Search results for " homogeneous"

showing 10 items of 37 documents

New upper bounds for some instances from benchmark for vector packing problem

2021

This dataset is a result of the research: Đorđe Stakić, Miodrag Živković, Ana Anokić, "A Reduced Variable Neighborhood Search Approach to the Heterogeneous Vector Bin Packing Problem", Information Technology and Control, 2021, 50(4), 808-826, https://doi.org/10.5755/j01.itc.50.4.29009 Files are given by algorithm described in it. This dataset consists of 14 solutions with better bounds for instances described in paper: Heßler, K., Gschwind, T., Irnich, S. Stabilized branch-and-price algorithms for vector packing problems. European Journal of Operational Research, 2018, 271(2), 401-419. https://doi.org/10.1016/j.ejor.2018.04.047 File structure: Instance name: UB: solut…

Better boundsTwo-dimensional homogeneous vector bin packing problem
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Interesterification of rapeseed oil catalyzed by tin octoate

2014

The interesterification of rapeseed oil was performed for the first time by using tin octoate as Lewis acid homogeneous catalysts and methyl or ethyl acetate as acyl acceptors in a batch reactor, within the temperature range 393e483 K. The yields in fatty acid ethyl esters (FAEE) and triacetin (TA) after 20 h of reaction time increased from 8% and 2%eto 61% and 22%, respectively, when the reaction temperature increased from423 to 483 K. An optimum value of 40 for the acyl acceptor to oil molar ratio was found to be necessary to match good fatty acid alkyl ester yields with high enough reaction rate. The rate of generation of esters was significantly higher when methyl acetate was used as acyl …

Biodiesel Interesterification Methyl acetate Ethyl acetate Tin octoate Homogeneous catalysisSettore ING-IND/27 - Chimica Industriale E Tecnologica
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Gδ covers of compact spaces

2018

We solve a long standing question due to Arhangel'skii by constructing a compact space which has a Gδ cover with no continuum-sized (Gδ)-dense subcollection. We also prove that in a countably compact weakly Lindelöf normal space of countable tightness, every Gδ cover has a -sized subcollection with a Gδ-dense union and that in a Lindelöf space with a base of multiplicity continuum, every Gδ cover has a continuum sized subcover. We finally apply our results to obtain a bound on the cardinality of homogeneous spaces which refines De La Vega's celebrated theorem on the cardinality of homogeneous compacta of countable tightness.

Cardinal function Gδ-cover Lindelof degree Homogeneous spaceSettore MAT/03 - Geometria
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Degrees of irreducible characters of the symmetric group and exponential growth

2015

We consider sequences of degrees of ordinary irreducible S n S_n - characters. We assume that the corresponding Young diagrams have rows and columns bounded by some linear function of n n with leading coefficient less than one. We show that any such sequence has at least exponential growth and we compute an explicit bound.

CharacterPower sum symmetric polynomialGeneral MathematicsApplied MathematicsMathematicsofComputing_GENERALComplete homogeneous symmetric polynomialExponential polynomialExponential growthCombinatoricsRepresentation theory of the symmetric groupSymmetric groupElementary symmetric polynomialMathematics (all)Ring of symmetric functionsCharacter groupSymmetric groupMathematics
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1,2,3-Triazole in Heterocyclic Compounds, Endowed with Biological Activity, through 1,3-Dipolar Cycloadditions

2014

1,3-Dipolar cycloaddition reactions can be considered a powerful synthetic tool in the building of heterocyclic rings, with applications in different fields. In this review we focus on the synthesis of biologically active compounds possessing the 1,2,3-triazole core through 1,3-dipolar cycloaddition reactions. The 1,2,3-triazole skeleton can be present as a single disubstituted ring, as a linker between two molecules, or embedded in a polyheterocycle. The cycloaddition reactions are usually catalysed by copper or ruthenium. Domino reactions can be achieved through dipolarophile anion formation, generally followed by cyclisation. The variety of attainable heterocyclic structures gives an ill…

Cycloaddition / Nitrogen heterocycles / Domino reactions / Homogeneous catalysis / Enzyme catalysis / Biological activity / Medicinal chemistrySettore CHIM/03 - Chimica Generale E InorganicaCycloaddition Nitrogen heterocycles Domino reactions Homogeneous catalysis Enzyme catalysis Biological activity Medicinal chemistrySettore CHIM/08 - Chimica Farmaceutica
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Triple solutions for nonlinear elliptic problems driven by a non-homogeneous operator

2020

Abstract Some multiplicity results for a parametric nonlinear Dirichlet problem involving a nonhomogeneous differential operator of p -Laplacian type are given. Via variational methods, the article furnishes new contributions and completes some previous results obtained for problems considering other types of differential operators and/or nonlinear terms satisfying different asymptotic conditions.

Dirichlet problemApplied Mathematics010102 general mathematicsMultiple solutionsp-LaplacianMultiple solutionType (model theory)Differential operator01 natural sciencesCritical point010101 applied mathematicsNonlinear systemOperator (computer programming)Critical point; Multiple solutions; Nonlinear elliptic problem; p-Laplacian; Variational methodsVariational methodsSettore MAT/05 - Analisi MatematicaNon homogeneousApplied mathematicsNonlinear elliptic problem0101 mathematicsLaplace operatorAnalysisMathematicsParametric statistics
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Radon–Nikodym Property and Area Formula for Banach Homogeneous Group Targets

2013

We prove a Rademacher-type theorem for Lipschitz mappings from a subset of a Carnot group to a Banach homogeneous group, equipped with a suitably weakened Radon-Nikodym property. We provide a metric area formula that applies to these mappings and more generally to all almost everywhere metrically differentiable Lipschitz mappings defined on a Carnot group. peerReviewed

Discrete mathematicsMathematics::Functional AnalysisProperty (philosophy)General Mathematicsmetric area formulata111Mathematics::Analysis of PDEsCarnot groupBanach homogeneous groupsalmost everywhere differentiabilityRadon-Nikodym propertyLipschitz continuityRadon–Nikodym theoremBanach homogeneous groups; metric area formula; almost everywhere differentiability; Radon-Nikodym propertyMetric (mathematics)Homogeneous groupMathematics::Metric GeometryAlmost everywhereDifferentiable functionMathematics
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The convolution operation on the spectra of algebras of symmetric analytic functions

2012

Abstract We show that the spectrum of the algebra of bounded symmetric analytic functions on l p , 1 ≤ p + ∞ with the symmetric convolution operation is a commutative semigroup with the cancellation law for which we discuss the existence of inverses. For p = 1 , a representation of the spectrum in terms of entire functions of exponential type is obtained which allows us to determine the invertible elements.

Discrete mathematicsPower sum symmetric polynomialTriple systemSpectra of algebrasApplied MathematicsSymmetric polynomialsStanley symmetric functionComplete homogeneous symmetric polynomialSymmetric convolutionSymmetric functionEntire functions of exponential typeElementary symmetric polynomialRing of symmetric functionsPolynomials and analytic functions on Banach spacesAnalysisMathematicsJournal of Mathematical Analysis and Applications
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Selective photooxidation of ortho-substituted benzyl alcohols and the catalytic role of ortho-methoxybenzaldehyde

2016

It has been recently reported by Palmisano et al. (2015) [1] that the oxidation of 2-methoxybenzyl alcohol (2-MBA) to 2-methoxybenzaldehyde (2-MBAD) proceeds in water under near-UV light with an unexpected catalytic effect of 2-MBAD. In order to investigate the catalytic role of aldehyde in photolytic oxidation of ortho-substituted benzyl alcohols (OSBAs), reactivity runs were carried out with 2-methylbenzyl alcohol (2-MeBA), 2-nitrobenzyl alcohol (2-NBA), 2-hydroxybenzyl alcohol (2-HBA) and 2-chlorobenzyl alcohol (2-CIBA) in the absence and in the presence of their corresponding aldehyde. None of those alcohols showed a measurable oxidation rate even in the presence of their aldehydes but …

General Chemical EngineeringGeneral Physics and AstronomyAlcohol2-MethoxybenzaldehydeHomogeneous photocatalysi010402 general chemistry01 natural sciencesAldehydeCatalysisFerulic acidPhysics and Astronomy (all)chemistry.chemical_compoundBenzyl alcoholOrganic chemistryChemical Engineering (all)Reactivity (chemistry)chemistry.chemical_classificationSettore ING-IND/24 - Principi Di Ingegneria Chimica010405 organic chemistryChemistryChemistry (all)General Chemistry0104 chemical sciencesAutocatalytic photooxidationAlcohol oxidationPhotocatalysis2-Methoxybenzaldehyde; Autocatalytic photooxidation; Benzyl alcohols; Homogeneous photocatalysis; Chemistry (all); Chemical Engineering (all); Physics and Astronomy (all)Selectivity
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Volatiles in pantellerite magmas: A case study of the Green Tuff Plinian eruption (Island of Pantelleria, Italy)

2013

Abstract The Green Tuff (GT) Plinian eruption, the largest in magnitude at Pantelleria, erupted 3 to 7 km3 DRE of pantellerite magma and a small volume of trachyte. Fifty-nine anorthoclase-hosted melt inclusions from the two basal pumice members were analyzed by FT-IR spectroscopy in order to assess the pre-eruptive H2O content in the pantellerite melt. Microanalytical methods were used to determine major element, Cl, F and S contents. Melt inclusions and glassy groundmasses have a nearly homogeneous pantelleritic composition (peralkaline index = 1.9-2.2) and variable water contents ranging from 1.4 to as high as 4.2 wt %, i.e. much higher than the 1.4 wt % of earlier published studies. The…

LavaSettore GEO/07 - Petrologia E PetrografiaGeochemistryTrachyteMagma chamberStrombolian eruptionGeophysicsEffusive eruptionGeochemistry and PetrologyPumiceMagmaThe Green Tuff (GT) Plinian eruption the largest in magnitude at Pantelleria erupted 3 to 7 km 3 DRE of pantellerite magma and a small volume of trachyte. Fifty-nine anorthoclase-hosted melt inclusions from the two basal pumice members were analyzed by FT-IR spectroscopy in order to assess the pre-eruptive H2Ocontent in the pantellerite melt. Microanalytical methods were used to determine major element Cl F and S contents. Melt inclusions and glassy groundmasses have a nearly homogeneous pantelleritic composition (peralkaline index = 1.9-2.2) and variable water contents ranging from 1.4 to as high as 4.2 wt % i.e. much higher than the 1.4 wt % of earlier published studies. The chlorine content is constant at about 1 wt %. Combined Cl and H2O data were used to estimate a confining pressure of about 50 MPa (depth around 2-3 km) for the GT magma chamber. The chamber was characterized by a compositional zoning with a dominant pantellerite overlying a trachyte magma. Soon after the GT eruption intra-caldera volcanism was dominated by the eruption of voluminous trachyte lavaflows while pantellerite melt production resumed after about 20 ka with numerous low-volume mildly explosive (Strombolian) to effusive eruptions. Comparison with data from the literature reveals that despite the differentexplosivity the post-caldera Strombolian eruptions and the GT Plinian eruption were fed by pantelleritic magmas with similar water contents. Chlorine and CO2contents suggest that the young magma reservoirs feeding the Strombolian to effusive activity were deeper (h≥4.5 km) than the much larger (based on erupted volumes) magma chamber which fed the GT eruptionGeologyMelt inclusionsJournal of Volcanology and Geothermal Research
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