Stone Matrix Asphalt (SMA) is a gap-graded asphalt concrete hot blend combining high-quality coarse aggregate with a rich asphalt cement content. This blend generates a stable paving combination with a powerful stone-on-stone skeleton that offers excellent durability and routing strength. The objectives of this work are: Studying the durability performance of stone matrix asphalt (SMA) mixture in terms of moisture damage and temperature susceptibility and Discovering the effect of stabilized additive (Fly Ash ) on the performance of stone matrix asphalt (SMA) mixture. In this investigation, the durability of stone matrix asphalt concrete was assessed in terms of temperature susceptibility, resistance to moisture damage, and sensitivity to the variation in asphalt content. Specimens of 63.5 mm height and 102 mm diameter were compacted using the Marshall method at 150 °C. The optimum asphalt content was determined. Additional specimens were prepared with (0.5) percent below and above the OAC requirement. Specimens were subjected to indirect tensile strength (ITS) determination at (25 and 40) °C, and double punch shear strength determination. Another group of specimens was subjected to Marshall properties determination and to moisture damage. It was observed that stone matrix asphalt exhibit lower sensitivity to the change in asphalt content from the resistance to moisture damage and temperature susceptibility points of view. However, the tensile and shear properties exhibit significant sensitivity to the variation in asphalt content.
A nanocrystalline thin films of PbS with different thickness (400, 600)nm have been prepared successfully by chemical bath deposition technique on glass and Si substrates. The structure and morphology of these films were studied by X-ray diffraction and atomic force microscope. It shows that the structure is polycrystalline and the average crystallite size has been measured. The electrical properties of these films have been studied, it was observed that D.C conductivity at room temperature increases with the increase of thickness, From Hall measurements the conductivity for all samples of PbS films is p-type. Carrier's concentration, mobility and drift velocity increases with increasing of thickness. Also p-PbS/n-Si heterojunction has been
... Show MoreIn this study three inorganic nano additives, namely; CaCO3, Al2O3 and SiO2 were used to prepare nanocomposites of unsaturated polyester in order to modify their mechanical properties, i.e. tensile strength, elongation, impact and hardness. The results indicated that all the three additives were effective to improve the mechanical properties up to 4% by weight. The effectiveness of them follows the order : CaCO3 > Al2O3 > SiO2 This is due to their particle size in which CaCO3 (13nm), Al2O3 (20-30nm) and SiO2 (15-20nm).
ZnO nanostructures were synthesized by hydrothermal method at different temperatures and growth times. The effect of increasing the temperature on structural and optical properties of ZnO were analyzed and discussed. The prepared ZnO nanostructures were characterized by X-ray diffraction (XRD), UV–Vis. absorption spectroscopy (UV–Vis.), Photoluminescence (PL), and scanning electron microscopy (SEM). In this work, hexagonal crystal structure prepared ZnO nanostructures was observed using X-ray diffraction (XRD) and the average crystallite size equal 14.7 and 23.8 nm for samples synthesized at growth time 7 and 8 hours respectively. A nanotubes-shaped surface morphology was found using scanning electron microscopy (SEM). The optic
... Show MorePolyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI
The purpose of this research is to highlight the relationship between the administrative investigation and the improvement of institutional performance, and the research sought to achieve a set of cognitive and applied goals. the administrative investigation is the modern trend of managing the offices of the general hginspectors and the main source to build the necessary standards to manage and invest its resources efficiently and effectively required to achieve the goals it seeks. The institutional performance is the cornerstone for the implementation of all tasks and duties carried out by institutions operating within the borders of a particular country, The significant change
... Show MoreIntroduction/Aim. Seminal fluid analysis (SFA) plays a crucial role in helping infertility clinics diagnose the underlying reason of male infertility. The aim of the study was to investigate seminal fluid patterns of male partners of an infertile couple with apparently fertile female partners. Materials and methods. A cross-sectional study was conducted between January 2019 and December 2022. Patients were attending consultations for delayed conception for more than 12 months with apparently fertile female partner. Results. Four hundred fifty-three patients were included in the study. The distribution of patients according to age groups showed that 277 patients were young, aged 21 - 30 years (61%). Two hundred sixty-two (58%) patien
... Show MoreThe influence of sintering and annealing temperatures on the structural, surface morphology, and optical properties of Ag2Cu2O4 thin films which deposited on glass substrates by pulsed laser deposition method have been studied. Ag2Cu2O4 powders have polycrystalline structure, and the Ag2Cu2O4 phase was appear as low intensity peak at 35.57o which correspond the reflection from (110) plane. Scan electron microscopy images of Ag2Cu2O4 powder has been showed agglomerate of oxide particles with platelets shape. The structure of thin films has been improved with annealing temperature. Atomic Force micrographs of Ag2Cu2O4 films showed uniform, homogenous films and the shape of grains was almost spherical and larger grain size of 97.85 nm has o
... Show MoreThis work investigates the effect of the gas nitriding process on the surface layer microstructure and mechanical properties for steel 37, tool steel X155CrVMo12-1 and stainless steel 316L. Nitriding was conducted at a temperature of 550 °C for 2 hours during the first stage and at 750 °C for 4 hours during the second stage. SEM and X-ray diffraction tests were performed to evaluate the microstructural features and the major phases formed after surface treatment. SEM and X-ray diffraction tests were performed to assess the microstructural features and the primary phases formed after surface treatment. The new secondary precipitates were identified as γ′-Fe4N, ε (Fe2–3N), and α-Fe, exhibiting an uneven chain-like pattern wit
... Show MoreKnowing the distribution of the mechanical rock properties and the far field stresses for the field of interest is an important task for many applications concerning reservoir geomechanics, including wellbore instability analysis, hydraulic fracturing, sand production, reservoir compaction, and subsidence. A major challenge with determining the rock's mechanical properties is that they cannot be directly measured at the borehole. Furthermore, the recovered carbonate core samples for performing measurements are limited and they provide discrete data for specific depths.
The purpose of this study is to build 2D and 3D geomechanical models of the Khasib reservoir in the East Baghdad oil field/ Central area. TECHLOG.2015.3 softwa
... Show MoreInthis investigation the epoxy was reinforced by orange peel and carbonized orange peel particles with percentages (5%, 10%, 15% and 20% by weight).Mechanical tests like:Tensile, flexural,Hardness, impact and compression were carried out on these natural epoxy composites. The results showed the tensile strength have a higher value by adding (15% by weight )of orange peel and carbonized orange peel particles to epoxy,while the value (10% by weight ) of addition is suitable to get improvement in the other mechanical properties as flexural strength, Hardness, impact and compressive strength. The epoxy / carbonized orange peel powder have the best valuesin all mechanical properties than t