Thèses et e-prints BICTEL/e
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Inégalités salariales dans les pays européens: concepts, mesures et niveaux d'analyse
No full textCette thèse de doctorat a pour objet les inégalités sur le marché de l'emploi en Europe, appréhendées principalement par le salaire, conçu tant comme le revenu du travailleur que comme indicateur de la position sur le marché du travail. D'un point de vue théorique, cette thèse s'articule autour de l'opposition entre les approches macro, centrées sur la comparaisons d'indicateurs nationaux d'inégalités, et les approches micro, centrées sur l'identification des facteurs de risques individuels. D'un point de vue méthodologique, les données SILC sont principalement utilisées, et la qualitative comparative analysis, la régression linéaire et la régression logistique sont les techniques principalement utilisées.Doctorat en Sciences politiques et socialesinfo:eu-repo/semantics/nonPublishe
The record of primitive IIE meteorites: Implications for the formation of silicate-bearing iron meteorites
No full textIron meteorites are Fe-Ni alloys that are thought to represent samples of the cores of differentiated asteroids. A minority of the iron meteorites contain silicate inclusions, the so-called silicate-bearing or non-magmatic iron meteorites. The presence of chemically evolved silicate inclusions in a high-density Fe-Ni metal raises questions about their origin. The IIE group belongs to the non-magmatic iron meteorites and contains primitive as well as evolved silicate inclusions. The object of this thesis is to investigate the formation processes of the silicate-bearing iron meteorites by examination of the primitive IIE irons. The first chapter provides an overview of the state of the art of silicate-bearing iron meteorites and highlights the existing open questions. The second chapter discusses the most important analytical techniques that have been used during this thesis. The third chapter contains all the research conducted on the Mont Dieu meteorite, a new primitive member of the IIE group. This meteorite represents a unique member of the IIE group as it contains chondrules in its silicate inclusions. Together with the Netschaëvo meteorite, they are the only two IIE irons that show such a primitive texture. Based on the mineralogy, the major element composition and the oxygen isotope composition, we conclude that Mont Dieu originated as an H chondrite. The observation of a series of features, including silicate darkening, thick metal veins containing angular clasts, and the need for a heterogeneous heat source, led to an impact-based origin for Mont Dieu. The fourth chapter is dedicated to the investigation of two samples of the primitive Netschaëvo IIE meteorite, that show lithologies that are very different to those described in the literature. The investigated pieces of Netschaëvo can be classified as impact melt rocks (IMR) and we show that the precursor material of these IMR and the primitive clasts both originated from the same parent body. The occurrence of both lithologies in the same meteorite suggests that Netschaëvo itself is a breccia containing metamorphosed and IMR clasts and that the meteorite formed as the result of an impact event. The fifth chapter focuses on the fine-grained matrix material found in the silicate inclusions of Netschaëvo IIE. This study provides insights into core-mantle boundary environments and confirms the impact-origin of Netschaëvo by the presence of minerals and textures pointing to a very rapid cooling. The investigations show that the re-partitioning of phosphorus from the metal into the silicate material during cooling might be a general process during planetary differentiation. In the sixth chapter, the veins present in the silicate inclusions of Mont Dieu are described in detail, and compared to the veining structures found in Techado IIE silicate. The characteristics of the processes causing the formation of these veins are discussed. The seventh chapter summarizes the conclusions of this thesis. The detailed petrographic and geochemical examinations conducted on the investigated samples show that collisions played a major role in the formation of the IIE iron meteorites. The work performed in the framework of this thesis provides a significant contribution towards a more complete and in-depth understanding of the formation mechanisms of silicate-bearing iron meteorites.Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe
Remote sensing of sediment characteristics from the noise field due to a moving ship
No full textQun-yan Ren received his Diploma in Electronic and Information Engineering, master degree in Underwater Acoustics Engineering both from Harbin Engineering University (HEU) in 2006 and 2009, respectively. Then he became a PhD student at the Environmental Hydroacoustics Laboratory, Ecole polytechnique de Bruxelles, Faculty of Applied Sciences, Universitie libre de Bruxelles (U.L.B.), Belgium, in co-tutelle with the National Key Laboratory of Underwater Acoustic Technology, HEU, China, under the co-supervision of Prof. Jean-Pierre Hermand and Prof. Piao Shengchun from U.L.B. and HEU, respectively. Since 2013, he became a full PhD student at the ULB. In Oct 2011, he obtained a four-year `Aspirantq{} grant from the Belgian National Fund for Scientific Research (F.R.S.-F.N.R.S.).Doctorat en Sciences de l'ingénieur et technologieinfo:eu-repo/semantics/nonPublishe
Les doubles minorités issues de l'immigration: Approche temporelle et dynamique de la construction identitaire et des processus d’acculturation
No full textLES DOUBLES MINORITES ISSUES DE L’IMMIGRATION :Approche temporelle et dynamique de la construction identitaire et des processus d’acculturationA travers les études présentées dans cette dissertation, nous avons mis en évidence l'impact du statut numérique des immigrés dans leur pays d’origine ainsi que celui de la gestion de la diversité culturelle au sein du pays d’origine, sur les processus d’acculturation des immigrés. Nos conclusions soulignent l’importance de considérer, dans les problématiques liées à l’acculturation des immigrés, l’influence du contexte social et politique précédant l’émigration. Nous rejoignons la vision que certains auteurs avancent sur les doubles minorités dans le pays d’accueil, les décrivant comme de nouveaux acteurs qui se réorganisent autour de leur identité ethnique d’origine distincte de l’identité nationale d’origine. Ces doubles minorités adoptent une attitude active de revendication mettant en avant leur situation au pays d’origine avec un discours victimaire et une remise en cause de la majorité du pays d’origine, accompagné d’un travail de lobbying dans le pays d’accueil (Ackermann, 2004 ;Atto, 2011) pour revendiquer les droits des minorités au sein du pays d’origine (Verkuyten & Yildiz, 2006). Nous relevons également la présence de stratégies acculturatifs proactives que les doubles minorités adoptent en fonction des attentes de la majorité d’accueil. Les résultats de cette dissertation sont mis en perspective avec les événements contemporains liés au Proche-Orient ;Les tensions entre Kurdes et Turques en Europe mais également entre ces deux communautés et les Chrétiens de Turquie ayant été victime d’un génocide. Plus récemment, l'émergence et les actions de « l’Etat Islamique » en Irak et en Syrie risquent de susciter des réactions de la part des différentes minorités du Moyen-Orient installés en Europe, amenant éventuellement à des tensions dans leurs relations réciproques.THE DOUBLE MINORITIES WITH A MIGRANT BACKGROUND :The temporal and the dynamics approach of identity constructionand acculturation processes Through the various studies presented in this dissertation, we highlighted the impact of both the numerical status of immigrants in their country of origin and the management of cultural diversity in their country of origin on the acculturation processes of immigrant populations. Our conclusions underline the importance of the social and political context preceding migration on the acculturation processes of immigrants. Arguing in favour of certain authors who have described immigrant populations as being new actors in their hosting countries that need to reorganise around their ethnical identity as opposed to their original national identity, these double minorities pursue an active attitude of demands, presenting their situation in their country of origin from a victim rhetoric and a questioning of the majority in their countries of origin, accompanied by an active lobbying in the hosting countries (Ackerman, 2004 ;Atto, 2011) in order to claim certain minority rights in their countries of origin (Verkuyten & Yildiz, 2006). We also focused on the presence of proactive acculturation strategies that double minorities tend to adopt in response to the expectations of the hosting majority. The results of this dissertation are put into perspective with contemporary events in the Middle East: the tensions between Kurds and Turks in Europe as well as tensions between both these communities and Christian minorities in Turkey, which have previously been victims of genocides. The recent actions of the Islamic State in Iraq and Syria will result in reactions of the different minorities from the Middle East settled in Europe leading to increased tensions in their reciprocal relations.Doctorat en Sciences psychologiques et de l'éducationinfo:eu-repo/semantics/nonPublishe
Synthèse et étude d'hétérostructures diélectrique/magnétique dans des membranes d'alumine nanoporeuse
Full text linkOver the last decade, the rapid development of nanotechnology has promoted the emergence of novel miniaturized devices based on nanoobjects, leading thus to an increased demand for new nanomaterials with different structures and improved properties. In this context of integration, extensive researches are focused on multifunctional materials such as multiferroic materials and in particular, magnetoelectric heterostructures that combine both ferromagnetic and ferroelectric materials with coupled properties through interfaces and strain effects. These nanomaterials are attractive due to the possibility to generate a spontaneous polarization or magnetization by an applied magnetic and electric field respectively.They are promising candidates for applications in microwave devices, chemical sensors, high density data storage devices, light emitters, etc. Magnetoelectric materials also provide tremendous attraction in biological and biomedical applications e.g. for hyperthermia processes used to treat cancer. Designing innovative architectures is thus a challenge in the field of magnetoelectric materials. In this thesis project, in order to promote theinterface coupling between ferroelectric and ferromagnetic phases, two strategies are followed for material design: i) 1-1 core-shell structure with ferromagnetic nanowires (1) inside ferroelectric nanotubes in a selfsupported tridimensionnal porous template (1) and ii) 1-3 structure where ferromagnetic nanowires (1) are supported on a substrate and embedded in a ferroelectric matrix (3).(FSA - Sciences de l'ingénieur) -- UCL, 2015Accès libre17/12/2015(FSA - Sciences de l'ingénieur) -- UCL, 2015Françai
Quality of life of persons living with HIV in Burkina Faso
No full textThe objective of our research was to assess the quality of life of persons living with HIV (PLWHIV) in Burkina Faso. Our research validated a tool to assess quality of life in the most spoken language in Burkina Faso, Moore. Studies conducted showed that symptomatic individuals and patients at the AIDS stage had a poor quality of life. Moreover, regardless of HIV status, the environmental domain recorded the lowest scores. During follow-up, deterioration in quality of life was observed in people not yet under treatment and those who perceived themselves as sick. PLWHIV highlighted elements which characterize their quality of life, such as health, feeding, employment, housing, marital status and the ability to overcome the HIV status in response to stigmatization. Improving quality of life of PLWHIV implies their empowerment through income-generating activities and their families’ involvement in their care.L'objectif de notre recherche était d'évaluer la qualité de vie des personnes vivant avec le VIH (PVVIH) au Burkina Faso. Elle a permis de valider un outil pour évaluer la qualité de vie dans la langue prépondérante, le Mooré. Les études menées ont montré que les individus symptomatiques et les patients au stade sida avaient une mauvaise qualité de vie. Quel que soit le statut VIH, le domaine environnemental a enregistré les plus bas scores. Au cours du suivi, il a été observé une détérioration de la qualité de vie des personnes non encore sous traitement et celles qui se voient malades. Les PVVIH ont relevé les éléments caractérisant leur qualité de vie :santé, alimentation, emploi, logement, état matrimonial et capacité à surmonter leur statut VIH. L’amélioration de la qualité de vie des PVVIH suppose leur autonomisation au travers d'activités génératrices de revenus et l’implication de leurs familles dans la prise en charge.(SP - Sciences de la santé publique) -- UCL, 2015Accès restreint16/12/2015(SP - Sciences de la santé publique) -- UCL, 2015Multilingu
La rencontre systématique en cancérologie :un outil clinique pour permettre à la demande d’émerger ?
No full textFollowing the increase number of patients with cancer, National Political Projects were created and contributed to the humanization of care in oncology by the commitment and training of psycho-oncologists. In the Cliniques universitaires Saint-Luc of Brussels, a psycho-oncology unit has been created, allowing better support of patients recently diagnosed with cancer. To optimize the psychological care, a systematic meeting with the psychologist was created within our institution. It is structured by three objectives: (1) present the psychological care, which is integrated in transdisciplinary support, (2) assess the needs, the level of distress and patients resources, and (3) allow the emergence of a demand for psychological support from patients. The main objective of this thesis is to evaluate the interest of a systematic meeting with a psycho-oncologist for recently diagnosed cancer patients. Through research conducted in cancer patients, we have assessed the impact of this intervention on the needs, the level of emotional distress (including anxiety and depressive symptoms) and coping strategies for patients. We also assessed the perception by patients of the clinical psychologist because the literature showed that fear of stigma is related with a possible barrier to psychological consultation. We thought that systematic meeting with the psychologist could promote demand of consultations from patients. The results of our studies have shown that patients were in favour of a systematic consultation with the psychologist, were satisfied with the meeting and were interested in sharing medical information. Moreover, women generally had a good perception of the clinical psychologist and required support as they deemed it necessary. When they met the psychologist systematically, they report a higher level of depression and developed more distractive and instrumental coping. Moreover, results showed that men had also a positive perception of the psychologist. Conversely, they requested psychological support only when they saw the psychologist. Systematic meeting also allowed men with cancer to report a higher level of distress. For these reasons, as the first interview with the psychologist seems to promotes psychological care we suggest that it could participle in the humanization of medical cares.(PSYE - Sciences psychologiques et de l'éducation) -- UCL, 2015Accès libre02/12/2015(PSYE - Sciences psychologiques et de l'éducation) -- UCL, 2015Multilingu
Special beer aging :contribution of oxidation related compounds and roasted-like phenols
No full textSince three decades, scientists have produced high amounts of literature on lager beer aging. Yet, our knowledge on top-fermentation beers behavior remains scarce. We started this study by the establishment of an overall picture of a panel of Belgian special beers. Esters, bringing nice freshness and fruity characters revealed quite stable in most beers, even after 12 months whereas a large variability of short chain fatty acid profiles emerged. Only isovaleric acid was found above its sensorial threshold, even after 2 years of aging. Study of theaspirane and sotolon, two unknown aromas for brewers although particularly relevant in oxidized beverages, were also investigated. For sotolon which emerged as responsible of the Madeira off-flavor found in some aged special beers, the key role of acetaldehyde, ascorbic acid and acetoin were highlighted. We also evidenced for the first time 6 interesting theaspirane oxidation derived compounds. Two of them revealed flavor-active: 4-hydroxy-7,8-dihydro-β-ionone exhaling a grenadine aroma and dihydrodehydro-β-ionone, with a nice Sauternes-like aroma (found under free and glucosilated forms in hop). The last part of the thesis was devoted to the torrefied character of Belgian brown beers through aging. Guaiacol and 4-methylphenol, two new markers of the use of torrefied malts, were found still more concentrated after aging, while vanillin displayed different patterns according to the type of beer. Vanillin, guaiacol and 4-methylphenol glucosides were evidenced for the first time in dark malts.(AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 2015Accès restreint18/09/2015(AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 2015Anglai
Expressive speech synthesis :research and system design with hidden Markov models
Full text linkWhile text-to-speech has long been centered on the production of an intelligible message of good quality, interest has recently shifted to the generation of more natural and expressive speech. This comes as an answer to the widespread criticism stating that current speech synthesizers lack fundamental human components. This thesis tackles that issue by considering three fundamental stages of HMM-based speech synthesis: the phonetic and prosodic annotations of the training corpus and their automatic alignment with the speech signal. We first propose a systematic step-by-step study of HMM-based phonetic alignment in which the models are directly trained on the corpus to align. Based on a detailed analysis of the errors made by this technique, we developed three fully-automatic improvement methods which are shown to significantly improve the alignment of highly variable and expressive corpora. We then define a two-level prosodic annotation of expressive corpora, describing accentual patterns and changes in speaking style. The integration of this manual annotation in the synthesis of sports commentaries positively impacts the naturalness of the expressivity. We also present an automatic annotator of accentual patterns in French and show that its integration in synthesis contributes to the naturalness of the voice. Finally, our study points out that the choice for phonetic variants in French is influenced by the speaking style and that their consideration in the synthesis of sports commentaries improves the naturalness of the message. It indicates that phonetic changes should be considered, both at training and synthesis stages.(FSA - Sciences de l'ingénieur) -- UCL, 2015Accès libre14/12/2015(FSA - Sciences de l'ingénieur) -- UCL, 2015Anglai
Multiscale modeling of the damage and failure of homogeneous and short-fiber reinforced thermoplastics under monotonic and fatigue loadings
No full textReinforced and unreinforced thermoplastic polymers (TPs) are widely used in a range of industrial sectors such as in automotive, aerospace, sporting goods, consumer electronics, and many other domains, because of their interesting properties and their relatively ease of production. Their behavior is rather complex as it is time, strain rate and temperature dependent and couples both viscoelastic and viscoplastic modes of deformation. As a result of their important expansion, produced parts are more likely to be subjected to extreme operating conditions such as fatigue, or exposed to aggressive environments. The effect of these demanding conditions is reflected in a degradation of the material’s mechanical properties throughout its lifetime, which is usually the cause of material failure. Hence numerical prediction tools for damage and failure are required, in order to obtain reliable estimates of the material response. The aim of this thesis is to numerically predict the damage and failure of both thermoplastic polymers (TPs) and misaligned short fiber reinforced thermoplastic polymers (SFRTPs), considered as heterogeneous materials mainly under mechanical fatigue loading with large number of cycles: high cycle fatigue (HCF). The modeling approaches take into account multiaxial stresses and the microstructure of the studied materials. To predict the effective response of the studied heterogeneous materials from their microstructure, multiscale approaches were employed. These approaches represent the modern way of modeling materials because they enable to understand, quantify and optimize the relationship between the final properties of a material or a part at the macroscopic scale and the microstructure. In the first part of this thesis, the focus is on the modeling of the behavior of unreinforced TPs, motivated by experimental observations showing the important role of the TP matrix in the behavior of the SFRTPs. In the second part some of the developed tools are applied to predict the fatigue behavior of the SFRTPs. A damage model, which takes into account the viscoelasticity coupled with viscoplasticity, was developed for homogenous TP materials. A key concept in the proposed approaches is that the damage and defects, causing TPs and SFRTPs failure under HCF, are localized at limited zones within the material, in agreement with experimental findings. Mean field homogenization techniques were developed and employed in order to take into account localized fatigue damage zones, the latter are modeled by so-called "weak spots", which are assumed to have a viscoelastic viscoplastic damaged behavior. The results of the different proposed modeling approaches were validated against available experimental results. For unreinforced TPs, the experimental data were collected from the open literature. However, for the SFRTPs, our partners in the EUREKA/DURAFIP project which aims at the lifetime investigation of short-glass fiber reinforced Polyamide 66, provided the experimental results of monotonic and fatigue tests.(FSA - Sciences de l'ingénieur) -- UCL, 2015Accès libre24/11/2015(FSA - Sciences de l'ingénieur) -- UCL, 2015Anglai