In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at these parameters and comparing them with the randomly used once. The experimental and analytical results showed that the Taguchi method was successful in optimizing the parameters that give the highest properties and it can find the most influential parameter regardless of the material used. Also it showed that the volume fraction was the most influential parameter on the tensile and impact strength. The difference between these composites was in the properties values and that the Kevlar composites have higher tensile and impact strength.
This study has contributed to understanding a delayed prey-predator system involving cannibalism. The system is assumed to use the Holling type II functional response to describe the consuming process and incorporates the predator’s refuge against the cannibalism process. The characteristics of the solution are discussed. All potential equilibrium points have been identified. All equilibrium points’ local stability analyses for all time delay values are investigated. The system exhibits a Hopf bifurcation at the coexistence equilibrium, which is further demonstrated. The center manifold and normal form theorems for functional differential equations are then used to establish the direction of Hopf bifurcation and the stability of the per
... Show MoreA first step in this research was to synthesize Schiff's bases(1-3)using an Amoxcilline intensification reaction with different aromatic aldehydes in absolute ethanol. In benzene and refluxing conditions,Schiff's bases were cyclized with succinic and Phthalic anhydride to give a new sequence of 1,3-oxazepine derivatives(4-6) and (7-9),respectively.The last step,cyclization reactions with sodium azide in THF solvent resulted in the formation of [10 and 11], which are supposed to be biologically significant.FT.IR, 1H-NMR and 13C-NMR (for compound 4,7,9, and 11),as well as melting points reported, were used to characterize these prepared compounds ,Bacillus (G+), Staphylococcus (G+), and E.Coli (G-)were screened against these compounds. . To i
... Show MoreBackground: The aim of this study was to evaluate the expression of fibroblast growth factor-2 and Heparanase in salivary pleomorphic adenoma, and to correlate the two studied markers with each other and with clinicopathological parameters including: age, sex, tumor site and histopathological presentation. Methods: Sections of twenty five formalin-fixed paraffin embedded tissue blocks specimens of salivary pleomorphic adenoma were immunostained using monoclonal antibodies (Fibroblast growth factor-2 and Heparanase) to assess their expression in this tumor. Results: The expression of fibroblast growth factor-2 and Heparanase were positive in all pleomorphic adenoma cases (100%). The positive expression of fibroblast growth factor-2 was signi
... 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 MoreThe world is witnessing a remarkable development in the use of technology, which has made it an essential means of investment, especially in the field of management, which provided many of the facilities experienced by the institutions, including improving revenues, shortening time and saving labor. Islamic investment technology as a successful means of management and we touched on the Zakat Foundation as an application model.
Correlation and path coefficient analysis were worked out for ten morphological traits in 30 three-way crosses of maize. Phenotypic and genotypic correlation analysis indicated that ear length; row numbers per ear, grain numbers per row, leaf area and leaves numbers had a positive significant correlation with grain yield per plant. Further partitioning of correlation coefficients into direct and indirect effects showed that traits days to silking, row numbers per row and leaves numbers had a positive direct effect on grain yield per plant. The traits ear length, grain numbers per row and leaf area had a maximum total effect on grain yield. Furthermore, PCA analysis has gave interested
Scams remain among top cybercrime incidents happening around the world. Individuals with high susceptibility to persuasion are considered as risk-takers and prone to be scam victims. Unfortunately, limited number of research is done to investigate the relationship between appeal techniques and individuals' personality thus hindering a proper and effective campaigns that could help to raise awareness against scam. In this study, the impact of fear and rational appeal were examined as well as to identify suitable approach for individuals with high susceptibility to persuasion. To evaluate the approach, pretest and posttest surveys with 3 separate controlled laboratory experiments were conducted. This study found that rational appeal treatm
... Show MoreThe present research aims at the following:
- Measure Classroom environment of university Student (research sample)- Measure
Cognitive motive and Reflective Thinking of university Student (research Sample) .
- In order to Know the relationship between the Scores of Classroom environment and
Scores of cognitive motive and Scores of Reflective Thinking of university Student
(research Sample) .
Sample of research consisted of (500) Students for both genders distrivbted upon ten
colleges in Baghdad University , (5) Scientific Colleges , and (5) human Colleges , Sample
was chosen by using radom method Research instruments were three , Prepared by the researcher ,The first is to measure
classroom environme
The objective of the investigation was to analyze the structure and administration of the political system in Iraq (post-ISIS). After 2003, the Iraqi political system suffered the fundamental problem of its failure to achieve the political and social inclusion that characterizes democratic systems, to guarantee the establishment of a "state for all", while respecting differences. Political representation has moved from the system of sectarian ethnic components, under the title of consensual democracy, to the representation of leaders and the realization of their interests and the interests of their parties at the expense of the groups that claim to represent them, which complicates the problem. In this sense, the new political syste
... Show MorePeriodontitis is a chronic inflammatory disease resulted from aggravated immune response to a dysbiotic subgingival microbiota of a susceptible host. Consequences of periodontitis are not only limited to the devastating effect on the oral cavity but extends to affect general health of the individual and also exerts economic burdens on the health systems worldwide. Despite these serious outcomes of periodontitis; however, they are avoidable by early diagnosis with proper preventive measures or non-invasive interventions at earlier stages of the disease. Clinically, diagnosis of periodontitis could be overlooked due to certain limitations of the conventional diagnostic methods such as periodontal charting and radiographs. Utilization of re
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