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See detailVision as Inference in a Hierarchical Markov Network
Piater, Justus ULg; Scalzo, Fabien; Detry, Renaud ULg

Conference (2008)

Detailed reference viewed: 15 (1 ULg)
Peer Reviewed
See detailLe genre et la diversité : enjeux et opportunités
Cornet, Annie ULg

Conference (2008)

Detailed reference viewed: 23 (5 ULg)
Peer Reviewed
See detailBetter use a mirror when assessing visual pursuit
Vanhaudenhuyse, Audrey ULg

Conference (2008)

Detailed reference viewed: 4 (1 ULg)
See detailLate Devonian plants from Australia: the anatomically preserved flora from Barraba, New South Wales.
Meyer-Berthaud, Brigitte; Blanchard, Romain; Decombeix, Anne-Laure et al

Conference (2008)

Detailed reference viewed: 14 (0 ULg)
Peer Reviewed
See detailArchaeometry at the Centre Européen d’Archéométrie-Université de Liège
Calvo Del Castillo, Helena ULg; Mathis, François ULg; Garcia Moreno, Renata et al

Conference (2008)

Detailed reference viewed: 33 (3 ULg)
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See detailExtraction, caractérisation et activités antimicrobiennes de quelques huiles essentielles des plantes du haut et moyen atlas du Maroc
Dahak, K.; Lakhmili, S.; Wathelet, Jean-Paul ULg et al

Conference (2008)

Notre étude a porté sur l'extraction des huiles essentielles (HE) de certaines plantes Marocaines du haut Atlas: région de Marrakech (Citrus aurantium, Lavandula dentata et Feoniculum vulgare) et du moyen ... [more ▼]

Notre étude a porté sur l'extraction des huiles essentielles (HE) de certaines plantes Marocaines du haut Atlas: région de Marrakech (Citrus aurantium, Lavandula dentata et Feoniculum vulgare) et du moyen Atlas: région d’azilal (Ouaouizerth) (Laurus nobilis et Lavandula officinalis). [less ▲]

Detailed reference viewed: 116 (2 ULg)
See detailVolatile blends and oxylipins profiles in potato leaves (Solanum tuberosum L.) exposed to insects infestations and mechanical wounding.
Gosset, V.; Göbel, Cornelia; Harmel, N. et al

Conference (2008)

Detailed reference viewed: 16 (4 ULg)
Peer Reviewed
See detailWATER QUALITY AND POLLUTION CONTROL IN PHNOM PENH, CAMBODIA
men, nareth; Ly, Sarann ULg; ann, vannak et al

Conference (2008)

The urban infrastructure, particularly water supply and drainage systems, have deteriorated severely in the past two decades in Phnom Penh, the capital city and the economic center of Cambodia. Water ... [more ▼]

The urban infrastructure, particularly water supply and drainage systems, have deteriorated severely in the past two decades in Phnom Penh, the capital city and the economic center of Cambodia. Water pollution caused by untreated wastewater is one of the serious problems that confront most developing countries (Kwai et al.1991). In Phnom Penh City, all kinds of wastewater are discharged to rivers, lakes and wetlands throughout the city without proper treatment causing serious surface water pollution. Water testing is an essential factor to control water pollution. However, water quality data and water quality testing systems are still poorly developed in Cambodia due to lack of facilities and technical expertise. Therefore, there is no information available on sewage water quality in Phnom Penh City. That’s why the work is aimed at collating basic information about the situation of water supply, waste water system and solid waste. The present information will provide the basis for targeting further field research. This is included the overview of sources and activities that may lead to pollution, with an appreciation of type of water pollutants involved, their magnitude and movement. Types of waste and effluent disposal including sanitation, liquid and solid waste management systems are described. After reviewing all the available, we found that the distribution of water has been well organized by the Phnom Penh Water Supply Authority while the managements of the wastewater, storm water and solid waste are poor due to the rapid urbanisation and industrialisation. [less ▲]

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See detailFrom strokes to model: a bottom-up approach for sketching activities analysis. Workshop.
Safin, Stéphane ULg; Juchmes, Roland ULg; Elsen, Catherine ULg et al

Conference (2008)

This paper proposes a framework for sketches analysis that could be useful for sketch-based interfaces development, in the particular context of preliminary activity-centred design. We will first describe ... [more ▼]

This paper proposes a framework for sketches analysis that could be useful for sketch-based interfaces development, in the particular context of preliminary activity-centred design. We will first describe our previous works on sketch-based support tools for the preliminary design phases and the context of these researches. The next chapter declares the concrete objectives of our approach, then the methodology of sketches analysis we propose is presented with a concrete example, and finally the last section is dedicated to the expected results and specifications of a sketch-based support tool that would follow our framework. [less ▲]

Detailed reference viewed: 78 (23 ULg)
See detailThermocline characterization on modeled and observed temperature profiles: a technique for model error evaluation
Alvera Azcarate, Aïda ULg; Barth, Alexander ULg; Beckers, Jean-Marie ULg

Conference (2008)

The thermocline position in the water column is an important variable in hydrodynamic modeling. Its characterization allows to verify the model accuracy, and analyze the parameter choice made by the ... [more ▼]

The thermocline position in the water column is an important variable in hydrodynamic modeling. Its characterization allows to verify the model accuracy, and analyze the parameter choice made by the modeler, such as the choice of the turbulence closure. A correct representation of the surface ocean boundary layer is also very important in order to correctly represent the air-sea exchanges. Moreover, coupled physicalbiological models require a good representation of the thermocline position, in order to correctly represent the population dynamics at the surface layers. We present a technique to calculate the parameters of the thermocline: depth, width and temperature. These are calculated by a least-squares fitting of individual temperature profiles (from model and observations) to a sigmoid function. The residual is also obtained, giving an estimate of the goodness of the fit. The parameters calculated allow for a comparison of the model thermocline to observations. Our approach consists in comparing the model thermocline depth, width and temperature to observations. By examining separately the accuracy of the model thermocline depth and temperature, we gain insight in the processes that need correction in the model. For example, if the model thermocline is too deep compared to observations, or the width of the thermocline is incorrect, mixing parameters and surface momentum fluxes should be revised. However, if the depth is well represented but the temperature is incorrect, the surface heat fluxes may be the source of the error. By simply comparing model and observed temperature profiles we are not able to differentiate between error sources. The technique presented here stands therefore as a useful method for model evaluation. [less ▲]

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Peer Reviewed
See detailMarine and fresh water palynomorphs from the Jauf Formation, Northwest Saudi Arabia
Miller, A.; Breuer, P.; Al-Ghazi, A. et al

Conference (2008)

Detailed reference viewed: 6 (0 ULg)
See detailVenus night airglow and implications for thermospheric composition and dynamics
Gérard, Jean-Claude ULg; Saglam, Adem ULg; Cox, Cédric ULg et al

Conference (2008)

Spatially resolved spectra of the NO delta and gamma ultraviolet bands have been obtained from 80 to 130 km on the Venus night side with the SPICAV instrument on board Venus Express. This NO airglow ... [more ▼]

Spatially resolved spectra of the NO delta and gamma ultraviolet bands have been obtained from 80 to 130 km on the Venus night side with the SPICAV instrument on board Venus Express. This NO airglow emission results from radiative recombination of oxygen and nitrogen atoms created on the dayside and transported by the subsolar to antisolar global circulation. Spectral images of the O2 (1 â delta g ) at 1.27 µm have also been made with the VIRTIS-M instrument both at nadir and at the limb. The O2 (1 â g ) emission is produced by three-body recombination of O atoms giving rise to an airglow layer near 96 km. The brightness of both emissions changes by over an order of magnitude. They also show variations in the altitude of the peak emission, with larger variability of the NO airglow. The characteristics of both airglows and their implications on global circulation and vertical transport on the nightside will be discussed. Concurrent observations of both limb airglows will be described. It will be shown that limb observations of the vertical and latitudinal distribution of the 1.27 µm emission make it possible to remotely determine the density of atomic oxygen in the upper mesosphere and improve current atmospheric models. One-dimensional models of the O and N distributions will be presented and global properties of the 1-D parameterization of turbulent transport will be discussed. [less ▲]

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See detailEvolution de l’économie rurale en Hainaut
Duquesne, Brigitte ULg

Conference (2008)

Detailed reference viewed: 10 (1 ULg)
See detailForesterie communautaire : les silences de la loi gabonaise
Vermeulen, Cédric ULg

Conference (2008)

Detailed reference viewed: 12 (2 ULg)
Peer Reviewed
See detailOn the complementarity of contrastive linguistics and interlanguage studies
Rasier, Laurent ULg; Hiligsmann, Philippe

Conference (2008)

Detailed reference viewed: 20 (1 ULg)
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See detailImprovement of He ion induced SiGe layer relaxation by a thin Si:C layer
Buca, D.; Trinkaus, H.; Holländer, B. et al

Conference (2008)

Detailed reference viewed: 9 (0 ULg)
Peer Reviewed
See detailDisturbed sense of agency in checking symptoms
Belayachi, Sanaa ULg

Conference (2008)

Detailed reference viewed: 14 (0 ULg)
Peer Reviewed
See detailThermo-hydro-mechanical simulation of Atlas in situ large-scale test in Boom clay
François, Bertrand ULg; Laloui, Lyesse

Conference (2008)

Detailed reference viewed: 11 (0 ULg)
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See detailDevonian mio-and megaspores in Western Gondwana
Steemans, Philippe ULg; Breuer, Pierre; Miller, M.

Conference (2008)

Detailed reference viewed: 17 (0 ULg)
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See detailOUFTI-1: The CubeSat developed at the University of Liège, Belgium
Galli, S.; Pisane, Jonathan ULg; Ledent, P. et al

Conference (2008)

Detailed reference viewed: 151 (23 ULg)
Peer Reviewed
See detailLa mondialisation multiple des musiques populaires
Pirenne, Christophe ULg

Conference (2008)

Detailed reference viewed: 22 (1 ULg)
Peer Reviewed
See detailEnglish and Spanish Size Noun-constructions, a locus of ongoing grammaticalization
Brems, Lieselotte ULg; Verveckken, Katrien

Conference (2008)

Detailed reference viewed: 6 (1 ULg)
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See detailLarge scale network and restoration of peatbogs and wetlands in Southern Belgium
Dufrêne, Marc ULg; Dierstein, Axelle; Frankard, Philippe et al

Conference (2008)

Detailed reference viewed: 22 (2 ULg)
See detailWave-particle duality in a two atom interferometer
Schilling, U.; Thiel, C.; Bastin, Thierry ULg et al

Conference (2008)

Detailed reference viewed: 3 (1 ULg)
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See detailEvolution de l’économie agricole en Province de Liège
Duquesne, Brigitte ULg

Conference (2008)

Detailed reference viewed: 18 (9 ULg)
See detailLes marqueurs de l'alcoolisme
Charlier, Corinne ULg

Conference (2008)

Detailed reference viewed: 17 (1 ULg)
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See detailEVALUACIÓN ACÚSTICA DE PAVIMENTOS ASFÁLTICOS. MAPA DE RUIDO DE RODADURA DE CIUDAD REAL
Paje, S.E.; Bueno, M.; Vinuela, U.. et al

Conference (2008)

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See detailMultidisciplinary approach to study of design cognitive process: the case of human errors in architectural preliminary design
Safin, Stéphane ULg; Leclercq, Pierre ULg; Blavier, Adelaïde ULg

Conference (2008)

This contribution aims to show a multidisciplinary method to understand and formalize design process, from a cognitive point of view, in the particular case of human errors in architectural preliminary ... [more ▼]

This contribution aims to show a multidisciplinary method to understand and formalize design process, from a cognitive point of view, in the particular case of human errors in architectural preliminary design process. We first emphasize the importance of error detection and recovery in the sketching phase in architecture. After the description of our methodology, we explain the general theory and model on human error, the short study we made and our proposition of a model on hu- man error in architectural design. We finally conclude by giving some first re- quirements from this model in order to improve to the development of sketch- based CAD tools. [less ▲]

Detailed reference viewed: 46 (2 ULg)
Peer Reviewed
See detailImpact of Prosthesis-Patient Mismatch on Short-term Mortality Following Mitral Valve Replacement.
Magne, Julien ULg; Mathieu, P; Dumesnil, JG et al

Conference (2008)

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailLong term Subjective Evaluation of the Effects of Vocal Therapy on Dysfunctional Dysphonia.
Morsomme, Dominique ULg; Faurichon de la Bardonnie, Marie; Verduykt, Ingrid et al

Conference (2008)

The goal of this study is the evaluation of the long-term efficiency of voice therapy (> to 6 months) in the treatment of dysfunctional dysphonia . Four subjective measurements were performed on 29 ... [more ▼]

The goal of this study is the evaluation of the long-term efficiency of voice therapy (> to 6 months) in the treatment of dysfunctional dysphonia . Four subjective measurements were performed on 29 patients: -A visual analogical scale (VAS) ranging from 0 (not efficient at all) to 100 (very efficient). -A question “Is the speech therapy still efficient?” Yes or no. -The G(rade), R(oughness) and B(reathiness) parameters from the GRBAS perceptual scale (evaluated by the patient measured on VAS). -The Voice Handicap Index-10 (VHI-10). The results show that 76% of the patients consider that the voice therapy is still efficient. In regard to G.R.B., we observe a high score for G (median: 77). The score for R is lower (median R: 12). G and R are significantly correlated (r Spearman=0.516, p=0.004), but the satisfaction of the vocal quality does not seem correlated to B (p=0,251, NS). The median values of VHI 10 shows a significant improvement from 15 to 10 (p=0,017). In addition, the correlations between the judgment on the treatment efficiency and vocal quality (r=0,623, p<0,001) and between VHI-10 and the length of treatment (r=0.416, p=0,035) are significant. The first correlation shows that the most satisfied patients when it comes to the vocal therapy are also the most satisfied when it comes to their vocal quality. The second correlation specifies that the longer the treatment, the higher the grade of vocal handicap. Voice therapy is efficient in the long term and is worth to be prolonged for difficult cases [less ▲]

Detailed reference viewed: 24 (0 ULg)
See detailUsing monovariate and multivariate EOFs to reconstruct missing data with DINEOF
Alvera Azcarate, Aïda ULg; Barth, Alexander ULg; Sirjacobs, Damien ULg et al

Conference (2008)

DINEOF (Data Interpolating Empirical Orthogonal Functions) is an EOF-based method to reconstruct missing data in geophysical data sets. DINEOF can be used to reconstruct monovariate data sets (as sea ... [more ▼]

DINEOF (Data Interpolating Empirical Orthogonal Functions) is an EOF-based method to reconstruct missing data in geophysical data sets. DINEOF can be used to reconstruct monovariate data sets (as sea surface temperature (SST), chlorophyll, etc), and multivariate data sets with little increase in complexity. For multivariate reconstructions, extended EOFs are used, which take into account the interrelationships between related variables to infer data at missing locations. Spatial maps of the standard deviation of the reconstruction error can be also calculated. In the past, DINEOF has been compared to Optimal Interpolation (OI) techniques for the Adriatic Sea SST. The results showed that DINEOF was faster than OI, making it very suitable for operational applications. DINEOF was also more accurate when compared to in situ data. Another advantage of DINEOF is that there is no need for a priori knowledge of the statistics of the reconstructed data set (such as covariance or correlation length), thus reducing the subjectivity of the analysis. DINEOF has been successfully used to reconstruct a large variety of domains over the world ocean, mostly at the regional scale. In addition to an overview of the technique's capabilities, limitations and future developments, recent work aimed to improve the quality of the reconstructions at the global and local scales will be presented. [less ▲]

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See detailThe Hybrid Finite-Element Mixing-Cell method: a new flexible method for large scale groundwater modelling
Orban, Philippe ULg; Brouyère, Serge ULg; Wildemeersch, Samuel ULg et al

Conference (2008)

Interest of end-users and policy makers for understanding and managing water systems at the regional scale has increased for years. At this scale, groundwater models of different complexity ranging from ... [more ▼]

Interest of end-users and policy makers for understanding and managing water systems at the regional scale has increased for years. At this scale, groundwater models of different complexity ranging from black-box models to physically based distributed models have been used in various hydrogeological conditions. Black-box models, such as transfer functions, have been applied for example to model groundwater in large scale hydrological models, to model karstic systems, in particular for the interpretation of isotopic data. Their concepts are simple and attractive because they require relatively few data. The main drawbacks are however that modelling results are not spatially distributed and their predictive capability is questionable due to the semi-empirical nature of process descriptions. On the contrary, due to a more advanced description of ongoing processes, physically-based distributed models are expected to have better predictive capabilities than black-box models. However, because such models require more data, they are generally applied for case studies that are better characterized from a hydrogeological point of view, for which the distribution of water levels or solute concentrations in the groundwater systems are needed. For large-scale modelling purposes, black-box models and physically-based distributed models have both proved their utilities and have their own justifications, advantages and disadvantages. However, few attempts have been made to combine the advantages of these two categories of approaches in a unified modelling application. A new flexible modelling approach, the Hybrid Finite-Element Mixing-Cell method (HFEMC), has been developed that allows combining in a single model, and in a fully integrated way, different mathematical approaches of various complexities for groundwater modelling in complex and large scale environments. This method has been implemented in the groundwater flow and solute transport numerical code SUFT3D. The approach has been first tested and illustrated using basic and advanced “synthetic” examples that allow validating and discussing its advantages over existing modelling concepts. The HFEMC approach is now applied for the development of a large scale groundwater flow and solute transport model in different groundwater basins in Belgium. [less ▲]

Detailed reference viewed: 126 (45 ULg)
See detailAperture imaging beyond the classical resolution limit by using incoherent photons
Thiel, C.; Bastin, Thierry ULg; von Zanthier et al

Conference (2008)

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailImpact of prosthesis-patient mismatch on short-term mortality following mitral valve replacement.
Magne, Julien ULg; Mathieu, P; Dumesnil, JG et al

Conference (2008)

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See detailRisk-aware decision making and dynamic programming
Defourny, Boris ULg; Ernst, Damien ULg; Wehenkel, Louis ULg

Conference (2008)

This paper considers sequential decision making problems under uncertainty, the tradeoff between the expected return and the risk of high loss, and methods that use dynamic programming to find optimal ... [more ▼]

This paper considers sequential decision making problems under uncertainty, the tradeoff between the expected return and the risk of high loss, and methods that use dynamic programming to find optimal policies. It is argued that using Bellman's Principle determines how risk considerations on the return can be incorporated. The discussion centers around returns generated by Markov Decision Processes and conclusions concern a large class of methods in Reinforcement Learning. [less ▲]

Detailed reference viewed: 112 (14 ULg)
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See detailConstruction et droit de la consommation: propos introdutifs
Kohl, Benoît ULg

Conference (2008)

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailAssessment of stress level in horses (Equus caballus): behavioural and physiological measurements in hospital.
Peeters, Marie ULg; Péters, F.; Sulon, J. et al

Conference (2008)

Detailed reference viewed: 41 (7 ULg)
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See detailThe Effects of Early Retirement on Youth Unemployment: The Case of Belgium
Jousten, Alain ULg

Conference (2008)

The paper studies the effect of the pension system on the unemployment of the young

Detailed reference viewed: 63 (29 ULg)
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See detailArchaeometry at the Centre Européen d'Archéométrie
Calvo Del Castillo, Helena ULg

Conference (2008)

Detailed reference viewed: 5 (0 ULg)
See detailCoupling of N Qubits to Any Dicke State via Projective Measurements
Thiel, C.; Maser, A.; Bastin, Thierry ULg et al

Conference (2008)

Detailed reference viewed: 7 (0 ULg)
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See detailHistoires parallèles de la sculpture moderne
Bawin, Julie ULg

Conference (2008)

Detailed reference viewed: 2 (0 ULg)
See detailTowards a new definition of Cooksonia Lang, 1937
Gonez, Paul ULg; Gerrienne, Philippe ULg

Conference (2008)

Detailed reference viewed: 6 (0 ULg)
See detail(Inter)subjectification in the Middle English Passive construction
Petré, Peter ULg

Conference (2008)

Detailed reference viewed: 6 (0 ULg)
See detailQuantum imaging with uncorrelated single photon sources
Bastin, Thierry ULg; Thiel, C.; Solano, E. et al

Conference (2008)

Detailed reference viewed: 4 (1 ULg)
Peer Reviewed
See detailHealthy and safe food for everybody
Jijakli, Haissam ULg

Conference (2008)

Detailed reference viewed: 3 (1 ULg)
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See detailPseudomonas aeruginosa and severity of ventilator associated pneumonia
BROUSSE, Murielle; LAYIOS, Nathalie ULg; LEDOUX, Didier ULg et al

Conference (2008)

Detailed reference viewed: 4 (0 ULg)
See detailOperational monitoring of multi-qubit entanglement classes via tuning of local operations
Bastin, Thierry ULg; Thiel, C.; von Zanthier, J. et al

Conference (2008)

Detailed reference viewed: 4 (0 ULg)
See detailIonospheric Products and Services from the Regional Warning Centers of the International Space Environment Service (ISES) for GNSS Users
Kunches, J.; Terkildsen, M.; Stanislawska, I. et al

Conference (2008)

Detailed reference viewed: 14 (0 ULg)
See detailTotal Electron Content monitoring using triple frequency GNSS data: a three-step approach
Spits, Sandrine; Warnant, René ULg

Conference (2008)

Detailed reference viewed: 16 (2 ULg)
See detailQuantum imaging with single photon sources
Thiel, C.; Bastin, Thierry ULg; von Zanthier, J. et al

Conference (2008)

Detailed reference viewed: 2 (0 ULg)
See detailThe Early Devonian plants from the Ancenis Basin (Armorican Massif, France): one century later...
Strullu-Derrien, Marie-Christine; Gerrienne, Philippe ULg

Conference (2008)

Detailed reference viewed: 9 (2 ULg)
See detailTotal Electron Content monitoring using triple frequency GNSS data: a three-step approach
Spits, Justine; Warnant, René ULg

Conference (2008)

Detailed reference viewed: 9 (1 ULg)
See detailLe droit scolaire
Maréchal, Benoît ULg

Conference (2008)

Seminar on the rights and duties at school and the admninistrative proceedings in case of litigation.

Detailed reference viewed: 101 (0 ULg)
See detailGeneration of arbitrary Dicke states in remote qubits using linear optics
Maser, A.; Thiel, C.; Schilling, U. et al

Conference (2008)

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See detailATOMIC STRUCTURES OF HEAVY ELEMENTS : RECENT PROGRESS AND PERSPECTIVES
Biémont, Emile ULg; Fivet, V.; Palmeri, P. et al

Conference (2008)

In the present paper, we discuss some recent advances concerning the determination of new radiative parameters (transition probabilities, oscillator strengths, radiative lifetimes, branching fractions ... [more ▼]

In the present paper, we discuss some recent advances concerning the determination of new radiative parameters (transition probabilities, oscillator strengths, radiative lifetimes, branching fractions, Landé factors) in heavy ions. We also emphasize the difficulties that are frequently met in the field and that sometimes prevent obtaining accurate atomic data for the transitions of astrophysical interest. We concentrate particularly on the determination of radiative parameters for selected rare-earth (RE) ions (lanthanides and actinides) and for some atoms and ions of the sixth row of the periodic table. [less ▲]

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See detailPrix de l’alimentation : une hausse sans faim
Duquesne, Brigitte ULg

Conference (2008)

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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: 71 (5 ULg)