Search results for "equation"

showing 10 items of 4219 documents

Green approach to corrosion inhibition of stainless steel in phosphoric acid of Artemesia herba albamedium using plant extract

2019

Essential oil from aerial parts of Artemisia herba-alba from Morocco was hydrodistilled and its chemical composition oil was investigated by capillary GC and GC/MS. The major components were 1,8-cineole (35.6%) and camphor (24.1%). Artemisia herba-alba essential oil AHAO was tested as corrosion inhibitor of stainless steel (SS) in 1M H3PO4 using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy measurements (EIS) and scanning electronically microscopy (SEM) studies. The results obtained showed that the essential oil of Artemisia reduces the corrosion rate. Tafel polarization method indicates that the plant extract behaves as a mixed type inhibitor. The inhibition…

lcsh:TN1-997Materials science02 engineering and technology01 natural sciencesEssential oilINGENIERIA QUIMICAAbsorciólaw.inventionCorrosionBiomaterialssymbols.namesakechemistry.chemical_compoundCorrosion inhibitorAdsorptionlaw0103 physical sciencesPhosphoric acidEssential oillcsh:Mining engineering. MetallurgyInhibition010302 applied physicsTafel equationArtemisia herba-albaMetals and AlloysLangmuir adsorption model021001 nanoscience & nanotechnologyStainless SteelSurfaces Coatings and FilmsDielectric spectroscopyCorrosionchemistryCeramics and CompositessymbolsAdsorptionAcer Corrosió0210 nano-technologyNuclear chemistry
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Rayleigh Equation Anomaloscope from Commercially Available LEDs

2012

Most precise classification of CVD (color vision deficits) can be provided by using anomaloscope. Today anomaloscopes are available, which can evaluate red-green (Rayleigh) and blue-green (Moreland) color defects.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1928

lcsh:TN1-997Materials scienceLEDsbusiness.industryColor visionanomaloscopeRayleigh equationAnomaloscopelaw.inventionsymbols.namesakeOpticslawsymbolsPWMGeneral Materials ScienceRayleigh scatteringRayleigh matchbusinesslcsh:Mining engineering. Metallurgycolor vision deficitsLight-emitting diodeMaterials Science
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Towards a sustainable leader-follower relationship: constructive dissensus, organizational virtuousness and happiness at work (haw)

2020

This paper examines how leaders and followers can interact positively under complex and bounded conditions. For this purpose, this paper conceptualizes and measures the concept of constructive dissensus. Constructive dissensus relates to a mutual understanding leading to a situation of coregulation. In addition, the relationship between constructive dissensus and happiness at work is examined on the basis of affective events theory. Furthermore, the mediating role of organizational virtuousness is assessed. Through structural equation modeling, a multilevel analysis was performed. Data from 130 bank branches and 606 employees were gathered. The results reveal a direct effect of constructive…

leadershipGeography Planning and DevelopmentTJ807-830050109 social psychologyAffective events theoryManagement Monitoring Policy and LawTD194-195:CIENCIAS ECONÓMICAS [UNESCO]ConstructiveRenewable energy sourcesStructural equation modeling0502 economics and businessFollowershipGE1-3500501 psychology and cognitive sciencesHappiness at workEnvironmental effects of industries and plantsRenewable Energy Sustainability and the Environment05 social sciencesMultilevel modelorganizational virtuousnesshappiness at workUNESCO::CIENCIAS ECONÓMICASEnvironmental sciencesBounded functionMediationPsychologySocial psychology050203 business & managementfollowership
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Within-student variability in learning experiences, and teachers’ perceptions of students’ task-focus

2016

In order to advance models of educational processes (intraindividual, intensive longitudinal), we propose a model in which we specify state and trait constructs, and an intraindividual variability construct. In our ecological momentary assessment study, we investigated how trait-level and intraindividual variability of students’ learning experiences (intrinsic and extrinsic motivation, task difficulty, effort exertion, help-seeking and competence evaluations) converged with teacher-reported student task-focus. 285 primary school students’ (Years 5 and 6) completed the Learning Experience Questionnaire using handheld computers, on average 13.6 learning episodes during one week (SD = 4.6; Ran…

learning experienceMultivariate statisticsmedia_common.quotation_subjectecological momentary assessmentStructural equation modelingEducationDevelopmental psychologyLearning experienceintraindividual variabilityPerceptionmultilevel structural equation modelTraitPsychologyCompetence (human resources)ta515media_commonIntrapersonal communication
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Within-students variability in learning experiences, and teachers' perceptions of students' task-focus

2016

In order to advance our understanding of educational processes, we present a tutorial of intraindividual variability. An adaptive educational process is characterised by stable (less variability), and a maladaptive process is characterised by instable (more variability) learning experiences from one learning situation to the next. We outline step by step how we specify a multilevel structural equation model of state, trait and individual differences in intraindividual variability constructs, which can be appropriately fitted to intraindividual data (e.g., time-points nested in persons, intensive longitudinal data). In total 285 primary school students’ (Years 5 and 6) completed the Learning…

learning experienceintraindividual variabilitymultilevel structural equation modelecological momentary assessment
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The dissipative linear Boltzmann equation for hard spheres

2005

The authors prove existence and uniqueness of a Maxwellian, normalized equilibrium state for a dissipative linear Boltzmann equation with hard-sphere collision kernel modeling a granular gas and, for initial data with finite temperature and entropy, strong L 1 convergence (obtained through compactness arguments) toward the equilibrium of the solutions in the space-homogeneous case. The form of the equilibrium state, which is universal for the family of collision operators including hard, soft and Maxwellian interactions, is guessed through a grazing collision asymptotics and then proved to be the equilibrium state through Fourier analysis. Uniqueness and strong L 1 convergence proofs follow…

linear Fokker–Planck equationtrend to equilibrium.Granular gaseequilibrium state
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Local regularity estimates for general discrete dynamic programming equations

2022

We obtain an analytic proof for asymptotic H\"older estimate and Harnack's inequality for solutions to a discrete dynamic programming equation. The results also generalize to functions satisfying Pucci-type inequalities for discrete extremal operators. Thus the results cover a quite general class of equations.

local Hölder estimateosittaisdifferentiaaliyhtälötABP-estimateApplied MathematicsGeneral Mathematicsp-LaplacianMathematics::Analysis of PDEs35B65 35J15 35J92 91A50elliptic non-divergence form partial differential equation with bounded and measurable coefficientsdynamic programming principleMathematics - Analysis of PDEsHarnack's inequalitytug-of-war with noiseFOS: MathematicsPucci extremal operatorpeliteoriaepäyhtälötAnalysis of PDEs (math.AP)
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An Inverse Problem for the Relativistic Boltzmann Equation

2020

We consider an inverse problem for the Boltzmann equation on a globally hyperbolic Lorentzian spacetime $(M,g)$ with an unknown metric $g$. We consider measurements done in a neighbourhood $V\subset M$ of a timelike path $\mu$ that connects a point $x^-$ to a point $x^+$. The measurements are modelled by a source-to-solution map, which maps a source supported in $V$ to the restriction of the solution to the Boltzmann equation to the set $V$. We show that the source-to-solution map uniquely determines the Lorentzian spacetime, up to an isometry, in the set $I^+(x^-)\cap I^-(x^+)\subset M$. The set $I^+(x^-)\cap I^-(x^+)$ is the intersection of the future of the point $x^-$ and the past of th…

mallintaminenMathematics - Differential GeometrymatematiikkaFOS: Physical sciencesStatistical and Nonlinear PhysicsyhtälötMathematical Physics (math-ph)hiukkasfysiikkaBoltzmannin yhtälöinversio-ongelmattiiviin aineen fysiikkaBoltzmann equationMathematics - Analysis of PDEsDifferential Geometry (math.DG)111 MathematicsFOS: MathematicsMathematical PhysicsAnalysis of PDEs (math.AP)
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PREDICTING SUCCESS INDICATORS OF AN INTERVENTION PROGRAMME FOR CONVICTED INTIMATE-PARTNER VIOLENCE OFFENDERS: THE CONTEXTO PROGRAMME

2013

Recent legal changes in Spain have led to an important increase in the number of men court-mandated to community-based partner violence offender intervention programmes. However, just a few of those interventions have been systematically examined. This study aims to predict success indicators of an intervention programme for convicted intimate-partner violence offenders. The sample consisted of 212 convicted intimate-partner violence offenders who participated in the Contexto Programme. Three "intervention gains" or target criteria were established (increasing the perceived severity of violence, increasing the responsibility assumption for one's actions, and reducing the risk of recidivism)…

maltratadoreslcsh:BF1-990structural equations modelperceived severity of violencelcsh:Psychologygravedad percibida de la violenciaasunción de responsabilidadrisk of recidivismriesgo de reincidencialcsh:Criminal law and proceduremodelos de ecuaciones estructuraleslcsh:K5000-5582responsibility assumptionpartner-violence offenders
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A blow-up result for a nonlinear wave equation on manifolds: the critical case

2021

We consider a inhomogeneous semilinear wave equation on a noncompact complete Riemannian manifold (Formula presented.) of dimension (Formula presented.), without boundary. The reaction exhibits the combined effects of a critical term and of a forcing term. Using a rescaled test function argument together with appropriate estimates, we show that the equation admits no global solution. Moreover, in the special case when (Formula presented.), our result improves the existing literature. Namely, our main result is valid without assuming that the initial values are compactly supported.

manifoldApplied MathematicsBlow-upMathematical analysisBoundary (topology)Riemannian manifoldWave equationManifoldcritical caseDimension (vector space)Settore MAT/05 - Analisi MatematicaNonlinear wave equationMathematics::Differential Geometryinhomogeneous semilinear wave equationAnalysisMathematicsApplicable Analysis
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