Monitoring a shallow geothermal experiment in a sandy aquifer using electrical resistivity tomography: a feasibility study

Poster (2010, May 06)

Geothermal resources, especially groundwater resources, are increasingly used around the world. It is therefore necessary to improve the characterisation of thermal parameters of the aquifers. This is ... [more ▼]

Geothermal resources, especially groundwater resources, are increasingly used around the world. It is therefore necessary to improve the characterisation of thermal parameters of the aquifers. This is done mostly with thermal response tests. In this work, we monitored with electrical resistivity tomography a geothermal test on the campus of Ghent University (Belgium). We injected warm water (45°C) into a sandy aquifer where the groundwater has a temperature of 10°C at a rate of 100 liter/hour during three days. Laboratory measurements indicated that we could expect at most a change of 2%/°C of the water electrical conductivity. The time-lapse series of electrical images show clearly the thermal plume corresponding to the injected water with a maximum change of minus 20% after 72 hours of injection. A comparison with a geothermal model shows that the anomaly is well detected but also distorded due to the inversion regularization (smoothness constraint). ERT enabled to follow the evolution of the injected heated water with more spatial coverage that traditionnal techniques. ERT is thus an interesting tool to monitor the exploitation of geothermal resources. In the future, it will be necessary to improve the inversion process to use quantitavely such results in a calibration process. [less ▲]

Monitoring an Odour in the Environment with an Electronic Nose: Requirements for the Signal Processing

in Gutierrez, Agustin; Marco, S. (Eds.) Biologically Inspired Signal Processing for Chemical Sensing (2009)

Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual odour measurement techniques use human olfaction or analytical techniques ... [more ▼]

Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual odour measurement techniques use human olfaction or analytical techniques. The first category represents the real odour perception but is not applicable to measure in continuous bad odours in the field. The second class of techniques gives the composition of the mixture but not the global information representative of the odour perception. The e-nose has the potentialities to combine “the odour perception” and the “monitoring in the field”. However to be able to reach this goal, the signal processing has to be adapted to work in complex environment. We have more than teen years experiments in the measure of environmental malodours in the field and the paper presents the minimal requirements that we consider essential for artificial olfaction system to become successful for this application. [less ▲]

Monitoring and mapping landslide displacements: a combined DGPS-stereophotogrammetric approach for detailed short- and long-term rate estimates

in Terra Nova (2006), 18(4), 290-298

Although desirable for a reliable hazard assessment, rate estimates of landslide motion rarely combine a good time resolution and a sufficiently long time of observation. Here, both angles are tackled for ... [more ▼]

Although desirable for a reliable hazard assessment, rate estimates of landslide motion rarely combine a good time resolution and a sufficiently long time of observation. Here, both angles are tackled for the Manaihan landslide (East Belgium), dramatically reactivated in September 1998. I monitored the landslide displacements by repeated Global Positioning System (GPS) surveys from 1999 to 2005. Two digital elevation models were also produced, one of the landslide topography in 1999 by GPS and a second by stereophotogrammetry from aerial photographs of 1953. Subtracting one model from the other, I mapped the height changes within the landslide over the 1953-1999 period. All measurements consistently showed that, beyond the sudden similar to 1.5 m slip of September 1998, the landslide moved at a mean rate of c. 20 cm yr(-1) since 1980. Most displacements occurred around the winter's end, when long-lasting precipitation combined with minimal evaporation and occasional intense daily rainfall. The motions are spatially determined by seepage from a broken sewage pipe inducing local high pore pressures. [less ▲]

Monitoring biomass, polysaccharides, glucose and lactate in an industrial fermentation of Streptococcus pneumoniae by Near-infrared Spectroscopic determination.

Poster (1999, July)

Monitoring color alteration of ornamental flagstones using digital image analysis.

in Prykryl, R. (Ed.) Dimension Stone (2004)

Le Monitoring de la pression artérielle en pratique médicale : apports et limites

in Blood Pressure Profil (1994), 3

"L'article de Mme Saint-Remy et de G. Rorive constitue une bonne mise au point sur les controverses qui continuent à se développer autour de la place à réserver au monitorage ambulatoire de la pression ... [more ▼]

"L'article de Mme Saint-Remy et de G. Rorive constitue une bonne mise au point sur les controverses qui continuent à se développer autour de la place à réserver au monitorage ambulatoire de la pression artérielle (MAPA) dans l'évaluation du patient hypertendu. La variabilité importante universellement admise de la pression artérielle rend le concept du monitorage pendant 24 heures particulièrement attrayant. L'utilité de cette nouvelle approche ne sera cependant définitivement établie que quand les résultats d'études prospectives visant à démontrer la supériorité du MAPA sur la mesure conventionnelle de la pression artérielle seront connus. Deux études sont au minimum actuellement en cours en ce sens : l'étude OVA et l'étude Systeur. En attendant, le manque de valeurs normatives est évidemment un handicap pour l'intérêt de la MAPA dans la pratique journalière et ce d'autant plus que le coût de cette nouvelle méthodologie reste élevé. Dans la revue de la littérature de ce numéro de Blood Pressure Profile, deux publications viennent confirmer ce qui est avancé dans l'article de Mme Saint-Remy. Bianchi et col, observant que la microalbuminurie est plus importante chez les hypertendus en l'absence de chute nocturne de la pression artérielle, argumentent en faveur du rôle de la MAPA dans l'évaluation du pronostic cardio-vasculaire du patient hypertendu. De plus, Mansoor et al, confirmant la meilleure reproductibilité de MAPA par rapport à la mesure conventionnelle de la pression artérielle, concluent également que la MAPA permettra de diminuer le nombre de patients à inclure dans des essais de pharmacologie clinique. Ces résultats, bien qu'encourageant pour les défenseurs du MAPA, ne doivent cependant pas nous faire oublier que la généralisation de l'utilisation de cette nouvelle technique est à l'heure actuelle prématurée" Prof. J.P. Degaute, Hypertension Clinic, Hôpital Universitaire Erasme, Chief Editor [less ▲]

Monitoring delivery chains in a supply chain using multivariate control charts

E-print/Working paper (n.d.)

The theory of the delivery chain considers the delivery of goods and services to customers within a specific time interval. Nowadays, organizations are focusing to satisfy their customers’ demands not ... [more ▼]

The theory of the delivery chain considers the delivery of goods and services to customers within a specific time interval. Nowadays, organizations are focusing to satisfy their customers’ demands not only to meet the expectations for products quality but also in delivery times through managing delivery chains. Obviously it is desirable that a company has minimum delivery time of goods and services to its customers. Therefore, establishing economic and reliable control charts for monitoring the key characteristics of delivery chain is of great importance especially for managers to improve the whole delivery chains performance. On the other hand, as we shall see in the present paper, the performance of a delivery chain is multivariate in nature because customers do not evaluate a delivery performance with a univariate mindset and also there are usually several production and delivery sites, and variety of different methods of transportation of goods and services. In this paper, we propose a relatively new application of the economic statistical design of the multivariate T2 control chart to monitor the delivery chain performance and it is illustrated through a case study in the TNT express mail in Iran. [less ▲]

Monitoring delivery chains using multivariate control charts

in Proceedings of the 2nd International Symposium on Statistical Process Control, Rio de Janeireo, 13-15 July 2011 (2011, July)

Monitoring des animaux vivants : exemple d’un échantillonnage pour la détection des PCBs et des dioxines chez les bovins de boucherie en Belgique

in Epidémiologie et Santé Animale (2000), 38

In February 1999, a poisoning episode broke out in several industrial poultry farms in Belgium. The source of this contamination was found to be a stock of recycled fat that had been delivered by a firm ... [more ▼]

In February 1999, a poisoning episode broke out in several industrial poultry farms in Belgium. The source of this contamination was found to be a stock of recycled fat that had been delivered by a firm to several compound feed producers, between 19 and 31 January 1999. A very good correlation was observed between dioxins (PCDFs and PCDDs) and PCBs. Consequently a contamination mainly by PCBs was hypothesized. This finding made it possible to detect contaminated animals and animal products by dosage of the PCBs, more specifically by the 7 congeners with numbers 28, 52, 101, 118, 138, 153 and 180. The advantages of the dosage of PCBs compared to dioxins were its rapid test protocol and the fact that a larger number of laboratories could participate. In the cattle sector, 409 herds (0,81 p. cent) were submitted to the risk of feed contamination. The methodology used to detect a PCBs/dioxins contamination in the Belgian cattle population that was not submitted to the risk, is presented. This population is directly or indirectly destined for human consumption. It consisted in the systematic sampling of all calve fattening stations and all lots of exported bovines, and in the random sampling of slaughter cattle. This methodology is compared to the approach described in directive 96/23/CE. [less ▲]

Monitoring des bandes riveraines : vitrine des cours d'eau wallons

Poster (2009, October 20)