Search results for "Fine grain"

showing 9 items of 9 documents

Fine‐grain beta diversity of Palaearctic grassland vegetation

2021

QUESTIONS: Which environmental factors influence fine-grain beta diversity of vegetation and do they vary among taxonomic groups? LOCATION: Palaearctic biogeographic realm. METHODS: We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database, covering a wide range of different grassland and other open habitat types. We derived extensive environmental and structural information for these series. For each series and four taxonomic groups (vascular plants, bryophytes, lichens, all), we calculated the slope parameter (z-value) of the power law species–area relationship (SAR), as a beta diversity measure. We tested whe…

0106 biological sciencesCzechAgriculture and Food SciencesFine grainelevation333.7: Landflächen NaturerholungsgebietehabitatPlant ScienceMaster planFine-grain beta diversity01 natural sciencesScale dependenceevolutionaryRICHNESSvascular plantsHABITATMacroecologyComputingMilieux_MISCELLANEOUSmedia_commonMean occupancyProductivity2. Zero hungerdisturbance0303 health sciencesEcologySettore BIO/02 - Botanica SistematicaEnvironmental researchPalaearctic grasslanddifferentiationenvironmental heterogeneityspecies-area relationship (SAR)gradientDIFFERENTIATION580: Pflanzen (Botanik)disturbance; elevation; fine-grain beta diversity; heterogeneity; land use; macroecology; mean occupancy; Palaearctic grassland; productivity; scale dependence; species–area relationship (SAR); z-valuescale dependencelanguagemacroecologyproductivitymedia_common.quotation_subjectmean occupancyLibrary scienceSpecies–area relationship (SAR)Environmental drivers Grasslands Lichens Mosses Species-area relationship SAR Vascular Plands010603 evolutionary biologySpecies-area curve03 medical and health sciencesspecies–area relationship (SAR)ExcellencePolitical scienceGRADIENTSlovak030304 developmental biologyspatial scalefine-grain beta diversityBiology and Life Sciencesland useDisturbance15. Life on landZ-valuelanguage.human_languageENVIRONMENTAL HETEROGENEITYEarth and Environmental Sciencesz-valueElevationLand useEVOLUTIONARYSPATIAL SCALESPECIES-AREA RELATIONSHIPSVASCULAR PLANTS[SDE.BE]Environmental Sciences/Biodiversity and EcologyheterogeneityHeterogeneityrichness
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Application of linear friction welding for joining ultrafine grained aluminium

2020

Abstract Ultrafine grained (UFG) materials are of great potential in industry due to their enhanced mechanical strength and other promising features, such as ability to superplastic deformation or excellent corrosion resistance. Nevertheless, one of the main limitations lies in their low thermal stability, which leads to excessive grain growth at elevated temperature. It influences mainly further processes performed at high temperature, such as joining. It causes detrimental problems during conventional fusion welding, as significant grain growth is observed and therefore the advantages as a result of small average grain size disappear. Therefore, the idea of applying solid state joining pr…

0209 industrial biotechnologyMaterials scienceStrategy and ManagementMetallurgySuperplasticity02 engineering and technologyWeldingManagement Science and Operations Research021001 nanoscience & nanotechnologyIndustrial and Manufacturing EngineeringGrain sizelaw.inventionGrain growthFusion welding020901 industrial engineering & automationSevere plastic deformationlawUltimate tensile strengthAluminiumFriction weldingUltrafine grained microstructureDeformation (engineering)0210 nano-technologyLinear friction weldingSettore ING-IND/16 - Tecnologie E Sistemi Di LavorazioneJournal of Manufacturing Processes
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Cell Parameters of Fine-Grain BaTiO<sub>3</sub> Powders

1993

Fine grainMaterials scienceMechanics of MaterialsMechanical EngineeringMetallurgyGeneral Materials ScienceCondensed Matter PhysicsMaterials Science Forum
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Destructuration of typical Sicilian calcarenites

2010

The paper discusses some interesting features of Sicilian fine grain calcarenites. Uniaxial, triaxial, oedometer and isotropic compression tests were undertaken on intact specimens of two types of calcarenite in order to investigate their mechanical characteristics. It was found that the strength and deformability is significantly influenced by the structure (fabric and bonding) and by the destructuration processes. A better understanding of fracture development behavior is gained through a combination of acoustic emission and photographic monitoring on non-homogeneous samples with natural pre-existing heterogeneities due to cementation or to density. The results show that the destructurati…

Fine grainSettore ICAR/07 - GeotecnicaGeologyGeotechnical Engineering and Engineering GeologyCementation (geology)Oedometer testlanguage.human_languageCalcareniteBrittlenessAcoustic emissionacoustic emission digital images fracture soft-rock destructurationlanguageGeotechnical engineeringSicilianGeologySize effect on structural strengthcalcarenite destrutturazione
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Welding abilities of UFG metals

2018

Ultrafine Grained (UFG) metals are characterized by an average grain size of <1 μm and mostly high angle grain boundaries. These materials exhibit exceptional improvements in strength, superplastic behaviour and in some cases enhanced biocompatibility. UFG metals barstock can be fabricated effectively by means of Severe Plastic Deformation (SPD) methods. However, the obtained welded joints with similar properties to the base of UFG material are crucial for the production of finished engineering components. Conventional welding methods based on local melting of the joined edges cannot be used due to the UFG microstructure degradation caused by the heat occurrence in the heat affected zone…

Heat-affected zoneMaterials scienceRecrystallization (metallurgy)SuperplasticityUltrafine Grained (UFG) Linear Friction Welding (LFW) Severe Plastic Deformation (SPD) Rotary Friction Welding (RFW) Friction Stir Welding (FSW)WeldingMicrostructurelaw.inventionlawGrain boundaryFriction weldingSevere plastic deformationComposite materialSettore ING-IND/16 - Tecnologie E Sistemi Di LavorazioneAIP Conference Proceedings
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From the Powder to the Electro and/or Magnetic Ceramic Component: Fine Grain Size and Properties

1997

Materials scienceFine grainMechanics of MaterialsComponent (thermodynamics)Mechanical Engineeringvisual_artMetallurgyvisual_art.visual_art_mediumGeneral Materials ScienceCeramicCeramic capacitorPerovskite (structure)Key Engineering Materials
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Iterative moment method for electromagnetic transients in grounding systems on CRAY T3D

1996

In this paper the parallel aspects of an electromagnetic model for transients in grounding systems based on an iterative scheme are investigated in a multiprocessor environment. A coarse and fine grain parallel solutions have been developed on the CRAY T3D, housed at CINECA, equipped with 64 processors working in space sharing modality. The performances of the two parallel approaches implemented according to the work sharing parallel paradigm have been evaluated for different problem sizes employing variable number of processors.

Scheme (programming language)Moment (mathematics)Fine grainComputer scienceGroundConjugate gradient methodMultiprocessingParallel computingcomputercomputer.programming_languageComputational science
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Potential and limits of combining studies of coarse- and fine-grained sediments for the coastal event history of a Caribbean carbonate environment

2013

The coastal deposits of Bonaire, Leeward Antilles, are among the most studied archives for extreme-wave events (EWEs) in the Caribbean. Here we present more than 400 electron spin resonance (ESR) and radiocarbon data on coarse-clast deposits from Bonaire’s eastern and western coasts. The chronological data are compared to the occurrence and age of fine-grained extremewave deposits detected in lagoons and floodplains. Both approaches are aimed at the identification of EWEs, the differentiation between extraordinary storms and tsunamis, improving reconstructions of the coastal evolution, and establishing a geochronological framework for the events. Although the combination of different method…

geographygeography.geographical_feature_categoryFloodplainLandformEvent historyGeologyOcean EngineeringStormFine grained sedimentslaw.inventionchemistry.chemical_compoundOceanographychemistrylawCarbonateRadiocarbon datingCoastal floodGeologyWater Science and TechnologyGeological Society, London, Special Publications
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La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde

2022

Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…

interface shear strengthPervious concreteSettore ICAR/07 - Geotecnicashear keys effect. Pervious concrete for deep trench drains used to stabilise slopes must simultaneously satisfy many requirements namely adequate hydraulic conductiv-ity adequate shear strength a few days after pour-ing capacity to act as a protective filter for soils in which the drain is installed good resistance to clog-ging and adequate residual hydraulic conductivity. The pervious concrete with appropriated mix-design can effectively satisfy all the abovementioned requirements. If the trenches depth is such that they intersect the sliding surface and if the trenches are adequate-ly "socket" in the layers of stable soil there is a fur-ther increase in shear strength due to the shear keys effect. This latter is in addition to the increase in shear strength resulting from the reduction of inter-stitial pressures that remains the principal scope of the draining trenches. Obviously the increase of shear strength due to the shear keys effect occurs if the trenches are filled with material that have enough strength and stiffness such as the porous concrete. In this case the beneficial effects of the draining trenches on stability are also due to the resistance at the concrete interface of the trench - soils and to the intrinsic resistance of the concrete at the area of the trench intersected by the sliding surface taken into consideration.The increase in resistance due to the shear keys effect can be very significant in relation to the thickness and interspace of the trenches. Results reported in the paper demonstrated that the interface fine grained soil-pervious concrete is higher than the residual shear strength of the soil.
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