@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}, 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} } @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} } @incollection{JavedScheyttBamidietal., author = {Javed, Abdul Rehman and Scheytt, J. Christoph and Bamidi, Eswara Rao and Kallfass, Ingmar and Krishnegowda, Karthik and Kraemer, Rolf}, title = {Real100G.COM}, 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-5914}, publisher = {BTU Cottbus - Senftenberg}, pages = {231 -- 293}, 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.COM; PSSS; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} } @article{BahnsKopkow2023, author = {Bahns, Carolin and Kopkow, Christian}, title = {Physiotherapy for patients with hip and knee osteoarthritis in Germany: a survey of current practice}, doi = {10.1186/s12891-023-06464-0}, year = {2023}, abstract = {Osteoarthritis (OA) of the hip and the knee is common and leads to pain, stiffness and disability. Clinical practice guidelines (CPG) provide recommendations to assist healthcare professionals in clinical decision-making. Although evidence-based physiotherapy has been shown to be effective in the management OA, a gap between clinical practice and guideline recommendations exists. Little is known about OA management provided by physiotherapists in Germany and whether treatment aligns with CPGs. The objectives of this study were (1) to investigate the current physiotherapy practice in patients with hip and/or knee OA in Germany, (2) to evaluate physiotherapists' adherence to guideline recommendations and (3) to explore barriers and facilitators to guideline use.}, subject = {Osteoarthrosis; Knee; Hip; Physical therapy; Arthrose; H{\"u}ftgelenk; Knie; Osteoarthrose; Physikalische Therapie; Arthrose; Knie; H{\"u}fte; Physiotherapie}, 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{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{MarkovaNenovaEnglerCordetal.2023, author = {Markova-Nenova, Nonka and Engler, Jan O. and Cord, Anna F. and W{\"a}tzold, Frank}, title = {Will passive acoustic monitoring make result-based payments more attractive? A cost comparison with human observation for farmland bird monitoring}, doi = {10.1111/csp2.13003}, year = {2023}, abstract = {Result-based payments (RBPs) reward land users for conservation outcomes and are a promising alternative to standard payments, which are targeted at specific land use measures. A major barrier to the implementation of RBPs, particularly for the conservation of mobile species, is the substantial monitoring cost. Passive acoustic monitoring may offer promising opportunities for low-cost monitoring as an alternative to human observation. We develop a costing framework for comparing human observation and passive acoustic monitoring and apply it to a hypothetical RBP scheme for farmland bird conservation. We consider three different monitoring scenarios: daytime monitoring for the whinchat and the ortolan bunting, nighttime monitoring for the gray partridge and the common quail, and day-and-night monitoring for all four species. We also examine the effect of changes in relevant parameters (such as participating area, travel distance and required monitoring time) on the cost comparison. Our results show that passive acoustic monitoring is still more expensive than human observation for daytime monitoring. In contrast, passive acoustic monitoring has a cost advantage for nighttime as well as day-and-nighttime monitoring in all considered scenarios.}, subject = {Performance-based payments; Monitoring costs; PAM; ARU; AudioMoth; Monitoringkosten; Ergebnishonorierung; Naturschutz; Landwirtschaft; Monitoring; V{\"o}gel; Erfolgshonorar; Kostenvergleich}, language = {en} } @article{FrimpongKorantengOpoku2023, author = {Frimpong, Bernard Fosu and Koranteng, Addo and Opoku, Fosu Senior}, title = {Analysis of urban expansion and its impact on temperature utilising remote sensing and GIS techniques in the Accra metropolis in Ghana (1986-2022)}, doi = {10.1007/s42452-023-05439-z}, year = {2023}, abstract = {The Accra Metropolis of Ghana has experienced rapid urban expansion over the past decades. Agricultural and forest-lands have been transformed into urban/built-up areas. This study analysed urban expansion and its relationship with the temperature of Accra from 1986 to 2022. Multi-source datasets such as remote sensing (RS) and other ancillary data were utilised. Land use land cover (LULC) maps were produced employing the random forests classifier. Land surface temperature (LST) and selected d(RS) Indices were extracted. Regression techniques assessed the interplay between LST and remote sensing indices. The LULC maps revealed increasing trends in the urban/built-up areas at the expense of the other LULC types. The analysis from the LST and the RS indices revealed a direct relationship between temperature and urban/built-up areas and an inverse relationship between temperature and vegetation. Thus, spatial urban expansion has modified the urban temperature of Accra. The integrated utilisation of RS and GIS demonstrated to be an efficient approach for analysing and monitoring urban expansion and its relationship with temperature.}, subject = {Urban expansion; Change detection; Land use land cover; Regression; Remote sensing; St{\"a}dtische Expansion; Erkennung von Ver{\"a}nderungen; Landnutzung Landbedeckung; Temperatur; Fernerkundung; Accra; Stadt; Expansion; Landnutzung; Temperatur; Fernerkundung}, 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{LangnerSieberRietigetal.2023, author = {Langner, Thomas and Sieber, Tim and Rietig, Anja and Acker, J{\"o}rg}, title = {A phenomenological and quantitative view on the degradation of positive electrodes from spent lithium-ion batteries in humid atmosphere}, doi = {10.1038/s41598-023-32688-0}, year = {2023}, abstract = {The present study deals with the phenomenological observation of the corrosion of the positive electrode foil of lithium-ion batteries containing LiNi0.6Co0.2Mn0.2O2 (NMC) as cathode material. Due to the presence of moisture, localized water accumulation is formed on the NMC surface. The water absorbed by the electrolyte reacts with the NMC under Li+/H+ exchange and the resulting pH increase leads to dissolution of the carrier foil and characteristic salt-like blooms on the NMC surface. With the increase in the relative area occupied by the holes in the aluminum foil per time, a sufficiently suitable parameter was found with which to quantitatively determine the extent of corrosion. The degree of degradation depends on time and ambient humidity. It was shown that functional recycling with the water jet method is no longer applicable for degraded foils, since the mechanical stability of the foils decreases as corrosion progresses. Lithium, aluminum, sulfur and oxygen were detected in the blooms using SEM-EDX and Laser-Induced-Breakdown-Spectroscopy (LIBS). The underlying NMC layer was found to contain mainly aluminum and significantly lower lithium content than the non-degraded material. SEM and Raman microscopy analyses also showed that the active material is also locally degraded and therefore no longer suitable for functional recycling.}, subject = {Analytical chemistry Surface chemistry; Inorganic chemistry; Materials chemistry; Process chemistry; Materials science; Analytische Chemie; Anorganische Chemie; Werkstoffchemie; Werkstoffkunde; Chemische Technik; Analytische Chemie; Lithiumbatterie; Elektrodenfolie; Korrosion; Recycling}, language = {en} }