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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
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Reflection of knowledge workers characteristics on knowledge acquision “Survey Study of the views of a sample of engineers and technicians in the Directorate of Electricity In the city of Sulaymaniyah
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Purpose: The research aims to diagnose the current availability of knowledge workers characteristics and the role of these characteristics in knowledge acquision in the city of Sulaimaniya Directorate of Electricity, and to identify the differences between personal and occupational characteristics of a sample of research and its impact on the availability of such properties.

Design/methodology/approach :to achieve the objectives of the research questionnaire was developed especially for it and then distributed to a sample of engineers and technicians working in the Directorate of Electricity city of Sulaimaniya, where the sample of the research (52) respondents.

Findings:  the most important conclusions reached

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Publication Date
Sun Oct 01 2017
Journal Name
Al–bahith Al–a'alami
Employ of Public Relations in Building Awareness of Security against Terrorism A Survey of the Employees of the Directorate General of Public Relations and Media at the Ministry of Interior
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This study aims at identifying the role played by Public Relations in the field of security awareness of the dangers of terrorism. The research is directed to the employees at the Directorate General of Public Relations and Media at the Ministry of Interior. And that on the basis that those who play an important role in the security awareness are the security institutions, primarily the Ministry of Interior, since this Directorate is responsible for all subjects related to the public security using public relations science. It aims at identifying the functions, methods and communication tools used by the Directorate to raise awareness about the dangers of terrorism. In order to achieve the research objectives, the researcher uses the sur

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Publication Date
Sun Dec 15 2019
Journal Name
Journal Of Global Pharma Technology
synthesis and characterization of heterocyclic compounds and polymers with studying the biological activity for some of them
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This paper deals with the preparation of new monomers and polymers which including heterocyclic unit. The diacid chlorides compounds [1-3] were prepared from the reaction of glutaric acid, adipic acid, terephthalic acid with thionyl chloride. Succinic acid reacted with ethanol to produce compound [4]. Compound [4] reacted with hydrazine hydrate to obtain succinic hydrazide [5].Compound [5] reaction with CS2 and KOH in absolute ethanol to produce compound [6].The polymers [7-12] have been created by reacting diacid chlorides compounds [1-3] with compound[5] or [6] in dry pyridine with some drops of DMF. The topology of produced compounds has characterized through their spectral and analytical data as in FT-IR spectra, Thermal analysis [DSC,

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Scopus
Publication Date
Tue Aug 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Effect of Light Source and Adenine Sulfate on the Multiplication and Rooting of Kalanchoe blossfeldiana in Vitro
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Abstract<p>This study was conducted in the Tissue Culture laboratory of the Horticultural Department of the Faculty of Agriculture at Karbala University to investigate the effects of a light source (Florescent, LED) and adenine sulfate (Ads) a 0, 40, 80, and 120 mg l-1 on the multiplication and rooting of <italic>Kalanchoe blossfeldiana</italic>. Results showed there are which achieved a 100% response percentage for multiplication and rooting when the addition of adenine sulfate (Ads) under LED light especially a concentration of 120 mg l-1 significantly increased the Shoot height, Shoot number, Number of leaves, Chlorophyll content and fresh, Dry weight. The results showed that they h</p> ... Show More
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Publication Date
Wed Jan 03 2024
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn 2789-3219 )
Proficiency and Knowledge of Community Pharmacists in the Use of Liraglutide and Semaglutide as Weight Reduction Agents
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Background: In recent years, the prevalence of obesity has climbed sharply. Still, only a few safe and effective medications are approved as weight-loss drugs. Objective: This study aims to assess the knowledge and practice of community pharmacists in Iraq regarding the use of Liraglutide and Semaglutide as weight-loss medications. Method: A cross-sectional survey was implemented using a validated questionnaire and a convenient sample of Iraqi community pharmacists from different governorates. The questionnaire was created after conducting a literature review of the most important articles about liraglutide and semaglutide. The questionnaire consists of three sections. The first part was used to collect demographic information. The second a

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Publication Date
Sun Mar 05 2017
Journal Name
Baghdad Science Journal
Preparation and study of the structural and optical properties of Bi2S3 thin films by Spray pyrolysis method
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In this research Bi2S3 thin films have been prepared on glass substrates using chemical spray pyrolysis method at substrate temperature (300oC) and molarity (0.015) mol. Structural and optical properties of the thin films above have been studied; XRD analysis demonstrated that the Bi2S3 films are polycrystalline with (031) orientation and with Orthorhombic structure. The optical properties were studied using the spectral of the absorbance and transmission of films in wavelength ranging (300-1100) nm. The study showed that the films have high transmission within the range of the visible spectrum. Also absorption coefficient, extinction coefficient and the optical energy gap (Eg) was calculated, found that the film have direct ener

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Publication Date
Wed Aug 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Use of Some Inorganic Additives to Retard Combustion and Flammabitity of Unsaturated Polyester and Epoxy Resins
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In  this  work,  three  inorganic  additives were 1,1sed,  these  are  (I)  ;

tetraethyl ammonium bromodichloro phenylphsphin, (II) Chlorinated paraffine. and (ITI) a mixture  of  (50%  by weight  of each) to study the synergetic effect.  These  additives \'v·cre used  as flame retardants with unsaturated  polyester  and  epoxy  resins.;, since  these  resins  are industrially important  and of \Vide uses in life.

Results showed efficiency of these  additives to retard  fl mmabillty and stop burning of resins throqght the ASTM tests used Measurement of Limiting oxygen  index (LOI), &nbs

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Publication Date
Sat Jul 18 2020
Journal Name
College Of Islamic Sciences
Soort of Hamid al-Taie and his sons in the poetry of Abu Tammam and Al-Bohtari
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The phenomenon of celebration of army leaders in the Abbasid era formed a distinct phenomenon at which the poets stood, and among those leaders was the Arab leader Hamid al-Taie, and the poets who stood on him and his sons Abu Tammam and al-Bohtari recorded in their poems the exploits of that leader, and the exploits of his sons through images that represented sadness, courage In this research, the generosity, and the rhetorical and artistic aspects of those images, have been spotted, balancing the poets.

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Publication Date
Tue Feb 25 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Computed tomographic localization of infraorbital foramen position and correlation with the age and gender of Iraqi subjects
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Background: The Infraorbital foramen is an anatomical structure with an important location in the maxilla, position of foramen in maxillofacial area is necessary in clinical situation requiring regional nerve blocks that are performed in children undergoing facial surgeries to avoid injury to corresponding nerve. The aim of study was to determine the position of the Infraorbital foramen and to correlate Infraorbital foramen position with age and gender using computed tomography. Subjects, Materials, and Methods: The sample consist of prospective study for 50 Iraqi subjects (21 male and 29 female) with age ranged from (5-17) years. The examination was performed on Multi – Slice Spiral Tomography scanner in Al-Karakh General Hospital. Using

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Publication Date
Wed May 15 2019
Journal Name
Al-khwarizmi Engineering Journal
Rheological and Thermal Properties of Lubricating Oil Enhanced by the Effect of CuO and TiO2 Nano-Additives
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The specifications of lubricating oil are fundamentally the final product of materials that have been added for producing the desired properties. In this research, spherical nanoparticles copper oxide (CuO) and titanium oxides (TiO2) are added to SAE 15W40 engine oil to study the thermal conductivity, stability, viscosity of nano-lubricants, which are prepared at different concentrations of 0.1%, 0.2%, 0.5%, and 1% by weight, and also their pour point, and flash point as five quality parameters. The obtained results show that CuO nanoparticles in all cases, give the best functionality and effect on engine oil with respect to TiO2. With 0.1 wt. % concentration, the thermal conductivity of CuO/oil and TiO2/

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