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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
Tue Jan 17 2023
Journal Name
Mesopotamian Journal Of Cyber Security
The Purpose of Cybersecurity Governance in the Digital Transformation of Public Services and Protecting the Digital Environment
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The process of digital transformation is considered one of the most influential matters in circulation at the present time, as it seeks to integrate computer-based technologies into the public services provided by companies or institutions. To achieve digital transformation, basics and points must be established, while relying on a set of employee skills and involving customers in developing this process. Today, all governments are seeking electronic transformation by converting all public services into digital, where changes in cybersecurity must be taken into account, which constitutes a large part of the priorities of nations and companies. The vulnerability to cyberspace, the development of technologies and devices, and the use

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Publication Date
Tue Feb 05 2019
Journal Name
Journal Of The College Of Education For Women
System of governance and administration in the state of the Ottoman Algeria (1518-1830)
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Algeria is one of the states that are important to the Ottoman state, because of its geographic location is important to the Mediterranean Sea, as well as the economic resources of the nature of its soil geography and climate,diverse, making it the focus of attention of the Ottomans, along with the van, which has increased the interest of the Ottomans in Algeriais the fall Andalusat the hands of the Spaniardsin1492, and force the Muslims to get out of them, and did not Only Europeans do it, butrushed to the prosecution of Muslims tothe coast of North Africa and seizing control of manyofits ports and cities, prompting the Ottoman state to go forth and back to the barn Muslims,Especially after hehad appealed to the Arabs of the Ottoman sta

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Publication Date
Thu Aug 31 2017
Journal Name
Journal Of Engineering
The Phenomenon of Division and Modification of The Individual Houses in Baghdad after 2003
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The Research deals with the negative phenomena which appeared in the urban scenes of the  Iraqi cities after 2003, particularly trespassing the architectural design of the urban Individual houses.  Many academic researchers , critics, and cultural circles, drawn attention to the impact of  political and cultural variable change on such phenomena  without detailed  analysis . The research problem  is set according to central questions : If the phenomena is the trespass , what
are the sides which are being trespassed  in the division of the individual house? , If the diagnosis of the phenomena denotes perceived repetition of the cases , So what's size of this transposes on the architectural design of t

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Publication Date
Tue Mar 31 2020
Journal Name
College Of Islamic Sciences
The position of women In Literary Literature Models of the Arabic and Kurdish literature
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This research deals with the topic of "the status of women" in the literature of Sufism. The researcher cites a bundle of mystical yarns, and examples of verses and poems from this high literature that look at women with reverence and appreciation. The researcher tried to find an appropriate explanation and away from the arbitrariness of the symbols used by the poets of Islamic Sufism In their poems.

    The research is considered a comparative study of the Arabic and Kurdish dialects, by selecting six famous poets from the literature of literature, three of them from Arabic literature, and the other three from Kurdish literature, so the research is di

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Publication Date
Tue Jan 02 2018
Journal Name
Journal Of Educational And Psychological Researches
The impact of learning strategies in the collection of biology and their systemic thinking
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Research Summary The aim of the search for knowledge of the effect generative learning strategy in: 1 - Achievement of the second grade. 2 - Systemic thinking for the second grade students when studying the biology. The study sample increased (60) students distributed into two equal experimental and control groups. Prepare the test of 40 pieces of multiple choice type and prepare a test for systematic thinking according to three skills 1. Understand the relationships between the parts of the systemic form and complement the sentences given 2 - complement the relationships between parts of the systemic form 3. Building the systemic form. It was a search result 1- There is a difference of statistical significance (at level 0.05) between th

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Publication Date
Sun Apr 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Using of the Correction Schwarzschild radius Equation and Its Application of the Black Holes
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  This study is a try to compare between the traditional Schwarzschild’s radius and the equation of Schwarzschild’s radius including the photon’s wavelength that is suggested by Kanarev for black holes to correct the error in the calculation of the gravitational radius where the wavelengths of the electromagnetic radiation will be in our calculation. By using the different wavelengths; from radio waves to gamma ray for arbitrary black holes (ordinary and supermassive).
 

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Publication Date
Thu Oct 12 1995
Journal Name
International Journal Of Environmental Studies
ON THE SPATIAL AND SEASONAL VARIATIONS OF HEAVY METALS OF THE RAZZAZAH LAKE, IRAQ
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Five heavy metals, namely Cd, Cu, Fe, Mn, and Pb in the surface water and through the water column were studied at 10 selected stations in the Razzazah lake and Karbala drainage canal for the period between November 1990 to October 1991*. pH and total hardness were also measured. Lead was found to be the highest in concentration as overall average values, followed by an manganese, iron, copper then cadmium at the surface as well as along the water column. All the studied metals were below or close to the maximum allowed limits of Iraqi standards for inland water. The spatial and seasonal variations were discussed.

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Publication Date
Tue Jun 30 2020
Journal Name
College Of Islamic Sciences
The position of women In Literary Literature Models of the Arabic and Kurdish literature
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This research deals with the topic (the position of women) in the literature literature, and the researcher cites a bouquet of woolen yarn, examples of verses and poems from this fine literature that looks at the woman with respect and appreciation. In their poems.
The research is a comparative search for Arab and Kurdish literature, by selecting six famous poets in the literature, three of them are from Arabic literature, and the other three are from Kurdish literature, and thus the research is divided into two subjects and six demands.
Finally, the researcher tried to set a brick that would be an entry point to find an indicative explanation and a suitable explanation that would break those symbols and signs that caused the exp

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
The influence of temperature and size on the absorption coefficient of CdSe quantum dots
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Abstract<p>Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 3</p> ... Show More
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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Engineering Science And Technology
THE INFLUENCE OF CHEMICAL COMPOSITION OF ASPHALT CEMENT ON THE PHYSICAL AND RHEOLOGICAL PROPERTIES
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Failure in asphalt mixture and distress in pavement are major issues to roads infrastructure. Selecting an appropriate chemical composition of asphalt cement is a key component in avoiding these issues. This work aimed to investigate the effect of the chemical composition of different polar fractions on the rheological and physical properties of asphalt cement. Four types of asphalt cement with penetration grades of 20/30, 40/50, 60/70 and 85/100 were divided into four fractions. Complex shear modules, rutting resistance and rotational viscosity of the asphalt cement were determined by using a Dynamic Shear Rheometer and a Rotation Viscometer, respectively. The results show that an increase in the asphaltene content and Gastel index resulte

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