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Evolution of blockchain consensus algorithms: a review on the latest milestones of blockchain consensus algorithms

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Cybersecurity 2024年第3期7卷 80-101页

作者： Ziad Hussein May A.Salama Sahar a.el-Rahman electrical Engineering Department Faculty of Engineering-ShoubraBenha UniversityCairoEgypt

Blockchain technology has gained widespread adoption in recent years due to its ability to enable secure and trans-parent record-keeping and data transfer.A critical aspect of blockchain technology is the use of consensus algorithms,which allow distributed nodes in the network to agree on the state of the *** this review paper,we exam-ine various consensus algorithms that are used in blockchain systems,including proof-of-work,proof-of-stake,and hybrid *** go over the trade-offs and factors to think about when choosing a consensus algorithm,such as energy efficiency,decentralization,and *** also look at the strengths and weaknesses of each algorithm as well as their potential impact on the scalability and adoption of blockchain technology.

关键词： Blockchain Consensus Proof of work Proof of stake Decentralization

Mafic and felsic magmatism in the Wadi Kalalat area, South Eastern Desert, Egypt: mineralogy, geochemistry and geodynamic evolution during the Neoproterozoic in the Nubian Shield

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Acta Geochimica 2024年第1期43卷 150-173页

作者： a.el A.Surour Ahmed A.Madani Mohamed a.el-Sobky Faculty of Science Galala UniversityNew Galala CitySuez 43511Egypt Department of Geology Faculty of ScienceCairo UniversityGiza 12613Egypt Egyptian Mineral Resources Authority P.O.Box 11517AbbasiyaCairoEgypt

In the south Eastern Desert of Egypt,two contrasting types of magmatism(mafic and felsic) are recorded in the Wadi Kalalat area,and form the Gabal el Motaghiarat and Gabal Batuga intrusions,*** two intrusions post-dates ophiolitic and arc associations represented by serpentinite and metagabbro-diorite,*** mafic intrusion has a basal ultramafic member represented by fresh peridotite,which is followed upward by olivine gabbro and anorthositic or *** mafic intrusion pertains to the Alaskan-type mafic-ultramafic intrusions in the Arabian-Nubian Shield(ANS)being of tholeiitic nature and emplaced in a typical arc *** the other hand,the Gabal Batuga intrusion comprises three varieties of fresh A-type granites of high K-calc alkaline nature,which is peraluminous and garnetbearing in parts.A narrow thermal aureole in the olivine gabbro of the mafic intrusion was developed due to the intrusion of the Batuga *** results in the development of a hornfelsic melagabbro variety in which the composition changed from tholeiitic to a calc-alkaline composition due to the addition of S_(i)O_(2),Al_(2)O_(3),alkalis,lithosphile elements(LILEs) such as Rb(70 ppm) and Y(28 ppm) from the felsic *** the thermal aureole,Rb amounts 2-8 ppm and Y lies in the range elieved that the Gabal Batuga felsic intrusion started to emplace during the waning stage of an arc system,with transition from the pre-collisional(i.e.,arc setting) to post-collisional and within plate *** from which the Gabal Batuga granites were fractionated is high-K calc-alkaline giving rise to a typical post-collisional A-type granite(A_(2)-subtype) indicating an origin from an underplating crustal ***,it is stressed here that the younger granites in the ANS are not exclusively post-collisional and within-plate but most likely they started to develop before closure of the arc *** possible source(s) of mafic magmas

关键词： Wadi Kalalat Gabal el Motaghairat mafic intrusion Gabal Batuga felsic intrusion Arc setting Post-collision Within-plate

Optimized system for combined production of electricity/green hydrogen for multiple energy pathways:a case study of Egypt

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Clean Energy 2024年第4期8卷 219-236页

作者： Reda Ragab Mohamed HamdiHafez a.el Salmawy Mohamed A.Ismail Mechanical Power Engineering Department Zagazig UniversityZagazig 44519Egypt Mechanical Engineering Department College of EngineeringKing Faisal UniversityAl-Ahsa 31982Saudi Arabia

By optimal sizing of a wind/photovoltaic hybrid renewable-energy(RE)system,trimming the surplus capacity to reduce the fluctuations in the electricity supplied to the grid,and using it to produce green hydrogen through electrolysis,a stable output with maximum possible capacity factor(CF)is generated to maintain the electricity grid ***,the trimmed energy is used in a secondary conversion path that minimizes the weighted average cost of the energy generated from the entire *** surplus power-to-gas conversion allows the use of green hydrogen to produce electricity,methanol,or ammonia subject to the resource availability,site characteristics,and financial *** on robust site selection criteria,the best performance is obtained at two sites:Ras Ghareb and Minya,achieving the lowest energy cost with some variance in their *** the Ras Ghareb site,the optimally sized RE plant provided the grid with a quasi-steady capacity of 423 MW with a CF of 80.04%and was capable of injecting 2965.8648 GWh throughout the year with the lowest cost of 2.4355¢/kWh.A surplus of 3.9%of the total energy produced from the plant was directed to produce 1922-ton H_(2)/year,achieving the lowest cost of hydrogen production of$1.9745/kg H_(2).For the other selected site,Minya,the clipped energy is used to produce 3330.47-ton H_(2)/year with an optimized lowest cost of$3.5268/kg H_(2).The difference in hydrogen costs was attributed to the number of full operating hours of the electrolyser in both *** cost is mainly affected by the electricity price and the electrolyser *** both tending to decrease,future forecasts show hydrogen cost reductions.

关键词： hybrid renewable-energy system(HRES) green hydrogen electrolysis power-to-gas methanol ammonia

Nonlinear boundary control problem of hyperbolic systems

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Journal of Control and Decision 2024年第1期11卷 73-83页

作者： A.Bouhamed a.el Kabouss H.Bouzahir ISTI Lab Ibn Zohr UniversityENSAAgadirMorocco Faculty of sciences Moulay Ismail UniversityMeknesMorocco

The paper is devoted to the study of optimal control of a hyperbolic system,where the control enters the system through the *** hyperbolic system is the wave equation on a smooth and open domain,where the boundary condition involves the normal derivative at the boundary of z,the time derivative of z times a constant k,and a nonlinear term ***,z is the state and u is the control,satisfying some boundedness condition depending on *** functional cost consists of the energy and the difference between the solution of the system at final time,and a desired state in *** a closed convex set,we prove the existence of an optimal control that minimises the cost functional using a priori ***,using the differentiability of the cost functional with respect to the control,we establish the characterisation by deriving necessary conditions that an optimal control must satisfy.A numerical approach is successfully illustrated by simulations.

关键词： Non-linear system hyperbolic system boundary control optimal control controllability

Large magnetocaloric effect and magnetic properties of EuRhO3

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Journal of Rare Earths 2024年第9期42卷 1724-1729页

作者： M.Lassri M.Sajieddine a.elouafi a.el Hachmi S.el Ouahbi R.Moubah Laboratory of Energy and Materials Engineering (LGEM) University of Sultan Moulay SlimaneFaculty of Science and Technology (FST) Institute of Applied Physics (IAP)-School of Industrial Management (EMINES) Mohammed Ⅵ Polytechnic University National School of Applied Sciences (ENSA) University of Sultan Moulay Slimane Laboratory of Mechanics Production and Industrial Engineering (LMPGI)Higher School of Technology of Casablanca (ESTC)University of Hassan Ⅱ Casablanca Laboratory of Radiation on Matter and Instrumentation (LRMI) Faculty of Science and Technology (FST) SettatHassan Ⅰ University Laboatory of Physics of Advanced Materials and Thermic (LPMAT) Faculty of Science Ain Chock (FSAC)University of Hassan Ⅱ Casablanca

We report on the structural,magnetic,and magnetocaloric properties of *** oxidation states of Eu and Rh ions were studied using X-ray photoelectron spectroscopy（XPS）.It is found that the Eu ions are mainly in the divalent oxidation state while the Rh ions have+4 ***3powders are found to be antiferromagnetic with a second order magnetic transition at Neel temperature（TN=2.9 K）.Analysis of the magnetic susceptibility versus temperature data in terms of the Curie=Weiss law:(χ=C/（T-θW）) for T>TN,yields θW=-3.1 K and effective magne tic moment ■,which is close to the theoretical value ■.The magnetic entropy change(-ΔSM),was determined by em ploying the thermodynam ic Maxwell's *** μ0H=5 T and near TN,■ and relative cooling power（RCP） exhibit large values of 33.7 J/（kg·K） and 238 J/kg,*** large magnitude of-ΔSMand RCP show that the EuRhO3compound could be a potential candidate to be used in cryogenic magnetic refrigeration.

关键词： Cryogenic magnetic refrigeration Magnetic properties Magnetocaloric effect Rare earths X-ray photoelectron spectroscopy

Multi-Objective Optimization Algorithm for Grouping Decision Variables Based on Extreme Point Pareto Frontier

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Computers, Materials & Continua 2024年第4期79卷 1281-1299页

作者： JunWang Linxi Zhang Hao Zhang Funan Peng Mohammed a.el-Meligy Mohamed Sharaf Qiang Fu College of Computer Science and Technology Shenyang University of Chemical TechnologyShenyang110142China Key Laboratory of Intelligent Technology for Chemical Process Industry of Liaoning Province Shenyang University of Chemical TechnologyShenyang110142China Industrial Engineering Department College of EngineeringKing Saud UniversityP.O.Box 800Riyadh11421Saudi Arabia

The existing algorithms for solving multi-objective optimization problems fall into three main categories:Decomposition-based,dominance-based,and *** multi-objective optimization problemsmainly focus on objectives,treating decision variables as a total variable to solve the problem without consideringthe critical role of decision variables in objective *** seen,a variety of decision variable groupingalgorithms have been ***,these algorithms are relatively broad for the changes of most decisionvariables in the evolution process and are time-consuming in the process of finding the Pareto *** solvethese problems,a multi-objective optimization algorithm for grouping decision variables based on extreme pointPareto frontier(MOEA-DV/EPF)is *** algorithm adopts a preprocessing rule to solve the Paretooptimal solution set of extreme points generated by simultaneous evolution in various target directions,obtainsthe basic Pareto front surface to determine the convergence effect,and analyzes the convergence and distributioneffects of decision *** the later stages of algorithm optimization,different mutation strategies are adoptedaccording to the nature of the decision variables to speed up the rate of evolution to obtain excellent individuals,thusenhancing the performance of the *** validation of the test functions shows that this algorithmcan solve the multi-objective optimization problem more efficiently.

关键词： Multi-objective evolutionary optimization algorithm decision variables grouping extreme point pareto frontier

Magneto-Photo-Thermoelastic Excitation Rotating Semiconductor Medium Based on Moisture Diffusivity

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 107-126页

作者： Khaled Lotfy A.M.S.Mahdy Alaa a.el-Bary E.S.elidy Department of Mathematics Faculty of ScienceZagazig UniversityZagazig44519Egypt Department of Mathematics Faculty of ScienceTaibah UniversityMadinah42353Saudi Arabia Department of Mathematics and Statistics College of ScienceTaif UniversityTaif11099Saudi Arabia Arab Academy for Science Technology and Maritime TransportAlexandria1029Egypt

In this research,we focus on the free-surface deformation of a one-dimensional elastic semiconductor medium as a function of magnetic field and moisture *** problem aims to analyze the interconnection between plasma and moisture diffusivity processes,as well as thermo-elastic *** study examines the photothermoelasticity transport process while considering the impact of moisture *** employing Laplace’s transformation technique,we derive the governing equations of the photo-thermo-elastic *** equations include the equations for carrier density,elastic waves,moisture transport,heat conduction,and constitutive *** stresses,thermal conditions,and plasma boundary conditions are used to calculate the fundamental physical parameters in the Laplace *** employing numerical techniques,the Laplace transform is inverted to get complete time-domain solutions for the primary physical domains under ***,thermoelastic,and thermoelectric characteristics are employed in conjunction with a graphical analysis that takes into consideration the effects of applied forces on displacement,moisture concentration,carrier density,stress due to forces,and temperature distribution.

关键词： Moisture diffusivity semiconductor photothermoelastic rotation thermomechanical waves laplace transform

Strain engineering in electrocatalysis:Strategies,characterization,and insights

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Nano Research 2024年第5期17卷 3603-3621页

作者： Qibo Deng Peng Xu Hassanien Gomaa Mohamed A.Shenashen Sherif a.el-Safty Cuihua An Li-Hua Shao Ning Hu School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China Department of Chemistry Faculty of ScienceAl-Azhar University71524AssiutEgypt Department of Petrochemical Egyptian Petroleum Research Institute(EPRI)Nasr City11727CairoEgypt Center for Functional Materials National Institute for Materials Science(NIMS)1-2-1 SengenTsukubaIbaraki-ken305-0047Japan State Key Laboratory of Reliability and Intelligence electrical Equipment Key Laboratory of Advanced Intelligent Protective Equipment TechnologyMinistry of Educationand School of Mechanical EngineeringHebei University of TechnologyTianjin 300401China National Key Laboratory of Strength and Structural Integrity Institute of Solid MechanicsSchool of Aeronautic Science and EngineeringBeihang UniversityBeijing100191China Advanced Equipment Research Institute Co. Ltd.of HEBUTTianjin 300401China

Strain engineering,as a cutting-edge method for modulating the electronic structure of catalysts,plays a crucial role in regulating the interaction between the catalytic surface and the adsorbed *** electrocatalytic performance is influenced by the electronic structure,which can be achieved by introducing the external forces or stresses to adjust interatomic spacing between surface *** challenges in strain engineering research lie in accura.ely understanding the mechanical impact of strain on *** paper first introduces the basic strategy for generating the strain,summarizes the different strain generation forms and their advantages and *** progress in researching the characterization means for the lattice strains and their applications in the field of electrocatalysis is also ***,the challenges of strain engineering are introduced,and an outlook on the future research directions is provided.

关键词： strain electrocatalysis characterization chemical reaction kinetics lattice mismatch

Comparative study between three carbonaceous nanoblades and nanodarts for antimicrobial applications

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Journal of Environmental Sciences 2024年第2期136卷 594-605页

作者： Mohamed S.Selim Ahmed M.Azzam Mohamed A.Shenashen Shimaa A.Higazy Bayaumy B.Mostafa Sherif a.el-Safty National Institute for Materials Science(NIMS) 1-2-1 SengenTsukuba-ShiIbaraki-Ken 305-0047Japan Petroleum Application Department Egyptian Petroleum Research InstituteNasr City 11727Egypt Department of Environmental Research Theodor Bilharz Research InstituteGizaEgypt

The design of nanostructured materials occupies a privileged position in the development and management of affordable and effective technology in the antibacterial ***,we discuss the antimicrobial properties of three carbonaceous nanoblades and nanodarts materials of graphene oxide(GO),reduced graphene oxide(RGO),and single-wall carbon nanotubes(SWCNTs)that have a mechano-bactericidal effect,and the ability to piercing or slicing bacterial *** demonstrate the significance of size,morphology and composition on the antibacterial activity mechanism,the designed nanomaterials have been *** minimum inhibitory concentration(MIC),standard agar well diffusion,and transmission electron microscopy were utilized to evaluate the antibacterial activity of GO,RGO,and *** on the evidence obtained,the three carbonaceous materials exhibit activity against all microbial strains tested by completely encapsulating bacterial cells and causing morphological disruption by degrading the microbial cell membrane in the order of RGO>GO>*** of the external cell wall structure and outer membrane proteins,the synthesized carbonaceous nanomaterials exhibited higher antibacterial activity against Gram-positive bacterial strains than Gram-negative and fungal *** had the lowest MIC values(0.062,0.125,and 0.25 mg/mL against ***,***,and ***,respectively),as well as minimum fungal concentrations(0.5 mg/mL for both *** and ***).At 12 hr,the cell viability values against tested microbial strains were completely *** lysis and death occurred as a result of severe membrane damage caused by microorganisms perched on RGO *** work gives an insight into the design of effective graphene-based antimicrobial materials for water treatment and remediation.

关键词： Antimicrobial properties Nanoblades Mechano-bactericidal effect RGO nanosheets Gram-positive bacteria Cell viability