Refine
Has Fulltext
- no (91) (remove)
Year of Publication
- 2019 (91) (remove)
Document Type
- Contribution to Periodical (35)
- Part of a Book (30)
- Doctoral Thesis (10)
- Report (7)
- Peer-Reviewed Article (5)
- Book (3)
- Conference Object (1)
Was ist synthetisches Gas?
(2019)
The earth as we know it can only continue to exist if humanity finds a way to switch to a sustainable use of energy and resources. This work contributes to the research carried out to achieve this goal by improving the coating of adsorptive materials. These are used in heat transformation and drying processes that allow for efficient temperature and humidity control in buildings. A central component of these adsorptive coatings is the binder that acts as "glue" in the manufacturing of the coating. In this work the methods to evaluate binder performance regarding their thermal stability under the process conditions, their mechanical stability and their influence on the adsorptive properties of the coating were established. The coatings have to meet special requirements due to the thermal stresses and low pressure atmosphere they experience in these applications. A selection of silicone binders was then characterized with the established tests according to these requirements. Additionally a selection of inorganic binders was investigated because they allow for the use of high desorption temperatures and thus a high energy efficiency of the process. Out of these binders Silres® MP50E emerged as the most promising one due to very good adsorptive properties of the coating, its good temperature stability and ease of use. While some of the inorganic binders showed very good adsorptive properties and temperature stability the mechanical stability of all inorganic binders was not sufficient for their use in adsorption heat transformation technology. This is the first time that a broad selection of binders was evaluated with regards to adsorptive coatings and the results published in literature. With a suitable binder identified, the next step was to optimize the coating of the heat exchangers in order to work out how to manufacture the most efficient and powerful heat exchangers. Samples with different coating thicknesses were manufactured in small scale and full scale and their adsorption behavior was characterized. It could be shown for the first time that it is possible to increase energy efficiency by improving the mass ration of adsorber to coating and increase the delivered power at the same time. This was shown for small and full scale samples. It was shown that under the corresponding conditions the heat transfer from the coating layer to the adsorber metal substrate is the limiting step in the process. These results can now be used for the planning and construction of adsorbers. With knowledge of a suitable binder and how to coat efficient, powerful adsorbers, the coating process itself was improved to allow for industrial scale manufacturing. A central point here is the ability to control slurry rheology. Out of many rheology additives those that are suited for the application in adsorption heat transformation were identified and their influence on the slurry rheology thoroughly characterized. Additionally the process of slurry preparation could be simplified for several different adsorbents. Here it was shown that the supersonic deagglomeration step is not necessary to prepare a slurry. Extending the possible coating techniques and in addition to the dip coating process used so far, the spray coating of adsorptive coatings was established for the first time in literature. This process is widely used in the industry and allows for easier plugin into existing coating processes. For the coating of high resolution patterns a proof of concept of the screen printing process was carried out.
Mit "InnovationCity Ruhr - Modellstadt Bottrop" soll ein typisches Stück Ruhrgebiet mit rund 70 000 Einwohnern bis zum Jahr 2020 klimagerecht umgebaut werden. Benjamin Best rekonstruiert den Partizipationsprozess des Projektes, er analysiert seine Begrenzungen und zeigt Weiterentwicklungsmöglichkeiten auf. Die empirische Studie basiert auf qualitativen Methoden der empirischen Sozialforschung, auf teilnehmenden Beobachtungen in der Modellstadt und der Teilnahme an ausgewählten Beteiligungsveranstaltungen. Mittels Interviews mit Expertinnen und Experten identifiziert der Autor kulturelle Faktoren, die die Form der Partizipation im Kontext von InnovationCity sowie den Verlauf des Gesamtprojektes bestimmt haben.
Responsible consumption and production is one of the Sustainable Development Goals of the United Nations. To achieve this goal the currently high extraction rates of natural resources, that our economy is based on, needs a transformation of the consumption and production system considering technological as well as social change. One of the promising transition approaches is seen in collaborative consumption with its many facets of socio-cultural innovations and fast growing number of participants and businesses. With a decreasing production of goods, due to a utilisation of underutilised assets, these offers might support an absolute reduction of the global resource use. However, a positive environmental effect depends on the setting and the social practices of such sharing offers and is not sustainable or resource efficient generally. Also, resource efficient practices with a low diffusion potential that stick in a niche offer no leverage to achieve sustainable consumption patterns. Thus, this paper describes a mixed method approach to analyse the resource efficiency and diffusion potential of 20 sharing offers in the area of mobility, housing & travel and everyday objects in Germany. Results show that the overall positive environmental connotation of sharing offers cannot be confirmed. We identified five clusters of offers that are all treated to be differently when it comes to deploying the positive potential and avoid unnecessary societal effort to achieve the mentioned Sustainable Development Goal.
Enhancing cross-functional integration in new product development becomes increasingly important for industrial players to keep up with shorter product life cycles in technological innovation dynamics. Abundant research reflects the topic's significance, yet ambiguity in empirical results persists and industrial adoption of existing methods remains incremental. This thesis employs a qualitative approach to build a case study at the design-manufacturing interface of new product development of electrified cars. Cross-functional coopetition, as the joint occurrence of cooperation and competition, is adopted to generate an in-depth understanding of integration dynamics. Socio-organizational and contextual aspects are found to shape integration in a new product development context substantially. A model of interface dynamics is developed which provides for analysis and prediction of these aspects' impact on effective integration. A grounded theory approach to enhance integration is explored that introduces constraints as stimuli to consider manufacturability aspects in the design process. Constraint introduction is found to positively impact both cross-functional integration and creativity, with eight characteristics of constraint quality identified as moderating factors. A theoretical model is contributed which outlines cause-effect relationships of constraints' impact on antecedents of new product development success. It substantiates constraints' role in innovation contexts and encourages application for design-manufacturing integration as well as for other interfaces or purposes.
Nun, es könnte wahrscheinlich auch anders sein : Eingriffspunkte einer Möglichkeitswissenschaft
(2019)
Die Städte nutzen den Raum
(2019)
Research on sustainability transitions has expanded rapidly in the last ten years, diversified in terms of topics and geographical applications, and deepened with respect to theories and methods. This article provides an extensive review and an updated research agenda for the field, classified into nine main themes: understanding transitions; power, agency and politics; governing transitions; civil society, culture and social movements; businesses and industries; transitions in practice and everyday life; geography of transitions; ethical aspects; and methodologies. The review shows that the scope of sustainability transitions research has broadened and connections to established disciplines have grown stronger. At the same time, we see that the grand challenges related to sustainability remain unsolved, calling for continued efforts and an acceleration of ongoing transitions. Transition studies can play a key role in this regard by creating new perspectives, approaches and understanding and helping to move society in the direction of sustainability.
The transformation of cities towards sustainable and inclusive development is a key objective of the New Urban Agenda (United Nations 2017). Transport infrastructure is a critical factor in shaping cities, determining the energy intensity of mobility and providing access to essential social and economic opportunities. The sector also plays an important role in global climate change mitigation strategies, as it currently accounts for about 23% of global energy-related greenhouse gas emissions (IPCC 2014).
There is substantial potential to improve urban access, air quality, safety and the quality of life in cities along with reducing Greenhouse Gas Emissions if an integrated policy approach is applied that combines all intervention areas for transport policy and involves all levels of government. A package that achieves low-carbon transport and fosters sustainable developed includes avoided journeys through compact urban design and shifts to more efficient modes of transport, uptake of improved vehicle and engine performance technologies, low-carbon fuels, investments in related infrastructure, and changes in the built environment. From a governance perspective, all relevant political institutions at the local and national level need to be involved in the coalition building along with key societal actors, such as unions, industry and civil society organisations. Bringing the policy objectives of these actors together with an integrated policy package is a vital step towards a low-carbon, sustainable mobility system.
Policy design and governance are critically interlinked as the ability of institutions to find a political consensus and to maintain policy stability heavily influences the success of measures to shape the transformation pathway towards sustainable mobility. This thesis aims to analyse these linkages and highlight the role of different policy and governance approaches. This analysis builds on transport and urban development research, but takes a transdisciplinary research perspective, building on the Multi-Level-Perspective on sustainability transitions (Geels 2002) and aims to highlight the potential for a consensus oriented policy approach (Lijphard 1999) that builds on co-benefits among key policy objectives and coalitions among key political actors, which leads to the main question for this thesis and the focus areas for the analysis.
To contribute to a better understanding of consumer food leftovers and to facilitate their reduction in out-of-home settings, our study analyzes the effects of two common intervention strategies for reducing leftovers in a holistic behavioral model. Based on a quasi-experimental baseline-intervention design, we analyzed how the display of information posters and the reduction of portion sizes take an effect on personal, social and environmental determinants in a structural equation model. Applying data from online surveys and observations among 880 guests (503 baseline, 377 intervention) during two weeks in a university canteen, the suggested model allows to assign effects from the two interventions on plate leftovers to specific changes in behavioral determinants. Portion size reductions for target dishes are found to relate to lower levels of plate waste based on conscious perception, represented in smaller portion size ratings. Effects from seeing information posters are found to base on changed personal attitudes, subjective norms and perceived behavioral control. However, depending on how an individual reacts to the information (by only making an effort to finish all food or by making an effort and additionally choosing a different dish in the canteen) there are opposite effects on these determinants and consequently also on plate leftovers. Overall, the differentiated results on intervention effects strongly support the benefits of more holistic and in-depth analyses of interventions to reduce plate leftovers and therefore to contribute to more sustainable food consumption in out-of-home settings.