Istituto Nazionale di Ricerca Metrologica
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PRIMARY CALIBRATION SYSTEMS FOR MULTICOMPONENT FORCE, MOMENT AND VIBRATION TRANSDUCERS
No full textIn recent decades, there has been a significant rise in the need for mechanical multicomponent transducers, in particular for the measurement of forces, moments and vibrations. These types of devices are commonly employed in various fields, including industrial automation, civil and aerospace engineering, and machine operations and applications in quality and production engineering. However, a specific traceability chain for these types of transducers is still lacking, internationally, along with standardized calibration methods. For this reason, their traceability is becoming increasingly necessary, as well as a current priority, as indicated in the emerging metrology requirements for the future in the strategy documents of the relevant Consultative Committees of BIPM [1,2]. The main problems related to the calibration of these transducers are the simultaneous generation of different components necessary to represent the typical use of these transducers, the costs in developing ad-hoc calibration machines, the large number of tests to get a suitable experimental plan to reach the lowest required uncertainty level and the lack of suitable calibration and uncertainty assessment procedure. At INRiM, multicomponent transducers, systems and methods for their calibration are under development. Such procedures allow to simultaneously evaluate the main and transverse (or cross-talk) sensitivities, thus providing the required metrological traceability, in static and dynamic domains. These systems involve the use of force or vibration primary reference standards integrated with tilted plates. Preliminary experiments showed consistent results. The feasibility of these systems can be exploited in the future to improve the current standards
Calibration of high accuracy accelerometers for ESA missions BepiColombo and JUICE at INRIM
Get PDFHigh sensitive triaxial accelerometers are used in several space missions to measure the
non-gravitational accelerations acting on the spacecraft. Among these, the capacitive
accelerometers developed for ESA missions Jupiter Icy moons Explorer (JUICE) and
BepiColombo were designed to measure accelerations of the order of 3 · 10−6 m s−2 with an
accuracy level of 300 ppm in the frequency range (3 · 10−5–0.1) Hz. Despite the signal to be
measured is of the same order of magnitude of the seismic noise on the earth, an accurate
on-ground calibration is needed. The facility set-up at INRIM to this purpose is based on a
simple principle: the base of the accelerometer is dynamically tilted by an angle α so that the
sensor undergoes a component of the gravitational acceleration g proportional to angle α. In
practice, several issues have to be addressed by the calibration facility, such as the seismic noise
limiting the signal-to-noise ratio, the generation and the accurate measurement of the tilt angle.
Furthermore, the calibration was performed taking into account different on-flight conditions
such as different operating temperatures and possible deformation of the accelerometers during
the launch. The experimental set-up and the calibration procedure are described in the paper.
The measurement results and the uncertainty budget show that a relative accuracy of 240 ppm
has been achieved
Regole di triangolazione per l’analisi di misure di elevatissima resistenza
Get PDFPresso l'Istituto Nazionale di Ricerca Metrologica, è stato ottimizzato un ponte di misura
commerciale di elevata resistenza elettrica mediante l'applicazione della Varianza di Allan e della
Densità Spettrale di Potenza. Questo ponte è basato su un ponte di Wheatstone modificato con due
calibratori di tensione e un rilevatore di zero (picoamperometro) per verificarne il bilanciamento. Il
metodo di misura su cui si basa è ampiamente descritto in letteratura. Questi strumenti statistici
hanno contribuito ad ottenere la miglior precisione per i rapporti di resistenza da 10 Tohm a 100 Tohm. La
procedura di misura che prevede più sessioni, in ognuna delle quali viene aggiornato il valore del
resistore in taratura, è stata ritenuta la migliore in termini di accuratezza
Biomimetic Electrospun Scaffold-Based In Vitro Model Resembling the Hallmarks of Human Myocardial Fibrotic Tissue
Get PDFAdverse remodeling post-myocardial infarction is hallmarkedbythe phenotypic change of cardiac fibroblasts (CFs) into myofibroblasts(MyoFs) and over-deposition of the fibrotic extracellular matrix (ECM)mainly composed by fibronectin and collagens, with the loss of tissueanisotropy and tissue stiffening. Reversing cardiac fibrosis representsa key challenge in cardiac regenerative medicine. Reliable in vitro models of human cardiac fibrotic tissue could beuseful for preclinical testing of new advanced therapies, addressingthe limited predictivity of traditional 2D cell cultures and animal in vivo models. In this work, we engineered a biomimetic in vitro model, reproducing the morphological, mechanical,and chemical cues of native cardiac fibrotic tissue. Polycaprolactone(PCL)-based scaffolds with randomly oriented fibers were fabricatedby solution electrospinning technique, showing homogeneous nanofiberswith an average size of 131 +/- 39 nm. PCL scaffolds were thensurface-functionalized with human type I collagen (C1) and fibronectin(F) by dihydroxyphenylalanine (DOPA)-mediated mussel-inspired approach(PCL/polyDOPA/C1F), in order to mimic fibrotic cardiac tissue-likeECM composition and support human CF culture. BCA assay confirmedthe successful deposition of the biomimetic coating and its stabilityduring 5 days of incubation in phosphate-buffered saline. Immunostainingfor C1 and F demonstrated their homogeneous distribution in the coating.AFM mechanical characterization showed that PCL/polyDOPA/C1F scaffolds,in wet conditions, resembled fibrotic tissue stiffness with an averageYoung's modulus of about 50 kPa. PCL/polyDOPA/C1F membranessupported human CF (HCF) adhesion and proliferation. Immunostainingfor alpha-SMA and quantification of alpha-SMA-positive cells showedHCF activation into MyoFs in the absence of a transforming growthfactor beta (TGF-beta) profibrotic stimulus, suggesting theintrinsic ability of biomimetic PCL/polyDOPA/C1F scaffolds to sustainthe development of cardiac fibrotic tissue. A proof-of-concept studymaking use of a commercially available antifibrotic drug confirmedthe potentialities of the developed in vitro modelfor drug efficacy testing. In conclusion, the proposed model was ableto replicate the main hallmarks of early-stage cardiac fibrosis, appearingas a promising tool for future preclinical testing of advanced regenerativetherapies
Taratura vibrometri secondo la norma ISO 16063-41 “Methods for the calibration of vibration and shock transducers Part 41: Calibration of laser vibrometers"
No full textEMN Quantum Strategic Agenda
Get PDFBy 2030 quantum technologies will be ubiquitous, but we are not there yet. Today quantum technologies are being steadily deployed into mainstream marketplaces, with both large and start-up companies beginning to develop and integrate quantum devices into their product lines.
Enhancing confidence in these technologies is essential to their success. This in turn relies on validation and certification, based on internationally agreed standards and metrological traceability, implemented by independent experts. EURAMET ́s European Metrology Network for Quantum Technologies supports this technological transformation
Study of the nonlinear dynamics of Josephson Traveling Wave Parametric Amplifiers
No full textRecent advances in quantum technologies have highlighted the need to detect extremely weak microwave signals. To this end, the Josephson travelling-wave parametric amplifier has been proposed as a cutting-edge cryogenic amplifier. This work deals with the numerical study of this device without approximating the nonlinearity of the key elements. In addition to the expected signal amplification we observe, depending on the operating mode of the system, undesirable effects (such as pump tone
harmonics, generation of incommensurate frequencies and
noise increase), which are not considered in the usual simplified approaches