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Ab–Initio large unit cell calculations of the electronic structure of Si and Ge nanocrystals
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Ab – initio restricted Hartree - Fock method within the framework of large unit cell (LUC) formalism is used to investigate the electronic structure of Si and Ge nanocrystals. The surface and core properties are investigated. A large unit cell of 8 atoms is used in the present analysis. Cohesive energy, energy gap, conduction and valence band widths are obtained from the electronic structure calculations. The results are compared with available experimental data and theoretical results of other investigators. The calculated lattice constant is found to be slightly larger than the corresponding experimental value because we use only 8 atoms and we compared the results with that of the bulk crystals, nanoclusters are expected to have stronger directional bonds that in their bulk structure. The surface states are found to be mostly non-degenerated because of the effect of surface discontinuity and the existence of oxygen atoms. Valence and conduction bands are found to be wider on the surface due to the splitting of energy levels due to the existence of oxygen atoms. The present method can be used to investigate the electronic structure of bulk, surface and nanocrystals.

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Publication Date
Mon Jan 01 2018
Journal Name
Aip Conference Proceedings
Synthesis and characterization study of n-Bi2O3/p-Si heterojunction dependence on thickness
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Publication Date
Mon Aug 12 2024
Journal Name
Applied Physics A
Fabrication and characterization of visible-enhanced CeO2/Si photodetectors using pulsed laser deposition
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Nanostructured photodetectors have garnered great attention due to their enriched electronic and optical properties. In this work, we aim to fabricate a high-performance CeO2/Si photodetector by growing a CeO2 nanostructure film on a silicon substrate using the pulsed laser deposition (PLD) technique at different laser energy densities. The impact of laser energy density and the number of pulses on the morphological, optical, and electrical properties was studied. Field emission scanning electron microscopy (FESEM) results show that the CeO2 film has a spherical grain morphology with an average grain size ranging from 33 to 54 nm, depending on the laser energy density. The film deposited at various numbers of laser pulses also has spherical

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Publication Date
Sat Jan 06 2018
Journal Name
American Institute Of Physics
Synthesis and characterization study of n-Bi2O3/p-Si heterojunction dependence on thickness
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Abstract. In this work, Bi2O3 was deposited as a thin film of different thickness (400, 500, and 600 ±20 nm) by using thermal oxidation at 573 K with ambient oxygen of evaporated bismuth (Bi) thin films in a vacuum on glass substrate and on Si wafer to produce n-Bi2O3/p-Si heterojunction. The effect of thickness on the structural, electrical, surface and optical properties of Bi2O3 thin films was studied. XRD analysis reveals that all the as deposited Bi2O3 films show polycrystalline tetragonal structure, with preferential orientation in the (201) direction, without any change in structure due to increase of film thickness. AFM and SEM images are used to investigate the influences of film thickness on surface properties. The optical measur

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Publication Date
Sun Mar 26 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Trend of Antibiotics Usage in the Intensive Care Unit in the Medical City in Baghdad
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High frequencies of multidrug resistant organisms were observed worldwide in intensive care units which is a warning as to use the only few effective antimicrobials wisely to reduce selective pressure on sensitive strains.

The aim of the current study is to asses the compliance of the currently followed antibiotic prescribing pattern in the intensive care unit in an Iraqi hospital with the international guidelines.A cross-sectional study was done in the intensive care unit (ICU) of the Surgical Specialties Hospital, Medical City in Bagdad from the 30th of November 2011 to the 5th of May 2012.Patients were followed until they were discharged or died to see any change in condition, response to drugs, devices u

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Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Crystal Growth of High – Purity Bi2Se3 and Study of Crystal Structure
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The Bi2Se3 compound was synthesis by fusing initial compounds consisting of
extra pure elements in stoichiometric ratio from elements compound, charged inside
quartz ampoule. The crystal growth of Bi2Se3 carried out using Brighaman technique
process from melting f (Bi+Se ) at temperature of 810 ºC for about 48 hrs. Single crystal
of Bi2Se3 has been grown in direction (211) after slow cooling on account of heat
gradient to zone furnaces at cooling rate (1-3) C/hr. The structure study of the compound
was determined by x-ray diffraction technique, which it has bismuthinite structure and
orthorhombic unit cell with lattice parameters of a=10.2678 Å, b=11.2392 Å and
c=5.1737 Å

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Publication Date
Thu Jun 01 2023
Journal Name
Microporous And Mesoporous Materials
Green synthesis of porous carbon cross-linked Y zeolite nanocrystals material and its performance for adsorptive removal of a methyl violet dye from water
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The cost-effective carbon cross-linked Y zeolite nanocrystals composite (NYC) was prepared using an eco-friendly substrate prepared from bio-waste and organic adhesive at intermediate conditions. The green synthesis method dependent in this study assures using chemically harmless compounds to ensure homogeneous distribution of zeolite over porous carbon. The greenly prepared cross-linked composite was extensively characterized using Fourier transform infrared, nitrogen adsorption/desorption, Field emission scanning electron microscope, Dispersive analysis by X-ray, Thermogravimetric analysis, and X-ray diffraction. NYC had a surface area of 176.44 m2/g, and a pore volume of 0.0573 cm3/g. NYC had a multi-function nature, sustained at a long-

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
The variation of the Firm’s value considering the relationship between the financial structure and earnings per share
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The current research aims to determine the relationship of the impact of the components of the financing structure, especially financing through debts, as well as the earnings per share in the value of the shares of companies listed in the Iraq Stock Exchange. The research sample and identifying the strength of the combined effect of the ratio of financing through debt and earnings per share in maximizing The market value of the firm and the real value, as well as the variation between these relationships according to model of the real value of the companies and the market value of the research sample companies. The research community is represented by the Iraq Stock Exchange, while a conditional deliberate sample

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Improve the efficiency of the cell Ch neutron irradiation and thermal annealing
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This research aims to study the effect of heat on the efficiency of solar cells of neutrons ranging from card to these cells in the case of dark and light before and after irradiation using the neutron source as well as electrical properties have been studied

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Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The impact of electronic payment systems on the effectiveness of monetary policy
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Information and Communication Technology  revolution has led to the emergence of electronic payment systems and their means And that the replacement of these modern means replace the traditional means (legal money) issued by the Central Bank has influenced the performance of monetary policy, especially that monetary policy is one of the most important policies used to achieve economic stability ,  The aim of the research is To know the impact of electronic payment systems on the tools of monetary policy as these means, such as cards and electronic money issued by credit institutions and companies, that is, the Central Bank is not responsible for issuance and spread And the lack of regulation by the Central Bank will lea

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Publication Date
Tue Oct 01 2019
Journal Name
Ceramics International
A first-principles study of the electronic, structural, and optical properties of CrN and Mo:CrN clusters
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