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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
Sun Dec 09 2018
Journal Name
Baghdad Science Journal
On Free Resolution of Weyl Module and Zero Characteristic Resolution In The Case of Partition (8,7,3)
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Publication Date
Fri Jun 29 2018
Journal Name
Journal Of Engineering
The Effect of Circular Perforation on a V-Corrugated Fin Performance under Natural Convection
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An experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching t

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Theoretical Study of the Effect of Permeability Tensor upon Drainage of Soils
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the influence of permeability tensor upon drainage of anisotropic soils under ponded water and steady recharge (rainfall) is theoretically investigated. Tensorial permeability has led to the formulation of mixed type partial differential equations. Since there is no analytical solution to this problem, the formulation is therefore solved numerically by the method of finite elements. The finite element formulation is implemented into a computer model which can be applied to any problem of seepage under steady state
conditions. Two different example problems representing two different flow conditions under full anisotropy have been studied. Results of the model for the isotropic case were checked against exact mathematical solutions de

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Publication Date
Thu Aug 01 2019
Journal Name
Iop Conference Series: Materials Science And Engineering
Effect of Embedment Depth on Raft Foundation Settlement Under Seismic Load
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Abstract<p>Dynamic loads highly influence soil properties and may cause real damage to structures and buildings. This article reports the experimental results from 24 tests to study the settlement of flexible and rigid raft foundation with different embedment depth rested on dense sandy soil. A small scale building model of dimension 200*200 mm and 320 mm in height was performed with reinforced concrete raft foundation of 10 mm thickness for flexible raft and 23 mm for rigid raft, The shaking table technique was used to simulate the seismic effect, the shaker was sat to give three different excitation frequencies 1,2,and3 Hz and displacement amplitude equal to 13 mm, the foundation was placed at</p> ... Show More
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Publication Date
Sun Feb 24 2019
Journal Name
Iraqi Journal Of Physics
Modelling of electron trajectories inside SEM chamber concerning mirror effect phenomenon
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A computational investigation is carried out to describe the behaviour of reflected electrons upon a charged insulator sample and producing mirror effect images. A theoretical expression for the scanning electron path equation is derived concerning Rutherford scattering and some electrostatic aspects. The importance of the derived formula come from its correlation among some of the most important parameters that controls the mirror effect phenomena. These parameters, in fact, are the trapped charges, incident angle and the scanning potential which investigated by considering its influences on the incident electrons. A pervious experimental operation requirements are adopted for operating the introduced expression. However, the obtained r

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Publication Date
Mon May 15 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Vibrational Zero-Point Energies of Iodo Compounds
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   In this study, the contribution of the bond C–I has been derived and incorporated in empirical formula to calculate zero-point energies (ZPE) of Iodo compounds. The calculated ZPE for 38 molecules containing this bond correlate well with experimental values. The comparison of these results with semiempirical (AM1) ZPE appears very satisfactory

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Publication Date
Thu Aug 08 2024
Journal Name
New Materials, Compounds And Applications
MOLECULAR MODELLING AND THEORETICAL DESIGN OF NOVEL NIRMATRELVIR DERIVATIVES AS SARS-COV-2 ENTRY INHIBITORS
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The pandemic SARS-CoV-2 is highly transmittable with its proliferation among nations. This study aims to design and exploring the efficacy of novel nirmatrelvir derivatives as SARS entry inhibitors by adapting a molecular modeling approach combined with theoretical design. The study focuses on the preparation of these derivatives and understanding their effectiveness, with a special focus on their binding affinity to the S protein, which is pivotal for the virus’s access to the host cell. Considering molecular docking aspects in the scope of a study on nirmatrelvir derivatives and S protein, dynamics simulations with 25 nanoseconds of their binding are explored. The study shows that these derivatives might work as effective antivi

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Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
F-Compact operator on probabilistic Hilbert space
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This paper deals with the F-compact operator defined on probabilistic Hilbert space and gives some of its main properties.

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Publication Date
Thu May 11 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
On Projective 3-Space Over Galois Field
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        The purpose of this paper is to give the definition of projective 3-space PG(3,q) over Galois field GF(q), q = pm for some prime number p and some integer m.

        Also, the definition of the plane in PG(3,q) is given and state the principle of duality.

        Moreover some theorems in PG(3,q) are proved.

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Publication Date
Sun Feb 01 2015
Journal Name
Journal Of Engineering
Effect of Saturation of Sandy Soil on the Displacement Amplitude of Soil Foundation System under Vibration
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In this study, the response and behavior of machine foundations resting on dry and saturated sand was investigated experimentally. A physical model was manufactured to simulate steady state harmonic load at different operating frequencies. The effect of relative density, depth of embedment, foundation area as well as the imposed harmonic load was investigated. It was found that the amplitude of displacement of the foundation increases with increasing the amplitude of dynamic force and operating frequency meanwhile it decreases with increasing the relative density of sand, degree of saturation, depth of embedment and contact area of footing. The maximum displacement was noticed at 33.34 to 41.67 Hz. The maximum displacement amplitude respons

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