years (2022-2026) based on the extent of application and documentation of cybersecurity measures in the Directorate and the scientific bases formulating the strategy. The present study is significant in that it provides an accurate diagnosis of the capabilities of the cyber directorate in terms of strengths and weaknesses in its internal environment and the opportunities and threats that surround it in the external environment, based on the results of the assessment of the reality of cybersecurity according to the global Cybersecurity index, which provides a strong basis for building its strategic dire

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Scopus
Publication Date
Mon Nov 19 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Estimation of pentraxin-3(PTX3)in Rheumatoid arthritis males patients with (with and without) type II diabetes mellitus in Iraq
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Rheumatoid arthritis is a chronic inflammatory autoimmune disease its etiology is  unknown . The classical autoimmune diseases, have adaptive immune genetic associations with autoantibodies and major histocompatibility complex(MHC) class II such as rheumatoid arthritis (RA), diabetes mellitus type two (DM II). Serum of99 males suffering from RA without DMII as group (G1), 45 males suffering from RA with DM II as group (G2) and 40 healthy males as group (G3) were enrolled in this study to estimation of alkaline phosphates (ALP),C-reactive protein(CRP) and Pentraxin-3(PTX). Results showed a highly significant increase in PTX3 levels in G1 and G2 compared to G3 and a significant decrease in G1comparing to G2. Results also revealed a si

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