Refine
H-BRS Bibliography
- yes (50)
Departments, institutes and facilities
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (50) (remove)
Document Type
- Article (21)
- Conference Object (19)
- Part of a Book (3)
- Research Data (2)
- Book (monograph, edited volume) (1)
- Contribution to a Periodical (1)
- Doctoral Thesis (1)
- Other (1)
- Preprint (1)
Year of publication
- 2022 (50) (remove)
Keywords
- HTS (2)
- Hydrogen storage (2)
- creep (2)
- modeling (2)
- synchronous generator (2)
- 3D-Druck (1)
- AI usage in sports (1)
- ASR (1)
- Additiv (1)
- Aerosol (1)
- Antioxidans (1)
- Applications in Energy Transport (1)
- Artificial Intelligence (1)
- Bachelor’s program (1)
- Biologische Datenbanken (1)
- Biologisches Prinzip (1)
- Biology Push (1)
- Charakterisierung (1)
- Christmas trees (1)
- Complex Systems Modeling and Simulation (1)
- Conformation (1)
- Contingency analysis (1)
- Crystal structure (1)
- DMA (1)
- DSC (1)
- Evolutionärer Algorithmus (1)
- Extrusionsblasformen (1)
- Forklifts (1)
- GFRP (1)
- Gas transport simulation (1)
- Gasturbinenschaufel (1)
- HS SPME–GC/MS (1)
- HSP90 (1)
- Hydrogen (1)
- Interdisciplinary education (1)
- Kriechen (1)
- Kunstruktionsarten (1)
- Lebensdauervorhersage (1)
- Ligands (1)
- Linear viscoelasticity (1)
- Lineare Viskoelastizität (1)
- Mathematical methods (1)
- Mechanische Prüfung (1)
- Metal hydride storage (1)
- Miscanthus (1)
- Molecular structure (1)
- Nadelhölzer (1)
- Natur nachbauen (1)
- New study course (1)
- Nickel-based superalloy (1)
- Nickelbasis-Superlegierung (1)
- Non-linear systems (1)
- PV model (1)
- Photovoltaic cell (1)
- Polymers (1)
- Praktische Bionik (1)
- Py-EGA-MS (1)
- Py-GC/MS (1)
- Py-MS (1)
- R-ratio (1)
- Ressource (1)
- Reverse Engineering (1)
- RheoTack analysis (1)
- Rosskastanie (1)
- SMPA loop (1)
- Schneeglöckchen (1)
- Schwindung (1)
- Simulations (1)
- Spectral effects (1)
- Stabilisator (1)
- Stabilization (1)
- Sustainability (1)
- Sustainable engineering (1)
- Synergie (1)
- TD-GC/MS (1)
- TGA-FTIR (1)
- TGA-MS (1)
- Technology Pull (1)
- Thyme (1)
- Thymian (1)
- Topological reduction (1)
- UV (1)
- VOCs (1)
- Verzug (1)
- Voltage measurement (1)
- Was kann Bionik (1)
- Weihnachtsbaum (1)
- West Africa (1)
- additive (1)
- adhesion factor (1)
- advanced applications (1)
- aircraft engine part (1)
- aluminum bonding wire (1)
- antioxidant (1)
- armature winding (1)
- automotive lever (1)
- biaxial stretching (1)
- bio-based (1)
- biobasiert (1)
- blown film extrusion (1)
- chain-extending cross-linker (1)
- characterization (1)
- complex problems (1)
- composite materials (1)
- coniferous woods (1)
- creep compliance (1)
- crystallization (1)
- cube in cube model (1)
- current limiting (1)
- deformation behavior (1)
- detaching (1)
- double pulse test (1)
- elementary volume (1)
- elite sports (1)
- employability (1)
- engineering plastics (1)
- error analysis (1)
- explainable AI (1)
- extrusion blow molding (1)
- failure analysis (1)
- fault ride through (1)
- fiber composites (1)
- fuel cell (1)
- fully superconducting (1)
- fully superconducting generator (1)
- gas transport networks (1)
- gas turbine blade (1)
- gas-to-power (1)
- geopolymer (1)
- glass fibers (1)
- grid-forming converter (1)
- horse chestnut (1)
- hydrides (1)
- hydrogen (1)
- integrative Simulation (1)
- integrative simulation (1)
- lifetime prediction (1)
- local chain orientation (1)
- mathematical and numerical algorithms and methods (1)
- measurement errors (1)
- mechanical testing (1)
- mesoscale coarse-graining (1)
- migration (1)
- molecular docking (1)
- nachhaltig (1)
- orthotropes prozessabhängiges Materialverhalten (1)
- orthotropic process-dependent material behavior (1)
- particulate composite (1)
- peer-assisted learning (1)
- phase angle jump (1)
- poly(butylene adipate terephthalate) (1)
- poly(lactic acid) (1)
- polyethylene (1)
- power converter (1)
- power electronics (1)
- power semiconductors (1)
- pressure sensitive adhesives (1)
- process-induced morphology (1)
- professors as mentors (1)
- protein microarray (1)
- rate of change of frequency (1)
- relaxation (1)
- ressources (1)
- retraction speed dependency (1)
- rubbers (1)
- sensor phenomena and characterization (1)
- shrinkage (1)
- simulation and modeling (1)
- small-scale fatigue testing (1)
- snowdrop (1)
- student activating approaches (1)
- superconductor (1)
- sustainable (1)
- synergism (1)
- thermal insulation materials (1)
- thermophoresis (1)
- triiodothyronine (1)
- warpage (1)
- wide band gap (1)
- wind energy (1)
In this paper, a gas-to-power (GtoP) system for power outages is digitally modeled and experimentally developed. The design includes a solid-state hydrogen storage system composed of TiFeMn as a hydride forming alloy (6.7 kg of alloy in five tanks) and an air-cooled fuel cell (maximum power: 1.6 kW). The hydrogen storage system is charged under room temperature and 40 bar of hydrogen pressure, reaching about 110 g of hydrogen capacity. In an emergency use case of the system, hydrogen is supplied to the fuel cell, and the waste heat coming from the exhaust air of the fuel cell is used for the endothermic dehydrogenation reaction of the metal hydride. This GtoP system demonstrates fast, stable, and reliable responses, providing from 149 W to 596 W under different constant as well as dynamic conditions. A comprehensive and novel simulation approach based on a network model is also applied. The developed model is validated under static and dynamic power load scenarios, demonstrating excellent agreement with the experimental results.
Jet engines of airplanes are designed such that in some components damage occurs and accumulates in service without being critical up to a certain level of damage. Since maintenance, repair, and component exchange are very cost-intensive, it is necessary to predict efficiently the component lifetime with high accuracy. A former developed lifetime model, based on interpolated results of aerodynamic and structural mechanics simulations, uses material parameters estimated from literature values of standard creep experiments. For improved accuracy, an experimental procedure is developed for the characterization of the short-time creep behavior, which is relevant for the operation of turbine blades of jet engines. To consider microstructural influences resulting from the manufacturing of thin-walled single crystal turbine blades, small-scale specimens from used turbine blades are extracted and tested in short- and medium-time creep experiments. Based on experimental results and literature values, a creep model, which describes the fracture behavior for a wide range of creep loads, is calibrated and is now used for the lifetime prediction of turbine blades under real loading conditions.
The design of a fully superconducting wind power generator is influenced by several factors. Among them, a low number of pole pairs is desirable to achieve low AC losses in the superconducting stator winding, which greatly influences the cooling system design and, consecutively, the efficiency of the entire wind power plant. However, it has been identified that a low number of pole pairs in a superconducting generator tends to greatly increase its output voltage, which in turn creates challenging conditions for the necessary power electronic converter. This study highlights the interdependencies between the design of a fully superconducting 10 MW wind power generator and the corresponding design of its power electronic converter.
This paper explores the role of artificial intelligence (AI) in elite sports. We approach the topic from two perspectives. Firstly, we provide a literature based overview of AI success stories in areas other than sports. We identified multiple approaches in the area of Machine Perception, Machine Learning and Modeling, Planning and Optimization as well as Interaction and Intervention, holding a potential for improving training and competition. Secondly, we discover the present status of AI use in elite sports. Therefore, in addition to another literature review, we interviewed leading sports scientist, which are closely connected to the main national service institute for elite sports in their countries. The analysis of this literature review and the interviews show that the most activity is carried out in the methodical categories of signal and image processing. However, projects in the field of modeling & planning have become increasingly popular within the last years. Based on these two perspectives, we extract deficits, issues and opportunities and summarize them in six key challenges faced by the sports analytics community. These challenges include data collection, controllability of an AI by the practitioners and explainability of AI results.
Bionik
(2022)
Wie machen die das… kann angesichts der erstaunlichen Fähigkeiten mancher Lebewesen gefragt werden. Die Bionik fragt noch weiter …und wie kann man das nachmachen? Hier liegt ein Schwerpunkt dieses Lehrbuches, das die Bionik nicht nur an zahlreichen Beispielen erklärt, sondern auch eine Vorgehensweise für die Identifizierung biologischer Lösungen und deren Übertragung auf technische Anwendungen vermittelt. Basisinformationen der Biologie und Grundlagen der Konstruktionstechnik gewährleisten einen leichten Zugang zum Stoff. Mit dem 3D-Druck als Schlüsseltechnologie und der Thematisierung der Nachhaltigkeit geht das Buch zudem auf aktuelle Entwicklungen ein. Dieser ganzheitliche Blick auf die Bionik soll den Leser zur Durchführung bionischer Projekte befähigen und motivieren. Die vorliegende Auflage wurde überarbeitet und um aktuelle Forschungserkenntnisse und Entwicklungen ergänzt. (Verlagsangaben)
Comparing Armature Windings for a 10 MW Fully Superconducting Synchronous Wind Turbine Generator
(2022)
Novel methods for contingency analysis of gas transport networks are presented. They are motivated by the transition of our energy system where hydrogen plays a growing role. The novel methods are based on a specific method for topological reduction and so-called supernodes. Stationary Euler equations with advanced compressor thermodynamics and a gas law allowing for gas compositions with up to 100% hydrogen are used. Several measures and plots support an intuitive comparison and analysis of the results. In particular, it is shown that the newly developed methods can estimate locations and magnitudes of additional capacities (injection, buffering, storage etc.) with a reasonable performance for networks of relevant composition and size.
The accurate forecasting of solar radiation plays an important role for predictive control applications for energy systems with a high share of photovoltaic (PV) energy. Especially off-grid microgrid applications using predictive control applications can benefit from forecasts with a high temporal resolution to address sudden fluctuations of PV-power. However, cloud formation processes and movements are subject to ongoing research. For now-casting applications, all-sky-imagers (ASI) are used to offer an appropriate forecasting for aforementioned application. Recent research aims to achieve these forecasts via deep learning approaches, either as an image segmentation task to generate a DNI forecast through a cloud vectoring approach to translate the DNI to a GHI with ground-based measurement (Fabel et al., 2022; Nouri et al., 2021), or as an end-to-end regression task to generate a GHI forecast directly from the images (Paletta et al., 2021; Yang et al., 2021). While end-to-end regression might be the more attractive approach for off-grid scenarios, literature reports increased performance compared to smart-persistence but do not show satisfactory forecasting patterns (Paletta et al., 2021). This work takes a step back and investigates the possibility to translate ASI-images to current GHI to deploy the neural network as a feature extractor. An ImageNet pre-trained deep learning model is used to achieve such translation on an openly available dataset by the University of California San Diego (Pedro et al., 2019). The images and measurements were collected in Folsom, California. Results show that the neural network can successfully translate ASI-images to GHI for a variety of cloud situations without the need of any external variables. Extending the neural network to a forecasting task also shows promising forecasting patterns, which shows that the neural network extracts both temporal and momentarily features within the images to generate GHI forecasts.
How self-reliant Peer Teaching can be set up to augment learning outcomes for university learners
(2022)
While many proteins are known clients of heat shock protein 90 (Hsp90), it is unclear whether the transcription factor, thyroid hormone receptor beta (TRb), interacts with Hsp90 to control hormonal perception and signaling. Higher Hsp90 expression in mouse fibroblasts was elicited by the addition of triiodothyronine (T3). T3 bound to Hsp90 and enhanced adenosine triphosphate (ATP) binding of Hsp90 due to a specific binding site for T3, as identified by molecular docking experiments. The binding of TRb to Hsp90 was prevented by T3 or by the thyroid mimetic sobetirome. Purified recombinant TRb trapped Hsp90 from cell lysate or purified Hsp90 in pull-down experiments. The affinity of Hsp90 for TRb was 124 nM. Furthermore, T3 induced the release of bound TRb from Hsp90, which was shown by streptavidin-conjugated quantum dot (SAv-QD) masking assay. The data indicate that the T3 interaction with TRb and Hsp90 may be an amplifier of the cellular stress response by blocking Hsp90 activity.
Typically, plastic packaging materials are produced using additives, like e.g. stabilisers, to introduce specific desired properties into the material or, in case of stabilisers, to prolong the shelf life of such packaging materials. However, those stabilisers are typically fossil-based and can pose risks to both environmental and human health. Therefore, the present study presents more sustainable alternatives based on regional renewable resources which show the relevant antioxidant, antimicrobial and UV absorbing properties to successfully serve as a plastic stabiliser. In the study, all plants are extracted and characterised with regard to not only antioxidant, antimicrobial and UV absorbing effects, but also with regard to additional relevant information like chemical constituents, molar mass distribution, absorbance in the visible range et cetera. The extraction process is furthermore optimised and, where applicable, reasonable opportunities for waste valorisation are explored and analysed. Furthermore, interactions between analysed plant extracts are described and model films based on Poly-Lactic Acid are prepared, incorporating analysed plant extracts. Based on those model films, formulation tests and migration analysis according to EU legislation is conducted.
The well-known aromatic and medicinal plant thyme (Thymus vulgaris L.) includes phenolic terpenoids like thymol and carvacrol which have strong antioxidant, antimicrobial and UV absorbing effects. Analyses show that those effects can be used in both lipophilic and hydrophilic surroundings, that the variant Varico 3 is a more potent cultivar than other analysed thyme variants, and that a passive extraction setup can be used for extract preparation while distillation of the Essential Oils can be a more efficient approach.
Macromolecular antioxidant polyphenols, particularly proanthocyanidins, have been found in the seed coats of the European horse chestnut (Aesculus hippocastanum L.) which are regularly discarded in phytopharmaceutical industry. In this study, such effects and compounds have been reported for the first time while a valorisation of waste materials has been analysed successfully. Furthermore, a passive extraction setup for waste materials and whole seeds has been developed. In extracts of snowdrops, precisely Galanthus elwesii HOOK.F., high concentrations of tocopherol have been found which promote a particularly high antioxidant capacity in lipophilic surroundings. Different coniferous woods (Abies div., Picea div.) which are in use as Christmas trees are extracted after separating the biomass in leafs and wood parts before being analysed regarding extraction optimisation and drought resistance of active substances. Antioxidant and UV absorbing proanthocyanidins are found even in dried biomasses, allowing the circular use of already used Christmas trees as bio-based stabilisers and the production of sustainable paper as a byproduct.
West Africa has great potential for the use of solar energy systems, as it has both a high solar radiation rate and a lack of energy production. West Africa is a very aerosol-rich region, whose effects on photovoltaic (PV) use are due to both atmospheric conditions and existing solar technology. This study reports the variability of aerosol optical properties in the city of Koforidua, Ghana over the period 2016 to 2020, and their impact on the radiation intensity and efficiency of a PV cell. The study used AERONET ground (Giles et al., 2019) and satellite data produced by CAMS (Gschwind, et al., 2019), which both provide aerosol optical depth (AOD) and metrological parameters used for radiative transfer calculations with libRadtran (Emde, et al., 2016). A spectrally resolved PV model (Herman-Czezuch et al., 2022) is then used to calculate the PV yield of two PV technologies: polycrystalline and amorphous silicon. It is observed that for both data sets, the aerosol is mainly composed of dust and organic matter, with a very increased AOD load during the harmattan period (December-February), also due to the fires observed during this period.