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The dynamics of nutrient, toxic phytoplankton, nontoxic phytoplankton and zooplankton model
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<p>The objective of this paper is to study the dynamical behavior of an aquatic food web system. A mathematical model that includes nutrients, phytoplankton and zooplankton is proposed and analyzed. It is assumed that, the phytoplankton divided into two compartments namely toxic phytoplankton which produces a toxic substance as a defensive strategy against predation by zooplankton, and a nontoxic phytoplankton. All the feeding processes in this food web are formulating according to the Lotka-Volterra functional response. This model is represented mathematically by the set of nonlinear differential equations. The existence, uniqueness and boundedness of the solution of this model are investigated. The local and global stability conditions of all possible equilibrium points are established. The occurrence of local bifurcation and Hopf bifurcation are investigated. Finally, numerical simulation is used to study the global dynamics of this model.</p>

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Publication Date
Tue Jul 14 2015
Journal Name
Ibn Al-haitham J. For Pure & Appl. Sci.
Effect of Annealing Temperature and Thickness on the Structural and Optical Properties of CdSeThin Films
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CdSe alloy has been prepared successfully from its high purity elements. Thin films of this alloy with different thicknesses (300,700)nm have been grown on glass substrates at room temperature under very low pressure (10-5)Torr with rate of deposition (1.7)nm/sec by thermal evaporation technique, after that these thin films have been heat treated under low pressure (10-2)Torr at (473,673)K for one hour. X-ray patterns showed that both CdSe alloy and thin films are polycrystalline and have the hexagonal structure with preferential orientation in the [100] and [002] direction respectively. The optical measurements indicated that CdSe thin films have allowed direct optical energy band gap, and it increases from (1.77- 1.84) eV and from

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Publication Date
Thu Mar 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Annealing Temperature and Thickness on the Structural and Optical Properties of CdSeThin Films
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CdSe alloy has been prepared successfully from its high purity elements. Thin films of this alloy with different thicknesses (300,700)nm have been grown on glass substrates at room temperature under very low pressure (10-5)Torr with rate of deposition (1.7)nm/sec by thermal evaporation technique, after that these thin films have been heat treated under low pressure (10-2)Torr at (473,673)K for one hour. X-ray patterns showed that both CdSe alloy and thin films are polycrystalline and have the hexagonal structure with preferential orientation in the [100] and [002] direction respectively. The optical measurements indicated that CdSe thin films have allowed direct optical energy band gap, and it increases from (1.771.84) eV and from (1.6-1

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Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Study Properties (Compressive And Tensile And Wear) For The Composite Materials Hybried
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  This study included prepared samples of epoxy reinforced by the novolac , aluminum , glass powder and epoxy reinforced by aluminum , glass powder and epoxy alone .They are used as reinforced materials of volum fraction amounting 40% .  The mechanical properties inclouded ( tensile , compressive and wear) where the wear test inclouded different applied loads (5,10,15) . From the results showed the epoxy reinforced by aluminum and glass powder has higher compressive strength (56.91) Mpa and higher tensile strength (132.2) Mpa .But the epoxy alone has higher wear rate and the epoxy reinforced by aluminum and glass powder which have higher elasticity of modulus from the tensile test (315.7) Mpa

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Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Achieve breastfeeding book and theft book To the end of the door cut the way of the manuscript Sailing Forum for Sheikh Ibrahim bin Mohammed Halabi (T: 659 H): Study and achieve
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Achieve breastfeeding book and theft book
To the end of the door cut the way of the manuscript
Sailing Forum for Sheikh Ibrahim bin Mohammed Halabi
(T: 659 H)

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Publication Date
Tue Feb 05 2019
Journal Name
Journal Of The College Of Education For Women
The Difficulties of the opening text between changing and collecting reading in poem (city without rain): The Difficulties of the opening text between changing and collecting reading in poem (city without rain)
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Abstract
This research deals with the technical of opening text during the critical
study about the poem of Al- ssiyab which is named ( city with out rain)
We chose this poem also to make connection with the western critical
theories.
Our study aims to explain the act of opening texts and critics and its
methods and directions in modern Arabic poetry.
It also aims to show the differences in the point of view between critics
and poetries.
The research depends on dimension vision of selective, and descriptive.

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Publication Date
Sun Mar 30 2003
Journal Name
College Of Islamic Sciences
Scientific interpretation of the Holy Qur’an and its impact on belief and thought
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Praise be to God, Lord of the Worlds, and prayers and peace be upon the Master of Messengers, Muhammad and his family

The good and pure and after his companions

God Almighty said: ( ) Do they not contemplate the Qur’an? If it had been from other than God, they would have found in it much discrepancy. God Almighty has made the well-being of people and their lives linked to faith in it. So what is the need of people today to return to the Book of their Lord so that they may return to the right path that God intended for His servants so that they may attain sustenance? Security and the good life. How could it not be, when many of the nations of the world no longer see security or stability because their leaders and politic

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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of The College Of Education For Women
Arabic prose poem and the antithesis of contrast: poetry _ prose and West _ East
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Arabic prose poem and the antithesis of contrast: poetry _ prose and West _ East

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Publication Date
Sun Dec 01 2002
Journal Name
Iraqi Journal Of Physics
Dependence of the Hall Mobility and Carrier Concentration on Thickness and Annealing Temperature
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Hall effect measurements have been made on a-As2Te3 thin films different thickness film in the range (200-350) nm. The Hall mobility in a-As2Te3 thin films decreases with increasing annealing temperature but the carrier concentration increases. When increasing the film thickness increases the Hall mobility decreases, while the carrier concentration increases.

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Publication Date
Tue Dec 30 2008
Journal Name
Al-kindy College Medical Journal
The Sensitivity and Specificity of Oral Tumors and Premalignant Lesions Diagnosis by Otolaryngologists
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Background: Tumors of the oral cavity are under
estimated in general dental and medical practice,
some authors describe it as the forgetting disease,
others wondering if the attention paid to this disease
compared to its fatality (The 5-year survival rate is
about 50%) is enough for disease control? However;
this disease deserves a comprehensive assessment by
all dental and medical fields assumed to examine the
oral cavity regularly, especially otolaryngologist.
Objectives: To find out the sensitivity and specificity
of clinical examination in diagnosing oral tumors and
premalignant conditions by otolaryngologist.
Methods: Across sectional retrospective study was
conducted in the:
-study design:

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Quantitative and qualitative assessment of the basic components and effective in Acol plant
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Key components estimated in Acol total plant leaves and the results were as follows plant Acol humidity 72%

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