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bsj-2666
Space-Charge Effect on the Theoretical Design of Electron Gun Operated under Zero Magnification Condition
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A computational investigation is carried out in the field of charged –particle optics with the aid of numerical analysis method using the personal computer. The work is concerned with the design of electron gun with space-charge effect. The Finite element method (FEM) used in the solution of Poison's equation for determine the axial potential distribution of the two-electrode immersion lens operated under zero magnification condition , and from the solution of the paraxial ray equation the optical properties such as the focal length , spherical and chromatic aberration coefficients are determined, also a calculation of the brightness and perveance for the lens. The electrodes geometry was determined in two and three dimension with the aid of new drawing software called SIMION 7 and the electron beam trajectory under zero magnification conditions has been determine for these electrodes.

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Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Optical Communications
320 Gbps Free Space Optic Communication System Deploying Ultra Dense Wavelength Division Multiplexing and Polarization Mode Division Multiplexing
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Abstract<p>This work aims to investigate the integrated ultra-dense wavelength division multiplexing (UDWDM) and polarization division multiplexing (PDM) schemes incorporated in the free space optic (FSO) communication system. Erbium-doped fiber amplifiers (EDFAs) are used as post and pre-amplifiers in the proposed UDWDM–PDM–FSO system to boost the transmission power for increasing the distance. Thirty-two channels are transported over the FSO link to realize the total data transmission of 160 and 320 Gbps with 0.08 and 0.1 nm channel spacing, respectively. Results are also reported with non-return to zero modulation schemes. The performance of the proposed UDWDM–PDM–FSO transmission sys</p> ... Show More
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Publication Date
Mon Dec 15 2014
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Soil Content, Drilling Parameters and Drilling Tool Diameter on the Vibration Assessment in the Drilling Rig
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Abstract

This paper represents a study of the effect of the soil type, the drilling parameters and the drilling tool properties on the dynamic vibrational behavior of the drilling rig and its assessment in the drilling system. So first, an experimental drilling rig was designed and constructed to embrace the numerical work.

The experimental work included implementation of the drill-string in different types of soil with different properties according to the difference in the grains size, at different rotational speeds (RPM), and different weights on bit (WOB) (Thrust force), in a way that allows establishing the charts that correlate the vibration acceleration, the rate of penetration (ROP), and the power

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Publication Date
Mon Mar 14 2022
Journal Name
Journal Of Craniofacial Surgery
The Effect of The Blue-Violet Light Emitting Diode (Led) Irradiation on the Bleeding and Pain Following Tooth Extraction
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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
ESTIMATION OF THE OPTIMUM BED THICKNESS OF A FLOWTHROUGH POROUS ELECTRODE (FTPE) WORKING UNDER MASS TRANSFER CONTROL
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In this paper, a theoretical analysis of optimum bed thickness operates under mass transfer control for realizing a high efficiency and reaction conversion of an electrochemical reactor has been made based on flowthrough porous electrode (FTPE) configuration. Many models have been used to represent the optimum bed thickness by taking a look into previous works concerned and collecting all related information, data, and models. The parameters that affect the optimum bed thickness have been visualized and reviewed, and almost all of them have been examined by experimental data from different sources and based on the various models. It has been found that the increase in electrolyte flow rate, concentration, limiting current density, and sp

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Publication Date
Fri Nov 01 2019
Journal Name
Renewable Energy
Test of solar adsorption air-conditioning powered by evacuated tube collectors under the climatic conditions of Iraq
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Publication Date
Tue Jul 01 2025
Journal Name
Journal Of Studies In Humanities And Educational Sciences
The Effect of the Needham Constructivist Model on the Achievement of Third Year Biology Department Students in the Subject of Teaching Methods
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The current research aims to know the effect of Needham's constructivist model on the achievement of third-year students in the Life Sciences Department in the teaching methods subject. To achieve the research objectives, the experimental method was followed for the experimental and control groups with dimensional measurement of the achievement variable of the teaching methods subject. The research sample included (62) students in the third year of the Life Sciences Department, distributed into two equal groups in the variables (self-assessment of learning methods - chronological age in years - intelligence level - previous information). To measure the level of students' achievement, an achievement test was constructed consisting of (40) te

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Publication Date
Wed Feb 01 2023
Journal Name
Journal Of Engineering
Effect of the Proposed Outlets on the Hydrodynamic Behavior and Water Quality of the South-West Part of the Al Hammar Marsh
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The current study aims to find a new plan to manage the water quality of the western part of the Hammar Marsh to reduce the salts that cause problems for the marshes and preserve their environmental life by isolating the southwestern part of the Hammar Marsh by closing the outlet under the railway embankment. The outlet is discharging saline water to the east-western part of Al Hammar Marsh. After isolating the southwestern part of the marsh, a new outlet is proposed. The impact of the flow hydrodynamics on improving the water quality was simulated using the SMS model. The hydrodynamics and water quality simulation models for the marsh are : a hydrodynamic model and average depth (SMS RMA2) and a two-dimensional water quality model (SMS

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Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Scope of using accounting of responsibility under contition of public badget
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Abstract

  The public budget in Iraq is still prepared according to the traditional base that allocates the  amounts of budget the current year based on the budget of previous year with an increase in estimations with random proportions without connecting the input (financial, human resources and asset )with their output (quantitatively and qualitatively)this caused waste and lose in the available resources therefore the output of budget showed be adapted is such a way that achieving connection between its input and output and to be appropriate with the organizational structure of the state without intrinsic change in its work .this may be realized by adopting the accounting of

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Publication Date
Wed Jan 01 2020
Journal Name
Plant Archives
Morpho-physiological study on the effect of lead stress and selenium foliar application on growth of dill plant anethum graveolens l
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The experiment was carried out in the green house of botanical garden belong to Department of Biology/College of Education for Pure Science Ibn AL-Haitham, University of Baghdad for growing season 2017-2018 to evaluate effect of lead stress with concentrations (0, 50, 100, 150) mg.L -1 and Selenium concentrations (0, 15, 30) mg.L-1 on growth of dill plant using pots. The experiment was designed according to completely randomized design (CRD) with three replications. Result indicated that dill plants subjected to lead stress with height concentrations caused decrease in plant parameters (plant height, no. of branches. plant-1, root length, shoot dry weight, the content of nitrogen, phosphorus and potassium, protein concentration, no. of umbe

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Publication Date
Mon Oct 01 2012
Journal Name
Iraqi Journal Of Physics
Study the effect of adding TiO2 nano-powder on some surface properties of TiO2 thin film prepared on stainless steel substrate
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In this research TiO2 nano-powder was prepared by a spray pyrolysis technique and then adds to the TiO2 powder with particle size (0.523 μm) in ratio (0, 5, 10, 15 at %) atomic percentage, and then deposition of the mixture on the stainless steel 316 L substrate in order to use in medical and industrial applications.
Structure properties including x-ray diffraction (XRD) and scanning electron microscope (SEM0, also some of mechanical properties and the effect of thermal annealing in different temperature have been studied. The results show that the particle size of a prepared nano-powder was 50 up to 75 nm from SEM, and the crystal structure of the powders (original and nano powder) was rutile with tetragonal cell. An improvement in

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