750 research outputs found
Spectral theory for linearized p-Laplace equations
No full textWe continue and completely set up the spectral theory initiated in Castorina et al. [D. Castorina, P. Esposito, B. Sciunzi, Degenerate elliptic equations with singular nonlinearities, Calc. Var. Partial Differential Equations, 34 (2009), 279–306] for the linearized operator arising from Δ_p u+f(u)=0. We establish existence and variational characterization of all the eigenvalues, and by a weak Harnack inequality
we deduce Hölder continuity for the corresponding eigenfunctions, this regularity being sharp. The Morse index of a positive solution can be now defined in the classical way,
and we will illustrate some qualitative consequences one should expect to deduce from
such information. In particular, we show that zero Morse index (or more generally, nondegenerate)
solutions on the annulus are radial
Regularity of the extremal solution for singular p-Laplace equations
No full textYour article is protected by copyright and all rights are held exclusively by Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. manuscripta math. 146, 519–529 (2015) © Springer-Verlag Berlin Heidelberg 2014 Daniele Castorina Regularity of the extremal solution for singular p-Laplace equation
Uniqueness of positive radial solutions for quasilinear elliptic equations in an annulus
No full textPrime riflessioni in merito alle nuove eccezioni relative agli appalti e le concessioni tra enti nell’ambito del settore pubblico, alla luce della vecchia giurisprudenza sull’in house
No full textRelazione nell'ambito della conferenza dal titolo Integrazione europea, servizi pubblici e diritti fondamentali.The article reproduces the speech at the seminar on the topic "European Integration, public services and fundamental rights", during which the Author has expressed some preliminary thoughts on the innovations introduced on the in-house requirements set by the new European Directives on public procurements. The seminar was organized by the Jean Monnet Chair of Prof. Emilio Castorina, which is focused on “public services, fundamental rights and European constitutionalism”, and took place in Catania, at the Department of Law (Villa Cerami) January 31, 2014
Fe isotopic ratios in selected groundwater samples from the Ravenna and Friuli coastal plains, NE Italy and significance for the environment
No full textHigh Fe concentrations (from 1.34 to 12.72 mg/L) were measured by Pezzetta et al.(2011) in groundwater samples from the Lower Friulan Plain near the north Adriatic seacoast. The research has unveiled a positive correlation between Fe concentrations and groundwater salinization (0.9–19679 mg/L Cl) and a particularly wide range of d56Fe (from –5.3 to +2.15‰ relative to IRMM-14 international standard, Castorina et al., 2013), compared with literature data. Furthermore, a positive correlation between d56Fe and Fe concentrations has been found. The present study has investigated the relationship of Fe isotopic ratios to Fe and chloride concentrations in groundwater samples from the Ravenna Plain near the north Adriatic seacoast aimed at comparing the results with those obtained from the Friulan Plain area. Therefore, the following characteristics have been recognized: a) Ravenna groundwater displays a smaller isotopic range (d56Fe from –2.6 to 0‰) than
Friulan groundwater, b) unlike the positive correlation in Friulan groundwater, no correlation exists between d56 Fe and Fe concentrations (<0.02–3.13 mg/L) in Ravenna
groundwater, c) there is a positive correlation between
d56Fe and pH in Ravenna groundwater while there are negative or nil correlations in Friulian groundwater, and d) there is a negative correlation between d56Fe and chloride concentrations(55–16,800 mg/L) in Ravenna groundwater, while there are positive or nil correlations in Friulian groundwater. These different characteristics of groundwater from the two
coastal Plains likely reflect different processes taking place in the two sites despite the broadly similar environments. The particularly isotopic lighter Fe compositions of most of groundwater samples from the Friulan Plain have been explained by isotopic fractionation during repeated cycling of Fe precipitation. This multi-staged process apparently does not significantly operate in the Ravenna Plain, where groundwater
generally contains much lower Fe concentrations, suggesting that redox conditions arecomparatively less exasperated. The low Fe concentrations may also explain the lack of any correlation with d56Fe as well as the positive correlation between d56Fe and pH in groundwater from the Ravenna Plain. Lastly, the negative correlation between d56Fe and Cl in Ravenna groundwater indicates that with increasing salinization, there is likely precipitation of 56 Fe-rich ferrihydrite, thus leaving groundwater 56Fe-poor. In contrast, in lower-salinity waters, probably biologically-mediated reduction of Fe(III) to Fe(II) in the
56 Fe-rich ferrihydrite present in sediments, can release 56
Fe-rich Fe(II) to groundwater, that thus acquires the 56
Fe-rich signature. Lastly, as the Friulan Plain was significantly disseminated of Fe wastes from smelter plants in the past, the more positive d56Fe values measured in those groundwater samples were explained by waste leaching (Castorina et al., 2013). As Fe industrial pollution does not occur in the Ravenna Plain, where however, isotopic values nearing those positive of the Friulan Plain, have also been measured, this may render the above explanation not fully plausible, suggesting that the more positive d56Fe measured in the Friulan Plain can be due mainly to more extreme natural causes.
References
1. E. Pezzetta, A. Lutman, I. Martinuzzi, C. Viola, G. Bernardis and V. Fuccaro, Iron concentrations in selected groundwater samples from the lower Friulian Plain, northeast Italy: Importance of salinity. Environ. Earth Sci., 62, pp. 377–391, 2011.
2. F. Castorina, R. Petrini, A. Galic, F.F. Slejko, U. Aviani, E. Pezzetta and G. Cavazzini, The fate of iron in waters from a coastal environment impacted by metallurgical industry in northern Italy: Hydrochemistry and Fe-isotopes. Applied Geochemistry, 2013 (in press)
On a singular Liouville-type equation and the Alexandrov isoperimetric inequality
No full textWe obtain a generalized version of an inequality, first derived by C.
Bandle in the analytic setting, for weak subsolutions of a singular Liouville-type
equation. As an application we obtain a new proof of the Alexandrov isoperimetric
inequality on singular abstract surfaces. Interestingly enough, motivated by
this geometric problem, we obtain a seemingly new characterization of local metrics
on Alexandrov’s surfaces of bounded curvature. At least to our knowledge,
the characterization of the equality case in the isoperimetric inequality in such a
weak framework is new as well
Non existence of bounded-energy solutions for some semilinear elliptic equations with a large parameter
No full text4 SELF GRAVITATING COSMIC STRINGS AND THE ALEXANDROV’S INEQUALITY FOR LIOUVILLE-TYPE EQUATIONS.
No full texta
Emanuele Castorina, I « Poetae Novelli ». Contributo alla storia della cultura latina nel II secolo D. C.
No full textManiet Albert. Emanuele Castorina, I « Poetae Novelli ». Contributo alla storia della cultura latina nel II secolo D. C.. In: L'antiquité classique, Tome 19, fasc. 2, 1950. pp. 480-481
A global existence result for a Keller-Segel type system with supercritical initial data
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