Search results for "Oscillation"

showing 10 items of 1257 documents

The Effect of Spectral Diffusion on the Saturation Transient Regime

1985

Saturation kinetics of inhomogeneous resonance lines has been investigated in very dilute ruby samples at T=4.2°K by the saturation transient technique. Experimental evidence of the effectiveness of intraline spectral diffusion is reported. Satisfactory agreement is found between the experimental results and a theoretical model in which spectral diffusion is ascribed to the time fluctuations of the hyperfine field. Spectral diffusion times of the order of 10-5 sec are determined.

Materials scienceField (physics)lawSaturation recoveryResonanceTransient (oscillation)Diffusion (business)Saturation (chemistry)Electron paramagnetic resonanceHyperfine structureMolecular physicslaw.invention
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SOIL IONIZATION DUE TO HIGH PULSE TRANSIENT CURRENTS LEAKED BY EARTH ELECTRODES

2009

This paper proposes a numerical model of the soil ionization phenomena that can occur when earth electrodes are injected by high pulse transient currents, as the one associated with a direct lightning stroke. Based on finite difference time domain numerical scheme, this model ascribes the electrical breakdown in the soil to the process of discharge in the air. In fact, as soon as the local electric field overcomes the electrical strength, the air in the voids trapped among soil particles is ionized, and the current is conducted by ionized plasma paths locally grown. The dimension of these ionized air channels is strictly dependent upon the local temperature. Thus, a local heat balance is en…

Materials scienceFinite-difference time-domain methodElectrical breakdownPlasmaMechanicsCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsPulse (physics)Settore ING-IND/31 - ElettrotecnicaSettore MAT/08 - Analisi NumericaElectric fieldIonizationTransient (oscillation)transient currentsElectrical and Electronic EngineeringCurrent (fluid)numerical modelfinite difference schemeProgress In Electromagnetics Research B
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Transient absorption and luminescence of LiNbO3 and KNbO3

2001

Abstract The results of time-resolved optical absorption spectra in congruent and stoichiometric LiNbO3 as well as KNbO3 crystals are reported. The role of different polaron types in transient absoiption and luminescence spectra and decay kinetics are discussed.

Materials scienceKineticsAnalytical chemistryLuminescence spectraCondensed Matter PhysicsPolaronElectronic Optical and Magnetic MaterialsOptical absorption spectraControl and Systems EngineeringUltrafast laser spectroscopyMaterials ChemistryCeramics and CompositesTransient (oscillation)Electrical and Electronic EngineeringLuminescenceStoichiometryIntegrated Ferroelectrics
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Quasi-static magnetoresistive sensor modeling for current-time conversion circuit applications

2011

In this paper we report a current-to-time converter (CTC) suitable for current sensor monitoring in low power applications. Based on a discrete resistence-to-frequency converter and a Giant MagnetoResistance (GMR) current sensor. Simulations have been done using a quasi-static electrical Verilog-A model for the GMR current sensor. A reduced set of parameters has been extracted to characterize the GMR sensor's behavior. The application has been analyzed making use of different sensors, whose device parameters were previously extracted. Finally, the accuracy of the models has been tested by comparing with experimental transient measurements.

Materials scienceMagnetoresistancebusiness.industryLow-power electronicsElectronic engineeringElectrical engineeringGiant magnetoresistanceCurrent sensorTransient (oscillation)businessDevice parametersQuasistatic processPower (physics)Proceedings of the 8th Spanish Conference on Electron Devices, CDE'2011
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Luminescence and Transient Optical Absorption in CdWO<sub>4</sub>

1997

Materials scienceMechanical EngineeringAnalytical chemistryScintillatorCondensed Matter Physicschemistry.chemical_compoundchemistryMechanics of MaterialsUltrafast laser spectroscopyCadmium tungstateGeneral Materials ScienceTransient (oscillation)LuminescenceAbsorption (electromagnetic radiation)Materials Science Forum
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Influence of mode stirrer and air renewal on controlled microwave drying of sliced zucchini

2017

An on-line temperature-controlled microwave (MW) system, based on infrared thermography, was developed for drying zucchini slices. Moreover, the effects of different configurations, including turntable rotation, mode stirrer and air renewal, alone or in combination, on drying kinetics and quality of dried product were evaluated. The combination of stirrer and air renewal reduced the drying time of zucchini slices by about 48% with respect to the basic configuration and by 22% with respect to air renewal only. The lowest oscillation of temperatures about the fixed level (65 °C) was found when operating with the stirrer mode, because of the improved uniformity of the MW distribution. The sa…

Materials scienceMeteorologyColour; Drying; Infrared thermography; Microwave; Temperature control; Zucchini; Control and Systems Engineering; Food Science; Animal Science and Zoology; Agronomy and Crop Science; Soil ScienceSoil ScienceColour0404 agricultural biotechnologyDrying timeComposite materialDryingTemperature controlTemperature controlOscillationMode (statistics)Zucchini04 agricultural and veterinary sciencesSettore AGR/15 - Scienze E Tecnologie Alimentari040401 food scienceControl and Systems EngineeringThermography040103 agronomy & agricultureInfrared thermography0401 agriculture forestry and fisheriesAnimal Science and ZoologyMicrowaveAgronomy and Crop ScienceMicrowaveFood Science
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Real-time manipulation of gold nanoparticles inside a scanning electron microscope

2011

Abstract The forces needed to overcome static friction and move 150 nm diameter Au nanoparticles on an oxidized Si substrate were measured in Normal and Shear oscillation modes inside a scanning electron microscope (SEM) in real time. The experimental setup consisted of a quartz tuning fork (QTF) mounted onto a high-precision 3D nanomanipulator used with a glued silicon or tungsten tip as a force sensor. Static friction was found to range from tens of nN to several hundred nN. Large variations in static friction values were related to differences in particle shape. Kinetic friction tended to be close to the detection limit and in most cases did not exceed several nN. The influence of therma…

Materials scienceNanomanipulatorSiliconbusiness.industryOscillationScanning electron microscopeNanoparticlechemistry.chemical_elementGeneral ChemistryTungstenCondensed Matter PhysicsShear (sheet metal)OpticschemistryMaterials ChemistryParticleComposite materialbusinessSolid State Communications
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Start-up and shutdown thermomechanical transient analyses of the IFMIF European lithium target system

2014

In the framework of the current IFMIF Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) phase, ENEA is responsible for the design of the European concept of the IFMIF lithium target system which foresees the possibility to periodically replace only the most irradiated and thus critical component (i.e., the backplate) while continuing to operate the rest of the target for a longer period (bayonet backplate concept). With the objective of evaluating the performances of the system in terms of temperature, stress and displacement fields evolution during start-up and shutdown phases, an uncoupled thermomechanical transient analysis has been performed in close collaboration w…

Materials scienceNuclear engineeringIFMIF Target assembly Bayonet backplate Thermomechanics Start-up ShutdownStart-upShutdown7. Clean energy01 natural sciencesThermomechanic010305 fluids & plasmasStress (mechanics)ThermomechanicsTarget assembly0103 physical sciencesThermalIFMIFGeneral Materials ScienceNeutron010306 general physicsBayonet backplateSettore ING-IND/19 - Impianti NucleariCivil and Structural EngineeringMechanical EngineeringNuclear dataFinite element methodIFMIF;Bayonet backplate;Thermomechanics;Start-up;Shutdown;Target assemblyNuclear Energy and EngineeringSystems designTransient (oscillation)Engineering design process
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Ultrasound-assisted bleaching: Mathematical and 3D computational fluid dynamics simulation of ultrasound parameters on microbubble formation and cavi…

2019

Abstract The implementation of ultrasound-assisted bleaching (UAB) is gaining interest in commercial oil refining, as an alternative to the current bleaching procedure (BP), because this technique has several advantages compared to the conventional BP. The mathematical and 3D computational fluid dynamics (CFD) simulation of the influence of ultrasound power, frequency and temperature for predicting microbubble formation and heat transfer in the ultrasonic treatment of soybean oil was assessed in order to optimize the UAB process. The fluctuation frequency and wave speed showed opposite effects on system response to the imposed pressure pulse. As the bubble radius shrinks to zero (after bubb…

Materials scienceOscillationBubbleInternal pressureGeneral ChemistryRadiusMechanicsIndustrial and Manufacturing EngineeringPhysics::Fluid DynamicsCavitationHeat transferUltrasonic sensorCurrent (fluid)Food ScienceInnovative Food Science & Emerging Technologies
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Confinement of charged dust particles by a hybrid-type electric curtain

2012

Abstract The hybrid-type electric curtain (HTEC) comprises a planar electric curtain and a perpendicular planar condenser. Serial cylindrical electrodes are supplied with AC voltage, whereas the condenser is fed with DC voltage. HTEC allows for better control of the particle position shift in space. The particle oscillation path within the hybrid curtain has been photographically analysed. The changing particle path was recorded according to a DC changing voltage value and a constant AC voltage value. The aim of the paper is to describe a successful method that enables one to experimentally determine the region where the particle can be stably oscillated.

Materials scienceOscillationbusiness.industryDust particlesHybrid typeElectrical engineeringCondensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsPlanarPerpendicularParticleElectrical and Electronic EngineeringAtomic physicsbusinessCondenser (heat transfer)BiotechnologyVoltageJournal of Electrostatics
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