Search results for " Barrier"
showing 10 items of 540 documents
Coulomb Corrections in Proton-Deuteron Scattering
1976
We present the first calculations of differential cross sections for elastic proton-deuteron scattering using a three-body formalism which correctly takes into account the Coulomb repulsion between the two protons.
Barriere verdi di protezione acustica e abbattimento polveri lungo le vie di grande comunicazione
2014
Barriere verdi di protezione acustica e abbattimento polveri lungo le vie di grande comunicazione
L'impianto, la gestione e la valorizzazione multifunzionale dei boschi periurbani
2014
I boschi periurbani, come tutti gli spazi verdi prossimi agli agglomerati urbani, migliorano le condizioni ambientali e la qualità dell'aria, contribuiscono alla conservazione della biodiversità, possono favorire l'aggregazione sociale. I boschi prossimi ai centri urbani rivestono inoltre un ruolo importante dal punto di vista paesaggistico e turistico e contribuiscono a contrastare i cambiamenti climatici. Questa pubblicazione, redatta con il supporto tecnico-scientifico dell'Accademia italiana di scienze forestali di Firenze, si propone di fornire linee guida per la progettazione, la realizzazione e la gestione dei boschi periurbani e delle fasce verdi nelle aree prossime agli agglomerati…
Le simbiosi in ambiente marino
2011
L’adattamento e la conseguente selezione naturale ha prodotto un’infinita varietà di organismi viventi, ciascuno dotato di peculiari caratteristiche, per consentire ad ogni specie di utilizzare l’ambiente in cui vive. I membri che formano le comunità naturali creano tra di essi dei complessi sistemi fatti di rapporti di competizione e di cooperazione. Questi, contribuiscono ad assicurare l’evoluzione delle specie nell’efficace opera di utilizzazione dell’ambiente. Nell’ambito delle relazioni tra individui di specie diverse esistono alcune singolari associazioni che si evolvono insieme, stabilendo un legame intimo e duraturo che comporta un elevato grado di specializzazione da parte dei cont…
RIPRISTINO DEI FONDALI DEGRADATI E RECUPERO DEL PAESAGGIO SOMMERSO NELL’AREA MEDITERRANEA
Amorphous semiconducting passive film-electrolyte junctions revisited. The influence of a non homogeneous density of state on the differential admitt…
2006
Abstract An analysis of the electronic properties of amorphous semiconductor-electrolyte junction is reported for passive films grown on Nb in alkaline solution and in a large range of thickness (~20nm ÷ ~250nm). A modelling of electronic density of state (DOS) has been carried out by fitting EIS spectra, at different potentials and in a range of frequencies (0.1 Hz ≤ f ≤100 kHz), and differential admittance (DA) data of a-Nb 2 O 5 /El interface. The fitting of EIS and DA curves was performed by using the theory of amorphous semiconductor Schottky barrier and a non-homogeneous DOS distribution.
Characterization of Thin Passive Film-Electrolyte Junctions.The Amorphous Semiconductor (a-SC) Schottky Barrier Approach
2016
The knowledge of the solid-state properties of passive film is a preliminary task for a full understanding of the electron and ion transfer processes at the metal/oxide and oxide/electrolyte interface. Both processes are of paramount importance in determining the mechanism of film growth and dissolution as well as in determining the nature of the breakdown during the growth of anodic oxide films or the onset of generalized or localized corrosion process (1-2). With very few exceptions, it is a common belief, that most of anodic oxide films, grown on metals and alloys in aqueous solutions, display a semiconducting or insulating behaviour. It is also very well known that in many cases the ini…
A critical analysis of the theory of amorphous semiconductor Schottky barrier for oxides
2014
Pd/Au/SiC Nanostructured Diodes for Nanoelectronics: Room Temperature Electrical Properties
2010
Pd/Au/SiC nanostructured Schottky diodes were fabricated embedding Au nanoparticles (NPs) at the metalsemiconductor interface of macroscopic Pd/SiC contacts. The Au NPs mean size was varied controlling the temperature and time of opportune annealing processes. The electrical characteristics of the nanostructured diodes were studied as a function of the NPs mean size. In particular, using the standard theory of thermoionic emission, we obtained the effective Schottky barrier height (SBH) and the effective ideality factor observing their dependence on the annealing time and temperature being the signature of their dependence on the mean NP size. Furthermore, plotting the effective SBH as a fu…
Room-Temperature Electrical Characteristics of Pd∕SiC Diodes with Embedded Au Nanoparticles at the Interface
2010
We investigate the effects of localized controlled nanometric inhomogeneities, represented by Au nanoparticles, on the electrical properties of Pd/SiC Schottky diodes. In particular, we investigate the effects of the nanoparticle radius R on the current-voltage characteristics. The main result concerns the strong dependence of the effective Schottky barrier height of the Pd/SiC contact on R, giving a practical technique to tailor, in a wide range, such a barrier height by simply changing the process parameters during the diode preparation. Then, from a basic understanding point of view, such data allow us to test the Tung model describing the effects of inhomogeneities on the electrical pro…