Search results for "Formula"

showing 10 items of 755 documents

Element-specific magnetic properties of Co2(Mn1−xFex)Si films probed by x-ray magnetic circular/linear dichroism

2011

Element-specific magnetic properties of epitaxial Co${}_{2}$Fe${}_{x}$Mn${}_{1\ensuremath{-}x}$Si/MgO(100) Heusler films prepared by laser ablation are measured by circular dichroism in x-ray absorption spectroscopy (XMCD). Surface and bulk magnetization of the 100-nm-thick films are equal as tested by comparing the total electron yield and transmission measurements and follow the generalized Slater-Pauling rule. For Co${}_{2}$FeSi, the large magnetization of 6 ${\ensuremath{\mu}}_{B}$ per formula unit indicates half-metallic behavior. Calculations using the local spin density approximation (LDA) result in a half-metallic band structure for this compound when an additional electron-electron…

Circular dichroismMagnetizationMaterials scienceAbsorption spectroscopyCondensed matter physicsX-ray magnetic circular dichroismFormula unitCondensed Matter PhysicsLinear dichroismElectronic band structureSpectral lineElectronic Optical and Magnetic MaterialsPhysical Review B
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Classification and non-existence results for weak solutions to quasilinear elliptic equations with Neumann or Robin boundary conditions

2021

Abstract We classify positive solutions to a class of quasilinear equations with Neumann or Robin boundary conditions in convex domains. Our main tool is an integral formula involving the trace of some relevant quantities for the problem. Under a suitable condition on the nonlinearity, a relevant consequence of our results is that we can extend to weak solutions a celebrated result obtained for stable solutions by Casten and Holland and by Matano.

Class (set theory)Trace (linear algebra)010102 general mathematicsRegular polygon01 natural sciencesRobin boundary conditionNon-existenceNonlinear systemClassification of solutionsMathematics - Analysis of PDEsSettore MAT/05 - Analisi Matematica0103 physical sciencesQuasilinear anisotropic elliptic equationsFOS: MathematicsLiouville-type theoremApplied mathematics010307 mathematical physicsIntegral formula0101 mathematicsAnalysisMathematicsAnalysis of PDEs (math.AP)
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Preclinical models for colonic absorption, application to controlled release formulation development.

2018

Oral controlled release (CR) formulations have many benefits and have become a valuable resource for the local and systemic administration of drugs. The most important characteristic of these pharmaceutical products is that drug absorption occurs mainly in the colon. Therefore, this review analyses the physiological and physicochemical features that may affect an orally administered CR product, as well as the different strategies to develop a CR dosage form and the methods used to evaluate the formulation efficacy. The models available to study the intestinal permeability and their applicability to colonic permeability determinations are also discussed.

ColonDrug Evaluation PreclinicalPharmaceutical ScienceAdministration Oral02 engineering and technologyPharmacology030226 pharmacology & pharmacyModels BiologicalDosage form03 medical and health sciences0302 clinical medicinemedicineOral routeAnimalsHumansIntestinal permeabilityChemistryGeneral Medicine021001 nanoscience & nanotechnologymedicine.diseaseControlled releaseColonic absorptionIntestinal AbsorptionPharmaceutical PreparationsControlled-Release FormulationsDelayed-Action PreparationsDrug DesignSystemic administration0210 nano-technologyBiotechnologyEuropean journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V
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The Cauchy problem for linear growth functionals

2003

In this paper we are interested in the Cauchy problem $$ \left\{ \begin{gathered} \frac{{\partial u}}{{\partial t}} = div a (x, Du) in Q = (0,\infty ) x {\mathbb{R}^{{N }}} \hfill \\ u (0,x) = {u_{0}}(x) in x \in {\mathbb{R}^{N}}, \hfill \\ \end{gathered} \right. $$ (1.1) where \( {u_{0}} \in L_{{loc}}^{1}({\mathbb{R}^{N}}) \) and \( a(x,\xi ) = {\nabla _{\xi }}f(x,\xi ),f:{\mathbb{R}^{N}}x {\mathbb{R}^{N}} \to \mathbb{R} \)being a function with linear growth as ‖ξ‖ satisfying some additional assumptions we shall precise below. An example of function f(x, ξ) covered by our results is the nonparametric area integrand \( f(x,\xi ) = \sqrt {{1 + {{\left\| \xi \right\|}^{2}}}} \); in this case …

CombinatoricsCauchy problemCauchy's convergence testDomain (ring theory)UniquenessNabla symbolCauchy's integral theoremCauchy's integral formulaMathematicsCauchy product
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A Characterization of Bispecial Sturmian Words

2012

A finite Sturmian word w over the alphabet {a,b} is left special (resp. right special) if aw and bw (resp. wa and wb) are both Sturmian words. A bispecial Sturmian word is a Sturmian word that is both left and right special. We show as a main result that bispecial Sturmian words are exactly the maximal internal factors of Christoffel words, that are words coding the digital approximations of segments in the Euclidean plane. This result is an extension of the known relation between central words and primitive Christoffel words. Our characterization allows us to give an enumerative formula for bispecial Sturmian words. We also investigate the minimal forbidden words for the set of Sturmian wo…

CombinatoricsChristoffel symbolsApproximations of πEuclidean geometrySturmian wordAlphabetMathematicsSturmian words Christoffel words special factors minimal forbidden words enumerative formula
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Direct Evaluation of Path Integrals

2001

Every time τ n is assigned a point y n . We now connect the individual points with a classical path y(τ). y(τ) is not necessarily the (on-shell trajectory) extremum of the classical action. It can be any path between τ n and τn−1 specified by the classical Lagrangian \(L(y,\dot{y},t).\)

CombinatoricsPath (topology)PhysicsFree particlePhase factorsymbols.namesakePath integral formulationTrajectorysymbolsHarmonic oscillatorAction (physics)Schrödinger equation
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A computational aeroelastic framework based on high-order structural models and high-fidelity aerodynamics

2023

A computational framework for high-fidelity static aeroelastic analysis is presented. Aeroelastic analysis traditionally employs a beam stick representation for the structure and potential, inviscid and irrotational flow assumptions for the aerodynamics. The unique contribution of this work is the introduction of a high-order structural formulation coupled with a high-fidelity method for the aerodynamics. In more details, the Carrera Unified Formulation coupled with the Finite Element Method is implemented to model geometrically complex composite, laminated structures as equivalent bi-dimensional plates. The open-source software SU2 is then used for the solution of the aerodynamic fields. T…

Composite structuresFluid-structure interactionCarrera unified formulationAerospace EngineeringEquivalent plate modellingCFDSettore ING-IND/04 - Costruzioni E Strutture AerospazialiStatic aeroelasticity
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Continuous reformulations and heuristics for the Euclidean travelling salesperson problem

2008

We consider continuous reformulations of the Euclidean travelling salesperson problem (TSP), based on certain clustering problem formulations. These reformulations allow us to apply a generalisation with perturbations of the Weiszfeld algorithm in an attempt to find local approximate solutions to the Euclidean TSP.

Computational MathematicsMathematical optimizationControl and OptimizationControl and Systems EngineeringProblem FormulationsEuclidean geometryApplied mathematicsComputer Science::Data Structures and AlgorithmsHeuristicsCluster analysisMathematicsESAIM: Control, Optimisation and Calculus of Variations
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An analysis of Ralston's quadrature

1987

Ralston's quadrature achieves higher accuracy in composite rules than analogous Newton-Cotes or Gaussian formulas. His rules are analyzed, computable expressions for the weights and knots are given, and a more suitable form of the remainder is derived.

Computational Mathematicssymbols.namesakeApplied MathematicsGaussianNumerical analysissymbolsApplied mathematicsRemainderAlgorithmGauss–Kronrod quadrature formulaMathematicsQuadrature (mathematics)Numerische Mathematik
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A comparison of STARFM and an unmixing-based algorithm for Landsat and MODIS data fusion

2015

article i nfo The focus of the current study is to compare data fusion methods applied to sensors with medium- and high- spatial resolutions. Two documented methods are applied, the spatial and temporal adaptive reflectance fusion model (STARFM) and an unmixing-based method which proposes a Bayesian formulation to incorporate prior spectral information.Furthermore, thestrengths of both algorithms arecombined ina novel data fusionmethod: the Spatial and Temporal Reflectance Unmixing Model (STRUM). The potential of each method is demonstrated using simulation imagery and Landsat and MODIS imagery. The theoretical basis of the algorithms causes STARFM and STRUM to produce Landsat-like reflecta…

Computer scienceBayesian formulationSpatial ecologySoil ScienceGeologyMETIS-308148Computers in Earth SciencesSensor fusionFocus (optics)ReflectivityAlgorithmNormalized Difference Vegetation IndexRemote sensingRemote Sensing of Environment
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