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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

Selective removal of Cr(Ⅵ)using polyvinylpyrrolidone and polyacrylamide co-modified MoS_(2) ccomposites by adsorption combined with reduction

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Chinese Chemical Letters 2024年第6期35卷 524-530页

作者： Shuqi Yu Yu Yang Keisuke Kuroda Jian Pu Rui Guo Li-An Hou State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Department of Environmental and Civil Engineering Toyama Prefectural UniversityImizuToyama 939-0398Japan Institute for the Advanced Study of Sustainability United Nations UniversityJingumae 5-53-70Shibuya-kuTokyo 150-8925Japan Technical Centre for Soil Agriculture and Rural Ecology and EnvironmentMinistry of Ecology and EnvironmentBeijing 100012China

Cr(Ⅵ),one of the most hazardous metal pollutants,poses significant threats to the environment and human ***,a novel MoS_(2) composite(MoS_(2)/PVP/PAM)modified by polyvinylpyrrolidone(PVP)and polyacrylamide(PAM)was synthesized to enhance the removal of Cr(Ⅵ).Characterization analysis including SEM,XRD,FTIR,and XPS indicated that PVP and PAM could increase the interlayer spacing and the dispersibility of MoS_(2),and introduce pyrrolic N and amino functional *** batch experiments showed that MoS_(2)/PVP/PAM represented excellent Cr(Ⅵ)removal performance over a wide p H range,and exhibited a significantly higher maximum Cr(Ⅵ)adsorption capacity(274.73 mg/g,at p H 3.0,and 298 K)than pure MoS_(2).The adsorption of Cr(Ⅵ)followed Langmuir and pseudo-second-order kinetic model,which was a homogeneous monolayer chemisorption ***_(2)/PVP/PAM showed stable removal of Cr(Ⅵ)in the presence of humic acid(HA),interfering cations and anions at different ***,it had excellent selectivity for Cr(Ⅵ)(K_(d) value of 1.69×10^(7)m L/g)when coexisting with a variety of competing *** characterization revealed that Cr(Ⅵ)was reduced to low toxicity Cr(Ⅲ)by Mo^(4+)and S^(2-),and then chelated on the surface of the adsorbent by pyrrolic *** research expanded the design concept for MoS_(2) composites by demonstrating the potential of MoS_(2)/PVP/PAM as a promising material for selective elimination of Cr(Ⅵ)in water.

关键词： Polyvinylpyrrolidone Polyacrylamide MoS_(2) Cr(Ⅵ)removal Adsorbent Reduction

Investigating the inflow into a granular bed using a locally resolved method

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Particuology 2024年第2期85卷 89-101页

作者： Maximilian Brommer Maik Scharnowski Enric Illana Mahiques Siegmar Wirtz Viktor Scherer Ruhr University Bochum Institute of Energy Plant TechnologyUniversitätsstraβe 15044780BochumGermany

Discrete Element Method-Computational Fluid Dynamics(DEM/CFD)simulations of industrial-scale granular systems employ spatial averaging(porous media approach)for the fluid-particle interaction in the whole domain,which can lead to poor accuracy,for instance at flow inlets,as local particle bulk morphology is not *** paper presents an approach where the interstitial flow in crucial areas with large gradients can be resolved locally in an otherwise unresolved domain,so that a mixed resolved-unresolved method is *** a generic example to show the feasibility and performance of the new approach,the inflow of ambient air into a flat-bottom hopper through a narrow orifice is *** an experimental setup,the vertical profile of the pressure decay through the inlet and across the packing is chosen for com-parison with respective *** obtained with the conventional porous media method and the locally resolved approach are compared to these experiments for varying volume flow rates and for two different particle *** of different size as well as dodecahedrons are *** is found that although averaging methods already provide good approximations,the locally resolved method can improve the result especially when conventional drag laws are not applicable due to wall effects or if large velocity gradients exist.

关键词： DEM/CFD Packed bed Pressure drop

Experimental study on influence of blade angle and particle size on particle mechanics on a batch-operated single floor of a multiple hearth furnace

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Particuology 2024年第2期85卷 224-240页

作者： Max Kriegeskorte Nikoline Hilse Phil Spatz Viktor Scherer Institute for Energy Plant Technology(LEAT) Ruhr University BochumUniversitätsstraβe 15044780 BochumGermany

In industry,multiple hearth furnaces are used for the thermal treatment of particulate *** current contribution concentrates on the experimental analysis of particle mechanics for a batch-operated single floor of a multiple hearth *** particles are agitated on the circular floor by a single,rotating rabble arm equipped with three flat rabble blades of 10 mm *** blade angle,defined as the angle,which the blade is inclined against the tangential direction,is varied from 0°to 90°.A single layer of spherical polyoxymethylene(POM)particles with three different diameters(5,10 and 20 mm)is placed on the *** analyze the results,two parameters have been extracted from image analysis when the bed of particles is agitated,first,the area not covered by particles and second,the frequency distribution of the mean distance among the *** particle free surface area increases with the inclination of the *** evolution of the particle free surface area differs for the different particle *** general,the maximum particle free area for all blade angles is the largest for the 5 mm particles followed by the 20 mm *** the 10 mm particles,the particle free surface area starts for a blade angle of 0°at larger values than for the 20 mm particles but the values fall below the values for the 20 mm particles for larger blade *** reason for this behavior is discussed in *** mean distance among the particles is a parameter characterizing the length scales dominating the effects on the *** frequency distribution of the mean distance among particles provides infor-mation about the morphology of the particle bulk,for example,whether the free surface area is inter-spersed with particles.

关键词： Hearth furnace floor Particle movement Spherical particles Particle free surface area Mean distance among particles

Three-dimensional crystal defect imaging by STEM depth sectioning

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Chinese Physics B 2024年第8期33卷 2-7页

作者： Ryo Ishikawa Naoya Shibata Yuichi Ikuhara Institute of Engineering Innovation The University of TokyoBunkyoTokyo 113-8656Japan

One of the major innovations awaiting in electron microscopy is full three-dimensional imaging at atomic *** the success of aberration correction to deep sub-angstrom lateral resolution,spatial resolution in depth is still far from atomic *** scanning transmission electron microscopy(STEM),this poor depth resolution is due to the limitation of the illumination *** overcome this physical limitation,it is essential to implement a next-generation aberration corrector in STEM that can significantly improve the depth *** review discusses the capability of depth sectioning for three-dimensional imaging combined with large-angle illumination ***,the statistical analysis approach remarkably improves the depth resolution,making it possible to achieve three-dimensional atomic resolution imaging at oxide *** will also discuss the future prospects of three-dimensional imaging at atomic resolution by STEM depth sectioning.

关键词： atomic-resolution STEM STEM depth sectioning depth resolution dopants surface topography

Wear dependent virtual flow rate sensor for progressing cavity pumps with deformable stator

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Petroleum Science 2024年第2期21卷 1346-1353页

作者： Jens Müller Sebastian Leonow Johannes Schulz Christian Hansen Martin Monnigmann Ruhr-Universitat Bochum Universit atsstraûe 150Bochum44801Germany SEEPEX GmbH Scharnh olzstraûe 344Bottrop46240Germany

This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this material loss on the volumetric efficiency. The results are combined with an established backflow model to implement a backflow calculation procedure that is adaptive to wear. We use a laboratory test setup with a highly abrasive fluid and operate a pump from new to worn condition to validate our approach. The obtained measurement data show that the presented virtual sensor is capable of calculating the flow rate of a pump being subject to wear during its regular operation.

关键词： Backflow Progressing cavity pump Virtual sensor Wear

NeuroPNM:Model reduction of pore network models using neural networks

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Particuology 2024年第3期86卷 239-251页

作者： Robert Jendersie Ali Mjalled Xiang Lu Lucas Reineking Abdolreza Kharaghani Martin Monnigmann Christian Lessig Otto-von-Guericke-Universitat Magdeburg Universitatsplatz 2Magdeburg39106Germany Ruhr-Universitat-Bochum Universitatstraβe 150Bochum44801Germany

Reacting particle systems play an important role in many industrial applications,for example biomass drying or the manufacturing of *** numerical modeling and simulation of such systems is therefore of great importance for an efficient,reliable,and environmentally sustainable operation of the *** complex thermodynamical,chemical,and flow processes that take place in the particles are a particular challenge in a ***,typically a large number of particles is involved,rendering an explicit treatment of individual ones impossible in a reactor-level *** approach for overcoming this challenge is to compute effective,physical parameters from single-particle,high-resolution *** can be combined with model reduction methods if the dynamical behaviour of particles must be *** network models with their unrivaled resolution have thereby been used successfully as high-resolution models,for instance to obtain the macroscopic diffusion coeffcient of *** parameter identification and model reduction have recently gained new impetus by the dramatic progress made in machine learning in the last *** report results on the use of neural networks for parameter identification and model reduction based on three-dimensional pore network models(PNM).We believe that our results provide a powerful complement to existing methodologies for reactor-level simulations with many thermally-thick particles.

关键词： Porenetwork models Neural networks Parameter estimation Reduced order model

A High Order Accurate Bound-Preserving Compact Finite Difference Scheme for Two-Dimensional Incompressible Flow

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Communications on Applied Mathematics and Computation 2024年第1期6卷 113-141页

作者： Hao Li Xiangxiong Zhang Department of Mathematics Purdue University150 N.University StreetWest LafayetteIN47907-2067USA

For solving two-dimensional incompressible flow in the vorticity form by the fourth-order compact finite difference scheme and explicit strong stability preserving temporal discretizations,we show that the simple bound-preserving limiter in Li et al.(SIAM J Numer Anal 56:3308–3345,2018)can enforce the strict bounds of the vorticity,if the velocity field satisfies a discrete divergence free *** reducing oscillations,a modified TVB limiter adapted from Cockburn and Shu(SIAM J Numer Anal 31:607–627,1994)is constructed without affecting the bound-preserving *** bound-preserving finite difference method can be used for any passive convection equation with a divergence free velocity field.

关键词： Finite difference Monotonicity Bound-preserving Discrete maximum principle Passive convection Incompressible flow Total variation bounded limiter

A plant growth chamber system equipped with aerosol generators for studying aerosol-vegetation interactions

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Particuology 2024年第2期85卷 122-132页

作者： Masao Gen Seiji Ikawa Masahiro Yamaguchi Fong Zyin Lim Takeshi Izuta I.Wuled Lenggoro Graduate School of Bio-Applications and Systems Engineering Tokyo University of Agriculture and TechnologyKoganeiTokyo184-8588Japan Institute of Multidisciplinary Research for Advanced Materials Tohoku UniversitySendai980-8577Japan Faculty of Agriculture Tokyo University of Agriculture and TechnologyFuchuTokyo183-8509Japan Graduate School of Fisheries and Environmental Sciences Nagasaki UniversityNagasaki852-8521Japan Institute of Agriculture Tokyo University of Agriculture and TechnologyFuchuTokyo183-8509 Japan Department of Applied Physics and Chemical Engineering Tokyo University of Agriculture and TechnologyKoganeiTokyo184-8588Japan Institute of Global Innovation Research Tokyo University of Agriculture and TechnologyFuchuTokyo183-8509Japan

Understanding aerosol-vegetation interactions is vital in ***,the interactions remain elusive partly due to the lack of suitable plant growth chamber ***,deposition of submicron particles on leaf surfaces is challenging due to its low deposition velocities compared to larger *** this work,we present a plant-growth chamber that was used to study the effect of sub-micron black carbon(BC)particles on the growth and photosynthesis of *** chamber system simultaneously enables the growth of multiple plants in pots and the deposition of submicron particles onto *** spraying methods assisted by ultrasonic and electrostatic forces were employed as aerosol generators to realize the particle *** flow regime inside the chamber was numeri-cally calculated to predict the transportation of aerosol particles,suggesting the optimal operating conditions of the *** gas-phase particle size distribution measurements showed that gener-ated BC particles were suspended in submicron diameter *** aerosol generators were examined in the chamber using three conductor and insulator substrates as a model of plant *** observations and spectroscopic analysis ascertained that submicron BC particles generated from our generators were deposited on all substrate *** the developed chamber system,systematic studies can be performed to advance the fundamental understanding of aerosol-vegetation interactions.

关键词： Aerosol Exposure chamber Spray drying Black carbon

Investigation of Inside-Out Tracking Methods for Six Degrees of Freedom Pose Estimation of a Smartphone in Augmented Reality

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Computers, Materials & Continua 2024年第5期79卷 3047-3065页

作者： Chanho Park Takefumi Ogawa Graduate School of Engineering The University of TokyoTokyo113-0033Japan Information Technology Center The University of TokyoChiba277-0882Japan

Six degrees of freedom(6DoF)input interfaces are essential formanipulating virtual objects through translation or rotation in three-dimensional(3D)space.A traditional outside-in tracking controller requires the installation of expensive hardware in *** inside-out tracking controllers have been proposed,they often suffer from limitations such as interaction limited to the tracking range of the sensor(e.g.,a sensor on the head-mounted display(HMD))or the need for pose value modification to function as an input interface(e.g.,a sensor on the controller).This study investigates 6DoF pose estimation methods without restricting the tracking range,using a smartphone as a controller in augmented reality(AR)*** approach involves proposing methods for estimating the initial pose of the controller and correcting the pose using an inside-out tracking *** addition,seven pose estimation algorithms were presented as candidates depending on the tracking range of the device sensor,the tracking method(e.g.,marker recognition,visual-inertial odometry(VIO)),and whether modification of the initial pose is *** two experiments(discrete and continuous data),the performance of the algorithms was *** results demonstrate enhanced final pose accuracy achieved by correcting the initial ***,the importance of selecting the tracking algorithm based on the tracking range of the devices and the actual input value of the 3D interaction was emphasized.

关键词： Smartphone inside-out tracking 6DoF pose 3D interaction augmented reality