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Particuology 2024年第6期89卷 258-269页

作者： Martin Oelofse Robert Rack Marcelle Hilden Peter Langguth Department of Pharmaceutical technology and Biopharmaceutics Johannes Gutenberg UniversityMainzGermany Carbon Advanced Solutions gmbh HeuchelheimGermany

Spraying parameters during particle agglomeration processes can affect the agglomeration kinetics and particle *** study was conducted to better understand the influence of the spraying parameters in a fluidized bed wet agglomeration process,and the influence on the stability characteristics of carbon tablets.A formulation based on fine carbon and peroxide powder,as well as carboxymethyl cellulose as a binder,was used to produce agglomerates in a first production *** in a second production step carbon tablets with a high porosity were molded for the customer goods *** optimization of the compressive strength of these carbon tablets was the goal of the *** agglomerates were produced with a laboratory scale granulator called“ProCell”and were compressed with a five-cavity mechanical *** screening of the agglomeration process parameters and their influence on the agglomerates quality,as well as the performance characteristics of the carbon tablets,were investigated using a multilevel factorial *** experimental runs were done by varying atomized air pressure and feed rate of the *** was determined by the design *** findings of the statistical trials showed that low atomized air pressure and a low feed rate lead to a higher tablet compressive strength.

关键词： Wet agglomeration Fluidized bed Design of experiments Carbon agglomerates and tablets

Testing and modelling of transient adhesion phenomena in rolling-sliding contacts

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Friction 2024年第5期12卷 1016-1027页

作者： Daniel KVARDA Alexander MEIERHOFER Klaus SIX Faculty of Mechanical Engineering Brno University of TechnologyBrno61669Czech Republic Virtual Vehicle Research gmbh Graz8010Austria

Transient adhesion effects in rolling–sliding contacts influence all aspects of train–track *** is of high importance specifically when these effects result in critically low adhesion,which poses a risk to traction and braking of railway *** study presents a model that can replicate the transient changes of the coefficient of adhesion with tested water and solid particle *** experimental data for the model are measured using a commercial ball-on-disc *** experimental results showed a liquid reservoir in front of the contact area that slowly reduces in *** observation was used in the modelling approach to divide the calculation into two stages where the reservoir is present and when it *** model was able to reproduce the occurrence of low adhesion region seen in experimental results with different particle concentrations.

关键词： coefficient of adhesion tribology transient effects wheel-rail contact

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 parameters are calibrated by analytically fitting the experimental dataset,showing the limitation of the Burgers *** micro-contact parameters are obtained from the macro parameters 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 parameters are scaled *** normal *** scaling parameter,calledα,is calibrated by minimizing the root mean square error between simulation and experimental 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 experimental dataset,again finding a good agreement.

关键词： DEM Rheology Numerical modeling Viscoelasticity

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 Zentrum Dresden-Rossendorf(HZDR) Helmholtz Institute Freiberg for Resource Technology(HIF)FreibergGermany ProGraphite gmbh UntergriesbachGermany Chemistry Department 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 dramatically 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—from 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 from the recycling process,the recycled graphite provides a remarkable 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

EFFECT OF DEEP COLD TREATMENT ON TWO CASE HARDENING STEELS

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Acta Metallurgica Sinica(English letters) 2008年第1期21卷 1-7页

作者： C.H.Surberg P.Stratton K.lingenhle V-Research Center of Competence for Tribology and Technical Logistics gmbh DornbirnAustriap The Linde Group UnterschleiβheimGermany lingenhle technology gmbh FeldkirchAustria

Although cold treatments have been used to reduce the retained austenite in the cases of carburised steel for many years, there is little data on deep cold temperatures below -70℃ or treatment times longer than an hour or two. This study set out to determine the effects of such deep cold treatments at temperatures -150℃ for 24 h. The study investigated the effects of deep cold on the microstructure, hardness profile, residual stress and internal oxidation on two typical carburising steels, 16MnCr5 and 21NiCrMo2. The study found that for both 16MnCr5 and 21NiCrMo2 carburised to a case depth of approximately 0.8 mm, the longer and colder the deep cold treatment, the more the austenite retained in the case was converted to martensite and the harder it became. After low temperature tempering, the hardness difference was smaller, but still significant. In both steels, the case appeared more refined and homogeneous after deep cold treatment. Deep cold treatment had a negligible effect on the core properties of either steel.

关键词： Carburised steel Deep cold Retained austenite

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Characteristics of the SOL ion-to-electron temperature ratio on the J-TEXT tokamak with different plasma configurations

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Plasma Science and technology 2024年第2期26卷 13-21页

作者：李存凯梁云峰江中和周松华建坤阳杰杨庆虎 Alexander KNIEPS Philipp DREWS 徐鑫毛飞越谢伟杨雨桐郭金龙李杨波任正康陈志鹏王能超 the J-TEXT Team International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China Forschungszentrum Jülich gmbh Institut für Energie-und Klimaforschung—PlasmaphysikPartner of the Trilateral Euregio Cluster(TEC)Julich 52425Germany 不详

Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion *** the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor *** edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,*** is broadly consistent with what has been observed previously from various tokamak ***,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate *** the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter *** results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.

关键词： ion temperature island divertor poloidal divertor retarding field analyzer(RFA)probe

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Metabolic characterization of selected probiotic consortia during gluten and wheat bread simulated digestion

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Food Science and Human Wellness 2024年

作者： Mirco Vacca Giuseppe Celano Olga Nikoloudaki Bodo Speckmann Francesco Maria Calabrese Marco Gobbetti Maria de Angelis Faculty of Science and technology， Free University of Bozen Evonik Operations gmbh Department of Soil Plant and Food Sciences， University of Bari Aldo Moro

While exerting their metabolic activities in the gastrointestinal milieu， probiotics impact the host well-being by boosting immunity， treating metabolic disorders， and modulating microbiota and metabolome. Due to the high incidence of gluten-based disorders， the present work aims to deeply explore the metabolism of two selected microbial consortia (MCs) during gluten digestion under simulated gastrointestinal conditions. Featured by high protease and peptidase activity， both MCs accounted for different lactic acid bacteria and Bacillus strains that were combined with two commercial protease enzymes. Gluten substrates were used as purified extracts， white and whole wheat breads. Control samples， instead， relied onto the microbial enzyme lack. Twenty-four hours of simulated digestion were sufficient to completely hydrolyze gluten in one of the two MC-containing experimental sets， and the relative 48 h-digested extract did not alter the cytokine expression in duodenal biopsies from celiac disease (CeD) patients. When digested samples were assayed for antioxidant and phytase activities， microbial enzymes demonstrated to significantly improve both ABTS and DPPH values and to decrease the phytic acid concentration. The inspection of the free amino acid profiles allowed for distinguishing the two MCs， whereas the detection of a heterogeneous panel of volatile organic compounds supported the presence/activity of microbial enzymes without statistically significant differences between MCs. As functional contribution， digested extracts with MCs also proved to reduce the inflammatory cytokine concentrations in cell lines exposed to lipopolysaccharide trigger. Therefore， in line with studies exploring novel adjuvant therapies， the present innovative probiotic consortium featured by high gluten-hydrolyzing metabolism also showed the capability to improve various parameters usually found to be altered in patients affected by gluten-based disorders or CeD.

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The difference of the ionomer–catalyst interfaces for poly(aryl piperidinium)hydroxide exchange membrane fuel cells and proton exchange membrane fuel cells

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Nano Research 2024年第7期17卷 6102-6110页

作者： Xuerui Liu Xingdong Wang Chanyu Zhang Yun Cai Bowen Chen Dongyue Xin Xiaoxiao Jin Wei Zhu Klaus Wippermann Hui Li Ruiyu Li Zhongbin Zhuang Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Lab of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Institute of Petroleum Processing SINOPECBeijing 100083China DeepHytec Co. Ltd.Shenzhen 518118China Institute of Energy and Climate Research(IEK-14) Forschungszentrum Jülich GmbHJülich 52425Germany Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical TechnologyBeijing 100029China

The microstructures of the ionomer–catalyst interfaces in the catalyst layers are important for the fuel cell performance because they determine the distribution of the active triple-phase ***,we investigate the ionomer–catalyst interactions in hydroxide exchange membrane fuel cells(HEMFCs)using poly(aryl piperidinium)and compare them with proton exchange membrane fuel cells(PEMFCs).It is found that different catalyst layer microstructures are between the two types of fuel *** ionomer/carbon(I/C)ratio does not have a remarkable impact on the HEMFC performance,while it has a strong impact on the PEMFC performance,indicating the weaker interaction between the HEMFC ionomer and *** dynamics simulations demonstrate that the HEMFC ionomer tends to distribute on the carbon support,unlike the PEMFC ionomer,which heavily covers the Pt *** results suggest that the poisoning effect of the ionomer on the catalyst is much weaker in HEMFCs,and the improved ionomer/catalyst interaction is beneficial for the HEMFC performances.

关键词： hydroxide exchange membrane fuel cells catalysts ionomer oxygen reduction reaction interfaces

Impact of T_(i)/T_(e )ratio on ion transport based on EAST H-mode plasmas

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Plasma Science and technology 2024年第4期26卷 68-78页

作者：刘建文臧庆梁云峰陈佳乐邬潇河 Alexander KNIEPS 扈嘉辉金仡飞张斌储宇奇刘海庆吕波段艳敏李妙辉陈颖杰龚先祖 the EAST Team Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China University of Science and technology of China Hefei 230026People’s Republic of China Forschungszentrum Jülich gmbh Institut für Energie-und Klimaforschung-PlasmaphysikPartner of the Trilateral Euregio Cluster(TEC)Jülich 52425Germany

At the EAST tokamak, the ion temperature(T_(i)) is observed to be clamped around 1.25 keV in electron cyclotron resonance(ECR)-heated plasmas, even at core electron temperatures up to 10 keV(depending on the ECR heating power and the plasma density). This clamping results from the lack of direct ion heating and high levels of turbulence-driven transport. Turbulent transport analysis shows that trapped electron mode and electron temperature gradient-driven modes are the most unstable modes in the core of ECR-heated H-mode plasmas. Nevertheless, recently it was found that the T_(i)/T_(e)ratio can increase further with the fraction of the neutral beam injection(NBI) power, which leads to a higher core ion temperature(Ti0). In NBI heating-dominant H-mode plasmas, the ion temperature gradient-driven modes become the most unstable ***, a strong and broad internal transport barrier(ITB) can form at the plasma core in high-power NBI-heated H-mode plasmas when the T_(i)/T_(e)ratio approaches ~1, which results in steep core Teand Tiprofiles, as well as a peaked neprofile. Power balance analysis shows a weaker Teprofile stiffness after the formation of ITBs in the core plasma region, where Ticlamping is broken,and the core Tican increase further above 2 keV, which is 80% higher than the value of Ticlamping in ECR-heated plasmas. This finding proposes a possible solution to the problem of Ticlamping on EAST and demonstrates an advanced operational regime with the formation of a strong and broad ITB for future fusion plasmas dominated by electron heating.

关键词： ion temperature clamping transport neutral beam injection stiffness internal transport barrier

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Application of dynamic image analysis to the optical characterisation of fibrous bulk material

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Particuology 2024年第7期90卷 51-60页

作者： Johannes Lunewski Eberhard Schmidt Institute of Particle technology University of WuppertalGermany

Dynamic image analysis provides an automated evaluation method to determine the size and shape of multiple particles. This method represents a common application for ordinary bulk material. The latest draft of ISO 13322–2:2021 describes the state of the art, but lacks instructions for handling fibrous bulk material. Interlocking fibres complicate the measurement conditions and require a disentanglement of fibrous samples during a pre-dispersion step. A further error source includes the fibre orientation inside the measurement zone of the device. If the thresholding algorithm fails to differentiate between the fibre projection area and the background, a subsequent image optimisation solves the problem. This article addresses the mentioned problems by analysing cotton cellulose and polyacrylonitrile fibres. Besides the execution of a pre-dispersion step, the experiments compare the discrepancies between dry and wet dispersion. Here, the software packages PAQXOS and ImageJ perform the image evaluation. In this case, the wet dispersion setup with a subsequent image evaluation by ImageJ provides comprehensible results.

关键词： Bootstrap method Dynamic image analysis Fibre diameter Fibre length distribution Natural fibres Synthetic fibres