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Communications on Applied Mathematics and Computation 2023年第2期5卷 751-775页

作者： gaspar j.machado Stéphane Clain Raphaël Loubère Centre of Physics and Department of Mathematics University of MinhoCampus of Azurém4800-058 GuimaraesPortugal CNRS and Institut de Mathématiques de Bordeaux(IMB) Universitéde BordeauxTalenceFrance

We propose an adaptive stencil construction for high-order accurate finite volume schemes a posteriori stabilized devoted to solve one-dimensional steady-state hyperbolic *** accuracy(up to the sixth-order presently)is achieved,thanks to polynomial recon-structions while stability is provided with an a posteriori MOOD method which controls the cell polynomial degree for eliminating non-physical oscillations in the vicinity of *** supplemented this scheme with a stencil construction allowing to reduce even further the numerical *** stencil is shifted away from troubles(shocks,discontinuities,etc.)leading to less oscillating polynomial *** on linear,Burgers',and Euler equations,we demonstrate that the adaptive stencil technique manages to retrieve smooth solutions with optimal order of accuracy but also irregular ones without spurious ***,we numerically show that the approach allows to reduce the dissipation still maintaining the essentially non-oscillatory behavior.

关键词： Finite volume MOOD Adaptive stencil Steady-state solution Euler equations High order

Finite element model with imposed slip surfaces for earth mass safety evaluation

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journal of Central South University 2014年第9期21卷 3627-3638页

作者： Nuno ARAUjO gaspar j.machado julio B.MARTINS Hugo M.R.D.SILVA C-TAC Territory Environment and Construction Research Centre School of EngineeringUniversity of Minho Guimaraes 4800-058 Portugal Centre of Mathematics School of Sciences University of Minho Guimaraes 4800-058 Portugal

The study of earth masses requires numerical methods that provide the quantification of the safety factor without requiring detrimental assumptions. For that, equilibrium analysis can perform fast computations but require assumptions that limit its potentiality. Limit analysis does not require detrimental assumptions but are numerically demanding. This work provides a new approach that combines the advantage of both the equilibrium method and the limit analysis. The defined hybrid model allows probabilistic analysis and optimization approaches without the assumption of interslice forces. It is compared with a published case and used to perform probabilistic studies in both a homogeneous and a layered foundation. Analyses show that the shape of the density probability functions is highly relevant when computing the probability of failure, and soil elasticity hardly affects the safety of factor of the earth mass.

关键词： slope stability probabilistic methods reliability genetic algorithms safety factor

Local Fourier Analysis for Edge-Based Discretizations on Triangular Grids

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Numerical Mathematics(Theory,Methods and Applications) 2015年第1期8卷 78-96页

作者： Carmen Rodrigo Francisco Sanz Francisco j.gaspar Francisco j.Lisbona Department of Applied Mathematics University of ZaragozaC/Maria de Luna 350018ZaragozaSpain BIFI University of Zaragoza C/Pedro Cerbuna 1250009ZaragozaSpain Department of Applied Mathematics University of ZaragozaC/Pedro Cerbuna 1250009ZaragozaSpain

In this paper,we present a local Fourier analysis framework for analyzing the different components within multigrid solvers for edge-based discretizations on triangular *** different stencils associated with edges of different orientation in a triangular mesh make this analysis *** resulting tool is demonstrated for the vector Laplace problem discretized by mimetic finite difference *** from the local Fourier analysis,as well as experimentally obtained results,are presented to validate the proposed analysis.

关键词： Multigrid local Fourier analysis edge-based discretizations mimetic finite differences

ON THE VALIDITY OF THE LOCAL FOURIER ANALYSIS

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journal of Computational Mathematics 2019年第3期37卷 340-348页

作者： Carmen Rodrigo Francisco j.gaspar Ludmil T.Zikatanov Departamento de Matematica Aplicada IUMAUniversidad de ZaragozaZaragozaSpain CWI Centrum Wiskunde & InformaticaScience Park 1231090 AmsterdamThe Netherlands Department of Mathematics The Pennsylvania State UniversityUniversity ParkPennsylvania 16802USAInstitute for Mathematics and InformaticsBulgarian Academy of SciencesSofia.Bulgaria

Local Fourier analysis(LFA)is a useful tool in predicting the convergence factors of geometric multigrid methods(GMG).As is well known,on rectangular domains with periodic boundary conditions this analysis gives the exact convergence factors of such met *** other boundary conditions are considered,however,this analysis was judged as been heuristic,with limited capabilities in predicting multigrid convergence *** this work,using the Fourier method,we extend these results by proving that such analysis yields the exact convergence factors for a wider class of problems,some of which can not be handled by the traditional rigorous Fourier analysis.

关键词： Local Fourier analysis Multigrid Fourier method

Measurement of in-plane deformations of microsystems by digital holography and speckle interferometry(Invited Paper)

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Chinese Optics Letters 2009年第12期7卷 1109-1112页

作者： G. Pedrini j. gaspar O. Paul W. Osten Institut fr Technische Optik Universitt Stuttgart Department of Microsystems Engineering-IMTEK Universitt Freiburg

The reliability of microsystems is an important issue and for their quality inspection, it is necessary to know the displacements or deformations due to the applied mechanical, thermal, or electrostatic loads. We show how interferometrical techniques like digital holography and speckle interferometry can be used for the measurement of in plane deformations of microsystems with nanometric accuracy and we give a description of the measurement uncertainties.

关键词： Invited Paper Measurement of in-plane deformations of microsystems by digital holography and speckle interferometry

Geological inferences about the upper crustal configuration of the Medellin-Aburra Valley(Colombia)using strong motion seismic records

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Geodesy and Geodynamics 2018年第1期9卷 67-76页

作者： jose David Henao Casas gaspar Monsalve Departamento de Geociencias y Medio Ambiente Universidad Nacional de ColombiaSede MedellínCarrem 80 No 65-223Facultad de MinasM2-314MedellinColombia

In regions of complex geology and tectonic assembly, strong motion seismic arrival time records can be used to test the plausibility of existing hypothesis about the origin of lithological and tectonic features and how they are related in space and time. In this study we use differential travel time residuals at some strong motion accelerographic stations in the Medellin-Aburra Valley, in the northern Central Cordillera of the Colombian Andes, to discuss some aspects of the geological configuration. We based our work on the hypothesis that the differences between seismic travel time residuals among pairs of stations are a function of the differences in the surface geology and the near-surface upper crustal configuration. Our results are consistent with the volcanic rocks of the Quebradagrande Complex being less mafic, more weathered or more tectonically affected than previously thought, with the presence of a relatively thin dunite body on top of the metamorphic basement, and with a large lateral heterogeneity in the mainly mafic San Diego Stock.

关键词： Aburrá Valley geology Strong motion networks Seismic wave arrivals Residuals Seismic anomalies

Effects of cropland abandonment and afforestation on soil redistribution in a small Mediterranean mountain catchment

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International Soil and Water Conservation Research 2023年第2期11卷 339-352页

作者： Makki Khorchani Leticia gaspar Estela Nadal-Romero jose Arnaez Teodoro Lasanta Ana Navas Instituto Pirenaico de Ecologia(IPE CSIC)Campus de Aula DeiAvda.Montanana100550059ZaragozaSpain School of Natural Resources University of Nebraska-LincolnLincolnNEUSA Estacion Experimental Aula Dei(EEAD CSIC)Campus de Aula DeiAvda.Montanana100550059ZaragozaSpain University of La Rioja DCHPhysical GeographyLogronioSpain

In slopes of Mediterranean mid-mountain areas,land use and land cover changes linked to the aban-donment of cropland activity affect soil quality and degradation and soil redistribution;however,limited attention has been paid to this issue at catchment *** paper evaluates the effects of cropland abandonment and post-land abandonment management(through natural revegetation and afforesta-tion)on soil redistribution rates using fallout ^(137)Cs measurements in the Araguás catchment(0.45 km^(2),Central Spanish Pyrenees).A total of 52 soil core samples,distributed in a regular grid,from the first 30-40 cm and 9 sectioned reference samples were collected across the catchment and soil properties were *** ^(137)Cs was measured in a 5 cm sectioned references samples and in bulk grid samples.^(137)Cs inventories were used to estimate soil erosion and deposition rates across the *** show that the highest erosion rates were recorded under sparsely vegetated sites in the badland area,while the lowest rates were found in the afforested area,but no significant differences were observed between the different uses and covers in soil redistribution rates likely due to a long history of human intervention through cultivation in steep slopes and afforestation ***,the recovery of the soil organic matter in afforested areas suggest that afforestation can reduce soil degradation at long-term *** information gained achieve a better understanding of soil redistribution dynamics and provide knowledge for effective land management after cropland abandonment of agroecosystems in Mediter-ranean mountain areas.

关键词： Land use and land cover changes Caesium 137 Erosion and deposition rates Afforestation Mediterranean mountain areas

Photoluminescent Tb^(3+)-based metal-organic framework as a sensor for detection of methanol in ethanol fuel

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journal of Rare Earths 2019年第3期37卷 225-231页

作者： Ramon R.F.Fonseca Rafael D.L.gaspar Ivo M.Raimundo jr. Priscilla P.Luz Department of Chemistry Federal University of Espírito Santo Institute of Chemistry University of Campinas

The sensing capability of a Tb^(3+)-metal-organic framework, based on its photoluminescence, was used for detection of methanol in ethanol fuel. It was synthesized using terbium and trimesic acid as a metal ion center and ligand, respectively. Powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy were employed to characterize the synthesized MOF-76 structural features. According to the results, MOF-76 was successfully obtained with minor synthetic modification and its activated form(named TbTMA) was tested as a sensor for methanol. Tb^(3+) luminescence intensity increases as the methanol concentration in ethanol fuel also increases and the water content does not affect this response. Our findings indicate TbTMA as an appropriate sensor for evaluating ethanol fuel adulteration by methanol addition above the allowed limit.

关键词： Lanthanide Metal-organic frameworks Luminescence Ethanol fuel Sensor Adulteration

Redistribution of Soil Organic Carbon Triggered by Erosion at Field Scale Under Subhumid Climate,Hungary

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Pedosphere 2016年第5期26卷 652-665页

作者： Zoltan SZALAI judit SZABO jozsef KOVACS Erzsebet MESZAROS gaspar ALBERT Csaba CENTERI Boglarka SZABO Balazs MADARASZ Dora ZACHARY Gergely jAKAB Geographical Institute Research Centre for Astronomy and Earth Sciences Hungarian Academy of SciencesBudapest 1112(Hungary) Department of Environmental and Landscape Geography Eotvos Lordnd UniversityBudapest 1117(Hungary) Department of Applied and Environmental Geology Eotvos Lordnd UniversityBudapest 1117(Hungary) Department of Cartography and Geoinformatics Eotvos Lordnd UniversityBudapest 1117(Hungary) Department of Nature Conservation and Landscape Ecology Szent Istvdn UniversityGodollo 2100(Hungary)

Soil organic carbon(SOC) has primary importance in terms of soil physics, soil fertility and even of climate change control. One hundred soil samples were taken from an intensively cultivated Cambisol to quantify SOC redistribution triggered by soil erosion under a subhumid climate, by the simultaneous application of diffuse reflectance(240–1 900 nm) and traditional physico-chemical *** representative sample points were collected from the solum along the slopes at the depth of 20–300 cm with a mean SOC content of 12 g kg^(-1). Hierarchical cluster analyses were performed based on the determined SOC results. The spatial pattern of the groups created were similar, and even though the classifications were not the same, diffuse reflectance had proven to be a suitable method for soil/sediment classification even within a given arable field. Both organic and inorganic carbon distributions were found to be a proper tool for estimations of past soil erosion processes. The SOC enrichment was found on two sedimentary spots with different geomorphological positions. Soil organic matter composition also differed between the two spots due to selective deposition of the delivered organic matter. The components with low-molecular-weight reached the bottom of the slope where they could leach into the profile, while the more polymerised organic matter compositions were delivered and deposited even before on a higher segment of the slope in an aggregated form. This spatial difference appeared below the uppermost tilled soil layer as well, referring the lower efficiency of conventional ploughing tillage in soil spatial homogenisation.

关键词： Cambisol carbon sequestration diffuse reflectance selective erosion soil organic matter composition

3D-printed aerogels as theranostic implants monitored by fluorescence bioimaging

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Bioactive Materials 2024年第11期41卷 471-484页

作者： Ana Iglesias-Mejuto Rui Pinto Pedro Faísca joséCatarino joão Rocha Luisa Durães Maria Manuela gaspar Catarina Pinto Reis Carlos A.García-González AerogelsLab I+D Farma Group(GI-1645)Department of PharmacologyPharmacy and Pharmaceutical TechnologyFaculty of PharmacyiMATUS and Health Research Institute of Santiago de Compostela(IDIS)Universidade de Santiago de CompostelaE-15782Santiago de CompostelaSpain Research Institute for Medicines(iMed.ULisboa) Faculty of PharmacyUniversidade de LisboaAv.Professor Gama Pinto1649-003LisboaPortugal joaquim Chaves Saúde Joaquim Chaves Laboratório de Análises ClínicasMiraflores1495069AlgésPortugal CECAV-Faculty of Veterinary Medicina-Lusófona University-Lisbon University Center Campo Grande 3761749-024LisboaPortugal Faculty of Veterinary Medicina-Lusófona University-Lisbon University Center Campo Grande 3761749-024LisboaPortugal University of Coimbra CERES-Chemical Engineering and Renewable Resources for SustainabilityDepartment of Chemical Engineering3030-790CoimbraPortugal Instituto de Biofísica e Engenharia Biomédica(IBEB) Faculdade de CiênciasUniversidade de LisboaCampo Grande1749-016LisboaPortugal

Aerogel scaffolds are nanostructured materials with beneficial properties for tissue engineering *** tracing of the state of the aerogels after their implantation is challenging due to their variable biodegradation rate and the lack of suitable strategies capable of in vivo monitoring the *** nanoparticles(UCNPs)have emerged as advanced tools for in vitro bioimaging because of their fluorescence *** this work,highly fluorescent UCNPs were loaded into aerogels to obtain theranostic implants for tissue engineering and bioimaging applications.3D-printed alginate-hydroxyapatite aerogels labeled with UCNPs were manufactured by 3D-printing and supercritical CO2 drying to generate personalize-to-patient *** physicochemical performance of the resulting structures was evaluated by printing fidelity measurements,nitrogen adsorption-desorption analysis,and different microscopies(confocal,transmission and scanning electron microscopies).Stability of the aerogels in terms of physicochemical properties was also tested after 3 years of *** was evaluated in vitro by different cell and hemocompatibility assays,in ovo and in vivo by safety and bioimaging studies using different murine *** profile,tissue index and histological evaluations of the main organs unveiled an in vivo downregulation of the inflammation after implantation of the ***-decorated aerogels were first-time manufactured and long-term traceable by fluorescence-based bioimaging until 3 weeks post-implantation,thereby endorsing their suitability as tissue engineering and theranostic nanodevices(*** implants).

关键词： Upconversion nanoparticles Aerogels Theranostic implants In vivo fluorescence