@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} } @article{DahmaniFellahHeziletal.2025, author = {Dahmani, Maewa and Fellah, Mamoun and Hezil, Naouel and Benoudia, Mohamed-Cherif and Obrosov, Aleksei and El-Hiti, Gamal A. and Weiss, Sabine}, title = {Bioactivity and tribological performance of a novel nano-biomaterial beta-type Ti-alloy}, series = {Journal of Materials Research and Technology}, volume = {36}, journal = {Journal of Materials Research and Technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2214-0697}, doi = {10.1016/j.jmrt.2025.03.180}, pages = {2297 -- 2316}, year = {2025}, abstract = {This study investigates the bioactivity; wear performance, and topography of a novel beta-type titanium-based alloy using techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and 2D and 3D analysis. The tribological test was evaluated using a ball-on-disk tribometer in a wet environment. Different loads of 2, 6, and 10 N were applied during the evolution. The data results indicate a significant effect of the milling process on the formation of the hydroxyapatite layer on the surfaces of the Ti-Nb-Mo alloy. Both the wear volume and rate showed a consistent trend of decrease as the milling time increased from 2 to 12 h for all applied loads. The minimum values of wear and volume were reached after 12 h of milling. The improvement in tribological behavior can be attributed to the improved mechanical properties of the alloys. In addition, the significant presence of niobium (Nb) and molybdenum (Mo) plays a critical role in achieving high coefficient of friction values. The primary wear mechanism observed in the Ti-25Nb-25Mo system was adhesive wear in addition to abrasive wear. With its lower Young's modulus and favorable biological and tribological properties, the Ti-25Nb-25Mo alloy represents a promising option for bone tissue applications in orthopedics.}, subject = {Ti-25Nb-25Mo; Milling time; Bioactivity; Hydroxyapatite; Friction coefficient}, language = {en} } @article{BuchwaldHasanuzzmanMerboldetal.2023, author = {Buchwald, Tom and Hasanuzzman, Gazi and Merbold, Sebastian and Schanz, Daniel and Egbers, Christoph and Schr{\"o}der, Andreas}, title = {Large-scale flow field and aerosol particle transport investigations in a classroom using 2D-Shake-The-Box Lagrangian Particle Tracking}, series = {Heliyon}, volume = {9}, journal = {Heliyon}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8440}, doi = {10.1016/j.heliyon.2023.e22826}, year = {2023}, abstract = {Infections with COVID-19 in enclosed public spaces, where virus-laden aerosol particles can accumulate over time, have significantly contributed to the rapid spread of the virus. It is therefore of great importance to understand the transport and dispersion process of aerosol particles in such spaces, especially against the background of future pandemics. In this work, we present a Lagrangian-Particle-Tracking experiment to assess the mixed convective flow in a classroom with different ventilation strategies. For this purpose, thermal plumes were created by heated dummies, and a collimated LED light-sheet with ~0.4 m thickness was used for illumination of helium filled soap bubbles (HFSB) acting as passive tracer particles. In this way, the Lagrangian trajectories of the particles were recorded at two approximately 4.2 m × 2.8 m large fields using the novel 2D-Shake-The-Box-Method. As a result, time-resolved trajectories of over 300,000 simultaneously tracked HFSB have been reconstructed, so that both small-scale and large-scale properties of the flow are visualized quantitatively across the entire cross-section of the room. The trajectories show that the thermal plumes create lengthwise circulating vortices, which cannot be destroyed across the entire cross-section of the room by opening or tilting a window. Furthermore, the mixing in the room through the operation of an air purifier is higher compared to opening a window, which suggests that this strategy in combination with its air filtering capability is the most effective strategy to prevent infections.}, subject = {Shake-the-box; Lagrangian-particle-tracking; Aerosol particle spreading; Room ventilation; Covid-19; Lagrangesche Partikelverfolgung; Ausbreitung von Aerosolpartikeln; Raumbel{\"u}ftung; Aerosol; Lagrange-Darstellung ; Bel{\"u}ftung; Klassenzimmer}, language = {en} } @article{LeeReb2025, author = {Lee, Roh Pin and Reb, Jochen}, title = {"Waste-to-Products" for the sustainability transformation of megacities : case analysis of impacts of public knowledge and perception on chemical recycling deployment in Singapore}, series = {Cleaner Waste Systems}, volume = {12}, journal = {Cleaner Waste Systems}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2772-9125}, doi = {10.1016/j.clwas.2025.100359}, year = {2025}, abstract = {Megacities generate significant amounts of unsorted domestic waste. Rather than being landfilled/incinerated, this could be used to substitute fossil resources for chemical production via chemical recycling (CR). CR thus represents an opportunity for a parallel achievement of multiple sustainability goals from resource efficiency, decarbonization to circularity and sustainable waste management. However, as an emerging technology, its potential contributions to a nation's sustainability transformation remain debated. While extant literature in the fields of waste management and CR have predominantly focused on waste sorting/segregation/collection as well as techno-economical-ecological feasibility of CR technologies respectively, insights into human factors which could hinder CR deployment in the forms of pyrolysis and gasification for the sustainable waste management in megacities remain lacking. To address this gap, this study implemented a representative online survey in Singapore - a megacity in Southeast Asia aiming to transit towards circularity and zero-waste by 2030 - and enabled first and novel insights into factors in the human dimension which would (1) influence proper waste separation/recycling behaviors - a prerequisite for the successful implementation of waste pyrolysis, and (2) impact societal support for using domestic waste for chemical production via waste gasification rather than for energy production via waste incineration - the dominant waste management approach in Singapore. Study insights regarding the impacts of the human factor and the identified opportunities for CR integration in a nation's waste system - besides extending extant waste management and CR literature - furthermore act as a blueprint for sustainable waste management and green chemistry for the sustainability transformation of other megacities.}, subject = {Chemical recycling; Waste pyrolysis; Waste gasification; Domestic waste; Perception}, language = {en} } @article{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} } @article{AlimovSviridovJenschetal.2023, author = {Alimov, Artem and Sviridov, Alexander and Jensch, Felix and Sydow, Benjamin and H{\"a}rtel, Sebastian}, title = {Additive manufacturing of hot-forming dies using laser powder bed fusion and wire arc direct energy deposition technologies}, volume = {13}, number = {11}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/met13111842}, year = {2023}, abstract = {Additive technologies are now widely used for the production of complex precise parts and have high potential for the production of forming dies. In this work, hot-forming dies optimized for additive manufacturing were developed and produced with wire arc direct energy deposition (WA-DED) and laser powder bed fusion (L-PBF) technologies. The concept of lightweight hot-forming dies with a 2D-lattice structure was developed, which reduced the weight of each die by 56\%, from 14.2 kg to 6.1 kg, in production using L-PBF. Maraging/precipitation-hardened steel 17-4PH was used as an alternative to traditional hot-working steels with slightly lower mechanical properties and a much higher processability in the additive manufacturing process. The workability of the manufactured dies was confirmed by forging tests on an industrial screw press.}, subject = {Additive manufacturing; Hot-forming dies; L-PBF; WA-DED; WAAM; Additive Fertigung; Warmumformwerkzeuge; L-PBF; WA-DED; WAAM; Warmumformen; Rapid Prototyping (Fertigung); Selektives Laserschmelzen}, language = {en} } @article{GruegerJenschDittrichetal.2024, author = {Gr{\"u}ger, Lennart and Jensch, Felix and Dittrich, Fabian and H{\"a}rtel, Sebastian}, title = {On the creation of a material bond between L-PBF manufac-2tured AZ91 and Ti-6Al-4V components in the context of medi-3cal applications}, series = {Materials}, volume = {17}, journal = {Materials}, number = {18}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma17184667}, year = {2024}, abstract = {Within the scope of these investigations, the feasibility of a material bond between Ti-6Al-4V and the magnesium alloy AZ91 is analyzed. Ti-6Al-4V is frequently used for implants due to its biocompatibility, corrosion resistance, and specific strength. However, depending on the surface quality, the attachment behavior of the bone to the implant varies. Magnesium implants promote the regeneration of bone tissue and biodegrade as the bone tissue heals. Combining the properties of both materials in one implant enables a reduced implant volume and increased stability. For this reason, this study aims to demonstrate the feasibility of creating a material bond between the materials Ti-6Al-4V and AZ91. For this purpose, Ti-6Al-4V truncated cones and AZ91 sleeves were produced using the additive manufacturing process of laser powder bed fusion (L-PBF). The as-built sleeves were then pressed onto machined truncated cones. Since zinc serves as a lubricant and has good diffusion properties with the materials used as a result of heat treatment, a comparison was made between zinc-coated and the as-built Ti-6Al-4V samples. This showed that a bond was created after hot isostatic pressing and that the push-out force could be increased by more than 4.5 times. Consequently, a proof of feasibility was demonstrated, and a high potential for applications in medical technology was shown.}, subject = {AZ91; Ti-6Al-4V; Additive manufacturing; L-PBF; Implant technology}, language = {en} } @article{SchuetzReissMooretal.2025, author = {Sch{\"u}tz, Raphael and Reiss, Franzika and Moor, Irene and Kaman, Anna}, title = {Lonely children and adolescents are less healthy and report less social support : a study on the effect of loneliness on mental health and the moderating role of social support}, series = {BMC Public Health}, volume = {25}, journal = {BMC Public Health}, publisher = {Springer Nature}, address = {Heidelberg}, issn = {1471-2458}, doi = {10.1186/s12889-025-23247-5}, year = {2025}, abstract = {Loneliness among children and adolescents has been increasingly recognized as a public health issue, for example, because of its associations with mental health problems. Nevertheless, there is a lack of evidence regarding the links between loneliness and mental health and the potential buffering role of social support. Thus, this study aims to investigate the prevalence of loneliness among children and adolescents in Germany and its associations with mental health. Furthermore, we analyze whether social support is negatively correlated with loneliness and mental health problems and whether it acts as a moderator of the association between loneliness and mental health issues. This study analyzed data from the Health Behavior in School-aged Children (HBSC) survey in Germany in 2022, which included 6,475 students aged 11, 13, and 15 years (girls: 50,6\%, Mage = 13,4, SD = 1,7). Loneliness was measured via the University of California-Los Angeles Scale (UCLA) and a single-item measure. The mental health indicators included subjective health, life satisfaction, and multiple psychosomatic complaints. Social support from family, teachers, and classmates was assessed. Chi-square tests, t tests, logistic regressions, and moderation analyses were conducted. A total of 17.2\% of the students reported high levels of loneliness. Compared with boys, girls and gender diverse students reported higher rates of loneliness. High levels of loneliness were strongly linked to poorer subjective health (OR = 5.56, p <.001), lower life satisfaction (OR = 7.32, p <.001), and increased psychosomatic complaints (OR = 7.38, p <.001). High social support from family, teachers, and students was associated with reduced loneliness and better mental health outcomes. Teacher support in grades 7 and 9 buffered the effect of loneliness on multiple psychosomatic complaints. The findings highlight that loneliness is a prevalent phenomenon among children and adolescents and is strongly associated with mental health issues. Greater social support is linked to reduced loneliness and better mental health, so targeted interventions to promote social support in schools and families are needed to address loneliness. Future research should explore longitudinal relationships and further elucidate the mechanisms underlying these associations.}, subject = {Loneliness; Mental health; HBSC; Children; Adolescents}, language = {en} } @article{HuberHeinrichsJaegerErben2024, author = {Huber, Andreas and Heinrichs, Harald and Jaeger-Erben, Melanie}, title = {Promoting neighbourhood sharing : infrastructures of convenience and community}, series = {Buildings \& Cities}, volume = {5}, journal = {Buildings \& Cities}, number = {1}, publisher = {Ubiquity Press}, address = {London}, issn = {2632-6655}, doi = {10.5334/bc.442}, pages = {349 -- 367}, year = {2024}, abstract = {Against the background of high levels of energy and resource demand in the residential sector, this paper investigates one potential way of making housing more sufficient: sharing at the neighbourhood level. Evidence from French and German case studies of 'collaborative housing' and 'developer-driven neighbourhood sharing' is used to identify two types of popular sharing practices: community-oriented and convenience-oriented. The first group of sharing practices is underpinned by creating, maintaining and experiencing social ties with neighbours. The second group of practices is guided by getting day-today tasks done smoothly and efficiently. To support the establishment of such sharing practices, some social and organisational measures are suggested. Thus, convenience-oriented sharing practices may be promoted by infrastructures and associated services that optimise the availability of sharing facilities and minimise temporal stretches and consumption work involved in practice performances. Community-oriented sharing practices may benefit from infrastructural arrangements that enable chance encounters, privilege community spaces over private areas and create welcoming spatial atmospheres.}, subject = {Housing; Sustainability; Neighbourhood; Sharing; Sufficiency; Wohnen; Nachbarschaft; Suffizienz; Nachhaltigkeit}, language = {en} } @article{GeyerWindischFritscheetal.2023, author = {Geyer, Thomas and Windisch, Thomas and Fritsche, Christoph and Sarradj, Ennes}, title = {Dataset on permeability of wings from owls and non-silently flying birds}, doi = {10.1016/j.dib.2023.109825}, year = {2023}, abstract = {The very soft and flow-permeable plumage is among the special adaptations of the owl that the silent flight is attributed to. Using a specially designed apparatus that provides a low-speed volume flow of air through a small sample of porous materials, measurements of the air flow permeability were performed in accordance to ISO 9053 on a total of 39 prepared wing specimen from six different bird species, including three species of silently flying owls and three non-silently flying bird species. The resulting data set described in the present paper contains the static airflow resistance measured at different positions on the wing.}, subject = {Owl wing; Air flow resistivity; Permeability; Silent flight; Acoustics; leiser Eulenflug; Str{\"o}mungswiderstand; Permeabilit{\"a}t; Eulenflug; Akustik; Eulen; Vogelflug; Str{\"o}mungswiderstand; Akustik; Permeabilit{\"a}t}, language = {en} } @article{AzamRoesslingGeitheetal.2024, author = {Azam, Hafiz Muhammad Husnain and R{\"o}ßling, Rosa Lise and Geithe, Christiane and Khan, Muhammad Moman and Dinter, Franziska and Hanack, Katja and Pr{\"u}ß, Harald and Husse, Britta and Roggenbruck, Dirk and Schierack, Peter and R{\"o}diger, Stefan}, title = {MicroRNA biomarkers as next-generation diagnostic tools for neurodegenerative diseases : a comprehensive review}, series = {Frontiers in Molecular Neuroscience}, volume = {17}, journal = {Frontiers in Molecular Neuroscience}, publisher = {Frontiers}, address = {Lausanne}, issn = {1662-5099}, doi = {10.3389/fnmol.2024.1386735}, year = {2024}, abstract = {Neurodegenerative diseases (NDs) are characterized by abnormalities within neurons of the brain or spinal cord that gradually lose function, eventually leading to cell death. Upon examination of affected tissue, pathological changes reveal a loss of synapses, misfolded proteins, and activation of immune cells all indicative of disease progression before severe clinical symptoms become apparent. Early detection of NDs is crucial for potentially administering targeted medications that may delay disease advancement. Given their complex pathophysiological features and diverse clinical symptoms, there is a pressing need for sensitive and effective diagnostic methods for NDs. Biomarkers such as microRNAs (miRNAs) have been identified as potential tools for detecting these diseases. We explore the pivotal role of miRNAs in the context of NDs, focusing on Alzheimer's disease, Parkinson's disease, multiple sclerosis, Huntington's disease, and Amyotrophic Lateral Sclerosis. The review delves into the intricate relationship between aging and NDs, highlighting structural and functional alterations in the aging brain and their implications for disease development. It elucidates how miRNAs and RNA-binding proteins are implicated in the pathogenesis of NDs and underscores the importance of investigating their expression and function in aging. Significantly, miRNAs exert substantial influence on post-translational modifications (PTMs), impacting not just the nervous system but a wide array of tissues and cell types as well. Specific miRNAs have been found to target proteins involved in ubiquitination or deubiquitination processes, which play a significant role in regulating protein function and stability. We discuss the link between miRNA, PTM, and NDs. Additionally, the review discusses the significance of miRNAs as biomarkers for early disease detection, offering insights into diagnostic strategies.}, subject = {Neurodegenerative diseases; MicroRNA; Diagnostic tools; Therapeutic tools; Protein post-translational modifications; Nervendegeneration; Biomarker; miRNS; Diagnose; Posttranslationale {\"A}nderung}, language = {en} } @incollection{TestaCartaEllingeretal., author = {Testa, Paolo Valerio and Carta, Corrado and Ellinger, Frank and Klein, Bernhard and Hahnel, Ronny and Plettemeier, Dirk}, title = {DAAB : on-chip integrated distributed amplifier and antenna systems in locally-backside-etched SiGe BiCMOS for receivers with ultra-large bandwidth}, 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-5910}, publisher = {BTU Cottbus - Senftenberg}, pages = {109 -- 138}, 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; DAAB; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} } @article{OttoAlipoursarbaniTorrentetal.2023, author = {Otto, Pascal and Alipoursarbani, Mozhdeh and Torrent, Daniel and Latorre-P{\´e}rez, Adriel and Paust, Thomas and Albert, Alfred and Abendroth, Christian}, title = {Microbiome characterization after aerobic digestate reactivation of anaerobically digested sewage sludge}, volume = {9}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2311-5637}, doi = {10.3390/fermentation9050471}, year = {2023}, abstract = {A demonstrator plant of a recently patented process for improved sludge degradation has been implemented on a municipal scale. In a 1500 m3 sewage sludge digester, an intermediary stage with aerobic sewage sludge reactivation was implemented. This oxic activation increased the biogas yield by up to 55\% with a 25\% reduction of the remaining fermentation residue volume. Furthermore, this process allowed an NH4-N removal of over 90\%. Additionally, 16S rRNA gene amplicon high-throughput sequencing of the reactivated digestate showed a reduced number of methane-forming archaea compared to the main digester. Multiple ammonium-oxidizing bacteria were detected. This includes multiple genera belonging to the family Chitinophagaceae (the highest values reached 18.8\% of the DNA sequences) as well as a small amount of the genus Candidatus nitrosoglobus (<0.3\%). In summary, the process described here provides an economically viable method to eliminate nitrogen from sewage sludge while achieving higher biogas yields and fewer potential pathogens in the residuals.}, subject = {Anaerobic digestion; Anaerobic microbiomes; Aerobic sludge activation; 16S rRNA sequencing; Water treatment; Belebtschlammverfahren; Schlammfaulung; Mikroorganismus; G{\"a}rung; Biogas; Stickstoff-Elimination; Anaerobe Verg{\"a}rung; Anaerobe Mikrobiome; Aerobe Schlammaktivierung; 16S-rRNA-Sequenzierung; Wasserversorgung}, language = {en} } @article{MurkuteSayeedPuchaCofrepetal.2024, author = {Murkute, Charuta and Sayeed, Mostafa and Pucha-Cofrep, Franz and Carrillo-Rojas, Galo and Homeier, J{\"u}rgen and Limberger, Oliver and Fries, Andreas and Bendix, J{\"o}rg and Trachte, Katja}, title = {Turbulent energy and carbon fluxes in an Andean montane forest : energy balance and heat storage}, series = {Forests}, volume = {15}, journal = {Forests}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {1999-4907}, doi = {10.3390/f15101828}, year = {2024}, abstract = {High mountain rainforests are vital in the global energy and carbon cycle. Understanding the exchange of energy and carbon plays an important role in reflecting responses to climate change. In this study, an eddy covariance (EC) measurement system installed in the high Andean Mountains of southern Ecuador was used. As EC measurements are affected by heterogeneous topography and the vegetation height, the main objective was to estimate the effect of the sloped terrain and the forest on the turbulent energy and carbon fluxes considering the energy balance closure (EBC) and the heat storage. The results showed that the performance of the EBC was generally good and estimated it to be 79.5\%. This could be improved when the heat storage effect was considered. Based on the variability of the residuals in the diel, modifications in the imbalances were highlighted. Particularly, during daytime, the residuals were largest (56.9 W/m2 on average), with a clear overestimation. At nighttime, mean imbalances were rather weak (6.5 W/m2) and mostly positive while strongest underestimations developed in the transition period to morning hours (down to -100 W/m2). With respect to the Monin-Obukhov stability parameter ((z - d)/L) and the friction velocity (u*), it was revealed that the largest overestimations evolved in weak unstable and very stable conditions associated with large u* values. In contrast, underestimation was related to very unstable conditions. The estimated carbon fluxes were independently modelled with a non-linear regression using a light-response relationship and reached a good performance value (R2 = 0.51). All fluxes were additionally examined in the annual course to estimate whether both the energy and carbon fluxes resembled the microclimatological conditions of the study site. This unique study demonstrated that EC measurements provide valuable insights into land-surface-atmosphere interactions and contribute to our understanding of energy and carbon exchanges. Moreover, the flux data provide an important basis to validate coupled atmosphere ecosystem models.}, subject = {Energy balance closure; Heat storage; Carbon fluxes; Eddy covariance; Andes Mountains}, language = {en} } @article{ManhiqueWaetzold2024, author = {Manhique, Henrique and W{\"a}tzold, Frank}, title = {Effects of institutional distrust on value estimates of stated preference surveys in developing countries : a choice experiment on conserving biodiversity within agricultural landscapes in a biodiversity hotspot}, series = {Q Open}, volume = {4}, journal = {Q Open}, number = {1}, publisher = {Oxford University Press}, address = {Oxford}, issn = {2633-9048}, doi = {10.1093/qopen/qoae014}, year = {2024}, abstract = {The use of stated preference surveys for the valuation of environmental goods in developing countries has to take into account that there is substantial public distrust towards institutions providing environmental goods under valuation. Thus, high protest responses and low-value estimates may indicate rejection/protest against the institutional setting of the survey, rather than the dislike or low welfare effects of these goods. In this context, we investigate the effects of institutional trust on value estimates by examining the performance of three different institutions government, conservation NGO, and farmers in a case study aimed at eliciting preferences for conserving different types of biodiver- sity within orchards in the Cape Floristic Region a biodiversity hotspot in South Africa threatened by the expansion and intensification of agriculture. We find that institutional trust has an effect on preferences and willingness to pay, with farmers leading to the highest level of trust and value estimates, followed rather closely by a conservation NGO, and, with some distance, by the government with the lowest trust level and value estimates. In terms of preferences for biodiversity conservation, our results show that respondents prefer measures to conserve endangered and endemic species over measures primarily aimed at providing ecosystem services. For future studies in developing countries, we recommend selecting an institutional setting based on the study's purpose: institutions with high levels of trust should be prioritised for studies aiming to value a good per se, while existing institutions should be prioritised for studies valuing a policy to provide a good within an existing institutional framework.}, subject = {Drivers of institutional distrust; Economics; Ecosystem services; Endangered species; Payment vehicle; Faktoren f{\"u}r institutionelles Misstrauen; Wirtschaft; {\"O}kosystemdienstleistungen; Bedrohte Arten; Zahlungsmittel; S{\"u}dafrika; Bekundete Pr{\"a}ferenz; Umweltschutz; Regierung; Nichtstaatliche Organisation; Landwirt; Misstrauen}, language = {en} } @article{MenaresSaizSchenketal.2024, author = {Menares, Esteban and Sa{\´i}z, Hugo and Schenk, No{\"e}lle and Riva, Enrique G. de la and Kraus, Jochen and Birkhofer, Klaus}, title = {Co-occrrence patterns do not predict mutualistic interactions between plant and butterfly species}, series = {Ecology and Evolution}, volume = {14}, journal = {Ecology and Evolution}, number = {11}, publisher = {Wiley}, address = {London}, issn = {2045-7758}, doi = {10.1002/ece3.70498}, year = {2024}, abstract = {Biotic interactions are crucial for determining the structure and dynamics of communities; however, direct measurement of these interactions can be challenging in terms of time and resources, especially when numerous species are involved. Inferring species interactions from species co-occurrence patterns is increasingly being used; however, recent studies have highlighted some limitations. To our knowledge, no attempt has been made to test the accuracy of the existing methods for detecting mutualistic interactions in terrestrial ecosystems. In this study, we compiled two literature-based, long-term datasets of interactions between butterflies and herbaceous plant species in two regions of Germany and compared them with observational abundance and presence/absence data collected within a year in the same regions. We tested how well the species associations generated by three different co-occurrence analysis methods matched those of empirically measured mutualistic associations using sensitivity and specificity analyses and compared the strength of associations. We also checked whether flower abundance data (instead of plant abundance data) increased the accuracy of the co-occurrence models and validated our results using empirical flower visitation data. The results revealed that, although all methods exhibited low sensitivity, our implementation of the Relative Interaction Intensity index with pairwise null models performed the best, followed by the probabilistic method and Spearman's rank correlation method. However, empirical data showed a significant number of interactions that were not detected using co-occurrence methods. Incorporating flower abundance data did not improve sensitivity but enhanced specificity in one region. Further analysis demonstrated incongruence between the predicted co-occurrence associations and actual interaction strengths, with many pairs exhibiting high interaction strength but low co-occurrence or vice versa. These findings underscore the complexity of ecological dynamics and highlight the limitations of current co-occurrence methods for accurately capturing species interactions.}, subject = {Biodiversity exploratories; Co-occurrence analysis; Flower visitations; Mutualistic interactions; Species associations}, language = {en} } @article{GnegelSchaudtClausenetal.2024, author = {Gnegel, Fabian and Schaudt, Stefan and Clausen, Uwe and F{\"u}genschuh, Armin}, title = {A graph-refinement algorithm to minimize squared delivery delays using parcel robots}, series = {Mathematics}, volume = {12}, journal = {Mathematics}, publisher = {MDPI}, address = {Basel}, issn = {2227-7390}, doi = {10.3390/math12203201}, year = {2024}, abstract = {In recent years, parcel volumes have reached record highs, prompting the logistics industry to explore innovative solutions to meet growing demand. In densely populated areas, delivery robots offer a promising alternative to traditional truck-based delivery systems. These autonomous electric robots operate on sidewalks and deliver time-sensitive goods, such as express parcels, medicine and meals. However, their limited cargo capacity and battery life require a return to a depot after each delivery. This challenge can be modeled as an electric vehicle-routing problem with soft time windows and single-unit capacity constraints. The objective is to serve all customers while minimizing the quadratic sum of delivery delays and ensuring each vehicle operates within its battery limitations. To address this problem, we propose a mixed-integer quadratic programming model and introduce an enhanced formulation using a layered graph structure. For this layered graph, we present two solution approaches based on relaxations that reduce the number of nodes and arcs compared to the expanded formulation. The first approach, Iterative Refinement, solves the current relaxation to optimality and refines the graph when the solution is infeasible for the expanded formulation. This process continues until a proven optimal solution is obtained. The second approach, Branch and Refine, integrates graph refinement into a branch-and-bound framework, eliminating the need for restarts. Computational experiments on modified Solomon instances demonstrate the effectiveness of our solution approaches, with Branch and Refine consistently outperforming Iterative Refinement across all tested parameter configurations.}, subject = {Integer programming; Layered graph refinement; Delivery robots; Electric vehicle-routing problem; Partial recharging}, language = {en} } @article{LiedtkeWeissSkifovetal.2023, author = {Liedtke, Victoria and Weiss, Romano and Skifov, Anastasia and R{\"o}diger, Stefan and Schenk, Lysann}, title = {Fully automated viability and toxicity screening : a reliable all-in-one attempt}, series = {Cancer Medicine}, volume = {13}, journal = {Cancer Medicine}, number = {12}, publisher = {Wiley}, address = {Weinheim}, issn = {2045-7634}, doi = {10.1002/cam4.7392}, year = {2023}, abstract = {The CRISPR/Cas9 technology is nowadays a common tool for genome editing to achieve new insights into, e.g., diagnostics and therapeutics in cancer and genetic disorders. Cell proliferation and anti-cancer drug response studies are widely used to evaluate the impact of editing. However, these assays are often time-consuming, expensive and reproducibility is an issue. To overcome this, we developed a fast and cheap assay that combines a fully automated multispectral fluorescence microscopy platform with a nuclei staining and open source software analysis. Here, we generated different LEDGF/p75 model cell lines to validate the effect on proliferation and chemosensitivity. Therefore, a fast protocol for an optimized all-in-one attempt for cytotoxicity screenings and proliferation analysis of adherent cells in a 96-well plate format was established using differential staining with two fluorescent dyes (Hoechst 33342 and propidium iodide) for live/dead cell discrimination. Subsequently, an automated cell nuclei count and analysis was performed using bioimage informatics. With the new established assay technology, up to 50000 cells/well can be detected and analyzed in a 96-well plate, resulting in a fast and accurate verification of viability and proliferation with consistency of 98 \% compared to manual counting. Our screening revealed that LEDGF depletion using CRISPR/Cas9 showed a diminished proliferation and chemosensitivity independent of cell line origin. Moreover, LEDGF depletion caused a significant increase in 𝛾H2AX foci, indicating a substantial increase in DNA double strand breaks. LEDGF/p75 overexpression enhanced proliferation and chemoresistance underlining the role of LEDGF in DNA damage response. Independent of cancer cell type, LEDGF/p75 is a central player in DNA damage repair and is implicated in chemoresistance. Moreover, our automated fluorescence biosensor technology allowed fast and reliable data acquisition without any fixation or additional washing steps. Additionally, data analysis was implemented using modular open source software that can be adapted as needed.}, subject = {Automated system; CRISPR/Cas9; Bioimage informatics; Viability; Cytotoxicity; Automatisiertes System; Vitalit{\"a}t; Bioimage-Informatik; Zytotoxizit{\"a}t; Multiparameteranalyse; Fluoreszenzmikroskopie; Cytotoxizit{\"a}t; Proliferation; Vitalit{\"a}t}, language = {en} } @article{AhmedZaforTrachte2024, author = {Ahmed, Rezwan and Zafor, Md. Abu and Trachte, Katja}, title = {Land-use and land-cover changes in Cottbus city and Spree-Neisse district, Germany, in the last two decades : a study using remote sensing data and Google Earth Engine}, series = {Remote Sensing}, volume = {16}, journal = {Remote Sensing}, number = {15}, publisher = {MDPI}, address = {Basel}, issn = {2072-4292}, doi = {10.3390/rs16152773}, year = {2024}, abstract = {Regular detection of land-use and land-cover (LULC) changes with high accuracy is necessary for natural resources management and sustainable urban planning. The produced LULC maps from Google Earth Engine (GEE) also illustrate the transformation of the LULC for the respective landscape over time. The selected study area, Cottbus City and the Spree-Neisse district in northeastern Germany, has undergone significant development over the past decades due to various factors, including urbanization and industrialization; also, the landscape has been converted in some areas for post-mining activities. Detection of LULC changes that have taken place over the last few decades thus plays a vital role in quantifying the impact of these factors while improving the knowledge of these developments and supporting the city planners or urban management officials before implementing further long-term development initiatives for the future. Therefore, the study aims to (i) detect LULC changes for the time slices 2002 and 2022, testing machine learning (ML) algorithms in supervised and unsupervised classification for Landsat satellite imageries, and (ii) validate the newly produced LULC maps with the available regional database (RDB) from the federal and state statistical offices, Germany, and the DynamicWorld (DW) near real-time 10 m global LULC data set powered by artificial intelligence (AI). The results of the Random Forest (RF) and the Smilecart classifiers of supervised classification using Landsat 9 OLI-2/TIRS-2 in 2022 demonstrated a validation accuracy of 88\% for both, with Kappa Index (KI) of 83\% and 84\%, respectively. Moreover, the Training Overall Accuracy (TOA) was 100\% for both years. The wekaKMeans cluster of the unsupervised classification also illustrated a similar transformation pattern in the LULC maps. Overall, the produced LULC maps offered an improved representation of the selected region's various land-cover classes (i.e., vegetation, waterbodies, built areas, and bare ground) in the last two decades (2022 to 2022).}, subject = {LULC; Machine learning; Landsat; Google Earth Engine; Landnutzung; Bodenbedeckung; Landsat; Google Earth; Maschinelles Lernen}, language = {en} } @article{KhanMushtaqAbbasetal.2024, author = {Khan, Muhammad Moman and Mushtaq, Muhammad Ahmed and Abbas, Nayyar and Fatima, Fariha and Gibbon, Marjorie J. and Schierack, Peter and Mohsin, Mashkoor}, title = {Occurrence, antimicrobial resistance and genomic features of Klebsiella pneumoniae from broiler chicken in Faisalabad, Pakistan}, series = {Frontiers in Veterinary Science}, volume = {11}, journal = {Frontiers in Veterinary Science}, publisher = {Frontiers}, address = {Lausanne}, issn = {2297-1769}, doi = {10.3389/fvets.2024.1433124}, year = {2024}, abstract = {The dissemination of antimicrobial resistance (AMR) in critical priority pathogens is a significant threat. Non-clinical reservoirs of AMR, such as agriculture and food production facilities, may contribute to the transmission of clinically relevant pathogens such as multidrug-resistant (MDR) Klebsiella pneumoniae. There is currently very limited knowledge regarding the population structure and genomic diversity of K. pneumoniae in poultry production in Pakistan. We explored healthy broilers in a commercial farm from Faisalabad, Pakistan, and identified six K. pneumoniae strains from 100 broiler birds. We characterized the strains, determining clonality, virulence and antimicrobial resistance genes using next generation sequencing. The evaluation of antimicrobial susceptibility revealed that all the strains were MDR. Genomic analysis showed that 3/6 strains belonged to ST152, harbouring acquired resistance aminoglycosides [aadA2, aph(4′)-Ia], β-lactams (blaSHV-187, blaLAP2), fosfomycin (fosA6), tetracycline (tetA), trimethoprim (dfrA12), quinolone (qnrS1), sulphonamides (sul2) and phenicol (floR). All the strains harboured the efflux pump genes oqxA, oqxB, emrR, kpnG, kpnH, kpnF, baeR, mtdB and mtdC. All six strains encoded identical virulence profiles possessing six genes, i.e., ureA, iutA, entB, allS, fimH and mrkD. Phylogenomic analysis of the dominant sequence type (ST152) present in our dataset with publicly available genomes showed that the isolates clustered to strains mainly from human sources and could pose a potential threat to food safety and public health. The combination of these findings with antimicrobial use data would allow a better understanding of the selective pressures that may be driving the spread of AMR. This is the first report of MDR K. pneumoniae isolated from broiler hens in Pakistan, and the finding suggests that routine surveillance of WHO critical priority pathogens in such settings would be beneficial to the development of effective control strategies to reduce AMR.}, subject = {Antimicrobial resistance; Poultry; Genomics; K. pneumoniae; Sequence type}, language = {en} } @article{FrimpongMolkenthinKoranteng2022, author = {Frimpong, Bernard Fosu and Molkenthin, Frank and Koranteng, Addo}, title = {Analysis of temperature variability utilising Mann-Kendall and Sen's slope estimator tests in the Accra and Kumasi metropolises in Ghana}, doi = {10.1186/s40068-022-00269-1}, year = {2022}, abstract = {Temperature variability may have direct and indirect impacts on the environments of the Accra and Kumasi Metropolises in Ghana. This study analysed temperature and trends in temperature in both cities using in-situ measurements from one meteorological station in both cities from 1986 to 2015. The temperature indices were computed using the RClimdex package from the Expert Team on Climate Change Detection Monitoring Indices (ETCCDMI). The temperature time series was pre-whitened before the Mann-Kendall trend and Sen's slope estimator analysis were applied. Initial analysis revealed minimal variation in temperature in both cities. The results from the analysed temperature indices revealed an increase in warm days and a general rise in the minimum temperature compared to maximum temperatures. Mann Kendall and Sen's slope revealed significant trends in the annual and seasonal (dry and wet seasons) in minimum temperature in both cities. These might lead to an increased rate of heat-stressed diseases and an overall rise in urban warming in both cities. The analysis of temperature, indices and trends provided comprehensive insights into the temperature of Accra and Kumasi. The results highlight the essence of evaluating temperature indices and trends in light of Climate Change concerns. It is recommended that urban green and blue spaces should be incorporated into land use plans as these policy directions can aid regulate the temperature in both cities.}, subject = {Temperature variability; Mann-Kendall test; Sen's slope estimator; Accra; Kumasi; Temperaturvarabilit{\"a}t; Sen-Slope Sch{\"a}tzer; Accra; Kumasi; Temperatur; Schwankung}, language = {en} } @article{KayatzBaroniHillieretal.2023, author = {Kayatz, Benjamin and Baroni, Gabriele and Hillier, Jon and Wattenbach, Martin}, title = {Supporting decision-making in agricultural water management under data scarcity using global datasets : chances, limits and potential improvements}, series = {Agricultural Water Management}, volume = {296}, journal = {Agricultural Water Management}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-3774}, doi = {10.1016/j.agwat.2024.108803}, year = {2023}, abstract = {Assessing alternative agricultural water management strategies requires long-term field trials or vast data collection for model calibration and simulation. This work aims to assess whether an uncalibrated agro-hydrological model using global input datasets for climate, soil and crop information can serve as a decision support tool for crop water management under data scarcity. This study employs the Cool Farm Tool Water (CFTW) at eight eddy covariance sites of the FLUXNET2015 dataset. CFTW is tested using global (CFTWglobal) and local (CFTWlocal) input datasets under current and alternative management scenarios. Results show that the use of global datasets for estimating daily evapotranspiration had little effect on the median Root Mean Square Error (RMSE) (CFTWglobal: 1.70 mm, CFTWlocal: 1.79 mm), while, however, the median model bias is much greater (CFTWglobal: - 18.6\%, CFTWlocal: - 4.3\%). Furthermore, the periods of water stress were little affected by the use of local or global data (median accuracy: 0.84), whereas the use of global data inputs led to a significant overestimation of irrigation water requirements (median difference: 110 mm). The model performance improves predominantly through the use of more representative local precipitation data, followed by local reference evapotranspiration and soil for some European growing seasons. We identify model outputs that can support decision-making when relying on global data, such as periods of water stress and the daily dynamics of water use. However, our findings also emphasize the difficulty of overcoming data scarcity in decision-making in agricultural water management. Furthermore, we provide recommendations for enhancing model performance and thus may increase the accessibility of reliable decision support tools in the future.}, subject = {Crop water use; Crop water requirement; Evapotranspiration; Irrigation; Cool farm tool; Wasserverbrauch der Kulturpflanzen; Wasserbedarf der Kulturpflanzen; Evapotranspiration; Bew{\"a}sserung; FAO56; Bew{\"a}sserungswirtschaft; Mathematisches Modell; Bew{\"a}sserung; Evapotranspiration; Wasserbedarf; Kulturpflanzen}, language = {en} } @article{LeunerHirschl2024, author = {Leuner, Bruna and Hirschl, Bernd}, title = {Biomass and bioenergy perspectives of a coal region : status quo, potential and scenarios in Lusatia}, series = {Frontiers in Energy Research}, volume = {11}, journal = {Frontiers in Energy Research}, publisher = {Frontiers}, address = {Lausanne}, issn = {2296-598X}, doi = {10.3389/fenrg.2023.1275733}, year = {2024}, abstract = {Coal has been one of the main fuels used in Europe. Its decreasing role due to the ongoing transformation of the energy system will create significant socio-economic challenges. The switch into renewable energy systems could be an alternative to maintain jobs and economic activities within the affected regions. Biomass use and bioenergy can play an important role in the energy transition. Instead of energy crops, forest and agricultural residues should be used as biogenic energy sources in the future to avoid impacts on land use and food security. The main objective of this article is to investigate the biomass potential of a coal region and to provide scenarios for the future development of bioenergy production. Due to the changing framework conditions and, as a result, the different biomass focuses, previous bioenergy potential estimates must be reviewed. The methods for determining the potential of biomass for energy production was used for Lusatia (in German: Lausitz), the second largest coal region in Germany. These methods can also be applied in other regions. As a first step, the regional status quo assessment of cultivated areas and yields had decisive relevance for calculating biomass potential ranges. In a second step, the current bioenergy facilities in the region were identified, with a focus on power and heat production. The third step was the estimation of future regional bioenergy use. Therefore, the regional potential was gathered with the generally supra-regional framework conditions. For this purpose, national scenario studies were used, which contain the relevant target values and framework conditions. Two scenarios were developed for future bioenergy estimations: a conservative path based on the current policies and a progressive path, derived from the goal of climate neutrality by 2045. The results show a qualitative comparison among both scenarios and the previously determined potential ranges. Bioenergy can probably contribute to achieving climate neutrality with an increase in wood-fired systems, while agricultural bioenergy potential is likely to decline. In the discussion section, however, the uncertainty of these results is pointed out, as future use of bioenergy will be heavily influenced by the regulatory framework, competition with material use and the influences of climate change.}, subject = {Regional biomass potential; Bioenergy scenarios; Coal region; Regional energy transition; Lusatia; Regionales Biomassepotenzial; Bioenergieszenarien; Kohleregion; Regionale Energiewende; Lausitz}, language = {en} } @article{KoenigSharmaKondaetal.2023, author = {K{\"o}nig, Paul and Sharma, Dikshant and Konda, Karunakar Reddy and Xie, Tianxiao and H{\"o}schler, Klaus}, title = {Comprehensive review on cooling of permanent magnet synchronous motors and their qualitative assessment for aerospace applications}, doi = {10.3390/en16227524}, year = {2023}, abstract = {The permanent magnet synchronous motor (PMSM) can be a suitable candidate for electrified propulsion in aviation. Despite the very high efficiency, heat dissipation during operation leads to performance limitations. Elevated temperatures in the electrical insulations and the magnets pose a potential safety risk that must be reduced by selective cooling. A comprehensive review is conducted to capture current research interests in cooling methods in PMSM. Cooling methods are described according to their heat transfer mechanism, grouped, and assigned to the components within the motor. Key findings of the literature reviewed are described in the context of PMSM cooling. Information on cooling media and potential combinations of cooling methods in components is gathered. Assessment parameters such as safety, weight, effectiveness, integrability, complexity and cost are defined to enable a subsequent qualitative analysis for six selected cooling methods. A point-weighted evaluation approach, according to VDI 2225, was applied to identify the most promising cooling approach for successful implementation in aviation.}, subject = {Electrical machines; Electric aviation; Motor cooling; PMSM; Thermal management; Elektrische Luftfahrt; Elektrische Maschinen; Motork{\"u}hlung; W{\"a}rmemanagement; Luftfahrt; Raumfahrt; Elektroantrieb; Dauermagneterregter Synchronmotor; K{\"u}hlung}, language = {en} } @article{BoltonLaaser2017, author = {Bolton, Sharon C. and Laaser, Knut}, title = {The moral economy of solidarity : a longitudinal study of special needs teachers}, publisher = {SAGE Publications}, address = {London, England}, issn = {0950-0170}, doi = {10.1177/0950017019871237}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-52124}, year = {2017}, abstract = {Based on a longitudinal study of a Pupil Referral Unit (PRU) in England for children excluded from mainstream schools and utilising a moral economy lens, this article explores how solidarity is created and maintained in a very particular community of teachers and learning support assistants (LSAs). A moral economy approach highlights the centrality of people's moral norms and values for understanding the multi-layered dimensions of solidarity in organisations and how it changes in the context of transformations in the labour process. The article illustrates how teachers and LSAs rely on mutuality, underpinned by moral norms of justice, and values of care, dignity and recognition, to cope with physically and emotionally demanding work that is under-resourced and undervalued. The analysis reveals that solidarity is not only against unjust workplace regimes, but also for connectivity and a humanised labour process.}, subject = {England; Moral economy; Inequality; Pupil Referral Unit; Schools; Solidarity; Sonderschule; Lehrerkollegium; Solidarit{\"a}t; Moral; Norm }, language = {en} } @article{LeunerHirschlBezerraetal.2025, author = {Leuner, Bruna and Hirschl, Bernd and Bezerra, Pedro Henrique and Pedrosa Quintino, Wellington and Bezerra, Roberta and Cavalcante Silva, Rodolfo}, title = {Indigenous bioeconomy in Brazil : how to determine the local biomass potential in indigenous territories}, series = {Journal of Integrative Environmental Sciences}, volume = {22}, journal = {Journal of Integrative Environmental Sciences}, number = {1}, publisher = {Taylor \& Francis}, address = {London}, issn = {1943-8168}, doi = {10.1080/1943815X.2025.2566009}, year = {2025}, abstract = {The increased expansion of agricultural areas in central Brazil has been cited as a contributing factor to deforestation, soil degradation and water pollution. The impact of this expansion extends beyond the boundaries of the territory of the Xavante indigenous group. These protected areas have experienced a marked decline in available food resources and an unreliable energy supply. The term "indigenous bioeconomy" represents a holistic approach that aims to enhance the well-being of indigenous communities. It recognises indigenous knowledge and promotes the sustainable use of resources. The indigenous bioeconomy contributes to climate protection, by avoiding deforestation and replacing the use of fossil fuels in isolated areas with biogenic alternatives. This paper analyses the local biomass potential of a community within the Pimentel Barbosa Indigenous Territory of the Xavante ethnic group. Participatory research was employed to gain an in-depth understanding of the customary Xavante practices. The theoretical biomass potential was estimated at around 2700 tonnes per year (t/a), which is defined as the total amount of selected biomass types available in the investigated area. Local practical biomass potential considers the per capita consumption of this biomass by the indigenous population. Furthermore, the authors quantified the unused biomass potential, representing biomass that could be used for various purposes including food, medicine and energy. Biomass residues have an untapped potential of around 180 t/a. The paper outlines possible utilisation scenarios for these residues and considers the challenges associated with food and energy security in indigenous territories.}, subject = {Indigenous bioeconomy; Local biomass potential; Cerrado biome; Xavante}, language = {en} } @article{KansokDuscheWettsteinFischeretal.2024, author = {Kansok-Dusche, Julia and Wettstein, Alexander and Fischer, Saskia and Wachs, Sebastian and Bilz, Ludwig}, title = {Associations between teachers' beliefs and their perception of hate speech in school : a study in Germany and Switzerland}, series = {Frontiers in Education}, volume = {9}, journal = {Frontiers in Education}, number = {Sec. Teacher Education}, publisher = {Frontiers}, address = {Lausanne}, issn = {2504-284X}, doi = {10.3389/feduc.2024.1432013}, year = {2024}, abstract = {Hate speech is a global issue that is also prevalent among adolescents and requires an educational response. Teachers handle hate speech as part of their professional role. To date, we know little about their beliefs in relation to the early stages of their interventional actions, specifically to their perception of hate speech in school. Thus, this study examined associations between teachers' social dominance orientation, their pluralist attitude, and their hate speech perception in school. A sample of 471 secondary school teachers from 38 schools (Germany: n = 251; Switzerland: n = 220) participated in a self-report survey from December 2020 to April 2021 (MAge = 42.8 years; 57.7\% females; 21.0\% with migration status). Data from a total of 3,560 students from grades 7 to 9 (Germany: n = 1,841; Switzerland: n = 1,719)were matched with teachers' data to control for students' hate speech perception in school.Fixed effects multilevel regressions were run, including covariates (teachers' age, gender, migration status, students' hate speech perception), teachers' social dominance orientation, pluralist attitude, and their hate speech perception in school. Teachers perceived a higher frequency of offline hate speech than online hate speech. Contrary to the hypotheses, social dominance orientation was positively associated with offline and online hate speech perception. As predicted, teachers' pluralist attitude was positively linked to their off-and online hate speech perception. Further research must now clarify how the investigated beliefs and attitudes and teachers' hate speech perception in school relate to other aspects of their professional competence.}, subject = {Hate speech perception; Teachers; School; Beliefs; Social dominance orientation; Hassrede; Integrit{\"a}t; Lehrer; Lehrerin; Studie; Intervention; {\"U}berlegenheit}, language = {en} } @article{ObrosovFallahHeziletal.2024, author = {Obrosov, Aleksei and Fallah, Mamoun and Hezil, Naouel and Bouras, Dikra and Bouchareb, Nabila and Perez Larios, Alejandro and El-Hiti, Gamal A. and Weiß, Sabine}, title = {Investigating the effect of Zr content on electrochemical and tribological properties of newly developed near β-type Ti-alloys (Ti-25Nb-xZr) for biomedical applications}, series = {Journal of Science: Advanced Materials and Devices}, volume = {9}, journal = {Journal of Science: Advanced Materials and Devices}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2024.100695}, year = {2024}, abstract = {In order to create alloys with exceptional properties for orthopedic uses, this study focuses on the impact of zirconium (Zr) content on the structural, electrochemical, and tribological qualities of nanostructured Ti-25NbxZr [x = 5, 10, 15, 20, 25, and 30 atomic (at.) \%] alloys. The structural evolution was investigated using XRD and SEM techniques. The mechanical characteristics of the produced alloys, including Vickers hardness and Young's modulus, were measured. In addition, the corrosion tests were performed using the OCP, EIS, and PD methods in Ringer's solution within the independent pH range at 37°C. A ball-on-disc tribometer was used to investigate the tribological behavior of the alloys under various loads and wet conditions using the Ringer solution. It has been verified that Zr content (at. \%) in the alloys had an impact on their morphologies, structural evolution, and mechanical characteristics. According to the morphological analysis, the particle and crystallite size decreases with increasing Zr content. Young's modulus and Vickers hardness show the same tendency. The EIS data demonstrated that a single passive film formed on the alloy surfaces, and the addition of Zr enhanced the corrosion resistance of the passive films. The polarization curves demonstrate that the alloys had low corrosion current densities and large passive areas without the passive films disintegrating. Likewise, the inclusion of Zr resulted in a reduction in the corrosion and passive current density values. All of these results suggested that the titanium alloys exhibit a more noble electrochemical activity caused by Zr. From the tribological perspective, it was found that the friction coefficient of the alloys reduced with increasing Zr content.}, subject = {Ti-Nb-Zr alloys; Nanobiomaterials; Tribological behavior; Ringer's solution; Biomedical applications; Ti-Nb-Zr-Legierungen; Nanowerkstoffe; Tribologisches Verhalten; Ringerl{\"o}sung; Biomedizinische Anwendungen; Biomedizin; Nanostrukturiertes Material; Titanlegierung; Zirconium}, language = {en} } @article{KrishnaSchifferRaisch, author = {Krishna, Ajay and Schiffer, Johannes and Raisch, J{\"o}rg}, title = {Distributed secondary frequency control in microgrids : robustness and steady-state performance in the presence of clock drifts}, doi = {10.26127/BTUOpen-5969}, abstract = {Microgrids are distributed systems with high share of inverter-interfaced renewable energy sources where stable and reliable system operation is realized by suitably controlling the inverters. In this work, we focus on secondary frequency control, which is an important ancillary service provided by the inverters. In the literature on secondary frequency control, the effect of clock drifts has often been neglected. However, clock drifts are practically unavoidable parameter uncertainties in inverter-based microgrids and we show that the most commonly employed distributed secondary frequency controllers exhibit performance deteriorations when taking clock drifts explicitly into consideration. Motivated by this, we propose a novel alternative control law called generalized distributed averaging integral (GDAI) control, which achieves the secondary control objectives of steady-state accurate frequency restoration and proportional power sharing in the presence of clock drifts. In addition, we derive a sufficient tuning criterion in the form of a set of linear matrix inequalities (LMIs) which guarantees robust stability of the closed-loop equilibrium point in the presence of uncertain clock drifts. Finally, our analysis is validated extensively via simulation with comprehensive comparisons to other related distributed control approaches.}, subject = {Microgrids; Distributed control; Consensus algorithms; Power systems; Secondary frequency control; Sekund{\"a}rfrequenzregelung; Mikronetze; Robustheit; Taktdifferenzen; Wechselrichter; Microgrid ; Wechselrichter; Taktfrequenz}, language = {en} } @article{CelikAtapekPolatetal.2023, author = {{\c{C}}elik, G{\"u}l{\c{s}}ah Akta{\c{s}} and Atapek, Şaban Hakan and Polat, Şeyda and Obrosov, Aleksei and Weiß, Sabine}, title = {Nitriding effect on the tribological performance of CrN-, AlTiN-, and CrN/AlTiN-Coated DIN 1.2367 hot work tool steel}, series = {Materials}, volume = {16}, journal = {Materials}, number = {7}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma16072804}, year = {2023}, abstract = {In this study, heat-treated and multisurface engineered DIN 1.2367 tool steel was subjected to room and elevated temperature wear tests, and the effect of nitriding on its tribological behavior was investigated. CrN, AlTiN, and CrN/AlTiN coatings with a total thickness of 2 µm were obtained by arc cathodic physical vapor deposition on conventional heat-treated and gas-nitrided steels. The white layer formed during nitriding was removed, and a diffusion layer (100 µm) was achieved in the cross section of the steel having a tempered martensitic matrix. The highest surface hardness was attained with an integral coating (CrN/AlTiN), and surface hardness increased even more after nitriding due to the formation of a multicomponent ceramic layer on top of the diffusion layer. The room temperature wear tests performed against an alumina counterpart revealed that (i) CrN/AlTiN-coated steel had the highest friction coefficient of 0.26, which further increased to 0.33 by nitriding due to the increase in shear strength, and that (ii) with increasing surface hardness, the specific wear rates (W) of the heat-treated and coated steels could be ranked as follows: WCrN/AlTiN < WAlTiN < WCrN. The wear rates decreased when nitriding was carried out prior to coating. In order to simulate the aluminum extrusion conditions, hot wear behavior of the surfaces against AA6080 alloy at 450 °C was investigated. The hot wear tests revealed that (i) high friction coefficients were reached due to the adhesive characteristic of aluminum to the surfaces, (ii) the nitrided and CrN/AlTiN-coated sample exhibited the lowest wear rate among all studied surfaces, and (iii) the film damage on the worn surfaces mostly occurred in the form of droplet delamination.}, subject = {DIN 1.2367; PVD coating; Wear; Characterization; PVD-Beschichtung; Verschleiß; Charakterisierung; Werkzeugstahl; Warmarbeitsstahl; Nitrierh{\"a}rten; Tribologie; Werkzeugpr{\"u}fung; Verschleiß}, language = {en} } @article{Zeissig2023, author = {Zeißig, Anke}, title = {Boredom as the originator of a desideratum : reflections on the creative and suppressive consequences of boredom in the school context}, doi = {10.3389/fsoc.2023.1214069}, year = {2023}, abstract = {Bored children begin to draw, do crafts, to fidget - or they do something bad. Others fall silent, withdraw, or become lethargic. Research on school-related boredom has focused primarily on the negative consequences of boredom, such as decreased cognitive performance, motivation or attentativeness, or disruptiveness. These negative aspects of boredom can be contrasted by the notion that boredom can promote creative performance. This paper reflects on boredom's creative and suppressive consequences as an interplay of personality traits and behavioral possibilities in school situations, on the one hand, and as an interplay of situational experiences with constituent developmental processes on the other. It is proposed that boredom is a gauge of the learner's resonance with school content, learning and/or developmental relationships. Boredom indicates a psychological need and its desideratum. Thus, both creative and suppressive potentials are inherent in boredom.}, subject = {Boredom; Creativity; Education; School; Langeweile; Kreativit{\"a}t; Bildung; Schule; Spiritualit{\"a}t; Bildung; Kind; Kognitive Entwicklung; Langeweile; Sozialp{\"a}dagogik; Boredom; Education}, language = {en} } @article{MathiazhaganKimVeginietal.2025, author = {Mathiazhagan, Akilan and Kim, Dongsuk and Vegini, George and Montemurro, Marco and Baltag, Serghei and Asli, Majid and H{\"o}schler, Klaus}, title = {Design strategies for enhancement of mechanical behaviour of hybrid cellular structures based on schwarz primitive geometry}, series = {Materials \& Design}, volume = {240}, journal = {Materials \& Design}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0264-1275}, doi = {10.1016/j.matdes.2025.115161}, year = {2025}, abstract = {Hybrid cellular structures are gaining attention for their multi-functionality in load-bearing, heat-transfer, and energy-absorption applications. Schwarz Primitive (SCP)-based geometries, a subclass of Triply Periodic Minimal Surfaces (TPMS), with their high surface area, tunable properties, and continuous topology, provide strong potential for such applications. To further enhance mechanical performance and stability, this work conducts a thorough investigation of hybrid designs that integrate SCP TPMS with Kelvin truss-based geometries, combining the high connectivity of TPMS with the reinforcement and directional stiffness benefits of struts. A theoretical strain-based homogenization framework was implemented over a design matrix that independently varies the relative densities of the SCP and the truss geometries, quantifying how each constituent proportion influences the overall mechanical response of the hybrid. These predictions were corroborated by finite element analyses in ANSYS 2023 and by mechanical testing of 3D-printed polylactic acid samples, providing independent validation of homogenization trends across orientations. The resulting formulation enables rapid property mapping, sensitivity analysis, and optimization of SCP-Kelvin hybrids, thereby reducing the prototyping effort while guiding application-based design selection and customization.}, subject = {Lightweight design; Anisotropy control; Homogenization; Triply periodic minimal surfaces; Periodic open cellular structures}, language = {en} } @article{AsliKimHoeschler2023, author = {Asli, Majid and Kim, Dongsuk and H{\"o}schler, Klaus}, title = {On the potentials of the integration of pressure gain combustion with a hybrid electric propulsion system}, doi = {10.3390/aerospace10080710}, year = {2023}, abstract = {As the issue of pollutant emissions from aviation propulsion escalates, research into alternative powertrains is gaining momentum. Two promising technologies are the Hybrid Electric Propulsion System (HEPS) and Pressure Gain Combustion (PGC). HEPS is expected to reduce pollutant emissions by decreasing fuel consumption, whereas PGC uses detonation in the combustor to increase the thermal efficiency of engines by elevating the total pressure during combustion. This study extensively explores the integration of these two emerging technologies, thoroughly assessing the advantages that arise from their combination. First, the renowned turboprop engine PW127 is benchmarked and modeled using Gasturb software. The model is integrated into Simulink using the T-MATS tool, with HEPS and pressure gain components added to analyze the thermodynamics of various configurations under different pressure gain values and HEPS parameters. The analysis, conducted up to the cruise phase of the baseline aircraft, reveals that applying pressure gain combustion through Rotating Detonation Combustion (RDC) results in a more significant increase in efficiency and decrease in fuel consumption compared to HEPS with conventional gas turbines. However, HEPS helps maintain a more uniform combustor inlet condition and reduces the Turbine Inlet Temperature (TIT) at the takeoff phase, where the highest TIT otherwise occurs. The results suggest that integrating HEPS with PGC can be beneficial in maintaining optimal combustor conditions and mitigating turbine efficiency degradation.}, subject = {Pressure gain combustion; Hybrid electric propulsion; Rotating detonation combustion; Druckverst{\"a}rkungsverbrennung; Rotierende Detonationsverbrennung; Hybrid-Elektroantrieb; Propeller-Turbinen-Luftstrahltriebwerk; Hybridantrieb; Verbrennung; Schadstoffemission; Emissionsverringerung}, language = {en} } @inproceedings{RuedaEscobedoMorenoSchiffer, author = {Rueda-Escobedo, Juan G. and Moreno, Jaime A. and Schiffer, Johannes}, title = {Finite-time estimation of time-varying frequency signals in low-inertia power systems}, doi = {10.26127/BTUOpen-5988}, pages = {2108 -- 2114}, abstract = {The ongoing and unprecedented transformation of power systems leads to a reduction in the number of conventional power plants, which are the classical actuators of the grid. In addition, this development results in a decreasing system inertia, which is expected to yield faster frequency dynamics. Therefore power-electronics-interfaced units have to take over system control tasks and, in particular, frequency control. For this purpose, accurate and fast estimation algorithms for time-varying frequency signals are needed. Motivated by this fact, we propose a time-varying parameter estimator and a tuning criterion, which for sufficiently small initial estimation errors allows to reconstruct the time-varying frequency signal of a symmetric three-phase waveform in finite time. The proposed estimator is derived by using a time-varying version of the super twisting algorithm and its performance is illustrated via numerical examples.}, subject = {Distributed power generation; Frequency control; Parameter estimation; Power plants; Power system control; Frequenzsignale; Massentr{\"a}gheit; Systemsteuerung; Transformation; Frequenzdynamik; Energieversorgung; Frequenzstabilit{\"a}t}, language = {en} } @article{BasuUlrbrichtRossol2025, author = {Basu, Syamantak and Ulrbricht, Ying and Rossol, Manuela}, title = {Healthy and premature aging of monocytes and macrophages}, series = {Frontiers in Immunology}, volume = {16}, journal = {Frontiers in Immunology}, publisher = {Frontiers}, address = {Lausanne}, issn = {1664-3224}, doi = {10.3389/fimmu.2025.1506165}, year = {2025}, abstract = {Aging is associated with immunosenescence, a decline in immune functions, but also with inflammaging, a chronic, low-grade inflammation, contributing to immunosenescence. Monocytes and macrophages belong to the innate immune system and aging has a profound impact on these cells, leading to functional changes and most importantly, to the secretion of pro-inflammatory cytokines and thereby contributing to inflammaging. Rheumatoid arthritis (RA) is an autoimmune disease and age is an important risk factor for developing RA. RA is associated with the early development of age-related co-morbidities like cardiovascular manifestations and osteoporosis. The immune system of RA patients shows signs of premature aging like age-inappropriate increased production of myeloid cells, accelerated telomeric erosion, and the uncontrolled production of pro-inflammatory cytokines. In this review we discuss the influence of aging on monocytes and macrophages during healthy aging and premature aging in rheumatoid arthritis.}, subject = {Monocytes; Macrophages; Aging; Immunosenescence; Rheumatoid arthritis}, language = {en} } @article{BasuRossol2025, author = {Basu, Syamantak and Rossol, Manuela}, title = {You are what you eat : metabolic recycling of phagocytosed bacteria modulates macrophage immunity}, series = {Signal Transduction and Targeted Therapy}, volume = {10}, journal = {Signal Transduction and Targeted Therapy}, publisher = {Springer Nature}, address = {London}, issn = {2059-3635}, doi = {10.1038/s41392-025-02222-x}, year = {2025}, abstract = {In a recent study show that phagocytosed bacteria can be recycled by macrophages to serve as an alternative nutrient source. Bacterial cAMP was identified as a signal for macrophages to differentiate between dead and live bacteria and to adjust the inflammatory response accordingly. You are what you eat - at least when it comes to macrophages. Macrophages have a high capacity to take up fluid, macromolecules, apoptotic cells, and microorganisms from the extracellular space. Uptake of macromolecules by macropinocytosis and subsequent degradation in lysosomes in an infectious or autoimmune setting can lead to excessive inflammation. It is also known that engulfment of apoptotic cells and digestion in phagolysosomes by the macrophages generates amino acids, nucleotides, and fatty acids that then act as metabolites and signalling molecules in the macrophages and influence their cellular functions. Up until now, it was largely believed that phagolysosomes containing engulfed microorganisms are tightly sealed vesicles, so that potentially harmful components from the foreign organisms aren't diffused in the cell. Lesbats et al. show here for the first time that macrophages recycle engulfed bacteria and use the components as nutrient source.}, subject = {Cell biology; Infection; Innate immune cells}, language = {en} } @book{VidermanKnierbeinKraenzleetal.2022, author = {Viderman, Tihomir and Knierbein, Sabine and Kr{\"a}nzle, Elina and Frank, Sybille and Roskamm, Nikolai and Wall, Ed}, title = {Unsettled urban space : routines, temporalities and contestations}, publisher = {Routledge}, address = {New York}, isbn = {978-0-429-29023-7}, doi = {10.4324/9780429290237}, publisher = {BTU Cottbus - Senftenberg}, pages = {279}, year = {2022}, abstract = {While urban life can be characterized by endeavors to settle stable and safe environments, for many people, urban space is rarely stable or safe; it is uncertain, troubled, imbued with challenges and perpetually under pressure. As the concept of unsettled appears to define the contemporary urban experience, this multidisciplinary book investigates the conflicts and possibilities of settling and unsettling through open and speculative analysis. The analytical prism of unsettled renders urban space an indeterminate ground unfolding through routines, temporalities and contestations in constant tension between settling and unsettling. Such contrasting experiences are contingent on how urban societies confront, undergo and overcome turbulence and difficulties in time and space. Contributions drawing on theoretical reflections and empirical accounts—from Argentina, Austria, Germany, Greece, Italy, the Netherlands, the UAE, the UK, the USA and Vietnam—give insights into plural occurrences of the unsettled, which might tie down or unleash transformative, liberatory and emancipatory potentials. This book is for students, professionals and researchers interested in the uncertainties, foundations, disturbances, inconsistencies, residuals and blind fields, which constitute the urban both as lived space and as social, cultural and political ideal.}, subject = {St{\"a}dtischer Raum; St{\"o}rungen; Unsicherheit; Siedlung; Unruhig; Urban space; Disturbances; Urban insecurity; Settlement; Unsettled; Siedlung; Stadtleben; Sesshaftigkeit; Unsicherheit; Konflikt}, language = {en} } @book{HoeflerJentschKoellneretal.2023, author = {H{\"o}fler, Frank and Jentsch, Juliane and K{\"o}llner, Gitta and Kramer, Thomas and Leßmann, Dieter and Richter, Gerd and Stopp, Horst and Schellnhuber, Hans-Joachim}, title = {Floating Architecture : construction on and near water}, editor = {Stopp, Horst and Strangfeld, Peter}, publisher = {LIT Verlag}, address = {Berlin}, isbn = {978-3-643-91435-4}, doi = {10.52038/9783643914354}, publisher = {BTU Cottbus - Senftenberg}, pages = {110}, year = {2023}, abstract = {Floating architecture is not only an issue for luxurious tourism but with the climatic change the building of floating structures becomes relevant for many areas in the world. In regions with rising sea levels, frequent flooding, or thawing permafrost, floating structures can be a solution to adapt existing settlement areas to these new conditions. The self-sufficient energy and supply systems required for floating settlements can also be used in rural areas with a lot of migration. The collection presents papers of conference series "International Conference on Amphibious and Floating Architecture, Design and Engineering (ICAADE)" organized by the Institute for Floating Buildings (IfSB e.V.) and the Faculty of Architecture, Civil Engineering and Urban Planning at Brandenburg University of Technology Cottbus-Senftenberg (BTU).}, subject = {Schwimmendes Bauwerk; Geb{\"a}udewert; Bauphysik; Building physics; Building value; Floating building; Schwimmendes Bauwerk; Geb{\"a}udewert; Bauphysik}, language = {mul} } @article{RadushevKarkossaBergetal.2024, author = {Radushev, Veselina and Karkossa, Isabel and Berg, Janina and Bergen, Martin von and Engelmann, Beatrice and Rolle-Kampczyk, Ulrike and Bl{\"u}her, Matthias and Wagner, Ulf and Schubert, Kristin and Rossol, Manuela}, title = {Dysregulated cytokine and oxidative response in hyperglycolytic monocytes in obesity}, series = {Frontiers in Immunology}, volume = {15}, journal = {Frontiers in Immunology}, publisher = {Frontiers}, address = {Lausanne}, issn = {1664-3224}, doi = {10.3389/fimmu.2024.1416543}, year = {2024}, abstract = {Obesity is associated with a plethora of health complications, including increased susceptibility to infections or decreased vaccine efficacy, partly due to dysregulated immune responses. Monocytes play a crucial role in innate immunity, yet their functional alterations in obesity remain poorly understood. Here, we employed proteomic and metabolomic analyses to investigate monocyte characteristics in individuals with overweight, obesity, impaired glucose tolerance (IGT), and type 2 diabetes (T2D), compared to lean donors. Our results revealed distinct molecular signatures in monocytes from individuals with obesity, with significant alterations in pathways related to metabolism, cellular migration, and phagocytosis. Moreover, LPS-induced activation of monocytes unveiled heightened metabolic reprogramming towards glycolysis in subjects with obesity accompanied by dysregulated cytokine responses and elevated oxidative stress. Additionally, monocytes from donors with obesity exhibited increased lipid droplet accumulation. These findings shed light on the immunometabolic dysregulation underlying obesity-associated immune dysfunction, highlighting potential targets for therapeutic intervention.}, subject = {Monocytes; Fettsucht; Glykolyse; Monazyt; Stoffwechsel; Immunsystem; Immunometabolism; Respiratory burst; Obesity; IL-8}, language = {en} } @article{BembnistaGailing2024, author = {Bembnista, Kamil and Gailing, Ludger}, title = {The socio-spatiality of energy borderlands : multidimensional discursive practices regarding the Tur{\´o}w coal mine conflict}, series = {Journal of Borderlands Studies}, volume = {39}, journal = {Journal of Borderlands Studies}, number = {3}, publisher = {Taylor \& Francis}, address = {London}, issn = {2159-1229}, doi = {10.1080/08865655.2024.2330058}, year = {2024}, abstract = {An important component regarding the climate and energy crisis and its implications is the upheaval in energy production and supply as a fundamental transition in favor of low-carbon energy. The regions of the German-Polish border area studied in this paper encounter different development paths of coal and renewable energy sources. One emblematic recent case in this context is the legal dispute over the closure of the Tur{\´o}w coal mine. The authors investigate to what extent these energy spaces develop between European frameworks, nation-state policies as well as regional and local implementations. The analysis is based on regional discourses of German and Polish newspapers with the highest circulation in the border area. The combination of a discourse analysis and a multidimensional, space-theoretical approach overcomes a simplification of socio-spatial strategies enables a differentiation of the borderlands. Additionally, the examination of the discursive practices provides insights on scaling and network activities as well as on strategies of placeprotection in socio-material energy spaces in the German-Polish borderland.}, subject = {Energy borderlands; Transition in coal regions; Multidimensional spatial analysis; Polish-German border; Energie-Grenzgebiete; {\"U}bergang in Kohleregionen; Multidimensionale Raumanalyse; Polnisch-Deutsche Grenze; Deutschland; Polen, Turow (Wroclaw); Grenzgebiet; Energieerzeugung; Erneuerbare Energie; Kohlenbergbau; Regionalanalyse; Energiepolitik}, language = {en} } @book{Ceritoglu2023, author = {Ceritoglu, Erdogan Onur}, title = {Salvaging Buildings : reclaiming a livelihood from the excesses of Istanbul's mass urbanization}, publisher = {transcript}, address = {Bielefeld}, isbn = {978-3-8394-6924-8}, doi = {10.14361/9783839469248}, publisher = {BTU Cottbus - Senftenberg}, pages = {268}, year = {2023}, abstract = {Turkey's demolition waste management is, to a great extent, dependent on {\c{c}}{\i}kmac{\i}s (reclaimers) who salvage condemned buildings for raw materials and architectural elements. Its urbanization history is full of key moments marked by building demolitions, which became a necessary material resource for informal urbanization. As early as the 1970s, the {\c{c}}{\i}kmac{\i}s helped the gecekondus [squatter houses] by supplying second-hand building materials and construction loans. They managed to turn a lack of infrastructure into an advantage and remain very adaptable to the ever-changing conditions of neo-liberalized urbanization. They depend on solidarity networks and other informal resources. Assemblage thinking helps to redefine the concept of informality, understand the relational dynamics between various actors, and focus on the agency of materials. The empirical data gained from 'follow the thing' ethnographic research in Turkey and Georgia reveals the double lives of {\c{c}}{\i}kmac{\i}s who move between village and city. Additionally, by following the example of a reclaimed window frame's journey from Istanbul to Tbilisi, we can more clearly see the second-hand trade network in the context of urbanization and incremental architecture. In the context of waste's materiality, the empirical part of the research shows the symbiotic relationship between {\c{c}}{\i}kmac{\i}s and the discarded demolition materials.}, subject = {Architecture; Urbanisation; Building salvage; Informality; Turkey; Architektur; Urbanisierung; Bergung von Geb{\"a}uden; Informalit{\"a}t; T{\"u}rkei; Istanbul; Verst{\"a}dterung; Stadtentwicklung; Geb{\"a}ude; Abbruch; Bauabfall; Recycling}, language = {en} } @book{Yadollahi2023, author = {Yadollahi, Solmaz}, title = {Urban heritage planning in Tehran and beyond : sequences of disrupted spatial-discursive assemblages}, publisher = {transcript}, address = {Bielefeld}, isbn = {978-3-8394-7162-3}, doi = {10.1515/9783839471623}, publisher = {BTU Cottbus - Senftenberg}, pages = {268}, year = {2023}, abstract = {Despite the impact of ideological rigidity, the primary challenge of heritage planning in Tehran and beyond lies not in the dominance of an inflexible Authorized Heritage Discourse, but rather in the absence of stable spatial-discursive and administrative structures. Solmaz Yadollahi maps the historical trajectory of conservation and urban heritage planning in Iran, depicting a discursive-spatial assemblage that tends to knock down its accumulated resources. This is in line with Katouzian's portrayal of Iran as a pick-axe society. Residing within this society, the studied assemblage strives to deconstruct the prevailing structures and usher in a fresh one, paradoxically perpetuating the very cycle it seeks to escape.}, subject = {Assemblage theory; Urban studies; Urban heritage; Qualitative social research; Iran; Assemblage Theorie; Qualitative Sozialforschung; Stadtforschung; St{\"a}dtisches Kulturerbe; Iran; Territorialstaat; Stadtverwaltung; Qualitative Sozialforschung; Kulturerbe; Denkmalpflege; Teheran; Sozialraum; Altstadtsanierung; Baudenkmal}, language = {en} } @inproceedings{Schmitt2023, author = {Schmitt, Rebecca Erika}, title = {The geometric design of Christoph Dientzenhofer's 'radical' vaults}, doi = {10.26127/BTUOpen-6408}, year = {2023}, abstract = {Christoph Dientzenhofer (1655-1722) is considered one of the most important Baroque master builders of Central Europe. From his extensive architectural oeuvre, a group of six church buildings with geometrically complex forms stands out, recognised by architectural historians as particularly innovative and influential. These churches, located in Bohemia (Czech Republic), and often collectively referred to as the 'radical', 'dynamic', 'Guarinesque', or simply 'Bohemian' group, are: St. Joseph in Obořiště (1702-11), the Castle Church in Smiřice (1702-11), St. Nicholas in the Lesser Town of Prague (1703-11), St. Clare in Cheb (1707-11), St. Margaret in Břevnov (1708-16), and the Church of the Holy Assumption in Nov{\´a} Paka (1709-24). The brick vaults of these six buildings, sequences of oval domes and double-curved vault areas, are of particular interest for building research. In this study, the geometric design of the vaults of Dientzenhofer's 'radical' churches is documented, analysed, and compared using 3D laser scans of the buildings as primary source. The 3D models generated from the scans enable a geometric analysis through the method of reverse geometric engineering, breaking down the vaults' complex three-dimensional forms into their basic two-dimensional components: segments of circles with different radii and orientations, curved in one or two directions. These forms can be found in the architectural and stereotomic treatises that were widespread at the time. By comparing the vault geometry of the six churches with each other and with the geometric concepts discussed in the treatises, general statements can be made about the architect's design choices. On the basis of this investigation, hypotheses are made about the design and underlying geometric ideas of the vaults of Dientzenhofer's 'radical group', and the results are placed in context.}, subject = {Geometric Design; Brick Vault; Christoph Dientzenhofer; Reverse Engineering; Stereotomy; Geometrischer Entwurf; Backsteingew{\"o}lbe; Reverse Engineering; Stereotomie; Dietzenhofer, Christoph; Kirchenbau; Baugestaltung; Gew{\"o}lbe; Ziegel; Geometrie; Dreidimensionales Modell}, language = {en} } @inproceedings{Schmitt, author = {Schmitt, Rebecca Erika}, title = {Geometric design and construction of a Late Baroque brick vault : Kilian Ignaz Dientzenhofer's Benedictine Church of the Holy Cross and St. Hedwig at Legnickie Pole}, doi = {10.26127/BTUOpen-5905}, abstract = {This paper investigates the case study of Kilian Ignaz Dientzenhofer's church of St. Hedwig in the Polish region of Silesia. The building, a popular pilgrimage church, is known in the history of art and architecture as a Late Baroque jewel with a curious design and famous frescoes. While the shape of the building and its vault has led to different interpretations in the past, its geometry has not yet been analysed on a reliable basis. Moreover, the construction of the brick vault has not yet been subject to scientific research. In order to investigate these aspects, a 3D laser scan of the vault's extrados and intrados was utilised as the primary source. The 3D model generated from the scan not only enabled the detailed description of structural ribs, brick patterns and construction details on the extrados, but also made a geometrical analysis using reverse geometric engineering possible. The results show a geometric design of the vault surfaces as well as double-curved arches based on simple plane circle segments. This clear geometric definition of the vault is associated with a remarkable simplicity of construction method and centering. In the context of other vault designs by members of the Dientzenhofer professional circle of master builders and architects, the vault of St. Hedwig can be seen as both a continuation and an improvement in terms of geometric design and construction details.}, subject = {Kilian Ignaz Dientzenhofer; Legnickie Pole; Geometric design; Construction; Vault; Geometrischer Entwurf; Konstruktion; Gew{\"o}lbe; Dientzenhofer; Kilian Ignaz; Wahlstatt (Liegnitz); Kirchenbau; Gew{\"o}lbe; Dreidimensionale Rekonstruktion; Geometrie}, language = {en} } @article{Yadollahi2020, author = {Yadollahi, Solmaz}, title = {Reflections on the past and future of urban conservation in Iran}, series = {Built heritage}, volume = {4}, journal = {Built heritage}, number = {19}, publisher = {Springer}, address = {Heidelberg}, issn = {2662-6802}, doi = {10.1186/s43238-020-00019-1}, year = {2020}, abstract = {The material authenticity of cultural heritage has been questioned by societies in which the modern paradigm of conservation has not developed from within the native culture. This paper examines the philosophical and practical traditions in Iran regarding the materiality and authenticity of past structures. By reviewing the emergence of the Western conservation paradigm in Iran, this paper highlights two key factors: the rapidness of this paradigm shift and the remarkable contradiction between the new and old paradigms. By borrowing the Deleuzo-Guattarian concept of a 'body without organs' (BwO), this paper problematises the rapidness and radicality of the paradigm shift in Iran. It suggests exploring the under-investigated possibilities between the pre-modern and modern paradigms to address the gap between native circumstances and Western standards.}, subject = {Cultural heritage; Authenticity; Iran; Conservation; Kulturelles Erbe; Authentizit{\"a}t; Denkmalschutz; Iran; Kulturerbe; Stadt; Denkmalpflege; Denkmalschutz; Authentizit{\"a}t; Materialit{\"a}t}, language = {en} } @article{RosenGribat2023, author = {Rosen, Christian and Gribat, Nina}, title = {Comparing hybrid urbanisms in the global south : water delivery configurations in Peru and Ghana}, series = {Urban Planning}, volume = {8}, journal = {Urban Planning}, number = {4}, publisher = {Cogitation}, address = {Lissabon}, issn = {2183-7635}, doi = {10.17645/up.v8i4.7155}, pages = {340 -- 350}, year = {2023}, abstract = {Urban development processes in the Global South (and North) are often described as characterized by formal and informal practices of different actors and their respective material realities. In critical urban studies, the disposition for this binary conception of formal and informal urbanisms has been discussed for many years. To a certain extent, these sometimes align rather problematically with contrasting notions of the "structural" versus the "everyday." In this article, we explore an understanding of formal and informal urban practices (and respectively "structure" and "everyday") as always interrelated, and we develop a methodology for a comparative examination of such hybrid urbanisms. In doing so, we address a missing link in the surging theoretical debate on comparative/southern urbanisms, which has rarely been substantiated by methodological explorations. The adapted concept of "delivery configurations" combines analyses of actor networks, material realities, rules and regulations, discourses, and heterogenous arrays of urban practices of negotiating these. However, bringing together local particularities and structural commonalities and exploring their interrelation only provides a basis for understanding case-specific complexities. We argue that embedding the analysis in a multi-scalar comparative framework can further its analytical rather than descriptive attributes and provide deeper insights into issues such as social inequality. To illustrate our methodological contribution, we provide first insights from a comparative research project of water delivery in different neighbourhoods in the secondary cities of Sunyani (Ghana) and Arequipa (Peru). We highlight the practical challenges of comparing diverse urban contexts and examining the rather complex relationships between infrastructure delivery, urban development, and social inequality.}, subject = {Water; Hybridity; Infrastructures; Multi-scalar comparison; Peru; Ghana; Wasser; Infrastruktur; Multiskalarer Vergleich; Infrastruktureinrichtungen}, language = {en} } @incollection{SchmittWendland2021, author = {Schmitt, Rebecca Erika and Wendland, David}, title = {Untersuchung der geometrischen Konzeption der Gew{\"o}lbe der Basilika Vierzehnheiligen auf Basis von 3D-Scanningdaten im Kontext der Stereotomie}, series = {Materialgerecht konstruiert!?! Tagungsband der F{\"u}nften Jahrestagung der Gesellschaft f{\"u}r Bautechnikgeschichte 10. bis 11. Juni 2021}, booktitle = {Materialgerecht konstruiert!?! Tagungsband der F{\"u}nften Jahrestagung der Gesellschaft f{\"u}r Bautechnikgeschichte 10. bis 11. Juni 2021}, publisher = {Michael Imhof Verlag}, address = {Petersberg}, isbn = {978-3-7319-1253-8}, doi = {10.26127/BTUOpen-6411}, publisher = {BTU Cottbus - Senftenberg}, pages = {105 -- 121}, year = {2021}, abstract = {Betrachtet wird die geometrische Konzeption der Gew{\"o}lbe der von Balthasar Neumann entworfenen Wallfahrtskirche Vierzehnheiligen. Ausgehend vom gebauten Objekt und basierend auf 3D-Scanningdaten, werden mithilfe der Methode des Reverse Geometric Engineering die geometrischen Eigenschaften des Gew{\"o}lbes untersucht und die Konzepte rekonstruiert, die bei der Planung zur Anwendung gekommen sein m{\"u}ssen. Dabei werden die Abteikirche Banz und die Hofkirche der Residenz W{\"u}rzburg als Vergleichsbauten mit einbezogen. Die Entwurfsmethoden werden in ihrem Zusammenhang mit den zeitgen{\"o}ssischen Traktaten der Stereotomie und Architektur, sowie mit bekannten Planungspraktiken bei geometrisch komplexen Bauten betrachtet; dabei wird auch der Bezug zu den Gew{\"o}lbeentw{\"u}rfen des italienischen Barockarchitekten Guarino Guarini diskutiert.}, subject = {Geometrischer Entwurf; Gew{\"o}lbe; Vierzehnheiligen; Balthasar Neumann; Geometric design; Vault; Fourteen Holy Helpers; Reverse engineering; Baustoffkunde und -chemie; Baukonstruktionen; Geschichte der Baukonstruktionen und -technologien}, language = {de} } @article{AhmedStraub2025, author = {Ahmed, Naveed and Straub, Andrea}, title = {A practical approach for measuring Chemical Oxygen Demand (COD) of Fats, oils, and grease (FOG) using tween 80 in wastewater}, series = {ChemEngineering}, volume = {9}, journal = {ChemEngineering}, number = {6}, publisher = {MDPI}, address = {Lausanne}, issn = {2305-7084}, doi = {10.3390/chemengineering9060138}, year = {2025}, abstract = {This study aims to estimate the organic load of oily wastewater by using Chemical Oxygen Demand (COD) measurements, addressing the analytical challenges posed by the hydrophobic, nonpolar, and often emulsified nature of Fats, oil and grease (FOG). This study established a reproducible and practical methodology for measuring COD in wastewater containing FOG at a laboratory scale, utilizing the nonionic surfactant T80 as a solubilizing and emulsifying agent. Precise gravimetric methods were employed to measure the mass of T80 (indirectly from volume (100-1400 µL/L)) added, and its correlation with COD was established. A strong linear relationship (R2 = 0.993-0.998) between T80 concentration and COD confirmed its stability and suitability as a calibration standard. Experiments with sunflower (1-4 mL/L) and rapeseed oils (1-3 mL/L) showed that COD increased linearly with oil concentration and stabilized after prolonged mixing (96-120 h), indicating complete emulsification and micellar equilibrium. Even under T80 overdose conditions, COD retained linearity (R2 > 0.99), though absolute values were elevated due to excess surfactant oxidation. Temperature variation (5 and 20 °C) and mild heating of coconut fat (30-32 °C) showed no significant effect on COD reproducibility, indicating that mixing time and surfactant dosage are the dominant factors influencing measurement accuracy. Overall, the study establishes T80 as a reliable surfactant for solubilizing oily matrices, providing a consistent and repeatable approach for COD assessment of wastewater containing FOG. The proposed method offers a practical basis and a step towards environmental monitoring and process control in decentralized and industrial wastewater treatment systems.}, subject = {Chemical oxygen demand; Fat; Oil; Wastewater; Tween 80}, language = {en} } @inproceedings{Lengenfeld2022, author = {Lengenfeld, Jonas}, title = {The complex masonry of the Sch{\"o}nburg Castle Keep chimney system (1201 CE) in the context of contemporary examples}, doi = {10.26127/BTUOpen-5980}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-59801}, year = {2022}, abstract = {High Medieval chimneys, although often the focal point of contemporary representative buildings, are rarely a topic of construction history. More often they appear in art or architectural history where they are discussed regarding their style and ornamentation. It is however worthwhile to examine these important representative objects with the tools of the construction historian. In them, we can find important information regarding the contemporary craftsmanship and skills. Based on extensive firsthand examinations and building archaeology this paper aims to discuss the planning and building process of the highly complex cut-stone chimney system in the keep of Sch{\"o}nburg Castle (1201 CE) using new methods of reverse engineering.}, subject = {Chimney; Medieval; Reverse engineering; Building archaeology; Kamin; Mittelalter; Bauforschung; Sch{\"o}nburg; Werkstein; Sch{\"o}nburg Naumburg, Saale; Kamin; Geschichte}, language = {en} } @book{OPUS4-7027, title = {Hybrid urbanisms in secondary cities of the global south : insights from urban planning and infrastructure delivery in Ghana and Peru}, editor = {Rosen, Christian and Gribat, Nina}, publisher = {Routledge}, address = {London}, isbn = {978-1-003-51113-7}, doi = {10.4324/9781003511137}, publisher = {BTU Cottbus - Senftenberg}, pages = {194}, year = {2025}, abstract = {This book presents the concept of Hybrid Urbanisms aiming to deconstruct the still-existing and often critiqued dualism of formalised and informalised practices in urban planning and infrastructure delivery. Using an innovative perspective, the book addresses this issue by focusing on the complex configurations in which both forms always co-exist and compete as powerful social constructs. It unveils the juxtaposition, simultaneity, dependency and intertwining of in-/formalised practices and highlights the relevance of this perspective to better understand urban development, especially in the global South. At the same time, the book focuses on secondary cities of Ghana and Peru that are often overlooked in the existing literature but play a relevant role in global urbanisation quantitively and qualitatively. In offering a comparative perspective on two very diverse geographical contexts, ten empirical studies are framed by a conceptualisation of 'Hybrid Urbanisms' and a concluding systematisation of perspectives on this central aspect of urban development. Taken together, this volume makes an innovative contribution on how to produce new and more diverse urban theories of cities of the global South. This book is essential for scholars, students and practitioners in the fields of urban planning, urban studies, infrastructure studies and international cooperation alike. In addition, it will be of interest to those in the fields of urban sociology, public policy, urban geography and development studies. This publication was supported by funds from the Publication Fund for Open-Access Monographs of the Federal State of Brandenburg, Germany and by the Faculty of Architecture, Civil Engineering and Urban Planning of Brandenburg University of Technology Cottbus-Senftenberg.}, subject = {Geography; Global development; Urban studies}, language = {en} } @incollection{SchmittWendland, author = {Schmitt, Rebecca Erika and Wendland, David}, title = {The geometric design of the "Guarinesque" vaults in Banz and Vierzehnheiligen in relation to the treatises of stereotomy}, doi = {10.26127/BTUOpen-5904}, publisher = {BTU Cottbus - Senftenberg}, abstract = {Johann Dientzenhofer's Banz Abbey Church (1710-1718) and Balthasar Neumann's church of Vierzehnheiligen (1743-1772), both located in Upper Franconia (Germany), are characterised by their masonry vaults, sequences of oval domes separated by double-curved arches. This Late Baroque architecture has been called "Guarinesque"; however, the conceptual connection between the vaults and Guarino Guarini's architecture remains to be thoroughly investigated. This paper resumes the discussion about the geometric definitions of these vaults using the modern methods of geometric analysis and reverse geometrical engineering, based on 3D laser scanning. The analysis of these scans reveals a design process based on plane circle segments and ovals, while more complex geometric procedures are not necessary to describe the vaults. Further, the relationship between these designs and the procedures of geometric design described in the treatises of stereotomy since the 16th century can be shown. On this background, the relation to Guarini's Architettura Civile (1737) is discussed.}, subject = {Balthasar Neumann; Johann Dientzenhofer; Vierzehnheiligen; Banz; Vault; Gew{\"o}lbe; Klosterkirche Banz (Bad Staffelstein); Wallfahrtskirche Vierzehnheiligen (Staffelstein); Kirchenbau; Gew{\"o}lbe; Dreidimensionale Rekonstruktion; Geometrie}, language = {en} } @incollection{WendlandGielen, author = {Wendland, David and Gielen, Mark}, title = {The design and construction of the vaults in Notre-Dame in Paris and the development of medieval vaulting and stereotomy : surveys, analyses and experiments}, doi = {10.26127/BTUOpen-6060}, publisher = {BTU Cottbus - Senftenberg}, abstract = {Among the many innovative church constructions in the {\^I}le-de-France during the twelfth century that immediately followed the ground-breaking new building of the abbey church of Saint-Denis, the high vaults in the cathedral of Notre-Dame in Paris mark a turning point - both in sheer dimensions and in their quality of execution as stone constructions. On the other hand, some solutions in design and construction that can be observed in these vaults remain unique within the dynamic development of Gothic vaulting in the great cathedrals built in the following years. On closer view it turns out that the general design of the vault as well as its construction details are hardly understood until now, mainly because they have been overlooked in a unifying perspective on Gothic architecture coined by the idealistic view of the Gothic Revival in the nineteenth century. Further, the particular relation between vault design and stereotomy needs to be clarified, and its significance needs to be understood.}, subject = {Vault; Medieval architecture; Gothic; Notre-Dame de Paris; Speyer Cathedral; Gew{\"o}lbe; Mittelalterliche Architektur; Gotik; Dom zu Speyer; Notre-Dame (Paris); Kirchenbau; Gew{\"o}lbe; Gotik}, language = {en} } @article{WeissLiedtkeStefan2025, author = {Weiss, Romano and Liedtke, Victoria and Stefan, R{\"o}diger}, title = {Cannabidiol does not cause DNA double-strand breaks in a human liver-derived cell model}, series = {Journal of Cannabis Research}, volume = {8}, journal = {Journal of Cannabis Research}, number = {12}, publisher = {BMC}, address = {London}, issn = {2522-5782}, doi = {10.1186/s42238-025-00365-w}, year = {2025}, abstract = {Cannabidiol (CBD) is a non-psychoactive cannabinoid with potential therapeutic applications, including anti-inflammatory, analgesic, and anticancer effects. However, experts raised concerns about its potential to induce DNA damage and chromosomal aberrations at low concentrations. Notably, these studies used liver cell lines, which may not fully reflect the metabolic processing of CBD, potentially limiting the generalizability of their findings. This study investigated the short time effects of CBD on DNA double-strand breaks (DSBs) and proliferation in the human liver-derived cell line HepG2. HepG2 cells were treated with CBD (5 - 50 μM, 3 - 72h incubation). To investigate potential imbalances in the expression of cannabinoid receptors 1 and 2 (CB1 / CB2) within HepG2 cells, we examined their expression using Western blot analysis. We hypothesized that such an imbalance could be associated with pathogenic processes. Double-strand breaks were then detected (5 μM Etoposide (ETP) served as positive control) via indirect immunofluorescence analysis using H2AX and 53BP1 antibodies, followed by quantification of DSB foci. Expression of CB2 but not CB1 was downregulated by 30 \% in HepG2 cells after exposure to 5 μM CBD (24h incubation; 0.05) and 70 \% downregulated after exposure to 50 μM CBD (24h incubation; 0.01). This effect was dose-dependent. Whilst ETP induced dose dependent DSBs, we could not confirm findings by others that CBD significantly increases the number of H2AX and 53BP1 foci between 5 μM and 50 μM (3h incubation; 0.05). In our model, CBD stimulated the cells, as confirmed by modulation of CB2 expression as well as changes in intracellular cAMP. Our results show that CBD in ranges between 5 μM to 50 μM does not significantly increase the amount of DNA double strand breaks in HepG2 cells compared to the control. However, we did observe a significant reduction in cell proliferation and a significant increase in intracellular cAMP levels following CBD treatment.}, subject = {Cannabidiol; DNA damage; Proliferation; CAMP; HepG2}, language = {en} } @article{OttoPuchol‑RoyoOrtega‑Legarretaetal.2024, author = {Otto, Pascal and Puchol‑Royo, Roser and Ortega‑Legarreta, Asier and Tanner, Kristie and Tideman, Jeroen and Vries, Sjoerd‑Jan de and Pascual, Javier and Porcar, Manuel and Latorre‑P{\´e}rez, Adriel and Abendroth, Christian}, title = {Multivariate comparison of taxonomic, chemical and operational data from 80 different full‑scale anaerobic digester‑related systems}, series = {Biotechnology for Biofuels and Bioproducts}, volume = {17}, journal = {Biotechnology for Biofuels and Bioproducts}, publisher = {BMC}, address = {London}, issn = {2731-3654}, doi = {10.1186/s13068-024-02525-1}, year = {2024}, abstract = {The holistic characterization of different microbiomes in anaerobic digestion (AD) systems can contribute to a better understanding of these systems and provide starting points for bioengineering. The present study investigates the microbiome of 80 European full-scale AD systems. Operational, chemical and taxonomic data were thoroughly collected, analysed and correlated to identify the main drivers of AD processes. The present study describes chemical and operational parameters for a broad spectrum of different AD systems. With this data, Spearman correlation and differential abundance analyses were applied to narrow down the role of the individual microorganisms detected. The authors succeeded in further limiting the number of microorganisms in the core microbiome for a broad range of AD systems. Based on 16S rRNA gene amplicon sequencing, MBA03, Proteiniphilum, a member of the family Dethiobacteraceae, the genus Caldicoprobacter and the methanogen Methanosarcina were the most prevalent and abundant organisms identified in all digesters analysed. High ratios for Methanoculleus are often described for agricultural co-digesters. Therefore, it is remarkable that Methanosarcina was surprisingly high in several digesters reaching ratios up to 47.2\%. The various statistical analyses revealed that the microorganisms grouped according to different patterns. A purely taxonomic correlation enabled a distinction between an acetoclastic cluster and a hydrogenotrophic one. However, in the multivariate analysis with chemical parameters, the mainclusters corresponded to hydrolytic and acidogenic microorganisms, with SAOB bacteria being particularly important in the second group. Including operational parameters resulted in digester-type specific grouping of microbes. Those with separate acidification stood out among the many reactor types due to their unexpected behaviour. Despite maximizing the organic loading rate in the hydrolytic pretreatments, these stages turned into extremely robust methane production units. From 80 different AD systems, one of the most holistic data sets is provided. A very distinct formation of microbial clusters was discovered, depending on whether taxonomic, chemical or operational parameters were combined. The microorganisms in the individual clusters were strongly dependent on the respective reference parameters.}, subject = {Anaerobic digestion; 16S rRNA sequencing; Core microbiome; Multivariate analysis; Parameter dependency; G{\"a}rung; Mikrobiom ; Multivariate Analyse; Laborparameter}, language = {en} } @article{KimGerstbergerAslietal.2025, author = {Kim, Dongsuk and Gerstberger, Ulf and Asli, Majid and H{\"o}schler, Klaus}, title = {U-Net Driven Semantic Segmentation for Detection and Quantification of Cracks on Gas Turbine Blade Tips}, series = {Results in Engineering}, volume = {29}, journal = {Results in Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2590-1230}, doi = {10.1016/j.rineng.2025.108864}, year = {2025}, abstract = {Crack detection and quantification on gas turbine blades is crucial for component validation during the development phase and for operational efficiency in service, as unexpected cracks can compromise blade integrity and lead to early engine removals. Gas turbine blades operate under extreme thermal and mechanical stresses, making them particularly susceptible to crack formation. At the same time deterministic predictions of crack formation are subject to high uncertainty in material data and actual loading conditions. Accurate detection and quantification of cracks, therefore, is essential for the validation and calibration of life predictions in order to prevent in-service failures, to extend component lifespan, and to reduce maintenance costs. This study introduces a U-Net based semantic segmentation model designed to automate crack detection on turbine blade tips. The model was trained on a dataset of 210 surface images with and without evidence of cracks, each divided into 128  ×  128 pixel patches. Data augmentation techniques were applied to address the class imbalance between cracked and non-cracked pixels. The U-Net architecture, optimized with a Dice loss function, achieved a validation IoU of 0.7557, along with approximately 85\% recall and precision in identifying cracked pixels. The pixel-based accuracy of the model primarily affects the quantification of cracks rather than their identification. A sliding window pipeline was implemented to extend the model's applicability, enabling segmentation of entire blade tip images for comprehensive crack localization. While the model may occasionally miss low-contrast cracks, it holds potential as a supplementary tool for manual inspection as part of the life prediction validation. By providing automated crack localization and quantification, the model can assist in analyzing crack characteristics relative to engine operating conditions.}, subject = {Crack detection; Semantic segmentation; Gas turbine blade; U-Net; Deep learning; Convolutional neural network}, language = {en} } @article{OleynikRyzhakSchlipfetal.2025, author = {Oleynik, Paul and Ryzhak, Diana and Schlipf, Jon and Alvarado Chavarin, Carlos and Yamamoto, Yuji and Berkmann, Fritz and Ratzke, Markus and Fischer, Inga Anita}, title = {Influence of illumination conditions on photoluminescence enhancement in an Al/Si/Ge metasurface}, series = {Optics Express}, volume = {34}, journal = {Optics Express}, number = {1}, publisher = {Optica Publishing Group}, address = {Washington D.C.}, issn = {1094-4087}, doi = {10.1364/OE.577751}, pages = {78 -- 86}, year = {2025}, abstract = {Strong field enhancement supported by metasurfaces at resonance can be used to control and enhance the spontaneous emission rate of emitters. This is particularly relevant for emitters with comparatively low quantum yield such as germanium. Here, we investigate the µ-photoluminescence response obtained from a hybrid metasurface comprising a square lattice of Al/Si/Ge pillars. We explore how variations in excitation energy, excitation intensity and number of excited meta-atoms affect the spectral dependence of the photoluminescence signal and, in particular, the contribution of the metasurface to it. Our metasurface exhibits a magnetic dipole collective lattice resonance, whose contribution to the photoluminescence signal increases with increasing number of excited meta-atoms. Measuring only one metasurface under different illumination conditions can potentially be an alternative approach to probe the transition between finite-size effects and collective effects.}, subject = {Field enhancement; Germanium; Light emitting diodes; Photonic crystals; Quantum light sources; Scanning electron microscop}, language = {en} } @article{MalkRiedelHinzetal.2025, author = {Malk, Konrad and Riedel, Ramona and Hinz, Christoph and Fischer, Thomas and Martienssen, Marion}, title = {Adsorption of phosphonates to iron- or aluminum-based flocculants in wastewater treatment}, series = {Water}, volume = {18}, journal = {Water}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w18010116}, year = {2025}, abstract = {In this study, we investigated the impact of varying iron (Fe) and aluminum (Al) contents on the adsorption of phosphonates to activated sludge. Phosphonates originating from household applications account for up to 40\% of the non-reactive dissolved phosphorus in domestic sewage treatment plants and thus can contribute to the eutrophication of water bodies. Although these substances are not readily degradable, substantial quantities, ranging from 40\% to more than 90\%, are removed by sludge adsorption. The results demonstrate a strong correlation between the adsorption of aminophosphonates and the Fe3+ content of the sludge. The maximum phosphonate loadings were 5.94 mmol g-1 Fe3+ for ATMP, 4.94 mmol g-1 Fe3+ for EDTMP, 4.74 mmol g-1 Fe3+ for DTPMP, and 2.25 mmol g-1 Fe3+ for glyphosate. In contrast to pure ferric hydride flocs, the adsorption of phosphonates was approximately threefold higher when the hydroxides were located within activated sludge flocs. It is concluded that native sludge flocs provide larger iron surfaces than ferric hydroxide alone. Based on the weight of the adsorbents, aluminum salts were four times less efficient than ferric salts. In sludge without ferric or aluminum hydroxides, phosphonate adsorption was negligible.}, subject = {Adsorption; Activated sludge; Ferrous oxide; Phosphonates; Wastewater treatment}, language = {en} } @article{SenguelReiterLotfietal.2025, author = {Seng{\"u}l, Akant and Reiter, Sebastian and Lotfi, Zahra and Efremenko, Julia and Laroussi, Arwa and Corley-Wiciak, Agnieszka Anna and Ratzke, Markus and Mirsky, Vladimir M. and Wenger, Christian and Fischer, Inga Anita}, title = {Titanium nitride plasmonic nanohole arrays with polymer coating : optical properties and their humidity-induced modifications}, series = {Optical Materials Express}, volume = {16}, journal = {Optical Materials Express}, number = {2}, publisher = {Optica Publishing Group}, address = {Washington D.C.}, issn = {2159-3930}, doi = {10.1364/OME.578871}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-72739}, pages = {184 -- 196}, year = {2025}, abstract = {The use of titanium nitride (TiN) for the fabrication of plasmonic structures such as nanohole arrays (NHAs) can enable their integration into optoelectronic devices on the silicon (Si) platform, for example, for the realization of on-chip chemical sensors and biosensors based on refractometric transduction. With a corresponding functionalization of the TiN nanohole arrays, these ultra-compact devices can be utilized in the development of various affinity sensors and sensor systems, such as cost-effective electronic noses for the early detection of gases in the food industry or agriculture. In this work, we focus on two types of coating for functionalization of TiN nanohole arrays: electrochemically synthesized poly-N-methylaniline and layer-by-layer deposited polyacrylic-acid/poly-allylamine (PAA/PAH). Our investigation comprises the experimental characterization of the optical properties of TiN nanhole arrays coated with polymer layers of different thicknesses as well as a comparison with simulation results. We demonstrate the potential of our setup sensing applications by measuring changes in optical properties of TiN nanohole arrays coated with PAA/PAH upon exposure to air of different humidity.}, subject = {Chemical sensors; Extraordinary optical transmission; Localized surface plasmon resonance; Optical coatings; Optical properties; Refractive index}, language = {en} } @article{SharmaRadomskyMathiazhaganetal.2025, author = {Sharma, Dikshant and Radomsky, Lukas and Mathiazhagan, Akilan and Asli, Majid and H{\"o}schler, Klaus and Mallwitz, Regine}, title = {Thermal analysis of metal foam integrated heatsink for electrified aircraft applications}, series = {International Journal of Thermofluids}, volume = {30}, journal = {International Journal of Thermofluids}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2666-2027}, doi = {10.1016/j.ijft.2025.101465}, year = {2025}, abstract = {Metal foams facilitate large heat dissipation in high-power dense systems such as power electronics for electrified propulsion application. This work addresses the cooling of a power semiconductor device with aluminium and copper metal foam integrated hybrid heatsink and its comparative analysis to a conventional finned heatsink using 0D and 3D modelling approach. Two-equation foam model in Fluent is utilized and the numerical approach is validated against experimental dataset. Inlet air velocity is varied such that the Darcy to turbulent regimes of the open-cellular foams are covered. Foam porosities from ∼ 0.85-0.95 with 10-20 PPI are investigated and the thermal performance of the heatsink is found to be independent of the foam material. High porosity (> 0.9), 20 PPI foams are found to aid forced-convection by improving the thermal resistance by more than 10\% against the 10 PPI counterparts. The hybrid heatsink outperforms the foam-based and conventional heatsink by 40\% and 15\% respectively when considering the reduction in junction temperatures, while the hydraulic resistance increases 10 times when compared to the conventional one. The 0D thermal resistance model is robust in predicting the junction temperatures for metal foam heatsinks with only a 5\%-6\% discrepancy for both the 50 W and 100 W heat load scenarios. The key and novel contribution of this study is the integration of detailed 3D simulations of a power electronics cooling environment with the development of a corresponding 0D thermal model. This approach not only eases the physical representation of the system but also enables the model to be extended to diverse heat load conditions.}, subject = {Electric propulsion; Electronics thermal management; Metal foam heatsink; Porous media; Forced convection}, language = {en} } @article{JuliaJuliaTobias2025, author = {Julia, Zscherneck and Julia, Binder and Tobias, Mettenberger}, title = {Rural network assemblages : disentangling egocentric networks of digital pioneers in peripheral German regions}, series = {Regional studies, regional science}, volume = {12}, journal = {Regional studies, regional science}, number = {1}, publisher = {Routledge}, address = {London}, issn = {2168-1376}, doi = {10.1080/21681376.2025.2594312}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-72787}, pages = {996 -- 1012}, year = {2025}, abstract = {Digital solutions are seen as promising ways of addressing current challenges in rural regions. Individual or group key actors accessing resources foster these developments through networks. In light of regional clustering and agglomeration effects on the one hand and increased virtual mobility on the other hand, assumptions about the spatiality of such networks are highly controversial. Our paper takes this as a point of departure, asking how spatiality is constructed in the networks of so-called 'digital pioneers' (DPs). The sampling process took place in two German rural regions with different preconditions for digital technology adoption, where we conducted egocentric network analysis and qualitative interviews. Employing the assemblage perspective, we analysed networks of 30 individuals in terms of the analytical categories of territoriality, stability and connectivity. Our findings distinguish between three important roles of network contacts: (1) multipliers in social networking, (2) users of the DP's products and services, as well as (3) close family members that are important in professional contexts. Although DPs are often deeply embedded in and feel attached to their region, networks vary significantly in their territorial radius, also including highly functional problem-solving contacts to distant places. Consequently, our evidence challenges static territorial models of innovation processes, advocating for processual and multidimensional perspectives that consider social networks and individual agency. Likewise, our study complements current research on rural governance by shifting the focus from key institutions and formal networks to less formally integrated actors and problem-solving networks.}, subject = {Qualitative network analysis; Assemblage; Bridging and bonding ties; Peripheral regions Germany}, language = {en} } @article{YangHenkeMoehlenkamp2025, author = {Yang, Yinghui and Henke, Markus and M{\"o}hlenkamp, Georg}, title = {Analytical investigation of short-circuit protection and post-fault operation in dual three-phase PMSMs for hybrid electric counter-rotating compressor applications}, series = {IEEE Access}, volume = {14}, journal = {IEEE Access}, publisher = {IEEE}, address = {New York}, issn = {2169-3536}, doi = {10.1109/ACCESS.2026.3658195}, pages = {17303 -- 17323}, year = {2025}, abstract = {The hybrid electric counter-rotating compressor (CRC) has the potential to improve power-specific fuel consumption in aircraft engines. However, due to its cascaded structure, a reduction or loss of driving power in a single compressor stage can significantly degrade the overall compressor performance. A short-circuit fault is a typical electrical failure in an electric motor that can lead to a complete loss of driving power. One innovative post-fault operation strategy is to utilize the braking capability of the failed motor at low speed to lock its corresponding compressor stage. In this way, the failed stage can function as a stator stage, still providing degraded flow-guiding capability and preventing reverse rotation. This article investigates the short-circuit protection strategy and post-fault operation of dual three-phase permanent magnet synchronous motors (DTP-PMSMs) for hybrid electric CRC applications. Analytical models are developed to characterize the post-fault behavior of the DTP-PMSM. Key design factors are defined, and their influence on post-fault performance is analyzed. Critical post-fault operating points are identified to evaluate and compare different protection strategies. Based on these results, an optimized shortcircuit protection strategy is proposed for DTP-PMSMs in CRC applications. Finally, the analytical findings and the proposed strategy are validated through simulation.}, subject = {Windings; Circuit faults; Rotors; Torque; Protection}, language = {en} } @article{MbuyaPawarJafarietal.2025, author = {Mbuya, Christel Olivier Lenge and Pawar, Kunal and Jafari, Mitra and Shafiee, Parisa and Okoye Chine, Chike George and Tarifa, Pilar and Dorneanu, Bogdan and Arellano-Garcia, Harvey}, title = {Tuning catalyst performance in methane dry reforming via microwave irradiation of nickel-silicon carbide systems}, series = {Journal of CO2 Utilization}, volume = {102}, journal = {Journal of CO2 Utilization}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-9820}, doi = {10.1016/j.jcou.2025.103270}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-72832}, year = {2025}, abstract = {The dry reforming of methane (DRM) is a promising route for converting greenhouse gases such as methane (CH4) and carbon dioxide (CO2) into valuable syngas, hydrogen (H2) and carbon monoxide (CO). However, traditional nickel (Ni)-based catalysts suffer from rapid deactivation due to carbon deposition and sintering, especially when supported on low thermal conductivity materials. In this work, a novel post-synthesis microwave irradiation (MIR) treatment is introduced to systematically optimize the performance of Ni - β - SiC and Ni - Ti - Cβ - SiC catalysts for DRM. Unlike previous studies that have used MIR during reaction or with different supports, this approach tunes the metal - support interactions and textural properties of Ni - β - SiC and Ni - Ti - Cβ - SiC catalysts by varying the MIR exposure time after catalyst synthesis. MIR post-treatment (10-25 s) increased the CH4 conversion to 65 \% and the CO2 conversions to 62 \% for Ni-β-SiC catalysts and improved the H₂/CO ratio to 0.80, with stable performance over 20 h. For Ni-Ti-Cβ-SiC, MIR (10-20 s) maintained CH4 conversion up to 60 \% and CO2 conversion to 58 \% over 20 h, while the untreated catalyst, though initially higher, deactivated rapidly. Excessive MIR (30 s) reduced performance for both catalyst types, underscoring the need for optimal exposure time. These findings demonstrate post-synthesis MIR provides a tuneable approach for enhancing both the activity and durability of Ni/SiC - based DRM catalysts through controlled modification of metal - support interactions. This work offers new insights for the design of robust catalysts aimed at greenhouse gas utilization and sustainable syngas production, with activity and stability enhancements linked to controlled changes in metal - support interactions.}, subject = {Carbon dioxide; Dry reforming; Methane; Microwave irradiation; Ni Silicon carbide catalysts}, language = {en} }