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The present study deals with the phenomenological observation of the corrosion of the positive electrode foil of lithium-ion batteries containing LiNi0.6Co0.2Mn0.2O2 (NMC) as cathode material. Due to the presence of moisture, localized water accumulation is formed on the NMC surface. The water absorbed by the electrolyte reacts with the NMC under Li+/H+ exchange and the resulting pH increase leads to dissolution of the carrier foil and characteristic salt-like blooms on the NMC surface. With the increase in the relative area occupied by the holes in the aluminum foil per time, a sufficiently suitable parameter was found with which to quantitatively determine the extent of corrosion. The degree of degradation depends on time and ambient humidity. It was shown that functional recycling with the water jet method is no longer applicable for degraded foils, since the mechanical stability of the foils decreases as corrosion progresses. Lithium, aluminum, sulfur and oxygen were detected in the blooms using SEM–EDX and Laser-Induced-Breakdown-Spectroscopy (LIBS). The underlying NMC layer was found to contain mainly aluminum and significantly lower lithium content than the non-degraded material. SEM and Raman microscopy analyses also showed that the active material is also locally degraded and therefore no longer suitable for functional recycling.
Possible synergy between FLEGT-VPA & REDD+ towards improving forest governance framework in Cameroon
(2023)
Illegal logging is seen as a serious impediment to achieving sustainable management of forests in the tropics. In addition, deforestation contributes in increasing carbon dioxide emissions in the atmosphere, resulting to biodiversity loss and climate change. Illegal logging and deforestation have affected Cameroon’s forest ecosystem negatively since the mid-1980s as a result of the economic crises, which intensified the exploitation of forest resources for multiple purposes. In response, some policy initiatives came up such as FLEGT-VPA and REDD+ to fight against the threats. It is due to the above background that this study was designed to examine the possible synergy between FLEGT-VPA and REDD+ towards improving the forest governance framework in Cameroon. The first part of the study assesses FLEGT-VPA in Cameroon with the application of interviews of key informants who were involved in the negotiation process of the EU-Cameroon Voluntary Partnership Agreement. The second part of the study assesses the management of Bimbia Bonadikombo Community Forest (BBCF), as one of the REDD+ pilot project sites around Mount Cameroon in the South West Region of Cameroon. The use of surveys, content analysis, and observations seeks to assess these two initiatives in their role in improving forest governance in Cameroon. The first part of the research reveals that since Cameroon ratified the FLEGT-VPA in 2011, there has been progressed concerning stakeholder participation in forest-related issues. Again, the study also reveals challenges faced with the setting up of a system to verify timber from legal origin as recommended by the European Union. The research further reveals a lack of commitment by the government in revising the current forest policies and re-organizing the domestic market for timber trade as part of the commitment made by the government during the ratification of the FLEGT-VPA. The second part of the study finds that the management of BBCF is not governed by the provision of the Cameroon community forestry manual or by its bylaws posing doubts if community forestry can halt emissions of greenhouse gases caused by deforestation, thus helping REDD+ achieve its objectives. The study recommends the need for rapid policy reform and a cross-sectoral transformation to enable FLEGT-VPA and REDD+ to synergize for a better policy outcome on issues concerning forestry and climate change.
The next generation of civil turbofan engines targets the by-pass ratios of up to 20:1, requiring an innovative fan design with a low fan pressure ratio, low specific thrust and a radically increased fan diameter. The aerodynamic stability of such a large slow rotating fan is very sensitive against the back-pressure variations in the by-pass duct, especially during the take-off operations. The back-pressure regulation can be achieved significantly through a Variable Area Fan Nozzle (VAFN). This work deals with the design development of VAFN concepts for ultra-high by-pass ratio engines which was researched in EU funded program ENOVAL and received funding under grant agreement number 604999.
A system engineering approach was implemented for the VAFN development by following the requirements in conceptual, preliminary and detailed design phases. The design domains in the rear nacelle and under the core fairing were selected for the concept generation. Several qualitative and quantitative trade studies were conducted to down-select the best-fit solution during each design phase. These included the kinematic simulations of various types of VAFN modulations; analytical calculations to understand the thermodynamics of the selected VAFN kinematics; aerodynamic performance predictions using CFD simulations on a large number of preliminary designs; 3D CFD simulations for detailed performance assessments including the design optimization of individual features and distortions due to failed modulations; and FEM calculations for the topology generation and optimization of structural components. The overall weighted effect was determined for each output parameter and the results were presented in percentile changes relative to that with a fixed nozzle reference geometry.
Two VAFN concepts were selected for the final detailed design phase, Flaps in rear nacelle domain and Variable Inner Fairing Structure (VIFS). Both concepts showed better outputs in terms of specific fuel consumption, noise emission and fan’s safety margin during the take-off, with an over-area exhaust position than those with a fixed nozzle operation. During the climb phase, with an under-area VAFN position, both concepts resulted in drawbacks due to higher aerodynamic losses relative to the fixed nozzle. During MCR, both the VAFN concepts with stowed positions caused losses mainly due to leakages and higher structural weights relative to the fixed nozzle configuration. For each VAFN concept, a detailed system definition was developed and the function trees for each operation were explained. A discrete modulation type with two positions was described and recommended for both concepts. This included an over-area deployed position for the take-off phase and a stowed position for the rest of the flight, based on the beneficial performance of the VAFN concepts over the fixed clean nozzle configuration.
The creation of adequate simulation models for complex assemblies is an extensive process that requires a lot of experience, and on the other hand involves a multitude of manual, tedious tasks. These are significant obstacles for improving the process performance and capabilities. The objective of this research is to develop methods which digitally imitate the way of thoughts of the engineer in the design process towards a digital system understanding and which support the automation of the involved manual workflow.
This thesis presents a strategy to translate engineering reasoning and actions to an equivalent in the computer domain. A cardinal step is to gain understanding of system arrangements, boundary conditions and its components. Based on this evaluation, the identification of assembly parts is forming the foundation for optimized process chains for the transfer to the analysis environment. Model complexity relates to computational effort, which in turn affects model capabilities and manageability. To achieve a satisfactory compromise of model quality and complexity, this transfer process is strongly dependent on the visual analysis, reasoning and manual implementation of skilled engineers.
The principle of translating engineering logics is pursued from the assembly system to its smallest parts. Component segmentation methods allow subdividing regions of interest into substructures which are assigned with a feature vector. This vector comprises metrics describing the substructures with regard to specific aspects and is the key decision point for subsequent steps as idealization, suitable Finite-Element modeling and ultimately building an analysis model. The created system database is continuously maintained and supports these process chains as well as the final setup of the assembly simulation model.
An automated workflow like this implies advantages for efficiency, but also creates opportunities for further use cases. This workflow has been exploited for generating a training data set from the different simulation variants as a basis to a knowledge representation imitating engineering experience. An algorithm from the graph neural network field is applied to this data set as a conceptual approach. The intention pursued in this concept is to model the learning progress about estimating the influence of modelling decisions on simulation results and quality.
This research proposes a holistic strategy and describes methods to achieve the objectives of decreasing manual effort, introducing an automated and geometry-based process and digitally replicating engineering experience by introducing a knowledge database.
Assessing authenticity in heritage conservation : case study : architectural conservation in Bahrain
(2023)
The thesis complements the authenticity discourse in heritage conservation with the perspective of laypeople and evaluates the pertinent methodology for the application of the normative concept in architectural heritage conservation. Based on the Nara Document on Authenticity, the Operational Guidelines for the Implementation of the World Heritage Convention anchor the concept in the credibility and truthfulness of internal and external factors – referred to as information sources – that communicate a heritage site’s cultural values. Conversely, the author explored the truthfulness of messages conveyed to site users in a qualitative research based on interviews focused on two urban reference sites in Bahrain. These stand for different eras and conservation approaches: the ensemble of colonial-style governmental buildings at Bab al-Bahrain in Manama and the vernacular Siyadi Shops in the market area Suq al-Qaisariya in Muharraq, which were restored in the course of a World Heritage nomination. The interpretive content analysis compares how architects and non-architects, who represent laypeople in architectural conservation, perceived their authenticity and also traces cultural contingencies. The empirical data confirms pronounced differences in the way architects and non-architects perceive authenticity but only a few between representatives of so-called Western and Eastern cultures. Assessed against international heritage conservation standards, the site in Muharraq proved more authentic than the one in Manama. However, the meanings produced in the interaction between the sites and the interviewees proved be of limited truthfulness in both cases. A key finding is hence that a constructivist authenticity concept can serve no normative function when heritage conservation is considered a discipline at the service of historiography. While all potential factors of authenticity as per the Nara Document proved to be relevant, perceived material authenticity was found to be an outstanding reason why the site in Muharraq was appreciated more. Its rehabilitation was found to successfully reconcile essentialist and constructivist authenticity understandings by paying tribute both to the documentary value of the historic site and to the experiential needs of its users. The findings support the ICOMOS Venice Charter’s material-focused approach while confirming the relevance of a broadened authenticity understanding and highlighting the importance of integrated, participatory approaches to heritage conservation. By illustrating the importance of expertise when assessing the authenticity of architectural heritage, the findings at the same time flag limits to democratizing architectural conservation practice. The author recommends developing practice-oriented guidance for the assessment of authenticity of heritage sites based on further research and to add interpretation facilities to the list of factors of authenticity.
In the summer term 2020 the Chair of Urban Management, BTU Cottbus-Senftenberg, conducted an excursion for Master students of planning and architecture to the region on both sides of the border between Romania and Serbia in a format of distance learning. Over three days the students and local experts of various professional backgrounds engaged online in discussion on urban development in Timișoara, Novi Sad and Belgrade. We explored how the dynamics of changing physical and social boundaries shape urban territories in a tension between centrality and periphery, while also engaging with the paradigm shift in planning centred on culture and people’s participation, as well as anticipations from flagship culture schemes to trigger positive urban changes. This publication provides summaries of some of the contributions, illuminating urban development as a complex process which involves a plurality of geopolitical shifts, engaged actors, interests, perspectives, hope-filled approaches and instruments.
This thesis deals with strategies for achieving high data throughput in wireless sensor networks that use a time division multiple access (TDMA) scheme to resolve medium access. The thesis uses a multi-sided approach that deals not only with the scheduling algorithm but also with the network layer and the interference model. The thesis proposes four solutions that significantly improve data throughput, fairness, and latency in the considered scenario.
The thesis starts with an overview of state-of-the-art medium access control (MAC) protocols, emphasizing TDMA. Based on this overview, it is concluded that not much space for improvement is left in the field of schedule calculation algorithms; many such algorithms are proposed up to date, and they can achieve schedule lengths close to the theoretical minimum. However, the research also reveals a lack of in-detail evaluation and comparison of these algorithms; this makes choosing the most suitable algorithm for a particular application hard and performance estimation inaccurate. Therefore, an extensive evaluation of state-of-the-art TDMA protocols using simulations and over 200 randomly generated networks was performed to tackle this issue. The results allow choosing an appropriate algorithm and estimating performance for each specific application.
Next, the problem of multiple packet transmissions during a single time slot is analyzed. State-of-the-art TDMA protocols assume that one packet can be transmitted in each slot and optimize the number of slots each node gets under this assumption. However, when nodes can transmit more than one packet, the performance of such a schedule is impaired. To solve this, the M-TreeMAC protocol is proposed; this protocol considers the actual number of packets transmitted in a time slot and optimizes the schedule accordingly. Furthermore, it is observed that the routing topology heavily impacts the schedule length created using this algorithm; an algorithm that optimizes the topology to result in the shortest schedule when M-TreeMAC is used is proposed, increasing benefits even further.
Finally, the accuracy of the 2-hop interference model, commonly used by state-of-the-art TDMA scheduling algorithms, is studied and simulated using a realistic radio model based on measurement results. The results show high packet loss ratios for packets traveling a large number of hops to reach the sink. The adaptive interference model is proposed to improve the 2-hop interference model. The proposed model can increase throughput significantly in networks with a height of ten or more hops.
In dieser Dissertation wurden Zuverlässigkeitsaspekte der NED-Aktoren betrachtet und ihre Langzeitstabilität untersucht. Die Langzeituntersuchungen an einzelnen NED-Aktoren haben gezeigt, dass insbesondere große elektrische Felder zur Verkürzung der Lebensdauer der Aktorik führen können. Elektrische Felder beschleunigen Oxidation der NED-Siliziumelektroden. Dabei wurden zwei unterschiedliche Oxidationsmechanismen beobachtet: die anodische Oxidation von Siliziumelektroden im Isolatorbereich und die feldemissionsunterstützte Oxidation. Die beiden Degradationsmechanismen begünstigen das Wachstum des Siliziumoxides an Siliziumelektroden und resultieren in der Veränderung der Oszillationseigenschaften der NED-Aktoren mit der Zeit. Weitere Untersuchungen an den NED-basierten Anwendungen – Mikrolautsprecher haben verdeutlicht, dass solche Faktoren wie Feuchtigkeit die Degradation am meisten forcieren. Durch Passivierung der Aktoren, wobei sie z. B. mit Aluminiumoxid im ALD-Verfahren verkapselt werden, können unerwünschte Degradationsmechanismen deutlich verlangsamt werden. Durch eine geeignete Materialwahl bei der Verkapselung kann sogar gleichzeitig die Effizienz der Aktoren verbessert werden.
Das Phänomen Hatespeech gewinnt zunehmend Aufmerksamkeit in der Öffentlichkeit und in der Forschung. Das ist insofern wichtig, weil Hass, Hetze und Diskriminierung gegenüber Menschen, die einer bestimmten Gruppe zugeordnet werden, vor allem über Informations- und Kommunikationstechnologien eine gesamtgesellschaftliche Verrohung zur Folge hat. Hatespeech schränkt die Meinungsvielfalt ein und bedeutet eine Bedrohung für die Demokratie. Sie stellt jedoch kein reines Netzphänomen dar, sondern basiert auf real existierende Macht- und Diskriminierungsstrukturen. Das Phänomen einzudämmen, ist die Intention verschiedener Stiftungen und Initiativen. Hatespeech ist jedoch allgegenwärtig und selbst in der Schule verbreitet. Sie stellt damit eine Gefahr insbesondere für junge Heranwachsende und weiterführend für das alltägliche Schulleben dar. Somit stellt sich die Frage, welche Mittel der Institution Schule zu Verfügung stehen, um dem Phänomen wirksam entgegenzutreten. Im Zuge von präventiven und interventiven Maßnahmen stehen schulbezogene Programme im Vordergrund. Die vorliegende Masterthesis befasst sich daher mit einer ersten Bestandsaufnahme von deutschsprachigen, schulbezogenen Programmen zur Prävention und Intervention bei Hatespeech unter Kindern und Jugendlichen (Jahrgangsstufen 5 bis 12). Insgesamt konnten 14 entsprechende Programme im Rahmen der Recherchearbeit identifiziert werden. Diese wurden auf ihre Inhalte und Durchführungsmodalitäten sowie anhand von fünf ausgewählten Qualitätskriterien analysiert und hinsichtlich ihrer Anwendung in der schulischen Praxis beschrieben und erörtert. Die Übersicht über Schwerpunkte, Stärken sowie Entwicklungspotentiale schulbezogener Hatespeech-Programme soll eine informierte Entscheidung über den Einsatz der Programme in der Schule und darüber hinaus in der offenen Kinder- und Jugendarbeit ermöglichen.
Die Stadt Cottbus ist seit mehreren Jahren durch extrem rechte und verschwörungsideologische Mobilisierung herausgefordert. Auch in der Covid-19-Pandemie ist Cottbus Schauplatz regelmäßiger Demonstrationen. Mit Beginn des russischen Angriffskriegs auf die Ukraine verschiebt sich der inhaltliche Fokus der sogenannten Montagsspaziergänger sukzessive weg von der Pandemie und hin zum Krieg. Die hier vorliegende Forschung wendet sich den Protestveranstaltungen zu, die im Zeitraum vom 28. Februar bis 24. Oktober 2022 in Cottbus in Reaktion auf den russischen Angriffskrieg organisiert werden und untersucht unter Anwendung der Grounded Theory ausgewählte Redebeiträge. Sie zielt darauf ab, die Inhalte und Darstellungsweisen der RednerInnen hinsichtlich der Gefahrenpotentiale einzuordnen und im Sinne anwendungsbezogener Forschung in Richtung Prävention und zivilgesellschaftlicher Gegenwehr weiterzudenken. Die Forschung zeigt: Ähnlich wie in anderen ostdeutschen Städten sind auch in Cottbus die Veranstaltungen von extrem rechten Akteuren und Gruppen dominiert; sie werden unterstützt von Teilen eines bürgerlichen Milieus der sogenannten gesellschaftlichen Mitte. Sichtbar wird außerdem: Akteure aus dem Coronaprotestmilieu haben sich weiter radikalisiert; verschwörungs- und insbesondere reichsbürgerideologische Inhalte dominieren die untersuchten Veranstaltungen und mischen sich mit prorussischen Positionen und dem Ideologem einer „eurasischen“ Neuordnung des europäisch-asiatischen Raums. Die Ablehnung „des Westens“ bildet ein wiederkehrendes Metanarrativ.
Background: Food sustainability is becoming increasingly important for the achievement of sustainable development goals, especially in light of recent global challenges of climate change, geopolitical conflict and the increasing vulnerability of food systems. The world is emphasising the importance of holistic approaches to agriculture and food systems to tackle these challenges. Germany’s Sustainable Development Strategy for 2030 associates SDGs 2, 3 12 and 15 with sustainable agriculture and food systems as crucial elements to achieve these goals. However, with the lack of knowledge in this area, and the scarcity of tools to monitor and assess food sustainability, it has become crucial to investigate potential holistic approaches and frameworks to assess the sustainability of food systems.
Purpose: This study uses the national framework of Sustainable Development Goals (SDGs), as the only available valid holistic framework, to explore the sustainability of the bread system in Germany. It operationalises the SDGs to bakery level to identify significant indicators that could, potentially, be used to assess the sustainability of artisan bakeries, and identify to which SDGs the bakeries contribute.
Methods: This study utilises a mixed-methods research design to address the multi-disciplinary nature of the food sustainability concept. It critically evaluates the SDG framework and identifies a set of indicators, which are expanded with further indicators to address the cultural dimension of bread as a cultural heritage. To collect data, a 26-item questionnaire was issued to 586 artisan bakeries with a response rate of 8.8% (n = 52); the 52 bakeries own 562 branches. This was followed by interviews with an acceptance rate of 19% (n = 10). Descriptive and inferential statistics were used to analyse the quantitative data, while the interviews were transcribed from German to English and coded using NVivo 11.
Results: Sustainable bread is redefined from a holistic perspective encompassing theory, policies and artisan bakeries. The results confirm that bakeries positively contribute to bread sustainability in Germany, as well as towards achieving the national SDGs. Progress areas include energy efficiency, sustainable packaging, local procurement, heritage promotion, waste reduction and ecolabels. Interestingly, individual bakeries appear to be slightly more sustainable than chains due to their flexibility in adapting to new practices and their use of organic products; however, chain bakeries are slightly less sustainable, but are proven to be more efficient in terms of productivity and market reach.
People in a social network are connected, and their homogeneity is reflected by the similarity of their attributes. For effective clustering, the similarities among people within a cluster must be much higher than the similarities between different clusters. Traditional clustering algorithms like hierarchical (agglomerative) or k-medoids take distances between objects as input and find clusters of objects. The distance functions used should comply with the triangle inequality (TI) property, but sometimes this property may be violated, thus negatively impacting the quality of the generated clusters.
However, in social networks, meaningful clusters can be found even though TI violates. One possibility is a quantum-logic-based clique-guided non-TI clustering approach. The commuting quantum query language (CQQL) is the base for this approach. The CQQL allows the formulation of queries that incorporate both Boolean and similarity conditions. It calculates the similarity value between two objects.
Furthermore, attributes may not have equal impact on similarity and affect the resulting clusters. CQQL incorporates weights to express the varying importance of sub-conditions in a query while preserving consistency with Boolean algebra. This enables personalization of results through relevance feedback (RF).
The main challenge of comparing clusterings is that there is no ground truth data. In such situations, human-generated gold standard clustering can be used. The question is how to compare the performance of clusterings. A noteworthy technique involves counting the pairs of objects that are grouped identically in both clusterings. By doing so, a clustering distance is calculated that measures the dissimilarity.
To validate the non-TI clustering approach, experiments are conducted on social networks of different sizes. Three central questions are addressed by the experiments mentioned: first, is it possible to find meaningful clusters even though TI violates; second, how does a user interact with the system to provide feedback based on their needs; and third, how fast do the detected clusters based on the proposed approach converge to the ideal solution?
To sum up, the experiments’ objective is to demonstrate the validity of a theoretical approach. The research findings presented here provide sufficient evidence for detecting meaningful clusters based on user interaction. Furthermore, the experiments clearly demonstrate that the non-TI clustering approach can be used as an RF technique in clustering.
The present research aims to analyze the possibilities of introducing the living “Intangible Cultural Heritage” as Supplement of Knowledge into the formal educational system particularly the Early Childhood Education in the Far North Region of Cameroon - irrespective of the 2003 Convention for the Safeguarding of the Intangible Cultural Heritage and the 2005 Convention on the Protection and Promotion of the Diversity of Cultural Expressions. This Region is purposively selected for its stronghold of multifarious and diverse ethno-cultural (id)entities and citadel of the country’s enshrined traditions. The rural area of Kolara is conveniently chosen to explore how to blend the receding ethno-cultural heritage with the formal education system in accordance with the aim of education in Cameroon and therefore could be an example of how to train citizens firmly rooted in their cultures but also opened to the world. It presupposes that the current formal primary educational system is not constructive for primary school starters. On the basis of a combination of participatory research and systematic data collection methods, three educational heritages could be outlined: the ethno-cultural traditional educations specific to the two major ethno-cultures Tupuri and Fulbé and the Islamic Arabic educational heritage peculiar to Muslims, predominantly Fulbé. In this context, it could be determined to what extend the formal education is ethno-cultural specific, environment related and learner centered.
In the time of increased awareness about the environment problems by the public opinion and also intensive international efforts to reduce emissions of greenhouse gases, as well increase of the generation of electrical energy to facilitate industrial growth, the conference offers broad contribution towards achieving the goals of diversification and sustainable development.
Focus of the student conference is to promote the discussion of views from scientists and students from Wroclaw University of Technology, Technical University of Ostrava and Brandenburg University of Technology Cottbus-Senftenberg.
The conference is a unique teaching session motivating the students to write science related papers, prepare presentations and discus future developments. It is a formal part of the curriculum offered as an elective module, accompanied by a technical excursion.
1. Erste Änderungssatzung zur Prüfungs- und Studienordnung für den Bachelor-Studiengang Bauingenieurwesen (B. Sc.) vom 21. September 2023
2. Lesefassung: Prüfungs- und Studienordnung für den Bachelor-Studiengang Bauingenieurwesen (B. Sc.) vom 04. Oktober 2022 i. d. F. der ersten Änderungs-satzung zur Prüfungs- und Studienordnung für den Bachelor-Studiengang Bauingenieurwesen (B. Sc.) vom 21. September 2023
1. Erste Änderungssatzung zur fachspezifischen Prüfungs- und Studienordnung für den Master-Studiengang Architektur vom 21. September 2023
2. Lesefassung: Prüfungs- und Studienordnung für den Master-Studiengang Architektur (M. Sc.) vom 29. September 2022 i. d. F. der ersten Änderungssatzung zur Prüfungs- und Studienordnung für den Master-Studiengang Architektur (M. Sc.) vom 21. September 2023
Im Zeitraum von März bis Juni 2023 wurde vom Lehrstuhl für Produktionswirtschaft der BTU Cottbus-Senftenberg die Studie mit dem Titel „Die Produktionssteuerung im digitalen Zeitalter“ als Online-Umfrage durchgeführt. 125 Personen mit operativen, planerischen und strategischen Funktionen in der Produktion oder des produktionsnahen Umfeldes beantworteten den Fragebogen. Die Studie zeigt, dass bei vielen Praktikern ein sehr klares Bild vorherrscht, was die Produktionssteuerung der Zukunft leisten muss. Die Erweiterung der Produktionssteuerung um Künstliche Intelligenz wird in sehr starkem Maße als sinnvoll erachtet, um die Effizienz am Shop-Floor bei hoher Komplexität der Leistungsprozesse auch in Zukunft aufrechtzuerhalten. Die ausgewerteten Daten zeigen, dass die aktuellen Systeme der Produktionssteuerung die Nutzer nicht in dem Ausmaß unterstützen, wie es erwartet wird. Die Nutzer sind gefordert, ihr Wissen und ihre Kompetenzen einzusetzen, um funktionale Defizite der Anwendungen zu kompensieren. Die Kooperation von Menschen und KI in der Produktionssteuerung wird als sinnvoll angesehen. Dabei wird eine Kombination aus menschlicher Arbeit und KI-Unterstützung bevorzugt, während eine vollautonome KI seltener favorisiert wird. Die Studienergebnisse zeigen eine wachsende Zustimmung und Offenheit für den Einsatz von KI als Werkzeug in der Produktionssteuerung, jedoch unter menschlicher Aufsicht und Beteiligung. Die Herausforderungen der Integration von Künstlicher Intelligenz in die Mensch-Maschine-Interaktion umfassen technische und soziale Aspekte. Um diesen Herausforderungen zu begegnen, sind geeignete Lösungsansätze notwendig, wie die Entwicklung sicherer Schnittstellen, robuste Datenschutzmaßnahmen aber auch Nutzerakzeptanzförderung durch Aufklärung und Schulung. Innerhalb eines hybriden Rahmens, wo der Mensch mit der KI arbeitet, müssen klare Regeln für die Interaktion definiert werden. Die KI soll die menschliche Entscheidungsfindung interaktiv unterstützen, neue Perspektiven bieten und alternative Vorschläge unterbreiten. Insgesamt betonen die Ergebnisse der Umfrage die Bedeutung von Sicherheit, Transparenz, Kontrolle und die Validierung von KI-Entscheidungen durch menschliche Akteure. Es zeigt sich, dass die Kombination von Menschen und KI nicht nur technologische Vorteile bietet, sondern auch dazu beitragen kann, nachhaltig wirtschaftlichere Ergebnisse zu erzielen.
During open-cast lignite mining in Lusatia (NE Germany), iron sulfide minerals associated with lignite, are exposed to air and weather. The weathering products iron (Fe), sulfate and acids subsequently enter the fluvial-lacustrine system Spree and its tributaries.
The aim of this work was to identify and explain the evolving biogeochemical signatures (spatio-temporal patterns) in River Spree. These signatures are significantly influenced by biogeochemical turnover processes triggered by iron input. To identify the signatures, a regional field study was conducted from the inland delta Spreewald to the mouth. This study was followed by two laboratory experiments under controlled redox conditions to investigate the effect of Fe on the long-term binding of phosphorus and the degradation of particulate organic material in the iron-enriched sediments.
Characteristic elements introduced by lignite mining (iron, sulfur, aluminum, cobalt, nickel) and by urban areas (zinc, lead, copper, chromium) could be determined by means of a principal component analysis. Based on these findings, the impact range of the open-cast mining was determined to be at least ~ 90 km downstream of the Spreewald. Within the urban-influenced systems Fürstenwalde and Berlin, the urban signature is more dominant than the mining signature. By means of sequential extractions and XRD analyses of the sediments, iron binding forms and characteristic iron minerals have been additionally identified (e.g., Fe(III) oxyhydroxides, pyrite, vivianite).
Sediment analyses and column experiments have shown that iron increases the phosphorus sorption and decreases the phosphorus release in the sediments of three studied lakes of the fluvial-lacustrine system. However, the application of different phosphorus retention models for Lake Neuendorfer See showed that Fe cannot reduce the eutrophic state of the lakes along the river, since the water retention times are too short and the external phosphorus loads are too high. Additionally, lake sediments with different Fe contents have been incubated with particulate organic material. Higher Fe contents resulted in reduced emissions of the greenhouse gases CO₂ and CH₄, which can be attributed to a reduced degradation of organic matter by Fe. Possible reasons include sorption processes of (dissolved) organic matter onto Fe oxyhydroxides and toxic effects of iron on microorganisms. Nevertheless, Fe (and sulfate) are available as electron acceptors during the decomposition of organic matter in River Spree.
The findings of this work deepen the understanding of the impact of iron from mining on sulfur, phosphorus and carbon turnover processes in fluvial-lacustrine systems. As a consequence of the Fe input from the Lusatian area, the signature will persist for decades in River Spree.