237 research outputs found

    Mechanical Properties of HPC Incorporating Fly Ash and Ground Granulated Blast Furnace Slag After Exposure to High Temperatures

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    The behavior of concrete structures after being exposed to elevated temperatures is considered one of the great vital concerns in Civil Engineering. Moreover, as elevated temperature have adverse effects on the mechanical properties of concrete members, itā€™s important to find solutions to improve these properties at elevated temperature. This study aims to investigate the effect of supplementary cementitious materials (SCM) on the high performance concrete (HPC) compressive, tensile, and flexural strengths after exposure to different temperatures of 200 Ā°C, 400 Ā°C, 600 Ā°C, and 800 Ā°C. In preparing HPC, different parameters were considered including SCM type, fly ash (FA) or ground granulated blast furnace slag (GGBFS), adding 0.5% (by volume fraction) steel fiber (SF), polypropylene fiber (PP) and hybrid fibers. The results were compared with those for high strength concrete (HSC) and normal strength concrete (NSC). The results showed that using FA and GGBFS, SF, and hybrid fibers can significantly improve the residual mechanical properties of HPC, while using PP fiber has an adverse effect on the residual mechanical properties of HPC especially residual tensile and flexural strengths. The standard code curves underestimate the residual mechanical properties of HPC after 200 Ā°C

    Docking of COVID-19 main protease and TD-DFT/DMOl3 simulated method, synthesis, and characterization with hybrid nanocomposite thin films and its applications

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    Using the precipitation polymerization method copolymer poly methyl methacrylate co acrylonitrile was synthesized. Hybrid nanocomposite thin films [P(MMA-co-AN)/ZnO]HNC were prepared using the dip casting method by adding ZnO nanoparticles by the ratios 0.25, 0.20, 0.15, and 0.10 according to the weight of P(MMA-co-AN). Fourier Transform Infrared Spectroscopy (FTIR), UVā€“Vis optical properties, and laser photoluminescence PL characterization techniques were used to study [P(MMA-co-AN)/ZnO]HNC films. In addition, density functional theory (DFT), optimization via TD-DFTD/Mol3, and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP) were used to perform the geometrical study. FTIR spectra from [P(MMA-co-AN)/ZnO]HNC indicates the interaction between the copolymer and ZnO nanoparticles. In the wavelength range of 190 ā€“ 800 nm, the optical properties of [P(MMA-co-AN)/ZnO]HNC were considered. The direct energy band gap was found to be changed from 4.1 eV for P (MMA ā€“ co ā€“ AN) to 3.19 eV for 0.25 ZnO, while the concentration of 0.20 ZnO was the highest in the Urbach energy with 0.17 eV. The refractive index nĪ»=700 ranges from 1.48 to 1.81 for the concentration of 0.15 ZnO. Three emission peaks at 393 nm, 527 nm, and 775 nm were figured in the laser photoluminescence spectra of [P(MMA-co-AN)/ZnO]HNC films. In order to attain the restrained action of studied ligands (hybrid nanocomposite) novel coronavirus (COVID 19) main protest (6LU7) molecular docking studies were performed. The predicted energy gab by TD-DFT/DMOl3 was found to be agreed with the experimental data in a good manner. Ā© 2023 Elsevier B.V

    Pattern of cesarean deliveries among women in an urban and rural district in Egypt

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    Aim: to compare patterns of delivery at an urban and a rural district in Egypt over 3 years. Methods: This retrospective study included 500 women and 50 obstetricians from each district from January, 2013 till December, 2015. Women answered a questionnaire about their deliveries. Obstetricians answered a questionnaire about their practiceof CS. Results: CS rate in the rural district was 57.2% compared to 54.8% in the urban district in 2013. In 2014 and 2015, CS rates increased to 65.3% and 69%, respectively in the rural district compared to 56% and 57.7%, respectively in the urban district. 66% of obstetricians in the rural district performed CS for more than 50% of their patients compared to 76% of obstetricians in the urban district. 52% and 4% of obstetricians in the rural and urban districts, respectively, performed CS upon maternal request. 70.3% of women in the rural district who delivered by CS preferred to deliver vaginally. 51.4% of urban women who delivered by CS preferred to deliver vaginally. Level of education was the only factor showing statistical significance. Conclusion: CS rates increased over time with higher rates in the rural area. Level of women's education was the only factor affecting delivery choice. Keywords: Cesarean sections; CS rate; urban area; rural area; Egypt; obstetricians

    Ion Flotation of Copper(II) and Lead(II) from Environmental Water Samples

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    The present study aims to develop a simple, rapid and economic procedure for copper(II) and lead(II) removal under the optimum conditions investigated. It is based on the complex formation between Cu2+ and Pb2+ ions and diphenylcarbazone (HDPC) followed by flotation with oleic acid (HOL) surfactant. The different parameters (namely: solution pH, HDPC, HOL, copper and lead concentrations, ionic strength, temperature and the presence of foreign ions) influencing the flotation process were examined. Nearly, 100% of Cu2+ and Pb2+ ions were removed from aqueous solutions at pHs 6 and 7, respectively at room temperature (~25 \ub0C). The procedure was successfully applied to recover almost copper(II) and lead(II) spiked to some natural water samples. Due to the rapid, simple and economic nature of the procedure, a flotation mechanism is suggested for metal removal in wastewater systems

    Hepatoprotective and Antioxidant Activities of Tribulus Terrestris

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    Tribulus terrestris L. has been used in folk medicine throughout history. The present study examined the acute toxicity of the total ethanolic extract of T. Terrestris followed by investigation of the hepatoprotective activity of the total ethanolic extract and different fractions of the aerial parts of the plant compared to silymarin against carbon tetrachloride- induced hepatic damage in rats. In addition, in vivo antioxidant activity was examined and linked to the previous in vitro DPPH free radical scavenging activity investigation. This study established the plantā€™s safety and the hepatoprotective effect of the total ethanolic extract of the aerial parts of the plant and its different fractions due to significant decrease in CCl4- induced rise in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin in rats. Treatment with the ethyl acetate fraction significantly reduced oxidative stress in CCl4- intoxicated rats, as evident by a decrease inmalondialdehyde (MDA) content associated with elevation of hepatic reduced glutathione (GSH) content and superoxide dismutase (SOD) activity. Hence, this hepatoprotective effect could be due to the antioxidant activity of the plant which is mainly imparted by the two major di-p-coumaroylquinic acid derivatives isolated from the ethyl acetate fraction

    Epidemiological aspects of some equine viral diseases

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    Although different equine virusesā€™ outbreaks have been recorded. However, the most important ones in are the African horse sickness virus (AHSV), equine influenza virus (EIV), equine viral arteritis (EVA), Equine infectious anaemia virus (EIAV), and equine herpes viruses (EHV). To combat these diseases, it is imperative to understand their epidemiological aspects. So, the current review aims to highlight some epidemiological aspects including; causative agents, clinical forms, history, prevalence and geographical distribution, source of infection, and methods of transmission. The AHSV mainly causes pulmonary, and cardiac forms with high morbidity and mortality rates in Africa. The EIV is found all over the world and results in respiratory signs. The EVA has low morbidity and mortality rates and is mainly found in the Americas and Europe, its significance is due to the reproductive problems as abortion in mares and subfertility in stallions. The EIAV has low morbidity and mortality rates and causes long time course disease mainly of fever, and chronic anaemia or death. The EHVs are the current most important pathogens due to their endemicity all over the world and their high morbidity. It causes respiratory, abortion, neonatal, and sometimes neurological manifestations. Aerosols and body excretions are the main sources of infection with EIV, EVA, and EHV. Venereal EVA transmission occurs through natural breeding or artificial insemination with the semen of infected or carrier stallions. The spreading of arboviruses is greatly affected by the vector activity like the AHSV which transmitted by the the Culicoide. imicola biting midges, and the EIAV by family Tabanidae. In general, it is recommended to take all epidemiological measures, including vaccinations and vector control, to limit the spread of such diseases and reduce economic losses

    Unlocking Tourismā€™s Potential: Pricing Strategies for the Post-COVID Renaissance

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    In response to the challenges faced by tourism managers in devising effective pricing strategies to overcome the impacts of the COVID-19 pandemic, this study aims to make a valuable contribution to the existing literature on tourism management and marketing. Specifically, we investigate the pricing strategies that tourists are most likely to prefer in the aftermath of the pandemic. To achieve this, we conducted semi-structured interviews with a sample size of experienced tourists in Egypt. Our findings reveal that tourists exhibit a strong inclination towards hedonic and bundling pricing strategies. This suggests that tourism managers should prioritize the incorporation of these strategies into their post-pandemic business plans. However, it is crucial for managers to carefully consider touristsā€™ behavioral responses to dynamic and pay-what-you-want pricing strategies, as these are influenced by various constraints that necessitate careful attention. Furthermore, our study highlights potential negative consequences associated with the implementation of the dual-pricing strategy following the pandemic. This strategy has the potential to compromise touristsā€™ intentions to utilize certain services, thereby leading to unfavorable behavioral outcomes for tourism destinations. The implications of this study are of practical significance for tourism managers seeking to design more effective pricing strategies to capitalize on the opportunities presented by the post-pandemic recovery period. By understanding touristsā€™ preferences and considering the potential drawbacks associated with certain pricing strategies, managers can make informed decisions that promote the sustainable and successful revival of the tourism industry. Moreover, our study employed the checkpoints method, which allowed us to identify respondentsā€™ priorities for the pricing strategies during the crisis, further enhancing the validity and reliability of our findings. Ā© 2023 by the authors.Deanship of Scientific Research, King Saud University; Kazan Federal University; King Faisal University, KFU: 3117, EGY-0026/20This study was conducted according to the guidelines of the Declaration of Helsinki and was approved by the Deanship of Scientific Research Ethical Committee (Grant No. 3117), King Faisal University.All authors thank the Deanship of Scientific Research, Vice Presidency for Graduate Studies and Scientific Research, King Faisal University, Saudi Arabia (Grant No. 3117), through its KFU Research Summer initiative. The researchers are supported by a full Ph.D. scholarship under the joint executive program between the Arab Republic of Egypt and Saint Petersburg State University for the second author (M.I.S), number EGY-0026/20 and Kazan Federal University for the third author (M.Y.H.), number Egy.6572/19

    Disease prevention not decolonization ā€“ a model for fecal microbiota transplantation in patients colonized with multidrug-resistant organisms

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    Fecal microbiota transplantation (FMT) yields variable intestinal decolonization results for multidrug-resistant organisms (MDROs). This study showed significant reductions in antibiotic duration, bacteremia and length of stay in 20 patients colonized/ infected with MDRO receiving FMT (compared to pre-FMT history, and a matched group not receiving FMT), despite modest decolonization rates
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