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showing 10 items of 19256 documents
Effect of Germacrene-Rich Essential Oil of Parentucellia latifolia (L.) Caruel Collected in Central Sicily on the Growth of Microorganisms Inhabiting…
2022
In the present study, the chemical composition of the essential oil from aerial parts of Parentucellia latifolia (L.) Caruel collected in Central Sicily was analyzed by gas chromatography and gas chromatography–mass spectrometry. The results showed the presence of sesquiterpene hydrocarbons, with germacrene D and germacrene B accounting, respectively, for 59.2% and 24.3% of the total oil. Different colonies of bacteria and fungi frequently affect cellulosic objects such as books stored in libraries and museums. The antibacterial and antifungal activity against some microorganisms infesting historical-artistic craftsmanship was determined, demonstrating that the essential oil was particular…
Functional a posteriori error estimates for boundary element methods
2019
Functional error estimates are well-established tools for a posteriori error estimation and related adaptive mesh-refinement for the finite element method (FEM). The present work proposes a first functional error estimate for the boundary element method (BEM). One key feature is that the derived error estimates are independent of the BEM discretization and provide guaranteed lower and upper bounds for the unknown error. In particular, our analysis covers Galerkin BEM and the collocation method, what makes the approach of particular interest for scientific computations and engineering applications. Numerical experiments for the Laplace problem confirm the theoretical results.
Refined instability estimates for some inverse problems
2022
Many inverse problems are known to be ill-posed. The ill-posedness can be manifested by an instability estimate of exponential type, first derived by Mandache [29]. In this work, based on Mandache's idea, we refine the instability estimates for two inverse problems, including the inverse inclusion problem and the inverse scattering problem. Our aim is to derive explicitly the dependence of the instability estimates on key parameters. The first result of this work is to show how the instability depends on the depth of the hidden inclusion and the conductivity of the background medium. This work can be regarded as a counterpart of the depth-dependent and conductivity-dependent stability estim…
Systematic implementation of higher order Whitney forms in methods based on discrete exterior calculus
2022
AbstractWe present a systematic way to implement higher order Whitney forms in numerical methods based on discrete exterior calculus. Given a simplicial mesh, we first refine the mesh into smaller simplices which can be used to define higher order Whitney forms. Cochains on this refined mesh can then be interpolated using higher order Whitney forms. Hence, when the refined mesh is used with methods based on discrete exterior calculus, the solution can be expressed as a higher order Whitney form. We present algorithms for the three required steps: refining the mesh, solving the coefficients of the interpolant, and evaluating the interpolant at a given point. With our algorithms, the order of…
On a numerical solution of the Maxwell equations by discrete exterior calculus
2014
Histoires de vie et mémoire de l'Italie en Erytrée. L'expérience et la narration
2010
A partire dall''analisi di storie di vita raccolte in Eritrea, nel corso di una ricerca sulla memoria coloniale (condotta nel 2003-2004), l''Autrice si interroga sui meccanismi della memoria e le modalità di restituzione di un passato all''incrocio tra storia individuale e storia collettiva. Ricostruendo il contesto della ricerca, il saggio discute sulle forme di oggettivazione e rappresentazione del processo di "raccolta dei dati", sulle figurazioni della voce del narratore e dei soggetti agenti, sul metalinguaggio e la sua efficacia nella costruzione della conoscenza e sul tipo di sapere che ne deriva.
Il costo burocratico per l’energia
2022
Il volume indaga a partire da analisi di caso le ragioni di diritto amministrativo che frenano la realizzazione di investimenti nelle infrastrutture energetiche nazionali
Assessing violence in the family : social work, courts, and discourses
2016
This article investigates social work, decision-making, and gendered violence in the family in Finland. Discourses on gendered violence in the family are compared in custody disputes, handled in district courts, and out-of-home placements, dealt with in administrative courts. Both data sets altogether include 237 cases. Proceedings in both courts share a legislative emphasis on the ‘child’s best interest’ principle, and both contexts also rely on documentation provided by social workers. The examination of the two studies is based on discourse analysis, through which we have identified hegemonic discourses that are active in both courts. The study found that violence was often disregarded o…
The average number of Sylow subgroups of a finite group
2013
We prove that if the average Sylow number (ignoring the Sylow numbers that are one) of a finite group G is ⩽7, then G is solvable.
Characterization of strong chain geometries by their automorphism group
1992
A wide class of chain geometries is characterized by their automorphism group using properties of a distinguished involution.