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.
numerical study is applied to the mercury-argon mixture by solving the boltzman transport equation for different mixture percentage.
That interdependence in Islam is cooperation, love and fraternity and give and take
and let him look rich to the poor, every Muslim is himself liable hungry and poor no matter
how many races and colors. That interdependence is cruel, spending for God and is the
greatest supporter of charities that deal with housing, food and medicine for the unemployed
and needy, and social solidarity the consolidation of the values of brotherhood and love,
where is the greatest support of corrupt and concerted community and causes prosperity in
societies and has a significant impact on the unity of Muslims and their club and their
collection. The Islamic regime tops major systems in entrusting the achievement claimed the
lives of
The research aims to prepare a report by the external auditor (Federal Office of Financial Supervision) for the control environment it is includes financial control, commitment and performance of the North Oil Company (extractive) according to the causes of pollution. The research problem it is not the Federal Office of Financial Supervision preparation a report on the things the environment include the prevent or reduction failure the administration of the causes of the pollution caused by oil mining industry by both bad planning or operational or related to efficient human resources as well as of technology to use and resulting from non-compliance local laws and instructions, as well as the inefficiency of spending on environme
... Show MoreLogic is understood so far as a product perspective, either formal or informal. The topic is still, though interesting, imprecise, sketchy and problematic. Besides, the relevance of logic to linguistics has not been explained. This research focuses on dealing with logic as a product and a process. It introduces how logic is relevant to understanding language. Logic is surely not irrelevant to real human language. In this research, we coin 'logical pragmatics' to refer to "the structure of an argumentation and its parts used by the speaker for the purpose of persuasion to have an effect in the addressee and passive audience”. As such, the research mainly aims at providing a definition of "logical pragmatics" as well as developing an ide
... Show MoreIn this research for each positive integer integer and is accompanied by connecting that number with the number of Bashz Attabq result any two functions midwives to derive a positive integer so that there is a point
The article aims to study the crisis of political change from three Phases . The first focuses on the crises of political legitimacy and democratic postponement, as fundamental issues in analyzing the phenomenon of power struggle through the dialectic between the concept of historical legitimacy and institutional fragility from the beginning of statehood in 1962 to the stage of multi-partyism and the cessation of the electoral process in the 1990s. While the second focuses on the question of the monopoly of power in the post-terrorism and national reconciliation according to considerations Political, social and security measures to prolong the life of the regime and avoid the demands of political change brought about
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Praise be to God, and prayers and peace be upon our master Muhammad, his family and companions until the Day of Judgment.
As for after:
It is the right of every nation to take care of its scientific heritage, and to reveal its human civilizational impact, and the Arabs are the richest nations in heritage, as they had in every period of time a sign and pride, the Arabs fulfilled their duty towards humanity, and they carried out a large part of their scientific activity towards humanity.
Therefore, highlighting some of the scientific aspects of the civilized activity of the Arabs, and removing some of the illusions spread by some malicious people, is a human duty before it is a national duty.
... Show MoreThe execution phase of the project is most dangerous and the most drain on the resources during project life cycle, therefore, its need to monitor and control by specialists to exceeded obstructions and achieve the project goals. The study aims to detect the actual reasons behind mismanagement of the execution phase. The study begins with theoretical part, where it deals with the concepts of project, project selection, project management, and project processes. Field part consists of three techniques: 1- brainstorming, 2- open interviews with experts and 3- designed questionnaire (with 49 reason. These reasons result from brainstorming and interviewing with experts.), in order to find the real reasons behind misman
... Show MoreThe need for an intellectual understanding of the context from many aspects' dictates understanding the ways through which the graphic designer walks in simulating the intent of the design process and elevating it to levels of communicative perception that leads to communicating the idea to the recipient, and it is thus a need closely related to the context, if it is historical. Culturally or socially, and between the mechanisms of selecting and operating the elements and units of the graphic and design achievement. On this basis, the role of context in graphic design can be studied.
The research included four chapters, the first chapter of the research problem and the need for it, and the aim of the research was (discovering the
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