his study aimed to investigate the usability of Recycled Concrete Aggregate (RCA) in warm mix asphalt (WMA) as the implementation of sustainable construction technology. Five replacement rates (0%, 25%, 50%, 75%, and 100%) were tested for the coarse fraction of virgin aggregate (VA) with 3 types of RCA: untreated RCA, HL-treated RCA, and HCL-treated RCA. Scanning electron microscopy (SEM) analyses were performed to investigate the surface morphology for both treated and untreated RCA. The optimum asphalt cement content for every substitution rate was determined using Marshall mix design method. Thereafter, asphalt concrete specimens were prepared using the optimum asphalt cement content, followed by the evaluation of their performance properties, including the moisture damage, resilient modulus, and permanent deformation characteristics. These properties were assessed using indirect tensile strength and uniaxial repeated loading tests, respectively. It was found that, for mixes with RCA content of 100%, the untreated RCA mixes possess higher OAC than that of treated RCA mixes by 0.26%. The moisture susceptibility was improved in case of HL and HCL treated RCA by 9.09% and 10.34% as compared to untreated RCA. However, the resilient modulus and resistance to permanent deformation for the mixes with 100% RCA were lower than those prepared with VA; the decrement in Mr values are 39.17%, 28.56% and 23.09% for the untreated RCA, HL-treated RCA and HCL-treated RCA, respectively. Finally, the cost, material, and energy-saving implications of RCA were discussed.
The current investigation examines the combined impacts of ultrasonic radiation and hydrogen donors on the viscosity of heavy crude oil. The impact of exposure time, power, duty cycle, and temperature on the viscosity of Iraqi heavy crude oil with 20.32 API was studied. Also, the viscosity of the oil samples, which were mixed with a hydrogen donor (decalin) and subjected to ultrasonic treatment under optimal conditions, was examined to evaluate the combined impact of ultrasonic radiation and hydrogen donor on the viscosity of crude oil. The viscosity experienced a decrease of 52.34% at 2 min of irradiation, 360 W ultrasonic power, 0.8 duty cycle, 35 ⁰C, and 8vol% decalin. To validate the outcomes of the experiments, asphaltene content, s
... Show MoreIn this work, a convex lens concentrating solar collector is designed and manufactured locally by using 10 convex lenses (concentrator) of a diameter 10cm and one Copper absorber tube of a diameter 12.5mm and 1mm in thickness 1m length. Two axes manual Tracking system also constructed to track the sun continuously in two directions. The experiments are made on 17th of May 2015 in climatic conditions of Baghdad. The experimental data are fed to a computer program to solve the thermal performing equation, to find efficiency and actual useful energy. Then this data is used in numerical CFD software for three different absorber diameters (12.5 mm, 18.75 mm and 25 mm). From the results that obtained the maximum the
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The current research aims to know the reality of the research's coefficients, to know correlation and effectiveness between the organizational Agility and high performance . The current research has been applied on the official banks , including a sample of senior administration members (120) ; besides , the research has used questionnaire that being considered as the main tool for gathering information and data . It includes 59 questions in addition to the personal interviews program as to support the questionnaire and to fulfill a great deal of reality. It has been anal
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The current research aims to test the relationship of the impact of sustainable leadership as an independent variable in organizational happiness as a dependent variable, in the departments and divisions of the Tourism Authority, to come up with a set of recommendations that contribute to raising the level of organizational happiness in the authority. And based on the importance of the research topic in the General Authority, and the prominent role that this body plays in society, the researcher adopted the descriptive and analytical approach in carrying out this research, by collecting data from the departments and divisions staff of (160) respondents in an exclusively comprehensive
... Show MoreIn this study, the water treatment plants located on the Tigris River within Baghdad city were subjected to qualitative and quantitative assessments. Based on location, the plants from upstream to downstream are Al-Karkh, East Tigris, Al-Karamah, Al-Wathbah, Al-Wehdah, Al-Kadiseyah, Al-Dora, and Al-Rashid. Data from 2009 to 2020 on the turbidity, total dissolved solids, Alkalinity, hardness, chloride, calcium, and temperature were used in the qualitative assessment while data on the treated water production and population served were used in the quantitative assessment. The above Data was acquired from the Municipality of Baghdad. The turbidity was mainly used as a fair gauge to assess the performance of the water treatment plants in Baghda
... Show MoreThis research aims to investigate and evaluate a reactive powder concrete (RPC) cast using economical materials. Its mechanical properties were investigated and evaluated by studying the effects of using different cement and silica fume contents and locally steel fibers aspect ratios as reinforcement for this concrete. A compressive strength of about 155.2MPa, indirect tensile strength of 16.0MPa, modulus of elasticity of 48.7GPa, flexural strength of 43.5MPa, impact energy of 3294.4kN.m and abrasion loss 0.59% have been achieved for reinforced RPC contains 910 kg/m3 cement content, silica fume content 185 kg/m3 of cement weight and fiber volume fraction 2%. The water absorption values w
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