Comparison between an optical pressure standard based on multi-reflection interferometric technique and conventional primary standards

An optical pressure standard, based on a multi-reflection interferometric technique, has been recently developed. This quantum-based standard realizes the pascal through the measurement of the refractive index of a gas by an unbalanced homodyne interferometer and it is currently capable of measuring gas pressure with a relative uncertainty of 10 ppm at 100 kPa. The performance of such optical-based standard have been preliminary evaluated by comparing it with two conventional primary pressure standards, namely a force balanced piston gauge and a pressure balance, in the range from 400 Pa to 120 kPa. This work describes the performed study and discusses the results, which demonstrated the agreement between the optical pressure standard and the conventional standards in the considered range, within their related uncertainties (k = 1)

Multivariate Approaches Boosting Lithium‐Mediated Ammonia Electrosynthesis in Different Electrolytes

Ammonia electrosynthesis through the lithium-mediated approach has recently reached promising results towards high activity and selectivity in aprotic media, reaching high Faradaic efficiency (FE) values and NH3 production rates. To fasten the comprehension and optimization of the complex lithium-mediated nitrogen reduction system, for the first time a multivariate approach is proposed as a powerful tool to reduce the number of experiments in comparison with the classical one-factor-at-a-time approach. Doehlert design and surface response methodology are employed to optimize the electrolyte composition for a batch autoclaved cell. The method is validated with the common LiBF4 salt, and the correlations between the FE and the amount of lithium salt and ethanol as proton donor are elucidated, also discussing their impact on the solid electrolyte interphase (SEI) layer. Moreover, a new fluorinated salt is proposed (i.e., lithium difluoro(oxalate) borate (LiFOB)), taking inspiration from lithium batteries. This salt is chosen to tailor the SEI layer, with the aim of obtaining a bifunctional interfacial layer, both stable and permeable to N2, the latter being an essential characteristic for batch systems. The SEI layer composition is confirmed strategic and its tailoring with LiFOB boosts FE values

Design and development of the Moore three axis measuring machine control system

The aim of this work is to update an existing interferometric three-axis measuring machine, used for measuring diameters and optical scales, by completely re-designing and implementing a new control system. The project involves the integration of new motors and drivers, along with the development of a C++ software program to manage the instrumentation. The upgraded machine features an advanced movement system and instruments for reading environmental parameters, which are crucial for calculating the refractive index of air for the correction of the laser wavelength and for compensating thermal errors. By incorporating these innovations, this research aims to minimize uncertainty in both positioning and interferometric measurements of the samples, thereby enhancing the reliability, traceability to the International System of Units (SI) and precision of the measurements. This technical report will explore the challenges encountered during the modernization process, including the selection of appropriate components and the calibration of the system. Additionally, it will present the methodologies employed to ensure accurate data acquisition and processing. Finally, this work aims to optimize the performance of the renewed measuring machine, improving the quality and the timing of the calibration service provided and opening the way to novel precise geometric measurements in various research applications (e.g. semiconductor, automotive, energy, etc.)

Analysis of ageing effects on static gas meters

Static gas meters are currently being installed in increasing quantities within gas distribution networks across Europe due to their up-to-date technology which intrinsically allows to comply with current requests from Normation and fiscal bodies; on the other hand, the technology on which such meters are based is still relatively new, therefore confidence in it must be built. In particular, for instance in Italy, regulation agencies require more frequent verification of static meters with respect to “classical” technology meters due to the lack of information about their long-term stability. In the present paper, we present a study about the effects of ageing on static gas meters, that was performed based on the calibration of over 1500 G25 gas meters based on thermal (CTTMF - Capillary Type Thermal Mass Flowmeter) technology after 8 years from their installation; the size of the sample and its remarkable homogeneity provides a good level of confidence in the validity of the conclusions. We will show that most of the meters provided a response within legal limits, and that a very high percentage of them largely outperformed the requests. The technical reasons behind this performance and its implications for the evaluation of the capabilities of CTTMF technology will be discussed

Towards high-performance dye-sensitized solar cells by utilizing reduced graphene oxide-based composites as potential alternatives to conventional electrodes: A review

Dye-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

An Approach for Reliable Calibrations of Ultra-high Value Resistors with the Dual Source Bridge

At the Istituto Nazionale di Ricerca Metrologica (INRiM), an approach for reliably calibrating ultra-high-value resistors with the dual source bridge (DSB) is proposed as part of the INRiM knowledge transfer task. This approach is particularly suitable for commercial DSBs, which can be used by electrical calibration laboratories for their activities for external clients. The approach is based on ratio measurements, metrological triangulation rule and measurement compatibility. The proposed reliable calibration value is the corrected weighted mean of three intermediate calibration values which must satisfy a strict triangulation rule and be compatible within small uncertainties. This approach helps to reduce systematic errors or to include them into the uncertainty of the corrected weighted mean. For this paper the method was applied to three high value resistors using a commercial DSB to obtain a reliable calibration value of a 1 PX resistor. This technique meets the requirements of the EN 17025 standard for risk assessment of calibration activities

A Concise Overview of the Use of Low-Dimensional Molybdenum Disulfide as an Electrode Material for Li-Ion Batteries and Beyond

The urgent demand for sustainable energy solutions in the face of climate change and resource depletion has catalyzed a global shift toward cleaner energy production and more efficient storage technologies. Lithium-ion batteries (LIBs), as the cornerstone of modern portable electronics, electric vehicles, and grid-scale storage systems, are continually evolving to meet the growing performance requirements. In this dynamic context, two-dimensional (2D) materials have emerged as highly promising candidates for use in electrodes due to their layered structure, tunable electronic properties, and high theoretical capacity. Among 2D materials, molybdenum disulfide (MoS2) has gained increasing attention as a promising low-dimensional candidate for LIB anode applications. This review provides a comprehensive yet concise overview of recent advances in the application of MoS2 in LIB electrodes, with particular attention to its unique electrochemical behavior at the nanoscale. We critically examine the interplay between structural features, charge-storage mechanisms, and performance metrics—chiefly the specific capacity, rate capability, and cycling stability. Furthermore, we discuss current challenges, primarily poor intrinsic conductivity and volume fluctuations, and highlight innovative strategies aimed at overcoming these limitations, such as through nanostructuring, composite formation, and surface engineering. By shedding light on the opportunities and hurdles in this rapidly progressing field, this work offers a forward-looking perspective on the role of MoS2 in the next generation of high-performance LIBs

Magnetic Resonance-Based Electric Properties Tomography via Green’s Integral Identity

A new approach to Magnetic Resonance-based Electric Properties Tomography (EPT) is presented. The method applies Green's integral identity to the equation that regulates the EPT problem. The resultant integral equations are used to impose the consistency of the measured values of the radiofrequency field. This is achieved by seeking dielectric properties values that allow satisfying the identity within suitable kernels of voxels. In each kernel, an overdetermined system of equations is written, and the corresponding problem is solved in the least squares sense, providing an index of trustworthiness of the solution. Both the complete formulation and its phase-based approximation are presented. The application of a filter, which post-processes the raw results based on the index of trustworthiness, is also discussed. The performance of the method is evaluated on synthetic data and experimental measurements acquired on a heterogeneous brain phantom and on four human volunteers. The reconstructions are compared to those produced through a Helmholtz-EPT with adaptive kernel. The new EPT method performs well in all tests