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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
Mon Aug 01 2022
Journal Name
Baghdad Science Journal
Subgroups and Orbits by Companion Matrix in Three Dimensional Projective Space
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The aim of this paper is to construct cyclic subgroups of the projective general linear group over  from the companion matrix, and then form caps of various degrees in . Geometric properties of these caps as secant distributions and index distributions are given and determined if they are complete. Also, partitioned of  into disjoint lines is discussed.

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Publication Date
Wed Jan 01 2020
Journal Name
Periodicals Of Engineering And Natural Sciences
Bayesian and non-Bayesian estimation of the lomax model based on upper record values under weighted LINEX loss function
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In this article, we developed a new loss function, as the simplification of linear exponential loss function (LINEX) by weighting LINEX function. We derive a scale parameter, reliability and the hazard functions in accordance with upper record values of the Lomax distribution (LD). To study a small sample behavior performance of the proposed loss function using a Monte Carlo simulation, we make a comparison among maximum likelihood estimator, Bayesian estimator by means of LINEX loss function and Bayesian estimator using square error loss (SE) function. The consequences have shown that a modified method is the finest for valuing a scale parameter, reliability and hazard functions.

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
The role of an active teacher in developing the curriculum by using educational techniqes a theoretical study
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Preparing teacher occupies the attention of many thinkers and philosophers since the age of
kaldinics ( people of mesoptam / 2342 pH ) to the Islamic age where moslems philosophers
focus their attention on thought and philosophy where the philosophy of that teaching
depends on : teacher , student and family begin .
So , the issue of preparing and training teacher occupies the attention of education scientists
depending on his vital and important role in implementing of teaching policies in philosophies
and Islamic educational thought , therefore , the preparing and development of the teacher
regards as one of the basics of teaching development because of its importance in
development of teaching performance and th

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
The economic implications of the housing problem In Iraq and ways to address it - a theoretical research
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The problem of housing in Iraq is a long-rooted and rooted problem, and it needs a great effort to find out its causes and thus give essential points that contribute to alleviating and addressing it, and it is worth noting that research into the housing problem and the housing sector in Iraq is not done in isolation from other sectors and studies. As well as the economic policies pursued and the social and political conditions. It is known that the Iraqi economy is a unilateral (rentier) economy, that is, it depends almost entirely on exporting oil and obtaining revenues, and that the economic decision and economic policies followed in Iraq are greatly affected by several factors, including the economic, social and political fact

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Publication Date
Fri Dec 01 2023
Journal Name
Al-khwarizmi Engineering Journal
PDF Comparison based on Various FSO Channel Models under Different Atmospheric Turbulence
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Recently, wireless communication environments with high speeds and low complexity have become increasingly essential. Free-space optics (FSO) has emerged as a promising solution for providing direct connections between devices in such high-spectrum wireless setups. However, FSO communications are susceptible to weather-induced signal fluctuations, leading to fading and signal weakness at the receiver. To mitigate the effects of these challenges, several mathematical models have been proposed to describe the transition from weak to strong atmospheric turbulence, including Rayleigh, lognormal, Málaga, Nakagami-m, K-distribution, Weibull, Negative-Exponential, Inverse-Gaussian, G-G, and Fisher-Snedecor F distributions. This paper extensive

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Publication Date
Sun Jun 06 2010
Journal Name
Baghdad Science Journal
Algebraic Coincidence Periods Of Self – Maps Of A Rational Exterior Space Of Rank 2
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Let f and g be a self – maps of a rational exterior space . A natural number m is called a minimal coincidence period of maps f and g if f^m and g^m have a coincidence point which is not coincidence by any earlier iterates. This paper presents a complete description of the set of algebraic coincidence periods for self - maps of a rational exterior space which has rank 2 .

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Publication Date
Sat Jan 01 2022
Journal Name
Geotechnical Engineering And Sustainable Construction
Numerical Modeling of Under Reamed Piles Behavior Under Dynamic Loading in Sandy Soil
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Under-reamed piles defined by having one or more bulbs have the potential for sizeable major sides over conventional straight-sided piles, most of the studies on under-reamed piles have been conducted on the experimental side, while theoretical studies, such as the finite element method, have been mainly confined to conventional straight-sided piles. On the other hand, although several laboratory and experimental studies have been conducted to study the behavior of under-reamed piles, few numer­ical studies have been carried out to simulate the piles' performance. In addition, there is no research to compare and evaluate the behavior of these piles under dynamic loading. Therefore, this study aimed to numerically investigate bearing capaci

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Publication Date
Mon Jun 01 2015
Journal Name
Int. J. Adv. Appl. Math. Andmech.
The effect of external source of disease on the epidemic model
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Publication Date
Tue Dec 30 2025
Journal Name
Baghdad Science Journal
Study the effect of position on the time of astronomical twilight
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Twilight is that light appear on the horizon before sunrise and after sunset, Astronomically it is known that sunrise and sunset are effected by high above sea level, but the effect of high above sea level on the time of astronomical twilight still not decided and controversy among astronomers, in This research we studies the effect of high above sea level on the time of astronomical twilight, through adding the equation correct high above sea level to equation computation of twilight and then calculate of changing in the time of twilight for different highest (0-10000) meters above sea level , and the ratio of increase for time with high between (15.45-20.5) minutes. It was found that there was an increase in the time of the twilight along

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Publication Date
Wed Dec 14 2022
Journal Name
Nasaq Journal
The Effect of Co-text on the Comprehensibility of World Englishes
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MR Younus, Nasaq Journal, 2022

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