Search results for "Magnet"
showing 10 items of 15436 documents
Magnetic Prospecting of Diachronic Structures (Antiquity to First World War) on the Site of the Sanctuary of Ribemont-sur-Ancre (Somme, France)
2001
International audience; The site of the sanctuary of Ribemont-sur-Ancre (Somme, France) is of major scientific interest for the knowledge of the Celtic civilization in Europe. It also presents other peculiarities: two clearly identifiable periods of occupation-the first one as early as third century BC-to the second century AD and the second one from 1914-1918. In the area disrupted through military operations, the remains of several epochs are intermingled. In order to obtain a precise knowledge of the space time organisation of each occupation, a magnetic survey was carried out. The comparison of geophysical results with the aerial photographs shot during the war allows an exact determina…
Age and Muscle Function Are More Closely Associated With Intracellular Magnesium, as Assessed by
2019
Total serum magnesium is a common clinical measurement for assessing magnesium status; however, magnesium in blood represents less than 1% of the body’s total magnesium content. We measured intramuscular ionized magnesium by phosphorus magnetic resonance spectroscopy (31P-MRS) and tested the hypothesis that this measure better correlates with skeletal muscle function and captures more closely the effect of aging than the traditional measure of total serum magnesium. Data were collected from 441 participants (age 24–98 years) in the Baltimore Longitudinal Study of Aging (BLSA), a study of normative aging that encompasses a broad age range. Results showed that intramuscular ionized magnesium …
EMI Worsening in a SMPS with Non-linear Inductor
2022
This paper is focused on the input current in a Switched Mode Power Supply (SMPS) in which the power inductor is exploited up to the saturation showing a non-linear behaviour. The input current exhibits a distortion due to the non-linearity. The electromagnetic interference (EMI) caused by the ripple at switching frequency, superimposed to the DC value of the input current, requires a suitable design of the input differential mode (DM) filter. The input current is analyzed both in the time and frequency domain for different operating conditions, and it is compared to a SMPS equipped with a traditional linear inductor.
Improved High-Fidelity IPMSM mathematical model Including Saturation, Cross-Coupling, Torque Ripple and Iron Loss effects
2022
For enhanced control algorithm design purposes, accurate and high-fidelity electrical machine mathematical models are fundamentals. Usually, accurate evaluation of electrical machine behaviour requires finite element analysis (FEA) with consequent high-computational times. This paper presents an improved high-fidelity Interior Permanent Magnet Synchronous Machine (IPMSM) mathematical model including saturation, cross-coupling, torque ripple and iron loss effects. This model has been implemented in Matlab®/Simulink environment and its parameters are implemented by the use of lookup tables. To validate the modelling approach proposed, a comparative analysis between the proposed Matlab®/Simuli…
Impact Evaluation of Innovative Selective Harmonic Mitigation Algorithm for Cascaded H-Bridge Inverter on IPMSM Drive Application
2021
This paper presents a detailed analysis of the use of a novel Harmonic Mitigation algorithm for Cascaded H-Bridge Multilevel Inverter in electrical drives for the transportation field. For this purpose, an enhanced mathematical model of Interior Permanent Magnet Synchronous Motor (IPMSM), that takes into account simultaneously saturation, cross-coupling, spatial harmonics, and iron loss effects, has been used. In detail, this model allows estimating accurately the efficiency and the torque ripple of the IPMSM, crucial parameters for transportation applications. Moreover, two traditional pulse width modulation strategies, Sinusoidal Phase-Shifted and Switching Frequency Optimal Phase-Shifted…
Formation, Structural Characterization, and Calculated NMR Chemical Shifts of Selenium-Nitrogen Compounds from SeCl4 and ArNHLi (Ar = supermesityl, m…
2004
Supermesityl selenium diimide [Se{N(C6H2tBu3-2, 4, 6)}2; Se{N(mes*)}2] can be prepared in a good yield from the reaction of SeCl4 and (mes*)NHLi. The molecule adopts an unprecedented anti, anti-conformation, as deduced by DFT calculations at PBE0/TZVP level of theory and supported by 77Se NMR spectroscopy and a crystal structure determination. An analogous reaction involving (C6H2Me3-2, 4, 6)NHLi [(mes)NHLi] unexpectedly lead to the reduction of selenium and afforded the selenium diamide Se{NH(mes)}2 that was characterized by X-ray crystallography and 77Se NMR spectroscopy. The Se-N bonds of 1.847(3) and 1.852(3) A show normal single bond lengths. The <NSeN bond angle of 109.9(1)° also indi…
Microchimerism in multiple sclerosis: The association between sex of offspring and MRI features in women with multiple sclerosis
2023
AimsDuring pregnancy, fetal cells can migrate to the mother via blood circulation. A percentage of these cells survive in maternal tissues for decades generating a population of fetal microchimeric cells (fMCs), whose biological role is unclear. The aim of this study was to investigate the association between the sex of offspring, an indirect marker of fMCs, and magnetic resonance imaging (MRI) features in women with multiple sclerosis (MS).MethodsWe recruited 26 nulliparous MS patients (NPp), 20 patients with at least one male son (XYp), and 8 patients with only daughters (XXp). Each patient underwent brain MR scan to acquire 3D-T2w FLAIR FatSat and 3D-T1w FSPGR/TFE. Lesion Segmentation To…
Microchimerism and multiple sclerosis: a study on the impact of the sex of offspring on clinical, radiological, and paraclinical features of maternal…
2023
Background. Multiple sclerosis (MS) is a chronic autoimmune disorder characterised by inflammation and neurodegeneration and representing one of the most common causes of neurologic disability among young adults. Over the last 40 years, several authors have confirmed the existence of fetal cells in maternal blood and their pregnancy-related origin, demonstrating that pregnancy may establish a long-term, low-grade chimeric state in women. The biological and clinical significance of fetal microchimeric cells (fMCs) in maternal health is largely unknown, although a role in autoimmune diseases have been hypothesised. Aims. The overarching aim of my PhD dissertation was to investigate the role o…
Multi-Chip RFID Antenna Integrating Shape-Memory Alloys for Detection of Thermal Thresholds
2011
Low-cost wireless measurement of objects' temperature is one of the greatest expectation of radiofrequency identification technology for the so many applications in cold supply-chain control and safety assessment in general. In this context, the paper proposes a dual-chip UHF tag embedding shape memory alloys (SMA) able to transform the variation of the tagged item's temperature into a permanent change of antenna radiation features. This event-driven antenna is hence able to selectively activate the embedded microchips according to the temperature above or below a given threshold. A general design methodology for the resulting two-ports tag antenna is here introduced and then applied to pro…
A Shape-based Statistical Method to Retrieve 2D TRUS-MR Slice Correspondence for Prostate Biopsy
2012
International audience; This paper presents a method based on shape-context and statistical measures to match interventional 2D Trans Rectal Ultrasound (TRUS) slice during prostate biopsy to a 2D Magnetic Resonance (MR) slice of a pre-acquired prostate volume. Accurate biopsy tissue sampling requires translation of the MR slice information on the TRUS guided biopsy slice. However, this translation or fusion requires the knowledge of the spatial position of the TRUS slice and this is only possible with the use of an electro-magnetic (EM) tracker attached to the TRUS probe. Since, the use of EM tracker is not common in clinical practice and 3D TRUS is not used during biopsy, we propose to per…