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reconstructing seafloor age distributions in lost ocean basins

Geoscience Frontiers 2021年第2期12卷 769-780页

作者： Simon Williams Nicky m.Wright John Cannon Nicolas Flament r.dietmar müller Department of Geology Northwest UniversityXi’an710069China State Key Laboratory of Continental Dynamics Northwest UniversityXi’an710069China research School of Earth Sciences The Australian National UniversityACT2601Australia ArC Centre of Excellence for Climate Extremes The Australian National UniversityACT2601Australia EarthByte Group School of GeosciencesUniversity of SydneyAustralia GeoQuEST research Centre School of EarthAtmospheric and Life SciencesUniversity of WollongongNorthfields AvenueNSW2522Australia

reconstructions of past seafloor age make it possible to quantify how plate tectonic forces,surface heat flow,ocean basin volume and global sea level have varied through geological time.However,past ocean basins that have now been subducted cannot be uniquely reconstructed,and a significant challenge is how to explore a wide range of possible reconstructions.Here,we investigate possible distributions of seafloor ages from the late Paleozoic to present using published full-plate reconstructions and a new,efficient seafloor age reconstruction workflow,all developed using the open-source software GPlates.We test alternative reconstruction models and examine the influence of assumed spreading rates within the Panthalassa Ocean on the reconstructed history of mean seafloor age,oceanic heat flow,and the contribution of ocean basin volume to global sea level.The reconstructions suggest variations in mean seafloor age of~15 myr during the late Paleozoic,similar to the amplitude of variations previously proposed for the Cretaceous to present.Our reconstructed oceanic age-area distributions are broadly compatible with a scenario in which the long-period fluctuations in global sea level since the late Paleozoic are largely driven by changes in mean seafloor age.Previous suggestions of a constant rate of seafloor production through time can be modelled using our workflow,but require that oceanic plates in the Paleozoic move slower than continents based on current reconstructions of continental motion,which is difficult to reconcile with geodynamic studies.

关键词： Plate reconstructions Sea level Seafloor spreading

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Global kinematics of tectonic plates and subduction zones since the late Paleozoic Era

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Geoscience Frontiers 2019年第3期10卷 989-1013页

作者： Alexander Young Nicolas Flament Kayla maloney Simon Williams Kara matthews Sabin Zahirovic r.dietmar müller School of Earth and Environmental Sciences University of Wollongong EarthByte Group School of Geosciences The University of Sydney Sydney Informatics Hub The University of Sydney

Detailed global plate motion models that provide a continuous description of plate boundaries through time are an effective tool for exploring processes both at and below the Earth's surface. A new generation of numerical models of mantle dynamics pre-and post-Pangea timeframes requires global kinematic descriptions with full plate reconstructions extending into the Paleozoic(410 ma). Current plate models that cover Paleozoic times are characterised by large plate speeds and trench migration rates because they assume that lowermost mantle structures are rigid and fixed through time. When used as a surface boundary constraint in geodynamic models, these plate reconstructions do not accurately reproduce the present-day structure of the lowermost mantle. Building upon previous work, we present a global plate motion model with continuously closing plate boundaries ranging from the early Devonian at 410 ma to present day.We analyse the model in terms of surface kinematics and predicted lower mantle structure. The magnitude of global plate speeds has been greatly reduced in our reconstruction by modifying the evolution of the synthetic Panthalassa oceanic plates, implementing a Paleozoic reference frame independent of any geodynamic assumptions, and implementing revised models for the Paleozoic evolution of North and South China and the closure of the rheic Ocean. Paleozoic(410-250 ma) rmS plate speeds are on average ～8 cm/yr, which is comparable to mesozoic-Cenozoic rates of ～6 cm/yr on average.Paleozoic global median values of trench migration trend from higher speeds(～2.5 cm/yr) in the late Devonian to rates closer to 0 cm/yr at the end of the Permian(～250 ma), and during the mesozoic-Cenozoic(250-0 ma) generally cluster tightly around ～1.1 cm/yr. Plate motions are best constrained over the past 130 myr and calculations of global trench convergence rates over this period indicate median rates range between 3.2 cm/yr and 12.4 cm/yr with a present day median rate estimated at～5 cm/yr. For Paleozoic times(410-251 ma) o

关键词： Tectonic reconstruction Paleozoic Plate velocities Subduction zone kinematics Lower mantle structure South China

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Inhibition of tubulin detyrosination:a novel strategy to promote central nervous system regeneration

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Neural regeneration research 2024年第12期19卷 2557-2558页

作者： Charlotte Zeitler marco Leibinger.dietmar Fischer Center of Pharmacology Institute for PharmacologyMedical Faculty and University of CologneCologneGermany

The adult mammalian central nervous system(CNS) coordinates essential functions such as sensation,movement,autonomic control,thought processes,and communication.Consequently,injuries or diseases of the CNS are often associated with devastating and permanent functional impairments because damaged axons normally fail to regenerate.An insufficient neuron-intrinsic growth capacity and an inhibitory environment at the injury site are the leading causes of this regenerative failure.

关键词： injuries sensation diseases

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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 m onnigmann ruhr-Universit at 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

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Bayesian geological and geophysical data fusion for the construction and uncertainty quantification of 3D geological models

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Geoscience Frontiers 2021年第1期12卷 479-493页

作者： Hugo K.H.Olierook richard Scalzo David Kohn rohitash Chandra Ehsan Farahbakhsh Chris Clark Steven m.reddy r.dietmar müller School of Earth and Planetary Sciences Curtin UniversityGPO Box U1987PerthWA6845Australia Centre for Translational Data Science University of SydneyNSW2006SydneyAustralia Sydney Informatics Hub University of SydneyNSW2006SydneyAustralia EarthByte Group School of GeosciencesUniversity of SydneyNSW2006SydneyAustralia Timescales of mineral Systems and John de Laeter Centre Curtin UniversityGPO Box U1987PerthWA6845Australia School of mathematics and Statistics University of New South WalesSydneyNSW2052Australia Department of mining Engineering Amirkabir University of Technology(Tehran Polytechnic)TehranIran

Traditional approaches to develop 3D geological models employ a mix of quantitative and qualitative scientific techniques,which do not fully provide quantification of uncertainty in the constructed models and fail to optimally weight geological field observations against constraints from geophysical data.Here,using the Bayesian Obsidian software package,we develop a methodology to fuse lithostratigraphic field observations with aeromagnetic and gravity data to build a 3D model in a small(13.5 km×13.5 km)region of the Gascoyne Province,Western Australia.Our approach is validated by comparing 3D model results to independently-constrained geological maps and cross-sections produced by the Geological Survey of Western Australia.By fusing geological field data with aeromagnetic and gravity surveys,we show that 89%of the modelled region has>95%certainty for a particular geological unit for the given model and data.The boundaries between geological units are characterized by narrow regions withrtainty,which are typically 400-1000 m wide at the Earth's surface and 500-2000 m wide at depth.Beyond~4 km depth,the model requires geophysical survey data with longer wavelengths(e.g.,active seismic)to constrain the deeper subsurface.Although Obsidian was originally built for sedimentary basin problems,there is reasonable applicability to deformed terranes such as the Gascoyne Province.Ultimately,modification of the Bayesian engine to incorporate structural data will aid in developing more robust 3D models.Nevertheless,our results show that surface geological observations fused with geophysical survey data can yield reasonable 3D geological models with narrow uncertainty regions at the surface and shallow subsurface,which will be especially valuable for mineral exploration and the development of 3D geological models under cover.

关键词： Capricorn orogen machine learning Bayesian inference markov chain monte Carlo Solid earth mineral exploration

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Decoding earth’s plate tectonic history using sparse geochemical data

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Geoscience Frontiers 2020年第1期11卷 265-276页

作者： michael G.Tetley Zheng-Xiang Li Kara J.matthews Simon E.Williams r.dietmar müller EarthByte Group School of GeosciencesUniversity of SydneyNSWAustralia Seismological Laboratory California Institute of TechnologyPasadenaCAUSA Data61 CSIROAustralian Technology ParkNSWAustralia Earth Dynamics research Group The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin University of TechnologyGPO Box U1987PerthWA 6845Australia

Accurately mapping plate boundary types and locations through time is essential for understanding the evolution of the plate-mantle system and the exchange of material between the solid Earth and surface environments.However,the complexity of the Earth system and the cryptic nature of the geological record make it difficult to discriminate tectonic environments through deep time.Here we present a new method for identifying tectonic paleo-environments on Earth through a data mining approach using global geochemical data.We first fingerprint a variety of present-day tectonic environments utilising up to 136 geochemical data attributes in any available combination.A total of 38301 geochemical analyses from basalts aged from 5-0 ma together with a well-established plate reconstruction model are used to construct a suite of discriminatory models for the first order tectonic environments of subduction and mid-ocean ridge as distinct from intraplate hotspot oceanic environments,identifying 41,35,and 39 key discriminatory geochemical attributes,respectively.After training and validation,our model is applied to a global geochemical database of 1547 basalt samples of unknown tectonic origin aged between 1000-410 ma,a relatively ill-constrained period of Earth’s evolution following the breakup of the rodinia supercontinent,producing 56 unique global tectonic environment predictions throughout the Neoproterozoic and Early Paleozoic.Predictions are used to discriminate between three alternative published rodinia configuration models,identifying the model demonstrating the closest spatio-temporal consistency with the basalt record,and emphasizing the importance of integrating geochemical data into plate reconstructions.Our approach offers an extensible framework for constructing full-plate,deeptime reconstructions capable of assimilating a broad range of geochemical and geological observations,enabling next generation Earth system models.

关键词： Plate tectonics Geochemistry Geodynamics Supercontinents rodinia Big data

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Expect the unexpected:Brown tumor of the mandible as the first manifestation of primary hyperparathyroidism

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World Journal of Clinical Cases 2024年第7期12卷 1200-1204页

作者： Ana majic Tengg maja Cigrovski Berkovic Ivan Zajc Ivan Salaric Danko müller Iva markota Department of Endocrinology DiabetesMetabolic Diseases and Clinical PharmacologyClinical Hospital DubravaZagreb 10000Croatia Department for Sport and Exercise medicine Faculty of Kinesiology University of ZagrebZagreb 10000Croatia Department of Oral Surgery Clinical Hospital DubravaZagreb 10000Croatia University of Zagreb School of Dental medicine Zagreb 10000Croatia Clinical Department of Pathology and Cytology Clinical Hospital DubravaZagreb 10000Croatia

Hyperparathyroidism(HPT)is a condition in which one or more parathyroid glands produce increased levels of parathyroid hormone(PTH),causing disturbances in calcium homeostasis.most commonly HPT presents with asymptomatic hypercalcemia but the clinical spectrum may include disturbances reflecting the combined effects of increased PTH secretion and hypercalcemia.Brown tumors are rare,benign,tumor-like bone lesions,occurring in 1.5%to 4.5%of patients with HPT,as a complication of an uncontrolled disease pathway,and are nowadays rarely seen in clinical practice.The tumor can appear either as a solitary or multifocal lesion and usually presents as an asymptomatic swelling or a painful exophytic mass.Furthermore,it can cause a pathological fracture or skeletal pain and be radiologically described as a lytic bone lesion.The diagnosis of a brown tumor in HPT is typically confirmed by assessing the levels of serum calcium,phosphorus,and PTH.Although when present,brown tumor is quite pathognomonic for HPT,the histologic finding often suggests a giant cell tumor,while clinical presentation might suggest other more frequent pathologies such as metastatic tumors.Treatment of brown tumors frequently focuses on managing the underlying HPT,which can often lead to regression and resolution of the lesion,without the need for surgical intervention.However,in refractory cases or when dealing with large symptomatic lesions,surgical treatment may be necessary.

关键词： Brown tumor Hyperparathyroidism Lytic bone lesions Giant cell tumor

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Alexa,let's train now!——A systematic review and classification approach to digital and home-based physical training interventions aiming to support healthy cognitive aging

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Journal of Sport and Health Science 2024年第1期13卷 30-46页

作者： Fabian Herold Paula Theobald Thomas Gronwald Navin Kaushal Liye Zou Eling D.de Bruin Louis Bherer Notger Gmüller research Group Degenerative and Chronic Diseases MovementFaculty of Health Sciences BrandenburgUniversity of PotsdamPotsdam 14476Germany Body-Brain-mind Laboratory Shenzhen UniversityShenzhen 518060China Institute of Interdisciplinary Exercise Science and Sports medicine MSH Medical School HamburgHamburg 20457Germany Department of Health Sciences School of Health&Human SciencesIndiana UniversityIndianapolisIN 46202USA Department of Health Sciences and Technology Institute of Human Movement Sciences and SportETH ZurichZurich 8093Switzerland Department of Neurobiology Care Sciencesand SocietyKarolinska InstituteStockholm 17177Sweden Department of Health OST-Eastern Swiss University of Applied SciencesSt.Gallen 9001Switzerland montreal Heart Institute MontrealQC H1T 1C8Canada Department of medicine Universite de MontrealMontrealQC H3T 1J4Canada Centre de recherche de l'Institut Universitaire de Geriatrie de montreal MontrealQC H3W 1W5Canada

Background:There is mounting evidence that regular physical activity is an important prerequisite for healthy cognitive aging.Consequently,the finding that almost one-third of the adult population does not reach the recommended level of regular physical activity calls for further public health actions.In this context,digital and home-based physical training interventions might be a promising alternative to center-based intervention programs.Thus,this systematic review aimed to summarize the current state of the literature on the effects of digital and home-based physical training interventions on adult cognitive performance.methods:In this pre-registered systematic review(PrOSPErO;ID:CrD42022320031),5 electronic databases(Pubmed,Web of Science,Psyclnfo,SPOrTDiscus,and Cochrane Library)were searched by 2 independent researchers(FH and PT)to identify eligible studies investigating the effects of digital and home-based physical training interventions on cognitive performance in adults.The systematic literature search yielded 8258 records(extra17 records from other sources),of which 27 controlled trials were considered relevant.Two reviewers(FH and PT)independently extracted data and assessed the risk of bias using a modified version of the Tool for the assEssment of Study qualiTy and reporting in EXercise(TESTEX scale).results:Of the 27 reviewed studies,15 reported positive effects on cognitive and motor-cognitive outcomes(i.e.,performance improvements in measures of executive functions,working memory,and choice stepping reaction test),and a considerable heterogeneity concerning study-related,population-related,and intervention-related characteristics was noticed.A more detailed analysis suggests that,in particular,interventions using online classes and technology-based exercise devices(i.e.,step-based exergames)can improve cognitive performance in healthy older adults.Approximately one-half of the reviewed studies were rated as having a high risk of bias with respect to completion adherence(≤85%)and monitoring of t

关键词： Brain Cognition Digital health Exercise-cognition Physical activity

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CO_(2)capture costs of chemical looping combustion of biomass:A comparison of natural and synthetic oxygen carrier

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Journal of Energy Chemistry 2024年第5期92卷 296-310页

作者： Benjamin Fleiß Juraj Priscak martin Hammerschmid Josef Fuchs Stefan müller Hermann Hofbauer Institute of Chemical Environmental and Bioscience EngineeringTU WienVienna1060 ViennaAustria BEST–Bioenergy and Sustainable Technologies GmbH Graz8010 StyriaAustria

Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and mitigate climate change.In this process,a metal oxide is used as oxygen carrier in a dual fluidized bed to generate clean CO_(2) via combustion of biomass.most commonly,natural ores or synthetic materials are used as oxygen carrier whereas both must meet special requirements for the conversion of solid fuels.Synthetic oxygen carriers are characterized by higher reactivity at the expense of higher costs versus the lower-cost natural ores.To determine the viability of both possibilities,a techno-economic comparison of a synthetic material based on manganese,iron,and copper to the natural ore ilmenite was conducted.The synthetic oxygen carrier was characterized and tested in a pilot plant,where high combustion efficiencies up to 98.4%and carbon capture rates up to 98.5%were reached.The techno-economic assessment resulted in CO_(2) capture costs of 75 and 40€/tCO_(2) for the synthetic and natural ore route respectively,whereas a sensitivity analysis showed the high impact of production costs and attrition rates of the synthetic material.The synthetic oxygen carrier could break even with the natural ore in case of lower production costs and attrition rates,which could be reached by adapting the production process and recycling material.By comparison to state-of-the-art technologies,it is demonstrated that both routes are viable and the capture cost of CO_(2) could be reduced by implementing the chemical looping combustion technology.

关键词： Chemical looping combustion BECCS Techno-economic assessment CO_(2)capture costs Oxygen carrier development Synthetic materials Ilmenite

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Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBASI GAVArI m.r.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible manipulator.The manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse deformation.To accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation effects.By applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape functions.The assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the other.In addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is investigated.Despite the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the arm.Finally,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element approach.The comparison confirms the validity of the proposed dynamic model for the system.According to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis

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