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ijs-5877
The Numerical Analysis for Electrical Streamer Discharge Behaviour in Transformer Oil
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      In this paper, a numerical analysis was carried out using finite element method to analyse the mechanisms for streamer discharges. The hydrodynamic model was used with three charge carriers equations (positive ion, negative ion and electron) coupled with Poisson equation to simulate the dynamic of streamer discharge formation and propagation. The model was tested within a 2D axisymmetric tip-plate electrodes configuration using the transformer oil as the dielectric liquid. The distance between the electrodes was fixed at 1 mm and the applied voltage was 130 kV at 46 ns rising time. Simulation results showed that the time has a clear effect on the streamer propagation along the symmetry axis. In addition, it was observed that the highest value of the voltage was recorded at 46 ns and the minimum voltage required for insulation breakdown was 112 kV at 200 ns. It was revealed that the streamer velocity recorded the highest value when the streamer reaches the plate electrode and the lowest value when the streamer begins to propagate. Results also showed that the streamer discharge was dominated by positive ions while the negative ions have a low effect.

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Publication Date
Thu Apr 28 2022
Journal Name
Iraqi Journal Of Science
ON SN-SPACES
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The aim of this paper is to introduce and study the concept of SN-spaces via the notation of simply-open sets as well as to investigate their relationship to other topological spaces and give some of its properties.

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Publication Date
Sat Mar 31 2018
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetic of Disinfection reaction by Sodium Hypochlorite Solution
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The present studier aims to study the kinetic of reaction at different experimental conditions depending on coliform bacteria concentration and hypochlorite ion. The effects that had been investigated were different of sodium hypochlorite doses, contact time, pH and temperature (20, 29, 37) o C. The water samples were taken from Al-Wathba water treatment plant in Risafa side of Tigris River in Baghdad. The biological tests included the most probable number (M.P.N) for indicating the concentration of coliform bacteria with different contact times and the total plate count (T.P.C) for indicating the amount of colonies for general bacteria. The iodimetry method (chemical test) was used for indicating the concentration of hypochlo

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Publication Date
Wed Mar 30 2022
Journal Name
Nasaq Journal
Lingual Sovereignty: Chinua Achebe’s Novel Things Fall Apart A Postcolonial Study
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The discourse surrounding lingual sovereignty within the African postcolonial context is profoundly intertwined with the fabric of cultural identity and self-determination. Language serves not merely as a conduit for communication but as a repository for a people's collective consciousness, encapsulating their traditions, thoughts, and perspectives. In the realm of postcolonial literature, this dialogue often grapples with the paradox of expressing indigenous narratives through the linguistic tools of former colonizers. Chinua Achebe's seminal work, "Things Fall Apart," exemplifies this conundrum, artfully weaving the orature and culture of Umuofia within the English language. Achebe's choice to write in English—a language imposed upon hi

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Publication Date
Mon Oct 30 2023
Journal Name
Iraqi Journal Of Science
On a Subclass of Meromorphic Univalent Functions With Fixed Second Coefficientsassociated with q-Differed Operator
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The main object of this article is to study and introduce a subclass of meromorphic univalent functions with fixed second positive defined by q-differed operator. Coefficient bounds, distortion and Growth theorems, and various are  the obtained results.

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Publication Date
Thu Apr 28 2022
Journal Name
Iraqi Journal Of Science
Multi-wavelength studies of NGC 4425 Galaxy
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In this work, ugzri images of NGC 4425 galaxy are analyzed. The galaxy images are obtained from the seventh Sloan Digital Sky Survey (SDSS) Data Release (DR7). This work was performed with Image Reduction and Analysis Facility (IRAF) and analyzed the structure of the galaxy a bulge, a bar, together with isophotal contour maps and performed a bulge/disk decomposition of the galaxy image. Also, we have estimated the disk position angle, ellipticity, B4 and inclination of the galaxy.

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Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Preparation and Spectroscopic Studies of Some Metal Ion Complexes of 2-((4-Formyl-3-Hydroxynaphthalen-2-yl) Diazenyl) Benzoic Acid
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New azo ligand 2-((4-formyl-3-hydroxynaphthalen-2-yl) diazenyl) benzoic acid (H2L) was synthesized from the reaction of 2-aminobenzoic acid and2-hydroxy-1-naphthaldehyde. Monomeric complexes of this ligand, of general formulae [MII(L)(H2O)] with (MII = Mn, Co, Ni, Cu, Zn, Pd, Cd and Hg ) were reported. The compounds were isolated and characterized in solid state by using 1H-NMR, FT-IR, UV–Vis and mass spectral studies, elemental microanalysis, metal content, magnetic moment measurements, molar conductance and chloride containing. These studies revealed tetrahedral geometries for all complexes except PdII complex is Square planar. The study of complexes formation via molar ratio of (M:L) as (1:1). Theoretical treatments of compounds in gas

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Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Pulsed laser deposition to investigate structural and optical properties of lead sulfide nanostructure
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In this work, the structure properties of nano Lead sulfide PbS thin films are studied. Thin samples were prepared by pulse laser deposition and deposited on glass substrates at wavelength 1064nm wavelength with a various laser energies (200,300,400,500)nm. The study of atomic force microscope (AFM) and X-ray diffraction as well as the effect of changing the laser energy on the structural properties has been studied. It has been observed that the membrane formed is of the polycrystalline type and the predominant phase is the plane (111) and (200). The minimum grain size obtained was 16.5 nm at a laser energy about 200 mJ. The results showed that thin films of average granular sizes (75 nm) could be prepared.As for the optical properties,

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Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Engineering
Impact of Preparing HMA with Modified Asphalt Cement on Moisture and Temperature Susceptibility
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Many researchers tried to prevent or reduce moisture damage and its sensitivity to temperature to improving the performance of hot mix asphalt because it is decreasing the functional and structural life of fixable pavement due to the moisture damage had exposed to it.

The main objective of this study is to inspect the effect of (fly ash “3%, 6%, 12%”, hydrated lime”5%, 10%, 20%” and silica fumes”1%, 2%, 4%) referring to previous research by the net weight asphalt cement as a modified material on the moisture and temperature sensitivity of hot mix asphalt. This was done using asphalt from AL-Nasiria refinery with penetration grade 40-50, nominal maximum size (12.5) mm (surface course) of aggregate and on

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Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Engineering
A Novel Analytical Model to Design Piezoelectric Patches Used to Repair Cracked Beams
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In this paper, an analytical solution describing the deflection of a cracked beam repaired with piezoelectric patch is introduced. The solution is derived using perturbation method. A novel analytical model to calculate the proper dimensions of piezoelectric patches used to repair cracked beams is also introduced. This model shows that the thickness of the piezoelectric patch depends mainly on the thickness of the cracked beam, the electro-mechanical properties of the patch material, the applied load and the crack location. Furthermore, the model shows that the length of the piezoelectric patches depends on the thickness of the patch as well as it depends on the length of the cracked beam and the crack depth. The additio

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Publication Date
Thu Apr 18 2019
Journal Name
Iraqi Journal Of Science
Spectral and Linear Optical Characterization of Rhodamine B and Fluorescein Sodium Organic Laser Dyes Mixture Solutions
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Spectral and linear optical properties for a mixture of Rhodamine B (RB) and Fluorescein Sodium (Na Fl) organic laser dyes were determined at different concentrations 10-3, 10-4 M in ethanol solvent at room temperature. The intensity of absorption range is towards longer wavelengths (red shift). The quantum efficiency diminished while the radiative and fluorescence life time increased when increment concentration, organic laser dyes have a spectrum within the range 540-500 nm. Results demonstrate that a mixture of laser dyes are effective optical materials when contrasted with individual laser dyes. It can be utilized as resonator in cavity lasers.

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