Failure 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 resulted in an increase in the complex shear modulus, rutting resistance and rotation viscosity of the asphalt cement. The addition of more asphaltene content and Gastel index resulted in a decrease in penetration and ductility values. This observation also revealed that asphalt cement with higher asphaltene content had higher stiffness. The findings from this study can assist in the understanding of the behavior of asphalt cements in its original state and improve the performance of asphalt cement for pavement applications.
ABSTRACT Background: One of the major problems of all ceramic restorations is their probable fracture against the occlusal forces. The objective of this in vitro study was to evaluate the effect of two gingival finishing lines (90°shoulder and deep chamfer) on the fracture resistance of full contour CAD/CAM and heat press all-ceramic crowns. Materials and Methods: Thirty two maxillary first premolars were prepared to receive full contour CAD/CAM (zolid) and heat press (Cergo Kiss) ceramic crowns using a special paralleling device (Parallel-A-Prep). The teeth were divided into four groups according to the type of finishing line prepared. Each crown was cemented to its corresponding tooth using self-etch, self-adhesive dual cure resin ceme
... Show MoreRare earth elements (Cerium, Lanthanum and Neodymium) doped CdS thin films are prepared using the chemical Spray Pyrolysis Method with temperature 200 oC. The X-ray diffraction (XRD) analysis refers that pure CdS and CdS:Ce, CdS:La and CdS:Nd thin films showed the hexagonal crystalline phase. The crystallite size determined by the Debye-Scherrer equation and the range was (35.8– 23.76 nm), and it was confirmed by field emission scanning electron microscopy (FE-SEM). The pure and doped CdS shows a direct band gap (2.57 to 2.72 eV), which was obtained by transmittance. The room-temperature photoluminescence of pure and doped CdS shows large peak at 431 nm, and two small peaks at (530 and 610 nm). The Current – voltage measurement in da
... Show MoreThis work reports the study of heat treatment effect on the structural, morphological, optical and electrical properties of poly [3-hexylthiophene] and its blend with [6,6]-phenyl C61 butyric acid methyl ester ( P3HT:PC61BM). X-ray diffraction (XRD) measurements show that the crystallinity of the films increased with annealing. The evaluation of surface roughness and morphology was investigated using atomic force microscope (AFM), and field emission scanning microscope(FESEM). The optical properties were emphasized a strong optical absorption of P3HT compared with the blend. Hall effect measurement was used to study the electrical properties which revealed there is an increase in the electrical conductivity and Hall mobility of th
... Show MoreMicrofinance Institutions (MFIs) offers small loans with easy repayment system and till now these institutions have served millions of needy people around the globe. This study highlights the hurdles influence the smooth working and growth of Microfinance institution in Egypt. The structured interviews were conducted from the top and mid-level managers of MFI's. This study revealed that interest rate, political and economic conditions, corruption, customer outreach, competition and technology are the important elements for MFI's success. It is evident that lack of use of technology and less importance drawn on customer outreach programs are the main challenges of MFI's in Egypt. This study provides a roadmap for practitioners and strategic
... Show MoreThis research aims to study the contribution of social costs contribution to achieving social luxury in Al-Furat General Chemical Industries company that has considered second largest contamination in the area after the invasive power to deal with chemicals in manufacturing and very dangerous to individual society and environment ,this is first to play an effective role by the senior parties related to sense of social responsibility of the internal and external environment of the company to identify costs that are preventing ,reduced and treating damage caused and achieving sustainable development ,to achieve this goal and what they reached are the difficulty of accounting for the environment and social costs from final accou
... Show MoreAssessment of the in service behavior of asphalt stabilized subgrade soil under environmental impact has got little attention by the research workers. However, the sustainability of the roadway depends mainly on the welfare of its subgrade soil condition. In this work, Gypseous soil was stabilized with asphalt emulsion for subgrade usage, the durability of the mixture has been assessed in term of its ability to maintain the compressive strength when practicing the environmental impacts. Specimens of 38 mm in diameter , and 76 mm in height have been prepared with various water-asphalt percentages, and subjected to 30 cycles of (freezing-thawing), (heating-cooling) and (wetting-drying) processes. Specimens have been tested for unconfined comp
... Show MoreThe polyaniline powder was chemically manufactured by direct oxidation of aniline. The resulting polymer was characterized by the results of optical, measurements by (FT-IR) spectroscopy, we have detected some of the absorption peaks located at 3498, 2858 cm-1, which correspond N-H vibrations, and C-H expansion of the aromatic ring respectively as well as stretching vibrations of quinoid ring have been observed. Structural properties, such as the surface topography using an atomic force microscope (AFM), and Surface composition by (SEM) have been studied. The structure of some pellets of polyaniline powder have been examined by using analytical X-ray diffraction technique, the pattern of obse
... Show MoreThe impact of a Schiff base namely 2-((thiophen-2-ylmethylene)amino)benzenethiol to corrode mild steel in 1 M HCl resolved was evaluated using different weight loss technique and scanning electron microscopy (SEM).different weight measurements to expand that the 2-((thiophen-2-ylmethylene) amino) benzenethiol inhibits the corrosion of mild steel through adsorbing of top for mild steel and block the active locality. The inhibitive impacts of 2-((thiophen-2-ylmethylene)amino)benzenethiol increase with increasing concentration and decrease with increasing temperature. SEM to checking revealed that the alloy surface was quite unaffected and formed protective film on its surface. The investigated
... Show MoreStable isotope (?18O, ?D) values were determined along with the chemical compositions at 10 different locations along the Tigris river between Baghdad-Ammara cities of Iraq. The physico-chemical parameters and isotopic data were measured. The sampling site represents 34 % of total Tigris river in the republic of Iraq. The systematically increased in values of stable isotope as move from the downstream of the river and the most significantly appears at Kut lake. This increase occurs as a result of several factors, viz. (a) evaporation occurs low water level in the river and its tributaries, and (b) return flow water to the river from irrigation water in groundwater systems. The change in ion distribution and in the isotopic values related di
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