Search results for " SEM"
showing 10 items of 1467 documents
Correlated barrier hopping in NiO films
1991
The ac conduction in NiO films has been investigated in the frequency range 10 Hz < v < 10^9 Hz and at temperatures between 10 and 300 K. The frequency and the temperature dependence of the electrical conductivity can be consistently explained within a model developed for the mechanism of charge transfer in amorphous semiconductors which proposes that charge carriers hop over potential barriers between defect sites, the height of the barriers being correlated with the intersite separation.
Two-Dimensional Indium Selenide for Sulphur Vapour Sensing Applications
2020
Surface-to-volume ratio in two-dimensional (2D) materials highlights among their characteristics as an inherent and intrinsic advantage taking into account their strong sensitivity to surface effects. For this reason, we have proposed in this work micromechanically exfoliated 2D nanosheets of InSe as an optical vapour sensor. As a proof of concept, we used 2-mercaptoethanol as the chemical analyte in vapour phase to monitor the change of the InSe photoluminescence (PL) before and after exposure to the analyte. For short vapour exposure times (at low analyte concentration), we found a PL enhancement of InSe nanosheets attributed to the surface localization of Se defects. For long vapour expo…
The Navier–Stokes equations in exterior Lipschitz domains: L -theory
2020
Abstract We show that the Stokes operator defined on L σ p ( Ω ) for an exterior Lipschitz domain Ω ⊂ R n ( n ≥ 3 ) admits maximal regularity provided that p satisfies | 1 / p − 1 / 2 | 1 / ( 2 n ) + e for some e > 0 . In particular, we prove that the negative of the Stokes operator generates a bounded analytic semigroup on L σ p ( Ω ) for such p. In addition, L p - L q -mapping properties of the Stokes semigroup and its gradient with optimal decay estimates are obtained. This enables us to prove the existence of mild solutions to the Navier–Stokes equations in the critical space L ∞ ( 0 , T ; L σ 3 ( Ω ) ) (locally in time and globally in time for small initial data).
New n-type molecular semiconductor–doped insulator (MSDI) heterojunctions combining a triphenodioxazine (TPDO) and the lutetium bisphthalocyanine (Lu…
2018
International audience; Molecular semiconductor–doped insulator (MSDI) heterojunctions were designed using a new family of sublayers, namely triphenodioxazines (TPDO). The device obtained by combining the tetracyano triphenodioxazine bearing two triisopropylsilylethynyl moieties as a sublayer with the lutetium bisphthalocyanine (LuPc2) as a top layer showed a nonlinear current–voltage characteristic independent of the sign of the polarization, which is the signature of MSDI heterojunctions. Thus, a TPDO was used in a chemical sensor for the first time. Despite LuPc2 being the only material exposed to the atmosphere, the positive response of the device under ammonia revealed the key role pla…
Micromorfologia fogliare comparata ed anatomia generale di Epipactis microphylla (Ehrh.) SW. ed E. helleborine (L.) Crantz (Orchidaceae) in Sicilia
2009
International Journal for the semiotics of law - Special Issue Animals in law
2018
This essay opens the Special Issue of the International Journal for the Semiotics of Law dedicated to Animality, entitled “Animals in Law”. It focuses on revealing the principal issues faced in the volume, by positioning the contributors’ works into the general theoretical perspectives which shape the social discourse over animals.
Martyrdom in Contemporary Animalist Discourses
2019
Is it possible to use the notion of martyrdom in order to explain the communicative strategies and the semiotic mechanisms of the animalist movement? Is the animal a sort of contemporary martyr? This study aims to apply the notion of martyrdom outside the traditional boundaries of religion and politics, testing it in another relevant socio–cultural phenomenon: the contemporary animalist discourse. This paper analyses texts from animalist advertising, essays and novels promoting animal rights and vegetarianism. The main features of the traditional notion of martyrdom are compared to the semiotic structures of the animalist discourse. The questions of the efficacy of images and that of the ex…
Anti-fouling additives for the consolidation of archaeological mortars in underwater environment: Efficacy tests performed on the apsidal fishpond of…
2020
This paper deals with the formulation of innovative mortars for the consolidation of archeological structures in underwater environment. The research was conducted within the frame of the MaTaCoS project (Advanced materials and technologies applied to the conservation of underwater cultural heritage) funded by MISE (Italian Ministry of Economic Development). The project concerns the design of advanced tools and methods for the protection of Underwater Cultural Heritage, through specific cleaning and consolidating procedures to be applied directly in situ. The fishpond of the archaeological site of Castrum Novum (Santa Marinella, Rome, Italy) was chosen as a pilot site for experimentation. I…
Il lavoro e l'arte della ricerca: Antonino Buttitta
2018
Si tratta della ricostruzione del profilo intellettuale e scientifico di Antonino Buttitta, tra i capiscuola delle discipline demoetnoantropologiche in Italia, al quale si deve una originale declinazione dell'approccio strutturalista nell'analisi dei fatti culturali nell'ambito della semiotica della cultura.