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Simultaneous Adsorption of Aqueous Pb2+, Cu2+, Zn2+, and Cd2+ Using Surfactant-modified and Unmodified Activated Carbon in a Fixed Bed Column

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Journal of Encapsulation and Adsorption Sciences 2024年第1期12卷 1-24页

作者： morufu A. Olatunji Kamoru A. salam Abdullahi m. Evuti department of Chemical Engineering University of Abuja Abuja Nigeria National Agency for Science and Engineering Infrastructure (NASENI) Abuja Nigeria

The goal of this work is to improve the simultaneous removal of Pb2+, Cu2+, Zn2+, and Cd2+ ions from synthetic wastewater in a fixed bed column by incorporating sodium dodecyl sulfate (SdS) onto the surface of activated carbon made from coconut shells. The activated carbons were characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy-energy dispersive x-ray (SEm-EdX). The adsorption column dynamics were studied by varying the flow rates (5, 10 and 15 mL/min), bed heights (10, 15 and 20 cm), and initial concentrations (50, 150, and 250 mg/L). The activated carbon has a pore volume of 0.715 cm3/g and a BET-specific surface area of 1410 m2/g. Sodium dodecyl sulfate (SdS) surfactant incorporation onto the surface of the activated carbon enhances its capacity for simultaneous adsorption of Pb2+, Cu2+, Zn2+, and Cd2+ from the aqueous medium. The affinity of the heavy metals to both unmodified (AC) and modified (AC-SdS) activated carbons followed the order of Pb2+ > Cu2+ > Zn2+ > Cd2+. The dynamic adsorption of the column depends on the flow rate, bed height, initial metal concentration, and SdS surface modification. With a 5 mL/min flow rate, a 20 cm bed height, and a 50 mg/L initial metal concentration, a maximum break-through time of 150 minutes for the unmodified activated carbon (AC) and 180 minutes for the SdS-modified activated carbon (AC-SdS) was reached.

关键词： Adsorption Surfactant-modified Activated Carbon multicomponent Breakthrough Adsorption Capacity Fixed Bed Column

Effect of Size and Initial Water Content on the Effective diffusion Coefficient during Convective drying of Sweet Potato Cut into Cubic and Cylindrical Shapes

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Journal of materials Science and Chemical Engineering 2024年第6期12卷 71-82页

作者： Ibrango Abdoul salam Ouoba Kondia honoré Bama désiré Traoré Yssa Zongo Karim Ouedraogo Salifou Laboratoire de matriaux de lhliophysique et Environnement (La.m.h.E.) Unit de Formation et de Recherche en Sciences. Exactes et Appliques (UFR/SEA) Universit Nazi BONI de Bobo-Dioulasso Bobo-Dioulasso Burkina Faso

In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples are 0.5, 1, 1.5, 1.75, 2, 2.5 and 3 cm edge with a respective initial water content of 2.7, 3.76, 3.48, 2.68, 3.28, 2.17 and 2.29 kg/kgms. For cylindrical samples, the radius is set at 0.5 cm and sample heights are 1, 1.5, 2, 2.5, 3, 3.5 and 4 cm with respective water contents of 2.2, 3.19, 2.85, 2.1, 2.17, 2.39 and 2.03 kg/kgms. The effective diffusion coefficients of cubic samples are of the order of 10−10 and 10−9 m2∙s−1 grew with sample edge. As for the cylindrical samples, the effective diffusion coefficients were of the order of 10−9 m2∙s−1 and there was no linear correlation between cylinder height and their effective diffusion coefficient. As for the examination of the initial water content on the effective diffusion coefficient, it turned out that the initial water content had no influence on the effective diffusion coefficient of the sweet potato samples.

关键词： Effective diffusion Coefficient Initial Water Content Sweet Potato Cubic Cylindrical

Effect of Conductive Fillers on the Cyclic Stress-Strain and Nano-Scale Free Volume Properties of Silicone Rubber

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Chinese Journal of Polymer Science 2014年第5期32卷 558-567页

作者： m.h.a.d-el salam S.el-Gamal m.mohsen d.m.Abd el-maqsoud Physics department Faculty of Education Ain Shams University Physics department Faculty of Science Ain Shams University

The effect of carbon black （CB） and graphite （G） powders on the macroscopic and nano-scale free volume properties of silicone rubber based on poly（di-methylsiloxane）（PdmS） was studied through thermal and cyclic mechanical measurements, as well as with positron annihilation lifetime spectroscopy （PALS）. The melting temperature of the composites （Tm） and the endothermic enthalpy of melting （Δhm） were estimated by differential scanning calorimetry （dSC）. Tm and the degree of crystallinity （χc） of PdmS composites were found to decrease with increasing the CB content. This can be explained due to the increase in physical cross-linking which results in a decrease in the crystallite thickness. Besides, χc was found to be dependent on the filler type. Cyclic stress-strain behavior of PdmS loaded with different contents of filler has been studied. mullins ratio （Rm） was found to be dependent on the filler type and content. It was found that, Rm increases with increasing the filler content due to the increase in physical cross-linking which results in a decrease in the size of free volume, as observed through a decrease of the o-Ps lifetime τ3 measured by PALS. moreover, the hysteresis in PdmS-CB composites was more pronounced than in PdmS-G composites. Furthermore, a correlation was established between the free volume Vf and the mechanical properties of PdmS composites containing different fillers. A negative correlation was observed between Vf and Rm.

关键词： Positron annihilation Positronium Free volume Si-rubber Composite Cyclic mechanical properties.

Tigris River Water Quality Quantifying Using the Iraq Water Quality Index (IraqWQI) and Some Statistical Techniques

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Engineering（科研） 2024年第6期16卷 149-166页

作者： Nadhir Al-Ansari salam hussein Ewaid Ali Chabuk Salwan Ali Abed mudhafar A. Salim Jan Laue Riyadh m. Salih department of Civil Environmental and Natural Resources Engineering Lule University of Technology Lule Sweden Technical College of Shatra Southern Technical University Basra Iraq department of Environmental Engineering College of Engineering University of Babylon Babylon Iraq department of Environment College of Science University of Al-Qadisiyah Diwaniyah Iraq Iraqi Organization for Conservation of Nature IOCN Baghdad Iraq National Center for Water Resources management Ministry of Water Resources Baghdad Iraq

Evaluation of water quality is important for the management of water resources. The current study is focused on the interpretation of the water quality monitoring data of the Tigris River in Iraq by the application of the principal component analysis (PCA), cluster analysis (CA), and water quality index (WQI). Twelve water quality parameters were taken from 14 stations along the river Ca2+, mg2+, Na+, K+, Cl−, SO42−, hCO3−, NO3−, Th, TdS, BOd5, and EC to apply the PCA and CA. The results show that the mean of all the parameters was under the standards except Ca2+, EC, mg2+, Th, and SO42−. The amount of EC is the critical factor that affects the river water quality. The PCA obtained one principal component responsible for 97% of the variation caused by different pollution sources. The CA divided the river into three regions of sampling stations with similar water quality, the best in the north, and the worst in the far south. In this paper, the computer-automated tool (IraqWQI) was presented and evaluated, which has been developed by authors to classify and measure the quality of Iraqi surface water. The proposed index is of hundred degrees and includes six variables for drinking water quality Cl−, Th, TdS, COd, dO, and total coliform (TC) according to the Iraqi specifications. The result of the IraqWQI application showed a decrease in the water quality of the river and its suitability for drinking in the south of the country. The best value of the index was (81.48, Good) in Fishkhabour during winter, and the worst value was (46.23, Bad) in Qurnah during summer. The result of this study proved the success and importance of using statistical techniques and WQI as useful tools for the management, control, and conservation of surface water. .

关键词： Component Formatting Style Styling

Simulation of buoyancy-induced turbulent flow from a hot horizontal jet

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Journal of hydrodynamics 2014年第1期26卷 104-113页

作者： el-AmIN m.F. SUN Shuyu salam Amgad Computational Transport Phenomena Laboratory (CTPL) Division of Physical Sciences and EngineeringKing Abdullah University of Science and Technology

Experimental visualizations and numerical simulations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different temperature differences and their corresponding Reynolds numbers are considered. Both experimental visualization and numerical computations are carried out for the same flow and thermal conditions. The realizable k-e model is used for modeling the turbulent flow while the buoyancy is modeled using the Boussinesq approximation. Polynomial approximations of the water properties are used to compare with the Boussinesq approximation. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank as well as the Froude number are analyzed. The experimental visualizations are performed at intervals of five seconds for all different cases. The simulated results are compared with the visualized results, and both of them show the stratification phenomena and buoyancy force effects due to temperature difference and density variation. After certain times, depending on the case condition, the flow tends to reach a steady state.

关键词： turbulent flow realizablc k - e turbulence model heat transfer jet heat storage

PERIOdIC mOTIONS OF SPINNING RIGId SPACECRAFT UNdER INFLUENCE OF GRAVITATIONAL ANd mAGNETIC FIeldS

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Applied mathematics and mechanics(English Edition) 2006年第8期27卷 1061-1069页

作者： Yehia A.Abdel-aziz m.h.Yehia F.A.Abd el-salam m.Radwan National Research Institute of Astronomy and Geophysics Helwan. Cairo Egypt mathematics department Faculty of Science Mansoura University MansouraEgypt Astronomy department Faculty of ScienceCairo UniversityCairo12613Egypt

The motion of a magnetized axisymmetric spacecraft about its center of mass in a circular orbit is considered, taking the gravitational and magnetic effects of the central body into account. Equations of motion of the reduced system are transformed to equations of plane motion of a charged particle under the action of electric and magnetic fields. Stationary motions of the system are determined and periodic motions near to them are constructed using the Lyapounoff theorem of the holomorphic integral.

关键词： periodic motions routhian rigid spacecraft

Spectral collocation method for solving continuous population models for single and interacting species by means of exponential Chebyshev approximation

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International Journal of Biomathematics 2018年第8期11卷 265-288页

作者： m. A. Ramadan m. A. Abd el salam mathematics department Faculty of Science Menoufia University Shebin El-KomEgypt mathematics department Faculty of Science Al-Azhar University Nasr-City Cairo Egypt

In this paper, an efficient and accurate method is presented to solve continuous population models for single and interacting species using spectral collocation method with exponential Chebyshev (EC) functions. The first problem is a logistic growth model in a population, while the second problem is a prey-predator model: Lotka-Volterra system, the tbird is a simple 2-species Lotka-Volterra competition model, and the final one is a prey-predator model with limit cycle periodic behavior. The high accuracy of this method is verified through some numerical examples. The obtained numerical results are compared with other methods, showing that the proposed method gives higher accuracy.

关键词： Exponential Chebyshev functions continuous population models spectral collocation method

Position and Velocity Time delay for Suppression Vibrations of a hybrid Rayleigh-Van der Pol-duffing Oscillator

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Sound & Vibration 2020年第3期54卷 149-161页

作者： Y.A.Amer A.T.el-Sayed m.N.Abd el-salam mathematics department Science FacultyZagazig UniversityZagazigEgypt Basic Sciences department Modern Academy for Engineering and TechnologyCairoEgypt Basic Sciences department Higher Technological Institute10th of Ramadan CityEgypt

In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–duffing *** system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external *** applied the multiple scales method to get the solution from first *** and numerically,we studied the system before and after adding time delay feedback at the primary resonance case(ffi!).We used mATLAB program to simulate the efficacy of different parameters and the time delay on the main system.

关键词： Position time delay feedback velocity time delay feedback multiple scales method resonance cases

A Suitable Active Control for Suppression the Vibrations of a Cantilever Beam

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Sound & Vibration 2022年第2期56卷 89-104页

In our consideration,a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried *** four types are the linear velocity feedback control,the cubic velocity feedback control,the non-linear saturation controller(NSC)and the positive position feedback(PPF)*** suitable type is the PPF controller for suppression the vibrations of the cantilever *** approximate solution obtained up to the first approximation by using the multiple scale *** PPF controller effectiveness is studied on the *** used frequency-response equations to investigate the stability of a cantilever *** notified that,there is a good agreement between the analytical solution and the numerical solution.

关键词： Cantilever beam cubic velocity feedback control linear velocity feedback control non-linear saturation controller(NSC) positive position feedback(PPF)controller