Refine
Document Type
- Master's Thesis (37) (remove)
Has Fulltext
- yes (37)
Is part of the Bibliography
- no (37)
Keywords
- Simulation (3)
- Energiewende (2)
- LES (2)
- Messsystem (2)
- Organischer Abfall (2)
- Ottomotor (2)
- Pflanzenkohle (2)
- Schluckspecht (2)
- biowaste (2)
- 3D printing (1)
Institute
- Fakultät Maschinenbau und Verfahrenstechnik (M+V) (37) (remove)
Open Access
- Closed Access (18)
- Closed (17)
- Open Access (2)
- Diamond (1)
The growing threat posed by multidrug-resistant (MDR) pathogens, such as Klebsiella pneumoniae (Kp), represents a significant challenge in modern medicine. Traditional antibiotic therapies are often ineffective against these pathogens, leading to high mortality rates. MDR Kp infections pose a novel challenge in military medical contexts, particularly in Medical Biodefense, as they can be deliberately spread, leading to resource-intensive care in military centres. Recognizing this issue, the European Defence Agency initiated a prioritised research project in 2023 (EDF Resilience PHAGE- SGA 2023). To address this challenge, the Bundeswehr Institute of Microbiology (IMB) leads BMBF- (Federal Ministry of Education and Research) and EU-funded projects on the use of bacteriophages as adjuvant therapy alongside antibiotics. Since 2017, the IMB has isolated and characterised Kp phages, collecting over 600 isolates and optimizing their production for therapy, in compliance with the EMA (European Medicine Agency) guidelines. This involves in vitro phage genome packaging to minimize endotoxin load, reduce manufacturing costs, and shorten production times. The goal of this work was to establish MinION sequencing (Oxford Nanopore Technology) as a quick and reliable way for initial identification and characterisation of phage genomes. Especially as a quick screening method for isolated on Kp, prior to more precise but also more expensive and time consuming sequencing methods like Illumina. This characterisation is crucial for developing a personalized pipeline aimed at producing magistral or Good Manufacturing Practice (GMP) quality medicinal phage solutions tailored individually for each patient. DNA extraction methods were compared to identify suitable input DNA for sequencing purposes. Additionally, the quality of this DNA was as- sessed to determine its suitability for in vitro phage packaging, which was successfully done achieving a phage titer of 103, confirming that the DNA used for MinION sequencing could indeed be used for acellular packaging. The created genomes were annotated and compared with Illumina sequencing, revealing high similarity in all five individually tested cases. Between the generated sequences only a 4% maximal percentual difference in genome size was observed, while simultaneously showing high similarity in the actual sequence. Throughout the course of this study, a total of 645.15 GB of sequencing data were generated. In total, 38 phages were successfully characterised, with 21 phage genomes assembled and annotated, and saved in the IMB database.
Steroid hormones (SHs) are a rising concern due to their high bioactivity, ubiquitous nature, and prolonged existence as a micropollutants in water, they pose a potential risk to both human health and the environment, even at low concentrations. Estrogens, progesterone, and testosterone are the three important types of steroids essential for human development and maintaining multiorgan balance, are focus to this concern. These steroid hormones originate
from various sources, including human and livestock excretions, veterinary medications, agricultural runoff, and pharmaceuticals, contributing to their presence in the environment. According to the recommendation of WHO, the guidance value for estradiol (E2) is 1 ng/L. There are several methods been attempted to remove the SH micropollutant by conventional water and wastewater technologies which are still under research. Among the various methods, electrochemical membrane reactor (EMR) is one of the emerging technologies that can address the challenge of insufficient SHs removal from the aquatic environment by conventional treatment. The degradation of SHs can be significantly influenced by various factors when treated with EMR.
In this project, the removal of SH and the important mechanism for the removal using carbon nanotube CNT-EMR is studied and the efficiency of CNT-EMR in treating the SH micropollutant is identified. By varying different parameters this experiment is carried out with the (PES-CNTs) ultrafiltration membrane. The study is carried out depending upon the SH removal based on the limiting factor such as cell voltage, flux, temperature, concentration, and type of the SH.
Decarbonisation Strategies in Energy Systems Modelling: APV and e-tractors as Flexibility Assets
(2023)
This work presents an analysis of the impact of introducing Agrophotovoltaic technologies and electric tractors into Germany’s energy system. Agrophotovoltaics involves installing photovoltaic systems in agricultural areas, allowing for dual usage of the land for both energy generation and food production. Electric tractors, which are agricultural machinery powered by electric motors, can also function as energy storage units, providing flexibility to the grid. The analysis includes a sensitivity study to understand how the availability of agricultural land influences Agrophotovoltaic investments, followed by the examination of various scenarios that involve converting diesel tractors to electric tractors. These scenarios are based on the current CO2 emission reduction targets set by the German Government, aiming for a 65% reduction below 1990 levels by 2030 and achieving zero emissions by 2045. The results indicate that approximately 3% of available agricultural land is necessary to establish a viable energy mix in Germany. Furthermore, the expansion of electric tractors tends to reduce the overall system costs and enhances the energy-cost-efficiency of Agrophotovoltaic investments.
As the population grows, so does the amount of biowaste. As demand for energy grows, biogas is a promising solution to the problem. Lignocellulosic materials are challenged of slow degradability due to the presence of polymers such as cellulose, lignin and hemicellulose. There are several pretreatment methods available to enhance the degradability of such materials, including enzymatic pretreatment. In this pretreatment, there are few parameters that can influence the results, the most important being the enzyme to solid ratio and the solid to liquid ratio. During this project, experiments were conducted to determine the optimal conditions for those two factors. It was discovered that a solid to liquid ratio of 31 g of buffer per 1 gram of organic dry matter produced the highest reducing sugar release in flasks when combined with 34 mg of protein per 1 gram of organic dry mass. Additionally, another experiment was carried out to investigate the impact of enzymatic pretreatment on biogas production using artificial biowaste as a substrate. Artificial biowaste produced 577,9 NL/kg oDM, while enzymatically pretreated biowaste produced 639,3 NL/kg oDM. This resulted in a 10,6% rise in cumulative biogas production compared to its use without enzymatic pretreatment. By the conclusion of the investigation, specific cumulative dry methane yields of 364,7 NL/kg oDM and 426,3 NL/kg oDM were obtained from artificial biowaste without and with enzymatic pretreatment, respectively. This resulted in a methane production boost of 16,9%. Additionally in case of the reactors with enzymatically pretreated substrate kinetic constant was lower more than double, where maximum volume of biogas increased, comparing to the reactors without enzymatic pretreatment.
In dieser Arbeit werden Untersuchungen an einem neuartigen Sensorkonzept zur Erfassung von Winkelbeschleunigungen durchgeführt. Ziel dieser Arbeit war es, die Möglichkeit, eine Miniaturisierung des Prototyps zu untersuchen. Hierfür wurde eine analytische und experimentelle Untersuchung durchgeführt. Für die analytische Betrachtung erfolgte eine Fehlerfortpflanzung nach Gauß, welche die Fertigungstoleranzen, Dimensionsfehler des Accelerometers, Rauschen und Messabweichungen von Accelerometer und Gyroskop berücksichtigt. Die Ergebnisse zeigen, dass bei Verwendung der hochwertigen Inertial Measurment Units (IMUs) eine theoretische Verkleinerung bis auf 21mm eine höhere Genauigkeit bietet als die numerischen Differentiationen der Winkelgeschwindigkeit.
Für die Verifizierung unter realen Bedingungen wurden verschiedene Prüfkonzepte verglichen.
Dabei erwies sich ein Pendelprüfstand als vielversprechender Ansatz. Durch die Verwendung von Kugellagern kann ein breites Spektrum an Winkelbeschleunigungen abgebildet werden. Die kontinuierliche Erfassung reflektierender Marker auf der Pendelstange ermöglicht die Ermittlung der Winkel, die als Grundlage für ein Modell dienen, wodurch sich reale Winkelbeschleunigungen mit den Messdaten des Sensors vergleichen lassen. Dabei stellt die Modellierung der Verlustterme eine zukünftige Herausforderung dar.
Die Ergebnisse zeigen, dass eine Miniaturisierung des Sensorprototyps möglich ist und das der Pendelprüfstand eine Methode zur Verifizierung darstellt. Dies trägt dazu bei, die Anwendungsmöglichkeiten des Sensorkonzepts in der Praxis zu erweitern.
In recent years, the demand for reliable power, driven by sensitive electronic equipment, has surged. Even minor deviations from the nominal supply can lead to malfunctions or failure. Despite technological advancements, power quality issues persist due to various factors like short circuits, overloads, voltage fluctuations, unbalanced loads, and non-linear loads.
This thesis extensively explores power quality anomalies in industrial and commercial sectors, using power system data as the primary analytical resource. It addresses the critical need for power supply reliability in today's evolving power grid industry, affected by non-linear loads, renewable energy integration, and electric vehicles. This field of study is paramount for ensuring power supply reliability and stability in the evolving power grid industry.
The core of this thesis involves a comprehensive investigation of power quality, with a focus on frequency, power, and harmonics in voltage and current signals. The research employs Python programming for advanced data analysis, utilizing techniques such as advanced Fast Fourier Transformation (FFT) analysis. The primary objective is to provide valuable insights aimed at elevating power supply quality and enhancing reliability in both industrial and commercial environments.
The cellulase-producing Trichoderma reesei strain RL-P37 exhibits significant potential, yielding 7.3 g/L of cellulase in 241 hours. Microscopic investigations reveal a link between spore formation and enzyme production, suggesting the need for research into the intricate relationship between enzyme production, stress responses, and the nutritional prerequisites of fungi. Comparatively, the use of sodium hydroxide (NaOH) treatment, as opposed to water treatment, results in the reduction of micronutrient content and carbon source extraction as filtrate. Despite these challenges, research by He et al. (2021) highlights NaOH's efficiency in cellulose extraction from plant-based sources. Using NaOH pretreatment can be proven as effective by designing a proper cultivation method. The selection of inducers for enzyme induction gains importance, with soluble inducers, as emphasized by Zhang et al. (2022), exhibiting superior effectiveness. Hence, adopting soluble inducers in designing cultivation methods for improved enzyme production in shaking flasks is recommended. Enzymatic treatment of bio-waste, as outlined by Hu et al. (2021), shows promise in augmenting essential component content by breaking down plant cell walls and intercellular compartments. However, the feasibility of using an artificial bio-waste medium for cultivating Trichoderma reesei is questioned. Investigating the impact of micronutrient levels, particularly the inhibitory role of zinc, on fungal growth becomes essential. These findings underscore the necessity for ongoing research and optimization in cellulase production, emphasizing both strain productivity and cultivation methodologies.
Estimation and projecting total steel industry production costs from 2019 to 2030 for Germany
(2023)
This thesis analyses the total production cost of the German steel industry from 2019 to 2022, as well as a projection of the German steel industry's total production cost until 2030. The research separates the costs of steel production into their primary components, such as raw materials, energy, CO2 cost, capital expenses and operating expenses. The cost of steel production is determined separately for primary steelmaking with the blast furnace and basic oxygen furnace (BF-BOF) and secondary steelmaking with the electric arc furnace (EAF).
The analysis indicates that, following the COVID-19 disaster and the fuel crisis, the overall cost of producing steel in Germany has progressively risen over the previous few years, reaching its peak in the first half of 2022. In addition, there are considerable disparities between the production costs of primary and secondary steelmaking processes, with primary steelmaking generally being more expensive.
In this analysis, the total cost of production for the German steel industry in the year 2030 has been estimated by taking into account historical trends as well as other predictions that are currently available.
This thesis provides overall insights on the economics of the German steel sector. By giving thorough information on production costs and changes over time, this research can assist guide crucial future investment decisions in this essential industry. To ensure long-term success, our findings emphasize the significance of investing in more sustainable and ecologically friendly steel production processes.
Ziel der vorliegenden Arbeit ist das netzdienliche Betreiben einer Wärmepumpe. Um diese Netzdienlichkeit zu erreichen, wird ein modellprädiktiver Regler entwickelt und implementiert, dessen Ziel es ist die Stromkosten einer Wärmepumpe zu senken. Dazu werden die Variablen Stromkosten und ein simulierter Heizbetrieb betrachtet.
Die Entwicklung eines modellprädiktiven Reglers setzt zunächst eine Modellierung der Komponenten des Heizsystems voraus. Ebenfalls muss eine Kostenfunktion formuliert werden, die es zu minimieren gilt. In einem Optimierungsproblem werden die Modelle als Randbedingungen und die Kostenfunktion als Zielfunktion der Optimierung formuliert. Dazu müssen gewisse Vereinfachungen getroffen werden, um das Optimierungsproblem zuverlässig und ohne enormen Rechenaufwand in einer Regelungsschleife lösen zu können.
Nun wird das Optimierungsproblem mit externen Modulen verknüpft, die eine Kommunikation mit der realen Wärmepumpen, Strompreisprognosen und Wettervorhersagen ermöglichen. Der dabei entwickelte Algorithmus wird auf einem Raspberry Pi Einplatinencomputer gespeichert und dort in einem regelmäßigen Zeitintervall von 15 Minuten ausgeführt, um den Betrieb der Wärmepumpe zu regeln.
Schließlich wird der modellprädiktive Regler in Betrieb genommen. Anschließend kann der modellprädiktive Betrieb mit dem konventionellen Betrieb verglichen werden. Aus dem Vergleich wird deutlich, dass eine modellprädiktive Regelung tatsächlich die Netzdienlichkeit einer Wärmepumpe verbessern kann. Andererseits werden auch die Entwicklungspotentiale identifiziert.
The purpose of this master's thesis was to set up a test bed for the absorption of chemical compounds by carbon-based sorbents and polymers and to develop a method for the detection of these substances applied by liquid chromatography.
The study made it possible to demonstrate the effectiveness of both polymers and biochars sorbents for the adosorption of specific substances. The results obtained open new paths on the study of biochar for the treatment of contaminated water. Some biochars made from plant-based materials have been shown to be almost as effective as commercial products used in plants. The developed chromatography method allows efficient separation of substances and their detection.