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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 schemes will be conducted via numerical experiments. The efficiency of the proposed schemes in terms of absolute errors, order of accuracy and computing time will be reported and discussed.

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Theoretical Study to Fatigue Crack Growth to Duplex Steel Alloy byGeneralized Paris Equation
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  A theoretical study was done in this work for Fatigue , Fatigue Crack Growth (FCG) and stress factor intensity range for steel .       It also includes Generalized Paris Equation and the fulfillment of his equation which promises that there is a relation between parameters C and n .          Usig Simple Paris Equation through which we concluded the practical values of C and n and compared them with the theoretical values which have been concluded by Generalized Paris Equation .           The value of da/dN and ∆K for every material and sample were concluded and compared with the data which was used in

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Publication Date
Wed Dec 30 2020
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Modifying an Equation to Predict the Asphaltene Deposition in the Buzurgan Oil Field
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Buzurgan oil field suffers from the phenomenon of asphaltene precipitation. The serious negatives of this phenomenon are the decrease in production caused by clogging of the pores and decrease in permeability and wettability of the reservoir rocks, in addition to the blockages that occur in the pipeline transporting crude oil. The presence of laboratories in the Iraqi oil companies helped to conduct the necessary experiments, such as gas chromatography (GC) test to identify the components of crude oil and the percentages of each component, These laboratory results consider the main elements in deriving a new equation called modified colloidal instability index (MCII) equation based on a well-known global equation called colloidal in

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Publication Date
Wed Jul 12 2023
Journal Name
Energies
Finite Time Disturbance Observer Based on Air Conditioning System Control Scheme
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A novel robust finite time disturbance observer (RFTDO) based on an independent output-finite time composite control (FTCC) scheme is proposed for an air conditioning-system temperature and humidity regulation. The variable air volume (VAV) of the system is represented by two first-order mathematical models for the temperature and humidity dynamics. In the temperature loop dynamics, a RFTDO temperature (RFTDO-T) and an FTCC temperature (FTCC-T) are designed to estimate and reject the lumped disturbances of the temperature subsystem. In the humidity loop, a robust output of the FTCC humidity (FTCC-H) and RFTDO humidity (RFTDO-H) are also designed to estimate and reject the lumped disturbances of the humidity subsystem. Based on Lyapunov theo

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Publication Date
Thu Mar 26 2009
Journal Name
Iraq Journal For Science
Calculation of time Entry and Exit of satellites from Earth Shadow
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The tracking of satellites motion and their path around the earth is important things in the mechanical of satellites motion. Significant parameters for the determination of time entrance and existence of the satellite could be obtained from the shadow of the earth. In the present work the tracking and time determination for entry and exit from earth shadow have been studied. In the present work we built a software for tracking the motion of satellites in orbit around the earth and determine the change of both distance and speed as a function of time. The perturbations effect on the satellite has been neglected from the earth atmosphere drag and the earth gravity and other effects. The equation for calculating the shadow is solved using num

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Publication Date
Thu Apr 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of the Synthesis Time on Structural Properties of Copper Oxide
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The structural properties of the CuO nanopowder oxide prepared reflux technique
without any templates or surfactant, using copper nitrate hydrate (Cu(NO)3 3H2O) in deionized
water with aqueous ammonia solution are reported. The Xrd analysis data and processing in origin
pro program used to get FWHM and integral width to study the effect of different synthesis times
was studied on the structural properties. It was found that values of crystal sizes are 17.274nm,
17.746nm, and 18.560nm, the size of nanoparticles is determined by Halder-Wagner, and 15.796
nm, 15.851nm, and 16.52nm, were calculated by Size-Strain Plot (SSP) method. The Sample was
considered to determine physical and microstructural paramete

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Publication Date
Thu Jan 16 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
Thu Oct 01 2015
Journal Name
Applied Mathematics And Computation
Identification of the time-dependent conductivity of an inhomogeneous diffusive material
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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Calculation of the Time Interval of Radio Storm Emitted from Jupiter
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A program in Visual Basic language was designed to calculate the time interval of radio storm by predict their type at specific Local Time (LT) from Baghdad location, such storms result from the Central Meridian Longitude (CML) of system ΙΙΙ for Jupiter and phase of Io’s satellite (ФIo). These storms are related to position of Io (Io- A,B,C,D). The input parameters for this program were the observer’s location (longitude), year, month and day. The output program results in form of tables provide the observer information about the date and the LT of beginning and end of each type of emitted storm. The year 2011 was taken to apply the results within twelve month; the results of the time interval of radio storm were between (0.08h-5

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Publication Date
Sat Aug 01 2015
Journal Name
Journal Of Engineering
Reducing of Manufacturing Lead Time by Implementation of Lean Manufacturing Principles
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Many organizations today are  interesting to implementing lean manufacturing principles  that should enable them to eliminating the wastes to reducing a  manufacturing lead time.  This paper concentrates on  increasing  the competitive level of the company in globalization markets and improving of the productivity by reducing the manufacturing lead time. This will be by using the main tool of lean manufacturing which is value stream mapping (VSM) to identifying all the activities of manufacturing process (value and non-value added activities) to reducing elimination of wastes (non-value added activities) by converting a manufacturing system to pull instead of push by applying some of pull system strategies a

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Publication Date
Sat Oct 01 2022
Journal Name
Journal Of Engineering
Numerical Study of Thermal Conductivity Effect on The Performance of Thermal Energy Storage
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In this study, the effect of the thermal conductivity of phase change material (PCM) on the performance of thermal energy storage has been analyzed numerically. A horizontal concentric shell-and-tube latent heat thermal energy storage system (LHTESS) has been performed during the solidification process. Two types of paraffin wax with different melting temperatures and thermal conductivity were used as a PCM on the shell side, case1=0.265W/m.K and case2=0.311 W/m.K. Water has been used as heat transfer fluid (HTF) flow through in tube side. Ansys fluent has been used to analyze the model by taking into account phase change by the enthalpy method used to deal with phase transition. The numerical simulatio

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