National Institute of Metrological Research INRiM

Sant'Ambrogio di Torino, Italy

National Institute of Metrological Research INRiM

Sant'Ambrogio di Torino, Italy

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Jiang Z.,International Bureau of Weights and Measures BIPM | Palinkas V.,Research Institute of Geodesy | Arias F.E.,International Bureau of Weights and Measures BIPM | Liard J.,Natural Resources Canada | And 44 more authors.
Metrologia | Year: 2012

The 8th International Comparison of Absolute Gravimeters (ICAG2009) took place at the headquarters of the International Bureau of Weights and Measures (BIPM) from September to October 2009. It was the first ICAG organized as a key comparison in the framework of the CIPM Mutual Recognition Arrangement of the International Committee for Weights and Measures (CIPM MRA) (CIPM 1999). ICAG2009 was composed of a Key Comparison (KC) as defined by the CIPM MRA, organized by the Consultative Committee for Mass and Related Quantities (CCM) and designated as CCM.G-K1. Participating gravimeters and their operators came from national metrology institutes (NMIs) or their designated institutes (DIs) as defined by the CIPM MRA. A Pilot Study (PS) was run in parallel in order to include gravimeters and their operators from other institutes which, while not signatories of the CIPM MRA, nevertheless play important roles in international gravimetry measurements. The aim of the CIPM MRA is to have international acceptance of the measurement capabilities of the participating institutes in various fields of metrology. The results of CCM.G-K1 thus constitute an accurate and consistent gravity reference traceable to the SI (International System of Units), which can be used as the global basis for geodetic, geophysical and metrological observations of gravity. The measurements performed afterwards by the KC participants can be referred to the international metrological reference, i.e. they are SI-traceable. The ICAG2009 was complemented by a number of associated measurements: the Relative Gravity Campaign (RGC2009), high-precision levelling and an accurate gravity survey in support of the BIPM watt balance project. The major measurements took place at the BIPM between July and October 2009. Altogether 24 institutes with 22 absolute gravimeters (one of the 22 AGs was ultimately withdrawn) and nine relative gravimeters participated in the ICAG/RGC campaign. This paper is focused on the absolute gravity campaign. We review the history of the ICAGs and present the organization, data processing and the final results of the ICAG2009. After almost thirty years of hosting eight successive ICAGs, the CIPM decided to transfer the responsibility for piloting the future ICAGs to NMIs, although maintaining a supervisory role through its Consultative Committee for Mass and Related Quantities. © 2012 BIPM & IOP Publishing Ltd.


Jiang Z.,Bureau International des Poids et Mesures BIPM | Francis O.,University of Luxembourg | Vitushkin L.,Bureau International des Poids et Mesures BIPM | Palinkas V.,Research Institute of Geodesy | And 35 more authors.
Metrologia | Year: 2011

The Bureau International des Poids et Mesures (BIPM), Sèvres, France, hosted the 7th International Comparison of Absolute Gravimeters (ICAG) and the associated Relative Gravity Campaign (RGC) from August to September 2005. ICAG 2005 was prepared and performed as a metrological pilot study, which aimed: To determine the gravity comparison reference values; To determine the offsets of the absolute gravimeters; and As a pilot study to accumulate experience for the CIPM Key Comparisons. This document presents a complete and extensive review of the technical protocol and data processing procedures. The 1st ICAG-RGC comparison was held at the BIPM in 1980-1981 and since then meetings have been organized every 4 years. In this paper, we present an overview of how the meeting was organized, the conditions of BIPM gravimetric sites, technical specifications, data processing strategy and an analysis of the final results. This 7th ICAG final report supersedes all previously published reports. Readings were obtained from participating instruments, 19 absolute gravimeters and 15 relative gravimeters. Precise levelling measurements were carried out and all measurements were performed on the BIPM micro-gravity network which was specifically designed for the comparison. © 2011 BIPM & IOP Publishing Ltd.


Biasetti J.,KTH Royal Institute of Technology | Spazzini P.G.,National Institute of Metrological Research INRiM | Hedin U.,Karolinska University Hospital | Gasser T.C.,National Institute of Metrological Research INRiM
Journal of the Royal Society Interface | Year: 2014

Shear-induced migration of red blood cells (RBCs) is a well-known phenomenon characterizing blood flow in the small vessels (micrometre to millimetre size) of the cardiovascular system. In large vessels, like the abdominal aorta and the carotid artery (millimetre to centimetre size), the extent of this migration and its interaction with secondary flows has not been fully elucidated. RBC migration exerts its influence primarily on platelet concentration, oxygen transport and oxygen availability at the luminal surface, which could influence vessel wall disease processes in and adjacent to the intima. Phillips' shear-induced particle migration model, coupled to the Quemada viscosity model, was employed to simulate the macroscopic behaviour of RBCs in four patient-specific geometries: a normal abdominal aorta, an abdominal aortic aneurysm (AAA), a normal carotid bifurcation and a stenotic carotid bifurcation. Simulations show a migration of RBCs from the near-wall region with a lowering of wall haematocrit (volume fraction of RBCs) on the posterior side of the normal aorta and on the lateralexternal side of the iliac arteries. A marked migration is observed on the outer wall of the carotid sinus, along the common carotid artery and in the carotid stenosis. No significant migration is observed in the AAA. The spatial and temporal patterns of wall haematocrit are correlated with the near-wall shear layer and with the secondary flows induced by the vessel curvature. In particular, secondary flows accentuate the initial lowering in RBC near-wall concentration by convecting RBCs from the inner curvature side to the outer curvature side. The results reinforce data in literature showing a decrease in oxygen partial pressure on the inner curvature wall of the carotid sinus induced by the presence of secondary flows. The lowering of wall haematocrit is postulated to induce a decrease in oxygen availability at the luminal surface through a diminished concentration of oxyhaemoglobin, hence contributing, with the reported lowered oxygen partial pressure, to local hypoxia. © 2014 The Author(s) Published by the Royal Society.


Kuepferling M.,National Institute of Metrological Research INRiM | Serpico C.,University of Naples Federico II | Pufall M.,U.S. National Institute of Standards and Technology | Rippard W.,U.S. National Institute of Standards and Technology | And 5 more authors.
Applied Physics Letters | Year: 2010

Vortex oscillations induced by dc currents (Idc) through a metallic nanocontact subject to in-plane magnetic fields (Hext) are studied by measuring voltage power spectra. Two oscillations modes exist: at large Idc the oscillation frequency (fosc) is substantially insensitive to Hext, whereas at low Idc, fosc decreases with Hext increasing. At intermediate Idc the two modes coexist. This behavior is ascribed to the magnetic states of the device ferromagnetic layers: in the first mode vortices are formed in both layers while in the second mode one layer is in a vortex state while the other is in a quasiuniform state. © 2010 American Institute of Physics.


Shoaib N.,National Institute of Metrological Research INRiM | Shoaib N.,The Petroleum Institute | Sellone M.,National Institute of Metrological Research INRiM | Brunetti L.,National Institute of Metrological Research INRiM | Oberto L.,National Institute of Metrological Research INRiM
Microwave and Optical Technology Letters | Year: 2016

This article presents the characterization measurements and related uncertainty evaluation of a non-magnetic material using the Vector Network Analyzer (VNA) at microwave frequencies. The permittivity of the material under test is computed from the scattering parameters (S-parameters). The aim of the work is to highlight the different uncertainty contributions affecting the permittivity. © 2016 Wiley Periodicals, Inc.


Shoaib N.,National Institute of Metrological Research INRiM | Kuhlmann K.,Physikalisch - Technische Bundesanstalt | Judaschke R.,Physikalisch - Technische Bundesanstalt | Sellone M.,National Institute of Metrological Research INRiM | Brunetti L.,National Institute of Metrological Research INRiM
Journal of Infrared, Millimeter, and Terahertz Waves | Year: 2015

This paper presents an investigation of verification artifacts in WR-03 waveguides. The waveguide verification artifacts include a cross-guide and a custom-made circular iris section. The investigation involves the transmission loss uncertainty analysis of the verification artifacts for vector network analyzer (VNA) waveguide systems operating at millimeter wavelengths. The measurement errors due to the dimensional tolerances and the flange misalignment are predicted by using a commercially available electromagnetic software package. The data analysis is carried out for complex-valued scattering parameters (S-parameters). The uncertainty due to different error sources is computed according to the Law of Propagation of Uncertainty. The real and imaginary data along with the associated uncertainties are converted to magnitude and phase representation via linear propagation of uncertainties. The experimental results are also compared with simulated results. © 2015, Springer Science+Business Media New York.


Niccolini G.,National Institute of Metrological Research INRiM | Durin G.,National Institute of Metrological Research INRiM | Lacidogna G.,Polytechnic University of Turin | Manuello A.,Polytechnic University of Turin | Carpinteri A.,Polytechnic University of Turin
Conference Proceedings of the Society for Experimental Mechanics Series | Year: 2011

We present a comparative statistical analysis between the time series of the acoustic emission (AE) events detected from the ancient Greek Athena temple in Syracuse (Eastern Sicily, UNESCO World Heritage List since 2005), and the time series of small and intermediate earthquakes occurred in this part of Sicily during the AE monitoring period. The waiting-time distributions for both time series and different magnitude thresholds are described by a unique scaling function indicating self-similarity over a wide range of magnitude scales. The similarity between the waiting times in AEs and earthquakes suggests a correlation between the microfracturing process accompanying ageing and deterioration of the monument and the regional seismicity. Our results reveal that the structure of the Athena temple is particularly sensitive to the normal seismic activity, suggesting structural AE monitoring as a useful tool for seismic hazard assessment. ©2010 Society for Experimental Mechanics Inc.


Schiavi A.,National Institute of Metrological Research INRiM | Niccolini G.,National Institute of Metrological Research INRiM | Tarizzo P.,National Institute of Metrological Research INRiM | Lacidogna G.,Polytechnic University of Turin | And 2 more authors.
Society for Experimental Mechanics - SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2010 | Year: 2010

Experimental results are presented for fracture tests carried out on concrete and rock specimens under compression, and an analysis is performed for low-frequency acoustic emissions (elastic emissions, or ELE) due to crack growth. ELEs are vibrations of the specimen surface with relevant amplitudes and low frequencies (between 1 kHz and 20 kHz), appearing at the very last stages of the test and then revealing imminent failure. A spectral analysis of the ELEs is performed by measuring with a calibrated transducer the local acceleration of the specimen surface in the application point of the transducer. Quantitative estimation of ELE released energy is given in terms of kinetic energy using a simple kinematic model. © 2010 Society for Experimental Mechanics Inc.


Troia A.,National Institute of Metrological Research INRiM | Cuccaro R.,National Institute of Metrological Research INRiM | Schiavi A.,National Institute of Metrological Research INRiM
22nd International Congress on Sound and Vibration, ICSV 2015 | Year: 2015

In this paper a novel formulation for the realization of homogenous transparent and tunable attenuating tissue-mimicking materials (TMMs) is reported. Although many hydrogel based materials have been proposed for high intensity ultrasonic field characterization, no one fully satisfies the requested acoustic and optical properties. Using concentrated inorganic salts solutions and different polysaccharide molecules, a simple preparation method has been developed to obtain this new class of TMMs. Physical properties of these TMMs have been investigated by an accurate mechanical and acoustic characterization. Furthermore a short discussion about the mechanism of ultrasonic absorption given by inorganic salt solution embedded in polymeric matrix is reported. Shown results supply a new starting point for the production of TMMs suitable for HIFU characterization.


Troia A.,National Institute of Metrological Research INRiM | Cuccaro R.,National Institute of Metrological Research INRiM | Schiavi A.,National Institute of Metrological Research INRiM
2015 IEEE International Symposium on Medical Measurements and Applications, MeMeA 2015 - Proceedings | Year: 2015

In this paper a novel formulation for the realization of homogenous transparent and tunable attenuating tissue-mimicking materials (TMMs) has been reported. Although many hydrogel based materials have been proposed for high intensity ultrasonic field characterization, no one fully satisfies the requested acoustic and optical properties. Using concentrated salts solutions and different polysaccharide molecules, a simple preparation method has been developed to obtain this new class of TMMs. Physical properties of these TMMs have been investigated by an accurate mechanical and acoustic characterization. Furthermore, a short discussion about the mechanism of ultrasonic attenuation given by salts solutions embedded in polymeric matrix has been conducted. Finally, by means of an experiment on protein denaturation induced by HIFU, the different mechanism underlying lesions formation occurring in a transparent TMM with and without salt has been revealed. Shown results supply a new starting point for the production of TMMs suitable for HIFU characterization. © 2015 IEEE.

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