<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

In this paper, the general framework for calculating the stability of equilibria, Hopf bifurcation of a delayed prey-predator system with an SI type of disease in the prey population, is investigated. The impact of the incubation period delay on disease transmission utilizing a nonlinear incidence rate was taken into account. For the purpose of explaining the predation process, a modified Holling type II functional response was used. First, the existence, uniform boundedness, and positivity of the solutions of the considered model system, along with the behavior of equilibria and the existence of Hopf bifurcation, are studied. The critical values of the delay parameter for which stability switches and the nature of the Hopf bifurcat

Abstract 

     This research aims to analyze the reality of the production process in an assembly line Cars (RUNNA) in the public company for the automotive industry / Alexandria through the use of some Lean production tools, and data were collected through permanence in the company to identify the problems of the line in order to find appropriate to adopt some Lean production tools solutions, and results showed the presence of Lead time in some stations, which is reflected on the customer's waiting time to get the car, as well as some of the problems existing in the car produced such as high temperature of the car, as the company does not take into account customer preferences,

Background: The Streptococcus genus are the predominant bacteria in the mouth and the Streptococcus sanguinis is one of them which performing a primary function for expansion of dental biofilm. Gingival and periodontal disorders are caused by dental biofilm, today, there is a necessity to discover naturally presenting antibacterial compounds from herbs with less side effects as a substitutive to the commonly handled chlorohexidine. Thus, the purpose of this study was to assess the antibacterial activity of thymus vulgaris oil on Streptococcus sanguinis bacteria In vitro. Materials and Methods: Human supragingival plaque samples were taken from 10 subjects, then morphological and microscopical examination, bioch

Background: Wounds are any disruption to the normal anatomic structure of tissue which leads to the loss of epithelial continuity with or without a loss of underlying connective tissue, as well as the anatomic and functional integrity of the living tissue . Wound healing is a complex process with overlapping phases haemostasis, inflammation, proliferation and maturation/matrix Remodeling. Each phase of wound healing requires different management strategies, and inappropriate treatment can delay wound healing. The aim of wound treatment is a rapid wound closure and re-establish tissue function,chia seeds oil are widely used herbal medicines because of their anti-inflammatory and antioxidant capacity as they considerd agood source of polyunsa

The current study examined the impact of using PowerPoint presentation on EFL student’s attendance, achievement and engagement. To achieve the aim of this study, three null hypotheses have been posed as follows: There is no statistically significant difference between the mean score of the experimental group attendance and that of the control one; there is no statistically significant difference between the mean score of the experimental group achievement and that of the control one, and there is no statistically significant difference between the mean score of the experimental group engagement and that of the control one. To verify a hypothesis, a sample of sixty students is chosen randomly from the third year, department of English,

The environment and the placesthat prince Faisal Bin AL-Husein influenced his childhood ,
behaviourand future . his expereence in his early life in leading the battles and
arabRevoluionenriched him . inspite of his short periedand harsh experience of leadersmp.
he gained an experienencein ruling iraqadter 1921 . The Syrian experiencetaught him how to
deal with the strong and establish the government as he beliered in the slogan: independence
is taken not given. He established the consititution and the election . he made a solid
basefeconomy of in his time, Iraq , Iraq be came the country number ( 53) as an
independency country on the third of November 1932 . he died peacefuliy after Iraq's
indepence.