Derivation of Auroral Conductances from IMAGE FUV

Conference (2001, May 01)

Auroral emissions are observed in 3 separate Far-Ultraviolet (FUV) wavelength regimes by IMAGE. The Wideband Imaging Camera (WIC) is sensitive mainly to N[SUB]2[/SUB] LBH and N I emissions in the 140-190 ... [more ▼]

Auroral emissions are observed in 3 separate Far-Ultraviolet (FUV) wavelength regimes by IMAGE. The Wideband Imaging Camera (WIC) is sensitive mainly to N[SUB]2[/SUB] LBH and N I emissions in the 140-190-nm range, while the Spectrographic Imager (SI) spectrally separates the OI 135.6-nm emission and Doppler shifted hydrogen emissions of the proton aurora at 121.8 nm. The brightness of the N[SUB]2[/SUB] LBH and OI 135.6-nm emissions depend in part on the spectrum and total energy flux of incoming electrons, and on the height-density profile of the respective species, and O[SUB]2[/SUB]. Due mainly to these atmospheric factors, the ratio of the N[SUB]2[/SUB] and OI emissions depends strongly on the characteristic energy of precipitating electrons which, once estimated, can in turn be used to calculate the total energy flux. The proton aurora generates secondary electrons, which excite additional emissions of N[SUB]2[/SUB] and OI. It is not possible to absolutely determine either the total proton energy flux or the characteristic proton energy (<E[SUB]p[/SUB]>) with a single proton imaging channel. However, the proton-induced N[SUB]2[/SUB] and OI emissions depend mainly on the total proton energy flux, so reasonable estimates of <E[SUB]p[/SUB]> can be used in the calculation of proton energy input. Ground-based or in-situ observations of proton energies can help in this determination. With accurate corrections for N[SUB]2[/SUB] and OI airglow emissions, and formulae such as those provided by Robinson et al. [1987], IMAGE FUV can provide global maps of height-integrated conductivity (conductance) in the auroral oval. It is also possible to examine the degree to which the proton aurora contributes to enhanced conductance on a global scale. The promise of providing these conductances using IMAGE's real-time capabilities will be discussed. Robinson, R. M., R. R. Vondrak, K. Miller, T. Dabbs, and D. Hardy, On Calculating Ionospheric Conductances from the Flux and Energy of Precipitating Electrons, J. Geophys. Res., 92, 2566, 1987. [less ▲]

Derivation of optimal scroll compressor wrap for minimization of leakage losses

in International Compressor Engineering Conference at Purdue, July 16-19, 2012 (2012, July)

The scroll wraps of a scroll compressor play a very important role in the compressor’s efficiency due to their impact on leakage and leakage irreversibilities. In this work, a short summary of the scroll ... [more ▼]

The scroll wraps of a scroll compressor play a very important role in the compressor’s efficiency due to their impact on leakage and leakage irreversibilities. In this work, a short summary of the scroll compressor geometry is presented. Using the geometry of the scroll wraps, an optimal scroll wrap geometry is derived for a given set of constraints on compressor displacement, scroll wrap thickness and volume ratio. This optimal scroll wrap geometry can be used as a starting point for further optimization in a detailed compressor model that includes the effects of mechanical losses. [less ▲]

Derivation of the 1.0-0.9 Ga ferro-potassic A-type granitoids of southern Norway by extreme differentiation from basic magmas

in Precambrian Research (2003), 124

Major and trace elements, Sr and Nd isotopic data as well as mineral compositions are presented for a selection of the 1.0 - 0.9 ferro-potassic A-type granitoids (Bessefjellet, Rustfjellet ... [more ▼]

Major and trace elements, Sr and Nd isotopic data as well as mineral compositions are presented for a selection of the 1.0 - 0.9 ferro-potassic A-type granitoids (Bessefjellet, Rustfjellet, Verhuskjerringi, Valle, Holum, Svöfjell, Handeland-Tveit, Åseral, Lyngdal gabbronorites) that occur close to the Mandal-Ustaoset Line of southern Norway. These hornblende biotite granitoids (HBG) define an extensive differentiation trend ranging from gabbronorites (50 wt % SiO2) to granites (77 wt % SiO2). This trend is interpreted as resulting from extreme fractional crystallization of several basaltic magma batches with similar major and trace elements compositions. At 930 Ma, the HBG suite displays a narrower range in ISr (0.7027 - 0.7056) than in Nd(t) (+1.97 down to -4.90) suggesting some assimilation of a Rb-depleted lower crust (AFC process) or/and source variability. An age of 929 ± 47 Ma is given by a Rb-Sr isochron on the Holum granite (Sri = 0.7046 ±0.0006, MSWD = 1.7). Geothermobarometers indicate a low pressure of emplacement (1.3-2.7 kbar) and an oxygen fugacity close to NNO. High liquidus temperatures are given by the apatite saturation thermometer (1005°C to 1054 °C) and are in agreement with results from other studies. The basaltic parent magmas of the HBG suite are partial melts of an hydrous mafic, potassic source lying either in the lithospheric upper mantle or in the mafic lower crust derived from it. This contrasts with the 930 Ma anorthosite-mangerite-charnockite suite (AMC) of the Rogaland Province for which a depleted lower crustal anhydrous gabbronoritic source has been indicated. The present data imply the penecontemporaneous melting of two contrasting sources in southern Norway. The source duality could result from an increasing degree of metamorphism (amphibolite to granulite) from East to West, an horizontal stratification of the lower crust or from the stratification of the lithosphere (melting of the lower crust or upper mantle). It may also indicate that the AMC and HBG suites formed in two distinct crustal segments. The linear alignment of the HBG suite along the Mandal-Ustaoset shear zone suggests that a linear uprise of the asthenosphere, following a lithospheric delamination under this structure, could be the vector of the mantle heat. [less ▲]

Derivatives of 2,5- and 3,5-disubstituted anilines, their preparation and use

Patent (1999)

Dérive

Book published by Dricot (2006)

Derived Categories for Functional Analysis

in Publications of the Research Institute for Mathematical Sciences (2000), 36(1), 19-83

We study the homological algebra of the category of locally convex topological vector spaces from the point of view of derived categories.

Derived Projective Limits of Topological Abelian Groups

in Journal of Functional Analysis (1999), 162(1), 135-177

We prove that the category of topological Abelian groups is quasi-Abelian. Using results about derived projective limits in quasi-Abelian categories, we study exactness properties of the projective limit ... [more ▼]

We prove that the category of topological Abelian groups is quasi-Abelian. Using results about derived projective limits in quasi-Abelian categories, we study exactness properties of the projective limit functor in the category of topological Abelian groups. [less ▲]

La dérivée schwarzienne

in Mathématique et Pédagogie (1996), 108

Dans cette note est introduit le concept de dérivée schwarzienne pour une fonction réelle univariée. Diverses propriétés et applications sont également proposées.

Dérivés et composés de 'Volkaaks' à 'Volsweren'

in Woordenboek der Nederlandsche Taal XXII/6 (1981)

Dérivés phosphorylés de la thiamine et bioélectrogenèse

Poster (1984, September)