Search results for "Heat capacity rate"

showing 3 items of 3 documents

The relative role of EUV radiation and X-rays in the heating of hydrogen-rich exoplanet atmospheres

2009

Aims. We study the relative role of EUV and X-ray radiation in the heating of hydrogen-rich planet atmospheres with different composition and electron content. Methods. An accurate photo-ionization model has been used to follow the primary photo-electron energy deposition throughout the atmosphere. Results. Heating rates and efficiencies have been computed, together with column density cut-offs at which photons of given energies stop their heating production inside the atmosphere. Assuming 100 eV as the energy borderline between the extreme ultraviolet spectral range and X-rays we find that when the absorbing hydrogen column density is higher than 10 20 cm −2 only X-rays can heat the gas. E…

PhysicsHydrogenchemistry.chemical_elementAstronomy and AstrophysicsAstrophysicsRadiationExoplanetHeat capacity rateAtmosphereAtmosphere of EarthchemistrySpace and Planetary ScienceExtreme ultravioletAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary AstrophysicsEmission spectrumAstronomy & Astrophysics
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Laser heating and ablation at high repetition rate in thermal confinement regime

2006

International audience; Laser heating and ablation of materials with low absorption and thermal conductivity (paint and cement) were under experimental and theoretical investigations. The experiments were made with a high repetition rate Q-switched Nd:YAG laser (10 kHz, 90 ns pulse duration and l = 532 nm). High repetition rate laser heating resulted in pulse per pulse heat accumulation. A theoretical model of laser heating was developed and demonstrated a good agreement between the experimental temperatures measured with the infrared pyrometer and the calculated ones. With the fixed wavelength and laser pulse duration, the ablation threshold fluence of paint was found to depend on the repe…

Materials sciencePACS: 81.65 Cf; 42.62 Cf; 61.82 Msmedicine.medical_treatmentGeneral Physics and Astronomy02 engineering and technology01 natural sciencesFluenceModellinglaw.invention010309 opticsThermal conductivityOpticslaw0103 physical sciencesmedicinePyrometerLaser ablationLaser heatingbusiness.industryPulse durationHigh repetition rateSurfaces and InterfacesGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter PhysicsAblationLaserLaser ablationSurfaces Coatings and FilmsHeat capacity rateThermal confinement regime0210 nano-technologybusinessApplied Surface Science
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Application of Mathematical Models in Analysis of Heat Losses in the Buildings

2006

Physical model of heat balance for separate living room is discussed, which allows to analyse the distributions of the flow of air and temperature depending on the physical conditions and geometry. The model enables to choose the optimal surface area of building elements and their properties in order to decrease the heat losses and improve the conditions of thermal comfort. Room with bounding constructions and real dimensions is modelled that helps to understand the peculiarities of heat transfer process in the room as well as distribution of various characteristic quantities and their dependence on the different conditions. Multiple parameters are varied in 2D calculations and their influe…

Sigma heatNTU methodConvective heat transferChemistryHeat transferMechanical engineeringThermal contactmathematical modelling; heat losses of building; heat balance of building; conductive convective and radiation heat losses; LBN 002-01; apportionment of heat losses and sources in building; HeatModHeat transfer coefficientFin (extended surface)Heat capacity rateEnvironment. Technology. Resources.
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