Search results for "Polar"

Polarimetric study of binding equilibria between cyclodextrins and some suitable organic guests

A 3D CZT hard x-ray polarimeter for a balloon borne payload

2012

Currently, it is widely recognised that a measurement of the polarization status of cosmic sources high energy emission is a key observational parameter to understand the active production mechanism and its geometry. Therefore new instrumentation operating in this energy range should be optimized also for this type of measurement. In this framework, we present the concept of a small high-performance spectrometer designed for polarimetry between 100 and 500 keV suitable as a stratospheric balloon-borne payload dedicated to perform an accurate and reliable measurement of the polarization status of the Crab pulsar, i.e. the polarization level and direction. The detector with 3D spatial resolut…

Extensive backthrusting features in the northern Sicily continental margin highlight a late collisional stage of the Sicilian Fold and Thrust Belt

2016

Backthrusting, nappe refolding, and normal faulting frequently characterize late collisional stage of an orogen. Shortening driven by backthrusting is widely reported in the Alpine orogen, and it has been proposed to be responsible for the increase of subsidence. Moreover delamination and backthrusting has been considered as related to subcritical condition of a Coulomb-type accretional wedge (Torres Carbonell et al., 2011). The Sicilian Fold and Thrust Belt (SFTB) was characterized by a three-stage evolution during the last 15 My: two main shortening events generated and developed at different structural levels (shallow- and deep-seated thrusts in thinskinned thrust-model) and different ti…

Marble and stone revetment and pavements: Context and provenance

2022

Earlier excavations and survey at Vagnari furnished hardly any evidence for the use of marble at the site, and so the vicus was considered to be a low status settlement, with only a few rooms having been elegant enough to decorate them with marble floors or revetment. The fragments recovered were not analysed scientifically to determine the location of the quarries from which the marbles came. Of particular interest, however, were two small fragments of inscriptions on white marble retrieved from the rubble fill dumped in the 4th century AD in the reservoir. These originally may have been attached, when intact, to votive or funerary monuments, suggesting that the occasional commemorative mo…

DEGRADO, MANUTENZIONE, RECUPERO. IL CASO DEL QUARTIERE ZEN 2 DI PALERMO

2009

Hybrid organic-inorganic membranes for low temperature H2-O2 fuel cell

2014

Selectivity of hydroxyl radical in the partial oxidation of aromatic compounds in heterogeneous photocatalysis

2007

Abstract The photocatalytic oxidation of different benzene derivatives has been investigated in order to understand how the substituent group affects the selectivity to hydroxylated compounds. Experimental runs were performed by using TiO2 (Merck) aqueous suspensions at natural pH irradiated by near-UV light. The organic molecules used as substrate contained an electron withdrawing group (EWG) (nitrobenzene, cyanobenzene, benzoic acid, 1-phenylethanone), an electron donor one (EDG) (phenol, phenylamine, N-phenylacetamide) or both an EWG and an EDG (4-chlorophenol). The results clearly indicated that the primary photocatalytic oxidation of aromatic compounds containing an EDG gives rise main…

Bipolar membrane (reverse) electrodialysis acid/base flow battery for energy storage: a multi-scale model for increased efficiency

2019

The renewable energy market is rapidly increasing. Most of renewable energy sources are intermittent, e.g. wind and solar among them. This has led to the need for new large scale energy storage systems. In this regard, the Acid/Base Flow Battery (AB-FB) represents an innovative, safe and sustainable way to store energy with high performances [1]. The energy density accumulated in an AB-FB, in the form of pH and salinity gradients, can theoretically reach 7 kWh/m8 which is higher than the values relevant to the most used technologies (e.g. pumped hydropower and compressed air). The core of the battery is the stack where two membrane separation processes are carried out: bipolar membrane elec…

Analysis of Operational Parameters in Acid and Base Production Using an Electrodialysis with Bipolar Membranes Pilot Plant

2023

In agreement with the Water Framework Directive, Circular Economy and European Union (EU) Green Deal packages, the EU-funded WATER-MINING project aims to validate next-generation water resource solutions at the pre-commercial demonstration scale in order to provide water management and recovery of valuable materials from alternative sources. In the framework of the WATER-MINING project, desalination brines from the Lampedusa (Italy) seawater reverse osmosis (SWRO) plant will be used to produce freshwater and recover valuable salts by integrating different technologies. In particular, electrodialysis with bipolar membranes (EDBM) will be used to produce chemicals (NaOH and HCl). A novel EDBM…

CFD parametrical study of the spacer geometry for Membrane Distillation

Membrane Distillation (MD) is a thermal process that separates water from aqueous solutions containing non-volatile components such as salt. Water vapor from the hot feed channel permeates through a hydrophobic membrane thanks to a partial pressure gradient, and condenses in the cool channel. One of the main advantages of MD is the easy coupling with renewable resources, as the solar thermal energy. In the various MD configurations developed, net spacers are used in order to support the membrane, thus creating the channels; moreover, they can counteract the side effects of temperature polarization by promoting mixing. However, the presence of the spacer involves an increase of pressure drop…