Search results for "SCALE"
showing 10 items of 5180 documents
Ultrafast amplification and non-linear magneto-elastic coupling of coherent magnon modes in an antiferromagnet
2021
We investigate the role of domain walls in the ultrafast magnon dynamics of an antiferromagnetic NiO single crystal in a pump-probe experiment with variable pump photon energy. Analysing the amplitude of the energy-dependent photo-induced ultrafast spin dynamics, we detect a yet unreported coupling between the material's characteristic THz- and a GHz-magnon modes. We explain this unexpected coupling between two orthogonal eigenstates of the corresponding Hamiltonian by modelling the magneto-elastic interaction between spins in different domains. We find that such interaction, in the non-linear regime, couples the two different magnon modes via the domain walls and it can be optically exploi…
Automatic orientation and 3D modelling from markerless rock art imagery
2013
This paper investigates the use of two detectors and descriptors on image pyramids for automatic image orientation and generation of 3D models. The detectors and descriptors replace manual measurements and are used to detect, extract and match features across multiple imagery. The Scale-Invariant Feature Transform (SIFT) and the Speeded Up Robust Features (SURF) will be assessed based on speed, number of features, matched features, and precision in image and object space depending on the adopted hierarchical matching scheme. The influence of applying in addition Area Based Matching (ABM) with normalised cross-correlation (NCC) and least squares matching (LSM) is also investigated. The pipel…
Severity of anxious symptoms in nursing students of the University of Palermo
2019
BACKGROUND: The university student is vulnerable to the adverse effects of many stress factors that can lead to an increase in the burden of illness in young people. The objective of the study was to estimate the prevalence of anxious symptoms in the student population of the degree course in nursing at the University of Palermo. METHODS: The study design is observational. In the month of April 2019, a survey was provided to all nursing students of University of Palermo of the three years of course, accompanied by informed consent. The statistical significance level chosen for all analyzes was 0.05. The results were analyzed using the STATA statistical software version 14.XX Results are exp…
A linear generator for a waveroller power device
2017
In this paper experimental tests on a small scale tubular linear generator to be applied to wave rollers device are presented. A reduced scale of gnerator is presented and experimental results obtained in on test bench are shown. Experimental waveforms of current and voltage are recorded. Simulation results are compared to the experimental ones in order to validate the mathematical models used.
La Seconda Vita dell'Ambiente Costruito
2021
Il contributo inquadra i saggi, gli studi, le ricerche e progetti pubblicati sul numero 9 di AGATHÓN su ‘La Seconda Vita dell’Ambiente Costruito’, tema di interesse per il mondo accademico, delle professioni e dell’industria. Cambiamenti climatici, eccessivo consumo di suolo e di risorse non rinnovabili, produzione sempre crescente di rifiuti, emergenza pandemica e crisi socio-economica globale sono entrati di fatto nel nostro quotidiano: seppur drammatiche, per certi versi, tali questioni possono essere colte come un’opportunità per ripensare il modo e il mondo in cui viviamo. In questo contesto di ‘rivoluzione’(Floridi, 2020) e di ‘policrisi’ (Losasso, 2020), e con riferimento specifico a…
L'intonaco Li Vigni nell'architettura del XX secolo a Palermo. Nuove conoscenze e applicazioni diagnostiche per la manutenzione
2013
Il saggio presenta lo studio degli intonaci formulati per imitare le pietre e i marmi naturali che si diffondono in Sicilia all’inizio del XX secolo ed evidenzia che le prime applicazioni e la diffusione delle nuove malte, anche nel resto dell’Italia, risentono delle sperimentazioni condotte in tutta l’Europa. Il contributo riassume i risultati di una rigorosa e capillare ricognizione tra i brevetti conservati presso l’Archivio Centrale dello Stato a Roma inerenti alle malte per il confezionamento dell’intonaco a “finta pietra”, ne analizza i contenuti in modo critico e pone in risalto i contatti culturali con le sperimentazioni dei materiali in atto nell’ambito dei grandi cantieri di resta…
Radial phononic thermal conductance in thin membranes in the Casimir limit: Design guidelines for devices
2014
In a previous publication, we discussed the formalism and some computational results for phononic thermal conduction in the suspended membrane geometry for radial heat flow from a central source, which is a common geometry for some low-temperature detectors, for example. We studied the case where only diffusive surface scattering is present, the so called Casimir limit, which can be experimentally relevant at temperatures below $\sim$ 10 K in typical materials, and even higher for ultrathin samples. Here, we extend our studies to much thinner membranes, obtaining numerical results for geometries which are more typical in experiments. In addition, we interpret the results in terms of a small…
Investigation of flashing phenomena in MSF chambers
2007
The MSF process has covered in the last years more than 50% of world production of desalinated water from the sea. Although this process has been used for several decades, the large energy requirements force to search for new and feasible ways to improve the overall thermal efficiency. Few studies have bee carried out in lab-scale, pilot and industrial MSF units, underlining the complexity of flashing phenomena and the importance of operating parameters settings for optimal performance. In the present work a study on fundamental phenomena occurring inside MSF chambers has been carried out, focusing on the dependence of flashing efficiency on operating parameters and the effects of flashing …
Empirical model building based on Weibull distribution to describe the joint effect of pH and temperature on the thermal resistance of Bacillus cereu…
2002
Abstract A mathematical model based on Weibull parameters was built to describe the joint effect of temperature and pH on thermal inactivation of Bacillus cereus spores (strain INRA TZ415). The effect of these factors on Weibull model parameters ( β , 1/ α ) was also studied. Heat inactivation tests were carried out in acidified carrot broth as vegetable substrate, following a full factorial design at four levels for temperature (80, 85, 90 and 95 °C) and pH (6.2, 5.8, 5.2 and 4.7). The Weibull distribution model provided good individual fits for the different combinations of temperature–pH tested, with discrepancy factors, D f , coming close to 25% for most cases. The temperature and pH di…
Hierarchical structure and cytocompatibility of fish scales from Carassius auratus
2014
Abstract To study the structure and the cytocompatibility of fish scales from Carassius auratus , scanning electron microscopy (SEM) was used to observe the morphology of fish scales treated with different processing methods. Based on varying morphologies and components, the fish scales can be divided into three regions on the surface and three layers in vertical. The functions of these three individual layers were analyzed. SEM results show that the primary inorganic components are spherical or cubic hydroxyapatite (HA) nanoparticles. The fish scales have an ~ 60° overlapped plywood structure of lamellas in the fibrillary plate. The plywood structure consists of co-aligned type I collagen …