Search results for "electric discharges"

showing 3 items of 3 documents

Individual arc-discharge synthesized multiwalled carbon nanotubes probed with multiple measurement techniques

2020

Arc-discharge synthesized multiwalled carbon nanotubes (AD-MWNT), or related MWNTs, exhibit a good quality compared to the more common type of MWNT synthesized by catalytic chemical vapor deposition methods. Yet experimental measurements on these are rather few and typically have not correlated data from different measurement techniques. Here, the authors report Raman spectroscopy, scanning probe microscopy, conductivity measurements, and force microscopy on single AD-MWNTs. The results demonstrate the high quality of AD-MWNTs and are compatible with the view of them as the best approximation of MWNTs as an assembly of defect-free concentric individual single-walled carbon nanotubes. The au…

Materials sciencescanning probe microscopyCarbon nanotubeConductivitylaw.inventionnanotubesElectric arcsymbols.namesakeScanning probe microscopyraman spectroscopyatomifysiikkalawelectric dischargesMicroscopyMaterials ChemistryElectrical and Electronic EngineeringatomivoimamikroskopiaInstrumentationatomic force microscopyPhysicsProcess Chemistry and TechnologyConductanceSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsChemical engineeringelectronic devicessymbolsscanning tunneling microscopynanoputketRaman spectroscopyEngineering sciences. TechnologyLayer (electronics)scanning electron microscopy
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Toward more realistic viscosity measurements of tyre rubber–bitumen blends

2014

AbstractThe measurement of rheological properties of the tyre rubber bitumen blends is often challenging due to presence of suspended tyre rubber’s crumbs. Furthermore, the phase separation during the course of measurements makes the viscosity of these non-homogeneous blends difficult to ascertain. In this study, a new dual helical impeller was designed and manufactured to be used with a rotational viscometer in order to have a real-time control of the viscosity while performing a laboratory mixing of the blends. Layer based manufacturing techniques showed to be a convenient method to produce complex shaped impeller prototypes before manufacturing the more expensive stainless steel assembly…

Recycled tyre rubberEngineeringbituminous materials Calibration Electric discharges Impellers Manufacture Rapid prototyping Rate constants Real time control Rubber Stainless steel Tires Viscometers Viscosity Viscosity measurementViscometryMixing (process engineering)ViscosityImpellerMaterials Science(all)Natural rubberRheologyElectrical discharge machiningSettore ICAR/04 - Strade Ferrovie Ed AeroportiGeneral Materials ScienceComposite materialCivil and Structural EngineeringComplex fluidRapid prototypingbusiness.industryViscometerBuilding and ConstructionDual helical impellerShear rateRubberised bitumenvisual_artvisual_art.visual_art_mediumSettore ICAR/08 - Scienza Delle CostruzionibusinessConstruction and Building Materials
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A study of VUV emission and the extracted electron-ion ratio in hydrogen and deuterium plasmas of a filament-driven H−/D− ion source

2019

Vacuum ultraviolet (VUV) emission diagnostics for studying differences of electron impact processes in hydrogen and deuterium plasmas are presented. The method is applied to study a filament driven multicusp arc discharge negative ion source by comparing the VUV-emission intensities of different emission bands and extracted currents of H−/D− ions and electrons. It was found that the ratio of coextracted electrons to extracted ions is four times higher for deuterium than for hydrogen. No significant differences of the VUV-spectra or volumetric rates of ionization, excitation, production of high vibrational states, and dissociation were found between the plasmas of the two isotopes. The volum…

diffusion rateisotoopitplasma diagnosticselectron impact ionizationplasmafysiikkavacuum ultraviolet radiationelectron impact emission spectroscopyion sourcesPhysics::Plasma Physicselectric dischargesPhysics::Atomic and Molecular Clustersisotopesvibrational statesplasma spectroscopy
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