Non-Smooth Dynamic Analysis of Local Seismic Damage Mechanisms of the San Felice Fortress in Northern Italy

Abstract The May 2012 seismic swarm, with epicenter in the Modena plane, in Northern Italy, had severe consequences on the historical buildings of the area. In particular, the fortified structures suffered specific, recurring damage and collapse mechanisms. The present paper deals with the case of the San Felice sul Panaro Fortress, which saw the collapse of 4 out of 5 towers and many other global and local effects. The work starts with an in-depth knowledge path, as a fundamental premise for a conscious intervention. The combination among historical analysis of the building, seismic history of the site, materials and pathological survey, structural identification, on-site inspections and tests, allowed to interpret the crack pattern and to identify the damage mechanisms activated by the earthquake, successively examined with specific structural analyses. In particular, the present paper concentrates on the numerical modelling of the identified local mechanisms, adopting a type of analysis first developed at the University of Parma for applied mechanics, based on the use of non-smooth dynamics software, through a Differential Variational Inequalities (DVI) formulation specifically developed for the 3D discrete elements method. It allows to follow large displacements and the opening and closure of cracks in dynamic field. Once the modelling instrument was calibrated, thanks to the comparison with the real damages previously inspected, it was also applied to foresee the behavior of the same mechanisms with different actions and with different types of strengthening

Growth of room temperature ferromagnetic Ge1-xMnx quantum dots on hydrogen passivated Si (100) surfaces

A method for the synthesis of room-temperature ferromagnetic dilute semiconductor Ge1-xMnx (5 % < x < 8 %) quantum dots by molecular beam epitaxy by selective growth on hydrogen terminated silicon (100) surface is presented. The functionalized substrates, as well as the nanostructures, were characterized in situ by reflection high-energy electron diffraction. The quantum dots density and equivalent radius were extracted from field emission scanning electron microscope pictures, obtained ex-situ. Magnetic characterizations were performed by superconducting quantum interference device vibrating sample magnetometry revealing that ferromagnetic order is maintained up to room temperature: two different ferromagnetic phases were identified by the analysis of the field cooled – zero field cooled measurements

Nanomaterials Characterisation through Magnetic Field Dependent AFM

Atomic force microscopy is a versatile technique allowing to exploit many different physical effects for measuring a number of materials properties. The magnetic properties of surfaces and thin films are traditionally accessed through magnetic force microscopy, which produces magnetic field gradient maps generated by the magnetisation distribution at the surface of the sample. However, more advanced techniques can be derived from this fundamental setup, allowing for a richer characterisation of magnetic samples. In this chapter, we will describe how to extend a magnetic force microscope to allow magnetic field-dependent characterisations. Magnetisation reversal processes, as well as full hysteresis loops, can be investigated with such a technique, with field resolution adequate for identifying significant features such as domains reversal, nucleation or annihilation of domains, and other irreversible mechanisms. The same principle can also be exploited for the measurement of magnetostriction on thin films, and can be taken as guideline for other advanced applications of atomic force microscopy

Experimental and Modelling Analysis of the Hyperthermia Properties of Iron Oxide Nanocubes

open10sìThe ability of magnetic nanoparticles (MNPs) to transform electromagnetic energy into heat is widely exploited in well-known thermal cancer therapies, such as magnetic hyperthermia, which proves useful in enhancing the radio- and chemo-sensitivity of human tumor cells. Since the heat release is ruled by the complex magnetic behavior of MNPs, a careful investigation is needed to understand the role of their intrinsic (composition, size and shape) and collective (aggregation state) properties. Here, the influence of geometrical parameters and aggregation on the specific loss power (SLP) is analyzed through in-depth structural, morphological, magnetic and thermometric characterizations supported by micromagnetic and heat transfer simulations. To this aim, different samples of cubic Fe3O4 NPs with an average size between 15 nm and 160 nm are prepared via hydrothermal route. For the analyzed samples, the magnetic behavior and heating properties result to be basically determined by the magnetic single- or multi-domain configuration and by the competition between magnetocrystalline and shape anisotropies. This is clarified by micromagnetic simulations, which enable us to also elucidate the role of magnetostatic interactions associated with locally strong aggregation.openhttps://zenodo.org/record/5040394#.YhVWyejMKUkFerrero, R; Barrera, G; Celegato, F; Vicentini, M; Sozeri, H; Yildiz, N; Dincer, CA; Coisson, M; Manzin, A; Tiberto, PFerrero, R; Barrera, G; Celegato, F; Vicentini, M; Sozeri, H; Yildiz, N; Dincer, Ca; Coisson, M; Manzin, A; Tiberto,

Improvement of Hyperthermia Properties of Iron Oxide Nanoparticles by Surface Coating

Magnetic hyperthermia is an oncological therapy that exploits magnetic nanoparticles activated by radiofrequency magnetic fields to produce a controlled temperature increase in a diseased tissue. The specific loss power (SLP) of magnetic nanoparticles or the capability to release heat can be improved using surface treatments, which can reduce agglomeration effects, thus impacting on local magnetostatic interactions. In this work, Fe3O4 nanoparticles are synthesized via a coprecipitation reaction and fully characterized in terms of structural, morphological, dimensional, magnetic, and hyperthermia properties (under the Hergt–Dutz limit). Different types of surface coatings are tested, comparing their impact on the heating efficacy and colloidal stability, resulting that sodium citrate leads to a doubling of the SLP with a substantial improvement in dispersion and stability in solution over time; an SLP value of around 170 W/g is obtained in this case for a 100 kHz and 48 kA/m magnetic field

Global volatile signature and polyphenols patterns in Vespolina wines according to vintage

The global volatile signature of Vespolina wines from different vintages was established using solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME/GC-qMS). Wines were also characterised in terms of bioactive compounds (such as individual polyphenols, biogenic amines and their precursors) by high-performance liquid chromatography (RP-HPLC). In addition, some physic ochemical parameters, such as the total phenolic content, total tannins and antioxidant capacity, were evaluated. Seventy-one volatile compounds and thirty-three bioactive compounds were identified in Ves polina wines. The application of multivariate analysis to the obtained data revealed that 2-phenylethyl acetate, ethyl nonanoate, 2-hexanol, isoamyl octanoate and ethyl 2-hydroxymethylbutanoate were the pri mary compounds responsible for Vespolina wines classification, mainly indicative for wines of 2015 and 2013 vintages. Conversely, wines from 2008 and 2009 vintages showed highest values of procyanidin B1, catechin, gallic acid, trans-piceid and trans-resveratrol.info:eu-repo/semantics/publishedVersio

Machine learning approaches for magnetic nanoparticle applications in biomedicine

&lt;p&gt;Presentation given at MMM 2023 Conference, Dallas, USA, on 31 October 2023&lt;/p&gt

Growth of room temperature ferromagnetic Ge 1-x

A method for the synthesis of room-temperature ferromagnetic dilute semiconductor Ge1-xMnx (5 % < x < 8 %) quantum dots by molecular beam epitaxy by selective growth on hydrogen terminated silicon (100) surface is presented. The functionalized substrates, as well as the nanostructures, were characterized in situ by reflection high-energy electron diffraction. The quantum dots density and equivalent radius were extracted from field emission scanning electron microscope pictures, obtained ex-situ. Magnetic characterizations were performed by superconducting quantum interference device vibrating sample magnetometry revealing that ferromagnetic order is maintained up to room temperature: two different ferromagnetic phases were identified by the analysis of the field cooled – zero field cooled measurements