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 of the system's parameters. The results show that system movement could happen around the positive equilibria, if the system stability conditions are met.
The effect of short range correlations on the inelastic longitudinal Coulomb form
factors for the lowest four excited 2+ states in 18O is analyzed. This effect (which
depends on the correlation parameter β) is inserted into the ground state charge
density distribution through the Jastrow type correlation function. The single particle
harmonic oscillator wave function is used with an oscillator size parameter b. The
parameters β and b are, considered as free parameters, adjusted for each excited state
separately so as to reproduce the experimental root mean square charge radius of
18O. The model space of 18O does not contribute to the transition charge density. As
a result, the inelastic Coulomb form factor of 18
The study of surface hardness, wear resistance, adhesion strength, electrochemical corrosion resistance and thermal conductivity of coatings composed from sodium silicate was prepared using graphite micro-size particles and carbon nano particles as fillers respectively of concentration of (1-5%), for the purpose of covering and protecting the oil distillation towers. The results showed that the sodium silicate coating reinforced with carbon nano-powder has higher resistance to stitches, mechanical wear, adhesive and thermal conductivity than graphite/sodium silicate composite especially when the ratio 5% and 1%, the electrochemical corrosion test confirmed that the coating process of stainless steel 304 lead to increasin
... Show MoreBrick factories distributed within the study area use fuel oil to complete the burning of the bricks, were high amounts of gases and suspended particles with different concentrations of heavy elements are produced and cause air and soil pollution. It is noted that the workers suffer from respiratory diseases and other health problems. This study is an attempt to detect the sources and concentrations of pollutants and to propose modalities for their treatment and reduction. Air and soil samples were collected from different sites in Abu Smeache brick factory in Al-Kifl area to the south of Babel city, Iraq, during two seasons (summer and winter). The process also included collecting and modelling of dust and soil
... Show MoreEfficiency of Pisum sativum plants in using tricalcium super phosphate (TSP) in presence and absence of mycorrhizal fungi was evaluated in the field experiment in College of Science / Al-Mustansiriyah University. The experiment comprised of (6) treatments prepared from the interaction of two levels of inoculation [non-inoculation with fungus F0 and inoculation with Glomus mosseae fungus (F1)]. And three levels of phosphorus: 0,20,40 Kg P/ha. The experimental size was (1x2)m. Irrigation and hand-weeding were done when needed. The following plant measurements were recorded: (Shoots dry weight, concentration of N and P% in addition to percentage of root infection with mycorrhizal fungi at flowering 50% of plants. The re
... Show MoreNew chlropheniramine maleate (CPM) selective electrochemical membranes were prepared by using chlropheniramine maleate -molecularly imprinted polymers. MIP was prepared by bulk polymerization using 2-hydroxyethyl methacrylate (2-HEMA) as monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker and a benzoyl peroxide (BPO) as an initiator at 600C. Three CPM-MIP electrodes were constructed by using tri-tolyl Phosphate (ToCP), tris (2- ethyl hexyl) Phosphate (TEHP) and tributyl Phosphate (TBP) as plasticizers in PVC matrix.Electrode parameters including slopes, working concentrations ph. The interference effect in the presence of (Na+, Mg+2, Al+3, Glycine, Alanine, Arginine and Phenylalanine) was studied using the separated a
... Show MoreIn this work an enzyme linked immunosorbent assay (ELISA) technique has been used for detection of some inflammatory markers in serum of acute coronary syndrome (ACS)-Patients Admitted to the cardiac care unit (CCU) of Iraqi Centre For Heart Diseases and Ibn AlNafees Teaching Hospital. The present method includes quantitative measurement of interleukine-6 (IL-6) and C-reactive protein (CRP), as their increase during symptoms may be responsible for identifying the mechanism of myocardial damag, in addition to their best performance than other quantitative tests perhaps due to their association with atherosclerotic process that belongs to the endothelial dysfunction. Aim of this study is to estimate the prevalence and correlation of IL-6 w
... Show Morestudy aims to examine education and the challenges of globalization in light of Corona pandemic. The examination involves surveying a randomly selected sample from the University of Baghdad’s professors, particularly from the colleges of Education for Women, Arts, and Sciences. The purpose of this examination is to learn about the dimensions of globalization, its effects on the educational process, and the importance of distance education during the spread of Corona virus quarantine. To achieve this, the researcher followed a descriptive and analytical approach by applying a questionnaire to a sample of 70 teachers who were randomly selected electronically. Results have shown that 78.6% emphasized the contribution of globalization duri
... Show MoreThe aim of this study is to investigate the nature of the relationship between domestic savings and domestic investment, or rather the efficiency of domestic savings in financing development in Algeria, in order to explain this relationship, identify the challenges to investment, and finance and accelerate economic growth. The economic measurement methodology has estimated the relationship between the savings rate and the local investment rate in the Algerian economy. We have annual data for the period 1970-2014. One of the most important conclusions is that there is no relationship between savings and investment, nor even an integration between them. To illustrate this, the use of some statistical tools, a
... Show MoreSince the introduction of the HTTP/3, research has focused on evaluating its influences on the existing adaptive streaming over HTTP (HAS). Among these research, due to irrelevant transport protocols, the cross-protocol unfairness between the HAS over HTTP/3 (HAS/3) and HAS over HTTP/2 (HAS/2) has caught considerable attention. It has been found that the HAS/3 clients tend to request higher bitrates than the HAS/2 clients because the transport QUIC obtains higher bandwidth for its HAS/3 clients than the TCP for its HAS/2 clients. As the problem originates from the transport layer, it is likely that the server-based unfairness solutions can help the clients overcome such a problem. Therefore, in this paper, an experimental study of the se
... Show MoreThis research discusses the rehabilitation of heritage markets in the historical centers of Islamic Arab cities and their use in the field of cultural tourism as one of the most important tourist attractions and the subsequent revival of the national economy in addition to preserving the urban heritage as these markets part of the historical centers of cities. The research also discusses the preservation of the continuity of heritage markets as a product of cultural heritage value within an integrated framework to preserve the urban heritage in the historic centers of cities. The study then reviews a number of experiences of Arab and Islamic countries in the field of preserving and rehabilitating heritage markets, which qualify them to b
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