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Search Results: 1 - 10 of 471791 matches for " Mahmoud A. El-Rais "
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Removal of Aniline Blue from Aqueous Solutions Using Ce1-xBixCrO3 (x = 0, 0.5, 1)  [PDF]
Labib A. Awin, Mahmoud A. El-Rais, Abdunnaser M. Etorki, Najat A. Mohamed, Wesal A. Makhlof
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2018, DOI: 10.4236/ojinm.2018.81001
Abstract: The removal of aniline blue dye from aqueous solutions using the A-site doped perovskite Ce1-xBixCrO3 (x = 0, 0.5, 1) was investigated. The perovskite oxides were synthesised using Sol-Gel method and characterised by conventional powder X-ray diffraction technique. The X-ray diffraction measurements suggested that doping with Bismuth Ion influences both the crystal structure and the particle size of the oxides, and consequently affects the adsorption properties. It was found that both CeCrO3 and Ce0.5Bi0.5CrO3 compounds are orthorhombic and have approximate particle size of 87 and 36 nm respectively, whereas BiCrO3 oxide has rhombohedral space group symmetry and the particle sizes are less than 49 nm. The batch mode study demonstrated that the removal capacities of Aniline Blue at 150 min and pH = 4.3 for Ce0.5Bi0.5CrO3, CeCrO3 and BiCrO3 are 779.67, 705.45 and 440.18 mg/g respectively. The results reflect the influence of the A site doping on the adsorption properties of the oxides. The removal of Aniline Blue was found to be negatively correlated with temperature and pH.
Removal of Some Heavy Metals from Wastewater by Using of Fava Beans  [PDF]
Abdunnaser Mohamed Etorki, Mahmoud El-Rais, Mohamed Tahher Mahabbis, Nayef Mohamed Moussa
American Journal of Analytical Chemistry (AJAC) , 2014, DOI: 10.4236/ajac.2014.54028
Abstract: The Fava Beans were used in this work as low cost adsorbent material for removal of Pb(II), Cd(II) and Zn(II) ions from aqueous solutions. The samples were prepared without farther treatment and sorted according to the particles diameter by standard sieves 250 - 500 μm. Batch adsorption experiments were carried out to study the adsorption process, several parameters such as Initial pH of adsorbent, effect of contact time, effect of adsorbent amount and effect of metal concentration were conducted in these experiments. The effects of any one of those previously mentioned parameters on the adsorption capacity were studied while the other parameters were kept constant. It was found that the obtained maximum adsorption capacities of Fave beans for the removal of selected heavy metals were very high. This provide us to use Fava beans as a low coast adsorbent material to clean up the water in the environment from toxic heavy metals such as Pb(II), Cd(II) and Zn(II) ions.
POPQ system and dynamic MRI in assessment of female genital prolapse  [PDF]
Mohamed N. El-Gharib, Manal A. Farahat, Mahmoud Daoud
Open Journal of Obstetrics and Gynecology (OJOG) , 2013, DOI: 10.4236/ojog.2013.32045
Abstract:

Aim: To assess the role of Magnetic resonance imaging (MRI) and pelvic organ prolapse quantification (POPQ) system in the evaluation of female pelvic organ prolapse. Design: Prospective study. Setting: TantaUniversityHospital. Patients: The study was carried out on 60 patients having clinical manifestations suggesting pelvic floor weakness. Intervention: All the patients were subjected to history taking, physical examination including POPQ, and pelvic MRI (static and dynamic) examination. Outcome measures: Quantitative measurements of genital prolapse. Results: All patients showed loss of the normal position of the perineal plate indicating generalized weakness of the whole pelvic floor muscles. Dynamic MRI exhibited pelvic floor abnormalities in 46 patients who did not show any abnormalities on the static images. Conclusion: Dynamic MRI is a helpful tool in defining the nature and quantitative measurements of pelvic organ prolapse. Also, MRI has and advantage over POPQ system in diagnosing lateral prolapse.

Assessment of Heavy Metal in Surface Sediments of Day River at Beni-Mellal Region, Morocco
A. Barakat,M. El Baghdadi,J. Rais,S. Nadem
Research Journal of Environmental and Earth Sciences , 2012,
Abstract: The Day River receives domestic and industrial untreated wastewaters from Beni-Mellal city and surrounding villages during the last decades. The present study was to obtain a preliminary assessment about the level and distribution of six heavy metals (Cd, Cr, Cu, Pb, Zn and Fe) in its surface sediment collected from 13 stations. The metal concentrations (in mg/kg) ranged: Cd, 0.6-6.27; Cr, 52.34-311.69; Cu, 32.69-740.75; Pb, 72.93- 140.36; Zn, 49.84-149.19; and Fe, 15670-36010. Significant spatial variation in concentrations was observed for all metals. Correlation analyses showed that metal content of sediment was controlled by organic matter and Fe contents. Pollution status was evaluated using the enrichment factor, geo-accumulation index and pollution load index and sediment quality guidelines. Based on geoaccumulation index and enrichment factors, Day sediment was treated as unpolluted to moderately polluted with Zn, Fe, Cr and Cu and moderate to considerable with Pb and Cd. Pollution load index and sediment quality guidelines showed that the metal levels exceed local and regional background concentrations, indicating contamination is high enough to be of risk to human health and ecosystem.
Isolation, Biochemical Characterization and DNA Identification of Yogurt Starters Streptococcus thermophilus & Lactobacillus delbrueckii ssp. bulgaricus in Gaza Strip  [PDF]
Kamal E. M. El Kahlout, Ismail M. El Quqa, Mahmoud W. El Hindi, Tarek A. El Bashiti
Advances in Microbiology (AiM) , 2018, DOI: 10.4236/aim.2018.812068
Abstract: Background: Milk is a healthy human nutrient, which is fermented to yogurt by lactic acid bacteria, mainly Streptococcus salivarius ssp, thermophilus and Lactobacillus. delbrueckii ssp. bulgaricus. This study aimed to isolate thermophilic starter bacteria from homemade yogurt made in Gaza Strip. The study sought to define both the biochemical and molecular characteristics of the isolated bacteria. Results: Three of the isolates were identified as Streptococcus thermophiles while two isolates were recognized as Lactobacillus delbrueckii ssp. bulgaricus. All five identified isolates showed worthy acidification capacity. Based on these characters, strains were applied for making yogurt either as single pure cultures or as mixed cultures. When using mixed cultures from S. thermophiles and L. bulgaricus, all tested combinations showed positive results. Conclusion: Isolated strains showed remarkable biotechnological characters. The isolates are expected to stimulate and improve quality of the yogurt when they are used as mixed starter cultures.
Modeling and Simulation for High Energy Sub-Nuclear Interactions Using Evolutionary Computation Technique  [PDF]
Mahmoud Y. El-Bakry, El-Sayed A. El-Dahshan, Amr Radi, Mohamed Tantawy, Moaaz A. Moussa
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.41009
Abstract: High energy sub-nuclear interactions are a good tool to dive deeply in the core of the particles to recognize their structures and the forces governed. The current article focuses on using one of the evolutionary computation techniques, the so-called genetic programming (GP), to model the hadron nucleus (h-A) interactions through discovering functions. In this article, GP is used to simulate the rapidity distribution \"\"?of total charged, positive and negative pions for p--Ar and p--Xe interactions at 200 GeV/c and charged particles for p-pb collision at 5.02 TeV. We have done so many runs to select the best runs of the GP program and finally obtained the rapidity distribution \"\"?as a function of the lab momentum \"\", mass number (A) and the number of particles per unit solid angle (Y). In all cases studied, we compared our seven discovered functions produced by GP technique with the corresponding experimental data and the excellent matching was so clear.
Synthesis of Novel Acid Dyes with Coumarin Moiety and Their Utilization for Dyeing Wool and Silk Fabrics  [PDF]
Mahmoud S. Bashandy, Fatma A. Mohamed, Mohamed M. El-Molla, Mahmoud B. Sheier, Ahmed H. Bedair
Open Journal of Medicinal Chemistry (OJMC) , 2016, DOI: 10.4236/ojmc.2016.61002
Abstract: This article describes the synthesis of some novel coumarin compounds to use as acid dyes by using compounds 1 - 4 as starting materials, which were prepared by interaction of 2-hydroxybenzaldehyde with ethyl 3-oxobutanoate, diethylmalonate, 4-nitrobenzenediazonium chloride and 4-sulfobenzenediazonium chloride, respectively. Compound 1 reacted with bromine and 2-cyanoacetohydrazide to give phenacyl bromide derivative 5 and 2-cyanoacetohydrazone derivative 6, respectively. Coupling of compound 6 with equimolar amount of 2-sulfo-4-((4-sulfophenyl) diazenyl)benzenediazonium chloride gave coumarin acid dye 8. Phenacyl bromide derivative 5 re-acted with potassium cyanide in refluxing ethanol to produce compound 7, which on coupling with equimolar amount of 8-hydroxy-6-sulfonaphthalene-2-diazonium chloride and 8-hydroxy-3,6-disulfonaphthalene-1-diazonium chloride gave coumarin acid dyes 9 and 10, respectively. Interaction of compound 2 with 2-amino-5-((4-sulfophenyl)diazenyl)benzenesulfonic acid, benzene-1,4-diamine and 3,3’-dimethoxy-[1,1’-biphenyl]-4,4’-diamine in refluxing ethanol afforded compounds 11, 12 and 14, respectively. Diazonium sulphate of compounds 12 and 14 coupling with 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid gave compounds 13 and 15, respectively. Cyclocondensation of compound 3 with ethyl 3-oxobutanoate, diethyl malonate and malononitrile afforded derivatives of 3-acetyl-2H-chromen-2-one 16, ethyl 2-oxo-2H-chromene-3-carboxylate 17 and 2-imino-2H-chromene-3-carbonitrile 18, respectively. Reaction of sodium benzenesulfonate derivative 4 with ethyl 3-oxobutanoate and hydrazine hydrate gave compounds 19 and 20, respectively. The structures of the newly synthesized compounds were confirmed by elemental analysis, UV/ VIS, IR, 1H NMR and Ms spectral data. The suitability of the prepared dyestuffs for dyeing of wool and silk fabrics has been investigated. The dyed fabric shows good light fastness, very good rubbing, perspiration, washing and excellent sublimation fastness. These dyes have been color shade from blue to violet with very good depth and levelness on fabrics. The dye bath exhaustion and fixation on fabric has been found to be very good.
Heat and Mass Transfer in MHD Visco-Elastic Fluid Flow through a Porous Medium over a Stretching Sheet with Chemical Reaction  [PDF]
Saleh M. Alharbi, Mohamed A. A. Bazid, Mahmoud S. El Gendy
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.16059
Abstract: This paper presents the study of convective heat and mass transfer characteristics of an incompressible MHD visco-elastic fluid flow immersed in a porous medium over a stretching sheet with chemical reaction and thermal stratification effects. The resultant governing boundary layer equations are highly non-linear and coupled form of partial differential equations, and they have been solved by using fourth order Runge-Kutta integration scheme with Newton Raphson shooting method. Numerical computations are carried out for the non-dimensional physical parameters. Here a numerical has been carried out to study the effect of different physical parameters such as visco-elasticity, permeability of the porous medium, magnetic field, Grashof number, Schmidt number, heat source parameter and chemical reaction parameter on the flow, heat and mass transfer characteristics.
Estimation of Generalized Pareto under an Adaptive Type-II Progressive Censoring  [PDF]
Mohamed A. W. Mahmoud, Ahmed A. Soliman, Ahmed H. Abd Ellah, Rashad M. El-Sagheer
Intelligent Information Management (IIM) , 2013, DOI: 10.4236/iim.2013.53008
Abstract:

In this paper, based on a new type of censoring scheme called an adaptive type-II progressive censoring scheme introduce by Ng et al. [1], Naval Research Logistics is considered. Based on this type of censoring the maximum likelihood estimation (MLE), Bayes estimation, and parametric bootstrap method are used for estimating the unknown parameters. Also, we propose to apply Markov chain Monte Carlo (MCMC) technique to carry out a Bayesian estimation procedure and in turn calculate the credible intervals. Point estimation and confidence intervals based on maximum likelihood and bootstrap method are also proposed. The approximate Bayes estimators obtained under the assumptions of non-informative priors, are compared with the maximum likelihood estimators. Numerical examples using real data set are presented to illustrate the methods of inference developed here. Finally, the maximum likelihood, bootstrap and the different Bayes estimates are compared via a Monte Carlo simulation study.

Dynamic Behaviour of Cast A356/Al2O3 Aluminum Metal Matrix Nanocomposites  [PDF]
E. Y. El-Kady, T. S. Mahmoud, A. A. El-Betar, M. Abdel-Aziz
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.311118
Abstract: The present work includes the study of the dynamic properties of the nanocomposites specimens. The dynamic properties of A356/Al2O3 nanocomposites were investigated through different fabrication conditions. The A356/Al2O3 nanocomposites specimens were fabricated using a combination between the rheocasting and squeeze casting routes. The composites were reinforced with Al2O3 particulates of 60 and 200 nm and different volume fractions up to 5 vol.%. The dynamic properties of the A356/Al2O3 nanocomposites were investigated through measuring the dynamic properties of specimens. Free vibration method is used to measure frequency response (fn ), and damping factor (ξ). The viscoelastic properties such as loss factor η, storage modulus (E'), and loss modulus (E\") were obtained. The results concluded that, the dynamic properties of nanocomposites were improved by increasing the volume fractions of nanoparticulates and decreasing the nanoparticulates size. The results indicated also that, the damping factor, and the related parameters (η, E' and E\") was strongly affected by increasing both volume fraction and the particulates.
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