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Surface engineering of ZnO electrocatalyst by N doping towards electrochemical CO_(2) reduction

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Journal of Energy Chemistry 2024年第1期88卷 71-81,I0002页

作者： Rohini Subhash Kanase Getasew mulualem Zewdie maheswari Arunachalam Jyoti Badiger Suzan Abdelfattah sayed Kwang-Soon Ahn Jun-Seok Ha Uk Sim Hyeyoung Shin Soon Hyung Kang department of Interdisciplinary Program for Photonic Engineering Chonnam National UniversityGwangju 61186Republic of Korea Graduate School of Energy Science and Technology(GEST) Chungnam National University99 Daehak-roYuseong-guDaejeon 34134Republic of Korea department of Chemistry Education and Optoelectronic Convergence Research Center Chonnam National UniversityGwangju 61186Republic of Korea department of Advanced Chemicals and Engineering Chonnam National UniversityGwangju 61186Republic of Korea School of Chemical Engineering Yeungnam UniversityGyeongsan 38541Republic of Korea department of Energy Engineering Korea Institute of Energy Technology(KENTECH)Naju 58217Republic of Korea

The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-based electrocatalyst was developed for use in gas-diffusion electrodes(GdE),and the effect of nitrogen(N)doping on the ECR activity of ZnO electrocatalysts was ***,a ZnO nanosheet was prepared via the hydrothermal method,and nitridation was performed at different times to control the N-doping *** an increase in the N-doping content,the morphological properties of the nanosheet changed significantly,namely,the 2d nanosheets transformed into irregularly shaped ***,the ECR performance of Zn O electrocatalysts with different N-doping content was assessed in 1.0 m KHCO_(3) electrolyte using a gas-diffusion electrode-based ECR *** the ECR activity increased after a small amount of N doping,it decreased for higher N doping *** them,the N:ZnO-1 h electrocatalysts showed the best CO selectivity,with a faradaic efficiency(FE_(CO))of 92.7%at-0.73 V *** hydrogen electrode(RHE),which was greater than that of an undoped Zn O electrocatalyst(FE_(CO)of 63.4%at-0.78 V_(RHE)).Also,the N:ZnO-1 h electrocatalyst exhibited outstanding durability for 16 h,with a partial current density of-92.1 mA cm^(-2).This improvement of N:ZnO-1 h electrocatalyst can be explained by density functional theory calculations,demonstrating that this improvement of N:ZnO-1 h electrocatalyst comes from(ⅰ)the optimized active sites lowering the free energy barrier for the rate-determining step(RdS),and(ⅱ)the modification of electronic structure enhancing the electron transfer rate by N doping.

关键词： ZnO N-doped ZnO Gas-diffusion electrode CO Selectivity Electrochemical CO_(2)reduction

Nonlinear study of the dynamic behavior of a string-beam coupled system under combined excitations

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Acta mechanica Sinica 2011年第6期27卷 1034-1051页

作者： Y.S. hamed m. sayed d.-X. Cao W. Zhang department of Engineering mathematics Faculty of Electronic Engineering Menouf 32952 Egypt College of mechanical Engineering Beijing University of Technology 100022 Beijing China department of mathematics and Statistics Faculty of Science Taif University Taif E1-Haweiah EO. Box 888 Zip Code 21974 Kingdom of Saudi Arabia （KSA）

In this paper,the nonlinear dynamic behavior of a string-beam coupled system subjected to external,parametric and tuned excitations is *** governing equations of motion are obtained for the nonlinear transverse vibrations of the string-beam coupled system which are described by a set of ordinary differential equations with two degrees of *** case of 1：1 internal resonance between the modes of the beam and string,and the primary and combined resonance for the beam is *** method of multiple scales is utilized to analyze the nonlinear responses of the string-beam coupled system and obtain approximate solutions up to and including the second-order *** resonance cases are extracted and *** of the system is studied using frequency response equations and the phase-plane *** solutions are carried out and the results are presented graphically and *** effects of the different parameters on both response and stability of the system are *** reported results are compared to the available published work.

关键词： 1:1 internal resonance - String-beam - multiple scales Chaotic response Stability

Exploring the impact of stratification on the dynamics of bioconvective thixotropic fluid conveying tiny particles and Cattaneo-Christov model:Thermal storage system application

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Propulsion and Power Research 2024年第3期13卷 416-432页

作者： T.Oreyeni m.d.Shamshuddin A.m.Obalalu A.Saeed Nehad Ali Shah department of Physical Sciences Mathematics Programme UnitPrecious Cornerstone UniversityIbadanNigeria department of Computer Science and Artificial Intelligence(mathematics) SR UniversityWarangalTelangana State 506371India department of mathematics Augustine University Ilara EpeLagosNigeria Center of Excellence in Theoretical and Computational Science(TaCS-CoE) Faculty of ScienceKing Mongkut’s University of Technology Thonburi(KMUTT)126 Pracha Uthit Rd.BangModThung KhruBangkok 10140Thailand department of mathematics and Statistics College of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh 11623Saudi Arabia

Stratified thermal storage promotes energy sustainability by storing excess energy during times of low demand for later use making it possible to integrate renewable energy sources like solar and *** communication discusses the significance of triple stratifica-tion using the Cattaneo-Christov model in the bioconvectiveflow of thixotropicfluid coexisting with nanoparticles and gyrotactic *** Cattaneo-Christov heat and massflux is incorporated into thefluid model allowing more accurate prediction of heat and mass phenomena in thefluid *** governing partial differential equations that describefluidflow are parametrized to yield an ordinary differential equation system by adopting suitable *** series solutions are obtained by applying the homotopy analysis method(ham).The effects of relevant parameters on the various profiles are revealed and accurately *** is observed that amplified thermal stratification lowers the temperature of ***,Brownian motion is used to illustrate the random movement of small particles suspended in liquids,and it is envisioned that the concentration distribution is significantly influenced by the Brownian motion of nanoparticles.

关键词： Cattaneo-Christov model Stratification Bioconvection Nanofluid

A Study of Linke Turbidity Factor over Qena / Egypt

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Advances in Atmospheric Sciences 1996年第4期13卷 519-532页

作者： sayed m. Elshazly department of Physics Faculty of Science South Valley University Qena/A.R. Egypt

data on instantaneous atmospheric Linke turbidity factor TL (m) are reported for clear days at Qena/Egypt in the period from June 1992 to may ***(m) is determined using the values of irradiance of direct solar radiation (I),which are calculated from global (G) and diffuse (d) - solar radiation *** and seasonally variations of both diurnal and daily average values of TL (m) increases steadily in the direction of sunset in the months from June to december 1992 as well as Summer and Autumn seasons,while it falls generally in this direction for the months from January to march and Winter *** April and may,TL (m) fluctuates obviously through the day hours,it is also shown that the average values of TL(m) are particularly large during Summer months compared to other months of the *** behavior of TL(m) is discussed in view of the variations of some weather elements,which affect the content of water vapor and dust particle in the atmosphere of the study *** seems t be of similar trends to that of other locations inside and outside *** virtual variation of TL(m) is eliminated by reducing its value to relative optical air mass m=2,according to Kasten *** resulting TL (2) is more representative for the content of dust particles and water vapor in the atmosphere.

关键词： Turbidity Linke turbidity factor Seasonal and diurnal variations Solar radiations components measurements Aerosol

The competitive and synergistic effect between adsorption enthalpy and capacity in d_(2)/H_(2)separation of m_(2)(m-dobdc)frameworks

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Chinese Chemical Letters 2021年第11期32卷 3562-3565页

作者： Fan Wu Liqiong Li Yanxi Tan El-sayed m.El-sayed daqiang Yuan State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of the Chinese Academy of Sciences Beijing 100049China College of Chemistry Fuzhou UniversityFuzhou 350108China Chemical Refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr CityCairo 11727Egypt

Hydrogen isotope separation is a challenging task due to their similar ***,based on the chemical affinity quantum sieve(CAQS)effect,the d_(2)/H_(2)separation performance of m_(2)(m-dobdc)(m=Co,Ni,mg,mn;m-dobdc^(4-)=4,6-dioxido-1,3-benzenedicarboxylate),a series of honeycomb-shaped mOFs with high stability and abundant open metal sites,are studied by gases sorption and breakthrough experiments,in which two critical factors,gas uptake and adsorption enthalpy,are taken into *** these mOFs,Co_(2)(m-dobdc)exhibits the longest d_(2)retention time of 180 min/g(H_(2)/d_(2)/Ne:1/1/98)at 77 K because of its second-highest adsorption enthalpy(10.7 kJ/mol for H_(2)and 11.8 kJ/mol for d_(2))and the best sorption capacity(5.22 mmol/g for H_(2)and 5.49 mmol/g for d_(2))under low pressure of 1 kPa and 77 K,which make it a promising material for industrial hydrogen isotope ***,the results indicate that H_(2)and d_(2)capacities under low pressure(about 1 kPa)dominate the final d_(2)/H_(2)separation property of mOFs.

关键词： Breakthrough experiment Open metal sites Hydrogen isotope separation Sorption and separation Chemical affinity quantum sieve

modeling particle sedimentation in viscous fluids with a coupled immersed boundary method and discrete element method

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Particuology 2017年第2期15卷 191-199页

作者： sayed m. derakhshani dingena L. Schott Gabriel Lodewijks Faculty of mechanical Maritime and Materials Engineering Delft University of Technology Delft Netherlands department of mechanical Engineering Faculty of Engineering University of Isfahan Isfahan Iran

Numerical techniques have increasingly been used to model fluid–particle two-phase flows. Coupling the immersed boundary method （IBm） and discrete element method （dEm） is one promising approach for modeling particulate flows. In this study, IBm was coupled with dEm to improve the reliability and accuracy of IBm for determining the positions of particles during the sedimentation process within viscous fluids. The required ratio of the particle diameter to the grid size （d/dx） was determined by comparing the simulation results with the analytical solution and experimental data. A dynamic mesh refinement model was utilised in the IBm model to refine the computational fluid dynamics grid near the particles. In addition, an optimum coupling interval between the IBm and dEm models was determined based on the experimental results of a single particle sedimentation within silicon oil at a Reynolds number of 1.5. The experimental results and the analytical solution were then utilised to validate the IBm–dEm model at Reynolds numbers of 4.1, 11.6, and 31.9. Finally, the validated model was utilised to investigate the sedimentation process for more than one particle by modeling the drafting-kissing-tumbling process and the Boycott phenomenon. Benchmark tests showed that the IBm–dEm technique preserves the advantages of dEm for tracking a group of particles, while the IBm provides a reliable and accurate approach for modeling the particle–fluid interaction.

关键词： Immersed boundary method discrete element method Particle sedimentation Boycott phenomenon

Vibrational, rotational, and triaxiality features in extended O(6) dynamical symmetry of IBm using three-body interactions

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Nuclear Science and Techniques 2020年第5期31卷 44-56页

作者： A.m.Khalaf Azza O.El-Shal m.m.Taha m.A.El-sayed Physics department Faculty of ScienceAl-Azhar UniversityCairoEgypt mathematics and Theoretical Physics department Nuclear Research CenterAtomic Energy AuthorityCairo 13759Egypt

The shape transition between the vibrational U(5)and deformed c-unstable O(6)dynamical symmetries of sd interacting boson model has been investigated by considering a modified O(6)hamiltonian,providing that the coefficients of the Casimir operator of O(5)are N-dependent,where N is the total number of *** modified O(6)hamiltonian does not contain the number operator of the d boson,which is responsible for the vibrational *** addition,the deformation features can be achieved without using the SU(3)limit by adding to the O(6)dynamical symmetry the three-body interaction[QQQ]^(0),where Q is the O(6)symmetric quadrupole ***,triaxiality can be generated through the inclusion of the cubic d-boson interaction[d+d+d+]^(3)·∣ddd∣^(3).The classical limit of the potential energy surface(PES),which represents the expected value of the total hamiltonian in a coherent state,is studied and *** modified O(6)model is applied to the even–even^124-132 Xe *** parameters for the hamiltonian and the PESs are calculated using a simulated search program to obtain the minimum root mean square deviation between the calculated and experimental excitation energies and B(E2)values for a number of low-lying levels.A good agreement between the calculations and experiment results is found.

关键词： Nuclear structure Extended O(6)of IBm Three-body interactions Coherent state

metaheuristic Optimization of Time Series models for Predicting Networks Traffic

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Computers, materials & Continua 2023年第4期75卷 427-442页

作者： Reem Alkanhel El-sayed m.El-kenawy d.L.Elsheweikh Abdelaziz A.Abdelhamid Abdelhameed Ibrahim doaa Sami Khafaga department of Information Technology College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia department of Communications and Electronics Delta Higher Institute of Engineering and TechnologyMansoura35111Egypt Faculty of Artificial Intelligence Delta University for Science and TechnologyMansoura35712Egypt department of Computer Science Faculty of Specific EducationMansoura UniversityEgypt department of Computer Science Faculty of Computer and Information SciencesAin Shams UniversityCairo11566Egypt department of Computer Science College of Computing and Information TechnologyShaqra University11961Saudi Arabia Computer Engineering and Control Systems department Faculty of EngineeringMansoura UniversityMansoura35516Egypt department of Computer Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia

Traffic prediction of wireless networks attracted many researchersand practitioners during the past decades. However, wireless traffic frequentlyexhibits strong nonlinearities and complicated patterns, which makes it challengingto be predicted accurately. many of the existing approaches forpredicting wireless network traffic are unable to produce accurate predictionsbecause they lack the ability to describe the dynamic spatial-temporalcorrelations of wireless network traffic data. In this paper, we proposed anovel meta-heuristic optimization approach based on fitness grey wolf anddipper throated optimization algorithms for boosting the prediction accuracyof traffic volume. The proposed algorithm is employed to optimize the hyperparametersof long short-term memory (LSTm) network as an efficient timeseries modeling approach which is widely used in sequence prediction *** prove the superiority of the proposed algorithm, four other optimizationalgorithms were employed to optimize LSTm, and the results were *** evaluation results confirmed the effectiveness of the proposed approachin predicting the traffic of wireless networks accurately. On the other hand,a statistical analysis is performed to emphasize the stability of the proposedapproach.

关键词： Network traffic soft computing LSTm metaheuristic optimization

Using BlazePose on Spatial Temporal Graph Convolutional Networks for Action Recognition

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Computers, materials & Continua 2023年第1期74卷 19-36页

作者： motasem S.Alsawadi El-sayed m.El-kenawy miguel Rio Electronic and Electrical Engineering department University College LondonLondonWC1E 7JEEngland department of Communications and Electronics Delta Higher Institute of Engineering and TechnologyMansoura35111Egypt Faculty of Artificial Intelligence Delta University for Science and TechnologyMansoura35712Egypt

The ever-growing available visual data(i.e.,uploaded videos and pictures by internet users)has attracted the research community’s attention in the computer vision ***,finding efficient solutions to extract knowledge from these sources is ***,the BlazePose system has been released for skeleton extraction from images oriented to mobile *** this skeleton graph representation in place,a Spatial-Temporal Graph Convolutional Network can be implemented to predict the *** hypothesize that just by changing the skeleton input data for a different set of joints that offers more information about the action of interest,it is possible to increase the performance of the Spatial-Temporal Graph Convolutional Network for HAR ***,in this study,we present the first implementation of the BlazePose skeleton topology upon this architecture for action ***,we propose the Enhanced-BlazePose topology that can achieve better results than its ***,we propose different skeleton detection thresholds that can improve the accuracy performance even *** reached a top-1 accuracy performance of 40.1%on the Kinetics *** the NTU-RGB+d dataset,we achieved 87.59%and 92.1%accuracy for Cross-Subject and Cross-View evaluation criteria,respectively.

关键词： Action recognition BlazePose graph neural network OpenPose skeleton spatial temporal graph convolution network