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.
There is no doubt that the oud is one of the most important folk musical instruments in Iraq. It has been known since the ages of ancient Iraq in its form, strings, and the way to play it through the clay number. On them, however, they have participated in showing the instrument the greatest potential and musical aesthetics, and the interested person may be wondering about ways to learn to play this instrument, so the training methods varied between personal interpretations on the one hand and systematic teaching in educational institutions on the other hand, especially that they have received the attention of educational institutions Miya, that which must adopt an appropriate and scientific strategy that accompanies global education pro
... Show MoreEverywhere carriers incur a measure of liability for the safety of the goods. Carriers are liable for any damage or for the loss of the goods that are in their possession as carriers unless they prove that the damage or loss is attributable to certain excepted causes. Damaged and lost items can unfortunately be a common problem when shipping freight. Legal responsibilities arise due to loss or damage during transit while cargo is in their care. This study intends to investigate the nature of the liability of the maritime carrier when this liability is realized, and the extent to which it can be paid or disposed of given the risks realized from the transportation process, which may result in damage or loss of the goods, and the damag
... Show MoreThe Shiite religious authority in Iraq has played an active and vital role over its long history in promoting values of tolerance, rejecting extremism, advocating unity and confronting external challenges. This role has increased significantly after 2003 as a result of the great challenges that have passed in Iraq. Despite its clear policy of non-interference in political matters, except in cases of necessity, but the great role it played in maintaining national unity and advocating the rejection of extremism and sectarianism has made it a necessary need in Iraq to confront any deviations, dispersions or threats that affect society and the state. Therefore, its role in the process of reform was prominent on the political level by calling
... Show MoreThe operation of production planning is a difficult operation and it's required High effect and large time especially it is dynamic activity which it's basic variables change in continuous with the time, for this reason it needs using one of the operation research manner (Dynamic programming) which has a force in the decision making process in the planning and control on the production and its direct affect on the cost of production operation and control on the inventory.
Abstrct
The administrations of Presidents Clinton and Bush Jr. have seen the emergence of neoconservatives. The neoconservative were the establishment of the Project for the New American Century (PNAC) project in 1997 during the Clinton administration. The neoconservatives, through the New Century Project, were able to make important foreign policy decisions, notably the Iraq Liberation Law, which was passed by Congress on January 26, 1998 and signed by President Clinton and became a law legitimized. Clinton became authorized to take whatever measures he saw fit to contribute to regime change in Iraq. The Bush administration has also undergone major and significant shifts in US strategy on US foreign policy. During the Bush admin
... Show MoreThe research aims to determine the mix of production optimization in the case of several conflicting objectives to be achieved at the same time, therefore, discussions dealt with the concept of programming goals and entrances to be resolved and dealt with the general formula for the programming model the goals and finally determine the mix of production optimization using a programming model targets to the default case.
Background:
Turkish policy towards Africa witnessed important developments over time that began before the Ottoman era and then developed during the Ottoman era when the Ottoman state played an important role in maintaining security by confronting Portuguese interventions in North Africa and sending military aid. Thus, the Ottoman state was able to develop its policy towards Africa for important considerations based mainly on the employment of the religious factor and the spread of Islam for the African acceptance of the Ottomans in the African territories and thus, achieve economic, strategic and political motives. Later, these relations declined in the Republican era due to the weak political and economic potential of Turkey on the one hand and th
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