In this research, damping properties for composite materials were evaluated using logarithmic decrement method to study the effect of reinforcements on the damping ratio of the epoxy matrix. Three stages of composites were prepared in this research. The first stage included preparing binary blends of epoxy (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5% and 10%). It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that; it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. The second stage included reinforcing the best blend matrix of epoxy-polysulfide (the blend matrix with the best percentage of polysulfide resulted from the previous stage), by different volume percentages of short fibers (Carbon& Glass) separately and randomly. The volume percentages of fibers were (2.5%, 5%, 7.5%, and 10%). The third stage included reinforcing the blend composites with highest percentages of carbon and glass fiber, by different weight percentages of nano-particles (Red mud& Fly ash) separately. The weight percentages of particles were (0.5%, 1%, 1.5%, and 2%). The experimental results showed that blending polysulfide rubber with epoxy increased the damping ratio. As for reinforcement materials, they decreased the damping ratio, where glass fiber composites have significantly higher damping ratio than other composites.
Many studies have recommended implying the skills and strategies of creative thinking, critical thinking, and reflective thinking in EFLT curriculum to overcome EFL teaching-learning process difficulties. It is really necessary to make EFL teachers aware of the importance of cultural thinking and have a high perception of its forces. Culture of thinking consists of eight cultural forces in every learning situation; it helps to shape the group's cultural dynamic. These forces are expectations, language, time, modeling, opportunities, routines, interactions, and environment. This study aims to investigate EFL student-teachers’ perceptions of cultural thinking. The participants are selected randomly from the fourth-stage students at the D
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Was expanded display high reflectivity of the spectral remote infrared (m j 14-8) adoption order Alcolmtin ????????? thickness optical northeastern quarter wavelength and compared with results of previous studies based Aldrashalhalah on Ndharah matrix distinctive amended and fall of light close to the vertical arrangement multilayer materials buffer and in thin films homogeneous and uniform properties deposited on germanium basis results showed that the best choice for governments and their kills to expand bandwidth high reflectivity is much easier for the infrared than the area visible in addition to the order of these stacks is the cornerstone of the filters other visual...
The inflammatory bowel disease (IBD), Crohn’s disease (CD) and ulcerative colitis (UC) are heterogenous chronic inflammatory disorders of the gastrointestinal tract. The most widely accepted etiopathogenic hypothesis for these disorders suggests an immune mediated process.
Objective: This study was performed to evaluate the role of interleukine-33 in pathogenesis of inflammatory bowel disease and to correlate their levels with the disease activity and/or severity.
Methods: Fifty five subjects with inflammatory bowel disease (41 ulcerative colitis patients and 14 Crohn’s disease patients) their ages range from 16-65 years and 25 apparently healthy volunteers their ages and sexes were matched with the patients were participated i
The research aims to measure the impact of knowledge management processes individually and in total in the innovative marketing.
We depart search of a problem expressed in a number of intellectual and practical questions, the application of this research in the General Company for Vegetable Oil Industry, represented composed a sample of (63) (Director General and Deputy Director General and Director of the Department and the Division) in the company researched, it has been designed measuring instrument to collect the necessary data either statistical means they are the percentage and the arithmetic mean and standard deviation and coefficient of variation and the coefficient of simple correlation and model
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The aim of the present study was to investigate the histological structure of the tongue in Mongoose (Herpestes javanicus) and its related to the feeding pattern. Five adult animals were used in this study . The tongues were dissected and fixed in 10% formalin, then prepared by following stages (dehydration, clearing, and embedding).The serial section(5µ) were stained with(H&E) and some special stains.The histological examination showed that the tongue consists of three tunicae (mucosa, submucosa and musclaris) and the lining epithelium of the filiform papillae is composed of keratinized stratified squamous epithelial tissue. The cylindrical papillae are covered with a highly keratinized stratified squamous epithelial tissue, whereas the k
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Agricultural development occupies an important position in the economies of developing countries, and its role is greater for the Arab countries. The first task is to provide food security for all the population through sustainable development, which includes the investment of available natural resources and employment opportunities for the rural population, As well as the provision of raw materials for agricultural processing in order to increase agricultural exports to reduce the balance of payments deficit. Sustainable development is linked to increased production and improvement, as well as to food security. On the one hand, it has to cope with the increase in population and if it is possible to achieve a surplus allocated for export, a
... Show MoreTobacco products of all kinds are harmful to public health, so legislation has paid great attention to regulating the process of tobacco production and distribution, whether at the level of national or international legislation, in a way that achieves legal protection for these products, so the establishment of civil liability for tobacco companies as a result of harm to the smoker The positive and the negative provoked a jurisprudential dispute due to the specificity of the work of these companies, and the jurisprudence differed in the legal nature of tobacco companies ’liability between contractual and tort liability in a way that enables the injured smoker to obtain his right to compensation.