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Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

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Applied Mathematics and Mechanics(english edition) 2024年第5期45卷 819-836页

作者： d.Lee s.CHANG j.Lee department of Automotive engineering Hanyang UniversitySeoul 04763Republic of Korea school of Mechanical engineering Chungnam National UniversityDaejeon 34134Republic of Korea department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random inputs.The method consists of a generalized polynomial chaos expansion(GPCe)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data set.In the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random inputs.This allows for avoiding repeated computations of invariant substructures while generating the input-output data set.Combining substructuring with static condensation further improves the computational efficiency of the reanalysis without losing accuracy.Consequently,the GPCe with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional inputs.The numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCe using full finite element analyses(FeAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCe) static reanalysis method static condensation substructuring

Kinetics of glyphosate and aminomethylphosphonic acid sorption onto montmorillonite clays in soil and their translocation to genetically modified corn

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journal of environmental sciences 2024年第1期135卷 669-680页

作者： Meichen Wang Kelly j Rivenbark Timothy d Phillips Veterinary Physiology and Pharmacology College of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityTX 77845USA

The co-occurrence of glyphosate(GLP)and aminomethylphosphonic acid(AMPA)in contaminated water,soil,sediment and plants is a cause for concern due to potential threats to the ecosystem and human health.A major route of exposure is through contact with contaminated soil and consumption of crops containing GLP and AMPA residues.However,clay-based sorption strategies for mixtures of GLP and AMPA in soil,plants and garden produce have been very limited.In this study,in vitro soil and in vivo genetically modified corn models were used to establish the proof of concept that the inclusion of clay sorbents in contaminated soils will reduce the bioavailability of GLP and AMPA in soils and their adverse effects on plant growth.effects of chemical concentration(1–10 mg/kg),sorbent dose(0.5%-3%in soil and 0.5%-1%in plants)and duration(up to 28 days)on sorption kinetics were studied.The time course results showed a continuous GLP degradation to AMPA.The inclusion of calcium montmorillonite(CM)and acid processed montmorillonite(APM)clays at all doses significantly and consistently reduced the bioavailability of both chemicals from soils to plant roots and leaves in a dose-and time-dependent manner without detectable dissociation.Plants treated with 0.5%and 1%APM inclusion showed the highest growth rate(p≤0.05)and lowest chemical bioavailability with up to 76%reduction in roots and57%reduction in leaves.Results indicated that montmorillonite clays could be added as soil supplements to reduce hazardous mixtures of GLP and AMPA in soils and plants.

关键词： Glyphosate AMPA Adsorption soil remediation Plant Hydroponic system

Adipose-derived regenerative therapies for the treatment of knee osteoarthritis

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World journal of stem Cells 2024年第4期16卷 324-333页

作者： Ilias e epanomeritakis Wasim s Khan division of Trauma and Orthopaedic surgery Addenbrooke’s HospitalCambridge University Hospitals NHS Foundation TrustCambridge CB20QQUnited Kingdom division of Trauma and Orthopaedic surgery Department of SurgeryUniversity of CambridgeCambridge CB20QQUnited Kingdom

Knee osteoarthritis is a degenerative condition with a significant disease burden and no disease-modifying therapy.definitive treatment ultimately requires joint replacement.Therapies capable of regenerating cartilage could significantly reduce financial and clinical costs.The regenerative potential of mesenchymal stromal cells(MsCs)has been extensively studied in the context of knee osteoarthritis.This has yielded promising results in human studies,and is likely a product of immunomodulatory and chondroprotective biomolecules produced by MsCs in response to inflammation.Adipose-derived MsCs(AsCs)are becoming increasingly popular owing to their relative ease of isolation and high proliferative capacity.stromal vascular fraction(sVF)and micro-fragmented adipose tissue(MFAT)are produced by the enzymatic and mechanical disruption of adipose tissue,respectively.This avoids expansion of isolated AsCs ex vivo and their composition of heterogeneous cell populations,including immune cells,may potentiate the reparative function of AsCs.In this editorial,we comment on a multicenter randomized trial regarding the efficacy of MFAT in treating knee osteoarthritis.We discuss the study’s findings in the context of emerging evidence regarding adipose-derived regenerative therapies.An underlying mechanism of action of AsCs is proposed while drawing important distinctions between the properties of isolated AsCs,sVF,and MFAT.

关键词： Knee osteoarthritis Mesenchymal stromal cells Adipose tissue stromal vascular fraction Micro-fragmented adipose tissue Regeneration

Nonlinear wave dispersion in monoatomic chains with lumped and distributed masses:discrete and continuum models

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Applied Mathematics and Mechanics(english edition) 2024年第4期45卷 633-648页

作者： e.GHAVANLOO s.eL-BORGI school of Mechanical engineering Shiraz UniversityShiraz 71963-16548Iran Mechanical engineering Program Texas A&M University at QatarDoha 23874Qatar

The main objective of this paper is to investigate the influence of inertia of nonlinear springs on the dispersion behavior of discrete monoatomic chains with lumped and distributed masses.The developed model can represent the wave propagation problem in a non-homogeneous material consisting of heavy inclusions embedded in a matrix.The inclusions are idealized by lumped masses,and the matrix between adjacent inclusions is modeled by a nonlinear spring with distributed masses.Additionally,the model is capable of depicting the wave propagation in bi-material bars,wherein the first material is represented by a rigid particle and the second one is represented by a nonlinear spring with distributed masses.The discrete model of the nonlinear monoatomic chain with lumped and distributed masses is first considered,and a closed-form expression of the dispersion relation is obtained by the second-order Lindstedt-Poincare method(LPM).Next,a continuum model for the nonlinear monoatomic chain is derived directly from its discrete lattice model by a suitable continualization technique.The subsequent use of the second-order method of multiple scales(MMs)facilitates the derivation of the corresponding nonlinear dispersion relation in a closed form.The novelties of the present study consist of(i)considering the inertia of nonlinear springs on the dispersion behavior of the discrete mass-spring chains;(ii)developing the second-order LPM for the wave propagation in the discrete chains;and(iii)deriving a continuum model for the nonlinear monoatomic chains with lumped and distributed masses.Finally,a parametric study is conducted to examine the effects of the design parameters and the distributed spring mass on the nonlinear dispersion relations and phase velocities obtained from both the discrete and continuum models.These parameters include the ratio of the spring mass to the lumped mass,the nonlinear stiffness coefficient of the spring,and the wave amplitude.

关键词： nonlinear mass-spring chain discrete model continuum model LindstedtPoincare method(LPM) method of multiple scales(MMs) dispersion phase velocity

Ground-based and additional science support for sMILe

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earth and Planetary Physics 2024年第1期8卷 275-298页

作者： j.A.Carter M.dunlop C.Forsyth K.Oksavik e.donovon A.Kavanagh s.e.Milan T.sergienko R.C.Fear d.G.sibeck M.Connors T.Yeoman X.Tan M.G.G.T.Taylor K.McWilliams j.Gjerloev R.Barnes d.d.Billet G.Chisham A.dimmock M.P.Freeman d.-s.Han M.d.Hartinger s.-Y.W.Hsieh Z.-j.Hu M.K.james L.juusola K.Kauristie e.A.Kronberg M.Lester j.Manuel j.Matzka I.McCrea Y.Miyoshi j.Rae L.Ren F.sigernes e.spanswick K.sterne A.steuwer T.sun M.-T.Walach B.Walsh C.Wang j.Weygand j.Wild j.Yan j.Zhang Q.-H.Zhang Planetary sciences Group School of Physics and AstronomyUniversity of LeicesterUniversity RoadLeicesterLE17RHUK Rutherford Appleton Laboratory space Science Technology Facilities CouncilOxfordshireUK school of space and environment Beihang UniversityBeijing 100191China Key Laboratory of space environment Monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100017China department of space and Climate Physics UCLMullard Space Science LaboratoryHolmbury St.MaryDorkingSurreyRH56NTUK Birkeland Centre for space science Department of Physics and Technology.University of BergenBergenNorway department of Physics and Astronomy University of Calgary2500 University DriveCalgaryAlbertaCanada T2N 1N4 British Antarctic survey CambridgeUK swedish Institute of space Physics KirunaSweden West Highfield Campus University of SouthamptonUniversity RoadSO171BJUK Goddard space Flight Center NASAGreenbeltMarylandUSA Athabasca University AthabascaCanada esTeC European Space AgencyNetherlands University of saskatchewan SaskatoonCanada The johns Hopkins University Applied Physics Laboratory LaurelMarylandUSA swedish Institude of space Physics UppsalaSE 75121Sweden Tongji University Shanghai 200092China Center for space Plasma Physics Space Science Institute4765 Walnut Street Suite BBoulderColorado80301USA Polar Research Institute of China Shanghai 200136China Finnish Meteorological Institute(FMI) Finland department of earth and environmental sciences(Geophysics) Ludwig Maximilian University of Munich(LMU)MunichTheresienstr.41MunichD-80333Germany Canadian space Agency MontrealCanada GFZ German Research Centre for Geosciences PotsdamGermany Nagoya University Institute for Space Earth Environment ResearchCenter for Integrated Data ScienceNagoyaAichiJP 464-8601 Northumbria University Newcastle upon TyneTyne and WearUK NE18ST National space science Center Chinese Academy SciencesBeijing 100190China Arctic Geophysics University Centre in Svalbard

The joint european space Agency and Chinese Academy of sciences solar wind Magnetosphere Ionosphere Link explorer(sMILe)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the sMILe mission.Here,we describe current community efforts to prepare for sMILe,and the benefits and context various experiments that have explicitly expressed support for sMILe can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional science Working Group,is facilitating these efforts.Preparations include constructing an online sMILe data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the sMILe mission,and we welcome novel ideas and insights from the solar-terrestrial community.

关键词： magnetosphere ionosphere magnetosphere-ionosphere coupling ground-based experimentation sMILe conjunctions missions

Converting TRex-RGB green-channel data to 557.7 nm auroral intensity:Methodology and initial results

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earth and Planetary Physics 2024年第1期8卷 258-274页

作者： jun Liang d.M.Gillies e.spanswick e.F.donovan University of Calgary CalgaryT2N 1N4Canada

The recently deployed Transition Region explorer(TRex)-RGB(red-green-blue)all-sky imager(AsI)is designed to capture“true color”images of the aurora and airglow.Because the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TRex-RGB camera is usually dominated by the 557.7 nm emission.Under this rationale,the TRex mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm aurora.In this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB data.We illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TRex spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-earth-orbit satellites,with the aid of an auroral transport model.We demonstrate the procedures and provide initial results for the TRex-RGB AsIs at the Rabbit Lake and Lucky Lake stations.The RGB response is found to be nonlinear.empirical conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TRex-RGB data users.The methodology established in this study will also be applicable to the upcoming sMILe AsI mission,which will adopt a similar RGB camera system in its deployment.

关键词： TRex RGB green-line aurora auroral transport model

The CCd instrument background of the sMILe sXI

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earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.W.j.Hubbard O.Hetherington d.j.Hall T.W.Buggey s.Parsons T.Arnold A.Holland C.Pagani s.sembay Centre for electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

The esA and CAs sMILe mission orbit is highly elliptical and will pass through multiple radiation environments.The soft X-ray Imager(sXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.The shutter door will close when passing below an altitude threshold to protect against trapped particles in the earth’s Van Allen Belts.Therefore,two radiation environments can be approximated based on the shutter door position:open and closed.The instrument background for the CCds(Charge-Coupled devices)that form the focal plane array of the sXI were evaluated for the two environments.due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.The results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.This is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

sMILe soft X-ray Imager flight model CCd370 pre-flight device characterisation

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earth and Planetary Physics 2024年第1期8卷 25-38页

作者： s.Parsons d.j.Hall O.Hetherington T.W.Buggey T.Arnold M.W.j.Hubbard A.Holland Centre for electronic Imaging the Open UniversityMilton KeynesMK76AAUK

Throughout the sMILe mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCd370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCds have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCd soft X-ray imager characterisation sMILe

estradiol increases cortical and trabecular bone accrual and bone strength in an adolescent male-to-female mouse model of gender-affirming hormone therapy

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Bone Research 2024年第1期12卷 95-106页

作者： Tian Nie Varun s.Venkatesh suzanne Golub Kathryn s.stok Haniyeh Hemmatian Reena desai david j.Handelsman jeffrey d.Zajac Mathis Grossmann Rachel A.davey department of Medicine Austin HealthUniversity of MelbourneHeidelbergVIC 3084Australia department of Biomedical engineering University of MelbourneParkvilleVIC 3010Australia ANZAC Research Institute University of Sydney and AndrologyConcord Repatriation General HospitalConcordNSW 2137Australia

The effects of gender-affirming hormone therapy on the skeletal integrity and fracture risk in transitioning adolescent trans girls are unknown.To address this knowledge gap,we developed a mouse model to simulate male-to-female transition in human adolescents in whom puberty is first arrested by using gonadotrophin-releasing hormone analogs with subsequent estradiol treatment.Puberty was suppressed by orchidectomy in male mice at 5 weeks of age.At 3 weeks post-surgery,male-to-female mice were treated with a high dose of estradiol(~0.85 mg)by intraperitoneal silastic implantation for 12 weeks.Controls included intact and orchidectomized males at 3 weeks post-surgery,vehicle-treated intact males,intact females and orchidectomized males at 12 weeks post-treatment.Compared to male controls,orchidectomized males exhibited decreased peak bone mass accrual and a decreased maximal force the bone could withstand prior to fracture.estradiol treatment in orchidectomized male-to-female mice compared to mice in all control groups was associated with an increased cortical thickness in the mid-diaphysis,while the periosteal circumference increased to a level that was intermediate between intact male and female controls,resulting in increased maximal force and stiffness.In trabecular bone,estradiol treatment increased newly formed trabeculae arising from the growth plate as well as mineralizing surface/bone surface and bone formation rate,consistent with the anabolic action of estradiol on osteoblast proliferation.These data support the concept that skeletal integrity can be preserved and that long-term fractures may be prevented in trans girls treated with GnRHa and a sufficiently high dose of GAHT.Further study is needed to identify an optimal dose of estradiol that protects the bone without adverse side effects.

关键词： treatment treatment strength