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Ottimizzazione del sistema di diluizione dinamica per la produzione di miscele dinamiche di gas
No full textIl sistema per la diluizione dinamica in uso presso il laboratorio “Miscele gravimetriche e analisi organica” dell’INRiM consente di generare miscele di gas pronte all'uso alla frazione molare desiderata, partendo da una miscela di gas maggiormente concentrata (o premiscela) e da un gas matrice. Questo lavoro ha lo scopo di descrivere il lavoro svolto e i risultati ottenuti dalla messa in funzione e ottimizzazione del sistema di diluizione dinamica per la generazione di miscele gassose a frazione molare e composizione isotopica note di biossido di carbonio, in matrice di azoto o aria sintetica.
Il sistema di diluizione dinamica nella versione ottimizzata sarà usato per la taratura di analizzatori a infrarossi non dispersivi (NDIR), per la verifica analitica della frazione molare di miscele gassose di CO2 mediante l’NDIR tarato e per la determinazione della composizione isotopica (δ13C) in miscele di CO2 mediante lo spettrometro FTIR (Fourier-Transform Infrared Spectroscopy). Il sistema ottimizzato consentirà di ridurre i tempi e il consumo di gas nelle suddette procedure di taratura e verifica.
Il punto focale del presente RT è stato quello di stabilire i tempi necessari per raggiungere una risposta stabile delle letture dell’NDIR per le miscele gassose generate, considerando le diverse portate di ingresso alla camera di miscelazione.The dynamic dilution system of the INRiM laboratory "Gravimetric mixtures and organic analysis" is used to generate ready-to-use gas mixtures with the desired mole fraction, starting from a more concentrated gas mixture (premixture) and a matrix gas. This work aims to describe the work done and the results obtained from the optimization of the dynamic dilution system for the generation of gas mixtures with known mole fraction and isotopic composition of carbon dioxide in a matrix gas of nitrogen or synthetic air.
The dynamic dilution system in the optimized version will be used to speed up the procedure for the calibration of the Non-Dispersive InfraRed analyzers (NDIR), the analytical verification of the CO2 molar fraction of the gas mixtures with the calibrated NDIR, and the determination of the isotope composition of δ 13C in the CO2 of the mixtures with the Fourier-Transform Infrared Spectroscopy (FTIR) instrument.
The focal point of the present Technical Report was to establish the needed times to reach a stable response of the NDIR readings for the generated gas mixtures, considering the different input flow rates to the mixing chamber
Temperature Tunable 4D Polymeric Photonic Crystals
Get PDFPhotonic crystals owe their multitude of optical properties to the way their structure creates interference effects. It is therefore possible to influence the photonic response by acting on their physical structure. In this article, tunable photonic crystals made by elastic polymers that respond to their environment are explored, in particular with a physical deformation under temperature variation. This creates a feedback process in which the photonic response depends on its physical structure, which itself is influenced by the environmental changes. By using a multi-photon polymerization process specifically optimized for soft responsive polymers such as Liquid Crystalline Networks, highly resolved, reproducible, and mechanically self-standing photonic crystals are fabricated. The physical structure of the 3D woodpile can be tuned by an external temperature variation creating a reversible spectral tuning of 50 nm in the telecom wavelength range. By comparing these results with finite element calculations and temperature induced shape-change, it is confirmed that the observed tuning is due to an elastic deformation of the structure. The achieved nanometric patterning of tunable anisotropic photonic materials will further foster the development of reconfigurable photonic crystals with point defects acting as tunable resonant cavities and, more in general, of 4D nanostructures
Magnesium-Vacancy Optical Centers in Diamond
Get PDFWe provide the first systematic characterization of the structural and photoluminescence properties of optically active centers fabricated upon implantation of 30-100 keV Mg+ ions in synthetic diamond. The structural configurations of Mg-related defects were studied by the electron emission channeling technique for short-lived, radioactive Mg-27 implantations at the CERN-ISOLDE facility, performed both at room temperature and 800 degrees C, which allowed the identification of a major fraction of Mg atoms (similar to 30 to 42%) in sites which are compatible with the split-vacancy structure of the MgV complex. A smaller fraction of Mg atoms (similar to 13 to 17%) was found on substitutional sites. The photoluminescence emission was investigated both at the ensemble and individual defect level in the 5-300 K temperature range, offering a detailed picture of the MgV-related emission properties and revealing the occurrence of previously unreported spectral features. The optical excitability of the MgV center was also studied as a function of the optical excitation wavelength to identify the optimal conditions for photostable and intense emission. The results are discussed in the context of the preliminary experimental data and the theoretical models available in the literature, with appealing perspectives for the utilization of the tunable properties of the MgV center for quantum information processing applications
EM-K13.a and b DC electrical Resistance Key Comparisons between INRIM and BIPM on 1 Ω and 10 kΩ Resistors
Get PDFThe technical report deals with the comparison BIPM.EM-K13.a (1 Ω standards) and
BIPM.EM-K13.b (10 kΩ standards) between the Bureau International des Poids et Mesures
(BIPM), acting as pilot laboratory, and the National Research Institute (INRIM). The comparison took part from October 2022 to February 2023, with initial and return
measurements at the BIPM. The differences between the results of INRIM and of BIPM were
within their expanded uncertainties. In particular these differences were: (−0.074 ± 0.134)×10–6 and (−0.045 ± 0.174)×10−6 respectively at 1 Ω and 10 kΩ at 2σ confidence leve
Study of the uncertainty behaviour for the specific total enthalpy of the hypersonic plasma wind tunnel scirocco at CIRA
Get PDFIn the mid eighties the European Space Agency (ESA) realizes the need of a particular facility to
carry out experimental ground tests. The intention was to realize a large Plasma Wind Tunnel, very
powerful, in order to test full scale component of spacecrafts in earth atmosphere re-entry conditions.
Indeed, in hypersonic, differently from other aerodynamic regimes, the heat fluxes distribution is
affected by the absolute sizes of the bodies inside the flow field. This means that it is not possible to
apply scaling factors, and so the possibility to have large size models in these plasma wind tunnels is
a huge advantage
Conferma Metrologica 2023 dei Sistemi di misura dei Parametri “S” in connessione N e nel campo di frequenza da 9 kHz a 18 GHz
No full textIn questo rapporto tecnico si descrivono le operazioni di Conferma Metrologica dei Sistemi di misura dei Parametri “S” in connessione N nel campo di frequenza da 9 kHz a 18 GHz.
Il risultato di queste operazioni è la determinazione dell’Indice di Compatibilità che, se <1 in valore assoluto, valida il sistema di misura INRIM
