@phdthesis{Eisentraut2024, author = {Eisentraut, Mark}, title = {Beschleunigung des Isothermschmiedens von Titanaluminiden durch gezielte Mikrostrukturentwicklung}, doi = {10.26127/BTUOpen-7000}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70000}, school = {BTU Cottbus - Senftenberg}, year = {2024}, abstract = {Titanaluminide (TiAl) sind vielversprechende Hochtemperaturwerkstoffe, die aufgrund ihrer geringen Dichte und hohen spezifischen Festigkeit insbesondere in der Luft- und Raumfahrtindustrie Anwendung finden. Die Mikrostruktur von TiAl-Legierungen spielt eine entscheidende Rolle f{\"u}r deren mechanische Eigenschaften und Bearbeitbarkeit. Durch gezielte Mikrostrukturentwicklung kann die Umformbarkeit und damit die Effizienz der Bearbeitungsprozesse verbessert werden. Deshalb wurde in der vorliegenden Arbeit eine neue Prozesskette f{\"u}r das Schmieden von Titanaluminiden entwickelt und erprobt, um die Prozesszeiten zu reduzieren und die Wirtschaftlichkeit des Werkstoffs zu erh{\"o}hen. Die Prozesskette umfasst drei Schritte: eine Vorw{\"a}rmebehandlung, eine beschleunigte Umformung und eine eigenschaftsbestimmende Nachw{\"a}rmebehandlung. Die spezifische Vorw{\"a}rmebehandlung zur Verbesserung der Umformbarkeit f{\"u}hrt zu einer Mikrostruktur mit einem geringen lamellaren Anteil, einem hohen β/β0-Gehalt und einem hohen Anteil an zellularen Reaktionen. Dadurch konnte die maximale Fließspannung im Vergleich zum geHIPten Zustand um ca. 20 \% gesenkt werden. Es wurde ein Prozessfenster definiert, in dem der w{\"a}rmebehandelte Zustand eine geringere Fließspannung und eine verbesserte Schadenstoleranz im Vergleich zum geHIPten Ausgangsmaterial aufweist. Basierend auf den Ergebnissen von Stauchversuchen mit konstanter Dehnrate wurden Dehnratenprofile mit variablen Dehnraten entwickelt, um den Umformprozess zu beschleunigen. Diese Umformung mit variabler Dehnrate wurde sowohl an zylindrischen Proben als auch an Gussrohlingen durchgef{\"u}hrt. Die Ergebnisse zeigten, dass die Prozesszeiten im Vergleich zur Umformung mit konstanter Dehnrate um 50 bis 70 \% reduziert werden konnten, ohne eine erh{\"o}hte Materialsch{\"a}digung zu verursachen. Zudem wurde festgestellt, dass die f{\"u}r diese Legierung entwickelten Dehnratenprofile auf andere TiAl-Legierungen {\"u}bertragbar sind. Abschließend wurde eine eigenschaftsbestimmende Nachw{\"a}rmebehandlung eingesetzt, die zu einer Mikrostruktur mit verbesserten Eigenschaften f{\"u}hrte. Die mechanischen Eigenschaften der mit der neuen Fertigungskette erzeugten Proben sind dabei mit denen der konventionellen Fertigungskette vergleichbar.}, subject = {Mechanische Eigenschaften; Mechanical properties; Titanaluminide; Titanium aluminides; TNM-B1; Umformung; Forming; Titanaluminide; Mikrostruktur; Schmieden; Umformen; Prozesskette; Optimierung}, language = {de} } @phdthesis{Eisold2020, author = {Eisold, Hans-Elmar}, title = {Zur{\"u}ck zur L{\"o}sung : eine kritische Analyse von Innovationsimperativ und Innovationskultur}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-52893}, school = {BTU Cottbus - Senftenberg}, year = {2020}, abstract = {Was bedeutet es, innovativ zu sein? Ausgangspunkt der vorliegenden Arbeit ist die weitverbreitete Verwendung des Innovationsbegriffes, f{\"u}r den aber Probleme der Unsch{\"a}rfe oder ein wichtiger historisch-systematischem Bedeutungswandel erkannt werden. Die vorgenommene Auseinandersetzung zur Innovation arbeitet die begriffiche Historie auf und benennt dabei wesentliche Schwerpunkte. Die vorgeschlagene Innovationsdefinition vom Mehrwert zum Zweck des eigenen Erfolgs dient als Ausgangspunkt, um zwischen bloßer M{\"o}glichkeit und tats{\"a}chlich genutzter L{\"o}sung unterscheiden zu k{\"o}nnen. Die Frage nach der Relevanz ist das Ergebnis dieser individuellen Bewertung. Dar{\"u}ber hinaus wird durch ein, in Anlehnung an bereits existierende Pfad- und Urnenmodelle, entwickeltes Kugelmodell verdeutlicht, dass (Markt)Bedeutung und technisches Potential eben nicht pauschal ineinander {\"u}berf{\"u}hrbar sind. Die Bedeutung von Relevanz zeigt sich auch in der Herausforderung, Forschung als mehr oder weniger sinnvoll bestimmen zu wollen. So ist im akademischen Umfeld der {\"o}konomische Nutzen im Kontext privater Forschung nachvollziehbar. Ein notwendiger gesellschaftlicher Effekt bleibt aber oft aus. Dieser ist oft nur mit akademischen Disziplinen umsetzbar (z. B. P{\"a}dagogik, {\"O}kologie), die sich der {\"O}konomisierung teilweise v{\"o}llig entziehen. Die Relevanz als Bezugswert akademischer Forschung ist damit nicht allein an {\"o}konomischer Tauglichkeit ausgerichtet, sondern auch an ihrer gesellschaftlichen Gestaltungsabsicht und Notwendigkeit. Dies beinhaltet dann jedoch auch eine kritische Bewertung falscher oder zum Selbstzweck betriebener Forschung ohne Gehalt, deren Ursachen sich u. a. in ihrer zwanghaften {\"O}konomisierung wiederfinden oder durch Fehler beteiligter Akteursgruppen (menschlicher Makel) hervorgerufen werden. Diese Thesen werden im Kontext einer sinnvollen Handlungsempfehlung diskutiert. Dabei wird ein aus den Elementen Reexion, Fokus und Pragmatismus bestehender Kulturhebel vorgeschlagen, der sowohl aus der Gegen{\"u}berstellung geschlossener und offener Innovation als auch klassischer Wissenschaft und Technoscience abgeleitet werden kann. Er beantwortet die eingangs gestellte Frage, was es bedeutet, innovativ zu sein: 1. Was? -> L{\"o}sungen schaffen, 2. Wie? -> Ideen/M{\"o}glichkeiten in den Relevanzhorizont bringen (relevant machen), 3. Wodurch? -> Reflektion {\"u}ber sich selbst, Fokus auf die Bed{\"u}rfnisse der Zielgruppe und Pragmatismus bei der Anwendung von F{\"a}higkeiten und Wissen (Kulturhebel). Die Auseinandersetzungen der vorliegenden Arbeit f{\"u}hren zu diesen Schlussfolgerungen hinsichtlich innovativen Handelns}, subject = {Innovation; Innovationskultur; Relevanz; Kulturhebel; Innovation; Innovation culture; Relevance; Culture lever; Innovationsforschung}, language = {de} } @phdthesis{Elattassi2020, author = {Elattassi, Najla}, title = {Learning from the past, designing for the future : sustainability of the Mediterranean vernacular}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-53091}, school = {BTU Cottbus - Senftenberg}, year = {2020}, abstract = {With climate change and the depleting ozone layer, awareness about protecting the environment is increasing and "Sustainable Architecture" is becoming an essential part of the architectural future of cities. However, sustainable buildings of today are being built with high cost, high tech systems which can be reduced by taking advantage of past technologies and systems. The brilliance of vernacular architecture and the way man adapted to his surroundings fascinated me and inspired me to do further research on the sustainable characteristics of vernacular settlements of the Mediterranean area in order to determine if these characteristics can be applied to present and future architecture in an innovative way to create sustainable buildings with least possible energy consumption. The method of research was based upon a general analysis of the passive design (solar and wind) characteristics of a town or settlement in Mediterranean climate starting from its site elements such as topography, vegetation, water. After that its urban structure, such as the geometry, block and street orientation and dimensions. Following that, the dwelling characteristics like dwelling shape, orientation and dimensions and finally the thermal regulating elements found in these dwellings, such as windows and vegetation. These elements were given a score according to their contribution to energy savings in buildings. Four case studies were chosen: two vernacular case studies from the region of study (the Mediterranean Coasts) and two modern case studies inspired by the Mediterranean vernacular. The analysis was repeated in the same sequence mentioned: Site, Settlement, Dwelling, Element, for the actual performance of each case study. The elements were given a number of points out of the score assigned for each element in the general analysis. A total score and rating for each case study resulted from this analysis. The objective of these scores were to compare the performance of the vernacular case studies to the vernacular inspired case studies in terms of energy savings. The final scores displayed comparable results between both types of case studies meaning that when these modern settlements were designed with an influence from the Mediterranean vernacular, their performance in energy savings was close to that of a vernacular settlement. That means that it is possible to design settlements which are influenced by vernacular settlements and can even defeat them by following the general guidelines of the vernacular passive design characteristics in addition to modern tools and innovative methods. These guidelines can be reflected in a handbook and rating system which can become a simple step by step guide for architects and planners to design sustainable settlements without the need for expensive and complicated rating systems and consultants.}, subject = {Vernacular architecture; Sustainable; Passive design; Mediterranean; Vernakul{\"a}re Architektur; Passives Design; Energieeinsparung; Bewertungssystem; Nachhaltigkeit; Mittelmeerraum; Stadtentwicklung; Architektur; Solararchitektur; Nachhaltigkeit}, language = {en} } @techreport{ElmerSchaafBiemeltetal.2011, author = {Elmer, Michael and Schaaf, Wolfgang and Biemelt, Detlef and Gerwin, Werner and H{\"u}ttl, Reinhard F.}, title = {The artificial catchment 'Chicken Creek' - initial ecosystem development 2005-2010}, organization = {Forschungszentrum Landschaftsentwicklung und Bergbaulandschaften}, issn = {1867-7800}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-23730}, year = {2011}, abstract = {This volume summarizes the monitoring activities and results at the 'Chicken Creek' catchment for the period 2005 to 2010. The development in all ecosystem compartments is assessed, classified, and compared to more mature systems with regard to functional relevance and succession stage. In a final synopsis, the whole catchment is evaluated with regard to ecosystem development and an outlook is given on the expected trends both in the short and the medium term.}, subject = {Welzow; Braunkohlentagebau; Rekultivierung; Wassereinzugsgebiet; {\"O}kosystem; {\"O}kosystem; K{\"u}nstliches Wassereinzugsgebiet; H{\"u}hnerwasser; Monitoring; Ecosystem; Artificial catchment; Chicken Creek; Monitoring}, language = {en} } @phdthesis{ELssaedi2008, author = {ELssaedi, Mosbah Mohamed}, title = {A new approach to Event-Driven Programming}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-4574}, school = {BTU Cottbus - Senftenberg}, year = {2008}, abstract = {In many applications, like embedded systems or systems with a strong user interaction, the program is mainly controlled by events. An event handler waits for any event to occur, and then processes that event by ignoring it or calling a corresponding action, a procedure declared in the program. In this way, events are coupled with actions and can influence the global state of the whole program. In order to design a well structured program, event handling and corresponding actions should be clearly separated. However, this aim is not always ensured. In this thesis, an approach is introduced, which enforces to design event-driven systems into two main parts: - An event-handling part, also called specification part, and - An action part, also called hand-built program part (hbp). The specification part is defined as a declarative specification of the event-handling in a special language. It is separated from the hand-built program part. Every event can only influence the state of this part, which contains the implementation of control functions, which calls the several actions defined in the hand-built program part and so connects both parts together. The prototype of a framework was implemented which allows to specify the eventhandling part by means of a special editor and generates from it some classes and templates. In order to complete the implementation, the programmer has to fill into the templates program code by hand (therefore called hand-built program part), which describe the actions.}, subject = {Ereignisgesteuerte Programmierung; Event-Driven Programming; Spezifizierung; Event-Driven Programming; Specification}, language = {en} } @article{EltaherBreuss2025, author = {Eltaher, Mahmoud and Breuß, Michael}, title = {Deep learning for unsupervised 3D shape representation with superquadrics}, series = {AI}, volume = {6}, journal = {AI}, number = {12}, publisher = {MDPI}, address = {Lausanne}, issn = {2673-2688}, doi = {10.3390/ai6120317}, year = {2025}, abstract = {The representation of 3D shapes from point clouds remains a fundamental challenge in computer vision. A common approach decomposes 3D objects into interpretable geometric primitives, enabling compact, structured, and efficient representations. Building upon prior frameworks, this study introduces an enhanced unsupervised deep learning approach for 3D shape representation using superquadrics. The proposed framework fits a set of superquadric primitives to 3D objects through a fully integrated, differentiable pipeline that enables efficient optimization and parameter learning, directly extracting geometric structure from 3D point clouds without requiring ground-truth segmentation labels. This work introduces three key advancements that substantially improve representation quality, interpretability, and evaluation rigor: (1) A uniform sampling strategy that enhances training stability compared with random sampling used in earlier models; (2) An overlapping loss that penalizes intersections between primitives, reducing redundancy and improving reconstruction coherence; and (3) A novel evaluation framework comprising Primitive Accuracy, Structural Accuracy, and Overlapping Percentage metrics. This new metric design transitions from point-based to structure-aware assessment, enabling fairer and more interpretable comparison across primitive-based models. Comprehensive evaluations on benchmark 3D shape datasets demonstrate that the proposed modifications yield coherent, compact, and semantically consistent shape representations, establishing a robust foundation for interpretable and quantitative evaluation in primitive-based 3D reconstruction.}, subject = {3D shape representation; Superquadrics; Deep learning; Unsupervised learning; Point clouds; Geometric modeling}, language = {en} } @phdthesis{Enculescu2006, author = {Enculescu, Mihaela}, title = {Wellenausbreitung in neuronalen Feldern mit retardierter Wechselwirkung}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-438}, school = {BTU Cottbus - Senftenberg}, year = {2006}, abstract = {Ein wesentlicher Aspekt der Dynamik elektrischer Aktivitaet in neuronalen Gewebe betrifft die Ausbreitung von Aktivitaet in Form von Wellen. In dieser Arbeit untersuchen wir die Existenz und Eigenschaften laufender Wellenloesungen einer nichtlinearen Neuronalen-Feld-Gleichung. Das Modell beruecksichtigt die nichtlokalen synaptischen Verbindungen und die Zeitverzoegerung bei der Kommunikation zwischen den Nervenzellen, die abstandsabhaengig ist. Die Modellgleichung hat daher die mathematische Form einer nichtlinearer, retardierter Integralgleichung. In der Arbeit wird zuerst gezeigt, wie man die Modellgleichung durch ein System von partiellen Differentialgleichungen approximieren kann, das leichter numerisch untersucht werden kann. Anschliessend werden laufende Wellenloesungen des Modells numerisch und analytisch untersucht.}, subject = {Neuronales Netz; Informationsverarbeitung; Neural fields; Wave propagation; Integral equations; Delayed equations}, language = {de} } @phdthesis{Engelbrecht2017, author = {Engelbrecht, Daniel}, title = {Untersuchung der Potentiale und Anforderungen an ein Wirkleistungsmanagement im Verteilnetz mit hohem Anteil von dezentralen Erzeugungsanlagen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-43479}, school = {BTU Cottbus - Senftenberg}, year = {2017}, abstract = {In der Dissertation werden neue Potentiale und Anforderungen sowie neue Verfahren und Methoden zur Bereitstellung von Systemdienstleistungen erarbeitet. Der Fokus wird dabei auf das Wirkleistungsmanagement im Verteilnetz gelegt. Bei einer zunehmenden Durchdringung von Erneuerbaren Energien steigt der gegenseitige Einfluss mit den technischen Systemen im Netzbetrieb und bestehenden sowie zuk{\"u}nftigen M{\"a}rkten. In der Arbeit werden organisatorische und technische L{\"o}sungen entwickelt, welche eine sichere Bereitstellung von Regelleistung sowie eine Unterst{\"u}tzung durch den Verteilnetzbetreiber f{\"u}r ein systemdienliches Engpassmanagement des {\"U}bertragungsnetzbetreibers erm{\"o}glichen. Anhand eines 110-kV-Modellnetzes werden die technischen L{\"o}sungen aufgezeigt und bewertet. Dabei zeigt sich, dass eine erweiterte Betriebsplanung im Verteilnetz notwendig wird. M{\"o}gliche Konflikte k{\"o}nnen im Vorfeld durch eine Netzzustandsbewertung und Informations{\"u}bermittlung gel{\"o}st werden. Weiterhin k{\"o}nnen Anforderungen des {\"U}NB zur Unterst{\"u}tzung zum Redispatch im Rahmen einer Vortagesplanung integriert werden. Zur Realisierung der Prozesse und somit Erf{\"u}llung der neuen Anforderungen sind zum Teil technische {\"A}nde-rungen in den Systemen der Netzf{\"u}hrung sowie organisatorische und rechtliche Anpassungen in der Handhabung des Engpassmanagements notwendig. Hierzu werden in der vorliegenden Arbeit konkrete Empfehlungen ausgesprochen.}, subject = {Wirkleistungsmanagement; Verteilnetz; Erneuerbare Energien; Regelleistung; Redispatch; Active power management; Distribution system; Control power; Redispatch; Renewable energy; Lastverteilung ; Erneuerbare Energien; Wirkleistung; Verteilungsnetz}, language = {de} } @phdthesis{Engelbrecht2019, author = {Engelbrecht, Steffen}, title = {Mikrobielle Stickstoffelimination mit kombinierter partieller Nitrifikation/ Anammox (PN/A) in membranbel{\"u}fteten hochsalinen und Niedrigtemperatur-Festbettreaktoren}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-48848}, school = {BTU Cottbus - Senftenberg}, year = {2019}, abstract = {Durch anthropogene Aktivit{\"a}t hat sich der N{\"a}hrstoffeintrag in die Umwelt stark erh{\"o}ht. Die Hauptquellen sind die Landwirtschaft, kommunales und industrielles Abwasser. Erh{\"o}hte Stickstofffrachten haben einen starken Einfluss auf den Stickstoffkreislauf. Das {\"U}berangebot an Stickstoff f{\"u}hrt zu Eutrophierung in Gew{\"a}ssern und somit zu einem weniger diversen, instabileren {\"O}kosystem. Die Stickstoffeliminierung aus Abw{\"a}ssern ist essentiell f{\"u}r den Schutz der {\"O}kosysteme. Das etablierte System der Nitrifikation/Denitrifikation ist aufgrund des hohen Sauerstoffbedarfs sehr energie- und somit auch kostenintensiv. Der Anammox-Prozess (anaerobe Ammonium Oxidation) ist eine potentielle Alternative zur konventionellen Stickstoffelimination. Anammox-Bakterien nutzen Ammonium und Nitrit als Elektronenakzeptor. Durch Nutzung der partiellen Nitrifikation in Kombination mit Anammox (PN/A) kann bis zu 60 \% der Bel{\"u}ftungsenergie eingespart werden. Trotz Erfolgen in der Teilstrombehandlung ist der Prozess noch nicht erfolgreich in der Hauptstrombehandlung eingesetzt worden. Die gr{\"o}ßten Herausforderungen sind die niedrigen Temperaturen, geringe Zulaufkonzentrationen und hohe Konzentrationen organischen Kohlenstoffs. Die vorliegende Arbeit konnte die Wirksamkeit von membranbel{\"u}fteten Biofilm Reaktoren unter Verwendung von synthetischem Abwasser bei niedrigen Temperaturen (18 - 8 °C) belegen. Die Innovation in diesem System ist die r{\"a}umliche Trennung von nitrifizierenden Bakterien und Anammox Bakterien. Die regelm{\"a}ßige mechanische Entfernung des Nitrifikanten-Biofilms erm{\"o}glichte einen langzeitstabilen Reaktorbetrieb. Diese Reaktorkonfiguration konnte auch erfolgreich f{\"u}r hochsaline Abw{\"a}sser (5 -30 g NaCl*L-1) bei einer Reaktortemperatur von 30 °C und auch unter Zugabe von TOC (40-100 mg TOC*L-1) genutzt werden. Weiterhin wurden Untersuchungen zur Aktivit{\"a}t von salzadaptierter Anammox-Biomasse und nicht adaptierter Biomasse in einem Bereich von 0 bis 50 g NaCl*L-1 durchgef{\"u}hrt. Bei Konzentrationen unter 30 g NaCl*L-1 konnten keine signifikanten Unterschiede im Abbauverhalten festgestellt werden. Allerdings war adaptierte Biomasse bei h{\"o}heren Salzkonzentrationen konkurrenzst{\"a}rker. Außerdem wurden Langzeitlagerungsversuche durchgef{\"u}hrt. Die Lagerungsbedingungen variierten in der Lagerungstemperatur, im Redoxpuffer und der N{\"a}hrstoffversorgung. Nach 106 Tagen bei 4 °C konnte die Anammox-Biomasse noch 91 \% ihrer urspr{\"u}nglichen Aktivit{\"a}t erhalten. Somit konnte eine einfache und kosteng{\"u}nstige Lagerungsmethode f{\"u}r Anammo-Bakterien entwickelt werden.}, subject = {PN/A; Niedrigtemperatur; Anammox; Mebranbel{\"u}fteter Biofilm-Reaktor; Hohe Salinit{\"a}t; PN/A; Low temperature; MABR; High salinity; N{\"a}hrstoffeintrag; Salzgehalt; Abwasser; Biofilmreaktor; Ammoniumoxidierer}, language = {de} } @phdthesis{Engelhorn2022, author = {Engelhorn, Thorsten}, title = {On the value of the wind's infeed and the costs of capacity build-up : a bottom-up modelling for the German market}, doi = {10.26127/BTUOpen-6122}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-61221}, school = {BTU Cottbus - Senftenberg}, year = {2022}, abstract = {In this dissertation, I present three research articles on the economics of wind energy in Germany. The first two chapters primarily assess onshore wind energy's empirical value in the wholesale market. The third chapter discusses the efficiency of the German wind support scheme. In the first chapter, a database on German onshore wind turbines installed was created by using a general method to fill incomplete stock data. By using the database and highly granular wind speed data, hourly infeed and annual market values of around 25,700 wind turbines in Germany from 2005 to 2015 were calculated, and its drivers - infeed-price-correlation and standard deviation of infeed - analysed. Further, the spread in market values on turbine level was shown, regional differences quantified and the effect of turbine age on market values discussed. Turbines in central Germany had, on average, lower market values than turbines in the north, south or west of Germany. Modern turbines reached higher market values than older turbines. The second chapter on wind turbines' market values covers the period until 2019. This analysis confirmed that market values were highly diverse on turbine level. Further, it explained why the market value of a single turbine matters in the market premium model. In this context, the magnitude of the outperformance of technologically advanced turbines was assessed. Last, the effect of inter-annual weather variability on wholesale electricity prices and market values was quantified, using 19 different years of winds speeds and infeed data. In the third chapter, it was analysed whether the German wind support scheme incentivised a cost-minimal capacity build-up. Two cost-minimal benchmark scenarios were developed and compared to the historical capacity build-up between 1995 and 2015. The costs of the benchmark scenarios were significantly lower than those of the historical build-up. The benchmark cost reduction largely stemmed from greater efficiency in terms of using better wind sites. It was further shown that a spatially concentrated capacity-build up, as induced in the benchmarks, is beneficial from a consumer's point of view.}, subject = {Onshore wind power; Direct marketing; Market value; Cost minimisation; Efficiency; Windenergie an Land; Direktvermarktung; Marktwert; Kostenminimierung; Effizienz; Windenergie; Kostenoptimierung; Marktwert}, language = {en} } @phdthesis{Enow2023, author = {Enow, Ernest Ako}, title = {Possible synergy between FLEGT-VPA \& REDD+ towards improving forest governance framework in Cameroon}, doi = {10.26127/BTUOpen-6536}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-65364}, school = {BTU Cottbus - Senftenberg}, year = {2023}, abstract = {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.}, subject = {Cameroon; FLEGT-VPA; REDD+; Illegal logging; Policy; Kamerun; Illegale Abholzung; Entwaldung; Politik; Kamerun; Umweltpolitik; Forstverwaltung; Rodung; Kohlendioxidemission; Klima{\"a}nderung; REDD; Forstrecht}, language = {en} } @phdthesis{Epping2004, author = {Epping, Thomas}, title = {Color sequencing}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-000000572}, school = {BTU Cottbus - Senftenberg}, year = {2004}, abstract = {In this dissertation, we present several solution approaches for the color change minimization problem that arises in the paint shop of an automobile plant. We give NP-completeness results for an abstract formulation of this problem and show that it is APX-hard, even in a restricted form. For this form, we establish a connection to binary matroids. When solving the color change minimization problem with the help of a line storage system, we present dynamic programs that use algorithms from computational biology, among others. Finally, we look into the color change minimization problem within the overall production process of an automobile plant. We describe an algorithm that sequences a daily production and that has been successfully developed with and implemented in the Ford Motor Company (Europe).}, subject = {Karosserie; Spritzlackieren; Farbwechseltechnik; Prozessoptimierung; Reihenfolgeproblem; APX-Hardness; Binary methods; Dynamic programming; Flexible manufacturing systems; Projekt management and scheduling}, language = {en} } @phdthesis{Erlewein2015, author = {Erlewein, Shina-Nancy}, title = {Screening Intangible Heritage : media, heritage and representation: the case of Kutiyattam Sanskrit Theatre, India}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-35985}, school = {BTU Cottbus - Senftenberg}, year = {2015}, abstract = {This research investigates the role of audio-visual media in the representation of intangible cultural heritage and provides a theoretically and empirically grounded concept of the interrelation of media, ICH and representation. It identifies both the potentials and risks involved in media representation, as well as responding to the question regarding how audio-visual representations can foster the safeguarding of ICH, aiming at its sustained transmission and recreation. The study conceptualizes representation as a process in which meaning is produced and negotiated. It refers to discourse in Social/Cultural Anthropology, Heritage Studies and Cultural Studies, particularly making use of the circuit of culture model, Hall's encoding/decoding model and Assmann's concept of memory. As ICH is culturally contextualized, the analysis focuses on one specific heritage manifestation: the Kutiyattam Sanskrit theatre. It explores in detail Kutiyattam's history, identity, performance practice and transformation, including after UNESCO's proclamation. It analyses the processes and conditions of production, encoding, circulation, reception, utilization and regulation of audio-visual representation and demonstrates the extent to which these dynamic and manifold reciprocal processes influence Kutiyattam practices and practitioners. In the form of a thick description, the study exemplifies that media and modern technologies foster continuity in practice, revitalization, valorization and self-assertion, that they enable education, research, promotion and dissemination of ICH, and contribute to identity construction and the (re)creation of communities. It shows that audio-visual representations - when produced in collaboration with the practicing communities, thereby facilitating culture-specific coding and community use - constitute significant vehicles within safeguarding measures. Differentiating between horizontal and vertical transmission of ICH as well as micro and macro level consumption, the study further identifies numerous challenges involved in the mediatization and digitization of ICH. It addresses issues of access, participation, appropriation and intellectual property and the conflict-ridden processes of homogenization, fragmentation, commercialization and popularization, among others. It argues that rather than being innocent and neutral reflections of cultural practices, audio-visual representations are actively involved in meaning making and knowledge constitution processes and deeply enmeshed in power. It proves that representations shape memory, cultural identity and history and exercise influence on cultural expressions and communities. The study concludes with the provision of general recommendations, giving guidance regarding the utilization of media as well as the production, consumption and regulation of media work, targeting heritage professionals and media professionals alike.}, subject = {Intangible Cultural Heritage; UNESCO; Mediatization and digitization; Audio-visual representation; Kutiyattam Sanskrit theatre; Immaterielles Kulturerbe; Mediatisierung und Digitalisierung; Audio-visuelle Repr{\"a}sentation; Kutiyattam Sanskrit Theater; Kudiyattam; Immaterielles Kulturerbe}, language = {en} } @article{ErtugrulEmdadiHaertel2025, author = {Ertugrul, G{\"o}khan and Emdadi, Aliakbar and H{\"a}rtel, Sebastian}, title = {Powder production and additive manufacturing of iron aluminide alloys using plasma ultrasonic atomization and laser-directed energy deposition}, series = {Additive Manufacturing Letters}, volume = {14}, journal = {Additive Manufacturing Letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2772-3690}, doi = {10.1016/j.addlet.2025.100313}, year = {2025}, abstract = {With a combination of desirable properties such as low density, high specific yield strength, low material cost, and excellent oxidation and corrosion resistance, iron aluminide (Fe-Al) has shown considerable potential to be an alternative to high-alloy chromium steels, and in some cases even nickel-based superalloys, in hightemperature applications. Due to these features, it is especially suitable for the aerospace and automotive industries. Recent advancements indicate an increasing interest in Fe-Al within the additive manufacturing industry, particularly in directed energy deposition (DED) processes. Despite this progress, processing of Fe-Al materials using the laser directed energy deposition (L-DED) has not been sufficiently investigated. In this study, Fe-Al powder material was produced from a commercial Al rod encased in a commercial low alloy-steel tube by a plasma-based ultrasonic atomization eliminating the need to cast an alloy ingot in advance. Subsequently, the produced powder was used in a L-DED process to fabricate an additively manufactured sample. The sample was investigated in terms of mechanical property, microstructure, chemical composition, and phase structure by scanning electron microscope (SEM) / energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and microhardness analyses.}, subject = {Iron aluminides (Fe-Al); Laser directed energy deposition (L-DED); Plasma ultrasonic atomization; Powder; Intermetallic phase}, language = {en} } @article{ErtugrulEmdadiJedynaketal.2025, author = {Ertugrul, G{\"o}khan and Emdadi, Aliakbar and Jedynak, Angelika and Weiß, Sabine and H{\"a}rtel, Sebastian}, title = {Hot forming behavior of tungsten carbide reinforced Ni-based superalloy 625 additively manufactured by laser directed energy deposition}, series = {Additive Manufacturing Letters}, volume = {13}, journal = {Additive Manufacturing Letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2772-3690}, doi = {10.1016/j.addlet.2025.100267}, year = {2025}, abstract = {The demands of high-performance industries such as aerospace, automotive, tool manufacturing, oil, and gas industries are driving the innovation in high-performance materials and their production methods. This study explores the impact of hybrid manufacturing, specifically the effect of the addition of tungsten carbide (WC/W2C) via Laser-Directed Energy Deposition (L-DED), on the hot workability, hardness, and microstructure of nickel-based superalloy Inconel 625 (IN625). IN625 is known for its high temperature and high corrosion resistance, and tungsten carbide for its high wear resistance and grain refinement effect. The integration of WC/W2C particles into the IN625 matrix, in addition to the use of the hybrid approach of additive manufacturing followed by a hot-forming process, significantly influences the microstructure and mechanical behavior of the material. Thus, while incorporation of the WC/W2C can strengthen the material and extend the mechanical limitations, its full impact, including any potential usages, should be thoroughly evaluated for the intended application of the materials. To understand the effect of WC/W2C, additive manufacturing of IN625 both with and without WC/W2C and isothermal hot compression was carried out. The objective is to analyze the differences in microstructure and properties between L-DED manufactured IN625, and WC-reinforced IN625, and their hot-forming behavior, focusing on the effects of WC addition and post-deformation on microstructure and mechanical properties. This work represents the first investigation into the effect of WC/W2C hard particles on the hot-forming process of additively manufactured Ni-based metal matrix composites.}, subject = {Hybrid manufacturing; Laser-directed energy deposition (L-DED); Hot-forming; Inconel 625 (In625); Microstructure manipulation}, language = {en} } @misc{EverthKassner2024, type = {Master Thesis}, author = {Everth, Stefanie and Kaßner, Astrid}, title = {„Die Pflege entwickelt sich weiter" : eine Forschungsarbeit zur Lehre in der Praxis}, doi = {10.26127/BTUOpen-7176}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71762}, school = {BTU Cottbus - Senftenberg}, year = {2024}, abstract = {Die Masterarbeit untersucht das pflegewissenschaftliche und pflegedidaktische Anleitungshandeln sowie die habitualisierten Praktiken von Lehrenden in der Praxis in der pflegeberuflichen Ausbildung. Verglichen werden akademische und berufsbildende Lehrende in der Praxis aus den pflegerischen Settings: akutstation{\"a}r, station{\"a}re Langzeitpflege und ambulante Pflege. Ziel ist es, empirische Erkenntnisse {\"u}ber die Gestaltung der Praxislehre und {\"u}ber das Selbstverst{\"a}ndnis zu gewinnen sowie Entwicklungsm{\"o}glichkeiten aufzuzeigen. Mittels qualitativer Sozialforschung wurden 14 leitfadengest{\"u}tzte Expertinnen- und Experteninterviews mit Lehrenden in der Pflegepraxis nach der Grounded-Theory-Methodologie durchgef{\"u}hrt und ausgewertet. Die Datenanalyse erfolgte durch offenes, axiales und selektives Kodieren inklusive der Anwendung des mentalen Felds als Forschungstool. Die Ergebnisse zeigen, dass die habitualisierten Praktiken im Anleitungshandeln von Lehrenden in der Praxis kontrastierende pflegewissenschaftliche und pflegep{\"a}dagogische Begr{\"u}ndungsmuster aufweisen. Ihr Berufsverst{\"a}ndnis, ihre Kompetenzbildung und Wissensbedarfe beeinflussen maßgeblich die Gestaltung der Praxislehre. Anhand von Fallrekonstruktionen werden unterschiedliche Anleitungsprofile herausgearbeitet. Die Forschungsarbeit begr{\"u}ndet empirisch die Notwendigkeit einer st{\"a}rkeren Professionalisierung der Lehrenden in der Pflegepraxis. Empfehlungen zur hochschulischen Qualifizierung unter Einbindung der berufsbildenden Lehrenden werden abgeleitet.}, subject = {Lehre in der Pflegepraxis; Habitualisierte Praktiken; Pflegeberufliche Ausbildung; Lehrendenprofessionalisierung; Anleitungshandeln; Teaching in nursing practice; Habitualised practices; Nursing education; Professionalisation of teachers; Instructional action; Pflegeberuf; Pflegep{\"a}dagogik; Pflegewissenschaft; Professionalisierung}, language = {de} } @phdthesis{Ewusi2006, author = {Ewusi, Anthony}, title = {Groundwater exploration and management using Geophysics : Northern Region of Ghana}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-378}, school = {BTU Cottbus - Senftenberg}, year = {2006}, abstract = {Groundwater has been identified as the best source for rural water supply in most rural communities in the Northern region of Ghana because it eliminates the problems of water borne diseases which have affected communities in the region over the years. The guinea worm disease is presently not totally eradicated in the area and there are signals that its occurrence will be increasing in the near future if adequate measures are not implemented to curtail the problem. Adequate groundwater exploration and management appears to be the key to ensure that potable and safe water is available for the entire population of the region and that its availability on a sustainable basis is guaranteed. Groundwater facilities being provided in the area include; engineered hand dug wells, boreholes fitted with hand pumps and mechanised small towns' piped schemes. Groundwater exploration programs implemented have however resulted in low success rates of borehole drilling because of the lack of a systematic and methodological approach. The available conventional geophysical techniques; one dimensional (1-D) electrical resistivity profiling and sounding as well as the electromagnetic (EM) methods have not been able to efficiently select suitable sites for successful borehole drilling because of their inability to successfully demarcate areas which are likely aquifer potential zones for successful groundwater abstraction. Current borehole drilling success rates especially in the Voltain rock formation are very low. The complex geological setting of groundwater systems in the area gives cause for the adoption and application of a systematic methodological approach in groundwater exploration utilising effective geophysical techniques. Available geophysical techniques which have been considered in this research work include; two dimensional (2-D) multi-electrode electrical resistivity survey, electro kinetic survey (EKS) and the radon survey.}, subject = {Ghana ; Grundwasser; Hydrologie; Geophysik; Grundwasser; Geophysikalische Methode; 2-D elektrische Widerstandskartierung; Elektrokinetisches Verfahren; Radon-Kartierung; Groundwater; Geophysical techniques; 2-D multi-electrode electrical resistivity survey; Electro kinetic survey; Radon survey}, language = {en} } @phdthesis{Extra2024, author = {Extra, Simon Karl}, title = {Ein Beitrag zur ganzheitlichen Optimierung in der Kerntriebwerksvorauslegung}, doi = {10.26127/BTUOpen-7145}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-71459}, school = {BTU Cottbus - Senftenberg}, year = {2024}, abstract = {Die etablierte Methode der Kerntriebwerksvorauslegung, die den Pfad immer gr{\"o}ßerer Komplexit{\"a}t und Abbildungsgenauigkeit bei abnehmender Abstimmung und Interaktion zwischen den Komponenten des Kerntriebwerks beschreitet, kann eine Systemverbesserung nicht zuverl{\"a}ssig herbeif{\"u}hren. Dabei beginnt die Betrachtung des zu entwerfenden Triebwerks mit einer Gesamtbetrachtung und wird anschließend an weitgehend getrennte Expertengruppen {\"u}bergeben. In diesen wird dann mit Auslegungswerkzeugen steigenden Detailgrads von analytischen Rechnungen mit empirischer Unterst{\"u}tzung {\"u}ber Stromlinienkr{\"u}mmungsverfahren hin zu 3D-CFD-Methoden der Entwurf durchgef{\"u}hrt. Das Ziel dieser Arbeit ist es, den Entwurfsprozess f{\"u}r das Kerntriebwerk weg von einer Optimierung einzelner Komponenten mit detaillierten Methoden hin zu einer ganzheitlichen Betrachtung der Qualit{\"a}t des Entwurfs zu f{\"u}hren. Dies {\"u}berwindet die oben beschriebenen Einschr{\"a}nkungen in der Auslegung und ist trotzdem in der Lage, auf bestehende validierte Analysewerkzeuge zur{\"u}ckzugreifen. Dazu werden die daf{\"u}r genutzten Kopplungsstrategien einer vergleichenden Untersuchung mithilfe eines analytischen Kerntriebwerksmodells unterzogen. Dabei wird die Wichtigkeit einer leistungsf{\"a}higen Kopplungsstrategie in Verbindung mit einem passenden Optimierungsalgorithmus dargestellt. Dies f{\"u}hrt nicht nur zu einer Verbesserung der Ergebnisqualit{\"a}t, sondern erm{\"o}glicht oftmals erst den Einsatz kooperativer Methoden. Ein Verfahren mit stochastischem Sampling und der Nutzung von Antwortfl{\"a}chen wird in diesem Kontext erl{\"a}utert und weiterentwickelt. Den Schnittstellen zwischen den Komponenten und ihrer Definition, Abbildung und Beeinflussung durch das Optimierungsverfahren kommt dabei entscheidende Bedeutung zu. Auf Basis dieses Vergleichs werden auf industriellen Methoden basierende Komponentenprozesse f{\"u}r die Analyse und Optimierung von Verdichter, Brennkammer und Turbine auf ihre Eignung im Rahmen einer ganzheitlichen Optimierung hin zun{\"a}chst untersucht und dann angepasst. Die evaluierten Kopplungsstrategien und die angepassten Komponentenoptimierungsprozesse werden in einen Systemoptimierungsprozess {\"u}berf{\"u}hrt. Dazu wird die gew{\"a}hlte Kopplungsstrategie hierf{\"u}r angepasst und demonstriert nach der Optimierung eine Verbesserung hinsichtlich der Systemzielfunktion, wodurch die Anwendbarkeit von kooperativen Auslegungsmethoden im industriellen Kontext gezeigt wird.}, subject = {Luftfahrtantriebe; Kerntriebwerk; Antwortfl{\"a}chen; Vorauslegung; Kopplungsstrategien; Aero engines; Core engine; Response surfaces; Pre-design; Coupling methods; Flugtriebwerk; Entwurf; Optimierung; Komplexes System; Bemessung}, language = {de} } @phdthesis{Eyb2022, author = {Eyb, Simona von}, title = {The future is a shared country : an application of the collaborative economic model in heritage tourism}, doi = {10.26127/BTUOpen-6130}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-61300}, school = {BTU Cottbus - Senftenberg}, year = {2022}, abstract = {This thesis contributes to the understanding of the collaborative economic model and its applicability in the development of heritage tourism in rural areas. It does so by examining the conceptual and operational attractiveness of the collaborative economy and by proposing a new collaborative model for tourism development. The first part of the research provides a broad theoretical contextualisation of the collaborative economic model. The main assumption is that the duality between individual and collective values lies at the core of all social interactions, and is essential in understanding the conceptual appeal of the collaborative model. The study draws upon concepts and paradigms from a wide range of academic disciplines to frame this assumption: moral philosophy, religion, history, national and political narratives, neuroscience, evolutionary biology, psychology, anthropology and World Heritage discourses. It continues with an analysis of this duality within various theoretical models in the history of Western political economy, and argues that the search for an ideal model of economic policy represented a constant balancing act between individualist or collective goals. The thesis further investigates this duality at the microeconomic level, in relation to specific aspects of economic behaviour: motivation, interaction, ownership, and modes of consumption. The research continues to examine the key characteristics of the collaborative economy, as an emerging model that challenges the structures of the dominant market economy. It demonstrates how the collaborative economy provides an ingenious manner to reconcile individual interests with a sense of community and cooperative action, developing a narrative that rehabilitates the social nature of economic activities. The second part of the thesis investigates the operational attractiveness of a potential collaborative tourism model. It explores the perspectives of both the providers (hosts) and the consumers (tourists) of travel experiences. With the help of data collected from a survey conducted at four selected locations in Romania (Hrabusna, Breaza de Sus) and India (Bhavikeri, Gokarn), the study identifies a high level of acceptance from potential hosts towards a small-scale collaborative tourism model. Similarly, data collected from an online survey offers valuable insights into the tourists' acceptance of a collaborative tourism model and the functional aspects of its implementation. Finally, the thesis proposes a new collaborative model for small-scale heritage tourism in rural areas - sharitage. The findings of this research provide a good basis for the elaboration of new socio-economic practices that would generate development opportunities and transparent benefits for vulnerable communities in rural areas, respond to the growing tourist demand for immersive, locally contextualised travel experiences, and contribute to the safeguarding of traditional knowledge and practices.}, subject = {World heritage; Heritage tourism; Collaborative economy; History of economic models; Individual and collective values; Welterbe; Kulturtourismus; Kollaborative Wirtschaft; Wirtschaftsgeschichte; Individuelle und kollektive Werte; L{\"a}ndlicher Raum; Wert; Sharing Economy; Wirtschaft; Geschichte; Welterbe; Bildungstourismus}, language = {en} } @phdthesis{Ezeamama2021, author = {Ezeamama, Anayo}, title = {Evaluating policy impacts of minimum energy performance standards (MEPS) on Nigeria's Nationally Determined Contribution (NDC) to the Paris Agreement}, doi = {10.26127/BTUOpen-5459}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-54598}, school = {BTU Cottbus - Senftenberg}, year = {2021}, abstract = {The Nigerian government has commenced the development of minimum energy performance standards (MEPS) as part of measures to achieve the energy and emissions savings target established in Nigeria's Nationally Determined Contribution (NDC) to the Paris Agreement. It is expected that the implementation of MEPS will also help to address the challenges of unreliability of electricity supply and facilitate the desired energy-efficient appliance market transformation. The MEPS currently covers the three most energy-consuming electrical products in households (lighting, refrigerators, and air conditioners). This research relied on data collected from the survey of 384 households in the case study area of Enugu to study the policy impacts of the current MEPS and identify the potential for its improvement. The research also, empirically, investigated policy and institutional barriers against appliance energy efficiency improvement in the country. Three different policy scenarios were conceptualized to model the policy impacts of current MEPS: a scenario assuming no MEPS or a business-as-usual (BAU) scenario, a policy scenario (PS) that considers the current MEPS, and an aggressive policy scenario (APS) that assumes the scaling up of the current MEPS to more stringent levels. The policy analysis modeling system (PAMS) was adopted to study the impacts of MEPS considering a policy implementation period of 2019 through 2030. The United Nations' integrated policy framework was also adopted as evaluation criteria to identify policy gaps in the existing policy measures and the identification of possible policy overlaps was conducted using content analysis. Based on the results, the implementation of the current standards would reduce annual residential electricity demand in the surveyed households by 37\% compared to BAU. National-level policy impacts show that the implementation of more stringent MEPS would contribute about 11.3\% of the national emissions reduction target reached in Nigeria's NDC. The research also finds out that key policy instruments (such as financial incentives) are still in their planning stages. Furthermore, the result from the content analysis reveals that the assigned institutional roles for the advancement of end-use energy efficiency are in some cases, not based on the statutory mandates of the respective institutions which create room for possible overlaps. To close the existing energy efficiency gaps and achieve effective energy-efficient appliance market transformation, the research underscores the need for a large-scale appliance market assessment to understand current baseline efficiency levels which will guide future policy designs and ensure that MEPS remain effective. The research also recommends key possible frameworks that can guide the design and implementation of financial incentive instruments to make energy-efficient investments more attractive.}, subject = {Mindeststandards f{\"u}r die Gesamtenergieeffizienz; Auswirkungen der Politik; Nationally Determined Contribution; Pariser Abkommen; Haushaltsger{\"a}te; Minimum Energy Performance Standards; Policy impacts; Nationally Determined Contribution; Paris Agreement; Appliances; Nigeria; Klimaabkommen von Paris; Energieeffizienz; Emissionsverringerung; Elektrisches Haushaltsger{\"a}t; Elektrizit{\"a}tsversorgung}, language = {en} }