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Neben einem populistischen Demokratieverständnis bildet auch ein majoritärer Relativismus Teil der deutschen politischen Kultur. Dieser Aufsatz argumentiert und liefert Evidenz dafür, dass es sich um zwei unterschiedliche, aber zugleich teils miteinander verwandte Demokratieauffassungen handelt und dass es wichtig ist, beide auseinanderzuhalten. Wie der Populismus erwartet der majoritäre Relativismus die möglichst unmittelbare und getreue Verwirklichung der Interessen in der Bevölkerung, er hält dabei jedoch ausdrücklich nicht an der Idee eines wahren und einheitlichen Volkswillens fest. Während beide positiv mit der Unterstützung der rechtspopulistischen Partei Alternative für Deutschland (AfD) zusammenhängen, zeigt nur der Populismus einen negativen Zusammenhang mit optimierendem Problemlösen durch künstliche Intelligenz in der politischen Führung, der majoritäre Relativismus hingegen sogar einen positiven Zusammenhang. Bemerkenswert ist zudem, dass der majoritäre Relativismus Unterstützung für die AfD besser vorhersagt als ein populistisches Demokratieverständnis. Damit leistet der Aufsatz einen wichtigen Beitrag zur Debatte über Populismus als Bestandteil der politischen Kultur in Deutschland.
Performance of pure OME and various HVO–OME fuel blends as alternative fuels for a diesel engine
(2022)
Since the potential for reducing CO2 emissions from fossil fuels is limited, suitable CO2-neutral fuels are required for applications which cannot reasonably be electrified, and therefore still rely on internal combustion engines in the future. Potential fuel candidates for CI engines are either paraffinic diesel fuels or new fuels like POMDME (polyoxymethylene dimethyl ether, short “OME”). Besides, also blends of these two types of fuels might be of interest. While many studies have been conducted on OME blends with fossil diesel fuel, the research on HVO–OME blends has been less extensive to date.
In the current work, pure OME and HVO–OME blends are investigated in a single-cylinder research engine. The test results of the various fuel blend formulations are compared and evaluated, particularly with regard to soot-NOx trade-off behavior. The primary objective of the study is to examine whether the major potential of blending these two fuels is already largely exploited at low OME content, or if significant additional emission reduction potential can still be found with higher content blends, but still without the need to switch to pure OME operation. Furthermore, the fuel blend which is best suited for the realization of an ultra-low emission concept under the current technical conditions should be identified. In addition, three different injector designs were tested for operation on pure OME3-5, differing both in hydraulic flow and in the number of injection holes as well as their layout. The optimum configuration is evaluated with regard to emissions, normalized heat release and indicated efficiency.
Due to an excellent ratio of high strength to low density, as well as a strong corrosion resistance, the titanium alloy Ti-6Al-4 V is widely used in industrial applications. However, Ti-6Al-4 V is also a difficult-to-cut material because of its low thermal conductivity and high chemical reactivity, especially at elevated temperatures. As a result, machining Ti-6Al-4 V is characterized by high thermal loads and a rapidly progressing thermo-chemical induced tool wear. An adequate cooling strategy is essential to reduce the thermal load and therefore tool wear. Sub-zero metalworking fluids (MWF) which are applied at liquid state but at supply temperatures below the ambient temperature, offer great potential to significantly reduce the thermal load when machining Ti-6Al-4 V. Within the presented research, systematically varied sub-zero cooling strategies are applied when milling Ti-6Al-4 V. The influences of the supply temperature, as well as the volume flow and the outlet velocity are investigated aiming at a reduction of the thermal loads that occur during milling. The milling experiments were recorded using high-speed cameras in order to characterize the impact of the cooling strategies and resolve the behavior of the MWF. Additionally, the novel sub-zero cooling approach is compared to a cryogenic CO2 cooling strategy. The results show that the optimized sub-zero cooling strategy led to a sufficient reduction of the thermal loads and does outperform the cryogenic cooling even at elevated CO2 mass flows.
We consider the optimization problem of a large insurance company that wants to maximize the expected utility of its surplus through the optimal control of the proportional reinsurance. In addition, the insurer is exposed to the risk of default of its reinsurer at the worst possible time, a setting that is closely related to a scenario of the Swiss Solvency Test.
There had been interesting interactions between philosophical reflections, technical developments and the work of artists, poets and designers, starting especially in the 1950s and 1960s with a stimulating cell in Stuttgart and Ulm in Germany spreading mutual international interactions. The paper aims to describe the philosophical background of Max Bense with his research on the intellectual history of mathematics and the upcoming studies on technology and cybernetics. Together with communication theories and semiotics, new aesthetics such as cybernetic aesthetics had been worked out, based on the notions of information and sign. This background stimulated international students, artists and researchers from different creative disciplines for methodical approaches leading to first computer art experiments. The interrelations in these fields with Latin America are in the focus of these studies. Students, artists, and poets from Latin America, especially Brazil, came to Germany for studies and exhibitions in the creative scientific cell around Max Bense. Some of them stayed in Europe, but the exchange developed also in the opposite direction, traveling to and working in Latin America. Some of those fruitful international interrelations will be described and reflected.
In the strive for the climate-neutral and ultra-low emission vehicle powertrains of the future, synthetic fuels produced from renewable sources will play a major role. Polyoxymethylene dimethyl ethers (POMDME or “OME”) produced from renewable hydrogen are a very promising candidate for zero-impact emissions in future CI engines. To optimize the utilisation of these fuels in terms of efficiency, performance and emissions, it is not only necessary to adapt the combustion parameters, but especially to optimize the injection and mixture formation process. In the present work, the spray break-up behavior and mixture formation of OME fuel is investigated numerically in 3D CFD and validated against experimental data from optical measurements in a high pressure/high temperature chamber using Schlieren and Mie scattering. For comparison, the same operating points using conventional diesel fuel were measured in the optical chamber, and the CFD modeling was optimized based on these data. To model the spray-breakup phenomena reliably, the primary break-up model according to Fischer is used, taking into account the nozzle internal flow in a detailed calculation of the disperse droplet phase. As OME has not yet been investigated very intensively with respect to its chemico-physical properties, chemical analyses of the substance properties were carried out to capture the most important parameters correctly in the simulation. With this approach, the results of the optical spray measurement could be reproduced well by the numerical model for the cases studied here, laying the basis for further numerical studies of OME sprays, including real engine operation.
Synthetic Biology is revolutionizing biological research by introducing principles of mechanical engineering, including the standardization of genetic parts and standardized part assembly routes. Both are realized in the Modular Cloning (MoClo) strategy. MoClo allows for the rapid and robust assembly of individual genes and multigene clusters, enabling iterative cycles of gene design, construction, testing, and learning in short time. This is particularly true if generation times of target organisms are short, as is the case for the unicellular green alga Chlamydomonas reinhardtii. Testing a gene of interest in Chlamydomonas with MoClo requires two assembly steps, one for the gene of interest itself and another to combine it with a selection marker. To reduce this to a single assembly step, we constructed five new destination vectors. They contain genes conferring resistance to commonly used antibiotics in Chlamydomonas and a site for the direct assembly of basic genetic parts. The vectors employ red/white color selection and, therefore, do not require costly compounds like X-gal and IPTG. mCherry expression is used to demonstrate the functionality of these vectors.
Many real-world optimization and decision-making problems comprise several, partly conflicting objective functions. The English saying “Quality has its price” is just as true on a large scale as it is in private sphere and, therefore, quality and price are a typical pair of conflicting objective functions that are very common in applications. Yet, in industrial applications, both quality and cost may be understood in the specific context and differ whether a transportation, a production, or a planning problem is considered. Other objective functions that are receiving increasing attention in real-world decision-making situations are, for example, robustness, time, sustainability, adaptability, or longevity.