26 research outputs found
Le développement durable (DD) au service des pourvoiries du Saguenay-Lac-Saint-Jean
Affiche présentée dans le cadre du Colloque de l'ARC, «La culture de la recherche au collégial», dans le cadre du 82e Congrès de l'Acfas, Université Concordia, Montréal, le 14 mai 2014.Au Québec, un vaste réseau hydroélectrique a été développé afin de satisfaire les besoins énergétiques de la population. Toutefois, certains territoires isolés n’ont pas d’accès à ce réseau. La demande d’électricité, de chauffage et de transport y est comblée par l’usage des combustibles fossiles, qui émettent d’importantes quantités de gaz à effet de serre. Au cégep de Jonquière, la Chaire de recherche industrielle en technologies des énergies renouvelables et du rendement énergétique (TERRE) travaille depuis 2013 au développement d’un outil d’analyse pour l’approvisionnement en énergies vertes des sites isolés. Une étude préliminaire a déjà été effectuée dans quatre pourvoiries du Saguenay– Lac-Saint-Jean afin de valider l’outil. Ce dernier, sous forme de tableur Excel, permet d’évaluer les thèmes issus des dimensions sociale, écologique, économique et de gouvernance qui sous-tendent le développement durable. L’outil permet de dresser une liste de priorités afin d'entamer un virage de développement plus vert. Les résultats préliminaires mettent l’accent sur la dépendance des sites isolés aux combustibles fossiles, mais également sur la volonté de diversifier leurs ressources en énergie. Au cours de la présente année, l’outil sera testé dans un plus grand nombre de pourvoiries et les résultats seront couplés à une analyse technico-économique qui mesurera le potentiel d’intégration des filières énergétiques renouvelables dans chacun des sites étudiés
HF radar detection of infrasonic waves generated in the ionosphere by the 28 March 2005 Sumatra earthquake
International audienceSurface waves generated by earthquakes create atmospheric waves detectable in the ionosphere using radio waves techniques: i.e., HF Doppler sounding, GPS and altimeter TEC measurements, as well as radar measurements. We present observations performed with the over-the-horizon (OTH) radar NOSTRADAMUS after the very strong earthquake (M=8.6) that occurred in Sumatra on March 28, 2005. An original method based on the analysis of the RTD (Range-Time-Doppler) image is suggested to identify the multi-chromatic ionospheric signature of the Rayleigh wave. The proposed method presents the advantage to preserve the information on the range variation and time evolution, and provides comprehensive results, as well as easy identification of the waves. In essence, a Burg algorithm of order 1 is proposed to compute the Doppler shift of the radar signal, resulting in sensitivity as good as obtained with higher orders. The multi-chromatic observation of the ionospheric signature of Rayleigh wave allows to extrapolate information coherent with the dispersion curve of Rayleigh waves, that is, we observe two components of the Rayleigh waves with estimated group velocities of 3.8 km/s and 3.6 km/s associated to 28 mHz (T~36 s) and 6.1 mHz (T~164 s) waves, respectively. Spectral analysis of the RTD image reveals anyway the presence of several oscillations at frequencies between 3 and 8 mHz clearly associated to the transfer of energy from the solid-Earth to the atmosphere, and nominally described by the normal modes theory for a complete planet with atmosphere. Oscillations at frequencies larger than 8 mHz are also observed in the spectrum but with smaller amplitudes. Particular attention is pointed out to normal modes 0S29 and 0S37 which are strongly involved in the coupling process. As the proposed method is frequency free, it could be used not only for detection of ionospheric perturbations induced by earthquakes, but also by other natural phenomena as well as volcanic explosions and particularly tsunamis, for future oceanic monitoring and tsunami warning systems
Apport des probabilités et des statistiques à la prédiction des perturbations induites par un téléphone portable sur des câbles
PARIS-BIUSJ-Thèses (751052125) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF
Influence of salt reduction on flavour release in ready-to-eat meal
International audienc
Astronomie radar et radioastronomie à l'aide du radar transhorizon Nostradamus: Un fleuron technologique français au service de la science
Dossier : Journées scientifiques d'URSI 2015 : "Sonder la matière par les ondes électromagnétiques"National audienceThe Nostradamus radar system is a set of 288 antenna elements distributed over the arms of a threebranchstar. It is operating in High Frequency waves (6 to 28 MHz) that bounce on the ionosphere,reaching areas far beyond the horizon. As an early warning radar system, its primary purpose was the detectionof aircraft at long ranges from 700 to 3 000 km. Whereas over-the-horizon (OTH) radars are usually bistatic andrequire huge linear antenna networks to beam the signals, the special surface distribution of Nostradamus makes itpossible to control the electronic beams both in azimuth and elevation. This original conception of the system allowsits use in many scientific fields.In the past years, research have been carried out on the ionosphere, on oceanography and on seismology. Morerecently, the radar has been used at trans-ionospheric frequencies to do radar astronomy by detecting meteoritesand the Moon, and radio astronomy by observing Jovian and Solar radio emissions. Few large instruments operateat decameter wave mainly because of man made radio frequency interference and because of the poor signal tonoise ratio of cosmic sources. However, interest for this frequency domain have recently been making something ofa comeback, as new giant telescopes are being built. After a quick presentation of the OTH radar, we present somespace observations that have been made. These radio observations are compared to data coming from a decameterradio telescope, the Nancay Decameter Array located in France. Finally, we will discuss about possible other experimentsthat could be carried out in the future
A comparison of salt perception and acceptance of salt reduced bread among children and adults
International audienc
A comparison of salt perception and acceptance of salt reduced bread among children and adults
International audienc