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See detailThe prediction of fund failure through performance diagnostics
Cogneau, Philippe ULg; Hübner, Georges ULg

in Journal of Banking and Finance (2015), 50

Using an international database featuring 1624 mutual funds over 15 years, this paper analyses the joint abilities of performance measures to predict subsequent fund failure. We examine the probability of ... [more ▼]

Using an international database featuring 1624 mutual funds over 15 years, this paper analyses the joint abilities of performance measures to predict subsequent fund failure. We examine the probability of disappearance over a time window, and expected fund survival time, and study the circumstances of a fund’s disappearance, its currency and domicile. By combining relevant measures, fund failure appears to a significant extent predictable, more than with single classical measures. Survivorship predictability has significant economic value. Such evidence suggests that past performance does not only influence investors’ perception of fund quality, but also reflects managers’ ability to sustain performance. [less ▲]

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See detailThe Harmonic Balance Method for Bifurcation Analysis of Nonlinear Mechanical Systems
Detroux, Thibaut ULg; Renson, Ludovic ULg; Masset, Luc ULg et al

in Proceedings of the SEM IMAC XXXIII (2015)

Because nowadays structural engineers are willing to use or at least understand nonlinearities instead of simply avoiding them, there is a need for numerical tools performing analysis of nonlinear large ... [more ▼]

Because nowadays structural engineers are willing to use or at least understand nonlinearities instead of simply avoiding them, there is a need for numerical tools performing analysis of nonlinear large-scale structures. Among these techniques, the harmonic balance (HB) method is certainly one of the most commonly used to study finite element models with reasonably complex nonlinearities. However, in its classical formulation the HB method is limited to the approximation of periodic solutions. For this reason, the present paper proposes to extend the method to the detection and tracking of codimension-1 bifurcations in the system parameters space. As an application, the frequency response of a spacecraft is studied, together with two nonlinear phenomena, namely quasiperiodic oscillations and detached resonance curves. This example illustrates how bifurcation tracking using the HB method can be employed as a promising design tool for detecting and eliminating such undesired behaviors. [less ▲]

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See detailDilthey et l'empirisme psychologique
Dewalque, Arnaud ULg

in Camilleri, Sylvain; Fagniez, Guillaume (Eds.) Dilthey et l'histoire (2015)

Je discute ici le projet diltheyen d'une "fondation psychologique des sciences de l'esprit". Je suggère que ce projet peut être rapproché d’un certain programme épistémologique baptisé "empirisme ... [more ▼]

Je discute ici le projet diltheyen d'une "fondation psychologique des sciences de l'esprit". Je suggère que ce projet peut être rapproché d’un certain programme épistémologique baptisé "empirisme psychologique". L’hypothèse qui se trouve à la base de l’empirisme psychologique est la suivante : l’expérience interne, psychologique, est la source des concepts au moyen desquels nous pouvons penser et connaître le monde. Après avoir brièvement reconstruit le programme diltheyen en ce sens, j'examine deux objections qui ont été soulevées contre lui: l'objection néokantienne (Windelband, Rickert) et l'objection psychologique (Ebbinghaus, Stumpf). La seconde, selon moi, met en évidence une difficulté réelle du projet de Dilthey: la "connexion structurelle de la vie" dans sa totalité peut difficilement être considérée comme "donnée" dans l'expérience interne, ainsi que l'affirme Dilthey. Je soutient donc que le programme de l'empirisme psychologique peut être poursuivi à condition de le débarrasser de cette thèse problématique. [less ▲]

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See detailSartre in Venedig: der Mann, der in die Kälte ging
Cormann, Grégory ULg; Viehöver, Vera ULg

in Bulletin d'Analyse Phénoménologique (2015), 11

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See detailFe–Ti–V–P ore deposits associated with Proterozoic massif-type anorthosites and related rocks
Charlier, Bernard ULg; Namur, Olivier; Bolle, Olivier ULg et al

in Earth-Science Reviews (2015), 141(0), 56-81

Magmatic rocks containing economic concentrations of iron, titanium, vanadium and phosphorous are commonly associated with massif-type anorthosites and related rocks. This rock association is part of the ... [more ▼]

Magmatic rocks containing economic concentrations of iron, titanium, vanadium and phosphorous are commonly associated with massif-type anorthosites and related rocks. This rock association is part of the anorthosite–mangerite–charnockite–(rapakivi-)granite suites that are restricted to the Proterozoic. Understanding the geochemistry and emplacement mechanisms of ilmenite, magnetite and apatite ore deposits is crucial for exploration, efficient mining operations and ore processing. This review discusses the controlling factors on the grade of an ore, its mineralogy, and its major and trace element distribution. We present petrogenetic models of currently mined deposits (Lac Tio, Tellnes, Damiao) and discuss the characteristics of minor ore bodies from anorthosite provinces worldwide (Grenville, North China Craton, East European Craton, Rogaland, Laramie). Models of formation of anorthosite and related rocks are presented, as well as the nature of the possible parental magmas of the suite. A mineralogical classification of Fe–Ti ores is proposed: (1) Gabbro-noritic ilmenite ore ± apatite ± magnetite; (2) Ti-magnetite-dominated ore; (3) Nelsonite (Fe–Ti oxides + apatite); and (4) Rutile-ilmenite ore. The stability of ilmenite and magnetite is then critically reviewed and the influence of various factors, particularly oxygen fugacity and crystallization pressure, is examined. We discuss liquidus compositions of Fe–Ti oxides and the behavior of important trace elements such as Cr and V, both of which are sensitive to fO2 variations. Post-cumulus evolution of both oxides can occur due to re-equilibration with trapped liquid, re-equilibration with ferromagnesian silicates, exsolution, oxidation, reaction between ilmenite and magnetite, and metamorphic overprinting. These various processes are described and their effects on the oxide geochemistry are emphasized. Several potential ore-forming processes have been invoked and can explain the formation of huge concentration of ilmenite, ± magnetite, ± apatite. Fractional crystallization can be combined with crystal sorting and plagioclase buoyancy to produce relative enrichment of dense ore minerals. Silicate liquid immiscibility can segregate conjugate Si-rich and Fe-rich melts, the latter being enriched in Fe–Ti–P. Magma mixing can produce hybrid magmas located in a single-phase field of the phase diagram and precipitate a pure ilmenite cumulate. Alternative processes are also described, such as ejection of Fe–Ti-enriched residual melts by filter-pressing and compaction, solid-state remobilization of ilmenite in veins, and hydrothermal transport of Fe and Ti from the host anorthosite followed by concentration in veins and lenticular ore bodies. The magnetic properties of Fe–Ti ore deposits present contrasting signatures, depending on whether the natural remanent magnetization is dominated by hemo-ilmenite or multi-domain magnetite. Micro- and macro-scale deformation features of ore rocks are intimately correlated with magma emplacement, and with ballooning of the anorthosite diapir associated with gravitational sagging of dense ore bodies. Exploration perspectives show that oxide-apatite gabbronorites are interesting targets because ilmenite in these rocks is poorer in Cr and Mg, and because the Ti-resource may be combined with apatite and vanadiferous magnetite. [less ▲]

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See detailConscience et représentation. Débats récents en philosophie de l'esprit
Dewalque, Arnaud ULg; Gauvry, Charlotte ULg

Book published by Vrin (projet soumis) (2015)

L’ambition de ce volume est d’introduire le lecteur aux débats récents, en philosophie de l'esprit, en mettant en lumière les principaux enjeux lié à l’approche représentationnelle de la conscience. Il s ... [more ▼]

L’ambition de ce volume est d’introduire le lecteur aux débats récents, en philosophie de l'esprit, en mettant en lumière les principaux enjeux lié à l’approche représentationnelle de la conscience. Il s'agit de montrer que, derrière l’étiquette de "théories représentationnelles" ou de "représentationalisme" se cachent une variété de positions alternatives : représentationalisme d’ordre supérieur, représentationalisme standard, auto-représentationalisme et théories de l’intentionnalité phénoménale. Il s’agit aussi, simultanément, d’examiner les présupposés théoriques de l’approche représentationnelle, qui est aujourd’hui la plus répandue. Nous avons donc réservé une place, dans ce recueil, à un petit échantillon de perspectives critiques, comme la théorie de l’intentionalisme modal de Tim Crane, le réalisme empirique de Bill Brewer et la critique contextualiste de Charles Travis. [less ▲]

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See detailEarly seed plants from Western Gondwana: Paleobiogeographical and ecological implications based on Tournaisian (Lower Carboniferous) records from Argentina
Prestianni, C.; Rustan, J.J.; Balseiro, D. et al

in Palaeogeography, Palaeoclimatology, Palaeoecology (2015), 417

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See detailQuantitative temperature monitoring of a heat tracing experiment using cross-borehole ERT
Hermans, Thomas ULg; Wildemeersch, Samuel ULg; Jamin, Pierre ULg et al

in Geothermics (2015), 53

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal ... [more ▼]

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal systems requires a multidisciplinary approach including geological and hydrogeological aspects. In this context, electrical resistivity tomography (ERT) can bring relevant, qualitative and quantitative information on the temperature distribution in operating shallow geothermal systems or during heat tracing experiments. We followed a heat tracing experiment in an alluvial aquifer using cross-borehole time-lapse ERT. Heated water was injected in a well while water of the aquifer was extracted at another well. An ERT section was set up across the main flow direction. The results of ERT were transformed into temperature using calibrated petrophysical relationships. These ERT-derived temperatures were then compared to direct temperature measurements in control piezometers collected with distributed temperature sensing (DTS) and groundwater temperature loggers. Spatially, it enabled to map the horizontal and vertical extent of the heated water plume, as well as the zones where maximum temperatures occurred. Quantitatively, the temperatures and breakthrough curves estimated from ERT were in good agreement with the ones observed directly during the rise and maximum of the curve. An overestimation, likely related to 3D effects, was observed for the tail of the heat breakthrough curve. The error made on temperature can be estimated to be between 10 to 20 %, which is a fair value for indirect measurements. From our data, we estimated a quantification threshold for temperature variation of 1.2°C. These results suggest that ERT should be considered when designing heat tracing experiments or geothermal systems. It could help also to assess the geometrical complexity of the concerned reservoirs. It also appears that ERT could be a useful tool to monitor and control geothermal systems once they are in operation. [less ▲]

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See detailClimate-controlled palynofacies and miospore biostratigraphy of the Early Devonian Jauf Formation, northern Saudi Arabia
Breuer, Pierre; Leszczynski, S.; Miller, M.A. et al

in Review of Palaeobotany and Palynology (2015), 212

The Jauf Formation miospore succession is synthesized in terms of paleoenvironments and sequence stratigraphy. The data set for this study is obtained from four overlapping, continuously cored, and ... [more ▼]

The Jauf Formation miospore succession is synthesized in terms of paleoenvironments and sequence stratigraphy. The data set for this study is obtained from four overlapping, continuously cored, and extensively sampled, boreholes that for a 940 ft composite section. The Jauf Formation ranges in age from late Pragian to latest Emsian. The palynological assemblages, recognized herein, provide the basis for recognizing depositional environments present in the Early Devonian of northern Saudi Arabia. Transgressive – regressive cycles are indicated, not only by lithology but by marked changes in the marine to terrestrially dominated palynological assemblages. Flooding events are recognized by the replacement of spore dominated assemblages by organic-walled microphytoplankton. The maximum flooding interval for the Jauf is reinterpreted based on a correlative event consisting of diverse acritarchs and abundant chitinozoans. [Add details on the paly and sequence stratigraphy here. No.cycles and order.] The new northern Gondwanan biozonation developed by Breuer and Steemans (2012) and used here allows a high-resolution regional biozonation for the Arabian Plate and more intercontinental [?] correlation of the Jauf Formation with other Gondwanan and Euramerican localities. One new spore genus (Zonohilates) and four spore species (Insculptospora maxima, Camarozonotriletes alruwailii, Devonomonoletes crassus and Zonohilates vulneratus) are newly proposed. [less ▲]

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See detailSpore assemblages from Upper Ordovician and Lowermost Silurian sediments recovered from the Qusaiba-1 shallow core hole, Qasim region, central Saudi Arabia
Wellman, Charles H.; Steemans, Philippe ULg; Miller, M.A.

in Review of Palaeobotany and Palynology (2015), 212

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See detailLe Transport de marchandises et de personnes sur le Nil en 823 A.H./1420 È.C.
Bauden, Frédéric ULg

in Schubert, Alexander T.; Sijpesteijn, Petra M. (Eds.) Documents and the History of the Early Islamic World (2015)

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See detailThe seed dispersal of the afro- tropical tree species Staudtia kamerunensis (Myristicaceae)
Hambuckers, Alain ULg

Scientific conference (2014, December 27)

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See detailETAT DE LIEU DE LA FILIERE APICOLE EN REPUBLIQUE DEMOCRATIQUE DU CONGO ET EVALUATION DES CAPACITES POLLINISATRICES DES ABEILLES DOMESTIQUES (Apis mellifera adansonii, L.) SUR LA CULTURE DE MELON AFRICAIN (Cucumeropsis mannii Naudin) A KISANGANI.
Posho Ndola, Boniface ULg

Doctoral thesis (2014)

La présente étude s’inscrit dans le cadre de la recherche d’une meilleure compréhension de la filière apicole en RDC, de l’influence de l’environnement sur la qualité de pains d'abeille et de miel pour la ... [more ▼]

La présente étude s’inscrit dans le cadre de la recherche d’une meilleure compréhension de la filière apicole en RDC, de l’influence de l’environnement sur la qualité de pains d'abeille et de miel pour la survie d’Apis mellifera adansonii, L. 1758 en RDC et de l’impact de la pollinisation des abeilles introduites (A. mellifera adansonii, L. 1758) sur la production de Cucumeropsis mannii (Naudin) à Kisangani. Trois approches ont été adoptées pour faire l’état de lieu de la filière apicole en RDC, dont (1) la distribution des questionnaires structurés aux apiculteurs, (2) des visites de ruchers et (3) des recherches documentaires. Dans le cadre de l’évaluation de la qualité de miels et pains d’abeilles, les échantillons de miels et de pollens ont été collectés dans trois sites écologiquement différents de la RDC. Les échantillons de miels ont été évalués suivant les critères et les protocoles établis par Codex Alimentarius; tandis que les pollens ont été évalués suivant les critères de teneur en protéines et en acides aminés essentiels. Les teneurs en protéines et en acides aminés essentiels de pains d’abeilles collectés ont été déterminées respectivement par la méthode Kjeldahl et par les hydrolyses acides et basiques. Les essais comparatifs de la pollinisation des abeilles domestiques ont été également conduits dans deux sites expérimentaux à Kisangani. Sur chaque site, deux champs d'un hectare séparés de 3 kilomètres ont été installés. Deux colonies d'abeilles ont été installées au milieu du champ expérimental de chaque site pendant la floraison (quand 10 % des plantes ont fleuri). Le second champ expérimental, sans colonies d’abeilles, a été considéré comme témoin. Les résultats obtenus après l’étude exploratoire sur l’apiculture en RDC montrent que l’apiculture congolaise reste encore semi traditionnelle; 54 % des apiculteurs congolais travaillent en coopérative; 100 % du cheptel apicole congolais est constitué d’A. mellifera adansonii, L. ; 96 % des apiculteurs utilisent les ruches Kenyanes; le nombre de ruches utilisé par un apiculteur congolais varie entre 2 et 120; la production d’une colonie par récolte oscille entre 1 et 25 litres de miel; la production annuelle par apiculteur est évaluée entre 10 et 900 litres de miel, le nombre de récoltes de miel effectué par an varie de 1 à 2. Cette étude a révélé que la teneur moyenne en protéines de pollens recueillies en RDC était 14,11 ± 5,27 %. Cette teneur en protéines était faible comparativement aux besoins alimentaires des abeilles en Europe. Tous les échantillons de pollen étaient constitués de dix acides aminés essentiels et leurs concentrations étaient dans la fourchette optimale des exigences alimentaires des abeilles en Europe. Les analyses des échantillons de miels ont révélé que la teneur en sucres réducteurs des échantillons de miel recueillies variait de 63,40 à 73,80 %, la teneur en saccharose était comprise entre 0,30 et 1,90 %, la teneur en eau oscillait entre 16,80 et 22,00 %, le pH des échantillons de miel analysés variait de 4,22 à 4,53, la moyenne de la conductivité électrique de miels récoltés a été ( 47,74 ± 13,93 ) S/cm et la concentration de HMF varié de 1,75 à 31,38 mg / kg de HMF miel. Les miels et les pollens collectés dans la forêt tropicale de Kisangani étaient moyennement plus nutritifs pour les abeilles que ceux de la savane de Kavwaya. Après les observations des essais comparatifs de pollinisation, il a révélé que la pollinisation des abeilles introduites a amélioré significativement le nombre de graines par fruit de 83,78 %, tandis que le nombre de fruits par plante et le poids de graines par fruit ont été améliorés respectivement de 422,89 % et 185,61 % par rapport au témoin. La taille de graine a été positivement influencée par la présence de colonie d’abeille dans le champ de C. mannii (Naudin). Dans cette étude, la distance par rapport aux ruches et l’orientation de vol des ouvrières n'ont pas influencé significativement le rendement et la taille des graines de C. mannii (Naudin) [less ▲]

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See detailUn guide de la rédaction du mémoire : pourquoi et comment ?
Grandjean, Geoffrey ULg

Scientific conference (2014, December 19)

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See detailGathering and Handling of Granular Materials under Microgravity Conditions
Opsomer, Eric ULg

Doctoral thesis (2014)

When a granular material is driven in microgravity environment, one can assist to the formation of dense and slow regions in the system. Indeed, given the dissipative character of the collisions in the ... [more ▼]

When a granular material is driven in microgravity environment, one can assist to the formation of dense and slow regions in the system. Indeed, given the dissipative character of the collisions in the media, energy is lost at each particle interaction and the grains begin to clump locally. The phenomenon has been observed for the first time in the late nineties during sounding rocket experimentation by Falcon and his coworkers and has attracted the interest of many scientists since then. However, precise laws describing the formation and the dynamics of such clusters are still lacking. In order to allow an intensive study of the phenomenon, the European Space Agency set up the SpaceGrains project. Small bronze spheres are enclosed in a rectangular cell and vertically driven by to pistons oscillating in phase opposition. Our work consists in the preparation of the SpaceGrains experiment via molecular dynamics simulations and the elaboration of models predicting the behaviour of the system. Before we started our study concerning SpaceGrains, we reproduced and extended Falcon’s sounding rocket experiments. We showed that, in addition to the granular gas and the cluster, another dynamical regime can be observed in the system. Indeed, for higher filling fractions, the entire granular media behaves like one single completely dissipative particle called the bouncing aggregate. Bouncing modes are observed and can be explained considering the bouncing ball paradigm. Moreover, we highlighted the role of the packing fraction φ as well as the size of the particles R on the different observed dynamics. Within the frame of the SpaceGrains device, we studied the impact of all tunable parameters of the experiment on the dynamics of the system. Thanks to an appropriate scaling all transition points that we obtained by varying the driving amplitude A, the packing fraction and the dimen- sions of the cell L fall along a same theoretical curve. The latter is explained regarding the energy transfer from the piston towards the center of the cell. Once the clustering was controlled, we investigated the handling of the agglomerate. By compartmentalizing the container, local trapping can be achieved and a granular pendant of Maxwell’s demon can be observed in microgravity. Based on the measured particle flux between the compartments, we realized a theoretical model predicting the asymptotic steady state of the system depending on the total number N of particles. In a clustered system, we investigated the impact of asymmetrical driving on the system’s dy- namics. We showed that the mean position of the cluster can be fully controlled via the amplitude ratio a. Moreover, the natural fluctuations of the agglomerate around its equilibrium position are dictated by the driving frequency f and the mass of the cluster. Finally, we realized simulations of driven bi-disperse gases and investigated the segregation phenomena in the system. We showed that clustering and segregation are strongly linked and that the size and the mass of the particles impact the segregation dynamics in different ways. [less ▲]

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See detailEtude et Modélisation de la contribution des macrophytes flottants (Lemna minor) dans le fonctionnement des lagunes naturellles
Tangou Tabou, Thierry ULg

Doctoral thesis (2014)

Waste stabilization ponds (WSP) are widely used in the treatment of domestic and industrial wastewaters in industrialized countries and in developing countries including the Democratic Republic of Congo ... [more ▼]

Waste stabilization ponds (WSP) are widely used in the treatment of domestic and industrial wastewaters in industrialized countries and in developing countries including the Democratic Republic of Congo. Several organisms (e.g., bacteria, algae, protozoa, and aquatic plants) are involved in the treatment process occurring in the WSP. Therefore, the performance of such systems strongly depends upon the management of the existing macrophytes (or at least the management of the most dominant species). Indeed, large biomass coverage of floating macrophytes can induce several dysfunctions within the ponds (e.g., second pollution due to the death and the settling of the macrophytes, difficulties in harvesting valuable biomass for animal feeding or pharmaceutical purposes, etc.) and can threaten the surrounding ecosystems (i.e., fauna and flora) through the releases of partially or unpurified waters. This study aimed at investigating the contribution of floating macrophytes, namely that of duckweed (Lemna minor), which are the most common species, in the functioning of natural WSP. Specifically, the objectives were: (i) the modeling of the growth kinetics of Lemna minor based on the key environmental influencing factors (nutrients concentrations, light intensity, pH, temperature); (ii) the characterizations of the stoichiometry of the growth of Lemna minor and the gas/liquid transfers in the ponds; and (iii) the set-up of a mathematical model, i.e. the MLLE (Modèle de Lagunage par Lentilles d'eau) through the mass balances approach based on the Petersen’s matrix. The study of the growth kinetics of L. minor was carried out in a growth chamber (phytotron) using a pilot involving initial fresh L. minor biomass and different set of concentrations in nutrient nitrogen (N) and phosphorus (P), light intensity, pH, and temperature. The growth was monitored using the gravimetric methods and digital images processing. The results showed that the growth of L. Minor was optimum for concentrations of N and P of circa 10 mg N-NH4+.L-1 and 1 mg P-PO43-.L-1, respectively, with a maximum growth rate of approximately 0.09 j-1. However, the growth decreased progressively when the respective concentrations of N and P reached approximately 16 mg N-NH4+L-1 and 6 mg P-PO43-.L-1. A possible inhibition due to the excess of substrates might be the cause of such decrease. Moreover, a light intensity greater than 450 μmol.m-².s-1 was potentially harmful for L. minor surviving (growth rate dropped by 60%), though the mortality rate was low (< 0.05 j-1). Characterizing the stoichiometry of L. minor resulted in the formulation of the plant biomol (C88H163O70N10P) and the description of biochemical processes occurring within the ponds, as well as the determination of the conversion rates substrate-biomass in each of these processes. The Lavoisier's principle (conservation of the matter) also was confirmed for the stoichiometric relationship developed for chemical oxygen demands through our experiments. Furthermore, the aeration test assays revealed the influence of the biomass coverage on the gaz/liquid transfers parameters. An exponential decrease of the transfer coefficients, the oxygenation capacity and hourly inputs was associated with increasing coverage rates in both absence and presence of plants. The hypothesis of a main release (about 80%) of oxygen (consumption of carbon dioxide) toward the atmosphere was also confirmed. The third fold of our study was then undertaken based on our findings on the biochemical processes (kinetics and stoichiometry of growth and mortality of plants) and findings on physical processes (gas/liquid transfer) occurring in WSP. A mathematical model, the MLLE, was thus developed and its validity assessed through the equilibrium of the Petersen's matrix. The impact of key nutrients (i.e., nitrogen and phosphorus) on the growth of duckweed, along with the influence of the release of oxygen (consumption carbon dioxide) by the floating macrophytes (L. minor) can be, therefore, thoroughly assessed based on the state variables of the model. Additional simulations using the West® (World Wide Engine for Simulation, Training and Automation) software could help in further calibrating and/or validating the MLLE, and guide in its implementation for industrial purposes. Keywords: Lemna minor, biomass, image processing, nutrient, biomole, gas/liquid transfer, model [less ▲]

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See detailEtude de l'assainissement non collectif en Afrique Subsaharienne : Application à la ville de Bujumbura
Bigumandondera, Patrice ULg

Doctoral thesis (2014)

Summary On-site sanitation sector in sub-Saharan African is a complex area that requires the involvement of a multidimensional approach mobilizing various actors and competencies. The main purpose of this ... [more ▼]

Summary On-site sanitation sector in sub-Saharan African is a complex area that requires the involvement of a multidimensional approach mobilizing various actors and competencies. The main purpose of this thesis is to conduct a study integrating the three links in the sanitation chain that compose the on-site sanitation sector, namely the upstream links regarding sanitation facilities installed at private homes, the intermediate link for evacuation of sludge and transport to a treatment site and the downstream link for disposal and treatment sludge. A sociological approach mobilizing both survey techniques and on-site observation has allowed understanding the on-site sanitation practices in the field of developing countries. Methodologies to initiate corrective action with respect to what is done so far are utilized. Such as a method for evaluating on-site sanitation using an indicator that is a combination of indicators developed taking into account the entire sanitation sector. At the same time, a procedure to select sanitation technologies based on a number of criteria was adopted. The proposed technologies as well as criteria used for their implementation follow the same logic as previously, i.e. that consisting of taking into account the entire sanitation sector. This study also examined the design procedure of the septic tank and of evaluated its performance on site given that it is used in many sanitation systems. Settling column tests were carried out show that the effluent who enters in the septic tank settles well but settable solids remain in the effluent leaving the septic tank remaining, parameter that needs to be taken into account in the establishment of the infiltration bed after the septic tank. Quantification of sludge accumulation rates in the septic tank shows that for a pump out period every 4 years, the design can be based on an average sludge accumulation rate of 0.22L/person/day. These values (as expressed in g COD/person/day) are useful both to assess withdrawal, but also to design sludge's disposal site. Analyses of these sludges reveal a poorly biodegradable product with a non-biodegradable COD fraction reaching 47.5%, thus as a product with a low methanogenic potential, limiting the interest of its application in anaerobic digestion as a substrate. But, their co-treatment with organic solids waste in a partial anaerobic co-digestion process followed by composting. In this case sludges are considered as digestion inoculums. Preliminary results are encouraging, particularly in terms of total time needed for the entire process. Among other advantages, this process reduces handling of the waste being processed and provides two end products directly recoverable: compost and methane. So we hope that this research will contribute to the establishment in African countries for more efficient on-site sanitation, able to meet the targets set by international organizations. [less ▲]

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See detailGenetic improvement of pig sire lines for production performances in crossbreeding
Dufrasne, Marie ULg

Doctoral thesis (2014)

Crossbreeding is widely used in pig breeding to benefit from advantages of heterosis effects and breed complementarity. Breeding programs are specialized between sire and dam lines, with different ... [more ▼]

Crossbreeding is widely used in pig breeding to benefit from advantages of heterosis effects and breed complementarity. Breeding programs are specialized between sire and dam lines, with different selection objectives. Sire lines are mainly selected for production traits (e.g., growth, carcass quality, feed efficiency). Moreover, selection is often in purebred lines while the goal of selection is to improve crossbred performances. Hence, genetic selection of purebred parents involved in crossbreeding requires models accounting for crossbreeding effects, and able to combine data from different genetic types (purebreds and crossbreds) and different environmental conditions. Therefore, the objective of this thesis was to develop genetic models to estimate genetic parameters and breeding values for production traits in crossbred populations of pigs. A genetic model was developed to estimate the genetic potential of Walloon purebred Piétrain boars for growth performances in crossbreeding based on test station and on-farm data from purebred and crossbred pigs. Weight records from both systems were considered as different traits. Results showed that weights recorded in test station and on-farm were different traits but genetically correlated. Moreover, combining both sources of data allowed to increase reliability of estimated breeding values and Genotype x Environment interactions were detected for growth in the Walloon breeding program. The introduction of dominance effects, linked to crossbreeding, into the genetic model for growth in the crossbred population showed that dominance effects existed on growth of crossbred pigs. Moreover, the total and the additive genetic merits were better estimated than with a strictly additive model. Research conducted on commercial crossbred data from US Duroc sires displayed that the sire genetic effects were not negligible on traits like piglet birth weight, preweaning mortality, mortality at different stages of the grow-finishing period and hot carcass weight. Furthermore, sire genetic effects increased with age. Genetic studies of mortality in the population from US Duroc sires showed that mortality traits had a low heritability, increasing with age and that mortality was not antagonistic with market weight. Besides, genetic parameters estimated for birth weight and its relation with other production traits in crossbred populations from Piétrain and Duroc sires showed that birth weight could be used as an early indicator trait to improve latter performances. Finally, production traits were genetically correlated and should be selected simultaneously to reach the breeding goal. [less ▲]

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See detailAllergie moléculaire & Diagnostic in-vitro, Optimalisation de la prescription
GADISSEUR, Romy ULg

Conference (2014, December 17)

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See detailComment alléger la charge des ménages dans le financement de la santé dans les pays du Sud: Résultats des Comptes Nationaux de la Santé 2010-11 en RD Congo
Manzambi Kuwekita, Joseph ULg

Learning material (2014)

Cette étude examine la part et l’affectation des dépenses des ménages dans le financement de la santé telle que présentée dans le rapport des Comptes Nationaux de la Santé 2010-11. Les dépenses courantes ... [more ▼]

Cette étude examine la part et l’affectation des dépenses des ménages dans le financement de la santé telle que présentée dans le rapport des Comptes Nationaux de la Santé 2010-11. Les dépenses courantes de santé sont à charge des ménages (40%) et réalisées par paiement direct sans partage de coûts (93,7%). L’hospitalisation est justifiée pour soigner les carences nutritionnelles (34%), le paludisme (12%) et les troubles mentaux (10%). Dans 82% des cas, les soins ambulatoires concernent le paludisme (71%) et les troubles mentaux (12,5%). Le fait que:71,58% des dépenses des hôpitaux, 96,49% des dépenses des centres ambulatoires, 98,48% des dépenses des labo, 72,42% des dépenses des pharmacies sont à charge des ménages: montre la nécessité de la mise en place de mécanismes de solidarisation du risque santé. le paludisme absorbe 71% des dépenses en soins ambulatoires: d’où la nécessité de renforcer les mesures de prévention, le traitement et l’assainissement du milieu. L’amélioration du pouvoir d’achat permettrait d’autonomiser les ménages dans la lutte contre le paludisme. les carences nutritionnelles sont la première cause de recours à l’hôpital: d’où la nécessité de changement des comportements et habitudes alimentaires, la sécurité alimentaires et l’amélioration du pouvoir d’achat des ménages. les troubles mentaux sont le troisième motif d’hospitalisation: d’où la nécessité de les prendre en compte dans les mécanismes de financement de la lutte contre la maladie. [less ▲]

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