This essay brings a fundamentally Americanist question to bear on Leo Marx’s fundamental piece of Americanist scholarship: What cultural work does the machine-in-the-garden trope perform in literary texts, texts that—as Marx highlighted—emphatically invoke the socio-economic upheavals of industrialization? Rather than asking what the trope means, I am interested in what it does in textual environments that, literally or metaphorically, navigate a protean discourse of class.1 I want to pursue this question in a reading of two texts that directly engage with industrialization and its machinery, two pieces of literature written in markedly different circumstances—one by an eminently canonical writer of the American Renaissance, Herman Melville, the other by a woman who worked in the factories of Lowell, the period’s model industrial town. My reading of these texts aims to draw attention to the ways in which representations of the machine in the garden are perspectivized: While engaging with the juxtaposition of nature and technology, these representations always also work on negotiating social subjectivities—on defining, contrasting, authorizing, critiquing subject positions in the rapidly shifting social matrix of an industrializing USA. In other words, I propose to not only attend to the texts’ images of the machine in the garden but also to the imaging that they depict. The texts with which I will be concerned dramatize this imaging as work that is deeply situated and entangled in other practices of selffashioning, practices which resonate with industrialism’s new regimes of social difference. Herman Melville’s short-story "The Tartarus of Maids" (1855) constructs a narrator who renders his encounter with industrialism in a rhetoric greatly informed by the machine-in-the-garden trope. By correlating this figurative practice with the notably limited and biased perspective of its narrator—a perspective whose marking laminates class and gender—the text exposes the work of socio-economic self-fashioning enabled by the trope. The sketch "A Merrimack Reverie" (1840), published in the "factory-girl"2 magazine The Lowell Offering, develops a motif that seems to invert the trope Marx identified—the motif of horticulture in the factory. This motif unfolds much ambiguity in the text which, I will suggest, registers the precarious quality of the magazine’s project to establish the ‘factory girl’ as an affirmative subject position. / "Der vorliegende Beitrag ist die pre-print Version. Bitte nutzen Sie für Zitate die Seitenzahl der Original-Version." (siehe Quellenangabe)

This essay brings a fundamentally Americanist question to bear on Leo Marx’s fundamental piece of Americanist scholarship: What cultural work does the machine-in-the-garden trope perform in literary texts, texts that—as Marx highlighted—emphatically invoke the socio-economic upheavals of industrialization? Rather than asking what the trope means, I am interested in what it does in textual environments that, literally or metaphorically, navigate a protean discourse of class.1 I want to pursue this question in a reading of two texts that directly engage with industrialization and its machinery, two pieces of literature written in markedly different circumstances—one by an eminently canonical writer of the American Renaissance, Herman Melville, the other by a woman who worked in the factories of Lowell, the period’s model industrial town. My reading of these texts aims to draw attention to the ways in which representations of the machine in the garden are perspectivized: While engaging with the juxtaposition of nature and technology, these representations always also work on negotiating social subjectivities—on defining, contrasting, authorizing, critiquing subject positions in the rapidly shifting social matrix of an industrializing USA. In other words, I propose to not only attend to the texts’ images of the machine in the garden but also to the imaging that they depict. The texts with which I will be concerned dramatize this imaging as work that is deeply situated and entangled in other practices of selffashioning, practices which resonate with industrialism’s new regimes of social difference. Herman Melville’s short-story "The Tartarus of Maids" (1855) constructs a narrator who renders his encounter with industrialism in a rhetoric greatly informed by the machine-in-the-garden trope. By correlating this figurative practice with the notably limited and biased perspective of its narrator—a perspective whose marking laminates class and gender—the text exposes the work of socio-economic self-fashioning enabled by the trope. The sketch "A Merrimack Reverie" (1840), published in the "factory-girl"2 magazine The Lowell Offering, develops a motif that seems to invert the trope Marx identified—the motif of horticulture in the factory. This motif unfolds much ambiguity in the text which, I will suggest, registers the precarious quality of the magazine’s project to establish the ‘factory girl’ as an affirmative subject position. / "Der vorliegende Beitrag ist die pre-print Version. Bitte nutzen Sie für Zitate die Seitenzahl der Original-Version." (siehe Quellenangabe)

Dans ce mémoire, nous avons étudié les convertisseurs d’interface permettant l’interconnexion d’une source basse tension non linéaire et d’un bus DC moyenne tension. La source choisie, pour l’étude, était une pile à combustible de type PEM. La structure de puissance retenue correspondant à la mise en cascade d’un convertisseur entrelacé en entrée et d’un convertisseur trois niveaux en sortie. Afin de dimensionner au mieux le convertisseur global, nous avons proposé un modèle analytique permettant de connaitre l’ensemble des pertes dans le système en fonction du point de fonctionnement et de ses paramètres. Nous avons montré que l’ensemble des pertes dans le convertisseur peut être modélisé par deux résistances non linéaires dont l’estimation est possible à partir des modèles moyens du convertisseur. Une commande basée sur le concept de platitude des systèmes différentiels a été utilisée pour assurer les différentes contraintes du système tout en obtenant des propriétés dynamiques élevées en asservissement et en régulation. Dans la dernière partie du mémoire, nous nous sommes intéressés aux solutions permettant de satisfaire les contraintes sur le taux d’ondulation de courant en entrée du convertisseur. Nous avons proposé et dimensionné une nouvelle structure de convertisseur permettant de supprimer les ondulations de courant générées par le convertisseur de puissance. Ce filtre actif se connecte en parallèle avec le convertisseur de puissance. Des résultats expérimentaux ont permis de montrer que le taux d’ondulation de courant d’un convertisseur élévateur a été réduit, le taux d’ondulation de courant passant de 23.3% à 1.9% / In this thesis, we studied interface converters enabling the interconnection of a low voltage nonlinear source and a medium voltage DC bus. The source selected for the study was a fuel cell PEM. The chosen power architecture corresponds to a cascaded structure constituted with an interleaved Boost converter at input stage and a three-level Boost converter at output stage. To design the converter, we proposed an analytical model to know the total losses in the system according to the operating point and its parameters. We showed that all losses in the converter can be modeled by two nonlinear resistors. An estimation of these resistors, deduced from average model of the converter, is developed. A control based on the concept of differential systems flatness has been used for the proposed converter structure. It allows taking into account the different system constraints. High dynamic properties as regard to external perturbations or parameters variations are achieved. In the last part of the thesis, we investigate solutions to respect the constraints on the rate of input current ripple. We propose a new active filtering converter connected in parallel with the power one. We have shown that the ripple current of a boost converter was reduced, the ripple current being reduced from 23.3% to 1.9%