Search results for "Instrumentation"
showing 10 items of 4914 documents
Note: Direct sensor resistance-to-frequency conversion with generalized impedance converter.
2010
In this note a squared output signal is generated from an astable circuit. Its frequency has a linear dependence on the resistance value of a resistive temperature sensor. The main circuit to obtain this direct relationship is the generalized impedance converter configured as a capacitor controlled by a sensor resistance. The proposed measurement method allows a direct analog-to-digital interface of information involved in resistive sensors. The converter finds applications in portable low voltage and low power design of instrumentation electronic systems.
Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor
2015
The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially whe…
Lineshapes and optical selectivity in high-resolution double-resonance ionization mass spectrometry
1999
Abstract Lineshapes expected in high-resolution double-resonance ionization spectroscopy are calculated using the density matrix formalism, integrated over experimentally realistic conditions including atomic velocity and angular distributions as well as laser intensity profiles. The results of these calculations are compared with experimental measurements on the system 4s2 1S0 → 4s4p 1P1 → 4s4d 1D1 → ion for calcium. The measurements of lineshape, with a dynamic range of >106, reveal and confirm subtle effects predicted by theory. These include the shape, position and intensity of the laser-induced structure in the spectra and the simultaneous presence of coherent and incoherent excitation…
High-resolution laser system for the S3-Low Energy Branch
2022
International audience; In this paper we present the first high-resolution laser spectroscopy results obtained at the GISELE laser laboratory of the GANIL-SPIRAL2 facility, in preparation for the first experiments with the S$^3$-Low Energy Branch. Studies of neutron-deficient radioactive isotopes of erbium and tin represent the first physics cases to be studied at S$^3$. The measured isotope-shift and hyperfine structure data are presented for stable isotopes of these elements. The erbium isotopes were studied using the $4f^{12}6s^2$$^3H_6 \rightarrow 4f^{12}(^3 H)6s6p$$J = 5$ atomic transition (415 nm) and the tin isotopes were studied by the $5s^25p^2 (^3P_0) \rightarrow 5s^25p6s (^3P_1)$…
A modified moiré technique for three-dimensional surface topography
2002
In this paper we present an optical technique based on the shadow moire method which allows the measurement and digitization of three-dimensional surfaces. The technique was tested through experimental work and the results were compared with those obtained by a coordinate measuring machine. Moving from the conventional shadow moire method, new features were implemented enabling us to overcome the main shortcomings of the conventional moire method. These include the need to assign the fringe order, the incapability of discerning concavity or convexity, the poor resolution and the complexity in the signal processing. All these problems have been solved by adding an element to generate a carri…
Rheological and Flocculation Analysis of Microfibrillated Cellulose Suspension Using Optical Coherence Tomography
2018
A sub-micron resolution optical coherence tomography device was used together with a pipe rheometer to analyze the rheology and flocculation dynamics of a 0.5% microfibrillated cellulose (MFC) suspension. The bulk behavior of the MFC suspension showed typical shear thinning (power-law) behavior. This was reflected in a monotonously decreasing floc size when the shear stress exceeded the yield stress of the suspension. The quantitative viscous behavior of the MFC suspension changed abruptly at the wall shear stress of 10 Pa, which was reflected in a simultaneous abrupt drop of the floc size. The flocs were strongly elongated with low shear stresses. With the highest shear stresses, the flocs…
Theory of the elliptical Penning trap
2008
Abstract An ideal “Elliptical Penning Trap” is an ideal cylindrically symmetric Penning trap with an additional electrostatic quadrupolar potential ∝ κ ( x 2 − y 2 ) . This configuration is here investigated for arbitrary strength κ of the additional potential. Aside from the decoupled axial motion the system is characterized by a generalized cyclotron and a generalized magnetron frequency. While the former depends only weakly on κ , the magnetron frequency decreases rapidly with increasing κ , vanishing at a maximum value κ max which represents the stability limit for the magnetron motion. Magnetron orbits are elliptical, with their numerical excentricity tending toward unity as κ approa…
Functional evaluation of a “lingual ring” oral device applied on patients affected by temporo-mandibular disorders tmds: A comparative clinical trial
2021
This study aims to evaluate the functional variations of the electromyographic response and clinical symptomatology in TMD patients. This study has been performed and compared before and after the application of a therapeutic protocol based on the use of an oral device working on the proper mandibular repositioning through the proprioceptive-based lingual re-education called “Lingual Ring”. Between January to December 2016, 32 TMD patients have been recruited out of a series of 321 individuals recruited at the Neurosensorial and Motorial Surgery Department, in Palermo (Italy). All the patients underwent the Surface Electromyography (sEMG) of Masseter and Temporal muscles, with different reg…
Search for ultrahigh-energy tau neutrinos with IceCube
2012
The first dedicated search for ultrahigh-energy (UHE) tau neutrinos of astrophysical origin was performed using the IceCube detector in its 22-string configuration with an instrumented volume of roughly 0.25 km3. The search also had sensitivity to UHE electron and muon neutrinos. After application of all selection criteria to approximately 200 live-days of data, we expect a background of 0.60±0.19(stat)+0.56−0.58(syst) events and observe three events, which after inspection, emerge as being compatible with background but are kept in the final sample. Therefore, we set an upper limit on neutrinos of all flavors from UHE astrophysical sources at 90% C.L. of E2νΦ90(νx)<16.3×10−8 GeV cm−2…
Search for neutrino-induced particle showers with IceCube-40
2013
We report on the search for neutrino-induced particle-showers, so-called cascades, in the IceCube-40 detector. The data for this search was collected between April 2008 and May 2009 when the first 40 IceCube strings were deployed and operational. Three complementary searches were performed, each optimized for different energy regimes. The analysis with the lowest energy threshold (2 TeV) targeted atmospheric neutrinos. A total of 67 events were found, consistent with the expectation of 41 atmospheric muons and 30 atmospheric neutrino events. The two other analyses targeted a harder, astrophysical neutrino flux. The analysis with an intermediate threshold of 25 TeV lead to the observation of…