In this paper, we investigate the impact of fear on a food chain mathematical model with prey refuge and harvesting. The prey species reproduces by to the law of logistic growth. The model is adapted from version of the Holling type-II prey-first predator and Lotka-Volterra for first predator-second predator model. The conditions, have been examined that assurance the existence of equilibrium points. Uniqueness and boundedness of the solution of the system have been achieve. The local and global dynamical behaviors are discussed and analyzed. In the end, numerical simulations are confirmed the theoretical results that obtained and to display the effectiveness of varying each parameter
The Necessity of College of Education for Woman from the Point of view of Students
Background: Nutritional status during childhood is very important for individual development and growth. Nutrition has local and systemic effect on the oral health by affecting dental health and salivary composition. This study was aimed to determine effect of iron, sodium and potassium ions in saliva on the nutritional status and to determine the effect of nutritional status on caries severity among preschool children. Material and Methods: The sample consists of 90 children aged 4 and 5 years of both genders, selected from 6 kindergartens in Al-Resafa aspect of Baghdad province. Children classified according to their nutritional status into three groups (normalweight, underweight and overweight). Nutritional status was determined by usi
... Show MoreA new laboratory study conducted on stepped spillways in order to investigate their efficiency of dissipating flow energy. All previous study on stepped spillway indicated that the flow energy dissipation decreased as increasing in discharge. Increasing in the step numbers and the spillway slope led to energy dissipation decrease. In this study, an experimental attempt to increase energy dissipation at variable discharges was performed on stepped spillway and that leads to decreasing the cost of initiating the stilling basin or may be ignoring it. Five spillways were constructed from concrete and tested to investigate and compare among them. Three were roughed by gravel with different size for each one, one of them was s
... Show MoreThis study aims to encapsulate atenolol within floating alginate-ethylcellulose beads as an oral controlled-release delivery system using aqueous colloidal polymer dispersion (ACPD) method.To optimize drug entrapment efficiency and dissolution behavior of the prepared beads, different parameters of drug: polymer ratio, polymer mixture ratio, and gelling agent concentration were involved.The prepared beads were investigated with respect to their buoyancy, encapsulation efficiency, and dissolution behavior in the media: 0.1 N HCl (pH 1.2), acetate buffer (pH 4.6) and phosphate buffer (pH 6.8). The release kinetics and mechanism of the drug from the prepared beads was investigated.All prepare
... Show MorePoliteness strategies are of significant importance to maintain the face of the addressee. Senders of formal congratulatory letters seek to create a positive image in the minds of their addresses by performing particular illocutionary acts and face-saving acts (FSAs) in the form of written texts. To the best knowledge of the researcher, this topic received little attention from linguistic researchers, especially on the pragma-stylistic level. The importance of this study arises from the fact that congratulatory formal letters are an effective tool in the successful performance of foreign relations and thus deserve investigation. The current study investigates the pragmastylistic aspects of illocutionary acts and FSA Politeness Stra
... Show MoreCerium oxide CeO2, or ceria, has gained increasing interest owing to its excellent catalytic applications. Under the framework of density functional theory (DFT), this contribution demonstrates the effect that introducing the element nickel (Ni) into the ceria lattice has on its electronic, structural, and optical characteristics. Electronic density of states (DOSs) analysis shows that Ni integration leads to a shrinkage of Ce 4f states and improvement of Ni 3d states in the bottom of the conduction band. Furthermore, the calculated optical absorption spectra of an Ni-doped CeO2 system shifts towards longer visible light and infrared regions. Results indicate that Ni-doping a CeO2 system would result in a decrease of the band gap. Finally,
... Show MoreSome species, such as the Eurasian Collared-Dove (S. decaocto) are fast expanding around the planet, while others, such as the European Turtle-Dove (S. turtur), are experiencing precipitous population declines. Climate change, habitat loss, greater cultivated areas, and hunting pressure are the major threats to the diversity of Streptopelia. A few species require urgent conservation action. Priority for subsequent research should be to redress outstanding taxonomic uncertainties, ascertain the effect of climate change on distributions, and put in place conservation measures for declining taxa. We provide here a detailed review on how it is possible to understand the diversity of Streptopelia and how such an understanding can con
... Show MoreAbstract This study seeks to deal academically with how the EU treats clandestine immigration, through adopting a purley security approach, based on the European understanding of security threats posed to the security of communities and States in EU at all levels. So they agreed upon criminalizing this threat within the bloc while using repressive tools and steps to limit illegal immigrants flow to European territories. Accordingly, the EU gave the phenomen a security character. So it takes it from low politics level , that of employment and economic field to that of high politics, as a new security problem lying within a new security language embraced by ruling European elites, in other words EU touched on this issue as a speech act emp
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