Search results for "electron"

showing 10 items of 24810 documents

Limits to CO2-Neutrality of Burning Wood. (Review)

2016

Abstract Consumption of wood as a source of energy is discussed with respect to efficiency and restraints to ensure sustainability of the environment on the grounds of a simple analytical model describing dynamics of biomass accumulation in forest stands – a particular case of the well-known empirical Richards’ equation. Amounts of wood harvested under conditions of maximum productivity of forest land are presented in units normalised with respect to the maximum of the mean annual increment and used to determine the limits of CO2-neutrality. The ecological “footprint” defined by the area of growing stands necessary to absorb the excess amount of CO2 annually released from burning biomass is…

sustainable supplyNatural resource economicsPhysicsQC1-999020209 energyGeneral EngineeringGeneral Physics and Astronomy02 engineering and technologybioenergyBioenergy0202 electrical engineering electronic engineering information engineeringNeutralitylimits to co2-neutralitywoodLatvian Journal of Physics and Technical Sciences
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Control of the Development of Swirling Airflow Dynamics and Its Impact on Biomass Combustion Characteristics

2017

Abstract The development of the swirling flame flow field and gasification/ combustion dynamics at thermo-chemical conversion of biomass pellets has experimentally been studied using a pilot device, which combines a biomass gasifier and combustor by varying the inlet conditions of the fuel-air mixture into the combustor. Experimental modelling of the formation of the cold nonreacting swirling airflow field above the inlet nozzle of the combustor and the upstream flow formation below the inlet nozzle has been carried out to assess the influence of the inlet nozzle diameter, as well primary and secondary air supply rates on the upstream flow formation and air swirl intensity, which is highly …

swirling flow dynamicsWaste managementPhysicsQC1-999020209 energyAirflowGeneral EngineeringEnvironmental engineeringHeat outputGeneral Physics and Astronomymixing of reactantsflame composition02 engineering and technologyheat outputBiomass combustioncombustion of volatiles0202 electrical engineering electronic engineering information engineeringLatvian Journal of Physics and Technical Sciences
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Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement

2021

Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, heart rate measurement was augmented with heat flux (HF) measurement, a form of direct calorimetry. A physical exercise test on a group of 15 people showed that HF measurement can improve the accuracy of calorie consumption estimates especially during rest and low-intensity activity when used in conjunction with heart rate information and vital backgr…

sykeCalorieComputer sciencebusiness.industry020208 electrical & electronic engineeringWearable computerPhysical exercise02 engineering and technologyIntensity (physics)ruumiinlämpömittaustekniikkaEnergy expenditureHeat fluxHeart rateStatistics0202 electrical engineering electronic engineering information engineeringanturitElectrical and Electronic EngineeringbusinessInstrumentationenergiankulutus (aineenvaihdunta)Wearable technologyIEEE Transactions on Instrumentation and Measurement
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On the Influence of Walking People on the Doppler Spectral Characteristics of Indoor Channels

2017

Author´s accepted manuscript © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. When modelling mobile radio channels with moving scatterers, it is generally assumed that the angles of departure (AODs), angles of arrival (AOAs), and the speed of the scatterers are time-invariant. However, this assumption is violated as the AODs and AOAs vary with the positions of t…

symbols.namesakeComputer scienceAcousticsGaussian0103 physical sciences0202 electrical engineering electronic engineering information engineeringsymbols020206 networking & telecommunications02 engineering and technology010301 acoustics01 natural sciencesDoppler effectCommunication channel
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Phase retrieval of vitreous floaters: simulation experiment

2020

Knowledge of the structure of vitreous floaters is crucial to evaluate the need for surgical removal of these floaters. We simulated the phase retrieval of microstructures simulating vitreous floaters by an algorithm PhaseLift and investigate the effects of various parameters on the retrieved phase. The object under test was modulated and the coded diffraction patterns were calculated. Next, PhaseLift was used to retrieve the phase. In the current study, we simulate the effect of Gaussian and Poison noise on the phase retrieval of pure phase objects. We apply an iterative algorithm PhaseLift for phase retrieval as this algorithm requires a very few modulating masks and is able to retrieve t…

symbols.namesakeComputer scienceIterative methodGaussian noiseGaussiansymbolsPhase (waves)Shot noisePoisson distributionPhase retrievalAlgorithmNoise (electronics)Optical Design and Testing X
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Enhanced Debye level in nano Zn1+xSb, FeSb2, and NiSb: Nuclear inelastic spectroscopy on121Sb (Phys. Status Solidi B 5/2014)

2014

symbols.namesakeCondensed matter physicsChemistryNano-symbolsCondensed Matter PhysicsSpectroscopyElectronic Optical and Magnetic MaterialsDebyephysica status solidi (b)
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One‐magnon Raman scattering in Ni c Mg 1–c O solid solutions

2005

The one-magnon Raman scattering was studied for the first time in antiferromagnetic NicMg1–cO solid solutions as a function of temperature and composition. We found that (i) the one-magnon frequency extrapolated to T = 0 K experiences an abrupt change between c = 0.99 and c = 0.9 and (ii) the one-magnon energy for highly diluted nickel oxide vanishes significantly below the Neel temperature. The obtained dependences are compared to the theoretical predictions within the mean field approximation. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

symbols.namesakeCondensed matter physicsMean field theoryChemistryNickel oxideMagnonsymbolsAntiferromagnetismCondensed Matter::Strongly Correlated ElectronsNéel temperatureRaman scatteringSolid solutionphysica status solidi (c)
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Structure and Photocatalytic Properties of TiO2-WO3Composites Prepared by Electrophoretic Deposition

2015

In this work TiO2-WO3 composite films containing different oxide concentrations were prepared by electrophoretic deposition on steel substrates. Composite coating structures were analyzed by X -ray diffraction, Raman spectra and scanning electron microscopy. The results showed an even distribution of WO3 particles in the entire composite layer. Light absorption measurements were used for photocatalytic properties evaluation. It was found that the removal ratio of methylene blue depends on the (TiO2):(WO3) concentration ratio. The most effective photodegradation was determined for the sample that was electrophoretically deposited from the suspension with the molar content ratio n(TiO2):n(WO3…

symbols.namesakeElectrophoretic depositionMaterials scienceScanning electron microscopeComposite numbersymbolsPhotocatalysisAnalytical chemistryRaman spectroscopyPhotodegradationLayer (electronics)Concentration ratioNuclear chemistryIOP Conference Series: Materials Science and Engineering
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Synthesis, Characterization of FexZr1-xO2Solid Solution Nanoparticles and Bulk Powders Prepared Using a Sol-Gel Technique

2015

symbols.namesakeMaterials scienceChemical engineeringTransmission electron microscopyPolymer characterizationScanning electron microscopeDifferential thermal analysisAnalytical chemistrysymbolsNanoparticleRaman spectroscopyCharacterization (materials science)Sol-gel
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Vibrational properties of semiconductor nanowires and nanowire heterostructures: ensembles and single nanowires

2013

symbols.namesakeMaterials scienceSemiconductorbusiness.industryNanowiresymbolsOptoelectronicsGeneral Materials ScienceHeterojunctionCondensed Matter PhysicsbusinessRaman scatteringphysica status solidi (RRL) - Rapid Research Letters
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