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Design of Dipoles for the RF Energy Harvesting System Dedicated to GSM Applications

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Energy and Power Engineering 2025年第1期17卷 1-12页

作者： Abdoul karim Mbodji mohamed El Moctar Malang Kambaye Ousmane Dieme Department of Physics Applied of UFR-SAT University Gaston Berger Saint-Louis Senegal

Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. This work presents the design of an RF energy harvesting system consisting mainly of a rectenna (antenna and rectification circuit) and an adaptation circuit. First of all, we designed two dipole type antennas. One operates in the GSM 900 MHz band and the other in the GSM 1800 MHz band. The performances of the proposed antennas are provided by the ANSYS HFSS software. Secondly, we proposed two rectification circuits in order to obtain conversion efficiencies at 0 dBm of 64% for the system operating at the frequency of 900 MHz and 37% for the system at the frequency of 1800 MHz RF-DC. The rectifiers used are based on Schottky diodes. For maximum transfer of power between the antenna and the rectification circuit, L-type matching circuits have been proposed. This rectifier offers DC voltage values of 806 mV for the circuit at the frequency of 900 MHz and 616 mV for the circuit at the frequency of 1800 MHz. The adaptation circuits are obtained by carrying out simulations on the ADS (Advanced Design System) software.

关键词： Rectenna Antenna RF-DC Conversion Schottky Diode Efficiency RF Energy Harvesting

Numerical Investigation of the Influence of a Magnetic Field on the Laminar Flow of a Yield-Stress Nanofluid over a Backward Facing Step

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Frontiers in Heat and Mass Transfer 2025年第1期23卷 185-206页

作者： karim Amrani Eugenia Rossi di Schio mohamed Bouzit Abderrahim Mokhefi Abdelkader Aris Cherif Belhout Paolo Valdiserri Mechanical Manufacturing Technology Research Laboratory (LaRTFM) National Polytechnic School of Oran Maurice Audin El mnaouar Bp 1523 Es-senia Oran 31000 Algeria Department of Industrial Engineering DIN Alma Mater Studiorum-University of Bologna Viale Risorgimento 2 Bologna 40136 Italy Laboratory of Maritime Sciences and Engineering LSIM Faculty of Mechanical Engineering University of Science and Technology of Oran Mohamed Boudiaf El Mnaouer Oran 31000 Algeria Mechanics Modeling and Experimentation Laboratory L2ME Faculty of Sciences and Technology Bechar University Bechar 08000 Algeria

The present study focuses on the flow of a yield-stress (Bingham) nanofluid, consisting of suspended Fe 3 O 4 nanoparticles, subjected to a magnetic field in a backward-facing step duct (BFS) configuration. The duct is equipped with a cylindrical obstacle, where the lower wall is kept at a constant temperature. The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity. The aim of the present investigation is to explore the influence of flow velocity (Re = 10 to 200), nanoparticle concentration ( φ = 0 to 0.1), magnetic field intensity (Ha = 0 to 100), and its inclination angle (γ = 0 to 90) and nanofluid yield stress (Bn = 0 to 20) on the thermal and hydrodynamic efficiency inside the backward-facing step. The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method. The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer. In contrast, a significant reduction is observed with an increase in Hartmann and Bingham numbers, resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid, accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle. This study sheds light on the complexity of this magnetically influenced fluid, with potential implications in various engineering and materials science fields.

关键词： Yield-stress nanofluid Bingham nanofluid backward-facing step BFS magnetic field heat transfer hydrodynamics

Resilient Control for Networked Control Systems Subject to Cyber/Physical Attacks

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International Journal of Automation and computing 2018年第3期15卷 345-354页

作者： Taouba Rhouma karim Chabir mohamed Naceur Abdelkrim Modeling Analysis and Control of Systems(MACS) Laboratory National Engineering School of Gabes (ENIG)University of Gabes

In this paper, we investigate a resilient control strategy for networked control systems（NCSs） subject to zero dynamic attacks which are stealthy false-data injection attacks that are designed so that they cannot be detected based on control input and measurement data. Cyber resilience represents the ability of systems or network architectures to continue providing their intended behavior during attack and recovery. When a cyber attack on the control signal of a networked control system is computed to remain undetectable from passive model-based fault detection and isolation schemes, we show that the consequence of a zero dynamic attack on the state variable of the plant is undetectable during attack but it becomes apparent after the end of the attack. A resilient linear quadratic Gaussian controller, having the ability to quickly recover the nominal behavior of the closed-loop system after the attack end, is designed by updating online the Kalman filter from information given by an active version of the generalized likelihood ratio detector.

关键词： Networked control systems (NCSs) cyber physical attacks Kahnan filtering resilient control anomaly detector.

A Parallel Hybrid Testing Technique for Tri-Programming Model-Based Software Systems

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Computers, Materials & Continua 2023年第2期74卷 4501-4530页

作者： Huda Basloom mohamed Dahab Abdullah Saad AL-Ghamdi Fathy Eassa Ahmed Mohammed Alghamdi Seif haridi Department of Computer Science Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia Department of Information Systems Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia Department of Software Engineering College of Computer Science and EngineeringUniversity of JeddahJeddah21493Saudi Arabia KTH Royal Institute of Technology StockholmSweden

Recently,researchers have shown increasing interest in combining more than one programming model into systems running on high performance computing systems(HPCs)to achieve exascale by applying parallelism at multiple *** different programming paradigms,such as Message Passing Interface(MPI),Open Multiple Processing(OpenMP),and Open Accelerators(OpenACC),can increase computation speed and improve *** the integration of multiple models,the probability of runtime errors increases,making their detection difficult,especially in the absence of testing techniques that can detect these *** studies have been conducted to identify these errors,but no technique exists for detecting errors in three-level programming *** the increasing research that integrates the three programming models,MPI,OpenMP,and OpenACC,a testing technology to detect runtime errors,such as deadlocks and race conditions,which can arise from this integration has not been ***,this paper begins with a definition and explanation of runtime errors that result fromintegrating the three programming models that compilers cannot *** the first time,this paper presents a classification of operational errors that can result from the integration of the three *** paper also proposes a parallel hybrid testing technique for detecting runtime errors in systems built in the C++programming language that uses the triple programming models MPI,OpenMP,and *** hybrid technology combines static technology and dynamic technology,given that some errors can be detected using static techniques,whereas others can be detected using dynamic *** hybrid technique can detect more errors because it combines two distinct *** proposed static technology detects a wide range of error types in less time,whereas a portion of the potential errors that may or may not occur depending on the 4502 CMC,2023,vol.74,no.2 operating environme

关键词： Software testing hybrid testing technique OpenACC OpenMP MPI tri-programming model exascale computing

Hydrometallurgy two stage process for preparation of (Nd,La,Ce)_(2)O_(3) from end-of-life NiMH batteries

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Journal of Rare Earths 2024年第2期42卷 415-423,I0007页

作者： karim Tanji Khalid Ouzaouit mohamed Belghiti Isam Lamsayety Hakim Faqir Intissar Benzakour Centre de recherche REMINEX-Groupe MANAGEM MarrakechMorocco

The present work aims to investigate the recovery of light rare earth elements(LREEs) oxides from end-oflife NiMH batteries using a hydro metallurgical process followed by effective *** operational leaching parameters such as phosphoric acid concentration,temperature,and the solid-liquid ratio were first optimized by Box-Behnken *** results reveal that under optimum conditions([H_(3)PO_(4)]=2 mol/L,T=80℃,and S/L=1:10 g/mL) the leaching efficiencies of Ni,Co reach 98.1% and99.3%.While La,Ce,and Nd elements remain in the leaching residue as(La,Ce,Nd)PO_(4) with yields of 98.2%,98.6%,and 99.6% for La,Ce,and Nd,***,the(La,Ce,Nd)PO_(4) is leached with HCl acid,then the rare earth oxalate was precipitated using oxalic acid at a pH of 1.8 and then the product was calcined at 800℃ for 2 h in order to synthesize the(Nd,La,Ce)_(2)O_(3).The analysis using scanning electron microscopy(SEM) coupled with energy dispersive X-ray spectroscopy(EDX) confirms the homogeneity of(Nd,La,Ce)_(2)O_(3) particles that have two morphologies,i.e.,flower and sticks with a particle size between 3and 6 μ*** unit cell parameters of(Nd,La,Ce)_(2)O_(3) were calculated after Rietveld refinement of the XRD patterns,in the space group of Fm-3m are a=b=c=0.57921 nm and the volume equal to 0.194322 nm^(3).

关键词： NiMH batteries Hydrometallurgical process Leaching Phosphoric acid Box-Behnken Light rare earth oxides

Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield:A review

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Acta Geochimica 2024年第3期43卷 588-622页

作者： Abdel-Aal MAbdel-karim mohamed MHamdy Adel A.Surour Geology Department Faculty of ScienceZagazig UniversityZagazig 44519Egypt Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt Department of Geological Sciences Faculty of ScienceNew Galala City 43511Egypt Geology Department Faculty of ScienceCairo UniversityGiza 12613Egypt

Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and *** addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the *** main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental *** information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic *** include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle *** volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed *** on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.

关键词： Island arc assemblage Magmatism Crustal growth Neoproterozoic Arabian–Nubian Shield Eastern Desert Egypt

Preparation of ammonium nitrate-based solid composite propellants supplemented with polyurethane/nitrocellulose blends binder and their thermal decomposition behavior

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Defence Technology（防务技术） 2022年第11期18卷 2023-2033页

作者： Sabri Touidjine Moulai karim Boulkadid Djalal Trache Samir Belkhiri Abderrahmane Mezroua mohamed Islam Aleg Afaf Belkebiche Energetic Propulsion Laboratory Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj-El-Bahri16046AlgiersAlgeria Energetic Materials Laboratory Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj-El-Bahri16046AlgiersAlgeria

To improve the performance of solid composite propellants(SCPs)supplemented with ammonium nitrate(AN)as an oxidizer,the incorporation of energetic ingredients such as explosives,energetic binders or catalysts is a common effective *** this purpose,polyurethane(PU),a typical inert binder,was mixed with nitrocellulose(NC)as an energetic *** composite solid propellant compositions based on AN and NC-modified polyurethane binder with different NC ratios were *** prepared formulations were characterized using Fourier transform infrared spectroscopy(FTIR),RAMAN spectroscopy,X-ray diffraction(XRD),electron densimetry,thermogravimetric(TG)analysis,and differential scanning calorimetry(DSC).A kinetic study was then performed using the iterative KissingerAkahira-Sunose(It-KAS),Flynn-Wall-Ozawa(It-FWO),and non-linear Vyazovkin integral with compensation effect(VYA/CE)*** theoretical performances,such as theoretical specific impulse,adiabatic flame temperature,and ideal exhaust gaseous species,were also determined using the NASA Lewis Code,Chemical Equilibrium with Application(CEA).Spectroscopic examinations revealed the existence of NC and full polymerization of PU in the prepared *** to density tests,the density of the propellant increases as the nitrocellulose component *** to the thermal analysis and kinetics study,the increase in NC content catalyzed the thermal decomposition of the AN-based composite solid *** on the theoretical study,increasing the amount of NC in the propellant increased the specific impulse and,as a result,the overall performance.

关键词： Composite propellants Polyurethane Nitrocellulose Ammonium nitrate Decomposition kinetics Thermal decomposition

Deep Learning for Depression Detection Using Twitter Data

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Intelligent Automation & Soft Computing 2023年第5期36卷 1301-1313页

作者： Doaa Sami Khafaga Maheshwari Auvdaiappan KDeepa mohamed Abouhawwash Faten Khalid karim Department of Computer Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Computational Intelligence SRM Institute of Science and TechnologyKattankulathurChennai603203India Department of Computer Science and Engineering M.Kumarasamy College of EngineeringKarur639113India Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)College of EngineeringMichigan State UniversityEast LansingMI48824USA

Today social media became a communication line among people to share their happiness,sadness,and anger with their *** is necessary to know people’s emotions are very important to identify depressed people from their *** depression detection helps to save people’s lives and other dangerous mental *** are many intelligent algorithms for predicting depression with high accuracy,but they lack the deﬁnition of such *** machine learning methods help to identify depressed *** the accuracy of existing methods was not *** overcome this issue,the deep learning method is used in the proposed method for depression *** this paper,a novel Deep Learning Multi-Aspect Depression Detection with Hierarchical Atten-tion Network(MDHAN)is used for classifying the depression ***,the Twitter data was preprocessed by tokenization,punctuation mark removal,stop word removal,stemming,and *** Adaptive Particle and grey Wolf optimization methods are used for feature *** MDHAN classiﬁes the Twitter data and predicts the depressed and non-depressed ***,the proposed method is compared with existing methods such as Convolutional Neur-al Network(CNN),Support Vector Machine(SVM),Minimum Description Length(MDL),and *** suggested MDH-PWO architecture gains 99.86%accuracy,more signiﬁcant than frequency-based deep learning models,with a lower false-positive *** experimental result shows that the proposed method achieves better accuracy,precision,recall,and *** also mini-mizes the execution time.

关键词： Depression detection twitter data tweets deep learning swarm intelligence multi-aspect depression detection prediction

Mineralogy,Chemical Characteristics and Upgrading of Beach Ilmenite of the Top Meter of Black Sand Deposits of the Kafr Al-Sheikh Governorate,Northern Egypt

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1326-1338页

作者： Abdel-Aal M. ABDEL-karim mohamed I. MOUSTAFA Adel H. EI-AFANDY mohamed G. BARAKAT Faculty of Science Zagazig University Egypt Engineering Colleges Northern Border University Saudi Arabia Nuclear Materials Authority P. O. Box 530 Maadi Cairo Egypt

Egyptian beach ilmenite occurs in a relatively high content in the naturally highly concentrated superficial black sand deposits at specific beach zones in the northern parts of the Nile Delta at Rosetta. Microscopic study shows that the ilmenite occurs as fresh homogeneous black or heterogeneous multicoloured altered grains and exhibits three types （homogeneous, exsolved and altered） of ilmenite varieties. XRD data of ilmenite indicates their association with minor hematite and quartz, whereas leucoxene shows its association with Nb-rutUe, pseudorutile and hematite. Grain size distribution suggests a very fine sand size of 〉89% and 80% and a fine sand size of 10.5% and 18.3% for fresh and altered ilmenites, respectively. The density of fresh, altered ilmenite and leucoxene concentrates varies from 2.70, 2.50 to 2.40 ton/m^3, suggesting a gradual decrease from high grade fresh to leucoxene and consistent with variation in magnetic susceptibility as a consequence of the leaching of iron. Mass magnetic susceptibility reveals 97.6% of ilmenite and 92% of the altered form are obtained at 0.20 and 0.48 ampere. Fresh iimenite exhibits variable TiO2 （47.18%） and Fe2O3^T （46.10%） with minor MnO, MgO and Cr2O3 （1.22, 1.10 and 0.51%）. The altered ilmenite is higher in TiO2 （76.16%） and SiO2 （4.68%） and lower in Fe2O3^T （14.45%）, MnO, MgO and Cr2O3 （0.39, 0.52 and 0.11%） compared with the fresh form. Three concentrates of ilmenites （G1, G2 and G3） were prepared from crude ore using a Reading cross belt magnetic separator under different conditions, revealing a gradual increase of TiO2, SiO2, Al2O3 and CaO accompanied by a decrease of Fe2O3^T, MgO and Cr2O3 with repetition of the separation processes. Several ore dressing techniques were carried out to upgrade the iimenite concentrate.

关键词： Beach ilmenite mineralogy chemistry upgrading Northern Egypt