<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

Many carbonate reservoirs in the world show a tilted in originally oil-water contact (OOWC) which requires a special consideration in the selection of the capillary pressure curves and an understanding of reservoir fluids distribution while initializing the reservoir simulation models.
An analytical model for predicting the capillary pressure across the interface that separates two immiscible fluids was derived from reservoir pressure transient analysis. The model reflected the entire interaction between the reservoir-aquifer fluids and rock properties measured under downhole reservoir conditions.
This model retained the natural coupling of oil reservoirs with the aquifer zone and treated them as an explicit-region composite system

In this paper has been building a statistical model of the Saudi financial market using GARCH models that take into account Volatility in prices during periods of circulation, were also study the effect of the type of random error distribution of the time series on the accuracy of the statistical model, as it were studied two types of statistical distributions are normal distribution and the T distribution. and found by application of a measured data that the best model for the Saudi market is GARCH (1,1) model when the random error distributed t. student's .

A3D geological model was constructed for Al-Sadi reservoir/ Halfaya Oil Field which is discovered in 1976 and located 35 km from Amara city, southern of Iraq towards the Iraqi/ Iranian borders.

Petrel 2014 was used to build the geological model. This model was created depending on the available information about the reservoir under study such as 2D seismic map, top and bottom of wells, geological data & well log analysis (CPI). However, the reservoir was sub-divided into 132x117x80 grid cells in the X, Y&Z directions respectively, in order to well represent the entire Al-Sadi reservoir.

Well log interpretation (CPI) and core data for the existing 6 wells were the basis of the petrophysical model (

The interplay of predation, competition between species and harvesting is one of the most critical aspects of the environment. This paper involves exploring the dynamics of four species' interactions. The system includes two competitive prey and two predators; the first prey is preyed on by the first predator, with the former representing an additional food source for the latter. While the second prey is not exposed to predation but rather is exposed to the harvest. The existence of possible equilibria is found. Conditions of local and global stability for the equilibria are derived. To corroborate our findings, we constructed time series to illustrate the existence and the stability of equilibria numerically by varying the different values

Arabic calligraphy is one of the greatest achievements of Islamic art. The visual form of Arabic calligraphy is the primary means of presenting ideas and messages for expressive communication in Arabic typefaces. Emerging computer technology with calligraphy is essential for effective visual designs; however, traditional typefaces are insufficient in number and quality to fulfill the requirements of the current Saudi industry. Thus, this research investigates the processes followed by graphic designers to create modern Arabic type designs inspired by Arabic calligraphy, and presents the characteristics of Arabic calligraphy. The research implemented a mixed experimental and descriptive method, exploring 10 typefaces designed by professio

Current research aims to find out:

1. Effect of using the active learning in the achievement of third grade intermediate students in mathematics.
2. Effect of using of active learning in the tendency towards the study of mathematics for students of third grade intermediate.

In order to achieve the goals of the research, the researcher formulated the following two hypotheses null:

1. There is no difference statistically significant at the level of significance (0.05) between two average of degrees to achievement

This study is marked by: The ignorant poem and body language
 Its main objective is to reveal the manifestations of this language in the text mentioned, and accordingly, the sieve poem has been read semantic (semantic) and hermeneutic, revealing the poet's ability to employ symbols and signals (body language) in the poem chosen for this purpose; The existence of such language in pre-Islamic poetry. After a long reflection and reading, the signs and symbols of the physical movement of the body, and its feminine and aesthetic manifestations were identified, and this was achieved through the use of modern critical methodologies that directly affect this language. The study consisted of an introduction and three topics, followed by t

This study deals with the time property in the cinema through two films: (The Knife) directed by Khalid Hamada and (The Deceived) directed by Tawfiq Saleh. These two films were excerpted by the cinema from two novels of the Palestinian writer Ghassan Kanafani, the first is from the novel (What is Left for You) and the second is from the novel (Men in the Sun).  If the Palestinian novel has imposed its presence on the Arab creative scene through a group of novelists who took it upon themselves to communicate their cause to the world,   the Palestinian cinema has been far from being a purely Palestinian, because many of the cinematic works have been provided by Arab countries on the issue, while this cinema is still seeking

The study of topography most important studies and depth of any literary or artistic text and occupy the thinking of many who work in art at generally. There is hardly any film scenario from description in general of the indispensable elements of the composition and place one. So the place starts form since the scriptwriter begins to view the result of the description begins to feature the emergence of there are simple operations in the scenario soon to receive growth as a final achievement in the film. The description of the place begins to take on an allegorical character as a language version in the script, soon translated into another language, the language of the picture. Which in turn complement the creative ring of cinematic art a