References of "Nicolas, Jacques"
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See detailAssessment of detection thresholds of metal oxide sensors based e-nose to the pollution emitted by odorous sources.
Nicolas, Jacques ULg; Romain, Anne-Claude ULg

in Proceedings of the Ninth international symposium on olfaction and electronic nose ISOEN'02 (2002, September)

The paper describes a method to assess the global concentration level of a complex odorous gas mixture which is detected by an electronic nose, and consequently to assess the detection threshold of the ... [more ▼]

The paper describes a method to assess the global concentration level of a complex odorous gas mixture which is detected by an electronic nose, and consequently to assess the detection threshold of the instrument for that particular odour. The studied case is the odour generated by urban waste composting facilities. The measurement is performed in the lab with an array of 12 tin oxide gas sensors on samples collected near the emission. The selected method consists in finding an equivalence between the response of each individual sensor to the concentrations of ethanol used as a standard gas and the responses to various dilution of the original sample. The main issues of that procedure are the order of magnitude of the "concentration" of the non-diluted compost emission sample expressed in ethanol-equivalent and the detection threshold of the sensor array for the compost gas. The latter result requires a suitable definition of the detection threshold, based on the signal to noise ratio. The conclusion is that the detection threshold of Tagushi sensors, expressed in equivalent-ethanol, is generally lower than 1 ppmv and is just slightly higher than the perception threshold of the human nose for the odour gener-ated by compost. [less ▲]

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See detailCampagne de mesure des odeurs sur le CET "Champ de Beaumont" à Monceau-sur-Sambre Estimation des nuisances olfactives Jacques NICOLAS – Anne-Sophie CHAPLAIN F.U.L. Arlon 12 Août
Nicolas, Jacques ULg; Chaplain, Anne-Sophie

Report (2002)

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection ... [more ▼]

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection technique based on the perception of a panel of experts sniffing the air around the region of interest and trying to delineate the odour plume. In a second step, the recorded meteorological data are entered into an atmospheric dispersion model and the odour emission rate of the facility is adjusted until the predicted odour impact zone fits about exactly the one which is measured in the field. The present report concerns the site of Monceau-sur-Sambre. [less ▲]

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See detailDétection des moisissures de l'habitat par un nez électronique
kuske, martyna; Romain, Anne-Claude ULg; Nicolas, Jacques ULg

in actes des conférences Eurodeur-airodeur (2002, June 25)

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See detailEtude comparative entre les différentes méthodes d'estimation de la distance minimum d'implantation pour des bâtiments d'élevage par rapport aux zones d'habitat et aux habitations isolées
Nicolas, Jacques ULg

Report (2002)

La première partie de l'étude est une recherche bibliographique sur les différentes formules de calcul de la distance maximale d'acceptation de l'odeur d'élevage entre les bâtiments de la ferme et les ... [more ▼]

La première partie de l'étude est une recherche bibliographique sur les différentes formules de calcul de la distance maximale d'acceptation de l'odeur d'élevage entre les bâtiments de la ferme et les habitations les plus proches. Neuf méthodes ont été particulièrement étudiées (France, Allemagne, Hollance, Québec, Autriche, Suisse, Flandre, ...) et détaillées. Elles ont été appliquées et comparées sur deux études de cas. [less ▲]

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See detailCampagne de mesure des odeurs sur le CET d'Hallembaye. Estimation des nuisances olfactives et ajustement de la méthodologie
Nicolas, Jacques ULg; Perez, Emmanuel

Report (2002)

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection ... [more ▼]

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection technique based on the perception of a panel of experts sniffing the air around the region of interest and trying to delineate the odour plume. In a second step, the recorded meteorological data are entered into an atmospheric dispersion model and the odour emission rate of the facility is adjusted until the predicted odour impact zone fits about exactly the one which is measured in the field. The present report concern the site of Hallembaye. [less ▲]

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See detailCampagne de mesure des odeurs sur le CET de Mont-Saint-Guibert Mise au point d'une méthode d'estimation des nuisances
Nicolas, Jacques ULg

Report (2002)

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection ... [more ▼]

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection technique based on the perception of a panel of experts sniffing the air around the region of interest and trying to delineate the odour plume. In a second step, the recorded meteorological data are entered into an atmospheric dispersion model and the odour emission rate of the facility is adjusted until the predicted odour impact zone fits about exactly the one which is measured in the field. The present report is the first one of a long series of measurement campaigns. It presents in details the used methodology and the results of the study. [less ▲]

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See detailMesure des odeurs par le nez électronique
Nicolas, Jacques ULg

Conference (2002, February)

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See detailThree years experiment with the same tin oxide sensor arrays for the identification of malodorous sources in the environment
Romain, Anne-Claude ULg; Nicolas, Jacques ULg; Andre, Philippe ULg

in Sensors and actuators. B, Chemical (2002), (84), 271-277

The paper discusses the ability of recognition models to classify malodours in the environment 3 years after their calibration, with the same sources releasing odours. Two methodologies applicable either ... [more ▼]

The paper discusses the ability of recognition models to classify malodours in the environment 3 years after their calibration, with the same sources releasing odours. Two methodologies applicable either in the lab or in the field are used. The effect of the long term drift of the sensors is highlighted on the results of principal component analysis (PCA) and of discriminant function analysis (DFA). The paper examines also the applicability of some drift counteraction methods proposed in the literature. Handled with some care, a correction based on the drift direction in the principal components subspace should be applicable to the classification of real odorous sources in the field. [less ▲]

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See detailLa mesure des odeurs dans l'environnement : des méthodes sensitives au nez électronique
Nicolas, Jacques ULg

Conference (2001, October)

La conférence vise à présenter l'évolution de la mesure des odeurs, depuis la perception par le nez humain, jusqu'à la détection par un réseau intelligent de capteurs gaz. Elle permet de remettre le ... [more ▼]

La conférence vise à présenter l'évolution de la mesure des odeurs, depuis la perception par le nez humain, jusqu'à la détection par un réseau intelligent de capteurs gaz. Elle permet de remettre le principe du nez électronique dans son contexte général de mesure de composés odorants et de le comparer aux méthodes classiques. [less ▲]

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See detailSolvent detection in indoor air with a sensor array
Maternova, J.; Romain, Anne-Claude ULg; Nicolas, Jacques ULg

in Proceedings of the 8th conference Eurodeur (2001, June)

Air composition in dwellings and public buildings is studied by means of gas chromatography and a sensor micro array 01D28 (MICROSENS, Swiss). Only benzene and its alkyl-derivatives are quantified. The ... [more ▼]

Air composition in dwellings and public buildings is studied by means of gas chromatography and a sensor micro array 01D28 (MICROSENS, Swiss). Only benzene and its alkyl-derivatives are quantified. The micro array 01D28 is composed of six metal oxide gas sensors (SnO2 doped by Pd) equipped with standard or inter-digited electrodes. Isothermal working mode (500oC for all sensors) is applied. Conductivities after 10 minutes of signal acquisition in the studied air are considered as characterizing its chemical composition. Discriminant Function Analysis (DFA) and different linear regression techniques (Inverse Least Squares, Principal Components Regression and Partial Least Squares) are applied to find a relation between the sensors signals and the indoor air composition as determined by the gas chromatography. The presented results suggest that the monitoring of aromatics substances in the indoor air by means of a micro-array of metal oxide gas sensors is possible. The array distinguishes polluted and non-polluted air and it can even evaluate the concentration of the benzene and the toluene. [less ▲]

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See detailTen years of data gathering of radon exhalation in the Belgian "Province of Luxembourg"
Kuske, Martyna; Debbaut, Vincent ULg; Bomboire, A. et al

in Proceedings of the Third eurosymposium on protection against radon (2001, May)

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See detailIdentification of several environmental odours with tin oxide sensor array : three years later
Romain, Anne-Claude ULg; Nicolas, Jacques ULg; Maternova, J.

Poster (2001)

The paper discusses the ability of recognition models to classify malodours in the environment three years after their calibration, with the same sources releasing odours. Two methodologies applicable ... [more ▼]

The paper discusses the ability of recognition models to classify malodours in the environment three years after their calibration, with the same sources releasing odours. Two methodologies applicable either in the lab or in the field are used. The effect of the long term drift of the sensors is highlighted on the results of principal component analysis and of discriminant function analysis. The paper examines also the applicability of some drift counteraction methods proposed in the literature. Handled with some care, a correction based on the drift direction in the principal components subspace should be applicable to the classification of real odorous sources in the field. [less ▲]

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See detailChemometrics methods for the identification and the monitoring of an odour in the environement with an electronic nose
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Maternova, J.

in Ramirez-Silva, Maria Theresa (Ed.) Sensors and chemometrics (2001)

The purpose of the paper is to briefly review some researches regarding the adaptation of the electronic nose principle to recognise some malodour sources in the environment, if possible directly in the ... [more ▼]

The purpose of the paper is to briefly review some researches regarding the adaptation of the electronic nose principle to recognise some malodour sources in the environment, if possible directly in the field, and to monitor the odour intensity continuously. Research aims at improving the portability and the user-friendliness of the instrument, together with testing what kind of signal may be used to monitor the odour. A laboratory-made electronic nose, constituted of an array of tin-oxide sensors, is used in different configurations. The ambient air is either sampled around environmental sources (landfill, urban waste composting facilities, …), or directly transferred into the sensor chamber in the field. Two main options are considered : firstly, identifying the source of odour in the background and among interfering odours and, secondly, when the malodour is recognised, trying to monitor it continuously in order, for example, to assess the nuisance or to control an odour abatement system. Chemometrics methods are generally used for both purposes. They provide quick answers and allow to evaluate the relationships between variables and between observations at a glance. They are applied on the sensor signals, eventually preprocessed by a suitable algorithm. Non-supervised analyses, such as Principal Component Analysis (PCA), provide basically a performance evaluation of the system during the development phase. On the contrary, supervised analyses, such as Discriminant Analysis (DA), or some Neural Networks algorithms are quite appropriate to make a reliable recognition in real time, when the system is developed. To predict the odour intensity, different techniques are tested : either using only one of the sensor elements, or applying different chemometrics techniques, such as Multilinear Regression (MLR) on the original measured sensor signals, Principal Component Regression (PCR), or Partial Least Squares regression (PLS). The latter seems to be the most adapted model for the intensity prediction. [less ▲]

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See detailIpNose : Electronic nose for remote bad odour monitoring system in landfill sites.
Perera, A.; Pardo, T.; Sundi, T. et al

in Proceedings of the 8th conference Eurodeur (2001)

Electronic noses are intelligent instruments that are able to classify and quantify different gas/odours. Here we suggest the integration of a small form factor computer inside the electronic nose. This ... [more ▼]

Electronic noses are intelligent instruments that are able to classify and quantify different gas/odours. Here we suggest the integration of a small form factor computer inside the electronic nose. This concept allows us to easily provide remote connectivity, large data storage and complex signal processing. The evolution of this technology will permit distributed sensing with applications to agriculture and environment. Proposed instrument allows incoming connections for remote control of bad odours in landfill sites. Preliminary approach to this application using commercial sensors and mixture model pattern recognition scheme is exposed. [less ▲]

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See detailOptimal heating control in a passive solar commercial building.
Kummert, Michaël; Andre, Philippe ULg; Nicolas, Jacques ULg

in Solar Energy (2001), 69(6), 103-116

A smart heating controller has a twofold objective: to save as much energy as possible while maintaining an acceptable comfort level in the building. Due to very large time constants in the building ... [more ▼]

A smart heating controller has a twofold objective: to save as much energy as possible while maintaining an acceptable comfort level in the building. Due to very large time constants in the building response, it has to anticipate internal and external disturbances. In the case of a passive solar commercial building, the need for anticipation is reinforced by important solar and internal gains. Indeed, large solar gains increase the energy savings potential but also the overheating risk. Optimal control theory presents an ideal formalism to solve this problem: its principle is to anticipate the building behaviour using a model and a forecasting of the disturbances in order to compute the control sequence that minimises a given cost function over the optimisation horizon. This cost function can combine comfort level and energy consumption. This paper presents the application of optimal control to auxiliary heating of a passive solar commercial building. Simulation-based and experimental results show that it can lead to significant energy savings while maintaining or improving the comfort level in this type of building [less ▲]

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See detailSensor arrays : an inspired idea or an objective measurement of environmental odours ?
Stuetz, R. M.; Nicolas, Jacques ULg

in Jiang, John Kaiyun (Ed.) Odour and Volatile Organic Compounds: Measurement, Regulation and Control Techniques (2001)

The measure of annoyance odours from sewage treatment, landfill and agricultural practise has become highly significant in the control and prevention of odorous emissions from existing facilities and is ... [more ▼]

The measure of annoyance odours from sewage treatment, landfill and agricultural practise has become highly significant in the control and prevention of odorous emissions from existing facilities and is crucial for new planning applications. Current methods (such as GC-MS analysis, H2S and NH3 measurements) provide an accurate description of chemical compositions or act as surrogates for odour strength, but tell us very little about the perceived effect, whereas olfactometry gives the right human response but is very subjectivity and expensive. The use of non-specific sensor arrays may offer an objective and on-line instrument for assessing olfactive annoyance. Results have shown that sensor array systems can discriminate between different odour sources (wastewater, livestock and landfill). The response patterns from these sources can be significantly different and that the intensity of sensor responses is proportional to the concentration of the volatiles. The correlation of the sensors responses against odour strenghts have also shown that reasonable fits can be obtained for a range of odour concentrations (100 - 800.000 ou m3). However, the influence of environmental fluctuations (humidity and temperature) on sensor baselines still remains an obstacle, as well as the need for periodic calibration of the sensory system and the choice of a suitable gas for different environmental odours. [less ▲]

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See detailSensor arrays : an inspired idea or an objective measurement of environmental odours ?
Stuetz, R. M.; Nicolas, Jacques ULg

in Water Science & Technology (2001), 44(9), 53-58

The measure of annoyance odours from sewage treatment, landfill and agricultural practise has become highly significant in the control and prevention of odorous emissions from existing facilities and is ... [more ▼]

The measure of annoyance odours from sewage treatment, landfill and agricultural practise has become highly significant in the control and prevention of odorous emissions from existing facilities and is crucial for new planning applications. Current methods (such as GC-MS analysis, H2S and NH3 measurements) provide an accurate description of chemical compositions or act as surrogates for odour strength, but tell us very little about the perceived effect, whereas olfactometry gives the right human response but is very subjectivity and expensive. The use of non-specific sensor arrays may offer an objective and on-line instrument for assessing olfactive annoyance. Results have shown that sensor array systems can discriminate between different odour sources (wastewater, livestock and landfill). The response patterns from these sources can be significantly different and that the intensity of sensor responses is proportional to the concentration of the volatiles. The correlation of the sensors responses against odour strengths have also shown that reasonable fits can be obtained for a range of odour concentrations (100 - 800,000 ou/m3). However, the influence of environmental fluctuations (humidity and temperature) on sensor baselines still remains an obstacle, as well as the need for periodic calibration of the sensory system and the choice of a suitable gas for different environmental odours. [less ▲]

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