The investigation of the effect of tempering on thermal analysis of
Al-Ti-Si alloy and its composites with MgO and SiC particles was
performed. Thermal analysis was performed before and after
tempering by DSC scan. Optical microscopy was used to identify the
phases and precipitations that may be formed in base alloy and
composites. X-ray diffraction test indicated that the Al3Ti is the main
phase in Al-Ti-Si alloy in addition to form Al5Ti7Si12 phase. Some
chemical reactions can be occurred between reinforcements and
matrix such as MgO.Al2O3 in Al-Ti/MgO, and Al4C3 and Al(OH)3 in
Al-Ti/SiC composite. X-ray florescence technique is used to
investigate the chemical composition of the fabricated specimens.
Heat treatment (Tempering) changes the microstructure of base alloy
and its composites which was assessed by DSC scan. Generally,
three main peaks appeared in DSC represented by GP zone, S phase
(precipitations) and dissolution of phases or precipitations. After
tempering, composite with SiC particles showed better results than
base alloy and composite with MgO. Since the optical microscopy
revealed reforming the stable phase Al3Ti with evaporation some
gases from composite. DSC analysis showed the stability of
composite with SiC was up to 270oC.
The financial analysis of the published financial statements is the means that enables businessmen, financial institutions, financial analysts and others to conduct their studies and conclusions to obtain information that helps them in the decision-making process, including decisions related to investment. National in making the decision on the investment activity, for the period from 2012 to 2018, through the information provided by the annual financial statements, by selecting a set of indicators provided by the financial statements, namely (liquidity ratio, activity percentage, profitability ratios) to measure the extent of this ability Indicators in determining their role in making an investment decision.
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
... Show MoreIn this work polymeric composites were done from unsaturated polyester as a matrix reinforced with glass fiber type (E-glass) with two different volume fraction 20% & 40%. Fatigue tests showed that the number of fatigue cycles to failure limit for samples reinforced with uniform (woven Roving 0-90°) E-glass fiber and random (continuous fibers) with volume fraction 40% more than that for the same samples with volume fraction 20%. Also the fatigue results showed that the uniform samples failed with fatigue cycles more than that of random.
In this study , Iraqi Bentonite clay was used as a filler for polyvinyl chloride polymer. Bentonite clay was prepared as a powder for some certain particle size ,followed by calcinations process at (300,700,900) OC ,then milled and sieved. The selected sizes were D ~75 µm and D ~150. After that polyvinyl Al-Cohool solution prepared and used as a coated layer covered the Bentonite powder before applied as a filler ,followed by drying , milling and sieving for limited recommend sizes. polyvinyl chloride solutions were prepared and adding of modified Bentonite power at certain quantities were followed .Sheet of these variables on the mechanical and thermal properties of the prepared reinforced particular polyvinyl chloride composite
... Show MoreAcrylic polymer/cement nanocomposites in dark and light colors have been developed for coating floors and swimming pools. This work aims to emphasize the effect of cement filling on the mechanical parameters, thermal stability, and wettability of acrylic polymer. The preparation was carried out using the casting method from acrylic polymer coating solution, which was added to cement nanoparticles (65 nm) with weight concentrations of (0, 1, 2, 4, and 8 wt%) to achieve high-quality specifications and good adhesion. Maximum impact strength and Hardness shore A were observed at cement ratios of 2 wt% and 4 wt%, respectively. Changing the filling ratio has a significant effect on the strain of the nanocomposites. The contact angle was i
... Show MoreParonomasia is a recognized rhetorical device by which poets could play with words that are similar or identical in form but different in meaning. The present study aims to identify paronomasia in Arabic and English. To achieve the aim of the study, a corpus of selected verses chosen from two famous figures in Arabic and English literatures and analyzed thoroughly. The analysis of data under investigation reveals that paronomasia is a crucial aid used by poets to portrait the real world as imaginative. It further shows that the concept of paronomasia in English is not the same as in Arabic. In English, there are echoes of the Arabic jinās, i.e., there are counterpart usages of similar devices, yet English rhetoricians have not defined or c
... Show MoreHistoric centers are often subject to urban renewal without the prior knowledge of the extent of the cohesion and attachment to place of its inhabitants. Identifying the rates of cohesion and place attachment can help urban designers to avoid decisions that lead to clashes with the reality of the social groups inhabiting the neighborhoods of the historic center. So the research aimed to measure cohesion and place attachment in a methodological approach based on a psychological instrument conducted by previous studies .The measurements were applied through a questionnaire given to the residents of six elected neighborhoods forming the historic center of Al- Adhamiya.The research assumed the relative disparity rates of cohesion and place atta
... Show MoreThis research deals with the perceived and the imagined in the texts of Yusef Al-Sayegh, considering language as the most important source in literature and theatrical criticism, and given the importance of the subject, the researcher monitored many philosophical and psychological opinions and theories related to (the perceived and the imagined), and they were discussed and their compatibility with the Iraqi theatrical t As for the second chapter, where (the theoretical framework), it included two topics, and the first topic was about the concept of the perceived and the imagined, and the second topic was about Youssef Al-Sayegh and the structure of the theatrical text.
In the third chapter, where (research procedures), the research