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See detailSeasonal variability of CO2 fluxes in the tropical lagoons of Ivory Coast
Koné, Y. J. M.; Gourene, G.; Abril, G. et al

Poster (2008)

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See detailTest de la marche de reconnaissance dans une unité forestière d’aménagement du sud-est du Cameroun
Marechal, Corinne ULg; Bastin, Didier

in Bois et Forêts des Tropiques (2008), 297(3), 81-85

Depuis les années 1990, le cadre légal de l’exploitation forestière dans les pays producteurs de bois du bassin du Congo a évolué vers une meilleure prise en compte de la biodiversité. Désormais, les ... [more ▼]

Depuis les années 1990, le cadre légal de l’exploitation forestière dans les pays producteurs de bois du bassin du Congo a évolué vers une meilleure prise en compte de la biodiversité. Désormais, les entreprises forestières ont l’obligation d’élaborer un plan d’aménagement des forêts concédées, en y intégrant l’aspect « faune ». Aujourd’hui, les inventaires de mammifères sont devenus un outil d’aide incontournable dans le processus de gestion des forêts de production. Cependant, ces inventaires souffrent encore de différences méthodologiques notables. L'article s’inscrit dans le cadre de la recherche d’une méthodologie standardisée, performante et adaptée au contexte de l’exploitation forestière dans le bassin du Congo. Nous examinons ici une procédure de collecte des données basée sur la technique du recce (marche de reconnaissance) pour évaluer l’état de la faune dans les concessions forestières et en présentons les avantages par rapport à celle adaptée au dispositif d’inventaire forestier. Le recce a été testé dans une concession du sud-est Cameroun en cours d’aménagement. Les taux de rencontre (IKA) des espèces observables et des activités de chasse obtenus sur les recces sont similaires à ceux sur des transects linéaires dans les mêmes zones, et ce pour un coût humain trois fois moindre. Nous proposons un protocole d’inventaire pragmatique basé sur le relevé d’indices lors de recces et des recommandations pour le monitoring de la faune dans les exploitations forestières. [less ▲]

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See detailRésumé C.E. n°180.553, du 6 mars 2008, Warbecq et Bouchez
Delnoy, Michel ULg

in Aménagement - Environnement (2008), 4

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See detailRésumé C.E. n°175.463, du 8 octobre 2007, ASBL Le Poumon Vert de La Hulpe
Delnoy, Michel ULg

in Aménagement - Environnement (2008), 2

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See detailRésumé CEDH, 14 février 2008, Butan et Dragomir
Delnoy, Michel ULg

in Aménagement - Environnement (2008), 4

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See detailRésumé C.E. n°175.035, du 27 septembre 2007, R.T.B.F.
Delnoy, Michel ULg

in Aménagement - Environnement (2008), 2

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See detailRésumé C.E. n°175.277, du 2 octobre 2007, SA Gery International
Delnoy, Michel ULg

in Aménagement - Environnement (2008), 2

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See detailRésumé T.P.I.C.E., 14 décembre 2006, aff. T-237/02
Delnoy, Michel ULg

in Aménagement - Environnement (2008), 2

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See detailReflexions, La Chimie Analytique Verte
Ziemons, Eric ULg; Mantanus, Jérôme ULg; Lebrun, Pierre ULg et al

Learning material (2008)

Au début des années 1990, est apparu le concept de “chimie verte” mieux connue sous le vocable anglais “Green Chemistry”. L’objectif principal de la chimie verte est de définir un cadre à la prévention de ... [more ▼]

Au début des années 1990, est apparu le concept de “chimie verte” mieux connue sous le vocable anglais “Green Chemistry”. L’objectif principal de la chimie verte est de définir un cadre à la prévention de la pollution résultante des activités chimiques prises au sens le plus large. Dans ce contexte, une partie des travaux de recherche du Service de Chimie Analytique du Département de Pharmacie porte sur le développement de nouveaux outils pour la préparation et l’analyse d’échantillons. [less ▲]

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See detailThe Dynamics of Fair Trade as a Mixed-form Market
Becchetti, Leonardo; Huybrechts, Benjamin ULg

in Journal of Business Ethics (2008), 81(4), 733-750

This article analyses the Fair Trade sector as a “mixed-form market,” i.e., a market in which different types of players (in this case, nonprofit, co-operative and for-profit organizations) coexist and ... [more ▼]

This article analyses the Fair Trade sector as a “mixed-form market,” i.e., a market in which different types of players (in this case, nonprofit, co-operative and for-profit organizations) coexist and compete. The purposes of this article are (1) to understand the factors that have led Fair Trade to become a mixed-form market and (2) to propose some trails to understand the market dynamics that result from the interactions between the different types of players. We start by defining briefly Fair Trade, its different dimensions (including the “fair” quality of the products) and its organizational landscape, focusing on the distinction between the pioneer “Alternative Trading Organizations” and the second-mover companies. Then, we recall the theoretical emergence factors for each type of organization (nonprofit, co-operative and for-profit) and apply these emergence factors to the context of Fair Trade. This analysis allows us to capture the specificities of each type of operator with regard to Fair Trade and, thus, to have a better understanding of the dynamics in the sector. Such dynamics includes competition, but also conflict and partnership. Our analysis includes elements on ethical imitation, consumers’ behaviors, effects on welfare and the role of the government. [less ▲]

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See detailInter-annual variability of the carbon dioxide oceanic sink south of Tasmania
Borges, Alberto ULg; Tilbrook, B.; Metzl, N. et al

Poster (2008)

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See detailHCCI engine modeling and experimental investigations - Part 2: The composition of a NO-PRF interaction mechanism and the influence of NO in EGR on auto-ignition
Machrafi, Hatim ULg; Guibert, Philippe; Cavadias, Simeon

in Combustion Science And Technology (2008), 180(7), 1245-1262

This article presents an investigation of the effect of NO in EGR on HCCI auto-ignition, by means of experiments and a NO-PRF interaction mechanism. The influence is investigated both numerically and ... [more ▼]

This article presents an investigation of the effect of NO in EGR on HCCI auto-ignition, by means of experiments and a NO-PRF interaction mechanism. The influence is investigated both numerically and experimentally. The numerical part is effected by a composition of a NO submechanism and the subsequent addition of this sub mechanism to a reduced validated n-heptane/iso-octane PRF mechanism, the latter of which is presented in a previous article, named article 1 (Machrafi et al., submitted 2006). The experimental part is effected on a CFR engine, operating at HCCI conditions, with an inlet temperature of 70 degrees C and a compression ratio of 10.2. Hereby n-heptane and PRF40 are used as the fuels, using different equivalence ratios in order to extend the interpretation domain. The NO adding concentration is experimentally varied between 0 and 160 ppm. The results showed that adding NO at low concentrations advances the ignition delays, the promoting reactions being more reactive than the inhibitory ones. The promoting effect seems to be at its maximum at an addition of 45 ppm concerning the fuel PRF40. At higher adding concentrations of NO the promoting effect becomes less and the inhibitory reactions become more reactive. The effect of NO on the auto-ignition of n-heptane seemed, however, to be unsignificant. The effect of NO was qualitatively well represented by the mechanism, while quantitatively the mechanism predicted a lower effect of NO at an addition of 45 ppm. [less ▲]

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See detailA parametric study on the emissions from an HCCI alternative combustion engine resulting from the auto-ignition of primary reference fuels
Machrafi, Hatim ULg; Cavadias, Simeon; Amouroux, Jacques

in Applied Energy (2008), 85(8), 755-764

The homogeneous charge compression ignition is an alternative combustion technology that can reduce automobile pollution, provided that the exhaust emission can be controlled. A parametric study can be ... [more ▼]

The homogeneous charge compression ignition is an alternative combustion technology that can reduce automobile pollution, provided that the exhaust emission can be controlled. A parametric study can be useful in order to gain more understanding in the emission reduction possibilities via this new combustion technology. For this purpose, the inlet temperature, the equivalence ratio and the compression ratio are changed, respectively, from 30 to 70 degrees C, 0.28 to 0.41 and 6 to 14. Also the diluting, thermal and chemical effects of exhaust gas recirculation were studied. The emission of CO, CO2, O-2 and hydrocarbons has been measured using primary reference fuels. It appears that an increase in the inlet temperature, the EGR temperature, the equivalence ratio and the compression ratio results into a decrease of the emissions of CO and the hydrocarbons of up to 75%. The emission of CO2 increased, however, by 50%. The chemical parameters showed more complicated effects, resulting into a decrease or increase of the emissions, depending on whether the overall reactivity increased or not. If the reactivity increased, generally, the emissions of CO and hydrocarbons increased, while that of CO2 increased. The increase of CO2 emissions could be compensated by altering the compression ratio and the EGR parameters, making it possible to control the emission of the HCCI engine. (c) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailExperimental validation of a kinetic multi-component mechanism in a wide HCCI engine operating range for mixtures of n-heptane, iso-octane and toluene: Influence of EGR parameters
Machrafi, Hatim ULg

in Energy Conversion And Management (2008), 49(11), 2956-2965

The parameters that are present in exhaust gas recirculation (EGR) are believed to provide an important contribution to control the auto-ignition process of the homogeneous charge compression ignition ... [more ▼]

The parameters that are present in exhaust gas recirculation (EGR) are believed to provide an important contribution to control the auto-ignition process of the homogeneous charge compression ignition (HCCI) in an engine. For the investigation of the behaviour of the auto-ignition process, a kinetic multi-component mechanism has been developed in former work, containing 62 reactions and 49 species for mixtures of n-heptane. iso-octane and toluene. This paper presents an experimental validation of this mechanism, comparing the calculated pressure, heat release, ignition delays and CO2 emissions with experimental data performed on a HCCI engine. The validation is performed in a broad range of EGR parameters by varying the dilution by N-2 and CO2 from 0 to 46vol.%, changing the EGR temperature from 30 to 120 degrees C, altering the addition of CO and NO from 0 to 170 ppmv and varying the addition of CH2O from 0 to 1400 ppmv. These validations were performed respecting the HCCI conditions for the inlet temperature and the equivalence ratio. The results showed that the mechanism is validated experimentally in dilution ranges going up to 21-30 vol.%, depending on the species of dilution and over the whole range of the EGR temperature. The mechanism is validated over the whole range of CO and CH2O addition. As for the addition of NO, the mechanism is validated quantitatively up to 50 ppmv and qualitatively up to 170 ppmv. (C) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailThree-stage autoignition of gasoline in an HCCI engine: An experimental and chemical kinetic modeling investigation
Machrafi, Hatim ULg; Cavadias, Simeon

in Combustion & Flame (2008), 155(4), 557-570

The alternative HCCI combustion mode presents a possible means for decreasing the Pollution with respect to conventional gasoline or diesel engines, while maintaining the efficiency of a diesel engine or ... [more ▼]

The alternative HCCI combustion mode presents a possible means for decreasing the Pollution with respect to conventional gasoline or diesel engines, while maintaining the efficiency of a diesel engine or even increasing it. This paper investigates the possibility Of using gasoline in an HCCI engine and analyzes the autoignition of gasoline in such an engine. The compression ratio that has been used is 13.5, keeping the inlet temperature at 70 degrees C, varying the equivalence ratio from 0.3 to 0.54, and the EGR (represented by N-2) ratio from 0 to 37 vol%. For comparison, a PRF95 and a Surrogate containing 11 vol% n-heptane, 59 vol% iso-octane, and 30 vol% toluene are used. A previously validated kinetic surrogate mechanism is Used to analyze the experiments and to yield possible explanations to kinetic phenomena. From this work, it seems quite possible to use the high octane-rated gasoline for autoignition purposes, even Under lean inlet conditions. Furthermore, it appeared that gasoline and its Surrogate, unlike PRF95, show a three-stage autoignition. Since the PRF95 does not contain toluene, it is Suggested by the Kinetic mechanism that the benzyl radical, issued from toluene, causes this so-defined "obstructed preignition" and delaying thereby the final ignition for gasoline and its surrogate. The results of the kinetic mechanism supporting this explanation are shown in this paper. (C) 2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved. [less ▲]

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See detailAn experimental and numerical investigation on the influence of external gas recirculation on the HCCI autoignition process in an engine: Thermal, diluting, and chemical effects
Machrafi, Hatim ULg; Cavadias, Simeon; Guibert, Philippe

in Combustion & Flame (2008), 155(3), 476-489

In order to contribute to the solution of controlling the autoignition in a homogeneous charge compression ignition (HCCI) engine, parameters linked to external gas recirculation (EGR) seem to be of ... [more ▼]

In order to contribute to the solution of controlling the autoignition in a homogeneous charge compression ignition (HCCI) engine, parameters linked to external gas recirculation (EGR) seem to be of particular interest. Experiments performed with EGR present some difficulties in interpreting results using only the diluting and thermal aspect of EGR. Lately, the chemical aspect of EGR is taken more into consideration, because this aspect causes a complex interaction with the dilution and thermal aspects of EGR. This paper studies the influence of EGR on the autoignition process and particularly the chemical aspect of EGR. The diluents present in EGR are stimulated by N-2 and CO2, with dilution factors going from 0 to 46 vol%. For the chemically active species that could be present in EGR, the species 0 and 170 ppm, while that of CH2O alters between 0 and 1400 ppm. For the investigation of the effect of the chemical species on the autoignition, a fixed dilution factor of 23 vol% and a fixed EGR temperature of 70 degrees C are maintained. The inlet temperature is held at 70 degrees C, the equivalence ratios between 0.29 and 0.41, and the compression ratio at 10.2. The fuels used for the autoignition are n-heptane and PRF40. It appeared that CO, in the investigated domain, did not influence the ignition delays, while NO had two different effects. At concentrations up until 45 ppm, NO advanced that ignition delays for the PRF40 and at higher concentrations, the ignition delayed. The influence of NO on the autoignition of n-heptane seemed to be insignificant, probably due to the higher burn rate of n-heptane. CH2O seemed to delay the ignition. The results suggested that especially the formation of OH radicals or their consumption by the chemical additives determines how the reactivity of the autoignition changed. (C) 2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved. [less ▲]

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See detailAn experimental and numerical analysis of the influence of the inlet temperature, equivalence ratio and compression ratio on the HCCI auto-ignition process of Primary Reference Fuels in an engine
Machrafi, Hatim ULg; Cavadias

in Fuel Processing Technology (2008), 89(11), 1218-1226

In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and ... [more ▼]

In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured, The inlet temperature was changed from 25 to 70 degrees C and the equivalence ratio from 0.18 to 0.41, while the compression ratio varied from 6 to 13.5. The fuels that were investigated were PRF40 and n-heptane. These three parameters appeared to decrease the ignition delays, with the inlet temperature having the least influence and the compression ratio the most. A previously experimentally validated reduced surrogate mechanism, for mixtures of n-heptane, iso-octane and toluene, has been used to explain observations of the auto-ignition process. The same kinetic mechanism is used to better understand the underlying chemical and physical phenomena that make the influence of a certain parameter change according to the operating conditions. This can be useful for the control of the auto-ignition process in an HCCI engine. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailAn experimental and numerical analysis of the HCCI auto-ignition process of primary reference fuels, toluene reference fuels and diesel fuel in an engine, varying the engine parameters
Machrafi, Hatim ULg; Cavadias, Simeon; Gilbert, Philippe

in Fuel Processing Technology (2008), 89(11), 1007-1016

For a future HCCI engine to operate under conditions that adhere to environmental restrictions, reducing fuel consumption and maintaining or increasing at the same time the engine efficiency, the choice ... [more ▼]

For a future HCCI engine to operate under conditions that adhere to environmental restrictions, reducing fuel consumption and maintaining or increasing at the same time the engine efficiency, the choice of the fuel is crucial. For this purpose, this paper presents an auto-ignition investigation concerning the primary reference fuels, toluene reference fuels and diesel fuel, in order to study the effect of linear alkanes, branched alkanes and aromatics on the auto-ignition. The auto-ignition of these fuels has been studied at inlet temperatures from 25 to 120 degrees C, at equivalence ratios from 0.18 to 0.53 and at compression ratios from 6 to 13.5, in order to extend the range of investigation and to assess the usability of these parameters to control the auto-ignition. It appeared that both iso-octane and toluene delayed the ignition with respect to n-heptane, while toluene has the Strongest effect. This means that aromatics have higher inhibiting effects than branched alkanes. In an increasing order, the inlet temperature, equivalence ratio and compression ratio had a promoting effect on the ignition delays. A previously experimentally validated reduced surrogate mechanism, for mixtures of n-heptane, iso-octane and toluene, has been used to explain observations of the auto-ignition process. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailPlace et rôle de l´éducateur physique dans la société contemporaine
Cloes, Marc ULg

in Antala, Branislav (Ed.) Školská telesná výchova z pohľadu výsledkov vedeckého výskumu (2008)

Le terme "éducateur physique" est une expression tirée du vocabulaire québecois. Il provient des institutions universitaires ayant proposé cette dénomination afin d'identifier leurs programmes de ... [more ▼]

Le terme "éducateur physique" est une expression tirée du vocabulaire québecois. Il provient des institutions universitaires ayant proposé cette dénomination afin d'identifier leurs programmes de formation dans le domaine de la motricité humaine. En partant principalament du contexte spécifique de la Communauté française de Belgique, nous nous attachons à identifier les missions des éducateurs sportifs et à déterminer l'impact de leur action. Nous cloturerons cette analyse en proposant quelques pistes d'action susceptibles d'améliorer la qualité de leur travail. ... [less ▲]

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