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See detailCoating of crystallized Yttrium Orthoferrite (o-YFeO3) by wet deposition methods
Stevens, Frédéric ULg

Doctoral thesis (2016)

L’objectif de cette thèse est d’obtenir un dépôt d’orthoferrite d’yttrium orthorhombique sur substrat conducteur. Ceci, en vue de d’étudier de nouveaux catalyseurs potentiels pour le clivage ... [more ▼]

L’objectif de cette thèse est d’obtenir un dépôt d’orthoferrite d’yttrium orthorhombique sur substrat conducteur. Ceci, en vue de d’étudier de nouveaux catalyseurs potentiels pour le clivage photoélectrochimique de l’eau. Le clivage photoélectrochomique de l’eau produit dudihydrogène et du dioxygène grâce à l’énergie solaire et un catalyseur. Le dihydrogène et le dioxygène sont les combustibles d’une réaction exothermique. Transformer l’eau en ces deux composés est donc une méthode de stockage de l’énergie. Plusieurs semiconducteurs sont étudiés comme catalyseurs pour ce clivage. Cette thèse se concentre sur l’étude de l’un d’eux : l’orthoferrite d’yttrium orthorhombique (o-YFeO3), et sur deux méthodes de dépôt de ce matériau sur substrat conducteur : la méthode de déposition par plongée (dip-coating) et la pyrolyse d’une vaporisation ultrasoniquement générée (USP). Dans un premier temps, deux méthodes de synthèse del’o-YFeO3, sous forme de poudre, ont été envisagées : l’une basée sur des chlorures de fer et d’yttrium, l’autre basée sur les nitrates de ces mêmes métaux. Les éventuels problèmes de proportion ou de précipitations successives ont été respectivement dissipés par une étude de masse et une analyse de l’évolution du pH. Ces poudres, issues des chlorures ou des nitrates, ont permis de caractériser la proportion et la pureté des phases cristallines en fonction de la température de calcination par l’étude de la diffraction des rayons X (XRD) ; de caractériser l’énergie de la bande interdite (band gap optique) par la spectroscopie de réflectance diffuse (DRS) et d’en observer leur morphologie par les microscopies électroniques à balayage (SEM) ou en transmission (TEM). Toutes ces analyses nous ont poussés à continuer notre étude en nous focalisant sur la synthèse basée sur les nitrates et d’utiliser une température de calcination de 850°C. Ensuite, ces mêmes analyses (pH, XRD, DRS) ont permis d’estimer l’influence de l’ajout de différents composés organiques en cours de synthèsesur la cristallinité, la pureté, la température de calcination et l’énergie de la bande interdite de ces poudres. Cette thèse a montré que l’additif qui améliore au maximum ces propriétés est l’acide citrique. Dans le cas des poudres, dès 450°C – soit 400°C de moins que la même synthèse sans acide citrique – l’o-YFeO3est cristallisé. Les solutions qui seront utilisées pour les méthodes dedéposition seront donc composées à partir, entre autre, de nitrate de fer, de nitrate d’yttrium et d’acide citrique. La méthode dite du « dip-coating » consiste à plonger le substrat qu’on compte recouvrir dans une solution de précurseurs – composée, entre autre, des nitrates métalliques et d’acide citrique – de le ressortir recouvert d’un film mince de cette solution pour ensuite le chauffer et ainsi obtenir un dépôt du matériau désiré. De nombreux problèmes d’adhérence, de stabilité de solution, de quantité de matière, d’homogénéité de dépôt et de cristallisation de composé ont eu raison de nos efforts pour la mise au point de tels dépôts par cette technique. L’autre méthode de déposition utilisée durant cettethèse est l’«USP ». Cette technique vaporise une solution de précurseurs au moyen de vibrations ultrasoniques. Le brouillard ainsi généré est propulsé vers le substrat par du gaz sous pression. Le substrat, pendant ce processus, est placé sur une plaque chauffante. La solution vaporisée chauffera au fur et à mesure qu’elle se rapprochera du substrat. Cette technique implique l’ajustement de plusieurs paramètres qui définissent le type de composés qui atteindront le substrat. Cette thèse a abouti à la mise au point de ces différents paramètres qui ont permis d’obtenir un dépôt d’orthoferrite d’yttrium orthorhombique sur un substrat conducteur. Ce dépôt présente une activité photoélectrochimique en tant qu’anode pour le clivage de l’eau, mais ses performances ne permettent pas, dans son état actuel, de concurrencer les semiconducteurs précédement décrit par d’autres chercheurs. Une poursuite des travaux dans ce domaine devraient se focaliser sur le dopage et/ou la structuration contrôlée de l’orthoferrite d’yttrium. [less ▲]

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See detailVers un nouvel ancrage sociétal du cours d’éducation physique
Cloes, Marc ULg

Conference (2016, February 24)

Since two decades, a growing number of publications underlines the increase of the sedentariness of the society and, in parallel, that of the number of overweight people. It has been demonstrated that ... [more ▼]

Since two decades, a growing number of publications underlines the increase of the sedentariness of the society and, in parallel, that of the number of overweight people. It has been demonstrated that these evolutions will have negative consequences on the health of the citizen at mid and long terms. School is identified as one of the main pillars of the promotion of a physically active lifestyle. By the competences that they acquire during their studies, physical educaiton teachers are considered as the potential corner stone of actions to be implemented in order to allow youth to become citizen responsible of their body and to learn how to use it longlife. That implies reinforcing application of principles that physical educators know very well but that are not necessary integrated systematically in the professional practice. Beforehand to the action on the gym, it means that specific appraoches of teachers education (pre- and in-service) have to be implemented. The presentation proposes to review the current developments and will emphasize the share of good practices in teaching as well as in teacher education. [less ▲]

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See detailCharles de Gaulle et la Belgique
Lanneau, Catherine ULg

Conference given outside the academic context (2016)

Panorama des relations et contacts entre la Belgique (francophone) et le général de Gaulle, centrée sur la période de "découverte" (1940-1945), sur les persistances d'un gaullisme anticommuniste et wallon ... [more ▼]

Panorama des relations et contacts entre la Belgique (francophone) et le général de Gaulle, centrée sur la période de "découverte" (1940-1945), sur les persistances d'un gaullisme anticommuniste et wallon (1946-1950) puis sur les deux principaux dossiers de la décennie gaullienne (1958-1969): l'Europe et les contacts recherchés dans les milieux gaullistes par les militants wallons. La conférence s'achève sur quelques réflexions concernant les "lieux de mémoire" gaulliens en Belgique et la persistance de références gaullistes ou gaulliennes chez certains hommes politiques belges actuels. [less ▲]

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See detailLivre Blanc Céréales
Watillon, Bernard; Bodson, Bernard ULg

Book published by Gembloux Agro Bio Tech (2016)

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See detail2. Implantation des cultures
Eylenbosch, Damien ULg; Meza Morales, Walter ULg; Monfort, Bruno et al

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2016, February 24)

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See detail4. La fumure azotée
Meza Morales, Walter ULg; Monfort, Bruno; Dumont, Benjamin ULg et al

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2016, February 24)

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See detail5. Régulateurs de croissance
Henriet, François; Monfort, Bruno; Meza Morales, Walter ULg

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2016, February 24)

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See detail6. Lutte intégrée contre les maladies
Bataille, Charlotte; Duvivier, Maxime; Heens, Benoît et al

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2016, February 24)

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See detail10.1. L'intérêt de la culture en association de froment et de pois protéagineux d'hiver dans un objectif d'autonomie protéique
Pierreux, Jérome ULg; Delaplace, Pierre ULg; Roisin, Christian et al

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2016, February 24)

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See detail10.2. Evaluation des cultures dérobées implantées en tant que surfaces d'intérêt écologique (SIE) dans le cadre de la PAC 2015-2020
Hancart, F.; Jenet, D.; Lambert, B. et al

in Watillon, B.; Bodson, Bernard (Eds.) Livre Blanc Céréales (2016, February 24)

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See detailModeling operational losses: a conditional Generalized Pareto regression based on a single-index assumption
Hambuckers, julien ULg; Heuchenne, Cédric ULg; Lopez, Olivier

Scientific conference (2016, February 24)

In this paper, we consider a regression model in which the tail of the conditional distribution of the response can be approximated by a Generalized Pareto distribution. Our model is based on a ... [more ▼]

In this paper, we consider a regression model in which the tail of the conditional distribution of the response can be approximated by a Generalized Pareto distribution. Our model is based on a semiparametric single-index assumption on the conditional tail index while no further assumption on the conditional scale parameter is made. The underlying dimension reduction assumption allows the procedure to be of prime interest in the case where the dimension of the covariates is high, in which case the purely nonparametric techniques fail while the purely parametric one are too rough to correctly fit to the data. We propose an iterative algorithm in order to perform their practical implementation. Our results are supported by some simulations. To illustrate the proposed approach, the method is applied to a novel database of operational losses from the bank UniCredit [less ▲]

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See detailLes sépulcrines de Visé (1616-2016) : des religieuses au service de la Réforme catholique
Henneau, Marie-Elisabeth ULg

Conference given outside the academic context (2016)

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See detailChapter 2. Low-Temperature Microassembly Methods and Integration Techniques for Biomedical Applications
Stoukatch, Serguei ULg

in Salvo, Pietro; Hernandez-Silveira, Miguel (Eds.) Wireless Medical Systems and Algorithms (2016)

Microassembly and packaging in a broad sense is a technique that interconnects microelectronics into a system level to form a functional product for the end user. Microassembly and packaging provide ... [more ▼]

Microassembly and packaging in a broad sense is a technique that interconnects microelectronics into a system level to form a functional product for the end user. Microassembly and packaging provide electrical and mechanical interconnection between microelectronics and the package. [less ▲]

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See detailMagnetic flux penetration in Nb superconducting films with lithographically defined micro-indentations
Brisbois, Jérémy ULg; Adami, Obaïd-Allah ULg; Avila Osses, Jonathan ULg et al

in Physical Review B (2016), 93(5), 054521

We present a thorough investigation by magneto-optical imaging of the magnetic flux penetration in Nb thin films with lithographically defined border indentations. We demonstrate that discontinuity lines ... [more ▼]

We present a thorough investigation by magneto-optical imaging of the magnetic flux penetration in Nb thin films with lithographically defined border indentations. We demonstrate that discontinuity lines (d-lines), caused by the abrupt bending of current streamlines around the indentations, depart from the expected parabolic trend close to the defect and depend on the shape and size of the indentation as well as on the temperature. These findings are backed up and compared with theoretical results obtained by numerical simulations and analytical calculations highlighting the key role played by demagnetization effects and the creep exponent n. In addition, we show that the presence of nearby indentations and submicrometer random roughness of the sample border can severely modify the flux front topology and dynamics. Strikingly, in contrast to what has been repeatedly predicted in the literature, we do not observe that indentations act as nucleation spots for flux avalanches, but they instead help to release the flux pressure and avoid thermomagnetic instabilities. [less ▲]

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See detailContribution à l'amélioration de la production laitière et de la reproduction des vaches Ankole et croisées Ankole x Frisonne en territoire de Beni, République Démocratique du Congo
Katungu Kibwana, Denise ULg

Doctoral thesis (2016)

Eastern Democratic Republic of the Congo, especially Kivu, is a large pastoral region but the cattle numbers of which considerably decreased following the conflicts that the country underwent over the ... [more ▼]

Eastern Democratic Republic of the Congo, especially Kivu, is a large pastoral region but the cattle numbers of which considerably decreased following the conflicts that the country underwent over the past two decades, with important losses in breeding skills. Cattle breeding currently practiced in Kivu may be described as "great unknown". Data available in literature relate to old studies and focuse on peripheral areas from Kivu. This study aimed, at first, to establish a diagnosis on dairy cattle breeding inhabits in the east of the Democratic Republic of the Congo, especially in the provinces of North Kivu. This diagnosis based on the choices adopted by breeders according to animal genetic, constraints related to feeding, animal housing and the main reproductive characteristics of females. The other objective of the study was to test an improved farming method taking into account the perceived constraints highlighted with the diagnostic investigation. The proposal took into account the realities of the south, and thus was characterized by simplicity and speed of implementation, in the emergency context that the population lives daily in the region. 1. Breeding cattle and milk production in tropical environments: Case of eastern region of the Democratic Republic of the Congo. Inventory and perspectives. In East of Democratic Republic of the Congo, cattle breeding is based on exploitation of non-selected dairy cattle raised in extensive unimproved rearing system. Extensive breeding of traditional type is the bulk of the pastoral activities in the region and the country. The main factors limiting cattle breeding in this area of D.R. of the Congo, as in most tropical environments, consist in: (i) low genetic potential of African cattle with low level of production and (ii) poor farming conditions due to low feed quality and health coverage, precarious livestock housing, poor management of reproduction and animal genetic resources, and low breeders’ technicity. These factors affect productive and reproductive performance of animals. Low milk production arising does not allow breeders to provide their needs and cover milk needs of the population, thus leading to importation of large amounts of milk and its derived products. 2. Extensive farming practices and cattle performances of the local breed and crossed with exotic dairy breeds in the Democratic Republic of the Congo The study was conducted in Beni, Democratic Republic of the Congo. It aimed to highlight the breeding cattle system and dairy production levels of both local cows and cows crossed with exotic dairy breeds raised in the environment, and reproductive parameters (age at first calving, interval calving and fertility) as well as mortality rate of animals. The data, obtained from 8464 animals, including 4805 cows (2309 local vs 2496 crossed with Sahiwal and exotic dairy breeds - Friesian, Brown Swiss and Jersey considered ameliorative) were analyzed by chi-square test for categorical data, by generalized linear model based on the genetic type, forage quality and type of supplementation for continuous data, and by Anova-One-way for to test the effect of the degree of specialization and professionalism of breeders. Non-parametric data were analyzed by Spearman correlation test. All factors studied had a significant influence on milk production (P <0.001); calving interval, meanwhile, was significantly influenced by breed (P <0.002) and the type of supplementation (P= 0.011), age at first calving was only influenced by the breed (P <0.001). Milk production, age at first calving, calving interval, fecundity rate and mortality rates of local cattle were respectively 2.6 ± 0.17 l/d, 41.1 ± 1.02 mo, 22.6 ± 0.73 mo, 53.0% and 4.8% between 0 and 1 year and 3.6% between 1 and 2 years vs 6.1 ± 0.21 l/d, 32.5 ± 1.21 mo, 19.1 ± 0.87 mo, 44.8%, 6.7% between 0 and 1 year and 4.4% between 1 and 2 years, respectively, in crossed type. Forage supplementation had a significant effect on milk production compared to the situation with natural forage (1.6 l/d more, P <0.001), and by-products supplementation associated or not to mineral permitted an increase of 0.9 liter of milk production compared to the situation without supplementation (P= 0.041). Increased supplementation with or without the mineral reduced calving interval by 3.6 mo compared to the situation without supplementation, and by 2.5 mo compared to the simple supplementation (P= 0.011). The type of forage had no significant effect on calving interval. The mortality rate was significantly influenced by breed (P= 0.017). A significant interaction between the genetic type and forage type was observed on milk production (P <0.001). Some parameters studied were also influenced by degree of specialization of the breeders - calving interval (P= 0.04 in crossbred type and P <0.001 in local bred) - age of first calving in local bred (P= 0.015); and by degree of professionalization - age of first calving in local bred (P= 0.04) - calving interval (P= 0.08) and milk production in crossbred type (P= 0.04). 3. Effect of improved feeding and housing, and of Friesian blood level on milk production of Ankole x Friesian crossbred cows The study was carried out at the Vitolu/Misugho farm extension, in Beni territory, Democratic Republic of Congo. The objective of this study was to quantify the effects of rearing conditions (feeding and housing in stall of night), and of Friesian blood level on milk production of Ankole x Friesian crossbreds cows. Data were obtained from 30 cows. The birth weights of calves were compared between groups using a Student test. Using the SAS software (Statistical Analysis System, version 9.1.3), data on average daily milk production were analyzed using a mixed model (proc mixed), including the effects of treatment group, Friesian blood level, day in milk, and the simple interactions between these effects. Day in milk within animal was included as a repeated measurement, and a type 1 autoregressive covariance structure was associated to. Differences were considered significant at P <0.05. The indicators of variation were expressed as standard deviation. The experimental unit was the cow. All factors affected significantly daily milk production (P <0.001). The results of these analyzes show that average milk production was higher group offered the improved feed and housed in the stable (6.8 ± 0.31 l/d vs 5.2 ± 0.31 l/d in the control group cows housed in kraal at night, P <0.001). The pic of milk production was observed around the 79th and 96th days respectively in IG and CoG. In both groups, cows adapted their milk production for the rainfall regime and milk production was significantly higher during the rainy season. Lactation curve was very dependent on rainfall regime and did not follow the shape of a normal curve. Improved milk production and highest values were observed with >25% of Friesian blood level (5.3 ± 0.31 l/d to 6.6 ± 0.23 l/d, from 25 to 44%, P <0.001). Interactions between treatment (improved feed and housing) and Friesian blood level were also observed (P <0.001). The IG cows showed the highest milk production compared to the control group (milk productions of 5.8 ± 0.50; 7.0 ± 0.66 and 7.8 ± 0.70 l/d were obtained with 25, 38 and 44% of blood Friesian, respectively, in the treated group vs. 4.8 ± 0.23; 5.5 ± 0.23 and 5.4 ± 0.16 l/d in the control group, P <0.001). [less ▲]

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See detailInfluence des stéréotypes sur les performances cognitives des personnes âgées
Marquet, Manon ULg

Conference given outside the academic context (2016)

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See detailRéflexions à propos du projet de loi sur l'internement
Englebert, Jérôme ULg

Conference given outside the academic context (2016)

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See detailDoping TiO2 films with carbon nanotubes to simultaneously optimise antistatic, photocatalytic and superhydrophilic properties
Léonard, Géraldine ULg; Remy, Simon; Heinrichs, Benoît ULg

in Journal of Sol-Gel Science and Technology (2016)

Pure and multiwall carbon nanotube (MWCNT)- doped titanium dioxide (TiO2) films, synthesised from two sol–gel routes (alcoholic and aqueous) and deposited by dipcoating on glass, have been developed as ... [more ▼]

Pure and multiwall carbon nanotube (MWCNT)- doped titanium dioxide (TiO2) films, synthesised from two sol–gel routes (alcoholic and aqueous) and deposited by dipcoating on glass, have been developed as conductive, photocatalytic and superhydrophilic materials. While already crystallised in anatase structure at low temperature when synthesised in water, samples prepared in alcohol are amorphous. Their crystallisation in air has been studied at increasing temperatures. Effective incorporation of functionalised MWCNTs is confirmed in both aqueous and alcoholic samples with a closer interaction with TiO2 particles in the case of aqueous synthesis. In alcoholic samples, 400 C seems to be an optimised calcination temperature since 300 C does not allow crystallisation into anatase and 500 C removes MWCNTs through burning. The purpose of MWCNT doping is to obtain coatings that exhibit easy-toclean or self-cleaning properties. This can be achieved through an optimised combination of electrical conductivity (for antistatic property), photoactivity and superhydrophilicity. These three properties require the crystallisation of TiO2 into anatase. MWCNT doping dramatically increases both conductivity and photocatalytic activity, especially in alcoholic samples for the former and in aqueous samples for the latter. On the other hand, MWCNT introduction does not significantly affect the (super)hydrophilicity of films, which depends solely on the crystallinity of TiO2. [less ▲]

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