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Particuology 2024年第1期84卷 158-167页

作者： Lucas Reineking Jonas Fischer Ali Mjalled Enric Illana Siegmar Wirtz Viktor Scherer Martin Monnigmann Automatic Control and System Theory Ruhr-Universität-BochumUniversitätstraße 150Bochum44801Germany Energy Plant Technology Ruhr-Universität-BochumUniversitätstraße 150Bochum44801Germany

The simulation of industry-scale reactive bulks is challenging due to the complex interaction between fluid and *** particles in the bulk and their interaction with the fluid flow can be described by combined Discrete Element Method-Computational Fluid Dynamics(DEM-CFD)***,the computational cost of the Finite Volume(FV)methods deployed in these models can become prohibi-tively expensive,especially for high inner-particle *** particle Reduced Models(RMs)can be used to achieve both fast and accurate descriptions of the processes in each *** an example of bulk systems comprising heat and mass transfer,we compared FV and RM simulations for the drying of wood chips in a bulk reactor.A manifold-based nonlinear interpolation was applied to resolve changing boundary conditions for the *** simulations showed that RMs provide accurate values for the thermodynamic state variables of the ***,the time required for the bulk simulation was reduced by 67%with the *** is evident that simulations with high inner-particle resolution can be accelerated by RMs if manifold-based nonlinear interpolation is used to address changing boundary conditions.

关键词： Reduced model Reactive bulk Discrete element method Manifold-based interpolation Drying of porous mediaDEM-CFD

Experimental and numerical investigation to elucidate the fluid flow through packed beds with structured particle packings

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Particuology 2024年第6期89卷 218-237页

作者： Shirin Patil Christian Gorges Joel Lòpez Bonilla Moritz Stelter Frank Beyrau Berend van Wachem Laboratory of Technical Thermodynamics Otto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany Chair of Mechanical Process Engineering Otto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany

The present paper presents an experimental and numerical investigation of the dispersion of the gaseous jet flow and co-flow for the simple unit cell(SUC)and body-centred cubic(BCC)configuration of particles in packed *** experimental setup is built in such a way that suitable and simplified boundary conditions are imposed for the corresponding numerical framework,so the simulations can be done under very similar conditions as the ***,a porous plate is used for the co-flow to achieve the uniform velocity and the fully developed flow is ensured for the jet *** SUC and BCC particle beds consist of 3D-printed spheres,and the non-isotropy near the walls is mostly eliminated by placing half-spheres at the channel *** flow velocities are analysed directly at the exit of the particle bed for both beds over 36 pores for the SUC configuration and 60 pores for the BCC configuration,for particle Reynolds numbers of 200,300,and *** particle image velocimetry is experimentally arranged in such a way that the velocities over the entire region at the exit of the packed bed are obtained *** numerical method consists of a state-of-the-art immersed boundary method with adaptive mesh *** paper presents the pore jet structure and velocity field exiting from each pore for the SUC and BCC packed particle *** numerical and experimental studies show a good agreement for the SUC configuration for all flow *** the BCC configuration,some differences can be observed in the pore jet flow structure between the simulations and the experiments,but the general flow velocity distribution shows a good overall *** axial velocity is generally higher for the pores located near the centre of the packed bed than for the pores near the *** addition,the axial velocities are observed to increase near the peripheral pores of the packed *** behaviour is predominant for the BCC configuration as compared to t

关键词： Uniform particle packing Packed bed reactor Stereo particle image velocimetry Immersed boundary method

Non-adhesive and adhesive contacts of an elastic quarter-or eighth-space with freely sliding sides

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Friction 2024年第9期12卷 2052-2063页

作者： Qiang LI Valentin L.POPOV Technische universität Berlin Berlin 10623Germany

The contact of an elastic quarter-or eighth-space is studied under the condition that the movement of the side surface of the quarter-space is constrained:It can slide freely along the plane of the side surface but its normal movement is blocked(for example,by a rigid wall).The solution of this contact problem can be easily achieved by additionally applying a mirrored load to an elastic ***-adhesive contact and the Johnson–Kendall–Roberts(JKR)-type adhesive contact between a rigid sphere and an elastic quarter-space under such a boundary condition is numerically simulated using the fast Fourier transform(FFT)-assisted boundary element method(BEM).Contacts of an elastic eighth-space are investigated using the same *** on the position of the sphere relative to the side edge,different contact behavior is *** the case of adhesive contact,the force of adhesion first increases with increasing the distance from the edge of the quarter-space,achieves a maximum,and decreases further to the JKR-value in large distance from the *** enhancement of the force of adhesion compared to the half-space-contact is associated with the pinning of the contact area at the *** provide the maps of the force of adhesion and their analytical approximations,as well as pressure distributions in the contact plane and inside the quarter-/eighth-space.

关键词： quarter-space eighth-space adhesion edge effect boundary element method(BEM)

ARBITRARILY HIGH-ORDER ENERGY-CONSERVING METHODS FOR HAMILTONIAN PROBLEMS WITH QUADRATIC HOLONOMIC CONSTRAINTS

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Journal of Computational Mathematics 2024年第4期42卷 1145-1171页

作者： Pierluigi Amodio Luigi Brugnano Gianluca Frasca-Caccia Felice Iavernaro Dipartimento di Matematica Università di BariItaly Dipartimento di Matematica e Informatica"U.Dini" Università di FirenzeItaly Dipartimento di Matematica Università di SalernoItaly

In this paper,we define arbitrarily high-order energy-conserving methods for Hamilto-nian systems with quadratic holonomic *** derivation of the methods is made within the so-called line integral *** tests to illustra... 详细信息

关键词： Constrained Hamiltonian systems Quadratic holonomic constraints Energy-conserving methods Line integral methods Hamiltonian Boundary Value Methods HB-VMs

A global analysis of the introduction pathways and characteristics associated with non-native fish species introduction, establishment, and impacts

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Ecological Processes 2024年第2期13卷 16-31页

作者： Camille Bernery Céline Bellard Franck Courchamp Sébastien Brosse Boris Leroy CNRS Agro Paris Tech Ecologie Systématique Evolution Université Paris-Saclay Unité Biologie des Organismes et Ecosystèmes Aquatiques (BOREA UMR 8067) Muséum National d’Histoire Naturelle Sorbonne Universités Université de Caen Normandie Université des Antilles CNRS IRD Laboratoire évolution & Diversité Biologique (EDB UMR5174) Université Paul Sabatier-Toulouse 3 CNRS IRD UPS

Background The invasion success of introduced freshwater fishes is influenced by many factors, including ecological, species, and socioeconomic characteristics. Most studies that document the importance of these characteristics are conducted at local scales and/or focus on a single step of the invasion process. In this study, we aim to determine the species characteristics, ecological characteristics, and socioeconomic characteristics of non-native freshwater fish invasions. Our assessment was done at the global scale and considers all three steps of the invasion(i.e., introduction, establishment, and impact). For this purpose, we applied generalized linear models to 20 variables collected for 307 non-native species and modeled them as a function of ecological characteristics(i.e., environmental features), species traits(i.e., functional and morphological), and socioeconomic characteristics(i.e., human use and introduction pathways). We considered the number of countries in which each species was introduced, established, or had ecological impacts as a proxy of invasion step success. We also explored the specifics of species introduced through the aquaculture and the ornamental fish trade *** We found that non-native freshwater fishes with broad diets, high parental care, and multiple introduction pathways are the most widely introduced and established worldwide. The number of countries with impacts reported was best explained by the type of introduction pathway(i.e., aquaculture or fisheries). Moreover, among non-native species introduced through aquaculture, those belonging to Cypriniformes and having broad diets were the most widely introduced and established species. In contrast, the species introduced through the ornamental fish trade pathway belonged to various taxonomic orders but were mainly native to tropical *** Considering several types of factors is important when analyzing the invasion success of freshwater fish and disentang

关键词： Aquaculture Ecology Exotic Freshwater fish Introduction pathway Invasion step Morphology Ornamental fish trade Socioeconomic Trait

A mediation system for continuous spatial queries on a unified schema using Apache Spark

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Big Earth Data 2024年第1期8卷 115-141页

作者： Thi Thu Trang Ngo François Pinet David Sarramia Myoung-Ah Kang universitéClermont Auvergne ISIMAAubièreFrance universitéClermont Auvergne INRAEUR TSCFClermont-FerrandFrance universitéClermont Auvergne CNRS/IN2P3LPCClermont-FerrandFrance

Recent advances in big and streaming data systems have enabled real-time analysis of data generated by Internet of Things(IoT)systems and sensors in various *** this context,many applications require integrating data from several heterogeneous sources,either stream or static *** such as Apache Spark are able to integrate and process large datasets from different ***,these frameworks are hard to use when the data sources are heterogeneous and *** address this issue,we propose a system based on mediation techniques for integrating stream and static data *** integration process of our system consists of three main steps:configuration,query expression and query *** the configuration step,an administrator designs a mediated schema and defines mapping between the mediated schema and local data *** the query expression step,users express queries using customized SQL grammar on the mediated ***,our system rewrites the query into an optimized Spark application and submits the application to a Spark *** results are continuously returned to *** experiments show that our optimizations can improve query execution time by up to one order of magnitude,making complex streaming and spatial data analysis more accessible.

关键词： Streaming data streaming data integration mediator geospatial data continuous queries

Approximate contact solutions for non-axisymmetric homogeneous and power-law graded elastic bodies:A practical tool for design engineers and tribologists

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Friction 2024年第2期12卷 340-355页

作者： Valentin L.POPOV Qiang LI Emanuel WILLERT Institute of Mechanics Technische Universität BerlinBerlin 10623Germany

In two recent papers,approximate solutions for compact non-axisymmetric contact problems of homogeneous and power-law graded elastic bodies have been suggested,which provide explicit analytical relations for the force–approach relation,the size and the shape of the contact area,as well as for the pressure distribution *** solutions were derived for profiles,which only slightly deviate from the axisymmetric *** the present paper,they undergo an extensive testing and validation by comparison of solutions with a great variety of profile shapes with numerical solutions obtained by the fast Fourier transform(FFT)-assisted boundary element method(BEM).Examples are given with quite significant deviations from axial symmetry and show surprisingly good agreement with numerical solutions.

关键词： normal contact non-axisymmetric indenter extremal principle generalized method of dimensionality reduction(MDR) functional elastic grading

Data-driven analysis of chemicals,proteins and pathways associated with peanut allergy:from molecular networking to biological interpretation

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Food Science and Human Wellness 2024年第3期13卷 1322-1335页

作者： Emmanuel Kemmler Julian Braun Florent Fauchère Sabine Dölle-Bierke Kirsten Beyer Robert Preissner Margitta Worm Priyanka Banerjee Institute for Physiology Charité-University Medicine BerlinBerlin 10115Germany Member of the KFO339 FOOD@Berlin 10115Germany Si-M/“Der Simulierte Mensch”a science framework of Technische universität Berlin and Charité-universitätsmedizin Berlin Berlin 10115Germany Charité-universitätsmedizin Berlin corporate member of Freie Universität BerlinHumboldt-Universität zu Berlinand Berlin Institute of HealthBerlin 10115Germany Division of Allergy and Immunology Department of DermatologyVenerology and AllergyCharité-Universitätsmedizin Berlincorporate member of Freie Universität Berlin and Humboldt-Universität zu BerlinBerlin 10115Germany Pediatrics Campus VirchowCharité-University Medicine BerlinBerlin 10115Germany

Peanut allergy is majorly related to severe food induced allergic *** food including cow's milk,hen's eggs,soy,wheat,peanuts,tree nuts(walnuts,hazelnuts,almonds,cashews,pecans and pistachios),fish and shellfish are responsible for more than 90%of food ***,we provide promising insights using a large-scale data-driven analysis,comparing the mechanistic feature and biological relevance of different ingredients presents in peanuts,tree nuts(walnuts,almonds,cashews,pecans and pistachios)and ***,we have analysed the chemical compositions of peanuts in different processed form raw,boiled and *** the data-driven approach we are able to generate new hypotheses to explain why nuclear receptors like the peroxisome proliferator-activated receptors(PPARs)and its isoform and their interaction with dietary lipids may have significant effect on allergic *** results obtained from this study will direct future experimeantal and clinical studies to understand the role of dietary lipids and PPARisoforms to exert pro-inflammatory or anti-inflammatory functions on cells of the innate immunity and influence antigen presentation to the cells of the adaptive immunity.

关键词： Allergy informatics Knowledge-graph Data analysis Food allergy Peroxisome proliferator-activated receptors Fatty acids

A Eulerian population balance/Monte Carlo approach for simulating laminar aluminum dust flames

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Particuology 2024年第5期88卷 323-343页

作者： Fabian Sewerin Jannis Finke Emmy Noether Group for Dispersed Multiphase Flows Chair of Mechanical Process EngineeringOtto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany

Recently,metal powders have been conceptualized as carbon-free recyclable energy carriers that may form a cornerstone of a sustainable energy *** combustion of metal dusts in oxidizing atmospheres is exothermal and yields oxide particles that could,potentially,be retrieved and,subsequently,recharged by conversion to pure metals using green primary energy *** a step towards a predictive tool for designing metal dust combustors,we present a fully Eulerian modelling approach for laminar particle-laden reactive flows that is,conceptually,based on a population balance description of the dispersed particles and relies on a stochastic Eulerian solution *** the population balance equation(PBE)is formulated for the number-weighted distribution of characteristic properties among all particles near a spatial location,it is kinetically informed by the rates at which mass,momentum and heat are exchanged between the carrier gas and the particulate phase on the single particle *** the scope of the Eulerian Monte Carlo solution scheme,the property distribution is discretely represented in terms of the total number density and a finite number of property samples and the computational work is channelled towards the Eulerian estimation of mean particle *** the case of reactive aluminum particles,we combine a kinetic description of the gas-particle heat and mass transfer with a transport-limited continuum formulation to obtain rate expressions that are valid across the entire particle size range from the free molecular through the continuum *** velocity,the particle properties include only the particle mass,temperature and oxide mass *** set of thermochemical degrees of freedom is retained also as phase transitions due to melting occur,drawing on a smooth blend of the solid and liquid thermodynamic and material *** particle-level formulation encompasses aluminum evaporation,surface oxidation,scavenging of oxi

关键词： Metal dust combustion Aluminum Population balance Eulerian Monte Carlo

A simulation study on spatial and time resolution for a cost-effective positron emission particle tracking system

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Particuology 2024年第5期88卷 312-322页

作者： Josephine Oppotsch Matthias Steinke Miriam Fritsch Fritz-Herbert Heinsius Thomas Held Nikoline Hilse Viktor Scherer Ulrich Wiedner Ruhr-universität Bochum Institut für Experimentalphysik I44801 BochumGermany Ruhr-universität Bochum Lehrstuhl für Energieanlagen und Energieprozesstechnik44801 BochumGermany

This work is the second part of a simulation study investigating the processing of densely packed and moving granular assemblies by positron emission particle tracking (PEPT).Since medical positron emission tomography (PET) scanners commonly used for PEPT are very expensive,a PET-like detector system based on cost-effective organic plastic scintillator bars is being developed and tested for its *** this context,the spatial resolution of a resting positron source,a source moving on a freely designed model path,and a particle motion given by a discrete element method (DEM) simulation is studied using Monte Carlo simulations and the software toolkit *** not only extended the simulation and reconstruction to a moving source but also significantly improved the spatial resolution compared to previous work by adding oversampling and iteration to the reconstruction ***,in the case of a source following a trajectory developed from DEM simulations,a very good resolution of about 1 mm in all three directions and an average 3D deviation between simulated and reconstructed events of 2.3 mm could be ***,the resolution for realistic particle motion within the generic grate system (which is the test rig for further experimental studies) is well below the smallest particle *** simulation of the dependence of the reconstruction accuracy on tracer particle location revealed a nearly constant efficiency within the entire detector system,which demonstrates that boundary effects can be neglected.

关键词： Positron emission particle tracking Monte Carlo method Time-of-flight Plastic scintillators Silicon photomultipliers(SiPMs)