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Particle Collisions in a Lumped Particle Model

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Communications in Computational Physics 2011年第9期10卷 823-843页

作者： omar al-khayat Are Magnus Bruaset Hans Petter Langtangen Computational Geosciences CBCSimula Research LaboratoryP.O.Box 134NO-1325 LysakerNorway Department of Informatics University of OsloP.O.Box 1080BlindernNO-0316 OsloNorway Center for Biomedical Computing Simula Research LaboratoryP.O.Box 134NO-1325 LysakerNorway

This paper presents an extension of the lumped particle model in[1]to include the effects of particle *** lumped particle model is a flexible framework for the modeling of particle laden flows,that takes into account fundamental features,including advection,diffusion and dispersion of the *** this paper,we transform a binary collision model and concepts from kinetic theory into a collision procedure for the lumped particle *** apply this new collision procedure to investigate numerically the role of particle collisions in the hindered settling *** hindered settling effect is characterized by an increase in the effective drag coefficient CD that influences each particle in the *** coefficient is given by CD=(1−φ)−nC∗D,whereφis the volume fraction of particles,C∗D is the drag coefficient for a single particle,and n≃4.67 for creeping *** obtain an approximation for CD/C∗D by calculating the effective work done by collisions,and comparing that to the work done by the drag *** our numerical experiments,we observe a minimal value of n=***,by allowing high energy dissipation,an approximation for the classical value for creeping flow,n=4.7,is *** also obtain high values for n,up to n=6.5,which is consistent with recent physical experiments on the sedimentation of sand grains.

关键词： Lumped particle model particle collision hindered settling

A Lumped Particle Modeling Framework for Simulating Particle Transport in Fluids

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Communications in Computational Physics 2010年第6期8卷 115-142页

This paper presents a lumped particle model for simulating a large number of *** lumped particle model is a flexible framework in modeling particle flows,embodying fundamental features that are intrinsic in particle laden flow,including advection,diffusion and *** this paper,the particles obey a simplified version of the Bassinet-Boussinesq-Oseen equation for a single spherical ***,instead of tracking the individual dynamics of each particle,a weighted spatial averaging procedure is used where the external forces are applied to a“lump”of particles,from which an average position and velocity is *** temporal evolution of the particles is computed by partitioning the lumped particle into smaller entities,which are then transported throughout the physical *** smaller entities recombine into new particle lumps at their target *** particles prone to the effects of Brownian motion or similar phenomena,a symmetric spreading of the particles is included as *** experiments show that the lumped particle model reproduces the effects of Brownian diffusion and uniform particle transport by a fluid and *** late time scale diffusive nature of particle motion is also reproduced.

关键词： Particle modeling framework particle transport lumped particle model

Performance Analysis of the Reconfigurable Intelligent Surfaces Communication Systems

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Journal of Communications and Information Networks 2024年第2期9卷 184-191页

作者： omar Abu Ella Department of Electrical and Electronic Engineering Misurata University2659 Zawiat AlmahjoubMisurataLibya

Reconfigurable intelligent surfaces (RIS) play a vital role in meeting the growing demand for higher data rates and reliability in wireless systems. This study focuses on analyzing the performance of RIS systems to gain a deeper understanding of their *** paper presents a mathematical analysis of the RIS system,deriving closed-form formulae that express its characteristics including signal-to-noise ratio(SNR)distribution,ergodic and effective capacity,outage,and error probability. The obtained formulae are newly derived and unconditionally valid solutions. Numerical results demonstrate a close agreement between the derived formulae and MonteCarlo simulation outcomes.

关键词： ergodic capacity effective capacity outage probability bit error rate Rayleigh fading channel RISassisted communication system

Critical assessment of R410A alternatives for mini-split air conditioners in the Egyptian market

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Energy and Built Environment 2024年第3期5卷 426-445页

作者： omar M.Zaki omar Abdelaziz Mechanical Power Engineering Department Faculty of EngineeringCairo UniversityGiza 12613Egypt Department of Mechanical Engineering The American University in CairoAUC AvenueNew Cairo 11835Egypt

In this study,the potential implementation of three different low-GWP refrigerants(R32,R452B,and R454B)as replacements for R410A was *** study was performed using a simulation tool developed by the authors called RACHP-Lab,which is a vapor compression system simulation tool developed based on physics-based simulation for typical mini-split air *** simulation study was carried out and validated using experimental performance data of 10 different air conditioning units available in the Egyptian *** units included fixed-speed or variable-speed compressors and operated in cooling or heating ***-in replace-ment with the new refrigerants was carried *** R32,the capacity increased between 4.9%and 13%for cooling cases,and 6.3%and 12.4%for heating ***,COP did not improve in all *** R452B and R454B with direct replacement,the capacity nearly remained the same,with an increase of COP between 1.6%and 8.0%.Soft optimization was also conducted on cooling cases where compressor suction superheat,condenser subcooling,and compressor volumetric speed were optimized to maximize COP while maintaining the original capacity of R410A.R32 showed an improvement of COP over R410A between 4.6%and 15.5%,while for R452B and R454B between 2.2%and 13.2%.

关键词： Air conditioner Heat pump alternative refrigerants Vapor compression cycle modeling

Genotype-based precision nutrition strategies for the prediction and clinical management of type 2 diabetes mellitus

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World Journal of Diabetes 2024年第2期15卷 142-153页

作者： omar Ramos-Lopez Medicine and Psychology School Autonomous University of Baja CaliforniaTijuana 22390Baja CaliforniaMexico

Globally,type 2 diabetes mellitus(T2DM)is one of the most common metabolic disorders.T2DM physiopathology is influenced by complex interrelationships between genetic,metabolic and lifestyle factors(including diet),which differ between populations and geographic *** fact,excessive consumptions of high fat/high sugar foods generally increase the risk of developing T2DM,whereas habitual intakes of plant-based healthy diets usually exert a protective ***,genomic studies have allowed the characterization of sequence DNA variants across the human genome,some of which may affect gene expression and protein functions relevant for glucose *** comprehensive literature review covers the impact of gene-diet interactions on T2DM susceptibility and disease progression,some of which have demonstrated a value as biomarkers of personal responses to certain nutritional ***,novel genotype-based dietary strategies have been developed for improving T2DM control in comparison to general lifestyle ***,progresses in other omics areas(epigenomics,metagenomics,proteomics,and metabolomics)are improving current understanding of genetic insights in T2DM clinical *** more investigation is still needed,the analysis of the genetic make-up may help to decipher new paradigms in the pathophysiology of T2DM as well as offer further opportunities to personalize the screening,prevention,diagnosis,management,and prognosis of T2DM through precision nutrition.

关键词： Type 2 diabetes mellitus Nutrigenetics Single nucleotide polymorphism Genotype Diet Precision nutrition

Rare earth based MgPm_(2)X_(4)(X=S,Se) spinel chalcogenides for spintronic and thermoelectric applications

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Journal of Rare Earths 2024年第8期42卷 1577-1585,I0006页

作者： Tariq M.al-Daraghmeh omar Zayed Ghulam M.Mustafa Taharh Zelai Bisma Younas Hind albalawi S.Bouzgarrou Othman Hakami Q.Mahmood Khaild I.Hussein Basic Sciences Department King Abdullah Ⅱ School of EngineeringPrincess Sumaya University For TechnologyP.O.Box 1438Al-jubaiha11941AmmanJordan Department of Physics Division of Science&TechnologyUniversity of EducationLahorePakistan Department of Physics Faculty of ScienceJazan University JazanSaudi Arabia Department of Physics The University of LahoreLahorePakistan Department of Physics College of SciencesPrincess Nourah bint Abdulrahman University(PNU)P.O.Box 84428Riyadh11671Saudi Arabia Department of Physics College of ScienceQassim UniversityPo.64BuraidahSaudi Arabia Laboratoire de Microelectronique et Instrumentation(UR 03/13-04) Faculte des Sciences de MonastirAvenue de I'Environnement 5000MonastirTunisia Department of Chemistry Faculty of ScienceJazan University JazanSaudi Arabia Basic&Applied Scientific Research Center Department of PhysicsCollege of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam 31441Saudi Arabia Department of Radiological Sciences College of Applied Medical SciencesKing Khalid UniversityAbha61421Saudi Arabia

In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were *** energy difference in ferromagnetic and antiferromagnetic states reveals the stability of MgPm_(2)(S/Se)_(4) in the ferromagnetic *** co mputation of enthalpy of formation also ascertains thermodynamic stability of crystal ***-dependent band structure and density of states analysis reveal ferromagnetic semiconducting character showing different electronic behavior in both spin *** room temperature ferromagnetism,spin polarization and Curie temperature are estimated from exchange energies *** addition,exchange constants(N_(0)α and N_(0)β),exchange energy Δ_(x)(pd),crystal ifeld energy,and double exchange mechanism were studied to explore the magnetic ***,the electrical conductivity,thermal conductivity,Seebeck co-efficient,and power factor show effect on electrons spin and their potential for thermoelectric devices.

关键词： Rare earth elements Spintronic applications Thermoelectric effects Exchange energies

Assessment of Heavy Metals Contamination of Topsoil and Street Dust around Cement Factory in Southern Jordan

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Journal of Environmental Protection 2024年第6期15卷 672-696页

作者： omar ali al-Khashman alia omar al-Khashman Navasingh Rajesh Jesudoss Hynes Hani M. alnawafleh Pitchumani Shenbaga Velu Department of Environmental Engineering Al-Hussein Bin Talal University Maan Jordan MD/Ministry of Health Amman Jordan Department of Mechanical Engineering Mepco Schlenk Engineering College Si-vakasi India Department of Mining and Mineral Engineering Al-Hussein Bin Talal University Maan Jordan Department of Mechanical Engineering PSR Engineering College Sivakasi India

Evaluation of assessment of the metal processes governing the metals distribution in soil and dust samples is very significant and protects the health of human and ecological system. Recently, special attention has given to the assessment of metals pollution impact on soil and dust within industrial areas. This study aims to assess the metal contamination levels in the topsoil and street dust around the cement factory in Qadissiya area, southern Jordan. The levels of seven metals (namely Fe, Zn, Cu, Pb, Cr, Cd, and Mn) were analyzed using Flame Atomic Absorption Spec-trophotometer (FAAS) to monitor, evaluate, and to compare topsoil and road dust pollution values of metals of the different types of urban area. The physicochemical parameters which believed to affect the mobility of metals in the soil of the study area were determined such as pH, EC, TOM, CaCO3 and CEC. The levels of metal in soil samples are greater on the surface but decrease in the lower part as a result of the basic nature of soil. The mean values of the metals in soil can be arranged in the following order: Zn > Pb > Mn > Fe > Cu > Cr > Cd. The relatively high concentration of metals in the soil sample was attributed to anthropogenic activities such as traffic emissions, cement factory and agricultural activities. Correlation coefficient analysis and the spatial distribution of indices and the results of statistical analysis indicate three groups of metals: Fe and Mn result by natural origin, Zn, Pb, Cu and Zn result by anthropogenic origin (mainly motor vehicle traffic and abrasion of tires) while Cd is mixed origin. The higher content level values of metals of anthropogenic source in soil samples indicate that it is a source of contamination of air in the studied area. .

关键词： Cement Dust Heavy Metals Contamination Risk Assessment Statistical Analysis Jordan

Explicit solutions to the time-fractional generalized dissipative Kawahara equation

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Journal of Ocean Engineering and Science 2024年第4期9卷 348-352页

作者： Marwan alquran Mohammed ali omar alshboul Department of Mathematics and Statistics Jordan University of Science and TechnologyIrbid 22110Jordan

In this paper,the generalized dissipative Kawahara equation in the sense of conformable fractional derivative is presented and solved by applying the tanh-coth-expansion and sine-cosine function *** quadratic-case and cubic-case are investigated for the proposed *** solutions are obtained with highlighting to the effect of the presence of the alternative fractional-derivative and the effect of the added dissipation term to the generalized Kawahara *** graphical analysis is presented to support the findings of the ***,we believe that the obtained results in this work will be important and valuable in nonlinear sciences and ocean engineering.

关键词： Time-fractional Kawahara equation Conformable-derivative Tanh-coth-expansion method Sine-cosine function method

Advanced Optimized Anomaly Detection System for IoT Cyberattacks Using Artificial Intelligence

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Computers, Materials & Continua 2024年第2期78卷 1525-1545页

作者： ali Hamid Farea omar H.alhazmi Kerem Kucuk Department of Computer Science Taibah UniversityMedina42315Saudi Arabia Department of Software Engineering Kocaeli UniversityKocaeli41001Turkey

While emerging technologies such as the Internet of Things(IoT)have many benefits,they also pose considerable security challenges that require innovative solutions,including those based on artificial intelligence(AI),given that these techniques are increasingly being used by malicious actors to compromise IoT *** an ample body of research focusing on conventional AI methods exists,there is a paucity of studies related to advanced statistical and optimization approaches aimed at enhancing security *** contribute to this nascent research stream,a novel AI-driven security system denoted as“AI2AI”is presented in this ***2AI employs AI techniques to enhance the performance and optimize security mechanisms within the IoT *** also introduce the Genetic algorithm Anomaly Detection and Prevention Deep Neural Networks(GAADPSDNN)sys-tem that can be implemented to effectively identify,detect,and prevent cyberattacks targeting IoT ***,this system demonstrates adaptability to both federated and centralized learning environments,accommodating a wide array of IoT *** evaluation of the GAADPSDNN system using the recently complied WUSTL-IIoT and Edge-IIoT datasets underscores its *** an impressive overall accuracy of 98.18%on the Edge-IIoT dataset,the GAADPSDNN outperforms the standard deep neural network(DNN)classifier with 94.11%***,with the proposed enhancements,the accuracy of the unoptimized random forest classifier(80.89%)is improved to 93.51%,while the overall accuracy(98.18%)surpasses the results(93.91%,94.67%,94.94%,and 94.96%)achieved when alternative systems based on diverse optimization techniques and the same dataset are *** proposed optimization techniques increase the effectiveness of the anomaly detection system by efficiently achieving high accuracy and reducing the computational load on IoT devices through the adaptive selection of active features.

关键词： Internet of Things security anomaly detection and prevention system artificial intelligence optimization techniques