Istituto Nazionale di Ricerca Metrologica
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Structural, morphological and optical characterization of CdS-doped silica aerogels synthesized through sol-gel method
Full text linkAerogels are highly porous materials characterized by ultra-low density. The incorporation of luminescent materials into silica aerogels results in luminescent aerogels, which have potential applications in light-emitting diodes and optoelectronic devices. In this study, the photoluminescence properties of CdS-doped silica aerogels are reported. The CdS-doped silica aerogels exhibited three distinct emission bands in the blue, green, and red regions. The blue emission is attributed to localized trap states on the CdS surface, while the green emission is associated with sulfur and cation vacancies. The red emission is linked to the substitution of sulfur traps by other counter ions. Supercritical drying of the CdS-doped aerogels resulted in the removal of quantum dots, indicating the non-covalent bonding of CdS nanoparticles to the silica matrix. However, a fraction of the quantum dots remained embedded in the aerogel, as evidenced by weak emission bands and the X-ray diffraction patterns of CdS nanocrystals
Automated DC voltage and DC resistance real-time multiple standard for artifact calibration of calibrators and multimeters
Full text linkAn automated temperature-controlled electrical DC voltage and DC resistance multiple
reference standard (MRS) has been developed by Measurements International (MI) with the scientific
support from the Istituto Nazionale di Ricerca Metrologica (INRIM). The MRS includes a 10V, a 1Ω,
and a 10 kΩ standards selectable via a switch unit. This setup allows the artifact calibration of high-end
calibrators and multimeters used in low-frequency electrical measurements. The two resistors are
high-stability standards from MI, while the 10V standard is based on a low-noise circuit developed by
INRIM in collaboration with MI. A key innovation is the internal real-time clock calendar, which
displays the calibration values of the MRS standards and their updated values internally calculated.
This ensures reliable use of the MRS standards over extended periods between calibrations, effectively
minimizing uncertainties due to their drift. The standards are housed in a thermal box, minimizing
temperature variations. The MRS standards meet the uncertainty requirements defined by calibrators
and multimeters manufacturers for artifact calibration and can also serve as laboratory references or
travelling standards for interlaboratory comparisons (ILCs). MI is currently commercializing the MRS
Towards high-performance dye-sensitized solar cells by utilizing reduced graphene oxide-based composites as potential alternatives to conventional electrodes: A review
Full text linkDye-sensitized solar cells (DSSCs) have recently emerged as one of the most promising new-generation photovoltaic devices due to their facile fabrication protocols, capacity to operate under diffuse light, and low-impact on the environment. However, their low power conversion efficiency (∼15.2%) hinders practical applications. This is primarily owing to ineffective dyes, significant recombination at solid/liquid interfaces, and limitations of TiO2, the conventional photoanode material, especially poor light harvesting and electron transport. Moreover, Pt, the traditional counter electrode material, is costly and unstable due to its scarcity and low corrosion resistance to I3ˉ, respectively. This increases the device cost and shortens its lifespan. Inspired by this, current research interests have shifted their focus from traditional materials to low-cost alternatives, including metal oxides, metal chalcogenides and perovskites, which offer competitive photovoltaic performance. Nonetheless, these alternative materials exhibit relatively low electrical conductivity, which compromises device performance. Thus, to improve device efficiency and sustainability, these materials have recently been coupled with highly conductive and stable carbon nanomaterials, particularly graphene-based materials. Among them, reduced graphene oxide (rGO) has been more appealing due to its compatibility with low-cost solution processing. Therefore, this review highlights the recent advances in DSSC efficiency and sustainability made over the last five-years (2020–2024) by developing TiO2-free photoanodes and Pt-free counter electrodes, in particular, by introducing rGO into metal oxides, metal chalcogenides and perovskites. Challenges and future directions for fabricating TiO2- and Pt-free DSSCs are discussed to close the gap between emerging nanomaterials and their traditional counterparts, thereby setting the stage for commercialization
Presentation of the new EPM 23RPT03 project “Metrology for standardised moisture/water content measurement in plant-origin bulk materials in support of International and European food safety and trade – GrainMet”
No full textThe EPM Project 23RPT03 GrainMet, aims to develop new measurement technologies, SI traceability paths and certified reference materials (CRMs) for plant origin bulk materials, and to transfer this knowledge to NMIs/DIs with emerging metrology systems. GrainMet intends to build capacity, infrastructure and engage with stakeholders in a coordinated fashion to deliver services at local level based on a common knowledge basis. In particular, GrainMet focuses on the development of a method for the water content determination in plant-origin bulk materials, based on volumetric Karl Fisher titration, which has the potential to become a primary method. A CRM for the water content consisting of grain or a derivative thereof, will be developed. Good practice guides, live and e-trainings will be produced and made available for the project stakeholders (e.g. Georgia, Moldova, Ukraine, Austria) to enhance their capabilities and to promote their participation in international trade
Effects of Wheat Bran-Derived Alkylresorcinols on the Physical and Oxidative Stability of Oil-in-Water Emulsions as related to pH
No full textAlkylresorcinols (ARs), a homolog series of phenolipids naturally occurring in many by-products, can meet the high demand of the food industry for natural antioxidants. In this study, ARs (C17–C25) were isolated from wheat bran, and their antioxidant activity was tested in oil-in-water emulsions at pH 3.5 and pH 7.0 at two concentrations (15 and 30 mg/L of emulsion) during 14 days of storage at 35 °C. Results revealed that lipid oxidation was affected by both ARs concentration and pH of the emulsion. Indeed, when ARs were added, a significant suppression of hydroperoxides and aldehydes (hexanal and nonanal) formation with a consequent prolongation of their lag phases (5-fold) was observed at pH 3.5, while at pH 7.0 the lag phases were doubled. No influence of ARs on emulsion particle size was found. The present work demonstrated how ARs could represent sustainable and innovative natural antioxidants for emulsion-based food
Development of testing protocols for the measurement of pure and blended hydrogen in natural gas grids: An outlook from the THOTH2 project
No full textTransporting or blending hydrogen (H2) into the existing gas infrastructure can be crucial in the European green transition. However, the regulation of this matter is still debated by interested stakeholders. The THOTH2 project aims to fill normative gaps by developing new protocols for assessing the limits and tolerances of state-of-the-art (SoA) instrumentation installed in natural gas (NG) transmission and distribution grids. This paper outlines the methodology used for selecting the devices and establishing the testing protocols for the various categories of instruments. These instruments are scheduled for experimental testing in the subsequent phase of the project
Flexible Ceramic Radiative Cooling Membranes with High Reflectivity in Solar Spectrum, Excellent UV and Fire Resistance
No full textTraditional radiative cooling technology, relying on polymers with high solar reflectivity and infrared (IR) emissivity, struggles to fulfill the requirements for building durability and fire resistance because of the polymers' inadequate ultraviolet (UV) aging resistance and flammability. To address this challenge, this work develops a fully inorganic and flexible ceramic membrane exhibiting ultra-high reflectance of 97.8% in the 0.25–2.5 μm solar spectrum and an IR thermal emissivity of 92.3% in the 8–13 μm atmospheric transparent window (ATW) band, for a maximum daytime sub-ambient temperature drop of 9.2 °C and a net radiative cooling power of 128.52 W m−2. At the same time, the flexible ceramic membranes can endure temperatures up to 1000 °C, are non flammable, and exhibit only a 1.2% decrease in solar band reflectance after 552 h of continuous 0.7 kW m−2 UV irradiation. The excellent UV, acid, and fire safety properties of the electrospun ceramic membrane hold promise for their long-term use in outdoor and extreme environments
A memristive computational neural network model for time-series processing
Full text linkIn this work, we introduce a novel computational framework inspired by the physics of memristive devices and systems, which we embed into the context of Recurrent Neural Networks (RNNs) for time-series processing. Our proposed memristive-friendly neural network architecture leverages both the principles of Reservoir Computing (RC) and fully trainable RNNs, providing a versatile platform for sequence learning. We provide a mathematical analysis of the stability of the resulting neural network dynamics, identifying the role of crucial RC-based architectural hyper-parameters. Through numerical simulations, we demonstrate the effectiveness of the proposed approach across diverse regression and classification tasks, showcasing performance that is competitive with both traditional RC and fully trainable RNN systems. Our results highlight the scalability and adaptability of memristive-inspired computational architectures, offering a promising path toward efficient neuromorphic computing for complex sequence-based applications. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC BY-NC-ND) license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
The measurement model of Copernicus TRUSTED Fiducial Reference Measurement drifting buoys for Sea-Surface Temperature
No full textThe European Union’s Copernicus-funded project Toward Fiducial Reference Measurements of Sea Surface Temperature by European Drifters (TRUSTED) has made progress toward fiducial reference measurements (FRMs) from drifting buoys for sea surface temperature (SST). These are a subset of surface drifting buoy measurements commissioned to ensure the quality of very high-accuracy (low uncertainty), climate-quality satellite SST observations. These buoys differ from the standard drifter platform in that they carry an additional TRUSTED Reference Sensor for Temperature (TRST) to comply with the World Meteorological Organization (WMO) agreed specification of High Resolution SST, version 2 (HRSST-2). Among the mandatory characteristics for an FRM, the traceability of measurements and the evaluation of measurement uncertainties are the most important ones, particularly for the validation of satellite data. A measurement uncertainty traceability diagram following metrological best practices has been defined as a first step in establishing a new standard for surface FRM drifting buoy measurements within the TRUSTED project. The derived measurements can be qualified as FRM. The diagram defines all sources of uncertainties, ranging from the calibration of the SST sensor through to the measurements at sea. It then allows a model to be developed that describes and quantifies the detected sources of uncertainties on the measured temperature value and to link this temperature measurement to the International System of Units (SI) with small uncertainties: between 2.5 and 3.5 mK for a TRST and between 5.5 and 6.5 mK for a buoy in the range 2°–35°C
Project on a fully automated evaluation of a virtual comparison of mass using the Digital Calibration Certificate (DCC) schema
No full textof this comparison is to demonstrate a possibility of digital transformation in metrology using an automated
evaluation chain of different tools as well as machine-interpretable files for data transfer and reporting. We
discuss the different tools and exchange formats as well as the performance of the virtual mass comparison in
detail