Spectrometric solar observations at the Jungfraujoch for long-term atmospheric monitoring.Zander, Rodolphe ; Mahieu, Emmanuel ; Demoulin, Philippe et alReport (1999) Detailed reference viewed: 4 (0 ULg) Spectrométrie dans l’infrarouge proche. Application à l’analyse rapide des protéines et des acides aminés de Vicia faba L.Sindic, Marianne ![]() Master's dissertation (1981) Le travail comprend tout d'abord la mise au point d'une technique de dosage rapide et précise de la matière protéique totale des graines de féverole (Vicia faba L.) par spectroscopie dans l'infrarouge à ... [more ▼] Le travail comprend tout d'abord la mise au point d'une technique de dosage rapide et précise de la matière protéique totale des graines de féverole (Vicia faba L.) par spectroscopie dans l'infrarouge à partir de résultats obtenus par kjeldahl sur 108 cultivars. La seconde partie est consacrée à l'analyse de 10 acides aminés essentiels de 68 variétés de féveroles par colonne de résine échangeuse de cations et réalisation de équations de calibration par NIR. [less ▲] Detailed reference viewed: 42 (3 ULg) La spectrometrie de masse appliquee a la determination de sequence de tres faibles quantites de peptides.Wathelet, Bernard ; ; et alin Bulletin des Recherches Agronomiques de Gembloux (1987), 22(2), Detailed reference viewed: 3 (0 ULg) Spectrométrie de masse MALDI-TOF en bactériologie clinique ou comment identifier une bactérie en une minuteDescy, Julie ; Meex, Cécile ; Melin, Pierrette et alin Revue Médicale de Liège (2010), 65(Suppl. Synthèse 2010), 29-34 The major application of MALDI-TOTOF mass spectrometry in clinical microbiology is the bacterial identification based on the analysis of all their proteins (ribosomal and membrane-associated proteins ... [more ▼] The major application of MALDI-TOTOF mass spectrometry in clinical microbiology is the bacterial identification based on the analysis of all their proteins (ribosomal and membrane-associated proteins). This technology allows the identification of most of bacteria within a few minutes. The method is fast, accurate, reliable and cost-effective by comparison to conventional phenotypic techniques. Other applications of MALDI-TOF mass spectrometry are still under development, as the detection of bacterial toxins or resistance mechanisms to antimicrobial agents. [less ▲] Detailed reference viewed: 518 (13 ULg) La spectrométrie des électrons AUGERNicolas, Jacques ; in Revue des Questions Scientifiques (1978), 149 La technique d'analyse des surfaces par la spectrométrie des électrons Auger est décrite. Après un rappel historique de la découverte du mécanisme de réémission électronique par Auger, en 1925, les ... [more ▼] La technique d'analyse des surfaces par la spectrométrie des électrons Auger est décrite. Après un rappel historique de la découverte du mécanisme de réémission électronique par Auger, en 1925, les aspects physiques fondamentaux de la méthode sont présentés. La spectrométrie des électrons Auger fournit des spectres caractéristiques de transitions entre les niveaux discrets des atomes qui constituent une véritable signature atomique de la matière. Le volume détecté par l'analyse des électrons Auger excités par un faisceau d'électrons primaires est déterminé essentiellement par la profondeur d'éjection des électrons s'échappant de l'échantillon, dépendant elle-même de l'énergie de ces électrons. On peut ainsi montrer que les électrons Auger sont caractéristiques d'une profondeur de quelques Angströms seulement. Leur analyse permet donc de caractériser qualitativement et quantitativement la surface de matériaux solides. [less ▲] Detailed reference viewed: 88 (6 ULg) Spectrophotometric Monitoring of Comet C/1995 O1 (Hale-Bopp): Pre- and Post-Perihelion; ; Arpigny, Claude et alin Bulletin of the American Astronomical Society (1998, September 01) Spectrophotometric observations of comet C/1995 O1 (Hale-Bopp) were performed at the European Southern Observatory (ESO), Chile. From April to September 1996 its gaseous activity was monitored over a ... [more ▼] Spectrophotometric observations of comet C/1995 O1 (Hale-Bopp) were performed at the European Southern Observatory (ESO), Chile. From April to September 1996 its gaseous activity was monitored over a heliocentric distance range from 4.6 AU to 2.9 AU. The monitoring is continued on Hale-Bopp's outbound path since September 1997 and covers up to now 3 AU to 5 AU heliocentric distance. Medium resolution spectra in the optical wavelength range from about 350 nm to 700 nm were taken at the 1.54m Danish and the 1.52m ESO telescope. Emission bands of the CN, C_3, C_2 and NH_2 radicals can be followed over the comet's orbit. We will present a first analysis of the post-perihelion activity evolution and compare to the pre-perihelion path. Currently, at 4.7 AU on the outbound path, we still see emission of CN, C_3, C_2 and NH_2. The production rate of CN showed a sudden increase around this heliocentric distance pre-perihelion (Rauer et al., Science 275, 1909). The post-perihelion activity evolution of CN and the other observed radicals in this distance range will be evaluated. [less ▲] Detailed reference viewed: 12 (1 ULg) Spectrophotométrie dans le proche infra-rouge. Une méthode d'analyse adaptée au secteur agro-alimentaire.Sindic, Marianne ![]() in Agoratech (1997) Detailed reference viewed: 13 (1 ULg) Spectrophotométrie dans le proche infrarouge : Une méthode d'analyse adaptée au secteur agro-alimentaire.Sindic, Marianne ![]() in Agoratech (1997), (8), Detailed reference viewed: 8 (1 ULg) Spectropolarimetry of the iron low ionization broad absorption line quasar Q 0059-2735; Hutsemekers, Damien ![]() in Astronomy and Astrophysics (2000), 356(Letters), 9-12 We present optical (ultraviolet rest-frame) spectropolarimetric observations of the rare iron low ionization broad absorption line (BAL) QSO Q 0059-2735. The continuum polarization increases to the blue ... [more ▼] We present optical (ultraviolet rest-frame) spectropolarimetric observations of the rare iron low ionization broad absorption line (BAL) QSO Q 0059-2735. The continuum polarization increases to the blue with a regular rotation of the polarization position angle, suggesting that at least two mechanisms are at the origin of the polarization. There is also some evidence for dilution by a ion {Fe}{ii} pseudo-continuum in emission. In the broad absorption lines, the polarization strongly rises, with the largest values ever reported. On the contrary, the ion {Fe}{ii} blends in absorption are not more polarized than the continuum, while they are clearly visible in the polarized flux. These different polarization properties of ion {Fe}{ii} absorption lines suggest a different origin and/or geometry. The observed properties of Q 0059-2735 are consistent with a hybrid QSO / starburst model. Based on observations collected at the European Southern Observatory, La Silla, Chile [less ▲] Detailed reference viewed: 5 (3 ULg) Spectropolarimetry of WR66; Hutsemekers, Damien ; Rauw, Grégor ![]() in Wolf-Rayet stars in the framework of stellar evolution ; 33rd Liege International Astrophysical Coll (1996) We have carried out spectropolarimetric observations of the Wolf-Rayet star WR66 (WN8) with EFOSC1 mounted on the ESO 3.6m telescope of La Silla. The results indicate a polarization level of about 5 to 6 ... [more ▼] We have carried out spectropolarimetric observations of the Wolf-Rayet star WR66 (WN8) with EFOSC1 mounted on the ESO 3.6m telescope of La Silla. The results indicate a polarization level of about 5 to 6 % in the continuum which is most probably due to interstellar polarization. [less ▲] Detailed reference viewed: 7 (3 ULg) Spectroscopic analysis of extreme metal-poor 'dwarfs'. I Observational material, Fe lines, and model atmospheresMagain, Pierre ![]() in Astronomy and Astrophysics (1984), 132 Abstract image available at: http://adsabs.harvard.edu/abs/1984A&A...132..208M Detailed reference viewed: 4 (2 ULg) Spectroscopic analysis of extreme metal-poor 'dwarfs'. II - Improved model atmospheres and detailed abundancesMagain, Pierre ![]() in Astronomy and Astrophysics (1985), 146 High resolution spectrophotometric data were obtained for the stellar objects HD 19445 and HD 140283. The spectra gathered were well-matched by model stellar atmospheres for the continuous flux and Fe I ... [more ▼] High resolution spectrophotometric data were obtained for the stellar objects HD 19445 and HD 140283. The spectra gathered were well-matched by model stellar atmospheres for the continuous flux and Fe I excitation equilibrium. HD 19445 was identified as a dwarf star and HD 140283 as a subgiant. Abundance analyses indicated an Fe abundance lower than previously estimated, oxygen overabundant relative to C and Fe, Mg, Si and Ca overabundant relative to Fe, and deficiencies of Al and Mn. Sr was overabundant relative to Ba. The abundance discrepancies are in disagreement with the standard nucleosynthesis model. Further such spectroscopic data are needed to develop accurate galactic chemical evolution models. [less ▲] Detailed reference viewed: 2 (0 ULg) Spectroscopic analysis of the Alpha Centauri system; Magain, Pierre ![]() in Astronomy and Astrophysics (1997), 328 A detailed spectroscopic analysis of the two components of the binary system alpha Centauri has been carried out on the basis of extensive high resolution and high signal-to-noise spectra. The ... [more ▼] A detailed spectroscopic analysis of the two components of the binary system alpha Centauri has been carried out on the basis of extensive high resolution and high signal-to-noise spectra. The temperatures of the stars have been determined from the Fei excitation equilibrium and checked from the H_alpha line wings. The abundances of 17 elements have been obtained and indicate a general overabundance of 0.24 dex relative to the Sun, with no significant difference between the two stars. All elements analysed, from CNO to the iron peak, show basically the same overabundance. Only nickel seems to be significantly more overabundant, while the neutron capture elements appear less enhanced. Based on observations carried out at the European Southern Observatory (La Silla, Chile) [less ▲] Detailed reference viewed: 11 (1 ULg) Spectroscopic anatomy of a meteor trail cross section with the European Southern Observatory Very Large Telescope; Jehin, Emmanuel ; et alin Meteoritics & Planetary Science (2004), 39 A meteor spectrum was recorded serendipitously at the European Southern Observatory (ESO) Very Large Telescope (VLT) during a long exposure in long-slit spectroscopic mode with FORS1. The -8 magnitude ... [more ▼] A meteor spectrum was recorded serendipitously at the European Southern Observatory (ESO) Very Large Telescope (VLT) during a long exposure in long-slit spectroscopic mode with FORS1. The -8 magnitude fireball crossed the narrow 1 × 7 slit during the observation of a high z supernova in normal service mode operation on May 12, 2002. The spectrum covered the range of 637-1050 nm, where the meteor's air plasma emissions from N2, N, and O dominate. Carbon atom emission was not detected in the relatively unexplored wavelength range above 900 nm, but the observed upper limit was only 3 sigma less than expected from the dissociation of atmospheric CO2. The meteor trail was resolved along the slit, and the emission had a Gaussian distribution with a dimension of FWHM = 7.0 (±0.4) * sin(a) * H (km)/90 m, where a is the unknown angle between the orientation of the meteor path and slit and H the assumed altitude of the meteor in km. To our knowledge, this is the first observation of a spatially resolved spectrum across a meteor trail. Unlike model predictions, the plasma excitation temperature varied only from about 4,300 to 4,365 K across the trail, based on the ratio of atomic and molecular nitrogen emissions. Unfortunately, we conclude that this was because the meteor at 100 km altitude was out of focus. [less ▲] Detailed reference viewed: 1 (0 ULg) Spectroscopic anatomy of a meteor with the very large telescope (ESO)Jehin, Emmanuel ; ; et alin Advances in Space Research (2007), 39 A meteor spectrum was recorded serendipitously with the ESO Very Large Telescope during a long exposure in long-slit spectroscopic mode with the instrument FORS1. The -8 magnitude fireball crossed the ... [more ▼] A meteor spectrum was recorded serendipitously with the ESO Very Large Telescope during a long exposure in long-slit spectroscopic mode with the instrument FORS1. The -8 magnitude fireball crossed the narrow (1 arcsec × 7 arcmin) slit during the observation of a high z supernova in normal service mode operation on May 12, 2002. The spectrum covers the range of 637 1050 nm, where the meteor’s air plasma emissions from N[SUB]2[/SUB], N and O dominate. The meteor trail appears moreover resolved along the slit but we conclude that this is because the meteor at 100 km altitude was out of focus for the VLT. The plasma excitation temperature varies only from about 4300 to 4365 K across the trail, based on the ratio of atomic and molecular nitrogen emissions. This is in agreement with the fact that the trail is not actually spatially resolved. Finally, carbon atom emission is not detected in the relatively unexplored range above 900 nm. [less ▲] Detailed reference viewed: 2 (0 ULg) Spectroscopic anatomy of a meteor with the Very Large Telescope (ESO)Jehin, Emmanuel ; ; et alin 35th COSPAR Scientific Assembly (2004) A meteor spectrum in the range 637 - 1050 nm was recorded serendipitously at the ESO Very Large Telescope during a long exposure in long-slit spectroscopic mode with FORS1. The meteor crossed the narrow 1 ... [more ▼] A meteor spectrum in the range 637 - 1050 nm was recorded serendipitously at the ESO Very Large Telescope during a long exposure in long-slit spectroscopic mode with FORS1. The meteor crossed the narrow 1" x 7' slit during normal service mode operation on May 12, 2002. To our knowledge, this is the first observation of a spatially resolved spectrum across a meteor trail. The trail is wider than expected and the plasma excitation temperature varies only from about 4,300 to 4,365 K across the trail, based on the ratio of atomic and molecular nitrogen emissions. The observed width could originate from a range of fragments that have spread significantly at the time of the observation. Finally, carbon atom emission is not detected in the relatively unexplored range above 900 nm. [less ▲] Detailed reference viewed: 6 (0 ULg) Spectroscopic and photometric observations of galaxies from the ESO/Uppsala list - Third catalogue; Surdej, Jean ; et alin Astronomy and Astrophysics. Supplement Series (1981), 46 Abstract image available at: http://esoads.eso.org/abs/1981A&AS...46...57W Detailed reference viewed: 2 (0 ULg) Spectroscopic and photometric observations of galaxies from the ESO/Uppsala list Second catalogue; ; et al in Astronomy and Astrophysics. Supplement Series (1978), 33 Abstract image available at: http://esoads.eso.org/abs/1978A&AS...33..243B Detailed reference viewed: 10 (1 ULg) Spectroscopic and photometric variability of O and Wolf-Rayet starsGosset, Eric ; Rauw, Grégor ![]() in Communications in Asteroseismology (2009, July 01), 158 Low-level line profile variability in the optical domain is a ubiquitous feature of O, Of and Wolf-Rayet type stars. This variability can arise from pulsations, from magnetic fields or wind structures ... [more ▼] Low-level line profile variability in the optical domain is a ubiquitous feature of O, Of and Wolf-Rayet type stars. This variability can arise from pulsations, from magnetic fields or wind structures (both small and large scales). For main-sequence O-type stars, the spectra display many absorption lines that provide stringent diagnostics of photospheric features. However, as the stars evolve off the main-sequence towards the Of and Wolf-Rayet stage, the stellar wind densities (and hence the wind optical depths) increase dramatically. The wind eventually dominates the formation of the entire spectrum rendering the investigation of photospheric structures more ambiguous. We discuss the observational analyses of the spectroscopic and photometric variability of massive stars of spectral type O, Of and WR. In particular, we highlight the search for a connection between the photospheric and the wind variability. [less ▲] Detailed reference viewed: 9 (3 ULg) Spectroscopic and photometric variability of the O9.5Vp star HD93521Rauw, Grégor ; De Becker, Michaël ; et alin Astronomy and Astrophysics (2008), 487(2), 659-670 Aims. The line profile variability and photometric variability of the O9.5Vp star HD93521 are examined in order to establish the properties of the non-radial pulsations in this star. Methods. Fourier ... [more ▼] Aims. The line profile variability and photometric variability of the O9.5Vp star HD93521 are examined in order to establish the properties of the non-radial pulsations in this star. Methods. Fourier techniques are used to characterize the modulations of the He I lambda lambda 5876, 6678 and H alpha lines in several spectroscopic time series and to search for variations in a photometric time series. Results. Our spectroscopic data confirm the existence of two periods of 1.75 and 2.89 h. The line profiles, especially those affected by emission wings, exhibit also modulations on longer time scales, but these are epoch-dependent and change from line to line. Unlike previous claims, we find no unambiguous signature of the rotational period in our data, nor of a third pulsation period (corresponding to a frequency of 2.66 d(-1)). Conclusions. HD93521 very likely exhibits non-radial pulsations with periods of 1.75 and 2.89 h with l similar or equal to 8 +/- 1 and l similar or equal to 4 +/- 1 respectively. No significant signal is found in the first harmonics of these two periods. The 2.89 h mode is seen at all epochs and in all lines investigated, while the visibility of the 1.75 h mode is clearly epoch-dependent. Whilst light variations are detected, their connection to these periodicities is not straightforward. [less ▲] Detailed reference viewed: 34 (6 ULg) |
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