Permanent deformation (Rutting) of asphalt pavements which appears in many roads in Iraq, have caused a major impact on pavement performance by reducing the useful service life of pavement and creating services hazards for highway users. The main objective of this research is investigating the effect of some contributory factors related to permanent deformation of asphalt concrete mixture. To meet the objectives of this research, available local materials are used including asphalt binder, aggregates, mineral filler and modified asphalt binder. The Superpave mix design system was adopted with varying volumetric compositions. The Superpave Gyratory Compactor was used to compact 24 asphalt concrete cylindrical specimens. To collect the required data and investigate the development of permanent deformation in asphalt concrete under repeated loadings, Wheel-Tracking apparatus has been used in a factorial testing program during which 44 slab samples; with dimensions of 400×300×50 mm; were tested to simulate . actual pavement. Based on wheel-tracking test results, it has been concluded that increasing the compaction temperature from 110 to 150ºC caused a decreasing in permanent deformation by 20.5 and 15.6 percent for coarse and fine gradation control asphalt mixtures respectively. While the permanent deformation decreased about 21.3 percent when the compaction temperature is increased from 110 to 150ºC for coarse gradation asphalt mixtures modified with styrene butadiene styrene SBS with 3 percent by asphalt binder weight.
The aim of this study is to assess the influence of some risks factors on the fistula development after palatoplasty to improve the outcome of the patients
A total of 48 patients (the males were 22, The females were 26) were included in this study. All the patients were examined weekly for the first month postoperatively to assess any breakdown in the wound by inspection and by asking the parents for any nasal regurgitation during fluids feeding.
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In this study, Al2O3 thin films were prepared by dc reactive sputtering technique using different gas mixtures of argon and oxygen gases (90:10, 70:30, 50:50, 30:70, and 10:90). These films were characterized to introduce their surface morphology and elemental composition as functions of the oxygen content in the gas mixture. The gas mixing ratio plays a crucial role in controlling the nanoscale morphology of the prepared thin films. The [Al]/[O] ratio varies non-linearly with the Ar:O2 mixing ratio. Increasing the oxygen content leads to a progressive decrease in surface roughness, resulting in smoother and more uniform films with finer granular features. These results presented herein are useful to optimize the sputtering process to ac
... Show MoreA total of 150 deep eutectic solvents (DESs) with varying salt, hydrogen bond donor, and molar ratios were studied to develop a screening tool for separating toluene-heptane mixtures. The activity coefficient at infinite dilution (γ∞) of each DES was predicted using COSMO-RS, and selectivity (S∞), capacity (C∞), and performance index (PI) were calculated. Key DES properties, including density, viscosity, melting/freezing point, surface tension, and conductivity, were compiled from the literature to create a DES property library. A comprehensive screening tool with four evaluation criteria was developed, which identified ethyl triphenylphosphonium bromide:ZnCl2 (1:4) as the optimal solvent for toluene-heptane separation. Tetrabutyl- b
... Show MoreFailure in asphalt mixture and distress in pavement are major issues to roads infrastructure. Selecting an appropriate chemical composition of asphalt cement is a key component in avoiding these issues. This work aimed to investigate the effect of the chemical composition of different polar fractions on the rheological and physical properties of asphalt cement. Four types of asphalt cement with penetration grades of 20/30, 40/50, 60/70 and 85/100 were divided into four fractions. Complex shear modules, rutting resistance and rotational viscosity of the asphalt cement were determined by using a Dynamic Shear Rheometer and a Rotation Viscometer, respectively. The results show that an increase in the asphaltene content and Gastel index resulte
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Thermal conductivity of compacted bentonite is one of the most important properties where this type of clay is proposed for use as a buffer material. In this study, Lee's disc method was used to measure the thermal conductivity of compacted bentonite specimens. The experimental results have been analyzed to observe the three major factors affecting the thermal conductivity of bentonite buffer material. While the clay density reaches to a target value, the measurement is taken to evaluate the thermal conductivity. By repeating this procedure, a relationship between clay dry density and thermal conductivity has been established in specimens after adjusting the water contents of the bentonite by placing its specimens in a drying oven for diffe
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As the major role of oil sector in financing and development of Iraqi economy this study tried to research on the factors which influencing the future of oil production in Iraq and for that study addressed the hypothesis (the production and export of crude oil in Iraq , influenced by many factors divided into internal and external factors this factors shared the effect varies in the size of their participation and runs from different sectors economic , political and social , in order to test the study hypothesis study addressed the subject of three axes(an overview of the history and facts of crude oil production in Iraq and factors internal Affecting the future of oil production in Iraq and external factors affecting the future
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