Istituto Nazionale di Ricerca Metrologica
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Metrological traceability path for marine pCO2 measurement results
Get PDFDespite the increasing availability of sensors for gathering data on the partial pressure of CO2 (pCO2) in the
waters of the world’s seas and oceans, there is a growing awareness within the scientific community of the
pressing need for very high quality measurements of the variable to help monitor the Ocean Acidification threat
and, more generally, the effectiveness of overall global CO2 emission mitigation strategies. This is because
discriminating observed variations ascribable to long-term trends from the ones due to natural fluctuations and
meeting established criteria to reach the “Climate goal” for marine carbonate system research and monitoring
require extremely accurate and traceable pCO2 measurements to be useable. Here, we present some details on
work being done to expand the use of reference-grade CO2 gas mixtures to help calibrate and/or assess the
performances of marine sensors employed for measuring seawater pCO2
Electric field control of magnetization reversal in FeGa/PMN-PT thin films
Get PDFArtificial magnetoelectric materials possess huge potential to be utilized in the development of energy efficient spintronic devices. In the past decade, the search for a good ferromagnetic/ferroelectric combination having the ability to create high magnetoelectric coupling, created new insights and also new challenges. In this report, the magnetoelectric effect is studied in the FeGa/PMN-PT(001) multiferroic heterostructures in the presence of electric fields via strain-mediated effects. The formation of magnetic anisotropy in FeGa is observed after changing the polarization of PMN-PT to out-of-plane orientations. The magnetic domain structures forming during the magnetization reversal were studied in compressive, tensile and remanent strained states. The changes in the magnetic properties were reversible after each cycling of the electric field polarity, hence creating a non-volatile system. The control of magnetization switching sustained by an ON-OFF electric field makes our multiferroic heterostructure suitable for application in low-power magnetoelectric based memory applications
Enhancing coating uniformity and performance with zinc oxide nanoparticles interface layer in dye-sensitized cells
No full textFor over 30 years, dye-sensitized solar cells have been investigated as photovoltaic devices that create a three-dimensional interface among their components. These cells have served as references in exploring new concepts. This study focuses on the impact of a layer of zinc oxide nanoparticles as blocking layers against electron recombination in such solar cells. Various experiments were conducted, including thermal treatments between spin-coating cycles, variations in the number of cycles, and a final thermal treatment. It was observed that the thermal treatment between cycles achieved a more uniform layer and an increase in the open-circuit voltage Voc with each additional cycle. Additionally, cells with nanoparticles showed improvements in the Voc (from 690 to 735 mV) but a reduction in the current density (Jsc) (from 9.5 to 5.5 mA) with more cycles. Those with layers treated at higher temperatures experienced an increase in the Jsc without changing the Voc
Analysis of an Improved Circuit for Laser Chaos and Its Synchronization
Get PDFThe exploration of chaos, synchronization, and circuit implementation in analog simulations unveils a versatile framework with diverse applications. Originating from a universal chaos model rooted in laser physics, its adaptability extends to neural dynamics and random number generation, where both rely on characteristic time scales. Circuit implementations using op-amps and analog multipliers offer tangible avenues for exploration. However, challenges like bias and trajectory distortion drive the need for innovative solutions. Through numerical integration and circuit simulations, analysis of chaotic regimes such as Sub-harmonic Chaos (SC) and Homoclinic Chaos (HC) reveals crucial behaviors for applications like secure communications. Despite experimental hurdles, advancements in circuit design promise novel pathways for chaos synchronization studies. Understanding the intricate interplay between chaos and these systems is vital, given their reliance on characteristic time scales. Additionally, exploring chaos synchronization, especially within analog circuits, shows potential for revolutionizing information processing capabilities, despite inherent challenges. Progress in circuit design persists, forging new avenues in chaos synchronization studies, shaping a dynamic landscape poised for further exploration and innovation
Anomalous Radiative Transfer in Heterogeneous Media
Get PDFMonte Carlo (MC) simulations are the gold standard for describing various transport phenomena and have largely contributed to the understanding of these processes. However, while their implementation for classical transport governed by exponential step-length distributions is well-established, widely accepted approaches are still lacking for the more general class of anomalous transport phenomena. In this work, a set of rules for performing MC simulations in anomalous diffusion media is identified, which is also applicable in the case of finite-size geometries and/or heterogeneous inclusions. The results are presented in the context of radiative transfer, however their implications extend to all types of anomalous transport. The proposed set of rules exhibits full compatibility with the pathlength invariance property for random trajectories, and with the important radiometric concept of fluence. Additionally, it reveals the counter-intuitive possibility of introducing interfaces between independent subdomains with identical properties, which arise from the fact that non-exponential step-length distributions have a “memory” that can in principle be reset when traversing a boundary. These results have far-reaching consequences not just for the physical interpretation of the corrections required to handle these discontinuities, but also for their experimental verification, due to their expected effects on the observable pathlength distributions
Microbial consortia inoculants differently shape ecophysiological and systemic defence responses of field-grown grapevine cuttings
Get PDFDespite microbe-based products for grapevine protection and growth improvement are available, only a few of them contain microbes directly isolated from vine tissues. Here, a collection of endophytic bacterial isolates obtained from grapevine woody tissues was used for producing an ad-hoc inoculum. Bacterial isolates were tested in biocontrol assays against some of the main grapevine pathogens and the seven most performing as biological control agents were selected for a consortium development (SynCom). Before putting them in field, a group of cuttings was inoculated with the developed SynCom, whereas a second one was inoculated with a commercial consortium formed by a mixed inoculum of arbuscular mycorrhizal fungi (AMF) and a rhizosphere Bacillus coagulans bacterial strain (B). After the transplanting in field, eco-physiological parameters were monitored, and samples for biochemical and molecular analyses were collected at the end of the experiment. Integration of physiological data with metabolite and transcriptome profiles have been performed. Results showed that the SynCom slowed down photosynthesis, suggesting a reallocation of energy towards defence pathways. Conversely, the AMF+B treatment led to more balanced physiological performances. Metabarcoding analysis revealed that SynCom-treated plants had a significantly lower abundance of wood-decay pathogens than control or AMF+B plants. Collectively, our findings provide information useful for enabling microbial inoculation exploitation with a refined awareness
Sistema di monitoraggio della pressione atmosferica con Arduino Nano ESP32 e database MySQL
No full textA seguito dell’installazione del nuovo sistema di monitoraggio delle temperature dei
laboratori (Forza, Accelerazione, Durezze) all’interno del padiglione Bray si è deciso di
aggiungere la misura automatica della pressione atmosferica e dell’umidità relativa, finora
condotte manualmente, valori utilizzati in alcune attività di ricerca.
Il sistema è stato sviluppato utilizzando la scheda di sviluppo Arduino Nano con a bordo il
modulo ESP32 che fornisce, tra le altre funzionalità, la connettività Wi-Fi. Tale aspetto è
stato considerato per poter realizzare un dispositivo il più possibile indipendente, compatto
e che potesse interagire con il database dei parametri ambientali già in opera.
La parte di misura è affidata al consolidato modulo BMP180 che restituisce misure di
pressione assoluta e temperatura attraverso il protocollo di comunicazione seriale I2C,
mentre l’umidità relativa è misurata utilizzando l’altrettanto consolidato DHT11.
Il dispositivo effettua le misure ad intervalli di tempo definiti (15 minuti) ottenendo le
informazioni orarie dal server NTP dell’INRiM. Il risultato delle misure viene memorizzato
nello stesso database MySQL su cui sono memorizzati i valori di temperatura dei laboratori
(v. R.T. 28/2023). È inoltre stata introdotta il supporto alla piattaforma Telegram che
consente, tramite un bot e token dedicati, di ottenere le misure e informazioni sullo stato del
dispositivo.
La visualizzazione e ricerca dei dati è affidata alla piattaforma Grafana utilizzata per la
gestione dei dati di temperatura, oltre alla possibilità di visualizzare i dati e inviare comandi
di configurazione tramite terminale seriale collegando direttamente il dispositivo al PC.In the wake of the installation of the new temperature monitoring system for the laboratories
(Force, Acceleration, Hardness) within the Bray pavilion, a decision has been made to
incorporate automatic measurements of atmospheric pressure and relative humidity, which
had previously been conducted manually and are utilized in various research activities.
This system has been developed using an Arduino Nano development board equipped with
an ESP32 module, which, among its myriad functionalities, provides Wi-Fi connectivity. This
feature was deliberately chosen to ensure the creation of a device that is as independent
and compact as possible, while also enabling interaction with the existing environmental
parameters database. The measurement aspect is entrusted to the reliable BMP180
module, which yields absolute pressure and temperature readings via the I2C serial
communication protocol, whereas relative humidity is assessed using the equally
dependable DHT11. The device conducts measurements at predefined time intervals (15
minutes), sourcing hourly data from the NTP server of INRiM. The results of these
measurements are stored in the same MySQL database that houses the laboratory
temperature values (refer to R.T. 28/2023). Support for the Telegram platform has also been
introduced, which allows, through a dedicated bot and token, to obtain measurements and
information on the status of the device.
Data visualization and retrieval are facilitated through the Grafana platform, which manages
temperature data, alongside the capability to visualize data and issue configuration
commands via a serial terminal by directly connecting the device to a PC
Vat photopolymerization of ultra-porous bioactive glass foams
Get PDFThe introduction of additive manufacturing technologies in the field of biomaterials science has opened new horizons for regenerative medicine. In this work, we pushed the potential of vat polymerization to the limit for fabricating ultra-porous bioactive SiO2-CaO-MgO-P2O5-CaF2-Na2O 2-CaO-MgO-P 2 O 5-CaF 2-Na 2 O glass scaffolds with bone-like architectural characteristics. The tomographic reconstruction of an open-cell foam was used as input file to the printing system and reliably reproduced in all its exquisite details, as assessed by morphological analyses of sintered scaffolds (thickness of single struts 35 mu m, exceptionally high porosity around 94 vol%, most pores with size from 500 to 900 mu m). Immersion studies in simulated body fluid (SBF) revealed the apatite-forming ability (i.e., in vitro bioactivity) of the scaffolds, the surface of which started being coated by calcium phosphate after just 3 days from the beginning of the experiments. Taken together, these results show great promise for application of such scaffolds in bone defect repair