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See detailMOISTURE CONTENT DETERMINATION OF FREEZE-DRIED PRODUCTS BY NEAR-INFRARED SPECTROSCOPY: A CASE STUDY FOR UNIVERSAL REGRESSION MODEL
Clavaud, Matthieu ULg; Roggo, Yves; Degardin, Klara et al

Poster (2016, June 06)

Karl Fischer titration is the reference method for moisture content determination in the pharmaceutical industry. Near-infrared spectroscopy is considered the most suitable alternative technique. Indeed ... [more ▼]

Karl Fischer titration is the reference method for moisture content determination in the pharmaceutical industry. Near-infrared spectroscopy is considered the most suitable alternative technique. Indeed, NIRS is a safe and fast method which does not require sample preparation. Nevertheless, the development and validation phases are time-consuming. In addition, the NIRS methods presented so far were mostly product specific. The main objective of this study is to highlight that an universal calibration model can be validated for several freeze-dried products in order to speed up the validation time. This objective was led in two steps. A universal model was first evaluated. A calibration set and a validation set were built up with three freeze-dried products. An antibody drug conjugate, a large molecule and a small molecule all packed in sealed vials were used to introduce more variability. Regression methods were then compared in order to optimize the prediction values. [less ▲]

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See detailScreening study of SFC critical method parameters for the determination of pharmaceutical compounds
Dispas, Amandine ULg; Lebrun, Pierre ULg; Sacre, Pierre-Yves ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2016), 125

Nowadays, supercritical fluid chromatography is commonly presented as a promising alternative technique in the field of separation sciences. Nevertheless the selection of chromatographic conditions and ... [more ▼]

Nowadays, supercritical fluid chromatography is commonly presented as a promising alternative technique in the field of separation sciences. Nevertheless the selection of chromatographic conditions and sample preparation of pharmaceutical compounds remain a challenge and peak distortion was previously highlighted. The main objective of the present work was to evaluate the impact of different critical method parameters (CMPs), i.e. stationary phase, mobile phase composition and injection solvent nature. The experiments were performed considering two groups of antimalarial molecules: one group with neutral/apolar compounds and the other one with salt form of polar compounds. In this context, another objective was to propose a suitable sample solvent for quantitative analysis. The interest of new generation stationary phase to obtain good peak shape and the interest to tune the mobile phase composition were demonstrated. During this study, design of experiments and desirability function approach enabled to highlight optimal chromatographic conditions in order to maximise peak capacity and to get acceptable value of symmetry factor. Regarding sample injection solvent composition, some counterintuitive results were observed: solvents closer to the mobile phase polarity (i.e heptane or 2-propanol/heptane mixture) did not provide best results in terms of peak symmetry. In addition, acetonitrile and short aliphatic alcohols offered an interesting alternative as injection solvent: toxicity of solvents used is clearly reduced and better quantitative performances could be expected while keeping high peak capacity and symmetric sharp peaks. Finally, the quantitative performances were evaluated by the method validation for the quantitative determination of quinine sulfate in a pharmaceutical formulation. These better understandings on critical method parameters led SFC to be an even more promising technique in the field of the analysis of pharmaceutical compounds. [less ▲]

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See detailLe cadre et l'oubli : Mallarmé après Mallarmé
Durand, Pascal ULg

Conference (2016, June 04)

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See detailHydrogeological assessment of non-linear underground enclosures
Pujades, Estanislao ULg; Jurado Elices, Anna ULg; Carrera, Jesus et al

in Engineering Geology (2016), 207

Excavations below the water table are usually undertaken by combining the protection of retaining walls with dewatering by pumping wells. Severe difficulties may arise if the retaining walls have defects ... [more ▼]

Excavations below the water table are usually undertaken by combining the protection of retaining walls with dewatering by pumping wells. Severe difficulties may arise if the retaining walls have defects. Therefore, their state must be determined and, if needed, the defects repaired or the dewatering system redesigned. The state of underground retaining walls can be evaluated using hydrogeological methods, but these methods are well-established only for linear excavations. The objective of this work is to propose a procedure to evaluate the state of non-linear underground enclosures by analyzing the groundwater response to pumping inside the enclosure. The proposed method, which is based on diagnostic plots (derivative of drawdown with respect to the logarithm of time), allows (1) determining if an underground non-linear enclosure has isolated openings or numerous defects and (2) computing its effective conductance or effective hydraulic conductivity. The methodology is tested with data collected during the excavation of a shaft required for the construction of the high speed train (HST) tunnel in Barcelona, Spain. The procedure can be applied using the wells drilled for dewatering. Although a test before the excavation is recommended to evaluate the underground retaining walls (Watertightness Assessment Test), the method can be applied using data collected at the beginning of the dewatering stage. [less ▲]

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See detailLe gisement paléolithique multistratifié d'Ormesson (Seine-et-Marne) : Palethnologie ou pâle ethnologie ?
Bodu, Pierre; Ballinger, Michèle; Dumarçay, Gaëlle et al

Conference (2016, June 01)

Il est exceptionnel de pouvoir appliquer la démarche palethnologique, si fréquemment développée pour le Magdalénien, aux gisement du Paléolithique supérieur ancien dans le Bassin parisien, dans la mesure ... [more ▼]

Il est exceptionnel de pouvoir appliquer la démarche palethnologique, si fréquemment développée pour le Magdalénien, aux gisement du Paléolithique supérieur ancien dans le Bassin parisien, dans la mesure où ils sont rares, c'est indéniable, mais aussi en raison d'un état de conservation généralement médiocre de la plupart d'entre eux. Le site d'Ormesson, situé en Seine-et-Marne, à proximité de la vallée du Loing et de la ville de Nemours, constitue depuis 2009, année de la première fouille, un gisement-laboratoire pour l'approche palethnographique de différentes populations de la fin du Paléolithique moyen au Badegoulien. A travers cet exemple devenu désormais une référence pour le Paléolithique supérieur ancien, nous nous poserons la question suivante : Palethnologie ou pâle ethnologie ? [less ▲]

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See detailAn Exact Method for Designing Shewhart X ̅ and S2 Control Charts to Guarantee the In-Control Performance
Faraz, Alireza ULg; Heuchenne, Cédric ULg

in Journal of Quality Technology (2016)

The in-control performance of the Shewhart X ̅ and S2 control charts with estimated in-control parameters has been evaluated by a number of authors. Results indicate an unrealistically large amount of ... [more ▼]

The in-control performance of the Shewhart X ̅ and S2 control charts with estimated in-control parameters has been evaluated by a number of authors. Results indicate an unrealistically large amount of Phase I data is needed to have the desired in-control average run length (ARL) value in Phase II. To overcome this problem, it has been recommended that the control limits be adjusted based on a bootstrap method to guarantee that the in-control ARL is at least a specified value with a certain specified probability. In our paper we present simple formulas for the required control limits so that practitioners do not have to use the bootstrap method. An assumption of normality is required. The advantage of our proposed method is in its simplicity; there is no bootstrapping and the control chart constants do not depend on the Phase I sample data. [less ▲]

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See detailL'Année sartrienne, n° 30
Cormann, Grégory ULg

Book published by GES (2016)

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See detailEfficient Computation of the Extrema of Algebraic Quality Measures for Curvilinear Finite Elements
Johnen, Amaury ULg; Geuzaine, Christophe ULg; remacle, Jean-François

Conference (2016, June)

The development of high-order computational methods for solving partial differential equations on unstructured grids has been underway for many years. Such methods critically depend on the availability of ... [more ▼]

The development of high-order computational methods for solving partial differential equations on unstructured grids has been underway for many years. Such methods critically depend on the availability of high-quality curvilinear meshes, as one bad element can degrade the solution in the whole domain. The usual way of generating curved meshes is to first generate a (high-quality) straight-sided mesh. Then, mesh entities that are classified on the boundaries of the domain are curved. This operation introduces a "shape-distortion" that should be controlled. Quality measures allow to quantify to which point an element is well-shaped. They also provide tools to improve the quality of meshes through optimization. In this work we propose an efficient method to compute several quality measures for curved elements, based on the Jacobian of the mapping between the straight-sided elements and the curved ones. Contrary to the approach presented in "A. Gargallo-Peiró, X. Roca, J. Peraire, and J. Sarrate. Distortion and quality measures for validating and generating high-order tetrahedral meshes. Engineering with Computers, pages 1–15, 2014.", which relies on an L2-norm over the elements, we compute the actual minimum and maximum of the local quality measure for each element. The method is an extension of previous works on the validity of those elements (A. Johnen et al., 2013). The key feature is that we can adaptively expand functions based on the Jacobian matrix and its determinant in terms of Bézier functions. Bézier functions have both properties of boundedness and positivity, which allow sharp computation of minimum or maximum of the interpolated functions. [less ▲]

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See detailLaboratory idenification of anaerobic bacteria isolated on Clostridium difficile selective medium
Rodriguez Diaz, Cristina ULg; Warszawski, Nathalie; Korsak Koulagenko, Nicolas ULg et al

in Acta Microbiologica et Immunologica Hungarica (2016)

Despite increasing interest in the bacterium, the methodology for Clostridium difficile recovery has not yet been standardised. Cycloserine cefoxitin fructose taurocholate (CCFT) has historically been the ... [more ▼]

Despite increasing interest in the bacterium, the methodology for Clostridium difficile recovery has not yet been standardised. Cycloserine cefoxitin fructose taurocholate (CCFT) has historically been the most used medium for C. difficile isolation from human, animal, environmental and food samples, and presumptive identification is usually based on colony morphologies. However, CCFT is not totally selective. This study describes the recovery of 24 bacteria species belonging to 10 different genera other than C. difficile, present in the environment and foods of a retirement establishment that were not inhibited in the C. difficile selective medium. These findings provide insight for further environmental and food studies as well as for isolation of C. difficile on supplemented CCFT. [less ▲]

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See detailDoes sector-specific experience matter? The case of European higher education ministers
Jacqmin, Julien ULg; Lefebvre, Mathieu ULg

in Research Policy (2016), 45(5), 987998

This paper looks at the relationship between higher education ministers and the performance of the sector that they govern. Using an original panel dataset with the characteristics of European higher ... [more ▼]

This paper looks at the relationship between higher education ministers and the performance of the sector that they govern. Using an original panel dataset with the characteristics of European higher education ministers, we find that having a past experience in the sector leads to a higher level of performance, as measured by ranking data. Making a parallel with the literature about the impact of education on the educated, we discuss potential explanations behind the impact of this on-the-job learning experience. As we find that this characteristic has no impact on the spendings of the sector, we argue that this academic experience makes them more prone to introduce adequate reforms that makes the sector more attractive for top-researchers. Furthermore, we find that this result is driven by ministers with both sector-specific and electoral experience, the latter measured by a successful election at the regional or national level. This tends to show that political credibility should not be overshadowed by the importance of the sector-specific experience of ministers. [less ▲]

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See detailDelivering Bad News to Customers: An Employee Perspective
Delcourt, Cécile ULg; Gremler, Dwayne; Greer, Dominique

in Conferences proceedings of SERVSIG 2016 (2016, June)

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See detailWelfare and the creation of Undocumented EU migrants in Belgium
Mescoli, Elsa ULg; Lafleur, Jean-Michel ULg

Conference (2016, June)

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See detailThe influence of customer characteristics on the customer need knowledge of frontline employees
Hüttel, Björn; Schumann, Jan Hendrik; Büttgen, Marion et al

Conference (2016, June)

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See detailExplaining the diversity of motivations behind community renewable energy
Bauwens, Thomas ULg

in Energy Policy (2016), 93

Community-based renewable energy initiatives may be important actors in the transition toward low-carbon energy systems. In turn, stimulating investments in renewable energy production at the community ... [more ▼]

Community-based renewable energy initiatives may be important actors in the transition toward low-carbon energy systems. In turn, stimulating investments in renewable energy production at the community level requires a better understanding of investors’ motives. This paper aims to study the heterogeneity of motivations that drive individuals to participate in community renewable energy projects and the underlying explanatory factors behind this, as well as the implications for their level of engagement in initiatives. Based on quantitative data from an original survey conducted with two renewable energy cooperatives in Flanders, the statistical analysis shows that cooperative members should not be considered as one homogeneous group. Several categories of members with different motives and levels of engagement can be distinguished. This heterogeneity is explained by contrasts in terms of institutional settings, spatial patterns and attitudes to the diffusion of institutional innovations. Regarding policy implications, the findings suggest that this heterogeneity should be taken into account in designing more effective supporting policies to stimulate investments at the community level. The activation of social norms is also shown to be a promising mechanism for triggering investment decisions, although the implications of its interplay with economic incentives should be further explored. [less ▲]

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See detailGeräusch, Gerücht, Gerede. Formen und Funktionen der Fama in Erzähltexten Theodor Storms und Arthur Schnitzlers
Leyh, Valérie ULg

Book published by Erich Schmidt Verlag (2016)

Seit der Antike sind Schriftsteller von der Fama fasziniert: Ob als allegorische Kunstfigur oder als anthropologisches Phänomen sozialer Kommunikation, sie findet Eingang in die unterschiedlichsten ... [more ▼]

Seit der Antike sind Schriftsteller von der Fama fasziniert: Ob als allegorische Kunstfigur oder als anthropologisches Phänomen sozialer Kommunikation, sie findet Eingang in die unterschiedlichsten literarischen Werke. Die vorliegende Studie behandelt ihre drei Erscheinungsformen Geräusch, Gerücht und Gerede erstmals in den narrativen Werken Theodor Storms und Arthur Schnitzlers und geht der Frage nach, wie die Autoren sie als Erzählverfahren einsetzen. In ausführlichen Textanalysen, die sich auf Ergebnisse der Anthropologie des Erzählens stützen und diese mit Ansätzen der klassischen und postklassischen Narratologie verknüpfen, legt Valérie Leyh die Fama als eine Strategie der Verunsicherung dar, die die Grenzen zwischen Schweigen und Reden, Mündlichkeit und Schriftlichkeit, Lüge und Wahrheit, Fiktion und Faktizität aufhebt. Dabei ist bereits bei Storm eine Internalisierung der Fama zu beobachten, die einige Jahrzehnte später in Schnitzlers psychologisch feinsinnigen Erzählungen zu voller Entfaltung kommt. [less ▲]

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See detailUpdating Failure Probability Of A Welded Joint In Offshore Wind Turbine Substructures
Mai, Anh Quang ULg; Sørensen, John D.; Rigo, Philippe ULg

in The 35th International Conference on Ocean, Offshore and Arctic Engineering (OMAE) (2016, June)

For offshore wind turbines, the support structure contributes with a significant part to the Levelized Cost Of Energy (LCOE). LCOE is the total cost to build and operate a whole offshore wind turbine ... [more ▼]

For offshore wind turbines, the support structure contributes with a significant part to the Levelized Cost Of Energy (LCOE). LCOE is the total cost to build and operate a whole offshore wind turbine structure over its lifetime divided by the total energy output of the wind turbine over that lifetime. That total expected cost of operation & maintenance may be lowered by application of reliability- and risk-based maintenance strategies and updating of the reliability based on e.g. inspections performed during the design lifetime. Updating the reliability (or alternatively the failure probability) of a welded joint can theoretically be done using Bayesian updating. However, for tubular joints in offshore wind turbine substructure when considering a two dimensional crack growth and a failure criterion combined brittle fracture and material strength, the updating is quite complex due to the wind turbine loading obtained during operation. This paper considers how the reliability (or the probability of failure) of welded steel details can be updated in the case where the fatigue failure is modelled by a fracture mechanics approach and a Failure Assessment Diagram (FAD) is used to define a limit state equation. Besides, it is shown how the probability of failure of fatigue critical joints can be updated for various inspection scenarios. A two dimensional bi-linear model is considered for the crack growth. Calculation of the crack depth and the crack length are coupled. The stress intensity factor is calculated following the sophisticated procedure in BS 7910:2005. The initial crack size, the yield and ultimate strengths of steel, the fracture toughness, the stress intensity factor, and the stress-ranges are considered as uncertain and modelled by random variables. The probability of detection is used to account for uncertainty in crack inspections. By using Monte Carlo simulations, stress-range histories are generated randomly and together with the calculated stress intensity factors used to check the limit state condition using the FAD approach. The probability of failure updating is done for three inspection scenarios: No crack detected; Crack detected and repaired; Crack detected but not repaired. The paper presents illustrative results for offshore wind applications for the three scenarios, including comparisons of application of the FAD approach for modelling the limit state equation with a ‘conventional’ approach where it is assumed that failure happens when crack-depth reaches the plate thickness or the stress intensity factor is equal to or larger than the fracture toughness of the material. Finally, it is discussed how application of the updating procedure can be used for inspection planning for offshore wind turbine support structures, and thus also for reducing the required safety factors at the design stage. [less ▲]

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See detailPolyphosphoesters as a new platform for the design of particulate drug delivery systems
Vanslambrouck, Stéphanie; Ergul Yilmaz, Zeynep; Debuigne, Antoine ULg et al

Conference (2016, June)

Thanks to their biocompatibility and degradability properties, polyphosphates are appealing polymers for biomedical applications. In contrast to aliphatic polyesters, such as poly(ε-caprolactone) and poly ... [more ▼]

Thanks to their biocompatibility and degradability properties, polyphosphates are appealing polymers for biomedical applications. In contrast to aliphatic polyesters, such as poly(ε-caprolactone) and poly(lactide), the pentavalency of the phosphorus atom allows the easy modification of the polyphosphate properties by simply adjusting the nature, the length and the functionality of the polyphosphate pendant groups. Therefore, macromolecular engineering of polyphosphoesters was applied to design well-defined architectures and functionalities adapted to drug nanocarriers. In a first approach, amphiphilic block copolymers are synthesized by organo-catalyzed ring-opening polymerization process for the synthesis of a range of PEO-b-polyphosphate bearing various pendant groups. Post-polymerization thiol-ene click reactions preformed on PEO-b-polyphosphate copolymers was also investigated to improve the hydrophobicity of the polyphosphate. The self-assembly of these PEO-b-polyphosphate copolymers into micelles was investigated, particularly, the effect of the nature of the polyphosphate pendant groups (i) on the micelles characteristics, (ii) on the encapsulation of a poorly soluble drug and (iii) on the drug release profile. The toxicity of the different amphiphilic block copolymers was also evaluated by live/dead cell viability assays. In a second approach, double hydrophilic copolymers based on polyphosphoesters have been used as templating agent for the synthesis of calcium carbonate particles. Indeed, the use of such microparticles is becoming more and more attractive in many fields especially for biomedical applications for which fine tuning of size, morphology and crystalline form of CaCO3 particles is crucial. Although some structuring compounds, like hyaluronic acid, give satisfying results, the control of the particle structure still has to be improved. To this end, we evaluated the CaCO3 structuring capacity of the well-defined double hydrophilic block copolymers composed of poly(ethylene oxide) and of a polyphosphoester segment with affinity for calcium like poly(phosphotriester)s bearing pendant carboxylic acids or poly(phosphodiester)s with a negatively charged oxygen atom on each repeating monomer unit. [less ▲]

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See detailCaractérisation des forêts à l’aide de la technologie lidar
Michez, Adrien ULg; Bauwens, Sébastien ULg; Bonnet, Stéphanie ULg et al

in Baghdadi, Nicolas; Zribi, Mehrez (Eds.) Observation des Surfaces Continentales par Télédétection: Agriculture et Forêt (2016)

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See detailDirect control service from residential heat pump aggregation with specified payback
Georges, Emeline ULg; Cornélusse, Bertrand ULg; Ernst, Damien ULg et al

in Proceedings of the 19th Power Systems Computation Conference (PSCC) (2016, June)

This paper addresses the problem of an aggregator controlling residential heat pumps to offer a direct control flexibility service. The service is defined by a 15 minute power modulation, upward or ... [more ▼]

This paper addresses the problem of an aggregator controlling residential heat pumps to offer a direct control flexibility service. The service is defined by a 15 minute power modulation, upward or downward, followed by a payback of one hour and 15 minutes. The service modulation is relative to an optimized baseline that minimizes the energy costs. The potential amount of modulable power and the payback effect are computed by solving mixed integer linear problems. Within these problems, the building thermal behavior is modeled by an equivalent thermal network made of resistances and lumped capacitances whose parameters are identified from validated models. Simulations are performed on 100 freestanding houses. For an average 4.3 kW heat pump, results show a potential of 1.2 kW upward modulation with a payback of 600 Wh and 150 Wh of overconsumption. A downward modulation of 500 W per house can be achieved with a payback of 420 Wh and 120 Wh of overconsumption. [less ▲]

Detailed reference viewed: 36 (9 ULg)
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See detailDetection of myocardial ischemic memory using 99mTc-fucoidan: preclinical validation
Mikail, N; Louedec, L; Aid, R et al

Conference (2016, June)

Detailed reference viewed: 9 (1 ULg)