Hydraulic devices play an essential role in mechanical engineering due to their high-power density, good controllability, flexible application and high robustness, which expose innovative methods of energy transmission. However, in applications where there is an increased risk of fire or explosion, the commonly used combustible mineral oils represent an unacceptable safety hazard. In such cases, fireresistant, water-based hydraulic fluids are in demand. A special feature of these liquids is their high cavitation tendency and the associated strong erosion wear. The aim of this research is to predict the cavitation behaviour of HFC and the subsequent erosion phenomena using numerical methods and to validate the results with experiments. Additionally, experimental results for HFC were compared with HLP. The findings help to implement further developments to decrease the erosive effect of cavitation in high-pressure differences in hydraulic components. For this purpose, flow geometries of typical hydraulic components, e.g. valve and pump, are used for experimental and numerical investigation. The large-eddy simulation (LES) turbulent modelling is used with Zwart-Gerber cavitation model. The cavitation aggressiveness is quantified by cavitation erosion indices according to Nohmi.

The goal of the PhD thesis is to investigate the role of behavioural economics considerations for the performance of conservation auctions. The findings of the three scientific articles suggest that behavioural economics considerations like social (distributional) preferences and reference-dependent preferences may affect the attractiveness and economic performance of conservation auctions, respectively. The results of the first and second articles are based on laboratory experiments conducted with university students, in Germany. The third article implements a field experiment to measure farmers’ preferences over Payments for Ecosystem Services (PES) allocation mechanisms and the role of fairness therein, in the context of agrobiodiversity loss in Benin.

The Influence of Normative Factors on Environmentally Friendly Consumer Behavior As consumer behavior is a type of environmentally significant behavior, it plays a fundamental role in environmental concerns of our time. In the long-term, current consumption and production patterns are not sustainable. The goal of this thesis was to investigate the influence of descriptive social norms on environmentally friendly consumer behavior using a randomized experiment quantitative approach. Data was collected using online surveys. Experiment results show that providing information about the behavior of others has an impact on how we perceive descriptive norms and that a change in descriptive norms influences our environmentally significant behavior intentions. This was, however, only confirmed under the circumstances when respondents identified themselves with a reference group, which was a carrier of descriptive norms. Thus, this thesis broadens our knowledge of the impact of descriptive norms on environmentally friendly behavior, because it was previously assumed that descriptive norms are a significant factor only in situations with strictly defined reference groups. On the contrary, this research shows the impact of descriptive norms even in cases of relatively abstract groups with defined criteria for...

This dissertation thesis deals with the exploration of the issue of electronic learning supports intended to boost controlled self-study within university environment. This paper proceeds from the presumption that electronic learning supports are a suitable tool with a didactic potential in education which will make university self-study more effective and which will help students to meet the demanded requirements even more effectively than with commonly used learning materials. The paper deals with the definition of conceptual constructs from the field of electronic learning supports and also with the analysis of their didactic capabilities, limits and ways of usage with added specification of functional and didactic aspects of audio-visual learning supports. The empiric part of the paper uses a pedagogic experiment to verify the influence of the electronic learning supports on the university student's results within the controlled self-study. The paper complexly develops the theory of electronic learning supports from the point of view of current didactic resource and its inclusion into current structures of pedagogy and didactics.

A novel constitutive characterization method for uncured rubber behaviour has been developed in this article. A systematic measuring procedure was designed to fully investigate the uncured rubber complex stress–strain behaviour under different deformation patterns, which integrated three kinds of tests – the uniaxial tensile, the compression test and the shear test. It can be found from the observed behaviour that the uncured rubber has similar but much pronounced non-elastic stress–strain relationship, which is highly non-linear and highly rate dependent. A generalized Maxwell model with modified Yeoh model is developed to constitutively describe the observed phenomena in which parameters are identified by an evolution optimization scheme. Good agreement can be found between the model and the test data. Another finding is that, similar to vulcanized rubber, multi-test data are needed to obtain compatible constitutive models. The test results, findings and the developed model help rubber engineers deeply understand the uncured rubber’s mechanical behaviour and provide a base for rubber manufacturing simulation.

En Guadeloupe, depuis 2008, les autorités locales ont fortement encouragé l’organisation des filières de traitement des déchets. En ce qui concerne les déchets organiques, une voie privilégiée de valorisation est le recyclage en compost. Dans cette thèse nous étudions les conditions d’émergence d’une filière de recyclage des déchets organiques du territoire à travers l'analyse des conditions d'adoption de la pratique d’utilisation de composts par les agriculteurs. Nous nous appuyons sur une approche originale combinant une analyse ex post des pratiques actuelles et des perceptions des agriculteurs et une analyse ex ante par Choice Experiment de leviers visant à favoriser l’adoption des composts. Nous testons donc des leviers d’ordre biotechniques concernant les propriétés des composts et les modalités de leur utilisation, et des leviers d’ordre économiques à travers des Mesures Agro-environnementales et Climatiques (MAEC), afin de proposer aux décideurs politiques des leviers d’actions pertinents. Nous constatons que le taux d’adoption est faible (18%) et dépend fortement de la filière agricole, des caractéristiques socio-économiques des agriculteurs et du manque d'organisation de la filière de recyclage des déchets (p.ex. information, transport, épandage, subventions). Nous montrons que les agriculteurs sont sensibles, sur le plan biotechnique, à une amélioration de la valeur fertilisante des composts ainsi qu’à un accompagnement logistique pour son transport et son épandage et, sur le plan économique, à la mise en place d’un dispositif d’accompagnement administratif et à une incitation collective sous la forme d’un bonus monétaire conditionnel versé individuellement aux agriculteurs. Dans l'ensemble, les résultats de ce travail montrent que les agriculteurs ne sont pas réfractaires à une utilisation conséquente et régulière du compost, à condition que les verrous organisationnels que nous avons identifiés soient levés, et que la valeur agronomique des composts répond aux attentes des filières agricoles. Des plans de développement peuvent maintenant être définis et mis en œuvre à l’échelle du territoire pour développer l’utilisation massive de composts issus du recyclage des déchets organiques du territoire. / Due to the limited availability of landfill sites, local authorities have strongly encouraged since 2008 the structuration of waste treatment channels. As concerns the organic wastes, a special attention has been paid for recycling them through composting. In this study, we focused on the conditions of development of a sector for recycling organic wastes in Guadeloupe through the assessment of the conditions affecting compost adoption by farmers. In order to identify and evaluate the determinants of farmers 'choices, we applied an original approach combining an ex-post analysis of current practices and farmers' perceptions, and an ex-ante analysis using the Choice Experiment method of levers for facilitating the adoption of compost. We test biotechnical levers concerning compost properties and the facilitation of practices with technical support, and economic levers mainly focused on the implementation of new AgroEnvironmental Schemes (AES) to promote economically the composts. We observed that the adoption rate is relatively low (18% of farmers) and highly dependent on the agricultural sector (i.e. banana, sugarcane, vegetables and food crops), the socio-economic characteristics of the farmers and the lack of organization of the waste recycling chain (e.g., information, transport, spreading, subsidies). We demonstrated that farmers are very sensitive to the improvement of compost quality by increasing its fertilizer value, as well as to the logistical, economic and administrative support for its transport and spreading. They are also willing to participate in a collective incentive in the form of a conditional monetary bonus paid individually to farmers. The results of this study indicated that farmers are not reluctant to a regular use of compost provided that organizational barriers identified are removed, and that the agronomic value of the composts meets the expectations of farmers. Regional plans can now be defined and implemented to develop the massive use of compost from the recycling of organic waste in Guadeloupe.

The phenomenon of "fake news", or misleading online content, is increasingly worrisome due to its large-scale socio-economic impact. Researchers and practitioners attempted to understand what drives the virality and believability of fake news and how to reduce its influence. This research aims to shed light on these questions. Building upon a theoretical account positing that people share fake news because they simply fail to engage in deliberate thinking, we designed an accuracy prompt intervention to encourage people to think effortfully. In a pre-registered study conducted via Prolific (N = 520), we find limited evidence supporting accuracy prompts stylized as warning labels, but only for increasing sharing discernment in true, not fake news. The veracity of news articles does not impact sharing intentions, despite having a sizeable effect on accuracy judgments. This and other findings support the dual processing theory of cognition in the context of fake news. Predispositions towards more intuitive thinking increased belief in fake news and higher distrust in true news. Conversely, a better ability to engage in effortful thinking increases truth discernment. In addition, confirmation bias decreases truth discernment and increases sharing intentions. Politically concordant true headlines are...

Unter Benutzng von 90.4/fb Daten, die das BABAR-Experiment in den Jahren 1999 bis 2002 genommen hat, wurden die Zerfälle Ds*+ -> Ds+ pi0 und Ds*+ -> Ds+ gamma mit zwei verschiedenen Methoden rekonstruiert. Die Rekonstruktions-Effizienzen wurden mittels Signal-Monte Carlo-Ereignissen und D*0-Zerfällen ermittelt. Auf diese Weise wurde das Partialbreiten-Verhältnis Gamma(Ds*+ -> Ds+ pi0) / Gamma(Ds*+ -> Ds+ gamma) auf vier verschiedene Weisen gemessen. Zusätzlich wurde das Partialbreiten-Verhältnis Gamma(D*0 -> D0 pi0) / Gamma(D*0 -> D0 gamma) gemessen. / Using 90.4/fb of data taken at the BABAR experiment in the years 1999 to 2002, the decays Ds*+ -> Ds+ pi0 and Ds*+ -> Ds+ gamma have been reconstructed with two different methods. Signal Monte Carlo events as well as D*0 decays have been used to determine the reconstruction efficiencies. Thereby, the partial widths ratio Gamma(Ds*+ -> Ds+ pi0) / Gamma(Ds*+ -> Ds+ gamma) has been measured in four different ways. Additionally, the partial widths ratio Gamma(D*0 -> D0 pi0) / Gamma(D*0 -> D0 gamma) has been measured.

Possibilities of Portal Vein Reconstruction during Surgical Treatment of Pancreatic Cancer - Experiment on a Large Animal Introduction: Pancreatic cancer is a fatal malignancy that is known as one of the leading causes of cancer mortality worldwide. The only potentially curative treatment is radical surgical resection. Because of the lack of early symptoms, the diagnosis is usually made in advanced stages of the disease. In the majority of patients, the tumor is already locally advanced or it has distant metastases at the time of diagnosis. Pancreatic cancer tends to infiltrate the portal vein (PV) or the superior mesenteric vein (SMV). Nowadays, resection of infiltrated parts of PV/SMV is recommended in specialized centers. There are several established techniques of PV/SMV reconstruction. The use of allogeneic venous grafts seems to be a method with minimal risk of adverse effects but there is only limited experience with these grafts. The optimal anatomical origin of allogeneic venous grafts for PV/SMV reconstruction remains unknown. Aims: The aim of this experiment was to compare two types of allogeneic venous grafts used for PV reconstruction in a large animal model of pancreatico- duodenectomy. These grafts were harvested from the systemic venous system (inferior caval vein grafts - IVC grafts) and...

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