Engineering of freestanding films

The PhD work is focuses on the study, characterization and formation of freestanding films. A film is a system in which two dimensions prevail over the third one. In case of freestanding films both surfaces are free; they can be supported by a solid mount of any geometry or float on a liquid, even bubbles are freestanding films. Many innovations were achieved such as a new quantitative, self-reference and full-field thickness map measurement technique. New advances in understanding the phenomenon of leveling of freestanding thin liquid films were also achieved. A totally new device to handle and form freestanding films was designed and build, this new device has a very high number of applications which are not only related directly to freestanding films. This device is capable of overcome many limitations and problems of other devices that forms freestanding films. Moreover, a new protocol for particle deposition on liquid-air (or liquid-liquid) was design. Finally, two novel methods were invented to control the buckling instability of Graphene Sheets particles with many possible applications in stretchable electronics and much more

Quantitative imaging of the complexity in liquid bubbles' evolution reveals the dynamics of film retraction

The dynamics and stability of thin liquid films have fascinated scientists over many decades. Thin film flows are central to numerous areas of engineering, geophysics, and biophysics and occur over a wide range of length, velocity, and liquid properties scales. In spite of many significant developments in this area, we still lack appropriate quantitative experimental tools with the spatial and temporal resolution necessary for a comprehensive study of film evolution. We propose tackling this problem with a holographic technique that combines quantitative phase imaging with a custom setup designed to form and manipulate bubbles. The results, gathered on a model aqueous polymeric solution, provide an unparalleled insight into bubble dynamics through the combination of full-field thickness estimation, three-dimensional imaging, and fast acquisition time. The unprecedented level of detail offered by the proposed methodology will promote a deeper understanding of the underlying physics of thin film dynamics

Quantitative imaging of the complexity in liquid bubbles’ evolution reveals the dynamics of film retraction

Thin liquid films: Seeing bubbles in a better light A procedure for imaging the complex fluid dynamics in bubbles could greatly assist efforts to understand and exploit thin liquid films in applications ranging through medicine, industrial chemistry and engineering. Thin liquid films are ubiquitous in nature, found in such varied systems as soap bubbles, biological membranes, detergents, oils, insulation, foods and geological magma. Researchers in Italy led by Biagio Mandracchia at the Institute of Applied Science and Intelligent Systems in Naples, devised a novel holographic phase imaging technique to watch bubbles as they form, develop, burst and retract. The researchers built customized apparatus to create and manipulate the bubbles. The unprecedented level of detail being revealed offers deeper understanding of the physics underlying thin film behavior. Insights into the complex fluid dynamics within bubbles could advance thin film technology for many applications

BLIND: A privacy preserving truth discovery system for mobile crowdsensing

Nowadays, an increasing number of applications exploit users who act as intelligent sensors and can quickly provide high-level information. These users generate valuable data that, if mishandled, could potentially reveal sensitive information. Protecting user privacy is thus of paramount importance for crowdsensing systems. In this paper, we propose BLIND, an innovative open-source truth discovery system designed to improve the quality of information (QoI) through the use of privacy-preserving computation techniques in mobile crowdsensing scenarios. The uniqueness of BLIND lies in its ability to preserve user privacy by ensuring that none of the parties involved are able to identify the source of the information provided. The system uses homomorphic encryption to implement a novel privacy-preserving version of the well-known K-Means clustering algorithm, which directly groups encrypted user data. Outliers are then removed privately without revealing any useful information to the parties involved. We extensively evaluate the proposed system for both server-side and client-side scalability, as well as truth discovery accuracy, using a real-world dataset and a synthetic one, to test the system under challenging conditions. Comparisons with four state-of-the-art approaches show that BLIND optimizes QoI by effectively mitigating the impact of four different security attacks, with higher accuracy and lower communication overhead than its competitors. With the optimizations proposed in this paper, BLIND is up to three times faster than the baseline system, and the obtained Root Mean Squared Error (RMSE) values are up to 42% lower than other state-of-the-art approaches

BODYTASKING. ANALYSIS AND PERCEPTIONS OF A DISTANCE DANCE EXPERIENCE.

To stop the spread of COVID-19 in March 2020, the Italian government declared a health emergency, imposing the national lockdown. A year later, the pandemic still blocks the non-professional sports sectors, including gyms and dance schools, to reopen. The distance created with remote, online training session might deprive all the cognitive, emotional, social and communication development expressed in the embodied theories. To investigate the perception of distanced learning in physical education, the multidisciplinary research team used the novel, holistic, dance-based intervention named bodytasking. Eight sessions, one each Monday, were carried out by two teachers between December 2020 and February 2021. Five students aged range between 6 and 10 years old, all girls took part in the study. Qualitative interviews were collected during and after the dance intervention to report students and teachers perspective on distanced learning. The results showed the benefits and the deficits of carrying out a sports practice in distanced learning. We reported the importance of using Information and Communications Technology tools such as videos and music tracks to challenge and stimulate the students and the role that imagination plays in the learning process

Full-Field and Quantitative Analysis of a Thin Liquid Film at the Nanoscale by Combining Digital Holography and White Light Interferometry

Visualizing and measuring thin-film thickness at the nanoscale during dynamic evolution has been an open challenge for long term. Here, a joint-imaging method and the thereof innovative procedure are presented for merging digital holography (DH) and white light colorimetric interferometry (WLCI) measurement data in a single intelligent tool. This approach allows a complete quantitative study of the dynamic evolution of freestanding thin films under high spatial resolution and full-field modality over a large area. By merging interferometric and holographic fringes, it is possible to overcome the lack of DH in thickness measurements of ultrathin layers, providing a reliable reference for full-field quantitative mapping of the whole film with interferometric accuracy. Thanks to the proposed approach, the time-related and concentration-related evolution of surfactant film thickness can be studied. The thickness distribution curves reveal the small changes in the film thickness with time and concentration. The reported tool opens a route for comprehending deeply the physics behind the behavior of freestanding thin liquid films as it provides an in situ, continuous monitoring of film formation and dynamic evolution without limits of thickness range and in full-field mode. This can be of fundamental importance to many fields of applications, such as fluids, polymers, biotechnology, bottom-up fabrication, etc

On the use of asymmetric PSF on NIR images of crowded stellar fields

We present data collected using the camera PISCES coupled with the Firt Light Adaptive Optics (FLAO) mounted at the Large Binocular Telescope (LBT). The images were collected using two natural guide stars with an apparent magnitude of R<13 mag. During these observations the seeing was on average ~0.9". The AO performed very well: the images display a mean FWHM of 0.05 arcsec and of 0.06 arcsec in the J- and in the Ks-band, respectively. The Strehl ratio on the quoted images reaches 13-30% (J) and 50-65% (Ks), in the off and in the central pointings respectively. On the basis of this sample we have reached a J-band limiting magnitude of ~22.5 mag and the deepest Ks-band limiting magnitude ever obtained in a crowded stellar field: Ks~23 mag. J-band images display a complex change in the shape of the PSF when moving at larger radial distances from the natural guide star. In particular, the stellar images become more elongated in approaching the corners of the J-band images whereas the Ks-band images are more uniform. We discuss in detail the strategy used to perform accurate and deep photometry in these very challenging images. In particular we will focus our attention on the use of an updated version of ROMAFOT based on asymmetric and analytical Point Spread Functions. The quality of the photometry allowed us to properly identify a feature that clearly shows up in NIR bands: the main sequence knee (MSK). The MSK is independent of the evolutionary age, therefore the difference in magnitude with the canonical clock to constrain the cluster age, the main sequence turn off (MSTO), provides an estimate of the absolute age of the cluster. The key advantage of this new approach is that the error decreases by a factor of two when compared with the classical one. Combining ground-based Ks with space F606W photometry, we estimate the absolute age of M15 to be 13.70+-0.80 Gyr.Comment: 15 pages, 7 figures, presented at the SPIE conference 201

dynamic simulation of a multi generation system for electric and cooling energy provision employing a sofc cogenerator and an adsorption chiller

Abstract Aim of this work is the dynamic simulation of the operation of a small-scale multi-generation system, based on a Solid Oxide Fuel Cell (SOFC) micro-cogenerator (μCHP) coupled to an adsorption chiller, to provide electric and cooling energy to a telecommunication shelter. The dynamic simulation model has been implemented in TRNSYS environment. The μCHP has nominal electric power of 2.5 kW and its thermal output is used to drive a thermally driven adsorption chiller, with nominal cooling power of 10 kW. The performance of both components were experimentally validated under controlled lab conditions. The developed model allowed to optimize the system configuration and to perform an energy and environmental analysis. This analysis demonstrated the possibility of achieving global energy efficiency up to 63% with a CO2 reduction proportional to the electric and cooling load of the telecommunication shelter

Managing of Migraine in the Workplaces: Knowledge, Attitudes and Practices of Italian Occupational Physicians

Background and Objectives: Migraine is a debilitating disorder, whose incidence peak in the age group of 30-39 years overlaps with the peak of employment years, potentially representing a significant issue for occupational physicians (OP). The present study was performed in order to characterize their knowledge, attitudes and practices on migraine in the workplaces. Materials and Methods: A convenience sample of 242 Italian OP (mean age 47.8 +/- 8.8 years, males 67.4%) participated in an internet-based survey by completing a structured questionnaire. Results: Adequate general knowledge of migraine was found in the majority of participants. Migraine was identified as a common and severe disorder by the majority of respondents (54.0% and 60.0%). Overall, 61.2% of participants acknowledged migraine as difficult to manage in the workplace, a status that made it more likely for OP understanding its potential frequency (Odds Ratio [OR] 3.672, 95% confidence interval [95%CI] 1.526-8.831), or reported previous managing of complicated cases requiring conditional fitness to work judgement (OR 4.761, 95%CI 1.781-2.726). Moreover, professionals with a qualification in occupational medicine (OR 20.326, 95%CI 2.642-156.358), acknowledging the difficult managing of migraine in the workplaces (OR 2.715, 95%CI 1.034-7.128) and having received any request of medical surveillance for migraine (OR 22.878, 95%CI 4.816-108.683), were more likely to recommend specific requirements for migraineur workers. Conclusions: Migraine was recognized as a common disorder, but also as a challenging clinical problem for OP. Participating OP exhibited a substantial understanding of migraine and its triggers, but residual false beliefs and common misunderstanding may impair the proper management of this disorder, requiring improved and specifically targeted interventions