In this paper a prey-predator-scavenger food web model is proposed and studied. It is assumed that the model considered the effect of harvesting and all the species are infected by some toxicants released by some other species. The stability analysis of all possible equilibrium points is discussed. The persistence conditions of the system are established. The occurrence of local bifurcation around the equilibrium points is investigated. Numerical simulation is used and the obtained solution curves are drawn to illustrate the results of the model. Finally, the nonexistence of periodic dynamics is discussed analytically as well as numerically.
Increasingly, public organizations in the federal state are required to work together, as well as to work with others to achieve their objectives. In Iraq there are two levels of organizations, including federal and local, and these organizations have been forced to work for many years in an environment in which the responsibility for service delivery is shared between policy makers and service providers, and between local governments and the federal government. It is sometimes difficult to manage the relationship between these organizations (federal and local) and do not always provide the best possible outcome of this relationship. This paper reviews how to manage the relationship between local administrations and
... Show MoreThis paper is an attempt to help the manager of a manufactory to
plan for the next year by a scientific approach, to maximize the profit and آ provide optimal آ monthly quantities of آ production, آ inventory,
work-force, prices and sales. The computer programming helps us to execute that huge number of calculations.
The Iraqi people were subjected to the most brutal crime in the history of humanity when ISIS violated the rights system and targeted women, children, civilians, minorities, religion, belief and the right to education and committed many crimes of genocide and crimes against humanity and the abandonment of millions of citizens and the recruitment of thousands of children, which constituted a flagrant violation of human rights and international law It emphasizes the gravity of the threat to international peace and security by the organization and its associated individuals, groups, institutions and entities, including foreign terrorist fighters.
That the legal characterization
... Show MoreThis Study aims to engineering geological evaluation of Fatha and Injana Formations in northern Hamrin anticline throughout geological and engineering geological Survey including Preparing engineering geological map (Scale1:90000) and Studying rock Slopes Stability in (6) Stations ,representing all types of failures (taken place and possible).General Survey for rock Slopes included Classification and engineering description according to [1], [2]. The slopes in the area are Classified based on the direction of the Strike Slopes and Strike of beds into Parallel, Oblique Lateral and orthogonal Slopes according to [3].Classification and the Slope Types are Concordant Slope and discordant Slope . The rocks in the area consists of two engineer
... Show MoreWellbore instability problems cause nonproductive time, especially during drilling operations in the shale formations. These problems include stuck pipe, caving, lost circulation, and the tight hole, requiring more time to treat and therefore additional costs. The extensive hole collapse problem is considered one of the main challenges experienced when drilling in the Zubair shale formation. In turn, it is caused by nonproductive time and increasing well drilling expenditure. In this study, geomechanical modeling was used to determine a suitable mud weight window to overpass these problems and improve drilling performance for well development. Three failure criteria, including Mohr–Coulomb, modifie
The theory of probabilistic programming may be conceived in several different ways. As a method of programming it analyses the implications of probabilistic variations in the parameter space of linear or nonlinear programming model. The generating mechanism of such probabilistic variations in the economic models may be due to incomplete information about changes in demand, production and technology, specification errors about the econometric relations presumed for different economic agents, uncertainty of various sorts and the consequences of imperfect aggregation or disaggregating of economic variables. In this Research we discuss the probabilistic programming problem when the coefficient bi is random variable
... Show MoreUnderstanding sedimentation behavior and its transport capacity in the Tigris River is of significant importance owing to the detrimental consequences caused by it. This study investigates the sediment amounts transported along the reach of the Tigris River in Baghdad. The CCHE2D model which is a common tool developed by the National Center for Computational Hydrological Science and Engineering (NCCHE) was applied to investigate the flow pattern and sediment amounts within 7 km reach. The model was initially calibrated and validated under steady-state conditions at the Sarai gauging station (upstream) and its performance was evaluated around the Abu Nawas water treatment plant (downstream). The result shows that the water surfac
... Show MoreIn this paper, we studied the effect of magnetic hydrodynamic (MHD) on accelerated flows of a viscoelastic fluid with the fractional Burgers’ model. The velocity field of the flow is described by a fractional partial differential equation of fractional order by using Fourier sine transform and Laplace transform, an exact solutions for the velocity distribution are obtained for the following two problems: flow induced by constantly accelerating plate, and flow induced by variable accelerated plate. These solutions, presented under integral and series forms in terms of the generalized Mittag-Leffler function, are presented as the sum of two terms. The first term, represent the velocity field corresponding to a Newtonian fluid, and the se
... Show MoreThis research represents outcrops of rocks at Cliffs of Tigris river ( Terraces ), most are Conglomerate, Sandstone, Siltstone and Clay stone. The research covers several aspects ; it includes a collection of field information from unstable rock slopes at (6) stations representing all the rock failure types that happened or likely to happen . In each station rock slopes are completely surveyed ; also the rocks are described in an engineering way and a complete discontinuity survey is carried out according to Anon (1972,1977) and their relationship with the rock failure is established. The field study shows that rock failures include toppling (mostly insecondary type ), rock fall. Point load test shows t
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