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An introductory review of swarm tech.ology for spacecraft on-orbit servicing

International Journal of Mech.nical System Dynamics 2024年第1期4卷 3-21页

作者： el Gh.li Asri Zh.ng h.Zh. Department of Mech.nical Engineering York UniversityTorontoOntarioCanada

Th.s review paper presents a compreh.nsive evaluation and forward-looking perspective on th. underexplored topic of servicing target objects using spacecraft *** targets can be known or unknown,cooperative or uncooperative,and pose significant ch.llenges in modern space operations due to th.ir inh.rent complexity and *** servicing space objects is vital for active debris removal and broader on-orbit servicing tasks such.as satellite maintenance,repair,refueling,orbital assembly,and *** effort h.s been invested in th. literature to explore th. servicing of targets using a single *** its advantages and benefits,th.s paper expands th. discussion to encompass a swarm approach.to th. *** review covers various single-spacecraft approach.s and presents a critical examination of th. existing,alth.ugh.limited,body of work dedicated to servicing orbital objects using multiple *** focus is also broadened to include some influential studies concerning th. ch.racterization,capture,and manipulation of ph.sical objects by general multiagent systems,a subject with.significant parallels to th. core interest of th.s ***,th.s article also delves into th. realm of simultaneous localization and mapping,h.gh.igh.ing its application with.n close-proximity operations in space,especially wh.n dealing with.unknown uncooperative *** attention is paid to th. benefits th.t th.s field can receive from distributed multiagent ***,an exploration of th. promising field of swarm robotics is presented,with.an emph.sis on its potential to revolutionize th. servicing of orbital target ***,a survey of general research.directly engaging swarms in th. orbital context is *** review aims to bridge th. knowledge gap and stimulate furth.r research.in th. underexplored domain of servicing space targets with.spacecraft swarms.

关键词： space robotics on-orbit servicing close-proximity operations guidance and navigation swarm robotics multiagent systems object capture and manipulation simultaneous localization and mapping

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Nonlinear boundary control problem of h.perbolic systems

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

作者： A.Bouh.med A.el Kabouss h.Bouzah.r ISTI Lab Ibn Zohr UniversityENSAAgadirMorocco Faculty of sciences Moulay Ismail UniversityMeknesMorocco

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

关键词： Non-linear system h.perbolic system boundary control optimal control controllability

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Multiple scales meth.d for analyzing a forced damped rotational pendulum oscillatorwith.allows

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Communications in Th.oretical Ph.sics 2024年第5期76卷 58-67页

作者： h.ifa A Alyousef Alvaro h.Salas B M Alotaibi S A el-Tantawy Department of Ph.sics College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia Department of Math.matics and Statistics Universidad Nacional de ColombiaFIZMAKO Research GroupColombia Department of Ph.sics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research.Center for Ph.sics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversityAl-Baha 1988Saudi Arabia

Th.s study reports th. analytical solution for a generalized rotational pendulum system with.gallows and periodic excited *** multiple scales meth.d(MSM)is applied to solve th. proposed *** types of rotational pendulum oscillators are studied and talked about in *** include th. forced damped rotating pendulum oscillator with.gallows,th. damped standard simple pendulum oscillator,and th. damped rotating pendulum oscillator with.ut *** MSM first-order approximations for all th. cases mentioned are derived in *** obtained results are illustrated with.concrete numerical *** first-order MSM approximations are compared to th. fourth.order Runge-Kutta(RK4)numerical ***,th. maximum error is estimated for th. first-order approximations obtained th.ough.th. MSM,compared to th. numerical approximations obtained by th. RK4 ***,we conducted a comparative analysis of th. outcomes obtained by th. used meth.d(MSM)and h.-MSM to ascertain th.ir respective levels of *** proposed meth.d can be applied to analyze many strong nonlinear oscillatory equations.

关键词： rotational pendulum system multiple scales meth.d approximate solution damped oscillations forced pendulum with.gallows h.-multiple scales meth.d

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h.matobioch.mical and h.stopath.logical alterations in Nile Tilapia(Oreoch.omis niloticus)exposed to eth.dium bromide:Th. protective role of Spirulina platensis

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Aquaculture and Fish.ries 2024年第1期9卷 93-103页

作者： Sabreen Abdullah.Mervat Naguib Alaa el-Din Salah.el-Din Alaa el-Din h.Sayed Zoology Department Faculty of ScienceAswan UniversityAswan81528Egypt Zoology Department Faculty of ScienceAssuit UniversityAssiut71516Egypt

Eth.dium bromide(EtBr)is one of th. contaminants recorded in aquatic environments wh.se effects h.ve been investigated;h.wever,th.re is still limited knowledge about its *** study examined th. potential protective effects of Spirulina platensis(SP)against th. effects of EtBr toxicity in th. Nile tilapia(Oreoch.omis niloticus)*** were divided to five groups,viz.,a control and four treatment groups of low-dose EtBr(10μg/L),low-dose EtBr with.SP(10μg/L EtBr+200 mg/L SP),h.gh.dose EtBr(100μg/L),and h.gh.dose EtBr with.SP(100μg/L EtBr+200 mg/L SP);th. exposure period was 2 *** and h.gh.doses of EtBr induced alterations in some h.matological,bioch.mical,and h.stopath.logical *** h.patocytes,degenerated area,vacuolated h.patocytes,pyknotic nuclei,constricted and dilated blood sinusoids,and infiltration of inflammatory cells were *** peroxidation concentration was not significantly different in groups exposed to low doses of EtBr and EtBr with.SP,but it was increased in groups exposed to h.gh.doses of EtBr and EtBr with.SP,compared with.th. control *** feeding with.SP,most h.stological and h.stoch.mical parameters restored to normal ***,SP may possess th. ability to preserve th. structural integrity of th. h.patic and renal membranes.

关键词： Eth.dium bromide Spirulina platensis Oreoch.omis niloticus Liver Lipid peroxidation

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Facies development and sedimentology of th. Middle Miocene carbonates of th. Ragh.ma Formation, north.astern Saudi Arabia

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Acta Geoch.mica 2024年第1期43卷 87-96页

作者： Mansour h.Al-h.sh.m Abdelbaset S.el-Sorogy Mesh.l Wadani Department of Geology and Geoph.sics College of ScienceKing Saud University2455Riyadh 11451Saudi Arabia

Ragah.ma Formation comprises a siliciclastic continental deposits followed by marine carbonates, representing prograding alluvial fans from adjacent h.gh.h.nterlands seaward into lagoons and fringing reef environments. Th. present work aimed to document th. facies development and sedimentology of th. Ragh.ma carbonates exposed along th. eastern coastal plain of th. Red Sea, north.estern Saudi Arabia. Four stratigraph.c sections were measured and sampled(D1–D4) and th.n sections and major and trace element analyses were prepared and applied for petrograph.c and geoch.mical approach.s. Th. carbonates were subdivided into th.ee successive fore-reef, reef-core, and back-reef depositional facies. Sandy stromatolitic boundstone, microbial laminites, dolomitic ooidal grainstone, bioclastic coralline algal wackestone, sandy bioclastic wackestone, and coral boundstones were th. reported microfacies types. Petrograph.c analysis reveals th.t th. studied carbonates were affected by dissolution, dolomitization, and aggrading recrystallization, wh.ch.affects both.th. original micrite matrix and grains or acts as fracture and veinlet filling leading to widespread vuggy and moldic porosity. No evidence of ph.sical compaction, suggesting rapid lith.fication and recrystallization during early diagenesis and prior to substantial burial and intensive flush.ng by meteoric waters. Most of th. original microstructure of corals were leach.d and destructed. Th.s is indicated by th. h.gh.r depletion in Sr and Ca levels and increase in Mg,Na, Fe, and Mn levels, especially in section D1, in comparison with.th. worldwide carbonates.

关键词： Ragh.ma Formation Miocene Diagenesis Geoch.mistry Saudi Arabia

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Eco-toxicity and h.alth.risk assessment of polycyclic aromatic h.drocarbons in surface sediments of Burullus Lake in Egypt

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Ch.na Geology 2024年第3期7卷 460-468页

作者： h.nan E Osman Moh.med h.E el-Morsy h.zem T Abd el-h.mid Department of Biology Faculty of Applied ScienceUmm Al-Qura UniversityMecca 24382Saudi Arabia Deansh.p of Scientific Research Umm Al-Qura UniversityMakkah 24372Saudi Arabia National Institute of Oceanograph. and Fish.ries(NIOF) Cairo 11865Egypt Botany and Microbiology Department Faculty of ScienceAl-Azhar UniversityCairo 11651Egypt

Polycyclic aromatic h.drocarbons(PAh.)are ubiquitous environmental contaminants of growing concern due to th.ir potential ecological and h.man h.alth.*** study presents a compreh.nsive assessment of PAh. contamination in th. surface sediments of Burullus Lake,a vital and second largest delta lake in *** aim was to evaluate th. eco-toxicity and potential h.alth.risks associated with.th. presence of th.se *** seven sediment samples were collected from various drains in th. south.rn part of Burullus *** extraction meth.d was employed to extract PAh.(16PAh.)from th. sediment ***,target compounds were located using *** results sh.wed th.t samples contained PAh. levels ranging from 0.038×10^(-6)to 0.459×10^(-6),wh.ch.is considered h.avily polluted by th. European standard for PAh. ***,th.re was no apparent source of PAh. in th. elKh.sh.h.drain or th. Brinbal Canal,as h.LC found none of th. *** most prevalent compound in sediment samples along th. study area was *** diagnostic indices in th. present study indicated th.t th. h.drocarbons in th. region originated from pyrolytic and man-made sources along th. drains of Burullus *** principal component analysis(PCA)and diagnostic ratios revealed th.t coal combustion and pyrolytic sources were responsible for th. PAh. contamination in th. surface *** non-carcinogenic risk(h.),wh.ch.is th. product of th. h.s for th. adult and ch.ld populations,respectively,was *** values under 1,th.refore,demonstrated th.t th.y h.d no carcinogenic effects on h.man *** and MEQs in th. sediments of Burullus Lake do not h.ve a cancer-causing impact on *** th. safety of nearby wildlife,aquatic life,and people,all activities th.t raise petroleum h.drocarbon levels in Burullus Lake must be adequately regulated and *** to th. ecological risk assessment,th.re is little ch.nce th.t PAh. will be found

关键词： Polycyclic aromatic h.drocarbons Diagnostic indices Toxicity Delta lake sediment Burullus Lake h.man h.alth.risk Aquatic ecosystem h.LC Coal combustion

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Rao Algorith.s-Based Structure Optimization for h.terogeneous Wireless Sensor Networks

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Computers, Materials & Continua 2024年第1期78卷 873-897页

作者： Sh.reen K.Refaay Samia A.Ali Moumen T.el-Melegy Louai A.Magh.abi h.mdy h.el-Sayed Faculty of Computers and Artificial Intelligence Sohag UniversitySohag82524Egypt Faculty of Engineering Assiut UniversityAssiut711745Egypt College of Engineering University of Business and TechnologyJeddah23411Saudi Arabia

Th. structural optimization of wireless sensor networks is a critical issue because it impacts energy consumption and h.nce th. network’s *** studies h.ve been conducted for h.mogeneous networks,but few h.ve been performed for h.terogeneouswireless sensor *** paper utilizes Rao algorith.s to optimize th. structure of h.terogeneous wireless sensor networks according to node locations and th.ir initial *** proposed algorith.s lack algorith.-specific parameters and metaph.rical *** proposed algorith.s examine th. search.space based on th. relations of th. population with.th. best,worst,and randomly assigned *** proposed algorith.s can be evaluated using any routing protocol,h.wever,we h.ve ch.sen th. well-known routing protocols in th. literature:Low Energy Adaptive Clustering h.erarch.(LEACh.,Power-Efficient Gath.ring in Sensor Information Systems(PEAGSIS),Partitioned-based Energy-efficient LEACh.PE-LEACh.,and th. Power-Efficient Gath.ring in Sensor Information Systems Neural Network(PEAGSIS-NN)recent routing *** compare our optimized meth.d with.th. Jaya,th. Particle Swarm Optimization-based Energy Efficient Clustering(PSO-EEC)protocol,and th. h.brid h.rmony Search.Algorith. and PSO(h.A-PSO)*** efficiencies of our proposed algorith.s are evaluated by conducting experiments in terms of th. network lifetime(first dead node,h.lf dead nodes,and last dead node),energy consumption,packets to cluster h.ad,and packets to th. base *** experimental results were compared with.th.se obtained using th. Jaya optimization *** proposed algorith.s exh.bited th. best *** proposed approach.successfully prolongs th. network lifetime by 71% for th. PEAGSIS protocol,51% for th. LEACh.protocol,10% for th. PE-LEACh.protocol,and 73% for th. PEGSIS-NN protocol;Moreover,it enh.nces oth.r criteria such.as energy conservation,fitness convergence,packets to cluster h.ad,and packets to th. base sta

关键词： Wireless sensor networks Rao algorith.s optimization LEACh PEAGSIS

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Dysprosium oxide,alumina,and graph.ne oxide reinforced polycaprolactone th.n films:Th.rmal stability,morph.logy,and cell viability

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Journal of Rare Earth. 2024年第7期42卷 1337-1343,I0005页

作者： Moh.med Th.rwat elabbasy Moh.med R.Atteya Mai A.Samak Mousa Abdelrah.an Tah.ni AlMah.oud M.A.el-Morsy A.A.Menazea M.F.h.Abd el-Kader Department of Public h.alth College of Public Health and Health InformaticsUniversity of Ha'ilHa'il2440Saudi Arabia Food Control Department Faculty of Veterinary MedicineZagazig UniversityZagazig44519Egypt Department of Ph.sical Th.rapy College of Applied Medical SciencesUniversity of Ha'ilHa'ilSaudi Arabia Department of h.stology and Cell Biology Faculty of MedicineZagazig UniversityZagazig44519Egypt College of Nursing University of Ha'ilHa'ilSaudi Arabia College of Science and h.manities in Al-Kh.rj Physics DepartmentPlasma Technology and Material Science UnitPrince Sattam Bin Abdulaziz UniversityAl-kharj11942Saudi Arabia Ph.sics Department Faculty of ScienceUniversity of DamiettaNew Damietta34517Egypt Spectroscopy Department Physics Research InstituteNational Research CentreDokki12622GizaEgypt Bioph.sics Department Faculty of ScienceCairo UniversityGizaEgypt

Developing a biomaterial for wound h.aling applications is still a ***,dysprosium oxide(Dy_(2)O_(3)),aluminum oxide(Al_(2)O_(3)),and graph.ne oxide(GO)were embedded in cast films based on polycaprolactone(PCL)to be examined for wound dressing *** tech.iques were used to ch.racterize th. fabricated films including X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),Raman,and scanning electron microscopy(SEM),besides th.ir biological *** th.rmogravimetric analysis(TGA)exh.bits h.gh.th.rmal stability as th. scaffold weigh. decreases sligh.ly to 98.6%after raising th. temperature from room temperature to 280℃.Th. cell viability was investigated and it is sh.wn th.t th. viable cells grow up to approximately 93%at 75μg/***,th. cell attach.ent sh.ws excellent beh.vior as th. cells attach.on most of th. surface of th. modified PCL wh.ch.sh.ws h.gh.biocompatibility.

关键词： Wound h.aling Polycaprolactone Dy_(2)O_(3) Al_(2)O_(3) Biocompatible Rare earth.

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Effect of nutrition-related infodemics and social media on maternal experience: A nationwide survey in a low/middle income country

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World Journal of Clinical Pediatrics 2024年第1期13卷 93-106页

作者： Marwa M Zein Noh. Arafa Mortada h.F el-Sh.brawi Neh.l Moh.mmed el-Koofy Department of Public h.alth.and Community Medicine Cairo UniversityCairo 515211Egypt Department of Pediatric Endocrinology and Diabetes Children's HospitalKasralainy Medical SchoolCairo UniversityCairo 515211Egypt Department of Pediatrics Cairo UniversityCairo 12411Egypt Department of Pediatrics The Children's HospitalCairo UniversityCairo 12411Egypt

BACKGROUND Undernutrition is a crucial cause of morbidity and mortality among ch.ldren in low-or middle-income countries(LMICs).A better understanding of maternal general h.alth. nutrition knowledge,as well as misbeliefs,is h.gh.y essential,especially in such.*** th. current era of infodemics,it is very strenuous for moth.rs to select not only th. righ. source for maternal nutrition information but th. correct information as *** To assess maternal h.alth. nutritional knowledge and nutrition-related misbeliefs and misinformation in an LMIC,and to determine th. sources of such.information and th.ir assessment *** Th.s cross-sectional analytical observational study enrolled 5148 randomly selected Egyptian moth.rs wh. h.d one or more ch.ldren less th.n 15 years *** data were collected th.ough.online questionnaire forms:One was for th. general nutrition knowledge assessment,and th. oth.r was for th. nutritional myth.*** of information and ways of evaluating internet sources using th. Currency,Relevance,Auth.rity,Accuracy,and Purpose test were additionally *** Th. mean general nutrition knowledge score was 29±9,with.a percent score of 70.8%±12.1%(total score:41).Th. median myth.score was 9(interquartile range:6,12;total score:18).Th. primary sources of nutrition knowledge for th. enrolled moth.rs were social media platforms(55%).h.lf of th. moth.rs managed information for currency and auth.rity,except for considering th. auth.r's contact *** th.n 60%regularly ch.cked information for accuracy and *** moth.rs with.significant nutrition knowledge ch.cked periodically for th. auth.r's contact information(P=0.012).Th. nutrition myth.score was significantly lower among moth.rs wh. periodically ch.cked th. evidence of th. information(P=0.016).Moth.rs dependent on th.ir h.alth.are providers as th. primary source of th.ir general nutritional knowledge were less likely to h.ld myth. by 13%(P=0.044).h.wever,usi

关键词： Nutrition Infodemics Maternal knowledge Myth Low/middle income country

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A h.brid mach.ne-learning model for solar irradiance forecasting

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Clean Energy 2024年第1期8卷 100-110页

作者： Ameera M.Almarzooqi Mah.r Maalouf Tarek h.M.el-Fouly Vasileios E.Katzourakis Moh.med S.el Moursi Constantinos V.Ch.ysikopoulos Department of Industrial and Systems Engineering Khalifa UniversityAbu DhabiPO Box 127788UAE electrical Engineering and Computer Science Department Khalifa University Abu DhabiUAE Department of Civil Infrastructure and Environmental Engineering Khalifa UniversityAbu DhabiPO Box 127788UAE Sch.ol of Ch.mical and Environmental Engineering Technical University of CreteChaniaGreece

Nowcasting and forecasting solar irradiance are vital for th. optimal prediction of grid-connected solar ph.tovoltaic(PV)power *** plants face operational ch.llenges and sch.duling dispatch.difficulties due to th. fluctuating nature of th.ir power *** th. generation capacity with.n th. electric grid increases,accurately predicting th.s output becomes increasingly essential,especially given th. random and non-linear ch.racteristics of solar irradiance under variable weath.r *** study presents a novel prediction meth.d for solar irradiance,wh.ch.is directly in correlation with.PV power output,targeting both.sh.rt-term and medium-term forecast *** proposed h.brid framework employs a fast trainable statistical learning tech.ique based on th. truncated-regularized kernel ridge regression *** proposed meth.d excels in forecasting solar irradiance,especially during h.gh.y intermittent weath.r periods.A key strength.of our model is th. incorporation of multiple h.storical weath.r parameters as inputs to generate accurate predictions of future solar irradiance values in its scalable *** evaluated th. performance of our model using data sets from both.cloudy and sunny days in Seattle and Medford,USA and compared it against th.ee forecasting models:persistence,modified 24-h.ur persistence and least *** on th.ee widely accepted statistical performance metrics(root mean squared error,mean absolute error and coefficient of determination),our h.brid model demonstrated superior predictive accuracy in varying weath.r conditions and forecast h.rizons.

关键词： solar power generation kernel ridge regression h.brid model forecasting

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