@phdthesis{Kared2025, author = {Kared, Trusha}, title = {Mathematical analysis, design, and validation of a high dynamic range, low noise differential mixer using SiGe microwave transistors}, doi = {10.26127/BTUOpen-7121}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71216}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {The limits imposed by the wireless environment require the designer to consider noise, linearity, and power consumption. Bipolar technology has been the most appealing silicon technology due to its high-speed performance and well-engineered base parasitics. Its high transition frequency and low base resistance have resulted in remarkable noise performance. These advantages, combined with scaling flexibility, have made bipolar devices the fundamental component of silicon RF front-ends. With the growing demand for high-performance wireless applications from satellite and radar systems to 5G infrastructure, there is a strong need for advanced mixer architectures that can deliver high isolation, gain, and low noise across wide frequency ranges. The purpose of this dissertation was to describe the differential mixer and its mathematical properties in terms of gain and noise figure, and to explore further optimizations. In fact, it turned out that the mixer design was greatly improved in terms of both the noise figure and the intercept point. The active double-balanced down-conversion mixer is built on SiGe technology. The circuit exhibits significant improvement in terms of the mixer's other performance parameter metrics. This dissertation presents a novel SiGe HBT-based differential double-balanced down-conversion mixer featuring significantly enhanced conversion gain, noise performance, linearity, dynamic range, and port-to-port isolation. Compared to existing designs, this mixer delivers outstanding performance, achieving a single-sideband (SSB) noise figure of 7 dB ± 0.4 dB, a conversion gain of 12 dB ± 1 dB, and exceptional isolation metrics RF-to-IF isolation greater than 35 dB, with LO-to-RF and LO-to-IF isolation exceeding 50 dB across the 0.5 GHz to 1.8 GHz frequency range. Furthermore, it has an Input third-order intercept point (IP3) of +4.7 dBm, an output third-order intercept point (OIP3) of +15 dBm, and a 1 dB compression point of -8 dBm. This high-performance down-conversion double-balanced mixer integrates several state-of-the-art innovations. A transformer-free single-ended-to-differential conversion enhances efficiency and eliminates unnecessary components at the RF stage. The dual-feedback linearization technique optimizes impedance matching while suppressing nonlinear distortion, ensuring superior linearity. Additionally, symmetrical active device layout and advanced multilayer PCB technology significantly mitigate LO-to-RF feedthrough, reducing crosstalk and maximizing port-to-port isolation. These advancements collectively result in a highly efficient, low-noise, and exceptionally linear mixer architecture, setting a new benchmark in SiGe HBT-based mixer technology rather than relying on noisy CMOS technology. Due to its higher fabrication complexity, lower yield at advanced nodes, and the necessity for more complicated design tactics in high-frequency applications, CMOS technology in small quantities is ultimately more costly than SiGe HBT-based designs. Although CMOS excels in low-power applications and large-scale digital integration, SiGe HBT remains a reasonably affordable option for high-performance RF}, subject = {Down-conversion double balanced mixer; Noise figure; Dynamic range; Marchand balun; LO mixing core; Doppelt balancierter Abw{\"a}rtsmischer; Rauschmaß; Dynamikbereich; Marchand-Balun; LO-Mischkern; Heterobipolartransistor; Siliciumhalbleiter; Germaniumlegierung; Mischer ; Rauschmessung}, language = {en} } @misc{OPUS4-7053, title = {Amtliches Mitteilungsblatt der BTU Cottbus-Senftenberg, 2025,28 (21.08.2025)}, doi = {10.26127/BTUOpen-7053}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70536}, year = {2025}, abstract = {Bekanntmachung {\"u}ber die Aufhebung des Master-Studienganges Verarbeitungstechnologien der Werkstoffe (M.Sc.)}, language = {de} } @techreport{SchrothDraegerGabrieletal.2025, author = {Schroth, Jil and Draeger, Susan and Gabriel, Janika and Santucci, Daniele}, title = {Hitze in der Stadt : eine sozial-r{\"a}umlich differenzierte Analyse f{\"u}r Klimaanpassungsmaßnahmen aus Sicht der Stadtnutzenden in Berlin}, doi = {10.26127/BTUOpen-7149}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71491}, year = {2025}, abstract = {Infolge des Klimawandels treten in Deutschland zunehmend extreme Wetterereignisse auf. Besonders Hitzewellen in St{\"a}dten stellen eine wachsende Belastung dar, da sich hier der st{\"a}dtische W{\"a}rmeinseleffekt mit einer hohen baulichen Dichte {\"u}berlagert. Diese Entwicklung hat direkte Auswirkungen auf das thermische Empfinden und die Gesundheit, insbesondere bei vulnerablen Gruppen wie {\"a}lteren Menschen, Personen mit Vorerkrankungen oder Kindern. W{\"a}hrend bisherige Forschung vor allem technische und planerische Anpassungsmaßnahmen betrachtet, fehlt es an fundierten sozialwissenschaftlichen Perspektiven. Das Forschungsprojekt „Hitze in der Stadt" schließt diese L{\"u}cke, indem es die Beziehung zwischen der gebauten Umwelt, mikroklimatischen Bedingungen und der subjektiven thermischen Wahrnehmung untersucht. Als Fallbeispiel diente ein dicht bebautes Berliner Gr{\"u}nderzeitquartier mit geschlossener Blockrandbebauung und vielf{\"a}ltigen Nutzungen, das eine hohe {\"U}bertragbarkeit auf andere europ{\"a}ische St{\"a}dte aufweist. Die methodische Vorgehensweise umfasste drei zentrale Bausteine: 1. Raumtypisierung - Das Untersuchungsgebiet wurde in sieben repr{\"a}sentative Stadtraumtypen unterteilt (z. B. breite Hauptstraße, enge Gasse, Brunnenplatz im Park), um systematische Vergleiche zu erm{\"o}glichen. 2. Gef{\"u}hrte Climate Walks mit integrierten mikroklimatischen Messungen - Zwei Gruppen, {\"a}ltere Stadtnutzende (≥ 65 Jahre) und eine j{\"u}ngere Vergleichsgruppe, durchquerten w{\"a}hrend sommerlicher Mittagshitze die definierten Raumtypen. In Echtzeit bewerteten sie ihre thermische Wahrnehmung und Aufenthaltsqualit{\"a}t. Parallel dazu wurden vor Ort Temperatur, Luftfeuchte, Windgeschwindigkeit, Strahlung und Oberfl{\"a}chentemperaturen (W{\"a}rmebild) gemessen und GPS-basiert verortet. Der Universal Thermal Climate Index (UTCI) diente als Referenz zur Bewertung der thermischen Belastung. 3. Fokusgruppen - In moderierten Diskussionen wurden die subjektiven Eindr{\"u}cke vertieft, Einflussfaktoren herausgearbeitet und Bedarfe an die Außenraumgestaltung identifiziert. Die Ergebnisse zeigen: Hitzestress wird nicht allein durch Temperatur bestimmt. Faktoren wie Begr{\"u}nung, Verschattung, L{\"a}rmpegel, Sauberkeit, Nutzungsart, Erwartung und Atmosph{\"a}re beeinflussen die Wahrnehmung erheblich. Begr{\"u}nte, ruhige und saubere Orte mit Sitzgelegenheiten wurden auch bei hohen Temperaturen als deutlich angenehmer erlebt, w{\"a}hrend stark versiegelte, verkehrsbelastete Fl{\"a}chen als besonders belastend galten - exemplarisch am Rosenthaler Platz. Aus der Analyse wurden sechs zentrale Handlungsempfehlungen abgeleitet: (1) Aufenthaltsqualit{\"a}t als festen Bestandteil in Klimaanpassungsstrategien integrieren, (2) Belastungsfaktoren wie L{\"a}rm und Verkehr reduzieren, (3) Maßnahmen differenziert nach Raumtyp und Nutzung entwickeln, (4) {\"o}ffentliche Wartezonen gezielt verbessern, (5) „k{\"u}hle Wege" zwischen wichtigen Zielen f{\"o}rdern, (6) geschlechter- und bildungssensible Ans{\"a}tze in Planung und Kommunikation ber{\"u}cksichtigen. Das Projekt macht deutlich, dass effektive urbane Hitzestrategien nur durch interdisziplin{\"a}re Ans{\"a}tze entstehen, die technische, gestalterische und soziale Dimensionen gleichwertig verbinden - mit dem Ziel einer klimaresilienten und sozial gerechten Stadtentwicklung.}, subject = {Urban heat island effect; Urban climate; Climate change; Heatstress; Climate adaption; W{\"a}rmeinseleffekt; Stadtklima; Klimawandel; Hitzestress; Klima{\"a}nderung; Berlin; Stadtsoziologie; Stadtleben; Stadtklima; Stadtplanung; W{\"a}rmeinsel; Klima{\"a}nderung; Hitzebelastung}, language = {de} } @phdthesis{Neisen2025, author = {Neisen, Martin}, title = {The impact of prudential regulation, digitalisation, and ESG on the performance of banks' business models in Europe}, doi = {10.26127/BTUOpen-7139}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71398}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {Banks' business models and performance are heavily influenced by the trends of prudential regulation, digitalisation and Environmental, Social and Governance (ESG) factors. The aim of this research is to analyse how and to what extent these three major trends in the banking industry influence the performance of the business models of European banks. The main research question is whether these trends improve or deteriorate the performance of banks' business models. The research question is divided into three sub-research questions, each focusing on one of the major trends and its impact on banks' business models. The methodology of this research is based on the cumulative approach, which consists of presenting a set of five papers that have been published in reputable journals in the field of banking and finance. Each paper focuses on a specific aspect of the research question. As trends in the banking industry are not a measurable variable, they are defined for the purpose of answering the research question as constructs that can be made measurable using the variable risk-weighted assets. Each of the used papers cover a separate problem for the banking industry. The first paper analyses regulatory changes in the wake of the COVID pandemic. The second paper covers the impact of the output floor on the performance of banks' business models. The third paper shows how ESG Ratings and additional capital requirements influence the performance of banks' business models. The fourth paper covers the impact of AI in modelling credit risks, and finally, the impact of the EU implementation of Basel IV used. The research results of each paper are used to measure the change in the RWA. In the second step, the change of RWA is used as the independent variable that changes the business model performance. The analysed trends significantly influence the performance of business models but depends on the respective trend and individual case. This research offers a novel viewpoint in the banking literature and a valuable source for both practitioners and academic research. As the banking sector undergoes constant transformation, the insights obtained here emphasise the importance of adeptly managing the interplay of these trends to optimise business model performance. Other researchers can leverage this work as a catalyst for further research into the dynamic interplay between prudential regulation, digitalisation, ESG considerations and bank business model performance. Additionally, the linear association detected between these constructs and bank business model performance as measured by RAROC creates possibilities for quantitative research. This research stimulates further scholarly inquiry on this topic by highlighting the significance of these trends in determining the banking sector's future.}, subject = {Bank business models; Prudential regulation; Digitalisation; ESG risks; AI; Bankenregulierung; Digitalisierung; ESG; Gesch{\"a}ftsmodelle; K{\"u}nstliche Intelligenz; Bank; Regulierung; Digitalisierung; K{\"u}nstliche Intelligenz; Environmental, Social and Governance}, language = {en} } @phdthesis{Kayatz2024, author = {Kayatz, Benjamin}, title = {Supporting accounting and decision-making in agricultural water management under data scarcity : chances, limits and potential improvements}, doi = {10.26127/BTUOpen-7067}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70672}, school = {BTU Cottbus - Senftenberg}, year = {2024}, abstract = {Alleviating water scarcity and ending hunger are two Sustainable Development Goals that are inextricably linked, as 70\% of water is used for agricultural production. However, assessing and identifying improved water management requires costly field trials or knowledge and data to run agro-hydrological models. This thesis addresses this challenge by integrating an agro-hydrological model with global soil, crop and climate datasets into a user-friendly, web-based agricultural water management assessment tool, the Cool Farm Tool Water (CFTW). This dissertation substantially contributes to the development and assessment of this modelling framework as well as identifies levers to enhance the model performance. Model results were compared to published scientific field trials, eddy covariance observations as well as Water Footprint Network data. Finally, the model framework was applied to five cereals across India between 2005 and 2014, representing a high spatial, inter- and intra-annual heterogeneity. The modelling framework explained 96\% of the variability in seasonal water footprints and reduced the error of water footprints by 70\% compared to state-level averages by the Water Footprint Network. However, CFTW captured only 50\% of the variance in seasonal crop water use. CFTW enables the assessment of the daily dynamics of evapotranspiration, can reproduce daily crop water stress but overestimates irrigation requirements by an average of 40\%. It helps identify relative improvements in agricultural water management but lacks the accuracy for absolute assessments. Using local input data reduced the bias from 18.6\% to 4.3\% for evapotranspiration. While results showed site- and season-specific differences, the greatest model improvement is replacing global precipitation data with local observations, reducing e.g. the bias by 70.6\% for daily water use. Water footprints and water use of India revealed the importance of considering crop-, season-, year- and location-specific differences. Total Rabi (dry season) water footprints were between 33.4\% and 45.0\% lower than Kharif (monsoon) water footprints. However, the Rabi blue water footprints accounted for up to 78.3\%. Overall, India increased cereal production by 26.4\% without utilising additional water resources, mainly through increases in yield, partly by shifting production to the higher-yielding Rabi season. CFTW supports addressing water scarcity and food security at seasonal timescales and, to some extent, at daily timescales. Global datasets combined with an uncalibrated agro-hydrological model can inform improved agricultural water management by providing water footprints, water use and water stress. However, model outcomes also revealed considerable offsets. These results highlight the difficulties of overcoming data scarcity in decision support tools for agricultural water management. The rapid development of global datasets may help to overcome identified limitations in the future.}, subject = {Argricultural water management; Cool Farm Tool; Decision support tool; Crop water use; Data scarcity; Landwirtschaftliches Wassermanagement; Entscheidungshilfe; Wassernutzung von Kulturpflanzen; Datenmangel; Bew{\"a}sserungswirtschaft; Wasserverbrauch; Wassereinsparung; Getreidebau; {\"O}kologischer Fußabdruck; Wasserstress}, language = {en} } @phdthesis{Walden2025, author = {Walden, Jasper V. M.}, title = {Advances in industrial heat recovery and heat pump integration : steady-state and time-resolved approaches}, doi = {10.26127/BTUOpen-7113}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71136}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {Decarbonizing the industrial sector requires efficient use and electrification of process heat. Industrial heat pumps offer an efficient way to electrify process heat of temperatures up to 450 °C depending on the process and economic boundary conditions. However, mere substitution of conventional boiler systems with heat pumps is non trivial, as the efficiency of a heat pump strongly depends on the temperature levels it operates between and consequently its integration point. Conventional heat pump integration provides thermodynamic guidance, though it does not assess economic- or ecological optimal integration. Furthermore, the existing methods typically consider static or semi-static process data, although most industrial processes experience temperature and heat load fluctuations in the process streams. The current thesis explores optimal heat pump integration and the incorporation of time-resolved process data in Process Integration methodologies. To establish the foundations of heat pump integration, an analytical equation for the optimal heat pump heat sink temperature is derived. The equation reveals key parameters influencing heat pump integration and their respective impact. While the analytical equation determines the optimal heat pump integration for stationary process data, real world heat pump integration is influenced by process fluctuations. These fluctuations can impact heat transfer, affecting the efficiency of both heat recovery and heat pumps. To account for process fluctuations in heat exchanger network design, hourly process data is clustered into a representative dataset. Consequently, a heat exchanger network is designed and evaluated through dynamic simulation. An annual heat recovery benchmark, derived from hourly heat recovery potentials, serves as a reference. For heat pump integration with time-resolved process data, a method utilizing mathematical programming is introduced. To quantify the benefits, the method is put into comparison with conventional approaches as the Time-Average-Model. The method was further extended to assess the impact and requirement for heat pump load flexibility by introducing a reduced-order part load heat pump model. The analytical equation revealed that the electricity-to-reference fuel price ratio is the most influential parameter for heat pump adoption in industry, thus offering valuable insight for policy development. Despite the added complexity of time-resolved process data, the work demonstrated that accounting for hourly process demands provides significant economic and environmental benefits while improving technical feasibility. This highlights the potential of leveraging time-resolved data in process design to improve both economic performance and decarbonization.}, subject = {Industrial heat pumps; Process integration; Heat recovery; Decarbonization; Industrial electrification; Industrielle Dekarbonisierung; Industrielle W{\"a}rmepumpen; Prozessintegration; Zeitaufgel{\"o}ste Prozessdaten; Energieeffizienz; Großw{\"a}rmepumpe; Zeitaufl{\"o}sung Prozessdaten; Dekarbonisierung; Energieeffizienz}, language = {en} } @article{MartienssenRiedelKuehne2024, author = {Martienssen, Marion and Riedel, Ramona and K{\"u}hne, Tom}, title = {Contribution of professional cleaning to indoor air and sewage pollution}, series = {Sustainable Chemistry}, volume = {5}, journal = {Sustainable Chemistry}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2673-4079}, doi = {10.3390/suschem5040019}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71378}, pages = {275 -- 286}, year = {2024}, abstract = {In this study, several professional cleaning products were analyzed for their impact on local air and sewage contamination. The products were first analyzed for their content of potentially harmful ingredients, their biodegradability, and the potential for the mobilization of hazardous substances from the floorings that were cleaned. The contribution of the cleaning products to sewage pollution with environmentally hazardous substances was studied at full scale. All commercially available cleaning products studied were declared to be environmentally friendly (labeled with the EU Ecolabel). However, despite being labeled as "green" products, between 16 and 24 volatile harmful ingredients were identified. An optimized experimental product, produced completely from natural raw materials, also contained several harmful substances originating from the herbal raw materials themselves. During the field study, we identified a range of trace substances in the sewage. Eight of these substances (e.g., p-cymene, butanone, eucalyptol) significantly originated from the cleaning products. Several others may have originated from the cleaning products, but other sources were also possible. The flooring materials that were cleaned contained several harmful substances themselves. The release of some substances (e.g., toluene) into the sewage significantly increased during the cleaning process.}, subject = {Professional cleaning agents; Trace substances; Biodegradability; Sewage pollution; Environmental impact}, language = {en} } @article{LeeReb2025, author = {Lee, Roh Pin and Reb, Jochen}, title = {"Waste-to-Products" for the sustainability transformation of megacities : case analysis of impacts of public knowledge and perception on chemical recycling deployment in Singapore}, series = {Cleaner Waste Systems}, volume = {12}, journal = {Cleaner Waste Systems}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2772-9125}, doi = {10.1016/j.clwas.2025.100359}, year = {2025}, abstract = {Megacities generate significant amounts of unsorted domestic waste. Rather than being landfilled/incinerated, this could be used to substitute fossil resources for chemical production via chemical recycling (CR). CR thus represents an opportunity for a parallel achievement of multiple sustainability goals from resource efficiency, decarbonization to circularity and sustainable waste management. However, as an emerging technology, its potential contributions to a nation's sustainability transformation remain debated. While extant literature in the fields of waste management and CR have predominantly focused on waste sorting/segregation/collection as well as techno-economical-ecological feasibility of CR technologies respectively, insights into human factors which could hinder CR deployment in the forms of pyrolysis and gasification for the sustainable waste management in megacities remain lacking. To address this gap, this study implemented a representative online survey in Singapore - a megacity in Southeast Asia aiming to transit towards circularity and zero-waste by 2030 - and enabled first and novel insights into factors in the human dimension which would (1) influence proper waste separation/recycling behaviors - a prerequisite for the successful implementation of waste pyrolysis, and (2) impact societal support for using domestic waste for chemical production via waste gasification rather than for energy production via waste incineration - the dominant waste management approach in Singapore. Study insights regarding the impacts of the human factor and the identified opportunities for CR integration in a nation's waste system - besides extending extant waste management and CR literature - furthermore act as a blueprint for sustainable waste management and green chemistry for the sustainability transformation of other megacities.}, subject = {Chemical recycling; Waste pyrolysis; Waste gasification; Domestic waste; Perception}, language = {en} } @article{vonWernerGlasauer2025, author = {von Werner, Dina and Glasauer, Stefan}, title = {Increased breathlessness in post-COVID syndrome despite normal breathing patterns in a rebreathing challenge}, series = {Scientific Reports}, volume = {15}, journal = {Scientific Reports}, publisher = {Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-025-11728-x}, year = {2025}, abstract = {Severe symptoms in the absence of measurable body pathology are a frequent hallmark of post-COVID syndrome. From a Bayesian Brain perspective, such symptoms can be explained by incorrect internal models that the brain uses to interpret sensory signals. In this pre-registered study, we investigate whether induced breathlessness perception during a controlled CO2rebreathing challenge is reflected by altered respiratory measures (physiology and breathing patterns), and propose different computational mechanisms that could explain our findings in a Bayesian Brain framework. We analysed data from 40 patients with post-COVID syndrome and 40 healthy participants. Results from lung function, neurological and neurocognitive examination of all participants were within normal limits on the day of the experiment. Using a Bayesian repeated-measures ANOVA, we found that patients' breathlessness was strongly increased (BF10,baseline=8.029, BF10,rebreathing=11636, BF10,recovery=43662) compared to controls. When excluding patients who hyperventilated (N = 8, 20\%) during the experiment from the analysis, differences in breathlessness remained (BF10,baseline=1.283, BF10,rebreathing=126.812, BF10,recovery=751.282). For physiology and breathing patterns, all evidence pointed towards no difference between the two groups (0.307 > BF10 < 0.704). In summary, we found intact breathing patterns and physiology but increased symptom perception in patients with post-COVID syndrome.}, subject = {Cognitive neuroscience; Fatigue; Perception; Respiratory signs and symptoms; Sensorimotor processing}, language = {en} } @article{HozadAbendroth2025, author = {Hozad, Ahmad Shabir and Abendroth, Christian}, title = {Electro-composting : an emerging technology}, series = {Fermentation}, volume = {7}, journal = {Fermentation}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {2311-5637}, doi = {10.3390/fermentation11070401}, year = {2025}, abstract = {This study focuses on electrical stimulation for composting. Using the PSALSAR method, a comprehensive systematic review analysis identified 22 relevant articles. The examined studies fall into four main systems: electric field-assisted aerobic composting (EAAC), electrolytic oxygen aerobic composting (EOAC), microbial fuel cells (MFCs), and thermoelectric generators (TEGs). Apart from the main systems highlighted above, bioelectrochemically assisted anaerobic composting (AnCBE, III) is discussed as an underexplored system with the potential to improve the efficiency of anaerobic degradation. Each system is described in terms of key materials, composter design, operating conditions, temperature evolution, compost maturity, microbial community, and environmental outcomes. EAAC and EOAC systems accelerate organic matter decomposition by improving oxygen distribution and microbial activity, whereas MFC and TEG systems have dual functioning due to the energy generated alongside waste degradation. These innovative systems not only significantly improve composting efficiency by speeding up organic matter breakdown and increasing oxygen supply but also support sustainable waste management by reducing greenhouse gas emissions and generating bioelectricity or heat. Together, these systems overcome the drawbacks of conventional composting systems and promote future environmental sustainability solutions.}, subject = {Electric field-assisted; Composting; Bioelectrochemical treatment; Energy generation; Waste management}, language = {en} } @article{OjoAsamoahAlbrechtetal.2025, author = {Ojo, Sola and Asamoah, Solomon and Albrecht, Eike and Ibrahim, Bachar}, title = {Integrating Sustainable Development and Disaster Mitigation into Climate Policies to Support Water Security in Africa}, series = {Earth}, volume = {6}, journal = {Earth}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2673-4834}, doi = {10.3390/earth6020057}, year = {2025}, abstract = {Africa's water security is inextricable from the recent patterns of climate variability. Effective formulation and implementation of climate policies require efficient integration of disaster mitigation and sustainable development to eliminate maladaptation and enhance water security. However, practical implementation is still lacking in many African countries. This study aims to examine practical measures and strategies for the integration of sustainable development and disaster mitigation into climate policies to enhance water security in Africa. A systematic bibliometric and thematic analysis was conducted using 95 peer-reviewed articles within the period 2010 to 2025 from the Scopus database. Software and frameworks such as VOSviewer and the Preferred Reporting Items for Systematic Reviews (PRISMA) were employed to analyze publication trends, co-authorship networks, keyword co-occurrence, and themes. The study revealed current research themes such as nature-based solutions for water security, climate-resilient infrastructure and technologies, and practical measures, such as eco-based adaptation and water energy food nexus, as some components of climate policy integration that can enhance water security in Africa. The study offers key policy recommendations for policymakers in the implementation of integrated climate policies adequate and effective enough to deal with water security issues in Africa.}, subject = {Water security; Sustainable development; Disaster prevention; Climate policy; Africa}, language = {en} } @article{DahmaniFellahHeziletal.2025, author = {Dahmani, Maewa and Fellah, Mamoun and Hezil, Naouel and Benoudia, Mohamed-Cherif and Obrosov, Aleksei and El-Hiti, Gamal A. and Weiss, Sabine}, title = {Bioactivity and tribological performance of a novel nano-biomaterial beta-type Ti-alloy}, series = {Journal of Materials Research and Technology}, volume = {36}, journal = {Journal of Materials Research and Technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2214-0697}, doi = {10.1016/j.jmrt.2025.03.180}, pages = {2297 -- 2316}, year = {2025}, abstract = {This study investigates the bioactivity; wear performance, and topography of a novel beta-type titanium-based alloy using techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and 2D and 3D analysis. The tribological test was evaluated using a ball-on-disk tribometer in a wet environment. Different loads of 2, 6, and 10 N were applied during the evolution. The data results indicate a significant effect of the milling process on the formation of the hydroxyapatite layer on the surfaces of the Ti-Nb-Mo alloy. Both the wear volume and rate showed a consistent trend of decrease as the milling time increased from 2 to 12 h for all applied loads. The minimum values of wear and volume were reached after 12 h of milling. The improvement in tribological behavior can be attributed to the improved mechanical properties of the alloys. In addition, the significant presence of niobium (Nb) and molybdenum (Mo) plays a critical role in achieving high coefficient of friction values. The primary wear mechanism observed in the Ti-25Nb-25Mo system was adhesive wear in addition to abrasive wear. With its lower Young's modulus and favorable biological and tribological properties, the Ti-25Nb-25Mo alloy represents a promising option for bone tissue applications in orthopedics.}, subject = {Ti-25Nb-25Mo; Milling time; Bioactivity; Hydroxyapatite; Friction coefficient}, language = {en} } @phdthesis{Loulit2024, author = {Loulit, Amine}, title = {Semi Markov Chain models and Cross Entropy approach : tools for industrial maintenance costs optimization}, doi = {10.26127/BTUOpen-7060}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70608}, school = {BTU Cottbus - Senftenberg}, year = {2024}, abstract = {Importance sampling methods, particularly the Cross Entropy (CE) Approach, were originally used to give estimates of rare events probabilities; but recent literature highlights also the usefulness of the Cross-Entropy Method for optimizations. The (CE) approach has its benefits for noisy optimization problems, for which the objective function has no closed analytical form. In this thesis, we present an example of such a noisy optimization problem: the minimization of the expected total cost per time unit of industrial maintenance actions over a fixed horizon. After giving a brief description of different maintenance philosophies (time based versus condition based, we embed our maintenance problem into a Semi Markov Chain (SMC) framework that allows for simulating failure occurrences in industrial systems. In the theoretical part of this PhD thesis, we show that convergence of the maintenance optimization problem reduces to proving the asymptotic stability of the Cross Entropy method that boils down to a stochastic differential equation of Robbins Monro form. The numerical part consists in considering (truncated) Gaussian and Weibull distributions as candidate distributions belonging to the so-called natural exponential family, and evaluating their impacts on minimizing maintenance costs.}, subject = {Maintenance optimization; Cross Entropy; Semi Markov Chain; Stochastic differential equation; Global convergence; Markov-Erneuerungsprozessen; Stochastische Differentialgleichungen; Robbins-Monro-Prozess; Zubov-Methode; Cross-Entropie-Methode; Semi-Markov-Prozess; Robbins-Monro-Prozess}, language = {en} } @phdthesis{MunozHernandez2025, author = {Mu{\~n}oz Hernandez, Hector Gerardo}, title = {Enhancing single-instruction multiple-threads FPGA-based processors with high-bandwidth-memory}, doi = {10.26127/BTUOpen-7130}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71301}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {The gap between memory bandwidth and processing power has been expanding continuously. Not long ago, some memory technology initiatives have been proposed in order to bridge this disparity. One of the most promising solutions comes in the form of 3D stacked memories like High-Bandwidth Memory (HBM). By adding several and wider memory channels that can do memory transactions in parallel, these memories increase significantly the data throughput and aim to close the aforementioned gap. A popular way to prototype and test these memories is to integrate them with Field Programmable Gate Arrays (FPGAs) due to their high reconfigurability. Graphic Processing Units (GPUs) are another inherently parallel targeted hardware, and so some advances in integrating GPUs with HBM are already present in the industry. This new technology integration brings a paradigm shift because in order to fully take advantage of the parallel nature of HBM, the hardware design has to also support this highly parallel data throughput. While GPUs provide high data processing parallelism, FPGAs are known for their flexibility. Intellectual Property (IP) blocks are an example of this flexibility, because they are a bundle of Hardware Description Language (HDL) code which can be included in an existing implementation of an FPGA, adding functionality to it. Soft-IP-cores implemented on reconfigurable hardware, are a solution that offers advantages from both worlds, where a soft-GPU could be hosted in an FPGA. There is, however, a gap in knowledge on how 3D stacked memories support soft-GPU-cores. This thesis analyses this gap and provides insights into how HBM memories can be exploited in soft-GPU-cores. To accomplish such an endeavor, this thesis presents, evaluates, and analyzes a complete open-source environment that consists of a soft-GPU with HBM compatibility. The contributions are composed of several different tools ranging from the model simulator, to easy-to-use implementation flow on real hardware. The environment also includes a roofline model which is used to analyze how applications from different domains behave and can be optimized in the custom hardware.}, subject = {Field programmable gate array; Soft-core; High-bandwidth-memory; RISC-V; Embedded systems; FPGA; HBM; Eingebettete Systeme}, language = {en} } @phdthesis{Dikariev2025, author = {Dikariev, Illia}, title = {Relaxierungen von Steuerungsproblemen mit unendlichem Zeithorizont : Young-Maße und Existenz optimaler L{\"o}sungen}, doi = {10.26127/BTUOpen-7107}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71078}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {The focus of this work is on the development of existence results for non-convex optimal control problems over an unbounded time horizon. The work is structured into three parts: - the elaboration of necessary functional-analytic foundations, - the derivation of equivalence relations between different types of relaxations, - existence statements for both compact and unbounded control domains. Particularly, the topology of compact convergence is introduced on the space of locally absolutely continuous functions. Further we develop embedding theorems and a Hardy inequality in relation to weighted reflexive Sobolev spaces, which are proposed as state spaces. The integrand of the objective functional is assumed to be a non-negative normal integrand, and the state equation is assumed to be a Carath{\´e}odory differential equation. The time interval is endowed with measures induced by weights. We present sufficient conditions to establish the equivalence of three pertinent types of relaxations Γ-regularization, generalized control, and sliding mode. To establish the existence results, we focus on the relaxation based on generalized controls (Young measures). In this context, we develop a suitable disintegration theorem and a weakened Prokhorov condition that are especially applicable to the case of generalized controls and non-linear state equations over an unbounded control domain. On the measure spaces, we introduce the vague or tight topology, depending on whether the control domain is compact or not. In the final part of the work we propose growth conditions on the integrand and on the right-hand side of the state equation to enforce closedness and compactness properties of an admissible set. Correspondingly, appropriate lemmas and existence theorems are presented for the cases of a compact resp. unbounded control domain, based on an existence theorem by Weierstrass. Finally, the existence results are illustrated through application examples.}, subject = {Optimal control; Optimale Steuerung; Infinite time horizon; Unendlicher Zeithorizont; Young measures; Young-Maße; Relaxed controls; Verallgemeinerte Steuerungen; Unbounded controls; Unbeschr{\"a}nkte Steuerungen; Optimale Kontrolle; Hardy-Raum; Sobolev-Raum; Carath{\´e}odory-Differentialgleichung; Young-Maß}, language = {de} } @article{KaestnerCaviedesVoulliemeHinz2025, author = {K{\"a}stner, Karl and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Formation of spatial vegetation patterns in heterogeneous environments}, series = {PLOS One}, volume = {20}, journal = {PLOS One}, number = {5}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {doi.org/10.1371/journal.pone.0324181}, year = {2025}, abstract = {Functioning of many resource-limited ecosystems is facilitated through spatial patterns. Patterns can indicate ecosystems productivity and resilience, but the interpretation of a pattern requires good understanding of its structure and underlying biophysical processes. Regular patterns are understood to form autogenously through self-organization, for which exogenous heterogeneities are negligible. This has been corroborated by reaction-diffusion models which generate highly regular patterns in idealized homogeneous environments. However, such model-generated patterns are considerably more regular than natural patterns, which indicates that the concept of autogenous pattern formation is incomplete. Models can generate patterns which appear more natural when they incorporate exogenous random spatial heterogeneities (noise), such as microtopography or spatially varying soil properties. However, the mechanism through which noise influences the pattern formation has not been explained so far. Recalling that irregular patterns can form through stochastic processes, we propose that regular patterns can form through stochastic processes as well, where spatial noise is filtered through scale-dependent biophysical feedbacks. First, we demonstrate that the pattern formation in nonlinear reaction-diffusion models is highly sensitive to noise. We then propose simple stochastic processes which can explain why and how random exogenous heterogeneity influences the formation of regular and irregular patterns. Finally, we derive linear filters which reproduce the spatial structure and visual appearance of natural patterns well. Our work contributes to a more holistic understanding of spatial pattern formation in self-organizing ecosystems.}, subject = {Linear filters; Anisotropy; Autocorrelation; Bandpass filters; Nonlinear systems}, language = {en} } @phdthesis{RodriguezHenriquez2025, author = {Rodr{\´i}guez Henr{\´i}quez, Jos{\´e} Juan}, title = {Fundamental study on surrogates for commercially available fuels under engine-like conditions}, doi = {10.26127/BTUOpen-7114}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71142}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {The increasing global energy demand, driven by technological advancements and population growth, has led to a significant rise in crude oil consumption. This trend is expected to continue until 2040 due to the lack of viable alternatives for sectors such as road freight, aviation, and petrochemicals. The combustion of fossil fuels, however, results in the emission of toxic and carcinogenic pollutants, including particulate matter (PM) and nitrogen oxides (NOx). This thesis aims to enhance the understanding of the formation and decomposition pathways of these pollutants under engine-like conditions using surrogate fuels. The research was conducted at the Brandenburg University of Technology Cottbus-Senftenberg, funded by the EU FP7 Marie Skłodowska Curie action, Initial Training Network (ITN) project ECCO-MATE. The project involved collaboration with 11 key partners from academia and industry across Europe and Japan. The primary objective was to develop and implement novel combustion technologies for marine and automotive engines to improve efficiency and meet stringent emission standards. Experimental studies were carried out using various analytical techniques, including gas chromatography, gas analysis, and luminescence techniques. These methods were optimized for engine-like conditions to investigate the formation of PM and NOx. The research utilized a range of experimental facilities, such as shock tubes and rapid compression machines, to measure ignition delay times and flame speciation. The study also involved the characterization of commercial fuels and the selection of surrogate fuels to represent their properties. The findings indicate that the addition of diluents, such as nitrogen and carbon dioxide, can significantly reduce the formation of NOx and PM. The use of oxygenated fuels, like dimethyl ether (DME), was found to enhance combustion efficiency and reduce pollutant emissions. The research also highlighted the importance of understanding the chemical kinetics of fuel decomposition and the role of polycyclic aromatic hydrocarbons (PAHs) in soot formation. Overall, this thesis provides valuable insights into the combustion behavior of surrogate fuels under engine-like conditions. The results contribute to the development of cleaner and more efficient combustion technologies for the automotive and marine sectors, aligning with global efforts to reduce the environmental impact of fossil fuel consumption.}, subject = {Combustion; Thermodynamics; Fuels; PAH; Verbrennung; Thermodynamik; Brennstoffe; Verbrennung; Ersatzbrennstoffe; Fossiler Brennstoff}, language = {en} } @techreport{OPUS4-7026, type = {Working Paper}, title = {Transformation der Innenstadt : Zukunftsvisionen resilienter Zentren von Klein- und Mittelst{\"a}dten in Brandenburg}, editor = {Hackenberg, Sinah and Heßmann, Alexandra and Weidner, Silke}, issn = {2941-7406}, doi = {10.26127/BTUOpen-7026}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70267}, year = {2025}, abstract = {Die Innenst{\"a}dte stehen unter Handlungsdruck. Der R{\"u}ckgang des Einzelhandels, zunehmende Leerst{\"a}nde, ver{\"a}nderte gesellschaftliche Anspr{\"u}che sowie Herausforderungen durch den Klimawandel, demografische Entwicklungen und neue Mobilit{\"a}tsbed{\"u}rfnisse machen eine grundlegende Neuorientierung notwendig. Besonders Klein- und Mittelst{\"a}dten in Brandenburg stehen vor der Aufgabe, ihre Zentren zukunftsf{\"a}hig zu gestalten. Im Rahmen des Bachelor-Seminars Vertiefung Stadtmanagement - Transformation der Innenstadt besch{\"a}ftigten sich Studierende der Architektur und Stadtplanung mit ausgew{\"a}hlten Fallstudien brandenburgischer St{\"a}dte. Ziel war die Analyse bestehender Strukturen, Aktkurskonstellationen und Entwicklungspotenziale sowie die Erarbeitung r{\"a}umlicher und konzeptioneller Strategien zur St{\"a}rkung der Resilienz und Nutzungsvielfalt in den Zentren. Fachvortr{\"a}ge aus der kommunalen Praxis und Einblicke in Modellprojekte des Bundesprogramms „Zukunftsf{\"a}hige Innenst{\"a}dte und Zentren" lieferten wertvolle Impulse. Die entwickelten Konzepte legen den Fokus auf konsumfreie Aufenthaltsqualit{\"a}ten, den Umgang mit Leerstand, die Aktivierung von Freir{\"a}umen sowie die F{\"o}rderung sozialr{\"a}umlicher Kooperationen. Die Ergebnisse zeigen auf, wie durch integrierte, partizipative und experimentelle Ans{\"a}tze langfristige Perspektiven f{\"u}r die Innenst{\"a}dte entwickelt werden k{\"o}nnen.}, subject = {Transformation; Innenstadt; Zukunftsvision; Brandenburg; Stadtmanagement; Transformation; City center; Inner city; Urban development; Urban management; Brandenburg; Kleinstadt; Mittelstadt; Innenstadt; Stadtmanegement; Stadtsanierung}, language = {de} } @techreport{OPUS4-7109, title = {Naples : continuity and disruption}, editor = {Viderman, Tihomir}, issn = {2702-6892}, doi = {10.26127/BTUOpen-7109}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71099}, year = {2025}, abstract = {This publication compiles the results of a study excursion to Naples undertaken by Master's students in architecture and planning at BTU Cottbus-Senftenberg from 2 to 9 October 2023. Framed by the conceptual tension between continuity and disruption, the excursion examined how these dynamics shape the material, social, and symbolic textures of the city. The publication presents paired posters created by each student: one produced prior to the excursion in response to Elena Ferrante's novel, and one developed afterward, drawing on situated encounters with urban space. These visualisations reflect how perceptions of Naples shifted through embodied experience and critical engagement with the politics of representation.}, subject = {Naples; Visualisation; Representation; Relational space; Situated learning; Neapel; Raumvorstellungen; Repr{\"a}sentation; Relationale R{\"a}ume; Lernen am Ort; Neapel; Stadtstruktur; Raumvorstellung; Kontinuit{\"a}t; Stadtleben}, language = {en} } @phdthesis{Schorradt2025, author = {Schorradt, Martin}, title = {The semantic and spatio-temporal structure of audible speech}, doi = {10.26127/BTUOpen-7087}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70875}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {The goal of the present thesis is to assess whether it is possible to rejuvenate voices of adults to a certain desired age. Therefore, in a set of recordings, two of the main voice features (i.e., pitch and formants) were manipulated in a systematic way. Since children do not only sound different from adults but also articulate in an other manner the resynthesized recordings were made unintelligible. The present thesis presents an evaluation of different entrenched techniques for semantic removal and furthermore, aimes to offer a new approach based on a morphological operator. To not just give insight about the capability of the conducted manipulations but also to provide valuable results in the field of perception of speech, a series of perceptual experiments was conducted.}, subject = {Age synthesis; Age regression; Speech synthesis; Speech processing; Semantic space; Alterssynthese; Altersregression; Sprachsynthese; Sprachverarbeitung; Semantischer Raum; Sprachverarbeitung; Automatische Sprachproduktion; Stimme; Lebensalter; Semantischer Raum; Wahrnehmung; Experiment}, language = {en} } @techreport{OPUS4-7063, title = {Researching policies for future heritage : applying cultural heritage approaches to the fighting game community}, editor = {Venne, Michel}, doi = {10.26127/BTUOpen-7063}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70630}, year = {2025}, abstract = {Over a period of six months, students of World Heritage Studies researched the Fighting Game Community (FGC) through a cultural heritage lens to attempt to identify the potential of the FGC as cultural heritage worthy of protection. The results of the students' self-guided work are found in this report. With case studies from Germany, Indonesia, South Korea, India, Tanzania, Iran, and Mexico, a wide range of topics and approaches were implemented to understand the FGC better. Additionally, two chapters cover the history and academic study of the FGC documented through a digital Zotero Library. Particularly of note is one chapter on the analysis of international standard-setting instruments and their relevancy in the theoretical protection of the FGC as cultural heritage, which highlighted the gaps in current standard-setting instruments for traditions like the FGC. As a result of all the work undertaken, this report identifies that the FGC has many elements which, when understood through current international standard-setting instruments, are not accounted for due to the hybrid digital / in presence nature of the FGC. Additionally, defining the values of the FGC often is context-dependent as demonstrated across case studies, make it difficult to apply a unified approach to the subject.}, subject = {Heritage; Digital heritage; Fighting game community; Standard-setting instruments; Erbe; Digitales Erbe; Standardsetzende Instrumente; Studentische Forschung; Kulturerbe; Kampfspiel; Standardisierung; Forschung}, language = {en} } @misc{Kadalassery2025, type = {Master Thesis}, author = {Kadalassery, Meenu}, title = {Big Data's role in shaping UNESCO's cultural policies : a critical analysis within the scope of the 2005 convention on the diversity of cultural expressions}, doi = {10.26127/BTUOpen-7093}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70934}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {The rise of digital technologies and the vast quantities of data they generate are transforming multiple sectors, including culture. However, the cultural sector's engagement with these technologies and their potential remains underexplored. Amid rising criticisms of the cultural sector for its inefficient use of existing data and its lack of innovation in leveraging new data sources for the sector's benefit, there are calls for a renewed approach to data use and a nuanced understanding of its impact on cultural policymaking. Big Data, an emerging topic of interest in policymaking, has been studied for its capacity to support evidence-based decision-making. Additionally, it is increasingly being explored as an alternate data source in research within the culture and heritage sector, especially for supporting policymaking. This study examines the broader discourse on the use of Big Data in cultural policymaking, focusing on its perception as an innovation, the stages of its adoption or rejection, and the types of innovation decisions that influence those stages. Anchored in the Diffusion of Innovation theory, the analysis is framed within UNESCO's 2005 Convention on the Diversity of Cultural Expressions. Additionally, the research identifies key challenges and opportunities for integrating Big Data into cultural policymaking, both within the framework of the 2005 Convention and in a broader context. The research proposes a conceptual framework that suggests considering Big Data as a potential facilitator for cultural policy innovation and advocates for its further examination. The research concludes with actionable recommendations and a broad-level guideline for advancing the discussion on the viability of Big Data as an innovation for cultural policymaking.}, subject = {Big Data; Cultural policymaking; Data innovation; 2005 UNESCO Convention; Diffusion of Innovations theory; Big Data; Kulturpolitik; Dateninnovation; UNESCO-Konvention von 2005; Theorie der Diffusion von Innovationen; Kulturpolitik; Kulturwirtschaft; Big Data; Innovation; Convention on the Protection and Promotion of the Diversity of Cultural Expressions (2005 Oktober 20)}, language = {en} } @phdthesis{Hoeppner2025, author = {H{\"o}ppner, Martin}, title = {Decisions under risk : an economic analysis}, doi = {10.26127/BTUOpen-7062}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70622}, school = {BTU Cottbus - Senftenberg}, year = {2025}, abstract = {This dissertation explores decision-making under risk through a comprehensive economic analysis. It aims to deepen our understanding of how individuals make choices when faced with uncertainty and risk, integrating various theoretical models and empirical findings. The thesis begins by surveying established models in the literature from economics, psychology and biology, highlighting their strengths and limitations. Subsequently, possible challenges and avenues forward are presented. To highlight the limitations of a constant risk preference assumption, an experiment was carefully designed for the second paper. This study compares these models in an online experiment, emulating real-world investment decisions. The findings reveal significant deviations from traditional theories, suggesting the need for more flexible and encompassing frameworks. A change in individual decision-making behavior is observed between different rounds of the experiment, not only indicating a variable risk preference, but an adaptive decision-making process altogether. To explore this on a theoretical level, this dissertation subsequently delves into the evolutionary dynamics of risk preferences, examining how different behavioral models survive and thrive in competitive environments. The results indicate that models which allow for adaptive risk preferences have an evolutionary advantage over those that do not. This questions the current empiric approach in search for a single risk preference parameter to explain and predict individual behavior. An observed change in the decision making process could be modelled with the assumption of bounded rationality, offering a more accurate depiction of human behavior. Overall, this dissertation contributes to the field of behavioral economics by providing a nuanced understanding of decision-making under risk, surveying a wide array of models, criteria to evaluate them, and offering practical implications for policy-making and risk management. The work underscores the importance of integrating empirical evidence with theoretical advancements to better comprehend and predict behavior in uncertain environments.}, subject = {Risk; Uncertainty; Decision theory; Decision models; Risk preferences; Entscheidungsmodelle; Entscheidungstheorie; Risiko; Risikopr{\"a}ferenzen; Unsicherheit; Entscheidung bei Risiko; Entscheidung bei Unsicherheit}, language = {en} }