Publications

Extremely robust cohesion triggered by calcium silicate hydrate (C-S-H) precipitation during cement hardening makes concrete one of the most commonly used man-made materials. Here, in this proof-of-concept study, we seek an additional nanoscale understanding of early-stage cohesive forces acting between hydrating model tricalcium silicate (C3S) surfaces by combining rheological and surface force measurements. We first used time-resolved small oscillatory rheology measurements (SAOSs) to characterize the early-stage evolution of the cohesive properties of a C3S paste and a C-S-H gel. SAOS revealed the reactive and viscoelastic nature of C3S pastes, in contrast with the nonreactive but still viscoelastic nature of the C-S-H gel, which proves a temporal variation in the cohesion during microstructural physicochemical rearrangements in the C3S paste. We further prepared thin films of C3S by plasma laser deposition (PLD) and demonstrated that these films are suitable for force measurements in the surface force apparatus (SFA). We measured surface forces acting between two thin C3S films exposed to water and subsequent in situ calcium silicate hydrate precipitation. With the SFA and SFA-coupled interferometric measurements, we resolved that C3S surface reprecipitation in water was associated with both increasing film thickness and progressively stronger adhesion (pull-off force). The lasting adhesion developing between the growing surfaces depended on the applied load, pull-off rate, and time in contact. These properties indicated the viscoelastic character of the soft, gel-like reprecipitated layer, pointing to the formation of C-S-H. Our findings confirm the strong cohesive properties of hydrated calcium silicate surfaces that, based on our preliminary SFA measurements, are attributed to sharp changes in the surface microstructure. In contact with water, the brittle and rough C3S surfaces with little contact area weather into soft, gel-like C-S-H nanoparticles with a much larger surface area available for forming direct contacts between interacting surfaces.

Exploiting robots for activities in human-shared environments, whether warehouses, shopping centres or hospitals, calls for such robots to understand the underlying physical interactions between nearby agents and objects. In particular, modelling cause-and-effect relations between the latter can help to predict unobserved human behaviours and anticipate the outcome of specific robot interventions. In this paper, we propose an application of causal discovery methods to model human-robot spatial interactions, trying to understand human behaviours from real-world sensor data in two possible scenarios: humans interacting with the environment, and humans interacting with obstacles. New methods and practical solutions are discussed to exploit, for the first time, a state-of-the-art causal discovery algorithm in some challenging human environments, with potential application in many service robotics scenarios. To demonstrate the utility of the causal models obtained from real-world datasets, we present a comparison between causal and non-causal prediction approaches. Our results show that the causal model correctly captures the underlying interactions of the considered scenarios and improves its prediction accuracy.

It is obvious that SCMs (supplementary cementitious materials) have diverse effects on the physical and chemical properties that can contribute in the development of the mechanical performance of cementitious materials. Moreover, the key factor to better use SCMs in blended cements is to control their fresh state properties. However, limited literature is available on the influence of SCMs on the rheological behavior of fresh pastes. In light of the increasing interest concerning the fresh state properties of hydraulic binders based SCMs, this contribution reports the rheological behavior of various hydraulic binders based GGBS (ground granulated blast-furnace slag), FA (fly ash), limestone or calcined clays, and explore the factors influencing the particle interactions during the structural build-up/breakdown process when stress is applied to the system. Yield stress and elastic modulus are considered to be the main indicators to quantify the structural changes of sheared fresh pastes. By introducing functionalized (–COO-) nanocellulose fibrils, the ability of water retention due to the hydrophilic character has reduced the mixing water in the fresh GGBS paste leading to the increase in the yield stress and viscosity. The use of limestone has increased the yield stress and elastic modulus of the cement paste. The angular shape of limestone particles and the filler effect can increase the friction and compact the cement suspensions leading to the loss of workability. However, the combination of limestone and FA can promote the fluidity of the paste due to the spherical shape of FA particles. On the other hand, when it is combined with calcined clays, limestone has a dilution effect leading to the reduction of the yield stress and elastic modulus of calcined clays blended cement at an early age while, the chemical equilibrium of limestone and calcined clays can provide strong structure network of the system and an increase in the yield stress and elastic modulus of the paste with time. However, calcined clays can reduce the mixing water in the slurry that can prevent the workability for extended durations.

This paper presents a workflow and digital filters for compensating speed and equalization errors that can impact digitized audio open-reel tapes. Thirty cases of mismatch between recording and reproducing speed (3.75, 7.5, 15, and 30 in/s) and equalization standards [National Association of Broadcasters (NAB), Consultative Committee for International Radio (CCIR) and Audio Engineering Society) were considered. For three frequent cases of mismatch (NAB 3.75 in/s-CCIR 7.5 in/s; NAB 3.75 in/s-CCIR 15 in/s; and NAB 7.5 in/s-CCIR 15 in/s) Multiple Stimuli with Hidden Reference and Anchor-inspired tests with ≥21 participants assessed the workflow and digital filters. using excerpts of music and voice. Two different corection filters were used, both of which provided promising results. Following this subsequent analyses examined predictive variables for correct and incorrect Multiple Stimuli with Hidden Reference and Anchor performance, as well as spectral and numerical differences between filters, which provide key insights and recommendations for further related work.

Coronavirus disease (COVID-19) has been a source of fear around the world. We asked whether the measurement of this fear is trustworthy and comparable across countries. In particular, we explored the measurement invariance and cross-cultural replicability of the widely used Fear of COVID-19 scale (FCV-19S), testing community samples from 48 countries (N = 14,558). The findings indicate that the FCV-19S has a somewhat problematic structure, yet the one-factor solution is replicable across cultural contexts and could be used in studies that compare people who vary on gender and educational level. The validity of the scale is supported by a consistent pattern of positive correlations with perceived stress and general anxiety. However, given the unclear structure of the FCV-19S, we recommend using latent factor scores, instead of raw scores, especially in cross-cultural comparisons.

This paper discusses historical-critical thought to address the problems of restoration and preservation of tape music, proposing viable solutions to the matter of digitizing the historically valuable data that exists on and is represented by magnetic tapes. A detailed program of research and restoration and some software for helping in creation of critical editions of the musical works are proposed. We also present some of the issues and controversies that must be considered and approaches we have applied in the preservation of tape music, highlighting how these interpretations can impact later performances (playback) of these tape documents. Fundamentally, we argue that the act of tape music restoration has a parallel with the interpretation of the “Urtext score” in the performance of music from the Common Practice Era.

Moving Picture, Audio and Data Coding by Artificial Intelligence (MPAI) is the first standards organization to develop data coding standards that have artificial intelligence (AI) as their core technology. MPAI believes that universally accessible standards for AI-based data coding can have the same positive effects on AI as standards had on digital media. Elementary components of MPAI standards-AI modules (AIMs)-expose standard interfaces for operation in a standard AI framework (AIF). As their performance may depend on the technologies used, MPAI expects that competing developers providing AIMs will promote horizontal markets of AI solutions that build on and further promote AI innovation. Finally, the MPAI framework licences (FWLs) provide guidelines to intellectual property right (IPR) holders facilitating the availability of compatible licenses to standard users.

In November 2020 a mortality episode (30%) in juvenile Siberian and Russian sturgeons (Acipenser baerii, Brandt, and A. gueldenstaedtii, Brandt & Ratzeburg) and GUBA hybrid sturgeons (A. gueldenstaedtii × A. baerii) occurred in a hatchery in Northern Italy, associated with severe coelomic distension and abnormal reverse surface swimming. The fish were reared in concrete tanks supplied by well water, fed at 0.4% of body weight (b.w.) per day. Thirty sturgeon specimens were collected for necropsy, histological, bacteriological and virological examination. Macroscopic findings included diffuse and severe bloating of gastrointestinal tracts due to foamy contents with thinning and stretching of the gastrointestinal walls. Histological analysis revealed variable degrees of sloughing and necrosis of the intestinal epithelium, and the presence of bacterial aggregates. Anaerobic Gram-positive bacteria were investigated, and Clostridium perfringens was isolated from the gut. Specific PCRs identified the toxinotype A and the β2 toxin gene. The daily feed administration was increased to 1.5% b.w. and after 5 days, the mortality ceased. A new animal cohort from the same groups was examined after 12 weeks, showing neither gut alterations nor isolation of C. perfringens. The imbalance of intestinal microbiota, presumably caused by underfeeding, favoured C. perfringens overgrowth and severe gas formation. The diet increase possibly restored the normal microbiota.

Self-driving vehicles and autonomous ground robots require a reliable and accurate method to analyze the traversability of the surrounding environment for safe navigation. This paper proposes a hybrid approach that combines geometric and appearance features for training Deep Encoder-Decoder architectures to detect the traversability score in real urban contexts. The proposed approach has been tested with two Deep Learning architectures on a public dataset of outdoor driving scenarios. Thanks to our approach, we are able to reach high levels of accuracy in detecting the correct traversability score in environments of highly variable complexity. This demonstrates the effectiveness and robustness of the proposed method.

Oral archives and digital technologies have gone hand-in-hand for a very long time. Both sides benefit from this interdisciplinary junction: technology enhances the preservation and diffusion of oral materials, while exploiting them to develop cutting-edge tools for their treatment. This chapter deals with an Italian instantiation of this mutual relationship: the Archivio Vi.Vo. project. Offering innovative solutions concerning metadata, audio restoration, description, and access, Archivio Vi.Vo. aims to build an online platform to host the oral archives from Tuscany. The project is powered by CLARIN-IT, which guarantees its compliance with standards and offers resources for data access and discoverability. Archivio Vi.Vo. has not been built from scratch: it is instead a crossfertilization of previous initiatives and research projects (e.g., the Gra.fo project). Moreover, the chapter presents the related, contemporary work of a multidisciplinary group striving to synthesize a Vademecum for future generations of oral archive researchers. Lastly, a brief list of tentative ideas for future developments of the Archivio Vi.Vo. platform will be presented.