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Impact of the spindle number on the material transport and mixing during planetary roller melt granulation Author links open overlay panel

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Particuology 2024年第8期91卷 260-267页

作者： tom Lang Jens Bartsch Laboratory of Solids Process Engineering Department of Biochemical and Chemical EngineeringTU Dortmund University44227DortmundGermany

In comparison to the established twin-screw machines,the application of a planetary roller granulator for continuous operation of melt granulation is a promising alternative based on the unique process *** initial study focused on the material transport during processing as a key driver for the overall ***,the impact of direct process parameters on the residence time distribution was the main *** investigations are complemented in this study by considering the free processing volume,which is defined by the number of planetary spindles applied within a *** impact on the processing conditions is evaluated with respect to the process setting in terms of feed rate and rotation *** results highlight the potential of altering the underlying transport function in planetary roller melt granulation(PRMG)via the investigated direct process and equipment *** impact of the feed rate is lower in comparison,while a higher rotation speed as well as a higher free processing volume promote material ***,a normalization of the determined residence time distribution(RTD)model data was feasible with respect to the process settings and the number of applied planetary spindles in the processing *** demonstrates the key role of the free processing volume in the fundamental mechanisms of material transport and mixing during PRMG.

关键词： Continuous manufacturing Melt granulation Planetaryroller granulator Quality-by-Design Residence time Material mixing

Liquid superlubricity of lubricants containing hydroxyl groups and their aqueous solution under rolling/sliding conditions

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Friction 2024年第1期12卷 164-173页

作者： tomáš POLÁČEK Petr ŠPERKA Ivan KŘUPKA Faculty of Mechanical Engineering Brno University of TechnologyBrno 61669Czech Republic

Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so *** purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(glycerol and polyethylene glycol(PEG)),providing superlubricous *** were carried out on an optical ball-on-disc tribometer under rolling/sliding *** film thickness was measured by the thin film colorimetric interferometry,and the viscosity of liquids was measured by rotational and high-pressure falling body *** results show that tribochemical reactions are not the mandatory reason for friction to reach the superlubricity level when using the water-based *** studied liquids themselves are almost *** the addition of water,the signs of shear thinning behavior disappear even *** conditions for this type of lubricant can be predicted using the known Hamrock–Dowson *** anomaly in the thickness of the lubricants was observed as an abrupt change at certain *** more PEG there is in the lubricant,the higher the thickness at the beginning of the jump.

关键词： macroscale superlubricity super low traction water-based lubricants elastohydrodynamic lubrication(EHL) film thickness

Predicting the coefficient of friction in a sliding contact by applying machine learning to acoustic emission data

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Friction 2024年第6期12卷 1299-1321页

作者： Robert GUTIERREZ Tianshi FANG Robert MAINWARING tom REDDYHOFF Tribology Group Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK Shell Global Solutions(US)Inc.Shell Technology Center Houston 3333 Highway 6 SouthHoustonTX 77082USA Shell International Petroleum Company Limited Shell CentreYork RoadLondon SE17NAUK

It is increasingly important to monitor sliding interfaces within machines,since this is where both energy is lost,and failures *** emission(AE)techniques offer a way to monitor contacts remotely without requiring transparent or electrically conductive ***,acoustic data from sliding contacts is notoriously complex and difficult to ***,we simultaneously measure coefficient of friction(with a conventional force transducer)and acoustic emission(with a piezoelectric sensor and high acquisition rate digitizer)produced by a steel‒steel rubbing *** data is then used to train machine learning(ML)algorithms(e.g.,Gaussian process regression(GPR)and support vector machine(SVM))to correlated acoustic emission with *** training requires the dense AE data to first be reduced in size and a range of processing techniques are assessed for this(e.g.,down-sampling,averaging,fast Fourier transforms(FFTs),histograms).Next,fresh,unseen AE data is given to the trained model and the resulting friction predictions are compared with the directly measured *** is excellent agreement between the measured and predicted friction when the GPR model is used on AE histogram data,with root mean square(RMS)errors as low as 0.03 and Pearson correlation coefficients reaching ***,predictions remain accurate despite changes in test conditions such as normal load,reciprocating frequency,and stroke *** paves the way for remote,acoustic measurements of friction in inaccessible locations within machinery to increase mechanical efficiency and avoid costly failure/needless maintenance.

关键词： acoustic emission condition monitoring friction machine learning Gaussian process regression support vector machine

Granger causal representation learning for groups of time series

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Science China(Information Sciences) 2024年第5期67卷 56-68页

作者： Ruichu CAI Yunjin WU Xiaokai HUANG Wei CHEN tom Z.J.FU Zhifeng HAO School of Computer Science Guangdong University of Technology Peng Cheng Laboratory College of Science Shantou University

Discovering causality from multivariate time series is an important but challenging *** existing methods focus on estimating the Granger causal structures among multivariate time series,while ignoring the prior knowledge of these time series, e.g., the group of the time series. Focusing on discovering the Granger causal structures among groups of time series, we propose a Granger causal representation learning method to solve this problem. First, we use the multiset canonical correlation analysis method to learn the Granger causal representation of each group of time series. Then, we model the Granger causal relationships among the learned Granger causal representations using a recurrent neural network with temporal information. Finally, we formulate the above two stages into one unified optimization problem, which is efficiently solved using the augmented Lagrangian method. We conduct extensive experiments on synthetic and real-world datasets to validate the correctness and effectiveness of the proposed method.

关键词： Granger causal discovery Granger causal representation learning time series data recurrent neural network multiset canonical correlation analysis

An integrated microfluidic platform for nucleic acid testing

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Microsystems & Nanoengineering 2024年第3期10卷 181-194页

作者： Antao Sun Petra Vopařilová Xiaocheng Liu Bingqian Kou tomášŘezníček tomášLednický Sheng Ni JiříKudr Ondřej Zítka Zdenka Fohlerová Petr Pajer Haoqing Zhang Pavel Neužil Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’anShaanxi 710072P.R.China Department of Chemistry and Biochemistry Mendel University in BrnoZemědělská161300 BrnoCzech Republic ITD Tech s.r.o Osvoboditelů100573581 BohumínCzech Republic Central European Institute of Technology Brno University of TechnologyPurkyňova 123Brno 61200Czech Republic Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina Department of Microelectronics Faculty of Electrical Engineering and CommunicationBrno University of TechnologyTechnická3058/10Brno 61600Czech Republic Military Health Institute U Vojenskénemocnice 120016200 Praha 6Czech Republic The Key Laboratory of Biomedical Information Engineering of Ministry of Education School of Life Science and TechnologyXi’an Jiaotong UniversityXi’anShaanxi 710049P.R.China Bioinspired Engineering and Biomechanics Center(BEBC) Xi’an Jiaotong UniversityXi’an 710049P.R.China

This study presents a rapid and versatile low-cost sample-to-answer system for SARS-CoV-2 *** system integrates the extraction and purification of nucleic acids,followed by amplification via either reverse transcriptionquantitative polymerase chain reaction(RT–qPCR)or reverse transcription loop-mediated isothermal amplification(RT–LAMP).By meeting diverse diagnostic and reagent needs,the platform yields testing results that closely align with those of commercial RT-LAMP and RT‒qPCR *** advantages of our system include its speed and *** assay is completed within 28 min,including sample loading(5 min),ribonucleic acid(RNA)extraction(3 min),and RT-LAMP(20 min).The cost of each assay is≈$9.5,and this pricing is competitive against that of Food and Drug Administration(FDA)-approved commercial *** some RNA loss during on-chip extraction is observed,the platform maintains a potential limit of detection lower than 297 *** makes the system particularly useful in environments where centralized laboratories are either unavailable or inconveniently *** key feature is the platform’s versatility,allowing users to choose between RT‒qPCR or RT‒LAMP tests based on specific requirements.

关键词： testing maintain versatile

Porphyrinic Acceptors forFullerene-Free MolecularPhotovoltaics

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CCS Chemistry 2024年第2期6卷 276-296页

作者： Jorge Labella Juan Laforga-Martin tomás Torres Department of Organic Chemistry Universidad Aut´onoma de Madrid28049 Madrid Institute for Advanced Research in Chemical Sciences Universidad Aut´onoma de MadridMadrid IMDEA—Nanociencia 28049 Madrid

Over the past few years,the development of nonfullerene acceptors(NFAs)has become a prominent focus in both organic and perovskite solar cell(OSCs and PSCs,respectively)research *** this context,porphyrinoids,compounds structurally related to porphyrins,have emerged as promising solar cell *** contrast to the widely used fullerene acceptors,porphyrinoids exhibit strong,broad absorption properties across the UV–vis/NIR spectrum,which can be easily tuned through chemical ***,they can be prepared and derivatized using cost-effective and straightforward methodologies,allowing for convenient adjustments in thin-film morphology,processability,supramolecular organization,and energy ***,these compounds offer higher thermal and photochemical stability,resulting in longer device lifetimes compared to their fullerene-based *** this review,we outline the utilization of porphyrinoids as NFAs in OSCs and PSCs,discussing essential aspects such as design guidelines,molecular properties,and device *** goal is to inspire and further promote the development of n-type porphyrinoids,which have not yet fully unleashed their potential.

关键词： fullerene-free molecular photovoltaics nonfullerene acceptors porphyrinic acceptors n-type porphyrinoids organic and perovskite solar cells

The first record of a Konservat-Lagerstätten in which early post-settlement stages of fossil archaeobalanids(Cirripedia:Balanomorpha)are preserved

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Integrative Zoology 2024年第2期19卷 200-223页

作者： tomáš KOCÍ Rok GAŠPARIC John BUCKERIDGE Martina KOCOVÁ VESELSKÁ Aleš ŠOSTER Ivancická581 PragueCzech Republic Palaeontological Department Natural History MuseumNational MuseumPragueCzech Republic Oertijdmuseum Bosscheweg 80Boxtel5293 WBThe Netherlands Institute for Palaeobiology and Evolution Novi TrgKamnikSlovenia Earth and Oceanic Systems Group RMIT UniversityMelbourneAustralia Museums Victoria CarltonVictoriaAustralia Department of Paleobiology and Paleoecology Institute of Geology of the Czech Academy of SciencesPragueCzech Republic Institute of Geology and Palaeontology Charles UniversityPragueCzech Republic Faculty of Natural Sciences and Engineering University of LjubljanaLjubljanaSlovenia

A diverse sessile barnacle fauna from a Miocene shallow-water deposit at Dolnja Stara vas in Slovenia is *** includes the first descriptions of early post settlement juveniles of Actinobalanus sloveniensis attached to mangrove *** represent three distinct growth phases,the earliest being interpreted as being less than 24 h post settlement,the others being 1 to 2 days post *** assessment of their taphonomy is *** adult balanomorphs are attached to a variety of organic substrates,including mangrove leaves and branches,fragments of the conifers?Taxodioxylon,Carapoxylon,pine cones,molluscs,and cetacean *** barnacles include ***,Amphibalanus venustus,and Perforatus perforatus—many with opercula retained within the *** retains some of the original shell *** is the second record of barnacle–plant associations from the Central Paratethys from Kamnik and *** paleoecology and paleogeography of the site are discussed.

关键词： acorn barnacles barnacle metamorphosis epibiont paleoecology taxonomy

A Probabilistic Trust Model and Control Algorithm to Protect 6G Networks against Malicious Data Injection Attacks in Edge Computing Environments

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 631-654页

作者： Borja Bordel Sánchez Ramón Alcarria tomás Robles Department of Computer Systems Universidad Politécnica de MadridMadrid28031Spain Department of Geospatial Engineering Universidad Politécnica de MadridMadrid28031Spain

Future 6G communications are envisioned to enable a large catalogue of pioneering *** will range from networked Cyber-Physical Systems to edge computing devices,establishing real-time feedback control loops critical for managing Industry 5.0 deployments,digital agriculture systems,and essential *** provision of extensive machine-type communications through 6G will render many of these innovative systems autonomous and *** full automation will enhance industrial efficiency significantly,it concurrently introduces new cyber risks and *** particular,unattended systems are highly susceptible to trust issues:malicious nodes and false information can be easily introduced into control ***,Denialof-Service attacks can be executed by inundating the network with valueless *** anomaly detection schemes require the entire transformation of the control software to integrate new steps and can only mitigate anomalies that conform to predefined mathematical *** based on an exhaustive data collection to detect anomalies are precise but extremely *** models,with their limited understanding of mobile networks,can achieve precision rates no higher than 75%.Therefore,more general and transversal protection mechanisms are needed to detect malicious behaviors *** paper introduces a probabilistic trust model and control algorithm designed to address this *** model determines the probability of any node to be *** channels are pruned for those nodes whose probability is below a given *** trust control algorithmcomprises three primary phases,which feed themodel with three different probabilities,which are weighted and ***,anomalous nodes are identified using Gaussian mixture models and clustering ***,traffic patterns are studied using digital Bessel functions and the functional scalar ***,the in

关键词： 6G networks noise injection attacks Gaussian mixture model Bessel function traffic filter Volterra filter

Effects of freeze-thaw cycles on sandstone in sunny and shady slopes

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2503-2515页

作者： Dian Xiao Xiaoyan Zhao Corrado Fidelibus Roberto tomás Qiu Lu Hongwei Liu Academy of Railway Sciences Corporation Limited BeijingChina Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengduChina Department of Civil Engineering University of AlicanteAlicanteSpain Department of Innovation Engineering University of SalentoLecceItaly Department of Earth and Environmental Sciences University of Milano BicoccaMilanItaly

A growing rock engineering activity in cold regions is facing the threat of freeze-thaw(FT)weathering,especially in high mountains where the sunny-shady slope effects strongly control the difference in weathering behavior of *** this paper,an investigation of the degradation of petrophysical characteristics of sandstone specimens subjected to FT cycle tests to simulate the sunny-shady slope effects is *** this aim,non-destructive and repeatable testing techniques including weight,ultrasonic waves,and nuclear magnetic resonance methods on standard specimens were *** the sunny slope specimens,accompanied by the enlargement of small pores,100 FT cycles caused a significant decrease in P-wave velocity with an average of 23%,but a consistent rise of 0.18%in mass loss,34%in porosity,67%in pore geometrical mean radius,and a remarkable 14.5-fold increase in ***,slight changes with some abnormal trends in physical parameters of the shady slope specimens were observed during FT cycling,which can be attributed to superficial granular disaggregation and pore throat *** shocks enhance rock weathering on sunny slopes during FT cycles,while FT weathering on shady slopes is restricted to the small pores and the superficial *** two factors are primarily responsible for the differences in FT weathering intensity between sunny and shady *** conclusions derived from the interpretation of the experimental results may provide theoretical guidance for the design of slope-failure prevention measures and the selection of transportation routes in cold mountainous regions.

关键词： Sunny-shady slope Freeze and thaw Pore structure Tight rocks Talus slope Cold regions