Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
See detailContribution to the study of physicochemical and functional properties of hemicelluloses and xylooligosaccharides (XOS) extracted from rapeseed meal
Mertens, Cécile ULg; Paquot, Michel ULg; Destain, Jacqueline ULg et al

Poster (2012, February 08)

Rapeseed meal is one of the main industrial co-products from agriculture in Belgium, with more than 30 000 T produced each year. Beside its agricultural and energetic applications, new paths of ... [more ▼]

Rapeseed meal is one of the main industrial co-products from agriculture in Belgium, with more than 30 000 T produced each year. Beside its agricultural and energetic applications, new paths of valorization are being developed in order to add value to the rapeseed meal, usually by extraction of interesting molecules. In this thesis project, the aimed molecules are hemicelluloses, which are obtained via a global fractionation method that is being developed and optimized, constituting the first part of this project. Indeed, while rapeseed meals are globally already well exploited (mainly for their feed value), rapeseed hemicelluloses have not yet been studied for food application. Yet, hemicelluloses can be used as food additives (thickener, stabilizer, etc) mainly in bakery products. The literature being incomplete regarding the chemical structure of rapeseed hemicelluloses, one of the objectives of this project is to study their physicochemical properties, in regard with their technofunctional properties. Rapeseed hemicelluloses can also be used as raw material to produce an emergent type of prebiotic: xylooligosaccharides (XOS). These molecules can be introduced as well in the food supplement sector. Their production will be achieved by enzymatic hydrolysis, for a polymerization degree between two and five. Thus, the production and the physicochemical and technofunctional characterization of rapeseed XOS constitute the last objective of this project. This thesis is part of the SYNBIOFOR project, which aim is to create new symbiotic ingredients. [less ▲]

Detailed reference viewed: 105 (22 ULg)
Full Text
Peer Reviewed
See detailContribution to the study of piano Key Weir hydraulics
Erpicum, Sébastien ULg; Machiels, Olivier ULg; Dewals, Benjamin ULg et al

in Proceedings of the 8th ICOLD European Club Symposium (2010)

Within the framework of updating the release and storage capacities of existing reservoirs, the use of piano key weirs (PKW) can be an interesting alternative either to increase the discharge of a free ... [more ▼]

Within the framework of updating the release and storage capacities of existing reservoirs, the use of piano key weirs (PKW) can be an interesting alternative either to increase the discharge of a free weir without changing the weir width on the dam crest nor the reservoir level, or to increase the threshold reservoir level before releasing water while keeping the weir width and the level of safety. Results of first experiments on scale models have shown the high efficiency of PKW in terms of discharge capacity. But, even if PKW projects start to be developed on real structures, lacks persist in the understanding of the flow behavior on this new type of weir, in the characterization of their hydraulic potential and in the availability of design guidelines. This paper presents the results of several research projects, based on both numerical and physical modeling, carried out on this topic at the Laboratory of Engineering Hydraulics of the University of Liege. The researches rely on physical experiments on scale models of idealized PKW elements or real structures, as well as on numerical modeling with specifically developed solvers. The paper presents an overview of these projects, emphasizing the most important results regarding PKW design and performance. [less ▲]

Detailed reference viewed: 14 (0 ULg)
Full Text
See detailContribution to the study of semiochemical slow release formulations. Development of flash chromatographic methods.
Heuskin, Stéphanie ULg; Farmakidis, Julien; Lorge, Stéphanie et al

Poster (2009)

Detailed reference viewed: 21 (7 ULg)
Full Text
See detailContribution to the study of semiochemical slow-release formulations as biological control devices
Heuskin, Stéphanie ULg

Doctoral thesis (2011)

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been widely considered within various integrated pest management (IPM) strategies. In the present thesis ... [more ▼]

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been widely considered within various integrated pest management (IPM) strategies. In the present thesis, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for their related properties as aphid enemy attractants. E-β-farnesene, the alarm pheromone of many aphid species, was also identified as a kairomone by attracting and inducing oviposition of aphid predators (Episyrphus balteatus De Geer (Diptera: Syrphidae)) and by attracting aphid parasitoids (Aphidius ervi Haliday (Hymenoptera: Braconidae)). E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas, another aphid predator. The two products were purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae) for E-β-farnesene and E-β-caryophyllene, respectively. Natural and biodegradable slow-release formulations were then investigated in order to deliver these molecules on crop fields for a long period of time as biological control devices. Due to their sensitivity to oxidation, both sesquiterpenes needed to be protected from oxygen degradation. For this purpose, alginate – hydrophilic matrix with low oxygen permeability – was used as polymer for the formulations: the main objective was to deliver semiochemical substances in the air in a controlled way. Consequently, a careful selection of alginates was realised. Formulated beads showed different structural and encapsulation properties depending on various formulation factors. Alginate formulations were characterized by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step of alginate bead characterisation consisted in studying release rate of semiochemicals in laboratory-controlled conditions by optimised trapping and validated Fast-GC procedures. Finally, the efficiency of formulations as aphid predator (Syrphidae) and parasitoids (A. ervi) attractants was demonstrated by field trapping and olfactometry experiments. [less ▲]

Detailed reference viewed: 60 (20 ULg)
Full Text
Peer Reviewed
See detailContribution to the study of stress cracking phenomenon by oxidative induction time measurements
Rigo, Jean-Marie ULg; Courard, Luc ULg; Detaille, Laurence et al

in Delmas, Philippe; Gourc, Jean-Pierre (Eds.) Proceedings of the Rencontres 95 (1995)

Detailed reference viewed: 8 (1 ULg)
Full Text
See detailContribution to the study of Strychnos usambarensis GILG, main ingredient of an African curarizing arrow poison
Angenot, Luc ULg

in Dissertation Abstracts (1974), 34(11), 338

The thesis is subdivided in four parts and two annexes . the first part concerns the choice of Strychnos usambarensis based on ethnobotanical considerations; the second part is dedicated to the study of ... [more ▼]

The thesis is subdivided in four parts and two annexes . the first part concerns the choice of Strychnos usambarensis based on ethnobotanical considerations; the second part is dedicated to the study of arrow poisons in the World and particularly in Africa; the third part describes the isolation of eight indole alkaoids ( 5 new and 3 known ones) and their structure determination thanks to modern spectroscopic methods.The fourth part is applied to the biosynthesis of these alkaloids and to the identification of loganic acid.The first appendix describes the phytochemical screening of 33 Rwandan plants mainly collected in the National Park of Akagera. The second appendix relates pharmacological experiments on crude fractions and some isolated alkaloids. [less ▲]

Detailed reference viewed: 20 (4 ULg)
Peer Reviewed
See detailContribution to the study of the allosteric properties of acetylcholinesterase
Gridelet, J.; Foidart, Jean-Michel ULg; Wins, P.

in Archives Internationales de Physiologie et de Biochimie (1970), 78

Detailed reference viewed: 9 (0 ULg)
Peer Reviewed
See detailContribution to the study of the flora and the ecology of cave blue-green algae.
Garbacki, Nancy ULg; Hoffmann, Lucien

Conference (1995)

Detailed reference viewed: 18 (0 ULg)
Full Text
See detailContribution to the study of the relations between fish of the family of Carapidae and their holothurian hosts
Parmentier, Eric ULg

in SPC Bêche de mer, Information Bulletin (2004), 19

Detailed reference viewed: 27 (0 ULg)
Full Text
Peer Reviewed
See detailContribution to the study of the resistance to drying of Pseudomonas fluorescens
Mputu Kanyinda, Jean-Noël ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013)

The objective of this thesis is to study the resistance to drying of Pseudomonas fluorescens. Freeze-drying is the most suitable method for drying P. fluorescens. However, freeze-drying induced loss of ... [more ▼]

The objective of this thesis is to study the resistance to drying of Pseudomonas fluorescens. Freeze-drying is the most suitable method for drying P. fluorescens. However, freeze-drying induced loss of cell viability. This loss of viability is mainly due to membrane rupture, temperature and oxidation of fatty acids, membrane proteins and glutathione. For this purpose, the use of protective compounds during freeze-drying has allowed us to obtain a powder having a high viability. We then studied the impact of these protective compounds, oxygen and storage temperature on the viability of P. fluorescens during storage. Analyses of fatty acids, proteins, glutathione and the study of membrane integrity during the various manufacturing processes and storage have established a link between the degree of oxidation and cell death. The results of flow cytometry showed that the freeze-drying longer affects the viability of P. fluorescens rather than storage. We have increased the yield of the production in bioreactor of P. fluorescens and time of culture was halved. [less ▲]

Detailed reference viewed: 55 (12 ULg)
Full Text
See detailA contribution to the study of β Canis Majoris.
Struve, Otto; Swings, Polydore ULg

in Astrophysical Journal (1941), 94

Coudé spectrograms obtained at the McDonald Observatory on January 22 and 24, 1941, show a velocity range of about 9 km/sec, in a period of 6 hours. The lines are diffuse and shallow near minimum velocity ... [more ▼]

Coudé spectrograms obtained at the McDonald Observatory on January 22 and 24, 1941, show a velocity range of about 9 km/sec, in a period of 6 hours. The lines are diffuse and shallow near minimum velocity and sharper and deeper near maximum velocity. The Ca II line K shares in the oscillations. It is probably a blend of a stellar and an interstellar line. The lines suggest turbulence of an appreciable amount. A line at λ 4469.71 is probably a blend of O II and forbidden He I. A comparison with β Cephei shows that β Canis Majoris is more luminous. It is, however, not a supergiant. The similarity in the periods suggests similarity of internal structure. [less ▲]

Detailed reference viewed: 3 (0 ULg)