Search results for " fisica"

The photophysics of distorted nanographenes: Ultra-slow relaxation dynamics, memory effects, and delayed fluorescence

2023

The controlled deformation and engineering of the sp2 carbon network in atomically-precise nanographenes, and their substantially larger size as compared to typical optical dyes, opens new opportunities for the modulation of optical and electronic properties, but the peculiar photophysics of these systems is still poorly understood. Here, through a detailed comparative study of two well-defined distorted nanographenes, we show that they can exhibit interesting photophysical features, such as triplet-triplet annihilation delayed fluorescence, ultra-slow excited state dynamics, and excitation-wavelength memory effects on the nanosecond and sub-nanosecond relaxation cascades. Some of these beh…

Graphene as a tunable resistor

2014

We present the design of a graphene-based electronically tuneable microstrip attenuator operating at a frequency of 5 GHz. The use of graphene as a variable resistor is discussed and the modelling of its electromagnetic properties at microwave frequencies is fully addressed. The design of the graphene-based attenuator is described. The structure integrates a patch of graphene, whose characteristics can range from being a fairly good conductor to a highly lossy material, depending on the applied voltage. By applying the proper voltage through two high-impedance bias lines, the surface resistivity of graphene can be modified, thereby changing the insertion loss of the microstrip attenuator.

Il Ruolo dei fenomeni vulcanici e dell'attività dell'uomo nel controllo di processi erosivi nell'isola di Vulcano

2009

HEp-2 intensity classification based on deep fine-tuning

2020

The classification of HEp-2 images, conducted through Indirect ImmunoFluorescence (IIF) gold standard method, in the positive / negative classes, is the first step in the diagnosis of autoimmune diseases. Since the test is often difficult to interpret, the research world has been looking for technological features for this problem. In recent years the methods of deep learning have overcome the other machine learning techniques in their effectiveness and robustness, and now they prevail in artificial intelligence studies. In this context, CNNs have played a significant role especially in the biomedical field. In this work we analysed the capabilities of CNN for fluorescence classification of…

Preliminary results of the project A.I.D.A. (Auto Immunity: Diagnosis Assisted by computer)

2014

In this paper, are presented the preliminary results of the A.I.D.A. (Auto Immunity: Diagnosis Assisted by computer) project which is developed in the frame of the cross-border cooperation Italy-Tunisia. According to the main objectives of this project, a database of interpreted Indirect ImmunoFluorescence (IIF) images on HEp 2 cells is being collected thanks to the contribution of Italian and Tunisian experts involved in routine diagnosis of autoimmune diseases. Through exchanging images and double reporting; a Gold Standard database, containing around 1000 double reported IIF images with different patterns including negative tests, has been settled. This Gold Standard database has been us…

Assessing the electricity consumption of outdoor lighting systems in the presence of automatic control: The OL-BAC factors method

2020

Abstract Building automation systems are able to influence significantly buildings’ energy performance. The BAC factors method, presented for the first time by the International Standard EN 15232, is the most used and simple instrument for evaluating the impact of such systems in terms of reduction of the electrical and thermal energy consumption of buildings services. Nevertheless, Standard EN 15232 does not take into consideration the automation of lighting systems serving buildings’ external areas like passages, gardens, entrance walkways, etc. In some cases, such areas can be very extended and, as a consequence, responsible for a not negligible percentage of the overall electricity cons…

Convezione Naturale in un Canale Verticale Riscaldato: un algoritmo per la gestione automatica mediante LabView della movimentazione della sonda anem…

2002

Si è progettato e realizzato un sistema semiautomatico per acquisizione dati finalizzato allo studio della convezione naturale in un canale verticale riscaldato, applicabile ad un’apparecchiatura sperimentale già esistente in un laboratorio del Dipartimento di Ricerche Energetiche ed Ambientali (DREAM). Tale sistema si è reso necessario in quanto detta apparecchiatura sperimentale era corredata da una serie di strumenti risalenti ad una configurazione in buona parte datata, e che quindi presentava molti limiti. In particolare essa utilizzava un vecchio linguaggio Basic HP ormai del tutto abbandonato, e pertanto non suscettibile di implementazione. Per di più non è compatibile con gli attual…

Template electrodeposition and characterization of nanostructured Pb as a negative electrode for lead-acid battery

2019

Abstract Despite Lead Acid Battery (LAB) is the oldest electrochemical energy storage system, diffusion in the emerging sectors of technological interest is inhibited by its drawbacks. The principal ones are low energy density and negative plate sulphating on high rate discharging. In this work, it is shown the possibility of overcoming such drawbacks by using nanostructured lead as a negative electrode. Lead nanowires (NWs) were fabricated by electrochemical deposition in template, which is an easy, cheap, and easily scalable process. Their morphology and crystal structure have been characterized by electron microscopy and X-ray diffraction, respectively. An electrochemical cell simulating…

Differential branching fractions and isospin asymmetries of B -> K ((*)) μ(+) μ(-) decays

2014

The isospin asymmetries of $B \to K\mu^+\mu^-$ and $B \to K^{*}\mu^+\mu^-$ decays and the partial branching fractions of the $B^0 \to K^0\mu^+\mu^-$, $B^+ \to K^+\mu^+\mu^-$ and $B^+ \to K^{*+}\mu^+\mu^-$ decays are measured as functions of the dimuon mass squared, $q^2$. The data used correspond to an integrated luminosity of 3$~$fb$^{-1}$ from proton-proton collisions collected with the LHCb detector at centre-of-mass energies of 7$\,$TeV and 8$\,$TeV in 2011 and 2012, respectively. The isospin asymmetries are both consistent with the Standard Model expectations. The three measured branching fractions, while individually consistent, all favour lower values than their respective Standard M…

Measurement of polarization amplitudes and CP asymmetries in B 0 → Φk *(892)0

2014

An angular analysis of the decay $B^0 \to \phi K^*(892)^0$ is reported based on a $pp$ collision data sample, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected at a centre-of-mass energy of $\sqrt{s} = 7$ TeV with the LHCb detector. The P-wave amplitudes and phases are measured with a greater precision than by previous experiments, and confirm about equal amounts of longitudinal and transverse polarization. The S-wave $K^+ \pi^-$ and $K^+K^-$ contributions are taken into account and found to be significant. A comparison of the $B^0 \to \phi K^*(892)^0$ and $\bar{B}^0 \to \phi \bar{K}^*(892)^0$ results shows no evidence for direct CP violation in the rate asymmetry, in th…