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See detailNonlinear analysis of compliant deployable structures: modelling, simulation and experimental validation
Dewalque, Florence ULiege

Doctoral thesis (2017)

Compliant mechanisms are flexible components which can store elastic energy when deformed and then passively release it to produce a motion. Their scope of applications encompasses various domains from ... [more ▼]

Compliant mechanisms are flexible components which can store elastic energy when deformed and then passively release it to produce a motion. Their scope of applications encompasses various domains from robotic orthoses to microscopes and grippers. In this work, the developments focus on compliant mechanisms called tape springs used in deployable space structures. Tape springs, due to their autonomous deployment capacity from a compact folded configuration, their high stiffness in the deployed equilibrium state and their simplicity of integration, represent efficient alternatives to common motorised hinges for space applications. Thus, they are currently used to deploy appendices on satellites such as solar panels or telescopes and are considered as valuable components in the design of future applications such as solar sails, deployable optics and inflatable structures. However, their structural behaviour is highly nonlinear and quite sensitive to the design parameters and to the various constraints encountered on Earth and in a space environment. The objective of this thesis is thus to develop validated high-fidelity dynamic models of tape springs which can be used to support the design process. The methodology involves the development of advanced finite element models and experimental tests based on an original set-up. First, a quasi-static model based on shell finite elements is established and used to investigate the nonlinear response of tape springs as well as the influence of various geometric parameters. This model is then exploited for the design of tape springs deploying a reflector based on an automatic optimisation procedure. The study is further extended to dynamic analyses, which are characterised by a self-locking of the tape springs in their final deployed configuration. In order to accurately capture these phenomena, the importance of a suitable representation of the physical structural dissipation in the model is demonstrated and, for metallic tape springs, a Kelvin-Voigt model is retained. An experimental set-up is then designed in order to validate the model and its capacity to represent the nonlinear phenomena inherent to tape springs which occur during quasi-static and dynamic tests. The experimental data are acquired by the means of an innovative 3D motion analysis system and a force plate. The reproducibility of the tests is assessed and a procedure, involving several elementary tests, is proposed to identify the parameters of the finite element model, in particular, the structural damping. In the end, a fair correlation between the experimental and numerical results is achieved. The proposed methodology, which relies on numerical and experimental methods, thus leads to a dynamic model of tape springs which can be used to predict their behaviour in various conditions. [less ▲]

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See detailThe acoustic correlates of hypnotic voice
Remacle, Angélique ULiege; Todovora, Tatiana; Zambra, Nurihan

Poster (2017, August 31)

Although the linguistic content of hypnotic suggestions has been investigated in various studies, the paralinguistic aspects – that is, the voice used by hypnotherapists – are little described. The few ... [more ▼]

Although the linguistic content of hypnotic suggestions has been investigated in various studies, the paralinguistic aspects – that is, the voice used by hypnotherapists – are little described. The few indications concerning vocal patterns that promote a state of hypnotic trance are limited to subjective descriptions based on clinical observations, as reported in textbooks (Grinder & Bandler, 1997; James, 2010). From an empirical point of view, voice characteristics have been assessed objectively with acoustic measures in the context of muscle relaxation (Knowlton & Larkin, 2006); however, to the best of our knowledge, such measures have not been applied to identify vocal indices of the voice used to induce hypnosis. The aim of this study is to investigate the existence of a voice pattern specific to hypnosis. To that end, 32 French-speaking therapists (18 women and 14 men) who practice hypnosis in a medical or psychological context were recorded while reading a single text in two conditions: with a normal voice and with a voice used for hypnotic induction. For each of these two conditions, the following acoustic analyses were conducted with Praat software: degree of voicing (in %), mean fundamental frequency (F0, in Hz), mean sound pressure level (SPL, in dB), and variability of F0 and SPL. Statistical analyses (Wilcoxon test) show that, compared to a normal voice, a hypnotic voice presents less voicing (p<.001), lower F0 and SPL (p<.001), less SPL variability (p=.003), and a trend toward less F0 variability (p=.056). These preliminary results allow us to provide objective acoustic correlates of a hypnotic voice, such as low frequency, low intensity, monotone and lack of voicing. These acoustic characteristics correspond to the subjective voice descriptions given in textbooks, such as quiet, gentle, reassuring, and warm, which tend to create a sense of intimacy and confidentiality. Regarding the lower degree of voicing in hypnotic voices, subsequent analyses will make it possible to test the hypothesis that the voice is breathy and whispery, at least at times, and that there are longer pauses than in a normal voice. Analyses of spontaneous speech during hypnosis sessions are currently under way to test the generalizability of the results presented here. References -Grinder, J., & Bandler, R. (1997). Patterns of the hypnotic techniques of Milton H. Erickson, M.D. Vol. I. Portland, OR: Metamorphous Press. -James, U. (2010). Clinical hypnosis textbook: A guide for practical intervention (2nd ed.). Oxford, UK, New York: Radcliffe Publishing Ltd. -Knowlton, G. E., & Larkin, K. T. (2006). The influence of voice volume, pitch, and speech rate on progressive relaxation training: Application of methods from speech pathology and audiology. Applied Psychophysiology and Biofeedback, 31(2), 173–185. doi:10.1007/s10484-006-9014-6 [less ▲]

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See detailVoice use among music theory teachers
Schiller, Isabel ULiege; Morsomme, Dominique ULiege; Sfez, Lou et al

Conference (2017, August 30)

In Belgium, there is a particular group of music teachers referred to as music theory teachers. Working at music schools, they convey theoretical knowledge and practical musical skills to groups of ... [more ▼]

In Belgium, there is a particular group of music teachers referred to as music theory teachers. Working at music schools, they convey theoretical knowledge and practical musical skills to groups of individuals who learn music during their free-time. Even though music theory teachers use both speaking and singing voice intensively at work, little is known about their voice use profiles. This study investigated the vocal loading among French-speaking music theory teachers. Objectives were (1) to describe their professional and extra-professional vocal loading, (2) to determine the relationship between vocal loading and background noise level and (3) to investigate whether objectively measured vocal loading is reflected in music theory teachers’ auto-evaluation of their voice. Using voice dosimetry, 13 music theory teachers were monitored for one workweek. Parameters analysed were F0, voice sound pressure level (SPL), phonation time, vocal loading index (VLI) and background noise SPL. At the end of each monitoring day, subjects self-assessed their voice use by means of visual analogue scales. Results revealed (1) significantly higher vocal loading in the professional context than in the extra-professional context, (2) significant positive correlations between background noise level and the parameters F0, voice SPL and phonation time and (3) significant correlations between the VLI and auto-evaluation data (e.g. voice quality and vocal fatigue). These results highlight that teaching music theory is a profession with high vocal demands. At work, music theory teachers are exposed to high background noise, which seems to influence their voice use and may potentially contribute to the development of voice problems among this population. Visual analogue scales provide a promising tool to subjectively investigate vocal loading among music theory teachers. [less ▲]

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See detailEvidence-Based Practice Applied To Voice Therapy
Morsomme, Dominique ULiege

Conference (2017, August 30)

Voice therapy supports dysphonic patients. To rehabilitate the dysphonic patient, each voice therapist uses different exercises. These exercises are mostly described in books, which offer a step-by-step ... [more ▼]

Voice therapy supports dysphonic patients. To rehabilitate the dysphonic patient, each voice therapist uses different exercises. These exercises are mostly described in books, which offer a step-by-step acquisition model of the required vocal motor gesture and propose techniques of voice rehabilitation. However, the same technique can cover different therapeutic aspects. Van Stan et al. (2015) recently suggested a taxonomy to clarify therapeutic programs, detail their content and classify them according to their direct intervention category (auditory, vocal function, somatosensory, musculo-skeletal, and respiratory). Sensitize the patient to vocal hygiene, teach the basics of respiratory support, adjust the subglottal pressure, encourage vocal placement in the resonators, replace the wrong motor gesture with another healthier, controlling glottal attacks are the rehabilitation principles basics for voice disorders. All exercises are generally based on raising awareness of both inadequate and adequate vocal gesture by increasing proprioception. The final goal is that the patient gradually regains control over his vocal gesture. To ensure the best treatment to the patient, our approach must rely on the evidence based practice (EBP) principles. The questions we must ask ourselves as clinician are: Which voice techniques, for which patients, with which diagnoses, in what environments, with what effectiveness? This workshop attempts answering the question: how can a voice therapist implement EBP in his clinical practice in order to ensure the best treatment to his patient? To illustrate the process, I opted for a therapeutic approach that has been questioned: manual therapy adapted to voice therapy. I will address the notion of therapeutic efficiency of the manual therapy in the light of the scientific literature, knowing that level 1A or 1B studies on the classification of evidence levels are rare in the field of vocology (Benninger, 2011). To end the workshop, I will present short video sequences of voice therapy with three patients and their therapist who have kindly accepted to be filmed during their sessions. These sequences illustrate how manual therapy is implemented in the treatment of these patients who suffer from presbyphonia, muscle tension dysphonia and nodules respectively. [less ▲]

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See detailEnjeux de la notion de genre en sémiotique
Badir, Sémir ULiege

in Semiotica (2017)

What is a genre? Applied to the textual domain, this question has received a descriptive answer in language studies. Genres would thus be dis- tinguished from one another through formal (syntactic and ... [more ▼]

What is a genre? Applied to the textual domain, this question has received a descriptive answer in language studies. Genres would thus be dis- tinguished from one another through formal (syntactic and lexical) traits and specific enunciative markers, as well as through the specificities of punctuation on the layout. Such response presupposes a global model where genres assem- ble texts (that actually undergo analysis) and are in turn integrated into dis- course. I question this model in the name of empiricism: genres, as governed by usage, do not allow for such integration. Genres are heterogeneous by nature and their description cannot be rigid. The reason is that genres are a product of a certain type of interpretative practice of texts and, beyond texts, of all sorts of works. The aim of this study is to show how genre is the categorization that corresponds to a hermeneutics of appropriation and, in this sense, is reluctant to being disclosed through a formal description. Greimas seems never to have doubted this, since his semiotic project was precisely centered in the neutraliza- tion of generic categories. [less ▲]

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See detailIdeal future dairy farm: a Walloon breeders’ point of view
Dalcq, Anne-Catherine ULiege; Soyeurt, Hélène ULiege; Dogot, Thomas ULiege et al

Conference (2017, August 30)

This research aims to characterize the dairy breeders regarding their idea of the ideal future farm ensuring them an income, in order to highlight their present situation and the ways to advise them ... [more ▼]

This research aims to characterize the dairy breeders regarding their idea of the ideal future farm ensuring them an income, in order to highlight their present situation and the ways to advise them towards their wished dairy model. The 245 answers to a survey of breeders, conducted between November 2014 and February 2015 provided information about, amongst others, their wishes concerning the intensification, the specialization, the technological innovation, the kind of workforce, structure, market and milk production (standard vs. differentiated quality milk). Based on this information, a Multiple Correspondence Analysis allowed to create 4 groups of breeders with a similar view of their ideal farm: global-based intensive (GBIb), local-based extensive (LBEb), intermediate and no-opinion breeders. The relationships between these groups and the other recorded qualitative variables as formation needed, obstacles and advantages of breeders organization, of diversification and so forth w ere studied using Chi Square tests and Correspondence Canonical Analysis. A moderate link was observed between the ideal future farm and the current situation of the respondent. This suggested that not all the breeders were in the production system that they considered as most profitable. As a brake to the transformation and diversification, GBIb tended to be more numerous to speak about the uncertainty of the customer loyalty (p-value = 0.07) and LBEb pointed out the size of the investments (p-value = 0.05). LBEb asked more for administrative (p-value = 0.04) and transformation and diversification formations (p-value = 0.03) while GBIb looked more for finance and management formation (p-value = 0.02). In conclusion, there were different ideal dairy farm models considered by the breeders. Their needs were not similar and indicated which tools must be developed and which domain must be studied to support them. [less ▲]

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See detailEvaluating Model Simulations of Twentieth-Century Sea Level Rise. Part 2: Regional Sea-Level Changes
Meyssignac, B.; Slangen, A.; Melet, A. et al

in Journal of Climate (2017), in press

Twentieth century regional sea-level changes are estimated from 12 climate models from the 5th phase of the Climate Model Intercomparison Project (CMIP5). The output of the CMIP5 climate model simulations ... [more ▼]

Twentieth century regional sea-level changes are estimated from 12 climate models from the 5th phase of the Climate Model Intercomparison Project (CMIP5). The output of the CMIP5 climate model simulations were used to calculate the global and regional sea-level changes associated with dynamic sea level, atmospheric loading, glacier mass changes and ice sheet surface mass balance contributions. The contribution from groundwater depletion, reservoir storage and dynamic ice sheet mass changes are estimated from observations as they are not simulated by climate models. All contributions are summed, including the GIA contribution, and compared to observational estimates from 27 tide gauge records over the twentieth century (1900-2015). We find a general agreement between the simulated sea level and tide gauge records in terms of inter-annual to multi-decadal variability over 1900-2015. But climate models tend to systematically underestimate the observed sea-level trends, particularly in the first half of the 20th century. The corrections based on attributable biases between observations and models that have been identified in the part-1-paper, result in an improved explanation of the spatial variability in observed sea-level trends by climate models. Climate models show that the spatial variability in sea-level trends observed by tide-gauge records is dominated by the GIA contribution and the steric contribution over 1900-2015. Climate models also show that it is important to include all contributions to sea-level changes as they cause significant local deviations; for example, the groundwater depletion around India which is responsible for the low 20th century sea-level rise in the region. [less ▲]

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See detailMultiple Uses of a 3D Point Cloud: the Castle of Franchimont (Province of Liège, Belgium)
Luczfalvy Jancsó, Andrea ULiege; Jonlet, Benoît ULiege; Hallot, Pierre ULiege et al

Poster (2017, August 29)

This poster presents the identified obstacles, needs and selected solution for the study of the medieval castle of Franchimont, located in the province of Liège (Belgium). After taking into account the ... [more ▼]

This poster presents the identified obstacles, needs and selected solution for the study of the medieval castle of Franchimont, located in the province of Liège (Belgium). After taking into account the requirements from all the disciplines at work as well as the problems that would have to be tackled, the creation of a 3D point cloud was decided. This solution would be able to deal with the characteristics and needs of a research involving building archaeology and related fields. The decision was made in order to manage all of the available data and to provide a common working tool for every involved cultural heritage actor. [less ▲]

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See detailMultifunctional Polyelectrolytes Bearing Pendant Catechol / Quinone for Energy and Environmental Applications
Patil, Nagaraj ULiege

Doctoral thesis (2017)

The discovery of 3,4-dihydroxyphenyl-L-alanine (L-DOPA), a catechol-functionalized amino acid as major component in mussel adhesion proteins, has triggered enormous interest in mussel-mimetic adhesives ... [more ▼]

The discovery of 3,4-dihydroxyphenyl-L-alanine (L-DOPA), a catechol-functionalized amino acid as major component in mussel adhesion proteins, has triggered enormous interest in mussel-mimetic adhesives. The design of innovative bioinspired polymers-containing catechols has rapidly gained widespread utility in the (bio)material field, ascribed to the versatility of the catechol chemistry that allows anchoring (bio)polymers, biomolecules, nanoparticles (metals and metal oxides) and other compounds onto almost any kind of surfaces without any pre-treatment. Amongst the various synthetic protocols to incorporate catechol functionalities into (bio)polymers, the radical polymerization of catechol-bearing vinyl monomers in their protected form has proven to be a versatile technique to impart intrinsic physico–chemical properties of the catechol pendants to polymers after appropriate deprotection. Importantly, the scope of applications of catechol-bearing polymers can potentially be drastically increased by developing controlled radical polymerization (CRP) techniques of their protected vinyl monomers. Indeed, these techniques will enable to precisely design the polymer with the appropriate structure, molar mass and functionality that fit at best the target application. When this thesis started in 2013, only very limited examples of functional catechol-bearing polymers prepared by CRP were reported. The aim of this PhD thesis was to develop well-defined innovative catechol-containing (co)polymers that find applications in energy storage and environmental fields by employing function-oriented macromolecular engineering approaches. In this work, numerous catechol-protected monomers have been prepared and their CRP investigated to afford well-defined (co)polymers with controlled and tunable molar masses, compositions, functionalities, and architectures (homopolymers, statistical and block copolymers). The potential of these innovative catechol-containing (co)polymers was then explored for applications in energy storage (as active-material in lithium-ion half-cells) and environment (as protein fouling/antifouling coatings). [less ▲]

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See detailFusion-based Additive Manufacturing for Processing Aluminum Alloys: State-of-the-Art and Challenges
Mertens, Anne ULiege; Delahaye, Jocelyn ULiege; Lecomte-Beckers, Jacqueline ULiege et al

in Advanced Engineering Materials (2017), 19(8), 1700003

Starting early 2015, the fusion-based additive manufacturing of Al alloys has been developing at an ever faster pace after undergoing a comparatively slow start with respect to other metallic materials ... [more ▼]

Starting early 2015, the fusion-based additive manufacturing of Al alloys has been developing at an ever faster pace after undergoing a comparatively slow start with respect to other metallic materials. This paper reviews the recent developments with the aim of identifying major challenges and opportunities for future work. Laser Beam Melting proves the most useful technique for the additive fabrication of Al components with strongly out-of-equilibrium microstructures and potentially enhanced mechanical behavior. Laser Cladding is also promising for specific applications such as repairs and coatings. However, a deeper understanding of the thermal history during fabrication is still needed to further optimize the microstructures and usage properties. The design of new high strength alloys and of Al-matrix composites, and the development of better adapted post-processing procedures to take greater advantage of the specificities of fusion-based additive techniques are two other important issues in view of reaching the full potential of additive Al components. [less ▲]

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See detailGiving an account of fictional discourse. Meinongian logics versus modal logics
Leclercq, Bruno ULiege

Conference (2017, August 29)

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See detailThe Economic Development Pole (EDP) approach in Niger: the case of the Niger-IFAD Program
Andres, Ludovic ULiege; Populin, Martha; Bodé, Sambo et al

Poster (2017, August 29)

Since 2012, the Niger-IFAD Programme uses a new non-administrative geographical intervention unit, the Economic Development Pole (EDP). The EDP is described as a space concentrating economic activities ... [more ▼]

Since 2012, the Niger-IFAD Programme uses a new non-administrative geographical intervention unit, the Economic Development Pole (EDP). The EDP is described as a space concentrating economic activities linked to the production and commercialization of the main agro-pastoral products of the neighbouring production basins. This poster aims to describe and analyze the concept of EDP, to show its first results when put into practice and to analyze its risks. [less ▲]

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See detailLes systèmes électoraux et leurs effets
Verjans, Pierre ULiege

Learning material (2017)

Le système politique belge fonctionne depuis plus d'un siècle sur le scrutin proportionnel. Quelles sont les conséquences des divers systèmes électoraux?

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See detailExperimental and theoretical investigation of SrFe12O19 nanopowder for permanent magnet application
Abraime, Brahim; Ait tamerd, Mohamed; Mahmoud, Abdelfattah ULiege et al

in Ceramics International (2017)

Strontium M-type hexagonal ferrites were synthesized at different calcination temperatures (800 °C, 1000 °C and 1100 °C) using sol-gel autocombustion method. Thermogravimetric analysis (TGA), X-ray ... [more ▼]

Strontium M-type hexagonal ferrites were synthesized at different calcination temperatures (800 °C, 1000 °C and 1100 °C) using sol-gel autocombustion method. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Mössbauer spectroscopy (MS) and superconducting quantum interference device magnetometer (SQUID) techniques were used to characterize crystal structure, phase composition, morphology and magnetic properties. TGA gives T = 800 °C as beginning of suitable calcination. Hexaferrite structure of single phase is obtained according to XRD results for all samples with crystallite size between 28 nm and 35 nm. SEM images show the growth of grain size with increasing of annealing temperature. (BH)max is calculated based on SQUID results and shows an enhancement between T = 800 °C and T = 1000 °C of 25%. The magnetic properties observed at low temperature are explained and confirmed by ab-initio calculations [less ▲]

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