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phZaZ4cBVTCNdQwC5Enp
Direct and inverse source problems for degenerate parabolic equations
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Abstract<p>Degenerate parabolic partial differential equations (PDEs) with vanishing or unbounded leading coefficient make the PDE non-uniformly parabolic, and new theories need to be developed in the context of practical applications of such rather unstudied mathematical models arising in porous media, population dynamics, financial mathematics, etc. With this new challenge in mind, this paper considers investigating newly formulated direct and inverse problems associated with non-uniform parabolic PDEs where the leading space- and time-dependent coefficient is allowed to vanish on a non-empty, but zero measure, kernel set. In the context of inverse analysis, we consider the linear but ill-posed identification of a space-dependent source from a time-integral observation of the weighted main dependent variable. For both, this inverse source problem as well as its corresponding direct formulation, we rigorously investigate the question of well-posedness. We also give examples of inverse problems for which sufficient conditions guaranteeing the unique solvability are fulfilled, and present the results of numerical simulations. It is hoped that the analysis initiated in this study will open up new avenues for research in the field of direct and inverse problems for degenerate parabolic equations with applications.</p>
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Publication Date
Mon Jun 22 2020
Journal Name
Baghdad Science Journal
Phase Fitted And Amplification Fitted Of Runge-Kutta-Fehlberg Method Of Order 4(5) For Solving Oscillatory Problems
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In this paper, the proposed phase fitted and amplification fitted of the Runge-Kutta-Fehlberg method were derived on the basis of existing method of 4(5) order to solve ordinary differential equations with oscillatory solutions. The recent method has null phase-lag and zero dissipation properties. The phase-lag or dispersion error is the angle between the real solution and the approximate solution. While the dissipation is the distance of the numerical solution from the basic periodic solution. Many of problems are tested over a long interval, and the numerical results have shown that the present method is more precise than the 4(5) Runge-Kutta-Fehlberg method.

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
First Order Nonlinear Neutral Delay Differential Equations
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The author obtain results on the asymptotic behavior of the nonoscillatory solutions of first order nonlinear neutral differential equations. Keywords. Neutral differential equations, Oscillatory and Nonoscillatory solutions.

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Publication Date
Tue Aug 03 2021
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
New Travelling Wave Solution of Burgers Equations
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     In this paper, we studied the travelling wave solving for some models of Burger's equations. We used sine-cosine method to solution nonlinear equation and we used direct solution after getting travelling wave equation.

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Publication Date
Mon May 11 2020
Journal Name
Baghdad Science Journal
Oscillation Criteria for Solutions of Neutral Differential Equations of Impulses Effect with Positive and Negative Coefficients: eventually positive solutions and differential inequalities
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In this paper, some necessary and sufficient conditions are obtained to ensure the oscillatory of all solutions of the first order impulsive neutral differential equations. Also, some results in the references have been improved and generalized. New lemmas are established to demonstrate the oscillation property. Special impulsive conditions associated with neutral differential equation are submitted. Some examples are given to illustrate the obtained results.

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Publication Date
Sat Sep 23 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Direct Estimation for Approximation by Bernstein Polynomial by Using Ditzian-Totik and Average in L Ja,h11 p < oo Modulus of Smoothness
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The  purpose  of  the  paper  is  to  tind  the  degree  of  the approximation of a functions  f be bounded , measurable and defined

in  interval   [a,h]by  Bernstein  polynomial  in  LP    space  1 $ p < oo by

 

using Ditzian-Totik modulus  of smootlmess  and  k 1n  average modvlus of smoothness.

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Publication Date
Thu Mar 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
International business particularly that centered on foreign direct investment
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While practicing of International business particularly that centered on foreign direct investment, let on one side, to achieving objectives of transnational corporations specially that represented in continuous pursue to improving its cash flows and maximization of stockholders wealth which is considered the most important objective to the transnational corporations, but in the same time its lead, on other side, to increasing the foreign exchange risk exposuring these corporations. So, the transnational corporations (TNCs) struggling to make strategies which are dealing in smart way, with this risk and its management in way that enable to avoiding risk comple

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Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Modern Physics
Direct Optical Energy Gap in Amorphous Silicon Quantum Dots
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Publication Date
Sat Jun 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Predicting of Temperature Distribution in Direct Contact Heat Transfer
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An experimental and theoretical investigation of three phase direct contact heat transfer by evaporation of refrigerant drops in an immiscible liquid has been carried out. Refrigerant Rl2 and R134a were used for the dispersed phase, while water and brine were the immiscible continuous phase. A numerical analysis is presented to predict the temperature distribution throughout the circular test column radially and axially is achieved. Experimental measurements of the temperature distribution have been compared with the numerical results and are discussed .A comparison between the experimental and theoretical results showed acceptable agreement and applicability of the derived equations. Comparison with other related work showed similar beh

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Publication Date
Sun Dec 01 2019
Journal Name
2019 First International Conference Of Computer And Applied Sciences (cas)
A Comparison for Some of the estimation methods of the Parallel Stress-Strength model In the case of Inverse Rayleigh Distribution
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Publication Date
Thu Nov 08 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Assessment of Health Problems for the Elderly at the Nursing Home in Baghdad city
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Objective: Assessment of health problems and identify demographical information to elderly. Methodology:
it is a descriptive study, data were collected by the researchers depended on the direct interview with the
elderly by using the study instrument (questionnaire) as well as review the records of the geriatric.
Results: The majority of study sample (66%) were males and (24.3%) were within age group (70-74) years,
(44.7%) were widows, and (41.7%) did not read and write. This study applied the international classification
of diseases(short-table) in (11) items, which stated that most of the elderly were complaining from
health problems: debility of hearing (80.65%), eczema or allergies (69.35%), debility of vision (66.9

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