123,189 research outputs found
La "consistenza dell'effimero":alcune riflessioni sul progetto "Riviste d'arte" e sui risultati della ricerca a Napoli
importanza delle riviste d'arte per la storia del dibattito storico- artistico e critico tra XIX e XX secol
Italian Academy Colombia Fellowship
During the fall semester spent at the Italian Academy , cosponsored by the Earth and Environmental Engineering Department of Columbia University of New York, I worked on the research project ‘ Climate changes from decade to century: flood/drought dynamics’.
Such a research project involves different partners and Institutions , namely Columbia University (USA) , University of Rome ‘ La Sapienza’(Italy) , National Research Center (CNR-Italy), Institute of Numerical Model (Russian Science Academy), University of Tuscia Italy).
The research goal is to produce scientifically sound scenarios of flood and drought risk in N. America and Europe and their projected changes under IPCC scenarios.
A novel integrated modelling approach is used to address this issue. The approach entails integration of analyses from a low order dynamical systems model, a medium resolution current ocean-atmosphere GCM, and statistical tools for connecting atmospheric moisture transport and extreme precipitation incidence to the underlying low frequency climate state.
A low order model explores the interactions of the key natural modes of ocean-atmosphere variability and their interaction with the mid-latitude atmosphere.
The CGM model INMCM3.0 (Volodin & Diansky 2006) allows to simulate planetary climatic conditions for long periods of time under current conditions and under enhanced greenhouse gases conditions. However, given its complexity only a limited number of ensemble runs can typically be performed for a fixed set of parameters. Thus, its use is complementary to the low order models where substantial exploration of the parameters and the associated regimes can be done.
In the Fall semester spent in the Italian Academy the research has been addressed to study:
- the organization and evolution of climate extremes in the mid-latitude as they are influenced by low-frequency climate modes associated with ocean-atmosphere interactions; specifically such influences have been explored by using observations and low-order models.
- precipitation extremes simulated by the medium resolution GCM ( INMCM3.0) as are analyzed for the Mediterranean region.
The main findings of the study are extensively discussed in the paper ‘Surface Temperature Gradient and their relation to Mid-latitude Circulation Dynamics & Interannual Precipitation variability: Trends and links to Enso in Observations and Low-order Climate Models ’ by C. Karamperidou, F. Cioffi & U. Lall, and in the two presentations at the AGU2010 Fall Conference , namely (a) ‘"Northern Hemisphere Meridional and Zonal Temperature Gradients and their Relation to Hydrologic Extremes at Mid-latitudes: Trends, Variability and Link to Climate Modes in Observations and Simulations" , by C. Karamperidou, U. Lall & F. Cioffi ; (b) GCM Projections of Precipitation Extremes in the Mediterranean: Changes and Low frequency Characteristics by F. Cioffi ; U. Lall , E. Volodin , C. Karamperidou , R. Purini .
These findings are summarized in the following. The analysis of rainfall patterns under global warming shows an increase of rainfall extremes in both frequency and intensity in northern Europe and a decrease in most of the Mediterranean. In the latter region an increase of dry conditions is also observed. The change in the rainfall patterns can be explained by a northward shift of the North Atlantic winter storm track that is one of the main factors in determining moisture and heat transport associated with extreme hydrological events. It depends on how the jet stream dynamics are modulated by large scale ocean-land boundary conditions which depend in turn on both the state of evolution of the known inter-annual and multi-decadal natural variability ( e.g. El Nino-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO)) and on changes in meridional and zonal surface temperature gradients ( Equator- Pole gradient (EPG) and Ocean-Land contrast ( OLC), respectively). From the 20th century observations is emerged that different combinations of EPG and OLC are associated with precipitation anomalies at mid-latitudes as Mediterranean and European regions. The Northward shift of the North Atlantic storm track and the associated rainfall patterns are related to a reduction of both EPG and OLC as a consequence of anthropogenic forcing
The effect of fluorides and strain on nickel release from nickel-titanium orthodontic wires
N- S- co-Doped Carbon as an Efficient Electrocatalyst toward Oxygen Reduction Reaction
Oxygen reduction reaction (ORR) is a pivotal reaction in many electrochemical systems, but, due to its kinetic hindrance, it needs electrocatalysts in order to “conveniently” proceed. Heteroatom-doped carbons have been studied for many years as cheap and efficient materials for this reaction thank to their specific properties imparted to the graphene plane by both heteroatom nature and by synergistic interaction between heteroatoms and carbon. In this work, we present some ORR results about cheap, easy-synthesized materials based on a metal modified- N/S co-doped carbon. These carbons have been characterized by physico-chemical methods: X-Ray Powder Diffraction, X-Ray Photoelectron Spectroscopy, Micro-Raman Spectroscopy, BET analysis, Scanning Electron Microscopy. A deep electrochemical study has been performed by using Rotating Disk- and Rotating Ring Disk Electrode. A correlation between nitrogen, sulphur amount, nature of carbon precursor, nature of metal, chemical nature of heteroatom on the surface and electrocatalytic properties will be presented. Results are very promising. The activity of some materials is better than that of the most used electrocatalyst based on Pt. Preliminary results about MeOH tolerance of some of them will be also presented
DS_10.1177_0022034519837249 – Supplemental material for Masseter Deoxygenation in Adults at Risk for Temporomandibular Disorders
Supplemental material, DS_10.1177_0022034519837249 for Masseter Deoxygenation in Adults at Risk for Temporomandibular Disorders by N. Shah, L. Melo, W.D. Reid and I. Cioffi in Journal of Dental Research</p
Green Synthesis and Analytical Characterization of Core-Shell Copper Sub-Microparticles
This study demonstrates a simple and reproducible approach to synthesize green core-shell copper sub-microparticles stabilized by poly(n-vinyl)pyrrolidone (PVP). Cu@PVP colloids were here prepared using copper sulfate pentahydrate as precursor and glucose as reducing agent. The presence of PVP in the synthetic medium eliminates the need for an inert atmosphere during the process, thus simplifying the whole method. Both the morphology and the spectroscopic properties of Cu@PVP colloids were investigated by transmission electron microscopy, and infrared, UV-Vis and X-ray photoelectron spectroscopies. Size distributions and average shell thickness were obtained by statistical analysis on TEM micrographs, and spectroscopies demonstrated the formation of a PVP layer around the copper core. The produced colloids were employed in composite thin films for potential antimicrobial application, in association with a highly-recyclable polymer: polycarbonate (4,4’-(1-methylethylidene)bis(phenol))
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