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Dynamic Vehicular Clustering Enhancing Video on Demand Services Over Vehicular Ad-hoc Networks

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Computers, materials & Continua 2022年第8期72卷 3493-3510页

作者： m.Almutiq L.Sellami b.Alaya Department of management Information Systems and Production management College of Business and EconomicsQassim University6633Buraidah51452Saudi Arabia CONPRI Laboratory University of GabesTunisia IResComath Laboratory University of GabesTunisia

Nowadays,video streaming applications are becoming one of the tendencies driving vehicular network users.In this work,considering the unpredictable vehicle density,the unexpected acceleration or deceleration of the different vehicles included in the vehicular traffic load,and the limited radio range of the employed communication scheme,we introduce the“Dynamic Vehicular Clustering”(DVC)algorithm as a new scheme for video streaming systems over vehicular ad-hoc networks(VANET).The proposed algorithm takes advantage of the small cells concept and the introduction of wireless backhauls,inspired by the different features and the performance of the Long Term Evolution(LTE)-Advanced network.Vehicles are clustered together to form dynamically ad-hoc sub-networks included in the vehicular network.The goal of our clustering algorithm is to take into account several characteristics,such as the vehicle’s position and acceleration to reduce latency and packet loss.Therefore,each cluster is counted as a small cell containing vehicular nodes and an access point that is elected regarding some particular specifications.based on the exceptional features of the LTE-Advanced network(small cells and wireless backhauls)the DVC algorithm is a promising scheme for video streaming services over VANET systems.Experiments were carried out with a virtual topology of the VANET network created with four clusters to implement the DVC algorithm.The results were compared with other algorithms such as Virtual Trust-ability Data transmission(VTD),Named Data Networking(NDN),and Socially Aware Security message Forwarding(SASmF).Our algorithm can effectively improve the transmission rate of data packets at the expense of a slight increase in end-to-end delay and control overhead.

关键词： 5G video-on-demand vehicular ad-hoc network mobility vehicular traffic load small cell wireless backhaul LTE-advanced latency packet loss

A modeling Framework for Coupling Plasticity with Species Diffusion

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Communications in Computational Physics 2022年第6期32卷 83-125页

作者： m.S.Joshaghani K.b.Nakshatrala Department of Civil and Environmental Engineering University of HoustonTexas

This paper presents a modeling framework—mathematical model and computational framework—to study the response of a plastic material due to the presenceand transport of a chemical species in the host material. Such a modeling frameworkis important to a wide variety of problems ranging from Li-ion batteries, moisturediffusion in cementitious materials, hydrogen diffusion in metals, to consolidation ofsoils under severe loading-unloading regimes. The mathematical model incorporatesexperimental observations reported in the literature on how (elastic and plastic) material properties change because of the presence and transport of a chemical species.Also, the model accounts for one-way (transport affects the deformation but not viceversa) and two-way couplings between deformation and transport subproblems. Theresulting coupled equations are not amenable to analytical solutions;so, we present arobust computational framework for obtaining numerical solutions. Given that popular numerical formulations do not produce nonnegative solutions, the computationalframework uses an optimized-based nonnegative formulation that respects physicalconstraints (e.g., nonnegative concentrations). For completeness, we also show theeffect and propagation of the negative concentrations, often produced by contemporary transport solvers, into the overall predictions of deformation and concentrationfields. Notably, anisotropy of the diffusion process exacerbates these unphysical violations. Using representative numerical examples, we discuss how the concentrationfield affects plastic deformations of a degrading solid. based on these numerical examples, we also discuss how plastic zones spread because of material degradation.To illustrate how the proposed computational framework performs, we report variousperformance metrics such as optimization iterations and time-to-solution.

关键词： Species diffusion plasticity non-negative solutions damage mechanics degradation/healing coupled problem

Conditional Probability Approach for Fault Detection in Photovoltaic Energy Farms

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Computer Systems Science & Engineering 2022年第9期42卷 1109-1120页

作者： Nagy I.Elkalashy Ibrahim b.m.Taha Electrical Engineering Department Faculty of EngineeringMenoufia University32511Egypt Electrical Engineering Department College of EngineeringTaif University21944Saudi Arabia

Detection of electric faults in photovoltaic (PV) farms enhances a sustainable service continuity of farm energy generation. In this paper, a probabilisticfunction is introduced to detect the faults in the PV farms. The conditional probability functions are adopted to detect different fault conditions such as internalstring faults, string-to-string faults, and string-to-negative terminal faults. As thediodes are important to make the PV farms in-service safely during the faults,the distribution currents of these faults are evaluated with different concepts ofdiode consideration as well as without considering any diode installation. Thispart of the study enhances the diode utilization in the PV farms concerning theprotection point of view. The PV string currents are used as inputs to the conditional probability detection algorithms. However, the setting of the fault detectiontechnique is not portable for the other PV systems due to broad ranges of PV system ratings. To accordingly generalize the proposed fault detection algorithm, thePV string currents are first normalized to the total array current for universallyapplying the detection function at different PV string ratings. The limiting faultresistances are evaluated to show the sensitivity of the proposed fault detector.The results ensure the application of the proposed probabilistic detection functionfor PV farms.

关键词： Photovoltaic farm fault detection conditional probability diodes

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied mathematics and mechanics(English Edition) 2024年第1期45卷 197-216页

作者： C.G.PAVITHRA b.J.GIREESHA m.L.KEERTHI Department of PG Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India Department of mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTm) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTm) trihybrid nanofluid magnetic field

Effects of stretching/shrinking on the thermal performance of a fully wetted convective-radiative longitudinal fin of exponential profile

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Applied mathematics and mechanics(English Edition) 2022年第3期43卷 389-402页

作者： b.J.GIREESHA m.L.KEERTHI G.SOWmYA Department of PG Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India Department of PG mathematics The National College(Auto)Bangalore 560070India

The present investigation focuses on the thermal performance of a fully wet stretching/shrinking longitudinal fin of exponential profile coated with a mechanism like a conveyer belt.The modeled equation is non-dimensionalized and solved by applying the Runge-Kutta-Fehlberg(RKF)method.The effects of parameters such as the wet parameter,the fin shape parameter,and the stretching/shrinking parameter on the heat transfer and thermal characteristics of the fin are graphically analyzed and discussed.It is inferred that the negative effects of motion and internal heat generation on the fin heat transfer rate can be lessened by setting a shrinking mechanism on the fin surface.The current examination is inclined towards practical applications and is beneficial to the design of fins.

关键词： fully wet longitudinal fin convection exponential profile internal heat generation moving fin

A case study of the stability of a non-typical bleeder entry system at a U.S.longwall mine

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International Journal of mining Science and Technology 2020年第1期30卷 25-31页

作者： T.m.Klemetti m.A.Van Dyke I.b.Tulu D.Tuncay NIOSH Pittsburgh mining Research Division Pittsburgh 15236USA Department of mining Engineering West Virginia UniversityMorgantown 26505USA

Longwall abutment loads are influenced by several factors,including depth of cover,pillar sizes,panel dimensions,geological setting,mining height,proximity to gob,intersection type,and size of the gob.How does proximity to the gob affect pillar loading and entry condition?Does the gob influence depend on whether the abutment load is a forward,side,or rear loading?Do non-typical bleeder entry systems follow the traditional front and side abutment loading and extent concepts?If not,will an improved understanding of the combined abutment extent warrant a change in pillar design or standing support in bleeder entries?This paper details observations made in the non-typical bleeder entries of a moderate depth longwall panel—specifically,data collected from borehole pressure cells and roof extensometers,observations of the conditions of the entries,and numerical modeling of the bleeder entries during longwall extraction.The primary focus was on the extent and magnitude of the abutment loading experienced due to the extraction of the longwall panels.Due to the layout of the longwall panels and bleeder entries,the borehole pressure cells(bPCs)and roof extensometers did not show much change due to the advancing of the first longwall.However,they did show a noticeable increase due to the second longwall advancement,with a maximum of about 4 mPa of pressure increase and 5mmof roof deformation.The observations of the conditions showed little to no change from before the first longwall panel extraction began to when the second longwall panel had been advanced more than 915 m.Localized pillar spalling was observed on the corners of the pillars closest to the longwall gob as well as an increase in water in the entries.In addition to the observations and instrumentation,numerical modeling was performed to validate modeling procedures against the monitoring results and evaluate the bleeder design.ITASCA Consulting Group’s FLAC3D numerical modeling software was used to evaluate the bleeder entries.The results of the models indicate

关键词： Abutment loading Longwall Instrumentation bore hole pressure cells Pillar loading Yield pillar bleeder pillar

Geochemistry and spectrometric prospection of younger granites and granitic pegmatites bearing uranium mineralization at G.Kab El Rakeb area, Central Eastern Desert, Egypt

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Acta Geochimica 2021年第4期40卷 575-601页

作者： Gehad m.Saleh bahaa m.Emad Ibrahim b.Abdel Kader Nuclear materials Authority El MaadiP.O.Box 530CairoEgypt

The present study deals with the detailed field geology,mineralogy,geochemistry,and spectrometric prospection of rare metals and radioactive minerals associated with granitic pegmatites in the Gabal Um LassafAbu Dob-Um Atelia-Kadabora-Kab El Rakeb area(LDAKK),which are situated in the central Eastern Desert of Egypt.The study area is composed of granodiorites and monzogranites.The latter is dissected by granitic pegmatites with a discriminatory distribution of economically important mineralization(rare-metals and U-Th minerals).The granitic pegmatites display a zoning structure composed of feldspar-rich zones enveloping pockets of mica(mostly muscovite) and all zoning internal quartz core.microscopically,the monzogranite and granitic pegmatites are composed of potash-feldspar,albite,and quartz with a small amount of biotite and muscovite.The mineralogical investigation of the highly radioactive zones in the granitic pegmatite shows enrichment in kasolite,uranothorite,thorite,xenotime,columbite,zircon,bismuth,and galena.Geochemically,the granitic pegmatites are enriched with high field strength elements(HFSE;Zr,Nb,Th,and U) and ion lithophilic elements(LILE;Rb,and Pb) and depleted in ba,Sr,and Eu.They are strongly peralkaline to metalumainous except for two samples,which are peraluminous.They are formed by partial melting of metagreywackes at depth.The studied granitic pegmatites could belong to the NYF family(Niobium-Yttrium-Fluorine family) according to the geochemistry of the trace elements.The studied granitic pegmatites show deep negative Eu anomaly and display a strong m-type tetrad effect of rare earth elements.The field spectroscopy measurements showed the localization of the radiometric anomalous associated with the granitic pegmatites,which are intruded in the granitic host rocks.Their eU and eTh contents reached up to 316 and 1367 ppm,respectively.Uranium and thorium occurrences in the investigated granitic pegmatites are related to magmatic(syngenetic)origin with hydrothermal(epigenetic) input.The magm

关键词： Geochemistry Gabal Um Lassaf-Abu Dob-Um Atelia-Kadabora-Kab El Rakeb area(LDAKK) Uranium REE Egypt

The possible source of uranium mineralization in felsic volcanic rocks,Eastern Desert,Egypt of the Arabian-Nubian Shield:Constraints from whole-rock geochemistry and spectrometric prospection

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Acta Geochimica 2021年第5期40卷 819-845页

作者： Gehad.m.Saleh bahaa.m.Emad Ibrahim.b.Abdel Kader Rania.m.Sakr Nuclear materials Authority El MaadiP.O.Box 530CairoEgypt

The present work deals with the detailed geology,mineralogy,geochemistry,and spectrometric prospection of the felsic volcanic rocks at the Eastern Desert,Egypt of the Arabian-Nubian Shield.Felsic volcanic rocks are an essential source for rare earth elements(REEs)and uranium occurrences in this area.They are compositionally uniform with tholeiitic to calc-alkaline affinities,peraluminous and belong to the series of rhyolite with high-K melt.They exhibit more enrichment in high field strength elements(HFSE,e.g.Zr,Ta,Nd,Th,and U)and large-ion lithophile elements(LILE,e.g.Pb and Rb)compared to the country rocks of the studied area,with REE ranging from 188.20 to 442.70 ppm and strong depletion in Ti,Sr,P with deep negative Eu oddities.The felsic volcanic rocks were mostly generated from the partial melting of quartz-amphibolite facies accreted during the Neoproterozoic.Positive oddities of Zr-U-Th for the felsic volcanic rocks determine the involvement of crustal materials.Felsic volcanic rocks are found in A-type suites of magma and represent highly fractionated rocks derived from rhyolitic magma,with insignificant interaction with continental crust in the low-pressure environment and during fractional crystallization.Felsic volcanic rocks have higher values of radioactivity in which eU range from 0.5 to 121 ppm and eTh from 1.0 to 415.10 ppm.The high values of eU and eTh can be ascribed to the mineralization of uranium and the presence of accessory minerals of radiogenic nature such as uranophane,uranothorite,zircon,and monazite.Uranophane is considered as the mineral with most enriched uranium contents in the studied felsic volcanic rocks in which(UO2=87.30 wt%).Also,they are enriched with REE-bearing accessory minerals comprising allanite,titanite,and apatite.The geological investigations of the felsic volcanic rocks in the studied areas are inappropriate to clear the feasible economic potentialities of rare earth elements and U occurrences;itemized and invaluable explorational work is as yet needed.Whilst,the e

关键词： Felsic volcanic rocks Geochemistry REE Uranium mineralization Egypt Arabian-Nubian Shield

Recycling of spent lithium-ion batteries as a sustainable solution to obtain raw materials for different applications

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Journal of Energy Chemistry 2023年第4期79卷 118-134页

作者： V.m.Leal J.S.Ribeiro E.L.D.Coelho m.b.J.G.Freitas Federal University of Espírito Santo Department of ChemistryLaboratory of Electrochemistry and ElectrochemistryAv.Fernando Ferrari514VitóriaES 29075-910Brazil

Lithium-ion batteries(LIbs)containing graphite as anode material and LiCoO_(2),Limn_(2)O_(4),and LiNi_(x)mn_(y)Co_(z)O_(2) as cathode materials are the most used worldwide because of their high energy density,capacitance,durability,and safety.However,such widespread use implies the generation of large amounts of electronic waste.It is estimated that more than 11 million ton of LIbs waste will have been generated by 2030.battery recycling can contribute to minimizing environmental contamination and reducing production costs through the recovery of high-value raw materials such as lithium,cobalt,and nickel.The most common processes used to recycle spent LIbs are pyrometallurgical,biometallurgical,and hydrometallurgical.Given the current scenario,it is necessary to develop environmentally friendly methods to recycle batteries and synthesize materials with multiple technological applications.This study presents a review of industrial and laboratory processes for recycling spent LIbs and producing materials that can be used in new batteries,energy storage devices,electrochemical sensors,and photocatalytic reactions.

关键词： Li-ion batteries Recycling Cathode battery Hydrometallurgical Pyrometallurgical