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See detailThe odd nitrogen distribution in the daytime upper atmosphere of Venus.
Gérard, Jean-Claude ULg; Deneye, E.; Lerho, M.

in Bulletin of the American Astronomical Society (1987, January 01)

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See detailL'odeur : question de sens ou de chimie
Romain, Anne-Claude ULg

Scientific conference (2014, August 28)

Afin de mesurer au mieux un paramètre, il faut préalablement connaître son identité. Concernant la métrologie de la pollution olfactive, toute la difficulté réside dans la particularité de cette pollution ... [more ▼]

Afin de mesurer au mieux un paramètre, il faut préalablement connaître son identité. Concernant la métrologie de la pollution olfactive, toute la difficulté réside dans la particularité de cette pollution. En effet, bien qu’associée à la pollution de l’air par les molécules volatiles qui la génèrent, elle en diffère par son effet sensoriel. Il va de soi que la pollution olfactive n’a de sens que par son odeur. Chaque individu a son propre odorat et dès lors sa propre interprétation de l’odeur. C’est cette subjectivité qui rend cette pollution si délicate à qualifier et à quantifier et qui la distingue de la pollution de l’air. De plus, contrairement à d’autres pollutions sensorielles de type sonore ou visuel, l’élément porteur ’est pas dans ce cas une grandeur physique telle que la longueur d’onde électromagnétique ou la variation de pression mais une grandeur physico-chimique particulière dont la mesure est beaucoup plus complexe. Un dictionnaire de langue française définit l’odeur comme « une émanation volatile, caractéristique de certains corps et susceptible de provoquer chez l’homme ou chez un animal des sensations dues à l’excitation d’organes spécialisés ». Cette définition de l’odeur met notamment en jeu deux disciplines : la chimie et la physiologie. En effet un chimiste pourrait présenter l’odeur comme un ensemble de molécules aux propriétés spécifiques qui inhalées par un individu génère une réaction, il s’intéresserait dès lors aux odorants alors qu’un physiologiste parlerait plutôt du stimulus induit par ces odorants et des mécanismes qui le provoquent au niveau des organes. Le traitement de l’information olfactive par le cerveau, la perception olfactive, conduit à plusieurs types de sensation. En effet, l’odeur perçue a trois grandes particularités : l’intensité, la qualité (ou la nature de l’odeur) et la tonalité hédonique ou affective (agrément/désagrément). A ces trois dimensions, il faut ajouter le caractère temporel du stimulus, dimension très utilisée dans le cadre de la pollution olfactive. [less ▲]

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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 ▲]

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See detailLes odeurs dans l'environnement: Résumé des législations européennes et nord-américaines
Nicolas, Jacques ULg; Otte, Benoît

Report (2005)

This short report synthesizes the policies concerning odour emissions applicable in Europe and North America. It was written in the frame of the project "Plan of air in Wallonia" aiming at inventory the ... [more ▼]

This short report synthesizes the policies concerning odour emissions applicable in Europe and North America. It was written in the frame of the project "Plan of air in Wallonia" aiming at inventory the policies, standards and measurement methods relative to air quality. [less ▲]

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See detailLes odeurs dans l'environnement: Sources d'odeur en Région Wallonne
Nicolas, Jacques ULg; Otte, Benoît

Report (2005)

The report was written in the frame of the project "Plan of air in Wallonia" aiming at inventory the policies, standards and measurement methods relative to air quality. The present report concerns more ... [more ▼]

The report was written in the frame of the project "Plan of air in Wallonia" aiming at inventory the policies, standards and measurement methods relative to air quality. The present report concerns more particularly the identification of possible sources of odour in Wallonia. Both the industrial and the agricultural sectors are investigated. [less ▲]

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See detailOdometers on regular languages
Berthé; Rigo, Michel ULg

in Theory of Computing Systems (2007), 40(1), 1-31

Odometers or "adding machines" are usually introduced in the context of positional numeration systems built on a strictly increasing sequence of integers. We generalize this notion to systems defined on ... [more ▼]

Odometers or "adding machines" are usually introduced in the context of positional numeration systems built on a strictly increasing sequence of integers. We generalize this notion to systems defined on an arbitrary infinite regular language. In this latter situation, if (A, <) is a totally ordered alphabet, then enumerating the words of a regular language L over A with respect to the induced genealogical ordering gives a one-to-one correspondence between N and L. In this general setting the odometer is not defined on a set of sequences of digits but on a set of pairs of sequences where the first (resp. the second) component of the pair is an infinite word over A (resp. an infinite sequence of states of the minimal automaton of L). We study some properties of the odometer such as continuity, injectivity, surjectivity, minimality,... We then study some particular cases: we show the equivalence of this new function with the classical odometer built upon a sequence of integers whenever the set of greedy representations of all the integers is a regular language; we also consider substitution numeration systems as well as the connection with beta-numerations. [less ▲]

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See detailOdor measurement : search for a proper analytical device
Nicolas, Jacques ULg

Conference (2010, March 30)

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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

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See detailOdour emissions impact of on-farm biogas production with co-digestion : a case study in four European farms of the Great Region
Adam, Gilles ULg; Gennen, Jérome; Ubeda Sanchez, Yolanda et al

Conference (2013, December 06)

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See detailOdour evaluation of a dairy farm with anaerobic digestion
Ubeda, Yolanda; Neyrinck, Roland ULg; Calvet, S. et al

Conference (2010, September)

The present work focuses on odour evaluation of a dairy farm with anaerobic digestion, located in the Luxembourg province (Belgium). This study pursues three main goals: 1.- To evaluate the effect of the ... [more ▼]

The present work focuses on odour evaluation of a dairy farm with anaerobic digestion, located in the Luxembourg province (Belgium). This study pursues three main goals: 1.- To evaluate the effect of the anaerobic digestion process on the odour level in the farm, 2.- To compare field and laboratory odour measurement techniques and 3.-To study the influence of the meteorological observation frequency on the odour plume, through the use of dispersion models. Three different approaches were used to characterize the odour: dynamic and field olfactometry and sniffing team method. Odour emissions from all sources were measured by duplicated through dynamic chamber and olfactometric analysis in two different situations: in normal conditions and after stirring the odour source. Two odour field measurement campaigns were conduced in the surroundings of the farm, and meteorological conditions were recorded two times per minute with a weather station. After comparing odour emissions with field measurements through dispersion modeling, we concluded that the best results were obtained using minimum and averaged odour emission rates. Emission rates measured in stirring conditions overestimated the reach of odour perceived in the field in three field campaigns. Overall odour emitted from the farm increased with the anaerobic digestion process. Although odour emission from digested manure is reduced in comparison with non-treated manure, the presence of agricultural wastes increases global odour emission. Finally, meteorological data were averaged each one, five and fifteen minutes. Odour shape was thinner and more extended with 15-minutes data, whereas it was larger and shorter with 30-secondes records. One minute and 5-minute values showed intermediate situations. In conclusion, different techniques to measure odours were compared in this study and, according to the results, field techniques seemed to be more realistic than dynamic olfactometry. [less ▲]

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See detailOdour measurement networks: e-noses and emission data
Romain, Anne-Claude ULg

Conference (2014, September 23)

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See detailOdour monitoring by sensors technology
Romain, Anne-Claude ULg

Conference (2013, December 18)

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See detailOdours identification in the environment by means of mathematical methods
Maternova, Jidrinska; Nicolas, Jacques ULg; Andre, Philippe ULg et al

in Odours & VOC's journal (1996), 1

The aim of the present paper is to test and compare some mathematical discrimination or pattern recognition methods in order to identify one among three air pollution sources.The basic material in this ... [more ▼]

The aim of the present paper is to test and compare some mathematical discrimination or pattern recognition methods in order to identify one among three air pollution sources.The basic material in this work are : - the standard gas chromatography/mass spectrometry analysis with concentrations values for different chemical compounds observed at about hundred sites in iron and steel industries : either coking plants, or cold rolling mills, or coil-coating plants. - the odours levels, measured by the method of dilution at the threshold. Generally speaking, coil-coating plants emit more chemical compounds than two others, however olfactive threshold is about the same in the three cases. Sums of compounds concentrations for different chemical families (e.g. alkanes, alcohol's, phenols, ...) are calculated and used for the mathematical treatments. Because the frequency histogram of the observed concentrations has a log normal distribution, logarithm of concentration is chosen as operating variable instead of concentration itself. The stepwise multiple linear regression is used in order to express the dilution factor at the olfactory perception threshold as a linear combination of the logarithm of concentrations. Results show that this factor can be estimated quite well on the basis of the concentrations of compounds belonging only to three chemical families. Nevertheless, these families differ following the emission source. To perform the optimal odour description of the three types of industrial plants a larger set of compounds families should be examined in a first step. Factor analysis is used with the aim of regrouping observed variables that are linked together in the plane of the first two factors. The representation of observation points is then superposed on this scheme. Some variable clusters are observed. The method, applied to the whole variables set, classes rather well the observations : the three emissions sources are well discriminated. Cluster analysis, discriminant analysis and neural network have also been used, but only with three variables common to all installations : concentrations of alkylbenzenes, polycyclic aromatics and alkanes. Cluster analysis is not a "supervised method". That means that it is free to create itself some groups showing similar behaviour with regard to the observed variables. Indeed, results show that cluster analysis does not allow to recognise the emission source. In discriminant analysis, target groups membership is provided for each set of variables values : it is a supervised method. The classification functions so deduced allow to discriminate quite well the three industrial plants and to predict the emission origin. A total of 87 % of the observations are correctly on the basis of the classification functions. Neural network approach, with backpropagation algorithm, is a so-called "pattern recognition technique" and is also a supervised method. It provides still better results than statistical ones. After the learning phase, the network is able to identify correctly 99.5 % of observations from 95.5 % the training set.The concentrations of compounds belonging to three chemical families, combined with a pattern recognition technique based either on discriminant analysis, or on neural network, prove to be efficient for recognising the source of odorous gaseous effluents. For the data set considered in this paper, the neural network exhibits better classification performances than discriminant analysis, but its learning phase is slower. However, applying one method or the other for further recognition of unknown patterns is quick and easy. [less ▲]

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See detailL'oedeme aigu pulmonaire cardiogenique
Stainier, P. Y.; Lancellotti, Patrizio ULg; Smeets, V. et al

in Revue Médicale de Liège (2004), 59(4), 196-200

Acute cardiogenic pulmonary oedema frequently occurs in clinical practice, frequently in an old patient. It consists in acute respiratory distress related to rapid development of transsudative fluid ... [more ▼]

Acute cardiogenic pulmonary oedema frequently occurs in clinical practice, frequently in an old patient. It consists in acute respiratory distress related to rapid development of transsudative fluid within the lung interstitium and alveolar accumulation. It requires rapid assessment and therapy to prevent progression to respiratory failure and cardiovascular collapse. The pathogenesis and identification of the underlying disease process are essential for optimal medical approach. The aetiology is multiple. [less ▲]

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See detailOedipe, devenir un homme
Stassart, Martine ULg

in Oedipe. Devenir un homme. (1994)

What is the latent significance of Oedipous' myth? Why is Oedipus a modern hero?

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See detailAn Oedometer for Studying Combined Effects of Temperature and Suction on Soils
François, Bertrand ULg; Laloui, Lyesse

in Geotechnical Testing Journal (2010), 33(2),

This paper reports the development of an advanced thermo-hydro-mechanical (THM) oedometer in order to characterize the behavior of soils under combined non-isothermal and unsaturated conditions. The ... [more ▼]

This paper reports the development of an advanced thermo-hydro-mechanical (THM) oedometer in order to characterize the behavior of soils under combined non-isothermal and unsaturated conditions. The simultaneous control of temperature, suction, and stress states within the sample required rigorous calibration. This THM oedometer accommodates samples 80 mm in diameter and 23 mm in height. The applied vertical stresses can reach values of up to 1 MPa, the controlled temperature ranges from 20 to 80°C, and the applied suction is up to 500 kPa. The paper thoroughly discusses the calibration of the device and presents some results of tests performed on sandy silt. [less ▲]

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See detailOeil en pénombre
Strivay, Lucienne ULg; Gossiaux, Pol-Pierre ULg

in Voir (1997), 14

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