In this work, yttrium oxide particles (powder) reinforced AL-Si matrix composites (Y2O3/Al-Si) and Chromium oxide particles reinforced AL-Si matrix composites (Cr2O3/AL-Si) were prepared by direct squeeze casting. The volume percentages of yttrium oxide used are (4, 8.1, 12.1, 16.1 vol %) and the volume percentages of the chromium oxide particles used are (3.1, 6.3, 9.4, 12.5 vol. %). The parameters affecting the preparation of Y2O3/Al-Si and Cr2O3/AL-Si composites by direct squeeze casting process were studied. The molten Al-Si alloy with yttrium oxide particles or with chromium oxide particles was stirred again using an electrical stirrer at speed 500 rpm and the molten alloy was poured into the squeeze die cavity. The pouring temperature that used for all castings is (700)˚C. The required squeeze pressure, 53 MPa, was then applied for 30 seconds at a delay time of 5. The die temp is (200˚C). The Y2O3/Al-Si composites and Cr2O3/Al-Si composites produced by squeeze casting have more microstructure refinement, higher hardness and lower wear rate than the unreinforced alloy.
A developed model has been put for the hypothesis of capturing moons in explaining the origin of Jupiter moons, and study the change of the orbital properties of these satellites as well as the distance from the planet. Jupiter moons were divided into two types according to their physical and orbital properties, they are the moons , which are formed from the same material as the planet, so it was named the original moons ,while the moons that have been captured from the surrounding space was renamed exotic moons . And the moons of exotic origin asteroid belt and the Kuiper belt in the region which is behind Neptune, the origin of each clique of moons is an asteroid fragmented after colliding previously with another body and
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Tin Oxide (SnO2) films have been deposited by spray pyrolysis technique at different substrate temperatures. The effects of substrate temperature on the structural, optical and electrical properties of SnO2 films have been investigated. The XRD result shows a polycrystalline structure for SnO2 films at substrate temperature of 673K. The thickness of the deposited film was of the order of 200 nm measured by Toulansky method. The energy gap increases from 2.58eV to 3.59 eV when substrate temperature increases from 473K to 673K .Electrical conductivity is 4.8*10-7(.cm)-1 for sample deposited at 473K while it increases to 8.7*10-3 when the film is deposited at 673K
In the present work a modification was made on three equations to represent the
experiment data which results for Iraqi petroleum and natural asphalt. The equations
have been developed for estimating the chemical composition and physical properties
of asphalt cement at different temperature and aging time. The standard deviations of
all equations were calculated.
The modified correlation related to the aging time and temperature with penetration
index and durability index of aged petroleum and natural asphalts were developed.
The first equation represents the relationship between the durability index with aging
time and temperature.
loge(DI)=a1+0.0123(2loge T
... Show MoreBackground: The quality of drinking water is directly related to community health. Therefore, improving the quality of drinking reflects positively on the health situation in general. The studies that deal with the quality of drinking water in the city of Baghdad in terms of chemical or microbial content are very scanty. Objective: The current review highlights the most important studies and research articles that concern the quality of drinking water, both bottled water and tap water, in terms of chemical and biological contamination and chemophysical specifications for drinking water. Abstract: Studies have shown that drinking water in the city of Baghdad, especially tap water, contains certain levels of heavy metals,
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Two grades of paving asphalt with penetration of 46 and 65 are studied for determining changes in their physical and chemical properties caused by ageing.
The ageing process has been conducted on two petroleum paving asphalt cement using thin film oven test at 150, 163 and 175 C, and ageing time 5, 10,15, 20, 25 and 30 hours. The effect of ageing time and temperature on penetration, kinematic viscosity, softening point, solubility in trichloroethylene, heat loss and changes in chemical composition are investigated. The results of thin film oven test process indicte that the asphaltenes concentration of all aged asphalt increases with increasing ageing time, while the opposite was observed for polar-aromatic and naphthene-aromatic. The
Islamic manuscripts are considered an identity for the civilizational, cognitive and cultural development of nations and the Islamic world as a whole, and to identify this identity
Islamic manuscripts are considered an identity for the civilizational, cognitive and cultural development of nations and the Islamic world as a whole, and to identify this identity, the closing statement usually written at the end of the manuscript helps us with this, meaning that the closing entries serve as the identity document of the manuscript
The study involved 45 male and 45 females of diabetic patients type- ?? aged from 40-69years , and with the same numbers of males and females for control , all the patients and controls were without any periodontal diseases and without any systemic disease. Diabetic patients were divided in to three groups according to the degree of periodontitis , and the inflamed gingiva of all groups of diabetic patients were treated with the dried fruits powder (crude) of medicinal plants Quercus robur , Thuja occidenalis , Terminalia chebula, Anethum graveolens , respectively and mixture. Some immunological and antimicrobial factors (IgA, Lactoferrin , Lysozyme ) , were detected in serum and saliva of diabetic patients and the control
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