Schwer zugängliche Anlagen müssen per Fernwartung projektiert und in Betrieb genommen werden. Während der Corona-Krise rückten die hierfür zugrundeliegenden Technologien auch in den Blickpunkt der Lehre, um Studierenden, die keinen Zugang zu den Versuchsaufbauten an der Hochschule hatten, die Interaktion mit realen Anlagen zu ermöglichen. Deshalb wurde an der Hochschule Mannheim ein System entwickelt, das Kommunikationskonzepte der Industrie 4.0 zur Vernetzung von Steuerungen im Internet, das cloudbasierte Engineering sowie die bildgestützte Inbetriebnahme an einer realen Experimentieranlage veranschaulicht. Eine automatische Bildauswertung soll die Anlage überwachen, um Störfälle, die etwa durch Programmierfehler eintreten könnten, zu vermeiden. Aber auch schlecht eingestellte Regler oder unzureichend kalibrierte Sensorik, was z.B. durch Alterung verursacht sein kann, soll durch die Bildverarbeitung automatisch erkannt werden. Die Bildverarbeitung dient somit zur automatisierten Erfolgskontrolle der entwickelten Software und der in Betrieb genommen Anlage.

Die Programmierung von SPS-Systemen erfolgt hauptsächlich händisch, obwohl große Teile des Programmcodes sehr ähnlich sind und sich häufig nur durch die eingesetzten Variablen unterscheiden. Der Beitrag befasst sich mit der Entwicklung und Testung einer Codegenerierungssoftware für das TIA Portal, um den Zeitaufwand der Programmierung zu reduzieren und Flüchtigkeitsfehler zu vermeiden.

Die gestellten Anforderungen an moderne Fertigungssysteme wachsen stetig. So werden neben einem großen Durchsatz bei gleichzeitig hoher Produktqualität auch Anforderungen in Hinblick auf Kompaktheit, Energieeffizienz, Erweiterbarkeit und Cyber-Resilienz gestellt. Derzeitige Fertigungssysteme basieren häufig auf einer Vielzahl an Subsystemen. Dies erhöht die Komplexität des Systems und es kann auf Grund der vielen Schnittstellen zu Performanceeinbußen in der Datenübertragung kommen. Um den Bedürfnissen für flexible und hochintegrierte Fertigungssysteme gerecht zu werden, werden daher leistungsfähige Steuerungen benötigt, die alle Funktionen zentral in einer Steuerung vereinen. In diesem Beitrag werden zwei Maschinendemonstratoren betrachtet, die eine Industrie-PC basierte Maschinensteuerung einsetzen und bei denen das Produkttransportsystem im Zentrum der Anlage steht. Die Vor- und Nachteile eines zentralen gegenüber einem dezentralen Konzept werden gegenübergestellt und diskutiert. Es wird außerdem demonstriert, dass durch die Verwendung einer zentralen Steuerung Synergien effizient ausgenutzt werden können, wodurch der Lebenszyklus des Fertigungssystems verlängert werden kann. So werden z. B. auf beiden Systemen Convolutional Neural Networks eingesetzt, um den Produktstrom in der Anlage zu steuern. Die Inferenzzeit der optimierten Modelle beträgt hierbei weniger als 430 μs bei einer Klassifizierungsgenauigkeit von 100%.

Religious institutions as transnational actors play a very important role within the context of transnational migration. Religious transnational space is formed and shaped with the involvement of different actors, particularly through the agency, commitment and religious practices of migrants that reproduce or reconstruct their religions in a new setting. Religious institutions, which are actively involved in all stages of migration or are pulled into the transnational space by migrants, gain a new area of agency within the transnational space. However, the extent of the involvement and agency of the religious institutions within the transnational migration space differ and to what extent religious institutions cope with this new area of agency requires a closer examination. The primary interest for this research initiative is, therefore; the role religious institutions play in the articulation of transnational ties as well as the processes through which transnational migration trigger structural and cultural changes in the way religious life is organized and experienced. In particular, this research project analyzes the way in which the Romanian Orthodox Church (ROC) acts, organizes and positions itself within the religious landscape of Italy following the mass migration of Romanians into Italy, its adaptive practices and socio-religious role within the receiving context and implications of this experience within the sending context as well as the extent of the ROC's agency within the Romanian-Italian transnational migration space.

Come si configurano i percorsi di militanza all’interno della Lega Nord? Quali processi di costruzione e rappresentazione di cultura, ideologia e identità emergono al suo interno? Che tipo di partito si incontra, spostando lo sguardo dall’attore politico, per osservare invece i processi situati che sostanziano l’organizzazione politica ? Questi i principali interrogativi alla base della ricerca etnografica condotta all’interno di due sezioni, l’una collocata in un piccolo centro della provincia veneta, l’altra in un contesto metropolitano lombardo.

The thesis investigates the impact of extra-individual factors on electoral participation, by providing a comprehensive theoretical framework aimed at highlighting the role of context. In particular, it analyzes the key-concepts of mobilization and interpersonal influence, with a focus on the Italian case. Both experimental and survey data are employed to answer the research questions. Concerning mobilization, main findings show that personal forms of contact, such as face-to-face interactions with party members, are more successful than impersonal forms, which prove to be ineffective. When looking at the interpersonal influence, the thesis shows that the exposure to political disagreement has differentiated effects on turnout, depending on the level of cohesiveness of the social circle where disagreement is experienced.

This project investigates the evolution multilateral nuclear non-proliferation arrangements to prevent state and non-state actors to access potentially destructive weapons and components thereof. While less scrutinized by political scientists and security experts, cooperative frameworks abound in practice. This begets questions as to the mechanisms and processes by which actors effectively cooperate in a crowded, complex and pluralist environment. Which factors determine the success and resilience of non-proliferation arrangements? How much explanatory power do cognitive beliefs and institutional practices command to understand and explain variance in governance effectiveness? While previous studies have focused on the ‘front-end’ of cooperation by examining factors leading states to cut deals, others have focused on the ‘back-end’ by focusing on the role of military and diplomatic means, such as alliances, coercion and the role of law. In addition, while scholarship on cooperation neglects sovereignty-conscious issues, non-proliferation studies disregard what happens between the ‘front- and the backend’ of the cooperation loop. This work analyzes three arrangements – the review process of the Nuclear Non- Proliferation Treaty, U.N. Security Council Resolution 1540 and the Nuclear Security Summits. Using case study analysis, elite interviews and participant observation, this study undertakes an investigation from a cognitivist perspective and examines the “principles, norms, rules, and decision-making procedures” governing non-proliferation. While factors related to knowledge and learning affect actors' understandings of risks and their mitigation pathways, their impact is intertwined with idiosyncratic factors, with crisis as overarching and crosscutting thread. Theoretically, compared to neorealism and neoliberal institutionalism, cognitive approaches to international regimes provide the most cogent explanations to account for governance effectiveness, but cannot wholly explain a case. Operatively, effective and resilient nuclear non-proliferation governance should provide for permanent interaction whereby novel implementation and monitoring mechanisms are experimented in a sovereignty-respecting way.

Cosmologies of destinations investigates some commonly neglected dimensions of forced migration. It examines the key symbolic structures and social mechanisms which encourage and sustain the mobility trajectories of Eritreans from their home country to Ethiopia, Sudan, Italy and beyond. The central argument is that, in refugee-producing countries which suffer from protracted crisis and livelihood disruption, refugee movements become much more than a form of reactive mobility. Within these communities, becoming a refugee is not only a way to escape oppressive conditions but also the outcome of socially and symbolically embedded strategies aimed at personal realization and family well-being. Building on a multi-sited ethnography of the everyday life of Eritrean refugees in a number of settings (including homes, refugee camps, urban squats, and other settings of sociability) in their home country as well as in Ethiopia, Sudan and Italy, the thesis explores the range of social and economic resources needed to circumvent legal and geographic borders, and the moral and cultural norms that underpin these practices. It contributes to the theorization of refugee mobility, which is currently somewhat underdeveloped, by providing a framework to analyse high-risk forced migration, based on an emic understanding and systematic description of the living conditions, life aspirations and risk perceptions of Eritreans in their home country and in transit to Europe. The study feeds into the broader debate on the blurring boundaries between labour and forced migration by emphasising the social and cultural, along with the structural, determinants of mobility and immobility. The thesis is divided into five chapters. The first analyses the conditions that make exit a widespread and legitimate, albeit controversial, option for young people in Eritrea. The second chapter provides accounts of refugees' everyday lives in the first safe countries (Ethiopia and Sudan), chronicling the dynamics that trigger secondary movements towards Europe. The third analyses the lives of Eritrean refugees in Italy, documenting the conditions that activate further mobility within Europe. The fourth chapter describes the migratory infrastructures that allow for these refugee movements, including the role played by transnational marriages, smugglers and family networks. The final chapter provides a micro-analysis of decision-making, aimed at explaining the willingness of refugees to take great risks at different stages of the migration process. A methodological note narrates how the research was carried out in the various sites and analyses the implications of multi-sited ethnographic fieldwork with refugees.

The work aims at addressing in a unified framework a variety environmental/contextual factors (geographical, campaign- and network-related). In doing so, theoretical and empirical relation between these various levels are investigated, as well as responses by which individuals can react to environmental stimuli. From the methodological side, hypotheses of the work are tested by means of multilevel regression models and agent-based simulations.

Le carbure de silicium (SiC), grâce à sa légèreté, son caractère réfractaire, sa tolérance à l’oxydation et sa faible absorption des neutrons, constitue un candidat intéressant pour des applications comme l’aéronautique, l’aérospatiale ou le nucléaire du futur. Cependant, son comportement fragile est un inconvénient majeur qu’il convient de dépasser pour ces applications. La réduction de la taille des grains à une échelle nanométrique pourrait contribuer à améliorer son comportement mécanique pour être utilisé sous forme monolithique, en tant que revêtement ou bien encore en tant que matrice dans un compositeCette thèse s’inscrit dans ce contexte, et s’intéresse à l’élaboration et à l’étude des propriétés thermomécaniques de composites à matrice SiC nanostructurée renforcée par des nanotubes de carbone. Dans un premier temps les travaux se sont portés sur l’élaboration et l’étude de l’effet de la nanostructuration de la matrice seule de SiC frittée sans ajout de frittage. Des échantillons nanostructurés (taille moyenne des grains de 100 nm) et denses à plus de 95,5% ont été obtenus grâce à la mise en place d’un procédé de dispersion efficace et à l’étude des effets des paramètres de frittage. Associés à ces hautes densités, de très bonnes duretés (jusqu’à 2200 Hv) et des ténacités convenables (3,0 MPa.m1/2) ont été atteintes. Ces travaux ont également montré l’importance primordiale de l’effet de polluants fréquemment rencontrés dans les poudres (oxygène et carbone) sur la microstructure et les propriétés mécaniques du SiC. Si l’oxygène, présent sous forme de silice ou d’oxycarbure de silicium semble favoriser les mécanismes de densification, un excès de carbone libre (3,5%m) provoque au contraire une diminution de la taille des grains et des densités. Les propriétés mécaniques (950 Hv et 2,4 MPa.m1/2) sont également sensiblement affectées. Une telle dégradation est expliquée par la localisation spécifique du carbone structuré entre les grains de SiC. La deuxième partie des travaux s’est concentrée sur l’ajout de Nanotubes de Carbone (NTC) dans la matrice SiC nanostructurée dans le but d’améliorer les propriétés mécaniques et de compenser la forte réduction de la conductivité thermique, détériorée par l’augmentation importante de la densité de joints de grains. Des crus chargés jusqu’à 5%m en NTC individualisés et répartis de façon homogène ont été réalisés. De manière similaire au carbone libre, la localisation spécifique des NTC cause une diminution de la taille des grains. L’établissement d’un réseau de percolation de NTC au-dessus de 1%m, associé à la méthode de frittage non conventionnel SPS, permet cependant d’améliorer les densités jusqu’à 97%. L’apport de NTC contribue également à l’obtention de dureté (jusqu’à 2550 Hv) et de ténacité (4,0 MPa.m1/2) plus élevées. Malgré les bonnes propriétés thermiques des NTC, l’augmentation de la densité des joints de grains amoindrit la conductivité thermique de nos composites. / Ceramic carbides materials such as SiC, due to their refractory nature and their low neutron absorption are believed to be promising candidates for high temperature nuclear or aerospace applications. However, SiC brittleness has limited its structural application. In this context this work examines in a first part the possibilities to perform dense nanostructured SiC matrix by SPS without the use of sintering additive. Indeed a reduction of grain size (below 100 nm) accompanied by a high final density seem to be the solutions to counteract the brittleness and thus to improve mechanical properties. Dense (95%) and nanostructured (grain size around 100 nm) SiC samples were obtained thanks to the realization of an effective dispersion technique and the study on the sintering parameters effect. High hardness (2200 Hv) and decent fracture toughness (3.0 MPa.m1/2) were achieved. This first work also showed the preponderant influence of recurrent pollutants (oxygen and carbon) found in SiC powders on the final microstructure and mechanical properties of sintered samples. The oxygen as silica or silicon oxycarbide seems to promote densification mechanisms while free carbon (3.5%wt) causes lower grain size and densification state. Mechanical properties with carbon are also negatively impacted (950 Hv and 2.4 MPa.m1/2). Such degradation is due by the specific localization of carbon structure between the grains. In return of the expected mechanical properties improvement by reducing the grain size, the thermal conductivity is drastically decrease of due to the phonon scattering at the grain boundaries. With the aim of reducing this effect, a second study was initiated by introducing multiwalled carbon nanotubes (MWCNTs) into the SiC matrix. The MWCNTs by exhibiting a high toughness could also help to enhance the mechanical properties. Green bodies with different amounts of well dispersed MWCNTs (0%wt to 5%wt) were realized. Like free carbon, MWCNTs are located between the grains and induce a reduction of grain size. However the appearance of CNTs percolation for an amount above 1%wt, with the SPS sintering technique, allows an improvement of densification up to 97%. Hardness (up to 2550 Hv) and fracture toughness (4.0 MPa.m1/2) are also achieved with the SiC/NTC composites. Despite the good thermal properties of MWCNTs, the increase of grain boundary decreases the thermal conductivity of these composites.