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Three Dimensional MHD Simulationof Comet Hale-Bopp Tail
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The interaction between comet Hale-Bopp tail with the solar wind is investigated in the present paper using magneto-hydrodynamic (MHD) numerical simulation, which accounts for the presence of the interplanetary magnetic field (IMF). The simulation is based on three-dimensional Lax-Wendroff explicit scheme, providing second-order accuracy in space and time. The ions produced from the nucleus of the comet will add considerable effects on the microstructure of the solar wind, thus severely altering its physical properties. The present simulation focuses on careful analysis of these properties by means of simulating the behavior of the comet Hale-Bopp’s tail at 1 AU from the sun. These properties include the changes of the plasma density, particle velocity, IMF changes, pressure, and internal energy. The results indicated that comet tail will highly disturb the physical properties of the solar wind for a considerable distance. These changes reflect the effect of including the source term in the present simulation. It is shown that the comet tail will retain its original shape faster as it approaches the sun. Practical comparisons are also presented in the present research with earlier work. The present simulation was made using MATLAB program.

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Publication Date
Sun Mar 19 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Security For Three-Tiered Web Application
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          Web application protection lies on two levels: the first is the responsibility of the server management, and the second is the responsibility of the programmer of the site (this is the scope of the research).  This research suggests developing a secure web application site based on three-tier architecture (client, server, and database). The security of this system described as follows: using multilevel access by authorization, which means allowing access to pages depending on authorized level; password encrypted using Message Digest Five (MD5) and salt. Secure Socket Layer (SSL) protocol authentication used. Writing PHP code according to set of rules to hide source code to ensur

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Publication Date
Wed Apr 01 2015
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
Security For Three -Tired Web Application
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Web application protection lies on two levels: the first is the responsibility of the server management, and the second is the responsibility of the programmer of the site (this is the scope of the research). This research suggests developing a secure web application site based on three-tier architecture (client, server, and database). The security of this system described as follows: using multilevel access by authorization, which means allowing access to pages depending on authorized level; password encrypted using Message Digest Five (MD5) and salt. Secure Socket Layer (SSL) protocol authentication used. Writing PHP code according to set of rules to hide source code to ensure that it cannot be stolen, verification of input before it is s

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Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
A three-stage blumlein-circuit to generate transversely excited atmospheric nitrogen laser by using three spark gaps
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In this research constructed N2 laser system by use developed method of electric discharge. In this method used four step of electric discharge by using four capacitors, three spark gaps, high tension power supply varying in range from 12kV to 24 kV and three resistors, this method called three stage blumlein circuit. The breakdown time delay of these parallel spark gaps cement strong ultraviolet preionization in the laser channel, thus the result of these amendments the laser output is many doubled and is more increasing than that obtained using the one and two stage blumlein circuits. This system has been designed and operated to give pulse laser with wavelength at 337.1 nm. This laser system can operate without mirrors and optical res

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Numerical Approximations of a One-Dimensional Time-Fractional Semilinear Parabolic Equation
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     The time fractional order differential equations are fundamental tools that are used for modeling neuronal dynamics. These equations are obtained by substituting the time derivative of order  where , in the standard equation with the Caputo fractional formula. In this paper, two implicit difference schemes: the linearly Euler implicit and the Crank-Nicolson (CN) finite difference schemes, are employed in solving a one-dimensional time-fractional semilinear equation with Dirichlet boundary conditions. Moreover, the consistency, stability and convergence of the proposed schemes are investigated. We prove that the IEM is unconditionally stable, while CNM is conditionally stable. Furthermore, a comparative study between these two s

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Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Two-dimensional Crystallization of Silica nanospheres using Coplanar DC Electric field
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Abstract:Two-dimensional crystal has been achieved and controlled with the aid of DC electric field applied between two electrodes at 5 millimeters separating distance between them. Sol-gel method has been used to prepared nanosilica particle which used in this work as well as TiO2 nanopaowder. The assembly of the silica particles is due to the interaction between the electrical force, the particles dipole, and the interaction between the particles themselves. When a DC voltage is applied, the particles accumulated and crystallized on the surface between the electrodes. The Light diffraction demonstrates that the hexagonal crystal is always oriented with one axis along the direction of the field. The particles disassemble when the field is

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Publication Date
Wed Aug 30 2023
Journal Name
Iraqi Journal Of Science
On the Stability of Four Dimensional Lotka-Volterra Prey-Predator System
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The aim of this work is to study a modified version of the four-dimensional Lotka-Volterra model. In this model, all of the four species grow logistically. This model has at most sixteen possible equilibrium points. Five of them always exist without any restriction on the parameters of the model, while the existence of the other points is subject to the fulfillment of some necessary and sufficient conditions. Eight of the points of equilibrium are unstable and the rest are locally asymptotically stable under certain conditions, In addition, a basin of attraction found for each point that can be asymptotically locally stable. Conditions are provided to ensure that all solutions are bounded. Finally, numerical simulations are given to veri

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Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Physics
Two-dimensional Crystallization of Silica nanospheres using Coplanar DC Electric field
...Show More Authors

Two-dimensional crystal has been achieved and controlled
with the aid of DC electric field applied between two electrodes at 5
millimeters separating distance between them. Sol-gel method has
been used to prepared nanosilica particle which used in this work as
well as TiO2 nanopaowder. The assembly of the silica particles is
due to the interaction between the electrical force, the particles
dipole, and the interaction between the particles themselves. When a
DC voltage is applied, the particles accumulated and crystallized on
the surface between the electrodes. The Light diffraction
demonstrates that the hexagonal crystal is always oriented with one
axis along the direction of the field. The particles disass

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Publication Date
Fri Aug 01 2014
Journal Name
Int. J. Mod. Eng. Res
Exact solutions for MHD flow of a viscoelastic fluid with the fractional Burgers’ model in an annular pipe
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This paper presents an analytical study for the magnetohydrodynamic (MHD) flow of a generalized Burgers’ fluid in an annular pipe. Closed from solutions for velocity is obtained by using finite Hankel transform and discrete Laplace transform of the sequential fractional derivatives. Finally, the figures are plotted to show the effects of different parameters on the velocity profile.

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Publication Date
Wed Jul 01 2020
Journal Name
Journal Of Physics: Conference Series
“Impress of rotation and an inclined MHD on waveform motion of the non-Newtonian fluid through porous canal”
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Abstract<p>Waveform flow of non-Newtonian fluid through a porous medium of the non-symmetric sloping canal under the effect of rotation and magnetic force, which has applied by the inclined way, have studied analytically and computed numerically. Slip boundary conditions on velocity distribution and stream function are used. We have taken the influence of heat and mass transfer in the consideration in our study. We carried out the mathematical model by using the presumption of low Reynolds number and small wave number. The resulting equations of motion, which are representing by the velocity profile and stream function distribution, solved by using the method of a domain decomposition analysis a</p> ... Show More
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Publication Date
Wed Jul 29 2020
Journal Name
Iraqi Journal Of Science
Influence of Inclined MHD on Unsteady Flow of Generalized Maxwell Fluid with Fractional Derivative between Two Inclined Coaxial Cylinders through a Porous Medium
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"This paper presents a study of inclined magnetic field on the unsteady rotating flow of a generalized Maxwell fluid with fractional derivative between two inclined infinite circular cylinders through a porous medium. The analytic solutions for velocity field and shear stress are derived by using the Laplace transform and finite Hankel transform in terms of the generalized G functions. The effect of the physical parameters of the problem on the velocity field is discussed and illustrated graphically.

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