Search results for " fisica"
showing 10 items of 4804 documents
Magnetic Field Dependence of Microwave Surface Resistance in MgB2
2008
Superconductivity explained with the tools of the classical electromagnetism. Educational path for secondary school and its experimentation.
2014
The work of this thesis describes an educational path for the presentation of superconductivity at the secondary school, together with the experimentation of some particular parts of the path with high school students. The educational path that we have developed is mainly centred on the phenomenological aspects of superconductivity and has been inspired by the two fluid theory of Gorter and Casimir (1934) where a superconductor is seen as a material in which two fluids are present, the normal fluid described by the Ohm's laws, and the superconductive fluid descibed by the London equation (1935). Both the Ohm's laws and the London equation give respectively the phenomenological descriptions …
The saturation of decaying counterflow turbulence in helium
2010
Liquid Structure Scenario of the Archetypal Supramolecular Deep Eutectic Solvent: Heptakis(2,6-di-O-methyl)-β-cyclodextrin/levulinic Acid
2023
The concept of supramolecular solvents has been recently introduced, and the extended liquid-state window accessible for mixtures of functionalized cyclodextrins (CDs) with hydrogen bond (HB) donor species, e.g., levulinic acid, led to the debut of supramolecular deep eutectic solvents (SUPRA-DES). These solvents retain CD’s inclusion ability and complement it with enhanced solvation effectiveness due to an extended HB network. However, so far, these promising features were not rationalized in terms of a microscopic description, thus hindering a more complete capitalization. This is the first joint experimental and computational study on the archetypal SUPRA-DES: heptakis- (2,6-di-O-methyl)…
UV-VISIBLE LUMINESCENCE OF SILICA NANOPARTICLES
Gas Phase Charged Aggregates of Bis(2-ethylhexyl)sulfo-succinate (AOT) and Divalent Metal Ions. First evidence of AOT solvated aggregates
2011
Assembling and chelating properties of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) towards divalent metal ions have been investigated in the gas phase by electrospray ionization mass spectrometry. A variety of positively charged monometallated and mixed metal aggregates are formed. Interestingly, several ions contain solvent (MeOH, H2O) molecules and constitute the most abundant AOT cationic aggregates not containing sodium. These species are the first example of solvated AOT-metal ion aggregates in the gas phase. By increasing the surfactant aggregation number, the abundance of solvated species becomes lower than that of unsolvated ones. Decompositions of ionic species have been studied…
Do electrospray mass spectra of surfactants mirror their aggregation state in solution?
2011
One important feature in the gas phase chemistry of surfactants is to ascertain whether their aggregates produced by electrospray ionization reflect those formed in the starting solution. With this aim, we have performed ESI-MS, ESI-MS/MS and ER-MS spectra of bis(2-ethylhexyl)sulfosuccinate (AOTNa) solutions in different solvents, i.e. water, water/methanol, methanol and n-hexane. The results clearly indicate that, notwithstanding the strongly different aggregation state in solution (direct micelles in water and in water/methanol, molecular dispersion in methanol and reverse micelles in n-hexane) and marked effects of the solvent polarity on the total ionic current, the surfactant aggregate…
Exploiting ArcGIS and Google Earthtm to assess an earth flow susceptibility model in central Sicily
2009
UTILIZZO DEL SISTEMA GOOGLE EARTH PER LA DEFINIZIONE DI UN MODELLO DI SUSCETTIBILITÀ DA FRANA: UN TEST IN SICILIA CENTRALE
2011
Exploiting Google EarthTM to assess a landslide susceptibility model: a test in central Sicily. A landslide susceptibility multivariate model, based on the conditional analysis approach, has been derived in the Tumarrano river basin (about 78 km2), by intersecting a GIS grid layer, expressing some selected geo-environmental conditions (outcropping lithology, steepness, plan curvature and topographic wetness index), and a landslide vector archive, produced by a Google EarthTM aided remote survey. The analysis of the Google EarthTM images dated at 2006, allowed to recognize 733 landslides (30 rotational slides and 703 flows), almost exclusively affecting clay and sandy clay rocks. Validation …
Greening a university campus: trends of energy consumption and possible sustainable paths
2014
Recent years have seen an increasing public interest in issues related to energy saving and environmental pollution reduction of public buildings, such as those in university campuses, that should set an example of sustainable development. University campuses are usually characterized by the daily presence of a high number of people working and living in a relatively limited area. They are sites of a wide spread of functions, ranging from teaching to laboratory activities, from housing and food preparation to local transportation. All these activities require remarkable amount of energy that, actually, are not always utilized with the best possible efficiency. This calls for a deep reconsid…