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Particuology 2014年第1期12卷 44-53页

作者： Guang Lu James r.Third christoph r.müller ETH Zürich Department of Mechanical and Process Engineering Institute of Energy Technology Laboratory of Energy Science and Engineering8092 Zürich Switzerland

Discrete-element-method （DEm） simulations have been performed to investigate the cross-sectional flow of non-spherical particles in horizontal rotating cylinders with and without wall rougheners. The non-spherical particles were modeled using the three-dimensional super-quadric equation. The influence of wall rougheners on flow behavior of grains was studied for increasing particle blockiness. moreover, for approximately cubic particles （squareness par.meters [555]）, the rotational speed, gravitational acceleration and particle size were altered to investigate the effect of wall rougheners under a range of operating conditions. For spherical and near-spherical particles （approximately up to the squareness par.meters [344]）, wall rougheners are necessary to prevent slippage of the bed against the cylinder wall. For highly cubic particle geometries （squareness par.meters larger than [3441）, wall rougheners resulted in a counter-intuitive decrease in the angle of repose of the bed. In addition, wall rougheners employed in this study were demonstrated to have a higher impact on bed dynamics at higher rotational speeds and lower gravitational accelerations. Nevertheless, using wall rougheners had a comparatively small influence on particle-flow characteristics for a bed composed of finer grains.

关键词： Granular flowNon-spherical particlesrotating cylinderDiscrete element method (DEm)Kiln

Validation of a discrete element model using magnetic resonance measur.ments

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Particuology 2009年第4期7卷 297-306页

作者： christoph r.müller Stuart A.Scott Daniel J.Holland Belinda C.Clarke Andrew J.Sederman John S.Dennis Lynn F.Gladden Depar.ment of Chemical Engineering and Biotechnology University of CambridgePembroke StreetCambridge CB2 3RAUnited Kingdom

The discrete element model （DEm） is a very pr.mising modelling strategy for two-phase granular systems. However, owing to a lack of exper.mental measur.ments, validation of numerical simulations of two-phase granular systems is still an important issue. In this study, a small two-dimensional gas- fluidized bed was simulated using a discrete element model. The dimensions of the simulated bed were 44mm × 10mm × 120 mm and the fluidized particles had a diameter dp = 1.2 mm and density ρp = 1000 kg/m^3. The comparison between DEm simulations and exper.ments are performed on the basis of time-averaged voidage maps. The drag-law of Beetstra et al. [Beetstra, r., van der Hoef, m.A., ＆ Kuipers,J. A. m. （2007b）. Drag force of intermediate reynolds number flow past mono- and bidispersed arrays of spheres. AIChE Journal, 53,489-501 ] seems to give the best results. The simulations are fairly insensitive to the coefficient of restitution and the coefficient of friction as long as some route of energy dissipation during particle-particle and particle-wall contact is provided. Changing the boundary condition of the gas phase at the side-walls fr.m zero-slip to full-slip does not affect the simulation results. Care is to be taken that the cell sizes are chosen so that a reasonable number of particles can be found in a fluid cell.

关键词： Discrete element modelling magnetic resonance imaging Voidage Gas-fluidized beds

magnetic resonance studies of a gas-solids fluidised bed:Jet-jet and jet-wall interactions

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Particuology 2010年第6期8卷 617-622页

作者： meenal Pore Daniel J.Holland Thusara C.Chandrasekera christoph r.müller Andrew J.Sederman John S.Dennis Lynn F.Gladden John F.Davidson Depar.ment of Chemical Engineering and Biotechnology University of CambridgePembroke StreetCambridgeCB2 3RAUK Depar.ment of mechanical and Process Engineering ETH ZurichSonneggstrasse 38092 ZurichSwitzerland

magnetic resonance imaging （mrI） gave images of air jets fr.m orifices in the distributor plate of a bed of poppy seeds. Attention focused on two features：（1） The interaction between nearby vertical jets fr.m two, three or four orifices; （2） Wall effects, where one or.more orifices created vertical jets near the vertical wall of the cylinder containing the particle bed. The results show that nearby jets are mutually attracted. Likewise a jet near a wall bends out of the vertical, towards the wall, For.multiple adjacent jets, the jet lengths show dependence on orifice layout： the lengths are in reasonable agreement with published measur.ments, by other.methods, for single jets. The mrI gives three-dimensional images of the single jets and of multiple jets, separate or.merging.

关键词： Fluidised bed mrI Jets Distributor design

Sol-gel derived B_(2)O_(3)-CaO borate bioactive glasses with hemostatic,antibacterial and pro-angiogenic activities

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regenerative Biomaterials 2024年第1期3卷 108-118页

作者： Kai Zheng Faina Bider.mahshid monavari Zhiyan Xu Christina Janko christoph Alexiou Ana m.Beltran Aldo r.Boccaccini Jiangsu Province Engineering research Center of Stomatological Translational medicine College of StomatologyNanjing Medical UniversityNanjing 210029China Jiangsu Key Laboratory of Oral Diseases Nanjing Medical UniversityNanjing 210029China Institute of Biomaterials University of Erlangen-Nuremberg91058 ErlangenGermany Depar.ment of Oto-rhino-Laryngology Head and Neck SurgerySection of Experimental Oncology and Nanomedicine(SEON)Else Kroener-Fresenius-Stiftung ProfessorshipUniversitaetsklinikum Erlangen91058 ErlangenGermany Departamento de Ingenier�ıa y Ciencia de los materiales y del Transporte Escuela Politecnica

Sol-gel borate bioactive glasses(BGs)are pr.mising ion-releasing biomaterials for wound healing ***,we report the synthesis of a series of binary B_(2)O_(3)-CaO borate BGs(CaO ranging fr.m 50 to 90mol%)using a sol-gel-based *** influence of CaO content in B_(2)O_(3)-CaO borate BG on morphology,structure and ion release behavior was investigated in *** dissolution(ion release)and crystallization could be observed in borate BGs when CaO content increased,while the morphology was not significantly altered by increasing CaO *** results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B_(2)O_(3)/CaO molar *** also evaluated the in vitro cytotoxicity,hemostatic,antibacterial and angiogenic activities of borate *** was validated for all borate ***,borate BGs exhibited composition-dependent hemostatic,antibacterial and angiogenic ***,higher contents of Ca in borate BGs facilitated hemostatic activity,while higher contents of B_(2)O_(3) were beneficial for pro-angiogenic *** synthesized sol-gel-derived borate BGs are pr.mising materials for developing advanced wound healing dressings,given their fast ion release behavior and favorable hemostatic,antibacterial and angiogenic activities.

关键词： borate glasses sol-gel processing glass composition wound healing

Interleukin-10 gives exhausted chimeric antigen receptor(CAr)T cells a second breath

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Cancer Communications 2024年第7期44卷 787-790页

作者： christoph Heuser-Loy Leibniz Institute for Immunotherapy Division for Functional Immune Cell ModulationRegensburgGermany

Adoptive cell therapy(ACT)represents a major pillar of modern *** or synthetically endowed with the ability to recognize tumor-associated antigens,tumor-infiltrating lymphocytes(TILs)or T cells engineered to transgenically express T cell receptors or chimeric antigen receptors(CArs)are expanded and infused to tumor patients to lyse tumor ***,despite tr.mendous response rates against liquid tumors,many patients undergo relapses,and treatment outcomes in solid tumors have been disappointing so far[1].The harsh tumor.microenvironment,including nutrient deprivation,acidification,hypoxia,and immunosuppressive signals[2,3],in conjunction with persistent antigen stimulation triggers a progr.m of exhaustion in T cells(Figure 1A).Exhausted T cells exhibit reduced cytotoxicity and minimal proliferation potential,physiologically balancing tissue health with control of chronic viral infection or of tumor growth[4,5].Strategies to disengage or rewire the“erroneously”deployed exhaustion progr.m to exploit the full potential of tumor-fighting T cells are highly sought after(Figure 1B).

关键词： Interleukin stimulation Figure

Implementation and validation of a bonded particle model to predict rheological properties of viscoelastic materials

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Particuology 2024年第6期89卷 198-210页

作者： michael mascara Arno mayrhofer Stefan radl christoph Kloss Institute of Process and Particle Engineering Graz University of TechnologyInffeldgasse 13Graz8010Austria DCS Computing GmbH Industriezeile 35Linz4020Austria

This work focuses on implementing a particle-based method able to characterize viscoelastic materials whose rheological properties,such as storage modulus G′and loss modulus G″,are *** is based on the bonded particle model,with the elastic constitutive relation here substituted with a viscoelastic one to capture time-scale *** Burgers model,vastly used in literature to model viscoelastic systems,is discretized and *** test case used for calibration comprises of a cubic lattice,sheared with a periodic motion,to mimic the effect of a shear *** appropriate filtering of the stress response,the rheological properties are obtained,highlighting the effect of the lattice geometry,as well as the particle size,on the accuracy of the ***,the Burgers par.meters are calibrated by analytically fitting the exper.mental dataset,showing the limitation of the Burgers *** micro-contact par.meters are obtained fr.m the macro par.meters through appropriate *** completing a frequency sweep,the simulated G′and G″show a relatively large error,around 25%for G’for *** this reason,a more robust model,namely the generalized maxwell model,has been *** calibration procedure is performed in the same fashion as for the Burgers ***,the tangential micro-contact par.meters are scaled *** normal *** scaling par.meter,calledα,is calibrated by minimizing the root mean square error between simulation and exper.mental data,giving errors below 10%in both G′and G″for a large ***,a full ring plate-plate rheometer setup is simulated,and the simulation is compared with the given exper.mental dataset,again finding a good agreement.

关键词： DEm rheology Numerical modeling Viscoelasticity

Spatial impact of digital finance on carbon productivity

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Geoscience Frontiers 2024年第3期15卷 358-372页

作者： Huaping Sun Tingting Chen christoph Nedopil Wang School of Finance and Economics Jiangsu UniversityZhenjiangChina School of Economics and management University of Science and Technology BeijingBeijingChina Fanhai International School of Finance Fudan UniversityShanghaiChina

Low carbon productivity has been identified as a key direction for China’s future *** an important driving force for economic growth,the question of whether digital finance that is reliant on digital technology can support the development of a low-carbon urban economy r.mains *** on the carbon productivity measured by panel data fr.m 201 cities for the period 2011-2020,this study applies the spatial Dubin model and threshold regression model to explore the impact of digital finance on carbon productivity,yielding the following key ***,the spatial distribution heterogeneity of carbon productivity in China’s eastern region is higher than that in the western region,and both productivity and digital finance are characterized by high(low)-high(low)dotted spatial ***,digital finance can significantly improve carbon productivity via two transmission channels:the human capital and marketization *** the same time,digital finance exerts a spatial spillover effect on carbon productivity,and rising local digital finance levels will increase carbon productivity in neighboring *** analysis indicates that the spillover effect of digital finance in urban agglomerations and eastern regions is more ***,fixed-asset investment has a positive nonlinear.moderating effect on digital finance,thus improving carbon *** the per capita investment in fixed assets does not exceed 682.73 yuan,digital finance exerts only a limit pulling effect on carbon productivity;when it is higher than this value,the pulling effect is intensified.

关键词： Digital finance Carbon productivity Spatial spillover effect Fixed-asset investment Spatial heterogeneity

Conception of a new 4-quadrant hydrogen compressed air energy storage power plant with an integrated electrolyzer

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Energy reviews 2024年第3期3卷 92-101页

作者： Hans-Peter Beck Ann-Kathrin Klaas christoph Klaas research Center Energy Storage Technologies Clausthal University of TechnologyAm Stollen 19A38640GoslarGermany Institute of Electrical Power Engineering and Energy Systems Clausthal University of TechnologyLeibnizstraße 2838678Clausthal-ZellerfeldGermany

A hydrogen compressed air energy storage power plant with an integrated electrolyzer is ideal for large-scale,long-term energy storage because of the emission-free operation and the possibility to offer.multiple ancillary services on the German energy *** paper defines analyzes such a storage concept and conducts an extensive comparison with four additional storage concepts based on various *** results show that the combination of storing compressed air and hydrogen offers a higher efficiency than storing only hydrogen and lower specific investment costs than storing only compressed *** result is confirmed with analysis of the optimal sizing of each power plant component for simultaneous participation on multiple energy markets with a linear optimization dispatch *** hydrogen compressed air energy storage(HCAES)power plant can utilize more revenue possibilities than a hydrogen energy storage because of the higher round-trip efficiency and the combination of the air compressor and the integrated electrolyzer during charging *** integration of the electrolyzer,however,offers a couple of challenges itself because of the highly flexible operation mode.A new concept for the controllable 24-pulse diode-thyristor rectifier of the electrolyzer is presented,that uses mostly common components while offering little to no grid harmonics and a long *** flexible integrated electrolyzer allows for the 4-quadrant operation of the storage power plant.

关键词： Long-term energy storage Hydrogen energy storage Compressed air energy storage mixed-integer linear progr.mming Electrolyzer 24-Pulse thyristor rectifier

recycled graphite for.more sustainable lithium-ion batteries

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Carbon Energy 2024年第5期6卷 15-24页

作者： mayokun Olutogun Anna Vanderbruggen christoph Frey martin rudolph Dominic Bresser Stefano Passerini Helmholtz Institute Ulm(HIU) Ulm Germany Karlsruhe Institute of Technology(KIT) KarlsruheGermany Helmholtz Zentr.m Dresden-rossendorf(HZDr) Helmholtz Institute Freiberg for Resource Technology(HIF)FreibergGermany ProGraphite GmbH UntergriesbachGermany Chemistry Depar.ment Sapienza University of RomeRomeItaly

The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dr.matically in the *** great success,however,urgently calls for the efficient recycling of LIBs at the end of their ***,we describe a froth flotation-based process to recycle graphite—the predominant active material for the negative electrode—fr.m spent LIBs and investigate its reuse in newly assembled *** has been found that the structure and morphology of the recycled graphite are essentially unchanged compared to pristine commercial anode-grade graphite,and despite some minor impurities fr.m the recycling process,the recycled graphite provides a r.markable reversible specific capacity of more than 350 mAh g^(−1).Even more importantly,newly assembled graphite‖NmC532 cells show excellent cycling stability with a capacity retention of 80%after 1000 cycles,that is,comparable to the performance of reference full cells comprising pristine commercial graphite.

关键词： anode graphite lithium-ion battery recycling sustainability

machine learning prediction of methane,ethane,and propane solubility in pure water and electrolyte solutions:Implications for stray gas migration modeling

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Acta Geochimica 2024年第5期43卷 971-984页

作者： Ghazal Kooti reza Taherdangkoo Chaofan Chen Nikita Sergeev Far.marz Doulati Ardejani Tao meng christoph Butscher Institute of Geotechnics TU Bergakademie FreibergGustav-Zeuner-Str.109599 FreibergGermany Depar.ment of Petroleum Engineering Amirkabir University of TechnologyTehranIran Freiberg Center for Water research ZeWaF TU Bergakademie Freiberg09599 FreibergGermany School of mining College of EngineeringUniversity of TehranTehranIran Taiyuan University of Science and Technology Taiyuan 030024China

Hydraulic fracturing is an effective technology for hydrocarbon extraction fr.m unconventional shale and tight gas reservoirs.A potential risk of hydraulic fracturing is the upward migration of stray gas fr.m the deep subsurface to shallow *** stray gas can dissolve in groundwater leading to chemical and biological reactions,which could negatively affect groundwater quality and contribute to atmospheric *** knowledge oflight hydrocarbon solubility in the aqueous environment is essential for the numerical modelling offlow and transport in the ***,we compiled a database containing 2129exper.mental data of methane,ethane,and propane solubility in pure water and various electrolyte solutions over wide ranges of operating temperature and *** machine learning algorithms,namely regression tree(rT)and boosted regression tree(BrT)tuned with a Bayesian optimization algorithm(BO)were employed to determine the solubility of *** predictions were compared with the exper.mental data as well as four well-established thermodynamic *** analysis shows that the BrT-BO is sufficiently accurate,and the predicted values agree well with those obtained fr.m the thermodynamic *** coefficient of determination(r2)between exper.mental and predicted values is 0.99 and the mean squared error.mSE)is 9.97×10^(-8).The leverage statistical approach further confirmed the validity of the model developed.

关键词： Gas solubility Hydraulic fracturing Thermodynamic models regression tree Boosted regression tree Groundwater contamination