Search results for "CONSTANT"

showing 8 items of 1718 documents

Constant sign and nodal solutions for parametric anisotropic $(p, 2)$-equations

2021

We consider an anisotropic ▫$(p, 2)$▫-equation, with a parametric and superlinear reaction term.Weshow that for all small values of the parameter the problem has at least five nontrivial smooth solutions, four with constant sign and the fifth nodal (sign-changing). The proofs use tools from critical point theory, truncation and comparison techniques, and critical groups. Spletna objava: 9. 9. 2021. Abstract. Bibliografija: str. 1076.

udc:517.9electrorheological fluidsElectrorheological fluidMaximum principleMathematics - Analysis of PDEsSettore MAT/05 - Analisi MatematicaFOS: Mathematicsconstant sign and nodal solutionsAnisotropyanisotropic operators regularity theory maximum principle constant sign and nodal solutions critical groups variable exponent electrorheological fluidsParametric statisticsMathematicsvariable exponentVariable exponentApplied MathematicsMathematical analysisudc:517.956.2regularity theoryAnisotropic operatorsanisotropic operatorsTerm (time)Primary: 35J20 35J60 35J92 Secondary: 47J15 58E05maximum principleConstant (mathematics)critical groupsAnalysisAnalysis of PDEs (math.AP)Sign (mathematics)
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Multimetallic Oxynitrides Nanoparticles for a New Generation of Photocatalysts

2019

A versatile synthetic strategy for the preparation of multimetallic oxynitrides has been designed and here exemplarily discussed considering the preparation of nanoscaled zinc-gallium oxynitrides and zinc-gallium-indium oxynitrides, two important photocatalysts of new generation, which proved to be active in key energy related processes from pollutant decomposition to overall water splitting. The synthesis presented here allows the preparation of small nanoparticles (less than 20 nm in average diameter), well-defined in size and shape, yet highly crystalline and with the highest surface area reported so far (up to 80 m2  g-1 ). X-ray diffraction studies show that the final material is not a…

urea glass routeDiffractionoxynitride010405 organic chemistryChemistryOrganic ChemistryNanoparticleGeneral Chemistry010402 general chemistrywater splitting01 natural sciencesDecompositionCatalysis0104 chemical sciencesCatalysismultimetallic nitrideReaction rate constantChemical engineeringSettore CHIM/03 - Chimica Generale E InorganicaOrganic dyePhotocatalysisWater splittingdye decompositionSettore CHIM/02 - Chimica FisicaChemistry – A European Journal
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A new picking algorithm based on the variance piecewise constant models

2022

AbstractIn this paper, we propose a novel picking algorithm for the automatic P- and S-waves onset time determination. Our algorithm is based on the variance piecewise constant models of the earthquake waveforms. The effectiveness and robustness of our picking algorithm are tested both on synthetic seismograms and real data. We simulate seismic events with different magnitudes (between 2 and 5) recorded at different epicentral distances (between 10 and 250 km). For the application to real data, we analyse waveforms from the seismic sequence of L’Aquila (Italy), in 2009. The obtained results are compared with those obtained by the application of the classic STA/LTA picking algorithm. Althoug…

variance piecewise constant modelEnvironmental EngineeringEarthquake Early WarningArrival timesChange-pointEnvironmental ChemistrySettore SECS-S/01 - StatisticaSafety Risk Reliability and QualityPickingGeneral Environmental ScienceWater Science and TechnologyStochastic Environmental Research and Risk Assessment
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Kinetic evidence for the incorporation of the [(pentamethylcyclopentadienyl) (2,2′-bipyridyl)(aquo)rhodium(III)] complex into DPPC vesicles

2008

Abstract The binding of the [(pentamethylcyclopentadienyl) (2,2′-bipyridyl)(aquo)rhodium(III)] complex [Cp*RhIII(bpy)H2O]2+, to l -α-dipalmitoylphosphatidyl choline (DPPC) vesicles has been estimated by studying the kinetics of the electron transfer reaction between the rhodium(III) complex and formiate ions. Kinetic measurements carried out under anaerobic conditions in absence and presence of DPPC show that the total reaction is composed of two steps. The rate of the first reaction increases with the phospholipid concentration, while that of the second process is independent of the concentration of DPPC. This is consistent with a reaction, where the two reacting species are partitioned be…

vesicles L-alfa-dipalmitoylphosphatidyl choline (DPPC) rate constant bindingAqueous solutionLiaisonStereochemistryVesicleKineticstechnology industry and agriculturePhospholipidchemistry.chemical_elementBinding constantRhodiumchemistry.chemical_compoundCrystallographyElectron transferColloid and Surface Chemistrychemistrylipids (amino acids peptides and proteins)Colloids and Surfaces A: Physicochemical and Engineering Aspects
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Volumes of aqueous block copolymers based on poly(propylene oxides) and poly(ethylene oxides) in a large temperature range: A quantitative description

2006

The focus of this paper was on a quantitative comprehension of temperature effect on the volumes of aqueous di-block and triblock copolymers, based on propylene oxide (PO) and ethylene oxide (EO) units. To this purpose, literature data dealing with (EO316PO94 + water) and (EO13PO30EO13 + water) mixtures were analyzed. The volume vs. temperature trends were rationalized on the basis of the (unimers + aggregate) equilibrium by taking into account the temperature effect on both the partial molar volumes of the unimeric and the aggregated copolymer as well as the equilibrium constant of micellization. The analysis extended to the expansibility allowed to quantify the contribution for the shift …

volumecopolymerAqueous solutionEthylene oxideaggregationAnalytical chemistryFraction (chemistry)expansibilityAtmospheric temperature rangeAtomic and Molecular Physics and Opticsmodellingchemistry.chemical_compoundVolume (thermodynamics)chemistryPolymer chemistryCopolymerGeneral Materials SciencePropylene oxidePhysical and Theoretical ChemistryEquilibrium constantThe Journal of Chemical Thermodynamics
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On the convergence of zero-point vibrational corrections to nuclear shieldings and shielding anisotropies towards the complete basis set limit in wat…

2016

The method and basis set dependence of zero-point vibrational corrections (ZPVCs) to nuclear magnetic resonance shielding constants and anisotropies has been investigated using water as a test system. A systematic comparison has been made using the Hartree–Fock, second-order Møller–Plesset perturbation theory (MP2), coupled cluster singles and doubles (CCSD), coupled cluster singles and doubles with perturbative triples corrections (CCSD(T)) and Kohn–Sham density functional theory with the B3LYP exchange-correlation functional methods in combination with the second-order vibrational perturbation theory (VPT2) approach for the vibrational corrections. As basis sets, the correlation consisten…

waterBiophysicsZero-point energyzero-point vibrational correctionMonotonic function010402 general chemistry01 natural sciencesQuantum mechanics0103 physical sciencesPhysics::Atomic and Molecular ClustersCCSD(T)Limit (mathematics)complete basis set limitPhysics::Chemical PhysicsPhysical and Theoretical ChemistryMolecular BiologyBasis setPhysics010304 chemical physicsBasis (linear algebra)Condensed Matter PhysicsNMR shielding constant0104 chemical sciencesCoupled clusterDensity functional theoryPerturbation theory (quantum mechanics)Molecular Physics
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Kinetics of phase separation in thin films: Lattice versus continuum models for solid binary mixtures

2008

A description of phase separation kinetics for solid binary (A,B) mixtures in thin film geometry based on the Kawasaki spin-exchange kinetic Ising model is presented in a discrete lattice molecular field formulation. It is shown that the model describes the interplay of wetting layer formation and lateral phase separation, which leads to a characteristic domain size $\ell(t)$ in the directions parallel to the confining walls that grows according to the Lifshitz-Slyozov $t^{1/3}$ law with time $t$ after the quench. Near the critical point of the model, the description is shown to be equivalent to the standard treatments based on Ginzburg-Landau models. Unlike the latter, the present treatmen…

wettingMaterials scienceStatistical Mechanics (cond-mat.stat-mech)Condensed matter physicscritical pointsGinzburg-Landau theoryTime evolutionFOS: Physical sciencesBinary numberfree energyLattice constantthin filmsCritical point (thermodynamics)Lattice (order)Ising modelWettingphase separationThin filmCondensed Matter - Statistical MechanicsWetting layerPhysical Review E
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Ground and first excited electronic state interaction of FAD with some β-carboline derivatives

1987

Abstract The spectrophotometric and thermodynamic properties of molecular complexes of flavine adenine dinucleotide (FAD) with some dihydro β-carboline derivatives have been investigated in aqueous solution. The molecular associations have been examined by means of electronic absorption spectra, since in each a new charge-transfer band has been located, and also the variation of the fluorescence emission of FAD on the solutions has been observed. The formation constants for the molecular complexes were determined from absorption data, using the Foster-Hammick-Wardley method. The quenching fluorescence phenomena observed in FAD is related to the concentration of the dihydro β-carboline deriv…

β carboline derivativesAqueous solutionExcited electronic statebiologyAbsorption spectroscopyChemistryGeneral EngineeringPhotochemistryFluorescenceCofactorStability constants of complexesbiology.proteinPhysical chemistryheterocyclic compoundsAbsorption (chemistry)Spectrochimica Acta Part A: Molecular Spectroscopy
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