Last 7 days     Results 1381-1400 of 57084.   65 66 67 68 69 70 71 72 73 74 75   SO(10) models with flavour symmetries: Classification and examplesIvanov, Igor ; Lavoura, Luisin Journal of Physics : G Nuclear & Particle Physics (2016), 43(10), 105005Renormalizable SO(10) grand unified theory (GUT) models equipped with flavour symmetries are a popular framework for addressing the flavour puzzle. Usually, the flavour symmetry group has been an ad hoc ... [more ▼]Renormalizable SO(10) grand unified theory (GUT) models equipped with flavour symmetries are a popular framework for addressing the flavour puzzle. Usually, the flavour symmetry group has been an ad hoc choice, and no general arguments limiting this choice were known. In this paper, we establish the full list of flavour symmetry groups which may be enforced, without producing any further accidental symmetry, on the Yukawa-coupling matrices of an SO(10) GUT with arbitrary numbers of scalar multiplets in the ${\bf{10}}$, $\bar{{\bf{126}}}$, and ${\bf{120}}$ representations of SO(10). For each of the possible discrete non-Abelian symmetry groups, we present examples of minimal models which do not run into obvious contradiction with the phenomenological fermion masses and mixings. [less ▲]Detailed reference viewed: 7 (1 ULg) La santé psycho-sociale des adolescents à l’épreuve de l’immigration : le cas des jeunes d’origine marocaine et turque en Belgique.Gavray, Claire Conference (2016, August 23)Cette communication s’appuie sur les analyses effectuées au départ des données belges de l’enquête ‘International Study on Self-reported Delinquency’. Nous investiguons la question du mal-être ... [more ▼]Cette communication s’appuie sur les analyses effectuées au départ des données belges de l’enquête ‘International Study on Self-reported Delinquency’. Nous investiguons la question du mal-être psychologique desadolescents autochtones et allochtones (via échelle réduite de dépression des adolescents de Moos) encomparaison et en lien avec leur contexte social, affectif et relationnel. Nous affinons l’analyse en ce qui concerne les jeunes d’origine turque et marocaine vivant en Belgique, sachant que si les deux sous-groupes nationaux partagent de nombreuses expériences dans leurs relations aux différentes sphères sociales, leur groupe d’origine se caractérise aussi par des stratégies économiques et d’insertion qui peuvent différer. Nous discutons le résultat selon lequel, malgré un contexte social et historique plus favorable, les jeunes d’origine belge manifestent une tendance dépressive plus prononcée que les autres et la conclusion selon laquelle ce n’est pas automatiquement et exactement les mêmes facteurs socio-relationnels qui expliquent le niveau de dépression dans chacun des groupes étudiés. [less ▲]Detailed reference viewed: 16 (1 ULg) The influence of background noise on vocal loading parameters in music theory teachersSchiller, Isabel ; Morsomme, Dominique ; Sfez, Lou et alPoster (2016, August 23)Background: Music theory teachers, who teach rhythm, singing and other music-related skills and topics, depend greatly on a well-functioning voice. Unlike other schoolteachers, who primarily use their ... [more ▼]Background: Music theory teachers, who teach rhythm, singing and other music-related skills and topics, depend greatly on a well-functioning voice. Unlike other schoolteachers, who primarily use their voice as a pedagogic tool, music theory teachers also use it as an instrument. Furthermore, they often engage in vocally demanding free-time activities requiring a singing voice. To date, few studies have specifically looked at the voice use of music theory teachers. This study aims (1) to measure the background noise level and the amount of vocal loading affecting this specific population, and (2) to describe the influence of background noise on vocal loading parameters. Methods: Thirteen French-speaking music theory teachers (9 females and 4 males) working in a music school were monitored for one workweek, using the VoxLog voice dosimeter (Sonvox). To investigate the professional and extra-professional environments, all subjects wore the dosimeter from early morning until the end of the day. The parameters analysed were background noise level, duration of phonation, sound pressure level (SPL) and fundamental frequency (F0) of voice. Results: Overall, the mean background noise level was 75.2 dB (SD=5.4). We measured higher background noise level at work (mean=78.2 dB, SD=5.8) than in the extra-professional environment (mean=72.2 dB, SD=5.2). As expected, a rise in background noise was accompanied by a significant rise in voice SPL in both males and females (r=.61, p<.001). A significant correlation between background noise and F0 was found in females (r=.41, p=.002), but not in males (r=.39, p=.055). Furthermore, our data exhibit a significant correlation between background noise and duration of phonation (r=.05, p<.001). Conclusion: Our data suggest, that in class, music theory teachers must cope with background noise levels that dramatically exceed the limit of 35 dB recommended by the WHO (Inserm, 2006). High background noise levels lead to an increase in voice SPL, a phenomenon known as the Lombard effect (Inserm, 2006). In female subjects, we also observed a rise in F0 further to high background noise. Like Ternström, Södersten, and Bohman’s (2002) study, our data indicate that high background noise levels increase the duration of phonation. In a noisy environment, subjects seem to prolong the voiced segments of speech to make themselves understood. In other words, high background noise levels result in higher vocal loading. In the long run, this may increase the risk of voice disorders such as hyperfunctional dysphonia or vocal fold pathologies consecutive to repeated microtrauma in music theory teachers. [less ▲]Detailed reference viewed: 38 (2 ULg) Occurrence rates of invasive plants in limestone quarries (Southern Belgium)Pitz, Carline ; Jorion, Alexis ; Mahy, Grégory et alConference (2016, August 23)In quarries, invasive plant species can slow down the installation of high conservation value vegetation. Successful management of invasive requires, at first, a quantitative assessment of invasion levels ... [more ▼]In quarries, invasive plant species can slow down the installation of high conservation value vegetation. Successful management of invasive requires, at first, a quantitative assessment of invasion levels. Although European legislation has adopted an ambitious strategy against invasive species, there is still a lack of knowledge about their occurrence in quarries. The aim of this study was to evaluate occurrence rates of invasive plant species in limestone quarries throughout Wallonia (Southern Belgium) and identify high priority and emerging invasive plants for adapted management. During 2016 vegetation period, forty quarries were selected by stratified sampling, using abandoned and active quarries as strata. Within selected quarries, two-meter wide transects were established to cross all activity sectors. Transects were divided in 10x2m plots, resulting in 2% of total surface of each quarry being surveyed. Cover and number of individuals of invasive plants species were recorded in each plot. Species considered were those of Harmonia list (67 species), the reference at the Wallonia scale. More than 30 000 plots were surveyed. Results of our recent study are presented (occurrences rates by species, mean percentage cover per site). First results indicate that dominant invasive species originate from different introduction paths: (i) planted (Robinia pseudoacacia); (ii) ornamentals (Cotoneaster horizontalis) and (iii) spontaneous colonization (Senecio inaequidens) - and follow various invasion dynamics. We propose research and management methods to be directed towards limitation of top ten frequent species (e.g. Buddleia davidii, Senecio inaequidens), and to establish a detection system for the emerging invasive plants. [less ▲]Detailed reference viewed: 26 (9 ULg) Development of innovative and practical management tools to improve sustainability of milk production and quality of dairy productsArnould, Valérie Doctoral thesis (2016)In the current complex economical context, novel strategies are needed to help local dairy farmers to face the European dairy sector crisis. This thesis was initiated in the framework of ManageMilk ... [more ▼]In the current complex economical context, novel strategies are needed to help local dairy farmers to face the European dairy sector crisis. This thesis was initiated in the framework of ManageMilk project and was globally aimed to investigate the possibility to develop some innovative and practical management tools helping dairy farmers in their daily decisions. To develop such management tools, several conditions must be fulfilled. Firstly, used data must be relevant. According to the literature, the milk composition, and in particular, the milk fatty acid (FA) profile, appears to be a suitable trait allowing useful information about the dairy cow’s health status or about the management system efficiency. These data must also be easily available at low cost from milk recording organization. Recently, the MIR spectrometry offers the possibility to build routinely cheaper and more important databases. To develop management tools, milk samples have to be collected using comparable sampling methods. Unfortunately, in order to decrease the milk quality control costs, the International Committee for Animal Recording allows alternative sampling schemes including the collection of samples from morning or evening only milkings. This alternative sampling scheme can interact with phenotypic and genetic parameters. Therefore, additionally to the development of conversion equations, this thesis is establishing if morning or evening only milkings are genetically different traits. Last condition concerns a useful phenotypic and genetic variability. Milk FA profile is, among others, altered by genetics. So, one paper of this thesis concerns the setup of a useful genetic evaluation model able to estimate accurately the genetic part of milk fat composition variations. Routine genetic evaluation of production traits in dairy cattle commonly uses random regression model (RRM). Recently, “splines” have been advocated as a good alternative to Legendre polynomials (LP) for analyzing test-day yields in RRM. Therefore, several models are compared. Obtained results show the possibility to propose a practical and robust method for estimating accurate daily major FA production from single milking, useful for a further development of practical management tools helping dairy farmers in their daily decisions. [less ▲]Detailed reference viewed: 59 (12 ULg) O acontecimento enunciativo na semiótica da imagemDondero, Maria Giulia ; Colas-Blaise, Marionin Mendes, Conrado; Muniz, Glaucia (Eds.) Em torno do acontecimento: uma homenagem a Claude Zilberberg (2016)Dans cet article, nous visons à montrer que la sémiotique tensive développée par Zilberberg permet de revisiter utilement les notions barthésiennes de studium et de punctum et, de surcroît, de devenir un ... [more ▼]Dans cet article, nous visons à montrer que la sémiotique tensive développée par Zilberberg permet de revisiter utilement les notions barthésiennes de studium et de punctum et, de surcroît, de devenir un outil pour l’analyse de l’image. Dans un premier temps, nous reprenons les notions de studium et de punctum dans le cadre d’une théorie de la photographie, en mettant également en valeur la manière dont Shairi & Fontanille (2001) enrichissent l’opposition entre studium et punctum à travers la gradualité des différentes positions énonciatives garanties par le tempo. Dans un deuxième temps, nous mettons la théorie barthésienne en regard avec la théorie zilberberghienne, ce qui nous amènera à l’analyse de quelques œuvres de Paul Klee et à considérer le punctum et l’événement de Zilberberg comme des effets de la composition énonciative au sein du médium pictural. [less ▲]Detailed reference viewed: 25 (2 ULg) Passive Linearization of Nonlinear System ResonancesHabib, Giuseppe ; Grappasonni, Chiara ; Kerschen, Gaëtan Conference (2016, August 22)In this work we demonstrate that the addition of properly-tuned nonlinearities to a nonlinear system can increase the range over which a specific resonance responds linearly. Specifically, we seek to ... [more ▼]In this work we demonstrate that the addition of properly-tuned nonlinearities to a nonlinear system can increase the range over which a specific resonance responds linearly. Specifically, we seek to enforce two important properties of linear systems, namely the force-displacement proportionality and the invariance of resonance frequencies. Theoretical findings are validated through numerical simulations and experiments. [less ▲]Detailed reference viewed: 20 (0 ULg) ANALYSE DE LA DEMANDE EN CHARBON DE BOIS PAR LES MÉNAGES URBAINS DE BUJUMBURA AU BURUNDISabuhungu, Emery Gaspard Doctoral thesis (2016)The objective of this study is to evaluate the demand for charcoal by urban households in Bujumbura in order to make recommendations ensuring the security of household energy and environmental protection ... [more ▼]The objective of this study is to evaluate the demand for charcoal by urban households in Bujumbura in order to make recommendations ensuring the security of household energy and environmental protection. To achieve this objective, the analysis of the related documentation and collection of secondary data were carried out in order to formulate specific objectives, hypotheses and the methodology used in the course of this study. The specific objectives are: to analyze the structure, operation and market performance of the charcoal market in the city of Bujumbura and to compare this market to the cities of Lubumbashi and Kigali; to determine the charcoal consumption pattern by urban households in Bujumbura; to identify the factors which influence the demand for charcoal by urban households in Bujumbura; to evaluate the demand for charcoal by urban households in Bujumbura. The assumptions made in this study are: the charcoal market in the city of Bujumbura is a competitive and effective market; charcoal is the dominating cooking fuel used by urban households in Bujumbura and is consumed exclusively or in combination with others; an urban household’s demand for charcoal in Bujumbura is essentially based on household income, the size of household, eating habits (preparation of food that requires a long cooking time), the frequency of use of carbon and the possession or not of improved cooking stoves; the demand for charcoal by urban households in Bujumbura is high and this leads to significant annual deforestation. Three surveys were conducted to collect primary data. The first survey, with the specific objective of analysing the charcoal market in Bujumbura, was conducted among the key players of the charcoal value chain produced in the communes of Mugamba and Muramvya and consumed in the city of Bujumbura. The remaining two surveys, with the specific objective of analysing the consumption of charcoal by households, were conducted among households-users of charcoal of different standards of living in three areas of the city of Bujumbura (areas Buterere, Cibitoke and Rohero). The results indicate that the charcoal market is competitive. The production, the commercialisation and the consumption of charcoal allow the creation of positive value added all along the charcoal value chain. The use of cooking fuels by households in Bujumbura shows that they have not yet achieved an energy transition. In fact, 83% of those surveyed only use charcoal; 12% combine charcoal and electricity and 5% combine charcoal and firewood. The results revealed that the main factors influencing households demand for charcoal are: household income, the price of charcoal, household size, number of cooking sessions per day, frequency of preparation of cassava leaves and the possession or not of improved braziers. To solve the energy and environmental problem, a rehabilitation of woodland, an implementation of the best techniques of woodland planting with the most adaptable species on productive land, a greater penetration of substitutable energy to wood fuel such as gas or electricity, a growth in the use of improved cooking stoves in households and greater efficiency in wood carbonisation will help reduce the number of hectares of deforestation for wood energy needs. [less ▲]Detailed reference viewed: 40 (15 ULg) Design of microstructures using stress-based topology optimizationCollet, Maxime ; Bruggi, Matteo; Noël, Lise et alConference (2016, August 22)This paper aims at designing microstructures using stress-based topology optimization. Most of the developments so far have been made for compliance design in various field of applications as reflected in ... [more ▼]This paper aims at designing microstructures using stress-based topology optimization. Most of the developments so far have been made for compliance design in various field of applications as reflected in the literature. The emergence of the new additive manufacturing techniques allows to consider porous material, such as lattice structures for instance, which ca be used for the design of structural components subject to various solicitations. Those components must account for the stress level to prevent failure everywhere in the microstructures and by extension the whole structure itself. This work proposes to design such microstructures using topology optimization with limitation on the stress level within the microstructures before printing the result. The homogenization technique is used to determine the equivalent material properties. The issues and perspectives are also discussed. [less ▲]Detailed reference viewed: 16 (3 ULg) Is the observer effect significant in vegetation assessment of restored metallicolous grassland?Boisson, Sylvain ; Mahy, Grégory Conference (2016, August 22)Projects that prospects habitat restoration require protocols of vegetation assessment to monitor the evolution of the restored ecosystems over time. In most cases, multiple assessors are needed and some ... [more ▼]Projects that prospects habitat restoration require protocols of vegetation assessment to monitor the evolution of the restored ecosystems over time. In most cases, multiple assessors are needed and some studies have shown that the variability among observer can be significant. In the context of tropical grassland, few studies quantified the impact of the observer on the results, reducing the capacity to replicate conclusions, and, therefore to plan restoration strategies at large scale. This study aims to quantify the variation among observers using two phytosociological methods on restored metallicolous grassland and to test whether variation in the assessment could involve the conclusions of the vegetation assessment. Four observers were selected to perform monitoring of quadrats in two distinct habitats identified in four restored ecosystems. All observers sampled seven metrics based on phytosociological methods and two of them also performed a complete vegetation sampling of the quadrat, including species identification and cover in quadrat. For metrics based on cover, variation of measure exists among the observers. For metrics based on counting, no variation is highlighted and the observers are able to distinguish and identify species. These results emphasize that a same method could lead to distinct results according to observer and, in restoration projects, it is crucial to ensure a correct transfer of protocols of vegetation assessment in order to reproduce equally the method. [less ▲]Detailed reference viewed: 11 (1 ULg) One pot synthesis by plasma treatment of Pt-based catalysts for PEM fuel cellsBusby, Yan; Gulas, Michal; Laurent-Brocq, Mathilde et alConference (2016, August 22)Detailed reference viewed: 11 (1 ULg) Ability of Tuta absoluta (Lepidoptera: Gelechiidae) to develop on alternative host plant speciesBawin, Thomas ; Dujeu, David; De Backer, Lara et alin Canadian Entomologist (2016), 148(4), 434-442The tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous crops. The characterization of its host ... [more ▼]The tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous crops. The characterization of its host range could help to understand and prevent the dispersion behavior of the insect in the environment. In this study, the ability of T. absoluta to develop on 12 cultivated or non-cultivated plants including Solanaceae, Chenopodiaceae, Convolvulaceae, Fabaceae and Malvaceae species under laboratory conditions was assessed. For each plant species, we monitored the development times of immature stages, survival, sex ratios and adult fecundity rates. All the 6 tested non-solanaceous plants, including Chenopodium, Convolvulus and Malva species, were not able to sustain (i.e. allow growth and development) T. absoluta larvae. Among Solanaceae, Solanum species were the most suitable host plants for the pest, but others could be opportunistically colonized with fewer incidences. T. absoluta appears to be strongly related to solanaceous plants which would predominantly support self-sustaining field populations. Preventing crop infestation by removing potential host plants in the immediate field vicinity and culture rotations with non-solanaceous crops is of primary importance. [less ▲]Detailed reference viewed: 75 (17 ULg) Editing Thomas More’s Utopia (Louvain, T. Martinus, 1516): an example of Erasmian networks in actionAdam, Renaud Conference (2016, August 19)Theodoricus Martinus Alostensis published the editio princeps of Thomas More’s Utopia at the end of the year 1516 in Louvain. Why did the English humanist give his text to this printer and not to someone ... [more ▼]Theodoricus Martinus Alostensis published the editio princeps of Thomas More’s Utopia at the end of the year 1516 in Louvain. Why did the English humanist give his text to this printer and not to someone like Johann Froben in Basel or Jodocus Badius Ascensius in Paris? In fact, Thomas More didn’t choose Theodoricus Martinus randomly, but had been guided by his friend Erasmus, who was living in Brabant at that time and was working directly with this printer. The humanist from Rotterdam then instructed his circle to monitor closely the printing of the text, to do the proofreading and to direct the publishing. He involved in this process his friend Petrus Aegidius – clerk of city of Antwerp and close friend of both More and Erasmus – and Gerardus Geldenhower. By studying the correspondence of Erasmus, we will first rebuild the process of printing the first edition of the Utopia. This will also be an opportunity to discover the role and the importance of a network of humanists within the workshop of a printer. Without this, Theodoricus Martinus would never have been able to build his identity as a “printer humanist” and to transform his workshop into one of the leading places for the diffusion of humanism in the Low Countries in the first decades of the 16th century. [less ▲]Detailed reference viewed: 9 (1 ULg) Aspects politiques et diplomatiques de l'exil des religieux français en Belgique (1901-1914)Murez, Jean-Baptiste Conference (2016, August 19)Detailed reference viewed: 18 (1 ULg) Aspects fonciers de l'exil des religieux français en Belgique (1901-1914)Murez, Jean-Baptiste Conference (2016, August 19)Detailed reference viewed: 27 (1 ULg) Les enquêtes de terrain du Musée de la Vie wallonne : Un outil au service de la collecte de la mémoire, des savoirs et savoir-faire régionauxPostula, Jean-Louis Conference (2016, August 19)Débutées dans les années 1920, la réalisation de reportages sur le terrain puis la diffusion régulière des résultats de ces recherches ont été pendant longtemps l’un des traits distinctifs de la fonction ... [more ▼]Débutées dans les années 1920, la réalisation de reportages sur le terrain puis la diffusion régulière des résultats de ces recherches ont été pendant longtemps l’un des traits distinctifs de la fonction scientifique mise en œuvre au Musée de la Vie wallonne. Jusqu’à la fin des années 1980 environ, les activités du Service des enquêtes ont permis au Musée de devenir le conservatoire d’une collection unique en son genre de documents d’archives multimédia – photographies, films et sons. La rénovation du Musée à partir de 2004, assortie de la réorientation de son projet muséal vers le modèle du « musée de société », a été l’occasion d’investir à nouveau du temps et des moyens dans la relance de cette riche tradition d’enquêtes ethnographiques. Grâce à de nombreux exemples, cette communication ambitionne de montrer l’évolution des terrains d’enquêtes du Musée, qui privilégie désormais l’exploration de nouvelles thématiques liées aux enjeux contemporains de nos sociétés urbaines, industrielles et post-industrielles. Oscillant entre continuité et renouvellement, les enquêtes du Musée de la Vie wallonne permettent à l’institution de se profiler comme un contributeur influent à la préservation du patrimoine culturel immatériel de notre région. [less ▲]Detailed reference viewed: 19 (0 ULg) Aggiornamento historiographique sur Godefroid Kurth (XIXème siècle-2016)Genin, Vincent Conference (2016, August 19)Detailed reference viewed: 15 (2 ULg) Two-Parameter Kinematic Approach for Shear Strength of Deep Concrete Beams with Internal FRP ReinforcementMihaylov, Boyan in Journal of Composites for Construction (2016), DOI: 10.1061/(ASCE)CC.1943-5614 .0000747Tests of deep concrete beams with internal fiber-reinforced polymer (FRP) reinforcement have shown that such members can exhibit lower shear strength than members with conventional steel reinforcement. To ... [more ▼]Tests of deep concrete beams with internal fiber-reinforced polymer (FRP) reinforcement have shown that such members can exhibit lower shear strength than members with conventional steel reinforcement. To model this effect, the current paper proposes an approach based on a two-parameter kinematic theory (2PKT) for conventional deep beams. The 2PKT is built on a kinematic model with two degrees of freedom that describes the deformation patterns of cracked beams. Using this theory shows that large strains in FRP longitudinal reinforcement result in reduced shear resistance of the critical loading zones (CLZ) of deep beams. The original 2PKT is therefore modified by introducing a reduction factor for the shear carried by the CLZ. The extended 2PKT approach is then applied to a database of 39 tests of FRP-reinforced deep beams from the literature, resulting in an average shear strength experimental-to-predicted ratio of 1.06 and a coefficient of variation of 18.3%. The results show that the 2PKT adequately captures the effects of the stiffness of the reinforcement, section depth, concrete strength, and shear-span-to-depth ratio on the shear strength of FRP-reinforced deep beams. [less ▲]Detailed reference viewed: 10 (3 ULg) L'environnement comme source d'inégalité? Pauvreté et désengagement citoyen dans la villeLejeune, Zoé E-print/Working paper (2016)Detailed reference viewed: 43 (19 ULg) BIG NOISE - Un orchestre belge- Un nouvel hommage, en live, au JAZZ style NEW ORLEANSSacré, Robert E-print/Working paper (2016)Compte Rendu du 3è opus du groupe BIG NOISE, un orchestre belge qui remet à l'honneur le jazz traditionnel style NEW ORLEANS ( album IGLOO RECORDS)Detailed reference viewed: 5 (1 ULg)