References of "Nicolas, Jacques"
     in
Bookmark and Share    
Full Text
See detailDeuxième campagne de mesure des odeurs sur le site de traitement des déchets de Tenneville Estimation des nuisances olfactives
Nicolas, Jacques ULg; Thomas, Jean-François; Delva, Julien et al

Report (2009)

The study is conducted in the frame of a programme of monitoring of all landfill sites in Wallonia. The "odour" part is assigned to ULg. The present report concerns more particularly a second campaign on ... [more ▼]

The study is conducted in the frame of a programme of monitoring of all landfill sites in Wallonia. The "odour" part is assigned to ULg. The present report concerns more particularly a second campaign on the site of Tenneville, which is more than a simple landfill area, as it includes also other waste treatment faciliities : composting, biogas production and drying of wastewater sludges. Besides the usual field inspection technique, the research group has applied a 3D analysis to study the shape and the size of the odour plume in this uneven region. [less ▲]

Detailed reference viewed: 30 (0 ULg)
Full Text
See detailOngoing desertification processes in the sahelian belt of West Africa: An evidence from the rain-use efficiency.
Hountondji, Yvon ULg; Sokpon, Nestor; Nicolas, Jacques ULg et al

in Röder, Achim; Hill, Joachim (Eds.) Recent Advances in Remote Sensing and Geoinformation Processing for Land Degradation Assessment (2009)

The implementation of the UNCCD needs the identification of areas that record declining productivity of the vegetation over long-time periods. In this scope, we analyze the state of the vegetation ... [more ▼]

The implementation of the UNCCD needs the identification of areas that record declining productivity of the vegetation over long-time periods. In this scope, we analyze the state of the vegetation productivity using 1982–1999 time series of NOAA-AVHRR NDVI data and compare it to rainfall data. For this, 354 rain gauges data distributed from yearly average isohyets 100 to 900 mm in five countries of West Africa are analyzed. We use for trends analysis, the ratio between integrated vegetation index (iNDVI) during the growing period (June to October) and the May to October sum of rainfall (RR). This ratio is a proxy of the Rain Use Efficiency is the widely accepted. Overall, 91% and 94% of RR and iNDVI data recorded positive trends over the 1982–1999 periods. Most stations in the Sahel were stable for the iNDVI/RR (49.5%). However, 37.8% showed strong to very strong negative change in the iNDVI/RR ratio, while only 1.3% showed positive trend. These strong negative trends recorded in more than 1/3 of the analyzed stations may reflect ongoing desertification processes in the Sahel and could be a starting point for the identification of hot-spots areas to determine where to take action within the National Action Programs (NAP) or Sub-Regional Action Programs (SRAP) to combat desertification. [less ▲]

Detailed reference viewed: 64 (6 ULg)
Full Text
Peer Reviewed
See detailLong Term Stability Of Metal Oxide-Based Gas Sensors For E-nose Environmental Applications: an overview
Romain, Anne-Claude ULg; Nicolas, Jacques ULg

in Pardo, Matteo; Sberveglieri, Giorgio (Eds.) OLFACTION AND ELECTRONIC NOSE: Proceedings of the 13th International Symposium on Olfaction and Electronic Nose (2009)

The e-nose technology has enormous potentialities for in site monitoring of malodors. However a number of limitations are associated with the properties of chemical sensors, the performances of the signal ... [more ▼]

The e-nose technology has enormous potentialities for in site monitoring of malodors. However a number of limitations are associated with the properties of chemical sensors, the performances of the signal processing and the realistic operation conditions of environmental field. From the experience of the research group in the field, the metal oxide based gas sensors (Figaro type) are until now the best chemical sensors for long term application, more than one year of continuous working in the field. To be usable for malodors measurement in the field, the e-nose has to deal with the lack of long term stability of these sensors. The drift and the sensors replacement have to be considered. In order to appraise the time evolution of the sensors and the effect on the results of an electronic nose, experimentation has been performed during three years on two identical sensor arrays. The two arrays contain the same six Figaro sensors and are in the same sensor chamber of the e-nose system. Both arrays have worked continuously during three years without break. [less ▲]

Detailed reference viewed: 74 (15 ULg)
Full Text
See detailMonitoring an Odour in the Environment with an Electronic Nose: Requirements for the Signal Processing
Romain, Anne-Claude ULg; Nicolas, Jacques ULg

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 ▲]

Detailed reference viewed: 123 (60 ULg)
See detailMethods of sensory evaluation of odour and 50 m3 test facility at Arlon laboratory
Romain, Anne-Claude ULg; Nicolas, Jacques ULg; Degraeve, Ch

Diverse speeche and writing (2008)

Detailed reference viewed: 19 (7 ULg)
See detailLes précurseurs d'ozone dans le secteur tertiaire
Romain, Anne-Claude ULg; Nicolas, Jacques ULg

Report (2008)

Une enquête réalisée par le laboratoire TAUW à la demande de la chambre de commerce a été menée sur un certain nombre d'entreprises du secteur tertiaire dans la province de Luxembourg(coiffeurs ... [more ▼]

Une enquête réalisée par le laboratoire TAUW à la demande de la chambre de commerce a été menée sur un certain nombre d'entreprises du secteur tertiaire dans la province de Luxembourg(coiffeurs, imprimeries, nettoyage, ...). Cette enquête portait sur une tentative d'évaluation des composés précurseurs d'ozone (solvants, ...). L'ULg a été chargée de l'analyse des résultats. Ceux-ci restent encore très partiels et ne donne pas de tendance précise pour la province. [less ▲]

Detailed reference viewed: 37 (6 ULg)
Full Text
Peer Reviewed
See detailOdour annoyance assessments around landfill sites:methods and results
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Delva, Julien ULg et al

in Chemical Engineering Transactions (2008, June), 15

Detailed reference viewed: 55 (10 ULg)
Full Text
See detailTroisième campagne de mesure des odeurs sur le CET "Champ de Beaumont" à Monceau-sur-Sambre - Estimation des nuisances olfactives.
Nicolas, Jacques ULg; Thomas, Jean-François; Delva, Julien et al

Report (2008)

The study is conducted in the frame of a programme of monitoring of all landfill sites in Wallonia. The "odour" part is assigned to ULg. The present report concerns more particularly a third campaign on ... [more ▼]

The study is conducted in the frame of a programme of monitoring of all landfill sites in Wallonia. The "odour" part is assigned to ULg. The present report concerns more particularly a third campaign on the site of "Champ-de-Beaumont" at Monceau-sur-Sambre. Besides the usual field inspection technique, the research group has used the results of a survey conducted in the surrounding population together with olfactometric measurements and chemical analyses performed on samples collected through a flux chamber placed on the waste area. [less ▲]

Detailed reference viewed: 14 (1 ULg)
See detailThe problem of odours when drying sewage sludges
Léonard, Angélique ULg; Nicolas, Jacques ULg; Romain, Anne-Claude ULg et al

Conference (2008, June)

Detailed reference viewed: 49 (23 ULg)
Full Text
See detailLes odeurs dans l'environnement : dimensions sensorielles et méthodes d'évaluation.
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Delva, Julien ULg

in Journal des Ingénieurs (Le) (2008), 109

Les différentes composantes de la nuisance olfactive ainsi que les diverses méthodes d'évaluation correspondantes sont présentées de manière concrète et en relation avec les normes existantes. L'article ... [more ▼]

Les différentes composantes de la nuisance olfactive ainsi que les diverses méthodes d'évaluation correspondantes sont présentées de manière concrète et en relation avec les normes existantes. L'article détaille les mesures d'intensité et de concentration de l'odeur en laboratoire, les techniques d'échantillonnage sur sources canalisées ou surfaciques, la méthode d'olfactométrie déambulatoire pour les sources fugitives et diffuses. Il présente également la notion d'exposition, traduite par la courbe représentant un percentile spatio-temporel de concentration d'odeur. Il est également montré que les riverains peuvent être impliqués dans le cadre d'enquêtes ou dans des réseaux de vigies pour estimer la nuisance. <br />Enfin, les potentialités des réseaux de capteurs-gaz (nez électroniques), bientôt commercialisés par Odometric, spin-off de l'unité de recherche de l'ULg, sont également présentées. [less ▲]

Detailed reference viewed: 103 (10 ULg)
Full Text
See detailProjet "NOSEMOLD" Appareil de diagnostic rapide des moisissures sur les matériaux de construction
Nicolas, Jacques ULg; Delva, Julien

Report (2008)

The report concerns a "FIRST spin-off" project aiming at creating a spin-off company based on the research of the unity of the university. The study concerned the design of an instrument, based on the ... [more ▼]

The report concerns a "FIRST spin-off" project aiming at creating a spin-off company based on the research of the unity of the university. The study concerned the design of an instrument, based on the "electronic nose" principle, to detect the presence of moulds on building materials from the analysis of the gas phase. The apparatus proved to be able of distinguishing pure material from contaminated one, but it was more difficult to identify the mould species. [less ▲]

Detailed reference viewed: 20 (4 ULg)
Full Text
Peer Reviewed
See detailDesertification process in the sahelian belt of West Africa: What's the state of play?
Hountondji, Yvon ULg; Sokpon, Nestor; Nicolas, Jacques ULg et al

in Ozer, André; Swinne, Danielle (Eds.) Desertification: Migration, Health, Remediation and Local Governance (2008)

Detailed reference viewed: 28 (4 ULg)
Peer Reviewed
See detailAir survey around MSW landfills in Wallonia: feedback of 8 years field measurements
Collart, Catherine; Lebrun, Vincent; Fays, Sébastien et al

in Proceedings ORBIT 2008, 6th Biomass and Organic Waste as Sustainable (2008)

For more than 8 years, an interdisciplinary air survey was achieved by ISSeP around 10 municipal solid waste (MSW) landfills in Wallonia (Belgium). Surveying campaigns include 4 axes of investigations ... [more ▼]

For more than 8 years, an interdisciplinary air survey was achieved by ISSeP around 10 municipal solid waste (MSW) landfills in Wallonia (Belgium). Surveying campaigns include 4 axes of investigations: landfill gas (LFG) surface emissions detection, ambient air quality control, odours annoyance assessment and measurements on exhaust fumes from LFG valorisation units. Especially the first 3 domains closely interact. Monitoring of landfill surface gas-emissions is performed by a simple low-cost method[1]. Portable FID measurements are taken on landfill surface along regular and dense grids. Krigging measured CH4 concentrations furnish continuous maps which localize higher and lower emission zones, assuming that, at a medium observation scale, high fluxes zones create high methane concentrations in the upper part of landfill capping. Air surveying campaigns on each landfill include ambient air quality measurement. During several weeks, 8 tracers parameters are analysed continuously by on site monitoring devices. They are placed near exploitation, downwind or in direction of the nearest neighbours. Measured values are compared to health threshold values. Local wind directions are simultaneously recorded in order to create “pollution roses”. These graphs show, for each sector of wind direction, the mean concentration of a tracer at the measured point when wind comes from the sector. This dual approach allows controlling that air quality remains safe for human health and checking if possible anomalies are produced by the landfill or not. Evaluating the odour annoyance created by a wide, heterogeneous diffuse and multiple sources such as MSW landfills is a difficult challenge. Classical flux chamber method combined with dynamic olfactometry does not allow apprehending the unique perception of an observer created by a so complex odour emitter. An interesting alternative approach, developed by the Environmental Monitoring Research Group, University of Liège, was applied to the wallonian landfills[2]. Field observers first delineate the regions in which odour impact is experienced. Emission rates are then manipulated in a dispersion model until the predicted size of the impact zone matches the one observed in the field, taking into account of measured meteorological conditions. Such back-calculation assesses global odour emission rates. In situ odour campaigns may guide the positioning of air monitoring devices. Inversely, analysing odorous compounds near a neighbour can corroborate its annoyance by analytical evidences. Knowing the intensity and localisation of LFG emissions often help to better understand LFG odour in the neighbourhood, and motivate the placement of H2S sensor at right place, for example. Finally, by combining results from three fields of investigation, one can obtain a really efficient and complete environmental impact study of a landfill on its surrounding ambient air. [less ▲]

Detailed reference viewed: 37 (7 ULg)
Full Text
Peer Reviewed
See detailImplementation of health aspects (ER N°3) in the Construction Products; Directive (CPD) regarding emissions to indoor air
Lor, Marc; Vause, Kevin; Goelen, Eddy et al

Poster (2008)

Standardisation work on test methods for dangerous substances released in the indoor air by construction products is currently ongoing at European level. The paper presents a study conducted in Belgium ... [more ▼]

Standardisation work on test methods for dangerous substances released in the indoor air by construction products is currently ongoing at European level. The paper presents a study conducted in Belgium, which compares methods in three different test chambers and aiming at assessing the performance of the products placed on the market. [less ▲]

Detailed reference viewed: 29 (4 ULg)
Full Text
Peer Reviewed
See detailComplementary approaches to measure environmental odours emitted by landfill areas
Romain, Anne-Claude ULg; Delva, Julien ULg; Nicolas, Jacques ULg

in Sensors and actuators. B, Chemical (2008), 131(1), 18-23

This paper presents different methods to assess the odour emission and the odour annoyance in the surroundings. It is shown, on the example of landfill areas and composting facilities, that chemical ... [more ▼]

This paper presents different methods to assess the odour emission and the odour annoyance in the surroundings. It is shown, on the example of landfill areas and composting facilities, that chemical analyses are helpful to identify key compounds of the odour release, and to set up the specification of a monitoring instrument. Sensitive methods, like dynamic olfactometry or sniffing team investigation, are mainly applicable to provide a global odour plume or an average annoyance zone. And the electronic nose can supply a warning signal to the plant manager or a real time estimation of the annoyance zone. [less ▲]

Detailed reference viewed: 38 (6 ULg)
Full Text
Peer Reviewed
See detailDevelopment and validating procedure of a formula to calculate a minimum separation distance from piggeries and poultry facilities to sensitive receptors
Nicolas, Jacques ULg; Delva, Julien ULg; Cobut, Pierre et al

in Atmospheric Environment (2008), 42(30), 7087-7095

A specific formula to calculate separation distance from piggeries and poultry facilities to sensitive receptor is developed for Walloon Region, in Belgium. The paper briefly presents the main principles ... [more ▼]

A specific formula to calculate separation distance from piggeries and poultry facilities to sensitive receptor is developed for Walloon Region, in Belgium. The paper briefly presents the main principles of the formula and discusses more deeply the compatibility of the distance approach with odour units, odour rate and percentiles usually applied to assess the odour annoyance zones. A method of validation is presented and tested to adjust the different parameters of the formula to Belgian field reality. A total of 43 farms of which 21 piggeries and 22 poultry facilities are visited and, for each case, the distance calculated by the formula is compared to the one deduced from odour annoyance criterion (10 ou m-3 at 98th percentile). Validation work results in discussing the sensibility of different factors of the formula and especially in adjusting a fitting factor to match the absolute distances to real field annoyance impression. Conclusions show that both approaches - separation distance formula and percentile evaluation - are coherent. The validation method allows parameter adjustment but should need further refinements to examine separately piggeries and poultry facilities. [less ▲]

Detailed reference viewed: 31 (1 ULg)
Full Text
Peer Reviewed
See detailSetting up a decision rule from estimated uncertainty : emission limit value for PCDD and PCDF incineration plants in Wallonia, Belgium.
Bergmans, B.; Idczack, F.; Maetz, P. et al

in Accreditation and Quality Assurance (2008), 13

Complex analytical procedures are often required to prove the non-compliance with a specific legislation. In the case of a small overlap of the limit, integration of the method uncertainty in the decision ... [more ▼]

Complex analytical procedures are often required to prove the non-compliance with a specific legislation. In the case of a small overlap of the limit, integration of the method uncertainty in the decision-making process is essential. The decision rule proposed in Wallonia, Belgium, for the non-compliance of waste incineration plants with the EU limit value for PCDD and PCDF emissions is presented. The method uncertainty was estimated annually over 6 years from duplicate measurements using two top-down approaches. Depending on the congener, the standard uncertainty varies from 30 to 85%, with a good correlation between calculations. The analytical contribution was estimated using a bottom-up evaluation. The impact of the sampling step was deduced from the whole estimation and represents more than 80% of the total uncertainty budget. No optimisation is foreseen at this time because of practical field constraints. Based on the average fraction of each congener, the uncertainty associated with the measurement result has been established and shows a high stability over the years. Using this value, a guard band has been calculated and will be proposed to the regulatory body. [less ▲]

Detailed reference viewed: 44 (9 ULg)
Full Text
Peer Reviewed
See detailSpécificités et contraintes de la mesure des odeurs dans l'environnement par réseaux de capteurs
Nicolas, Jacques ULg

Conference (2008)

L'estimation de la nuisance olfactive dans l'environnement est une tâche rendue particulièrement difficile par la multiplicité des sources, leur grande variabilité, leur caractère parfois très diffus et ... [more ▼]

L'estimation de la nuisance olfactive dans l'environnement est une tâche rendue particulièrement difficile par la multiplicité des sources, leur grande variabilité, leur caractère parfois très diffus et fugitif et surtout par la subjectivité de l'appréciation de la gêne. Aussi faut-il mettre en œuvre plusieurs méthodes complémentaires qui vont de l'analyse chimique (GCMS) aux enquêtes de riverains, en passant par l'olfactométrie dynamique impliquant un panel de personnes reniflant différentes dilutions d'un échantillon prélevé sur le terrain. Or, aucune de ces méthodes ne permet un suivi continu des odeurs qui viserait, par exemple, à détecter l'émergence d'une émission particulière dans une ambiance. A ce niveau, la technologie des nez électroniques semble très prometteuse et particulièrement attractive. Basée sur la réponse globale d'un réseau de capteurs non spécifiques, elle permet non seulement d'identifier qualitativement une source particulière, mais également de la suivre en continu. L'unité "Surveillance de l'Environnement" de l'ULg applique cette technique pour suivre les odeurs en périphérie de sites émetteurs et notamment un centre de compostage. Les appareils développés sont basés sur des capteurs commerciaux à oxydes métalliques. La méthode exige une calibration préalable afin de créer et de valider le modèle de reconnaissance et la loi qui relie les signaux des capteurs à une variable quantitative comme la concentration d'odeur. Bien que testée avec succès autour d'installations en vraie grandeur, la technique des "nez électroniques" reste soumise à de nombreuses limitations et contraintes. Parmi ces contraintes, il faut citer la dérive des capteurs, l'influence de l'humidité et de la température, la difficulté de trouver un gaz étalon représentatif des odeurs environnementales ou encore celle de calculer un indicateur global qui serait l'image "électronique" de la nuisance olfactive. En général, la méthode du nez électronique peut être envisagée pour le suivi d'odeurs ponctuelles à la source, par exemple dans un hall de compostage ou dans un bâtiment d'élevage, pour autant que l'ambiance ne soit pas trop agressive. L'unité de recherche teste actuellement le principe de réseaux de nez électroniques placés tout autour d'un site. En ajoutant l'information en provenance d'une station météorologique, un tel système permet la prédiction en temps réel de zones de nuisance olfactive dans l'environnement. Cependant, dès que l'on s'éloigne de l'émission et que l'on s'intéresse à la mesure de l'ambiance olfactive à proximité des habitations des riverains, la technique des nez électroniques présente une limitation sévère due au seuil de détection des capteurs. En effet, le nez humain est parfois sensible à de très faibles concentrations de composés volatils qui ne sont pas détectées par les capteurs. Il devient alors indispensable de piéger ces composés dans des dispositifs de pré-concentration en ligne. De tels dispositifs, actuellement en développement, autoriseraient un élargissement du champ d'application des nez électroniques, notamment vers le domaine très vaste de l'environnement intérieur. [less ▲]

Detailed reference viewed: 70 (5 ULg)
Full Text
See detailLes nuisances olfactives à habay
Nicolas, Jacques ULg; Romain, Anne-Claude ULg

Conference given outside the academic context (2007)

Detailed reference viewed: 13 (1 ULg)