Search results for "fluid"

showing 10 items of 5513 documents

Measures with predetermined regularity and inhomogeneous self-similar sets

2016

We show that if $X$ is a uniformly perfect complete metric space satisfying the finite doubling property, then there exists a fully supported measure with lower regularity dimension as close to the lower dimension of $X$ as we wish. Furthermore, we show that, under the condensation open set condition, the lower dimension of an inhomogeneous self-similar set $E_C$ coincides with the lower dimension of the condensation set $C$, while the Assouad dimension of $E_C$ is the maximum of the Assouad dimensions of the corresponding self-similar set $E$ and the condensation set $C$. If the Assouad dimension of $C$ is strictly smaller than the Assouad dimension of $E$, then the upper regularity dimens…

Pure mathematicsAssouad dimensionGeneral MathematicsOpen set01 natural sciencesMeasure (mathematics)Complete metric space54E35010305 fluids & plasmasSet (abstract data type)Dimension (vector space)0103 physical sciencesClassical Analysis and ODEs (math.CA)FOS: Mathematicsinhomogeneous self-similar setMathematics::Metric Geometry28A200101 mathematicsMathematics010102 general mathematicsta111doubling metric space54F45lower dimensionMathematics - Classical Analysis and ODEs28A75uniform perfectness
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On the Energy of Distributions, with Application to the Quaternionic Hopf Fibrations

2001

The energy of an oriented q-distribution ? in a compact oriented manifold M is defined to be the energy of the section of the Grassmannian manifold of oriented q-planes in M induced by ?. In the Grassmannian, the Sasaki metric is considered. We show here a condition for a distribution to be a critical point of the energy functional. In the spheres, we see that Hopf fibrations \(\) are critical points. Later, we prove the instability for these fibrations.

Pure mathematicsGeneral MathematicsMathematical analysisCritical point (mathematics)law.inventionSection (fiber bundle)Mathematics::Algebraic GeometrylawGrassmannianSPHERESMathematics::Differential GeometryMathematics::Symplectic GeometryManifold (fluid mechanics)Energy (signal processing)Distribution (differential geometry)Energy functionalMathematicsMonatshefte für Mathematik
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On the index form of a geodesic in a pseudoriemannian almost-product manifold

1986

Pure mathematicsIndex (economics)GeodesiclawGeneral MathematicsProduct (mathematics)Invariant manifoldGeometryAlgebra over a fieldManifold (fluid mechanics)law.inventionMathematicsRendiconti del Circolo Matematico di Palermo
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Remarks about the Besicovitch Covering Property in Carnot groups of step 3 and higher

2016

International audience

Pure mathematicsProperty (philosophy)Applied MathematicsGeneral Mathematicsta111010102 general mathematics[MATH.MATH-CA]Mathematics [math]/Classical Analysis and ODEs [math.CA]16. Peace & justiceHomogeneous quasi-distances01 natural sciencesCarnot groups; Covering theorems; Homogeneous quasi-distances; Mathematics (all); Applied Mathematics010305 fluids & plasmasCombinatoricssymbols.namesakeCarnot groupsCovering theorems0103 physical sciencessymbolsMathematics (all)[MATH]Mathematics [math]0101 mathematicsCarnot cycle[MATH.MATH-MG]Mathematics [math]/Metric Geometry [math.MG]ComputingMilieux_MISCELLANEOUSMathematicsProceedings of the American Mathematical Society
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Fractional Laplacians in bounded domains: Killed, reflected, censored, and taboo Lévy flights.

2018

The fractional Laplacian $(- \Delta)^{\alpha /2}$, $\alpha \in (0,2)$ has many equivalent (albeit formally different) realizations as a nonlocal generator of a family of $\alpha $-stable stochastic processes in $R^n$. On the other hand, if the process is to be restricted to a bounded domain, there are many inequivalent proposals for what a boundary-data respecting fractional Laplacian should actually be. This ambiguity holds true not only for each specific choice of the process behavior at the boundary (like e.g. absorbtion, reflection, conditioning or boundary taboos), but extends as well to its particular technical implementation (Dirchlet, Neumann, etc. problems). The inferred jump-type …

Pure mathematicsQuantum PhysicsStochastic processmedia_common.quotation_subjectPhysical systemAmbiguity01 natural sciencesDirichlet distribution010305 fluids & plasmassymbols.namesakeLévy flightBounded function0103 physical sciencessymbolsNeumann boundary conditionMathematics - Numerical Analysis010306 general physicsBrownian motionCondensed Matter - Statistical MechanicsMathematical PhysicsMathematics - ProbabilityMathematicsmedia_commonPhysical review. E
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Neumann p-Laplacian problems with a reaction term on metric spaces

2020

We use a variational approach to study existence and regularity of solutions for a Neumann p-Laplacian problem with a reaction term on metric spaces equipped with a doubling measure and supporting a Poincare inequality. Trace theorems for functions with bounded variation are applied in the definition of the variational functional and minimizers are shown to satisfy De Giorgi type conditions.

Pure mathematicsTrace (linear algebra)Applied MathematicsGeneral Mathematics010102 general mathematicsPoincaré inequalityType (model theory)p-Laplacian operator Measure metric spaces Minimalp-weak upper gradient Minimizer01 natural sciencesMeasure (mathematics)010305 fluids & plasmasTerm (time)symbols.namesakeMetric spaceSettore MAT/05 - Analisi Matematica0103 physical sciencesBounded variationsymbolsp-Laplacian0101 mathematicsMathematics
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Anomalous Anosov flows revisited

2017

This paper is devoted to higher dimensional Anosov flows and consists of two parts. In the first part, we investigate fiberwise Anosov flows on affine torus bundles which fiber over 3-dimensional Anosov flows. We provide a dichotomy result for such flows --- they are either suspensions of Anosov diffeomorphisms or the stable and unstable distributions have equal dimensions. In the second part, we give a new surgery type construction of Anosov flows, which yields non-transitive Anosov flows in all odd dimensions.

Pure mathematicsdiffeomorphismsMathematics::Dynamical Systems37D30Fiber (mathematics)General Mathematics010102 general mathematics37D30 (primary)TorusGeometric Topology (math.GT)Dynamical Systems (math.DS)Type (model theory)01 natural sciencesMathematics::Geometric TopologyPhysics::Fluid DynamicsMathematics - Geometric Topology0103 physical sciencesFOS: Mathematics010307 mathematical physicsAffine transformation0101 mathematics[MATH]Mathematics [math]Mathematics - Dynamical SystemsMathematics::Symplectic GeometryMathematics
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Derivatives not first return integrable on a fractal set

2018

We extend to s-dimensional fractal sets the notion of first return integral (Definition 5) and we prove that there are s-derivatives not s-first return integrable.

Pure mathematicss-dimensional Hausdorff measureIntegrable systemApplied MathematicsGeneral MathematicsNumerical analysis010102 general mathematicss-setFirst return integrals-derivative01 natural sciences010305 fluids & plasmasSettore MAT/05 - Analisi Matematica0103 physical sciencesFractal set0101 mathematicsAlgebra over a fieldHenstock–Kurzweil integralMathematics
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Occurrence of illicit drugs in two wastewater treatment plants in the South of Italy

2017

In this study the occurrence and the behavior of illicit drugs and their metabolites have been investigated for two wastewater treatment plants (WWTPs) (namely, WWTP-1 and WWTP-2) located in Sicily (island of Italy). Samples were analyzed for methamphetamine, cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA), methadone (METH), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), 3,4-methylenedioxy amphetamine (MDA); 3,4-methylenedioxy ethylamphetamine (MDEA), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) and Benzoylecgonine (BEG). The BEG, COC, MOR and THC-COOH were found at the highest concentration in both WWTPs. The Wastewater-based epidemiology calculation for BEG, COC…

PyrrolidinesHealth Toxicology and Mutagenesis0208 environmental biotechnology02 engineering and technologyWastewater010501 environmental sciencesSettore MED/42 - Igiene Generale E ApplicataWaste Disposal Fluid01 natural sciencesMethamphetamineIllicit drugchemistry.chemical_compoundCocaineSettore BIO/10 - BiochimicaCannabidiolWater treatmentDronabinolSicilyDrug behavioreducation.field_of_studybiologyTraditional medicineChemistry (all)MDMAGeneral MedicineMethamphetaminePollutionContaminants of emerging concernSubstance Abuse DetectionDrug CombinationsBenzoylecgoninemedicine.drugEnvironmental EngineeringPopulationmedicineHumansEnvironmental Chemistryeducation0105 earth and related environmental sciencesSettore ICAR/03 - Ingegneria Sanitaria-AmbientaleIllicit Drugsbusiness.industryAmphetaminesCodeinePublic Health Environmental and Occupational HealthGeneral Chemistrybiology.organism_classificationEthylamphetamine020801 environmental engineeringAmphetaminechemistryCannabisbusinessWater Pollutants ChemicalMethadoneChemosphere
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Une spéléogenèse à acide sulfurique dans le piémont nord-pyrénéen ?

2018

Tout au long de l’histoire de structuration des Pyrénées, le jeu des grands accidents tectoniquesfont de la zone de piémont nord-pyrénéen une aire privilégiée de circulation de fluides. Parmiceux-ci, la présence de saumures profondes riches en CO2 et H2S a été attestée dans les réservoirspétroliers sud-aquitains d’âge Crétacé. Impliqués dans des processus de migration vers les margesde bassin, ces fluides sont susceptibles de former des cavités dans l’encaissant calcaire là où lesremontées d’H2S entrent en contact avec du dioxygène, produisant ainsi du H2SO4. C’est cettehypothèse de spéléogenèse à acide sulfurique (SAS) que la présente étude cherche à explorer dansles Pyrénées.Les premières…

Pyrénéesspéléogenèse à acide sulfuriquerocheinteractions fluide[SDU.STU.AG] Sciences of the Universe [physics]/Earth Sciences/Applied geologykarst hypogènegéomorphologiegéologie structurale[SDU.STU] Sciences of the Universe [physics]/Earth Sciences[SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geologyisotopie du soufreComputingMilieux_MISCELLANEOUS
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