Search results for " fisica"
showing 10 items of 4804 documents
The Effect of Electrolytic Solution Composition on the Structure, Corrosion, and Wear Resistance of PEO Coatings on AZ31 Magnesium Alloy
2020
Plasma electrolytic oxidation coatings were prepared in aluminate, phosphate, and silicate-based electrolytic solutions using a soft-sparking regime in a multi-frequency stepped process to compare the structure, corrosion, and wear characteristics of the obtained coatings on AZ31 magnesium alloy. The XRD results indicated that all coatings consist of MgO and MgF2, while specific products such as Mg2SiO4, MgSiO3, Mg2P2O7, and MgAl2O4 were also present in specimens based on the selected solution. Surface morphology of the obtained coatings was strongly affected by the electrolyte composition. Aluminate-containing coating showed volcano-like, nodular particles and craters distributed over the …
Novel techniques for wind speed spatial estimation
2007
Estimation of wind velocity over a complex terrain using the Generalized Mapping Regressor
2010
Abstract Wind energy evaluation is an important goal in the conversion of energy systems to more environmentally friendly solutions. In this paper, we present a novel approach to wind speed spatial estimation on the isle of Sicily (Italy): an incremental self-organizing neural network (Generalized Mapping Regressor – GMR) is coupled with exploratory data analysis techniques in order to obtain a map of the spatial distribution of the average wind speed over the entire region. First, the topographic surface of the island was modelled using two different neural techniques and by exploiting the information extracted from a digital elevation model of the region. Then, GMR was used for automatic …
Proceeding Book of 12th European Symposium on Religious art, Restoration & Conservation
2022
Fundamental contribution to filling out the condition reports of the work of arts involved in temporary exhibitions is provided by non-invasive investigation techniques. Investigation, carried out before and after the movement, allow to collect objective data to monitoring the surface or structural alterations and defining the state of conservation, representing an important moment of deepening of knowledge. Generally, these aspects often are left to photographic documentation and observations by conservators and curators. An example of good practice is represented by the case of the Saint Gregory Polyptych (Antonello da Messina, 1473) belonging to the Regional Museum of Messina (Italy). Th…
Composition and corrosion phases of Etruscan Bronzes from Villanovan Age
2008
A neutron diffraction (ND) and neutron tomography (NT) study of laminated ancient bronzes was performed at the ISIS (Rutherford Appleton Laboratory, UK) neutron source and at the BENSC reactor (Hahn-Meitner Institut, Germany). The samples are part of an 8th century BC Etruscan collection discovered in the necropolises of Osteria-Poggio Mengarelli and Cavalupo in the Vulci area (Viterbo, Italy). The study allowed us to derive-in a totally non-destructive manner-information related to the main composition of the objects, possible presence of alterations and their nature, crusts and inclusions, as well as structure of the bulk. The presence of some components is linked to a variety of question…
ytterbium nanoparticles: properties, recent synthesis, developments and prespectives
2011
Material science interest is more and more directed to the synthesis and characterization of nano-sized particles. This interest is justified by the fact that the reduction of the particle size of a given material to the nanometer scale causes the rising up of exotic properties that are not present in the bulk state due to size-dependent quantum effects and huge increase of the interfacial species. Further striking features can be gained by controlling nanoparticle shape or through the building up of spatially ordered mono-, bi- and three-dimensional nanoparticle arrays. Then, the wise selection of the nanoparticle synthetic strategy offers the possibility of preparing a wide class of novel…
Effect of pulse amplitude on depression and potentiation of ZrO2(Y)-based memristive synaptic device
2022
The effect of the amplitude of depressing and potentiating pulses on the synaptic plasticity (potentiation and depression) of a memristive device based on the Ta/ZrO2(Y)/Pt stack has been experimentally studied. It is shown that the amplitude of depressing and potentiating pulses affects the synaptic plasticity, namely, the value of current passing through the memristive device. The presented results demonstrate the prospects of using the ZrO2(Y)-based memristive devices as stable and low-power elements of neuromorphic systems.
Statistical Approximation of Fourier Transform-IR Spectroscopy Data for Zinc White Pigment from Twentieth-Century Russian Paintings
2017
We present a statistical model for approximation of experimental Fourier transform-IR spectroscopy (FTIR) data for paint samples from paintings of different ages. The model utilizes random variations in some parameters (initial ageing rate, degree of change in ageing rate and time at which the change occurs). We determine the parameters characterizing variation in the paint composition and the storage conditions for the paintings. The numerical calculation is qualitatively consistent with the experimental data. In the proposed model, changes in the initial composition of the paint and the storage conditions make about the same contribution to the experimentally observed scatter in the data …