Title Promoter Affiliations Abstract "Integration of damping in wave based simulation models for mid-frequency vibro-acoustic analysis and design." "Wim Desmet" "Production Engineering, Machine Design and Automation (PMA) Section" "Growing customer expectations regarding vibro-acoustic performance together with more restrictive regulations on noise emission levels and human exposure to noise and vibrations, have forced design engineers to takethe vibro-acoustic behaviour of their products into account in the development process. Moreover, following the current ecological trends, lightweight designs are emerging to save material costs and to reduce fuel consumption. This may, however, lead to strongly deteriorated noise and vibration insulation properties. Machine and vehicle manufacturers face the challenging task to meet several, often conflicting, design requirements.Numerical prediction techniques allow the design engineer toevaluate the sensitivity of different parameters on the design criteria, and limit the need for time-consuming and expensive prototypes. Unfortunately, none of the currently available prediction techniques are capable of giving accurate predictions in the mid-frequency range, which is also the region where for many industrial applications the human hearing is most sensitive. At these frequencies, deterministic prediction techniques lead to unfeasible model sizes, and consequently calculation times,while statistical prediction techniques cannot be applied since the underlying assumptions are not yet met. The inclusion of lightweight poroelastic damping materials in vibro-acoustic models even further restricts the applicable frequency range of the classical deterministic predictiontechniques.This dissertation fits in the development of a deterministic Wave Based Method, which aims at accurately predicting the low and mid frequency response of steady-state dynamic problems. By approximating the dynamic field variables by a set of wave-like basis functions,an affordable procedure is obtained, allowing predictions up to higher frequencies as compared to conventional deterministic approaches. The method has shown its effectiveness and efficiency for bounded and unbounded acoustic, structural and vibro-acoustic problems.With the increasing importance of lightweight damping materials in mind, the current PhD project focuses on the extension of the Wave Based Method towards the Biot equations, which accurately describe the coupled dynamic behaviour of the fluid and solid phase of those materials. Efficient schemes areobtained for 2D Cartesian and axisymmetric problems. Whereas the formercan be applied for general problems, axisymmetric Wave Based schemes allow to model for instance an acoustic impedance tube in an affordable way.An important point of attention in the modelling of poroelastic materials, is the existence and treatment of singularities. Infinite values of solid stresses and fluid displacements can occur in the vertices of poroelastic problem domains. Physically, this is of course impossible, but due to linearisations in the theory of elasticity, singularitiescan occur in the mathematical model. The smooth wave-like basis functions have difficulties describing those steep gradients and as a result, the efficiency of the Wave Based Method deteriorates when singularities are present. This dissertation derives criteria to predict when singularities can be present in acoustic and poroelastic problem domains. Specialpurpose enrichment functions are included in the set of basis functionsto counter the adverse effect of singularities.The developed procedures are supported by a number of validation cases, illustrating theapplicability and the efficiency of the proposed approaches." "Investigation of the construction of integrating world views" "Diederik Aerts" "Centre for Logic and Philosophy of Science, French National Centre for Scientific Research, University of Bucharest, Vienna University of Technology, University of Twente, Roskilde University, Ohio State University, Western Sydney University, University of Science and Technology of China, Université catholique de Louvain, University of Leicester, KU Leuven, University of British Columbia, Ghent University, Universidad de Buenos Aires, Gdańsk University of Technology, Centre Leo Apostel" "The research planned for the new research community 'Research on the construction of integrated worldviews' is a continuation of the research within the former research communities (1995-2000, 2000-2005, 2005-2010). The new research community still uses as a framework the five main elements of a worldview. Research is planned to deepen the understanding of each of these key elements: (1) The construction of a model of the world: research into the nature and functioning of the world (A). (2) An explanatory model of the world: in addition to describing one also explains (A). (3) A value model of the world: how do we value the global reality (B). (4) An example of model construction: each model, albeit descriptive, explanatory or evaluative, implies a model structure (A, C). (5) An integrated action model: we are not only knowing, appreciative and emotionally involved in the world, but also active (B, C). (A) 'Quantum Structural Research and Modeling Scheme': Previous results have clarified how 'the influence of context and environment' and the non-classical, non deterministic, and/or non-Boolean structure of entities and processes from the domain of the social sciences can be studied by means of models that originate in the non classical (e.g. quantum) exact sciences. This is very similar to the 'complexity and chaos approach' of the eighties, where formal models of classical science were used to study entities and processes in the social sciences. However, complexity and chaos models are unable to model 'the influence of context and environment', since they arise from classical mechanical theories. The models in the new approach are non-classical, and therefore are able to describe the influence of context and environment in a natural way. In the new research community there will be a continuation of the 'Quantum Structural Research and Modeling Scheme' program, started in the foregoing five years of the research community, where it gave rise to 30 joint articles of which 17 in ISI Impact factor journals, and several workshops, conferences and symposia, and publications in proceedings and books. This research program is a collaboration between seven groups (i) CLEA (Diederik Aerts); (ii) CLPS (Erik Weber); (iii) QIEG (Marek Czachor); (iv) CCE (Liane Gabora); (v) EC (Graciela Domenech); (vi) QDTG (Emmanuel Haven) and (vii) QPQI (Jian-Wei Pan). The global research aim for the coming five years is to elaborate the 'quantum structural modeling scheme' - technically using the standard complex Hilbert space quantum formalism as well as the generalized SCOP formalism - and elaborate it into a complete theory, applying it in even greater detail to the modeling of human thought, the way conceptual structures are handled and decisions are made. And specifically extending its application to situations in economics (for this reason the new group QDTG, headed by Emmanuel Haven has been invited to join). We also intend to investigate semantic analysis theories, information retrieval techniques, and holographic reduced memory structures in further detail. We want to apply the insights gained to (re)consider well known problems in quantum structure research itself, more specifically the problem of contextuality and the problem of the description of compound quantum entities. Also the possibility of new experiments relevant for these problems of quantum physics will be investigated (for this reason the new group QPQI - a young Chinese top level experimental and theoretical quantum physics group, e.g. three publications in Nature in 2010 - headed by Jian Wei Pan, has been invited to join). The general methodology consists in working on two planes with continuous feedback from the one to the other, more specifically in: (a) elaborating further the structural and mathematical aspects of the formalism itself (SCOP and how complex Hilbert spaces are used), and (b) working out very concrete examples, usually with data sets of experimental results from the different fields of application; (c) putting forward concrete models applying the general theory for these data sets pertaining to the different fields of application. The global aim is to arrive at a general theory which introduces a fundamental new mathematical modeling of human thought and decision processes and which, unlike existing approaches, is realistic in that it allows modeling (i) the influence of context and (ii) the influence of the constant emergence of new concepts when the human mind engages in conceptual combinations; while this emergence has not been identified in existing approaches, it has been revealed experimentally, for example in the 'pet fish problem', the 'disjunction effect' and the 'conjunction fallacy'. (B) 'Identity, Boundary and Difference': The new research community continues also the research on 'Identity, Boundary and Difference' as research into the foundations of world views itself. This research program concerns a deep investigation into the difference between the self/same and the other. As a fundamental examination of the (implicit and explicit) materials of a worldview, it explores the genesis of identities and differences and their intersection. In a contemporary context, this means a philosophicalanthropological research into sense and meaning. This topic breaks down into four different projects to be conducted in collaboration between the Centre Leo Apostel, VUB and partners in Flanders as well as in the international sphere. 1. Starting from a reflection on the mechanism of experience and meaningfulness (as well as its deepening and broadening processes), the relationship between identity and citizenship will be explored. What dimensions of citizenship can be regarded as important sources of meaningfulness and a meaningful life within a late-modern, globalised society? Partnerships will be established with PRAGODI and CICI. 2. The contemporary body versus spirit debate will serve as a framework to examine how concepts in the area of awareness, the self and the body emerge as distinct notions and thus how identity is invested with meaning in the Western and in the indigenous Indian techno-scientific and medico-legal definitions of brain death and the related practice of organ acquisition. There will be close collaboration with CALC and CSCS. 3. Within a Sri Lankan context, research is conducted into how, as far as the need for food is concerned, the category of the person is being co-produced through an everyday combination of precarious life-sustenance and fragile relationality. This process highlights a self constituted in its dynamic relations, rather than a self which is singular. Close collaboration with CALC, IARA, LAAP, and ICES. 4. The fourth research project focuses on the context of globalisation and alterglobalisation, investigating the way in which identities of worldviews gain legitimacy in the contemporary global discourse. To this end, the implications of a philosophical meaning of the same or other ways of globalisation as a political moment will be examined. For this project, there will be collaboration with CCR and with DCS. (C) 'Knowledge, Technology and Culture': The third main research program on 'Knowledge, Technology and Culture' contributes to the normative dimension of the global worldviews project. This research program will expand on the work that has been done over the last ten years on 'knowledge and constructivism' and which has mainly concentrated on a radical constructivist account of how scientific knowledge emerges from human activity starting from the insight that cognitive systems are subject to evolutionary and ontogenetic development. Within the current program, this approach is broadened towards studying the co-evolution of knowledge, technology and culture from a number of different though interrelated perspectives: historical, philosophical and socio-political. This research program encompasses collaboration between CLEA, TRG, SSU, PMT, CDO, CTK, FEM, SPHERE, CLPS and CHS. The global research aim for the coming five years is the elaboration of an a-modern conceptual framework that, on the one hand thinks beyond one-sided instrumental techno-scientific and substantive social frameworks and, on the other hand attends to the concrete practices science and technology are involved in. In this respect, the postphenomenological perspective as developed by Don Ihde (TRG) and further explicitated by Peter-Paul Verbeek (PMT) in terms of the technological mediation of the co-constitution of subjectivity and objectivity presents a valuable and rich basis to explore more deeply the entanglements between the natural order and the social order, that is to say between the world of science and technology on the one hand and that of society and politics on the other. The insights gained will also be used in reconsidering the role of science and technology in the pursuit of sustainability, in this way contributing more concretely to the normative dimension of the global worldviews project. In practice, the 'knowledge, technology and culture' program will be further unpacked in four mutually complementary, interactive research tracks: (a) study the entanglement between scientific knowledge production and societal formations, with a particular historical focus on the concrete practices and experiments of science (CLEA, CHS, TRG, CTK, SSU, FEM, SPHERE, CLPS); (b) study how a typically modern interpretation of knowledge production, which resulted in the occultation of this entanglement, took shape in the early modern period (CLEA, CHS, FEM, SPHERE); (c) study the entanglement between humans and technology, with a particular focus on the social and cultural roles of technology and the ethical and anthropological aspects of concrete human-technology relations (CLEA, TRG, PMT, SSU); (d) study the evolution of socio-technical formations (such as systems of mobility, housing and feeding) with a particular focus on developing entry points for actively steering or influencing this evolution in more sustainable patterns (CLEA, PMT, CDO, SSU, CHS, CTK)." "The origin, development and standardization of the medieval historia in the Low Countries (10th-14th centuries): a contribution to the repositioning of chant in Early Music historiography." "Mark Delaere, David Burn" "Musicology, Leuven" "1 A challenge to Early Music historiography (Middle Ages end of the Ancien Régime) Chant (Gregorian chant, plainchant) is traditionally considered to be a repertory that originated in the early Middle Ages, that was consolidated by the Carolingian and Ottonian era, and that was transmitted more or less unaltered through the following centuries. As a result, the traditional understanding of chant in Early Music history is mostly restricted to the repertory of the so-called vieux fonds (up to c. 1000 AD). In contrast to this traditional view, a number of important chant genres emerged from the 10th century on. The continued addition of new feasts to the liturgical calendar occasioned the composition of new music (not only polyphony, but important works of chant as well), in genres such as the hymn, prosula, sequence, trope and new office chant (historiae). Examples include Gottschalks sequence for the feast of the Divisio apostolorum (11th century), the historia Regali natus for the canonization of Charlemagne (12th century), and Fernando de Talaveras historia for the liberation of Granada in 1492. Indeed, the composition of new historiae persisted until the 17th century. The emergence of these new chant genres undermines the traditional historiography of Early Music. As a consequence, the traditional view of the liturgical music of the Ancien Régime (the Middle Ages and Renaissance in particular) is distorted: it strongly emphasizes polyphony, but almost ignores the later developments in chant, and the novelty, quality and quantity of particular genres. Redressing the balance between plainchant and polyphony in Early Music history thus constitutes a major challenge to musicologists. The historia offers ideal material with which to address this challenge. It was the most important new chant genre in the Low Countries, and may be considered as the most representative genre of sacred monophony by virtue of its wide dissemination across Europe, as well as the quality and quantity of music in preserved sources. The present research project will demonstrate that the Low Countries prominence, productivity and European influence in historia composition occupied a place in musical life that is fairly comparable to that of Renaissance polyphony a number of centuries later. To bring this challenge to a good end, the traditional methods of analysis are not sufficient. In order to come to a full musical understanding of the historiae, the proposed research demands complementary and innovative methodologies, which will contribute to a new and integral view of Early Music history and analysis. 2 The study of historiae The designation historia refers to a liturgical office for a saint or another feast, such as Trinity or Corpus Christi, in which the narrative lessons (for Matins) and the antiphons and responsories tell a story, written in prose or in poetry. From the 10th to the 14th century, composers of historiae developed procedures and techniques that became characteristic of the genre, such as specific types of rhyme, verse and meter, a stricter modal organization and specific melodic goals. From the 10th century on, the heartland of historia composition was northern France and the Low Countries (including Liège). Music-historically, these historiae are important for many reasons. They are among the earliest musical compositions that can be reliably dated and attributed to a specific composer. A significant number of compositions from the Low Countries were disseminated throughout Europe (Stephen of Lièges historia for the Trinity, the historiae for Corpus Christi, Sts Servatius, Livinus, Maternus). Among medieval chant genres, the historia was undoubtedly the most elaborate (an average historia contains 40 to 50 sung items) and the one with the highest rate of production. Manuscripts and documentary sources confirm both the high artistic quality of the historiae (such as the early historiae from Ghent, Liège, Echternach, and Maastricht) and their continued composition from the 10th to at least the 17th century (e.g. the late historia for St Bavo in Haarlem/Ghent). Moreover, these sources survive in impressive numbers: research preliminary to this project has thus far yielded a checklist of more than 250 antiphoners (the most important source for historiae) from the Low Countries. As the number of historiae increased, finally, the genre was documented and commented upon by the most influential liturgists, such as Durandus of Mende (13th century) and Radulphus de Rivo (1403). Despite its richness and importance, the genre of the historia not only lacks a place in the broader history of music, but also in the history of chant and in the history of music in the Low Countries. Audas study of the three historiae by Stephen of Liège (1923) is outdated, and the work of later scholars often covers individual historiae only. While leading chant scholars have worked on historiae from Germany (Hiley, Hankeln), England (Hughes) and France (Goudesenne), and by single composers (Chartier on Hucbald), the contribution of the Low Countries to the genre has not yet been studied systematically (Hagghs work on the saints' offices of Ghent being a singular exception). Cantus Planus, the chant study group of the International Musicological Society (IMS), has set up a series of critical studies and editions, entitled Historiae, enabling major progress in the field; in this series, however, historiae from the Low Countries are not represented. Thus, even though international interest in the historia is growing, the genre and its sources in the Low Countries have been unjustly neglected. Therefore, the present research project will provide a detailed assessment of the origin, development and standardization of the historia in the Low Countries. 3 Methodology Given the very large dimensions of the entire repertory, four representative case-studies are proposed, allowing investigation of the chronological and geographical evolution of the genre. Since some of the earliest historiae were composed in the Low Countries and the composition of historiae reached an undisputed peak in production between the 10th and the 14th centuries, these elements offer a logical geographical and chronological demarcation. Consequently, the focus of the four case-studies is on the earliest, formative and most productive period of the genre in the Low Countries (after the 14th century, most historiae were contrafacts, parodies, or compilations of older chant). Moreover, the four selected historia-studies are differentiated regarding the types of communities and institutions they represent, their respective sociological backgrounds and relationships to (political) power and influence. In order to make the position, contribution and influence of historiae from the Low Countries in a European context clearly visible, the genre will be studied from a comparative point of view. Indeed, the development of historiae is not simply a local phenomenon, but one which invites comparison of their evolution in the Low Countries to that in other European regions, most importantly the adjacent countries. Furthermore, the analysis of the selected historiae will make full use of the tools that have been developed hitherto in chant scholarship. These include, on the one hand, textual analysis of meter, rhythm, and dependence on Latin vitae or other hagiography, and, on the other hand, musical analysis of modal order and melodic construction. However, as mentioned above, the project also proposes the introduction of new methodologies to complement those that already exist. More precisely, it is necessary to adopt an innovative approach to the following three important parameters of chant: modality, the notions of genre and style, and the interpretation of musical context. First, the modal construction of the historiae is the outcome of a decision made by a composer, not of a gradually evolving chant tradition, as was the case in the vieux fonds. An analysis of historiae that wants to avoid anachronisms must take into account such a major change in musical culture, as it throws a different light on the older historiography of chant dialects (such as the East- and West-Frankish variants) and reforms (such as the Cistercian reform). Second, the increasing standardization of the genre and the corollary changes in use of melody and modality led to a new style of historia chant, one that sometimes shared features with genres that were subject to a similar standardization, such as the sequence and the hymn. As new sequences and hymns became necessary for the celebration of a new feast, they were mostly composed together with the new historia, in a related style. The study of this process of standardization will therefore have to distinguish between genre-specific features that remained intact, and stylistic features that were common to historiae, sequences and hymns in the new style. Third, a full understanding of historiae requires an assessment of the historical and cultural contexts in which they functioned. More precisely, the performance context of historiae will be considered: historia chants were not only sung in their proper (primary) settings of the liturgy of the hours, but were also performed in the secondary settings of processions and commemorations. These secondary settings involved a deliberate selection of chants, with selective repetition as a result. Such use of chant promoted civic and religious awareness, as well as community identity." "Rigidity and conservation laws of Hamiltonian partial differential equations in hyperkähler Floer theory." "Fundamental Mathematics" "Named after the Irish physicist, astronomer, and mathematician W. R. Hamilton (1805-1875), Hamiltonian systems are an important class of dynamical systems with certain conservation laws and rigidity features. A well-known classical example is the n-body problem (`movement of the planets around the sun'). In fact, Hamiltonian systems appear in many shapes throughout mathematics, physics, chemistry, biology, and engineering.Classical Hamiltonian problems are formulated as systems of ordinary differential equations on finite dimensional spaces. Nevertheless, there are also equations that can be reformulated as Hamiltonian systems, but this time on infinite dimensional spaces. Such systems are called Hamiltonian partial differential equations, in short Hamiltonian PDEs. Examples are the Korteweg-de Vries equation, the Sine-Gordon equation, the nonlinear Schrödinger equation, nonlinear sigma models etc.This project has two main aspects: - On the one hand, we start with a `triholomorphic' Dirac-type equation on a so-called hyperkähler manifold that can be transformed into a Hamiltonian PDE on the infinite dimensional loop space of the manifold, and then studies conservation laws, integrability (`extra symmetries'), and features from modern symplectic geometry (`non-squeezing' properties, symplectic capacities etc.) of this Hamiltonian PDE. - On the other hand, we investigate the occurrence and bifurcation behavior of singularities with hyperbolic components in 4-dimensional integrable Hamiltonian systems and classify the associated fibers." "Classification, symmetries and singularities at the frontiers of algebra, analysis and geometry." "Stefaan Vaes" "Mathematics, Kulak Kortrijk Campus, Algebra, Analysis, Geometry" "The main goal of this Methusalem research program is to bring together KU Leuven's leading researchers in pure mathematics to focus on some of the most challenging problems in algebra, analysis, and geometry, and their numerous interactions.This Methusalem research program has the following main goals:Algebraic geometry. The goal is to uncover geometric properties of solution sets of algebraic equations. Combining different methods from arithmetic and algebraic geometry, we study problems in number theory, singularity theory and the birational classification of algebraic varieties, with a special focus on Calabi-Yau varieties and motivic integration.Classical analysis. This part centers around eigenvalue distributions of random matrices. The main goal is to exhibit universality phenomena in the local eigenvalue correlations of large random matrices.Differential geometry. We construct global, group-like objects associated to infinitesimal geometric structures such as singular foliations or Poisson spaces. The goal is to exploit the algebraic properties of the former to study the symmetries of these singular spaces.Functional analysis. The dynamic and ergodic properties of discrete groups and their actions on probability spaces are captured by the associated algebras of operators on a Hilbert space. The main goal is to classify these von Neumann algebras coming from the free groups or from lattices in Lie groups.Group theory. Infra-nilmanifolds are geometric objects that arise naturally in topology and dynamical systems. We study their geometric and topological properties through their associated nilpotent Lie algebras, resulting in applications for fixed point problems." "Variations on Component-by-Component Construction Algorithms of Lattice Rules" "Dirk Nuyens" "Numerical Analysis and Applied Mathematics (NUMA), NUMA, Numerical Analysis and Applied Mathematics Section" "In the conducted research we develop efficient algorithms for constructing node sets of high-quality quasi-Monte Carlo (QMC) methods which can be used for approximating high-dimensional integrals of multivariate functions. In particular, we study the construction of rank-1 lattice rules and polynomial lattice rules, which are both specified by a generating vector, for numerical integration in weighted function spaces such as Korobov, Sobolev and Walsh spaces. The obtained construction schemes are mainly greedy algorithms which generate QMC point sets that, as we demonstrate, achieve optimal error convergence rates in the respective function spaces. We show that under certain conditions on the weights, which are incorporated in the definitions of the considered function spaces, the obtained error estimates become independent of the dimension, and thus the integration problem becomes tractable. Furthermore, we derive fast implementations of the numerous construction algorithms and confirm our theoretical findings with numerical results and experiments. As an application, we investigate one of the considered algorithms for the construction of QMC finite element methods for a class of elliptic PDEs with random diffusion coefficients and carry out a combined error analysis.   " "Microstructural Analysis and Mechanical Behaviour of Bamboo Fibres and Bamboo Fibre Composites" "Ignace Verpoest" "Structural Composites and Alloys, Integrity and Nondestructive Testing, Structural Composites and Alloys, Integrity and Nondestructive Testing (SCALINT)" "Among natural fibres, bamboo fibres are an ideal option to reinforce polymers in the new era of sustainable materials, thanks to their availability and singular characteristics. Moreover, bamboo plants have always been present in many cultures around the world, and they have played an important role for the local economy where they grow.In order to make an adequate use of this new material as reinforcement for composites, it is indispensable to fully evaluate the fibre mechanical properties and get a complete understanding of its behavior in function of the microstructure, as well as to study the effect of severe conditions, like the presence of moisture, on the mechanical behaviour of bamboo fibres and bamboo fibre composites. These are the two main topics that will be presented in this doctoral thesis.In a first stage of the research, (tensile) mechanical properties have been studied at four different span lengths to determine the fibre quality after the extraction process and the mechanical performance of the material. The tensile strength has a small variation at the different span lengths and remains around 800 MPa. This indicates that the extraction process did not significantly affect the fibre quality. The Young’s modulus is around 43 GPa. Bamboo fibre composites were also produced using untreated and chemically-treated fibres to evaluate the effectiveness of the reinforcing material. Good results were achieved with untreated fibres in epoxy resin.The morphology of technical bamboo fibre and the microstructure of the elementary fibre have been observed and examined by using different techniques applied in the study of wood anatomy. Observations have provided us with a vast knowledge of the complex microstructure of this natural fibre from the macro down to the micro scale level, where different features like the distribution of the elementary fibres within the fibre bundle, dimensions and the layering pattern of the elementary fibres and the main microfibril angles could be measured. This information allows further selection of fibres based on growing conditions, location in the culm, etc.The mechanical properties such as strength and Young’s modulus of the elementary fibre were calculated using a novel approach that combines the micromechanics of composite materials, commonly used for unidirectional short fibre composites, and the fibre microstructure. The estimated Young’s modulus of the elementary fibre is 50 GPa and the tensile strength 1150 MPa for an aspect ratio (length/diameter) larger than 38. Also, the failure modes of single fibres after tensile testing are analyzed by microscopic observations, to have an indication of the stress development in the elementary fibres and the different failure mechanisms.The impact of moisture on the mechanical properties of bamboo fibres was studied focusing on the effect of different humidity levels. Due to high variation in the obtained results, it was difficult to get statistically significant results. Nevertheless, the fibres are influenced by the humidity treatment. It was found that an increase in moisture level induces an increase in ultimate strain. Increase in humidity changes the fibre behaviour from a brittle behaviour to a more ductile behaviour. Remarkably, the fibre modulus hardly decreases at high humidity.To verify the effect of moisture on the mechanical properties of bamboo fibre composites, unidirectional composites were acclimatized to extreme humidity conditions. While the mechanical properties of the individual fibres did show little impact by the humidity, the bamboo fibre composites were more influenced when they were acclimatized. A high humidity level induces plasticization in the composite. Also there is a significant increase in strength due to the presence of moisture.During the preparation of bamboo fibres to be used as reinforcement in polymeric matrices, the fibres are exposed to different humidity states. It is therefore necessary to study the effect of these changes of humidity on the mechanical properties of the fibres. The effect of harsh wetting and drying cycles on bamboo technical fibres was investigated. Technical fibres were subjected to three, eight and thirteen cycles of wetting and drying. Tensile test results did not show a significant decrease of Young’s modulus, irrespective to the amount of cycles. On the other hand, a slight decrease (-10%) in tensile strength was observed as the fibres were subjected to longer cycling conditions. This slight decrease has a linear tendency. It is thus advised to prevent the technical fibres from wetting/drying conditions as much as possible to prevent irreversible damages in the fibre structure.Five samples of cross-ply bamboo/epoxy composites were kept in environmental conditions and five samples were subjected to three wetting/drying cycles. No significant influence of moisture on mechanical properties was observed compared to untreated composites. SEM images of the cross-ply composites’ surfaces show brittle fracture surfaces. This can be explained thanks to the good bonding between the epoxy resin and the bamboo fibres. It was observed that the cracks are more prone to propagate through the technical fibres, hence following the middle lamellae, rather than through the interface.The last part of the research was focused on the study of the transverse tensile and off-axis behaviour of unidirectional bamboo fibre composites, where the fibres were placed at a defined angle (30, 45, 60 and 90 degrees). The calculated value of the transverse tensile modulus of bamboo fibre is close to the modulus of the neat resin. As is the case for other unidirectional fibre composites, the composite Young’s modulus was affected when the fibres were not placed in the load direction. Results indicated the high anisotropy of bamboo fibres which is a common characteristic for natural fibres. Also, the composite shear modulus was estimated based on the relationship between off-axis Young’s modulus, and the principal properties of a 2-D composite ply.In conclusion, the results obtained during this doctoral research allowed us to confirm that bamboo fibres have adequate technical characteristics to be used as reinforcement in different composite applications, and are an actual alternative to other natural and synthetic fibers, currently used in the composites industry. In addition, the development of bamboo fibres can not only contribute to valorise the abundant natural resource but also, to stimulate the correct exploitation and management of bamboo plantations, which can have positive social, environmental and technological impacts.     " "Arc spaces and contact loci of hyperplane arrangements" "Nero Budur" Algebra "In this thesis we study the contact loci and restricted contact loci of hyperplane multi-arrangements. We decompose any contact locus of a hyperplane multi-arrangement into connected components, each component is the complement  of a hyperplane arrangement. Based on this, we give an explicit expression for their cohomology rings and show that they are combinatorial invariants. We compute the naive motivic zeta function of any hyperplane multi-arrangement and express it as a rational function, without using resolution of singularities.We also give a decomposition into connected components for any restricted contact locus, where each component is the Milnor fiber of an associated hyperplane arrangement. Additionally, we prove the degeneracy of a spectral sequence related to the restricted contact loci of a hyperplane arrangement and which conjecturally computes algebraically the Floer cohomology of iterates of the Milnor monodromy. We also give formulas for the Betti numbers of contact loci and restricted contact loci in generic cases." "Bridging the gap: Linking noticing and the implicit L2 acquisition of grammatical subregularities in a natural second language." "Alex Housen" "Language and literature" "While some researchers have claimed that, compared to children, adults have a reduced ability or are incapable of learning language unconsciously (implicitly), studies using artificial languages have shown that adults can acquire grammar rules implicitly, provided they receive ample language input. This project extends the latter line of research by investigating whether these findings also hold when a purely natural language (German) is used. In addition, we link the question of implicit learning with that of noticing the gap, that is, the conscious registration of a mismatch between the learner’s interlanguage form (eg. *the sheeps) and the input target form (eg. the sheep). L2 German learners of intermediate to advanced proficiency level will take part in two experiments targeting a stem vowel change (eg. sprechen > spricht) in strong German verbs. The first experiment measures the learners' ability to perceive the stem-vowel change in spoken input when production data suggest this form is not fully acquired yet. The second experiment, which involves the same participants and takes place one year later, tests participants’ ability to use the stem vowel as a cue to grammatical number (singular or plural) during real-time listening. By combining performance data on both tasks, we can study whether noticing the gap (experiment 1) functions as a precursor to learning (experiment 2) and integrate these two distinct lines of research in the literature."