Trends in European Climate Change Perception: Where the Effects of Climate Change go unnoticed

Climate change threatens global impacts in a variety of domains that must be limited by adaptation and mitigation measures. The successful implementation of such policies can strongly benefit from the general public’s cooperation motivated by their own risk perceptions. Public participation can be promoted by tailoring policies to the populations they affect, which in turn results in the need for a deeper understanding of how different communities interact with the issue of climate change. Social media platforms such as the microblogging service Twitter have opened unprecedented opportunities for research on public perception in recent years, offering a continuous stream of user-generated data. Simultaneously, they represent a crucial discursive space in which members of the public develop and discuss their opinions and concerns about climate change. Subsequently, this thesis gains insight into the characteristics of public reactions to individual climate change effects and processes by investing corresponding corpora of tweets spanning a decade. For seven western European countries, the spatial, temporal, and thematic reaction patterns are determined with a further assessment of the drivers behind each finding. Tweets are collected, classified, georeferenced, and clustered using a selection of Geographic Information Retrieval as well as Natural Language Processing methods before being analysed regarding thematic trends in their content, spatial distributions and influences of environmental factors, as well temporal distributions and impacts of real-world events. The findings illustrate diverse climate change perceptions that vary across spatial, temporal, and thematic dimensions. Communities tend to focus more on issues relevant to their local or national environment, leading populations to develop a certain degree of specialisation for these aspects of climate change. This typically coincides with a substantially more domestic discourse on the subject and a decrease in interest for corresponding international events. In a similar sense, the tangibility of an event drives the magnitude of reactions. However, while more tangible events are more frequently recognised and discussed, less tangible events tend to be more frequently attributed to climate change as the public shifts their focus from immediate impacts on the personal scale to impacts on the global scale. Additionally, traditional news media are shown to retain a high level of control over science communication and the climate change discourse on Twitter, likely influencing the public’s perspective on global warming. Individual real-world events such as major climate conferences and scientific releases only occasionally elicit strong public reactions when they are topically related to an event type, whereas global protests can lead to significant discussion across various event types. Inversely, global crises such as the COVID-19 pandemic significantly reduce public concern about climate change processes

Stochastic Yield Catastrophes and Robustness in Self-Assembly

A guiding principle in self-assembly is that, for high production yield, nucleation of structures must be significantly slower than their growth. However, details of the mechanism that impedes nucleation are broadly considered irrelevant. Here, we analyze self-assembly into finite-sized target structures employing mathematical modeling. We investigate two key scenarios to delay nucleation: (i) by introducing a slow activation step for the assembling constituents and, (ii) by decreasing the dimerization rate. These scenarios have widely different characteristics. While the dimerization scenario exhibits robust behavior, the activation scenario is highly sensitive to demographic fluctuations. These demographic fluctuations ultimately disfavor growth compared to nucleation and can suppress yield completely. The occurrence of this stochastic yield catastrophe does not depend on model details but is generic as soon as number fluctuations between constituents are taken into account. On a broader perspective, our results reveal that stochasticity is an important limiting factor for self-assembly and that the specific implementation of the nucleation process plays a significant role in determining the yield

Standard-Compliant Gasoline by Upgrading a DTG-Based Fuel through Hydroprocessing the Heavy-Ends and Blending of Oxygenates

Methanol-to-gasoline (MTG) and dimethyl ether-to-gasoline (DTG) fuels are rich in heavy aromatics such as 1,2,4,5-tetramethylbenzene, resulting in low volatilities due to a lack of light ends, increased emission tendencies and drivability problems due to crystallization. Approaches addressing these issues mainly focus on single aspects or are optimized for petroleum-based feedstocks. This research article introduces an upgrading strategy for MTG and DTG fuels through hydroprocessing (HP) heavy-ends and applying a sophisticated blending concept. Different product qualities were prepared by HP heavy gasoline (HG) and Fischer-Tropsch wax using commercially available Pt/HZSM-5 and Pt/SAPO-11 catalysts in a fixed-bed reactor. The products were used for blending experiments, focusing on gasoline volatility characteristics. Accordingly, methanol, ethanol, methyl tert-butyl ether (MTBE), and ethyl tert-butyl ether (ETBE) were evaluated in a second blending experiment. The results were finally considered for preparing blends meeting EN 228. HP of HG was found to improve the amount of light-ends and the vapor pressure of the DTG fuel with increasing reaction temperature without, however, satisfying EN 228. The front-end volatility was further improved by blending methanol due to the formation of near-azeotropic mixtures, while ethyl tert-butyl ether (ETBE) considerably supported the mid-range volatility. A final blend with an alcohol content of less than 3 vol.%, mostly meeting EN 228, could be provided, making it suitable even for older vehicles

Entwurf eingebetteter Systeme: Ausführbare Modelle und Fehlersuche

Graphische Modelle können mit Hilfe modellgetriebener Ansätze als Programmiersprachen für eingebettete Systeme genutzt werden. Die Arbeit schließt vorhandene Lücken und liefert einen Beitrag zur Zustandsvisualisierung während der Laufzeit zum Zweck der Fehlersuche in solchen Modellen. Dieser resultiert in der flexiblen Debugging-Architektur ModelScope. Die Leistungsfähigkeit von ModelScope wird durch Anbindung unterschiedlicher Modellierungsparadigmen und Ausführungsplattformen validiert

Untersuchung von irregulären Verbrennungsphänomenen an aufgeladenen Ottomotoren mit Direkteinspritzung

In dieser Arbeit wurden der Einfluss der Thermodynamik, der Gemischbildung, von Ablagerungen und Kraftstoffeigenschaften auf das Vorentflammungsverhalten anhand von experimentellen Untersuchungen mit konventioneller Messtechnik an aufgeladenen Mehrzylinder-Ottomotoren mit Direkteinspritzung bewertet. Zusätzlich wurden einige ausgewählte Betriebspunkte mit Hilfe einer High-Speed-Kamera in Kombination mit einer Lichtleiter-Zündkerze detaillierter analysiert

Jeffrey Herf: Unerklärte Kriege gegen Israel

Jeffrey Herf: Unerklärte Kriege gegen Israel: Die DDR und die westdeutsche radikale Linke, 1967–1989. Aus dem Englischen von Norbert Juraschitz, Göttingen: Wallstein 2019, 518 S., ISBN: 978-3-8353-3484-7, EUR 39,00. Besprochen von Philipp Graf

Manufacturing Change Management - A Survey On Current Challenges, The State Of Digitalization And The Application Of Change Impact Analysis In Industrial Practice

Modern manufacturing companies operate in a complex and highly dynamic environment. External factors such as new legislations and customer demands, as well as internal factors such as fluctuations in production rates and frequent product changes, make it essential for companies to respond quickly and effectively to changes of all kinds. Scientific literature already provides various processes and methods to manage Manufacturing Changes (MCs) efficiently and to precisely assess their possible impacts. Building upon the existing literature, this survey-based study aims to gain practical insights into the implementation of Manufacturing Change Management (MCM) and Change Impact Analysis (CIA) in real-world industrial settings. By examining the current challenges and exploring the state of digitalization, this research provides valuable insights to complement and further develop the existing theoretical frameworks. In order to gather diverse knowledge from experts across various industries, a web-based survey was conducted, with 99 participants representing 15 different industries. After introducing the necessary theoretical foundations and the current state of research in MCM literature, this contribution describes in detail the methodology of the survey development. The survey findings are then outlined and discussed thoroughly. Finally, the contribution concludes by offering an outlook on future research perspectives based on the identified industry challenges

Serological Response to Treatment of Syphilis According to Disease Stage and HIV Status

The serological response to treatment was studied in 264 syphilis patients; it was influenced by syphilis stage but not by human immunodeficiency virus infection and reinfection. Some of the recommendations of current guidelines are critically discussed, and amendments are propose