120 research outputs found
Occupation, race, and empire: Maxence Van der Meersch\u27s Invasion 14
No full textIn his 1935 novel Invasion 14, Maxence Van der Meersch painted a nuanced picture of the German invasion and occupation of northern France during World War I. Despite local controversy, Invasion 14 won national and international praise, losing the Prix Goncourt by a single vote. Though neglected in the wake of World War II, when the author\u27s treatment of Franco-German relations between 1914 and 1918 ran headlong into evolving myths of widespread resistance between 1940 and 1944, Invasion 14 has garnered renewed attention as a window onto the occupation of World War I. Heretofore unappreciated, however, is Van der Meersch\u27s use of colonial themes of race and empire. Based on research in the Archives Maxence Van der Meersch, this study explores the author\u27s treatment of colonial motifs, demonstrating their centrality to the novel and the debate it generated. © Berghahn Journals
Oscilador H para medição de capacitâncias
No full textCapacitive sensors operate based on capacitance variation in response to a
stimulus, offering a wide range of applications. Among the various measurement
techniques, oscillator circuits stand out for providing a stable, direct, and reliable
response. However, in applications where isolating the sensor electrodes is not feasible, the
presence of a resistive component associated with capacitance—often overlooked—can
compromise oscillator-based measurement systems by destabilizing the circuit and
interrupting its operation, especially at high frequencies. Although the literature addresses
this issue, most solutions focus solely on low-frequency applications and propose large,
complex circuits, hindering the development of efficient systems and limiting the use of
high-frequency sensors. In light of this, this work presents a new sinusoidal oscillator
topology, based on the Colpitts oscillator, for measuring non-ideal capacitive loads in the
frequency range from hundreds of kilohertz to hundreds of megahertz, referred to here as
the H Oscillator. This topology is designed to maintain oscillation criteria even in the
presence of variations in the sensitive elements. The scientific framework adopted for the
oscillator’s development, as well as its theoretical formulation, are detailed in this work.
Simulations were performed using LTSpice and QucsStudio simulation environments,
employing capacitive sensor models. The results demonstrate the circuit’s robustness
against parameter variations, enabling the measurement of different capacitive loads
without oscillation interruption. Furthermore, the theoretical formulation was validated,
with errors of only 0.78% between the expected and measured frequency variation curves
and 1.47% for amplitude variation. Thus, this dissertation presents a novel approach to
capacitive load sensor measurement, with potential for various applications.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESSensores capacitivos operam com base na variação da capacitância em resposta a
um estímulo, apresentando ampla versatilidade de aplicações. Dentre as diversas formas
de medição, circuitos osciladores se destacam por oferecerem uma resposta estável, direta
e confiável. No entanto, em aplicações onde não é possível isolar os eletrodos do sensor, a
presença de uma componente resistiva associada à capacitância, frequentemente
negligenciada, pode comprometer sistemas de medição baseados em osciladores ao
desestabilizar o circuito e interromper sua operação, especialmente em alta frequência.
Embora a literatura aborde essa problemática, a maioria das soluções se concentra apenas
em aplicações de baixa frequência e propõe circuitos grandes e complexos, dificultando o
desenvolvimento de sistemas eficientes e limitando o uso de sensores que operam em altas
frequências. Diante disso, este trabalho apresenta uma nova topologia de oscilador
senoidal, baseada no oscilador de Colpitts, para a medição de cargas capacitivas não
ideais na faixa de frequência de centenas de quilohertz a centenas de megahertz, aqui
denominada Oscilador H. Esta topologia foi projetada para manter os critérios de
oscilação mesmo diante de variações dos elementos sensíveis. A construção científica
adotada para o desenvolvimento do oscilador proposto, assim como seu equacionamento
teórico, são detalhados neste trabalho. Simulações foram realizadas nos ambientes de
simulação LTSpice e QucsStudio, utilizando modelos de sensores capacitivos. Os
resultados demonstram a robustez do circuito frente à variação dos parâmetros,
permitindo a medição de diferentes cargas capacitivas sem interrupção da oscilação. Além
disso, a coerência do equacionamento desenvolvido foi validada, com erros de apenas
0,78% entre as curvas esperada e medida para a variação de frequência e 1,47% para a
variação de amplitude. Assim, esta dissertação apresenta uma nova abordagem para a
medição de sensores de carga capacitiva, com potencial para diversas aplicações.São Cristóvã
Maxence Van der Meersch, herald of the common people
No full textCette thèse se propose d’examiner la place de Maxence Van der Meersch dans la littérature populaire, notamment en confrontant les choix esthétiques et les oeuvres romanesques de l’écrivain aux courants populiste et prolétarien, mais aussi en étudiant les rapports personnels que le romancier entretint avec le peuple. L’examen de ses idéologies sociales et politiques permet de mieux cerner un homme qui, fidèle à ses convictions, refusa d’intégrer un groupe qui ne le représentât pas intégralement et demeura ainsi inclassable tant sur le plan littéraire que politique. Les thèmes de prédilection du romancier sont passés en revue, femmes pécheresses, rachat par la souffrance, figures christiques, personnages d’hercules, etc. ; et l’analyse de ces différents poncifs et clichés, populaires ou non, conduit à une remise en questions des reproches de manichéisme et de simplification extrême souvent faits à l’écrivain. Si son engagement et sa volonté de convaincre l’amenèrent parfois à des prises de position très tranchées, la principale cause qu’il voulut défendre fut celle du peuple, pour lequel son attachement ne se démentit jamais. L’étude s’appuie sur les romans publiés et inédits de l’auteur, ainsi que sur les nombreux et précieux documents présents au Fonds Maxence Van der Meersch de Wasquehal et dans les archives Albin Michel à l’IMEC. Elle est complétée par des annexes qui exhument des textes jusque là restés inédits.This thesis proposes to examine Maxence Van der Meersch’s place in popular literature, especially by confronting the writer’s aesthetic choices and novels with populist and proletarian movements, and also by studying the personal relationship the novelist had with the popular classes. The examination of his social and political ideologies allows to grasp better a man who, true to his convictions, refused to integrate a group that would not have represented him entirely and therefore remained unclassifiable both in the political and literary fields. The novelist’s favourite themes are reviewed : sinful women, atonement by suffering, Christly figures, Herculean characters, etc. ; and the analysis of those different stereotypes and commonplaces, whether popular or not, leads to a questioning of the criticisms about Manicheism and extreme simplification that are often made to the writer. If his commitment and his will to convince sometimes induced him to very clear-cut standpoints, the main cause he wanted to defend was that of the workers, for whom his attachment was never denied. The study is based on published and unpublished novels of the author, and on the numerous and precious documents from the Maxence Van der Meersch Resource of Wasquehal and from Albin Michel archives at IMEC. It is completed with appendixes that bring to light so far unpublished texts
Conception et élaboration d'un micro-détecteur de biomolécules en milieu liquide couplant transducteur à ondes de Love et matrice poreuse
No full textLove wave sensors are used in a wide range of applications in liquid medium, offering very high sensitivities. However, still today, they are not able to detect very low weight molecules such as cyanotoxins. These thesis works focus on the use of mesoporous titanium oxide layers on a Lov wave sensor in order to improve its sensitivity.A new conceptual model of the sensor is proposed, enabling the enrich ment of its response and then the quantification of its sensitivity to rheological and dielectric variations of a liquid medium. These results are used to obtain a set of Finite Element models, completing our“toolbox“. Finally, several methods of mesostructured thin film layers deposition are studied. The so-obtained sensors are characterized in a liquid medium and demonstrate the improvement of the sensitivity performance under some conditions. The further use of finite element models highlights optimization strategies for Love wave sensors using mesostructured layers.Les capteurs à ondes de Love sont utilisés dans une large gamme d’applications en milieu liquide, avec des sensibilités très importantes. Néanmoins, ceux-ci ne permettent pas, encore aujourd’hui, de détecter des molécules de très faibles poids telles que les cyanotoxines. Ces travaux de thèse portent sur l’utilisation de couches mésoporeuses d’oxyde de titane sur un capteur à ondes de Love afin d’améliorer sa sensibilité. Après avoir obtenu un nouveau modèle conceptuel du capteur permettant d’enrichir sa réponse, sa sensibilité à des effets de variations rhéologiques et diélectriques est quantifiée en milieu liquide. Ces résultats sont ensuite utilisés pour obtenir un ensemble de modèles par éléments finis, venant compléter notre « boite à outils ». Enfin, plusieurs méthodes de dépôt de couches mésostructurées en films minces sont étudiées. Les capteurs ainsi obtenus sont caractérisés en milieu liquide et permettent de conclure sur une amélioration des performances en sensibilité sous un certain nombre de conditions. Ces conditions sont étudiées à l'aide des modèles par éléments finis et permettent de tracer une voie d’optimisation des capteurs à ondes de Love utilisant des couches mésostructurées
Conception et élaboration d'un micro-détecteur de biomolécules en milieu liquide couplant transducteur à ondes de Love et matrice poreuse
No full textLove wave sensors are used in a wide range of applications in liquid medium, offering very high sensitivities. However, still today, they are not able to detect very low weight molecules such as cyanotoxins. These thesis works focus on the use of mesoporous titanium oxide layers on a Lov wave sensor in order to improve its sensitivity.A new conceptual model of the sensor is proposed, enabling the enrich ment of its response and then the quantification of its sensitivity to rheological and dielectric variations of a liquid medium. These results are used to obtain a set of Finite Element models, completing our“toolbox“. Finally, several methods of mesostructured thin film layers deposition are studied. The so-obtained sensors are characterized in a liquid medium and demonstrate the improvement of the sensitivity performance under some conditions. The further use of finite element models highlights optimization strategies for Love wave sensors using mesostructured layers.Les capteurs à ondes de Love sont utilisés dans une large gamme d’applications en milieu liquide, avec des sensibilités très importantes. Néanmoins, ceux-ci ne permettent pas, encore aujourd’hui, de détecter des molécules de très faibles poids telles que les cyanotoxines. Ces travaux de thèse portent sur l’utilisation de couches mésoporeuses d’oxyde de titane sur un capteur à ondes de Love afin d’améliorer sa sensibilité. Après avoir obtenu un nouveau modèle conceptuel du capteur permettant d’enrichir sa réponse, sa sensibilité à des effets de variations rhéologiques et diélectriques est quantifiée en milieu liquide. Ces résultats sont ensuite utilisés pour obtenir un ensemble de modèles par éléments finis, venant compléter notre « boite à outils ». Enfin, plusieurs méthodes de dépôt de couches mésostructurées en films minces sont étudiées. Les capteurs ainsi obtenus sont caractérisés en milieu liquide et permettent de conclure sur une amélioration des performances en sensibilité sous un certain nombre de conditions. Ces conditions sont étudiées à l'aide des modèles par éléments finis et permettent de tracer une voie d’optimisation des capteurs à ondes de Love utilisant des couches mésostructurées
Contribution to the design and the elaboration of a microsensor for biomolecules in liquid medium coupling Love waves and porous matrix
No full textLes capteurs à ondes de Love sont utilisés dans une large gamme d’applications en milieu liquide, avec des sensibilités très importantes. Néanmoins, ceux-ci ne permettent pas, encore aujourd’hui, de détecter des molécules de très faibles poids telles que les cyanotoxines. Ces travaux de thèse portent sur l’utilisation de couches mésoporeuses d’oxyde de titane sur un capteur à ondes de Love afin d’améliorer sa sensibilité. Après avoir obtenu un nouveau modèle conceptuel du capteur permettant d’enrichir sa réponse, sa sensibilité à des effets de variations rhéologiques et diélectriques est quantifiée en milieu liquide. Ces résultats sont ensuite utilisés pour obtenir un ensemble de modèles par éléments finis, venant compléter notre « boite à outils ». Enfin, plusieurs méthodes de dépôt de couches mésostructurées en films minces sont étudiées. Les capteurs ainsi obtenus sont caractérisés en milieu liquide et permettent de conclure sur une amélioration des performances en sensibilité sous un certain nombre de conditions. Ces conditions sont étudiées à l'aide des modèles par éléments finis et permettent de tracer une voie d’optimisation des capteurs à ondes de Love utilisant des couches mésostructurées.Love wave sensors are used in a wide range of applications in liquid medium, offering very high sensitivities. However, still today, they are not able to detect very low weight molecules such as cyanotoxins. These thesis works focus on the use of mesoporous titanium oxide layers on a Lov wave sensor in order to improve its sensitivity.A new conceptual model of the sensor is proposed, enabling the enrich ment of its response and then the quantification of its sensitivity to rheological and dielectric variations of a liquid medium. These results are used to obtain a set of Finite Element models, completing our“toolbox“. Finally, several methods of mesostructured thin film layers deposition are studied. The so-obtained sensors are characterized in a liquid medium and demonstrate the improvement of the sensitivity performance under some conditions. The further use of finite element models highlights optimization strategies for Love wave sensors using mesostructured layers
Social environment and feeding state influence movement decisions in a web‐building spider
No full textIt is well recognized that feeding rate has a major influence on the amount of movement between microhabitats for many animals. However, the role of other extrinsic and intrinsic factors, and particularly how these factors may interact, is not well understood. This three-part study examines the movement decisions of a web-building spider, Latrodectus hesperus, by assessing microhabitat tenacity in established spiders and by testing how the presence of conspecific neighbours and the combined influence of individual feeding state (determined by prior feeding experience) and neighbour presence influence microhabitat residence time in unestablished spiders. The results show that naturally established spiders did not leave their microhabitats readily, emphasizing the importance of choosing a profitable location. Unestablished spiders stayed longer in microhabitats occupied by conspecifics than in unoccupied ones, and there was practically no cannibalism even though neighbours shared webs. Furthermore, feeding state and neighbour presence showed an interactive effect on microhabitat residence time. When spiders were housed alone, microhabitat residence time increased with feeding state. However, in the presence of conspecifics, spiders had a low propensity to move, regardless of feeding state. Together, these results demonstrate the combined importance of grouping dynamics and feeding state in shaping movement decisions. [ABSTRACT FROM AUTHOR]Peer reviewedfinal article publishe
Western black widow spiders express state-dependent web-building strategies tailored to the presence of neighbours
No full textWeb-building spiders are territorial animals whose webs serve several purposes including foraging, reproduction and protection. Two factors are predicted to be of primary importance in determining a spider's web-building strategy: (1) current nutritional state (a function of prior feeding rate), which determines the net value of a web, and (2) the presence of co-occurring spiders with whom it may have to interact and partition resources. I conducted a laboratory experiment to test whether western black widow spiders, Latrodectus hesperus, express state-dependent web-building strategies that vary with the presence of conspecific or heterospecific (Tegenaria agrestis and T. duellica) spiders in a microhabitat. I maintained L. hesperus females on two different diets (high- versus low-food) and tested their web-building behaviour in the presence or absence of neighbours. When sharing a microhabitat with con- or heterospecific spiders, L. hesperus increased their web-building investment by producing higher-density webs containing more silk and by initiating web-building sooner. Web building was further influenced by nutritional state, such that well-fed spiders produced more silk and built denser webs than their poorly fed counterparts. Furthermore, microhabitat occupancy level and nutritional state showed a combined effect on the different components of web-building behaviour in L. hesperus. I discuss how this behavioural plasticity might optimize microhabitat settlement investments in the context of constraints on web-building activities imposed by nutritional state and cohabitation.Peer reviewedfinal article publishedbehavioural plasticitywestern black widow spiderweb buildingtrade-offsstate-dependent behaviourspider webLatrodectus hesperushabitat selectionforagingcohabitatio
Habitat use by western black widow spiders (Latrodectus hesperus) in coastal British Columbia: evidence of facultative group living
No full textAnimal social systems come in a wide range of forms characterized by different types of group-living relationships. Species that express facultative group-living behaviours, where individuals only associate under certain conditions or at certain times, are especially interesting for studying social evolution. We investigated the social structure of the western black widow spider (Latrodectus hesperus Chamberlin and Ivie, 1935) over 5 years in a coastal British Columbia habitat, and present the first comprehensive evidence of facultative group living in the genus Latrodectus Walckenaer, 1805. Latrodectus hesperus have a flexible social structure that varies seasonally, wherein individuals (mostly females) either form groups or live solitarily. In the fall and early winter, females spontaneously form groups of 2-8 individuals, but live alone during the oviposition season in the spring and summer. When living in groups spiders share large webs and are tolerant of each other, although they appear to forage individually. We also report on the relationships between different ecological factors and the social structure of L. hesperus, including the interaction of these spiders with two co-occurring species of introduced spiders (Tegenaria agrestis (Walckenaer, 1802) and Tegenaria duellica Simon, 1875). Our findings suggest that L. hesperus is a good model system with which to explore the mechanisms involved in the evolution of sociality. [ABSTRACT FROM AUTHOR]Peer reviewedfinal article publishe
The natural diet of a polyphagous predator, Latrodectus hesperus (Araneae: Theridiidae), over one year
No full textThe natural diets of many terrestrial predators such as spiders have yet to be investigated. In this study, I analyzed the diet of a web-building spider, Latrodectus hesperus Chamberlin & Ivie (1935), over one year in a natural habitat of coastal British Columbia, Canada. This is the first study to document the natural diet of L. hesperus over several months. I identified and measured 1599 prey items collected from L. hesperus webs and web sites between January and December. Spiders fed on ground-active prey from eight different orders of arthropods. Coleoptera and Hymenoptera were the predominant prey of L. hesperus in this habitat, combinely accounting for . 85% of the total prey catches and biomass. The other prey orders included, in order of abundance, Isopoda, Araneae, Dermaptera, Orthoptera, Lepidoptera and Diptera. Spiders captured prey mostly between May and October, when females oviposit, juveniles grow, and prey are most active. These results show that L. hesperus is a polyphagous predator that feeds primarily on prey from two orders of insects.Peer reviewedfinal article publishedFeeding regimespiderspreypredator-prey interactionsforagin
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