Reflective cracking is one of the primary forms of deterioration in pavements. It is widespread when Asphalt concrete (AC) overlays are built over a rigid pavement with discontinuities on its surface. Thus, this research work aims to reduce reflection cracks in asphalt concrete overlay on the rigid pavement. Asphalt Concrete (AC) slab specimens were prepared in three thicknesses (4, 5, and 6 cm). All these specimens were by testing machine designed and manufactured at the Engineering Consulting Office of the University of Baghdad to examine for the number of cycles and loads needed to propagate the reflection cracking in the asphalt concert mixture at three temperatures (20, 30, and 30°C). It was noticed that the higher thickness AC mixtures increased the reflection cracking performance life of the AC overlay. Also, it was found that the number of crack initiation and failure cycles increased as the temperature increased. In contrast, the increased temperature decreased the required load to crack initiation and failure load in the sample.
The purpose of this paper is to depict the effect of adding a hydraulic accumulator to a hydraulic system. The experimental work includes using measuring devices with interface to measure the pressure and the vibration of the system directly by computer so as to show the effect of accumulator graphically for real conditions, also the effects of hydraulic accumulator for different applications
have been tested. A simulation analysis of the hydraulic control system using MATLAB.R2010b to study was made to study the stability of the system depending on the transfer function, to estimate the effect of adding the accumulator on stability of the system. A physical simulation test was made for the hydraulic system using MATLAB to show the ef
Gypsum is one of the important construction materials in Iraq in plastering surfaces and gypsum board , the ability of gypsum to give a comfortable an aesthetic ambiance as a construction material increase the need of gypsum , The particle size , total surface area and particle size distribution were factors affecting plaster properties used for construction properties . In this study gypsum paste was used with different mixing ratios of particle size and studied the physical properties of these types of pastes named (standard consistency ,setting time ,density) and compressive strength . The results showed that the water to gypsum ratio increased with increasing the fineness of the gypsum to (0.75%) and the setting time to the maxi
... Show MoreInelastic transverse and longitudinal form factors of same parity have
been studied for B 10 nucleus in the frame work of the shell model for
many particles, by using He 4 as an inert core and the remaining
particles were distributed in 3 / 2 1 / 2 1p ,1p which form the model
space. The calculations of the present work based on the harmonic
oscillator potential with fixed size parameter (b). Here we use the
first order correction for the perturbation theory and the interaction
from Cohen-Kurath (CK). Adding the core-polarization effects to
form factors calculations gave a good agreement with the
experimental data. Calculations have been performed for the
transverse excited states of: (1 ,0 )at ( E 0.178M
An experimental and computational study is conducted to analyze the thermal performance of heat sinks and to pick up more profound information in this imperative field in the electronic cooling. One important approach to improve the heat transfer on the air-side of the heat exchanger is to adjust the fin geometry. Experiments are conducted to explore the impact of the changing of diverse operational and geometrical parameters on the heat sink thermal
performance. The working fluid used is air. Operational parameters includes: air Reynolds number (from 23597 to 3848.9) and heat flux (from 3954 to 38357 W/m
2 ). Conformational parameters includes: change the direction of air flow and the area of conduct
BixSb2-xTe3 alloys with different ratios of Bi (x=0, 0.1, 0.3, 0.5, and 2) have been prepared, Thin films of these alloys were prepared using thermal evaporation method under vacuum of 10-5 Torr on glass substrates at room temperature with different deposition rate (0.16, 0.5, 0.83) nm/sec for thickness (100, 300, 500) respectively. The X–ray diffraction measurements for BixSb2-xTe3 bulk and thin films indicate the polycrystalline structure with a strong intensity of peak of plane (015) preferred orientation with additional peaks, (0015) and (1010 ) reflections planes, which is meaning that all films present a very good texture along the (015) plane axis at different intensities for each thin film for different thickness. AFM measureme
... Show MoreAtotal of 75 different clinical samples were collected from different hospitals in Baghdad Biochemical and morphological characterization tests showed that forty isolates were identified as Staphylococcus aureus Antibiotic susceptibility tests of all isolates towards ten antibiotics were carried out and results showed that many isolates (97.5 %) were resistant to ?-lactam antibiotic , 70 % were resistant to Tetracyclinee , 62.5% were resistant to co-trimoxazole , 60 % were resistant to ciprofloxacin , 55% were resistant both of chloramphenicol and erythromycin , 52.5% were resistant to gentamicin , 35% were resistant to rifampicin , 10% were resistant to vancomycin . According to the above results the S.aureus I1 which is isolated
... Show MoreThe effect of internal acoustic excitation on the leading-edge, separated boundary layers and the aerodynamic performance of NACA23015 cross section airfoil are examined as a function of excitation location with ranging frequency range (50-400) Hz of the introduced acoustic. Tests are separately conducted in two sections, open type wind tunnels at the Reynolds number of 3.3x105 for measurement at angle of attack (0, 3, 6, 9 &12) deg. and 3x104 for the visualization at angle of attack (12) deg. based on the airfoil chord. Results indicated that the excitation frequency and the excitation location are the key parameters to alter the flow properties and thus to improve the aerodynamic performance. The most effective excitation frequency
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The current study aims to determine the extent of SOMO's interest in strategic alignment operations and whether this interest is sufficient to be reflected in enhancing its organizational reputation. The field of research was in the oil marketing company SOMO. The managers in the top management within this company were targeted and the questionnaire was used as a data collection tool. The study population (109), (105) questionnaires were distributed, (94) questionnaires and (11) questionnaires were not retrieved, and the valid questionnaires had reached (91) and the analytical and descriptive approach was used for the study, the current research found to find A direct relationship and a positive effect of strategic
... Show MoreThe products of composites material are very sesetive to many variables, such as manufacturing process, additive materials, …. etc. Filler or additive plays a major role to determine the formation of the properties and behavior of the composites. In this study, polyethylene terephthalate-based compounds were produced and characterized. The work is concerned to prepare samples of Polyethylene terephthalate (PET) - zinc-ferrite (ZnFe2O4) with different addition ratio as zinc-ferrite (1, 2, 5, 10, 15 and 20) wt% obtained from mixing the solution with a hot pressing method applied under optimum conditions. The densities of the composites for all samples were calculated. Through the work the diffusion of zinc-ferrite i
... Show MoreThe general assumption of linear variation of earth pressures with depth on retaining structures is still controversial; investigations are yet required to determine those distributions of the passive earth pressure (PEP) accurately and deduce the corresponding centroid location. In particular, for rigid retaining walls, the calculation of PEP is strongly dependent on the type of wall movement. This paper presents a numerical analysis for studying the influence of wall movement on the PEP distribution on a rigid retaining wall and the passive earth thrust location. The numerical predictions are remarkably similar to existing experimental works as recorded on scaled test models and ful