Search results for "MAGNETIC FIELD"

showing 10 items of 1488 documents

STUDIO DI UNA FRIZIONE MAGNETOREOLOGICA PER AUTOVEICOLI

2013

Dopo un’accurata ricerca bibliografica sui fluidi magnetoreologici, il loro comportamento ed impiego, si è passati alla progettazione di una frizione magnetoreologica per autoveicoli. Considerando le caratteristiche di coppia trasmessa e potenza, il dispositivo è stato dimensionato tenendo presente i vincoli di ingombro del veicolo preso in esame. Sottoponendo il dispositivo ad analisi magnetostatica agli elementi finiti, si è determinato l’andamento delle linee di flusso del campo magnetico nel meato di fluido e nelle zone di maggior interesse, calcolando la coppia teoricamente trasmessa dall’innesto.È stato anche eseguito il confronto delle prestazionifra una frizione MR ed una frizione t…

Settore ING-IND/14 - Progettazione Meccanica E Costruzione Di MacchineAfter a thorough literature search on magnetorheological fluids their behavior and use it has gone to the design of a magnetorheological clutch for motor vehicles. Considering the characteristics of transmitted torque and power the device is dimensioned taking into account the constraints of space of the examined vehicle. Subjecting the device to magnetostatic finite element analysis it was determined the trend of the flow lines of the magnetic field in the gap of fluid and in areas of greater interest calculating the torque transmitted theoretically by the clutch. The performance comparison between a traditional clutch and a MR clutch was also performed pointing out that the MR clutch presents shorter response times with high energy savings. The study carried out shows that the device is well suited to a vehicle with automatic or robotic or otherwise with very short response times but requires a control system for the starting the vehicle.
researchProduct

Bio-electromagnetic Numerical Modeling for Health Diagnostics

Settore ING-IND/31 - ElettrotecnicaSettore MAT/08 - Analisi Numericabioelectromagnetic fields bioelectromagnetism numerical methods medical imaging neuroimaging brain activity electroencephalography magnetoencephalography EEG MEG meshfree meshless method of fundamental solutionscampi bioelettromagnetici bioelettromagnetismo metodi numerici diagnostica per immagini attività cerebrale elettroencefalografia magnetoencefalografia metodo delle soluzioni fondamentali
researchProduct

Homomorphic Approach to RF-Inhomogeneity Removal Based on Gabor Filter

2007

In this paper a bias correction algorithm for magnetic resonance imaging (MRI) is presented. The magnetic resonance (MR) images affected by this artifact, also called RF-inhomogeneity, exhibit irregular spatial brightness variations caused by magnetic field inhomogeneity. Here we present an original algorithm based on E2D - HUM, already proposed by some of the authors, where a modified Gabor filter is introduced in the elaboration chain to provide directional capabilities to suppress the artifact. The process of restoration doesn't care about the structure of the image and it has been applied to MR images of different parts of body like knee, abdomen, pelvis and brain. A comparison with oth…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniBrightnessArtifact (error)medicine.diagnostic_testbusiness.industryComputer scienceProcess (computing)Homomorphic encryptionBias artifactGabor filterMagnetic resonance imagingMagnetic fieldIntensity correctionRF inhomogeneityGabor filtermedicineComputer visionArtificial intelligencebusinessImage restorationIllumination correction
researchProduct

Noise Filtering Using Edge-Driven Adaptive Anisotropic Diffusion

2008

This paper presents a method aimed to noise removal in MRI (Magnetic Resonance Imaging). We propose an improvement of Perona and Malik's anisotropic diffusion filter. In our schema, the diffusion equation of the filter has been modified to take into account the edges direction, This allows the filter to blur uniform areas, while it better preserves the edges. Both quantitative and qualitative evaluation is presented and the results are compared with other methods.

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniNoise Removal Magnetic Resonance Images Anisotropic Diffusion Brain MRIDiffusion equationNoise measurementComputer scienceAnisotropic diffusionWiener filterComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONFilter (signal processing)Edge-preserving smoothingMagnetic fieldAdaptive filtersymbols.namesakeComputer Science::Computer Vision and Pattern RecognitionsymbolsAlgorithm2008 21st IEEE International Symposium on Computer-Based Medical Systems
researchProduct

Mobile phone and auditory system: update

2009

The aim of this study is to asses the non-thermal effects of the electromagnetic fields generated by 915 MHz GSM cellular phones on the human cochlear activity using transient evoked otoacoustic emissions (TEOAE). The study was carried on 205 young and healthy volunteers (age 18-30 years) with normal hearing which were randomly divided into two samples consisting of 85 (Gcase) and 120 (Gcontrol) respectively. The first one was exposed to genuine 10 minutes of GSM electromagnetic fields while the second, undergone sham exposure, was considered as control group for the statistical investigations. All the participants were blind to the genuine or sham exposure. The TEOAEs were measured in the …

Settore MED/31 - OtorinolaringoiatriaGSM Electromagnetic Fields Auditory system Outer sensory cells TEOAESettore MED/32 - Audiologia
researchProduct

Influence of mobile phone electromagnetic fields on TEOAEs recordings

2006

Settore MED/31 - Otorinolaringoiatriaelectromagnetic fieldTEOAEMobile phoneSettore MED/32 - Audiologia
researchProduct

EPIDEMIOLOGICAL STUDIES ON POSSIBLE LONG-TERM EFFECTS OF EXTREMELY LOW FREQUENCIES ELECTRICAL AND MAGNETIC FIELDS

2008

Settore MED/42 - Igiene Generale E ApplicataELF LONG-TERM EFFECTS MAGNETIC FIELDS.
researchProduct

Magneto-elastic oscillations and the damping of crustal shear modes in magnetars

2010

In a realistic model of magneto-elastic oscillations in magnetars, we find that crustal shear oscillations, often invoked as an explanation of quasi-periodic oscillations (QPOs) seen after giant flares in soft gamma-ray repeaters (SGRs), are damped by resonant absorption on timescales of at most 0.2s, for a lower limit on the dipole magnetic field strength of 5 10 13 G. At higher magnetic field strengths (typical in magnetars) the damping timescale is even shorter, as anticipated by earlier toy-models. We have investigated a range of equations of state and masses and if magnetars are dominated by a dipole magnetic field, our findings exclude torsional shear oscillations of the crust from ex…

Shear (sheet metal)PhysicsDipoleSpace and Planetary ScienceAstrophysics::High Energy Astrophysical PhenomenaAstronomy and AstrophysicsAstrophysicsResonant absorptionMagneto elasticMagnetohydrodynamicsMagnetarLower limitMagnetic fieldMonthly Notices of the Royal Astronomical Society: Letters
researchProduct

Flexible magnetic filaments in a shear flow

2006

By flexible magnetic filament model its behavior under the simultaneous action of the shear flow and the magnetic field is investigated. It is found that for magnetoelastic numbers larger as the critical value, which depends on the shear rate, the periodic regime is established. For the values of the magnetoelastic number close to the critical the periodical regime is characterized by a rather slow development of the buckling instability due to the action of magnetic torques with the subsequent stage of the fast straightening of the filament. For the magnetoelastic numbers below the critical slightly bent shape of the filament orientated along the flow is established. The application of the…

Shear rateProtein filamentPhysicsShear (sheet metal)Condensed matter physicsMagnetorheological fluidCondensed Matter PhysicsCritical valueShear flowViscoelasticityElectronic Optical and Magnetic MaterialsMagnetic fieldJournal of Magnetism and Magnetic Materials
researchProduct

Inferring possible magnetic field strength of accreting inflows in EXor-type objects from scaled laboratory experiments

2021

Aims. EXor-type objects are protostars that display powerful UV-optical outbursts caused by intermittent and powerful events of magnetospheric accretion. These objects are not yet well investigated and are quite difficult to characterize. Several parameters, such as plasma stream velocities, characteristic densities, and temperatures, can be retrieved from present observations. As of yet, however, there is no information about the magnetic field values and the exact underlying accretion scenario is also under discussion. Methods. We use laboratory plasmas, created by a high power laser impacting a solid target or by a plasma gun injector, and make these plasmas propagate perpendicularly to …

Shock waveAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesField strengthAstrophysicsstars: pre-main sequence01 natural sciencesmagnetohydrodynamics (MHD)Settore FIS/05 - Astronomia E Astrofisicaaccretion0103 physical sciencesProtostarAstrophysics::Solar and Stellar Astrophysics010306 general physics010303 astronomy & astrophysicsSolar and Stellar Astrophysics (astro-ph.SR)Astrophysics::Galaxy AstrophysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)Physics[PHYS]Physics [physics]accretion disksAstronomy and AstrophysicsRadiusPlasmashock wavesAccretion accretion disksAccretion (astrophysics)Magnetic fieldT Tauri starAstrophysics - Solar and Stellar AstrophysicsSpace and Planetary Scienceinstabilitiesstars: individual: V1118 OriAstrophysics::Earth and Planetary Astrophysics[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph]Astrophysics - High Energy Astrophysical Phenomena[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
researchProduct