@article{LiedtkeWartmannShietal.2025, author = {Liedtke, Victoria and Wartmann, Thomas and Shi, Wenjie and Kahlert, Ulf D.}, title = {Linking LEDGF/p75 overexpression with microsatellite instability and KRAS mutations : a small-scale study in colorectal cancer}, series = {Cancer Control}, volume = {32}, journal = {Cancer Control}, publisher = {Sage}, address = {London}, doi = {10.1177/10732748251313499}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-69673}, pages = {1 -- 9}, year = {2025}, abstract = {Colorectal cancer (CRC) ranks third in men and second in women, with 153,020 new cases and 52,550 deaths in 2023, and with a projected incidence of 2.2 million new cases by 2030 due to lifestyle changes and enhanced diagnostic capabilities. Identification and analysis of new biomarkers, like lens epithelium-derived growth factor splice variant of 75 kDa (LEDGF/p75), which is known to play a crucial role as stress-related oncogene, can make a significant contribution in facilitating early CRC detection. This study analyzed the expression of LEDGF/p75 and the ubiquitin E2 conjugating enzyme UBC13 in 15 CRC tissue samples and adjacent non-tumor tissues. All patient samples underwent NGS-based mutation analysis beforehand. The western blot technique was used for protein analysis, and the results were further validated using mRNA expression data from 521 patient samples from the TCGA database. LEDGF/p75 expression was significantly elevated in nearly all tumor tissue samples compared to adjacent tissue (11/15, 73.3\%). Additionally, the UBC13 enzyme, a key regulator in the degradation of signaling molecules, was also increased in most tumor tissue samples (9/15, 60.0\%). Co-overexpression of LEDGF/p75 and UBC13 was evident in 6/6 patients. Patients with KRAS and MSH2 mutations showed a 75\% and 100\% correlation with LEDGF/p75 overexpression, respectively. This study confirms the upregulation of LEDGF/p75 in CRC and shows its correlation with KRAS and MSH2 mutations. The interaction of LEDGF/p75 with DNA damage response proteins may contribute to drug resistance and increased tumor aggressiveness. LEDGF/p75's potential as a prognostic biomarker independent of lymph node involvement or CEA levels highlights its potential in personalized therapy, and warrants further research into its therapeutic targeting.}, subject = {LEDGF/p75; Colorectal cancer; Biomarker; Personalized therapy; DNA repair}, language = {en} } @book{Kuennemann2022, author = {K{\"u}nnemann, Andreas}, title = {Existenz- und Regularit{\"a}tstheorie der zweidimensionalen Variationsrechnung mit Anwendungen auf das Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-658-41640-9}, doi = {10.1007/978-3-658-41641-6}, publisher = {BTU Cottbus - Senftenberg}, pages = {247}, year = {2022}, abstract = {Die vorliegende Arbeit behandelt f{\"u}r eine breite Klasse zweidimensionaler Variationsprobleme eine Existenz- und Regularit{\"a}tstheorie, die der L{\"o}sung von Randwertproblemen partieller Differentialgleichungssysteme dient. Dabei werden bekannte Ergebnisse gr{\"u}ndlich untersucht und umfassend aufgearbeitet. Teilweise wird eine geeignete Anpassung der Voraussetzungen einiger Resultate vorgenommen. Speziell wird die Theorie auf das Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung im R3 angewendet. Eingangs wird das Konzept der direkten Methoden der Variationsrechnung erl{\"a}utert. {\"U}ber einen fundamentalen Satz zur schwachen Unterhalbstetigkeit von Funktionalen wird die Existenz eines Minimierers f{\"u}r eine breite Klasse von Variationsproblemen nachgewiesen. Da die Existenztheorie in Sobolev-R{\"a}umen agiert, sind Untersuchungen zur Regularit{\"a}t eines Minimierers notwendig. Im Rahmen der Regularit{\"a}tstheorie wird das Dirichletsche Wachstumstheorem von Morrey gezeigt, welches ein hinreichendes Kriterium f{\"u}r die H{\"o}lder-Stetigkeit einer Funktion X ∈ W1,2(G) liefert. Zum Nachweis der Anwendbarkeit des Dirichletschen Wachstumstheorems auf einen Minimierer wird ein Wachstumslemma verwendet. Dabei werden eine Verkn{\"u}pfung des Dirichlet-Integrals mit Fourierreihen sowie das Dirichlet- Integral der harmonischen Ersetzung einer Funktion mit L2-Randwerten genutzt. Infolgedessen ergibt sich die H{\"o}lder-Stetigkeit im Inneren f{\"u}r einen Minimierer. Zudem wird die Stetigkeit des Minimierers bis zum Rand gezeigt, sodass die Existenz eines stetigen Minimierers f{\"u}r eine breite Klasse von Variationsproblemen gesichert ist. Anschließend erfolgt die Berechnung der ersten Variation sowie die damit verbundene Herleitung der schwachen Euler-Lagrange-Gleichung, welche eine Beziehung zur L{\"o}sungstheorie von Differentialgleichungen im Sinne des Dirichletschen Prinzips herstellt. Ausgehend von der schwachen Euler-Lagrange-Gleichung wird die H{\"o}lder-Stetigkeit der ersten Ableitungen eines Minimierers bewiesen. F{\"u}r die L{\"o}sung von Randwertproblemen mit partiellen Differentialgleichungen zweiter Ordnung mithilfe der Variationsrechnung ist der Nachweis stetiger zweiter Ableitungen des Minimierers notwendig. Dabei wird der Fokus auf sogenannte Minimierer vom Poissonschen Typ gelegt. Eine C2,σ-Rekonstruktion, die auf der Schaudertheorie basiert, liefert in diesem Fall die gew{\"u}nschte Regularit{\"a}t. In Anwendung dessen werden das Randwertproblem harmonischer Abbildungen in Riemannschen R{\"a}umen sowie das Dirichletproblem des H-Fl{\"a}chen-Systems behandelt, indem jeweils ein geeignetes Variationsproblem aufgestellt wird. Als Erweiterung des Dirichletproblems des H-Fl{\"a}chen-Systems wird das allgemeine Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung mit den erarbeiteten Methoden der Variationsrechnung untersucht. Zudem wird das Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung in Kugeln, in Zylindern sowie insbesondere im Einheitskegel gel{\"o}st. Insgesamt wird eine ausf{\"u}hrliche, in sich geschlossene und gut verst{\"a}ndliche Existenzund Regularit{\"a}tstheorie der zweidimensionalen Variationsrechnung zur Behandlung von Randwertproblemen partieller Differentialgleichungssysteme dargestellt, welche sich in besonderer Weise bei der L{\"o}sung des Plateauschen Problems f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung entfaltet.}, subject = {Variationsrechnung; Variationsrechnung; Dimension 2; Mittlere Kr{\"u}mmung; Plateau-Problem; Partielle Differentialgleichungen; Plateausches Problem; Regularit{\"a}tstheorie; Morrey; Variation calculation; Partial differential equations; Plateau problem; Regularity theory}, language = {de} } @article{RichterRachowIsraeletal.2023, author = {Richter, Jana and Rachow, Fabian and Israel, Johannes and Roth, Norbert and Charlafti, Evgenia and G{\"u}nther, Vivien and Flege, Jan Ingo and Mauss, Fabian}, title = {Reaction mechanism development for methane steam reforming on a Ni/Al2O3 catalyst}, doi = {10.3390/catal13050884}, year = {2023}, abstract = {In this work, a reliable kinetic reaction mechanism was revised to accurately reproduce the detailed reaction paths of steam reforming of methane over a Ni/Al2O3 catalyst. A steadystate fixed-bed reactor experiment and a 1D reactor catalyst model were utilized for this task. The distinctive feature of this experiment is the possibility to measure the axially resolved temperature profile of the catalyst bed, which makes the reaction kinetics inside the reactor visible. This allows for understanding the actual influence of the reaction kinetics on the system; while pure gas concentration measurements at the catalytic reactor outlet show near-equilibrium conditions, the inhere presented temperature profile shows that it is insufficient to base a reaction mechanism development on close equilibrium data. The new experimental data allow for achieving much higher quality in the modeling efforts. Additionally, by carefully controlling the available active surface via dilution in the experiment, it was possible to slow down the catalyst conversion rate, which helped during the adjustment of the reaction kinetics. To assess the accuracy of the revised mechanism, a monolith experiment from the literature was simulated. The results show that the fitted reaction mechanism was able to accurately predict the experimental outcomes for various inlet mass flows, temperatures, and steam-to-carbon ratios.}, subject = {1D modeling; Reaction rates; Methane steam reforming; Fixed-bed reactor experiments; Nickel catalyst; 1D-Modellierung; Reaktionsgeschwindigkeiten; Methan-Dampfreformierung; Festbettreaktor-Experimente; Nickel-Katalysator; Katalysator; Reaktionsmechanismus; Festbettreaktor; Steamreforming; Reaktionsgeschwindigkeit}, language = {en} } @article{AsliMhgoubKlaus2025, author = {Asli, Majid and Mhgoub, Mosaab and Klaus, H{\"o}schler}, title = {Numerical investigation of a turbine working with a highly unsteady exhaust flow of a hydrogen-driven rotating detonation combustion}, series = {International Journal of Thermofluids}, volume = {29}, journal = {International Journal of Thermofluids}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2666-2027}, doi = {10.1016/j.ijft.2025.101356}, year = {2025}, abstract = {Traditionally, turbomachines are designed for steady-state operations around which they achieve optimal performance and efficiency. However, in novel applications, a turbomachine may be exposed to unsteady flow forcing the machine to operate under fluctuating off design conditions. Pressure Gain Combustion (PGC) through detonation can be an extreme example of unsteady flow which affects the turbine performance adversely. The efficient way of energy extraction from PGCs is still an open question which needs extensive turbine design optimizations for such unsteady flow. Any flow field optimization problem in such applications needs a multitude of simulations, which can be too computationally expensive to be utilized as it is realized as an unsteady 3D-CFD problem. In this regard, the current study aims at proposing and evaluating an approach for optimizing a turbine working under highly unsteady exhaust flow of a Rotating Detonation Combustion (RDC). A two stage turbine is placed downstream an RDC and the turbine inlet condition is calculated by a 2D-Euler simulation tool. A turbine optimization problem is defined and three optimization processes with an objective of minimizing entropy are performed using steady-state 3D-CFD simulation as the objective function evaluator. The turbine inlet boundary conditions in the three optimization efforts include peak, mean and trough values of the RDC outlet pulsating flow condition. Finally, detailed unsteady simulations are carried out for the three new geometries and compared with the baseline turbine. The results showed that the steady-state Reynolds Averaged Navier Stocks (RANS) simulations can be utilized using either mean or trough values of the pulsating boundary condition in iterating a design optimization problem, instead of full unsteady RANS simulations applying time and circumferential location dependent boundary conditions. Given the specific RDC boundary condition and the turbine geometry in this study, the optimized turbine exhibited up to 7.71\% less entropy generation and up to 7\% higher output power compared to the baseline counterpart in unsteady operation. This approach enables a more efficient design optimization process while accounting for the complex dynamics of the RDC exhaust flow. Overall, the approach presented in this paper is practical for optimizing highly unsteady turbomachines specifically for the case of RDCs during any early design optimization procedure, addressing the computational challenges associated with simulating unsteady flows while ensuring the turbine's effectiveness under real operating conditions.}, subject = {Unsteady turbine; Entropy generation; Rotating detonation; Optimization; Computational fluid dynamic}, 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{RimHezilFellahetal.2025, author = {Rim, Imen and Hezil, Naouel and Fellah, Mamoun and Saoudi, Adel and Aleksei, Obrosov and El-Hiti, Gamal A.}, title = {Enhancing kaolin performance through organic molecule modification and assessing its efficiency for lead and copper adsorption}, series = {Environmental Technology \& Innovation}, volume = {36}, journal = {Environmental Technology \& Innovation}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1864}, doi = {10.1016/j.eti.2024.103904}, year = {2025}, abstract = {The research aimed to enhance the efficacy of kaolin in water treatment by incorporating diphenylamine (DPA) and to evaluate its effectiveness in adsorbing lead and copper in wastewater in comparison to natural kaolin (Nat-kaolin). This entailed modifying kaolin with DPA to create DPA-kaolin and conducting comprehensive characterization utilizing a range of techniques, including X-ray diffraction analysis (XRD), scanning electron microscope (SEM), energy dispersion X-ray (EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analysis. The results demonstrated the successful modification of DPA, as evidenced by an increase in BET-specific surface area of about 25 \% (from 66.69 m².g⁻¹ to 71.35 m².g⁻¹), indicating enhanced adsorption capacity. XRD analysis confirmed the composition of the samples, while TGA/DTA indicated changes in water adsorption and dehydroxylation. SEM and EDX illustrated the tubular nature of the clay with a decrease in the amount of Al, about 10.76 \%, and the amount of Si, about 10.38 \%, on the DPA-kaolin. Notably, the FTIR spectrum of DPA-kaolin showed the presence of new vibration bands at 1248 cm⁻¹, indicating the presence of DPA. In terms of adsorption, the DPA-kaolin exhibited significantly higher maximum adsorption capacities for Pb(II) and Cu(II) compared to the nat-kaolin, with values of 151 μmol/g and 134 μmol/g, respectively.These values were significantly higher than those observed for Nat-kaolin, which demonstrated adsorption capacities of 103 μmol/g for Pb(II) and 91 μmol/g for Cu(II). The adsorption kinetics indicated that the pseudo-second-order kinetic model described the sorption mechanism for both Pb(II) and Cu(II). This was evidenced by the values of R², which were 0.999 and 0.996, respectively. The study provides clear evidence that DPA-kaolin is more effective than Nat-kaolin in removing lead (Pb(II)) and copper (Cu(II)) from wastewater. Through rigorous experimentation, it was observed that DPA-kaolin exhibited notably enhanced adsorption capabilities for both Pb(II) and Cu(II) compared to Nat-kaolin. These findings serve to emphasize the practical importance and potential.}, subject = {Kaolin clay; Water treatment; DPA-Kaolin; Chemical treatment; Adsorption; Isotherms}, language = {en} } @article{FrankenNetzerMaussetal., author = {Franken, Tim and Netzer, Corinna and Mauss, Fabian and Pasternak, Michal and Seidel, Lars and Borg, Anders and Lehtiniemi, Harry and Matrisciano, Andrea and Kulzer, Andre Casal}, title = {Multi-objective optimization of water injection in spark-ignition engines using the stochastic reactor model with tabulated chemistry}, publisher = {SAGE Publications}, address = {London, England}, issn = {1468-0874}, doi = {10.1177/1468087419857602}, abstract = {Water injection is investigated for turbocharged spark-ignition engines to reduce knock probability and enable higher engine efficiency. The novel approach of this work is the development of a simulation-based optimization process combining the advantages of detailed chemistry, the stochastic reactor model and genetic optimization to assess water injection. The fast running quasi-dimensional stochastic reactor model with tabulated chemistry accounts for water effects on laminar flame speed and combustion chemistry. The stochastic reactor model is coupled with the Non-dominated Sorting Genetic Algorithm to find an optimum set of operating conditions for high engine efficiency. Subsequently, the feasibility of the simulation-based optimization process is tested for a three-dimensional computational fluid dynamic numerical test case. The newly proposed optimization method predicts a trade-off between fuel efficiency and low knock probability, which highlights the present target conflict for spark-ignition engine development. Overall, the optimization shows that water injection is beneficial to decrease fuel consumption and knock probability at the same time. The application of the fast running quasi-dimensional stochastic reactor model allows to run large optimization problems with low computational costs. The incorporation with the Non-dominated Sorting Genetic Algorithm shows a well-performing multi-objective optimization and an optimized set of engine operating parameters with water injection and high compression ratio is found.}, subject = {Ottomotor; Water injection; Genetic optimization; Spark-ignition engine; Stochastic reactor model; Detailed chemistry; Wassereinspritzung; Prozessoptimierung; Stochastisches Modell}, language = {en} } @article{AliKhanKolendaetal.2023, author = {Ali, Aamir and Khan, Muhammad Moman and Kolenda, Rafal and Olowe, Olugbenga Adekunie and Weinreich, J{\"o}rg and Li, Ganwu and Schierack, Peter}, title = {The role of AJB35136 and fdtA genes in biofilm formation by avian pathogenic Escherichia coli}, doi = {10.1186/s12917-023-03672-7}, year = {2023}, abstract = {Background Infections caused by avian pathogenic Escherichia coli (APEC) result in significant economic losses in poultry industry. APEC strains are known to form biofilms in various conditions allowing them to thrive even under harsh and nutrient-deficient conditions on different surfaces, and this ability enables them to evade chemical and biological eradication methods. Despite knowing the whole genome sequences of various APEC isolates, little has been reported regarding their biofilm-associated genes. A random transposon mutant library of the wild-type APEC IMT 5155 comprising 1,300 mutants was analyzed for biofilm formation under nutrient deprived conditions using Videoscan technology coupled with fluorescence microscopy. Seven transposon mutants were found to have reproducibly and significantly altered biofilm formation and their mutated genes were identified by arbitrary PCR and DNA sequencing. The intact genes were acquired from the wild-type strain, cloned in pACYC177 plasmid and transformed into the respective altered biofilm forming transposon mutants, and the biofilm formation was checked in comparison to the wild type and mutant strains under the same conditions. Results In this study, we report seven genes i.e., nhaA, fdeC, yjhB, lysU, ecpR, AJB35136 and fdtA of APEC with significant contribution to biofilm formation. Reintroduction of AJB35136 and fdtA, reversed the altered phenotype proving that a significant role being played by these two O-antigen related genes in APEC biofilm formation. Presence of these seven genes across nonpathogenic E. coli and APEC genomes was also analyzed showing that they are more prevalent in the latter.}, subject = {APEC; Biofilm; Gene; Complementation; Transposon mutant; VideoScan; Genkomplementierung; Transposon-Mutanten; Gefl{\"u}gelkrankheit; Escherichia coli; Biofilm; Komplementation; Transponson; Mutant}, language = {en} } @article{RakhiMauss2024, author = {Rakhi, and Mauss, Fabian}, title = {Numerical investigation of equilibrium and kinetic aspects for hydrogenation of CO₂}, series = {Catalysts}, volume = {14}, journal = {Catalysts}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2073-4344}, doi = {10.3390/catal14090562}, year = {2024}, abstract = {Even if huge efforts are made to push alternative mobility concepts, such as electric cars and fuel-cell-powered cars, the significance and use of liquid fuels is anticipated to stay high during the 2030s. Biomethane and synthetic natural gas (SNG) might play a major role in this context, as they are raw material for chemical industry that is easy to be stored and distribute via existing infrastructure, and are a versatile energy carrier for power generation and mobile applications. Since biomethane and synthetic natural gas are suitable for power generation and for mobile applications, they can therefore replace natural gas without any infrastructure changes, thus playing a major role. In this paper, we aim to comprehend the direct production of synthetic natural gas from CO₂ and H₂ in a Sabatier process based on a thermodynamic analysis as well as a multi-step kinetic approach. For this purpose, we thoroughly discuss CO₂ methanation to control emissions in order to maximize the methane formation along with minimizing the CO formation and to understand the complex methanation process. We consider an equilibrium and kinetic modeling study on the NiO-SiO₂catalyst for methanation focusing on CO₂-derived SNG. The thermodynamic analysis of CO₂ hydrogenation is preformed to define the optimal process parameters followed by the kinetic simulations for catalyst development. The investigation presented in this paper can also be used for developing machine learning algorithms for methanation processes.}, subject = {Equilibrium calculations; Thermodynamic analysis; Kinetic modeling; CO₂ Methanation; Gibbs free energy minimization}, language = {en} } @article{ShafieeDorneanuArellanoGarcia2025, author = {Shafiee, Parisa and Dorneanu, Bogdan and Arellano-Garcia, Harvey}, title = {Improving catalysts and operating conditions using machine learning in Fischer-Tropsch synthesis of jet fuels (C8-C16)}, series = {Chemical Engineering Journal Advances}, volume = {21}, journal = {Chemical Engineering Journal Advances}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2666-8211}, doi = {10.1016/j.ceja.2024.100702}, year = {2025}, abstract = {Fischer-Tropsch synthesis (FTS) offers a promising route for producing sustainable jet fuels from syngas. However, optimizing catalyst design and operating conditions for the ideal C8-C16 jet fuel range is challenging. Thus, this work introduces a machine learning (ML) framework to enhance Co/Fe-supported FTS catalysts and optimize their operating conditions for a better jet fuel selectivity. For this purpose, a dataset was implemented with 21 features, including catalyst structure, preparation method, activation procedure, and FTS operating parameters. Moreover, various machine-learning models (Random Forest (RF), Gradient Boosted, CatBoost, and artificial neural networks (ANN)) were evaluated to predict CO conversion and C8-C16 selectivity. Among these, the CatBoost model achieved the highest accuracy (R2 = 0.99). Feature analysis revealed that FTS operational conditions mainly affect CO conversion (37.9 \%), while catalyst properties were primarily crucial for C8-C16 selectivity (40.6 \%). The proposed ML framework provides a first powerful tool for the rational design of FTS catalysts and operating conditions to maximize jet fuel productivity. .}, subject = {Jet fuels (C8-C16); Machine learning (ML); Fischer-Tropsch synthesis (FTS); Operational conditions; Catalyst preparation}, language = {en} } @article{BerneckerGebhardtAmoretal.2025, author = {Bernecker, Maximilian and Gebhardt, Marc and Amor, Souhir Ben and Wolter, Martin and M{\"u}sgens, Felix}, title = {Quantifying the impact of load forecasting accuracy on congestion management in distribution grids}, series = {International Journal of Electrical Power and Energy Systems}, volume = {168}, journal = {International Journal of Electrical Power and Energy Systems}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-3517}, doi = {10.1016/j.ijepes.2025.110713}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-70351}, year = {2025}, abstract = {Digitalization is a global trend in energy systems and beyond. However, it is often unclear what digitalization means exactly in the context of energy systems and how the benefits of digitalization can be quantified. Providing additional information, e.g., through sensors and metering equipment, is one concrete angle where digitalization contributes. This paper provides a framework to quantify the value of such additional information in distribution grids. We analyze to what extent smart meters improve the accuracy of day-ahead load forecasts and quantify the savings in congestion management costs resulting from the improved accuracy. To quantify the cost reduction, we conduct a case study employing a simplified IEEE test system. Historical electricity load data from over 6,000 smart meters was used to improve day-ahead load forecasts. We assessed and compared the forecasting performance to estimates based on standard load profiles with multiple load forecast simulations in the network based on uncertainty parameterizations from forecasts with and without smart meter data. Calculating redispatch cost in the distribution grid, we find that the forecast based on smart meter data reduces key redispatch parameters such as the share of expected voltage violations, the amount of rescheduled generation by more than 90\%. These improvements translate into a reduction in congestion management costs by around 97\%. Furthermore, we shed light on whether the gains increase linearly with the number of smart meters and available data in the grid. When smart meter shares are increased uniformly throughout the grid, savings are concave, i.e., the first 10\% of smart meters reduces congestion management costs by around 20\% while the last 10\% reduces these costs only marginally. Focusing smart meter installation on the most congested nodes reduces congestion management costs by around 60\% with just 10\% smart meter coverage, significantly outperforming a uniform rollout. However, savings in congestion management alone are not likely to recover the installation and operation costs of the installed smart meter.}, subject = {Distribution Grid; Congestion management; Uncertainty; Forecasting; Smart Meter}, language = {en} } @article{HasanuzzamanEivaziMerboldetal.2022, author = {Hasanuzzaman, Gazi and Eivazi, Hamidreza and Merbold, Sebastian and Egbers, Christoph and Vinuesa, Ricardo}, title = {Enhancement of PIV measurements via physics-informed neural networks}, doi = {10.1088/1361-6501/aca9eb}, year = {2022}, abstract = {Physics-informed neural networks (PINN) are machine-learning methods that have been proved to be very successful and effective for solving governing equations of fluid flow. In this work we develop a robust and efficient model within this framework and apply it to a series of two-dimensional three-component (2D3C) stereo particle-image velocimetry datasets, to reconstruct the mean velocity field and correct measurements errors in the data. Within this framework, the PINNsbased model solves the Reynolds-averaged-Navier-Stokes (RANS) equations for zeropressure-gradient turbulent boundary layer (ZPGTBL) without a prior assumption and only taking the data at the PIV domain boundaries. The TBL data has different flow conditions upstream of the measurement location due to the effect of an applied flow control via uniform blowing. The developed PINN model is very robust, adaptable and independent of the upstream flow conditions due to different rates of wall-normal blowing while predicting the mean velocity quantities simultaneously. Hence, this approach enables improving the mean-flow quantities by reducing errors in the PIV data. For comparison, a similar analysis has been applied to numerical data obtained from a spatially-developing ZPGTBL and an adverse-pressure-gradient (APG) TBL over a NACA4412 airfoil geometry. The PINNs-predicted results have less than 1\% error in the streamwise velocity and are in excellent agreement with the reference data. This shows that PINNs has potential applicability to shear-driven turbulent flows with different flow histories, which includes experiments and numerical simulations for predicting high-fidelity data.}, subject = {Machine learning; Particle image velocimetry; Turbulent boundary layer; Large Eddy Simulation; Measurement; Maschinelles Lernen; Turbulente Grenzschicht; Physikalisch informiertes neuronales Netz; Messung; Turbulente Grenzschicht; Neuronales Netz; Maschinelles Lernen; Particle-Image-Velocimetry}, language = {en} } @article{HasanuzzamanBuchwaldSchunketal.2024, author = {Hasanuzzaman, Gazi and Buchwald, Tom and Schunk, Christoph and Schr{\"o}der, Andreas and Egbers, Christoph and Hampel, Uwe}, title = {DATIV - Remote enhancement of smart aerosol measurement system using Raspberry Pi based distributed sensors}, series = {Sensors}, volume = {24}, journal = {Sensors}, number = {13}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s24134314}, year = {2024}, abstract = {Enclosed public spaces are the hotspots for airborne disease transmission. To measure and maintain indoor air quality in terms of airborne transmission, an open source, low cost and distributed array of Particulate Matter Sensors has been developed and named as Dynamic Aerosol Transport for Indoor Ventilation or DATIV system. This system can use multiple Particulate Matter Sensors (PMS) simultaneously and can be remotely controlled using a Raspberry Pie based operating system. The data acquisition system can be easily operated using the GUI within any common browser installed on a remote device such as a PC or Smartphone with corresponding IP address. The software architecture and validation measurements are presented together with possible future developments.}, subject = {Particulate matter; Aerosol; Low cost measurement system; Distributed sensors; Indoor ventilation}, language = {en} } @article{BarthWernerOttoetal.2024, author = {Barth, Maximilian and Werner, Magdalena and Otto, Pascal and Richwien, Benjamin and Bahramsari, Samira and Krause, Maximilian and Schwan, Benjamin and Abendroth, Christian}, title = {Microwave‑assisted organic acids and green hydrogen production during mixed culture fermentation}, series = {Biotechnology for Biofuels and Bioproducts}, volume = {17}, journal = {Biotechnology for Biofuels and Bioproducts}, publisher = {BMC}, address = {London}, issn = {2731-3654}, doi = {10.1186/s13068-024-02573-7}, year = {2024}, abstract = {Background The integration of anaerobic digestion into bio-based industries can create synergies that help render anaerobic digestion self-sustaining. Two-stage digesters with separate acidification stages allow for the production of green hydrogen and short-chain fatty acids, which are promising industrial products. Heat shocks can be used to foster the production of these products, the practical applicability of this treatment is often not addressed sufficiently, and the presented work therefore aims to close this gap. Batch experiments were conducted in 5 L double-walled tank reactors incubated at 37 °C. Short microwave heat shocks of 25 min duration and exposure times of 5-10 min at 80 °C were performed and compared to oven heat shocks. Pairwise experimental group differences for gas production and chemical parameters were determined using ANOVA and post-hoc tests. High-throughput 16S rRNA gene amplicon sequencing was performed to analyse taxonomic profiles. After heat-shocking the entire seed sludge, the highest hydrogen productivity was observed at a substrate load of 50 g/l with 1.09 mol H2/ mol hexose. With 1.01 mol H2/ mol hexose, microwave-assisted treatment was not significantly different from oven-based treatments. This study emphasised the better repeatability of heat shocks with microwave-assisted experiments, revealing low variation coefficients averaging 29\%. The pre-treatment with microwaves results in a high predictability and a stronger microbial community shift to Clostridia compared to the treatment with the oven. The pre-treatment of heat shocks supported the formation of butyric acid up to 10.8 g/l on average, with a peak of 24.01 g/l at a butyric/acetic acid ratio of 2.0. The results support the suitability of using heat shock for the entire seed sludge rather than just a small inoculum, making the process more relevant for industrial applications. The performed microwave-based treatment has proven to be a promising alternative to oven-based treatments, which ultimately may facilitate their implementation into industrial systems. This approach becomes economically sustainable with high temperature heat pumps with a coefficient of performance (COP) of 4.3.}, subject = {Acidification; Hydrogen production; Volatile fatty acids production; Microwave heat shocks; 16-S-rRNA sequencing}, language = {en} } @incollection{BhutaniBoesGoetteletal., author = {Bhutani, A. and Boes, F. and Goettel, B. and Schaefer, J. and Eisenbeis, J. and Zwick, T. and Malz, Stefan and Rodriguez Vazquez, Pedro and Grzyb, Janusz and Pfeiffer, Ulrich}, title = {Real100G.RF : a fully integrated, multi-purpose radio front-end for wireless 100 Gbps}, series = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, booktitle = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, doi = {10.26127/BTUOpen-5915}, publisher = {BTU Cottbus - Senftenberg}, pages = {295 -- 354}, abstract = {In 2012 a group of researchers proposed a basic research initiative to the German Research Foundation (DFG) as a special priority project (SPP) with the name: Wireless 100 Gbps and beyond. The main goal of this initiative was the investigation of architectures, technologies and methods to go well beyond the state of the art. The target of 100 Gbps was set far away from the (at that time) achievable 1 Gbps such that it was not possible to achieve promising results just by tuning some parameters. We wanted to find breakthrough solutions. When we started the work on the proposal we discussed the challenges to be addressed in order to advancing the wireless communication speed significantly. Having the fundamental Shannon boundary in mind we discussed how to achieve the 100 Gbps speed.}, subject = {100 Gbps; Wireless; Drahtlos; Real100G.RF; Fully integrated; Multi-purpose radio front-end; Vollst{\"a}ndig integriert; Vielseitig anwendbare Funkeingangsstufe; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} } @incollection{BuechnerNolteHasanietal., author = {B{\"u}chner, Steffen and Nolte, J{\"o}rg and Hasani, Alireza and Kraemer, Rolf and Lopacinsiki, Lukasz}, title = {End2End100 : communication protocol processing for ultra high data rates}, series = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, booktitle = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, doi = {10.26127/BTUOpen-5916}, publisher = {BTU Cottbus - Senftenberg}, pages = {359 -- 396}, abstract = {In 2012 a group of researchers proposed a basic research initiative to the German Research Foundation (DFG) as a special priority project (SPP) with the name: Wireless 100 Gbps and beyond. The main goal of this initiative was the investigation of architectures, technologies and methods to go well beyond the state of the art. The target of 100 Gbps was set far away from the (at that time) achievable 1 Gbps such that it was not possible to achieve promising results just by tuning some parameters. We wanted to find breakthrough solutions. When we started the work on the proposal we discussed the challenges to be addressed in order to advancing the wireless communication speed significantly. Having the fundamental Shannon boundary in mind we discussed how to achieve the 100 Gbps speed.}, subject = {100 Gbps; Wireless; Drahtlos; End2End100; Communication protocol processing; Kommunikations-Protokoll-Prozessierung; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} } @incollection{JohannsenHoeherPeitzmeieretal., author = {Johannsen, Nils L. and Hoeher, Peter A. and Peitzmeier, Nikolai and Manteuffel, Dirk}, title = {M4 : multi-mode massive MIMO}, series = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, booktitle = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, doi = {10.26127/BTUOpen-5912}, publisher = {BTU Cottbus - Senftenberg}, pages = {167 -- 212}, abstract = {In 2012 a group of researchers proposed a basic research initiative to the German Research Foundation (DFG) as a special priority project (SPP) with the name: Wireless 100 Gbps and beyond. The main goal of this initiative was the investigation of architectures, technologies and methods to go well beyond the state of the art. The target of 100 Gbps was set far away from the (at that time) achievable 1 Gbps such that it was not possible to achieve promising results just by tuning some parameters. We wanted to find breakthrough solutions. When we started the work on the proposal we discussed the challenges to be addressed in order to advancing the wireless communication speed significantly. Having the fundamental Shannon boundary in mind we discussed how to achieve the 100 Gbps speed.}, subject = {100 Gbps; Wireless; Drahtlos; M4; Multi-mode massive MIMO; Multi-Mode-massiv-MIMO; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} } @incollection{ScheyttJavedBhutanietal., author = {Scheytt, J. Christoph and Javed, Abdul Rehman and Bhutani, Akanksha and Zwick, Thomas and Kallfass, Ingmar and Bamidi, Eswara Rao and Krishnegowda, Karthik and Kraemer, Rolf}, title = {Real100G : ultrabroadband wireless communication at high mm-wave frequencies}, series = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, booktitle = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, doi = {10.26127/BTUOpen-5913}, publisher = {BTU Cottbus - Senftenberg}, pages = {213 -- 230}, abstract = {In 2012 a group of researchers proposed a basic research initiative to the German Research Foundation (DFG) as a special priority project (SPP) with the name: Wireless 100 Gbps and beyond. The main goal of this initiative was the investigation of architectures, technologies and methods to go well beyond the state of the art. The target of 100 Gbps was set far away from the (at that time) achievable 1 Gbps such that it was not possible to achieve promising results just by tuning some parameters. We wanted to find breakthrough solutions. When we started the work on the proposal we discussed the challenges to be addressed in order to advancing the wireless communication speed significantly. Having the fundamental Shannon boundary in mind we discussed how to achieve the 100 Gbps speed.}, subject = {100 Gbps; Wireless; Drahtlos; Real100G; Ultrabroadband wireless communication; Ultrabreitband-drahtlos-Kommunikation; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} } @article{DikraFellahBarilleetal.2023, author = {Dikra, Bouras and Fellah, Mamoun and Barille, Regis and Weiß, Sabine and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Improvement of photocatalytic performance and sensitive ultraviolet photodetectors using AC-ZnO/ZC-Ag2O/AZ-CuO multilayers nanocomposite prepared by spin coating method}, series = {Journal of science: advanced materials and devices}, volume = {9}, journal = {Journal of science: advanced materials and devices}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2023.100642}, year = {2023}, abstract = {Morphological and optical properties of a multilayer film (CAZO/CZAO/ZACO) prepared by spin-coating method and deposited on a glass substrate were evaluated. The study was initially carried out for each layer, individually and then as a multilayer subsequently. Structural properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectra (IR) and X-ray photoelectron Spectroscopy (XPS) showed the presence of three phases of zinc, copper and silver oxides at different levels. The CZAO sample observed with scanning electron microscope (SEM) showed an excellent porous surface with a large deformation in the multilayer configuration. Doping with zinc and copper in the silver crystal lattice improved the crystal structure and reduced the optical energy gap, thus increasing the optical absorbance and refractive index. The dielectric constants and showed an increase in the optical polarization values for lower photonic energies. The maximum degradation rate for photocatalysts of methylene blue was 89 \% for a 5-h exposure period with CAZO/CZAO/ZACO while it reached 71 \% for the CZAO sample during the same time period. The sensitivity of samples to light proved that the presence of ultraviolet radiation increases the number of holes trapped by oxygen ions and causes more free electrons and contribute to a better production of photocurrent than in darkness.}, subject = {Multilayer CAZO/CZAO/ZACO; Photocatalysis; Photodetector; Nanostructures; Nanocomposites; Multilagenbeschichtung CAZO/CZAO/ZACO; Rotationsbeschichtung; Photokatalyse; Nanostrukturen; Nanokompositen; Nanokomposit; Mehrschichtsystem; Beschichtung; Fotokatalyse; Photodetektor}, language = {en} } @article{KondaFranzkiSharmaetal.2024, author = {Konda, Karunakar Reddy and Franzki, Jonas and Sharma, Dikshant and K{\"o}nig, Paul and Mathiazhagan, Akilan and Henke, Markus and H{\"o}schler, Klaus}, title = {Quantitative assessment of cooling methods for electrical machines in aircraft drives}, series = {IEEE Access}, volume = {12}, journal = {IEEE Access}, publisher = {IEEE}, address = {New York}, issn = {2169-3536}, doi = {10.1109/ACCESS.2024.3517319}, pages = {192768 -- 192785}, year = {2024}, abstract = {Transformation of the aviation sector towards climate-neutral solutions such as electrification is urgent. Aviation electrification requires reasoned selection of suitable technologies which has to meet strict requirements and standards. Cooling of electrical components plays a vital role in the sizing and overall performance of the electrical drive system and must achieve high effectiveness and reliability at low weight. Three cooling methods - air cooling, direct slot cooling and cooling jacket - are sized for a 300 kW commuter aircraft (CS23) all-electric propulsion system. They are further evaluated quantitatively for weight, drag, reliability and effectiveness in a conservative assessment. A lumped parameter thermal network (LPTN) approach is utilized to assess and evaluate the thermal performance of the cooling systems. The LPTN model served as the basis to determine the temperature limits and capabilities of the cooling system which are then utilized to size the auxiliary components. Reliability is assessed via fault tree analysis, drag via scoop inlet characteristics and effectiveness via the heat load dissipated per weight of the system and the required cooling power per mechanical power. Cooling jacket achieves the highest effectiveness closely followed by slot cooling. Air cooling proves to be most reliable and lightest.}, subject = {Cooling systems; Electric aircrafts; Motor drives; Sizing; Thermal management}, language = {en} }