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Non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid over a cylindrical disk

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Applied mathematics and mechanics(English Edition) 2020年第5期41卷 725-740页

作者： m.KHAN m.SARFRAZ J.ahmed L.AHmAD C.FETECAU Department of mathematics Quaid-i-Azam UniversityTaxila 47050Pakistan Department of Basic Sciences University of Engineering and TechnologySheringal Upper Dir 18000Pakistan Department of mathematics Shaheed Benazir Bhutto UniversitySheringal Upper Dir 18000Pakistan Academy of Romanian Scientists Bucuresti 050094Romania

The study of non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid along with magnetohydrodynamic(mHD) and non-linear Rosseland thermal radiation over a cylindrical disk in the existence of the time-independent free stream is considered. moreover, the notable impacts of thermophoresis and Brownian motion are analyzed by Buongiorno’s model. The momentum, energy, and concentration equations are converted into the dimensionless coupled ordinary differential equations via similarity transformations, which are later numerically solved by altering the values of the pertinent parameters. The numerical and asymptotic solutions for the large shear-to-strain rate ratio γ =a/bfor the parameters of the displacement thicknesses and the wall-shear stress are computed by perturbative expansion and analyzed. Furthermore, the technique bvp4c in mATLAB is deployed as an efficient method to analyze the calculations for the non-dimensional velocities, temperature, displacement thickness, and concentration profiles. It is observed that the two-dimensional displacement thickness parameters α andβ are reduced due to the viscoelasticity and magnetic field effects. moreover, when the shear-to-strain rate ratio approaches infinity, α is closer to its asymptotic value, while βand the three-dimensional displacement thickness parameter δ1 show the opposite *** outcomes of the viscoelasticity and the magnetic field on the skin friction are also determined. It is concluded that ■ reaches its asymptotic behavior when the shearto-strain rate ratio approaches infinity. meanwhile, ■ shows different results.

关键词： Walter’s B fluid cylindrical disk nanofluid magnetic field non-linear thermal radiation stagnation-point flow

Implications of Onshore Development on Global Software Engineering

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Computers, materials & Continua 2023年第2期74卷 3029-3044页

作者： Abdulrahman m.Qahtani ahmed S.Ghiduk College of Computers and Information Technology Taif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of mathematics and Computer Science Faculty of ScienceBeni-Suef UniversityBeni-Suef62521Egypt

Recently software industry has paid significant attention to customizing software products across distributed *** the requirements of multiple clients across distributed borders is a crucial challenge for the software customization *** decision-making and local development at the client site are considered methods for reducing difficulties in communicating the requirements of multiple clients across distributed *** paper introduces a new model called the onshore development model(ODm)for accomplishing the customization requests in the distributed development process of *** model presents a scenario for enhancing the onsite development of specific requirements to reduce delays andmisunderstandings between the clients and the team *** model depends on moving the development process to the client’s *** empirical studies were conducted to evaluate the proposed model to measure its productivity,time performance,and cost *** proposed model has been compared with two other models:the basic model(Bm),which allocates the decision-making process and the development process for teams at the vendor’s location,and the local decision-making model(LDec),which assigns the decision-making process for team at the client’s *** results of the empirical studies showed significant outperforming of the proposed model over the basic model and local decision-making model in productivity,time performance,and cost *** productivity of the proposed model improved by 39%and 10%more than the basic model and the local decision-making model,*** addition,the time performance of the proposed model became faster by 49%and 20.8%than the basic model and the local decision-making model,***,it reduced the total cost of the development process by 31%in terms of the salaries of all persons involved in requirements collecting,decision-making,and development.

关键词： Distributed development local development software customization

Experimental approaches and analytical technique for determining heavy metals in fallen dust at ferrosilicon production factory in Edfu, Aswan,Egypt

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 708-718页

作者： SOLTAN m.E RAGEH H.m RAGEH N.m ahmed m.E Department of Chemistry Faculty of Science at Aswan South Valley UniversityEgypt Department of Chemistry Faculty of Science at Qena South Valley UniversityEgyptDepartment of Chemistry Faculty of Science at Qena South Valley UniversityEgyptDepartment of Environment Egyptian Ferroalloy Edfu AswanEgypt

In this study aimed to evaluate the pollution extent of metals and nonmetals inside and outside the ferrosilicon production factory in Edfu, Aswan, Egypt, raw materials (quartz, cokes, iron oxides), ferrosilicon alloy, silica fume, dust and suspended dust (at different sites) samples were collected from the factory, and fallen dust samples were collected from outside the factory, horizontally (at different sites and different distance and directions) and vertically (at different floors in the selected buildings). Gravimetric methods, X-ray fluorescence (XRF), flame photometer, wide range carbon determinator and atomic absorption spectroscopy tools were used for elements determination. The results indicating that the fallen dust and its element contents on southern factory walls being higher than those on eastern factory walls may be due to the nature of the dusts and effects of wind force and wind direction. Fallen dust levels in different regions outside the factory were found to be affected by the distance, direction and floors. The nature of dust samples was affected by gravity and the suspended dust in different factory units depended on the work capacity and method of handling materials by personnel in different production units. Silica fume was a complicated problem, had dangerous effect against the workers' health, and was characterized by high concentrations of SiO2(90.6%～93.6%) and heavy metals (mn, 420.6×10-6～520.3×10-6; Fe, 2354×10-6～2685×10-6; Co, 80.7×10-6～101.6×10 6 and Ni,5.3× 10-6～6.05× 10-6). The TSP (Total Suspended Particulate) levels in all factory units were higher than the recommended air quality value (70 μg/m3) under Egyptian law. The effect of ferrosilicon factory fallen dust on the surrounding regions decreased with increasing distance between the factory and these regions. The suspended dust samples in the factory units and their components greatly exceeded national and international standards, so health and environmental criteria must be

关键词： Air pollution Dust Heavy metals Fallen dust

magnetic transitions and butterfly-shaped hysteresis of Sm-Fe-Al-based perovskite-type orthoferrite

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Journal of Rare Earths 2015年第9期33卷 965-971页

作者： m.A.ahmed N.G.Imam m.K.Abdelmaksoud Y.A.Saeid materials Science Lab. Physics Department Faculty of Science Cairo University materials Science Lab. Experimental Physics Department Nuclear Research Center Atomic Energy Authority

A1 doped SmFeO3 （SmFel_xmlxO3; 0.0〈x〈0.15; step 0.05） were prepared by double sintering ceramic technique. The obtained samples were crystallized in single phase structure except the sample with x=0.15. The unit cell volume was found to decrease with increasing AI substitution in orthoferrite. The effective magnetic moment （μeff） and the Curie constant （C） were calculated from the reciprocal of the molar magnetic susceptibility （Z-1） versus absolute temperature plot and found to attain maximum value for the parent sample. The magnetic behavior showed two different magnetic transitions, viz, N6el temperature （TN） and spin reorientation （TsR） transitions. The m-H hysteresis loop of the parent sample took butterfly-shape as a result of different contributions anisotropies. From the magnetic properties measurements, it was obviously found that B-site cation dilution resulted in a drastic decrease in the magnetization. Surprisingly large value of the coercive field was obtained for the undoped sample;Hc=6198.80e. Based on the mentioned results, one can recommend the use of such orthoferrite in magnetic recording media and as pining layer in spin valve for spin- tronic applications.

关键词： SmFeO3 magnetization FESEm crystal structure spintronics spin reorientation butterfly-shaped hysteresis anisotropy rare earths

Wastewater degradation by iron/copper nanoparticles and the microorganism growth rate

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Journal of Environmental Sciences 2018年第12期30卷 19-31页

作者： Tareq W.m.Amen Osama Eljamal ahmed m.E.Khalil Nobuhiro matsunaga Earth System Science and Technology Interdisciplinary Graduate School of Engineering Sciences Kyushu University Department of Chemical Engineering Faculty of Engineering Cairo University

Nowadays, trends in wastewater treatment by zero-valent iron（ZVI） were turned to use bimetallic NZVI particles by planting another metal onto the ZVI surface to increase its reactivity. Nano size zero-valent iron/copper（NZVI/Cu0） bimetallic particles were synthesized in order to examine its toxicity effects on the wastewater microbial life, kinetics of phosphorus, ammonia stripping and the reduction of chemical oxygen demand（COD）.Various concentrations of NZVI/Cu0 and operation conditions both aerobic and anaerobic were investigated and compared with pure NZVI experiment. The results showed that addition10 mg/L of NZVI/Cu0 significantly increased the numbers of bacteria colonies under anaerobic condition, conversely it inhibited bacteria activity with the presence of oxygen. Furthermore,the impact of nanoparticles on ammonia stripping and phosphorus removal was also linked to the emitted iron ions electrons. It was found that dosing high concentration of bimetallic NZVI/Cu0 has a negative effect on ammonia stripping regardless of the aeration condition. In comparison to control, dosing only 10 mg/L NZVI/Cu0, the phosphorus removal increased sharply both under aerobic and anaerobic conditions, these outcomes were obtained as a result of complete dissolution of bimetallic nanoparticles which formed copper-iron oxides components that are attributed to increasing the phosphorus adsorption rate.

关键词： Iron bimetallic Wastewater biodegradation Bacterial life Contaminants removal

Numerical Study of mixed Convective Peristaltic Flow through Vertical Tube with Heat Generation for moderate Reynolds and Wave Numbers

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Communications in Theoretical Physics 2018年第4期69卷 449-460页

作者： Tariq Javed B.ahmed m.Sajid Department of mathematics and Statistics International Islamic University

The current study focuses on the numerical investigation of the mixed convective peristaltic mechanism through a vertical tube for non-zero Reynolds and wave number. In the set of constitutional equations, energy equation contains the term representing heat generation parameter. The problem is formulated by dropping the assumption of lubrication theory that turns the model mathematically into a system of the nonlinear partial differential equations. The results of the long wavelength in a creeping flow are deduced from the present analysis. Thus, the current study explores the neglected features of peristaltic heat flow in the mixed convective model by considering moderate values of Reynolds and wave numbers. The finite element based on Galerkin's weighted residual scheme is applied to solve the governing equations. The computed solution is presented in the form of contours of streamlines and isothermal lines, velocity and temperature profiles for variation of different involved parameters. The investigation shows that the strength of circulation for stream function increases by increasing the wave number and Reynolds number. Symmetric isotherms are reported for small values of time-mean flow. Linear behavior of pressure is noticed by vanishing inertial forces while the increase in pressure is observed by amplifying the Reynolds number.

关键词： mixed convection peristaltic flow moderate Reynolds number finite element method

Use of biopolymers in wastewater treatment:A brief review of current trends and prospects

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Chinese Journal of Chemical Engineering 2023年第12期64卷 292-320页

作者： ahmed m.Elgarahy m.G.Eloffy Eric Guibal Huda m.Alghamdi Khalid Z.Elwakeel Egyptian Propylene and Polypropylene Company(EPPC) Port-SaidEgypt Environmental Chemistry Division Environmental Science DepartmentFaculty of SciencePort Said UniversityPort SaidEgypt National Institute of Oceanography and Fisheries(NIOF) CairoEgypt Polymers Composites and Hybrids(PCH) C2MAIMT Mines AlesAlèsFrance University of Jeddah College of ScienceDepartment of ChemistryJeddahSaudi Arabia

Indeed,polymeric materials have thrived in worldwide sectors over the last five decades due to their versatility and durability,to the point that we can no longer envisage a product that does not contain ***,many synthetic polymers that have been produced are mostly sourced from petroleum and coal as raw materials,making them environmentally incompatible because they cannot be integrated with what is a natural recycling *** of the most important aspects of the transition to a circular bioeconomy(CBE)is the provision of more sustainable strategies for resource and waste *** the environmental consequences associated with petroleum-based polymers(PBPs),natural biopolymers,originating from biomass,can be conceived as a promising solution to gradually replace the PBPs,and address,and resolve the potential challenges and prevailing research gaps in the *** biopolymers have significant advantages over PBPs in terms of low-cost/zero-cost precursors,environmental friendliness,and *** present review dissects the sources,synthesis pathways,structures,characterization,and employment of biopolymers and their composites in water and wastew-ater treatment applications via different ***,the CBE model framework proposes potential approaches to applying CBE principles in the wastewater management sector,with a heavy emphasis on not only technology but also organizational and societal *** sum up,the reliance on biopolymers can be considered a crucial tool for assessing the global progress toward CBE,as well as future environmental management and planning.

关键词： Biopolymers Biomass Bioseparation Coagulation Photocatalysis Sustainability

Chemical and Thermal Characterization of Cement mortar Containing Ground Palm Oil Fuel Ash as a Partial Cement Replacement

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Journal of Wuhan University of Technology(materials Science) 2023年第3期38卷 575-581页

作者： SUmRA Yousuf PAYAm Shafigh IFTIKHAR ahmed Channa m Rizwan TANVEER ahmed Khan BELAL Alsubari mUSTABSHIRHA Gul l.Department of Building and Architectural Engineering Faculty of Engineering&TechnologyBahauddin Zakariya University60000 MultanPakistan Centre for Building Construction&Tropical Architecture(BuCTA)Faculty of Built EnvironmentUniversity of Malaya50603 Kuala LumpurMalaysia Department of metallurgical Engineering NED University of Engineering and Technology74200 KarachiPakistan Department of Civil Engineering Faculty of EngineeringMiami College of Henan UniversityKaifeng475001China Department of mechanical Engineering University of Malaya50603 Kuala LumpurMalaysia Department of mechanical Engineering Faculty of Engineering&TechnologyBahauddin Zakariya University60000 MultanPakistan

This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were supplemented by thermal gravimetric analysis(TGA). moreover, the resistance of G-POFA blended cement mortars to water absorption and sorptivity was determined. Further, the k-value test was carried out to explain the pozzolanic and filler behavior of G-POFA and to support the results obtained from TGA. It was found that there was no significant impact of several curing conditions on the pH of mortars. The mortar with 10% G-POFA in replacement of cement(G-POFA-10) exhibited the best resistance against water absorption and sorptivity.

关键词： curing condition Ca(OH)_(2)content k-value pH palm oil fuel ash

maximizing the Benefit of Rate Transient Analysis for Gas Condensate Reservoirs

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Energy Engineering 2021年第5期118卷 1411-1423页

作者： mahmoud Abdo Tantawy ahmed A.m.Elgibaly ahmed mohamed Farag Faculty of Petroleum and mining Engineering Suez UniversitySuezEgypt Abu Qir Petroleum Company AlexandriaEgypt

In recent years,many trials have been made to use the Rate Transient Analysis(RTA)techniques as a method to describe the gas condensate *** problem with using these techniques is the multi-phase behavior of the gas condensate ***,the Pressure Transient Analysis(PTA)is commonly used in this case to analyze the reservoir *** this paper,we are going to compare the results of both PTA and RTA of three wells in gas condensate *** comparison showed a great match between the results of the two mentioned techniques for the first time using a reference GOR of 75,000 SCF/***,we concluded that we could depend on RTA instead of PTA to spare the cost associated with the PTA in the gas condensate reservoirs.

关键词： Rate transient analysis production data analysis well testing permeability skin factor gas condensate