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See detailOptimisation of SFE method on-line coupled to FT-IR spectroscopy for the real-time monitoring of the extraction of tagitinin C in T-diversifolia
Ziemons, Eric ULg; Mbakop, N. W.; Rozet, Eric ULg et al

in Journal of Supercritical Fluids (2007), 40(3), 368-375

The monitoring in real time of dynamic extractions of tagitinin C from Tithonia diversifolia leaves was carried out with a home made high-pressure fiber optic cell which coupled a supercritical fluid ... [more ▼]

The monitoring in real time of dynamic extractions of tagitinin C from Tithonia diversifolia leaves was carried out with a home made high-pressure fiber optic cell which coupled a supercritical fluid extractor with carbon dioxide as the extraction medium and a FT-IR spectrometer equipped with a mercury cadmium telluride detector (MCT). The shape of extraction curves obtained during the monitoring was used to decide when to stop the supercritical fluid extraction (SFE). No significant density dependence of the molar absorption coefficient or wavenumber of the C=O stretching vibration (v(C=O)) of tagitinin C at 1668 cm(-1) was noticed. The physical characteristics of SCCO2 governing the extraction yield of the active component from leaves were optimized by means of a central composite design (CCD). The studied variables were temperature (40, 60 and 80 degrees C) and pressure (8.0, 14.0 and 20.0 MPa) of the supercritical fluid. The composition profile of T diversifolia extracts obtained by SFE was investigated in the range from 3400 to 2600 cm-1 according to the pressure and temperature conditions of SCCO2. The qualitative approach of the extracts composition was accomplished through the CH stretching vibrations of components. [less ▲]

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See detailOptimisation of ship structures
Rigo, Philippe ULg; Caprace, Jean-David ULg

in Guedes Soares, Carlos; Garbatov, Y.; Fonseca, N. (Eds.) et al Marine Technology and Engineering (2011, May)

Limiting CO2 emissions is a great challenge being faced by society today. Society, through the United Nations Framework Convention on Climate Change (UNFCCC), and actors like the EU, is applying pressure ... [more ▼]

Limiting CO2 emissions is a great challenge being faced by society today. Society, through the United Nations Framework Convention on Climate Change (UNFCCC), and actors like the EU, is applying pressure on all industries, including the shipping industry, to reduce CO2 emissions. This paper presents a way to decrease the GHG emissions by ship scantling optimisation, i.e. decreasing steel weight and keeping the production cost at an acceptable level. The authors first review the links between “Design” and “Optimization” and secondly define the place of “Ship Structure Optimization” within the general framework of a “Ship Optimization”. Then, the LBR-5 ship structure optimisation software is presented. It is based on a convex lin-earization coupled with a dual approach and is based on a rational assessment of the ship structures behaviour. Few applications of structures optimization are then presented. [less ▲]

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See detailOptimisation of slow-release formulations as biological control devices
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Debatty-Mestdagh, Michelle et al

Poster (2010, May 05)

E-β-Farnesene, the alarm pheromone of many aphid species and β-caryophyllene, recently identified as one of the possible component of the aggregation pheromones of the Asian ladybeetles Harmonia axyridis ... [more ▼]

E-β-Farnesene, the alarm pheromone of many aphid species and β-caryophyllene, recently identified as one of the possible component of the aggregation pheromones of the Asian ladybeetles Harmonia axyridis Pallas, are considered as two sesquiterpenes attractive for aphids’ predators and parasitoids, Epysirphus balteatus De Geer and Aphidius ervi Haliday, respectively. In the present research, alginate gel beads formulations were optimised as semiochemical slow-release devices. The formulations were evaluated in terms of volatiles release capacity, protection efficiency of sesquiterpenes against oxidation, and biological activity towards Epysirphus balteatus and Aphidius ervi. Moreover, the sesquiterpenes used in the formulations were obtained from natural matrices. Indeed, they were purified by flash chromatography fractionation of essential oils of Matricaria chamomilla L. and Nepeta cataria L., for obtaining E-β-farnesene and β-caryophyllene, respectively. The purities of the fractions were determined by means of a fast GC analytical method optimised for a good resolution of terpenes in less than five minutes. The experiments can conclude that the alginate gel beads formulations are efficient as biological control devices considering the results obtained with the various biological tests led on predators and parasitoids. Moreover, the sesquiterpenes are more protected when formulated in alginate beads than without formulation. The devices allow also a slow-release of semiochemicals during a long time (at least 40 days) depending on physico-chemical parameters (temperature, relative humidity). A mathematical modelisation of semiochemicals release is presently in study. [less ▲]

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See detailOptimisation of Stiffened Structures
Rigo, Philippe ULg

in Dept. of Naval Architecture and Marine Engineering (2001)

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See detailOptimisation of strength training in trailrunners
Rodriguez de la Cruz, Carlos ULg; Godon, Bernard ULg; Lehance, Cédric ULg et al

in Abstract book du Premier Congrès Olympique Belge de Médecine et des Sciences du Sport (2008)

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See detailThe Optimisation Of The Helix/Helix Interaction Of A Transmembrane Dimer Is Improved By The Impala Restraint Field
Ducarme, P.; Thomas, Annick ULg; Brasseur, Robert ULg

in Biochimica et Biophysica Acta-Biomembranes (2000), 1509(1-2), 148-54

A continuous membrane model (IMPALA) was previously developed to predict how hydrophobic spans of proteins insert in membranes (Mol. Mod. 2 (1996) 27). Using that membrane model, we looked for the ... [more ▼]

A continuous membrane model (IMPALA) was previously developed to predict how hydrophobic spans of proteins insert in membranes (Mol. Mod. 2 (1996) 27). Using that membrane model, we looked for the interactions between several hydrophobic spans. We used the glycophorin A dimer as an archetype of polytopic protein to validate the approach. We find that the native complex do not dislocate when it is submitted to a 10(5) steps optimisation whereas separated spans converge back to a native-like complex in the same conditions. We also observe that IMPALA restraints are not strictly mandatory but do increase the efficiency of the procedure. [less ▲]

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See detailOptimisation of xanthan gum production by palm date (Phoenix dactylifera L.) juice by-products using response surface methodology
Ben Salah, Riadh; Chaari, Kacem; Besbes, Souhail et al

in Food Chemistry (2010), 121(2), 627-633

The present study was undertaken investigate and optimise the possibility of xanthan gum production by Xanthomonas campestris NRRL B-1459 in batch experiments on date palm juice by-products. Using an ... [more ▼]

The present study was undertaken investigate and optimise the possibility of xanthan gum production by Xanthomonas campestris NRRL B-1459 in batch experiments on date palm juice by-products. Using an experimental Response Surface Methodology complemented with a Central Composite Orthogonal Design, three major independent variables (date juice carbon source, nitrogen source and temperature) were evaluated for their individual and interactive effects on biomass and xanthan gum production. The optimal conditions selected were: 84.68 g/l for carbon source, 2.7 g/l for nitrogen source, and 30.1 degrees C for temperature. The experimental value obtained for xanthan production under these conditions was about 43.35 g/l, which was close to the 42.96 g/l value predicted by the model. Higher yields of biomass production could be obtained at 46.68 g/l for carbon source, 4.58 g/l for nitrogen source and 30 degrees C for temperature. The maximum value obtained for biomass production was 3.35 g/l, which was higher than the 2.98 g/l value predicted by the model. The xanthan formed was subjected to HPLC and TLC analyses and its molecular weight as well as pyruvate content were identified. The findings indicated that this polysaccharide contained glucose, glucoronic acid and mannose. Overall, the date palm juice by-products presented in the current study seem to exhibit promising properties that can open new pathways for the production of efficient and cost-effective xanthan gum. (C) 2010 Elsevier Ltd. All rights reserved. [less ▲]

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See detailOPTIMISATION TOPOLOGIQUE : DU MILIEU CONTINU A LA STRUCTURE ELASTIQUE
Duysinx, Pierre ULg

Doctoral thesis (1996)

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See detailOptimisation topologique de micropoutres en vue de maximiser la tension de pull-in
Lemaire, Etienne ULg

Master of advanced studies dissertation (2006)

Detailed reference viewed: 57 (17 ULg)
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See detailL’Optimisation Topologique en Mécanique
Duysinx, Pierre ULg

Article for general public (1999)

Detailed reference viewed: 27 (3 ULg)
Peer Reviewed
See detailOptimised contrast enhanced nanoCT for volumetric analyses of in vitro manufactured tissue-engineered bone constructs
Sonnaert, Maarten; Kerckhofs, Greet ULg; Papantoniou, Ioannis et al

Conference (2013)

Detailed reference viewed: 8 (1 ULg)
See detailOptimiser l'expression orale en travaillant sur les stratégies de communication (1re partie)
Dahmen, Manfred; Doppagne, Véronique ULg; Simons, Germain ULg

Conference given outside the academic context (2001)

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See detailOptimiser l'expression orale en travaillant sur les stratégies de communication (2nde partie).
Dahmen, Manfred; Doppagne, Véronique ULg; Simons, Germain ULg

Conference given outside the academic context (2002)

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See detailOptimiser l'usage des fourrages auto-produits et viser l'autonomie protéique
Beckers, Yves ULg

Conference given outside the academic context (2011)

Detailed reference viewed: 21 (5 ULg)
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See detailOptimiser une prise de décision fondée sur la preuve scientifique
Vandeweerd, Jean-Michel ULg; Vandenput, Sandrina ULg

in Point Vétérinaire (2009), 40(298), 37-40

les deux premières étapes de la démarche de la médecine factuelle sont la formulation correcte de la question posée et l'élaboration précise de la requête dans les bases de données bibliographiques

Detailed reference viewed: 31 (11 ULg)
See detailOptimisez votre maison
Guillemeau, Jean-Marc ULg; Hauglustaine, Jean-Marie ULg; Wagelmans, Paul ULg

Book (2003)

A comfortable house, limited costs of heating and reduced CO2 emissions… Three opposite objectives? Nothing is less true! The thermal regulation in Walloon region indeed aims at reconciling them. The ... [more ▼]

A comfortable house, limited costs of heating and reduced CO2 emissions… Three opposite objectives? Nothing is less true! The thermal regulation in Walloon region indeed aims at reconciling them. The great principles in the middle of this regulation relate to the good orientation, the good insulation and the good ventilation of the dwelling as well as the choice of a system of adequate heating. This booklet explains these principles and invaluable councils into practice to put them at the moment design or restoration of your house gives you. [less ▲]

Detailed reference viewed: 61 (14 ULg)