References of "Toye, Dominique"
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See detailInfluence of back-mixing on the convective drying of sewage sludge: The structural characteristics
Li, Jie; Fraikin, Laurent ULiege; Salmon, Thierry ULiege et al

in Drying Technology (in press)

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See detailDetermination of local fluid dynamic parameters in structured packings through X-ray tomography: overcoming image resolution restrictions
Bolenz, Lukas; Fischer, Florian; Toye, Dominique ULiege et al

in Chemical Engineering Science (2021)

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See detailRecent Advances in Experimental Techniques for Flow and Mass Transfer Analyses in Thermal Separation Systems
Hampel, U.; Schubert, M.; Alexander, D. Ö. ß et al

in Chemie Ingenieur Technik (2020), 92(7), 926-948

Modelling flow and mass transfer of thermal separation equipment constitutes one of the most challenging tasks in fluids process engineering. The difficulty of this task comes from the multiscale ... [more ▼]

Modelling flow and mass transfer of thermal separation equipment constitutes one of the most challenging tasks in fluids process engineering. The difficulty of this task comes from the multiscale multiphase flow phenomena in rather complex geometries. Both analysis of flow and mass transfer on different scales as well as validation of models and simulation results require advanced experimental and measurement techniques. As a follow-up to intensive discussions during the 2019 Tutzing Symposium “Separation Units 4.0” a wide set of available modern experimental technologies is presented. © 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [less ▲]

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See detailOptimization of microbeads for amplification of stem cells
Rocca, Coralie ULiege; Toye, Dominique ULiege; Grandfils, Christian ULiege

Poster (2019, November 07)

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See detailCaractérisation hydrodynamique d’un photobioréacteur pour la culture de microalgues encapsulées
Weck, Klara ULiege; Calvo, Sébastien ULiege; Delafosse, Angélique ULiege et al

Conference (2019, October)

Les défis énergétiques de ces dernières années poussent aujourd’hui les industriels et les scientifiques à caractériser et intensifier les procédés de culture de microalgues. L’extraction des métabolites ... [more ▼]

Les défis énergétiques de ces dernières années poussent aujourd’hui les industriels et les scientifiques à caractériser et intensifier les procédés de culture de microalgues. L’extraction des métabolites d’intérêts qui s’accumulent dans les microalgues est difficile et coûteuse énergétiquement, car il faut isoler les microalgues du milieu de culture et ensuite extraire les métabolites qu’elles contiennent. Le présent projet ValoAlgue vise à développer un procédé de culture de microalgues encapsulées pour produire des métabolites excrétés dans le milieu de culture. L’utilisation de métabolites excrétés permet d’éviter l’étape d’extraction. L’encapsulation, quant à elle, facilite l’étape de séparation microalgues/milieu de culture. Elle permet aussi l’utilisation de réacteurs continus et limite les contaminations. Cependant, la faisabilité industrielle de ce type de procédé est difficile à évaluer étant donné le manque d’études à grande échelle sur les microalgues encapsulées. L’objectif du projet est de développer un photobioréacteur pour la culture à l’échelle pilote (5 litres) et préindustrielle (20 litres) de microalgues encapsulées. Une souche algale de Chlamydomonas reinhardtii, modifiée génétiquement pour excréter de la luciférase, est encapsulée dans des billes de 2 à 3 mm constituées d’un matériau transparent. Elles sont cultivées dans un photobioréacteur rectangulaire à lit fluidisé. La suspension des billes est obtenue par l’injection du milieu de culture à travers une fente de 1 mm d’épaisseur en pied de réacteur. La fluidisation améliore le transfert du CO2 et le renouvellement des billes à proximité des parois éclairées. Afin d’optimiser la recirculation des billes et obtenir une dispersion homogène de celles-ci dans le réacteur, une paroi interne verticale et un prisme en pied de réacteur ont été ajoutés. Afin de modéliser l’ensemble des phénomènes physiques intervenant dans le photobioréacteur, un modèle compartimenté est développé sous Matlab. Dans ce modèle, l’hydrodynamique est décrite sur base de résultats de simulations CFD (ANSYS 19.0), qui sont implémentés dans une géométrie également discrétisée, mais constituée d’éléments (compartiments) dont le volume est nettement plus important que les mailles CFD, ce qui diminue considérablement les temps de calcul. La taille et le nombre des compartiments parfaitement mélangés sont optimisés pour conserver une description suffisamment précise des grandeurs liées à l’écoulement. Ce type de modèle permet donc d’intégrer facilement la description de phénomènes physico-chimiques (circulation des billes, transfert du CO2 , atténuation de la lumière) ou biologiques (croissance de la biomasse, production de métabolites). Le modèle compartimenté prendra en compte l’écoulement liquide et le mouvement des billes en suspension. Les modèles de transfert seront ensuite implémentés. Enfin, la dispersion de la lumière au sein du réacteur sera intégrée et couplée aux informations relatives à la fréquence de passage des billes, et donc des microalgues, au sein des zones d’éclairement du réacteur. Le modèle CFD décrivant l’écoulement monophasique de liquide a été réalisé et validé expérimentalement par Vélocimétrie par Image de Particules (PIV). Le régime laminaire chaotique mis en évidence par PIV au sein du réacteur est ici bien décrit par le modèle CFD. Le modèle diphasique, prenant en compte les interactions solide-liquide, a été développé pour prédire le mouvement des microalgues encapsulées à l’intérieur du photobioréacteur. Le modèle Granular Eulerian est utilisé pour modéliser la phase solide. Ce modèle est en cours de validation sur base de mesures de la répartition spatiale de la fraction solide (billes d’alginate). Ces expériences sont menées sur maquette froide et se basent sur une mesure de l’atténuation de la lumière. [less ▲]

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See detailAssessing soil crack dynamics during dryings from reduced tillage and conventional tillage fields
Ralaizafisoloarivony, Njaka Andriamanantena ULiege; Degré, Aurore ULiege; Mercatoris, Benoît ULiege et al

Poster (2019, September 02)

Crack formation and development has been a general concern in the agricultural science. Cracks contribute to the soil aeration, aggregate formation, and easy root penetration. However, cracks accelerated ... [more ▼]

Crack formation and development has been a general concern in the agricultural science. Cracks contribute to the soil aeration, aggregate formation, and easy root penetration. However, cracks accelerated the soil desiccation, allowed deep infiltration of pesticides/pollutants through preferential flow, and polluted the shallow water-table in Belgium. Cracks were mostly studied on pure clay or on high clay content soil (Vertisol). Yet in Wallonia, cracks were present even on silt-loam soil (Luvisol). This study tried to cover this gap by analysing crack dynamics and evaporation process, during drying kinetics of the Luvisol found in Gembloux. Soils were collected right from the agricultural field and processed on a small drying chamber in which evaporation test was taking place. Ceramic-IR-emitter heated the chamber while sensors (DHT22) measured the temperature and relative humidity. Digital camera took photos of the soil surface at 30min interval. Balance and tensiometer were linked to datalogger (CR800) and recorded the soil hydraulic properties (evaporation, water retention, etc.). Cracks were assessed from small samples (~5cm x 1cm thick) and big samples (~20cm size x 1.6 cm thick). Three treatments were considered including: disturbed soil, conventional tillage and reduced tillage. For big samples, results showed higher cracks formation on disturbed soil > reduced-tillage > conventional-tillage due to loose of soil cohesion, soil organic content, soil aggregation, biological activities, and soil porosity. The soil evaporation rate was also greater in disturbed soil > reduced-tillage > conventional tillage. Cracks opening exposed profound-soil-water to the atmosphere without passing through the soil matrix. For small samples, the repetitive drying experiments increased cracks length/width, especially for the dense samples. Future study is needed to assess the presence of pre-(micro)-cracks in soil using X-ray microtomography. [less ▲]

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See detailExperimental and Numerical Investigation of the Drying of an Agricultural Soil
Ralaizafisoloarivony, Njaka Andriamanantena ULiege; Tran, Duc Kien ULiege; Degré, Aurore ULiege et al

in EUNSAT (2019)

Due to climate change, soil desiccating became a serious concern in the agricultural area of Belgium. Knowing soil evaporation kinetic can help to elucidate and predict: the soil moisture regime, soil ... [more ▼]

Due to climate change, soil desiccating became a serious concern in the agricultural area of Belgium. Knowing soil evaporation kinetic can help to elucidate and predict: the soil moisture regime, soil water retention and soil water content. Those parameters are vital for water use efficiency and sustainable agriculture. This research analysed the mechanism of soil evaporation both under laboratory experiment and numerical modelling. Soil samples (Luvisol) were collected from the agricultural field in Gembloux-Belgium, and processed in a small drying chamber. Sensors measured the chamber temperature and humidity, while digital camera monitored the soil surface throughout the experiment. HYPROP device recorded the water change, soil suction, and soil water retention curve. During three evaporation experiments, four periods were observed rather than three according to the common theory. The modelling considered thermo-hydro-mechanical framework for predicting the drying process of Luvisol. The model used the finite element code LAGAMINE created at the University of Liege. The Software aims at assessing the mechanism of water transport between soil and atmosphere. The results of the simulation showed major domination of Darcean flow during desiccating, while some short vapour diffusion occurred only after the soil surface began to de-saturate. [less ▲]

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See detailTailored-made biodegradable polymers for drug delivery and tissue engineering
Grandfils, Christian ULiege; Vandeberg, Romain ULiege; Sevrin, Chantal ULiege et al

Scientific conference (2019, June 05)

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See detailFull Pre-Steady-State Kinetic Analysis of Single Nucleotide Incorporation by DNA Polymerases
Renders, M.; Frère, Jean-Marie ULiege; Toye, Dominique ULiege et al

in Current protocols in nucleic acid chemistry (2019), 78(1), 98

By measuring a DNA polymerase incorporation reaction on a very short time scale (5 ms to 10 s) and with a high enzyme concentration, the isolated event of a single nucleotide incorporation can be analyzed ... [more ▼]

By measuring a DNA polymerase incorporation reaction on a very short time scale (5 ms to 10 s) and with a high enzyme concentration, the isolated event of a single nucleotide incorporation can be analyzed. Practically, this is done using a quench-flow instrument, which allows the rapid mixing of the enzyme-primer/template with the nucleotide substrate, after which the reaction is quenched and analyzed. We describe how to titrate the enzyme active site, how to determine, via a scouting experiment, the rate-limiting step in the polymerization reaction, and how to measure the apparent kpol , Kd(DNA) , and Kd(N) using burst or single-turnover experiments. We include equations for the calculation of the processivity of the polymerase, its nucleotide incorporation specificity and preference, and the activation energy difference for the incorporation of an incorrect nucleotide. Data analysis is discussed, as this is an essential part of accurate data generation in kinetic analyses. © 2019 by John Wiley & Sons, Inc. © 2019 John Wiley & Sons, Inc. [less ▲]

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See detailKinetic analysis of N-alkylaryl carboxamide hexitol nucleotides as substrates for evolved polymerases
Renders, M.; Dumbre, S.; Abramov, M. et al

in Nucleic Acids Research (2019), 47(5), 2160-2168

Six 1,5-anhydrohexitol uridine triphosphates were synthesized with aromatic substitutions appended via a carboxamide linker to the 5-position of their bases. An improved method for obtaining such 5 ... [more ▼]

Six 1,5-anhydrohexitol uridine triphosphates were synthesized with aromatic substitutions appended via a carboxamide linker to the 5-position of their bases. An improved method for obtaining such 5-substituted hexitol nucleosides and nucleotides is described. The incorporation profile of the nucleotide analogues into a DNA duplex overhang using recently evolved XNA polymerases is compared. Long, mixed HNA sequences featuring the base modifications are generated. The apparent binding affinity of four of the nucleotides to the enzyme, the rate of the chemical step and of product release, plus the specificity constant for the incorporation of these modified nucleotides into a DNA duplex overhang using the HNA polymerase T6G12 I521L are determined via pre-steady-state kinetics. HNA polymers displaying aromatic functional groups could have significant impact on the isolation of stable and high-affinity binders and catalysts, or on the design of nanomaterials. © The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License [less ▲]

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See detailAn approach to separation efficiency modelling of structured packings based on X-ray tomography measurements: Application to aqueous viscous systems
Große Daldrup, A.; Crine, Michel ULiege; Marchot, Pierre ULiege et al

in Chemical Engineering Science (2019), 204

The objective of this work is the development of a model to predict the separation efficiency of structured packings for aqueous viscous systems. The modelling approach is based on a hydrodynamic analogy ... [more ▼]

The objective of this work is the development of a model to predict the separation efficiency of structured packings for aqueous viscous systems. The modelling approach is based on a hydrodynamic analogy between the real complex flow patterns and simplified fluid dynamic elements. Understanding of dominating liquid flow patterns inside structured packing is essential for the model development. Therefore, in this work, X-ray tomography is used to investigate liquid flow morphology. To study the influence of viscosity, water and water/glycerine mixtures are employed as working liquids. X-ray tomography permits the spatial distribution of liquid in the cross-section of a column filled with MellapakPlus 752.Y packing elements to be determined. The resulting images are used to evaluate liquid hold-up and gas-liquid interfacial area. Furthermore, liquid flow patterns (film flow, contact-point liquid, flooded regions) are identified, and their contribution to the overall hold-up is determined in dependence on flow rate and liquid viscosity. The results of the liquid flow morphology analysis help to develop a hydrodynamic analogy model. To implement the gas-liquid contact area and the flooded regions into this model, the packing is represented as a bundle of dry, filled and irrigated cylindrical channels, while the ratio between different channel types is determined from the analysis of tomographic images. This simplified hydrodynamic description allows a direct application of rigorous partial differential transport equations, and their solution yields local concentration fields which are used for the evaluation of the separation efficiency. The new modelling approach is validated by comparison with separation efficiency data obtained from experiments with CO2 desorption from saturated water-glycerine mixtures into air. © 2019 Elsevier Ltd [less ▲]

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See detailOptimization of the Impeller Design for Mesenchymal Stem Cell Culture on Microcarriers in Bioreactors
Loubière, C.; Delafosse, Angélique ULiege; Guedon, E. et al

in Chemical Engineering and Technology (2019), 42(8), 1702-1708

When agitating mesenchymal stem cells adhered on microcarriers in bioreactors, a compromise has to be found between sufficient particle suspension and limitation of hydromechanical stresses. The present ... [more ▼]

When agitating mesenchymal stem cells adhered on microcarriers in bioreactors, a compromise has to be found between sufficient particle suspension and limitation of hydromechanical stresses. The present study proposes a strategy to improve the design of an ‘elephant ear' impeller at the just-suspended state by varying its relative size, blade slope angle, and position in the reactor. To do that, computational fluid dynamics simulations were coupled with multi-objective optimization to minimize the hydromechanical stress encountered by the microcarriers. Two minimization criteria were considered: (P/V)@p and the energy dissipation function EDC. On the basis of 31 conditions, an optimal impeller geometry is proposed. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [less ▲]

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See detailTomographische Untersuchung der Fluiddynamik viskoser Systeme in Packungskolonnen
Bolenz, L.; Fischer, F.; Toye, Dominique ULiege et al

in Chemie Ingenieur Technik (2019), 91(12), 1892-1896

Fluid dynamics in structured packings is investigated by X-ray tomography. The focus is set on the influence of liquid viscosity varied between 5 and 50 mPa s. Film flow is the dominant flow pattern, but ... [more ▼]

Fluid dynamics in structured packings is investigated by X-ray tomography. The focus is set on the influence of liquid viscosity varied between 5 and 50 mPa s. Film flow is the dominant flow pattern, but there are also contact-point liquid patterns representing liquid accumulated at contact points between adjacent packing sheets. The holdup fractions of both flow patterns are quantified, and the average surface-to-volume ratio is determined. Furthermore, the wetting ratio of the structured packing is examined for different viscosities and liquid loads. © 2019, Wiley-VCH Verlag. All rights reserved. [less ▲]

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See detailConvective drying of sawdust-sludge mixtures: The effect of the sludge matrix
Li, Jie; Wu, C.-W.; Fraikin, Laurent ULiege et al

in Drying Technology (2019), 37(7), 920927

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See detailCaractérisation hydrodynamique d’un photobioréacteur pour la culture de microalgues encapsulées
Weck, Klara ULiege; Calvo, Sébastien ULiege; Delafosse, Angélique ULiege et al

Scientific conference (2019)

Le présent projet ValoAlgue vise à développer un procédé de culture de microalgues encapsulées pour produire des métabolites à haute valeur ajoutée. L’utilisation de métabolites excrétés dans le milieu de ... [more ▼]

Le présent projet ValoAlgue vise à développer un procédé de culture de microalgues encapsulées pour produire des métabolites à haute valeur ajoutée. L’utilisation de métabolites excrétés dans le milieu de culture permet d’éviter une étape d’extraction. L’encapsulation, quant à elle, facilite l’étape de séparation microalgues/milieu de culture. Elle permet aussi l’utilisation de réacteurs continus et limite les contaminations. Cependant, la faisabilité industrielle de ce type de procédé est difficile à évaluer étant donné le manque d’études à grande échelle sur les microalgues encapsulées. L’objectif du projet est de développer un photobioréacteur pour la culture à l’échelle pilote (5 litres) et préindustrielle (20 litres) de microalgues encapsulées. Une souche algale de Chlamydomonas reinhardtii, modifiée génétiquement pour excréter de la luciférase, est encapsulée dans des billes de 2,8 mm constituées d’un matériau transparent. Elles sont cultivées dans un photobioréacteur rectangulaire à lit fluidisé. La suspension des billes est obtenue par l’injection du milieu de culture à travers une fente de 1 mm d’épaisseur en pied de réacteur. La fluidisation améliore le transfert du CO2 et le renouvellement des billes à proximité des parois éclairées. Afin de modéliser l’ensemble des phénomènes physiques intervenant dans le photobioréacteur, un modèle compartimenté est développé sous Matlab. Dans ce modèle, l’hydrodynamique est décrite sur base de résultats de simulations CFD (ANSYS 19.0), qui sont implémentés dans une géométrie également discrétisée, mais constituée d’éléments (compartiments) dont le volume est nettement plus important que les mailles CFD, ce qui diminue considérablement les temps de calcul. Ce type de modèle permet donc d’intégrer facilement la description de phénomènes physico-chimiques (circulation des billes, transfert du CO2, atténuation de la lumière) ou biologiques (croissance de la biomasse, production de métabolites). Le modèle compartimenté prendra en compte l’écoulement liquide et le mouvement des billes en suspension. Un modèle CFD décrivant l’écoulement monophasique de liquide a été réalisé et validé expérimentalement par Vélocimétrie par Image de Particules (PIV). Le régime laminaire chaotique mis en évidence par PIV au sein du réacteur est ici bien décrit par le modèle CFD. Le modèle diphasique, prenant en compte les interactions solide-liquide, a été développé pour prédire le mouvement des microalgues encapsulées à l’intérieur du photobioréacteur. Le modèle Granular Eulerian est utilisé pour modéliser la phase solide. Ce modèle est en cours de validation sur base de mesures de la répartition spatiale de la fraction solide (billes d’alginate). Ces expériences sont menées sur maquette froide et se basent sur une mesure de l’atténuation de la lumière. [less ▲]

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See detailX-RAY COMPUTED TOMOGRAPHY: AN OUTSTANDING VISUALISATION TOOL FOR DRYING RESEARCH – Feedback on the last 20 years at University of Liège
Léonard, Angélique ULiege; Fraikin, Laurent ULiege; Plougonven, Erwan ULiege et al

in Barresi, Antonello (Ed.) Proceedings of the 7th European Drying Conference (2019)

Detailed reference viewed: 20 (4 ULiège)