Istituto Nazionale di Ricerca Metrologica
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Life cycle assessment of passive radiative cooling materials
Full text linkPassive cooling has been a subject of research interest for decades, due to its ability to provide low-cost heat rejection. Recently, the science of passive radiative cooling materials has shown rapid progress, with the synthesis of raw materials that exhibit lower-than-ambient temperature even under direct sunlight, which however requires the use of pigments at very high-volume fractions. As the development of these materials is still in the research stage, it is important to have a deeper understanding of their environmental impact. For this purpose, in this study, a life cycle assessment is performed on different compositions of materials that have shown the potential for passive cooling under full sunshine with high emissivity and reflectance The compositions studied are based on calcium carbonate, barium sulphate, P(VDF-HPF) and P(FA) polymers, with a life cycle assessment focused on the production of these materials. The results indicate that polymer-based material shows the highest environmental impact due to the use of PFA. In the meantime, the lower footprint is found for the calcium carbonate used as the base and water and ethanol as solvents. Overall, for the future fabrication of passive radiative cooling materials, it is suggested to use materials that do not require extensive processing and are abundant. Finally, organic solvents should be replaced by more environmentally friendly substances
Self-organizing neuromorphic nanowire networks as stochastic dynamical systems
Full text linkNeuromorphic computing aims to develop hardware platforms that emulate the effectiveness of our brain. In this context, brain-inspired self-organizing memristive networks have been demonstrated as promising physical substrates for in materia computing. However, understanding the connection between network dynamics and information processing capabilities in these systems still represents a challenge. In this work, we show that neuromorphic nanowire network behavior can be modeled as an Ornstein-Uhlenbeck process which holistically combines stimuli-dependent deterministic trajectories and stochastic effects. This unified modeling framework, able to describe main features of network dynamics including noise and jumps, enables the investigation and quantification of the roles played by deterministic and stochastic dynamics on computing capabilities of the system in the context of physical reservoir computing. These results pave the way for the development of physical computing paradigms exploiting deterministic and stochastic dynamics in the same hardware platform in a similar way to what our brain does
Enabling data-driven design of block copolymer self-assembly
Full text link: Here we present a database composed of scanning electron microscope images of self-assembled block copolymers. The fabrication process parameters, structural properties and microscope information are all contained in the image metadata, making a group of images a database on its own. This approach has numerous advantages including ease of sharing, reusability of information and resilience against user errors. This database follows the digital International System of Units principles and is complemented by a graphical user interface for process metadata insertion and an automated algorithm for image analysis to retrieve structural properties of the nanostructures. Databases such as this one, together with data-driven approaches, enable users to rationally design new materials with the desired properties by understanding the relationship between fabrication parameters and material structure. The here reported database, that contains around 1747 images of lamellar phase and lying down cylinders self-assembled block copolymers along with associated metadata, is structured so it can be continuously expanded by the research community including also samples with different block copolymers morphologies
Progettazione e realizzazione particolari meccanici per sospensione bombole comparatore Gas Massa
No full textAnalisi delle attività INRiM inerenti i servizi metrologici nel 2024
No full textQuesto rapporto tecnico descrive i numeri dell’attività dell’INRiM nel 2024 concernente tarature e prove, confronti di misure fra laboratori (ILC), produzione di materiali di riferimento, attività di prova per l'Associazione per la Certificazione delle Apparecchiature Elettriche (ACAE) e la fornitura di documentazione tecnica e servizi su contratto, utilizzando sia metodi standardizzati che metodi sviluppati internamente. Queste attività sono ascrivibili al ruolo di Istituto Metrologico Primario (ruolo IMP). Tali attività sono conformi alla norma ISO/IEC 17025:2017, Opzione A, per le attività di taratura e prova, alla norma ISO 17034:2016 per la produzione di materiali di riferimento certificati, e alla norma ISO/IEC 17043:2023 per i fornitori di confronti di misure fra laboratori (ILC). Nel 2024, l’INRiM ha mantenuto 448 Capacità di Taratura e Misura (CMC) e ha emesso 1659 certificati di taratura e misura, 84 rapporti di prova e relazioni e 81 rapporti di confronti di misure fra laboratori (ILC)
Enhanced Photoluminescence in a Neuromorphic 2D Memitter Based on WS2 via Plasmonic Nanoparticle Self-Assembly
Full text linkAll-optical neuromorphic devices based on adaptive two-dimensional (2D) materials have the potential for mimicking the complex processing and memory capabilities of biological synapses. Recent research demonstrated synaptic plasticity and visual memory in WS2 monolayer-based 2D memitters (i.e., an emitter with memory). However, improving their optical performances is crucial for extending their scalability. Since the neuromorphic functionalities of 2D memitters relies on O2 and H2O desorption/absorption on WS2, a careful balance between photoluminescence intensity and surface preservation is critical. Here, we investigate the enhancement of time-dependent photoluminescence response, achieved through coupling WS2 flakes with plasmonic nanoparticles obtained by liquid phase infiltration of gold in self-assembled block copolymer micelles. The localized surface plasmon resonance of gold nanoparticles amplifies the electric field and improves light-matter interactions. This method enhances the 2D memitter optical properties while preserving its adaptive photoluminescence response, thus enabling neuromorphic behavior under optical stimuli
Evaluation of the influence of rain on air surface temperature measurements
Full text linkReliable measurements of surface air temperature are crucial in meteorology and climatology. Thermometers must be shielded to avoid atmospheric influence factors, such as solar radiation and rainfall, compromise their accuracy. In the standard document ISO 17 714, which defines test methods for performance comparison of different screens, potential error sources caused by rainfall are mentioned. Besides the well-known psychrometric effect, an error on the temperature reading related to the difference between air and rain temperature causing heat transfer from water to the thermometer is identified. Despite the high relevance, no studies are available in literature that analyze this effect. The work described in this paper aims at quantifying the influence of the rain on the readings of temperature sensors, with radiation screens of different types. The study was performed by introducing an artificial rainfall generator where the water temperature and rain intensity was controlled and comparing the readings of thermometers under the generated rainfall with respect to a developed reference system not affected by rain. The tests show that the error for especially naturally ventilated thermometers can be unacceptably large, up to -4.0 (0.2) K, whereas for the artificially ventilated air thermometers the errors observed are less significant, smaller than -1.1 (0.2) K. This preliminary study underscores the critical influence of rain temperature and intensity on thermometer readings and highlights the importance of further research to develop standardized testing protocols. The reported methodology can also help to develop future standardized test protocol to qualify the device with regards to the measurement error
Composite Raman-Nath heterodyne interferometry with relevance for precise spectroscopy
Full text linkTest di contatori di energia elettrica in condizioni di power quality registrate sul campo
No full textPresso l'INRIM è operativo un sistema di taratura e verifica dei contatori di energia elettrica attiva. Il sistema consente di effettuare test anche in condizioni di bassa power quality. Sono stati implementati sia test con forme d'onda standard secondo normativa vigente, sia test in condizioni reali, campionate da impianti elettrici in condizioni operative. I risultati su contatori commerciali da impianto mostrano che la conformità a test effettuati con forme d'onda specificate in normativa non sempre garantisce il buon funzionamento in condizioni operative