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See detailEffets de la pression partielle en hydrogène sur la production anaérobie de bioH2 par une bactérie chimiotrophe du genre Clostridium dans un nouveau réacteur à cylindre horizontal rotatif.
Beckers, Laurent ULg; Hiligsmann, Serge ULg; Hamilton, Christopher ULg et al

in Récents Progrès en Génie des Procédés (2011, December), 101

Hydrogen is widely considered as the most promising energetic carrier. At an industrial scale, steam reforming of methane is currently the major hydrogen producing process. But it may also be produced ... [more ▼]

Hydrogen is widely considered as the most promising energetic carrier. At an industrial scale, steam reforming of methane is currently the major hydrogen producing process. But it may also be produced from renewable biomass. Indeed, the fermentative production of hydrogen from renewable biomass using anaerobic bacteria could at least partially reduce our dependence on fossil fuel, decrease the carbon dioxide emissions and produce “green” energy. It offers the potential production of usable hydrogen from a variety of renewable resources such as carbohydrates wastes from agriculture or agro-food industries. This technology is based on anaerobic fermentation, called dark fermentation, by chemotrophic bacteria. The investigations carried out at CWBI involve selection and characterization of bacteria strains able to produce biohydrogen efficiently and with a wide range of substrate. The selected strains at the laboratory has been characterised as Clostridium sp. In order to produce hydrogen at high yields and production rates, the biotechnological process needs to be further optimized and efficient bioreactors must be designed. At CWBI, a new reactor called “horizontal rotating cylinder bioreactor” allows the production of biohydrogen from glucose with our Clostridium sp. strain with a high yield and production rate. This reactor, working continuously, has an internal volume of 2.3l but a working volume (liquid phase) of 300ml. Firstly, it enhances the hydrogen production rate by partially fixing the bacteria on the porous cylinder and thus increasing the cell concentration in the bioreactor. Secondly, the rotative cylinder enables efficient gas transfer (mainly hydrogen) from the liquid phase where it is produced by the bacteria. This is an important way to enhance hydrogen production yield by allowing the bacteria metabolism to shift in a fermentation type that produces more hydrogen. This was confirmed by increasing or decreasing the total pressure in the bioreactor and observing the influence of hydrogen production. The liquid to gas hydrogen transfer is possibly an important factor to enhance the biogas production. Our investigation confirmed this by testing different liquid to gas transfer condition in BHP test (batch fermentation in 250ml serum bottles).This was made either by decreasing total and partial pressure or by increasing the mixing state of the media. Our work concludes the importance of providing good liquid to gas transfers in the biohydrogen producing reactors to enhance the hydrogen production and reach higher yields and production rates. [less ▲]

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See detailEffets de la qualité des données sur la courbe d'apprentissage des forêts aléatoires
Brostaux, Yves ULg

Scientific conference (2008, April 11)

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See detailLes effets de la qualité paysagère sur les marchés fonciers et immobilier
Henneberry, John; Halleux, Jean-Marie ULg

in Creating a Setting for Investment (2008)

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See detailEffets de la répétition des traitements Progestagènes/PMSG chez la chèvre
Baril, G.; Leboeuf, B.; Remy, Benoit et al

(1998, April 30)

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See detailLes effets de la retraite sur la mémoire
Adam, Stéphane ULg

Conference (2014, September 16)

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See detailLes effets de la Révolution sur l'architecture liégeoise
Gilles, Isabelle ULg

Scientific conference (2014, January 21)

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See detailEffets de la sénescence sur les neurones GABAergiques
Delwaide, P. J.; Delwaide, Jean ULg

in Encéphale (L') (1987), 13

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See detailEffets de la substitution du tourteau d’arachide par la fève de coton conventionnel en production de poulet de chair au Sénégal
Diaw, Mamadou Tandiang; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Tropicultura (2010), 28(3), 139-147

A study has been conducted on 400 chicks to evaluate conventional cottonseed kernels on broilers production. Groundnut cake has been substituted by cottonseed kernels at 0, 25, 50 and 75% levels ... [more ▼]

A study has been conducted on 400 chicks to evaluate conventional cottonseed kernels on broilers production. Groundnut cake has been substituted by cottonseed kernels at 0, 25, 50 and 75% levels. Cottonseed kernel incorporation decreased significantly (p< 0.001) the growing parameters, feed intake, feed efficiency and nutrients digestibility of the experimental diets. This reduction was proportional to the level of substitution. The study suggests that only the level of gossypol in cottonseed kernels limits their incorporation in broilers diets and that this by-product should be excluded from the formulation in broilers production or that its level of incorporation should be limited to a maximal level of 10% when production duration is not a constraint for breeders. [less ▲]

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See detaileffets de la substitution totale du tourteau d’arachide par la fève de coton glandless sur les performances zootechniques de poulets de chair au sénégal
Diaw, Mamadou; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Revue d'Elévage et de Médecine Vétérinaire des Pays Tropicaux (2012), 65(1-2), 17-23

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a ... [more ▼]

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a commercial diet (Tém_C), and a very simple diet containing only corn, FCG and a mineral and vitamin concentrate. From the start, the Tém_C and FCG animals showed the highest growths. After 43 days of breeding, there were major differences in body weights between the groups, essentially caused by differences in feed intake, so that the best growth rates were not necessarily linked to better feed conversion ratios. Low body weights, low intakes and high mortality levels were observed with the simple diet. [less ▲]

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See detailEffets de la surface disponible et du type de sol sur les émissions gazeuses lors de l’élevage de truies gestantes
Philippe, François-Xavier ULg; Cabaraux, Jean-François ULg; Canart, Bernard et al

in 42èmes Journées de la Recherche Porcine (2010)

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See detailEffets de la variation de pression sur la qualité des jets de pulvérisation et leur contribution aux risques de pollution environnementale.
Boukhalfa, Hassina dite Hafida ULg

Conference (2011, November 16)

Un traitement phytosanitaire s’effectue en visant un triple objectif: être efficace, ne pas mettre en danger l’opérateur et protéger l’environnement. (MOREAU et al., 1997). La quantité de pesticides ... [more ▼]

Un traitement phytosanitaire s’effectue en visant un triple objectif: être efficace, ne pas mettre en danger l’opérateur et protéger l’environnement. (MOREAU et al., 1997). La quantité de pesticides appliquée chaque année est estimée à 2.5 millions de tonnes mais la part de cette quantité qui entre en contact avec les organismes indésirables est très faible. La plupart des chercheurs l’évaluent à moins de 1% (ELAISSAOUI et al., 2004), ce qui veut dire que 99% des substances chimiques entre en contact avec le milieu environnant d’une manière non ciblé et sont potentiellement dangereux pour les écosystèmes entiers. D'après FAGOT et LARRAT (2002), la pression a un effet direct sur la répartition du produit et le volume de bouillie appliqué par son action sur la taille des gouttelettes et sur l'angle du jet de pulvérisation. Dans le but d’accroître l’efficacité de pulvérisation de pesticides et de réduire les pertes diverses de bouillie qui en résultent, nous avons étudie l’influence de la variation de pression sur la forme et la composition d’un jet de pulvérisation à l’aide d’un pulvérisateur à pression de liquide à jet projeté avec une buse à turbulence. Le travail a été effectue avec 5 valeurs de pression 0.5 bar, 1 bar, 1.5 bar, 2 bar et 2.5 bar. Les résultats obtenus nous ont permit d'en déduire que la pression de 1bar donne la meilleure couverture et répartition du jet de pulvérisation. A partir de la pression de 1.5 bar commence la dérive, et des pressions plus élevées rendent le jet irrégulier et hors cible. L'augmentation de pression augmente les pertes en bouillie et la quantité de fines gouttelettes. [less ▲]

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See detailEffets de la vibrotonie corporelle totale sur le risque de chute de la personne âgée: Mise au point
Buckinx, Fanny ULg; Reginster, Jean-Yves ULg; Petermans, Jean ULg et al

in Ortho-Rhumato (2014), 12(6), 6-9

Les chutes constituent un problème majeur de santé publique. Si le bénéfice de l’exercice physique sur la prévention des chutes est avéré, les exercices classiques ne sont pas toujours adaptés pour les ... [more ▼]

Les chutes constituent un problème majeur de santé publique. Si le bénéfice de l’exercice physique sur la prévention des chutes est avéré, les exercices classiques ne sont pas toujours adaptés pour les personnes âgées. C’est pourquoi la vibrotonie corporelle totale, en permettant la réalisation d’exercices isométriques, pourrait théoriquement s’avérer être une bonne alternative pour les séniors. Depuis les années 2000, plusieurs études ont évalué les effets de la vibrotonie corporelle totale sur le risque de chute. Les résultats individuels de ces recherches sont assez variables, ce qui pourrait, entre autres, s’expliquer par la variété des protocoles utilisés, des populations cibles, des critères d’évaluation choisis et de la qualité méthodologique. Globalement, il semblerait que les appareils de vibrotonie du corps entier puissent améliorer, de manière statistiquement significative, différents paramètres de la marche et de l’équilibre et pourraient dès lors réduire le risque de chute des patients âgés. Toutefois, les durées d’exposition, les fréquences de stimulation et les amplitudes d’oscillations varient sensiblement d’une étude à l’autre et il est actuellement impossible d’en dégager un protocole précis. [less ▲]

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See detailEffets de lisière et sex-ratio de rongeurs forestiers dans un écosystème fragmenté en République Démocratique du Congo (Réserve de Masako, Kisangani)
Iyongo Waya Mongo, L; De Cannière, C; Ulyel, J et al

in Tropicultura (2013), 31(1), 3-9

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See detailEffets de lisière sur la productivité du teck (Tectona grandis L.f.): étude de cas des teckeraies privées du Sud-Bénin
Toyi, Mireille Scholastique; Bastin, Jean-François ULg; Andre, Marie ULg et al

in Tropicultura (2013), 31(1), 62-70

The present study aims to improve the production of teak wood (Tectona grandis L.f.) in private plantations in southern Benin through the application of a central concept in landscape ecology: the edge ... [more ▼]

The present study aims to improve the production of teak wood (Tectona grandis L.f.) in private plantations in southern Benin through the application of a central concept in landscape ecology: the edge effect. As teak is an heliophilous species, the hypothesis of a higher wood production in edges was tested on the basis of the basal area. Sixty-two private teak plantations were investigated and 10,667 trees were measured. The stratified sampling scheme in three distinct parts for each plantation (the centre, the edge and the summits) permitted to highlight the edge effect on wood production. For each part, a plot was installed and the diameter at breast height (dbh) was measured for all trees. The leaf area between the edge and the centre of plantations was measured. Finally, the influence of the spatial configuration of plantations and the direction of each side of these plantations on the production of wood was tested. Results show that the edge effect on the production of teak wood affects four planting lines, the first presenting a production of 150% relative to the centre. We noticed a significant influence of the edge on the leaf area of about 218% relative to the centre. No influence of the direction of the sides of the plantation was observed. The shape of the plantations presents a significant influence on the wood production. These results permitted to propose a planting model included in an agroforestry system that optimizes the production of wood per area and having a succession of two planting lines interrupted by fields. [less ▲]

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