To decrease the impact on the environment of building waste, the recycled aggregate may be used in various sustainable engineering applications, such as roller compacted concrete pavement (RCCP). This research examined how using recycled aggregate as a partial replacement for natural aggregate as coarse or fine affected the mechanical properties of roller-compacted concrete pavement. The recycled aggregate was crushed and sieved to coarse and fine aggregate before being used in the roller-compacted concrete pavement. Compressive strength, splitting tensile strength, and flexural strength were all evaluated after the samples were prepared at 28 and 90 days of curing. According to the study's findings, the partial replacement of coarse or fine aggregate with recycled aggregate by (10, 15 and 20%) by volume resulted in decreasing the mechanical properties and increasing the absorption and porosity of RCCP due to the contaminated cement paste on the surface of RCA when compared to the reference mix made with natural aggregate. Because the recycled aggregate contains un-hydrated cement particles, the results have improved after 90 days.
Research on the role of organizational change in easing the organizational conflict focuses for being one of the important topics and relatively modern and which have a significant impact on the future of organizations, so this study was to identify the relationship and the impact of organizational change and of deportation (technological, organizational structure, human resources, the change in the task) at the organizational conflict in the Earth company link Iraq, in order to reach the goals of the research, it has been the development of a questionnaire distributed to a random sample of (100) composed employees from managers and heads of departments and the people and staff at the Earth company link Iraq, the study found: the
... Show MoreThe problem of job burnout has become one of the main problems for researchers in social welfare organizations (social protection bodies) - one of the formations of the Ministry of Labor and Social Affairs. Its negative effects increased in light of the COVID-19 pandemic, and in light of the Corona pandemic, the pressures and burdens of workers varied, which resulted in high rates of anxiety, tension, and intellectual and physical exhaustion, and then negatively affected their efficiency in performing work at the individual and organizational level, especially after the increasing tasks of these Bodies in carrying out their role in achieving the general goals and objectives as beingThe general goals are that they are responsible for providi
... Show MoreIn this research work, synthesis, antimicrobial and antioxidant bioactivity of a chain of compounds having unsaturated ketones bond and isoxazoline moiety have been described. New chalcone derivatives containing isoxazoline moiety have been synthesized. Generally, Chalcones are unsaturated ketones bearing (-CO-CH=CH-) as reactive ketoethylenic group that give the bright yellow colored compounds due to this chromophore group. Firstly, chalcones (IIa-d) have been prepared by cyclocondensation (Claisen-Schmidt condensation) of triphenyl aminobenzaldehyde with different substituted acetophenone in ethyl alcohol to produce a series of chalcones compounds with bright yellow colored as a
... Show MoreABSTRACT: Polypyrrole and polypyrrole / silver nanocomposites were fabricated by in-situ polymerization employing Ammonium Persulphate as an oxidizing agent. Nanocomposites were synthesized by combining polypyrrole and silver nanoparticles in various weight percentages (0.1%, 0.5%, 3%, 5% and 7% wt.). Crystallographic data were collected using X-ray diffraction. PPy particles were found to have an orthorhombic symmetry. In contrast, PPy/Ag nanocomposites were reported to have monoclinic structure. The crystallite size was determined by XRD using Scherrer equation and considered to be within 49 nm range. DC conductivity of pelletized samples was evaluated in the temperature range of 323.15k to 453.15k. The conductivity displayed an
... Show MoreSixty four local isolated of Klebsiella spp. have been isolated from environment samples (soil and water). These isolates were identified and diagnosis according to phenotype and biochemical tests. These isolates were subjected to primary and secondary screening, to select the isolate with the highest laccase activity. Fifteen isolates chosen from primary screening for screening their enzyme activity in secondary screening. It has been found the Klebsiella(K7) has the highest productivity of the enzyme (12 Unit/ml).Klebsiella(K7) isolate was diagnosis by Vitak 2 system, it was identified asK. pneumonia. The laccase purified was characterization, the experiments showed that: The molecular weight of laccase was 120KD and the optimum pH for th
... Show MoreIn this research , design and study a (beam expander) for the Nd – YAG laser with (1.06 ?m) Wavelength has been studied at 5X zoom with narrow diversion in the room temperature. by using (ZEMAX) to study the system. Evaluate its performance via (ZEMAX) outputs, as bright Spot Diagram via (RMS), Ray Fan Plot, Geometric Encircled Energy and the value of Focal shift. Then study the effect of field of view on the outputs in the room temperature.
Cerium oxide CeO2, or ceria, has gained increasing interest owing to its excellent catalytic applications. Under the framework of density functional theory (DFT), this contribution demonstrates the effect that introducing the element nickel (Ni) into the ceria lattice has on its electronic, structural, and optical characteristics. Electronic density of states (DOSs) analysis shows that Ni integration leads to a shrinkage of Ce 4f states and improvement of Ni 3d states in the bottom of the conduction band. Furthermore, the calculated optical absorption spectra of an Ni-doped CeO2 system shifts towards longer visible light and infrared regions. Results indicate that Ni-doping a CeO2 system would result in a decrease of the band gap. Finally,
... Show MoreIn this study, aromatic polyamide reverse osmosis membranes were used to remove zinc ions from electroplating wastewater. Influence of different operating conditions such as time, zinc concentration and pressure on reverse osmosis process efficiency was studied. The experimental results showed, concentration of zinc in permeate increase with increases of time from 0 to 70 min, and flux of water through membrane decline with time. While, the concentrations of zinc in permeate increase with the increase in feed zinc concentration (10–300 mg/l), flux decrease with the increment of feed concentration. The raise of pressure from 1 to 4 bar, the zinc concentration decreases and the flux increase. The highest recovery percentage was found is 54.
... Show MoreThis research included the preparation of 2-mercaptobenzoxazole (N1) by the reaction of ortho-aminophenol with carbon disulfide in an alcoholic potassium hydroxide solution. The 2-mercapto benzoxazole (N1) was then treated with hydrazine to obtain the 2-hydrazino benzoxazole (N2). A number of hydrazones (N3-N5) were prepared through the reaction of N2 with different benzaldehydes. The compound (N6) was also prepared whereby the ring closing of hydrazone (N3) using chloroacetylchloride, while the compound (N7) was prepared by treating 2-hydrazino benzoxazole with acetylacetone. When the compound (N1) was treated with formaldehyde, it afforded the compound (N8). Also, the N9 was obtained from the reaction of N1 with chloroacetic acid in th
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