Preferred Language
Articles
/
ijp-760
Ab–Initio large unit cell calculations of the electronic structure of Si and Ge nanocrystals
...Show More Authors

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.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Oct 01 2012
Journal Name
Iraqi Journal Of Physics
Effect of carbon nanotube and Zn particles addition on the some mechanical properties and thermal conductivity of unsaturated polyester
...Show More Authors

In this research work a composite material was prepared contains a matrix which is unsaturated polyester resin (UPE) reinforced with carbon nanotube the percentage weight (0.1, 0.2, 0.4.0.5) %, and Zn particle the percentage weight (0.1, 0.2,0.4,0.5)%.
All sample were prepared by hand lay-up, process the mechanical tests contains hardness test, wear rate test, and the coefficient of thermal conductivity. The results showed a significant improvement in the properties of overlapping, Article containing carbon nano-tubes and maicroparticles of zinc because of its articles of this characteristics of high quality properties led to an, an increase in the coefficient of the rmalconductivity, and increase the hardness values with increased pe

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Synthesis and Polymerization of Poly Acryl Imide and One of Their Derivatives Then Curing the Product with Alkyl Halide
...Show More Authors

The present work involved four steps: First step include reaction of acrylamide ,N-?-Methylen-bis(acryl amide) and N-tert Butyl acryl amide with poly acryloyl chloride in the presence of triethyl amine (Et3N) as catalyst, the second step include homopolymerization of all products of the first step by using benzoyl peroxide(BPO) as initiator in (80-90)Co in the presence of Nitrogen gas(N2). In the third step the poly acrylimide which prepare in second step was convert into potassium salt by using alcoholic potassium hydroxide solution. Fourth step include Alkylation of the prepared polymeric salts in third step by react it with different alkyl halides(benzyl chloride, allylbromide , methyl iodide) by using DMF as solvent for(10-12) hours.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jan 08 2020
Journal Name
Environment, Development And Sustainability
Groundwater availability and water demand sustainability over the upper mega aquifers of Arabian Peninsula and west region of Iraq
...Show More Authors

View Publication
Crossref (89)
Crossref
Publication Date
Wed Jul 01 2015
Journal Name
Journal Of Engineering
A comparative Isothermal and Kinetic Study of the Adsorption of Lead (II) from Solution by Activated Carbon and Bentonite
...Show More Authors

This work is aiming to study and compare the removal of lead (II) from simulated wastewater by activated carbon and bentonite as adsorbents with particle size of 0.32-0.5 mm. A mathematical model was applied to describe the mass transfer kinetic.

The batch experiments were carried out to determine the adsorption isotherm constants for each adsorbent, and five isotherm models were tested to choose the best fit model for the experimental data. The pore, surface diffusion coefficients and mass transfer coefficient were found by fitting the experimental data to a theoretical model. Partial differential equations were used to describe the adsorption in the bulk and solid phases. These equations were simplified and the

... Show More
View Publication Preview PDF
Publication Date
Sun Sep 29 2024
Journal Name
Journal Of Global Innovations In Agricultural Sciences
The Impact of pH and Growth Phases on Photosynthetic Pigments and Carotene of Coelastrella saipanensis N. Hanagata (Scenedsmacese, Shaerophleales)
...Show More Authors

The present study aimed to investigate the effects of level pH and the growth phases of Coelastrella saipanensis on Chlorophyll a,b, total, and Carotene. The algae were cultured in BG11 media and grown at different pH levels. We measured chlorophyll a, b, total chlorophyll, growth phases, and carotene concentrations. The results showed that at pH 8.5, the measurements of photosynthetic pigments-chlorophyll a, Chlorophyll b, and the total chlorophyll (0.183, 0.268, and 0.433 mg L-1, respectively). The highest values of chlorophyll a (0.185 mg L-1), and b (0.339 mg L-1), and the total chlorophyll (0.492 mg L-1) were recorded in the stationary phase. In addition, the study found that at pH 8.5 and the beginning of the stationary phase,

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Crossref
Publication Date
Wed Sep 01 2021
Journal Name
Baghdad Science Journal
Effect of Salt and Osmotic Stresses on the Activity of Some Antioxidant Enzymes and Biochemical Traits in Catharanthus roseus
...Show More Authors

Abstract

The experiment has been carried out in the Syrian National Commission of Biotechnology, during the growing season 2018/2019, to study the effect of abiotic stresses (salinity and osmotic stresses) on the activity of some antioxidant enzymes and biochemical traits in Catharanthus roseus. The experiment has been laid according to (CRD) with three replications. The seeds have been sterilized by NaOCl solution (0.5% v/v), then planted on MS medium. Plantlets have been moved to MS medium enriched with NAA (1 mg.L-1) and BA (2 mg.L-1). The callus has been initiated from leaves using MS medium containing NAA (1 mg L-1) and KIN (2 mg.L-1). After 60 days, callus

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Int. J. Agricult. Stat. Sci
THE EFFECT OF PUTRESCINE AND SPERMIDINE ON SOMATIC EMBRYOGENESIS AND REGENERATION OF DATE PALM (PHOENIX DACTYLIFERA L.) CV. BARHEE
...Show More Authors

The present study was conducted to determine the effect of different concentrations of putrescine and spermidine at all stages of regeneration (callogenesis, somatic embryos multiplication, germination and rooting)) of date palm cultivar Barhee. Shoot tips were eradicated from 2-3 years old offshoots, surface sterilized and inoculated onto Murashiege and Skoog, 1962 (MS) medium supplemented with 20 mg/L 2,4-D and 3 mg/L N6-2-isopentyl adenine (2ip). Primary callus was obtained after 24 weeks on the nutrient medium. Calli were then transferred onto fresh MS medium containing 0.0, 50, 100 or 150 mg/L of putrescine or spermidine individually. Results were recorded after 12 weeks. A significant increase in embryonic callus fresh weights reached

... Show More
Preview PDF
Scopus (3)
Scopus
Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
The relationship between human investment and economic growth in Iraq(1985-2010) and measuring return of investment of human
...Show More Authors

Abstract:

Investment in human capital of renewable energy can be relied upon to get to achieve the goals of development is important for Iraq through the intellectual community cards creative able to innovate and develop what is so is study the effect of human investment on economic growth through the adoption of the index of national income as a function of variables independent ( human capital, physical capital) and this is built on the premise that the relationship direct correlation between economic growth and human investment, and it can measure the return on human investment, which is an incentive to increase human capital through education and the development of the economy in general have shown th

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Dec 16 2024
Journal Name
Polimery
Synthesis and photochemical stability of polymeric derivatives formed by the reaction of acrylamide and succinic anhydride copolymer with dyes
...Show More Authors

A new derivative of PAM, acrylamide was copolymerized with succinic anhydride, and the reaction product reacted with three dyes, anthocyanin, bromophenol, and thymol. The prepared polymers were characterized by X-ray diffraction, FT-IR and UV-visible spectroscopy, proton nuclear magnetic resonance spectrometry, and thermal analysis. FT-IR spectroscopy showed the disappearance of two bands near 3450 and 3380 cm-1 for the stretching vibrations of the primary amine which indicates for the formation of amides. The UV-photolysis of aqueous solutions of different concentrations of the polymers was studied. Polyacrylamide-g-succinic anhydride showed an increase in polymerization under light. An increase of ~ 50% was observed for a 200 mg/L

... Show More
View Publication
Scopus Clarivate Crossref
Publication Date
Tue Mar 03 2020
Journal Name
International Journal Of Psychosocial Rehabilitation
A Study of Some Biochemical Variables and Functional Indicators and Their Relationship to the Achievement of 200m Young Runners
...Show More Authors

ES Hussein

View Publication