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A reduced model for particle calcination for use in DEM/CFD simulations

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PARTICUOLOGY 2024年第10期93卷 316-327页

作者： Mieg, Lucas Bergold, Torben Mahiques, enric.Illana Scherer, Viktor Moennigmann, Martin Ruhr Univ Bochum Automat Control & Syst Theory Bochum Germany Ruhr Univ Bochum Energy Plant Technol Bochum Germany

We treat the accurate simulation of the calcination reaction in particles, where the particles are large and, thus, the inner-particle processes must be resolved. Because these processes need to be described with coupled partial differential equations (PDEs) that must be solved numerically, the computation times for a single particle are too high for use in simulations that involve many particles. Simulations of this type arise when the Discrete Element Method (DEM) is combined with Computational Fluid Dynamics (CFD) to investigate industrial systems such as quicklime production in lime shaft kilns. We show that, based on proper orthogonal decomposition and Galerkin projection, reduced models can be derived for single particles that provide the same spatial and temporal resolution as the original PDE models at a considerably reduced computational cost. Replacing the finite volume particle models with the reduced models results in an overall reduction of the reactor simulation time by about 40% for the sample system treated here. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// ***/licenses/by/4.0/).

关键词： Calcination Reactive bulk Model reduction Discrete element method Galerkin projection SOLID HEAT-TRANSFER DEM-CFD SIMULATION MASS-TRANSFER WOOD CHIPS DECOMPOSITION COMBUSTION REDUCTION LIMESTONE DYNAMICS FLOW

Shape-changing particles for locally resolved particle geometry in DEM simulations

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Particuology 2024年第6期89卷 185-190页

作者： enric.Illana Klidi Qyteti Maik Scharnowski Maximilian Brömmer Siegmar Wirtz Viktor Scherer Institute of Energy Plant Technology Ruhr-University BochumBochumGermany

Taking into account the complex shape of particles in discrete element method (DEM) simulations of large-scale granular systems is computationally demanding due to the time-consuming contact detection algorithms for polyhedral particles. In this short communication, a novel approach that locally resolves the particle shapes where needed and uses a simplified representation elsewhere, to accelerate simulations without compromising accuracy, is presented. For this purpose, a method employing a smooth transition of the particle shape representation from analytical spheres to shape-resolving polyhedra is introduced in DEM. The feasibility and correct implementation of this approach are demonstrated through simulations of hopper discharge involving spherical and dodecahedral particles from a flat bottom silo or shaft kiln. The model capabilities, in terms of accuracy as well as reduction in computational effort, are quantified for a moving bed with continuous outflow.

关键词： Polyhedron Size change Shape change Locally resolved DEM

Convective drying of wood chips:Accelerating coupled DEM-CFD simulations with parametrized reduced single particle models

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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

Comparing two IBM implementations for the simulation of uniform packed beds

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Particuology 2024年第3期86卷 1-12页

作者： Christian Gorges Maximilian Brommer Christin Velten Siegmar Wirtz enric.Illana Mahiques Viktor Scherer Katharina Zahringer Berend van Wachem Mechanical Process Engineering Otto-von-Guericke-Universitat MagdeburgUniversitatsplatz 239106MagdeburgGermany Department of Energy Plant Technology Ruhr-Universitat BochumUniversitatsstraBe 15044780BochumGermany Laboratory of Fluid Dynamics and Technical Flows Otto-von-Guericke-Universitat MagdeburgUniversitatsplatz 239106MagdeburgGermany

Nowadays,the design of fixed packed bed reactors still relies on empirical correlations,which,especially for small tube to particle diameter ratios,are mostly too inaccurate because of the presence of wall ***,the simulation of fixed packed bed reactors plays an important role to predict and control the flow and process parameters in such,nowadays and in the *** of its straightforward applicability to non-uniform packings with particles of arbitrary shapes,the immersed boundary method(IBM)has advantages over other numerical methods and is used more and more *** paper compares two approaches of IBMs for the simulation of fixed bed reactors with spherical shaped *** classic,smooth approach is compared to the straightforward to implement blocked-off method for velocity fields above the fixed bed for particle Reynolds numbers of 300 and *** from experimental inline PIV-measurements of the reactor to be simulated serve as a basis for *** good agreement with the experiment is found for both simulation methodologies with higher resolutions,considering the more stable flow at a particle Reynolds number of *** in the different IBM approaches occurred for the more unsteady flow at a particle Reynolds number of *** to the blocked-off method,the smooth IBM reflects the formation of additional jets and recirculation zones better right above the bed,though increasing the fluid mesh resolution improves the accuracy of the blocked-off ***,a more diffusive behaviour is found for the blocked-off simulations due to the stairstep representation,which is avoided by using interpolation stencils as in the smooth *** higher mesh refinement in the blocked-off IBM this effect can be reduced,but this also increases the computational effort.

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

Debaryomyces hansenii supplementation in low fish meal diets promotes growth,modulates microbiota and enhances intestinal condition in juvenile marine fish

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Journal of Animal Science and Biotechnology 2024年第1期15卷 253-276页

作者： Ignasi Sanahuja Alberto Ruiz Joana P.Firmino Felipe E.Reyes-López Juan B.Ortiz-Delgado Eva Vallejos-Vidal Lluis Tort Dariel Tovar-Ramírez Isabel M.Cerezo Miguel A.Moriñigo Carmen Sarasquete enric.Gisbert Aquaculture Program Institute of Agrifood Research and Technology(IRTA)La Rapita 43540Spain Centro de Biotecnologia Acuicola Universidad de Santiago de ChileSantiagoChile Instituto de Ciencias Marinas de Andalucia(ICMAN-CSIC) Avda.Republica Saharaui no 2Campus Universitario Rio San PedroPuerto RealCadiz 11510Spain Nucleo de Investigaciones Aplicadas en Ciencias Veterinarias y Agronomicas Facultad de Medicina Veterinaria y AgronomiaUniversidad de Las AmericasSantiagoChile Department of Cell Biology Physiologyand ImmunologyUniversitat Autonoma de BarcelonaBarcelonaSpain Centro de Investigaciones Biologicas del Noroeste SC CIBNORLa PazMexico Department of Microbiology Instituto de Biotecnologia Y Desarrollo Azul(IBYDA)Faculty of SciencesUniversity of Malaga29010 MalagaSpain SCBI Bioinformatic UnitUniversity of Malaga29590 MalagaSpain

Background The development of a sustainable business model with social acceptance,makes necessary to develop new strategies to guarantee the growth,health,and well-being of farmed *** hansenii is a yeast species that can be used as a probiotic in aquaculture due to its capacity to i)promote cell proliferation and differen-tiation,ii)have immunostimulatory effects,iii)modulate gut microbiota,and/or iv)enhance the digestive *** provide inside into the effects of *** on juveniles of gilthead seabream(Sparus aurata)condition,we inte-grated the evaluation of the main key performance indicators coupled with the integrative analysis of the intestine condition,through histological and microbiota state,and its transcriptomic *** After 70 days of a nutritional trial in which a diet with low levels of fishmeal(7%)was supplemented with 1.1%of ***(17.2×10^(5) CFU),an increase of ca.12%in somatic growth was observed together with an improve-ment in feed conversion in fish fed a yeast-supplemented *** terms of intestinal condition,this probiotic modu-lated gut microbiota without affecting the intestine cell organization,whereas an increase in the staining intensity of mucins rich in carboxylated and weakly sulphated glycoconjugates coupled with changes in the affinity for certain lectins were noted in goblet *** in microbiota were characterized by the reduction in abundance of several groups of Proteobacteria,especially those characterized as opportunistic *** microarrays-based transcrip-tomic analysis found 232 differential expressed genes in the anterior-mid intestine of ***,that were mostly related to metabolic,antioxidant,immune,and symbiotic *** Dietary administration of *** enhanced somatic growth and improved feed efficiency param-eters,results that were coupled to an improvement of intestinal condition as histochemical and transcriptomic tools *** probiotic ye

关键词： Debaryomyces hansenii Intestine condition Low fish meal diet Microbiota Transcriptomics Yeast probiotic

Regulation of Iron Uptake by IRT1： Endocytosis Pulls the Trigger

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Molecular Plant 2015年第7期8卷 977-979页

作者： Zelazny, enric.Vert, Gregory Univ Paris 11 CEA CNRS Inst Integrat Biol Cell I2BC F-91190 Gif Sur Yvette France

The past two decades of research on plant iron nutrition have completed the casting of the major transporters involved in iron uptake from the soil, long-distance transport, and intracellular distribution. Among these transporters, most of the attention was given to the root iron transporter IRT1, which plays a critical role in iron uptake from the soil and mediates transport of other non-iron metals （zinc, manganese, cobalt, cadmium） under iron-limiting conditions.

关键词： Regulation Uptake Endocytosis

On subgroup functors of finite soluble groups

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Science China Mathematics 2017年第3期60卷 439-448页

作者： BALLESTER-BOLINCHES Adolfo COSME-LLOPEZ enric.KAMORNIKOV Sergey Fedorovich Departament d'Algebra Universitat de Valencia Burjassot 46100 Spain Gomel Branch of International University "MITSO" Gomel 246029 Belarus

The principal aim of this paper is to study the regular and transitive subgroup functors in the universe of all finite soluble *** prove that they form a complemented and non-modular lattice containing two relevant **... 详细信息

关键词： finite group soluble group lattices of subgroups subgroup functors formations

Late Miocene/Early Pliocene vertebrate fauna from Mallorca(Balearic Islands,Western Mediterranean):an update

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Integrative Zoology 2014年第2期9卷 183-196页

作者： Pere BOVER Juan ROFES Salvador BAILON Jordi AGUSTÍ Gloria CUENCA-BESCÓS enric.TORRES Josep Antoni ALCOVER IMEDEA(CSIC-UIB) Mediterranean Institute for Advanced StudiesDepartment of Biodiversity and ConservationBalearic IslandsSpain Research Associate Division of Vertebrate Zoology/Mammalogy Department American Museum of Natural HistoryNew YorkNYUSA Department of Stratigraphy and Paleontology University of the Basque CountryLeioaSpain Grupo Aragosaurus-IUCA Area of PaleontologíaEarth Sciences DepartmentUniversity of ZaragozaZaragozaSpain UMR 7209-7194 of CNRS Department of Ecology and Biodiversity ManagementNational Museum of Natural HistoryParisFrance ICREA Institut Catalàde Paleoecologia Humana i EvolucióSocial(IPHES)Universitat Rovira i VirgiliTarragonaSpain

The vertebrate fossil record from the Balearic Islands(western Mediterranean)has improved considerably over the past decade,especially in Mallorca and *** Menorca,the Pliocene terrestrial fauna was updated by the discovery and description of the large-sized leporid Nuralagus,several reptiles and an *** Mal-lorca,paleontological exploration yielded 2 deposits with a Late Miocene/Early Pliocene chronology,Calóden Rafelino(CdR)and Na Burguesa-1(NB-1).So far,4 new mammalian taxa and 2 new reptiles have been iden-tified for the CdR deposit,whereas the faunal assemblage from the recently discovered deposit(Apr 2012)of NB-1 is currently composed of,at least,6 terrestrial mammals,8 reptiles and an *** faunal composi-tion and some primitive characteristics of the obtained taxa suggest that the chronology of this deposit is slight-ly earlier than the *** terrestrial vertebrates recorded in these 2 Mallorcan deposits are changing the view of the paleofaunal assemblage previously known for the Plio-Pleistocene of the *** charac-teristics displayed by some of the taxa suggest that these faunas would be at the beginning of an isolated *** this paper we present a preliminary report on the fossils recovered from the NB-1 deposit,as well as some unpublished data from CdR,and we analyze the whole fauna from both Mallorcan deposits,focusing on taxonomical and paleobiogeographical aspects.

关键词： Early Pliocene Late Miocene Mallorca new fauna paleobiogeography

Pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension: How can patients be better selected?

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World Journal of Cardiology 2013年第3期5卷 18-21页

作者： Juan C Grignola enric.Domingo Department of Pathophysiology Faculty of Medicine University of the Republic Pulmonary Hypertension Unit Maciel Hospital Ministry of the Public Health Area of the Heart University Hospital of Vall d' Hebron Department of Physiology University Autonoma of Barcelona Campus de Bellaterra

Chronic thromboembolic pulmonary hypertension (CTEPH) comprises organizing thrombotic obstructions in the pulmonary arteries by nonresolving thromboemboli, formation of fibrosis and remodeling of pulmonary blood vessels. Surgical pulmonary endarterectomy (PEA) is the therapy of choice for patients with surgically accessible CTEPH, which leads to a profound improvement in hemodynamics, functional class and survival. Select- ing the candidates that will benefit from surgery is still a challenging task. Criteria for surgical suitability have been described but the decision-making for or against surgical intervention remains still subjective. The optimal characterization of the reciprocal contribution of large vessel and small vessel disease in the elevation of pulmonary vascular resistance is crucial for the indication and outcome of PEA. Recently, Toshner et al intended to validate the partition resistance into small and large vessels compartments (upstream resistance:Rup) by the occlusion technique in the preoperative assessment of PEA. We discuss the advantages and disadvantages of Rup and compare it with other hemodynamic predictor to evaluate operative risk in CTEPH patients.

关键词： Pulmonary endarterectomy Operability Chronic thromboembolic pulmonary hypertension Pulmonary artery occluded pressure Pulmonary vascular resistance